2026-06-13T23:20:43Z https://lup.lub.lu.se/student-papers/oai

oai:lup-student-papers.lub.lu.se:9200398 2025-09-02T14:55:01Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Honia Rasul author 9097543 Ingemar André supervisor Mathematics (Faculty of Sciences) v1000666 department Macrocyclic peptides (MCPs) are a promising drug modality for targeting protein–protein interactions, offering high selectivity, metabolic stability, and potential cell permeability. However, predicting their membrane permeability remains challenging due to their conformational flexibility, environment-dependent polarity, and ability to adopt chamaleonic behavior, e.g. by changing the number of intramolecular hydrogen bonds. These features, combined with their frequent violation of Lipinski’s Rule of Five, make traditional small-molecule models poorly suited for MCPs. This exploratory thesis investigates whether computational tools can accurately predict permeability-relevant properties of MCPs and how well these predictions align with experimental data. Machine learning models were developed using the CycPeptMPDB database and trained on both 2D and 3D molecular descriptors. A curated subset of 60 matched MCP pairs, differing slightly in structure but showing significant differences in permeability, was analyzed to evaluate descriptor–permeability relationships. To bridge the gap between computational predictions and experimental validation, two matched pairs (four peptides) were synthesized. Their logP values were determined using the shake-flask method, and their conformations were analyzed in polar and apolar solvents using NMR spectroscopy. These experimental data, provided by colleagues at the company, were compared with structures generated from molecular dynamics (MD) simulations. The results showed that key descriptors such as logP, PSA, and the presence of intramolecular hydrogen bonds strongly correlate with permeability, but also that static descriptor calculations often fail to capture stereochemical effects or dynamic folding behavior. MD simulations and structural shape metrics provided more nuanced insights into conformational differences affecting permeability. Overall, this exploratory study demonstrates that integrating machine learning, dynamic modeling, and experimental validation offers a powerful approach for understanding and predicting the permeability of MCPs, advancing their rational design in the beyond-rule-of-five chemical space. Makrocykliska peptider är en ny typ av läkemedelskandidater som kan påverka mål i kroppen som vanliga läkemedel ofta inte kommer åt – till exempel när två proteiner ska interagera. Trots att dessa peptider är relativt stora och komplexa, har vissa visat sig kunna tas upp i kroppen vid tablettintag, något som annars är ovanligt för större molekyler. Men det är fortfarande oklart vilka egenskaper som gör att vissa av dessa peptider kan ta sig igenom cellens skyddande membran och bli aktiva i kroppen. Syftet med det här explorativa examensarbetet var att undersöka om datorbaserade metoder kan hjälpa till att förutsäga vilka makrocykliska peptider som har god förmåga att passera cellmembran. För att göra detta analyserades nästan 7000 olika peptider med hjälp av maskininlärning och molekyldynamiska simuleringar. Datorn tränades att hitta samband mellan olika egenskaper, som fettlöslighet, förmåga att binda till vatten (polär yta) och inre vätebindningar, och hur lätt peptiderna tar sig in i celler. För en mer detaljerad analys valdes 60 peptidpar ut där varje par bestod av två nästan identiska molekyler med olika förmåga att ta sig in i celler. Det visade sig att små strukturella förändringar kunde påverka hur peptiderna veckade sig och hur de interagerade med sin omgivning, faktorer som i sin tur påverkar deras upptag i kroppen. Fyra av peptiderna tillverkades i labb av kollegor på företaget och testades med experimentella metoder, där resultaten stämde väl överens med datorns förutsägelser. Slutsatsen är att en kombination av datorberäkningar och experimentella tester kan ge en bättre förståelse för hur framtidens läkemedel kan utformas för att fungera effektivt i kroppen, även när de bryter mot de klassiska reglerna för läkemedelsdesign. https://lup.lub.lu.se/student-papers/record/9200398/file/9200469.pdf application/pdf 2885987 no 2025 eng Descriptors Machine learning Macrocyclic peptides Membrane permeability Molecular dynamics Mathematics and Statistics Biology and Life Sciences Chemistry 1404-6342 2025:E55 LUNFTB-3001-2025 9200398 2025-06-16T14:11:18+02:00 2025-09-02T16:55:01+02:00 2025-09-02T16:55:01+02:00

oai:lup-student-papers.lub.lu.se:2372662 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsM2 Emelie Flood author 2372660 Elna Heimdal Nilsson supervisor Senior lecturer Carl-Erik Magnusson supervisor Department of Physics v1000621 department Combustion Physics v1000625 department Combustion of methanol is being used widely and the chemistry in the process is therefore important to know. When being mixed with formaldehyde and combusted previous measurements with the heat flux method have shown results not consistent with the theoretical models present today. These experiments are in this paper being repeated. A statistical examination of the burners used for the measurements is also conducted. The results are a calibration of the burners and values of the laminar burning velocity that are consistent with the previous values. This calibration is used on the methanol formaldehyde mixtures and gives a result that, as previous results also do, differs from the model. Large scatter is observed in the temperature distribution as measured by the thermocouples. The experimental values consist of some outliers and this can be the result by water contamination. This conclusion is verified by a density determination of the methanol formaldehyde mixtures. https://lup.lub.lu.se/student-papers/record/2372662/file/2372663.pdf application/pdf 680129 no 2012 eng Methanol formaldehyde statistical analysis burner heat flux method Matlab biofuel combustion fuel density temperature laminar burning velocity acetone thermocouple equivalence ratio Earth and Environmental Sciences Chemistry Physics and Astronomy 2372662 2012-03-19T03:10:37+01:00 2012-11-12T22:40:49+01:00 2012-04-10T17:00:36+02:00

oai:lup-student-papers.lub.lu.se:2493389 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Dario Stjärnemyr Ghidini author 2493387 Kimberly Dick Thelander supervisor Atomic Physics v1000622 department In this thesis epitaxial growth of Ga(P1-xSbx) and analysis by electron microscopy are presented. To the authors knowledge Ga(P1-xSbx)has not been grown in the form of nanowires before and the main motivation of this work is to investigate the possibility of overcoming the miscibility gap (1-99%) in nanostructures. The goal of this project is to gain a better understanding of the general behavior of Sb-based materials (precursors) in Metal-Organic Vapor Phase Epitaxy (MOVPE) growth system and its influence on the growth of Sb-containing compounds. Our findings can be used to improve the understanding of growth and enhance the level of control of other Sb-containing binary and ternary material systems. The nanowires were analyzed by both Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In order to get chemical composition, X-ray Energy Dispersive Spectroscopy (EDS) was performed in combination with TEM.<br /> <br /> The results of the growth experiments indicate that the incorporation of Sb into a GaP-based matrix is limited when attempting the growth of ternary nanowires grown on a GaP stem. Within this study, the growth conditions of the experiments were pushed towards the technical limit of the machine setup (the molar flows were maximized and minimized, respectively) and we found indications that successful growth of ternary Ga(P1-xSbx) nanostructures with variable Sb content 0&lt;x&lt;1 might take place at even more extreme conditions. The presence of Sb-based species in the growth system has induced up to 90% reduction of the growth rate of the nanowires and it is likely due to Sbs surfactant and surface wetting properties. Further, the growths of Ga(P1-xSbx) performed with a ratio between P and Sb molar fractions lower than 2:1 have shown deviations from the standardly found AuxGa1-x particle composition and resulted in the formation of a two-phased particle with a second gold phase-AuSb2. This project has shown previously unknown properties of Sb and Sb-containing ternaries and has opened up the material system for further investigations. https://lup.lub.lu.se/student-papers/record/2493389/file/2493391.pdf application/pdf 3986549 no 2012 eng Material Science Nanowire GaPSb Physics and Astronomy Chemistry Technology and Engineering 2493389 2012-04-24T09:50:53+02:00 2012-11-28T22:30:02+01:00 2012-11-28T22:30:02+01:00

oai:lup-student-papers.lub.lu.se:3879044 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsM2 Emelie Graham author 3878676 Elna Heimdal Nilsson supervisor Department of Physics v1000621 department With a rising global mean temperature caused by increased emission of greenhouse gases into the atmosphere biofuels are considered as a possible solution to the greenhouse effect. One of the potential biofuels is furans and this report aims to determine their lifetime in polluted air. This is done by determining the rate constant of the decay of furan, 2,3-DHF and 2,5-DHF due to reaction with tropospheric ozone. The experiment was performed in a mixture with synthetic air in a 250 L gas cell at 750 torr, 298 K and scanned by a Fourier Transform Infrared spectrometer. Due to experimental difficulties only two of the three examined rate constants could be determined, these were 2.42 and 4.64*10^-18 cm^3/molecules*s for furan and 2,5-DHF, respectively. From these results the atmospheric lifetimes was estimated to be 81 and 4 hours for furan and 2,5-DHF, respectively. Due to their completely different lifetimes furan and DHF are estimated to affect the atmosphere on different scales. Furan is predicted to decay first when it leaves the urban areas and is able to react with OH, while DHF will start to decay as soon as it is emitted and is in contact with ozone. Future work is essential in the understanding of how furans influence the atmospheric chemistry. https://lup.lub.lu.se/student-papers/record/3879044/file/3879045.pdf application/pdf 2444290 no 2013 eng Atmospheric science Tropospheric chemistry Kinetics Rate constant Absolute rate method Biofuels Furan Ozone Physics and Astronomy Chemistry Earth and Environmental Sciences https://lup.lub.lu.se/student-papers/record/3879044/file/3917932.pdf application/pdf no 3879044 2013-06-24T20:38:48+02:00 2013-07-09T00:31:23+02:00 2013-07-09T00:31:23+02:00

oai:lup-student-papers.lub.lu.se:3917656 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Jonas Evertsson author 2219792 Johan Gustafson supervisor Department of Physics v1000621 department In this project four reactors for studies of heterogeneous catalysis have been developed. They were tested using case studies, especially concerning methane oxidation over palladium. The test measurements showed that the reactors work or would work very well after slight modifications.<br /> The first reactor allowed for activity measurement using mass spectrometry for temperatures up to at least 1000°C. The reactor was tested with methane oxidation over different palladium foil samples. <br /> With the second reactor it is possible to perform activity measurements of three catalysts simultaneously using planar laser induced fluorescence. The reactor was tested with CO oxidation over three different monolith catalysts. From the measurement it was possible to follow the activation process of the three catalysts simultaneously. However, it was not possible to study methane oxidation due to the higher temperature needed to run this reaction, but with minor modifications, this should be possible as well.<br /> The third and fourth reactor allowed for structural studies of powder catalysts using X-ray diffraction. It was tested using methane oxidation over Pd/Al2O3 powder catalyst. The result showed that it is possible to see when the palladium particles are metallic and when they are oxidized. But also here a slight modification is needed before really good result can be achieved.<br /> The different case studies also reveal some interesting results, which are discussed further in the report and would be interesting to study further in the future. Utveckling och testning av reaktorer för katalysmätningar<br /> <br /> Katalysatorer är oumbärliga i såväl livsprocesser som industriella tillämpningar. Bilismen är ett exempel där katalysatorer används vid såväl bränsletillverkning som avgasrening. Men detta är långt ifrån det enda användningsområdet. Katalysatorer är också delaktiga i tillverkningen av uppemot 90% av alla kemikalier. <br /> <br /> Industriella katalysatorer för oxidering av kolmonoxid och metan, CO och CH4, är mycket komplexa system som ofta består av katalytiskt aktiva nanopartiklar utspridda i ett supportmaterial. Sådana katalysatorer är svåra att undersöka med ytfysikens metoder. Därför har det under många år använts modeller med enkla kristallprover, ultrahögvakuum och ex situ metoder, tillvägagångssätt som långt ifrån avspeglar industriella katalysatorer. Under senare år har nya in situ tekniker utvecklats och därmed möjligheter till att studera mer realistiska modeller som i sin tur bidrar till ökad förståelse.<br /> <br /> I mitt examensarbete har jag bidragit till detta genom att testa och utveckla fyra typer av reaktorkammare där masspektrometri, lasertekniken PLIF och röntgendiffraktion har använts för att karakterisera flera typer av katalytiska system, från enklare modeller till mer verkliga som används av industrin.<br /> <br /> Med den första reaktorn var det möjligt att göra aktivitetsmätningar av katalysatorer med masspektrometri för temperaturer upp till minst 1000°C. Med reaktorn gjordes flera aktivitetsmätningar av metan oxidering över olika palladiumfolier, vilket visade på flera intressanta resultat.<br /> <br /> Med den andra reaktorn användes PLIF för att göra aktivitetsmätningar av tre katalysatorer samtidigt. Detta testades för CO oxidation och resultatet var lovande. Men mindre ändringar behövs för att kunna göra metan oxidation.<br /> <br /> Den tredje och fjärde reaktorn möjliggjorde kombinerad masspektrometri och röntgendiffraktionsmätningar av både gasen och den atomära strukturen hos katalysatorerna. Mätningen med den fjärde reaktorn var lovande och det var möjligt att följa strukturförändringar samtidigt som det pågår reaktioner på katalysatorerna. Men också här skulle det behövas en mindre förändring för att kunna följa processen tydligare.<br /> <br /> Eftersom många delar av världen är på väg att industrialiseras behövs troligtvis bättre, billigare men också nya katalysatorer till reaktioner där katalysatorer tidigare inte använts. För att utveckla dessa måste troligtvis kunskapen om katalys på grundläggande atomär nivå öka, vilket i sin tur betyder att också nya metoder behövs. https://lup.lub.lu.se/student-papers/record/3917656/file/3917872.pdf application/pdf 1809381 no 2013 eng X-ray Diffraction PLIF Planar Laser Induced Fluorescence activity measurement reactor catalyst catalytic processes XRD Mass spectrometry Heterogeneous catalysis Chemistry Physics and Astronomy https://lup.lub.lu.se/student-papers/record/3917656/file/3917688.pdf application/pdf no 3917656 2013-07-04T10:19:54+02:00 2013-07-09T00:35:29+02:00 2013-07-09T00:35:29+02:00

oai:lup-student-papers.lub.lu.se:4017495 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Sara Thorberg author 3810121 Cathleen Perlman supervisor Karin Fröjd supervisor Department of Physics v1000621 department The aim of this study has been to enhance LOGE&#39;s semi-detailed Cu-ZSM-5 SCR catalyst model in areas where it lacks to catch important effects. It is important to have an accurate and CPU efficient kinetic model for the catalysis in the work towards minimizing polluting NOx in the exhaust gas from diesel engines. <br /> <br /> Investigations were done on the kinetic model through a few transient experiments including NO oxidation, NH3 oxidation and a NH3 SCR experiment. The effects were tested when adjusting different parameters and an adsorption reaction for NO2 was added to the kinetic model. The simulated results were compared with experimental values. Adjustment on the kinetic parameters in the NO oxidation reaction led to a slight enhancement and results also showed that the additional adsorption reaction was sufficient to catch the desired effects.<br /> <br /> This work shows that a semi-detailed kinetic model is sufficient to capture important effects in the catalytic reduction. The model would however need to be validated through more experiments in order to generalize the results. For further improvements on the model a more complex kinetic model would be required, which could include adsorption of more species and alternative reactions. Syftet med den här studien har varit att förbättra LOGEs semidetaljerade katalysatormodel Cu-ZSM-5 på dem delarna där modellen missar viktiga effekter. Det är viktigt att ha en riktigt och CPU-effektiv kinetisk modell för katalysatorn i arbetet mot att minska förorenande NOx i avgaserna från en dieselmotor.<br /> <br /> Undersökningen av den kinetiska modellen utfördes genom transienta experiment som NO oxidation, NH3 oxidation och ett NH3 SCR experiment. Effekterna undersöktes när olika parametrar ändrades och en adsorptionsreaktion för NO2 lades till i den kinetiska modellen. Resultaten från simuleringar jämfördes med experimentella värden. Justering av de kinetiska parametrarna i NO oxidationen ledde till en viss förbättring. Dessutom visade resultat att den tillagda adsorptionsreaktionen var tillräcklig för att fånga dem önskvärda effekterna. <br /> <br /> Det här arbetet visar att en semidetaljerad kinetisk modell är tillräcklig för att fånga viktiga effekter i den katalytiska reduceringen. Modellen behöver dock bli validerad genom flera experiment innan resultaten kan ses som generella. För ytterligare förbättringar på modellen krävs troligtvis en mer komplex kinetisk modell. En sådan skulle kunna innehålla adsorption av flera slag och alternativa reaktioner. https://lup.lub.lu.se/student-papers/record/4017495/file/4022548.pdf application/pdf 1036760 no 2013 eng Catalyst Cu-ZSM-5 SCR modelling chemical kinetics. Physics and Astronomy Chemistry https://lup.lub.lu.se/student-papers/record/4017495/file/4017546.pdf application/pdf yes 4017495 2013-09-05T12:59:40+02:00 2013-09-12T19:23:45+02:00 2013-09-12T19:23:45+02:00

oai:lup-student-papers.lub.lu.se:2862334 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsM2 Stina Ausmeel author 2862332 Elna Heimdal Nilsson supervisor Department of Physics v1000621 department Combustion Physics v1000625 department There has been a worldwide debate about “the climate change” over the past years, accompanied with the efforts in finding a more environmental friendly way to live. One area of research is to find replacements for the fossil fuels, which is the major energy source today. The aim of this project is to investigate the atmospheric properties of a new potential group of biofuels, i.e. the group of compounds called furans, and especially the two molecules 2-Methyltetrahydrofuran and <br /> 2,2-Dimethyltetrahydrofuran. The reason for this is that the environmental impact of a large scale use must be well known before any production can be considered. Therefore the reaction between these molecules and the atmospheric chlorine atoms will be investigated with respect to reaction speed and what products that will be formed. <br /> The project is based on experimental work performed at the Copenhagen Centre for Atmospheric Research. A smog chamber which can be filled with a desired mixture of atmospheric gases, can be exposed to UV-light for a specific time and a detector can register the infrared light from a laser that goes through the gas mixture. This was used to test how the reactions proceeded between chlorine atoms and 2-Methyltetrahydrofuran and 2,2-Dimethyltetrahydrofuran respectively. The speed of the reaction, which is represented by a rate constant, was determined by analysing data and using the relative rate method. The products were studied by comparing infrared spectra from different molecules. <br /> The results from the experiments were that the rate constants for the two compounds have the values k2-MTHF+Cl = 1.3∙10-10 cm3molecule-1s-1 and k2,2-DMTHF+Cl = 1∙10-10 cm3molecule-1s-1. The products that are known to be formed are hydrogen chloride, HCl, carbon dioxide, CO2, carbon monoxide, CO, water, H2O and formic acid, HCOOH.<br /> This project resulted in the conclusion that the reaction with chlorine is fast and can be very important in some urban areas. This work has been one of the first of its kind, and even if it does not absolutely describe the atmospheric implications of these two potential fuels, it has laid a foundation for future research in the area. På grund av den världsomfattande diskussionen rörande ”klimatförändringen” som pågått under de senaste åren, så har försök gjorts för att få människor att ändra sina vanor och för att hitta alternativa energikällor. I dag är det fossila bränslen som dominerar som energikällor men eftersom de ger upphov till höga koldioxidhalter pågår det forskning för att ta fram alternativa bränslen. En grupp av ämnen som har föreslagits är de som kallas furaner, som kan framställas av socker och som brinner väldigt lätt. De två ämnen som undersöks är 2-Metyltetrahydrofuran och 2,2-Dimetyltetrahydrofuran. Det är viktigt att ta reda på hur dessa ämnen kommer reagera med andra ämnen som finns i atmosfären för att kunna undersöka hur de kommer påverka miljön. Målet med detta arbete är därför att undersöka hur dessa ämnen skulle reagera med kloratomer i atmosfären om de eventuellt skulle börja användas i större skala. <br /> Experiment utfördes i ett laboratorium på Copenhagen Centre for Atmospheric Research. I en så kallad smog kammare kan en valfri blandning av gaser som liknar en sammasättning i atmosfären undersökas. Reaktionerna undersöks med avseende på hur mycket blandningen bestrålats av UV-ljus. Det som undersöktes var hur snabbt reaktionerna mellan 2-Metyltetrahydrofuran respektive 2,2-Dimetyltetrahydrofuran och klor sker, dvs. reaktionernas hastighetskonstant, samt vilka produkter som bildas. <br /> Resultaten analyserades med hjälp av dataprogram och de produkter som bland annat bildas är väteklorid, HCl, koldioxid, CO2, kolmonoxid, CO, vatten, H2O och myrsyra, HCOOH. De värden på hastighetskonstanterna som erhölls var: k2-MTHF+Cl = 1.3∙10-10 cm3molekyl-1s-1 och k2,2-DMTHF+Cl = 1∙10-10 cm3molekyl-1s-1. Slutsatserna som kan dras av detta är att klor reagerar mycket snabbt med dessa ämnen och att det kan ha betydelse i områden där klorhalterna i luften är förhöjda, till exempel på grund av luftföroreningar. <br /> Detta är första gången som dessa reaktioner mellan 2-Metyltetrahydrofuran respektive 2,2-Dimetyltetrahydrofuran och klor undersöks. Även om dessa potentiella biobränslens påverkan på atmosfären och miljön inte är fullt kartlagda än, så har idéerna och undersökningsmetoden förbättrats och kan förhoppningsvis vara till hjälp för framtida forskning inom området. https://lup.lub.lu.se/student-papers/record/2862334/file/2862338.pdf application/pdf 2922834 no 2012 eng furan fuel environment chemistry climate atmosphere Earth and Environmental Sciences Chemistry Physics and Astronomy 2862334 2012-07-12T23:30:40+02:00 2012-11-12T22:27:48+01:00 2012-08-14T14:34:39+02:00

oai:lup-student-papers.lub.lu.se:9072305 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Ilmari Turunen author 9072281 Professor Tönu Pullerits supervisor Department of Physics v1000621 department Computational Biology and Biological Physics - Has been reorganised v1000644 department Department of Astronomy and Theoretical Physics - Has been reorganised v1000642 department Cavity quantum electrodynamics (QED) is a theory that is used for describing the interaction between matter and cavity modes. Not until relatively recently, cavity QED has been extended to the study of photosynthetic light-harvesting complexes (LHCs). Multiple phenomena unique to strongly cavity-coupled molecular systems have also been observed in LHCs in cavities. Of such phenomena, one is the formation of highly coherent states delocalized among thousands of molecules. These states have a partial light character, and are known as molecular polaritons. In this thesis, I explore the formation of polaritons by computationally modelling the light-harvesting complex 2 (LH2) of the purple bacterium Rhodopseudomonas acidophila in a microcavity. I also show the possibility of energy transfer between noninteracting LH2s via coupling to a cavity, providing a potentially new way in which photosynthetic energy transfer pathways could be artificially optimized. The world around us is a colorful place to behold. Behind this colorful splendor is a fine interplay between light and matter, in which some materials absorb certain wavelengths of light which we perceive as colors that other materials do not. Absorption of light can be properly understood through the framework of quantum mechanics: in an absorption event, a quantum of light -- a photon -- is absorbed by electrons in a molecule, after which the molecule gains the energy of the absorbed photon. The molecule is then said to be in an excited state. In the case of plants and algae and some microbes that are capable of photosynthesis, the characteristic green hue is caused by special light-absorbing pigments, the chlorophylls. The wavelengths of light that are absorbed by these pigments are crucial for making photosynthesis and consequently most of life on earth possible.<br /> <br /> Multiple chlorophyll molecules close to each other can interact as a group, leading to striking changes in the wavelengths of light that are absorbed. In such circumstances it is no longer possible to determine with certainty which of the chlorophylls partake in the absorption event -- it is as if all of the chlorophylls act as a single excited entity. Such collective quantum states of matter are called excitons. It turns out that there is a photosynthetic group of bacteria, the purple bacteria, which harness a special light absorbing structure called LH2. The wavelengths that the LH2 absorbs can only be explained using the theory of excitons, giving a hint of the importance of quantum mechanics in biology.<br /> <br /> The story does not end with excitons, however. Over the last few years, researchers have become increasingly more interested in investigating the properties of pigments in cavities, that is, between two mirrors. When light of suitable wavelength is shone into the cavity, the light not only excites the molecules in the cavity but also partakes in the excited state itself. Such an excited state, which is partially light and partially matter, is known as a polariton. A polariton is a highly delocalized state, meaning that all of the excited molecules in the cavity are a part of it. It is like a tensed bowstring, which remains tensed by the action of light.<br /> <br /> In my thesis, I explore these light-matter states in the case of the LH2 of the purple bacterium Rhodopseudomonas acidophila. I explain the observed absorption properties of the LH2 inside a cavity with computational models. I also take a step further and investigate what happens after the excitation of polaritons: how do they finally break down and where does their energy transfer? It is already known that polaritons harness many interesting properties, such as the capability of enhancing chemical reactions. Furthermore, the quantum properties of groups of molecules are known to be enhanced in cavities. In addition to validating more well known properties of polaritons involving LH2s, I show that the delocalized nature of the polaritons enable energy to be transferred between spatially separated LH2s. My thesis might thus offer tools for not only obtaining a clearer understanding on the significance of quantum mechanics in biology, but also for potential applications related to utilizing photosynthesis -- perhaps in solar powered technologies of the future. https://lup.lub.lu.se/student-papers/record/9072305/file/9072324.pdf application/pdf 1587441 no 2022 eng Cavity QED LH2 Chlorophyll Exciton Polariton Transition dipole moment Absorbance Physics and Astronomy Chemistry Biology and Life Sciences 9072305 2022-01-19T08:10:11+01:00 2022-01-26T09:52:08+01:00 2022-01-26T09:52:08+01:00

oai:lup-student-papers.lub.lu.se:8987675 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Shan Anjum author 8987648 Joakim Stenhammar supervisor Biophysical Chemistry v1000649 department Microswimmer is a term that denotes small selfpropelling agents, such as bacteria, algea or artificial robots. Depending on the flow field they set up they can be categorized into two classes: pushers (e.g. E. coli ) and pullers (e.g C. reinhardtii ). The occurrence of jets, eddies and flocking have been observed in systems of dens pusher suspension. This phenomenon is called active turbulence. The transition to active turbulence has been attributed to hydrodynamic interactions reorienting and aligning pushers, whereas the same type of hydrodynamic interactions destroy collective motion in puller suspensions. This thesis sets out to investigate the properties of active turbulence in mixtures of pushers and pullers by means of particle-based Lattice Boltzmann simulations. Two body interactions between microswimmers and properteis regarding fluid statistics and swimmer statistics in 3-dimensional suspensions were investigated. Similar studies were also performed on a class of nonswimming particles, so called shakers. Our results shows that the presence of pullers in a pusher suspension can inhibit active turbulence. Furthermore we have<br /> observed that a suspension consisting equal parts pullers and pushers will display properties similar to a noninteracting system. Bakterier som lever i vatten brukar ta sig fram med hjälp av långa trådliknande utskott,så kallade flageller. Denna simteknik är väldigt annourlunda jämfört med det vi oftast ser i vår omvärld, att simma med fenor eller åror är nämligen inte särskilt effektivt för bakterier. Detta har att göra med vattnets radikalt annourlunda hydrodynamiska egenskaper på mikroskalan. Man brukar tala om det så kallade Reynoldstalet, Re Det sammanfattar hur tröghetskrafter och friktionskrafter på en fast kropp i en vätska jämför sig gentemot varandra. Då vi människor brukar simma upplever vi höga Reynoldstal (Re ∼ 10E6 ). Detta innebär att tröghetskrafterna dominerar, och förklarar varför man kan fortsätta glida en bra bit efter att man tagit ett rejält simtag. För en E. coli bakterie, brukar friktionskrafterna dominera. Då den slutar rotera med flaggelerna så stannar den omedelbart (Re ∼ 10E−5 ). För en människa skulle detta motsvara att simma i honung. Bakterier och andra mikroorganismer har därför utvecklat andra, mer effektiva simtekniker. <br /> Det kan förefalla opraktiskt att leva i en sådan högviskös värld; dock leder de hyrdodynamiska egensakperna till väldigt exotiska och spännande fenomen. Ett av de mest utforskade fenomen har observerats i koncenterade bakteriesuspensioner av E. coli och Sallmonella. Vid volymkoncentrationer större än 2 procent har man observerat att bakteriernaslutar simma på ett oorganiserat sätt och börjar då iställer bilda ”flockar”. Flockarna rör sig på ett koordinerat sätt på långa längskalor med hastigheter mycket större än de indivudella simmarnas. Bakteriernas simmmande ger även upphov till kaotiska flödesmönster väldigt lika turbulens. ”Klassisk” turbulens, som man t.ex kan observera kring en flygplansvinge, brukar dock ske för höga Reynoldstal (Re &gt; 1000). Detta fenomen, kallat bakteriell turbulens, sker vi betydligt lägre Reynolds tal och har därför en annan underliggande mekanism.<br /> <br /> Då en bakterie simmar ger den upphov till ett flödesfält. Bakterier i närheten av flödesfältet kommer då att orienteras i flödet så att de börjar simma i samma riktning. Det är detta som ger ger upphov till bakteriell turbulens. Bakteriell turbulens uppstår dock inte i alla typer av mikroorganism-suspensioner. I koncenterade suspensioner av den encelliga algen C. reinhardtii går det inte att observera bakteriell turbulens. Flödesfältet som C. reinhardtii genrerar är nämligen annourlunda än det som går att observera hos t.ex E. coli och kan inte ge upphov till bakteriell turbluens.<br /> <br /> I det här examensarbetet studeras egenskaper hos suspensioner bestånde av blandningar av flödesfält som genererar aktiv turbulens, så kallade pushers, och de som inte gör det, så kallde pullers. Vi har gjort dessa studier i form utav numeriska beräkningar och datorsimulationer. Vi försöker först med att förstå oss på tvåkroppsinteraktionen mellan par av pushers, pullers och blandade pusher/puller par. Vi studerar även beteendet av flocking och den omgivande vätskans egenskaper för olika koncentrationer och blandningar av pushers och pullers. Slutligen studerar vi även egenskaper hos ickesimmande pushers respektive pullers, så kallde shakers.Våra resultat visar att närvaron av pullers i en pusher suspension kan ha en destruktiv effekt på bakteriell turbulens. Blandningsfraktionen av pullers och pushers påverkar många egenskaper gällande den bakteriella turbulensens hydrodynamiska egenskaper. Vi har även observerat att suspensioner bestående av lika många pushers som pullers uppvisar liknande egenskaper som icke-växelverkande suspensioner. <br /> <br /> Dessa resultat kan komma till användning då det kommer till att förstå processer där bakterier och andra mikroorganismer är relevanta. Då de nästan alltid existerar i kolonier och utgör en grundstomme i många ekologiska och biologiska processer är det lätt att tänka sig att våra resultat kan komma till användning i många olika studier. Baktierer är t.ex viktiga i kolets kretslopp, syrets kretslopp, matsmältningprocessen och infektionsförlopp. Våra resultat kan även generaliserar till artificiella mikropskopiska robotar, s.k.”artificial microswimmers”. I framtiden kommer man kanske kunna använda dessa för drug delivery, kirurgi och i mikrofludiska applikationer. https://lup.lub.lu.se/student-papers/record/8987675/file/8987677.pdf application/pdf 1454497 no 2019 eng biophysics active matter collective motion microswimmers biohydrodynamics non-equilibrium physics low reynolds number physics biophysical chemistry biofysikalisk kemi Physics and Astronomy Chemistry Technology and Engineering 8987675 2019-06-24T23:45:18+02:00 2019-07-04T16:12:49+02:00 2019-07-04T16:12:49+02:00

oai:lup-student-papers.lub.lu.se:9020903 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH1 Rima Zuriah Amdani author 9020488 Christian Brackmann supervisor Frederik Ossler supervisor Department of Physics v1000621 department Combustion Physics v1000625 department Porous carbon obtained from low cost and abundant biomass has gained attention as renewable material feedstock. In this study, porous carbon biochar produced through pyrolysis was investigated by Raman spectroscopy to disclose the structural properties. The measured samples were in form of pellets (identified as WP, 139, 233, 226), and lumber wood (Pine, a softwood type and Beech, a hardwood type). The resulted spectra, which consisted of two broadened overlapped peaks were fitted with two Gaussian curves. The intensity ratio of the curves (ID/IG) were calculated to analyse the aromaticity of the samples. The aromaticity represents the proportion of the total C phases (amorphous and crystalline) within the samples. The result indicates that the aromaticity of the samples increased as the pyrolysis temperature was raised. Furthermore, the biochar obtained for higher temperature had larger crystalline surface area, which is indicated by La (crystalline length). The La values obtained were around 9-10 Å and exhibit a highly disordered structure with turbostratic arrangement. As complementary, the data from Raman measurements were also compared with elemental analysis results to show the amount of carbon content in the samples. The results from elemental analysis present that the higher temperature will produce higher carbon proportion in the samples. Thereby, both Raman spectroscopy and elemental analysis give similar trends for evaluating the structure of the samples. In comparison with a soot sample, biochar exhibits less carbonization since the aromaticity and crystalline surface area (defined by La) of the soot have higher values. The Raman signal increases for higher laser power and detector integration acquisition time. However, high power and long acquisition time promote fluorescence background. Thus, moderate laser power and integration time was preferably chosen for reliable Raman measurements. https://lup.lub.lu.se/student-papers/record/9020903/file/9020916.pdf application/pdf 12092114 no 2020 eng Raman Spectroscopy Porous Carbon Biochar Carbonization Aromaticity Physics and Astronomy Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/9020903/file/9020927.pdf application/pdf In this study, biomass samples have been heated at various temperatures, and then measured with the Raman method to examine the structural properties through the spectral shapes of the spectra. The results show that the heating treatment can change the carbon structures. The increasing temperature can raise the aromaticity and surface area of the crystalline carbon structure. no 9020903 2020-06-22T10:36:18+02:00 2020-07-02T21:38:43+02:00 2020-07-02T21:38:43+02:00

oai:lup-student-papers.lub.lu.se:9211781 2025-09-16T06:29:17Z PhysicsChemistryMaths Technology

studentPublicationsH2 Pratik Bharat Bhagwat author 9210969 Tönu Pullerits supervisor Sankaran Ramesh supervisor Department of Physics v1000621 department The ability to manipulate spin states with light forms the basis of spin-based photonics. The development of semiconductors with tunable spin properties will enable devices that use spin for information storage, circular polarized light emission, etc. With the recent reports of a chirality-induced spin selectivity (CISS) effect in electrons, the question arises whether structural chirality provides a handle to tune spin dynamics in chiral semiconductors and nanomaterials.<br /> <br /> This thesis is focused on the investigation of ultrafast exciton and spin dynamics of chiral two-dimensional (2D) lead halide perovskite thin films using circularly polarized pump-probe or transient absorption (TA) spectroscopy. The chiral (R-MBA)2PbI4 and racemic (rac-MBA)2PbI4 2D thin films were prepared using simple solution-based methods. X-ray diffraction confirmed the formation of highly ordered 2D octahedral structures of lead iodide with chiral interlayers of methylbenzylammonium. A strong circular dichroism (CD) observed close to the excitonic resonance confirmed the optical chirality of the chiral samples, which were distinguished by the lack of a CD signal from the racemic samples. To understand the influence and role of chirality on spin relaxation mechanisms, ultrafast TA measurements were performed with different pump and probe pulse polarizations (co- and counter-circular, linear). Spectral analysis identifies three features: 2 positive photoinduced absorptions and 1 negative ground state photobleaching. With multi-exponential fitting of kinetics, distinct time decay components are identified, assigned to thermalization, exciton-exciton annihilation, exciton recombination, and trapping or de-trapping process. Comparative spin dynamics between chiral and racemic samples suggest differences in the spin relaxation process, even if their kinetics are similar. Both chiral and racemic exhibit longer-lived spin polarization around 400ps.<br /> <br /> These findings are critical to understanding spin-dependent processes in chiral metal halide perovskite materials. The experimental framework presented in the study further establishes a base for probing CISS phenomena and the optimization of spin relaxation processes in emerging opto-spintronic materials. When we imagine light, we usually think of brightness or colour. Light can also be seen as energy packets called photons, which have their own ”twist” or ”polarization”. These twists can be associated with the spin of electrons in certain materials, which can be controlled with light. As these spins can be controlled using light, it opens the door to novel research and technologies where information is stored and processed not only through charge, but also through spin. This interesting field is known as opto-spintronics.<br /> <br /> This thesis work delves into the ultrafast realm to study time-resolved excitons and spin dynamics in chiral two-dimensional lead halide perovskites. Chiral means the mirror images of the structure or material do not match perfectly, and a classic example is our hand (left and right). This handedness characteristic means the material interacts with light differently when compared with left- or right-circularly polarized light. It is like how a right glove does not fit our left hand. It is not just a curiosity, but this is a unique behaviour of chirality that influences the behaviour of electron spins. This phenomenon is called chirality-induced spin selectivity or CISS.<br /> <br /> We fabricated thin films of chiral and non-chiral (racemic) perovskite to explore selective chirality and compared their features. Films are usually made using a solution-based process, and basic characterizations are done to confirm the growth of crystals and other properties. X-ray Diffraction (XRD) was used to check their structure, and chiroptical activity or circular dichroism (CD) by shining circularly polarized light and measuring the differential absorbance. The chiral thin film samples absorbed one twist of light more than the other, whereas the racemic sample showed no such difference. Then, using modified ultrafast circularly (left/co-circular, or right/counter-circular) polarized pump-probe spectroscopy, we observed how spins and excitons behave over a picosecond scale (trillionths of a second). https://lup.lub.lu.se/student-papers/record/9211781/file/9211842.pdf application/pdf 6848625 no 2025 eng Ultrafast spectroscopy circularly polarized pump-probe spectroscopy transient absorption (TA) chirality perovskite X-ray diffraction (XRD) circular dichroism (CD) exciton spin dynamics. Physics and Astronomy Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/9211781/file/9211841.pdf application/pdf no 9211781 2025-09-05T15:29:33+02:00 2025-09-16T08:29:17+02:00 2025-09-16T08:29:17+02:00

oai:lup-student-papers.lub.lu.se:9092999 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Jake Lumsden author 9092997 Tobias Ambjörnsson supervisor Computational Biology and Biological Physics - Has been reorganised v1000644 department Department of Astronomy and Theoretical Physics - Has been reorganised v1000642 department Fitting a model to a time-dependent ensemble average is a process repeated frequently<br /> throughout biophysics. A selected ensemble-averaged observable (⟨y(t)⟩) for a given system<br /> can be predicted through the use of an estimated ensemble average, where the estimated<br /> ensemble average is created via simulated or experimental data sets. Fitting a model to<br /> this estimated ensemble average allows for estimations of ⟨y(t)⟩.<br /> <br /> Often, one tests the quality of a fitted model through the use of a ’goodness-of-fit’ (GOF)<br /> procedure. The quality of the model is determined by the placement of a test statistic<br /> (S) on its associated probability distribution (φ(S)). Traditional choices of S, such as<br /> the normalised residual sum of squares (RSS), neglect correlations in fluctuations of the<br /> ensemble average around the fitted model. Under this assumption, the normalised RSS<br /> is distributed according to the χ2-distribution (φχ2(S)), with mean (μ) and variance (σ2)<br /> proportional to the degree of freedom (υ) of the fitted model. The inability of the traditional<br /> χ2-GOF procedure to account for these correlations can lead to less reliable evaluations of<br /> the quality of a fitted model.<br /> <br /> The thesis covers the derivation and validation of the correct form of φ(S) when correla-<br /> tions are considered, for use in a new GOF procedure. The new GOF procedure was tested<br /> under varying parameters, correlation types and ensemble make-ups. Testing environments<br /> included three ensemble generating prototype models, and three movies of noisified sim-<br /> ulations of vesicle movement. It is demonstrated that the new GOF procedure correctly<br /> accepts and rejects well and poor fitting models respectively, and is a valid indicator of<br /> model quality. Furthermore, it is shown that compared to the traditional χ2-GOF proce-<br /> dure, the new GOF procedure is a more accurate measure of model quality under a variety<br /> of correlation types, is reliable in a greater region of parameter space, and performs better<br /> in all tested scenarios. Studies of micro and nanoscopic particles and molecules have been of huge benefit to the<br /> biophysics community. The ability to conduct experiments at the microscopic level has<br /> generated new knowledge about once unseen biological processes from virus incubation to<br /> the life cycle of bacteria.<br /> <br /> At the microscopic level, the recorded trajectories of a given system of particles are often<br /> grouped into what is referred to as a time dependent ensemble average. A time dependent<br /> ensemble average describes a given system of particles as a single stream of time dependent<br /> data, that data being a chosen metric by which to average over time. Time dependent<br /> ensemble averages allow for easier and more reliable interpretation of a system of particles,<br /> and for the extraction of certain system dependent parameters, such as how and the rate<br /> at which certain particles move under a set of pre-defined conditions.<br /> <br /> Fitting a model to the time dependent ensemble average allows for predictions further in<br /> time to be made, and further parameters to be extracted, such as the rate of diffusion.<br /> <br /> In practice, one often estimates a chosen ensemble-averaged observable (⟨y(t)⟩) through<br /> the use of an estimated ensemble average made up of simulated or experimental data sets<br /> containing ⟨y(t)⟩. Fitting a model to this estimated ensemble average then allows for the<br /> extraction of a prediction of ⟨y(t)⟩.<br /> <br /> For both predictions and extracted parameters to be accurate, one must make sure that the<br /> model is well fitting. Goodness-of-fit (GOF) procedures are used frequently throughout<br /> various scientific communities to ensure that models are well fitting to their ensemble<br /> counterparts. Traditional GOF procedures, such as the χ2-GOF procedure, neglect any<br /> correlation among the fluctuations of the ensemble average around the fitted model, leading<br /> to less reliable determination of a fitted model’s quality.<br /> <br /> This thesis fills this gap in traditional GOF procedures, developing a new GOF proce-<br /> dure which includes the correlations in fluctuations of a ensemble average around a fitted<br /> model. The new GOF procedure will allow scientists within the biophysics community to<br /> make more reliable predictions and extract more accurate parameters from a given time<br /> dependent ensemble average. The hope is that researchers will take to and use this new<br /> GOF procedure to further the knowledge of intricate biological particles and processes, for<br /> example, virus structure and transmission, or the diffusion of molecules through the lipid<br /> membrane. https://lup.lub.lu.se/student-papers/record/9092999/file/9093009.pdf application/pdf 1872039 no 2022 eng Physics and Astronomy Mathematics and Statistics 9092999 2022-06-23T15:38:54+02:00 2022-06-29T14:02:58+02:00 2022-06-28T09:04:38+02:00

oai:lup-student-papers.lub.lu.se:9187695 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Anton Pedersen author 9187693 Melvyn B Davies supervisor PhD Dragi Anevski supervisor Mathematical Statistics v1000668 department Close stellar encounters play a critical role in shaping planetary systems by perturbing the orbits of minor body populations like the Oort Cloud and the orbits of planets. Using data from the Gaia DR3 catalogue, this work quantifies close stellar encounters, investigating both Sun-star and star-star interactions. <br /> <br /> Assuming that stars move in straight lines, encounter distances and times were computed. A sampling method was used to derive confidence intervals for the encounter parameters. In the case of solar encounters, an analytical expression for the encounter distance distribution was derived and used to estimate encounter rates. The results indicate that approximately 2% of Sun-like stars experience an encounter within 100 AU over 4.6 Gyr.<br /> <br /> After filtering out bound systems, 193 star pairs with median encounter distances of less than 0.05 pc were identified. For solar encounters, six stars were found to approach within 0.5 pc. The closest being Gliese 710 with a median encounter distance of 0.051 pc.<br /> <br /> This study enhances our understanding of the local dynamical environment and establishes a framework for identifying significant close encounters. Av de tusentals stjärnor som analyserats i detta arbete framträder stjärnan Gliese 710 som särskilt intressant. Denna stjärna förväntas passera solen på ett avstånd av ungefär 10000 gånger avståndet mellan jorden och solen, om cirka 1.3 miljoner år. Även om detta låter avlägset kan en sådan förbiflygning störa det avlägsna Oort-molnet som omger solsystemet, vilket potentiellt kan öka antalet kometer som rör sig inåt i solsystemet mot Jorden. Med framtida data från Gaia kommer vi att kunna förutsäga sådana händelser med större precision, vilket är avgörande för att bedöma långsiktiga risker för solsystemet.<br /> <br /> Utöver solens närmöten har jag även studerat interaktioner mellan stjärnpar, solen exkluderad, och identifierat 193 stjärnpar med så nära förbiflygningar att de är värda vidare undersökning. Dessa fall är inte bara intressanta för vår förståelse av galaxens dynamik, utan också potentiellt i sökandet efter tecken på intelligent liv. Nära passager mellan stjärnor skulle kunna vara optimala tillfällen för en teknologiskt avancerad civilisation att resa mellan planetsystem. Detta kan liknas vid hur vi utnyttjar specifika tidpunkter för att skicka rymdsonder till Mars på energisnåla banor.<br /> <br /> Stjärnor kretsar omkring Vintergatans centrum med olika omloppsbanor, vilket ibland leder till nära möten. Dessa interaktioner kan påverka omloppsbanor av planeter, asteroider och kometer i planetsystem, vilket i sin tur kan leda till instabila förhållanden. Ett aktuellt exempel är asteroiden 2024 YR4, som nyligen orsakade oro när den bedömdes ha en förhöjd risk att kollidera med jorden år 2032. Även om risken nu anses vara minimal, illustrerar detta hur objekt i vårt solsystem kan få banor som för dem nära jorden, möjligen som ett resultat från ett av Solens tidigare närmöten med en annan stjärna.<br /> <br /> För att beräkna dessa möten antog jag att stjärnor rör sig i raka banor, det vill säga att jag bortsåg från den övergripande gravitationen i galaxen. Genom omfattande analys av data från Gaia (ett huvuduppdrag från Europeiska rymdorganisationen) och användandet av statistiska metoder uppskattade jag både tidpunkten och avståndet för dessa nära förbiflygningar. Utöver detta härledde jag en matematisk modell för att bedöma hur troligt det är att en stjärna passerar inom ett visst avstånd från Solen. Genom att applicera denna modell bakåt i tiden kan vi skatta hur många nära stjärnpassager solen har upplevt under dess 4.6 miljarder år långa historia – en pusselbit i förståelsen av hur solsystemet har utvecklats till sin nuvarande form. https://lup.lub.lu.se/student-papers/record/9187695/file/9187696.pdf application/pdf 1951780 no 2025 eng Stellar encounters Close stellar approaches Gaia DR3 Encounter rate Isotropic velocities Minimum separation distribution Binary star filtering Linear motion approximation Physics and Astronomy Mathematics and Statistics 1654-6229 2025:K2 LUNFMS-4078-2025 https://lup.lub.lu.se/student-papers/record/9187695/file/9187698.pdf application/pdf no 9187695 2025-04-17T15:01:57+02:00 2025-04-22T09:53:42+02:00 2025-04-22T09:53:42+02:00

oai:lup-student-papers.lub.lu.se:2861324 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:9007405 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:8965237 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:1336616 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:4192051 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:3469989 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:7508770 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:9043678 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:8986824 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:4178404 2025-07-29T13:03:30Z PhysicsChemistryMaths

oai:lup-student-papers.lub.lu.se:1857523 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH3 Mikael Särnholm author Professor Lovisa Björnsson supervisor Associate professor Pål Börjesson supervisor Biotechnology v1000653 department In these times, when global warming is escalating and the finite<br /> resources of the world are consumed in a fast pace, it is very<br /> important to find sustainable solutions for the near future. Transport<br /> is one of the sectors that need to find alternative solutions to the<br /> utilisation of fossil fuels. This master thesis investigates biogas<br /> production from ley crops, which is a mixture of different species of<br /> clover and grass. At first the methane potential was determined<br /> through laboratory experiments to an average of 270 Nm3 CH4/ton TS or<br /> 50 Nm3 CH4/ton wet weight. It was concluded that there was no<br /> significant difference in methane potential between ley crops<br /> fertilized with bio fertilizer and mineral fertilizer. The methane<br /> potential from the first harvest was however significantly higher than<br /> from the second harvest of the year. The average methane potential was<br /> then used in an energy and environmental systems analysis, where<br /> energy consumption and greenhouse gas emissions were analysed in a<br /> cradle-to-grave perspective, covering all aspects from cultivation of<br /> ley crops to bioconversion to biogas and use as a fuel for transport.<br /> Comparing direct land use changes, the emissions where lower if the<br /> ley crops were grown on land that had previously been used for<br /> cultivation of grain, due to an increased soil carbon content, than if<br /> it had been used for cultivation of ley crops. The study also showed<br /> that if system expansion was used, which means that the digestion<br /> residue produced was used as bio fertilizer replacing mineral<br /> fertilizer, both energy consumption and emissions were lowered. The<br /> energy input ranged from 28 to 38 percent of the produced biogas, and<br /> the emissions ranged from 3 to 32 g CO2e per MJ of biogas. https://lup.lub.lu.se/student-papers/record/1857523/file/1857526.pdf application/pdf 6586875 no 2011 swe Chemistry 1857523 2011-03-21T09:58:02+01:00 2011-03-22T23:16:42+01:00 2011-03-21T11:25:48+01:00

oai:lup-student-papers.lub.lu.se:4300408 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Alexander Christea author 4316598 Dr. Petter Persson supervisor Department of Chemistry v1000647 department The aim of the study was to theoretically investigate if a proton coupled electron transfer (PCET) was feasible for a molecular system consisting of a light harvesting complex, ruthenium(tris-2,`2-bipy)2+, with different organic moieties serving as PCET (proton coupled electron transfer) relays. These light harvesting complexes are also sometimes referred to as dyes.<br /> By studying the energy levels for when the proton is bound to the acceptor and when it is bound to the donor we can deduce which configuration is more energetically favorable and thus if the system is likely to undergo a proton coupled electron transfer reaction. The study was conducted using Gaussian 09[1], Molden 4.8[2] and GaussView 5.0.9[3] software. B3LYP was the DFT used for all the calculations while more than one basis sets were used (such as 6-31G*, 6-31G(d,p) and SDD) in the calculations. The molecules were first optimized and then the molecular orbitals, energy levels and electron density data were extracted for review and study. The data revealed that for the large Ru(II)tbpy-L-complex in the excited (triplet) state there are two possible configuration for our complexes (1, 2 and 4) while in the ground state only 1 exhibited two local minima. The methylated moieties 2 and 4 showed that the configuration (where the proton is bound to the nitrogen) is, energetically, the lowest possible configuration as both converged to the same coordinate, Q(NH). Populärvetenskaplig sammanfattning<br /> Morgondagens energi<br /> Vind-, och vattenkraft tillsammans med solenergi är de enda energikällorna vi har som inte leder till avfall som ökar växthuseffekt eller avfall som vi inte kan göra oss av (från t ex kärnkraftverk). Men solpanelerna som finns idag för kommersiellt privat bruk ligger på en effektivitet kring 15%. Att utveckla nya molekyler som kan omvanlda solljus till energi med en hög effektivitets grad är en viktig och nödvändig process. Mänskligheten använder ca 168PWh av energi (från olika energikällor), varav endast en liten bråkdel kommer från förnybara energiresurser. Om man skulle täcka en yta på ca 250 000 km2 i norra Afrika med solpaneler som har en effekt på 100% så skulle vi få ut mer än det dubbla av den totala förbrukningen av energi per år. Därför är det väldigt viktigt att vi uppnår en högre effektivitet genom att fortsätta studera dessa fotokemiska processerna i detalj.<br /> Det finns många olika typer av solceller och den solcell vi har fokuserat oss på bygger på ett metall-ligand-komplex, Ruthenium(tris-2,`2-bipy), med olika slags ’reläer’ på en av liganderna. När ljuset har absorberats av komplexet så exiteras en elektron och förflyttar sig från reläet ner mot metall kärnan (mer specifikt över den bryggande liganden) via de molekylära orbitalerna. När detta sker så har vi en energi förändring som tar plats i systemet, denna förändring är oftast inte något som medför till en stabil molekyl. Men om man använder sig utav en proton överföring i samband med elektron överföringen så kan man få ett stabilt komplex som sedan tillåter en energiutvinning från elektronen, som inte nödvändigtvis är lika benägen att återkombinera (förflytta sig till där den var från början). Studien går då ut på för att se om de olika reläerna stabiliserar det exiterade komplexet genom att en proton kopplad elektron överföring sker.<br /> Ruthenium(tris-2,`2-bipy)L betyder att metallkärnan är en ruthenium atom (även kallad övergångsmetall) och tris indikerar att tre av bipy är bundna till metallen. L, kort för ligand i vanliga fall, använder vi för att beskriva våra reläer, 1-4. Bipy står sedan för bipyridin och siffrorna 2 och `2 indikerar två olika positioner för var kvävet i bipy sitter!<br /> Resultat<br /> Det visade sig att energinivåerna i det exciterade tillståndet för ruthenium komplexet (med reläerna fästa) var precis tvärtom till det vi trodde, dvs istället för en stabil nivå för det exciterade tillståndet så fann vi två stabila lokala minima (med den lägsta av de två då protonen är bunden till syret). Det visade sig även att 1 inte är benägen att genomgå en proton kopplad elektron överföring (PCET, proton coupled electron transfer) överhuvudtaget, varken från syret till kvävet eller vice versa. Vidare studier måste göras för att fastställa varför 1, som även hade den kortaste distansen mellan donator och acceptor, inte överförde sin proton i någon av fallen. Det krävs vidare studier (med konsekvent bas set användning) för att kunna avgöra vad som krävs för att en PCET ska ske, t ex fastställa storleken på aktivitetsbarriären, studera hur vinklarna mellan acceptor/donator påverkar processen, etc. https://lup.lub.lu.se/student-papers/record/4300408/file/4300452.pdf application/pdf 1318818 yes 2013 eng Theoretical Chemistry teoretisk kemi Chemistry 4300408 2014-02-10T14:51:15+01:00 2014-02-14T13:46:29+01:00 2014-02-14T13:46:29+01:00

oai:lup-student-papers.lub.lu.se:4406776 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 David Ahlstrand author 4406860 Klara Jonasson supervisor Department of Chemistry v1000647 department Pincer complexes, bicyclic complexes between a tridentate pincer ligand and a transition metal center, have been known since the 1970s and possesses a lot of advantages. They have various applications, but they are mainly used as catalysts at this point. Their desirable catalytic properties can be explained by the rigid bicyclic structure and that the σ-bond between the transition metal and the anionic carbon prevents dissociation of the metal. The large amount of structural alternatives also results in fine-tuning possibilities of the properties of a certain complex. However, aromatic pincer complexes are far more investigated than the aliphatic which means that studying the latter could be of significant interest since the structural differences might effect the properties clearly.<br /> One powerful tool in organic synthesis are the transition metal catalyzed cross coupling reaction between Grignard reagents and organic halides, named Kumada coupling after one of the discoverers. The reaction was limited to aryl and vinyl halides in the beginning, but advances have been made with the catalysts during the last decade which enables Kumada couplings for alkyl halides as well. Otherwise highly reactive functionalized halides have been selectively coupled in some cases by using Pincer complexes as catalysts.<br /> The aliphatic pincer complex 1 has previously been synthesized but its properties have not been investi-gated before. Due to the reported successful uses of pincer complexes as catalysts in Kumada couplings, it was studied whether the complex 1 could catalyze this reaction. The reaction was not successful under any conditions for alkyl halides, with obtained yields below 10 % according to GC. The yields was somewhat improved while using aryl halides, but they did not exceed 20 %. The similar complexes 2, 3 and 4 were also tested with comparable results. It was therefore concluded that the complexes 1, 2, 3 and 4 are proba-bly no good catalysts for Kumada couplings, and that it will be of more interest to investigate their possi-bility to catalyze other reactions. Populärvetenskaplig sammanfattning<br /> Inom vissa delar av den kemiska industrin, exempelvis läkemedelsindustrin, är det viktigt att kunna de-signa och skräddarsy organiska molekyler så att de har precis den strukturen man eftersträvar. Till sin hjälp finns det en mängd olika organiska reaktioner som kan användas för att koppla ihop och bygga molekyler på olika sätt. En molekyl med en optimerad struktur kan exempelvis öka effektiviteten markant hos ett läkemedel, så en större repertoar av reaktioner att använda sig av ger utökade möjligheter till en lyckad syntes.<br /> Till många av dessa organiska reaktioner behövs katalysatorer, ett ämne som förbättrar förutsättningarna för en reaktion att ske, användas. En katalysator kan göra en reaktion mer effektiv på flera vis, så som att reaktionsprodukten bildas snabbare eller att en möjlig produkt selektivt bildas framför en annan. Ett sätt att utöka repertoaren av reaktioner att använda sig av i en syntes kan alltså vara att optimera en katalysator så att fler sorters ämnen kan användas i en redan befintlig typ av reaktion.<br /> Många katalysatorer inom organisk syntes består av metallatomer bundna till organiska molekyler, så kalla-de metallkomplex. Den stora mängden olika metaller som finns gör det möjligt att finjustera ett sådant komplex för att optimera dess egenskaper. En sorts metallkomplex som framgångsrikt har använts som katalysatorer är de så kallade pincettkomplexen, ett komplex mellan en pincettliknande organisk del som binder med tre atomer till en metallatom. Strukturen på dessa komplex gör dem ovanligt stabila när de utsätts för höga temperaturer, vilket också är en anledning till att de är bra katalysatorer.<br /> Målet med projektet har varit att undersöka fyra liknande pincettkomplex för att se om de är lämpliga katalysatorer till en organisk reaktion som heter Kumadakoppling. En fördel med Kumadakoppling är att ämnena som reagerar med varandra i den reaktionen ofta är ganska billiga samt relativt miljövänliga och ofarliga jämfört med andra liknande organiska reaktioner. Att hitta katalysatorer som gör Kumadakopp-lingar möjliga för fler sorters startmaterial är därför önskvärt, och andra typer av pincettkomplex har redan varit framgångsrika i detta syfte.<br /> I de utförda experimenten har ett av de två startmaterialen samt det aktuella pincettkomplexet lösts i olika lösningsmedel i ett speciellt sorts kärl som möjliggör att reaktionen utförs under kvävgas istället för luft. När det i reaktionsmiljön är tillräckligt mycket kvävgas har det andra startmaterialet sedan tillsatts, och därefter fick reaktionen fortgå under olika lång tid och i olika temperaturer. Anledningen till att reaktionen utförs under kvävgas är att ett av startmaterialen reagerar snabbt med syrgas. För alla fyra pincettkomplex utfördes reaktionen mycket dåligt oavsett lösningsmedel, temperatur eller reaktionstid. Det är därför tro-ligt att dessa komplex inte är optimala som katalysatorer för Kumadakopplingar, däremot kan det vara intressant att se om de kan katalysera andra reaktioner som pincettkomplex tidigare har kunnat användas till. https://lup.lub.lu.se/student-papers/record/4406776/file/4406777.pdf application/pdf 667245 yes 2014 eng Oorganisk kemi Inorganic Chemistry Chemistry 4406776 2014-04-24T16:33:51+02:00 2014-04-25T10:30:51+02:00 2014-04-25T10:30:51+02:00

oai:lup-student-papers.lub.lu.se:4406790 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Karin Carlsson author 4406858 Leif Dahlberg supervisor Department of Chemistry v1000647 department The aim of this project was to examine how S100A9 binding to target molecules was affected by structural modifications with oxidizing agent in vitro.<br /> S100A9 was cultivated, purified and oxidative modifications were induced. The oxidative modifications where characterized with tryptohan fluorescence, Surface Plasmon Resonance technique (SPR) and MALDITOF-MS.<br /> To get access to protein to study recombinant human S100A9 was expressed in E.coli and purified in three chromatographic steps.<br /> Tryptophan fluorescence measurements gave decreased fluorescence signal that correspond to increased oxidizing levels of HOCl or H2O2 added to rhS100A9.<br /> SPR confirmed rhS100A9 correct folding against EMMPRIN or RAGE and a decreasing complex formation between rhS100A9 and antirhS100A9 antibody in presence of H2O2 and HOCl.<br /> MALDI-TOF-MS demonstrate methionine sulfoxide formation of M63, M81, M83, M93 in the presence of HOCl or H2O2 in vitro.<br /> The conclusion was that oxidative modification could be induced and characterized in S100A9 with tryptophan fluorescence and MALDI-TOFMS. SPR showed that the function of S100A9 in terms of binding ability to a receptor, decreased when oxidizing agents were added. Populärvetenskaplig sammanfattning<br /> Oxidativa modifieringar av S100A9 S100A9 är ett protein i kroppen som får en förändrad struktur och funktion när det reagerar med syre. De strukturella förändringarna kallas oxidativa<br /> modiferingar. För att förstå processen skulle man kunna jämföra S100A9 med järn. När järn kommer i kontakt med syre får det en rödaktig färg och strukturen går från att vara stark till att bli skör och vittra sönder. Det är det här som kallas för att järnet rostar. När S100A9 reagerar med syret i kroppen blir aminosyrorna, proteinets byggstenar, förändrade och det påverkar i sin tur hela proteinets struktur.<br /> Syret i kroppen produceras främst av immunförsvaret för att skydda kroppen från angrepp från bakterier och virus. Proteiner och andra molekyler som reagerar med syret blir icke-funktionella i angriparna. Syret kan även ge sig på och skada kroppens egna celler. För att förhindra att syret bryter ner vävnader i kroppen plockar S100A9 upp syret. Syret<br /> i S100A9 kan därefter oskadliggöras med hjälp av vissa processer, så att S100A9 får tillbaka sin ursprungliga struktur. Ibland kan inte syret plockas bort från S100A9 och då blir proteinet icke-funktionellt.<br /> I det här arbetet har inverkan av syre på S100A9 undersökts i provrör. S100A9 har analyserats med avseende på vilka strukturella förändringar som sker och hur dessa påverkat proteinets funktion.<br /> Strukturen har undersökts med två olika metoder; Tryptofanfluorescens och MALDI-TOF-MS. Tryptofanfluoresens innebär att man mäter det ljus som aminosyran tryptofan återutsänder när den bestrålas med ljus av en viss våglängd. Förändringar i ljussignalen berättar att strukturen runt tryptofan och proteinets struktur har ändrats. MALDI-TOFMS är en metod där man kan titta på enskilda aminosyror i proteinet och ser om de har bundit in syremolekyler eller fått andra förändringar.<br /> S100A9 förmåga att binda till andra proteiner har undersökts med hjälp av metoden Surface Plasmon Resonance technique(SPR).<br /> Studien visade att S100A9 fick oxidativa modifieringar som skulle kunna tillbakabildas. Modifieringarna var beroende av vilken mängd och vilken typ av syre som tillsattes; HOCl eller H2O2. En högre koncentration syre gav en större signalnergåang i fluorescensmätningarna. MALDITOF-MS visade att aminosyran metionin fick inbundet syre. SPR gav en minskad inbindningsförmåga mellan S100A9 och ett annat protein i närvaro av syre. https://lup.lub.lu.se/student-papers/record/4406790/file/4406793.pdf application/pdf 3430008 yes 2014 eng Protein Science Proteinvetenskap Chemistry 4406790 2014-04-24T18:00:27+02:00 2014-04-25T10:29:02+02:00 2014-04-25T10:29:02+02:00

oai:lup-student-papers.lub.lu.se:4075050 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mohammad Bilal Akhtar author Dr. Arkady Yartsev supervisor Prof. Anne L'Huillier supervisor Atomic Physics v1000622 department Chemical Physics v1000658 department A time correlated single photon counting (TCSPC) setup is built to measure the fluorescence decay of samples, such as solar cell materials. TCSPC is a sensitive technique for measuring fluorescence decays on nanosecond time scale and longer. The principle of TCSPC is based on the precise registration of the arrival time of fluorescence photons from a sample. A fluorescence decay curve is constructed from the TCSPC measurement, this curve is used to extract the fluorescence lifetime. The<br /> setup is novel with respect to the conventional method of collecting a fluorescence signal. It is a simplified setup as there is no need of complex geometry of optics to focus the excitation beam or to image the fluorescence on to the detector. Instead, the excitation beam is unfocused and the sample is placed as close to the detector as possible. This approach allows for the usage of low excitation density of photons.<br /> The low level of light that this setup could detect made it very sensitive for measuring samples with low emission. The setup is characterised with two different samples: Coumarin-152 (7-N,N-dimethylamino-4-trifluoromethyl-1,2-benzopyrone) and APFO3 (poly[2,7-(9,9-dioctylfluorene)-alt-5,5-(4,7′-di-2-thienyl-2′,1′,3-<br /> benzothiadiazole)]). Coumarin-152 is a commercial laser dye and APFO3 is a polymer solar cell material. These measurements reveal that the single and non exponential curves could be obtained using this setup. The verification of the setup is further carried out by classifying different errors that can influence the measurements. Popular Science Abstract<br /> <br /> This thesis is about the construction and demonstration of time correlated single photon counting (TSCPC) setup. The technique is essentially digital and is based on detection and counting of single photon, recognizing quantum nature of light. The time is measured between excitation pulse and detected photons and is stored in histogram with x-axis corresponding to time interval. The sample is excited repeatedly and resulting histogram of intensity versus time called as fluorescence decay curve.<br /> <br /> Generally speaking, fluorescence or emission spectroscopy is one of the fundamental spectroscopic techniques. This is the study of fluorescence phenomenon which is the emission of photons from singlet excited state. The emission is red shifted relative to absorption maxima due to loss of energy as heat during relaxation process. In the time resolved fluorescence decay experiment, the sample is excited with pulse of laser<br /> light, it starts with high intensity and then decays, rapidly. Later on from appropriate fitted functions, type of decay, lifetime and amplitudes are calculated. In case of photon counting, the measured data is in form of discrete time function. But still the fitted functions provide the same information. Then question arises about additional<br /> advantage of our TCSPC technique over other life time measurements. The additional benefits come from simplicity of integrated setup i.e. lack of focussing lenses and very low excitation density is required.<br /> <br /> The setup has been characterized by measuring the fluorescence decay from organic dye and polymer solar cell material. The data has been fitted with exponential functions and fluorescence life times are calculated with good accuracy. Other than life time measurements, the technique is being successfully used for single molecule detection, TCSPC imaging, and fluorescence correlation spectroscopy in combination<br /> with fluorescence microscopy etc. https://lup.lub.lu.se/student-papers/record/4075050/file/4075066.pdf application/pdf 785665 no 2010 eng Chemistry 4075050 2013-10-02T11:26:04+02:00 2015-12-14T13:30:19+01:00 2013-10-02T11:35:54+02:00

oai:lup-student-papers.lub.lu.se:4114224 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Lars Erik Andreas Ehnbom author 4139635 André Fleckhaus supervisor Department of Chemistry v1000647 department Populärvetenskaplig sammanfattning<br /> Metallorganisk kemi är en gren av kemin som fokuserar på att utveckla nya reaktioner med hjälp av övergångsmetaller som t.ex. järn, kobolt och guld. Genom att använda övergångsmetaller i kemi är det möjligt att bilda nya reaktioner som man med konventionell organisk kemi inte kan få tillgång till. Dessutom är selektivitet, avfallsminskning, minimering av biprodukter, förkortad reaktionstid eller en sänkning av reaktionstemperaturen några exempel på viktiga egenskaper som övergångsmetallkatalyserade reaktioner kan erbjuda. Lägre temperatur innebär att mindre energi förbrukas vilket är av stor betydelse för industrin, vilket i sin tur naturligtvis påverkar vår miljö. Sammanfattningsvis kan metallorganisk kemi användas för att förbättra livet för människan.<br /> <br /> Metallorganisk kemi har också många tillämpningar, t.ex. vid bildning av polymerer som plaster. I princip varje plast som används idag är tillverkad ur reaktioner som skapar kol-kol-enkelbindningar, och detta i processer som använder övergångsmetaller. Andra användningsområden är i produktionen av jordbrukskemikalier, så att vi kan odla grödor i den omfattning som behövs för att föda den växande globala befolkningen. En relativt ny applikation är organiska lysdioder (oLED), som nu är i användning i moderna mobiltelefoner och som gör skärmen flexibel. Inom kort skulle detta möjligen kunna användas som ett material för att bakgrundsbelysa ett helt rum genom att tapetsera med oLEDs.<br /> <br /> Guld är ett exempel på en övergångsmetall och den betecknas Au (lat. aurum). Elementärt guld finns överallt i vårt dagliga liv, t.ex. i smycken. Denna form av guld har ett lågt oxidationstillstånd ,Au(0), och byter inte gärna elektroner. Elementärt guld visar sålunda en låg reaktivitet och är svår att använda i den kemi som är beskriven ovan. Istället kan de två andra oxidationstillstånden hos guld, nämligen guld (I) och guld (III) nyttjas. Dessa former är mer reaktiva. I mitt arbete har jag skapat guld (I) komplex för att studera reaktiviteten och få en grundläggande kunskap kring deras kemi. Det är viktigt att på djupet studera och förstå denna grundläggande kemi om vi vill kunna bygga nya applikationer som de ovan nämnda. Anledningen att använda guld i kemi snarare än t.ex. platina eller rodium, som traditionellt används, är att guld är förvånansvärt billigt i jämförelse med rodium och platina samtidigt som det finns gott om guldreserver på jorden. Several N-heterocyclic gold (I) complexes were synthesized featuring both the bis-(2,4,6-trimethylphenyl)imidazolium carbene (IMes) ligand and the bis-(1,3-diisopropylphenyl)imidazolium carbene(IPr) ligand. Complexes of the form LAuCl, LAuOtBu, and LAuPh (L = IMes, IPr) were synthesized and characterized using 1H-NMR. Two updated crystal structures of IMesAuPh and<br /> chloro(dimethylsulfide)gold(I) were established. The reaction between IMesAuPh and iodobenzene in deuterated benzene at 90°C and 110°C, using an internal standard (cyclooctane) was studied in detail. According to Johnson1 et al, the reaction was novel of its kind by showing a complete new reactivity involving Au(I) species. The primary objective was to study the kinetics of this novel reaction. Surprisingly, additional investigation unfolded data which supported the likelihood of Au(0) catalysis where the NHC Au(I) species would serve as an intermediate in CC coupling. Observation of a purple coating on the Young tubes together with a very late formation of biphenyl supported Au(0) catalysis. At slightly lower reaction temperature (90°C), no observable amount of crosscoupling product could be observed, even after vastly prolonged reaction times. Additional control experiments using both a catalytic and stoichiometric additive of a palladium pincer complex (PCP-PdCl) yielded similar reactivity pattern as earlier reported, thus rendering biphenyl as in the gold(I)-only case accompanied by the simultaneous forming IMesAuI. Copper impurities is likely not affecting catalysis as different intermediates are observed compared to when Pd or non Pd experiments are run. Clearly, palladium sources may be a<br /> contributing factor in the formation of cross-coupling product. This new data identifies the pivotal need to run further control experiments, to exclude any involvement of palladium responsible for catalysis and not Au(0) by as well study the effect of any in situ Au(0) formation. https://lup.lub.lu.se/student-papers/record/4114224/file/4117150.pdf application/pdf 2952675 no 2013 eng Oorganisk kemi inorganic chemistry Chemistry 4114224 2013-10-22T13:49:31+02:00 2013-10-30T10:59:57+01:00 2013-10-30T10:59:57+01:00

oai:lup-student-papers.lub.lu.se:4121643 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Maxim Morin author 4139636 Malin Zackrisson supervisor Department of Chemistry v1000647 department Populärvetenskaplig sammanfattning<br /> Protein-protein växelverkan för det globulära proteinet laktoferrin har studerats vid låg elektrolythalt (5 mM) med hjälp av statisk ljusspridning och mätningar av andra virial koefficienten, B2 som innehåller information om protein-protein växelverkan. Växelverkan mellan proteinmolekyler är mycket komplex vilket beror på de ingående aminosyrornas egenskaper. Dessa proteininteraktioner är starkt beroende av lösningens pH och jonstyrka som påverkar proteinets laddning och även den sammanlagda växelverkan på ett inte självklart sätt. Från MC datorsimuleringar har man funnit att laktoferrin har en fläckvis attraktiv växelverkan och denna attraktion skall under vissa betingelser (pH nära PI samt låg jonstyrka) ge upphov till dimerbildning. Vi avser använda laktoferrin som modelsystem för fläckvis attraktion och i detta arbete har den andra virial koefficienten, B2, bestämts vid lågt pH och jonstyrka, vilket motsvarar repulsiv växelverkan. In this work the effect of pH and ionic strength on interactions for the globular protein lactoferrin has been studied using static and dynamic light scattering. The interactions were investigated in terms of the second virial coefficient, B2, and the collective diffusion coefficient, Dcoll, at different concentrations of electrolyte. The conditions investigated in this work will serve as a stable point-of-departure from which we will set out, in a controlled way, to explore the phase diagram with the aim to use lactoferrin as a model protein to investigate the role of patchy attractive interactions, i.e. charged groups and hydrophobic groups are unevenly distributed at the protein surface. The charged groups depend strongly on both pH and ionic strength. The overall reproducibility and stability against time are crucial and shown here to be highly satisfactory. From determination of B2 the interactions are found to be, at the investigated pH and ionic strength, overall repulsive and in agreement with computer simulations and preliminary SAXS measurements. However, the collective diffusion coefficient appears to be, under the same conditions, not as repulsive which calls for further measurements and analysis. https://lup.lub.lu.se/student-papers/record/4121643/file/4121646.pdf application/pdf 1224654 no 2013 eng Fysikalisk kemi Physical Chemistry Chemistry 4121643 2013-10-23T09:52:28+02:00 2013-10-30T11:02:03+01:00 2013-10-30T11:02:03+01:00

oai:lup-student-papers.lub.lu.se:4124524 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Henrik Engström author 4124522 Jan Åke Jönsson supervisor Marja Boström supervisor Department of Chemistry v1000647 department Selective serotonin reuptake inhibitors (SSRIs) have been found in waste water treatment plant effluents and surface water at detectable concentrations. Although the medical effects and side effects of pharmaceuticals and personal care products are investigated through safety and toxicology studies the potential environmental impacts are less studied, and information concerning ecotoxicological risks and the distribution in sludge, surface water and water living organisms is rather scarce.<br /> <br /> In this thesis, sertraline (SER), fluoxetine (FLU) and its N-desmethyl metabolite norfluoxetine (norFLU) were chosen as model substances to develop a method for detection. Fish was chosen as the model matrix because fish is a top predator with possible high analyte concentrations because of biomagnification. Hollow fibre liquid-phase membrane extraction (HF-LPME) was used as the extraction, clean-up and enrichment technique and LC-MS was used to detect the SSRIs in fish muscle tissue.<br /> <br /> This analytical method showed enrichment factors ranging 1500-1800 for fish samples and 3000-6300 for water samples. The R2-values of the linearity were 0.936, 0.990, 0.966 for norFLU, FLU and SER, respectively. The detection limits of the method for norFLU, FLU and SER were in the range of 130-280 ng L-1. The method was successfully applied to detect the analytes in exposed crucian carp; 1.7 μg g-1 FLU and 2.8 μg g-1 SER were found after exposure to a 51 μg L-1-mixture for 3 days. The FLU metabolite norFLU was not added in the exposure solution and it was not formed in detectable concentrations during the exposure. In unexposed crucian carp, none of the analytes were detected. The developed analytical method might be extended to estimate the distribution or the fate of norFLU, FLU and SER in other biota or human beings. Spår av antidepressiva läkemedel i fisk<br /> Läkemedel hjälper till att behandla och förebygga sjukdomar hos både djur och människor. Rigorösa utredningar krävs för att kartlägga deras effekter och bieffekter, men när de inte bryts ner helt i kroppen hamnar de i sjöar och vattendrag. Här är deras påverkan på djur och natur inte alls lika kartlagd.<br /> Depression är bland de äldsta sjukdomarna kända för människan. Sedan den antidepressiva läkemedelsgruppen selektiva serotoninåterupptagshämmare (SSRI) introducerades behandlas även mildare former av depression med medicin. Detta har gjort SSRI-mediciner till de mest utskrivna psykofarmakan. Då forskning har visat att psykofarmaka inte helt bryts ner i kroppen är det av största vikt att hitta sätt att analysera denna typ av läkemedel i vattenlevande organismer.<br /> <br /> Förutom låg koncentration är det alltid komplicerat att analysera ämnen i biologiska prover på grund av mängden andra, oönskade, ämnen som ofta skymmer sikten. Forskning har dock utvecklat metoder som är selektiva och högt anrikande av de önskade molekylerna.<br /> <br /> En sådan teknik är hålfiberteknik, eller Hollow Fibre Liquid Phase Membrane Extraction (HF-LPME). Med hjälp av en tunn, porös slang (hålfiber), koncentreras de önskade molekylerna tusenfalt. Detta för också med sig att endast små mängder lösningsmedel behöver användas, vilket gör metoden miljövänlig.<br /> <br /> I ett arbete utfört på Centrum för analys och syntes vid Lunds universitet, användes tekniken för att analysera SSRI i ruda från Revingehed. Arbetet visade att då fiskarna exponerades för SSRI i vattnet, kunde de antidepressiva läkemedlen även hittas i fiskvävnaden. https://lup.lub.lu.se/student-papers/record/4124524/file/4124526.pdf application/pdf 13925331 no 2013 eng HF-LPME LC-MS SSRI selective fish analytical chemistry analytisk kemi Chemistry 4124524 2013-10-26T21:49:55+02:00 2019-02-26T11:06:32+01:00 2019-02-26T11:06:32+01:00

oai:lup-student-papers.lub.lu.se:4286248 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Vivek Srinivas author 4293334 Marjolein Thunnissen supervisor Department of Chemistry v1000647 department Popular Summery<br /> My Experiments with Protein Crystallography<br /> Visualization of proteins is very important to understand their structure – function relationship, it helps to identify and work with important drug targets. X-ray crystallography is basically a kind of high-resolution microscopy allowing us to realize such structures of proteins. In principle, the electron density of a macromolecule diffracts X-rays, which carries information regarding the respective electron density to a detector. Such diffraction data is used mathematically to backcalculate structural information on the macromolecule. A protein molecule individually is not great diffractor of X-Rays, but when arranged continuously in a 3-dimentional array the diffraction signal is amplified. The higher the order in such 3-dimentional arrays, better the diffraction data.<br /> <br /> The sitting drop vapor diffusion method of crystallization uses a concentrated reservoir solution and a protein sample diluted with the reservoir solution in a sealed environment. Water diffuses from the diluted (protein) solution to a concentrated (reservoir) solution, increasing both protein and precipitant solutions in the sample drop. This will drive the system towards supersaturation where slow precipitation of the protein takes place and as water molecules become more scares, selforganization of the protein molecules through non-covalent bonds can eventually lead to nucleation and crystal formation.<br /> <br /> Crystallization trials of MID764<br /> The protein I choose for this work is from Moraxella catarrhalis. It is a gram-negative bacterium known to cause several respiratory tract infections, such as otitis media, sinusitis and it can elevate symptoms of COPD. The immunoglobulin D (IgD)-binding (MID) protein of M. catarrhalis is a 200-kDa outer membrane, capable of binding to IgD without inducing an immunological response and to human alveolar cells (MID764-913). MID protein helps M. catarrhalis in the first steps of infection and hence defines its virulence.<br /> <br /> The aim of this study was to produce protein crystals of MID764 capable of diffracting to a resolution enough to solve its structure. The MID764 protein was successfully expressed and purified in large quantities. Initial trials failed but magnesium chloride was observed to enhance the crystallization. Crystal seeding and changed drop ratios let to formulation of MID764 crystals in 0.24M Lithium sulfate monohydrate 0.10M Tris hydrochloride pH 8.25, 21.00% w/v Polyethylene glycol 4,000 and 12mM Magnesium Chloride (shown), diffracting up to a resolution of 2.7Å, for which a native diffraction data set was collected. XDS software package showed that the crystal was in Space Group C2221. Attempts were made to collect anomalous data but with little or no success. Moraxella catarrhalis, a gram negative bacterium has the rare ability to bind to immunoglobulins without inducing an immunological response. M. catarrhalis is known to cause several respiratory tract infections, such as otitis media, sinusitis and it can elevate symptoms of COPD. The immunoglobulin D (IgD)-binding protein of M. catarrhalis is a 200 kDa outer membrane autotransporter capable of binding to IgD (MID962-1200) and to human alveolar cells (Adhesive / MID764-913). MID protein defines the virulence of M. catarrhalis.<br /> Immunization studies showed effective clearance of M. catarrhalis in mice immunized with MID764-913, proving it to be an important candidate in M. catarrhalis vaccination.<br /> <br /> The aim of this study was to structurally define MID764-913 using X-Ray crystallography. MID764-913was purified by Ni-NTA affinity chromatography followed by size exclusion chromatography. Initial crystallization trials failed, but the addition of magnesium chloride appeared to enhance the crystal quality. Successive trials proved crystal seeding and changing drop ratio to complement crystallization of MID764-913. Eventually crystals diffracting up to 2.7Å were grown in 0.24M lithium sulfate monohydrate 0.10M Tris hydrochloride pH 8.25, 21.00% w/v polyethylene glycol 4,000 and 12mM magnesium chloride with crystal seeding at MAX Lab, Lund, Sweden. A native data set of space group C2221 was collected, followed by several attempts to obtain an anomalous data set by MAD and MIR phasing by co-crystallization and soaking experiments, but failed to yield any significant results. https://lup.lub.lu.se/student-papers/record/4286248/file/4286253.pdf application/pdf 988640 yes 2013 eng Proteinvetenskap Protein Science Chemistry 4286248 2014-02-06T08:14:18+01:00 2014-02-07T13:05:09+01:00 2014-02-07T13:05:09+01:00

oai:lup-student-papers.lub.lu.se:4286381 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Nima Rajabi author 4293329 Acetals Exploring reactivity for improved carbohydrate synthesis Markus Ohlin supervisor Department of Chemistry v1000647 department Fast and convenient synthesis of a daunosamine thioglycoside donor and the aromatic O-glycosylation with simple phenols<br /> Anthracyclines are currently some of the most widely used and most effective chemotherapeutic agents. Since the first isolation of daunorubicin and doxorubicin, a large number of semi-synthetic anthracycline analogues have been synthesized. However, there are no reports of analogues where the substituted cyclohexene ring has been replaced with an aromatic ring. Such compounds could be synthesized through aromatic O-glycosylation of glycoside donors with suitable aromatic aglycones. However, aromatic O-glycosylations are sometimes problematic. In this study, a fast and convenient synthesis of a daunosamine thioglycoside donor is described. This donor was used in the O-glycosylation of cyclohexanol and three different phenols and three new daunorubicin analogues were obtained after deprotection and reduction of the resulting glycosides. None of these analogues showed any cytotoxic activity against MCF7 and JIMT1 breast cancer cells. However, it is possible that this synthesis could be used for O-glycosylation of multicyclic aglycones, with an aromatic A-ring, similar to the aglycone in DAU/DOX, which could afford promising anthracycline analogues. Nya versioner av gamla anticancer läkemedel<br /> Varje år dör miljontals av människor av olika typer av cancer runt om i världen. Cancer kan behandlas på olika sätt, och en av de vanligaste behandlingsmetoderna är kemoterapi. Antracykliner är idag några av de mest använda och mest effektiva kemoterapeutiska läkemedel som finns. De första antracyklinerna, daunorubicin och doxorubicin, isolerades på 1960-talet från bakterier och dessa läkemedel kan användas för att behandla många typer av cancer t.ex. leukemier, lymfom, bröst- och lung cancer. Behandling med antracykliner kan däremot skada hjärtat, vilket begränsar deras användning. Följaktligen har en hel del forskning varit inriktad på att hitta nya antracyklinversioner med bättre kliniska egenskaper.<br /> Strukturen för daunorubicin, är illustrerad i Figur 1. Antracykliner har ofta liknande strukturer och har två viktiga beståndsdelar; en sockerdel och en icke-sockerdel, som ofta kallas aglykon. Genom att modifiera dessa beståndsdelar har nya antracyklinversioner framställts.<br /> Reaktioner där en aglykon binds till en sockermolekyl, genom en syre atom, kallas O-glykosyleringar. Sockermolekyler har däremot oftast flera positioner som är reaktiva. O-glykosyleringar kräver därför oftast en glykosiddonor dvs. en sockermolekyl som har blivit modifierad så att kopplingen till aglykonen bara kan ske på en position.<br /> Det finns inga antracyklinversioner med en aglykon där A-ringen har blivit ersatt med en aromatisk ring dvs. en ring som ser ut som ring B och D. Sådana versioner skulle kunna framställas genom O-glykosylering med en lämplig aromatisk aglykon till en glykosiddonor.<br /> Huvudmålet med detta examensarbete var att syntetisera nya versioner av daunorubicin med aromatiska aglykoner. En glykosiddonor framställdes med en ny smidig metod. Tre nya versioner av daunorubicin med aromatiska aglykoner framställdes och två av dessa testades mot två typer av bröstcancer. De hade dock ingen anticancer effekt, men denna metod kan användas för att framställa andra versioner av antracykliner. https://lup.lub.lu.se/student-papers/record/4286381/file/4286385.pdf application/pdf 556377 yes 2014 eng Organisk kemi Organic Chemistry Thioglycoside donor aromatic O-glycosylation anthracycline daunorubicin analogue Chemistry 4286381 2014-02-06T11:29:45+01:00 2014-02-07T13:00:56+01:00 2014-02-07T13:00:56+01:00

oai:lup-student-papers.lub.lu.se:4295194 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Iacopo Galleano author 4316586 Ulf Nilsson supervisor Ingela Fritzson supervisor Department of Chemistry v1000647 department Popular summery<br /> Malaria is a parasitic disease caused by five species of the genus Plasmodium (P. falciparum, P. vivax, P. ovale, P. malariae and P. knowlesi) that affect humans. The most deadly form of Malaria is due to Plasmodium Falciparum and it is mostly spread in African areas. Almost half of the world population is at risk to contract the infection and every year malaria causes around half million deaths.<br /> Since an effective vaccine is still not available, malaria treatment relies on chemotherapeutics. It is important to find new targets and new drugs to fight the parasite because it has an inherent ability to develop resistance.<br /> Biological background and discussion<br /> Dihydroorotate dehydrogenase (DHODH) is the enzyme which catalyzes the fourth and rate limiting step of de novo pyrimidine biosynthesis. It is an interesting target because the parasites rely on this pathway to get pyrimidines, while mammalian cells can also get them from salvage of “used pyrimidines”; if DHODH is inhibited in the parasite (PfDHODH), it will not be able to synthesize DNA so its growth will be impeded. Furthermore, dissimilarities between the human and the parasite enzyme in the primary structure allow the design of species-specific inhibitors.<br /> Some 4-aminocoumarin derivatives earlier showed micro molar IC50. In this study we have synthesized new 4-amino-3-benzylcoumarin and 4-amino-8-azacoumarin derivatives, after calculations with molecular modeling, trying to optimize the interactions with the protein.<br /> Conclusion<br /> In the end we got nine derivatives which will be tested on the purified recombinant pfDHODH. These results will aid us towards further optimization of the coumarin scaffold. Abstract<br /> Plasmodium falciparum is the causative agent of the most serious and fatal malarial infections, and it has developed resistance to commonly employed chemotherapeutics. The de novo pyrimidine biosynthesis enzymes offer potential as targets for drug design, because, unlike the host, the parasite lacks pyrimidine salvage pathway.In search for new Plasmodium falciparum dihydroorotate dehydrogenase (pfDHODH) inhibitors as antimalarials, modifications of original 4-aminocoumarin scaffold were synthesized. 4-Amino-3-benzylcoumarin derivatives are inactive against the recombinant enzyme, while results for the 4-Amino-8-azacoumarin derivatives are still not available. These results demonstrate that position-3 in the coumarin scaffold cannot be expanse most likely due to the steric hindrance in the hydrophobic subsite of the binding site. https://lup.lub.lu.se/student-papers/record/4295194/file/4295230.pdf application/pdf 1434075 no 2013 eng organisk kemi Organic Chemistry Chemistry 4295194 2014-02-10T10:50:41+01:00 2014-02-14T13:40:35+01:00 2014-02-14T13:40:35+01:00

oai:lup-student-papers.lub.lu.se:4295251 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Stefan Mattsson author 4316585 Björn Borgström supervisor Department of Chemistry v1000647 department This report concerns the synthesis of 20-epi salinomycin, a diastereomer of the antibiotic salinomycin (SA), and the proposed design of a fluorescent conjugate of SA.<br /> SA has recently shown properties to selectively reduce the proportion of cells associated with cancer stem cell (CSC) properties through mechanisms yet unknown.<br /> We hypothesize, however, the potency being connected to ion transport over cell membranes. SA attached to a probe would aid in localizing SA in cells and facilitate deduction of a mechanism.<br /> A protected conjugate of 20-epi SA has previously been synthesized through a Mitsunobu reaction, however in low yields. Included in this thesis is an optimization of the Mitsunobu reaction, resulting in a more than twofold increase in yield by NMR.<br /> The remaining step towards 20‐epi SA is the removal of the protective TMS-ethyl ester functionality.<br /> Computational models have shown that the inversion of C20 allows for an attached fluorescent probe to sterically interact less with the SA core compared to a C20‐non-inverted analog. Models also indicated that the proposed probe with polyethylene glycol linker chain is not likely to interact with the core structure to a great extent, at least in membranes and other non‐polar environments. A synthetic route to the proposed probe attached to SA is also suggested. Cancer är något som nästan alla människor i dagens samhälle har någon slags relation till, genom att till exempel en närstående som är eller har varit cancersjuk. Enligt en mycket omfattande studie från 2008 genomförd på uppdrag av Världshälsoorganisationen (WHO) kommer en av fyra i den industrialiserade världen att drabbas av cancer före 75 års ålder. Även om dödligheten har minskat genom utvecklad behandling av cancer finns en risk för återfall. Om cancern återkommer är ofta dödligheten betydligt högre.<br /> <br /> På senare år har forskningen börjat fokusera på så kallade cancerstamceller. Även om mycket ännu inte har besvarats kring vad cancerstamceller är kan de kort beskrivas som cancerceller kapabla att reproducera sig själva och ge upphov till nya, vanliga cancerceller. På så vis spekuleras det kring om cancerstamceller spelar en nyckelroll i både återkommande cancer och spridning av cancer i kroppen.<br /> <br /> 2009 upptäcktes ämnet salinomycin ha egenskapen att selektivt döda cancerstamceller när över 16000 ämnen testades mot bröstcancerstamceller. Salinomycin var känt sedan tidigare, som antibiotika som bland annat ges till höns inom livsmedelsindustrin. Sedan dess har studier gjorts på flera typer av cancerstamceller och även i människor, men det är ännu inte känt hur salinomycin verkar i cellen.<br /> <br /> Den här rapporten behandlar en modifikation på salinomycins 20:e kolatom, en så kallad invertering, som enkelt uttryckt byter plats på en väteatom och en syreatom med en annan väteatom bunden till sig. På denna nya molekyl, 20-epi‐salinomycin skulle man kunna fästa en annan molekyl med egenskapen att den lyser tillbaka med grönt ljus (så kallad fluorescens) när man lyser på den med ljus av en viss färg. Med hjälp av denna fluorescerande ”svans” skulle man kunna lysa på celler som blivit utsatta för salinomycin och se var i cellen molekylen har sökt sig, för att få ledtrådar om hur det potentiella anti-cancerstamcellsläkemedlet verkar. Rapporten föreslår därför, förutom hur 20-epi‐salinomycin bättre kan tillverkas, en metod för att fästa en sådan ”svans” på 20-epi-salinomycin. https://lup.lub.lu.se/student-papers/record/4295251/file/4295324.pdf application/pdf 2569704 yes 2013 eng organisk kemi Organic Chemistry Chemistry 4295251 2014-02-10T11:01:40+01:00 2015-02-01T15:03:13+01:00 2015-02-01T15:03:13+01:00

oai:lup-student-papers.lub.lu.se:4295328 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Viktor Persson author 4316587 Ulf Olsson supervisor Gerd Olofsson supervisor Department of Chemistry v1000647 department Isothermal calorimetry measurements were conducted on the homologous peptide series AnK where A is alanine, K is lysine and n=6, 8, 10, in order to determine the enthalpy for the aggregation of the peptides. The obtained curves were then integrated to determine the differential enthalpy of the processes involved. Previous studies into the same peptides showed that the peptides had very different concentrations on which aggregation occurred, these limits were hard to see using this type of technique. Measurements were conducted on different concentrations, temperature, injection volume and with added electrolytes. The resulting graphs showed that the processes involved were very complicated in some cases, further studies surrounding the interpretation of the data gathered is required before any conclusions can be made into the behaviour of the peptide aggregation. Popular summery<br /> I detta kandidatarbete användes som titeln säger kalorimetri, en metod som går ut på att man mäter hur mycket värme som antingen avges eller tas upp av den lösning man mäter på. Den lösning som mätts består av en peptid, som är ett varierande antal aminosyror sammansatta som ett protein, som lösts upp i vatten och sedan tillsätts en ren vattenlösning stegvis medan instrumentet läser av hur mycket värme denna lösning behöver för att hålla samma temperatur som kontrollösningen i ett anslutande kärl, vilket har fyllts med rent vatten. Målet är att mäta värmet som avges eller upptas när ett peptidaggregat, efter utspädning, löser upp sig i vatten.<br /> Det är främst under senare år som denna typen av peptider har studerats närmare, mycket på grund av att det tidigare har varit svårt att framställa precis de peptider man vill ha och även svårt att få ut dem rent, dvs. inte en massa olika peptider som man inte vet vilken som är vilken. Men nu när man kan detta är förhoppningen att man ska förstå vad som händer när dessa peptider klumpar ihop sig och bildar större partiklar. Denna typ av hopklumpning är nära relaterat till flera neurodegenerativa sjukdomar som t.ex. Alzheimer’s och Creutzfeldt-Jacob (galna ko-sjukan) och man har förhoppningar om att man skulle kunna hitta behandlingar mot denna typ av sjukdomar om man kan förstå hur de fungerar.<br /> I detta arbete har tre olika peptider studerats, alla med liknande utseende. Samtliga avslutas med en lysin (aminosyra) men de har olika antal alanin (aminosyra) innan; 6, 8 samt 10 stycken. Detta val av ökning av den ena byggstenen beror på att vi vill avgöra hur sammanslagningen av peptider förändras ju mer vattenavstötande vi gör den, både i utseende på partiklarna men även med avseende på hur de slår ihop sig.<br /> För att djupare undersöka detta gjordes även mätningar på lösningarna vid olika temperaturer men även i koksaltlösning istället för vatten.<br /> Upplösningsprocessen verkar vara komplex, det är tydligt efter detta projekt att ytterligare evaluering av dessa data krävs innan några vidare slutsatser kan dras angående dessa peptider. https://lup.lub.lu.se/student-papers/record/4295328/file/4295330.pdf application/pdf 624406 yes 2013 eng fysikalisk kemi Physical Chemistry Chemistry 4295328 2014-02-10T11:39:56+01:00 2014-02-14T13:41:43+01:00 2014-02-14T13:41:43+01:00

oai:lup-student-papers.lub.lu.se:4295332 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Cam-Bich Tu author 2302291 Ronny Lindell supervisor Farideh Khabbaz supervisor Erik Thyboll Pettersson supervisor Department of Chemistry v1000647 department Populärvetenskaplig sammanfattning<br /> Monomerer är mindre kemiska byggstenar som bygger upp en större molekylstruktur kallad<br /> polymer och kan jämföras med tegelstenar i ett hus. Monomererna i vår produkt binds samman<br /> genom så kallade esterbindningar och polymeren som bildas kallas därför en polyester.<br /> Polyestrar har många användningsområden såsom plast i PET flaskor, färg, och konstfiber i<br /> textilmaterial som till exempel fleecetröjor, duschdraperier med mera.<br /> I detta projekt var vi ute efter att minska belastningen på miljön genom att ersätta de<br /> traditionella produkterna som framställts från oljebaserade råvaror med förnyelsebara och icke<br /> oljebaserade råvaror. Genom detta minskas även koldioxidutsläppet vid<br /> produktframställningen. Ett mått på utsläppen av växthusgaser såsom koldioxid, som uppstår<br /> till följd av en aktivitet, en grupp aktiviteter eller en produkt, kallas för ”carbon footprint”.<br /> Denna faktor beräknas för att kunna mäta samt minska ett företags påverkan på klimatet. Det<br /> är viktigt att hålla koldioxidutsläppet så lågt som möjligt för ett mer hållbart samhälle vilket är<br /> anledningen till att vi vill använda oss av förnyelsebara alternativ.<br /> Hållbarhet i samhället är viktigt för att vi ska fortsätta ha vatten, material och tillgångar för att<br /> kunna skydda det ekologiska kretsloppet och miljön. En produkt som ständigt behöver bytas ut<br /> kan tära mycket på miljön. Det finns många sätt att värna om miljön och människan, och alla<br /> kan göra skillnad. Bland annat kan man släcka lampor som inte används, duscha istället för att<br /> bada, använda vattenkokare istället för att koka på kokplatta, återvinna för att spara på<br /> resurser samt energi, panta burkar och flaskor, cykla eller gå för små sträckor. Återvinning är<br /> nödvändigt då de oljebaserade råvarorna är begränsade resurser. I detta projekt siktar vi på att<br /> utveckla nya produkter som både håller länge och är skonsammare mot miljön genom att byta<br /> ut de oljebaserade råvarorna mot förnyelsebara alternativ. The main purpose of the study was to investigate the effect of reaction conditions such as<br /> reaction temperature and time on the isomerization of 1‐methylidene ethane‐1,2‐dicarboxylic<br /> acid (MIA) during the synthesis of MIA to 1‐methyl‐trans‐ethene‐1,2‐dicarboxylic acid (MTA)<br /> and 1‐methyl‐cis‐ethene‐1,2‐dicarboxylic acid (MCA) based polyesters. Twelve batches of<br /> poly(neopentyl itaconate) and one batch of poly(PEG 200 itaconate) were synthesized through<br /> the condensation reaction with neopentyl glycol (NPG) or poly(ethylene glycol) (PEG) and MIA.<br /> Different reaction temperatures (160, 180, 200, 225 and 250°C) and reaction times (between 5<br /> min to 11 h) were tested. The kinetics of the isomerization of MIA to MTA was measured and<br /> the activation energy was calculated.<br /> Isomerization experiments under basic conditions were also studied and divided into two parts<br /> using two different batches. One batch of MIA‐NPG polyester was exposed to different amines;<br /> primary‐, secondary‐ and tertiary amines at 60 °C to study the effect of basic conditions on the<br /> isomerization of MIA polyesters. In the second batch, isomerization studies were done on a<br /> water soluble system using MIA‐PEG polyester by exposing it to acidic (pH 2.7, reference<br /> sample), neutral and basic pH (7, 8, 9, and 10) both at R.T and at 40 °C.<br /> The synthesized polyesters were characterized using potentiometric titration (acid value and<br /> hydroxyl value), size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR)<br /> spectroscopy.<br /> The results showed that isomerization and etherification occurred during the synthesis of MIA<br /> based polyesters. Isomerization of MIA to both MCA and MTA was observed, but higher<br /> conversion to MTA than to MCA was found. The conversion of MIA to MTA was almost the<br /> same at 160 °C and 180 °C (6 %) but was significantly higher at 200 °C (19 %), 225 °C (34 %) and<br /> 250 °C (41 %). The conversion of MIA to MCA was rapid in the beginning but remained almost<br /> constant (about 11 %) during the rest of the experiments. The MIA isomerization fitted well to a<br /> first order reaction.<br /> When testing the amines under non aqueous conditions, the tertiary amine affected the<br /> isomerization the most. The isomerization was not affected by the primary amine while some<br /> isomerization had occurred during the end of test period using the secondary amine.<br /> Tests with different pH were also performed on a water soluble MIA‐PEG polyester where no<br /> difference could be seen for acidic (pH 2.7, reference sample), neutral and basic pH (7, 8, 9, and<br /> 10) both at R.T and at 40 °C during the test period. https://lup.lub.lu.se/student-papers/record/4295332/file/4295335.pdf application/pdf 1114174 yes 2013 eng fysikalisk kemi Physical Chemistry Chemistry 4295332 2014-02-10T11:45:09+01:00 2014-02-14T13:43:16+01:00 2014-02-14T13:43:16+01:00

oai:lup-student-papers.lub.lu.se:4295372 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Javier De Prada Lopez author 4316594 Viveka Alfredsson supervisor Ola Karlsson supervisor Department of Chemistry v1000647 department Oredered mesoporous materials present many potential applications. But beforehand, thorough understanding of these materials and their synthesis is required.<br /> This Thesis focuses on the observation of the hydrolysis process of TMOS, one of the silica sources used in the synthesis of these materials, at real synthetic conditions.<br /> The study was performed using a reactor calorimeter, a type of calorimeter design to resemble real reactors, and at pseudo-isothermic contditions The focus of the thesis is to explore the hydrolysis step of the silica source in the synthesis of mesoporous silica materials.<br /> These materials are made of the same material as the sand, but they have pores in the order of the nanometers (1nn=0.000001mm), all of them of similar size, and with those pores arranged in a certain and constant pattern in all the material; These materials are formed as particles.<br /> To generate such pattern, it is also required a surfactant, that is a molecule with a fragment that tends to be close to water, and another fragment that tries to escape from water. Because of this, when this surfactant is put in water, the fragments that want to escape from water hide by getting closer to similar fragments from other molecules of surfactant, while at the same time the fragments that like water, are sent to face the water; this generates structures formed of an envelope of fragments that want to be close to water surrounding those fragments that want to hide from water; these structures are called micelles (an the shape can be sphererical, rod-like, or they can be as cylinders), and at certain conditions, you can find that most of the micelles present are similar in shape and size, moreover, the &quot;relate&quot; with each other so it can be seen certain order among them. Then, when that silica forms around these micelles, and afterwards the micelles are eliminated, the reult are those order pores of similar size.<br /> But to form the silica, you first need a so-called silica source, that is simply a compound that when immersed in water transforms in a way that allows it to join creating silica. This project aimed at see what happened with one of those silica sources just before it starts to join, to see that first transformation, meassuring the heat that transformation generates. 2013 eng fysikalisk kemi Physical Chemistry Chemistry 4295372 2014-02-10T13:16:17+01:00 2015-02-01T15:11:12+01:00 2015-02-01T15:11:12+01:00

oai:lup-student-papers.lub.lu.se:4295423 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Lars Erik Andreas Ehnbom author 4139635 Hassan Norouzi Arasi supervisor Department of Chemistry v1000647 department During the time range of this project, various compounds were synthesized. All of them will be used to synthesize the final compounds 2 and 3. Consequently, the compounds will build up a supramolecular cavity, which will be used to study a catalytic epoxidation of olefins. The aim of the project was furthermore to gain experience in laboratory work. Populärvetenskaplig sammanfattning<br /> Supramolekylär kemi är en relativt ny gren av kemin som involverar stora kemiska strukturer/enheter. Ett exempel på en ”supramolekyl” man dagligdags träffar på är klorofyll. Klorofyll (Figur 1 till vänster) består av en metall (magnesium) och en större kolvätestruktur som kallas porfyrin. Porfyriner finns i många olika varianter och används ofta i olika biologiska sammanhang. I klorofyll fungerar porfyrinen som ”infångare” av elektroner som gör att fotosyntesen fungerar. Även i kroppen förekommer porfyriner, i hemoglobin finns en snarlik porfyrinstruktur som den i klorofyll. Funktionen hemoglobin är att binda in en annan metall - järn vars funktion i sin tur är att binda in syrgas och koldioxid för att transportera dessa ämnen i blodbanan.<br /> Andra supramolekyler som är använda i vårt projekt involverar skapandet/syntes av snarlika porfyriner (Figur 1 till höger) för vidare användning inom kemin. Tanke med porfyrinerna i projektet är att kunna genomföra kemiska reaktioner vid ytan av porfyrinenheten. Porfyriner används tack vare sin goda förmåga att binda in vissa typer av ämnen och påskynda en omvandling av de inbundna ämnena att omformas till ett nytt ämne. Porfyriner kan alltså ha en katalytisk (påskyndande) förmåga och den utnyttjar vi. Den katalytiska förmågan är ytterst viktigt att förstå och genom att studera dessa reaktioner kan man få en förståelse i hur kemiska reaktioner sker och tillämpa denna förståelse på de biologiska systemen. Målen är att kunna framställa ännu effektivare katalysatorer för olika ändamål, t.ex. att överbrygga svåra syntetiska problem för att ge oss nya metoder och syntesvägar till t.ex. läkemedelsframställning, alltså för att skapa nya ämnen med metoder skiljda från de konventionella metoder som finns. Men som även nämnts är tanken att få en ökad förståelse för de biologiska fenomen som sker vid porfyriner. https://lup.lub.lu.se/student-papers/record/4295423/file/4300373.pdf application/pdf 290002 yes 2013 eng organisk kemi Organic Chemistry Chemistry 4295423 2014-02-10T13:47:05+01:00 2014-02-14T13:45:21+01:00 2014-02-14T13:45:21+01:00

oai:lup-student-papers.lub.lu.se:3053542 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Atef Mannaa author 3053438 Associate Professor Patrik Önnerfjord supervisor Department of Chemistry v1000647 department MMP13 (Collagenase 3) is a member of the matrix metalloproteinase (MMP) family. In<br /> pathology it is overexpressed in rheumatoid arthritis (RA), osteoarthritis (OA) and human<br /> carcinomas. It is secreted in its inactive proforms from which it can be activated. The project<br /> studies how MMP13 can degrade/digest the normal femoral head human articular cartilage.<br /> Peptides were separated using reversed phase chromatography coupled on-line with various<br /> mass spectrometry techniques including ion trap, quadropole Time-Of-Flight (Q-TOF) and<br /> triple quadropole (QQQ) instruments. Guanidine hydrochloride (GuHCl) was used to extract<br /> proteins from the cartilage tissue. Sodium dodecyl sulfate poly acrylamide gel electrophoresis<br /> was used also to give visualize similarities and differences between the control and the<br /> MMP13 treated sample. MMP13 showed an effect on both media (released proteins from the<br /> cartilage tissue via the buffer solution) and a little effect on the cartilage tissue (pellet). The<br /> main result showed that the tissue sample preparation was critical in order to obtain sufficient<br /> release of proteins. The powderisation of tissue was much better in releasing proteins than<br /> intact tissue plugs probably due to larger contact area and shorter diffusion distance. https://lup.lub.lu.se/student-papers/record/3053542/file/3053545.pdf application/pdf 3007321 no 2012 eng Analytisk kemi Chemistry 3053542 2012-09-17T08:48:35+02:00 2019-01-08T09:10:38+01:00 2012-09-19T11:27:25+02:00

oai:lup-student-papers.lub.lu.se:3053555 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Stanislaw Wosicki author 3054585 Dr Sindra Peterson Årsköld supervisor Department of Chemistry v1000647 department The plant plasma membrane H+-ATPase was activated by the binding of a 14-3-3 protein. This complex can be stabilized by the fungal toxin - fusicoccin. During this activation H+/ATP stoichiometry changed (1). This work presents approaching to find the new stoichiometry. The main part presents looking for the best preparation of plasma membrane vesicles for measurements. A new pH indicator – Glu3 – was trapped inside vesicles in a few different ways such as Brij 58 treatment or sonication. Membranes were washed by ultracentrifugations or gel chromatography. The tight of prepared vesicles was examined by acid titration. The best result was achieved by sonication and gel chromatography. Brij 58 also affects the size of plasma membrane vesicles what was demonstrated. The average diameter decreases with increasing concentration of detergent. https://lup.lub.lu.se/student-papers/record/3053555/file/3053556.pdf application/pdf 1960026 no 2011 eng biokemi Chemistry 3053555 2012-09-17T09:25:07+02:00 2012-09-19T11:28:30+02:00 2012-09-19T11:28:30+02:00

oai:lup-student-papers.lub.lu.se:3053563 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Daniel Svensson author 3054586 Eliana Maldonado supervisor Department of Chemistry v1000647 department An investigation of Eupatorium lasiophthalmum yielded fourteen sesquiterpene lactones (1-14) including one new epimer (7) and a revision of the reported stereochemistry of 2 is suggested. One known sesquiterpene (15) and one triterpene (16) with a novel skeleton were found. Two known flavonoids (17-18) were also isolated. Michael adducts were prepared out of 1, 4 and 5 and their reversibility studied. The isolates 1-5, 7, 9, 15 and a cysteine ester adduct (19) were subjected to biological test to determine cytotoxicity against five different breast cancer cell lines. The adduct 19 showed significantly less cytotoxic efficacy compared to the sesquiterpene lactones. The anti-inflammatory activity of 4 was evaluated on LPS stimulated human monocytes. https://lup.lub.lu.se/student-papers/record/3053563/file/3053564.pdf application/pdf 4299784 no 2012 eng Organisk kemi Chemistry 3053563 2012-09-17T09:34:28+02:00 2012-09-19T11:29:35+02:00 2012-09-19T11:29:35+02:00

oai:lup-student-papers.lub.lu.se:3053576 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Erik Hallin author 2971410 Professor Hans-Erik Åkerlund supervisor Department of Chemistry v1000647 department Plants need light to convert earbon dioxide to organic compounds, but when exposed to too much light the photosynthetic machinery takes damage. This is prevented by conversion of violaxanthin to zeaxanthin, which participate in a process that converts the excess light into heat. The conversion of violaxanthin to zeaxanthin is done by the enzyme violaxanthin de-epoxidase.<br /> <br /> VDE from spinach have been sequenced and expressed in E. coli. After harvesting of periplasmic proteins VDE has been purified using DEAE column, two-step precipitation and lipid affinity precipitation with MGDG.<br /> <br /> By not reducing VDE while running it on a SDS-PAGE gel and avoiding reducing substances in purification methods and sample preparation for mass spectroscopy the disulfide bonds should be intact. When analyzing non-reduced VDE with MS new mass peaks should appear, representing masses of two peptides linked tagether with a disulfide bond.<br /> <br /> These peaks were found in the spectrum using Peptidemap. Then these peaks were further analyzed with MS/MS and data interpreted with xQuest. Four disulfide bonds could be confirmed with MS/MS according to xQuest. https://lup.lub.lu.se/student-papers/record/3053576/file/3053579.pdf application/pdf 9676049 no 2009 eng Biokemi Chemistry 3053576 2012-09-17T10:01:14+02:00 2012-09-19T11:33:39+02:00 2012-09-19T11:33:39+02:00

oai:lup-student-papers.lub.lu.se:3053586 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Jenny Andersson author 3054588 Irene Rodriguez Meizoso supervisor Sofia Lindahl supervisor Department of Chemistry v1000647 department There are many valuable substances present in nature such as antioxidants. The conventional method for extracting the antioxidants employs organic solvents. Subcritical Water Extraction (SWE) is a sustainable method for extraction of high valuable compounds. This method uses subcritical water as a solvent instead of organic solvents but leaves the compounds in a water solution. Keeping the antioxidants in water can decrease their stability and to remove water from a solution is harder then to remove an organic solvent. It is not environmentally friendly to transport a large amount of solvent so the water has to be removed and in a way that avoids decomposition of the valuable compounds. The process developed in this project, WEPO, extracts the antioxidants with subcritical water and mixes the extract with SC-CO2 to form an emulsion that when led to atmospheric pressure forms an aerosol that can be dried quickly with hot N2 giving particles. The compound extracted in the project is quercetin, an antioxidant that can be extracted from onion. To evaluate the efficiency of the process the particles formed were analysed to determine the water content, size and morphology, antioxidant capacity and concentration of antioxidants. For comparison the same analysis were done on extracts dried with freeze-drying. Antioxidant capacity measured with a DPPH method showed about the same capacity for the particles produced by WEPO and the freeze-dried extract. SEM pictures taken of the extracts showed hollow spheres from the WEPO particles in the size range of 250 nm – 4 μm. For the freeze-dried extracts no particles were observed. The WEPO particles and the freeze-dried extracts were analysed with an HPLC-UV method and showed about the same concentrations of quercetin species. For particle formation of the extracts the WEPO process is superior to freeze-drying the extracts and matches it in antioxidant activity and concentration of quercetin and derivates. https://lup.lub.lu.se/student-papers/record/3053586/file/3053587.pdf application/pdf 1498339 no 2012 eng Analytisk kemi Chemistry 3053586 2012-09-17T10:33:05+02:00 2012-09-19T11:35:42+02:00 2012-09-19T11:35:42+02:00

oai:lup-student-papers.lub.lu.se:3053630 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 You Lv author 1895202 Christopher Söderberg supervisor Department of Chemistry v1000647 department The I subunit of magnesium chelatase is an AAA+ protein which binds and<br /> hydrolyzes ATP to drive the insertion of Mg2+ into protoporphyrin IX during bio-synthesis of bacteriochlorophyll and chlorophyll. The purification method and co-crystallization conditions of the Rhodobacter capsulatus BchI (bacteriochlorophyll Magnesium Chelatase I subunit) protein with either ADP or AMPPNP and crystallization conditions of Synechocystissp sp 6803 ChlI (chlorophyll Magnesium Chelatase I subunit) protein are described. This is the first report of a successful preparation of the crystals of BchI-ADP complex, the crystals of BchI-AMPPNP complex and crystals of ChlI protein. The crystals of both proteins will be used for further structure determination. https://lup.lub.lu.se/student-papers/record/3053630/file/3053634.pdf application/pdf 642073 no 2011 eng Magnesium chelatase BchI ChlI AAA+ protein Proteinvetenskap Chemistry 3053630 2012-09-17T11:12:36+02:00 2012-09-19T11:48:11+02:00 2012-09-19T11:48:11+02:00

oai:lup-student-papers.lub.lu.se:3053636 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 You Lv author 1895202 Professor Jure Piskur supervisor Department of Chemistry v1000647 department This study focused on expression, purification and functional characterization of three key proteins (Urc1p, Urc2p and Urc8p) in the newly discovered uracil catabolism (URC) pathway. A novel expression system was established by using Saccharomyces kluyveri as a host organism for expression of 6-His tagged Urc1p and Urc2p. Moreover, URC8 gene was cloned in pET151/D-TOPO vector and expressed in Escherichia coli. All three recombined proteins were purified on nickel columns. The SDS-PAGE showed Urc1p and Urc8p are of correct size and high purity. This novel expression system provides an alternative or a complementary choice for eukaryotic protein production. The functional characterization assay suggested that Urc1p might open the pyrimidine ring of uridine in the URC pathway and Urc8p is a NADPH dependent reductase converting malonic semialdehyde to 3-hydroxypropionate, which is one of the final products in the URC pathway. https://lup.lub.lu.se/student-papers/record/3053636/file/3053639.pdf application/pdf 358132 no 2011 eng Uracil degradation URC pathway Saccharomyces kluyveri expression system Proteinvetenskap Chemistry 3053636 2012-09-17T11:23:20+02:00 2012-09-19T11:49:12+02:00 2012-09-19T11:49:12+02:00

oai:lup-student-papers.lub.lu.se:3053641 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Caroline Anderberg Haglund author 3054593 Viveka Alfredsson supervisor Department of Chemistry v1000647 department The aim of this thesis project was to study the reaction solution’s effect on the formation dynamics and material properties of the mesoporous silica SBA-15.<br /> The common synthesis procedure of SBA-15 was applied at 60°C, with 2.5 wt% Pluronic P104 dissolved in 1.6 M hydrochlorid acid. Simple sodium salts (NaCl, NaBr, NaI) or short to medium length alcohols (MeOH, EtOH, 1-PrOH, 2-PrOH, 1-BuOH, 2-BuOH), in the concentration range 0-1 M, was added prior to the addition of the silica source, tetramethyl orthosilicate. The material was hydrothermally treated and approximately half of the sample was calcined.<br /> UV-Vis spectrophotometry was used to establish the flocculation time. The spectrophotometric measurements showed a decrease in flocculation time for the salts and an increase in flocculation time for the alcohols. The different effects of the additives relate to their effect on the solubility of Pluronic. The salts increase the polarity of the solution, decreasing the solubility of the surfactant. Previous research shows an increased solubility of Pluronic on addition of sodium iodine, a trend not seen here. The added alcohols decrease the polarity of the solution, thus increasing the solubility of Pluronic, a trend not expected for the butanols which acts as cosurfactants.<br /> Small angle x-ray diffraction was used to determine the structure of the products from the syntheses with additives. All, except the highest concentration of 1-butanol showed a hexagonal structure. The unit cell parameter decreased with increasing concentration for all additives.<br /> The morphology of the particles was studied using scanning electron microscopy. The silica with added sodium salts resulted in fibrous particles at the higher concentrations, to different extent depending on the salt species. This oriented aggregation was not seen in the silica with added alcohols, leading to large undefinable particles randomly aggregated. As for the salts, the extent of the effect depends on the alcohol species and concentration, with the largest effect obtained by the alcohols with the longest alkylic chain.<br /> The cause of the unexpected behavior of the sodium iodine and the two types of butanols was not studied in this project and further investigation is needed. https://lup.lub.lu.se/student-papers/record/3053641/file/3053652.pdf application/pdf 2940253 no 2012 eng Fysikalisk kemi Chemistry 3053641 2012-09-17T11:30:09+02:00 2012-09-19T11:50:27+02:00 2012-09-19T11:50:27+02:00

oai:lup-student-papers.lub.lu.se:3053658 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Nasir Sallau Lawal author 3054594 Ola Wendt supervisor André Fleckhaus supervisor Department of Chemistry v1000647 department The substitution reaction of complexes, (PCNR)PdCl, where R = (methyl) (1), (ethyl) (2) and(propyl) (3), with iodide where studied in 1-10 mM LiCl in methanol. The substitution was followed under pseudo first order conditions with an excess of incoming and leaving ligand. The high reactivity of complex 1 was attributed to the low steric bulkiness of the methyl substituent. The order of reactivity of the complexes followed 1 &gt; 2 ≈ 3. The large negative values reported for entropy of activation for the complexes confirmed an associative substitution mode. The substitution reaction proceeds via the solvolytic pathway. https://lup.lub.lu.se/student-papers/record/3053658/file/3053663.pdf application/pdf 969640 no 2012 eng Oorganisk kemi Chemistry 3053658 2012-09-17T11:43:17+02:00 2012-09-19T11:51:43+02:00 2012-09-19T11:51:43+02:00

oai:lup-student-papers.lub.lu.se:3119317 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Magnus Berglund author Olov Sterner supervisor Martin H Johansson supervisor Centre for Analysis and Synthesis v1000651 department FR96001M, (4R,5R)-4,5-Dihydroxy-5-((S)-1-hydroxy-heptyl)-cyclopent-2-enone, is a new antibacterial compound isolated from Cyphellopsis anomalia TA96001. Its structure was determined by spectroscopic methods. The absolute structure was determined with a FT-NMR version of Mosher´s method. FR96001 is very similar to the previously known antibacterial pentenomycins, wich is produced by Streptomyces eurythermus.<br /> Derivatives to evaluate structure activity relationship were synthesized. The antibacterial and antifungal activity of new derivatives were tested on different species of bacteria and fungi. The results indicated that the double bond is essential for the activity, the tertiary hydroxyl group important for selectivity against bacteria and the hydroxyl group in the carbon tail important for the activity. Synthetic routes to pentenomycins were found in the literature at least one of them could probably be modified and used to produce racemic FR96001. https://lup.lub.lu.se/student-papers/record/3119317/file/3123024.pdf application/pdf 10307444 no 2001 eng organisk kemi organic chemistry Chemistry 3119317 2012-09-26T16:16:38+02:00 2015-12-14T13:31:00+01:00 2012-09-28T16:07:46+02:00

oai:lup-student-papers.lub.lu.se:3132325 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 My Mattsson author 3164029 Emma Sparr supervisor Gerd Olofsson supervisor Department of Chemistry v1000647 department The purpose of this study was to understand cardiolipins behavior in different pH: 5.5, 7 and 9. Cardiolipins miscibility in other bilayers as 1,2-dimyrilstoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) were also studied. The instrument used in this study was a differential scanning calorimetry. The conclusions that could be drawn from the scans were that cardiolipin has different phase behavior in different pH because of the charge and that the phase behavior get more complex with higher charge. With the mixed systems with cardiolipin and DMPC it was shown that cardiolipin was miscible in DMPC bilayers with a low concentration cardiolipin and that the miscibility decreased with increased concentration of cardiolipin. But with higher pH values cardiolipin was miscible in even higher concentrations of cardiolipin. This indicates that with higher charge on the cardiolipins headgroup it is easier for cardiolipin to dissolve in a bilayer. It was also show that cardiolipin was easier dissolved in bilayers in liquid crystalline phase as DOPC, than bilayers in a solid phase as DMPC. Populärvetenskaplig sammanfattning<br /> Cellerna i kroppen speciella cellmembran som består till största delen av protein och lipider och kolhydrater. Det finns flera sorts lipider, de består av en huvudgrupp som kan ha olika laddning och som är hydrofil, vilket innebär att den är vatten älskande samt en eller flera kolsvansar som är hydrfoba, det vill säga, ogillar vatten. Dessa lipiderna kommer organisera sig i strukturer av bilager i vattenmiljöer. De vattenogillande kolkedjorna vänder sig då mot mitten och de vatten älskande huvudgrupperna mot vattnet. Dessa bilagerna kan ha olika fas beteende i den meningen att kolkedjorna kan vara i ett fast eller flytande tillstånd beroende på temperatur, pH, salt koncentration etc.<br /> <br /> Den lipiden som studeras i denna studie heter cardiolipin. Det är en lipid med fyra kolkedjor och har en huvudgrupp som kan ha en laddning på -1 till -2 beroende på pH. Frågorna som denna studie kretsar runt hur cardiolipins fasbeteende beror på pH, och hur bra cardiolipin löser sig i andra lipidbilager. Detta undersöktes via en kaliometri-metod. En kaliometer mäter hur mycket energi, i form av värme, som krävs för att en lipid ska ändra fas.<br /> <br /> Resultatet som kunde ses från denna studie var att cardiolipins fasbeteende såg olika ut i olika pH på grund av de olika laddningarna cardiolipin har vid olika pH. Vid högre laddning på cardilolipin så var det ett mer komplext fasbeteende. När cardiolipins blandbarhet med andra bilager undersöktes så kunde det konstateras att vid små koncentrationer av cardiolipin så lyckades cardiolipin blanda sig i bilagret. Men med ökad koncentration av cariolipin så minskade blandbarheten i bilagret. Vid höga pH blandade sig dock cardiolipin även vid de högre koncentrationerna av cardiolipin. Detta beror antagligen på den högre laddningen på huvudgruppen vilket gör att lipiderna repellerar varandra och kan slinka in i lipid bilagret enklare. det kunde även visas att det var enklare att blanda cardiolipin i ett bilager med flytande kolkedjor än ett bilager med fasta kolkedjor. https://lup.lub.lu.se/student-papers/record/3132325/file/3132326.pdf application/pdf 936092 no 2012 eng Fysikalisk kemi Chemistry 3132325 2012-10-24T13:14:43+02:00 2012-11-05T10:58:43+01:00 2012-11-05T10:58:43+01:00

oai:lup-student-papers.lub.lu.se:3132334 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Otto Larsson author 3164046 Murtaza Hyder supervisor Jan Åke Jönsson supervisor Department of Chemistry v1000647 department Populärvetenskaplig sammanfattning:<br /> Aerosoler är små partiklar i luften. Partiklarna är uppbyggda av föreningar som kommer från till exempel bilavgaser eller vedeldning. Föreningarna kan också bildas på naturlig väg i växter och avges då främst sommartid. Smog i storstäder är ett tydligt exempel där höga koncentrationer av aerosoler orsakar både försämrad sikt och hälsorisker. En del av aerosolpartiklarna är så små att de når ända ner i lungorna till alveolerna, vilket har negativa hälsoeffekter som bland annat kan ge astma och kronisk bronkit.<br /> Det är av stort intresse att studera aerosolernas koncentrationer och hur de rör sig i atmosfären eftersom de har påverkan på klimatet. En stor del av aerosolerna består av polära organiska föreningar. Även vatten är en polär förening vilket gör att vattenånga i atmosfären lätt kondenserar på aerosolpartiklarna. Det gör att aerosoler påverkar molnbildningen och hur länge molnen kan hålla nederbörden, vilket i sin tur leder till att olika regioner kan få mer eller mindre nederbörd än de tidigare fått. Aerosoler påverkar också klimatet på liknande sätt som växthusgaser, de håller kvar värme i atmosfären och förskjuter jordens energibalans. Deras påverkan är dock betydligt svårare att bedöma då de har mycket kortare livstid.<br /> I den här studien samlades aerosolproverna in på Söderåsen i Skåne, detta för att undvika närliggande antropogena föroreningskällor. Proven togs mellan 2009-12-13 och 2010-11-03. Proven togs vid olika vindriktningar för att kunna studera om aerosolkoncentrationerna varierar beroende på vilket väderstreck vindarna kommer ifrån.<br /> Proverna samlades in på kvartsfilter med en provtagare som samlar in alla partiklar mindre än 10 mikrometer. Filterna extraherades med metanol och diklormetan. Slutanalysen gjordes med GC-MS (gaskromatografi-masspektrometri).<br /> I studien analyserades tolv organiska syror. Azelainsyra och bärnstenssyra hade de högsta medelkoncentrationerna på 14,3 respektive 14,1 Studien visade inte på några tydliga trender för variationer vad gäller aerosolkoncentrationerna mellan olika vindriktningar. Det enda som statistiskt kunde styrkas var att koncentrationen för syringasyra, vanillinsyra och 4-hydroxybenzoesyra var högre vid östliga vindar jämfört med nordliga vindar. De tre syrorna bildas vid förbränning av biomassa. En sak som stack ut var att de uppmätta koncentrationerna för samtliga syror var mycket högre i provet från 2010-10-01 jämfört med övriga datum (för vissa syror så mycket som 5 gånger högre). In this study 12 organics acids that are common in aerosols were analyzed. Of them there were seven aliphatic dicarboxylic acids (C3-C9). Also pinonic acid, pinic acid, syringic acid, vanillic acid and 4-hydroxybenzoic acid were analyzed. All the 19 samples were taken at Vavihill background station at Söderåsen between 2009-12-13 and 2010-11-03. The samples were collected with a PM10-sampler on quartzfilters. The filters were extracted with methanol:dichloromethane 1:3. Analytes were derivatized with N-methyl-N-(trimethylsilyl)-triflouroacetamide (MSTFA) containing 1 % trimethylsilylchloride before analyzed with GC-MS. Highest average concentrations were measured for azelaic acid with an average concentration of 14,3±14,2 (maximum 70,3 and succinic acid with an average concentration of 14,1±15,7 (maximum 73,7 . Syringic acid, vanillic acid and 4-hydroxybenzoic acid were found to have the lowest concentrations; all with an average below 1 All 12 acids analyzed had their maximum concentration 2010-10-01. The wind conditions were different for the different sampling dates, all wind directions were represented. The results did not show a statistical significant difference in the total concentration of the 12 acids with different wind directions. The sum of concentrations for syringic acid, vanillic acid and 4-hydroxybenzoic acid were found to be significantly higher when the wind came from the east compared to northern winds (p-value 0.04). For the groups C3-C6 and C7-C9, no significant differences were found. https://lup.lub.lu.se/student-papers/record/3132334/file/3132336.pdf application/pdf 1360977 no 2012 swe Analytisk kemi Chemistry 3132334 2012-10-24T13:30:34+02:00 2012-11-05T10:59:28+01:00 2012-11-05T10:59:28+01:00

oai:lup-student-papers.lub.lu.se:3132338 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Roberta Pigliapochi author 3158010 Daniel Topgaard supervisor Department of Chemistry v1000647 department Popular Science Description<br /> Surfactants are compounds broadly used in daily life products as cosmetics, soaps or detergents. A better understanding of the processes occurring at a molecular scale leads to an improvement of their applications. The following work presents a 13C NMR procedure that allows to study the dynamics of these systems: an important insight into the motional mechanisms is hence obtained thorugh common experimental analysis. The following work presents a theoretical model for evaluating the eective correlation time, e, in regards to surfactants in lamellar phase, by focusing on nuclear spin relaxation processes. The dynamics of the C-H bonds is studied through a specic form of the autocorrelation function, g( ), which undergoes a plateau region at intermediate time-scales equals to the square of the order parameter, S2 CH. Thus, the area between the curve and its plateau is dened to be equal to (1 - S2CH)e. The presented experimental scheme shows how to measure e through 13C Solid State NMR analysis, basing on the dependence of R1 and R1 rate constants on the spectral density j(w), Fourier Transform of the correlation function, at particoular frequencies. The results are compared with measurements of the eective correlation time through MD simulations. Furthemore, regarding the latter method, a better insight into the structure of the lamellar phase system is shown. https://lup.lub.lu.se/student-papers/record/3132338/file/3132340.pdf application/pdf 2727939 no 2012 eng Fysikalisk kemi Chemistry 3132338 2012-10-24T13:40:08+02:00 2012-11-05T11:00:22+01:00 2012-11-05T11:00:22+01:00

oai:lup-student-papers.lub.lu.se:3132359 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Sofi Nöjd author 3164027 Peter Schurtenberger supervisor Marc Obiols-Rabasa supervisor Department of Chemistry v1000647 department Populärvetenskaplig sammanfattning<br /> Microgelpartiklar är runda partiklar som har förmågan att ändra storlek beroende på olika yttre påverkan. I detta projekt har vi tittat på partiklar som blir upp till 10 gånger mindre när temperaturen höjs från 15˚C till 39˚C. Detta beror på att det nätverk som partiklarna är uppbyggda börjar ogilla lösningsmedlet när temperaturen höjs och hellre vill vara nära sig själva vilket medför att de drar ihop sig. Eftersom microgeler kan ändra storlek under kontrollerade former vill man titta på hur de beter sig om man ökar antalet partiklar. Detta kan man sedan jämföra med mer komplicerade system så som proteiner och hur de beter sig i närheten av varandra. För att titta på detta har vi använt oss av neutroner och en metod som gör det möjligt att titta på enbart ett fåtal microgelpartiklar i en lösning med väldigt många. Neutroner stålas på provet, microgelpartiklarna, och beroende på hur stora partiklarna i provet är kommer neutronerna efter kollisionen med partiklarna att böja av åt olika håll. Det går sedan att räkna hur många neutroner som har böjt av i olika vinklar och utifrån det få reda på hur stora partiklarna i provet är och vilken form de har. Det är av olika anledningar komplicerat att räkna ut storleken på partiklar i prover med hög koncentration. För att komma runt det har vi använt en metod som går ut på att proverna blandas på ett visst sätt så att information om enskilda microgelpartklar är det ända som mäts. På så vis kan storleken mätas utan att mängden partiklar stör mätningen. Det visade sig att metoden fungerade bra och information om de enskilda partiklarna kunde erhållas. En storleksminskning med ökad temperatur påvisades vilket var väntat då partiklarna drar ihop sig när temperaturen höjs. Det visades även att storleken inte påverkades mycket när antalet partiklar ökades. Detta bevisar att partiklarna gå in i varandra eftersom deras yttersta skal är väldigt fluffigt. Microgel particles have been widely investigated for their ability to undergo a volume phase transition due to different stimuli such as solvent quality, pH or salt addition. Their ability to reversibly change their size and thus the volume fraction makes them suitable to perform thorough<br /> studies on intra and inter‐particle interactions and various phase transitions. In this research work<br /> we show how the particle interactions were affected with changing temperature, and thereby volume fraction, in highly concentrated suspensions. For this purpose, the zero average contrast method (ZAC) has been employed, which allows canceling the effects of interparticle interactions<br /> in the scattering data, thus giving information about the form factor of the particles even at very high volume fractions. The results show that at low temperatures, i.e. in the fully expanded state, the microgel size appears almost independent of volume fraction, with a small decrease of the outer<br /> fuzzy shell only at concentrations far above close packing. With increasing temperature we find a shift in the form factor to higher q, which was expected due to a decrease in particle size: particles collapse when water starts to act as a poorer solvent at temperatures above the LCST (Lower Critical<br /> Solution Temperature). This temperature‐induced collapse of the particle size is found to be independent of the effective volume fraction eff even at ultrahigh densities up to eff = 1.7, i.e., far above close packing. These results clearly demonstrate that the temperature‐responsive behavior of the microgels is not altered by the interpenetration of the particles at high densities, and that the effective volume fraction of the microgels is a function of the temperature only. https://lup.lub.lu.se/student-papers/record/3132359/file/3132407.pdf application/pdf 2129513 no 2012 eng Fysikalisk kemi Chemistry 3132359 2012-10-24T14:15:05+02:00 2012-11-05T10:06:31+01:00 2012-11-05T10:06:31+01:00

oai:lup-student-papers.lub.lu.se:3165680 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Chrisje Henrikus Jozef Evers author 2174870 Thorbjörn Andersson supervisor Associate Prof. Mikael Lund supervisor Marie Skepö supervisor Department of Chemistry v1000647 department Populärvetenskaplig sammanfattning<br /> Självfästande Filmjölk<br /> Många upplever vid frukostbordet att det är bökigt och kladdigt att hälla ur all filmjölk ur paketet, så när konsumenten anser att förpackningen är tom finns det<br /> cirka 10% kvar av produkten. Detta är något som gemene man inte reflekterar över. Eftersom en del av filmjölken fäster på förpackningens insida så innebär det att det slängs mängder med förstaklassig mat, och att minst 130 tusen av EU:s kossor producerar mjölk i onödan. Svårtömda förpackningar medför alltså stora kostnader för konsumenten, negativ miljöpåverkan från produktionen av bortkastad mjölk, men även problem med återvinningen av förpackningsmaterial. I samarbete med Tetra Pak, världens ledande företag inom process- och förpackningslösningar för livsmedel, har en del av det molekylära ursprunget av detta problem undersökts.<br /> Filmjölk är en komplex blandning som huvudsakligen består av vatten, fett, kolhydrater och mjölkproteiner. De senare verkar vara en viktig anledning till att filmjölk fäster på förpackningens insida. För att få en helhetsbild av varför filmjölk blir kvar i förpackningen, och för att så småningom kunna utveckla bättre förpackningar exempelvis genom ytmodfiering eller genom att använda ett annat material, är det väsentligt att förstå växelverkan mellan proteinmolekyler och förpackningens yta. Det är anledningen till att vi har utvecklat en modell där vi undersöker hur det mest koncentrerade proteinet, alltså β-kasein, växelverkar med ytor med olika egenskaper. Med hjälp av datorsimuleringar har vi studerat hur proteinet uppför sig i närheten av olika ytor som ska motsvara<br /> förpackningsytor.<br /> Kasein adsorption på förpackningar<br /> Resultat från datorsimuleringar visar att β-kasein fäster på många olika sorters ytor, främst därför att proteinet består av delar med olika egenskaper. Dessutom beter sig proteinet som en kameleont, det vill säga, det anpassar sina egenskaper till omgivningen. Om β-kasein till exempel är i närheten av en yta<br /> med negativa laddningar, då blir vissa delar av proteinet mer positivt laddade. Positiva och negativa laddningar attraheras och de positiva delarna fastnar på ytan. Försöker man undvika det, genom att exempelvis byta ut de negativa ytladdningar mot positiva, så svarar proteinet med att bli mer negativt laddat, och<br /> fäster med den negativt laddade delen. Är ytan även hydrofob, alltså vattenskyende, då blir adsorptionen ännu starkare.<br /> Resultaten i denna uppsats har gett oss en ökad insikt i hur β-kasein växelverkar och fäster på olika ytor. Vår förhoppning är att denna förståelse kan användas för att utveckla nytt icke-fästande förpackningsmaterial. På grund av filmjölkens komplexa natur som alla växelverkar olika med förpackningsytan så är utvecklingen av ett material som minskar vidhäftningen helt klart en stor utmaning. Caseins are the most abundant proteins in milk products and are thought to<br /> be crucial for many of its properties, like texture, viscosity, but also adhesion to packaging materials. The latter leads to a product loss of about 10%, and economical and environmental problems, and its molecular origin is here investigated from the interaction between β-casein and dierent surface materials.<br /> A theoretical zero model has been assembled, and a coarse grained model with implicit salt interactions is developed for Monte Carlo simulations. For small peptides, good agreement between the zero model and simulations is observed, but to investigate larger peptides simulations are necessary. These show that β-casein-surface adsorption is an interplay of electrostatic, hydrophobic, and charge regulation phenomena. Due to its amphiphilic properties and its high charge capacitance, β-casein acts as a molecular chameleon, adapting its charge to its environment and utilizing dierent adsorption mechanisms depending on the surface properties. Changing the surface parameters has therefore a clear effect on the adsorption mechanisms, but adsorption is nevertheless seen on most surfaces. https://lup.lub.lu.se/student-papers/record/3165680/file/3165682.pdf application/pdf 2508981 no 2011 eng Nanokemi Chemistry 3165680 2012-11-08T08:24:55+01:00 2012-11-20T15:52:13+01:00 2012-11-20T15:52:13+01:00

oai:lup-student-papers.lub.lu.se:3165685 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Kalyani Sanagavarapu author 3173546 Sara Linse supervisor Department of Chemistry v1000647 department General rules for rational design as well as prediction of tertiary structure and functionality of a protein can be described by investigating the interactions and the role of particular amino acids in protein structure. Mutagenesis has been used commonly to generate stable variants, with an ultimate goal to unravel the rules of protein stability and folding. Besides, reconstitution of dissected proteins has been used as well as an approach to find variants of particular proteins with increased affinity which could lead ultimately to enhancement of stability. In this project a random library of a hapten specific scFv, Anti Fluoroscien IsoThioCyanate (scFv) dissected into the fragments 1-124 (Heavy chain) and 125-246 (Light chain) was interrogated in order to find variants with improved affinity to be tested in further studies for stability enhancement of the corresponding intact protein variants. The split GFP system, a genetically codified biosensor, was used as a method to detect in vivo reconstitution of scFv (Heavy chain 1-124 + Light chain 125-246).<br /> Firstly, reconstitution of a single chain antibody (scFv) fragment 1-124 (Heavy chain) and 125-246 (Light chain) was detected. Secondly, a random library of the Light chain fragment 125-246 cloned into the GFP system was screened to find variants with higher fluorescence intensity than WT Light chain. An increase in fluorescence is suggested to arise from increased affinity which in turn could be used to select for stabilized intact variants. However we failed to detect green fluorescence. This may be due to problems in the expression of one of the partners (heavy chain-CGFP) or steric constraints and hence we were not able to screen any high affinity mutants. Various suggestions for improving the expression of the protein or relieving steric constraints are discussed here. If these problems are solved, libraries will be screened for the possible stabilizing role of the found substitutions. This can be discussed in terms of establishment of favorable hydrophobic interactions, stabilization of secondary structure and indirectly destabilization of the unfolded structure. The insight into the interactions and roles played by specific amino acids can be used to understand protein design of other proteins. https://lup.lub.lu.se/student-papers/record/3165685/file/3165686.pdf application/pdf 2052493 no 2012 eng Proteinvetenskap Chemistry 3165685 2012-11-08T08:48:46+01:00 2012-11-20T15:55:01+01:00 2012-11-20T15:55:01+01:00

oai:lup-student-papers.lub.lu.se:3165689 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Van Nhien Tommy Jun Dam author 3173549 Dr. Deanna D'Alessandro supervisor Department of Chemistry v1000647 department Metal-organic frameworks (MOFs) are micro porous crystalline solids consisting of inorganicorganic<br /> compounds, and have been developed rapidly in design and synthesis due to their<br /> chemical diversity and potential application in gas storage, molecular separation and<br /> heterogeneous catalysis. The strategies for synthesizing photoactive frameworks are still<br /> under development. Our goal is to successfully graft a photoactive compound onto different<br /> frameworks and the frameworks with photoswitchable membrane will be investigated for<br /> gas separation upon irradiation of light. We have completed the early stage of synthesizing<br /> MOFs but further work is needed to determine if we successfully attached the photoactive<br /> compounds onto the frameworks. Populärvetenskaplig sammanfattning<br /> Metal-organic frameworks (MOFs) är kristaller med små hållrum eller porer som man sedan<br /> kan sätta dit en dörr där den kan öppnas eller stängas. Denna dörren är en organisk förening<br /> som kan bli krökt när man lyser med en speciel lampa. När kristallen utsätts för t.ex. vätgas<br /> kan kristallen sedan stänga dörrarna med hjälp av speciel lampa och då bevaras gasen inuti<br /> kristallen. Yt arean på ett gram kristall kan mostsvara upp till en halv fotbolls plan. En tom<br /> cylinder med ett högt tryck innehålla upp till 40 kg vätgas per kvadrat meter medan en<br /> kristall kan ta up mer än 150 kg vätgas per kvadrat meter vid normal tryck. Genom att<br /> framställa olika typer av MOFs kan dessa kristaller ha olika egenskaper. En del MOFs kan t.ex.<br /> fungerar som ett filter, och separera syre och kväve genom låta luft strömma igenom<br /> kristallen. https://lup.lub.lu.se/student-papers/record/3165689/file/3165690.pdf application/pdf 1125895 no 2012 eng Oorganisk kemi Chemistry 3165689 2012-11-08T09:05:07+01:00 2012-11-20T15:57:50+01:00 2012-11-20T15:57:50+01:00

oai:lup-student-papers.lub.lu.se:3222074 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Michaela Klische author 3232554 Sami Dawaigher supervisor Department of Chemistry v1000647 department This project work was done at the Centre for Analysis and Synthesis (CAS)at the Department of Chemistry at Lund University in cooperation with the Universität Leipzig in the period of November 2011 to April 2012. In that time the synthesis of the precursor leading to the so called tris-Tröger&#39;s base was accomplished. Starting point of the synthesis was 4-bromo-3-methylaniline, which was functionalized in para-position to the methyl group with an iodine residue, followed by a condensation reaction to the Tröger&#39;s base. Two dierent reactions were tested for the removal of the iodine moiety. The dehalogenation<br /> with zinc powder and HCl in EtOH proved to be the more suitable than the<br /> lithiation with n-BuLi and exchange with a proton. The bromine substituents were transformed into amine groups via a Buchwald-amination and were subsequently protected with TMS-groups. The racemic mixture was lithiated with t-BuLi and further reacted with R-menthyl chloroformate. The corresponding diastereomers of the Tröger&#39;s base were formed and separated with column chromatography. With the single diastereomer at hand the ester was reduced to an alcohol with LAH.<br /> <br /> From there the next steps would have been the alkylation of the hydroxyl<br /> groups, the deprotection with TBAF and the monoprotection by triuoroacetic anhydride to achieve a desymmetrization. This would have been necessary for the following condensation with paraformaldehyde in TFA that leads to the tris-Tröger&#39;s base. This molecule should have been the subject of further isomerization studies. Optimization of the syntheses and the full characterization of the compounds were also in the focus of this project. Popular Science Summary<br /> The aim of this project was the synthesis of the tris-Tröger&#39;s base, a molecule with three Tröger’s base units<br /> and four aromatic rings fused together linearly. Because syn-syn-tris-Tröger&#39;s bases have a unique concave<br /> structure, the idea stands to reason, that if several bases in syn-syn conformation are combined in a linear way<br /> a helical structure will be taken. These helical nanotubes generated by this novel approach could be integrated<br /> into membranes for mass transport or if they intercalate preferentially with cancer DNA it could be used for<br /> cancer treatment.<br /> When the target molecule would be synthesized, not only its structure would have been of interest, which<br /> should be determined by X-ray diffraction analysis, but also its behaviour in non-aqueous acidic conditions.<br /> Under these conditions isomerization should occur and three different diastereoisomers would be possible<br /> (syn-syn, anti-anti, syn-anti), with syn-syn being the preferred one. It is of great importance to determine which<br /> one is preferably formed, if and how one can influence this equilibrium, so one has a tool at hand to<br /> interconvert these diastereomers.<br /> Starting from the 4-bromo-3-methylaniline the wanted tris-Tröger’s base should be synthesized in ten reaction<br /> steps. Seven reaction steps were carried out and the optimization of the reaction conditions and the scale-up<br /> were at the focus of the work. The target molecule was almost obtained. Its structure determination via X-ray<br /> diffraction analysis is still pending, as well as the studies concerning its isomerisation behaviour. https://lup.lub.lu.se/student-papers/record/3222074/file/3222079.pdf application/pdf 2239007 no 2012 eng Organisk kemi Chemistry 3222074 2012-12-03T11:02:44+01:00 2012-12-11T15:55:52+01:00 2012-12-11T15:55:52+01:00

oai:lup-student-papers.lub.lu.se:3222108 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Josep Casellas Soler author 3232555 Ola Karlsson supervisor Department of Chemistry v1000647 department A classification of amino acid residues based on the interfacial and<br /> partitioning properties was introduced by Khokhlov et al. [1] [2] Amino acid<br /> residues are characterized by two parameters: the standard free energy of<br /> adsorption of an amino acid at an octanol/water interface and the standard<br /> free energy of the partition of an amino acid between octanol and water,<br /> both of them normalized by kT. As a result, five groups of amino acids<br /> having similar values of the parameters are identified.<br /> This classification for the amino acids is based in trace correlations between<br /> two one-dimensional parameters which are related with the interactions in<br /> the biological environment: hydrophilic / hydrophobic behaviour (partition)<br /> and activity at the interface (surface tension). This method is believed to be<br /> able to provide promising results in the search of correlation giving rise to<br /> protein sequences.<br /> A comparison of the parameters in question gives information on energetic<br /> preferences of the molecules to be located at the interface or in a bulk<br /> phase. This study is applied on serine, threonine, aspartic acid, glutamic acid<br /> and tyrosine. Popular Science Summary<br /> The protein folding is the physical process in which a protein withdraws into<br /> its characteristic three-dimensional structure and function. Each protein<br /> begins as a linear chain of amino acids, resulted from a sequence of our<br /> genetic material, and does not have three-dimensional structure. However,<br /> each amino acid chain has certain chemical characteristics that can influence<br /> to the folding like hydrophobia and hydrophilia.<br /> These amino acids interact with each other in their cellular environment to<br /> produce a well-defined three-dimensional shape, the folded protein, known<br /> as native state. The mechanism of protein folding is not completely<br /> understood.<br /> However, the three-dimensional protein structure is essential to perform its<br /> function. If the protein does not fold into the desired shape, typically<br /> produce inactive proteins with different properties including toxic. Some<br /> neurodegenerative diseases among others are considered the consequence<br /> of the accumulation of incorrectly folded proteins. Therefore it is important<br /> to know which factors affect the protein folding and how we can predict its<br /> final structure. https://lup.lub.lu.se/student-papers/record/3222108/file/3222112.pdf application/pdf 842733 no 2011 eng Fysikalisk kemi Chemistry 3222108 2012-12-03T11:27:36+01:00 2012-12-07T16:55:53+01:00 2012-12-07T16:55:53+01:00

oai:lup-student-papers.lub.lu.se:3232419 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Andreas Andersson author 1467072 Hanna Hedman supervisor Department of Chemistry v1000647 department The gene MYCN encodes a transcription factor with a fundamental role in many neuroendocrine tumors, especially neuroblastoma. The gene and protein are very similar to the closely related c-Myc protein, except for the 3´untranslated region (3´UTR), suggesting that it may be an important factor in determining their very different expression pattern at the post-transcriptional level. MicroRNA (miRNA) are small non-coding RNA that bind to the 3´UTR and prevent translation of their target mRNA. Targets can be predicted with computational algorithms, but the number of targets seems to be greatly overestimated. The target sequence of several interesting miRNAs exist in the MYCN 3´UTR that may explain its regulation and deregulation. To test if these targets are true, an in vitro approach with a plasmid-encoded reporter gene can be used. Here, the MYCN 3´UTR has been inserted downstream of the firefly luciferase gene. Renilla luciferase, on the same plasmid or separate, is used as a control. Three plasmids with different insert lengths were generated. Populärvetenskaplig sammanfattning<br /> Genen MYCN kodar för N-Myc, ett protein som fungerar som transkriptionsfaktor, det vill säga det kontrollerar vilka gener som transkriberas aktivt från DNA till RNA. Många neuroendokrina tumörer, speciellt neuroblastoma, uppvisar ofta onormalt höga nivåer av N-Myc, och eftersom N-Myc startar transkriptionen av många gener som är viktiga för cellens delning, tillväxt och mobilitet, skulle det kunna vara en bidragande orsak till cancerutveckling. Både genens och proteinets struktur är mycket lika de för det närbesläktade c-Myc, med undantag för den 3´icke-translaterade regionen (3´UnTranslated Region, 3´UTR). När messenger RNA (mRNA) translateras till protein är det inte allt som kodar för protein och den icke-kodande sekvensen som ligger efter mRNAts stopkodon kallas 3´UTR. Att just den sekvensen skiljer sig så mycket mellan N-Myc och c-Myc antyder att den skulle kunna vara viktig när det gäller bestämmandet av det vitt skillda uttrycket mellan dem, speciellt med tanke på att 3´UTR är den regionen som är utsatt för den största andelen av mRNA reglering. MicroRNA (miRNA) är små, icke-kodande RNA som binder till 3´UTR och förhindrar translation av mRNA. Datorbaserade algoritmer kan förutsäga vilket mRNA som de binder till, men dessa beräkningar tycks göra en grov överskattning av deras antal. Datorprogrammen är därför en bra indikation på vilka interaktioner som skulle kunna ske, men de kan inte ge någon säker information. Inbindningssekvenserna för flera intressanta miRNA är beräknade till att befinna sig i MYCNs 3´UTR och skulle kunna föklara dess reglering. Vissa av dessa miRNA är sedan tidigare kända för att reglera cellulära processer med motsatt utgång i förhållande till N-Myc. Vissa ligger i en kromosomal region som ofta har blivit förlorad i neuroblastoma celler. Ifall det skulle visa sig att de förhindrar N-Myc protein från att bildas skulle detta ge en klarare av hur N-Myc interagerar i cellen. För att undersöka detta sattes här olika delar av MYCNs 3´UTR in nedanför eldfluge-luciferasgenen på en plasmid. Plasmider är små cirkulära DNA-molekyler som kodar endast för ett fåtal protein. Luciferas är ett enzym som skapar luminiscens och dess aktivitet kan mätas med en luminometer. När MYCN 3´UTR sätts in efter dess stopkodon påverkar regleringen av denna (t.ex genom miRNA) hur mycket av luciferasets mRNA som hindras från att translateras. På detta sätt skapades en reporterplasmid som visar hur MYCN skulle kunna regleras av miRNA när den transfekteras in i humana celler.Transfektion med en miRNA prekursor eller inhibitor av samma cell som har plasmiden kan visa effekten av denna på mängden luciferasprotein. Renilla-luciferas, ett annat luciferas från sjöpennan Renilla reniformis används som en kontroll för transfektioneffektiviteten. Denna kodas antingen från samma plasmid eller från en helt annan. Tre olika plasmider konstrurerades i detta syfte och testades med siRNA, en motsvarigheten till miRNA som ofta används för att på konstgjord väg blockera translationen av det mRNA de binder till. https://lup.lub.lu.se/student-papers/record/3232419/file/3232423.pdf application/pdf 472612 no 2012 eng biokemi Chemistry 3232419 2012-12-07T10:25:09+01:00 2012-12-07T16:57:00+01:00 2012-12-07T16:57:00+01:00

oai:lup-student-papers.lub.lu.se:4497639 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Caroline Anderberg Haglund author 3054593 Karin Schillén supervisor Solmaz Bayati supervisor Department of Chemistry v1000647 department The interaction between two block copolymers (Pluronic® P65 and F127) and the bile salt sodium glycodeoxycholate (NaGDC) was investigated by means of static and dynamic light scattering (SLS and DLS) and differential scanning calorimetry (DSC). First a temperature study on pure P65 (1.0 wt%) in water in the temperature interval 5-80 °C revealed a critical micellization temperature of about 40 °C from SLS and 38 °C from DSC. The approximate hydrodynamic radius of unimers and micelles determined by DLS were 0.8±0.5 nm (at 45 °C) and 6.43±0.09 nm (at 50 °C), respectively. The interactions of P65 and F127 (1.0 and 5.0 wt%) with NaGDC at MR 0, 0.3, 0.6, and 2.9 (MR=n_NaGDC⁄n_polymer ) was thereafter investigated. For both block copolymers, small additions of NaGDC were observed to enhance the micellization of the polymers, shifting the onset temperature towards lower temperatures with increasing MR. In the case of the P65/NaGDC system larger additions have the opposite effect, however this was not observed for the F127/NaGDC system. DLS experiments on block copolymer/NaGDC mixed systems indicate the presence of repulsive electrostatic interactions between the block copolymer micelle/NaGDC mixed complexes that are formed at lower molar ratios. For the P65 system at the highest molar ratio the DLS data showed a bimodal relaxation time distribution, which is interpreted as the diffusion of two species; small NaGDC-rich and P65 micelle/NaGDC complexes. The effect of NaGDC is not as evident on F127, explained by the difference in hydrophilicity between the polymers. For both mixed systems a decreased relaxation time and Rayleigh ratio is observed with increased MR, indicating that the value of the second virial coefficient grows larger with increased MR and which also confirms the observed increase in the electrostatic repulsion among the complexes upon increasing the NaGDC content. From these results it was concluded that NaGDC interacts with block copolymers P65 and F127 in a similar fashion to the previously studied ionic surfactants sodium dodecyl sulfate and hexadecyltrimethylammonium chloride, with an enhanced micellization at low surfactant additions and a breakup of the micelles at higher additions. https://lup.lub.lu.se/student-papers/record/4497639/file/4497690.pdf application/pdf 1901075 yes 2014 eng bile salt NaGDC sodium glycodeoxycholate triblock copolymer Pluronic P65 Pluronic F127 PEO-PPO-PEO Chemistry https://lup.lub.lu.se/student-papers/record/4497639/file/4497699.pdf application/pdf no 4497639 2014-06-19T14:51:25+02:00 2014-07-01T16:29:42+02:00 2014-07-01T16:29:42+02:00

oai:lup-student-papers.lub.lu.se:4529905 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Daniel Svensson author 3054586 Ebbe Nordlander supervisor Department of Chemistry v1000647 department The metal cluster [H4Os4(CO)12] was treated with various chiral ferrocenyl diphosphines of the Walphos family. The new compounds; [H4Os4(CO)10{μ -1,2-W001}], [H4Os4(CO)10{μ -1,2-W002}], [H4Os4(CO)10{μ -1,2-W003}] and [H4Os4(CO)10{μ -1,2-W005}] were characterized,<br /> and [H4Os4(CO)10{μ -1,2-W001}] was investigated in its enantioselective catalytic properties in the hydrogenation of tiglic acid. It was demonstrated that the enantioselectivity with this compound is insignificant (6% ee) and that it is not a suitable hydrogenation catalyst at our conditions (31% conversion). https://lup.lub.lu.se/student-papers/record/4529905/file/4529906.pdf application/pdf 621653 no 2012 eng Oorganisk kemi Chemistry 4529905 2014-07-01T15:15:03+02:00 2014-07-01T15:28:33+02:00 2014-07-01T15:28:33+02:00

oai:lup-student-papers.lub.lu.se:3919793 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Abdelrazek Mousa author 2539339 André Fleckhaus supervisor Department of Chemistry v1000647 department New (PCNMe) pincer Pd(II) complexes were synthesized and their properties were studied in various reactions. (PCNMe)Pd-Br was synthesized and employed as catalyst for Suzuki cross-coupling reactions of aryl halides (e.g. bromobenzene, 4-bromotoulene and 4-bromobenzaldehyde) with phenylboronic acids (e.g. phenylboronic acid, 4-formyl phenylboronic acid and p-tolyl boronic acid). High yields and high turnover numbers were achieved using catalyst loading of only 0.05 %.<br /> To gain deeper insight into the mechanism of this coupling reactions (PCNMe)Pd complexes bearing palladium carbon bonds were synthesized and its reactivity with aryl halides (or phenyl bromide) was studied. In kinetic experiments the influence of different additives on the reaction were analyzed to investigate their role in the C-C coupling step. Popular Science Summary<br /> <br /> Synthesis and Reactivity of (PCNMe) Pincer Pd(II) Complexes<br /> Cross coupling reactions are considered one of the most important in the field of organic chemistry where C-C and C-X (X= Heteroatom) bonds easy to form in presence of catalyst. These reactions have been employed to synthesize different types of drugs, polymers and agricultural chemicals.<br /> Palladium complexes were employed as catalysts for these reactions especially the complexes which are produced from the cyclometallation of tridentate ligand known as pincer ligand with palladium.<br /> Pincer palladium complexes are thermally stable and are not sensitive to air and moisture so it’s easy to be handled in contrast to the traditional Pd(0) complexes.<br /> The aim of this work is to study the mechanism of C-C bond formation. Therefore, (PCNMe)Pd-Phenylacetylide was synthesized and was reacted with bromobenzene in presence and absence of additives.<br /> Nuclear Magnetic Resonance (NMR) was very useful tool during this study where 1 H- and 31P-NMR spectra were measured during the course of the reaction. By interpreting the spectra and by studying the influence of different additives in the progress of the reaction, a mechanism involving soluble Pd(0) would be suggested for the formation of the cross coupling product. https://lup.lub.lu.se/student-papers/record/3919793/file/3919798.pdf application/pdf 473143 no 2013 eng oorganisk kemi inorganic chemistry Chemistry 3919793 2013-07-09T10:21:01+02:00 2013-07-22T15:49:44+02:00 2013-07-22T15:49:44+02:00

oai:lup-student-papers.lub.lu.se:3920710 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Kuo Guo author 3954389 Professor Hans-Erik Åkerlund supervisor Erik Hallin supervisor Department of Chemistry v1000647 department Non photochemical quenching (NPQ) is an important way for plants to protect themselves from photooxidative damage. In higher plants, the major and most rapid part of NPQ is qE, which is controlled by the Violaxanthin de-epoxidase (VDE) and zeaxanthin epoxidase (ZE). VDE converts Violaxanthin (Vx) to Antheraxanthin (Ax), and then to Zeaxanthin (Zx). Several experiments were carried through to analyze functional and structural properties of VDE. All the 13 Cysteines(Cys) in VDE were mutated to Serine (Ser) to detect the Cys that contribute to VDE activity. 12 mutations were found with decreased VDE activity. The function of the region between the N-terminal domain and the lipocalin domain was investigated by expression of the peptide before and after the linker region in different lengths combination and followed activity measurement. The results showed that the two independent domains lost majority of activity and N-terminal part of linker region was more important for activity. An experiment was set up to analyze the function of C-terminal by measuring the activity of VDE after cleaving different length of C-terminal. The result showed different degrees of activity loss that was caused by removal of different lengths of the C-terminal. A number of experiments suggests that VDE acts as a dimer that is formed at low pH. These experiments will contribute to further research of the function and structure of VDE. Popular Science Summary<br /> There is a saying that the sun supports the life living on earth. In general, the sunlight supports plants living, and plants become the base of almost all forms of ecosystems. A reaction called photosynthesis exists in all kinds of plants and is the foundation of usage of sunlight energy. In the photosynthesis process, energy in the sunlight converted into the energy stored in plants, the latter is used in various kinds of biochemical reactions. And during photosynthesis, oxygen is released into the environment and supports the metabolism of all living things. In the photosynthesis process, sunlight energy is gathered by a complex called light harvesting system, and excites chlorophyll, a molecule absorbs light. The excited chlorophyll continues to transfer the energy to the following photochemical reactions. In nature, the intensity of the sunlight is changing all the time. Sometimes, plants receive more sunlight energy than they need for the biochemical reactions in photosynthesis, that means not all excited chlorophyll are in use. And excited chlorophyll will dissipate its energy and return to the ground-energy state. The release of energy can form reactive oxygen species, a molecule that is harmful to plants cells. To prevent the formation of oxidative species, plants have evolved some other ways to release the energy in the excited chlorophyll. One typical way of de-excitation of excited chlorophyll is called non-photochemical quenching; it dissipates the energy into heat. Our research is mainly about an enzyme which is important to the major component of the non-photochemical quenching in higher plants. The enzyme is called violaxanthin de-epoxidase (VDE). VDE converts violaxanthin (a chain-structure pigment which contains two epoxy groups) to zeaxanthin (a chain-structure pigment without the two epoxy groups). And zeaxanthin is believed to quench the excited chlorophyll. Our research of VDE is to investigate the structure and function of VDE by using molecular and biochemistry methods. We produce different parts of the VDE molecule and we change cysteines (one kind of amino acid which can form covalent bond to each other) in VDE into another amino acid. We measure the activity of the protein we produced. We found that cysteines are important for VDE activity. Another discovery of ours is that the VDE molecule gives its activity only when two VDE molecules contact to each other in low pH, and this contact is influenced by the end part of VDE. We also found that VDE consists of two independent functional parts; each part can form its own structure independently. We believe our discoveries may contribute to the further functional and structural research of VDE. https://lup.lub.lu.se/student-papers/record/3920710/file/3920714.pdf application/pdf 2041840 no 2013 eng Proteinvetenskap Protein Science Chemistry 3920710 2013-07-12T13:08:49+02:00 2013-07-22T15:50:46+02:00 2013-07-22T15:50:46+02:00

oai:lup-student-papers.lub.lu.se:3920749 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Viktoria Bågenholm author 3954388 Oskar Aurelius supervisor Renzo Johansson supervisor Department of Chemistry v1000647 department Popular Science Summary<br /> Konsten att kunna ta bort ett syre<br /> Alla celler har DNA, som måste repareras och kopieras för att livet ska fortgå. För att kunna göra detta måste det finnas byggstenar. En av alla processer som ser till att alla delar finns i rätt mängd innefattar bara ett protein. Ett protein som får instruktioner från många håll för att gå igenom en komplicerad process som tillverkar dessa byggstenar: genom att bara ta bort ett enda syre.<br /> Livet består av celler som innehåller DNA, instruktionsboken för hur alla proteiner i kroppen ska byggas upp. Proteinerna är cellens arbetshästar som utför alla de funktioner som cellen behöver. När kroppen tillverkar protein gör den först en arbetskopia av DNA, RNA, som läses av för att veta hur proteinerna ska tillverkas. Man tror att livet började med att använda RNA som instruktionsbok, men det blir fel mycket mer sällan man kopierar DNA. Eftersom instruktionsboken måste kopieras väldigt ofta tror man att livet bytte till den nuvarande organisationen.<br /> Både DNA och RNA består av samma typ av byggstenar: dA, dT, dG och dC för DNA och A, U, G, och C för RNA. Detta ”alfabet” beskriver hur alla proteiner ska se ut. Kroppen måste kunna reparera sitt DNA, samt kunna kopiera DNA till nya celler. För att kunna göra det behövs dessa byggstenar i lagom stora mängder, till exempel genom att göra om byggstenarna i RNA: den enda skillnaden mellan dessa två typer av molekyler är nämligen ett syre. Problemet är att detta syre sitter väldigt hårt på molekylen. Det protein som tar bort det syret heter ribonukleotid reduktas, eller RNR.<br /> Hur fungerar RNR? Och hur ser det ut?<br /> Eftersom RNR behöver göra alla byggstenar till DNA i rätt mängd kontrolleras den av dessa byggstenar, som sätter sig på en specifik plats i proteinet. Till exempel: när dG sätter sig på RNR säger den åt RNR att göra dA. A sätter sig på en annan plats i proteinet, där ett syre tas bort och man får dA. Om man vet hur dessa två platser ser ut kan man försöka räkna ut hur det hela fungerar.<br /> Eftersom byggstenarna i DNA är så viktiga så finns RNR nästan överallt och har utvecklats olika i olika organismer. Därför behöver RNR tittas på, för att förstå hur de olika typerna fungerar. En sorts RNR är anaerob, dvs den förstörs av syre. För de andra typerna har man vetat hur proteinet ser ut när alla de olika byggstenarna sätter sig på det, men för den anaeroba typen har man bara vetat hur det ser ut när byggstenarna i DNA sitter på den och säger vad den ska göra. Detta projekt har lyckats ta fram bilder på hur detta protein ser ut både med endast byggstenarna i DNA, samt när både byggstenarna i DNA och RNA sitter på det. Detta öppnar dörren till ökad förståelse för vad exakt det är som händer när syret i RNA molekylen försvinner. The protein ribonucleotide reductase catalyses the de novo synthesis of deoxyribonucleotides (dNTPs) from ribonucleotides (NTPs), using radical chemistry. It is under strict allosteric regulation, partly from the dNTPs it synthesises that regulate what substrate should be synthesised, but also from dATP/ATP, which regulates overall activity. It is a protein that is found in almost every living organism and it has been subdivided in to three main classes: class I is strictly aerobic, class II indifferent to the presence of oxygen and class III is anaerobic. They all share a similar fold and reaction mechanism and most of them, with the exception of class II, require two different sets of homodimers to function: one generating the radical, the other carrying out the synthesis.<br /> <br /> This project continues previous work on the class III ribonucleotide reductase from Thermotoga maritima (tmNrdD), a thermophile first discovered in the vicinity of sea vents off the coast of Italy. The protein was expressed in Escherichia coli, purified and the purification optimised. Crystallisation was carried out and optimised for substrate and effector binding. X-ray diffraction data were collected to obtain structures of the various effector substrate complexes, to study their differences in structure for further insight into the protein’s allosteric substrate specificity regulation.<br /> <br /> tmNrdD was successfully purified and several structures with effector, as well as with effector and substrate, were obtained. The effector-substrate complex dATP-CTP bound in accordance with structures of the same effector substrate complex from class II. https://lup.lub.lu.se/student-papers/record/3920749/file/3920750.pdf application/pdf 2733727 2014-12-31 no 2013 eng Proteinvetenskap Protein Science Chemistry 3920749 2013-07-12T14:37:50+02:00 2014-12-31T03:58:35+01:00 2013-07-22T15:48:21+02:00

oai:lup-student-papers.lub.lu.se:3457313 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Hanna Bergenholtz author 3411362 Solmaz Bayati supervisor Karin Schillén supervisor Department of Chemistry v1000647 department In the present work, the formation of complex coacervate micelles and aggregates of the oppositely charged diblock copolymers poly(N-isopropylacrylamide)27-b-poly((3-acrylamidopropyl)trimethylammoniumchloride)15 [PNIPAAM27-b-PAMPTMA15(+)] and poly(N-isopropylacrylamide)27-b-poly(2-acrylamido-2-methyl-1-propanesulfonic sodium)15 [PNIPAAM27-b-PAMPS15(-)] in aqueous solution have been studied at different concentrations and temperatures. The cloudpoints measured for the concentrations 0.2-0.5 wt% are in accordance with the lower critical solution temperature of PNIPAAM (about 32 °C). A turbidity maximun was observed at about 36 °C, after which the turbidity decreases. The Rayleigh ratio, determined by static light scattering was found to increase with temperature with a sharp transition point at 26 °C. From dynamic light scattering experiments, two relaxation modes were obtained for all concentrations, corresponding to micelles and larger intermicellar aggregates for the 0.2-0.5 wt% solutions, and to unimers and unimer aggregates in the case of 0.1 wt%. Polymerer är naturliga eller syntetiska makromolekyler som är uppbyggda av flera repeterande enheter, monomerer. I blocksampolymerer är de ingående typerna av monomerer fördelade i olika block i polymeren, t.ex. A och B. Blocksampolymerer är ett intressant forskningsområde med möjliga tillämpningar inom bland annat läkemedelstransport, så kallad controlled drug release, d.v.s för kontrollerad frisättning av ett läkemedel i kroppen. I detta projekt har växelverkan mellan blocksampolymererna PNIPAAM27-b-PAMPTMA15(+) och PNIPAAM27-b-PAMPS15(-) i vattenlösning studerats. Dessa polymerer består av en neutral del (PNIPAAM27) och en laddad del (PAMPTMA15(+) eller PAMPS15(-)). PNIPAAM (poly(N-isopropylakrylamid)) är en temperaturkänslig polymer som under ca 32 °C är vattenlöslig. Vid temperaturer över 32 °C blir PNIPAAM mindre och mindre vattenlöslig och genomgår till slut en så kallad fasseparation. I denna studie består den ena blocksampolymeren av PNIPAAM bunden till det positivt laddade polymerblocket PAMPTMA. Den andra blocksampolymeren består av PNIPAAM bunden till det negativt laddade polymererblocket PAMPS. När de två blocksampolymererna blandas i vatten bildas avgränsade strukturer, så kallade miceller, genom elektrostatisk attraktion mellan de två laddade polymerblocken. Micellerna består av en kärna av PAMPTMA15(+)/PAMPS15(-) och en temperaturkänslig korona av PNIPAAM27.<br /> Syftet med denna studie var att undersöka bildandet av elektrostatiskt sammanhållna miceller som funktion av temperatur och koncentration, med hjälp av ljusspridnings- och turbiditetsmätningar. Även förekomst av andra typ av aggregat har studerats. Undersökning av grundläggande fysikaliska egenskaper hos de bildade micellerna lägger förhoppningsvis grund till vidare forskning som kan leda till intressanta tillämpningar i framtiden. https://lup.lub.lu.se/student-papers/record/3457313/file/3457346.pdf application/pdf 822910 yes 2013 eng electrostatic interaction complex coacervate core micelles PNIPAAM light scattering mixed micelles diblock copolymers physical chemistry fysikalisk kemi Chemistry 3457313 2013-02-04T14:13:20+01:00 2019-02-26T10:59:08+01:00 2019-02-26T10:59:08+01:00

oai:lup-student-papers.lub.lu.se:3458344 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Chuixiu Huang author 3460219 Jan Åke Jönsson supervisor Marja Boström supervisor Department of Chemistry v1000647 department NSAIDs (Non steroid anti-inflammatory drugs) have widely been found in STP (sewage treatment plant) effluents and surface water with different concentrations. However, the information concerning ecotoxicological risks, surface water and water living organisms is rather scarce. In this thesis, KET (ketoprofen), NAP (naproxen), DIC (diclofenac) and IBU (ibuprofen) were chosen as four model substances to study the bioaccumulation factor, the distribution, and the fate of the NSAIDs.<br /> A combination of HF-LPME (hollow fiber liquid-phase membrane extraction) and LC-MS/MS (liquid chromatography tandem mass spectrometry) was used to simultaneously extract and detect the NSAIDs in fish. For the freeze-dried fish tissue, this new analytical method showed an average enrichment factor of 3000 times. For water, the average enrichment factor was increased to 3700 times. The average R2 of the linearity were 0.9902, 0.9945, 0.9802 and 0.9890 for KET, NAP, DIC and IBU, respectively. Method detection limits for KET, DIC, NAP and IBU in the range of 1-3 ng/L. Moreover, this method could be successfully applied to detect the analytes in the real samples. For the wild cod fish, only NAP was found with a concentration of 26 ng/g (dry fish). For the wild rudd fish, two NSAIDs (78 ng/g of KET and 40 ng/g of NAP) were found. When the rudd fish was exposed to the NSAIDs, the four NSAIDs were determined in the range of 6-83 ng/g in the dry fish. Interestingly, for the exposed rudd, the concentrations of KET and DIC in dead rudd fishes were almost twice as that in the alive fish.<br /> The developed analytical methodology might be extended to be used to estimate the distribution or the fate of the four NSAIDs in other biota, animals or human beings. Popular summary<br /> The fate of non-steroidal anti-inflammatory drugs<br /> The knowledge about distribution of drugs between sewage sludge, water phases and water living organisms is vital for predictions of the fate and transport routes of toxic substances to the environment. And the distribution of drugs in the environment can be used as a base for risk assessments and it also can be used to define desired properties of future drugs as well.<br /> NSAIDs (Non steroid anti-inflammatory drugs) have widely been found in STP (sewage treatment plant) effluents and surface water with different concentrations. It means that the water living organisms, such as fish, might be exposed to the NSAIDs in the environment. However, the information concerning potential negative effects on water living organisms is rather scarce. In this project, KET (ketoprofen), NAP (naproxen), DIC (diclofenac) and IBU (ibuprofen) were chosen as four model substances to study the distribution and the fate of the NSAIDs.<br /> A new and direct method to determine KET, NAP, DIC and IBU in fish was developed based on HF-LPME (hollow fiber liquid-phase membrane extraction) and analysis with LC-MS/MS (liquid chromatography tandem mass spectrometry). The NSAIDs are trapped and enriched inside the hollow fiber and the average enrichment for the four NSAIDs was over 3000 times for both pure water and freeze-dried fish tissue.<br /> This method could be successfully applied to analyze the real samples. For wild cod fish, only NAP was found with a concentration of 26 ng/g (dry fish). For wild rudd fish, two NSAIDs (78 ng/g of KET and 40 ng/g of NAP) were found. When rudd fish were exposed to the NSAIDs solution containing KET, NAP, DIC and IBU, these compounds were determined as 83, 32, 6, 19 ng/g in the fish that were alive at the end of the experiment, respectively. Interestingly, the concentrations of KET and DIC in the rudd fish that died during the experiment were almost twice as high as that in the surviving fish.<br /> The amount of NSAIDs in sediments of sludge, surface water and fish will give information about the distribution of NSAIDs. And the breakthrough of this analytical method is significant for determination the trace level of this type of compounds in environmental samples. Thus this method is really important, and the feedback of the measurements could be used to adjust the sewage treatment and to assess the risk of drugs. https://lup.lub.lu.se/student-papers/record/3458344/file/3458351.pdf application/pdf 453983 no 2012 eng F-LPME LC-MS/MS selective NSAID fish analytisk kemi Chemistry 3458344 2013-02-06T08:01:44+01:00 2013-02-11T11:49:47+01:00 2013-02-11T11:49:47+01:00

oai:lup-student-papers.lub.lu.se:3458359 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Negar Kavoosi author 3460216 Staffan Nilsson supervisor Department of Chemistry v1000647 department The explosive increase in expansion of diabetes mellitus, particularly type 2 diabetes (T2D) is becoming a threat to public health which is associated with modern lifestyle, abundant nutrient supply, reduced physical activity, and obesity. It is realized that T2D only develops in insulin-resistance subjects which can start with β-cell dysfunction. In order to clarify the relationship between hormone release and metabolism in isolated pancreatic islets, the secretory effects of a non-fuel stimulator like acetylcholine was studied.<br /> <br /> The miniaturized &quot;airborne system&quot; (acoustic levitation and shooter) was combined with MALDI-MS to acquire data from single Langerhans islets and further β-cell metabolism. Levitation technique is a method which has been developed to study intra-and extra- cellular reactions at single or few cell levels. With this technique it is possible to handle 50 nl to 1500 nl sample volumes without contamination from solid walls. In combination with this method a CCD camera was used to check the islet in droplet during the experiments for surveillance of the droplet, for example it was possible to take pictures in different periods of time to calculate droplet size after evaporation to understand change in concentration by time. With usage of piezoelectric dispenser it was possible to keep size of droplet constant by time.<br /> <br /> MALDI-TOF mass spectrometry is a sensitive analytical technique with good limit of detection. In this work it was combined with airborne system (levitation technique) to analyze proteins/peptides that are released from Langerhans islets. α-cyano-4-hydroxy Cinnamic acid (CHCA) was used as matrix to crystallize the sample on MALDI plate. Samples were analyzed with MALDI-MS spectrometry. Spectra observed from mass spectrometry gave information about molecular mass, intensity and charge of the detected proteins and peptides. Popular summary<br /> Using Airborne System in Type 2 Diabetes<br /> The explosive increase in expansion of diabetes mellitus, particularly type 2 diabetes (T2D) is becoming a threat to public health which is associated with modern lifestyle, abundant nutrient supply, reduced physical activity, and obesity. It is realized that T2D only develops in insulin-resistance subjects which can start with β-cell dysfunction. In order to clarify the relationship between hormone release and metabolism in isolated pancreatic islets, the secretory effects of a non-fuel stimulator like acetylcholine was studied. <br /> <br /> The miniaturized &quot;airborne system&quot; (acoustic levitation and shooter) was combined with MALDI-MS to acquire data from single Langerhans islets and further β-cell metabolism. Levitation technique is a method which has been developed to study intra-and extra- cellular reactions at single or few cell levels. With this technique it is possible to handle 50 nl to 1500 nl sample volumes without contamination from solid walls. In combination with this method a CCD camera was used to check the islet in droplet during the experiments for surveillance of the droplet, for example it was possible to take pictures in different periods of time to calculate droplet size after evaporation to understand change in concentration by time. With usage of piezoelectric dispenser it was possible to keep size of droplet constant by time.<br /> <br /> MALDI-TOF mass spectrometry is a sensitive analytical technique with good limit of detection. In this work it was combined with airborne system (levitation technique) to analyze proteins/peptides that are released from Langerhans islets. α-cyano-4-hydroxy Cinnamic acid (CHCA) was used as matrix to crystallize the sample on MALDI plate. There are three different components in the MS 1.Ionizer, 2.Mass analyzer, and 3.Detector. An Ionizer is used to ionize the proteins and peptides from activated single Langerhans islet, then there is a Mass analyzer that differentiates the Ions with respect to the Mass/Charge (M/Z) finally a detector to measure the Ion beam current. <br /> <br /> In this study, a single Langerhans islet picked for each experiment and it was positioned in the levitator with a fused silica capillary. Stimulation of insulin secretion from the islets of Langerhans was accomplished by adding acetylcholine to the levitated droplet and addition of stimulators were stopped after desired concentration. A piezoelectric dispenser was used to add all the reagents to the droplet. At the end, epinephrine was added to stop the reaction and a fused silica capillary was used to transfer the droplet to MALDI plate. Sample was crystallized with CHCA matrix and it was analyzed with MALDI-MS spectrometry.<br /> <br /> Spectra observed from mass spectrometry gave information about molecular mass, intensity and charge of the detected proteins and peptides. https://lup.lub.lu.se/student-papers/record/3458359/file/3458361.pdf application/pdf 9408633 no 2012 eng Insulin acetylcholine chloride MALDI-TOF mass spectrometry MALDI LTQ Orbitrap XL Epinephrine biokemi Chemistry 3458359 2013-02-06T08:23:08+01:00 2013-02-11T11:47:41+01:00 2013-02-11T11:47:41+01:00

oai:lup-student-papers.lub.lu.se:3458402 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Anita Hoang author 3460192 Ebbe Nordlander supervisor Department of Chemistry v1000647 department Gold is a transition metal that can be use as catalyst in a various reactions, when coordinated<br /> to ligands. In this study two dinuclear gold(I) complexes bearing chiral ligands have been<br /> synthesized and tested as catalyst for asymmetric hydrogenation of α,β-unsaturated carboxylic<br /> acids. Asymmetric synthesis is also known as enantioselective synthesis and is a very<br /> important synthesis method in drug manufacturing because of many reasons where economy<br /> is one of them. The catalysts showed good enantioselectivity and high conversion but the<br /> drawback was the poor reproducibility of the catalyst. Popular summary<br /> Guld är en ädelmetall som är mycket älskad av människan och har varit eftertraktad under<br /> århundraden. Guld har används som betalningsmedel, som värdebeständig tillgång och som<br /> smycken. Men guld har även andra egenskaper som kan vara till stor nytta för människan. En<br /> av egenskaperna undersöktes i det här projektet. Guld kan nämligen kopplas till en molekyl<br /> och på så sätt få egenskapen att kunna påskynda en reaktion. Ett ämne eller en förening med<br /> den egenskapen kallas för katalysator. Syftet med projektet är att försöka göra katalysatorer<br /> som kan påskynda en reaktion och som samtidigt kan styra reaktion till forma en specifik<br /> molekyl. Målet är att göra selektiviteten så pass bra att katalysatorn kan gynna endast en av<br /> två molekyler som till synes är identiska men som är spegelbilder av varandra. Fördelar med<br /> den här sorten av katalysator är enormt. Inom läkemedelstillverkning är det mycket önskvärt<br /> om den här sorten katalysator fungerar bra eftersom det är ekonomisk gynnsam och i vissa<br /> fall livsviktigt när läkemedel ska produceras. Guldmolekylerna som gjordes visade sig vara en<br /> god katalysator med hög selektivitet under vissa omständigheter men nackdelen är att det är<br /> svårt att få samma resultat när reaktionen ska upprepas. https://lup.lub.lu.se/student-papers/record/3458402/file/3458419.pdf application/pdf 603731 no 2012 eng Oorganisk kemi Chemistry 3458402 2013-02-06T08:57:51+01:00 2013-02-11T11:45:01+01:00 2013-02-11T11:45:01+01:00

oai:lup-student-papers.lub.lu.se:3458435 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ruiyu Lin author 3460190 Viveka Alfredsson supervisor Department of Chemistry v1000647 department Popular summary<br /> This master thesis was focused on the influence of salt, such as NaCl and CaCl2, in the formation<br /> of carboxylic functionalized mesoporous silica materials.<br /> Mesoporous silica materials are one type of porous materials with a pore size between 2 and 5<br /> nm (1݊݉ = 0.000000001 ݉ ). The walls of the pores in this kind of materials consist of silicon<br /> dioxide, which is called silica (sand). The mesoporous silica materials, or rather the mesoporous<br /> silica particles, are formed by amphiphilic molecules, a kind of molecule with one part that loves<br /> water and one part that hates water, and a silica source. Within the group of amphiphilic<br /> molecules, surfactants are mostly used. The surfactants are molecules with positive or negative<br /> charged head groups, which love water, and long organic tails, that hate water. Examples of<br /> surfactants in our daily life are shampoo and detergent. When the surfactants have been<br /> dissolved in water, the tails that hate water will get together and only leave the charged head<br /> groups outside in contact with the water. In this case, the grouped surfactants can form different<br /> shapes with the tails inside and the head groups on the surface of the shapes. The silica source<br /> will build up walls around these shapes. Accordingly, the “mesopores” of the materials are filled<br /> with surfactants during their creation. When the surfactants are removed, the mesopores arise,<br /> and the mesoporous materials with silica walls are formed. The networks of mesopores are often<br /> well ordered in various structures. When adding acid or salt into the formation mixture of<br /> mesoporous silica materials, the structure or the shape of the materials (particles) can sometimes<br /> be changed. The process is like baking, when adding different things, such as baking powder or<br /> salt, the shape or the texture of the pastries can be changed.<br /> In the work of this thesis, a surfactant with positive charged head group was used. Moreover,<br /> one kind of molecule consists of a negative part and a silicon part was added in the mixture. The<br /> negative part of this molecule is called carboxylic group, which is the major component of<br /> vinegar. In the mixture, this molecule will be in contact with the surfactant head group via the<br /> carboxylic part and in contact with the silica source via the silicon part. After the formation,<br /> when the surfactants are removed, the carboxylic groups will remain within the pores, therefore,<br /> carboxylic functionalized mesoporous silica (CFMS) materials are formed. Addition of acid can<br /> change the structures of the CFMS materials. The shapes of the particles can change depending<br /> on the structure. In this work we show that addition of salt can change the structures and the<br /> shapes of the CFMS particles. Additionally, the particle sizes increase when the amount of salt<br /> increases. Some of the CFMS particles have interesting and well-defined shapes, as shown in<br /> Figure 1. This means that salts can be used as control chemicals in the formation. Carboxylic group functionalized mesoporous silicas (CFMSs) were synthesized using cationic<br /> Gemini surfactant (C18-3-1) as structure director and an anionic co-structure directing agents<br /> (CSDA). Well ordered mixture of CCP (Fm3തm) and HCP (P63/mmc), and cubic Fd3തm structures<br /> were obtained. Non-uniform morphologies were observed.<br /> This thesis has been focused on the salt influence on the formation of CFMS materials and how<br /> the material properties are affected. Monovalent NaCl and divalent CaCl2 have been added to the<br /> syntheses.<br /> The structure, the morphology and the particle size of the CFMSs were investigated with small<br /> angle x-ray diffraction (SAXD) and scanning electronic microscopy (SEM). Addition of salt<br /> influenced the structure transformation within a limited pH range. Further the morphology and<br /> the particle size was influenced in the entire pH-range investigated. Moreover, well defined<br /> morphologies are more easily obtained with a high salt concentration. The influence of NaCl and<br /> CaCl2 showed qualitative similar but quantitative different results. https://lup.lub.lu.se/student-papers/record/3458435/file/3458452.pdf application/pdf 8148724 no 2012 eng Nanokemi Chemistry 3458435 2013-02-06T09:27:57+01:00 2013-02-11T11:51:04+01:00 2013-02-11T11:33:43+01:00

oai:lup-student-papers.lub.lu.se:3458454 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Irem Nasir author 3460176 Emma Sparr supervisor Sara Linse supervisor Department of Chemistry v1000647 department Popular summary<br /> Parkinson&#39;s Disease is a disorder caused by brain that affects patients&#39; coordination, movement as well as causing tremor. The onset of Parkinson&#39;s Disease is found to be the<br /> large fibrillar aggregates in the brain which consists mostly alpha-synuclein protein. The disease propagation has also been associated with membrane disruption. It is important to investigate the interaction of alpha-synuclein with lipid membranes since it gives an idea about how the things work in a cell.<br /> <br /> In this project, the fibrillation kinetics and surface properties of alpha-synuclein in presence or without the presence of lipids are studied in model systems using several different techniques, including fluorescence spectroscopy, quartz crystal microbalance with dissipation (QCM-D) and ellipsometry. It is found that the presence of anionic lipids makes fibrillation process faster than when protein without any additives in solution. Lipid to protein ratio is found out<br /> to be inversely proportional to the time waited before fibrillation starts. Lastly, both the binding of fluorescent probes and the surface technique studies suggest that the aggregates that contain only peptide have different surface properties compared to the ones that contain lipids. Alpha-synuclein is a protein that has been found in Lewy bodies and Lewy neurites, which are filamentous aggregates that known are as the onset of Parkinson&#39;s Disease. The purpose of this study to investigate how the presence of phospholipid vesicles affect alpha-synuclein fibrillation different than when alpha-synuclein fibrillated in buffer, hydrophobicity during the aggregation process, monitored by fluorescence spectroscopy. The surface properties of different alpha-synuclein aggregates further investigated by two complementary adsorption techniques; namely quartz crystal microbalance with dissipation (QCM-D) and ellipsometry. Results revealed that the presence of lipid vesicles alters the fibrillation process as monitored with noncovalent dye ANS, while lipid containing aggregates are predicted to have less hydrophobicity than the ones contain pure alpha-synuclein. Accelearing trend has also been seen with different lipid mixtures, possessing the same charge. It is observed that lipid to protein ratio is inversely proportional to the lag time. Adsorption is more in pure peptide aggregates, however different type of experiments need to be done to be sure of the aggregate properties. https://lup.lub.lu.se/student-papers/record/3458454/file/3458487.pdf application/pdf 39330274 no 2011 eng Nanokemi Chemistry 3458454 2013-02-06T09:54:54+01:00 2013-02-11T11:50:46+01:00 2013-02-11T11:29:11+01:00

oai:lup-student-papers.lub.lu.se:3461176 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Kourosh Hooshmand author 3516378 Peter Immerzeel supervisor Associate professor Henrik Stålbrand supervisor Department of Chemistry v1000647 department The aim of this project was to purify xylan which is the major hemicellulose in wheat bran from dried distiller’s grains with solubles (DDGS). DDGS is a by-product from the fuel ethanol industry which uses wheat grain as a raw material. The wheat grain is used for the fermentation of starch to produce ethanol in the presence of yeast. The ethanol produced in this way is purified by distillation.<br /> <br /> The by-product DDGS is nowadays used as an animal feed. In this project we have investigated if it was possible to produce a value-added product from DDGS namely prebiotic xylooligosaccharides. The DDGS contains wheat bran rich in xylan and other hemicelluloses and compounds like starch, proteins, and fats. The DDGS was diluted in water and the extraction step was done to obtain the water-soluble xylans. The major impurity after the water extraction step is starch which is soluble in water. The hemicellulose fraction was purified from starch by using thermostable destarching enzymes, alpha-amylase and amyloglucosidase, followed by ethanol precipitation and dialysis. Xylan can be converted to xylooligosaccharides (XOS) by the treatment of xylan with xylanase. The obtained XOS have been analyzed with HPLC (High-performance liquid chromatography). The obtained xylooligo- saccharides have potential prebiotic properties. This prebiotic material can be used as a source of energy for bacteria called probiotic bacteria. Previous studies have shown many benefits of probiotic bacteria in human intestine for human health, which are widely used in a diary product such as yogurt.<br /> <br /> Small scale experiments were first performed to judge if enough purified xylan could be gained at the end of the purification procedures. In order to observe the prebiotic effect of this wheat based source, in vitro fermentation of probiotic bacteria was applied. The conclusion from the project was that xylooligosaccharides can be produced from DDGS. It was also indicated that probiotic bacteria can utilize XOS as carbon source. https://lup.lub.lu.se/student-papers/record/3461176/file/3461203.pdf application/pdf 717947 no 2012 eng biokemi Chemistry 3461176 2013-02-13T11:29:15+01:00 2013-02-24T17:44:37+01:00 2013-02-24T17:44:37+01:00

oai:lup-student-papers.lub.lu.se:3461227 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Fredrik Ericson author 3516379 Valera Veryazov supervisor Department of Chemistry v1000647 department Ionic conductors have seen increased use over time. These are found in ion detectors,<br /> gas detectors and supercapacitors but finds special use in fuel cells and solar cells.<br /> Some ionic conductors are not only used as a conductor, but finds uses as insulators,<br /> ceramic blades or even as a diamond simulant. Most other works no ionic conductors<br /> concentrate on the general or macroscopic properties. Here the mechanism of the<br /> ionic conduction is studied in microscopic detail.<br /> A theoretical model has been chosen to simulate the conductivity in a crystal lattice<br /> using a quantum chemical software to calculate the energies. A few structures were<br /> chosen for study, CaF2 a known non-ionic conductor, LaF3 and ZrO2 both known<br /> ionic conductors. The model may not simulate the ionic conduction perfectly but<br /> initial results are promising as relatively good agreement between experimental<br /> results and simulations can be observed, especially in the simulation with zirconia. A<br /> clear difference was seen between a non-conductor and a conductor and between<br /> systems with and without defects. The ions most likely move one at a time.<br /> Doing studies on more detailed and modified paths as well as introducing dopants<br /> may yield further results. Populärvetenskaplig sammanfattning<br /> Jonledning i Bränsleceller<br /> Jonkonduktivitet, eller jonledning, är viktigt i bl.a. bränsleceller. Bränsleceller använder sig av ett oxidationsmedel (oftast syrgas) och bränsle precis som andra förbränningskällor. Till skillnad från motorer som förbränner högenergetiskt bränsle med låg effektivitet och vanliga batterier som använder metaller med låg effektivitet kan bränsleceller använda högenergetiskt bränsle med högre effektivitet. Beroende på bränsletypen kan olika typer av bränsleceller användas.<br /> De vanligaste och mest populära är sådana som använder vätgas. Jonledningen sker i ett membran som befinner sig mellan bränslet och oxidationsmedlet. En<br /> atom avger eller tar upp en elektron som går runt i en elektrisk krets och den jon som bildats passerar genom membranet.<br /> Jonledning är en egenskap som inte har studerats i detalj. De vanligaste studierna omfattar makroskopiska egenskaper för jonledningsförmåga i ett material, d.v.s. hur bra ett ämne leder elektrisk/jonisk ström och hur denna kan påverkas av diverseförändringar. Själva mekanismen bakom ledningsförmågan är oftast förbisedd. I detta arbete har vi undersökt jonledningsförmågan i ett par keramiska eller kristallina ämnen. Med en teoretisk modell försöker vi beskriva mekanismen i detalj. Detta kan öka förståelsen för hur den fungerar och varför vissa ämnen leder bättre än andra.<br /> Temperaturbarriärer<br /> Resultat från simulering visar tecken på tydliga barriärer i de flesta fallen. Endast ett av de simulerade fallen visade en något annorlunda form av barriär. Barriärerna uppkommer då jonen förflyttas nära eller mellan andra joner i kristallstrukturen, helt enkelt för att den lämnar sitt jämviktsläge. Barriärerna kunde användas till att uppskatta den temperatur som skulle krävas för att materialet ska bli ledande.<br /> Om barriären är relaterad till jonledningsförmågan måste dåliga jonledare eller icke-jonledare ha en högre barriär. Bra jonledare har då en mycket lägre barriär, som skulle motsvara en temperatur lägre än smältpunkten för materialet.<br /> Simuleringarna visar en tydlig skillnad mellan en mycket dålig ledare och en mycket bra ledare. Detta kan ses som ett steg i rätt riktning i utvecklingen av en modell som skulle kunna beskriva mekanismen för jonledning. https://lup.lub.lu.se/student-papers/record/3461227/file/3461233.pdf application/pdf 1427952 no 2013 eng teoretisk kemi Chemistry 3461227 2013-02-13T11:53:14+01:00 2015-12-14T08:06:11+01:00 2013-02-24T17:46:54+01:00

oai:lup-student-papers.lub.lu.se:3516440 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Amita Jahangiri author 3561321 Ola Wendt supervisor Daniel Strand supervisor Department of Chemistry v1000647 department The Wendt group at LU has recently developed a new class of sp3 pincer type ligands through<br /> the selective C-H bond activation which introduced a rare example of PC(sp3)P pincer Pd(II)<br /> complex.<br /> In the present study, we aim to obtain insight into the selective cleavage of the sp3 C-F bond<br /> by insertion of iridium metal. We are particularly interested in performing this reactivity on a<br /> gem-diflouro, syn-diphosphine structure for studying sp3 C-F bond activation to generate an<br /> entirely new class of coordination compounds. Popular Science Summary<br /> The aim of this thesis is to develop a method for the selective cleavage of a carbon fluorine<br /> bond with a transition metal. The main focus is directed towards the synthesis of a gemdifluoro,<br /> syn-diphosphine compound XX. When treated with iridium the metal should bind to<br /> the phosphines which keeps it close enough to the carbon fluorine bond to break it and form<br /> what is known as a PC(F)P pincer type product like XX which would represent an entirely<br /> new class of coordination compounds.<br /> Two synthetic reaction pathways were examined for the synthesis of the gem-difluoro<br /> compound XX. The first attempt was a three-step synthesis outgoing from a known<br /> cyclization of an acetonedicarboxylate followed by a fluorination reaction. The result of this<br /> proposed synthetic pathway was not successful and leading to design another synthetic<br /> reaction route which was a seven step reaction sequence where we selectively mask parts of<br /> the molecule that can cause side reactions at various points. Unfortunately this route led to the<br /> formation of a related vinyl fluoride compound rather than the desired XX.<br /> In conclusion, the desired gem-difluoro compound XX for as not reached via the two<br /> examined strategies and towards a molecular vehicle for the study of sp3 C-F activation<br /> further investigations are required. https://lup.lub.lu.se/student-papers/record/3516440/file/3516442.pdf application/pdf 1788624 2013-06-01 no 2012 eng Organisk kemi Chemistry 3516440 2013-02-25T08:54:40+01:00 2013-06-01T03:39:40+02:00 2013-03-04T11:01:28+01:00

oai:lup-student-papers.lub.lu.se:3563089 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ellen Sunneskär author 3563515 Professor Björn Bergenståhl supervisor Emma Magnusson supervisor Lars Nilsson supervisor Department of Chemistry v1000647 department The coalescence of emulsion droplets during the homogenization process is governed by the emulsifier adsorption rate. This is in turn affected by the size and shape of the adsorbing molecule which can be dependant of the aggregation states.<br /> The aim of this thesis was to develop a model system suitable for measuring the efficiency of emulsifier during homogenization and to evaluate the hypothesis that the efficiency is dependant of the emulsifier aggregation state. The idea was to compare the degree of coalescence during emulsification when the emulsifier is adsorbing from a micellar respectively liposomal dispersion. The intension was to do this by using the method of fluorescence. The liposomes used were soybean phosphatidylcholine (PC) and mixed micelles of sodium cholate (NaC) and PC.<br /> The efficiency of liposomal and micellar emulsifiers during homogenization could not be evaluated. The liposomes had no emulsifying properties possibly due to insufficient mixing and in the current case poor solubility of lecithin in the aqueous phase. The mixed micelles could not be formed. The methods used in this work are not to be recommended since the emulsifier must be soluble in the aqueous phase and the desired aggregation state easily prepared. https://lup.lub.lu.se/student-papers/record/3563089/file/3563090.pdf application/pdf 1277221 no 2012 eng Nanokemi Chemistry 3563089 2013-03-11T08:23:23+01:00 2013-03-12T11:17:07+01:00 2013-03-12T11:17:07+01:00

oai:lup-student-papers.lub.lu.se:3563105 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Shaun Hoang author 2971374 Ann-Louise Noresson supervisor Department of Chemistry v1000647 department Galectins play an important role in inflammation, immunity, cancer progression and are potential targets for novel anti-cancer and anti-inflammatory compounds. Coumarin thiodigalacoside hydrid had proved to be potent, nanomolar, and selective inhibitor of galectin-3. Three novel coumarin thiodigalactoside derivatives have been synthesized by copper-catalyzed multicomponent reaction. Two compounds exhibited better inhibition than an earlier coumarin thiodigalactoside hybrid and possessed potentially useful fluorescence properties. Galectin är ett protein som har visats vara involverad i biologiska processer som intracellulär<br /> transport, cellsignalering, celldöd och celladhesion. Dessa processer kan i sin tur vara<br /> relaterade till inflammation, cancer och immunitet. I galectin finns det kolhydrat<br /> igenkännande domäner där β-galaktosid kan binda in. β-Galaktosid är en glykosid som<br /> innehåller galaktos. Glykosider är ämnen med två distinkta kemiska delar, den ena en<br /> sockerart och den andra någon sockerart eller annan typ av substans. Umbelliferon (figur 1)<br /> förekommer rikligt i naturen och tillhör familjen kumariner. Kumarin används bland annat<br /> inom läkemedel, som fluorescens indikatorer, färgämne inom laserteknik och i tillverking av<br /> parfym. Inom läkemedel har kumarin visat aktivitet mot svamp, cancer och HIV. Genom att<br /> kombinera dessa egenskaper hoppas vi kunna syntetisera nya föreningar som är anticancer<br /> och antiinflammatoriska. https://lup.lub.lu.se/student-papers/record/3563105/file/3563106.pdf application/pdf 1035179 no 2013 eng Organisk kemi Chemistry 3563105 2013-03-11T08:44:37+01:00 2013-03-12T11:15:53+01:00 2013-03-12T11:15:53+01:00

oai:lup-student-papers.lub.lu.se:2857072 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Alak Al Shiekh author 2857094 Christopher Polonyi supervisor Hanna Hedman supervisor Department of Chemistry v1000647 department Since its discovery, RNA interference (RNAi) has turned into an invaluable research tool for regulating gene expression. Furthermore, this naturally occurring phenomenon in mammalian cells is of interest in cancer research, both as a possible therapeutic approach and a target for cancer treatment. Platinum anticancer agents like cisplatin are considered one of the most active cancer drugs used either alone or in combination therapy. Cisplatin has made its way from the accidental discovery in 1965 to the first patient treated in 1971. The validated target of platinum cancer treatment is DNA. Other targets include RNA and protein. In this work, the aim was to shed more light on the interaction between platinum based drugs and RNA, investigating the interaction with double stranded RNAs that are 20 nucleotides in length. The effect of platination on RNA thermodynamic stability and function in a cellular environment was studied. Purther knowledge in this area will be helpful in developing siRNA-based therapies, and to elucidate possible interactions that might arise from the combination of platinum based treatments and small interfering RNA (siRNA) based therapeutics e.g. the possibility of synergistic effects. Endogenous miRNA play a major role in the cancerous cell environment. A doser look at the interplay between platinum-based treatment and oncomiRs could be verified as additional therapeutic targets of platinum drugs. Several synthetic siRNA sequences that were designed to target regions of 3&#39;-UTR of the proteins BRCAI and Wnt5a were studied in the present work, both proteins have a strong association with human cancers. The ehosen sequences were evaluated by thermal melting studies and platination reactions. Purification of platination products was performed to investigate the effects of cisplatin and oxaliplatin on both duplex stability and down regulating capacity in a cellular environment. siRNAs were studied by denaturing poly acrylamide gel electrophoresis (PAGE).<br /> <br /> The down regulating ability was investigated in a cellular system consisting of MCF-7 breast cancer cells by using two model protein systems. The effect of siRNA on endogenous BRCAI protein levels was evaluated by Western blot. The effect of platination on siRNA&#39;s downregulation capacity was investigated by Luciferase assays with Wnt5a 3 &#39;-UTR as atarget. Purified platination products or native siRNAs were transfected into MCF-7 cells and<br /> comparison of luciferase productian by luminometry was measured. lntroduction of oxaliplatin in concentrations below previously determined IC50 values in MCF-7 celllines after transfection ofunplatinated siRNAsserved to evaluate the effect on down regulation capacity. https://lup.lub.lu.se/student-papers/record/2857072/file/2857092.pdf application/pdf 22283272 no 2012 eng Proteinvetenskap Chemistry 2857072 2012-06-29T14:14:01+02:00 2012-06-29T14:50:06+02:00 2012-06-29T14:50:06+02:00

oai:lup-student-papers.lub.lu.se:2857096 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mathijs De Jong author 2857161 Claire Vallance supervisor Cathy Rushworth supervisor Department of Chemistry v1000647 department Cavity ring-down spectroscopy (CRDS) is a sensitive absorption spectroscopy technique, used in the detection of very weak transitions and trace species. A laser pulse is trapped in an optical cavity, in which the intensity decays exponentially. The decay is faster in the presence of an absorbing or scattering material. In this work the method is applied in two analytical techniques. In the first, a liquid chromatography detector, the evaporative light scattering detector (ELSD), was modified to include CRDS. Solutes are detected in the ELSD by measuring light scattering. The modification was successful and detection was achieved with CRDS. However, the detection limit of CRDS (1 g L−1 ) was not better than before modification (&lt; 1 mg L−1 ). Reasons for the poor sensitivity were explored and the result is confirmed by calculations. The second technique to which CRDS was applied, was headspace analysis. To circumvent common problems with this spectroscopic method in liquid samples, the vapour phase of a dye in solution was probed. Not enough dye molecules were present to make detection possible, supported by calculations. In specific applications with more volatile compounds this method might be successful. https://lup.lub.lu.se/student-papers/record/2857096/file/2857098.pdf application/pdf 2453799 no 2012 eng Nanokemi Chemistry 2857096 2012-06-29T14:51:24+02:00 2017-08-02T06:40:07+02:00 2012-06-29T17:12:00+02:00

oai:lup-student-papers.lub.lu.se:2857137 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Abdalla Abdelwahab author 2857166 Kaibo Zheng supervisor Department of Chemistry v1000647 department In this project, solar cell based on CdSe quantum dots sensitized onto ZnO nanowires was well fabricated. The following quantum dot-nanowire linker molecules were used: 3- mercaptoproponic acid (3-MPA) and 2-mercaptoproponic acid (2-MPA). The best solar cell efficiency was observed with 3-MPA linker molecule. Solar cell efficiency for different lengths of ZnO NWs and different sensitization times was also investigated. https://lup.lub.lu.se/student-papers/record/2857137/file/2857148.pdf application/pdf 1011175 no 2012 eng Nanokemi Chemistry 2857137 2012-06-29T16:25:47+02:00 2012-06-29T17:14:05+02:00 2012-06-29T17:14:05+02:00

oai:lup-student-papers.lub.lu.se:2857153 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Atif Hussain author 2857165 Jan Åke Jönsson supervisor Department of Chemistry v1000647 department A highly sensitive (LOD= 0.04-0.4 ng/ml) method was developed for the detection and quantification of monocarboxylic and dicarboxylic acids (C3 -C10) by GC-MS. These compounds exist in trace amount as essential components of secondary organic aerosols i.e. they are important constituents of atmospheric aerosols. Membrane extraction technique was utilized for selective enrichment (1-4300 times) of the target compounds. Good repeatability (RSD% ≤ 10%) using a selective organic phase (10% TOPO in DHE) was achieved with three-phase HF-LPME. Target compounds in real samples (aerosols), after ultrasonic assisted extraction were quantified through GC-MS. Effective derivatization of each target compound was performed with BSTFA reagent. Gas chromatography, having a capillary column and interfaced with mass spectrometry was used for detection, separation and quantification of the target compounds. https://lup.lub.lu.se/student-papers/record/2857153/file/2857157.pdf application/pdf 1178087 no 2011 eng UAE samples BSTFA Derivatization analytisk kemi HF-LPME TOPO DHE TMS Chemistry 2857153 2012-06-29T16:38:21+02:00 2012-06-29T17:12:55+02:00 2012-06-29T17:12:55+02:00

oai:lup-student-papers.lub.lu.se:2860689 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Linnea Ruderfelt author 2860439 Joachim Sturve supervisor Per Sundberg supervisor Michael Axelsson supervisor Division of Water Resources Engineering v1000225 department In this thesis the possibility of using mussels as a sensor for contaminants in drinking water intakes was evaluated. Oxygen consumption, heart rate and valve movement was measured upon exposure to oil, caffeine (a marker for waste water) and copper. Valve movement was measured both by time lapse recordings of the mussels and by attaching strain gauges to their shells. One species of freshwater mussels (Sinanodonta woodiana, Chinese pond mussel) and on species of salt water mussels (Mytilus edulis, blue mussel) was used. The freshwater mussels were obtained in the belief that they were of the species Anodonta cygnea native to Sweden. Sinanodonta woodiana is an invasive mussel species originating from China that is not advisable to use in Swedish water monitoring.<br /> <br /> The results show that the best parameter to monitor is valve movement. The freshwater mussels responded to neither oil nor caffeine at concentrations low enough to suffice in monitoring of drinking water. They can also withstand high concentrations of copper. This might be due to that the invasive species has acquired higher tolerance to contamination. The blue mussels were tested to ensure the sensitivity of the method and they reacted to lower concentrations of copper. Since salt water is not used as a raw water source, blue mussels cannot be used for monitoring. A freshwater mussel species native to Sweden should be tried instead of Sinanodonta woodiana. Anodonta anatina, which is the most common freshwater mussel species in Sweden, might be a good example. https://lup.lub.lu.se/student-papers/record/2860689/file/2863360.pdf application/pdf 1864740 LU/LTH access 2012 eng Mytilus edulis crude oil copper caffeine. Sinanodonta woodiana mussels Biological early warning system Biology and Life Sciences Technology and Engineering Chemistry 1101-9824 12/5017 Examiner: Kenneth M. Persson 2860689 2012-07-04T18:57:11+02:00 2019-03-29T09:30:12+01:00 2012-08-20T12:40:29+02:00

oai:lup-student-papers.lub.lu.se:2861363 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Hasan Cicek author Ingemar André supervisor Department of Chemistry v1000647 department Protein design can be used to make better variants of a protein by changing the primary structure of proteins. An assay is needed to select for a better protein variant, generally these assays work on proteins with an activity. But sometimes proteins are designed to obtain a specific structure instead of an activity or function. These proteins often have no activity and there is no easy way to select for this kind of proteins at the present time. Formation of the correct protein structure is not easily assayed; however solubility is both a good indicator of a stable protein and of a folded protein. In this thesis a high-through-put method that measure solubility that is intended to work with proteins without function was developed. Instead of looking at the protein of interest, the attention is turned to the response of Escherichia coli that produces the proteins. Previous research has shown that E. coli induces a heat-shock response when unfolded proteins are over-expressed. By using this phenomena and measuring the over-expression of a protein of interest and at the same time measure the induction of a heat-shock protein promoter, a sensitive system that select for proteins with higher solubility can be obtained. The heat shock promoter and the over-expression of the protein of interest were produced on separate vectors, and were then co-expressed in one plasmid using ligation independent cloning (LIC) .To test if our developed system works as intended, two co-expression vectors were designed. One of the co-expression vectors over-express a variant of the lambda repressor (N102LT) which is folded at 37 °C and the other co-expressed vector over-express a variant of N102LT which has a single mutation(LA57) which renders the protein unfolded at 37 °C. The co-expressed vector with LA57 construct was cloned into the vector, while the construct with N102LT was not obtained. Both constructs are needed to evaluate our system. Fluorescence proteins are used as reporters, and to evaluate the strength of the fluorescence signal from ECFP in a cell culture, ECFP was expressed by itself and a strong signal was obtained. This indicates that fluorescence measurement can be up scaled to fit 96-microtitre plates to make it high-through-pu https://lup.lub.lu.se/student-papers/record/2861363/file/2861370.pdf application/pdf 1630993 LU/LTH access 2012 eng Proteinvetenskap Chemistry 2861363 2012-07-06T14:20:35+02:00 2015-10-01T12:20:12+02:00 2012-07-06T15:16:33+02:00

oai:lup-student-papers.lub.lu.se:2861376 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Juri Kazakevych author Klas Flärdh supervisor Department of Chemistry v1000647 department Streptomyces species are known for their bacteria-untypical growth and sporulation. Growth by tip extension building up a mycelium consisting of long branching hyphae is a highly polar and regulated process. An essential protein invalved in hyphal growth and branching regulation is DiviVA.<br /> <br /> <br /> In S. coelicolor branching and growth is regulated by phosphorylation of DiviVA by the serine/tlu•eonine lcinase AfsK. The phosphatase SppA dephosphorylates DiviVA and leads to less branching growth, an interaction to be further investigated in this project.<br /> <br /> <br /> The aim of this project was to combine a sppA knockout mutation with different afsK modifications, such as deletion and overexpression mutants. A cosmid carrying a new ilsppA::vph allele was constructed using the Å-Red system in E. coli. The allele was transfened to S. coelicolor and recombinant strains with replacement of the sppA gene were selected. Of special interest was the ilsppA ilafsK double lu1ockout to reveal possible additional DiviVA phosphorylation due to other kinases and to check if the wild type colony size phenotype (previously small colonies were observed in ilsppA strains) would be regained. The obtained strains were examined for growth phenotypes and phosphorylation patterns of DiviVA were visualized by Western blotting. sppA knockout mutants were tested for increased sensitivity to overexpression of afsK.<br /> <br /> <br /> The obtained results suppmi the previously raised hypothesis, that SppA and AfsK are direct counteractors on DiviVA phosphorylation. The sppA afsK double knockout mutant pmily regains the wild type colony size. Sensitivity to overexpression of ajsK seems to be strongly increased by an sppA knockout. As time was limited the results are preliminary and further experiments should be carried out with the generated strains to confirm and extend the results. https://lup.lub.lu.se/student-papers/record/2861376/file/2861379.pdf application/pdf 12084522 no 2011 eng Biokemi Chemistry 2861376 2012-07-06T14:28:20+02:00 2012-07-06T15:15:20+02:00 2012-07-06T15:15:20+02:00

oai:lup-student-papers.lub.lu.se:2861381 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Alexandra Franzén author Lennart Lindfors supervisor Department of Chemistry v1000647 department This report is a continuation of the report, Crystal nucleation of poorly soluble drugs, I Method development and initial results. [1]<br /> The aim of the studies was to experimentally investigate the crystallization process. The focus has been on crystal growth, crystal dissolution and primary nucleation.<br /> For three model substances, Bicalutamide, Linaprazan and Felodipine, experiments have been carried out. The experimental results have been compared to existing theoretical models to see how well the models can describe these processes.<br /> For crystal growth and dissolution, a surface integration/disintegration constant, λ, can be used to try to describe the processes. The dissolution experiments could be well described by this model, while growth could not. The model does however work better at high supersaturations than low ones, concerning growth.<br /> The Hillig- Nielsen, polynuclear surface nucleation model was also used to evaluate the growth experiments. The model was able to describe the growth process better.<br /> Obretenov interpolation, a model where both mono- and polynuclear growth are included, was also used to try to describe crystal growth. This model gave the best agreement between experimental results and theory so far.<br /> Nucleation experiments were also conducted, and from the experiments the interfacial tension was to be determined. The development of this experimental method has been an important part of this work. https://lup.lub.lu.se/student-papers/record/2861381/file/2861408.pdf application/pdf 3435478 no 2011 eng Fysikalisk kemi Chemistry 2861381 2012-07-06T14:40:11+02:00 2012-07-06T15:14:01+02:00 2012-07-06T15:14:01+02:00

oai:lup-student-papers.lub.lu.se:2862841 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Shaun Hoang author 2971374 Vishal Rajput supervisor Department of Chemistry v1000647 department In many biological mechanisms galectins play important roles. The galectins are important in<br /> inflammation, immunologic response and cancer. A key function of galectins is cross-linking<br /> of their glycoprotein ligands which are connected with the biological activities. Carbohydrate<br /> recognition domains (CRD) are responsible for the cross-linking. The galectin CRDs are<br /> divided into subsites A-E and it has been discovered that there is a binding affinity for Arg144<br /> in subsite A-B of galectin-3. In a recent study they discovered that diacetyl is binding<br /> covalently to N-α-acetylarginine. It is interesting to synthesize a galectin inhibitor with<br /> diketone functionality and test if it binds to Arg144. https://lup.lub.lu.se/student-papers/record/2862841/file/2862842.pdf application/pdf 412871 no 2011 eng Organisk kemi Chemistry 2862841 2012-07-18T07:59:28+02:00 2012-08-14T14:04:31+02:00 2012-08-14T14:04:31+02:00

oai:lup-student-papers.lub.lu.se:2862846 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ingrid Albertsson author 2607573 Hanna Hedman supervisor Department of Chemistry v1000647 department Cancer is today a common disease in our society. There are several forms of cancer and some can be treated with cytostatic drogs. The most common form of cancer among men in the age of 20-35 is testicular cancer. Testicular cancer can be treatedwith cisplatin or oxaliplatin. The therapeutic use of cisplatin was discovered in the late 60&#39;s by Barnett Rosenberg. The main target of cisplatin is to bind DNA and prevent the cell from dividing. In order for cisplatin to work, it has to be activated. Cisplatin in the bloodstream is stable due to the high<br /> concentration of chloride ions, but when it enters the cell, the chloride ion concentration is lower the chloride ligands are exchanged for two water ligands. This makes it possible for cisplatin to bind to DNA.<br /> <br /> Upon temperature increase the two strands in double stranded DNA will separate into single strands. The definition of the thermal melting point is when half of the DNA is double stranded and half of the DNA is single stranded. The thermal melting point of the DNA decreases when cisplatin binds to it. This is due to the altered structure of the DNA. In this study, the difference was measured to be 10 °C. The thermal melting point measurement showed that RNA had a higher value than DNA. Though there was no difference between the platinated and unplatinated RNA.<br /> <br /> The oligonucleotide was enzymatically digested, to be able to study were cisplatin was bound to the DNA. The components were separated by chromatography. A reverse phase C18 column was used. The polar bases will elute earlier than the more non-polar bases. https://lup.lub.lu.se/student-papers/record/2862846/file/2862847.pdf application/pdf 13234332 no 2011 eng Biokemi Chemistry 2862846 2012-07-18T08:27:26+02:00 2012-08-29T16:12:57+02:00 2012-08-29T16:12:57+02:00

oai:lup-student-papers.lub.lu.se:2862849 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Amr Al-Haidari author 2971376 Henrik Thorlacius supervisor Department of Chemistry v1000647 department Background: Chemokines are small molecular weight proteins, which mainly function as a chemoattractant cytokines for leukocyte migration. Emerging data indicate that chemokines may also play a role in cancer biology. Colon cancer is one of the most leading causes of death especially in the industrial world. The most common causes of mortality are due to the metastasis of colon cancer.<br /> Aim: The aim of the study was to understand how chemokines may contribute to colon cancer metastasis.<br /> Materials and Method: Chemokine receptors CXCR (CXCR4, CXCR3, CXCR7) and CCR receptors (CCR4, CCR6, CCR7, CCR8) mRNA expression were evaluated by Real Time – Polymerase Chain Reaction (RT-PCR) in HT29 and 19/97* colon cancer cell lines. Following gene expression, flowcytometry was used to assess chemokine receptors protein expression. Finally, functional receptors were verified in both cell lines using a migration assay with their corresponding ligands.<br /> Results: Both cell lines expressed all chemokine receptors mRNA except CXCR7 with the highest expression being detected for CXCR4, CXCR3 and CCR4. Flowcytometry for the expressed receptors also revealed protein surface expression. The chemokine ligands TARC/CCL17 and SDF-1/CXCL12 induced a significant increase in colon cancer cell migration in a dose- and time- dependent manner.<br /> Conclusions: Our data demonstrate increased expression of functional CCR4, CXCR3, and CXCR4 in colon cancer cells, suggesting that their chemokine ligands might be involved in the regulation of colon cancer metastasis. https://lup.lub.lu.se/student-papers/record/2862849/file/2862850.pdf application/pdf 2175499 no 2012 eng Chemokines Chemokine receptors Proteinvetenskap Metastasis IV Colon cancer Chemistry 2862849 2012-07-18T08:37:40+02:00 2012-08-29T16:14:51+02:00 2012-08-29T16:14:51+02:00

oai:lup-student-papers.lub.lu.se:2862852 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Andreas Andersson author 1467072 Tönu Pullerits supervisor Department of Chemistry v1000647 department Absorption and emission of photons by any molecule is strongly in<br /> uenced by the molecular environment. When several chromophores are packed together<br /> their spectral properties are known to be altered and this is canonically ex-<br /> plained by quantum theory as electromagnetic interactions between the dipole<br /> moments. If the interaction is strong, the absorption process might be best<br /> described as the creation of a so-called exciton. These are not fully understood,<br /> especially not in biologically relevant systems. In addition, electronic transitions<br /> are in some molecules accompanied by vibrational transitions by such a high<br /> probability that these cannot be neglected. Models including these eects have<br /> not been used for many systems so far. The peridinin-binding protein complex<br /> PCP is an interesting system for exciton investigations but the vibrational<br /> coupling in carotenoids need to be accounted for. The present work deals with<br /> this problem in PCP. https://lup.lub.lu.se/student-papers/record/2862852/file/2862853.pdf application/pdf 889780 no 2012 eng Kemisk fysik Chemistry 2862852 2012-07-18T08:44:46+02:00 2012-08-14T14:09:33+02:00 2012-08-14T14:09:33+02:00

oai:lup-student-papers.lub.lu.se:2862856 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Abdelrazek Mousa author 2539339 Mahmmoud Sayed supervisor Department of Chemistry v1000647 department Colloidal semiconductor nanocrystals or quantum dots (QDs) have recently attracted much attention because of their unique electronic and optical properties and potential for a wide range of applications. Near-infrared (NIR) PbS QDs were synthesized using oleic acid (OA) as a surfactant for stabilizing the nanocrystals. PbS QD’s of different diameters were obtained by varying the injection temperature from 90-120 oC. The absorption and fluorescence measurements were recorded and the fluorescence quantum yield relative to IR-125 dye has been measured. https://lup.lub.lu.se/student-papers/record/2862856/file/2862857.pdf application/pdf 1065569 no 2011 eng Kemisk fysik Chemistry 2862856 2012-07-18T09:09:15+02:00 2012-08-14T14:11:01+02:00 2012-08-14T14:11:01+02:00

oai:lup-student-papers.lub.lu.se:2862859 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Marcus Ljungberg author 2971378 Ulf Nilsson supervisor Department of Chemistry v1000647 department The continued search for compounds exhibiting a better inhibition of Galectin-3 and -1 has been performed in this thesis. It has been shown that the Galectins are over-expressed in cancer cells and play an important role in inflammatory conditions connected to apoptosis (cell death). The focus in this research project has been to explore if halogen-bonding, which gives a hydrogen-bond like character, can be used to improve the affinity for binding to the galectins. Activity was also found in synthesized monosaccharides but not nearly as good as previously tested disaccharides. But the results are a good foundation for future research on developing more drug candidates which are monosaccharides. https://lup.lub.lu.se/student-papers/record/2862859/file/2862860.pdf application/pdf 701693 no 2011 eng Organisk kemi Chemistry 2862859 2012-07-18T09:15:12+02:00 2012-08-14T14:12:06+02:00 2012-08-14T14:12:06+02:00

oai:lup-student-papers.lub.lu.se:2862862 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Lasse Kofoed Bech author 2372031 Gitte Moos Knudsen supervisor Nic Gillings supervisor Department of Chemistry v1000647 department Measuring pharmacokinetic properties is notoriously difficult. The invitro/ex vivo laboratory experiments seek to mimic the physiological<br /> responses of the body to the drug, but it rarely gives a good estimate of what happens in vivo.<br /> Lipophilicity is traditionally measured by the shake-flask method,in which the distribution of the analyte between two immiscible phases<br /> (one organic, one aqueous) is investigated. It is a tedious process, and faster and less laborious methods are desirable. Calibration of<br /> a column/eluent-system on HPLC has been proposed, but the chromatographic process does not mimic the distribution process perfectly,<br /> and the results need to be related to each other.<br /> In the research group, plasma protein binding is traditionally measured by equilibrium dialysis, a method that relies on passive diffusion.<br /> This may take a long time (+24 hours), and ultracentrifugation is proposed as a new and much faster method (app. 1 hour).<br /> In this project, new methods for measurement of lipophilicity and plasma protein binding are developed and evaluated. The group of<br /> compounds measured by the methods are all established or potential PET-tracers.<br /> LogD-values obtained by shake-flask and HPLC was not in accordance, especially not for logD-values in the low range. For plasma<br /> protein binding, accordance between the methods was found in the range 0-10 % free fraction, but for higher free fractions accordance<br /> was only found for some compounds. https://lup.lub.lu.se/student-papers/record/2862862/file/2862863.pdf application/pdf 1130533 no 2012 eng HPLC equilibrium dialysis Analytisk kemi Lipophilicity shake-flask plasma protein binding ultracentrifugation. Chemistry 2862862 2012-07-18T09:20:31+02:00 2012-08-14T14:13:03+02:00 2012-08-14T14:13:03+02:00

oai:lup-student-papers.lub.lu.se:2862867 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Michael Kontaiteh Fonjang author 2971384 Ivan Scheblykin supervisor Department of Chemistry v1000647 department The narrow and redshirted absorption bands of J–aggregates relative to the monomer absorption, coupled with their ability to coherently and incoherently delocalise exciton wave function over several hundreds of molecules has made this class of molecules very important in high technology fields. This has provided new impetus to study the properties of J–aggregates and to explore the mechanism involved in their production. We have investigated the absorption and fluorescence of THIATS J-aggregate dye as a function of Temperature and concentration in aqueous solotion.1mL of 1M solution of sodium chloride was added to each monomer solution to enhance aggregation. The formation of a beautiful intense blue colour and a shift of the absorption band from 515nm to 625nm is a tremendous indication that the THIATS monomers aggregate in aqueous solution. The monomer spectra show no fluorescence peak, while the aggregate spectra show a fluorescence peak at 638nm.Plots of absorption and fluorescence graphs show that stokes shift decreases with concentration. The temperature–dependent absorption spectra show an isobestic point at λ=530nm, which indicates an equilibrium situation between monomer and aggregate. From the data obtained, we calculated an aggregation number (n=4), an equilibrium constant(K=3.067M-1), and Gibbs free energy (ΔG=-2.925KJ/mol).Furthermore, we calculated the Gibbs free energy required to construct one supramolecule of THIATS aggregate (5*10-21J), and compared it with the thermal energy per molecule (4.39*10-21).Consequently, our experiments have shown that they are comparable. A possible improvement on the properties of THIATS J-aggregate may be the synthesis of derivatives that will enhance its ability to delocalize exciton energy, and consequently better its application in high technology fields. https://lup.lub.lu.se/student-papers/record/2862867/file/2862868.pdf application/pdf 1030652 no 2012 eng Kemisk fysik Chemistry 2862867 2012-07-18T09:30:31+02:00 2012-08-14T14:15:07+02:00 2012-08-14T14:15:07+02:00

oai:lup-student-papers.lub.lu.se:2862998 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Anette Mårtensson author 2295570 Associate professor Henrik Stålbrand supervisor Anna Rosengren supervisor Department of Chemistry v1000647 department Hemicellulose is next to cellulose the most abundant polysaccharide on earth and as such an important renewable resource. Mannans are the major hemicellulose in so:ftwodd and are found as storage polysaccharide in various plants. -mannanases are the main mannan degrading enzymes. In this work the -1,4-mannanase from the soilliving bacteria Cellulosamas Jimi was studied and special focus was put on the product profile.<br /> <br /> Mannans are frequently used in the food-, paper- and textile industries and the field of possible applications is large. Deeper knowledge in the mannan degrading enzymes and the products fmmed from hydrolysis is required in order to enter this field and to optimize cmTent utilization.<br /> <br /> -1,4-mannanase, CfMan26A, from C. Jimi is an endo acting enzyme consisting of five domains. The first one is a glycosidehydrolase family 26 catalytic domain and the third is a family 23 carbohydrate binding domain (CBM) which binds mannans. Two variants of the enzyme were expressed, one fullength form comprising all five domains and one truncated fmm with only the first two domains, e.i. excluding the CBM. The hydrolysis products of mannohexaose and galactamannan (guar gum) from the two enzymes were studied with HPACD-PAD. The products from guar gum hydrolysis were also analyzed by the use ofsize exclusion chromatography. The results showed a striking difference in product profile for mannohexaose hydrolysis and a probable difference in the profile from guar gum hydrolysis, indicating that the CBM affected the product pattem.<br /> <br /> The activity on galactomam1an (locust bean gum and guar gum) was not significantly different between the two variants. But the results showed that both enzymes where restricted by the galactase side groups.<br /> <br /> In addition the affinity of the fullength enzyme to soluble galactamannans was confnmed with affinity gel electrophoresis.<br /> <br /> To conclude, this study showed that a CBM can affect the hydrolysis products of a -1,4- mannanase without significantly affecting the rate ofhydrolysis. This is of special importance when considering applications for the hydrolysis products. These findings can also be a<br /> fmiher step in elucidating the action of the CBM. https://lup.lub.lu.se/student-papers/record/2862998/file/2863004.pdf application/pdf 13969883 no 2011 eng Biokemi Chemistry 2862998 2012-07-18T13:25:46+02:00 2012-08-14T14:16:22+02:00 2012-08-14T14:16:22+02:00

oai:lup-student-papers.lub.lu.se:2863024 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anette Mårtensson author 2295570 Mikael Mattsson supervisor Department of Chemistry v1000647 department Fc gamma receptors (FcγRs) are membrane-bound receptors which bind the Fc fragment of antigen-bound IgGs. The binding generates cell signaling and subsequently an immunological response. In this way FcγRs are important links between the humoral and cellular parts of the immune system. Three families of FcγRs have been identified in human, FcγRI, FcγRII and FcγRIII. FcγRI has high affinity for IgG and is the only receptor capable of binding IgG in monomeric form. The other receptors have low to intermediate affinity for IgG and can only bind immune complexes. The receptors vary in IgG subclass specificity and also differ in the cellular response they give rise to upon IgG binding. The total immune response is a balance between activating and inhibiting signals.<br /> The use of therapeutic antibodies for treatment of human diseases has grown immensely since the introduction in the 80s. Second and third generation antibodies are now entering the market. Much research is conducted on optimizing IgG regarding FcγR binding since this interaction to large extent dictates the cellular immunological response of IgG. An appropriate and reliable screening method to measure and compare the affinities of FcγRs for IgG in vitro would be of great assistance in the evaluation of therapeutic antibodies. In this work two such assays were developed, one based on ELISA and one on flow cytometry, both suitable for screening of approximately 24 IgGs. A number of human and murine FcγRs were expressed in soluble and cell-bound form and the apparent affinities of these for different IgGs were assayed using antigen-independent immune complexes. Receptor-specific IgG binding could be detected with both assay set-ups and discrimination between IgGs with different apparent affinity could be made. https://lup.lub.lu.se/student-papers/record/2863024/file/2863028.pdf application/pdf 1974993 no 2012 eng Proteinvetenskap Chemistry 2863024 2012-07-18T14:24:27+02:00 2012-08-14T14:30:26+02:00 2012-08-14T14:30:26+02:00

oai:lup-student-papers.lub.lu.se:2863036 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Cristina Scret author 2971408 Staffan Bergström supervisor Department of Chemistry v1000647 department The non-enzymatic browning of glucose was investigated by accelerating the glucose degradation with or without heating glucose solutions for 1 h at 100°C with different reagents. Evaluation of the glucose degradation was performed using two types of glucose, glucose A and glucose B, in order to investigate the influence of the glucose manufacturing process on glucose discoloration. The color formation was determined by measuring the UV-absorbance between 260-605 nm. The glucose degradation was also investigated by the formation of 5-hydroxymethylfurfural and 2-furfural, which were determined by HPLC.<br /> The accelerated glucose discoloration method was optimised in order to differentiate between different glucose qualities with respect to color stability, i.e. the conditions selected were based on maximizing the difference in glucose discoloration for glucose A and B. Direct measurement of the absorbance difference at 350 nm, on 33 % (w/w) glucose/water solution kept at room temperature for 1 h was found to be the optimum conditions for differentiating between glucose A an B. Further investigation on Maillard reactions was made, and for the investigated conditions, the reaction was found to be most accelerated for the glucose samples, 33% (w/w), heated at 100°C for 1 hour in the presence of L-alanine. https://lup.lub.lu.se/student-papers/record/2863036/file/2863038.pdf application/pdf 860004 no 2011 eng Analytisk kemi Chemistry 2863036 2012-07-18T14:33:51+02:00 2012-08-14T14:31:45+02:00 2012-08-14T14:31:45+02:00

oai:lup-student-papers.lub.lu.se:2863045 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Erik Hallin author 2971410 Professor Hans-Erik Åkerlund supervisor Department of Chemistry v1000647 department Plants require sunlight to be able to perform photosynthesis but an excess of intense sunlight is harmful to the organism and therefore needs a method to protect itself. Violaxanthin De-Epoxidase (VDE) is located inside the thylakoid lumen and catalyzes the de-epoxidation of violaxanthin to zeaxanthin. Zeaxanthin absorbs the harmful light and dissipates the energy by emitting heat. How this enzymatic reaction is done by VDE is unknown as well as the structure of the full enzyme. The low natural abundance of this protein makes it hard to isolate from its original host and it is therefore overexpressed in Escherichia coli. Isolation and purification of VDE using the soluble proteins fraction resulted in low amounts of VDE with low specific activity but solubilization and refolding of the insoluble protein fraction resulted in high amounts of active VDE. Further purification steps including two-step precipitation and gel-filtration that resulted in monomeric, active VDE (determined to 99 % of protein composition with SDS-PAGE. Verification of expressed protein was made by SDS-PAGE and mass spectroscopy. Protein characterization by Circular Dichcroism (CD), Differential Scanning Fluorimetry (DSF), Dynamic Light Scattering (DLS) and metal analysis was preformed. Crystallization screens JCSG+ and PACT Premier were used to acquire protein crystals but was however not successful. Investigation of enzymatic activity by inhibition with low pH and DTT showed that both these factors can inhibit VDE separately and that the DTT inhibition is reversible. https://lup.lub.lu.se/student-papers/record/2863045/file/2863046.pdf application/pdf 1228145 no 2011 eng Proteinvetenskap Chemistry 2863045 2012-07-18T14:39:21+02:00 2012-08-14T14:36:09+02:00 2012-08-14T14:36:09+02:00

oai:lup-student-papers.lub.lu.se:2863069 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Andreas Andersson author 1467072 Associate Professor Marita Cohn supervisor Department of Chemistry v1000647 department RNA interference (RNAi) has recently been discovered in the budding yeast Saccharomyces castellii. As in other organisms, artificial RNAi could be a useful genetic tool in budding yeast, but the method needs first to be established. S. castellii is also a useful model for telomerase studies, and a knockdown of the telomerase catalytic subunit Est2p could be a new way of unrevealing its functions and interactions in the cell. The aim of this work was to construct a long hairpin RNA directed against the EST2 mRNA. A region of 172 nucleotides was amplified by PCR using two different primer pairs with different restriction sites to obtain two fragments that could be inserted into a vector in opposite directions. One of these fragments was successfully inserted. The other fragment was inserted into pUC18 to facilitate amplification for insertion into the final vector. RNA was isolated from S. castellii; the method used for RNA isolation proved to be appropriate for future measurements of mRNA levels after knockdown experiments. https://lup.lub.lu.se/student-papers/record/2863069/file/2863070.pdf application/pdf 885763 yes 2012 eng Biokemi Chemistry 2863069 2012-07-18T15:39:34+02:00 2018-10-19T14:07:08+02:00 2012-08-14T14:37:12+02:00

oai:lup-student-papers.lub.lu.se:5043457 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Josefin Flodgren author 5043455 Dr Åsa Davidsson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Slam från konventionell avloppsvattenrening innehåller näringsämnen samt mullbildande ämnen vilket medför att materialet utgör en resurs som växtnäring och jordförbättringsmedel. Problematiken med att använda slam är att det även innehåller främmande ämnen som metaller och svårnedbrytbara organiska föreningar. <br /> <br /> Syvab är ett kommunalt bolag som driver Himmerfjärdsverket men ansvarar också för några pumpstationer och huvudtunneln som leder avloppsvattnet till verket. Himmerfjärdsverket är sedan augusti 2010 certifierade enligt Revaq. Detta innebär bland annat att Syvab kontinuerligt arbetar för att förbättra slammets kvalitet. Två metaller som är prioriterade i Syvabs uppströmsarbete är kadmium och nickel. Syftet med utredningen är att kartlägga var i sam-hället de båda metallerna återfinns samt källor till dessa metaller uppströms Himmerfjärdsverket. <br /> <br /> Avloppsvattnet som leds till Himmerfjärdsverket härstammar från kommunerna Botkyrka, Nykvarn, Salem, Södertälje samt delar av Huddinge och sydvästra Stockholm. För att minska mängden inkommande kadmium och nickel är fordonstvättar, verkstäder, bilverk-städer, tryckerier, tvätterier, energianläggningar, ytbehandlare, pappersbruk, flygplatser, deponier och vattenverk prioriterade verksamheter. Prioriterade verksamheter i de anslutna kommunerna har sammanställts för vidare uppströmsarbete.<br /> <br /> Kadmium är en mycket giftig metall som med några undantag är förbjuden i Sverige sedan 1982. Under 2013 inkom 4,7 kg kadmium till Himmerfjärdsverket. En uppskattning av fördelningen mellan olika källor visar på att 71 % härrör från hushåll, varav 27 % från BDT-vatten, 25 % från urin och fekalier samt 19 % från övrigt i hushållen. Dock finns indikationer på att hushållens bidrag minskar och med inaktuell beräkningsdata kan andelen antas vara lägre. Anslutna A- och B-verksamheter står för 4 %, konstnärsverksamhet för 7 % och tillförda substrat för 9 %. Den mängd kadmium som inte kunnat härledas, dvs. kadmium av okänt ursprung står för 9 %, men då hushållens bidrag antas vara mindre medför detta att den okända andelen antas vara större. I kategorin okänt ingår bland annat utsläpp från mindre verksamheter och dagvatten samt eventuellt sediment i ledningar.<br /> <br /> Nickel är giftigt i högre koncentrationer men används brett i den moderna industrin. Under 2013 inkom 340 kg nickel till Himmerfjärdsverket. I fördelningen mellan olika källor till inkommande nickel uppskattas hushållen stå för 43 % där BDT-vatten och dricksvatten ut-gör de största andelarna, båda på 20 % vardera. A- och B-verksamheter står för 5 %, substrat för 24 % och tillförd fällningskemikalie för 21 %. Okända källor står för 7 %, dessa utgörs bland annat av utsläpp från mindre verksamheter och dagvatten.<br /> <br /> För att kartlägga utsläpp av metaller genomfördes under våren 2014 en tunnelprovtagning uppströms Himmerfjärdsverket. Provtagningen var den andra efter en likvärdig provtagning genomförd fyra år tidigare, vintern 2010. I tunnelprovtagningen ingick tio provpunkter i tunnelsystemet samt en provpunkt för inkommande vatten till verket. I fyra provpunkter uppmättes förhöjda kadmiummängder och i en av dessa samt ytterligare tre provpunkter uppmättes förhöjda nickelmängder. Fyra provpunkter visade på ökade kadmiummängder mellan 2010 och 2014. Tre av dessa visade även på ökade nickelmängder och ytterligare en visade endast på ökade nickelmängder. <br /> <br /> För att minska mängden inkommande kadmium och nickel till Himmerfjärdsverket har en åtgärdsplan tagits fram. Sludge is produced in conventional waste water treatment. The sludge contains nutrients and humic formaing substances which make it useful as a fertilizer. The problem with using sludge is that it also contains toxicants as heavy metals and persistent organic compounds. <br /> <br /> Syvab is a municipal owned corporation that manage the wastewater treatment plant Him-merfjärdsverket. Since August 2010 Himmerfjärdsverket is certified by Revaq. This entails that Syvab continuously works to improve the quality of the sludge. Two metals that are in priority to reduce are cadmium and nickel. The purpose of this study is to examine where in the society this metals are found and to pinpoint sources upstream Himmerfjärdsverket. <br /> <br /> The incoming wastewater to Himmerfjärdsverket origin from the municipalities Botkyrka, Nykvarn, Salem, Södertälje and parts from Huddinge and southwest Stockholm. To reduce the incoming amount of cadmium and nickel vehicle washers, workshops, auto repair shops, printing shops, laundries, power plants, surface treatment workshops, paper mills, airports, landfill sites and waterworks are priority businesses. Priority businesses in the connected municipalities have been compiled for further work. <br /> <br /> Cadmium is a very toxic metal and is, with some exceptions, since 1982 forbidden to use in Sweden. During 2013 the amount of incoming cadmium to Himmerfjärdsverket was 4.7 kg. An estimation of the distribution between different sources indicates that 71% comes from households, of which 27% from grey water, 25% from urine and faeces, and 19 % from other sources in the households. However, there are indications that the amount from household is decreasing and with not updated data the contribution is assumed to be lower. Connected A- and B-businesses accounts for 4%, artist paints for 7% and added substrates for 9%. The amount of cadmium that could not be derived, i.e. cadmium of unknown origin, account for 9%. Since the contribution from households is assumed to be lower the part with unknown origin may be greater. The category with unknown origin includes emissions from smaller businesses, storm water and sediments in pipes. <br /> <br /> Nickel is toxic in high concentrations but is broadly used in the modern industry. During 2013 the amount of incoming nickel to Himmerfjärdsverket was 340 kg. An estimation of the distribution between different sources indicates that 43% comes from households, the largest parts are grey water and drinking water, both at 20%. A- and B-businesses accounts for 5%, added substrates for 24% and precipitation chemicals added at the plant for 21%. Sources of unknown origin account for 7%, these include emissions from smaller businesses and storm water. <br /> <br /> During the spring 2014 a sampling project was conducted in the tunnel upstream Himmerfjärdsverket. Water samples were collected in ten locations in the tunnel system to map out important areas to focus on for reduce incoming cadmium and nickel. Samples were also collected in incoming water to the plant. The sampling project was the second after a similar one made four years earlier. High amounts of cadmium were measured in four locations, in one of these and additional three locations high amount of nickel were found. Four locations indicated increased amount of cadmium between 2010 and 2014. Three of these and one additional location also indicated increased amount of nickel. <br /> <br /> An action plan has been developed to decrease the amount of incoming cadmium and nickel to Himmerfjärdsverket. För att få ett fungerade kretslopp måste de viktiga näringsämnen som finns i avloppsslam tas till vara. Problematiken med att sprida slam på åkrar är att det även innehåller oönskade ämnen vilka kan anrikas i marken och tas upp av grödor. Kadmium och nickel är två giftiga tungmetaller som i större mängder varken hör hemma i jordbruksmark eller på matbordet. Men hur hamnar då dessa två metaller i avloppsslammet och hur kan vi förhindra att de kommer dit? <br /> <br /> På Himmerfjärdsverket, som renar avloppsvatten från södra Stockholmsregionen, arbetar man kontinuerligt med att förbättra slamkvalitén. Här stävar man efter att producera ett slam som inte innehåller annat än de ämnen, och inte heller i högre koncentrationer, än som finns i kiss och bajs. Tyvärr är det inte bara toalettavfall som följer med avloppsvattnet till verket. I arbetet att minska mängden oönskade ämnen som hamnar i slam, så kallat uppströmsarbete, är kadmium och nickel prioriterade för Himmerfjärdsverket. <br /> <br /> Under 2013 inkom 4,8 kg kadmium till Himmerfjärdsverket. Ganska mycket med tanke på att metallen sedan 80-talet, med några få undantag, är förbjuden att använda i Sverige. En uppskattning visar på att så mycket som 71 % kan härröra från hushåll, troligtvis är dock hushållens andel mindre eftersom forskning tyder på att kadmiummängden i hushållens avloppsvatten minskar. Omkring en tredjedel av hushållens bidrag kommer från det vi äter och dricker, läskigt eller hur? Andra källor till kadmium är större verksamheter på 4 % och konstnärsverksamhet på 7 %. Det är nämligen så att ett av undantagen i kadmiumförbudet gäller konstnärsfärger och produkter i kulörer av rött och gult kan innehålla stora mängder kadmium. På Himmerfjärdsverket tillförs olika substrat innan slammet rötas, detta för att öka biogasproduktionen. Tillförda substrat står för 9 % av inkommande mängd kadmium. Återstående andel utgör 9 % och representerar okända källor där det bland annat ingår dagvatten, utsläpp från mindre verksamheter samt eventuellt sediment som ligger kvar i ledningar. <br /> <br /> Inkommande mängd nickel har under 2013 beräknats till 340 kg, alltså mer än 70 gånger så mycket jämfört med kadmium. Men nickel är en metall med många bra egenskaper och används brett i den moderna industrin. Av dessa 340 kg uppskattas 43 % komma från hushåll och framförallt från vatten använt i kök, badrum och tvätt. Större verksamheter står för 5 %, substrat för 24 % och processkemikalier använda på Himmerfjärdsverket för 21 %. Kvarvarande 7 % representerar okända källor som bland annat utgörs av utsläpp från mindre verksamheter och dagvatten. <br /> <br /> Verksamheter kan ge utsläpp till avloppsvattnet via olika processer och aktiviteter men även via kemikalier och våtstädning. De verksamheter som påvisats ge utsläpp av kadmium och/eller nickel är fordonstvättar, verkstäder, bilverkstäder, tryckerier, tvätterier, energianläggningar, ytbehandlare, pappersbruk, flygplatser, deponier och vattenverk.<br /> <br /> Avloppsvattnet leds till Himmerfjärdsverket i ett 50 km långt tunnelsystem. Genom en omfattande provtagning i tio provpunkter har viktiga områden uppströms verket prioriterats för vidare spårning av både kadmium och nickel. För att minska mängden inkommande metaller är viktigt och med hjälp av en åtgärdsplan ska man framöver arbeta med att minska inkommande mängder av kadmium och nickel. https://lup.lub.lu.se/student-papers/record/5043457/file/5044631.pdf application/pdf 5575053 no 2015 swe Avloppsvatten metaller uppströmsarbete kadmium nickel slam Chemistry 5043457 2015-02-04T14:27:08+01:00 2015-02-10T19:34:52+01:00 2015-02-10T19:34:52+01:00

oai:lup-student-papers.lub.lu.se:5045868 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Stephanie Jephthah author 5045856 Marie Skepö supervisor Department of Chemistry v1000647 department The aim of this thesis was threefold: (i) study the association behaviour of β-casein, (ii) study the electrostatic and conformational properties of β-casein, and (iii) evaluate the possibility of using β-casein as a model protein for the acidic proline rich protein (PRP-1).<br /> <br /> Dynamic light scattering (DLS) was used to determine the size of β-casein aggregates that were formed in aqueous solutions as an effect of protein concentration, salt (NaCl) concentration and calcium ion concentration. There proved to be three possible types of aggregates forming for solutions with the protein concentration close to the critical aggregation concentration. It was also observed that the protein solutions precipitated in the absence of any salt and caused the results to be polydisperse, showing odd peaks known as &quot;slow modes&quot;. The aggregate size was shown to be increased with both the protein- and salt-concentration. It was also observed that the aggregates were generally smaller in the presence of calcium ions. Furthermore, there seemed to be a connection between the ionic strength and the aggregate size when there were calcium ions present. <br /> <br /> Both β-casein and PRP-1 were studied using a coarse-grained model simulated by a Metropolis Monte Carlo algorithm. Their properties, such as net charge and radius of gyration, were analyzed and compared. The behaviour of the two proteins was very similar apart from the shifted values due to the size difference between them. These results indicated that it might be possible for β-casein to work as a model protein for PRP-1 and further investigation is recommended. Muntorrhet är en åkomma som uppkommer på grund av salivbrist eller om salivens sammansättning ändras. Sådana förändringar i salivproduktionen kan uppstå på grund av flera olika anledningar. De vanligaste orsakerna är Sjögrens syndrom, diabetes, ätstörningar eller näringsbrist. Muntorrhet kan även uppstå som en bieffekt av strålbehandlingar och receptbelagd medicin. Muntorrhet kan ge upphov till värre symptom som till exempel tandlossning, tandröta och ökad infektionsrisk. Det är svårt att bota sjukdomen men symptomen kan mildras genom att dricka mycket vatten, ta munvatten, tugga sockerfria tuggummin och genom att undvika alkohol och koffein. I vissa fall används även salivsubstitut.<br /> <br /> Saliv är en vätska som består av mer än 99 % vatten, olika salter samt en mängd varierande proteiner. Proteinerna står för de flesta av funktionerna i saliven. Det optimala salivsubstitutet innehåller de nödvändiga proteiner som förhindrar symptomen som är associerade med muntorrhet. Det finns till exempel ett protein som hjälper till att återmineralisera tänderna genom att binda och hantera kalciumjoner. Proteinet kallas acidic proline rich protein (PRP-1) och det återfinns enbart i saliv. Detta är ett problem då det gör det väldigt svårt att få tag på PRP-1 i tillräckliga mängder för att kunna tillverka ett effektivt salivsubstitut. Det har dock observerats att det finns ett annat mer lättillgängligt protein som har egenskaper liknande de hos PRP-1. Detta protein är ett mjölkprotein som kallas β-kasein. Målet med detta arbete var då att undersöka dessa egenskaper hos de båda proteinerna och utforska möjligheten att använda β-kasein som ersättning för PRP-1 vid tillverkning av salivsubstitut. <br /> <br /> En egenskap som studerades var micellbildning av β-kasein, det vill säga hur flera β-kaseinkedjor klumpar ihop sig till större proteinkluster (aggregat), och hur det påverkas av pH, salthalt och tillsats av kalciumjoner. Detta gjordes genom att lösa upp β-kasein i olika lösningar och sedan analysera dessa med hjälp av en metod som kallas \textit{dynamisk ljusspridning} (DLS). Resultaten visade att aggregaten blir större vid hög salthalt men mindre vid tillsats av kalciumjoner. Detta beror på att växelverkningarna som finns mellan proteinkedjorna skärmas när det är mycket salt/joner i lösningarna, det vill säga de hindrar proteinerna från att känna av varandra. Skärmningen leder till att fler eller färre proteiner kan samlas och bilda aggregat, beroende på vilken typ av interaktion som skärmas. <br /> <br /> Egenskaper som laddning, kapacitans och storlek vid olika pH studerades för de båda proteinerna med hjälp av datorsimuleringar. Det visade sig att PRP-1 och β-kasein beter sig enhetligt då de utsätts för samma miljö och resultaten indikerar att det finns en god möjlighet för att kunna använda β-kasein som ersättning för PRP-1. Däremot krävs vidare undersökningar innan en slutsats kan dras. https://lup.lub.lu.se/student-papers/record/5045868/file/5045935.pdf application/pdf 845952 yes 2015 eng Monte Carlo DLS saliva PRP-1 KEMK08 β-casein teoretisk kemi simulations Chemistry 5045868 2015-02-09T10:32:27+01:00 2015-07-02T14:42:36+02:00 2015-07-02T14:42:36+02:00

oai:lup-student-papers.lub.lu.se:5114700 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Aamar Mehmood Iqbal author Ulf Olsson supervisor Department of Chemistry v1000647 department Swelling Properties of Pure Na and Ca bentonites<br /> <br /> Swelling of natural bentonite, with mono and divalent counter ions and mixture of both bentonites, in heavy water is studied. For this purpose, pure Na and Ca bentonites are prepared by ion exchange method. 2HNMR technique is used to measure qudrupolar splitting. Electrostatic interaction between platelets is mainly responsible in swelling in case of Na bentonite dispersions. Quadrupolar splitting increases linearly with increase of concentration of pure Na bentonite up to Фc= 0.005. At higher concentrations, positive deviation from straight line is consequence of ordering of platelets. Dominant of van der Waals attraction between two platelets of montmorillonite causes limited swelling of pure Ca bentonite. The results obtained from NMR and crosspolarizer experiments were used to study different phases in mixture of Ca bentonite- Na bentonite-water. Swelling Properties of Pure Sodium and Calcium bentonites<br /> <br /> <br /> Bentonite water system is found very useful in many industries. Due to its large number of applications especially in nuclear waste management, it has come under focus of many research groups around the world. The aim of this work is to study swelling properties of bentonite with mono and divalent counter ions in water. In present work natural MX-80 bentonite, a type of clay, was used to prepare sodium bentonite and Calcium bentonite by a special chemical process called ion exchange method. <br /> The techniques used were NMR and Cross polarizer. It was observed that bentonite with monovalent counter ion swells in water to form gel like liquid. Swelleing increases with increase of water. The swelling of bentonite, with divalent counter ion, was limited and in this case bentonite sediment in water. In case of mixtures of both the clay, Calcium bentonite, which was settle down in water, dissolved in sodium bentonite suspension up to some extent, after that when amount of calcium bentonite was increased, it started to sediment. <br /> This study gives more chance to know about swelling of bentonite in water, and this can be useful for research related to nuclear waste disposal. 2012 eng Fysikalisk kemi Physical Chemistry Chemistry 5114700 2015-02-25T14:22:09+01:00 2022-05-11T09:14:15+02:00 2022-05-11T09:14:15+02:00

oai:lup-student-papers.lub.lu.se:5205552 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Marcus Johansson author 4646330 Valera Veryazov supervisor Dr Per-Olof Widmark supervisor Department of Chemistry v1000647 department A new code for automatic detection of point groups and for symmetrization of molecular geometry and wavefunctions is presented. Performance and accuracy improvements to a previously designed algorithm for point group determination and an algorithm for symmetrization of said point groups, using linear transformations onto predefined coordinates is described. The new algorithm can find the 120 symmetrized operations of Ih in C720 in under 30 ms. An algorithm for symmetrization of molecules using projections onto an n- dimensional basis is described, as well as an algorithm for determining the projection operators and subspaces of the irreducible representations for the symmetry adapted linear combinations of atomic orbitals. An algorithm for symmetrization of molecular orbitals is also described. Code was implemented and integrated into the Molcas quantum chemistry software, as well as the Luscus graphical molecular modelling software. Symmetri är något vi växer upp med. Från vår första kontakt med ett ansikte, till fjärilar och blommor. Vi står på två likadana fötter och har därför lättare att balansera under jordens dragningskraft, fåglar har lika långa vingar och kan därför lättare flyga.<br /> På samma sätt som vi undviker att tippa med hjälp av det spegel-plan som går mellan våra ögon, kan symmetri användas för att undvika att kemiska beräkningar tippar över, ger felaktiga resultat eller för att snabba upp komplexa beräkningar.<br /> Kemiska beräkningar kan sällan göras för hand, utan utförs av datorer. Datorer har inte samma uppfattning av symmetri som vi människor har, så algoritmer för att beskriva, hitta och använda denna symmetri måste kunna köras automatiskt under beräkningens gång.<br /> Detta projekt gick ut på att formulera och implementera just sådana algoritmer, samt att integrera dessa med programvara som utför kvantkemiska beräkningar.<br /> Resultaten visar att användningen av symmetri kan ge förbättrade resultat när man beskriver positioner av atomer eller beräknar elektronkonfigurationer i molekyler. Projektet gav också upphov till programvara som kan visualisera och bygga upp denna symmetri, vilket kan vara till nytta för modellering av molekyler eller för utbildning av framtida teoretiska kemister. https://lup.lub.lu.se/student-papers/record/5205552/file/5205609.pdf application/pdf 12958295 no 2015 eng Quantum Chemistry Symmetry Symmetrization Molecular Orbitals Wavefunction Point Group Algorithm Projection Molecular Modelling Code Chemistry 5205552 2015-03-25T14:47:17+01:00 2015-12-14T08:06:30+01:00 2015-05-08T16:08:05+02:00

oai:lup-student-papers.lub.lu.se:5364243 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Anna Lidskog author 5364241 Satish Bhat supervisor Department of Chemistry v1000647 department Oxygenases are a group of enzymes that use molecular oxygen to oxidize a substrate, a very important process both biologically and industrially. High-valent Fe(IV)-oxo species have long been implicated as the key reactive intermediates in heme and non-heme iron oxygenases. Since the first well-characterized mononuclear non-heme iron(IV)-oxo complex was reported in 2003, much effort have been put into developing functional active site models. In this study, a new tetradentate ligand (N-[(1-methyl-2-benzimidazolyl)methyl]-N,N-bis[(6-methyl-2-pyridyl)methyl]amine) has been synthesized and characterized by ESI-MS, IR and 1H and 13C NMR. Two iron complexes, [FeL1(CH3CN)2] and [FeL1(OTf)2], were synthesized, of which the latter was determined to be an Fe(II) complex. Both complexes were found to be high-spin. In addition, a Ru(II) complex, [RuCl(L1)(DMSO)]Cl, was synthesized. The metal complexes were characterized by IR, UV/Vis and 1H NMR. The generation of an Fe(IV)-oxo complex was attempted by reacting [FeL1(OTf)2] with mCPBA and PhIO respectively at low temperatures, but no conclusive results for the formation of an Fe(IV)-oxo complex were obtained. Nästan alla organiska föreningar innehåller kol-vätebindningar (C-H). Kolväten i naturen, så som naturgas och råolja, är exempel på energirika och billiga kemiska råmaterial. Aktiveringen, och speciellt oxideringen, av dessa kol-vätebindningar är en väldigt viktig reaktion med både biologisk och industriell relevans. Ett exempel på detta är omvandlingen av metan till metanol. Metan (CH4) är huvudbeståndsdelen i naturgas och är ett bra bränsle, men är svårt att transportera och därför mindre lämpligt som drivmedel i t.ex. bilar. Metanol (CH3OH) är däremot betydligt enklare att transportera. Denna omvandling genomförs idag industriellt, men processen är dyr och kräver mycket energi.<br /> <br /> I naturen finns redan enzymer som effektivt oxiderar olika substrat. Dessa enzymer kallas oxygenaser och använder molekylärt syre (O2) som oxidationsmedel. Det aktiva sätet (den del av enzymet där substratet binder och reaktionen sker) i oxygenaser innehåller metalljoner av vanligt förekommande övergångsmetaller som järn, koppar och mangan. Den intressanta och användbara reaktiviteten hos dessa enzymer har inspirerat forskare att utveckla modellkomplex som efterliknar de strukturella eller funktionella aspekterna hos de aktiva sätena. Det här arbetet har fokuserat på funktionella modellkomplex för icke-heminnehållande oxygenaser där de aktiva sätena innehåller en järnjon. I dessa järnoxygenaser har det föreslagits att oxidationsreaktionerna sker via skapandet av högvalenta Fe(IV)-oxo-intermediat.<br /> <br /> Syftet med det här projektet har varit att syntetisera en ny tetradentat ligand och dess Fe(II)-komplex och även om möjligt det motsvarande Fe(IV)-oxokomplexet. Den nya liganden har karaktäriserats och använts för att syntetisera och karaktärisera två Fe(II)-komplex samt ett Ru(II)-komplex. Ett av Fe(II)-komplexen reagerades även med olika oxidationsmedel i ett försök att generera ett Fe(IV)-oxokomplex. Inga definitiva resultat erhölls, men det är möjligt att ett högspinn Fe(IV)-oxokomplex bildades. 2015 eng Inorganic Chemistry oorganisk kemi Chemistry 5364243 2015-04-30T17:04:36+02:00 2015-07-02T15:27:48+02:00 2015-07-02T15:27:48+02:00

oai:lup-student-papers.lub.lu.se:5425777 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anna Gustafsson author 5425775 Dr Åsa Davidsson supervisor Anders Hjort supervisor Khang Duong Nguyen supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Anaerobic digestion is a cost-effective way of treating high organic content wastewater, as it efficiently removes large amounts of organics at the same time as biogas is produced. The production of starch from cassava roots, named tapioca, creates large amounts of high organic content wastewater and uses large amounts of thermal energy for drying the starch. At Wusons tapioca factory in southern Vietnam the wastewater is treated in an anaerobic covered pond, a low technology system for anaerobic digestion which has become popular at tapioca factories in Vietnam. The performance of the digester is however not optimal and process failures occur regularly which can partly be ascribed to the fact that the understanding of the system is poor and other than pH no measurements has previously been done on the wastewater. In this project the influent and effluent wastewater from the digester has therefore been characterised and the conditions at the factory investigated with the aim of coming up with in-situ adapted suggestions of how the performance of the digester could be improved. <br /> The results from the characterization showed that the influent wastewater was close to optimal for anaerobic digestion, with a ratio between organics and nutrients (nitrogen and phosphorus) close to the theoretically optimal value commonly found in literature. Furthermore the results showed that the concentration of nitrogen and phosphorus were kept constant through the digestion process, but the ammonia concentrations doubled, according to the expected. Solids removal showed to be high, as did the removal of organics, but the discharge standards were still not met for any of these parameters. Cyanide, present in the wastewater because of the cassava roots special composition, was found to be removed very well and the levels met the discharge standards. <br /> The results indicate that the digester had problem with low pH, which is normal for this kind of wastewater. This problem could be addressed by for example adding calcium carbonate in the influent to increase the alkalinity (instead of sodium hydroxide which is used at the factory today), using fungi as primary treatment for increasing alkalinity or separating the acidifying phase of the digestion from the biogas-forming phase. Furthermore it was found that sodium hydroxide, which is used both for cleaning the equipment in the factory and regulating pH, might have an inhibitory effect on the digester and alternatives should be sought for. It was also found that improvements to the digestion process could be done by regulating the flow to the digester. During the project an additional anaerobic covered pond was built at the factory but as the results of the wastewater characterization performed showed that there was not much biodegradable matter left in the effluent from the first digester and that ammonia levels were high it is suggested that the flow is regulated for better use of both anaerobic ponds. For example the ponds could be used to separate the phases of the digestion process as suggested above. Further suggestions consider the removal of big solids in the influent wastewater, better usage of primary pond, and keeping the outlet from the digester clean.<br /> In addition to the above it was found that the factory should keep better track of what is happening in the digester by starting to monitor some parameters and in this way introduce some forward planning and thus avoid process failures. First of all alkalinity should be measured instead of pH to be able to regulate the alkalinity before pH drops and causes process failure as was observed. The flow should also be monitored as the big variations, that are normal in the factory, can cause problems for the digester. Under en tio veckors period i Vietnam hösten 2014 genomförde jag ett SIDA finansierat projekt med målet att hitta enkla och billiga lösningar på hur en befintlig biogasanläggning som behandlar industriellt avloppsvatten från en tapiokafabrik skulle förbättras. Jag gjorde mätningar på vattnet som gick in och ut ur lagunen för att försöka komma fram till vad som skedde där inne, och vad det var för fel på den. För så mycket visste jag; att det var någonting fel inne i lagunen som gjorde att fabriken inte fick tillräckligt med biogas. Mina mätningar visade att det framförallt var problem med att vattnet var för surt, någonting som är vanligt för den här typen av vatten och som fabriken egentligen redan var medvetna om och försökt att lösa. Efter att ha tagit mig igenom språkbarriären med hjälp av papper och penna och enkla skisser visade det sig att fabriken tillsatte stora mängder natriumhydroxid, eller soda som det kallas i folkmun, för att neutralisera surheten. Det de inte var medvetna om är att soda i för stora mängder kan döda de bakterier som lever inne i biogasanläggningen och är anledningen till att biogasen bildas. Kort efter att jag uppmärksammade detta byttes sodan ut mot det i många avseenden bättre alternativet karbonat, och anläggningen har sedan dess fungerat mycket bättre - de hade till och med ett överskott av biogas under högsäsongen den följande våren. De andra problem jag uppmärksammade på anläggningen var inte lika enkla att direkt koppla till produktionen av gas och hade inte lika enkla lösningar. Framförallt krävde de fortsatta undersökningar och stegvisa beslutstaganden för att kunna genomföras. Hur det blir med dessa förslag är därför oklart, antagligen kommer de inte att göra någonting nytt på fabriken förrän de återigen får för liten produktion av biogas. För i slutändan handlar det inte om att rädda miljön utan att skapa vinst för företaget. <br /> Dagens teknik möjliggör fantastiska lösningar på många av de miljöproblem som industrier ger upphov till. I Sverige strävar vi efter att använda oss av bästa möjliga teknik, och vi har lagar och regler som tvingar industrin att ligga i framkant snarare än att göra minsta möjliga, någonting som kan vara kostsamt men som på längre sikt ska gynna båda företagen och miljön. I Vietnam och andra utvecklingsländer ser läget annorlunda ut, i första hand för att ny bättre teknik helt enkelt är för dyr men också för att kunskapsnivån för att kunna använda sig av den är för låg. Här blir det därför extra viktigt att försöka hitta win-win lösningar, som både gynnar företagen ekonomiskt och bidrar till en hållbar utveckling och minskad miljöpåverkan. Biogas är ett utmärkt exempel på win-win lösningar där avloppsvatten renas samtidigt som värdefull biogas bildas, men som det visat sig på fabriken där jag var räcker det inte med att införa en smart lösning – det svåra är ofta att få det att fungera praktiskt i det långa loppet. Finns inte kunskapen om hur systemet fungerar kommer det förr eller senare att brista eftersom i princip alla system behöver någon slags underhåll. Enkelt och billigt har därför varit målramen när olika lösningar på hur fabriken ska förbättra sitt system har föreslagits, och förslagen på hur det ska göras kan därför i första avseende verka triviala men det är det som gör dem så bra. Ett förslag på förbättring var att sätta in ett filtersteg som tar bort de bitar som ändå inte kan brytas ned i anläggningen och som istället förkortar livslängden på den genom att fylla den med oanvändbart material. Om detta relativt enkla förslag genomförs kanske livslängden på anläggningen förlängs och dessutom kan det bidra till att processen förbättras i helhet. Små åtgärder som gör stor skillnad. Om de genomförs på rätt sätt. https://lup.lub.lu.se/student-papers/record/5425777/file/5425796.pdf application/pdf 2817027 no 2015 eng Vietnam biogas tapioca cassava anaerobic digestion wastewater treatment minor field study environmental engineering vattenförsörjningsteknik avloppsteknik Chemistry 5425777 2015-05-21T14:58:23+02:00 2015-06-12T08:29:38+02:00 2015-06-12T08:29:38+02:00

oai:lup-student-papers.lub.lu.se:7860001 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Maria Jansson author 7852782 Marie Skepö supervisor Jan Forsman supervisor Department of Chemistry v1000647 department The aim of this thesis was to evaluate the accuracy of a one-parameter non-virial scaling equation of state (EOS) for polyethylene glycol in water by Cohen et al. through osmotic pressure measurements using membrane osmometry and Monte Carlo simulations. PEG20 was set as the reference system and the polymer chain length effect was investigated through simulations of PEG10 and PEG35. For PEG35 experimental data was obtained from a previous work. The EOS was shown to be in a good agreement in a quite broad concentration range, where the experimental and simulated data coincided in the dilute region. The second virial coefficient, A2, was positive confirming that water is a good solvent for PEG. Also the conformational properties for the above PEG’s were evaluated from the root-mean-square end-to-end distance, &lt;Ree2&gt;^(1/2), and the root-mean-square radius of gyration, &lt;Rg2&gt;^(1/2), obtained from the Monte Carlo simulations. From the relation between the &lt;Ree2&gt;^(1/2) and &lt;Rg2&gt;^(1/2) the shape factor, r, was determined, concluding that the polymer behaves as a random coil. For the reference system the temperature effect was investigated through the hydrodynamic radius, Rh, measured with dynamic light scattering at 25 and 50°C, and the solvent effect was evaluated by membrane osmometry using an isotonic solvent (Ringer solution). No conformational change was observed when comparing the hydrodynamic radius at 25 and 50°C. Also the osmotic pressure was not affected by using an isotonic solvent indicating that there was no deviance from the ideal system. Målet med detta arbete var att studera de termodynamiska och strukturella egenskaperna hos polyetylenglykol genom att tillämpa en kombination av experiment och datorsimuleringar. Den experimentella huvudtekniken var membran osmometri och datorsimuleringarna baserades på Monte Carlo metoden. <br /> <br /> Polyetylenglykol även förkortat PEG är en neutral linjär polymer med amfifilisk karaktär, vilket menas att den löslig i vatten såväl som i många organiska lösningsmedel. Den kemiska strukturen för PEG är H-(OCH2CH2)n-OH där den repeterade enheten, också kallad en monomer, är en oxyetylengrupp. På grund av detta brukar PEG även kallas för polyetylenoxid (PEO). PEG finns att tillgå i en mängd olika molekylvikter, allt ifrån ett par hundra till tiotusentals g/mol. Vid rumstemperatur är lågmolekylära PEG (&lt;600) en viskös, genomskinlig vätska och vid högre molekylvikter (&gt;800) övergår PEG till ett fast vaxartat vitt material. Vattenlösningar av PEG har vissa specifika egenskaper jämfört med andra polymerer till exempel som att lösligheten minskar vid ökad temperatur. Detta gör att PEG både har en undre och en övre kritisk lösningstemperatur. Vattenlösligheten beror också på polymerens storlek, där lösligheten minskar med ökad molekylvikt. Detta beror på att andelen hydrofobiska (vattenskyende) kolskelett ökar och fraktionen av de hydrofila (vattenälskande) hydroxylgrupperna minskar. Eftersom PEG är en stabil polymer med låg toxicitet och god förmåga att binda vatten är det en av de mest industriellt använda polymererna. Områden där PEG används är allt från hudvårdsprodukter, hygienartiklar, kosmetika till läkemedel.<br /> <br /> Membran osmometri är en teknik som bygger på osmos där två kammare, en med ett rent lösningsmedel och en med ett upplöst ämne i, till exempel en polymer, är separerade med ett semipermeabelt membran. På grund av porstorleken på membranet och koncentrationsskillnaden mellan vätskorna kommer lösningsmedelsmolekylerna att vandra igenom membranet och späda ut polymer lösningen. Denna rörelse kallas för osmotiskt flöde. Det tryck som krävs för att stoppa detta flöde är definierat som det osmotiska trycket, och beräknas genom vätskornas höjdskillnad då system har nått jämvikt. I den här studien har det osmotiska trycket använts för att bestämma polymerens molekylvikt och den andra virialkoefficienten. Det senare är ett mått på växelverkan mellan två polymererna i systemet. De experimentella resultaten jämfördes sedan med en analytisk tillståndsekvation framtagen av Cohen och medarbetare.<br /> <br /> Den polymermodell som användes i datorsimuleringarna består av N stycken fritt ledade sfäriska kulor, där en kula representerar en monomer. Monomererna är sammanlänkade med en stel fixerad bindning. Bindningslängden och diametern på kulorna var valda för att passa tidigare experimentella data av det osmotiska trycket och gyrationsradien, alltså medelstorleken av polymeren. Monte Carlo simuleringarna baserades på en ”isobaric-isothermal” ensemble, där antalet partiklar, trycket och temperaturen hålls konstant medan volymen tilläts att variera. För att undvika yteffekter introducerades periodiska randvillkor. Det senare innebär att antalet partiklar i simuleringslådan bevaras genom utöka denna låda till ett oändligt gitter, det vill säga, om en partikel i lådan flyttas kommer alla identiska partiklar att flyttas och om en partikel skulle flyttas utanför lådan ersätts den med en identisk partikel i samma kvantitet. Från Monte Carlo simuleringarna utvärderades de strukturella egenskaperna för polyetylenglykol genom den medelkvadratiska gyrationsradien samt det medelkvadratiska änd-till-änd avståndet, varpå formen på polymeren kunde bestämmas.<br /> <br /> Vi ser en mycket god överensstämmelse mellan experiment, teori och simuleringar. 2015 eng Teoretisk kemi theoretical chemistry Chemistry 7860001 2015-09-07T13:12:21+02:00 2015-09-16T08:50:52+02:00 2015-09-16T08:50:52+02:00

oai:lup-student-papers.lub.lu.se:7989842 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Ida Lindström author 7988400 Johan Bonde supervisor Pure and Applied Biochemistry v1000655 department All biological information is located in the genome. However, not all of the genome is available for transcription at all times. In the nucleus, genomic DNA is tightly packed around histones which are further packed into nucleosomes and chromatin. The packing of DNA inhibits transcription factors from transcribing the underlying DNA. To make the DNA more accessible, the packing can be modified in several different ways, such as the remodeling of nucleosomes. A protein complex that is involved in nucleosome remodeling is the Nucleosome Remodeling and Deacetylase complex (NuRD). The complex consists of at least 10 proteins with varying functions. NuRD is one of two complexes that has two different nucleosome remodeling activities, histone deacetylation and ATP-dependent nucleosome remodeling. There have been indications that the NuRD complex binds a protein called PWWP2A. There is not much information available about the protein but what is known is that it has a PWWP-domain. Other proteins with the PWWP-domain function as transcription factors. They are involved with cell growth, differentiation, cell division and some bind to histones. The connection between the PWWP2A protein and the NuRD complex is investigated in this project. The experimental work showed that a fragment of PWWP2A containing the PWWP-domain could be expressed in bacteria and 1D 1H-NMR experiments suggest that the domain was structured in solution. Interaction between the PWWP2A protein and MTA1, as well as, HDAC1 components of the NuRD complex was also observed. NuRDigt värre<br /> All genetisk information finns i DNA:t. Det är där informationen finns som bestämmer ifall någon får bruna eller blåa ögon, att vi har (oftast) tio tår, att vår lever producerar galla, all information som gör oss till oss helt enkelt. Informationen i DNA:t transkriberas till RNA som i sin tur kan translateras till protein. Alla våra celler bär på exakt samma DNA men ändå skiljer de sig åt och har olika funktioner i vår kropp, vad beror det på då? Det beror på att vårt DNA är så stort att det måste packas för att få plats i cellerna. Detta görs genom att DNA:t lindar sig runt proteiner som kallas histoner, histonerna packas i sin tur vidare till nukleosomer och vidare till kromatin. Allt detta packande gör att delar av DNA:t inte är tillgängligt för enzymerna som är ansvariga för att transkriptionen. Genom att lätta på packningen kan alltså DNA:t bli tillgängligt igen och proteinerna kan tillverkas. I olika celler är olika delar av DNA:t tillgängligt och de kan därmed producera proteiner som är typiska för just den typen av celler. <br /> Packningen och uppackningen av DNA sköts av olika slags protein. Ett exempel på detta är det så kallade NuRD komplexet. Det består av minst 10 olika protein med olika funktioner men än så länge så vet man inte hur komplexet är uppbyggt, exakt vad det gör och vilka andra protein det samarbetar med. Forskare vill hitta svaret till alla dessa frågor eftersom fel vid regleringen av DNA transkriptionen kan leda till olika former av sjukdomar som till exempel cancer. <br /> Ett annat protein som uttrycks i våra celler är PWWP2A proteinet. Man vet nästan inget om proteinet än. En del av proteinet, PWWP-domänen, finns dock även i andra protein. I de andra proteinerna binder domänen till histoner, DNA och är med och verkar i transkriptionen. Tidigare experiment har även visat att det finns någon slags interaktion mellan PWWP2A proteinet och NuRD komplexet. Eftersom proteinet binder till histoner och NuRD komplexet reglerar transkriptionen så kan man tänka sig att proteinerna samarbetar och det är just detta som man börjat titta på i detta projekt. Man vill veta mer om PWWP2A proteinet på grund av dess möjliga samarbete med NuRD komplexet. <br /> I det här projektet var målet att undersöka hur olika delar av PWWP2A proteinet betedde sig, ifall proteinet band till nukleosomer och ifall proteinet och NuRD komplexet interagerade med varandra. Resultaten visade att en del av PWWP2A proteinet hade en tre dimensionell struktur. Nu när man vet det, kan man i framtiden försöka lösa exakt hur denna struktur ser ut. Vetskapen om ett proteins struktur är intressant eftersom det kan ge en indikation om proteinets funktion. På grund av tids begränsningar hann man inte undersöka ifall PWW2A proteinet band till nukleosomer. Resultaten visade dock även att PWWP2A proteinet band till MTA1 och HDAC1 proteinerna i NuRD komplexet. Detta var ett första steg i undersökningen av det möjliga samarbetet mellan PWWP2A proteinet och NuRD komplexet. Nu när man vet att proteinerna interagerar kan man försöka förstå varför det gör det och därmed ta ännu ett steg i att förstå NuRD komplexets funktion. 2015 eng applied biochemistry tillämpad biokemi Technology and Engineering Chemistry 7989842 2015-09-23T21:56:34+02:00 2016-02-01T16:21:32+01:00 2016-02-01T16:21:32+01:00

oai:lup-student-papers.lub.lu.se:7991366 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 My Bratbakken Lundvall author 7991364 Johan Svensson Bonde supervisor Pure and Applied Biochemistry v1000655 department Chronic pesticide exposure has been linked to several human diseases including cancer, Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, cardiovascular disease, and kidney disease. Due to the potential risks to human health, the usage of pesticides has been a controversial topic. Paraquat (PQ), a commonly used pesticide worldwide, has toxic effects due to its generation of reactive oxygen species (ROS) in mitochondria and other cellular compartments. Mitochondria are an essential organelle in eukaryotic cells responsible for energy production, and thus it is intuitive that there exists a dedicated stress response pathway to protect their function. This study focuses on the mitochondria-associated degradation (MAD) pathway, which promotes mitochondrial protein quality control through identification, retrotranslocation, ubiquitination, and degradation of damaged, dysfunctional mitochondrial proteins. We have identified two novel proteins, Y and Z, in MAD, potentially as E3 ubiquitin ligases. Protecting Mitochondria - a Matter of Life and Parkinson’s Disease<br /> <br /> As we age, our cells accumulate oxidative damage, especially in the mitochondria. Failure to remove damaged mitochondria has been connected to severe neurodegenerative diseases such as Parkinson’s disease. Our study has revealed two proteins involved in the cellular mechanisms dedicated to protect mitochondria and maintain their fitness and health.<br /> <br /> Parkinson’s disease affects 1 out of 100 persons over the age of 60, and in most cases there is no specific known cause. However, as modern research advances, scientists find more clues to what factors may cause Parkinson’s. Recently, defects in mitochondria have emerged as a potential cause for disease.<br /> <br /> The mitochondrion is a very important part of our cells. It works as the cell’s power plant by producing energy, and it plays a central role in metabolism and programmed cell death. Due to its many important roles it is crucial for the cell to maintain the health and fitness of the mitochondria. The mechanisms of mitochondrial quality control are not well known, but are becoming increasingly interesting to scientists. One reason is that failure to remove damaged mitochondria have been connected to severe neurodegenerative diseases such as Parkinson’s disease.<br /> <br /> What causes this detrimental damage to mitochondria? During energy-production, highly reactive oxygen molecules are produced as a natural side-effect in the mitochondria. These molecules immediately react with other structures, such as proteins, fats, and DNA, causing molecular damage known as oxidative damage. Over time there is an accumulation of oxidative damage in the cell, which is the reason why many scientists argue that oxidative damage is the cause of aging. This is also the reason why food containing anti-oxidants are claimed to have anti-aging effects.<br /> <br /> As mitochondria are highly important organelles, but also the major source of reactive oxygen molecules, there are several mechanisms dedicated to reduce damage to the mitochondria. One of these is the mitochondria-associated degradation pathway (MAD). The purpose of MAD is removal of mitochondrial proteins that have been damaged, in many cases through oxidation by reactive oxygen species. In MAD, the damaged proteins are recognized and transported to the mitochondrial surface where a “degradation-flag” is attached to the damaged protein. The flag is made up of at least four ubiquitins, a small signaling protein. Due to the attached ubiquitin-flag, the damaged protein is sent to the proteasome, the protein recycling center, where it is degraded into its building blocks; amino acids.<br /> <br /> Although we have a good idea of the general principle of how MAD works, the molecular players involved are not yet identified. To study MAD we used common baker’s yeast, as yeast cells are easier to work with than human cells, but still similar enough to draw interesting conclusions from. MAD is however not particularly active during normal conditions. To increase the level of oxidative damage, and to mimic conditions of aging, we added the common pesticide Paraquat to the growth medium. Paraquat is toxic because it causes damage similar to exceptionally rapid aging. It is taken up by cells and transported to the mitochondria, where it causes the formation of massive amounts of reactive oxygen molecules. Interestingly, chronic exposure to Paraquat has also been linked to Parkinson’s disease.<br /> <br /> In our studies we knocked out yeast genes that had previously been identified as potential players in MAD. We then studied the relative health and oxidation levels of mitochondria, to see whether the gene was important to maintain general mitochondrial fitness. We also studied the amount of protein that carried the ubiquitin degradation-flag, to see whether the gene was involved in the MAD pathway. Our studies identified two proteins involved in MAD, likely acting to attach ubiquitin to the damaged proteins.<br /> <br /> Further research on these two proteins, MAD and other mitochondrial quality control mechanisms may in the future lead to identification of new therapeutic targets for treatments to prevent development of neurodegenerative diseases such as Parkinson’s. https://lup.lub.lu.se/student-papers/record/7991366/file/7991381.pdf application/pdf 954811 no 2015 eng Mitochondrial Quality Control Oxidative Stress Ubiquitin ligases Ubiquitin Yeast Parkinson's Disease Mitochondria Paraquat Oxidative Damage Superoxides tillämpad biokemi applied biochemistry Technology and Engineering Chemistry Biology and Life Sciences 7991366 2015-09-24T17:59:03+02:00 2016-01-13T15:28:12+01:00 2016-01-13T15:28:12+01:00

oai:lup-student-papers.lub.lu.se:7994828 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Malin Johansson author 7994826 Charlotta Turner supervisor Department of Chemistry v1000647 department Heptan, går det att ersätta?<br /> Mycket brandfarlig vätska och gas; irriterar hud, giftig för vattenlevande organismer med långtidseffekter, kan vara dödlig vid förtäring samt inandning.<br /> Detta är en varningstext från ett säkerhetsblad till HEPTAN, ett vanligt förekommande lösningsmedel vid kemiska analyser i Sverige. Bara i ett provupparbetningsförsök på en produkt och för en analys på ett före-tag i Sverige används 18 liter per vecka, på ett år blir det 800 liter!<br /> Vad ska vi göra för att minska eller eliminera volymen av organiska lösningsmedlen i våra analyser? Hur ska vi gå vidare- när vi vill förbättra eller utveckla nya metoder? Finns det några alternativ?<br /> En ny, gammal metod som har kommit i fokus, är att använda superkritiska vätskor, bland dessa är koldi-oxid särskilt vanlig. En superkritisk vätska är ett speciellt tillstånd som uppstår för en förening vid en kri-tisk temperatur och tryck, som är olika för olika ämnen. När man ökar trycket och temperaturen kan kol-dioxid pressas samman till en vätska. När temperaturen ökas så minskar vätskans täthet samtidigt som trycket ökar, vilket gör gasen tätare, se figur 1 nedan. Om man följer gränssnittet mellan vätska och gas i diagrammet vid ökad temperatur och tryck når man till slut den kritiska punkten vilket för koldioxid är 32°C och 72 bar. Vid den kritiska punkten övergår tvåfassystemet av vätska och gas till en fas, det så kal-lade superkritiska tillståndet. I detta tillstånd får man helt andra egenskaper än vid rumstemperatur och normal tryck.<br /> <br /> Detta projekt syftar till att undersöka ifall Superkritisk koldioxid kan ersätta heptan som lösningsmedel vid extraktion och separation för bestämning av nikotin och nikotinrelaterade substanser från nikotin-tuggummi.<br /> För att bestämma vilka nikotinrelaterade substanser som finns i tuggummi och hur mycket av dem så behöver man först extrahera föreningarna från tuggummi det vill säga att frigöra och samla upp desamma i en vätska. Idag används heptan som extraktionsvätska.<br /> Varför är då superkritisk koldioxid att föredra framför heptan?<br /> Superkritisk koldioxid har liknade lösningsmedelsegenskaper som heptan och bör därför kemiskt kunna ersätta heptan. Den superkritiska vätskans lösningsegenskaper ökar med ökad densitet som lätt kan ändras genom att ändra trycket. Superkritiska vätskor har också likt gaser lätt för att diffundera genom fasta material som tuggummi. Detta ger en utmärkt förutsättning för effektiv och snabb extraktion.<br /> Efter extraktion leds koldioxiden ner i en vätska för att samla nikotinföreningar samtidigt som trycket lättas och koldioxiden återgåt till gasfas. Nikotinföreningarna i denna lösning måste bestämmas en och en varför de separeras i en kromatograf. Det vanligaste lösningsmedel som används vid separationsprocessen består av en blandning av vatten och acetonitril. I denna studie har denna lösningsmedelsblandning också ersatts av just superkritiskt koldioxid. Vid separationen behövs också en kolonn som de olika föreningarna löser sig mer eller mindre bra i förhållande till den superkritiska koldioxiden. Detta utgör grunden för separationen då det tar olika lång tid för olika föreningar att passera kolonen innan de slutligen detekteras med en spektrofotometer.<br /> Experimenten indikerar att det är möjligt att ersätta heptan med superkritisk koldioxid vid extraktion av nikotin och dess relaterade substanser i tuggummi. Dock behöver fler studier göras innan resultaten kan erhålla någon trovärdighet. Separationssteget av nikotinstandarder med superkritisk koldioxid fungerade riktigt bra.<br /> Det som har visats i detta projekt, är att det finns andra metoder att ta till som inte kräver organiska lös-ningsmedel i den omfattning som konventionella metoder gör.<br /> Vad är det som gör koldioxid miljövänligare och ”grönt” alternativ? Atmosfärisk koldioxid trycksätts och värms för att bilda den superkritiska vätskan. Efter användning lättar men på trycket och koldioxiden återgår i gasform till atmosfären, nettosumman är lika med noll. Ingen syntes av lösningsmedel behövs, inte heller någon slaskhantering. 2015 swe Kromatografi Grön provupparbetning Superkritisk vätska extraktion Nikotin analytisk kemi analytical chemistry Chemistry https://lup.lub.lu.se/student-papers/record/7994828/file/7994835.pdf application/pdf yes 7994828 2015-09-26T15:37:45+02:00 2015-11-11T14:05:26+01:00 2015-11-11T14:05:26+01:00

oai:lup-student-papers.lub.lu.se:8053612 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Mohamad Nesrini author 8052308 Wolfgang Knecht supervisor Louise Slot Christiansen supervisor Pure and Applied Biochemistry v1000655 department Thymidine kinase 1 from tomato (ToTK1) is a newly discovered deoxyribonucleoside kinase (dNK) that has been subject to study due to its in vitro and in vivo properties making it an interesting suicide gene candidate for the treatment of brain tumors. The ToTK1 phosphorylates the nucleoside analogue 3-azido-2,3-dideoxythymidine (azidothymidine, AZT) equally well as its natural substrate thymidine (dThd). A truncated ToTK1 showed improved activity twice as high as the wild-type ToTK1, and also an increased specificity towards AZT. The combination of ToTK1 and AZT has been previously tested in two animal studies for its efficiency and use in suicide gene therapy for malignant glioma. In the present study, the C-terminal truncated version of ToTK1 (ToTK1ΔC25) has been successfully expressed in E. coli and purified by means of affinity chromatography (IMAC). Although, the purified ToTK1ΔC25 of bacterial origin displayed no significant enzymatic activity, expression was attempted in two insect cell lines, Spodoptera frugiperda (Sf9) and Trichoplusia ni (Hi5) using the baculovirus expression vector system (BEVS). Significant TK activities were detected in the crude extracts of insect cells transfected with recombinant baculoviruses bearing N- and C-terminal His-tagged ToTK1ΔC25 constructs. The findings of this project pave the way to determine the 3D structure of ToTK1 for understanding the structure-function relationships of nucleoside activation by this enzyme and thereby show routes towards further improvement of ToTK1 and other TK1-like dNKs for use in suicide gene therapy. Deoxyribonucleoside kinases (dNKs) are important enzymes in the synthesis of dNTPs, the building blocks of DNA, and also have several important applications in medicine and biotechnology. The thymidine kinase 1 from tomato (ToTK1) is a newly discovered dNK that has been subject to study due to its in vitro and in vivo properties. The ToTK1 has the ability to phosphorylate the nucleoside analogue 3-azido-2,3-dideoxythymidine (azidothymidine, AZT) equally well as its natural substrate thymidine (dThd). AZT has a safe clinical profile and can easily cross the blood brain barrier, which makes ToTK1/AZT a promising suicide gene/prodrug combination in the treatment of malignant glioma (brain tumors). The combination of ToTK1 and AZT has been previously tested in two animal studies and compared to the well-studied Herpes simplex virus thymidine kinase (HSV-TK) with ganciclovir as prodrug showing that ToTK1/AZT is a good alternative to HSV-TK/GCV. Furthermore, several mutants of ToTK1 with improved kinetic properties for AZT activation have been previously developed using random protein engineering and N- and C- terminal truncations. Interestingly, a truncated ToTK1 showed improved activity twice as high as the wild-type ToTK1, and also an increased specificity towards AZT. In the present study, the C-terminal truncated version of ToTK1 (ToTK1ΔC25) has been successfully expressed in E. coli and purified by means of affinity chromatography (IMAC). Although, the purified ToTK1ΔC25 of bacterial origin displayed no significant enzymatic activity, expression was attempted in two insect cell lines, Spodoptera frugiperda (Sf9) and Trichoplusia ni (Hi5) using the baculovirus expression vector system (BEVS). Significant TK activities were detected in the crude extracts of insect cells transfected with recombinant baculoviruses bearing N- and C-terminal His-tagged ToTK1ΔC25 constructs. The findings of this thesis pave the way to determine the 3D structure of ToTK1 for understanding the structure-function relationships of nucleoside activation by this enzyme and thereby show routes towards further rational improvements of ToTK1 and other TK1-like dNKs for use in suicide gene therapy. https://lup.lub.lu.se/student-papers/record/8053612/file/8053619.pdf application/pdf 2288549 no 2015 eng protein expression protein engineering Azidothymidine thymidine kinase deoxyribonucleoside kinases nucleosides nucleoside analog suicide gene therapy tillämpad biokemi applied biochemistry BEVS. Technology and Engineering Chemistry 8053612 2015-10-08T16:42:47+02:00 2015-10-20T15:48:09+02:00 2015-10-20T15:48:09+02:00

oai:lup-student-papers.lub.lu.se:8167025 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Michael Hellman author 8167023 Johan Svensson supervisor Pure and Applied Biochemistry v1000655 department The MICOS complex protein MicF has recently been identified to play a vital role in the mitochondrial DNA inheritance checkpoint, a control system that halts cell cycle progression in cells lacking mitochondrial DNA (mtDNA). We show in this report that another member of the complex, MicA, also plays an important role in the mtDNA inheritance checkpoint as its deletion led to cell cycle progression in cells lacking mtDNA (Rho0 cells). We observed that deletion of MicA, just like deletion of MicF, led to aggregated mtDNA in addition to the severe defects in the architecture of the inner mitochondrial membrane observed in all MICOS deletion strains. These findings lead us to believe that MicA and MicF might be involved in the signal transduction from mtDNA across the mitochondrial membranes and that their deletion leads to loss of contact sites between the membranes and thereby renders transduction across the membranes impossible. Defect in a mitochondrial protein opens up the door for a multitude of severe diseases<br /> <br /> Severe diseases such as Alzheimer’s Disease, Diabetes type II and Cancer have all been linked to one common source – unhealthy mitochondria. Mitochondria stay healthy (or self destruct if they can not) and thereby avoid these diseases with the help of its own quality control mechanism. Defects in a recently discovered protein complex called the MICOS complex have now been shown to override this mechanism, thereby opening up for these terrible diseases.<br /> <br /> Alzheimer’s disease is a sad and incurable disease, from which according to estimations by the World Health Organization (WHO) around 35.6 million people were suffering from in 2012. Unfortunately, it is estimated that these numbers will be more than tripled (115.4 million) by 2050. At the same time, the amount of people suffering from metabolic diseases such as diabetes type II is continually growing. According to WHO, an estimation of 9% above 18 years of age are suffering from diabetes, out of which 90% of the cases are diabetes type II. The fact that these numbers are huge, and even worse that they are rapidly increasing, speaks for how great the urge for getting to the root of the problem is. Finding this root to the diseases by mapping out what goes wrong in the mitochondria is probably the best way to start the search for a solution to the problem.<br /> <br /> The mitochondrion has its own DNA, called mtDNA. When the mtDNA is damaged or absent in the mitochondrion, signals are sent out to the cell nucleus that the mtDNA needs to be repaired, and if that is not possible that the cell should be killed. A mitochondrial protein complex called the MICOS complex has recently been shown to be involved in sending this signal on from the mitochondrion to the cell nucleus. How the proteins of the complex are involved has however remained unknown until now. Mapping out this unknown area is an important step in understanding how many severe diseases arise and how they can be prevented. Doing that by characterizing the role of the MICOS complex in the quality control mechanism has been the focus of my project.<br /> <br /> Mitochondria consist of two membranes. The outer membrane has a relatively smooth oval shape. The inner membrane however has a different architecture, and is formed more like a switchback road in the Alps, or like hairpin turns. The MICOS complex is located to this inner membrane. To get a better picture of what roles the 6 proteins of the MICOS complex have these proteins were deleted one by one in yeast cells. Yeast cells are much easier to work with than human cells, but are similar enough to get a good clue of the situation in humans. <br /> <br /> The effects of the protein knockouts were studied by microscopy and by looking at their growth rate as well as how they multiply. We saw that all of the proteins of the MICOS complex were important for the specific architecture of the inner membrane that is seen in mitochondria. This architecture might be important for the mitochondria to function optimally, but it does not affect the mentioned quality control mechanism. <br /> <br /> Further examination however showed that especially two of the MICOS proteins play very important roles not only for the mitochondrial architecture, but also for keeping the mtDNA healthy and for the quality control mechanism to function properly. It was seen that when any one of these proteins were knocked out, even cells that had no mtDNA continued to grow and divide even though they should have signaled for self destruction. Our conclusion drawn from this observation is that these proteins are vital for a functioning quality control mechanism by making sure that signals for self-destruction from inside the mitochondria to the outside can be sent when needed.<br /> <br /> In summary, our results showed that problems with the two most important MICOS proteins open up the door for a lot of severe diseases. Further research can hopefully figure out how problems with these proteins arise and how to avoid it, leading to prevention of tragic diseases for millions of people around the world. https://lup.lub.lu.se/student-papers/record/8167025/file/8167070.pdf application/pdf 25120601 no 2015 eng tillämpad biokemi applied biochemistry Chemistry Technology and Engineering Biology and Life Sciences 8167025 2015-11-06T14:26:30+01:00 2016-01-13T15:23:44+01:00 2016-01-13T15:23:44+01:00

oai:lup-student-papers.lub.lu.se:8167534 2025-07-29T13:03:30Z AgricultureVeterinaryMedForestry LifeEarthScience PhysicsChemistryMaths

studentPublicationsM2 My Olsson author 8167532 Eva Jonsson supervisor Studies in Environmental Science 011084000 department The process of how a maximum level is created for mycotoxins in the European Union is described here. The focus is on the mycotoxin T-2/HT-2 that is formed by Fusarium, a fungus that infects grains. T-2/HT-2 has been an issue for a long time without having a maximum level. This literature study will give an overview of how the process of creating a maximum level works. <br /> <br /> Risk analysis is the name of the process that investigates if a maximum level has to be set. The risk analysis contains several steps. One step is called hazard characterization. Here is the critical effect decided and by using the statistical method BMD a TDI of 100 ng was set for T-2/HT-2. The next step is the exposure assessment and the highest intake level within the 95 % percentile was discovered to be 91 ng. In the risk characterization the TDI was regarded as safe because it was not exceeded by any individual in the exposure assessment. The last step is called risk management and it was decided that no maximum level needs to be set but a recommendation on how the treatment of T-2/HT-2 needs to be developed. <br /> <br /> My conclusion is that it is not T-2/HT-2 itself that is hazardous but probably the total toxicity in the specific food. There is lack of data for vegan and vegetarian exposure that perhaps eat more grains than others and at the same time they are exposed for the total toxicity. It could be beneficial for the risk manager to take into consideration an ecological point of view in its assessment and not only a socioeconomic one. The toxic effect could be minimized in a sustainable way and the risk manager can contribute by sending a request to Efsa in that direction. Fara för trichotecener i spannmål?<br /> med fokus på T-2/HT-2<br /> <br /> Det går att undvika bekämpningsmedel i våra livsmedel eftersom det finns ekologiskt odlade livsmedel. Däremot går det inte att undvika mykotoxiner.<br /> De bildas av svampar. I spannmål påträffas bland annat mykotoxinet T-2/HT-2 som tillhör mykotoxingruppen trichotecener och kommer från svampsläktet Fusarium. Riskanalys är den vedertagna metoden som avgör i vilken halt ett mykotoxin är farligt för människor. Genom att följa denna process med fokus på T-2/HT-2 går det att skapa en förståelse kring hur riskbilden ser ut för mykotoxiner i EU.<br /> <br /> Riskanalysen består av riskbedömning, riskhantering och riskkommunikation. Efsa är det EU-organ som har ansvar för riskbedömningen. I den ska ett tolererbart dagligt intag (TDI) bestämmas. Det är den halt en människa kan inta utan att drabbas av en negativ hälsoeffekt. Sedan ska exponeringshalten bestämmas. Den utgår från koncentrationen i livsmedlen och våra konsumtionsvanor. Till sist jämförs TDI- värdet med exponeringshalten. Riskhanteraren, den Europeiska kommissionens uppgift är att bedöma om ett gränsvärde ska bli tillsatt. De bedömer att inget gränsvärde behövs eftersom exponeringsdosen inte överstiger TDI-värdet. Däremot behöver toxinet övervakas och förebyggande åtgärder behöver utvecklas. Riskkommunikationen handlar om kommunikationen mellan hanteraren, bedömaren och andra berörda intressenter.<br /> <br /> Den här riskanalysen grundar sig på bristfälliga studier och djurförsök. Äldre konsumtionsdata har använts och det saknas förebyggande åtgärder att begränsa förekomsten av T-2/HT-2. Riskanalysen innefattar både ett antal djurförsök och dietundersökningar vilket är omfattande och resurskrävande. Det finns även ett flertal mykotoxiner som inte har genomgått en riskanalys. Följdaktligen så verkar inte EU ha kontroll över riskbilden gällande mykotoxiner. <br /> <br /> Eftersom det finns fler toxiner än T-2/HT-2 i spannmål borde den totala toxiciteten vara mer relevant att undersöka. Forskning har utvecklat en metod att mäta den totala toxiciteten. Ett fokus på den totala toxiciteten istället för enskilda toxin hade antagligen medfört ett gränsvärde. Ett ekologiskt perspektiv saknas vid bedömningen av ett gränsvärde. Däremot finns ett ekonomiskt och socialt perspektiv inberäknat. Forskning har exempelvis påvisat att det kan finnas lägre förekomst fusariumtoxiner i ekologiska produkter samt att toxinerna är av mindre toxicitet. Om ökad forskning kunde genomföras inom detta område kan det också medföra förebyggande åtgärder. Detta skulle inte bara medföra bättre livsmedelssäkerhet utan även en livsmedelsförsörjning som är ekologiskt hållbar i framtiden.<br /> <br /> Handledare: Eva Jonsson<br /> Examensarbete 15 hp i miljö och hälsoskydd, 2015<br /> Centrum för miljö- och klimatforskning, Lunds universitet https://lup.lub.lu.se/student-papers/record/8167534/file/8167535.pdf application/pdf 542154 no 2015 swe Mykotoxin Trichotecener T-2 HT-2 Spannmål Toxin EU Efsa Europeiska kommissionen Riskanalys Biology and Life Sciences Earth and Environmental Sciences Chemistry Agriculture and Food Sciences 8167534 2015-11-08T22:12:16+01:00 2015-11-09T10:57:14+01:00 2015-11-09T10:57:14+01:00

oai:lup-student-papers.lub.lu.se:8168555 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Nada Abdulla author 8167925 Tommy Cedervall supervisor Sara Linse supervisor Department of Chemistry v1000647 department Nanoparticles (NPs) are the particles between 1 and 100 nm. They are widely used in the medical field as delivery vehicles, therapeutics and contrast agents in cancer diagnosis and treatment. There are different types of NPs divided according to the source of used materials. The agglomeration of NPs can be prevented by adding different polymers to their surfaces. The optical properties of gold nanoparticles (GNPs) make them a good system for following the behaviour of NPs in vivo. The surface properties are determined according to the purpose and type of the target. The protein layers covering GNPs is called corona. The composition of corona depends on the particle material, size and surface properties. In this study, different methods (DLS, disc centrifuge and SDS-PAGE) were used to investigate the effect of different proteins, including PGB1, IgG and plasma proteins (cow and calf) on the aggregation of GNPs and how these aggregations could be prevented. It was found that PGB1 did not aggregate the particles while IgG did and the amount of aggregation depends on IgG concentration. In addition, PBS aggregated the particles while the water stabilized them. Finally, some experiments were done on carboxylated and biotinylated GNPs trying to conjugate to PGB1 and streptavidin respectively, but the results were unclear and more studies are needed. Nanotechnology is a rapidly growing field. It includes fabrication of very small particles (nanoparticles). There are different types of nanoparticles depending on the material source. Some nanoparticles are used as a vehicle to deliver drugs to cells (e.g. cancer cells). Due to their large surface area relative to their volume, they can carry large amount of drugs. Nanoparticles can aggregate in salty solutions as in normal human blood. Specific molecules can be added to the particles surface to prevent aggregation. One of the widely used particles is gold nanoparticles. They can have different shapes like spheres and rods. One of the advantages of using gold nanoparticles is that the behavior of the particles in the solution can be detected primarily by the color. A purple colored means that small particles are stable in solution. While grey color is an indication of particle aggregation. When a particle enters blood the particle surface starts to interact with components in blood. Some components interact strongly while other interacts weakly with the particle surface. Proteins is one component in blood that often interacts with nanoparticles. Some proteins aggregate the particles and others not. Different techniques are used to measure the size of the particles in protein rich medium. Comparing the particles size naked particles in protein rich medium with protein conjugated particles, gives information about if the protein cause aggregations of the particles or not. Studying the effect of proteins on nanoparticles is important to evaluate the particle toxicity, safety, and suitability as drug carrier. https://lup.lub.lu.se/student-papers/record/8168555/file/8168556.pdf application/pdf 10819591 no 2015 eng cow serum and IgG PGB1 corona Gold nanoparticles Protein Science proteinvetenskap Chemistry 8168555 2015-11-10T14:28:39+01:00 2015-11-11T14:03:27+01:00 2015-11-11T14:03:27+01:00

oai:lup-student-papers.lub.lu.se:8168689 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Fredrik Jonsson Larsson author 8168687 bitr. universitetslektor Baozhong Zhang supervisor Centre for Analysis and Synthesis v1000651 department For the juice package to protect and keep your juice fresh it is important that the different layers in the packaging material sticks very well together. The ability for two things to stick together is called adhesion. For the people that create juice packages, this is important to measure so that the packages don’t leak. This measurement has turned out to be very tricky, but this study has shown that there might be a new method making the measurement of the adhesion possible, with the help of using plasma and ordinary super glue.<br /> <br /> How come that the juice in the package doesn’t wet and destroys the carton material and leaks out on the table? For this not to happen, the carton is covered by a really thin plastic layer, keeping the juice away from the carton. Sometimes there is a need for packages to have an extra layer between the carton and the inside plastic layer. This layer is made out of aluminum, and it is used to make sure that no sun light or air gets through the package material and makes the juice go bad.<br /> <br /> What all these carton packages has in common is that they should protect and keep the food that they contain fresh. For this to be possible, it is important that the different layers in the packaging material sticks together. The phenomenon how well two material sticks together is called adhesion. When you are using tape to stick a piece of paper to the wall, it is the adhesion between the glue on the tape and the wall that does this. Adhesion could be created in many different ways. It could be created when two materials come in close contact and the surfaces hook onto each other, but it could also be that the molecules on the surfaces attracts each other, similar to the way to magnet acts when they are close to each other.<br /> <br /> For companies producing packages and packaging material it is important to be able to measure the adhesion between the used material layers. This is to make sure that they don’t come off when they are filled with milk or juice, transported to the supermarket, and then finally used by you. To be able to measure this adhesion between the layers the material could be put into a machine that pulls the two layers apart. This has turned out be a real challenge because the plastic layer in the material won’t stick to any glue used.<br /> The aim of this project was get a metal stud to stick to the plastic layer with the help of an ordinary super glue. The material would then be put into a machine that would pull the two layers apart. For this to be possible, the adhesion between the plastic layer and the glue had to be improved.<br /> <br /> To increase the ability for the glue to stick to the plastic surface, the plastic material was treated with a very reactive gas, called plasma. This treatment was performed inside of a microwave oven where the gas was generated. This method helped to change the molecules on the surface of the plastic layer, making it attracting the glue in a similar way two magnets attracts each other.<br /> In an experiment where different layers were pulled apart, it was shown that the plasma-treated and glued samples were able to hold on to each other five times stronger than before.<br /> When the plasma-treated samples were further analyzed it turned out to be the lack of adhesion between the aluminum and the glue now limiting this new way of measuring adhesion.<br /> <br /> It also turned out that the super glue used unfortunately wandered through the thin plastic layer and affected the adhesion between the aluminum foil and the plastic layer, making the new pull test not useful. That is why a new glue must be found that does not wander through the plastic. In the future it would be interesting to look at the possibilities to increase the adhesion between aluminum foil and the glue, suggestible with a similar plasma treatment. https://lup.lub.lu.se/student-papers/record/8168689/file/8170170.pdf application/pdf 2781910 yes 2015 eng polymerteknologi polymer technology Technology and Engineering Chemistry 8168689 2015-11-11T08:48:55+01:00 2015-11-18T15:23:49+01:00 2015-11-18T15:23:49+01:00

oai:lup-student-papers.lub.lu.se:8171532 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Emma Lundin author 8171530 Margareta Sandahl supervisor Krister Severinsson supervisor Magnus Palmlöf supervisor Centre for Analysis and Synthesis v1000651 department Den första delen av arbetet gick ut på att ta fram och utvärdera en behandlingsmetod som kan användas för att på ett kontrollerbart sätt minska den specifika ytan på amorf silika med hög porositet. Den specifika ytan är en viktig egenskap för amorf silika när det kommer till dess applikationer som absorptions- och adsorptionsmaterial. Parametrarna som studerades var pordiameter, partikelstorlek, tid, temperatur och silikakoncentration. Ytminskningen var ungefär 1.0 ± 0.3 m2/g h för silika med en pordiameter på 85Å när den behandlades i 100-gradigt Milli-Q vatten upp till 24 h. Resultaten indikerade att ytminskningen var långsammare efter 24 h och 2-3 gånger långsammare när behandlingstemperaturen ändrades till 80°C. Ytminskningen skedde även långsammare när pordiametern ändrades till 110Å. De utförda experimenten visade att varken partikelstorlek eller silikakoncentration påverkade ytminskningen. <br /> <br /> Behandlingsmetodens påverkan på pordiametern, porvolymen och de kromatografiska egenskaperna undersöktes också. Behandlingsmetoden hade inte en tydlig effekt på porvolymen. Eftersom pordiametern är omvänt proportionell mot den specifika ytan så ökade pordiametern när den specifika ytan minskade.<br /> <br /> Den andra delen av arbetet gick ut på att hitta tekniker som kan användas för att studera silikans silanolgrupper. Termogravimetrisk analys (TGA) och spektroskopiska tekniker som nuclear magnetic resonance (NMR), Raman, infrared (IR) och near infrared (NIR) användes i arbetet. De olika teknikerna visade inte tydligt och systematiskt att behandlingsmetoden påverkade silanolkoncentrationen. Kromatografiska mätningar indikerade att den relativa mängden av vicinala silanoler ökade med behandlingen och NMR mätningar indikerade att geminala silanoler minskar. De kvalitativa och kvantitativa mätningarna av silanolgrupper försvårades på grund av vatten i silikaproverna. A treatment method that can be used to controllably reduce the specific surface of amorphous silica with high porosity has been developed. The specific surface of amorphous silica is important for its adsorption and absorption applications. The parameters that were studied were the pore diameter, the particle size, the time of treatment, the temperature and the silica concentration. The reduction of the specific surface for silica with a pore diameter of 85Å was approximately 1.0 ± 0.3 m2/g h when the silica was treated in Milli-Q water up to 24 h at a temperature of 100 °C. The results indicated that the surface reduction decreased after 24 h and the specific surface was reduced approximately 2-3 times slower when the temperature was changed from 100 °C to 80 °C. When the pore diameter was changed to 110Å the surface reduction rate also was slower. The experiments showed that neither the particle size nor the concentration of silica had an impact on the surface reduction. <br /> <br /> The impact of the treatment methods on the pore diameter, the pore volume and the chromatographic performance were also studied. The investigated treatment methods did not have an impact on the pore volume. Since the pore diameter is inversely proportional to the surface area the pore diameter increased when the specific surface decreased.<br /> <br /> The second part of the work consisted of finding techniques that can be used to study the silanol groups on the surface of silica. Thermogravimetric analysis (TGA) and the spectroscopic techniques nuclear magnetic resonance (NMR), Raman, infrared (IR), and near infrared (NIR) were used in this work. The different techniques did not evidently and systematically show that the treatment methods result in an increase of the silanol concentration. NMR measurements indicated that the relative amount of geminal silanols was decreased by the treatment and chromatographic measurements indicated that the relative amount of vicinal silanols was increased. The presence of water in the samples was the main problem in the qualification and quantification of silanol groups. https://lup.lub.lu.se/student-papers/record/8171532/file/8171533.pdf application/pdf 2756178 yes 2015 eng amorphous silica high porosity specific surface surface reduction silanol groups TGA NMR IR NIR Raman spectroscopy materials chemistry Chemistry https://lup.lub.lu.se/student-papers/record/8171532/file/8171535.pdf application/pdf no 8171532 2015-11-16T20:46:57+01:00 2024-03-04T11:22:23+01:00 2024-03-04T11:22:23+01:00

oai:lup-student-papers.lub.lu.se:8507055 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Petter Ekman Hyberg author 8506147 Erik Ekengard supervisor Department of Chemistry v1000647 department This bachelor project was about investigating new synthetic routes for metal complexes that are potential anti-malarial agents. The testing for anti malarial activity is to be carried out after the end of this project. The focus will thus be on presenting the laboratory work that was achieved; some synthetic strategies that can be used and further developed and some that should be avoided when synthesizing these kinds of metal complexes. <br /> It is believed that four different metal complexes with potential anti-malaria activity were successfully synthesized, of which two were pure and two needs further purification.<br /> This report describes the synthesis and structures of for the ligands L’ L1, HL2 and HL3 that were used in the attempted syntheses to form the different complexes. The routes for making the complexes (1) – (5) are thought to have been successful (complex (3) was an intermediate) and the desired complexes (6) – (10) could not be synthesized. Det här kandidatarbetet gick ut på att syntetisera ett antal olika ämnen som i efterhand ska testas för att se om de kan användas i en malariamedicin. Arbetet fokuserade således på att beskriva sjukdomen malaria, olika ämnen som skulle kunna fungera som medicin och slutligen hur dessa ämnen kan tillverkas. Det innehåller dessutom beskrivningar av några tillvägagångssätt som inte fungerar vid tillverkning av de här ämnena.<br /> Malaria är en sjukdom som orsakas av en parasit (en encelligt eukaryot) som via myggstick kommer in i människan. I kroppen bryter den ner röda blodkroppar, vilket leder till symptom såsom feber och smärta, och i värsta fall kan en malariainfektion leda till döden. När malariaparasiten bryter ner hemoglobin ifrån de röda blodkroparna frisätts haem, ett järninehållande ämne som är en del av hemoglobin och som är giftigt för parasiten. Detta sker i en så kallad födovakuol, en speciell blåsa i parasiten som fungerar som dess mage. I födovakuolen klumpas haemet ihop till en ogiftig, fast form. <br /> Klorokin är en gammal malariamedicin verkar genom att tränga in i födovakuolen och hindra att järnet klumpar ihop sig, vilket leder till att parasiten dör av haemförgiftning. Tyvärr har många parasiter på senare år utvecklat en födovakuol med en cellvägg som gör att klorokinet transporteras ut så fort det kommer in, vilket gör parasiterna klorokinresistenta. Det finns idag även en annan typ av medicin, artemesinin, men parasiterna börjar utveckla resistans mot den också. Enligt Världshälsoorganisationen är ett av de största problemen med malaria att parasiterna utvecklar resistens, och det är därför viktigt att utveckla nya mediciner. <br /> Ämnena som tillverkades under kandidatarbetet påminner om klorokin men innehöll också en metall, vilket förhoppningsvis ska göra att de fungerar på parasiter med en utvecklad födovakuol. Det finns idag ett nyutvecklat ämne som heter ferrokin, vilket påminner om en klorokinmolekyl som är kopplad till en järnatom. Ferrokin kan döda malariaparasiter även om de har en utvecklat klorokinresistans, men ämnet är så pass ny att det ännu inte används som medicin eftersom det fortfarande forskas på det. Detta visar dock att en gammal icke-fungerande medicin kan fungera igen om den görs om så att den innehåller en metall. <br /> Att en medicin innehåller metall är en ganska ny idé, det finns idag endast ett fåtal mediciner som gör det. Eftersom det förmodligen finns så mycket nytt att upptäcka är det därför ett spännande område att utforska inom kemin.<br /> Under arbetet testades att sammanfoga metallerna rutenium, rodium och renium men några organiska molekyler som påminner om klorokin. Resultatet blev att totalt fyra olika molekyler som inte tidigare har gjorts tillverkades: Två som innehöll rodium och två som innehöll renium. Dessa kommer förhoppningsvis att kunna testas för att se om de biter på malariaparasiter med klorokinresistans. Inga fungerande sätt att tillverka specifika molekyler som innehöll rutenium hittades. En anledning till detta är att rutenium kunde bilda många olika föreningar på en gång då det reagerades med en organisk molekyl. Dessutom katalyserade rutenium nedbrytandet av vissa molekyler som metallen var tänkt att bilda föreningar med. https://lup.lub.lu.se/student-papers/record/8507055/file/8507064.pdf application/pdf 1238966 no 2015 eng oorganisk kemi inorganic chemistry renium rhodium ruthenium chloroquinolin Malaria metal complexes Chemistry 8507055 2016-01-05T10:41:33+01:00 2016-01-13T14:44:52+01:00 2016-01-13T14:44:52+01:00

oai:lup-student-papers.lub.lu.se:8514032 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Samuel Butler author 8514030 Johan Svensson Bonde supervisor Pure and Applied Biochemistry v1000655 department The use of fusion proteins has become prevalent within<br /> biotechnical applications, offering a method of supplementing a protein<br /> with physical or chemical properties inherent to multiple full size proteins<br /> or peptides. The thesis work presented in this report was designed to<br /> attempt such a fusion, between a recombinant human amelogenin and a<br /> fungal cellulose binding domain peptide.<br /> The extracellular matrix protein, amelogenin is commonly<br /> associated with early tooth development and enamel formation in a large<br /> variety of mammals. Amelogenin possesses a pH dependent ability to<br /> assemble into higher order structures comprised of a large amount of<br /> protein molecules, and depending on experimental conditions, this nanostructure<br /> may be a spherical or rod-like shape.<br /> Cellulose binding domains, or CBDs, are peptides generally<br /> present on cellulose degrading enzymes, cellulases, and afford the enzyme<br /> an increased affinity for insoluble cellulose, through a semi-permanent<br /> adsorption.<br /> This report has been focused on attempting a fusion protein of<br /> amelogenin and a CBD, herein referred to as rh174CBD, and<br /> determining changed, retained and supplemented protein properties.<br /> Amongst these analyses are: pH dependent solubility, the quaternary<br /> structure formation of amelogenin and adsorption capabilities to cellulose.<br /> rh174CBD presented changed solubility characteristics when<br /> compared to the non-tagged analogue, rh174. The solubility profile was<br /> shifted towards higher pH, resulting in a comparably low solubility at<br /> physiological pH.<br /> A dynamic light scattering analysis on the rh174CBD provided<br /> evidence of an inability to assemble into nano-spheres at previously<br /> studied, physiological pH. However, at alkaline pH, the fusion protein<br /> assembled into particles, highly similar in size to those of rh174.<br /> ii<br /> Analyses of the protein’s ability to adsorb to cellulose have shown a<br /> clear trend in which rh174CBD adsorption to cellulose greatly surpasses<br /> that of rh174. Furthermore, the experimental details have been analysed<br /> to some extent, providing data, which suggests that binding efficacy is<br /> increased at alkaline pH.<br /> Adsorption ability of protein mixtures containing both rh174CBD<br /> and rh174 were assessed, resulting in adsorption averages exceeding those<br /> of the summed subset contributions of rh174CBD adsorption percentage<br /> and non-specific binding.<br /> The results present conclusive evidence of the ability to create a<br /> functional amelogenin fusion protein. rh174CBD remains stable and<br /> functional at highly alkaline pH and retains its inherent ability of nanoparticle<br /> assembly. Furthermore, this report provides the first conclusive<br /> evidence of compound amelogenin nano-sphere assembly, comprised of<br /> tagged and non-tagged amelogenin. Hence, the results provide a proof of<br /> concept for future functionalization of amelogenin nano-spheres,<br /> consisting of various tagged protein types. Proteiner är kroppens byggstenar och verktyg, som bland annat<br /> bygger upp håret på vårt huvud och ser till så att vår matsmältning fungerar,<br /> men det är långt ifrån allt. Denna mångfald bland proteinerna har lett till<br /> att man börjat använda dem inom en mängd olika områden, dels för att<br /> effektivisera gamla metoder, men också till helt nya produkter.<br /> För att producera proteiner som har förmågan att revolutionera<br /> dagens industri, teknik och sjukvård, använder sig många forskare av<br /> tekniker som kan förflytta genetisk kod, DNA, från en levande organism,<br /> till en annan. På detta sätt kan man få en bakterie eller jästcell att tillverka<br /> ett nyttigt protein som vi sen kan använda. På så sätt kan man idag till<br /> exempel producera insulin, för vård av diabetiker, på ett effektivt och säkert<br /> sätt.<br /> En möjlighet som uppstår från denna typ av forskning är att skapa<br /> nya, sammansatta proteiner, s.k. fusionsproteiner, som genom<br /> sammanfogning kan få egenskaper från de båda ursprungsproteinerna. Det<br /> presenterade examensarbetet designades med avsikt att utvärdera ett sådant<br /> fusionsprotein, bestående av proteinet Amelogenin och en kort<br /> proteinkedja, en peptid, med förmågan att fästa till cellulosa, ursprungligen<br /> från ett annat protein.<br /> Bland alla de olika proteiner som skapas i våra kroppar finns det<br /> ett protein som kallas för Amelogenin. Detta protein utsöndras från celler i<br /> vår käke när vi som barn får tänder, och proteinet bidrar till att skapa<br /> emaljen som gör ytan på våra tänder så hård. Förutom detta har forskare<br /> upptäckt att Amelogenin bildar små sfärer som inte är mer än 30<br /> nanometer breda, det vill säga 30 miljonte delar av en millimeter. Dessa<br /> sfärer är alltså vad man skulle kunna beskriva som biologiska nanopartiklar.<br /> Den korta proteinkedjan som binder till cellulosa kommer<br /> ursprungligen från ett protein som bryter ner cellulosa, en huvudsaklig<br /> beståndsdel i växter och träd. Den använda peptiden binder in till<br /> cellulosan och gör på så sätt att ursprungsproteinet kommer tillräckligt nära<br /> och håller sig kvar tillräckligt länge, för att bryta ner växtmaterialet. Denna<br /> typ av peptid kallas också för Cellulosa Bindande Domäner, CBD’er.<br /> <br /> Fokus<br /> <br /> Fokus i denna rapport låg i att skapa fusionsproteinet rh174CBD,<br /> bestående av Amelogenin och en CBD, samt att utvärdera förändrade,<br /> bevarade och förvärvade egenskaper hos det nya proteinet. Dessutom<br /> undersöktes möjligheten att skapa en nanopartikel bestående av både de nya<br /> och de ursprungliga Amelogenin proteinerna.<br /> <br /> Resultat och diskussion<br /> <br /> Det finns två intressanta egenskaper hos Amelogenin som<br /> undersöktes för det nya proteinet. Den ena är den, tidigare nämnda<br /> förmågan att bilda nanosfärer, den andra är hur lösligt proteinet är i olika<br /> sura eller basiska vätskor. Utöver dessa bedömdes också fusionsproteinets<br /> förmåga att binda in till cellulosa och om det tillsammans med vanligt<br /> Amelogenin kan skapa nanosfärer bestående av de båda proteintyperna.<br /> Jämfört med det normala Amelogeninet hade den förändrade<br /> varianten en lägre löslighet vid fysiologiskt pH, det pH som finns i den<br /> mänskliga kroppen. Dessutom bildades inga nanosfärer av fusionsproteinet<br /> vid detta pH-värde. Däremot ökades lösligheten vid högre pH och<br /> dessutom bildades nanosfärer med samma storlek som man förr sett hos<br /> vanliga Amelogenin.<br /> När kraven för bildandet av nanosfärer hade bestämts testades<br /> förmågan att binda in, adsorbera, till cellulosa. Testerna visade att<br /> nanopartiklar skapade med fusionsproteinet kunde adsorbera till cellulosa<br /> med i genomsnitt 80 procents effektivitet. Detta jämfördes med vanligt<br /> Amelogenin som bara band in med 5 procent under samma<br /> omständigheter.<br /> Om man blandar de båda proteinerna och sen ökar pH skapas<br /> sammansatta nanopartiklar, bestående av de båda proteintyperna. Detta<br /> bestämdes med hjälp av ett flertal tester, och det experiment som slutligen<br /> fastställde slutsatsen framställs i figurerna nedan. I den första figuren visas<br /> minskningen av obundet protein i vätskan runt cellulosan. Denna<br /> minskning innebär att protein bundit in till cellulosan och i figuren ser man<br /> att när andelen av fusionsproteinet ökar i blandningen ökar också andelen<br /> adsorberat protein. I den andra figuren ser vi istället procentandelen bundet<br /> protein för de olika blandningarna och jämför det med den förväntade<br /> adsorptionskurvan, som baseras på de genomsnittliga inbindningseffekterna<br /> från de båda proteinerna. På detta sätt bevisas att den genomsnittliga<br /> mängden adsorberat protein är högre än summan av den bidragande<br /> faktorn från andelen rh174CBD summerat med den för ospecifik<br /> inbindning. Vilket bara hade kunnat hända om proteinerna tillsammans<br /> bildar sammansatta nanopartiklar.<br /> <br /> Figur 1. Ursprungskoncentration och koncentration av obundet protein<br /> efter inbindningsförsök av proteinblandningar med olika andelar av<br /> fusionsproteinet (överst) samt procentandel av inbundet protein<br /> jämfört mot förväntad adsorptionskurva (nederst). *Se PDF*<br /> <br /> Resultaten från detta examensarbete erbjuder fullständiga bevis för<br /> möjligheten att skapa funktionella fusionsproteiner med Amelogenin. Det<br /> skapade, rh174CBD, består och förblir funktionellt i högt basiska<br /> förhållanden, och bibehåller dessutom sin förmåga att sammanfogas till<br /> nanopartiklar.<br /> Detta arbete bidrar med de första fullständiga bevisen för<br /> skapandet av funktionaliserade nano-partiklar bestående av en<br /> sammansättning av nativt, rekombinant Amelogenin och en modifierad typ<br /> av detsamma. Därmed bestyrker dessa resultat konceptet av att i framtiden<br /> skapa biologiskt nedbrytbara, funktionella, Amelogenin nanopartiklar,<br /> bestående av ett flertal modifierade varianter av proteinet. https://lup.lub.lu.se/student-papers/record/8514032/file/8514037.pdf application/pdf 3022745 yes 2015 eng tillämpad biokemi applied biochemistry Molecular biotechnology Nano-particle Amelogenin Cellulose Binding Domain Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/8514032/file/8514041.pdf application/pdf yes 8514032 2016-01-07T22:51:27+01:00 2016-01-08T09:31:56+01:00 2016-01-08T09:31:56+01:00

oai:lup-student-papers.lub.lu.se:8516394 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Maxim Morin author 4139636 Malin Zackrisson Oskolkova supervisor Department of Chemistry v1000647 department The aim of this work was to investigate the phase behaviour of sterically stabilized colloids.<br /> Here, steric stabilization is achieved by a grafted poly(ethylene glycol) polymeric layer on the<br /> surface of polystyrene particles. This translates under good solvent conditions to colloidal<br /> particles exhibiting hard sphere behaviour, which was confirmed by static light scattering and<br /> osmotic pressure measurements. An attraction is induced by worsening the quality of the<br /> solvent by increasing the temperature and by addition of divalent salt. The resulting phase<br /> diagram, in terms of temperature and volume fraction showed the existence of two regions:<br /> the quench-induced, fast “flocculation”, boundary and another region or phase located at<br /> significantly lower temperatures. Light scattering measurements were used to determine the<br /> loci of the critical point on the binodal curve, which is otherwise not accessible due to<br /> flocculation, at a volume fraction φ = 0.07 surprisingly much lower than what is expected for<br /> similar attraction potentials. The maxima in isothermal compressibility, provided by<br /> extrapolation of the structure factor to zero scattering angle, served as an indication of the<br /> critical point. Kolloidala system används idag i de flesta industriella områden och har blivit en viktig del av människans liv. Ett vanligt krav är att systemet ska vara stabilt vilket beror till huvudsak på växelverkan, eller krafterna, mellan partiklarna. Attraktiva krafter, om de är tillräckligt starka,leder till aggregation vilket innebär att partiklarna går samman och klumpar ihop sig. För att stabilisera en lösning måste man förhindra partiklar från att komma för nära varandra. Ett sätt är så kallad sterisk stabilisering där man tar hjälp av långa molekyler, polymerer, fästa på<br /> partiklarnas yta. Dessa polymerer repellerar varandra och motverkar närkontakt mellan partiklar. Huruvida ett system är stabilt eller inte kontrolleras nu med val av lösningsmedel,med avseende på polymeren, och kan vara bra, marginella eller dåliga. Temperatur, saltkoncentration eller närvaro av lösliga polymerer är faktorer som reglerar lösningsmedlets<br /> kvalitet och, som en direkt konsekvens, partiklarnas växelverkan och beteende i lösning. I det här arbetet har stabiliteten hos sterisk stabiliserade polystyrenpartiklar studerats som funktion av temperatur och divalent salt. Sterisk stabilitet försäkras genom att ha<br /> polyetylenglykol (PEG) kemiskt fäst på partiklarnas yta, så kallad PEGylering. PEG är en polymer som har väldigt hög löslighet i vatten vid rumstemperatur, men vatten är inte ett alls ett bra lösningsmedel vid högre temperaturer vilket slutar i fasseparation. Det inversa temperaturberoendet hos PEG används här till att reglera stabiliteten för partiklarna och på det sättet omvandla repulsivt sterisk lager till attraktivt vilket resulterar i en reversibel<br /> aggregation som benämns flockulering. Flockulering är ett diffust begrepp som inte passar in i termodynamiskt framräknade fasdiagram. Huruvida en sådan övergång är en jämnviktegenskap är oklart. Vi har här visat på ett mycket rikare fasdiagram för sterisk stabilisering. Nu uppvisas istället två flockuleringsregimer vid låga koncentrationer samt den<br /> välbekanta binodala gas- vätskeseparationen vid högre koncentrationer inklusive positionen av den kritiska punkten för PEGylerade partiklar som dyker upp vid en oväntat låg koncentration. https://lup.lub.lu.se/student-papers/record/8516394/file/8516431.pdf application/pdf 23415723 LU/LTH access 2015 eng phase diagram steric stabilization attractive colloids Physical chemistry Collidal chemistry short-range attractions nanokemi Organizing molecular matter Chemistry 8516394 2016-01-11T10:59:08+01:00 2016-01-13T14:53:35+01:00 2016-01-13T14:53:35+01:00

oai:lup-student-papers.lub.lu.se:8521229 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Benedikt Kugler author 8520900 Ebbe Nordlander supervisor Department of Chemistry v1000647 department High-spin oxoiron(IV) complexes are often postulated as intermediates in the catalytic cycle of nonheme iron oxygenases. Their C−H bond cleaving ability is attributed to the highly reactive quintet (S = 2) spin state. However, as of today, there are very few synthetic complexes that enforce the high spin state and even fewer that retain a high reactivity. <br /> In this study, a new tripodal tetradentate {N4} donor ligand has been synthesized, based on the TPA (TPA = tris(2-pyridylmethyl)amine) framework, 2-(Pyridin-2-yl)-N-(pyridin-2-ylmethyl)-N-(quinolin-2-ylmethyl)ethane-1-amine (L1 (5)), where one pyridyl arm has been substituted by a corresponding quinoline-containing moiety and a methylene linker was introduced to another. The ligand was analyzed by 1H and <br /> 13C NMR, as well as high resolution mass spectrometry.<br /> The complex [FeII(CH3CN)(L1)]2+ was synthesized and characterized by 1H NMR, UV-vis spectroscopy and high resolution mass spectrometry. The corresponding ruthenium complex [RuII(CH3CN)(L1)]2+ was synthesized and characterized by <br /> 1H NMR to gain further insight into the metal-ligand binding. An attempt was made to obtain the ferryl complex [FeIV(O)(L)]2+ by oxidation with iodosylbenzene, but the desired species could not be observed by spectroscopic means. Metal centers play an important role in biological systems. As parts of enzymes, they catalyze (i.e. speed up) a number of essential reactions. These reactions are often accompanied by various changes at the metal center. Therefore, an analysis of the sub-steps may grant further insight into the biological process. Because these snapshots cannot be isolated from nature, it is the task of Bioinorganic Chemistry to create model systems. The goal of this project work was to synthesize one such model system of a crucial intermediate found in nonheme iron oxygenases, namely an iron(IV) complex with a terminally bound oxido (O2-) ligand, and to assess its electronic state. 2016 eng inorganic chemistry oxygenases high spin oorganisk kemi iron KEMP32 bioinorganic chemistry Chemistry 8521229 2016-01-15T12:02:04+01:00 2016-02-01T16:23:24+01:00 2016-02-01T16:23:24+01:00

oai:lup-student-papers.lub.lu.se:8521798 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Henric Helgesson author 8521796 Marcus Abrahamsson supervisor Division of Risk Management and Societal Safety v1000224 department Risk Management and Safety Engineering (M.Sc.Eng.) v1000311 department Föroreningar från metallurgiska processer som sprids genom skorstenar och ventilationssystem är ett välkänt problem inom metallurgisk industri. På senare tid har även spridning av föroreningar i form av damm uppmärksammats som ett problem. Föroreningarna uppstår troligen från diffusa källor, vilket innebär att de inte kan härledas till en specifik punktkälla. Detta arbete uppstod som en följd av att Boliden Bergsöe AB i Landskrona fick avslag sin ansökan om att öka produktionen på grund av att mark- och miljööverdomstolen ansåg att Bergsöe inte kunde påvisa att de kunde hålla nere spridningen av föroreningar genom damm vid ökad produktion. Detta arbete har haft som mål att ta fram viktiga aspekter till en metod för att kontrollera damm i samband med metallurgiska processer. <br /> Arbetet inleddes med en litteraturstudie om hur damm kontrolleras inom industrin och inom metallurgiska processer. Litteraturstudien användes därefter som underlag för att kunna analysera intervjuerna. Därefter genomfördes en intervjustudie med anställda på Boliden Bergsöe för att kunna besvara rapportens huvudfrågeställning: vilka viktiga aspekter bör beaktas vid utformandet av en metod för att kontrollera damm i samband med metallurgiska processer. Boliden Bergsöes smältprocess har fått representera metallurgiska processer i rapporten och anställda med olika kompetens intervjuades under intervjustudien. <br /> Resultatet från litteraturstudien visade att det fanns en del kända källor till farligt damm inom metallurgisk industri. Materialet var däremot begränsat och det finns inga väletablerade standarder eller riktlinjer för hur dammet ska kontrolleras. Detta ledde till att hur damm minskas industriellt studerades för att kunna applicerade detta inom metallurgiska processer. Resultatet från intervjustudien visade att en del källor till damningen stämde överens med det som framkommit i litteraturstudien men att det även fanns platsspecifika källor på Boliden Bergsöe. Litteraturen belyste även att damningen inte enbart minskas utifrån införandet av tekniska åtgärder. En samsyn inom organisationen belyses vilket är beroende av ledningens engagemang i frågan.<br /> En del svårigheter och utmaningar lyftes fram av de intervjuade där en av de främsta svårigheterna var att dammet uppstår från många olika källor. Detta beskrivs göra det svårt att kunna härleda dammet tillbaka till ursprungskällan och att veta hur mycket varje enskild källa bidrar till den totala damningen. En metod konstruerades inte under detta arbete utan resultatet presenterades i form av en redovisning av viktiga aspekter. <br /> I diskussionsavsnittet diskuterades hur väl frågeställningarna besvarades och hur väl Boliden Bergsöe representerar metallurgiska processer. Pollution in the metallurgical industry has been a well-known problem in terms of dispersal through stacks and ventilation systems. In recent times attention has been drawn to fugitive dust emissions as a pollution problem. This paper aims to illustrate important aspects to develop a method to control dust emissions. The method of this report consisted of a literature and an interview study. The results showed some known sources of dust in the metallurgical industries but the material was limited. The literature highlighted the importance of good risk management to reduce dust emissions. The result from the interview study presented sources to dust emissions and how it could be reduced. Also, problems were highlighted where one of the biggest difficulties was described as identifying each single dust source and knowing how much each dust source emitted. The criteria’s presented in this report are to be used in the construction of a method to satisfy the needs of the organization in question. Spridning av metaller till omgivningen sker i form av damm från metallurgiska processer<br /> <br /> En av de främsta svårigheterna med att minska uppkomsten och spridningen av damm från metallurgiska processer är att de uppstår från så kallade diffusa källor. Vilket innebär att de inte uppstår från en specifik punktkälla utan många olika källor och kan sedan spridas på en rad olika sätt. Detta försvårar arbetet med att minska spridningen vilket gör att det kan vara lämpligt att bygga in större delar av produktionen för att på så sätt få kontroll på dammet och kunna rena luften innan den når omgivningen. <br /> <br /> Detta är ett problem eftersom damm som innehåller metaller kan ha en skadlig effekt på både människan och miljön vid exponering. Problemet har bland annat uppmärksammats i Landskrona där det sekundära blysmältverket Boliden Bergsöe AB har fått avslag på sin ansökan om utökad produktion, då mark- och miljööverdomstolen i Landskrona ansåg att spridningen av metallhaltigt damm inte kunna hållas nere i tillräckligt stor utsträckning.<br /> <br /> Resultat i rapporten visar på att det finns en del kända källor till dammning inom metallurgiska processer som hantering av torrt och pulverformigt material, som ett resultat av förbränningsprocesser eller där flytande metaller exponeras för luft. Men dessa täcker däremot inte in alla. Detta leder till att en väl utformad mätmetod behövs tas fram för att i ett första steg kunna identifiera dammet. Damm är per definition partiklar i storleksintervallet 1-150 mikrometer i diameter. Damm av den mindre storleksordningen går inte att se med det mänskliga ögat vilket gör det missvisande att identifiera damm genom synen. Meteorologiska förhållande påverkar en mätmetod med vindriktningar, vindhastigheter och nederbörd. Vilket leder till att det tar lång tid innan tydliga trender kan urskiljas från mätresultaten. I nästa steg behöver dammet analyseras med avseende på sammansättning eftersom allt damm inte är skadligt för människan och miljön.<br /> <br /> För att minska uppkomst och spridningen av damm kan det vara lämpligt att använda strategin att attackera dammet så nära källan som möjligt. Denna strategi är vanlig att tillämpa generellt inom industrin för att minska damm. Att utveckla åtgärdsstrategier vid transporten av dammet som bevattning för att hålla dammet nere på marken åtgärdar bara problemet för stunden. På så sätt anses det vara mer effektivt att härleda dammet tillbaka till källan för att åtgärda den där som med att inkapsla den eller att eliminera den helt.<br /> <br /> För att effektivt minska dammningen kan det vara lämpligt att inte enbart fokusera på införandet av olika tekniska åtgärder som till exempel bevattning för att hålla dammet nere på marken. Andra aspekter som arbetare i produktionen har en viktig roll då hur de utför sina arbeten påverkar spridningen av dammet. På så sätt är nyckeln till att effektivt minska damningen att skapa en samsyn inom organisationen där alla arbetar mot samma mål. Ledningens roll kommer in i bilden genom att visa engagemang för att kunna skapa denna samsyn.<br /> <br /> Resultatet i arbetet baseras på en litteraturstudie och en fallstudie. Fallstudien utfördes på Boliden Bergsöe vilket och resultatet har därefter generaliserats för att kunna tillämpas på andra fabriker inom metallurgisk industri. Framställningen på Boliden Bergsöe sker på ett pyrometallurgiskt sätt vilket är den andra huvudgrenen inom metallurgisk industri. Detta innebär att framställningen sker under torra förhållande jämfört med den andra huvudgrenen, hydrometallurgi, där framställningen sker under våta förhållande. Under våta förhållande menas med att framställningen sker i olika typer av lösningar. Detta medför att ur ett dammande perspektiv är resultatet bra generaliserbart till pyro metallurgiska grenen men det kan förekomma skillnader för fabriker inom den hydrometallurgiska grenen. https://lup.lub.lu.se/student-papers/record/8521798/file/8521802.pdf application/pdf 1590298 LU/LTH access 2016 swe Damm Metallurgiska processer diffus damning Technology and Engineering Chemistry LUTVDG/TVRH--5018—SE TVRH-5018 8521798 2016-01-16T08:46:17+01:00 2020-12-03T14:26:10+01:00 2016-02-01T14:03:09+01:00

oai:lup-student-papers.lub.lu.se:8564590 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Indrek Veidenberg author 8564588 Angelo Sanzone supervisor Department of Chemistry v1000647 department Palustrine, a piperidine alkaloid, was retrosynthetically analyzed and two branches of a route to a key<br /> intermediate aziridine tried – namely, nitrene formation through UV irradiation and 1,3-dipolar<br /> cycloaddition. Neither approach gave any positive results. After this the synthesis of a model<br /> compound was attempted, but ran into unexpected problems with performing radical terminal<br /> bromination of sorbates. The project overall achieved no notable positive results. Palustrine is a substance found in a swamp plant. It is harmful to animals, and so we need to study it and its harmful effects to keep us and other animals safe. To do this, first we need to have a reasonable amount of palustrine. Extracting substances from plant matter is often expensive and uses a lot of chemicals harmful to the environment. This project aimed to develop a method to synthesize palustrine from simple molecules, so we wouldn&#39;t have to extract it from the plants. Two different ways were tried to make it. One of the ways uses heating, the other one irradiation with UV light. Sadly, neither of these ways worked and the overall result of the project was negative. https://lup.lub.lu.se/student-papers/record/8564590/file/8564621.pdf application/pdf 761271 no 2016 eng organic chemistry organisk kemi Chemistry 8564590 2016-01-21T14:28:44+01:00 2016-04-29T10:50:38+02:00 2016-04-29T10:50:38+02:00

oai:lup-student-papers.lub.lu.se:4643648 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Karin Carlsson author 4406858 Aakash Chawade supervisor Olof Olsson supervisor Department of Chemistry v1000647 department The aim of this project was to answer the question “Which proteins are responsible for cold tolerance in crown samples from oat?” Proteins were extracted from cold treated oat crown samples, purified with gel electrophoresis, trypsinated through in-gel digestion and identified in LTQ orbitrap mass spectrometer. Data interpretation involved analysis of found proteins according to functional annotation and significance for cold treatment. Optimization procedure of protein extraction and trypsination increased the average protein concentration from 3.8*103 to 2.8*104μg/ml, decreased the contamination, and thereby increased the detection quality in mass spectrometry. Data interpretation found 136 proteins that varied significantly over time of cold induction in the cold-hardy oat lines LPWH and Win/Nor, 105 proteins in intermediate-cold-hardy oat lines CIAV and Gerald and 193 proteins in non-cold-hardy oat lines Belinda and Stork. When 88 cold genes annotated from proteins in hardy oat lines were compared with a list of 164 known cold induced genes, none of the gene overlapped. This means that new cold-associated proteins may have found in this project that had not been studied before. En studie över havres köldtoleranta proteiner<br /> När vintern kommer får djur och människor tjockare päls eller byter till varmare kläder. Det kan inte växter göra! De måste anpassa sig genom att ändra vilka molekyler som uttrycks. Proteiner är en slags molekyl som kan göra växter mer motståndskraftiga mot kylan. <br /> Havre kan anpassa sig till kallt klimat, men olika sorter är mer eller mindre köldtåliga. Vissa havrelinjer kan klara en mild svensk vinter medan andra måste planteras på våren för att överleva. Det här projektet studerar vilka proteiner som uttrycks i både vinterhärdiga och mindre vinterhärdiga havrelinjer. Förhoppningen är att på sikt skapa en köldtålig svensk havresort. <br /> Generellt kan man säga att växter drar upp näring och vatten genom sina rötter för transport till de övriga delarna. Bladen får vatten genom rötterna och använder solljus och koldioxid för att skapa socker. Genom näringsämnen i jorden, vatten och solljus får växten allting den behöver för att klara sig. När vintern kommer sjunker temperaturen och det blir svårare att överleva. Mer solenergi fångas upp av bladen än vad som kan omvandlas till socker. Överskottsenergin omvandlas till farliga molekyler. Dessa molekyler kan förstöra solfångarsystemet i växten. De kan också angripa cellväggarna och få dem att läcka. <br /> Havre har en speciell taktik för att klara vintern. När temperaturen sjunker vissnar växten ner och bara en liten underjordisk del överlever. Denna del kallar för kronan och från den kan hela växten återskapas när våren kommer. <br /> När temperaturen sjunker ännu mer kan marken frysa och is bildas på växtvävnader som kronan. Isen drar ut vatten från växtens celler. Det gör att cellerna krymper ihop. De krympande cellerna kan få en annorlunda struktur och har svårt att återfå sin normala storlek. När isen smälter suger cellerna åt sig vatten igen, men kan inte växa och går istället sönder. Vissa växter kan anpassa sig till ett kallt klimat, andra klarar inte omställningen. <br /> En havrelinje som kan anpassar sig till kyla kan använda sig av speciella proteiner. Proteiner som stabiliserar cellväggen så att de inte krymper av is. Proteiner som förhindrar att is bildas på växtens vävnader. Dessa proteiner har studerats under projektet och dessa proteiner kan användas för att skapa en svensk vinterhärdig havresort.<br /> <br /> Det här var projektet:<br /> * Proteiner utvanns från nerkylda havreplantor, renades från andra ämnen och identifierades<br /> * Protein-uppreningsprocessen optimiserades för att få fler och renare proteiner<br /> * Renade proteiner analyserades för att förstå deras biologiska inverkan i köldtolerans<br /> <br /> Slutsatser:<br /> * Optimiseringen gav högre proteinkoncentrationer och fler proteiner som kunde identifieras<br /> * Proteinerna i de köldhärdigaste havrelinjerna jämfördes med tidigare forskning och ingen av de hittade proteinerna hade kopplats till köldtålighet tidigare. https://lup.lub.lu.se/student-papers/record/4643648/file/4643649.pdf application/pdf 1268408 yes 2014 eng biokemi biochemistry Chemistry 4643648 2014-09-09T13:30:59+02:00 2014-09-12T16:38:25+02:00 2014-09-12T16:38:25+02:00

oai:lup-student-papers.lub.lu.se:4645225 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Marcel Ollila author 4646341 Malin Zackrisson supervisor Department of Chemistry v1000647 department The aim of this work was to investigate the phase behavior of attractive model colloid particles. The attractions is imposed by having a layer of poly(ethylene glycol) (PEG) polymers grafted to the surface which provides steric stabilization in water. Raising the temperature decreases the solvency of the PEG layer, and combined with addition of a salt containing a divalent anion, causing particles to aggregate reversibly. A detailed phase study was undertaken pointing to a time-dependence of the locus of the flocculation boundary and a &quot;true&quot; location appearing at a significantly lower temperature as first anticipated. The lowering of the boundary is mostly pronounced at lower volume fractions. The existence of the Widom line in the phase diagram was investigated using both Small-angle X-ray Scattering (SAXS) and 3D Light scattering (3D-DLS/SLS). The Widom line is a second order phase transition and considered to be an extension of the critical point. A more complex phase diagram for water-borne thermal colloids is presented, including a preliminary Widom line, with a subsequent position of the critical point, at a surprisingly low particle concentration in terms of volume fraction. The Widom line is, to our knowledge, for the first time experimentally located. Kolloida partiklar är små partiklar i nanostorlek. Dessa har många användningsområden och har ofta viktiga funktioner i till exempel bläck till skrivare och i färger. I dessa är det väldigt viktigt att kunna kontrollera stabiliteten av partiklarna. En metod för att få stabila lösningar är sterisk stabilisering vilket är till exempel den metod mjölkens partiklar är stabiliserad med. Sterisk stabilisering går ut på att partiklarna är täckta med ett lager polymerer, långa molekylkedjor. Dessa kedjor lägger sig som en borste runt partikeln vilket gör det svårt för partiklarna att komma nära varandra, precis som när man försöker pressa två täta borstar mot varandra. I vissa användningsområden vill man att lösningen är stabil, så att dem inte klumpar ihop sig, aggregerar. I andra tillfällen behöver man kanske styra stabiliteten mellan en stabil lösning och en aggregerad lösning för att till exempel koncentrera upp lösningen. För att kunna åstadkomma detta är det viktigt att känna till partiklarnas fasbeteende, i vilken form de existerar vid olika betingelser som t.ex. temperatur och koncentration.<br /> Vår undersökning går ut på att studera små nanopartiklar, cirka 50 nm i diameter, stabiliserade med hjälp av ett lager med vattenlösliga glykolpolymerer (PEG), så kallade PEGylerade partiklar. Dessa PEG polymerer har en mycket underlig egenskap i att de är mindre lösliga i vatten vid högre temperaturer. Eftersom partiklarna är täckta med denna polymer minskar stabiliteten hos partiklarna när temperaturen höjs, och vid tillräckligt hög temperatur, aggregerar. Denna aggregering är fullt reversibel. Sänker man temperaturen löser sig partiklarna igen, vilket kan göras om och om igen. Teoretiska modeller har visat att liknande nanopartikar ska kunna fasseparera, d.v.s. övergå i en fas med hög koncentration i jämnvikt med en fas med låg koncentration. Detta betyder att det ska finnas en kritisk punkt, vilket är den punkt vid den lägsta temperatur och en viss koncentration vid vilken partiklarna börjar fasseparera. Att förstå var denna finns är viktigt för ökad förståelse för partiklarnas växelverkan och fasbetende. Denna punk är det ingen som har experimentellt visat var den finns, dessutom, med den hör Widomlinjen som inte heller har fastställts experimentellt, för något system.<br /> De PEGylerade partiklarna karaktäriserades gällande form, lagertjocklek och storlek med ljusspridning och lågvinkelröntgenspridning. Partiklarnas fasbetende studerades noggrant och med hjälp av statisk ljusspridning har vi för första gången indikationer på var den kritiska punkten finns och den medföljande Widomlinjen. https://lup.lub.lu.se/student-papers/record/4645225/file/4645226.pdf application/pdf 1603194 yes 2014 eng Fysikalisk kemi Physical Chemistry Chemistry 4645225 2014-09-10T08:09:04+02:00 2014-09-12T16:37:25+02:00 2014-09-12T16:37:25+02:00

oai:lup-student-papers.lub.lu.se:4645231 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Manjuma Asheka author 4646340 Per-Åke Albertsson supervisor Sinan Cem Emek supervisor Department of Chemistry v1000647 department In earlier studies it was revealed that thylakoid membranes inhibit activity of pancreatic lipase/colipase. More studies have shown that these membranes induce satiety hormone CCK and reduce hunger hormone of rats and human. Appethyl® used in this project is processed from spinach leaves in such a way that it reserves most amounts of thylakoid membranes. The results, in this project, shows that Appethyl® can inhibit the activity of lipase/colipase after digestive treatment. Separate reactions indicate highest inhibition capacity of Appethyl® after pepsin and gastric juice digestion. The positive thing is that, Appethyl® shows inhibition capacity on lipase/colipase even after treatment with pepsin, trypsin, pepsin/ trypsin, gastric juice (GJ), pancreatic juice(PJ), gastric/pancreatic juice. Treatment with GJ followed by long time in PJ also does not affect the thylakoid membranes present in Appethyl®. This conclusion was based on SDS-PAGE electrophoresis gel picture with Appethyl® incubated 45 minutes in GJ and 0-6 hours in PJ. This is also supported by the result of inhibition capacity by Appethyl® as 36%- 31% after GJ /PJ treatment. SDS-PAGE gel treated and untreated Appethyl® showed that there were protein bands at the MW position for LCH II and Rubisco large chain and Rubisco small chain. Fat digestion refers to breaking down of lipid to free fatty acids; this process is termed as lipolysis. Lipolysis includes a reaction between lipase enzymes and triacylglycerol, where lipase is activated by its coenzyme colipase and colipase is activated by bile salt which is secreted from gall bladder in the form of bile acid. Free fatty acids are absorbed by body; releasing less fatty acid is related to less absorption. This releasing process can be made slow by inhibiting lipolysis in presence of bile salt. In earlier studies, it was observed that lipolysis can be delayed by thylakoid membranes. Thylakoid membranes were extracted from chloroplast of plant leave cells. Other studies have shown that these membranes induce satiety hormone CCK and reduce hunger hormone ghrelin. Pure thylakoid membranes are extracted mechanically with chemicals and can inhibit lipolysis up to 80%. Appethyl® is a powder form of thylakoids which is also extracted from plant leave cells, especially from spinach leave cells. This product does not contain pure thylakoid membranes due to its preparation procedure but the extraction process does not involve any harmful chemical for human physiology. Additionally, it contains other cell organelles from spinach leaves. Due to the impurities it did not show the same level of inhibition capacity. The positive thing is that, Appethyl® shows inhibition capacity on lipase/colipase even after the treatment with pepsin, trypsin, pepsin/ trypsin, gastric juice, pancreatic juice, gastric/pancreatic juice. In conclusion, Appethyl® delays fat digestion in stomach and in duodenum. This leads to delayed absorption of fat by the body. Treatment with gastric juice followed by a long time in pancreatic juice also did not affect the thylakoid membranes present in Appethyl®, this conclusion was based on Appethyl® incubated for 0-6 hours in pancreatic juice after 45 minutes incubation in gastric juice. This indicates that Appethyl® stays a long time in duodenum, and remains almost undigested and thus works better. https://lup.lub.lu.se/student-papers/record/4645231/file/4645232.pdf application/pdf 915141 yes 2014 eng biokemi biochemistry Chemistry 4645231 2014-09-10T08:29:26+02:00 2014-09-12T16:36:39+02:00 2014-09-12T16:36:39+02:00

oai:lup-student-papers.lub.lu.se:4645245 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 David Carrasco Flores author 4646338 Evelina Kulcinskaja supervisor Johan Svantesson Sjöberg supervisor Department of Chemistry v1000647 department Microalgal feedstock are gaining more and more attention due to a wide range of potential and emerging commercial and industrial applications, from biofuel production to nutrition, cosmetics and pigment extraction among others. The presence and roles of mannans and endomannanases in three industrially relevant microalgaes were studied in this project. Chlorella vulgaris has seven putative endomannanase genes in the genome, but no activity has been detected in the experimental work and its cell wall has a low mannan content (&lt;5%). Chlorella protothecoides has similar amounts of mannan in the cell wall, but mannanase activity was detected when grown in a mannan-rich media. This mannanase could perhaps be involved in mannan uptake and degradation. Scenedesmus quadricauda seems to have endomannanase activity when grown without mannan in the media. Furthermore, an endomannanase from Bacillus cellulosilyticus with four carbohydrate binding modules and extreme optimum conditions (60ºC and pH 11) has been cloned, characterized and proven to be able to degrade the microalgal cell-wall, being a good candidate to be industrially used with this purpose. All living organisms are equipped with sets of tools that allow them to perform reactions and functions that otherwise they couldn’t accomplish because they would occur too slow or not happen at all. These powerful tools are called enzymes, and they work by catalyzing biologically relevant chemical reactions<br /> In this work, a specific type of enzymes called mannanases are studied. Mannanases are responsible of the breakdown of long and complex chains of sugars, called mannan polysaccharides, into the small primary subunits which form these complex chains. This process is similar to the one that occurs when we eat starch (a slow energy release carbohydrate), in which the small primary subunits of sugar are released by enzymes to be used as energy for our cells. The main differences between starch and mannans are the primary sugar subunits used and the bond used to link them together.<br /> Mannan polysaccharides constitute approximately 20% of the soft wood, and are one of the main residues of the paper industry which, right now, are mainly released in side-streams or waste. It thus is an enormous potential source of energy, as once the sugars are released from the complex chains they can be used with feeding purposes or biofuel production like biodiesel or biogas among others. Another, in essence unutilized, resource are the mannans present in the cell-walls of some industrial microalgaes. Mannans thus have a great potential to be established as a renewable resource and its increased utilization will contribute to a sustainable society based on the so-called “bioeconomy” which will be less dependent on fossil resources.<br /> The aim of this work is to identify and characterize mannanases from types of organisms previously not studied for this purpose. These organisms were a type of soil bacteria (Bacillus cellulosilyticus) and three microalgaes (Chlorella vulgaris CCAP211/52, Chlorella protothecoides CCAP211/8D, Scenedesmus quadricauda CCAP276/4B) where S. quadricauda was shown to have mannan in the cell wall. The mannanases may be assumed to have different functions: Either modification/modulation of endogenous cell-wall mannan (which might serve as a model for plant mannans) or degradation of environmental mannans. The latter might have properties relevant for industrial processes (e.g. conversion of plan or microalgal waste-mannans).<br /> Thus, four organisms have been involved in this study. The first of them, a soil bacteria called Bacillus cellulosilyticus, was found to have a mannanase which is able to work in really alkaline environments, temperatures as high as 60ºC, and seems to tolerate chemicals, making it a really good candidate for industrial scale processes where the normal working conditions are similar to the ones the enzyme seems to prefer.<br /> The other organisms involved in the study are microalgaes used for biofuel production, Chlorella and Scenedesmus. Its cell debris, which can be around half of its dry weight, is rich in mannan polysaccharides. At the same time, it contains mannanases which can degrade them. The interesting part of this is the possibility of using Chlorella’s own tools to degrade its cell debris, achieving a process where nothing is left behind and everything is used. There are evidences that mannanases exist in Chlorella, but more work is needed to be able to use them in industrial process as the tip of this iceberg has just been glimpsed. https://lup.lub.lu.se/student-papers/record/4645245/file/4645246.pdf application/pdf 3212987 yes 2014 eng proteinvetenskap protein science Chemistry 4645245 2014-09-10T08:51:45+02:00 2014-09-12T16:35:49+02:00 2014-09-12T16:35:49+02:00

oai:lup-student-papers.lub.lu.se:4645523 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Pegah Nosrati Hefzabad author 4646332 Ulf Olsson supervisor Manja Behrens supervisor Department of Chemistry v1000647 department Cellulose textile fibers may be an alternative to cotton if the cellulose is first dissolved in a<br /> suitable solvent followed by regeneration through spinning. Ionic liquids have been<br /> highlighted for this purpose, and in this project, an aqueous solution of tetrabutyl ammonium<br /> hydroxide (TBAH, 40 wt%) is used for the dissolution process. The resulting mixtures have<br /> been analyzed with scattering methods and light microscopy, and from the obtained results it<br /> is noticeable that the cellulose polymer changes its structure and shape with solvent<br /> concentration, and that the cellulose to TBAH ratio has an obvious effect on these properties.<br /> The structure of the solvent does not appear to be affected by cellulose addition, however,<br /> there are other matters one must take into account when using TBAH(aq) as a solvent. Under<br /> 27.4 °C the water molecules in the ionic liquid can form clathrates and the mixture can<br /> undergo crystallization, thereby significantly reducing its cellulose dissolving properties.<br /> In this study it has been established that 40 wt% TBAH in water is likely to be a good solvent<br /> for cellulose dissolution. Kläderna vi bär består till allra största del av bomull, som planteras och förädlas runtom i<br /> världen. För att kunna odla bomullen krävs det ett passande klimat, stora jordarealer och<br /> tillgång till en mycket stor mängd vatten, en kombination som har lett till att<br /> bomullsproduktionen på senare tid har stagnerat trots en ständigt ökande efterfrågan på<br /> textilfibrer och kläder. För att kunna avlasta bomullsberoendet och därmed minska<br /> påfrestningen på vår planet letar forskarna efter nya, alternativa textilfiberkällor, där cellulosa<br /> är en av dessa. Cellulosa består av en lång kedja av sockermolekyler, en polymer, som kan<br /> utvinnas i mycket stora kvantiteter från exempelvis trämassa, och har visat sig fungera som ett<br /> alternativ till textilfiber gjorda av bomull. För att kunna använda cellulosan som textilfiber<br /> måste den emellertid först lösas upp i ett passande lösningsmedel för att sedan dras ut som<br /> långa textilfibertrådar, och det förstnämnda har visat sig vara svårare än vad forskarna trott.<br /> Detta examensarbete syftar till att försöka få fram ett optimalt lösningsmedel för<br /> upplösningen av cellulosan, för att på sikt kunna bilda nya textilfibrer och på så sätt bidra till<br /> att minska bomullsberoendet runt om i världen.<br /> I detta projekt har en vattenlösning av en jonvätska (ett salt som är flytande i rumstemperatur)<br /> vid namn tetrabutyl ammoniumhydroxid (TBAH) använts för cellulosaupplösningen. För att<br /> försöka bedöma vad som sker i en lösning bestående av cellulosa och TBAH har<br /> lågvinkelspridning med röntgenstrålar använts, där strålarna får passera genom<br /> cellulosalösningen och ge information om hur det ser ut inuti provet. Även ljusmikroskopi har<br /> används för att få kunskap om lösningarnas inre.<br /> Ljusspridningsexperimenten visade att en lösning bestående av cellulosa och TBAH ser olika<br /> ut beroende på lösningsmedelskoncentrationen. Vid lägre TBAH-koncentration i förhållande<br /> till cellulosamängd kommer cellulosapolymeren att anta en mer flexibel, självavstötande<br /> konfiguration, medan höga lösningsmedelskoncentrationer ger en stelare, mer rigid<br /> cellulosastruktur. Även storleken på cellulosanystanet verkar ändras vid ändrad<br /> lösningsmedelskoncentration; Lägre koncentrationer av TBAH ger ett större cellulosanystan<br /> medan det omvända förhållandet ger ett mindre nystan. De större nystanen är svårare att lösa<br /> upp än de mindre.<br /> Vidare karaktäriserades även rena TBAH-lösningar, det vill säga lösningar utan cellulosa, för<br /> att undersöka det rena lösningsmedlets egenskaper. Det visade sig att temperaturen är av vikt,<br /> eftersom lösningsmedlet kan kristallisera vid temperaturer mellan 19.1 – 27.4 °C. Denna<br /> kristallisation beror på att vattenmolekylerna i lösningen inte kan binda till den kemiskt olika<br /> TBAH-molekylen, och därför måste binda till andra vattenmolekyler istället. Då bildas det<br /> burar av vattenmolekyler som omringar varje TBAH-molekyl, vilket leder till att<br /> lösningsmedlet antar en tjock, fast och ordnad struktur istället för den vanliga, flytande<br /> formen vi är vana vid.<br /> Experimenten visade även att 40 viktprocent TBAH i vatten fungerade som ett fullgott<br /> lösningsmedel för cellulosaupplösningen. https://lup.lub.lu.se/student-papers/record/4645523/file/4645531.pdf application/pdf 1884338 yes 2014 eng fysikalisk kemi physical chemistry Chemistry 4645523 2014-09-10T13:38:55+02:00 2014-09-12T16:34:54+02:00 2014-09-12T16:34:54+02:00

oai:lup-student-papers.lub.lu.se:4645536 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Marcus Johansson author 4646330 Dr Per-Olof Widmark supervisor Department of Chemistry v1000647 department An algorithm for point group determination using moments of inertia equivalence set partitioning and geometrical properties is described.<br /> The algorithm does not generate any symmetry operation through testing, but through deduction based on geometrical properties of an equivalence set tree, and the reduction of compatible operations of this tree.<br /> The approach can handle point group determination of large molecules, where all symmetry elements of a C720 fullerene and the biological assembly of type II 3-­‐dehydroquinase were found in 0.40 seconds and 6.6 seconds respectively. Kan en havsanemon bli konståkare?<br /> När vi tittar på en person från sidan kan vi genast skapa oss en bild av hur den personen ser ut från andra sidan, men om vi tittar bakifrån kan vi inte avgöra hur denne ser ut framifrån. Hur kommer det sig? Anledningen har att göra med symmetri. Människor har ett spegelplan som går mitt mellan ögonen, men inget som går från öra till öra. D.v.s. om man speglar den vänstra sidan ser den likadan ut som den högra. En sjöstjärna kan rotera ett femtedels varv och se precis likadan ut som om den stod stilla, en människa måste rotera ett helt varv för att göra en piruett, medan en havsanemon i princip kan rotera hur lite eller mycket som helst utan att det går att avgöra om den rört sig.<br /> Symmetri är inte bara bra för att utesluta havsanemoner från OS, utan kan också hjälpa oss att förstå var kemiska egenskaper hos molekyler kommer ifrån. T.ex. vilken färg den får, eller hur den reagerar med andra molekyler. Det underlättar också i kemiskaberäkningar som idag utförs av datorer. Om man roterar eller speglar, en havsanemon, människa eller molekyl, måste resultatet se likadant ut som innan. Genom att ta bilder från olika vinklar, kan man dela in platser där bilderna ser likadana ut i samma grupp. Man kan därmed bryta ner ett stort problem i många små. T.ex. så ser vi likadana ut från ett öra som från det andra, så öronen måste vara lika. Detta begränsar antalet möjligheter till symmetri avsevärt. För alla dessa grupper kan man sedan bestämma en allmän struktur – t.ex. plan, cigarrformad eller havsanemon.<br /> Denna allmänna struktur kan sedan användas för att leta upp symmetriegenskaper för gruppen och därefter för hela molekylen. För oss människor är det oftast ganska lätt att avgöra om något är symmetriskt -­‐ en havsanemon är rund ett bord rektangulärt och människor har spegelplan.<br /> För en dator är det däremot inte så enkelt. För den är allt bara siffror och algoritmer – en atom här, en annan där -­‐ strukturen som helhet är svår att se. Alla dessa modeller av atomer, molekyler, grupper och symmetri måste översättas till något som en dator förstår. Detta projekt går ut på att beskriva allt detta och hur man räknar på det för en dator. T.ex. vad en atom är, varifrån bilderna ska tas, hur de ska se ut och hur de representeras av några siffror eller hur man ser vilken form en havsanemon har och hur hjälper det oss bestämma om den kan delta i OS. https://lup.lub.lu.se/student-papers/record/4645536/file/4645584.pdf application/pdf 1819874 yes 2014 eng teoretisk kemi theoretical chemistry Chemistry 4645536 2014-09-10T14:00:55+02:00 2014-09-12T16:33:54+02:00 2014-09-12T16:33:54+02:00

oai:lup-student-papers.lub.lu.se:4645591 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Linda Månsson author 4646328 Peter Schurtenberger supervisor Dr Jerome Crassous supervisor Department of Chemistry v1000647 department The ability of microgels to adsorb to the interface of emulsion oil droplets has previously beenn reported in the literature.1 The resulting emulsions carry the thermoresponsiveness of the adsorbed microgels, and can be destabilized on demand by increasing the temperature above the volume phase transition temperature of the microgels. This thesis describes the synthesis and characterization of cross-linked poly-N-isopropylacrylamide (PNIPAM) and poly-N-isopropylmethacrylamide (PNIPMAM) microgels, either positively or negatively charged and fluorescently labeled through covalent incorporation of either fluorescein or rhodamine derivatives. The ability to adsorb to the oil-water interface of polydimethylsiloxane (PDMS) emulsion droplets was then studied with two of the synthesized microgels, green PNIPMAM and red PNIPAM, respectively, both positively charged. Envisioned was to form colloidal atoms with well-defined patches and thus a well-defined valency. Colloidal atoms can be used as building blocks for the construction of more advanced structures, colloidal molecules,2 with the patches directing the assembly process. Here, polydimethylsiloxane (PDMS) oil droplets were employed as anchors for microgels, which, due to the dependence of their size and interaction potential with temperature, may serve as tunable interaction sites. Aiming at forming colloidal atoms with well-defined patches, explored was the possibility to control the number of microgels adsorbed to the interface of oil droplets, this by limiting the droplet size and the surface area per droplet accessible for microgels to adsorb to. This was accomplished by mixing with microgel an emulsion of μm-sized PDMS oil droplets, prepared by polymerization of dimethyldiethoxysilane (DMDES) under basic catalysis by ammonia.3 Alternatively, microgel decoration of oil droplets was achieved by having the microgels present during the oil droplet synthesis. Microgel decoration of PDMS oil droplets was accomplished with both microgels independently, as well as both microgels simultaneously. Decoration with two microgels should offer the resulting decorated droplets the most interesting properties, considering that it now carries two different types of patches, both tunable with temperature, but with different transition temperatures. Många processer i biologiska system utförs av maskinerier som är uppbyggda av molekyler av kolloidala dimensioner, d.v.s. i storleksordningen 1 μm till 1 nm, såsom proteiner. Dessa molekyler är ofta alldeles för komplexa till sin natur för att vi ska kunna förstå de “lagar” som styr hur de kommer samman för att bygga upp avancerade strukturer med biologisk funktion. I detta syfte behöver vi skapa enklare modellsystem som efterliknar de byggnadsprocesser vi vill studera. Så kallade ”fläckiga” kolloidala partiklar är exempel på sådana modellsystem. Även inom områden såsom materialvetenskap och kolloidbaserad nanoteknologi är dessa modellsystem viktiga. I detta projekt utnyttjades mikrogelers förmåga att anrikas i ytan av oljedroppar i en emulsion, detta med målet att skapa kolloidala partiklar med temperaturresponsiva “fläckar” (Fig. 1).<br /> ”Fläckiga” partiklar benämns ofta “kolloidala atomer”, då de i likhet med atomer har specifika bindingsställen. Genom interaktion mellan “fläckar” på olika kolloidala atomer kan mer avancerade strukturer, ”kolloidala molekyler”, byggas upp. Antalet bindningsställen, vilket är detsamma som antalet “fläckar”, bestämmer hur många interaktioner varje partikel kan delta i. Detta kallas för partikelns valens.<br /> Mikrogeler, vattenfyllda kolloidala polymerpartiklar, är i dessa sammanhang särskilt passande som byggstenar. Mikrogeler är termoresponsiva, vilket innebär att de svarar på temperaturf<br /> örändringar: vid rumstemperatur är gelpartiklarna “vattenälskande” och svullna, men då man överstiger en viss kritisk temperatur blir polymeren olöslig, och den nu vattenskyende gelpartikeln<br /> krymper. Dessutom är de attraktiva krafter som verkar i riktning mot hopklumpning av gelpartiklarna större i det krympta tillståndet. Inte enbart mikrogelernas storlek, utan också attraktionen mellan dem kan således regleras med hjälp av temperaturen. Det följer att interaktionen mellan “fläckiga” partiklar, vars “fläckar” utgörs av mikrogeler, kan styras på samma<br /> vis.<br /> Detta projekt bestod av två delar. I dess första del tillverkades sex olika typer av mikrogeler. Skillnaden mellan de olika var valet av polymer, vilket påverkar den kritiska temperatur vid<br /> vilken mikrogelen krymper, och laddning (positiv eller negativ). Mikrogelerna märktes med en fluorescerande molekyl, antingen rodamin (röd) eller fluorescein (grön). Detta möjliggjorde att<br /> de kunde studeras i ett så kallat konfokalmikroskop, en typ av avancerat mikroskop som genom punktbelysning med laser och bortfiltrering av ljus som inte är i fokus, erbjuder högre upplösning<br /> jämfört med ett vanligt mikroskop. I projektets andra del studerades adsorption, d.v.s. vidhäftning, av två av mikrogelerna, båda<br /> positivt laddade men uppbyggda av olika polymerer och med olika färg, till ytan av negativt laddade oljedroppar av polydimetylsiloxan (PDMS) i en emulsion. Utmaningen var här att kontrollera antalet mikrogeler som adsorberar till varje oljedroppe, med andra ord att kunna styra antalet bindningsställen och partiklarnas valens. Detta kunde åstadkommas genom att begränsa dropparnas storlek och därmed den yta som är tillgänglig för gelpartiklarna att adsorbera till.<br /> Med denna strategi tillverkades oljedroppar, ca 2 μm i diameter och på ytan dekorerade med ett tjugotal mikrogeler. Vi hoppas att framöver kunna reducera oljedropparnas storlek ytterligare<br /> och därmed de “fläckiga” partiklarnas valens. https://lup.lub.lu.se/student-papers/record/4645591/file/4645604.pdf application/pdf 20616399 yes 2014 eng physical chemistry fysikalisk kemi Chemistry 4645591 2014-09-10T14:43:36+02:00 2014-09-12T16:32:49+02:00 2014-09-12T16:32:49+02:00

oai:lup-student-papers.lub.lu.se:4645871 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ellen Rieloff author 4646327 Emma Sparr supervisor Adriana Mihut supervisor Department of Chemistry v1000647 department This study investigates the association behavior of microgel particles onto giant unilamellar vesicles (GUVs). The GUVs composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine(DMPC), and binary lipid mixtures of DMPC:1,2-dioleoyl-sn-glycero-3-phosphocholine(DOPC)and DMPC:1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), were prepared by application of an alternating electric eld, in presence of microgel particles.<br /> Under these conditions, we nd that the microgel particles adsorb to the GUVs. To gain more insight on the interaction of these colloidal particles and lipid membranes, the particle size, softness and hydrophobicity was varied as a function of temperature, and studied with dierent lipid phases. These results show that soft particles adsorb to <br /> fluid membranes, forming two-dimensional hexagonally packed arrays at the GUVs surfaces,whereas on solid membrane, the particles partially adsorb and disordered arrangements are observed. Moreover, we establish that there is a clear preferential adsorption of soft microgel particles onto fluid membrane, illustrated by their adsorption behavior onto coexisting domains of fluid and solid membrane, in binary lipid mixture composed of<br /> DMPC:DOPC. Additionally, above the volume phase transition of the microgel particles, the now hard and hydrophobic particles experience either partial or complete wrapping.<br /> Here we notice that an additional coating of the particles with an excess of lipids, leads to adsorption of lipid-loaded microgel clusters at the GUVs surfaces. The adsorption mechanisms are reversible and can be adjusted with temperature. Vägen mot smarta läkemedel<br /> Tänk om läkemedel skulle vara målsökande, så att de bara angriper sjuka celler. Då skulle läkemedlen bli mer effektiva och ge mindre biverkningar. Om medicinen dessutom skulle kunna sätta sig på kroppens celler och långsamt släppa ut en kontrollerad dos, skulle man inte behöva ta sin medicin lika ofta. Detta kan vara på väg att bli verklighet, till exempel genom att använda nanopartiklar som selektiva medicinbärare. För att kunna tillverka sådan här smart medicin av nanopartiklar, måste man veta hur partiklarna samspelar med celler. Ibland, som i cancerbehandling, är det önskvärt att partiklarna ska gå in i cellen genom dess yttersta vägg (cellmembran), för att kunna skada cellen. I andra fall är målet att nanopartikeln ska fastna på cellmembranet, för att kunna släppa ut medicin under en lång tid. Så nanopartikeln måste designas efter önskemålen och det har redan visats att nanopartiklarnas form, storlek och sammansättning påverkar samspelet med cellmembran.<br /> Figure 1: En stor vesikel, som är en modell av ett cellmembran. Förstoringen visar hur lipiderna orienterar sig med huvudena mot vatten och svansarna inåt.<br /> Cellmembran består till största delen av lipider, som är molekyler med vattenälskande huvuden och vattenogillande svansar. I vattenlösning kan lipider bilda vesiklar, vilket är vätskefyllda blåsor där väggen utgörs av två lager lipid, med svansarna mot varandra och huvudena ut mot vattnet (se Figur 1). I denna studie framställs stora vesiklar och används som enkla modeller av cellmembran. Membranet kan precis som andra ämnen befinna sig i olika faser, bland annat en fast och en ytande fas, illustrerade i Figur 2. I den flytande fasen är det lättare för lipiderna att flytta på sig och mer av deras vattenogillande svansar är synliga. Dessutom är membranet lättare att forma och böja.<br /> Möjligheten till gynnsam interaktion för partiklarna är således olika för de olika faserna. Partiklarna som jag använder, så kallade mikrogelpartiklar, har egenskaper som varierar<br /> med temperatur. De består av långa tvärbundna molekyler och ser ut ungefär som nystan. Vid låga temperaturer är dessa nystan vattenfyllda och därmed stora, mjuka och formbara. När temperaturen höjs slutar de dock att tycka om vatten och drar ihop sig, vilket gör att de blir små och hårda som kulor.<br /> Figure 2: Fasövergang i cellmembran. I den fasta fasen ligger svansarna välpackade, så huvudena sitter tätt. I den flytande fasen har lipiderna mer rörlighet, så det är längre avstånd mellan huvudena. Ett flytande membran är mer formbart och böjligt än ett fast. Genom att undersöka samspelet mellan partiklarna och membranen vid olika temperaturer, det vill säga när de har olika egenskaper, kan man få reda vad partiklarna tycker om hos membranet. Alltså kan man få svar på frågan varför partiklarna vill sätta sig på membranet eller till och med gå igenom det. Tidigare har det varit mycket fokus på hur partiklarnas egenskaper påverkar interaktionen, men i denna studie tar vi även med membranets egenskaper, vilket ökar möjligheterna att få svaret på varför partiklar vill sätta sig på membran. För att följa partiklarna och membranets samspel används ett konfokalmikroskop, vilket påminner om ett vanligt mikroskop, men ger tydligare bilder och mindre saker kan studeras. Ett konfokalmikroskop kan också fokusera på ett plan i provet i taget, vilket innebär att man kan ta bilder i olika höjdled och sen lägga samman till en tre-dimensionell bild. Studien visade att partiklarna vill mycket hellre sätta sig på flytande membran än fasta. Hårda partiklar formar också det flytande membranet, vilket tyder på en stark attraktion. Detta ger indikationer om vad som driver partiklarna till att sätta sig på membranet, men för att helt lösa vad som styr samspelet behövs mer forskning. https://lup.lub.lu.se/student-papers/record/4645871/file/4645882.pdf application/pdf 73115019 yes 2014 eng physical chemistry fysikalisk kemi Chemistry 4645871 2014-09-11T09:04:26+02:00 2016-02-04T04:00:31+01:00 2014-09-12T16:31:49+02:00

oai:lup-student-papers.lub.lu.se:4645884 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Marcus Lockowandt author 4646325 Alak Alshiekh supervisor Department of Chemistry v1000647 department RNA interference (RNAi) plays a major role in regulation of gene expression in most eukaryotic organisms. On a basic level it is a protein complex named RNA induced silencing complex (RISC) that binds a RNA strand, a micro RNA (miRNA) or a small interfering RNA (siRNA), which guides it to its intended target, an mRNA. The RISC then disrupts translation of the bound mRNA, either by restricting it thereby causing its degradation, or through interactions with other proteins that cause a halt in translation. Mutations in these miRNAs can therefore cause dysfunction of protein regulation. This in turn can lead to a wide range of diseases 1.<br /> One of the most important issues with dysregulation of miRNAs is the correlation between aberrant miRNAs and cancer. Several different types of cancers show miRNA profiles that differ from normal cells. This can be used to determine what type of cancer a patient has, and what treatment might be the most efficient. It is also a possibility to give the patient siRNAs down regulating specific proteins that might make cancer cells more susceptible towards treatment. One such example is the breast cancer type 1 susceptibility protein (BRCA1). This protein is involved in multiple pathways that affect among other things, cell checkpoints and double-strand break repair. A low amount of, or deficient BRCA1 has an oncogenic effect on cells. However once the cancer needs to be treated, a low enough amount of BRCA1 increases the efficiency of DNA alkylating agents such as platinum-based drugs2. This means that if a cancer is not responding well to the therapy, it might be possible to supplement the platinum drugs with a miRNA down-regulating BRCA1 and thus sensitizing the cancer cells.<br /> One miRNA that is responsible for regulating BRCA1, among others, is miR-125a-3p. In this work, the aim was to look at changes in regulation of modified miR-125a-3p, using luciferase expressed in human MCF-7 cells and constructing a simplified model system in Escherichia coli. The BRCA1 3’ UTR was attached to the luciferase coding DNA sequence (CDS) on a plasmid, thus causing a direct correlation between the down regulating efficiency of the miRNA and the amount of luciferase measured. The plasmid was then transfected into MCF-7 cells together with the miRNA that was to be tested. The cells were lysed at a specific time and the amount of luciferase in the sample was measured, thus allowing us to draw conclusions on the efficacy of the miRNA tested. These tests showed a significant down-regulation when using a miR-125a-3p that has full complementarity to its target region of BRCA1’s 3’ UTR compared to the native miR-125a. The remaining protein producation went from approximately 60% of normal expression with the native miR-125a-3p to 20% with the modified miR-125a-3p.<br /> Initial attempts towards construction of a model system that expresses Ago2, the protein required for minimal functionality of a RISC (recognition and restriction of mRNA), together with superfolded GFP with a 3’ UTR in E. coli were also made. Electroporation was then supposed to be used to transfect the E. coli cells with the miRNAs. The effect these would have on the amount of sfGFP in the cells would then be measured in order to determine the efficiency of down-regulation. Due to problems with Gibson assembly this part of the project was never completed to the point that results confirming the function of the model system could be achieved. Det finns tre grundläggande nivåer vid vilken en cell kan reglera mängden av ett visst protein. Den första nivån är i vilken omfattning den kodande delen av en gen transkriberas från DNA till RNA. Den andra delen är i vilken omfattning detta RNA, även kallat messengerRNA (mRNA), translateras till ett färdigt protein. Den tredje och sista delen är i vilken utsträckning detta protein bryts ner.<br /> RNA-interferens (RNAi) kontrollerar mängden protein vid nivå två. Detta sker med hjälp av ett proteinkomplex samt korta RNA strängar (mikroRNA). Proteinkomplexet kallas för RNA induced silencing complex (RISC). Detta proteinkomplexet binder ett mikroRNA som fungerar som en guide för RISC och leder det till rätt mål. RISC kan sedan förhindra translation antingen genom att bryta ner mRNAt om mikroRNAt basparar fullkomligt med mRNAt, eller genom att binda till andra proteiner som sitter på mRNAt och på så vis förhindra att ribosomerna (protein som translaterar mRNA till ett protein) kan binda in. Beroende på vilket mikroRNA som är bundet till RISC kan alltså olika mRNA väljas ut som mål för RISC.<br /> I denna studie har målet varit att försöka förstå vilken påverkan olika förändringar i mikroRNAt har på dess effektivitet. Som model valdes breast cancer type 1 susceptibility protein (BRCA1) som är ett mål för ett mikroRNA vid namn miR-125a. BRCA1 är intressant eftersom det som namnet antyder är relaterat till en ökad risk för vissa typer av cancer. För att kunna mäta förändringar i regleringen via olika modifikationer av miR-125a användes ett protein som heter luciferas som reporter. Luciferas får vid tillsats av ett specifikt substrat detta att börja lysa olika mycket beroende på koncentrationen av luciferas. Genom att koppla den kodande delen av genen för luciferas till den del av BRCA1 som är mål för miR-125a så är det alltså möjligt att mäta förändringar i uttryck av luciferas och koppla dessa till förändringar i miR-125a.<br /> För att kompletera data från luciferas-mätningarna skulle ett modelsystem utvecklas i Escerichia coli. I detta modelsystem skulle ett av proteinen (Ago2) från humant RISC uttryckas i E. coli. Ago2 klarar ensamt av att binda in ett mikroRNA och om det basparar fullkomligt med mRNAt, att klyva det. Avsikten var därför att konstruera två olika plasmider dvs. ett litet, cirkulärt, icke-genomiskt DNA som tillåter uttryck av gener i bakterier; en som innehöll genen för humant Ago2 och en som var utformade för att uttrycka en annan reporter som kallas för Green fluorescent protein (GFP). GFP var kopplat till BRCA1s 3’ UTR på samma sätt som beskrevs i paragrafen ovan med luciferas. Tanken var att sedan introducera mikroRNAn i cellerna med hjälp av en elektrisk chock. Eftersom varje GFP molekyl avger en viss mängd ljus vid 509 nm efter excitation vid 395 nm, så kan vi mäta hur mycket GFP som finns i cellerna. På så sätt kan vi räkna ut hur effektivt mikroRNAt vi tillsatt varit på att begränsa translation av mRNAt för GFP till den färdiga GFP molekylen. Av detta kan sedan slutsatser dras om hur effektivt mikroRNAt är mot sitt mål. https://lup.lub.lu.se/student-papers/record/4645884/file/4645885.pdf application/pdf 1853109 yes 2014 eng proteinvetenskap protein science Chemistry 4645884 2014-09-11T09:37:16+02:00 2014-09-12T16:24:13+02:00 2014-09-12T16:24:13+02:00

oai:lup-student-papers.lub.lu.se:4645887 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mohamad Ali author 4646324 MD PhD Artur Schmidtchen supervisor Department of Chemistry v1000647 department The evolution of new pathogens and the increase in antibiotic resistance have alerted researchers that new approaches are needed for infection management. Here we defined the epitope responsible for antimicrobial activity in the C-terminal TFPI-2 derived peptide EDC34, and showed that the net positive charge accompanied with the length of the peptide is crucial for antimicrobial activity. In addition, we proved that EDC34 peptide is an immunomodulatory molecule where it binds to immunoglobulins and may boost innate immune responses. These findings have confirmed that EDC34 peptide could be an attractive candidate for therapeutic development. Sökandet efter nya skyddssystem i vårt immunförsvar har blivit oundvikligt på grund av det ökade antalet infektioner och den bakteriella resistensen. Detta har attraherat många forskare till att studera antimikrobiella peptider och försök till att använda dem för att skydda vår kropp mot patogener.<br /> Antimikrobiella peptider kommer från Tissue Factor Pathway Inhibitor-proteiner, som finns naturligt i vår blodplasma. När kroppen blir infekterad av bakterier aktiveras dessa peptider och försvarar kroppen genom att lokalisera sig vid infektionsplatsen och eliminera bakterierna. I tidigare studier har vi visat att den antimikrobiella peptiden EDC34 hade en effektiv antimikrobiell aktivitet mot bakterier. Den här studiens syfte var att få en bättre förståelse för funktionen av EDC34 och peptidens aktivitet i olika miljöer. Vårt första mål var att skapa en kostnadseffektiv antimikrobiell peptid genom att försöka korta ner längden av den ursprungliga EDC34 utan att påverka dess antimikrobiella aktivitet. Sedan skapade vi en miljö liknande mänskligt blod i provrör och studerade hur EDC34 agerade i den miljön. Slutligen tog vi en djupare titt på interaktionen mellan den antimikrobiella peptiden EDC34 och andra proteiner som är involverade i immunförsvaret.<br /> Resultaten från detta projekt belyser potentialen av den antimikrobiella peptiden EDC34 som en lovande kandidat för terapeutisk behandling. https://lup.lub.lu.se/student-papers/record/4645887/file/4645888.pdf application/pdf 855661 yes 2014 eng proteinvetenskap protein science Chemistry 4645887 2014-09-11T09:48:46+02:00 2014-09-12T16:23:24+02:00 2014-09-12T16:23:24+02:00

oai:lup-student-papers.lub.lu.se:4646120 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anita Hoang author 3460192 Kirill Popov supervisor Jakob Danielsson supervisor Department of Chemistry v1000647 department The fascinating molecular structure of indoline alkaloids, especially that of the communesins and perophoramidine (Figure 1), has encouraged the studies towards the total synthesis of the representatives of this alkaloid family, in particular perophoramidine. Finding methodologies to construct the vicinal quaternary stereocenters with the stereochemistry of perophoramidine is one of the main challenges in planning the total synthesis. In this project, samarium mediated reductive dialkylation of isoindigo derivatives and a stepwise procedure involving reduction of isoindigo followed by dialkylation with a chelating base has been employed to explore the strategy. The first mentioned method was unsuccessful and several modifications have been tested without any success. Diastereoselective dialkylation with a chelating base has been successfully employed to construct the vicinal quaternary stereocenters with the stereochemistry of perophoramidine. Syntetisk framställning av naturligt förkommande substans med anti-cancer egenskap.<br /> Naturprodukt är naturligt förkommande substans som är producerat av levande organismer och har oftast anti-cancer eller andra gynnsamma egenskaper. Genom evolutionen har levande organismer skapat dessa naturprodukter för att skydda sig själv mot angrepp. Dessa naturprodukter med läkande egenskaper finns oftast i mycket små mängder i växter, svampar och havsdjur. För att kunna undersöka ifall dessa okända naturprodukter har läkande egenskaper behöver man ha tillgång till stora mängder av ämnet i fråga. För att lösa problemet kan man därför försöka framställa naturprodukten på syntetisk väg, inom kemi kallas det för totalsyntes. Syftet med det här projektet är att framställa Perophoramidine (Figur 1), en naturprodukt som finns i Perophora Namei, en sjöpungsart som kan hittas i Indiska Oceanen. Framställning av denna produkt är av intresse eftersom Perophoramidine har uppvisat anti-cancer, antibiotiska och svampdödande egenskaper. Projektets fokus är att kunna konstruera bindningen mellan kol nummer 1 och kol nummer 2 med rätt rymdgeometri (Figur 1).<br /> Två olika metoder har testats och en av metoderna har visats vara givande. Den metoden som har fungerat förlitar sig på användandet av natrium jon för att hålla molekylen i rätt rymdgeometri för att konstruera bindningen. Natrium jon fungerar som ett handtag mellan de två atomer och tvingar molekylen till rätt rymdgeometri. Med den metoden etablerad så är nyckelsteget fastställd och skapar därmed möjligheten att kunna konstruera perophoramidine på syntetisk väg. https://lup.lub.lu.se/student-papers/record/4646120/file/4646130.pdf application/pdf 671629 yes 2014 eng organisk kemi organic chemistry Chemistry 4646120 2014-09-12T09:33:52+02:00 2014-09-12T16:22:21+02:00 2014-09-12T16:22:21+02:00

oai:lup-student-papers.lub.lu.se:4646159 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Hanan Al-Yahyaai author 4646323 Egle Virzintiene supervisor Department of Chemistry v1000647 department NADH:upiquinone oxidoreductase, or complex I, is the first and largest enzyme in the respiratory chain. It is the last known enzyme in the chain due to its complexity of being a very large complex comprising of a hydrophilic and a hydrophobic domains of about 46 subunits in total in the eukaryote enzyme. Another reason of its complexity is that the hydrophobic domain does not have any redox centers or prosthetic groups making this part in particular difficult to study.<br /> The transfer of two electrons from NADH molecule to FMN in the hydrophilic domain of complex I and then through the Fe/S clusters up to quinone is coupled to proton translocation by the hydrophobic domain of the complex. Recently, the structure of the whole complex was solved. However, the coupling mechanism of the electron transfer and the proton translocation is still unknown.<br /> Understanding complex I mechanism is of great importance as it is related to production of reactive oxygen species (ROS). The production of such component leeds to mutations in the mitochondrial DNA and thus causing serious health disorders.<br /> The hydrophobic domain subunits show a high sequence similarity to a Na+/H+-antiporter called Mrp-complex. NuoL, NuoM and NuoN, NuoK and NuoJ subunits in complex I are homologoues to MrpA, MrpD, MrpC and last part of MrpA subunits in Mrp-complex respectively. Such high sequence similarity between the two complexes indicates a functional similarity too, leading to a conclusion that complex I might pump sodium in exchange to protons. The structural similarity of the two complexes would be the strongest link between complex I and Mrp-complex. However, the structure of Mrp-complex has not been solved yet, thus solving the structure of the Mrp-antiporter and understanding its mechanism will solve the mystery of complex I coupling mechanism.<br /> This project is aiming to crystalize the Mrp-complex from Bacillus subtilis. Mrp-subcomplex composed of four subunits MrpA, MrpB, MrpC and MrpD has been successfully constructed so that a his-tagged cytochrome c550 domain was added to the C-terminal end of MrpD subunit, which would facilitate purification and quantification of the complex. MrpABCDcytH complex was successfully produced in E. coli, purified and analyzed for further experiments. All living organisms need energy to survive, because it is required for all processes such as respiration, growth, thinking, muscle movement etc. Food is decomposed through a series of chemical reactions and energy is released in the form of electrons. The released electrons are carried by electron carrier molecules such as NADH. These molecules are the major source of electrons that are donated to the main energy production machinery - the respiratory chain.<br /> Complex I, or NADH:upiquinone oxidoreductase, is the first and largest protein in the chain. Electrons from NADH are delivered to complex I and the transfer of electrons through the complex leeds to proton translocation to the periplasm (outside the membrane) by its smaller proteins located in the membrane. Other complex proteins in the chain translocate protons too through electron transfer in the chain except complex II. Finally, these protons are used by the ATP synthase complex where they are pumped to the inside of the membrane, aiding the energy synthesis.<br /> The mechanism by which the electron transfer is coupled to proton translocation in complex I is still unknown. The interest in understanding the coupling mechanism is due to the fact that it is linked to many serious health disorders. Studies have shown that complex I subunits (smaller proteins) that are located in the membrane are homologous (similar to) Mrp-complex subunits. Mrp complex is an antiporter protein that pumps sodium outside the cell in exchange for protons. NuoL, NuoM, NuoN, NuoK and NuoJ subunits in complex I are homologous to MrpA, MrpD, MrpC and last part of MrpA subunits in Mrp-complex, respectively. As the two complexes have a high degree of similarity, this gives an indication that both are probably having similar modes of action.<br /> Up to date, there is no structure of Mrp-complex avaliable. In this project, an attempt to solve the Mrp structure has been made. https://lup.lub.lu.se/student-papers/record/4646159/file/4646160.pdf application/pdf 1711331 yes 2013 eng proteinvetenskap protein science Chemistry 4646159 2014-09-12T11:21:16+02:00 2014-09-12T16:21:26+02:00 2014-09-12T16:21:26+02:00

oai:lup-student-papers.lub.lu.se:4646162 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Wadia Kaddoura author 4646322 Charlotta Turner supervisor Margareta Sandahl supervisor Merichel Plaza supervisor Department of Chemistry v1000647 department Polyphenols are a group of compounds that are widely spread in the plant kingdom. These compounds are of great interest for researchers because of their antioxidant properties that are important for both plant life and human health. Sample preparation is a crucial step for the determination of phenolic compounds and their metabolites in biological samples. Methods for isolation and preconcentration of these compounds from human urine matrices by using C-18 HyperSepTM tips associated with micro-solid phase extraction (micro-SPE) technique have been tested in this study. A broad range of polyphenols, namely; phenolic acid, flavonol and anthocyanin standards were separated and identified by Reversed Phase High Temperature Liquid Chromatography (RP-HTLC) coupled to Ultra Violet/ Visible Light (UV/VIS) and PhotoDiode Array detector (PDA). The RP-HTLC-method has been validated; the limit of detection for the phenolic acids ranged between 0.15 and 0.76 μgmL-1 and the calibration curves showed excellent linearity all with R2 &gt; 0.99. The precision of the overall analytical procedure was estimated as the relative standard deviations (RSD %) through repeating the analysis seven times in one day. The RSDs for all retention times were &lt; 1 % and for all peak areas, &lt; 10 %. The Micro-SPE methods studied showed poor recovery which was at best 25 % recovery of vanillic acid and 27 % recovery of 3, 4-dihydroxyphenylacetic acid. An analytical method for isolation and identification of phenolic compounds in human urine samples<br /> Polyphenols are a group of compounds that play an important role in both plant life and human health. This importance arises from their antioxidant properties. These antioxidants spread widely in the plant kingdom especially fruits, vegetables and spices and are believed to lower the risk of many chronic diseases and disorders such as cancer, heart disease, stroke, Alzheimer’s disease and Rheumatoid arthritis, in addition to their role in anti-aging and to healthy look. Antioxidants neutralize the reactive radicals produced inside and outside our bodies and prevent them from damaging our cells. Because of these effects scientists and researchers work actively and continuously in reporting and reviewing scientific literature considering the types and quantities of antioxidants that are needed for healthy life. To achieve these objectives modern and sensitive instruments are used. In this work a broad range of phenolic compounds were separated and identified by using a separation technique coupled to a detector to separate and detect these compounds with good accuracy and at reasonable time. Method for isolation of phenolic compounds from complex matrices like human urine was also developed to meet the objective of this project. This method showed poor recovery and that is due to both complexity of the these matrices and the technique used for isolation. https://lup.lub.lu.se/student-papers/record/4646162/file/4646163.pdf application/pdf 622671 yes 2013 eng analytisk kemi analytical chemistry Chemistry 4646162 2014-09-12T11:32:27+02:00 2014-09-12T16:20:36+02:00 2014-09-12T16:20:36+02:00

oai:lup-student-papers.lub.lu.se:4646165 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mingzhe Sun author Ebbe Nordlander supervisor Department of Chemistry v1000647 department Two novel tetradentate ligands N, N’-Dimethyl-N, N’-bis(2-(chloromethyl)-1-methylbenzimidazole)-<br /> ethane-1,2-diamine (mepL), (-)-2-(((S)-2-((S)-1-(benzimidazol-2-ylmethyl)<br /> pyrrolidin-2-yl) pyrrolidin-1-yl)methyl)benzimidazole (PDPL) and their iron complexes<br /> [Fe(mepL)(CH3CN)2](SbF6)2 (SbF62), [Fe(CF3SO3)2(PDPL)] (OTf1) and [Fe(PDPL)<br /> (CH3CN)2](SbF6)2 (SbF61) were synthesized and characterized with IR, UV-VIS, 1H<br /> NMR and ESI. X-ray crystallographic analysis was performed on OTf1. The complexes’<br /> catalytic capabilities in asymmetric epoxidation reactions were studied using mainly<br /> cyclohexenone as substrate. The influence of several factors on the results have been<br /> investigated, such as carboxylic acid type and loading, catalyst loading, reaction<br /> temperature, oxidant loading and different methods of addition of the catalyst. This thesis is concerned with the preparation of novel iron complexes of new<br /> tetradentate N4 iron complexes and tests of their catalytic capabilities in asymmetric<br /> epoxidation.<br /> Catalytic oxidation of C-H bonds are among the most important reactions in the<br /> chemical industry. Development of effective catalyst for asymmetric oxidation of C-H<br /> bonds and asymmetric epoxidation of olefins are some of the hottest topics in this<br /> field. In recent years, several tetradentate ligand systems have been developed and<br /> their iron complexes have been proven to be capable of providing high yields,<br /> conversions and selectivities in catalytic asymmetric oxidation of various substrates.<br /> It has recently been discovered that high valent ferryl (Fe(IV)=O) or perferryl<br /> (Fe(V)=O) species are generated during the oxidation process and are the direct<br /> oxidants of the carbon hydrogen bonds. In the successful catalysts developed so far,<br /> the basic idea is the utilization of the ligand to alleviate the positive charge from the<br /> metal centre during the intermediate stage, which leads to better stabilization of the<br /> high valent ferryl species. This gave the inspiration for the design of the two<br /> tetradentate N4 ligand systems in this work and the catalytic properties of their FeII<br /> complexes were examined in the asymmetric epoxidation of cycloalkenone which is a<br /> difficult type of substrate to oxidize in a highly selective way. https://lup.lub.lu.se/student-papers/record/4646165/file/4646168.pdf application/pdf 1622269 yes 2014 eng oorganisk kemi inorganic chemistry Chemistry 4646165 2014-09-12T11:42:11+02:00 2014-09-12T16:19:38+02:00 2014-09-12T16:19:38+02:00

oai:lup-student-papers.lub.lu.se:4647765 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Filip Paulsen author 4648316 Henrik von Wachenfeldt supervisor Department of Chemistry v1000647 department A novel tandem cyclocondensation/1,2-oxazole rearrangement cascade reaction for the synthesis of 4-vinyl oxazoles from γ-chloro-propargylamines was developed and applied towards a short modular synthesis of natural product siphonazole B. The proposed seven-step route, enabled by the use of 4-vinyl oxazoles as precursors for 4-carboxyl oxazoles, would be the shortest to date. Simply removing the cause of a known regioselectivity issue and using a 4-hydroxymethyl-oxazole as a masked 4-carboxyl-oxazole nucleophile solved the problem and enabled the key reaction – a regioselective aldol-type fragment coupling. Due to difficulties of achieving a latestage formal dehydrogenation the strategy was re-evaluated leading to a formal synthesis of siphonazole B. Studies towards achieving the last step of the total synthesis – a tandem oxidative amidation/ketone formation are currently underway. https://lup.lub.lu.se/student-papers/record/4647765/file/4647766.pdf application/pdf 5430492 yes 2014 eng organisk kemi organic chemistry Chemistry https://lup.lub.lu.se/student-papers/record/4647765/file/4647768.pdf application/pdf no 4647765 2014-09-18T08:30:03+02:00 2014-09-22T11:04:27+02:00 2014-09-22T11:04:27+02:00

oai:lup-student-papers.lub.lu.se:4699366 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Atef Mannaa author 3053438 Staffan Nilsson supervisor Department of Chemistry v1000647 department In this work, lipid nanoparticles were used as pseudostationary phase, PSP, for protein separation in capillary electrochromatography, CEC. The aim of the work was to use a new analytical separation technique for future analysis of protein drugs by using lipid nanoparticles as a pseudo-stationary phase with conventional UV-detection.<br /> PSP-CEC was combined with UV-detection to study proteins elution. The tested proteins BSA, cytochrome c and insulin have been selected according to different hydrophobicities, sizes and isoelectric points (pI). A zwitter ionic buffer, MOPS, was used as an electrolyte at pH 7.4. The nanoparticles were tested for their compatibility with MALDI-TOF/MS (Matrix assisted laser desorption/ionization-time of flight). MADI-TOF/MS works with a suspension of lipid nanoparticles in MOPS that contains insulin and it can be a future possible detection method for PSP-CEC. All three proteins were successfully eluted with PSP-CEC combined with UV-detection. Nanoparticles coated with silver might be studied with “surface enhanced Raman spectroscopy”-detection. Popular Science Summery<br /> Capillary electrophoresis, CE is a separation technique in which analytes are separated according to their size to charge ratio in the interior of the capillary.<br /> Capillary electrochromatography, CEC is a combination of CE and HPLC. The fundamental difference between CE and CEC is that the separation is not based on the electrophoretic mobility difference only but on the interaction with the stationary phase as well. Lipid nanoparticles were used as pseudostationary phase (moving phase). The aim of current work is to separate different proteins, BSA, cytochrome c and insulin have been separated according to their charge and size. They have been successfully separated. It was found that PSP-CEC in combination with UV-detection is a good methodology to elute Proteins. An identification technique named MALDI-TOF/MS was used to identify the insulin that has been dissolved in nanoparticles. Insulin has been successfully identified. MADI-TOF/MS works well with lipid nanoparticles and it can be used as a future possible detection of PSP-CEC. https://lup.lub.lu.se/student-papers/record/4699366/file/4699368.pdf application/pdf 3523337 no 2013 eng PSP-CEC UV MALDI-TOF/MS Chemistry 4699366 2014-10-21T16:47:10+02:00 2019-01-08T09:12:42+01:00 2014-10-21T22:55:16+02:00

oai:lup-student-papers.lub.lu.se:4699482 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Dóra Stefansdottir author 4697418 Jes la Cour Jansen supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Implementing anammox based processes in the mainstream at municipal wastewater treatment plants is challenging and requires carefully constructed control strategies in order to be successful. A method to measure the specific anammox activity (SAA) was further developed and implemented in the mainstream anammox pilot plant at Sjölunda Wastewater Treatment Plant. The developed method was found to be reliable and reproducible. The influence of initial nitrite and ammonium concentrations on the SAA as well as temperature dependency were analysed. The tests, based on continuously monitored manometric batch tests, were performed on MBBR carriers type K1®. The SAA showed a dependency of initial nitrite concentrations below 75 mg N L-1 whereas the activity was independent of initial concentrations in the interval of 75–125 mg N L-1. Temperature dependency of the specific anammox activity as expressed in Ea increased at lower temperatures (10–20°C) compared to higher temperatures (20–30°C). Decreasing temperature from 30°C to 10°C resulted in 95-98% loss of the anammox activity. https://lup.lub.lu.se/student-papers/record/4699482/file/4699493.pdf application/pdf 2376718 no 2014 eng Activity test anammox: mainstream MBBR temperature dependency vattenförsörjnings- och avloppsteknik Chemistry 4699482 2014-10-22T10:18:39+02:00 2014-11-07T16:50:28+01:00 2014-11-07T16:50:28+01:00

oai:lup-student-papers.lub.lu.se:4730957 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Andreas Nygren author 4730955 assoc prof Bernt Nilsson supervisor Department of Chemistry v1000647 department Chemical Engineering (M.Sc.Eng.) v1000299 department Numerical, transient simulations of a meandering bubble plume in a rectangular flat bubble column was carried out, using the commercial CFD package ANSYS Fluent 15 within the framework of a Eulerian-Eulerian description. A Sensitivity analysis of turbulence closure was performed using four turbulence models: standard, RNG, Realizable k − epsilon and the Reynolds stress model. The effect of dispersed phase turbulence on the continuous phase was also investigate. The interaction force term included drag, virtual mass and turbulent dispersion. Some simulations were also made using lift and wall lubrication forces. The available drag and dispersion models available in Fluent were evaluated. Lastly, the impact of numerical methods was investigated where the model was tested for discretization scheme, gradient limiter, time step and grid size. <br /> <br /> The standard and Realizable k − epsilon models resultsed in a meandering bubble plume that oscillated with a period of 32.5 seconds. The Reynolds stress model did not reach a quasi-steady state, as the period kept increasing during the flow-time. The RNG k − epsilon model produced an oscillating plume, but the recorded time series show that the velocity fluctuated in a more chaotic way. The analysis of the dispersed phase turbulence modelling showed that the chaotic oscillations predicted by the RNG k − ² was a results of under predicting the turbulent viscosity. Comparing drag models showed that the drag coefficient influenced the amplitude of the velocity measurements, and that higher drag coefficient yield a higher amplitude. It was also found that including the turbulent dispersion force is imperative to capture the dispersion of the bubble plume. The lift force did not influence the oscillation frequency of the plume, but only the dispersion. Including the lift force caused the non-physical effect of pushing the bubbles towards the back and forth wall. It was also shown that this effect could be counteracted by including wall lubrication, and keeping the dispersive effect of the lift force. The choice of time step had the largest impact on the oscillation frequency. Decreasing the time step below 4 ms caused the oscillation frequency to decrease rapidly. If a time step of 2.5 ms was used, the time between peaks doubled. En bubbelkolonn är en väldigt vanlig operation i modern kemisk industri, då den utgör en billig och effektiv lösning för kemiska reaktioner mellan gas- och vätska. Detta då gasen, som kommer in från botten står för själva omrörningen, vilket gör att man inte behöver använda någon omrörare. I detta arbete så studerades möjligheten att simulera flödet i en bubbelkolonn, och hur resultatet påverkades av olika fysikaliska- och matematiska modeller. Arbetet utfördes i en kommersiell simuleringsmjukvara genom att variera de matematiska- och fysikaliska modeller som fanns tillgängliga. För att utvärdera hur väl simuleringarna stämde överens med verkligheten så jämfördes de med experimentell data från vetenskaplig litteratur. <br /> <br /> Arbetet visade att simuleringarna stämde bra överens med experiment. Dock så visade det sig att resultatet var känsligt när det gällde val av fysikaliska modeller. Det visade sig att systemet var väldigt känsligt för modelleringen av turbulens, men även för hur interaktionen mellan gas och vätska beskrevs. Dock visade det sig att om fysikaliska modeller väljs på ett intelligent vis, så kan en bubbelkolonn beskrivas med matematiska medel på ett sätt som stämmer väl överens med verkligheten. Simulering av bubbelkolonner kan användas som underlag för att dimensionera verkliga kolonner till som skall användas i industrin. Detta kan vara ett mycket kostnads- och tidseffektivt alternativ till att utföra experiment. https://lup.lub.lu.se/student-papers/record/4730957/file/4730975.pdf application/pdf 3732017 no 2014 eng Computational Fluid Dynamics Bubble Column Turbulence Modelling Eulerian-Eulerian framework Chemistry 4730957 2014-10-27T11:39:59+01:00 2014-10-28T13:57:08+01:00 2014-10-28T13:57:08+01:00

oai:lup-student-papers.lub.lu.se:4774164 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Jasenko Gavran author 4812629 Malin Zackrisson Oskolkova supervisor Kajsa M Paulsson supervisor Department of Chemistry v1000647 department Tapasin is a membrane protein, which plays a crucial role involved antigen presentation for certain MHC alleles in antigen presentation. Tapasin acts as a link between Transported Associated with antigen Processing (TAP) and MHC class l by. It acts as quality control in choosing high affinity peptides to be presented. Refolding conditions for the N-­terminal region of tapasin have here been investigated. Two sequences have been tried, Tpn1-­87-­GrpE and Tpn1-­271, where GrpE is for increased solubility. Folding has been monitored by dynamic light scattering and circular dichroism. Folding using the nonionic surfactant pluronics following separation of it was tried. Various folding conditions without surfactants were screened as well. The circular dichroism spectrums for Tpn1-­87-­GrpE and GrpE are evaluated. Popular Abstract<br /> Våra celler presenterar med hjälp av protein på sina ytor korta peptidfragment härrörande från intracellulära proteiner med syfte att signalera till utsidan om hur cellen mår. Är cellen sjuk ändras peptidrepertoaren, dvs de peptidfragment som uppvisas, vilket direkt upptäcks av kroppens cirkulerande T-celler som då förstör cellen. En viktig del i processen är att välja vilka små fragment som ska presenteras. Proteinet tapasin spelar en viktig del i detta genom att reglera peptid-urvalet, samt stabilisera vissa protein-peptid-komplex. För att förstå hur detta utförs är det viktigt att veta hur tapasin ser ut. Tidigare studier har visat att en liten del av tapasin, de första 87 aminosyrorna, är nog för att bibehålla dess funktion. I detta arbete har vi funnit att Tpn1-87 bibehåller även till viss del sin veckade, nativa protein-struktur, trots att det föreligger i aggregerad form. Huruvida Tpn1-87 är monomerer och stabilt i lösning har undersökts och utvärderats med centrifugalfiltrering och dynamisk ljusspridning. Preliminära resultat visar att med hjälp av icke-joniska tensider erhålls protein i monomerform. https://lup.lub.lu.se/student-papers/record/4774164/file/4774170.pdf application/pdf 882984 yes 2014 eng Physical Chemistry Fysikalisk kemi Chemistry 4774164 2014-11-10T09:12:29+01:00 2014-11-23T21:41:04+01:00 2014-11-23T21:41:04+01:00

oai:lup-student-papers.lub.lu.se:4779519 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Gerda Kamsma author 4780122 Lennart Piculell supervisor Tommy Nylander supervisor Department of Chemistry v1000647 department Surface coatings are used in many applications. An advantage of coating a surface using<br /> particles from a dispersion is that a change in, for example, temperature can control the<br /> compactness of the surface coverage. In this research the competition between bulk<br /> aggregation and surface adsorption of colloidal silica spheres was investigated. The system<br /> used contained aqueous dispersions of industrial Ludox silica particles and flat silica surfaces.<br /> The attractive force between the particles and between a particle and the surface was varied<br /> by adding polyelectrolyte to induce a depletion flocculation.<br /> Bulk aggregation was investigated and phase diagrams were established by observing phase<br /> separation visually and using dynamic light scattering. Above a certain polymer concentration<br /> the systems showed a liquid-liquid or a liquid-solid phase separation. The dynamic light<br /> scattering experiments, corrected for changes in viscosity, showed that below the phase<br /> boundary no particle aggregates formed.<br /> Surface adsorption was monitored using mainly ellipsometry and a quartz crystal<br /> microbalance. Surface adsorption occurred at lower polymer concentrations than bulk<br /> aggregation. For different Ludox concentrations, the concentration of polymer required to<br /> make the particles adsorb at the surface (the adsorption boundary) showed the same trend as<br /> the bulk phase boundary. Between the two boundaries an increase of polymer gave an<br /> increase in surface adsorption. A raise of the concentration of Ludox particles also increased<br /> the adsorption. Below the phase boundary no aggregation was found. In the theory of<br /> Wennerström and Linse [1] surface adsorption occurs at a lower interaction strength than bulk<br /> aggregation. This research is in agreement with the latter theory. https://lup.lub.lu.se/student-papers/record/4779519/file/4779532.pdf application/pdf 6705247 yes 2014 eng fysikalisk kemi physical chemistry Chemistry https://lup.lub.lu.se/student-papers/record/4779519/file/4779531.pdf application/pdf no 4779519 2014-11-14T13:35:56+01:00 2014-11-17T11:30:20+01:00 2014-11-17T11:30:20+01:00

oai:lup-student-papers.lub.lu.se:4780260 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anna Olsson author 4693759 Associate Professor Karin Jönsson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Syftet med denna rapport är att granska och utvärdera den praxis som finns idag i fråga om hur kommuner hanterar anslutning av industrier och verksamheter till det kommunala, REVAQ-certifierade reningsverket. Anledningen till detta är att det slam som uppstår vid rening av avloppsvatten har ett högt innehåll av närsalter. Detta innebär att slammet kan nytt-jas som gödningsmedel, förutsatt att det inte innehåller för höga halter av ämnen som är oöns-kade i livsmedelsproduktionen. Granskningen av praxis kommer att baseras på de befintliga policys och dokument som är framtagna av olika svenska kommuner. Åtta dokument från olika kommuner granskas och utvärderas. <br /> Den aktuella teorin och forskningen på området framhåller att det finns många positiva egen-skaper hos slammet och att man måste arbeta med att få ner halterna av oönskade ämnen i det. Dessutom så finns det både svensk lagstiftning och EU lagstiftning som berör slamfrågan. Denna lagstiftning inkluderar bland annat miljöbalken och lagen om allmänna vattentjänster (LAV) på nationell nivå, samt vattendirektivet och REACH på EU-nivå. När det kommer till den nationella lagstiftningen finns det en väsentlig skillnad mellan miljöbalken och LAV för den förstnämnda riktar sig till verksamhetsutövare medan den sistnämnda reglerar förhållan-det mellan huvudmannen och fastighetsägaren. När det gäller den aktuella lagstiftningen kan man baserat på avfallsförordningen föra en argumentation om huruvida slammet ska betraktas som ett avfall eller en biprodukt. Kärnan i denna argumentation blir vad som kan betraktas som ”normal industriell praxis”. <br /> När de olika dokumenten från olika kommuner som inkluderats i denna rapport granskats och utvärderats framkom många likheter mellan dem, men också vissa skillnader. De granskade dokumenten var baserade på antingen P95 från Svenskt Vatten eller agerade som ett förtydli-gande av de allmänna bestämmelser för nyttjande av vatten- och avloppsanläggning (ABVA) som finns. I granskningen finns dokument som både baseras på P95 och förtydligar de ABVA som finns i den aktuella kommunen. Dessutom var det vanligt att man inkluderade en beskriv-ning av de processer som finns på reningsverket samt kortfattade beskrivningar av den lag-stiftning som man fann vara relevant. Vilken lagstiftning som inkluderades kunde variera lite, men lagen om allmänna vattentjänster och miljöbalken var återkommande inslag i alla doku-ment som granskats i denna rapport. VA SYD var ett stort undantag i granskningen, för man använder sig enbart av ABVA för att vägleda industrier och verksamheter, utan något kom-pletterande dokument. <br /> De slutsatser som drogs efter arbetet med denna rapport är att det är viktigt att man poängte-rar att slammet har många positiva egenskaper om man ska skriva ett dokument av samma typ som granskats i denna rapport. Som bas för ett sådant dokument kan man med fördel använda P95 från Svenskt Vatten och ABVA. Vad som också är genomgående i de dokument som granskats är en tabell med de gräns- och riktvärden man har. Detta gör det tydligt för verk-samhetsutövare att se vilka krav som ställs på deras utgående vatten. Avslutningsvis är det viktigt med ett samarbete över förvaltningsgränserna inom en kommun för att ta tillvara på all den kompetens som finns, både ur ett miljömässigt och ett tekniskt perspektiv. https://lup.lub.lu.se/student-papers/record/4780260/file/4780662.pdf application/pdf 1681314 no 2014 swe Certifierat slam spillvatten från industri nuvarande praxis gräns- och riktvärden Chemistry 4780260 2014-11-17T17:02:00+01:00 2014-11-19T13:37:20+01:00 2014-11-19T13:37:20+01:00

oai:lup-student-papers.lub.lu.se:4780405 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Monika Kruszyk author 4780503 Björn Borgström supervisor Department of Chemistry v1000647 department Abstract is attached at the heading Related Materials. According to the World Health Organization (WHO), cancer is the second most common cause of death worldwide, accounting for more than 8 million deaths. The number of diagnosed cases is expected to increase from 14 million (in 2012) to 22 million annually in 20 years.<br /> <br /> Resistance to chemotherapy, cancer recurrence and metastasis are common clinical problems for patients suffering from cancer. A hypothesis is that these are caused by a small population of cells within a tumor, so-called cancer stem cells (CSCs) which are also believed to drive tumorigenesis. Current anticancer therapies are based on their ability to shrink tumors, leaving the population of CSCs largely untouched. This means that such therapies may fail, because they leave the cells that can regenerate and spread the tumor. Novel anticancer therapies aim to target also CSCs. Combined with currently used drugs such treatments could lead to cancer regression.<br /> <br /> Studies performed in 2009 by Gupta and co-workers showed that salinomycin, a polyether antibiotic commonly used in veterinary medicine, was the most efficient out of 16000 compounds to decrease the population of cells with stem-like properties. The mechanism of action for this compound still remains unknown. We aimed towards the attachment of a suitable fluorescent probe to the salinomycin core structure, which would result in a new derivative that is visible in fluorescence microscopes. This would allow localizing SA in<br /> cells and would provide useful information in explaining the molecular mode of action of SA against CSCs. 2014 eng organisk kemi organic chemistry Chemistry https://lup.lub.lu.se/student-papers/record/4780405/file/4780415.pdf application/pdf no 4780405 2014-11-18T11:17:32+01:00 2014-11-18T15:40:49+01:00 2014-11-18T15:40:49+01:00

oai:lup-student-papers.lub.lu.se:4780425 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Valentina Grippo author 4780505 Prof Lo Gorton supervisor Department of Chemistry v1000647 department Cyanobacteria possess unique and exciting features among photosynthetic microorganisms for energy conversion applications. This thesis project focuses on conversion of solar energy into photocurrent generation comparing three different strains of Cyanobacteria, Leptolyngbia sp. from New Zealand (CYN82), Leptolyngbia sp. from Antarctica (CYN65), Chroococcales sp. from Antarctica (CYN67) and one eukaryotic organism, Paulschulzia pseudovolvox from Lake Tikitapu, New Zealand (UKE). By illuminating with light (intensity 400 W/m2) each bacterium (immobilized on a graphite electrodes in mediated electron transfer conditions) a photocurrent is generated through the extraction of electrons from water photolysis. <br /> Different mediators were explored: two soluble mediators 0.5 mM para-benzoquinone (pBQ) and 0.5 mM ferricyanide solution dissolved in buffer, a redox polymeric mediator Os(bpy)2Cl complexed with poly(1-vinylimidazole) and a combination of pBQ and Os-polymer. The photocurrent values from chronoamperometric experiments were collected and compared. The maximum currents density was 47.167 μA•cm-2 from CYN67 using a double mediator system. <br /> Further investigations on CYN67 in different buffer concentrations, pBQ concentrations and light intensity conditions showed that the best electrogenic activity for this cyanobacterium yields a current density of 58.368 μA•cm-2. According to current projections the global population will reach 9 billion people by the year of 2050 and this population will need to be supplied with energy. Todays we strongly depend on non-renewable energy sources with all their related problems of scarcity and environmental impact. Several alternative energy sources have been developed and solar energy is one of the best candidates, because it is the most accessible and abundant renewable energy source available to us. A steadily improving understanding of natural photosynthesis at the molecular level has inspired researchers to develop systems that mimic (or use) natural photosynthesis to convert solar energy to fuel. <br /> In nature, the process, which converts solar energy into chemical energy, is called photosynthesis. This chemical energy is stored as carbohydrate molecules, which are synthesized from water and carbon dioxide. The process takes place in cyanobacteria, algae and higher plants in the presence of sun light. <br /> This study focused on the imitation of photosynthesis for energy production. As biological material different cyanobacterial strains and algae were used. By illuminating graphite electrodes modified with cyanobacteria or algae, photocurrent densities were detected and compared. This was done in the presence of substances, so-called mediators, which act as electron shuttles and help the electron transfer between the cells and the electrode. Various experimental conditions, such as light intensity, ionic strength, mediator concentration, were also tested. Through the use of a pesticide, diuron, that blocks the photosynthetic system, these microorganisms were confirmed to be the source of the registeted photo current. https://lup.lub.lu.se/student-papers/record/4780425/file/4780426.pdf application/pdf 3335305 yes 2014 eng analytisk kemi analytical chemistry Chemistry 4780425 2014-11-18T11:46:02+01:00 2014-11-18T15:42:12+01:00 2014-11-18T15:42:12+01:00

oai:lup-student-papers.lub.lu.se:4780433 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Olga Aleksejeva author 4780504 Kamrul Hasan supervisor Department of Chemistry v1000647 department Development of environmentally friendly and cost-efficient energy sources has been a challenge for modern society since long ago. Sunlight is an infinite and costless source of energy on Earth, so it would be an enormous advantage to efficiently harvest and transform it into electrical energy used in our everyday life. In nature the process, which converts light energy into chemical energy, is called photosynthesis. In green plants photosynthesis takes place in chloroplasts, which contain network of thylakoid membranes – sites of sunlight energy harnessing. The main feature of this process is high-energy electrons produced as a result of photoexcitation of thylakoid membrane components, photosystem I (PSI) and photosystem II (PSII), by visible light of certain wavelength. A lot of efforts have been devoted to employ electrons, generated by photosynthetic membranes and chlorplasts as well as by isolated PSI and PSII, for energy production. However, isolated reaction centers (RC-s) imply a complicated extraction procedure, are compatible only with precious metal electrodes and suffer from instability, chloroplasts in their turn significantly restrict communication between photosynthetic components of thylakoid membranes and electrodes. Therefore thylakoid membranes, which allow stability of the photosynthetic components, are relatively easy to immobilize and extract, were considered as the best option to work with. This project can be viewed as a small puzzle-piece in worldwide research on the development of alternative energy sources, as well as an extensive continuation of earlier investigations made in the field of photosynthetic electricity. In the present study electrochemical communication between thylakoid membranes, isolated from spinach, and graphite electrodes was investigated to improve the photocurrent generation. For this a number of parameters were considered, e.g. different mediators for efficient electron transfer, various strengths and pHs of phosphate buffer saline (PBS). The maximum photocurrent generation (95.78 µA cm-2) was obtained while two mediators were used together, e.g. an osmium redox polymer and p-benzoquinone, at 50 mM PBS pH7. Os-polymeric mediators, immobilized onto the electrode, represent a novel approach, which allows save costs and environment because a lower amount of mediator is needed, as well as provide a robust and simple system. The photocurrent origin was confirmed by using known herbicides, such as DCMU (3-(3,4-dichlorophenyl)-1,1-dimethyl urea) and CCCP (carbonyl cyanide 3-chlorophenylhydrazone), and resulted in ca 90 % inhibition compared to a non-inhibited system. To enhance the experimental stability cross-linkers PEGDGE (poly(ethylene glycol) diglycidyl ether), PEI (polyethylenimine) and glutaraldehyde were used. Although the stability was increased by using glutaraldehyde, e.g. current remained stable for 4500 s, the photocurrent density fell drastically. To minimize the photo-oxidative damage of thylakoid membranes superoxide dismutase (SoD) and catalase (Cat) were used, that resulted in a little increase of the photocurrent. Open circuit potential measurements for non-mediated and mediated systems, of importance for a future biofuel cell construction, resulted in 0.120 V and 0.180 V respectively. Development of environmentally friendly and cost-efficient energy sources has been a challenge for modern society since long ago. Sunlight is an infinite and costless source of energy on the Earth, so it would be an enormous advantage to efficiently harvest and transform it into electrical energy used in our everyday life. This study is a tiny part of global research on solar fuels, the main idea of which is to harness light energy by using biological material and transform it into electrical power.<br /> In nature the process of light energy transformation into chemical energy is called photosynthesis, which takes place in thylakoid membranes of chloroplasts, which are components of green plants leaf cells. It uses sunlight to convert CO2 and H2O into molecular O2, which we all breathe, and sugars, which are energy source for plant growth as well as for animals. <br /> Since long ago researchers noticed, that energy derived from photosynthesis has a potential to be employed in sustainable sunlight conversion. A driving force for the whole process is the generation of high energy electrons, which are kicked out from receptor molecules by light of a certain wavelength. These electrons participate in several transfer reactions, and it is certainly challenging to employ them for energy production. In the modern world electrical energy is needed for heating, driving cars, running household and industrial machines etc. At the same time there is a continuous need for the development of environmentally friendly and cost-efficient energy sources, because natural resources, such as coal, gas and oil, are not infinite. <br /> This study focused on the imitation of photosynthesis for energy production. As a biological material for the experiments thylakoid membranes, isolated from spinach leaves, were used. By illuminating the electrodes modified with thylakoid membranes, with light of a certain intensity, remarkable current densities were detected. This was done in the presence of substances called mediators, which help transfer electrons to the electrode. Various experimental conditions, such as electrolyte strength and pH, were also tested.<br /> Thylakoid membranes consist of several components, which are involved in electron generation and transfer reactions. A part of this project was to find out which component is the main source of photocurrent by means of photosynthetic inhibitors – known herbicides. This study once again confirmed that the main source of electrons is a protein complex, which has the name “photosystem II”.<br /> Unfortunately, the biological material suffers from a short active life time under illumination, which means degradation and decrease of current with time. This study also attempted to keep the obtained photosynthetic electricity stable, with the help of cross-linking materials. As a result stability was achieved, but not the same current output. <br /> As a consequence of strong illumination highly reactive oxygen species (ROS), damaging the protein environment of thylakoid membranes, are produced. Some experiments were made to neutralize them by using certain enzymes. As a result higher currents were generated proving that ROS are one of the main sources of photodamage.<br /> This project can be considered as a small puzzle-piece in the worldwide investigation on development of alternative energy sources. The results obtained are noteworthy, and give challenge for future studies, especially with a focus on generation of stable photocurrent. https://lup.lub.lu.se/student-papers/record/4780433/file/4780435.pdf application/pdf 768523 yes 2014 eng analytisk kemi analytical chemistry Chemistry 4780433 2014-11-18T12:02:08+01:00 2014-11-18T15:41:34+01:00 2014-11-18T15:41:34+01:00

oai:lup-student-papers.lub.lu.se:4780449 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Helena Mateos author 4780502 Tobias Harlang supervisor Villy Sundström supervisor Department of Chemistry v1000647 department Dye sensitized solar cells (DSSCs) recently attracted much attention as a relatively efficient and inexpensive light-to-electricity energy conversion solution. So far the best performing DSSC devices were produced employing ruthenium (RuII) complexes as the active material, nevertheless limited resources of this metal initiated the research of new alternatives. Iron is one of the most abundant elements on earth and has similar electronic properties to ruthenium, being in the same group 8 in the periodic table, therefore, most recent studies of DSSCs are based on iron complexes. In this thesis, the process of electron injection from a novel iron (FeII) complex based on σ-donating N- heterocyclic carbene (NHC) ligands into the conduction band of titanium dioxide (TiO2) is investigated as a function of different conditions. Processes like the effect of molecular structure and presence of the electrolyte are also analyzed. The time-resolved absorption (TA) spectroscopy studies allowed to investigate ultrafast processes occurring within timescales as short as femtoseconds. The introduction of the carboxylic acid group into the molecular complex resulted in double the lifetime of metal-to-ligand charge transfer (MLCT) triplet state, which is an indication of more efficient electron generation processes. It was also found that the presence of the electrolyte alone could increase the lifetime of MLCT3 states. Finally, observations of transient absorption in films of TiO2 with the active material suggested possible electron injection, which is essential step for current generation in solar cell devices. The actual cost of production of conventional solar cells is too high, and they are only profitable for large commercial applications, therefore, research of new alternatives of solar cells is becoming increasingly important. Among this kind of research-cells, dye-sensitized solar cells are a promising future alternative due to the possible low cost and high performance ratio that could achieve, having the possibility of becoming good enough to be competitive with fossil fuel electrical power generation. Nevertheless, one of the main problems of this cells is the expensive materials needed for their fabrication based on ruthenium. The use of much cheaper iron materials instead, could be a future possibility and for this reason, further investigations of these molecules are of crucial importance. In this thesis, a promising new material based on iron is investigated by simulation of different performing solar-cell conditions.<br /> Dye sensitized solar cells are a new promising technology for harvesting solar energy. It’s advantages compared to conventional solar cells is that they are simple to produce, easy to incorporate into materials, and that they show high performance ratios, enabling them to be competitive with fossil fuel electrical power generation. One of the main challenges of these cells is that the most efficient ones are achieved using the rare earth element Ruthenium, of which the abundance is too low for large scale production. Iron is an obvious replacement candidate for Ruthenium, but so far no one has been able to produce an efficient iron compound for this purpose. In this thesis, a promising new material based on iron is investigated by simulation of different performing solar-cell conditions, and it is shown for the first time how the iron compound converts the solar energy into electricity. 2014 eng Dye sensitized solar cells DSSC transient absorption metal-ligand charge transfer electron injection iron complexes kemisk fysik chemical physics Chemistry 4780449 2014-11-18T13:07:16+01:00 2014-11-18T15:39:53+01:00 2014-11-18T15:39:53+01:00

oai:lup-student-papers.lub.lu.se:4780456 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anita Hoang author 3460192 Jakob Danielsson supervisor Department of Chemistry v1000647 department Abstract is attached at the heading Related Materials. Popular summery is attached at the heading Related Materials. https://lup.lub.lu.se/student-papers/record/4780456/file/4780461.pdf application/pdf 671629 yes 2014 eng organisk kemi organic chemistry Chemistry https://lup.lub.lu.se/student-papers/record/4780456/file/4780458.pdf application/pdf no https://lup.lub.lu.se/student-papers/record/4780456/file/4780460.pdf application/pdf no 4780456 2014-11-18T13:26:39+01:00 2014-11-18T15:38:54+01:00 2014-11-18T15:38:54+01:00

oai:lup-student-papers.lub.lu.se:4780491 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Marco Schröter author 4780667 Joachim Seibt supervisor Department of Chemistry v1000647 department The excitation energy transfer properties of dimer systems and the light harvesting complex 2 of purple bacteria are investigated using the hierarchy equations of motion approach. While the bacteriochlorophyll molecules are modeled as electronic two level systems applying the Frenkel exciton Hamiltonian, intramolecular vibrations and environmental uctuations are included via an experimental and model spectral densities. A Fourier analysis method is used to unveil the origin of oscillatory features in the evolution of the populations and coherences of the reduced density matrix. It is demonstrated that the underlying vibronic level structure is directly responsible for the observed long living oscillations. The photosynthesis of plants, algae and purple bacteria is a highly ecient process. Light, collected by huge antenna systems, is transfered via excitation energy transfer to the reaction center, where the energy is used to drive chemical reactions. Recent experiments gave rise to a discussion whether the transfer eciency is enhanced via a wavelike character of the transfer through a system. We investigate the transfer step in the light harvesting complex 2 of purple bacteria on the basis of reduced models, using the hierarchy equations of motion approach. This approach is highly ecient and allows an in principle exact description of the whole system which makes it possible to have a closer look at the origins of the experimental results. Our results indicate that vibrations of the molecules and the environment play an important role in the underlying mechanisms. https://lup.lub.lu.se/student-papers/record/4780491/file/4780506.pdf application/pdf 1016954 yes 2014 eng kemisk fysik chemical physics Chemistry 4780491 2014-11-18T15:09:08+01:00 2014-11-19T12:03:37+01:00 2014-11-19T12:03:37+01:00

oai:lup-student-papers.lub.lu.se:4780508 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Stefano Mensa author 4780666 Professor Salam Al-Karadaghi supervisor Department of Chemistry v1000647 department The abstract is attached under the heading Related materials. The popular summery is attached under the heading Related materials. https://lup.lub.lu.se/student-papers/record/4780508/file/4780523.pdf application/pdf 2687397 yes 2014 eng Molekylär biofysik molecular biophysics Chemistry https://lup.lub.lu.se/student-papers/record/4780508/file/4780516.pdf application/pdf no https://lup.lub.lu.se/student-papers/record/4780508/file/4780518.pdf application/pdf no 4780508 2014-11-18T16:01:15+01:00 2014-11-19T12:02:53+01:00 2014-11-19T12:02:53+01:00

oai:lup-student-papers.lub.lu.se:4780525 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anna Munke author 4780665 Sara Linse supervisor Department of Chemistry v1000647 department The aggregation of amyloid-β peptide (Aβ) into amyloid fibrils and plaques is one culprit to Alzheimer’s disease pathogenesis. Once a small concentration of amyloid fibrils has formed through primary nucleation, a fibril-catalysed secondary nucleation takes over, leading to a close to exponential growth. Here, we have investigated the effect of five (J46, I48, J44, I68 and J7) out of twelve previously selected, single chain antibody fragments (scFv’s) on Aβ42 aggregation. By monitoring Thioflavin (ThT) fluorescence as a function of time, a retarding effect on Aβ fibrillation was observed in presence of all scFv’s. The kinetic curves indicate at least three mechanisms of action; 1) J46 only affects the lag time, which suggest inhibition of the primary nucleation; 2) I48 and J44 only affect the elongation rate, which suggest inhibition of the secondary nucleation; and 3) I68 and J7 affect both the lag time and elongation rate, which suggest either a combination of the two mechanisms or an inhibition of fibril elongation. Spot Array and surface plasmon resonance (SPR) analyses of I48 and I68 confirmed their affinity for Aβ42 fibrils and suggested recognition of a conformational epitope. The SPR measurements also served to estimate the rate (ka and kd) and binding (KD) constants. The various amino acid compositions of the scFv’s complementary determining regions (CDR’s), revealed by DNA sequencing, imply that different intermolecular interactions are important for their binding to Aβ fibrils. This study shows that even though antibodies are selected against fibrils with the same technique, they can exhibit different properties. Thus, we suggest more in vitro studies during preclinical trials, as a complement to the in vivo, to increase understanding of the molecular effects on Aβ aggregation. Alzheimers sjukdom är den vanligaste orsaken till demens. Bland dem som är 65 år eller äldre, lider var åttonde person av sjukdomen. Åldrande, våld mot huvudet och nära släktskap med någon med Alzheimer är några riskfaktorer. Orsaken till symptom, såsom förvirring och minnesförlust, är att hjärncellerna bryts ner. Nedbrytningen beror i sin tur på att det sker en ökad produktion av det så kallade beta-amyloidproteinet, vilket hopar sig i hjärnan till plack. Det är själva anhopningsprocessen (”aggregeringen”) eller någon av de former som bildas på vägen som är giftiga. Det finns ännu inget läkemedel som kan fördröja eller stoppa sjukdomsprocessen. En behandlingsform som det forskas på är antikroppar; antikroppar som angriper beta-amyloidproteinet och hindrar det från att aggregera och därmed också förhindrar skadorna på hjärnan. De antikroppar som hittills testats i kliniska prövningar på personer med Alzheimer har haft dålig effekt och orsakat svåra biverkningar. I detta arbete har ett antal olika antikroppar mot beta-amyloidproteinet studerats. Alla undersökta antikroppar fördröjde aggregeringen. Till vilken grad och på vilket sätt aggregeringen fördröjdes, skiljde däremot mellan antikropparna. Vi fann att de aminosyror som är nödvändiga för att binda till beta-amyloidproteinet varierade mellan de olika antikropparna. Vidare försökte vi hitta vilka aminosyror hos beta-amyloidproteinet som binder antikropparna. Detta lyckades inte, vilket kan betyda att antikropparna endast känner igen beta-amyloidproteinet då det är i sin aggregerade form. Denna studie visar på hur olika egenskaper antikroppar mot beta-amyloidproteinet kan har. För att framtida kliniska prövningar ska lyckas bättre, föreslår vi därför en utökning av studier som denna under ett tidigt skede vid utvecklingen av ny antikropp. https://lup.lub.lu.se/student-papers/record/4780525/file/4780526.pdf application/pdf 5824084 yes 2014 eng proteinvetenskap protein science Chemistry 4780525 2014-11-18T16:25:25+01:00 2014-11-19T11:55:01+01:00 2014-11-19T11:55:01+01:00

oai:lup-student-papers.lub.lu.se:4780534 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Elsaid Sami Mohamed author 4780664 Torbjörn Åkesson supervisor Marie Skepö supervisor Department of Chemistry v1000647 department Milk is a complex liquid, which contains many different species, for example proteins, fat, minerals etc. It is the primary source of nutrition for young mammals before they are able to digest other types of food. The proteins can be divided into two groups: caseins and whey. Whey proteins are about 20 wt % of the total protein amount in milk, whereas the caseins corresponds 80 wt % of the total protein content in milk. The largest structures in the fluid portion of the milk are &quot;casein micelles&quot; which are aggregates of several thousands of protein molecules. The micelle is considered to be spherical and the diameter is in the micrometer size.<br /> <br /> The caseins can be divided in four types: αs1-­casein, αs2-­casein, β-casein, and κ-­casein. ß-­casein is one of the most abundant caseins and it also self-assembles to larger aggregates. In this thesis we have used a simple model to try to capture how electrostatic interactions affects the structure of β-casein micelles in milk. The micelles have been modeled as hard spheres, with a central net charge of -­ 140e, and a radius of 75 Å. These parameters have been taken from experimental data published in the literature. The structure of the solution has been studied by comparing the radial distribution functions for different solution conditions, such as the salt concentration and valency, pH, and the temperature. Milk is a complex liquid, which contains many different species, for example proteins, fat, minerals etc. It is the primary source of nutrition for young mammals before they are able to digest other types of food. The proteins can be divided into two groups: caseins and whey. Whey proteins are about 20 wt % of the total protein amount in milk, whereas the caseins corresponds 80 wt % of the total protein content in milk. The largest structures in the fluid portion of the milk are &quot;casein micelles&quot; which are aggregates of several thousands of protein molecules. The micelle is considered to be spherical and the diameter is in the micrometer size.<br /> <br /> <br /> In this thesis we have used a simple model and computer simulations to try to capture how electrostatic interactions affects the structure of β-­casein micelles in milk. The micelles have been modeled as hard spheres, with a central net charge of -­140e, and a radius of 75 Å. The volume fraction of was set to 5%, which is the actual volume fraction in the real product. The structure of the solution has been studied by comparing the radial distribution functions for different solution conditions, such as the salt concentration and valency, pH, and the temperature.<br /> <br /> <br /> It was noticed that due to the fact that the micellar charge is very large, the electrostatic repulsive interaction dominates, and the mean distance between the micelles are almost always obtained. Moreover, an increase of the temperature does not affect the structure at all i.e. the entropic contribution due to increased temperature can be neglected in comparison with electrostatic repulsion between the micelles. Also, there might also be an influence of the electric permittivity since it was kept constant during the simulations,<br /> <br /> <br /> When the salt concentration was increased to 80 mM, which corresponds to the ionic strength in milk, the structure of the β-­casein micelles resembles the structure of an ideal gas i.e. the electrostatic repulsive interactions are screened. https://lup.lub.lu.se/student-papers/record/4780534/file/4780540.pdf application/pdf 3136752 yes 2014 eng teoretisk kemi theoretical chemistry Chemistry 4780534 2014-11-18T16:45:26+01:00 2015-12-14T08:06:23+01:00 2014-11-19T11:54:15+01:00

oai:lup-student-papers.lub.lu.se:4780555 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ali Mouefaq Said Al-Salehi author 4780663 Ingela Fritzson supervisor Erik Hallin supervisor Department of Chemistry v1000647 department Malaria is one of the diseases that spread by insect vectors. The disease is carried to humans by female Anopheles mosquitoes. It is caused by the plasmodium types. The most prevalent and dangerous type of plasmodium is Plasmodium falciparum (Pf). The disease occurs in 104 countries and approximately 216 million new cases of malaria and around 655,000 deaths takes place every year. Many drugs have been developed against malaria, but unfortunately a lot of cases of malaria parasites’ resistance to these drugs have been recorded in many malaria regions, indicating a need for new drugs. The polyamine and pyrimidine biosynthesis pathways are highlighted as drug targets, due to their importance for the survival and reproduction of the parasites. One of the key enzymes in the polyamine biosynthesis pathways of Plasmodium falciparum is spermidine synthases (SpdS), while in the pyrimidine biosynthesis pathways it is the dihydroortate dehydrogenase (DHODH). The enzyme DHODH catalyzes the fourth step in the pyrimidine biosynthesis pathways. The conversion of dihydrorotate to orotic acid, while the SpdS converts putrescine to spermidine in the polyamine biosynthesis pathway.<br /> The aim of this project is to crystallize PfDHODH with different ligands. The co-crystallization technique requires using different methods (such as enzyme assay) to optimize various conditions, and also requires testing ligand binding when new molecules are available by using Differential Scanning Fluorimetry (DSF). In addition, we used Dynamic Light Scattering (DLS) to optimize protein buffer conditions and prevent protein aggregation. Malaria är en av de tropiska sjukdomarna som utgör ett stort hälsoproblem i många delar av världen. Sjukdomen orsakas av en så kallad tropisk parasit av släkte Plasmodium och överförs till människor via mygghonan Anopheles. Den vanligaste och mest dödliga formen av sjukdomen orsakas av Plasmodium falciparum (Pf). Den förekommer i 104 länder där ca. 216 miljoner nya fall registreras årligen. Av dessa leder ca. 655,000 fall till döden, mest bland barn. <br /> För närvarande har flera kända läkemedel mot sjukdomen blivit verkningslösa beroende på att malariaparasiten har utvecklat resistens. Detta medför en akut behov av nya läkemedel. Enzymer inom pyrimidinbiosynteskedjan har tidigare utpekats som möjliga mål i utvecklingen av nya läkemedel mot malariaparasiten. Inhibering av en så kallad mål-molekyl påverkar vanligtvis överlevnad och reproduktion av parasiten. Ett av de nyckelenzymerna i pyrimidinbiosynteskedjan är dihydroorotatdehydrogenas (DHODH), som katalyserar omvandlingen av dihydroorotat till orotat.<br /> Syftet med detta projekt var kristallisering av P. falciparum DHODH i komplex med olika ligander. Vid kristallisering av proteiner använder man olika biofysikaliska metoder för att optimera kristallisationsbetingelserna. Till exempel med så kallad Differential Scanning Fluorimetri (DSF) kan man undersöka om ligand binder till proteinet, medan Dynamisk Ljusspridning (DLS) används till att optimera buffertsammansättningen för att förhindra proteinaggregering.<br /> Flera nyproducerade föreningar har utvecklats med hjälp av virtuell screening och strukturbaserad läkemedeldesign. Potensen hos dessa föreningar (förmågan att hämma enzymet) uppskattades med hjälp av IC50-värden. Intervallen av IC50-värden för de undersökta föreningarna varierade mellan 300 nm och ≥ 250 µm, medan en del andra föreningar visade sig vara oförmögna att inhibera enzymet. Selektiviteten testades också för de hämmare som hade IC50 mellan 300 nm och 50 µm. Detta uppnåddes genom att skanna dessa hämmare mot humana enzymet (HsDHODH). Ingen av dessa föreningar visade dock aktivitet mot HsDHODH.<br /> En förening med arbetsbeteckningen AA_237729, som visade sig ha det lägsta IC50 värde valdes för kristallisering med PfDHODH. Kristaller som växte i dropparna hade en rektangulär form med dimensioner runt 0,05 mm x 0,04 mm. Dessa kommer att testas vid ett senare tillfälle i Röntgenstrålning. https://lup.lub.lu.se/student-papers/record/4780555/file/4780557.pdf application/pdf 3255910 yes 2014 eng molekylär biofysik molecular biophysics Chemistry 4780555 2014-11-18T18:05:38+01:00 2014-11-19T11:53:30+01:00 2014-11-19T11:53:30+01:00

oai:lup-student-papers.lub.lu.se:7373747 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Tinna Pálmadóttir author 7373745 Sara Snogerup Linse supervisor Department of Chemistry v1000647 department The formation of α-synuclein amyloid fibrils and accumulation in inclusion bodies termed Lewy bodies are considered the hallmark of Parkinson’s disease. It has been found that the formation of fibrils is highly pH dependent, which is thought to be linked to the highly negatively charged C-terminal tail of α-synuclein. The aim of this project was to study if the pKa values of the C-terminal tail in fibrils are upshifted compared to monomers. In order to investigate this, a method for the determination of pKa values of monomers and fibrils was developed and evaluated. The formation of fibrils in water was kinetically followed using Thioflavin-T dye and the morphology was observed by Cryo-TEM . Potentiometric titrations were performed on monomers and fibrils in water. Moreover, Metropolis Monte Carlo simulations were performed. One of the findings of this project was that the pH increases about one pH unit (5.3-6.3) as monomers form fibrils, providing strong indications of proton uptake during fibrillation and an upshift in the pKa values of the acidic residues. This is most likely linked to close proximity between the acidic residues of the C-terminal tail of monomers within the fibrils. Further experimental and theoretical studies need to be performed in order to get better understandings of the pH dependence of the underlying mechanism and the electrostatic interaction in amyloid formation of α-synuclein. Parkinson’s disease is the second most common neurodegenerative disease. The most common symptoms of this disease are shaking, rigidity and difficulties with motion, such as walking. The disease is caused by a loss of cells in the brain. The loss of cells is associated with the formation of rope-like structures. These structures are called amyloid fibrils and are formed from a smaller structural unit – a protein – that is called α-synuclein. The process of the formation of the fibrillar structure is toxic and kills the cells. Therefore, it is very important to understand how these fibrils form and what can affect their formation. In the case of Parkinson’s disease, research on the protein α-synuclein is important. <br /> A part of this protein is thought to affect the formation of the fibrils. This part of the protein is flexible and is called “the tail”. The tail has many negative charges. They negative charges do not like to be close to each other and therefore they push each other away. Because of that, the tail is flexible and stretched out. The tail is thought to affect the formation of the fibrils. For example, it is believed that the negative charges and flexibility of the tail has a protecting role and decreases the likelihood of the protein forming fibrils. Studies of the tail are therefore important and can provide a better understanding of the formation of fibrils.<br /> The tail was of central interest in this project. The goal was to measure special values – called pKa values – of the tail. The aim was to measure the values both before the protein forms fibrils and after the protein forms fibrils. These values are related to the pH scale which tell us how acidic or basic solutions are. The pKa values that we are interested in in this project tell us at which pH value the tail loses its negative charges. The hypothesis of the project was that these values change when the protein forms fibrils. Knowing this can increase our understanding about the behaviour of the tail and the effect of the tail on the formation of fibrils. One of the findings of this project was that when the protein forms fibrils the pH value of the sample increases. This finding strongly indicates that the pKa values increase as the protein forms fibrils. Further studies are important to increase our understanding of the fibril formation and the effects of the tail. 2015 eng potentiometric titration pKa values fibrils amyloid α-synuclein C-terminal tail protein science proteinvetenskap Parkinson's disease Chemistry 7373747 2015-06-19T12:46:29+02:00 2015-07-02T15:28:44+02:00 2015-07-02T15:28:44+02:00

oai:lup-student-papers.lub.lu.se:7373871 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Stella Persson author 5472131 Prashant Ranjan Verma supervisor Centre for Analysis and Synthesis v1000651 department Lymphangiogenesis, i.e. novel formation of lymph vessels, is known to be one of the underlying causes to the progression of a number of medical conditions, e.g. cancer, inflammation, graft rejection, and lymphedema. Galectin-8 is a tandem-repeat galectin comprised of two carbohydrate domains (CRDs), defined as the N-terminal (galectin-8N) and C-terminal (galectin-8C) CRDs. Galectin-8 has been observed to have a positive effect on signaling mechanisms inducing lymphangiogenesis. It has been shown that inhibition of galectin-8 antagonizes lymphangiogenesis and thus reduces the progression of the aforementioned disorders. The aspiration of efficiently treating these conditions subsequently motivates the development of high affinity inhibitor candidates of galectin-8N. Earlier studies have shown that galectin-8N naturally retains a high affinity to 3-O-sialylated lactose. Our aim was to explore and further develop the favorable binding interactions of galectin-8N and 3-O-sialylated lactose. This approach was carried out by chemically modifying a simplified version of the previously studied inhibitor by implementing carboxylic acid isosteres in order to introduce new functional groups on the 3-O position of galactose. Synthetic procedures were subsequently developed to enable the introduction of hydroxamate and sulfonamide functionalities on a β-D-galactopyranoside derivative. It was found that synthesized inhibitor candidates retaining a hydroxamate functional group possessed similar affinities (down to 520 µm) to galectin-8N compared to the corresponding carboxyl-substituted compound. These findings were interpreted as the combined effect on binding from the substituted arene and the hydroxamate functional group was comparable to the binding strength of the corresponding carboxyl-substituted compound. However, it could not be concluded which of and to what degree these functional groups contributed to the binding. The similar affinities of the synthesized inhibitors suggested a rather superficial structure activity relationship (SAR), which opens up for further optimization of the left-hand side substituents from the hydroxamate linker group Organisk kemi är läran om kolföreningarnas kemi och är en vetenskap som ligger till grund för att förstå praktiskt taget alla naturvetenskapliga områden. En viktig applikation är att med hjälp av kemisk syntes ta fram nya läkemedel. I takt med att vi blir allt äldre och vår livsstil förändras uppstår likväl alltfler problem med nya sjukdomar i en annan omfattning än tidigare och behovet av nya effektiva läkemedel tycks aldrig upphöra. Genom att framställa småmolekyler med rätt struktur kan dessa föreningar interagera med biologiska system i kroppen, vilket i sin tur kan leda till botande eller förmildrande av olika sjukdomar. Kroppens lymfsystem bidrar i normala fall till att dränera kroppens vävnader på vätska och återföra denna till blodcirkulationen och har även en viktig roll i immunsystemet. Lymfsystemet utvecklas till största del redan under fosterstadiet och i vuxen ålder sker nybildning av lymfkärl normalt i väldigt liten utsträckning. En onormal lymfkärlsfunktion har visats vara centralt i en rad sjukdomar och tillstånd, t.ex. inflammation, cancer, lymfödem och bortstötande av transplanterade organ. Galektin-8 är ett protein som förekommer naturligt i kroppen och som man har sett kan inducera nybildning av lymfkärl. I denna aktiveringsprocess binder galektin-8 till särskilda receptorer som i sin tur signalerar om att lymfkärl ska bildas. Genom att syntetiskt framställa molekyler som efterliknar delar av dessa receptorer kan man genom inbindning till galektin-8 hämma lymfkärlsbildning. På så vis kan man möjligtvis också förhindra fortskridandet av tidigare nämnda sjukdomar. I det här projektet har målet varit att syntetiskt framställa och utvärdera inbindningen av en ny serie galektin-8-hämmare. För de molekyler som framställdes i det här projektet såg vi att de hade liknande inbindningsstyrka som tidigare testade substanser. Med den information som erhölls kan vi se indikationer på hur särskilda kemiska strukturer korrelerar med hur proteininbindningen sker. Denna information kommer att användas för att förbättra designen av de befintliga kemiska strukturerna. På längre sikt kan detta leda till läkemedelskandidater som hämmar lymfkärlsnybildning genom stark inbindning till galektin-8. https://lup.lub.lu.se/student-papers/record/7373871/file/7373872.pdf application/pdf 3813990 yes 2015 eng Biology and Life Sciences Chemistry https://lup.lub.lu.se/student-papers/record/7373871/file/7373874.pdf application/pdf LU/LTH access 7373871 2015-06-20T17:40:31+02:00 2015-06-25T15:34:37+02:00 2015-06-25T15:34:37+02:00

oai:lup-student-papers.lub.lu.se:7440494 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH3 Joakim Andersen author 7440489 Gerhard Barmen supervisor Division of Engineering Geology v1000204 department Environmental Engineering (M.Sc.Eng.) v1000290 department PFOS (Perfluoroktansulfonat) har genom sina unika ytaktiva och beständiga egenskaper använts i en mängd olika tillämpningar och blivit ett av jordens mest spridda ämnen. Metallytbehandling, hydrauloljor till flygplan och impregnering av textilier hör till ämnets användningsområden, men mest uppmärksammat är nog tillsatsen till brandsläckningsskum där PFOS är den aktiva beståndsdelen. Upprepade släckningsövningar under en lång tid på samma plats har på platser där hydrogeologin är sårbar lett till spridning till dricksvattentäkter och påföljande upptag hos människor.<br /> I detta examensarbete har förekomsten av PFOS i Staffanstorps kommun kartlagts genom att potentiella källor identifierats och från dessa har spridningsförutsättningarna analyserats. Aktuella platser är: Brandövningsplatsen vid Lomma-Staffanstorps brandstation, den nedlagda kommuntippen och Staffanstorps reningsverk. De två senare har inkluderats på grund av en ansamling av diffusa utsläpp (från exempelvis tvätt och deponering av impregnerade textilier) som potentiellt kan koncentreras till punktutsläpp på dessa platser. Brandövningsplatsen har varit igång sedan slutet på 80-talet och övning med AFFF-skum har förekommit här vilket gjort ett utsläpp av PFOS sannolikt.<br /> Utsläppet från brandövningsplatsen har skett i ett område med dominerande moränlera, en ogenomsläpplig jordart, och låga skyddsvärden. Vattentäkter i form av en kalkstensakvifer, och ännu viktigare Alnarpsakviferen, är skyddsobjekt i närheten, som skulle kunna kontamineras av ett utsläpp om utbredda linser finns av genomsläppligare jordarter som sand och grus. De senare är ovanliga i området och i kombination med en dominerande grundvattenriktning bort från Alnarpssänkan, relativt små utsläpp och adsorberande och utspädande faktorer i jorden får en betydande påverkan anses ej trolig. De eventuella utsläppen från deponi och reningsverk är av en annan karaktär, spridning sker huvudsakligen i ytvatten, och halterna är troligtvis mycket lägre än vid brandövningsplatsen. Skyddsvärdet är på dessa platser dock väsentligt högre, då föroreningen riskerar påverka organismer i den för kommunen ovanliga biotopen kärr, som hyser ett mycket rikt växt- och djurliv.<br /> Provtagning och analys av PFOS (och relaterade ämnen) från brandövningsplatsen rekommenderas på grund av att halterna lokalt kan vara mycket höga. En undersökning här kan följaktligen ge ett bättre underlag för att bedöma behovet av, och möjligheterna för, saneringsåtgärder. PFOS (Perfluorooctane sulfonate) has, through its unique surface active and non-reactive properties been used in a range of applications and has become one of the earth’s most wide spread substances. Metal plating, hydraulic fluids and textile repellants are among the chemical’s field of application, but most attention has probably been given the presence in fire-fighting foam, where PFOS constitutes the active substance in AFFF. Repeated fire training during a long time at the same spot has in places with vulnerable hydrogeology lead to a spreading to aquifers used as drinking water resource and a following uptake in humans.<br /> In this thesis the presence of PFOS in the municipality of Staffanstorp has been mapped through identifying possible sources, and from that analyzing the conditions for spreading from those sites. Identified objects are the fire training site by the fire station, an old waste dump and the waste water treatment plant. The two latter are included due to the potential of diffuse emissions (from e.g. washing and disposal of impregnated textiles) concentrating at these sites. The fire training ground has been in use since the late 80’s and training with AFFF has occurred, making an emission of PFOS likely.<br /> The emission from the training ground has taken place in an area of mainly clay till, an impermeable deposit, and low protective values. Aquifers with drilled wells in form of a limestone bedrock and, more important, the Alnarp sediments could be in the risk of contamination if large layers of permeable soil such as sand or gravel would exist. These are however rare in the area, and combined with a dominating groundwater movement away from the Alnarp trough, relatively low emissions and adsorbing and diluting properties of the soil a significant impact remains unlikely. The potential emissions from the waste dump and waste water treatment plant are of another kind, spreading occurs mainly in surface water, and the levels of PFOS are most likely low. The value of protecting these places are however much higher, since the pollutant risks affecting organisms in the uncommon biotope fen, which has a very rich fauna and flora.<br /> Sampling and analysis of PFOS (and related substances) from the fire training site are recommended due to the fact that the levels may be locally very high. A better knowledge of the pollution level at the site would lead to possibilities of deciding the need and possibilities for decontamination. Brandskumskemikalien PFOS – så påverkar den Staffanstorp<br /> <br /> Det giftiga och bioackumulerande ämnet PFOS har upptäckts i dricksvattnet i flera kommuner, efter att invånarna helt ovetandes druckit det förorenade vattnet under många år. Höga halter i fisk har orsakat fiskeförbud i flera sjöar, och i rovdjur som uttrar konstateras oroväckande nivåer. Finns samma problem i Staffanstorp?<br /> PFOS (Perfluoroktansulfonat) är ett av jordens mest spridda ämnen och har uppmätts även i isbjörnar långt bort från mänsklig aktivitet. I Staffanstorp har de troligaste utsläppen av PFOS skett vid brandövningsplatsen, reningsverket och den gamla kommuntippen. Användningen av PFOS i brandskum är vad som orsakat de uppmärksammade fallen av förgiftat dricksvatten i bland annat Kallinge och Tullinge.<br /> Men allting började i USA på 50-talet, när några kemister spillde ut en blandning på sina skor. Fläcken gick inte att tvätta bort, och ingenting tycktes fastna på den. Blandningen innehöll PFOS och utvecklades till ett impregneringsmedel som både skyddade mot vatten och smuts och därför blev mycket populärt. Den utbredda användningen i impregnering av kläder och mattor (som slits bort när man tvättar produkterna eller slänger dem i en soptipp) är en av anledningarna till varför reningsverk och deponier har identifierats som utsläppskällor.<br /> En mycket viktig grundvattentillgång som bland annat förser Malmö med dricksvatten är belägen rakt under Staffanstorp. Som en skyddande barriär ligger ett tjockt lager av tät moränlera ovanpå dricksvattentäkten och hindrar tätortens utsläpp av föroreningar från att tränga ner. Dricksvattnet här kommer med största sannolikhet alltså inte förgiftas av PFOS.<br /> Men hur påverkas miljön i Staffanstorp? Utanför reningsverket och deponin finns för området unika naturområden där djur riskerar att påverkas av en utsläppt förorening. Halterna som släpps ut här är dock mycket lägre än från brandövningsplatser och kommer förmodligen inte upp i skadliga nivåer. Leverpåverkan och reproduktionsstör-ningar är annars effekter som skulle kunna uppstå hos de djur som lever här; och samma risker finns även för människor som druckit förorenat vatten.<br /> Spridningen av PFOS från brandövnings-platsen är troligtvis långsam, och området där utsläppet sker är mestadels industriområde. Så varför ska Staffanstorp ens bry sig om att ämnet finns här?<br /> PFOS bryts ALDRIG ner. Det vi släpper ut kommer finnas kvar i vår miljö även efter att utsläppen slutat. Om utspädningen är låg som vid brandövningsplatsen kommer höga halter finnas på ett begränsat område – och då är de förorenade massorna möjliga att gräva bort och bränna upp. Provtagning och analys av PFOS kan nu bli aktuellt i Staffanstorp för att om möjligt bli av med en del av det problematiska ämnet.<br /> <br /> Författare: Joakim Andersen<br /> Examensarbete: PFOS i Staffanstorps kommun<br /> En kartläggning av förorenade områden och analys av spridningsförutsättningar<br /> Avd. Teknisk geologi, Lunds tekniska högskola https://lup.lub.lu.se/student-papers/record/7440494/file/7440529.pdf application/pdf 3641911 no 2015 swe PFOS förorenade områden MIFO hydrogeologi miljö hälsa Chemistry Technology and Engineering Earth and Environmental Sciences ISRN LUTVDG / (TVTG-5138) / 1-45 /(2015) ISRN LUTVDG / (TVTG-5138) / 1-45 /(2015) https://lup.lub.lu.se/student-papers/record/7440494/file/7440534.pdf application/pdf no Examinor: Torleif Dahlin 7440494 2015-06-23T12:00:43+02:00 2020-09-10T09:44:56+02:00 2015-06-23T14:33:46+02:00

oai:lup-student-papers.lub.lu.se:7440629 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Neha Pimpalwar author 7371906 M.D., Ph.D. Björn Nilsson supervisor Department of Chemistry v1000647 department Background: Sequence variation within transcriptional factor binding sites can influence gene expression. We have found a four-nucleotide genetic variant in the Basigin (BSG) promoter region that disrupts a predicted GATA-1 binding site. BSG encodes a red blood cells surface protein on that is exploited as an invasion receptor by the malaria parasite Plasmodium falciparum. Hence the identified variant could mediate resistance, which is common in West Africa <br /> Aims and Objective: The aim of the study was to test the functional relevance of the GATA polymorphism and evaluate the effect of variant on the transcription of BSG by CRISPR-Cas9 genome editing as well as genotyping and real time PCR of samples of African origin to correlate BSG expression and protein levels. Furthermore to study the binding of GATA-1 transcription factor at reference/variant DNA sequences by electrophoretic mobility shift assay (EMSA).<br /> Methods and Results: EMSA was performed by incubating nuclear extract from K562 cells with reference sequence (i.e., promoter containing the identified GATA motif) and variant sequence (i.e., promoter lacking the GATA motif) probes followed by separation on gel, the EMSA assay showed stronger binding to the reference site than the variant. Additionally the genome editing CRISPR-Cas9 technique was employed to create cuts in the promoter near the site of the variant-of-interest. The Cas9-sgRNA vector successfully cut DNA and repaired by non-homologous end joining (NHEJ) as verified by Sanger sequencing. Finally we analyzed blood samples from African American blood donors by directed genotyping (Taqman assay) and qPCR to test for correlation between the variants and BSG expression. The genotyping data gave a minor allele frequency (MAF) of 2.1%, however in the 1000 Genomes database, the variant is found in 45 out of 1322 alleles (MAF = 3.4%) in the African super population a frequency of 0.02% of the variant allele. And preliminary qPCR amplification results showed lower transcript expression for homozygous sample than heterozygous.<br /> Conclusion: The EMSA showed differential binding to the reference and variant sites. We created a cutting vector to allow edits of the identified region in human cells. The calculated frequency for the deletion variant found to be slightly lower found in thousand genome database. Preliminary qPCR need some more optimization and further findings to understand the correlation between BSG expression and variant. <br /> Keywords: CRISPR, Basigin, GATA-1, Cas9, Plasmodium falciparum Genetic variation within transcription factor binding sites can effect gene expression. For example, variants (i.e. variation in a single or a few nucleotides across a given population) that interrupt binding sites of transcription factors can lead to decreased gene expression, or even null phenotypes where the gene is not expressed at all. We found a variant in Basigin (BSG) gene promoter region, which could affect the binding of GATA-1, a transcription factor essential for the development of red blood cells. <br /> BSG is a protein present on red blood cells that is hijacked as an invasive receptor by the malaria parasite Plasmodium falciparum. The found variant is present in malaria-endemic regions of West Africa and we hypothesise that it confers some form of resistance against malaria infection by decreasing expression of BSG. <br /> In this project we explored the functional effects of the BSG variant by CRISPR-Cas9 genome editing technology. In specific we aimed to insert the variant into a cell line by CRISPR and then test the expression levels by qPCR and western blotting. We are currently creating a cell line carrying the variant on both alleles and to do so we successfully created a cut in the BSG gene near the variant site by CRISPR-Cas9. The next step is to insert a donor template (carrying the variant) into the target DNA sequence, giving the desired cell line. Once the cell line is created, we will examine BSG expression in these cells. We also tested the association between the BSG expression and the variant in vivo by analyzing blood samples from 215 Africans American donors. We found 9 samples carrying the variant on one allele, but unfortunately did not find any samples carrying deletion on both alleles, making BSG gene expression in vivo difficult. <br /> Theoretically, clarifying the functional effect(s) of this variant will increase our understanding towards resistance to malaria by genetic variation. 2015 eng CRISPR Basigin Cas9 Plasmodium falciparum genotyping EMSA q-PCR proteinvetenskap protein science Chemistry 7440629 2015-06-23T13:23:24+02:00 2015-07-02T15:31:46+02:00 2015-07-02T15:31:46+02:00

oai:lup-student-papers.lub.lu.se:7442427 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Gerald Perry Estavillo Marin author 7442425 PhD Erik Andersson supervisor Packaging Logistics v1000238 department One of the leading challenges presented in 21st century for packaging industry is to address the growing environmental problems related to non-renewable flexible packaging. This leads to new growing interest in bio-based materials, among them cellulose nanocrystals (CNCs), which have already shown good performance in improving anti-fog and oxygen &amp; water vapor barrier properties when applied to flexible film. A fast and low-cost CNC extraction was explored in this research by using unbleached Kraft pulp as the cellulosic source and treatment with ammonium persulfate as sustainable method for extraction. Presence of CNCs and its properties were verified and investigated using fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and x-ray diffraction (XRD). CNCs were then used to coat PET plastic film and were subjected to contact angle measurement, oxygen permeability, transparence, and haze for comparison. Tests have shown excellent barrier and optical properties, comparable to cotton linter CNC coating extracted using acid hydrolysis, even with lower amount of CNC and thinner coating used by Kraft pulp. Making CNC bio-coating more affordable can reduce the amount of plastic usage in production leading to reduction of total weight, which can provide economic benefit to producers and environmental benefit through reduced energy use during transport. PET Coating from Nano-cellulose Makes Plastics More Sustainable<br /> <br /> One of the leading challenges presented in 21st century for packaging industry is to address the growing environmental problems related to non-renewable flexible packaging. But are we ready for a plastic-free world?<br /> Not quite, but we are getting there. Regardless of the ongoing debates on whether we should push for biodegradable plastics, or plastics made from bio-based materials, packaging researchers are also trying to find a new way to start making plastic more sustainable – through bio-coatings.<br /> We may have all seen coatings in packaging in our daily lives, such as the aluminum enclosed by thin plastic film in your bag of chips. Coatings act as barriers to oxygen and water vapor, which can greatly increase the shelf life of food. This substitutes the other option of using very thick plastic – saving material, energy and transportation costs. With the new trend of going nano-scale in the scientific world from electronics to health, nanotechnology is also creating new opportunities to improve our current state of packaging, particularly in the field of bio-coating.<br /> According to latest research performed in University of Milan’s PackLab, it is possible to extract cellulose nanocrystals (CNCs) from one of the ingredients in paper-making, called Kraft pulp, which is very cheap compared to other possible sources. These crystals can then be used as bio-coatings for packaging application.<br /> A fast, low-toxicity, sustainable and low-cost extraction of CNCs was explored in this research by using an oxidizer called ammonium persulfate. Making CNC bio-coating more affordable can reduce the amount of plastic usage in production leading to reduction of total weight, which can provide economic benefit to producers and environmental benefit through reduced energy use during transport.<br /> Tests of CNC-coated PET have shown excellent barrier and optical properties, comparable to cotton CNC coating. The results revealed astounding findings – Kraft CNC double coating managed to block oxygen by almost 10 times better than bare film. This result is comparable to Cotton CNC coating, even though the Kraft CNC were more diluted. Furthermore, it does not decrease visibility of the product inside packaging, when it was tested as packaging for breadsticks and readability of small print for as small as font 6.<br /> With the success of this exploratory research on the possibility of utilizing cheaper cellulosic source and its applicability for coating in flexible packaging, more researches are now being lined up. In the far future, bio-coatings can also be applied directly on paper, to make a 100% biodegradable packaging with all the gas and water/ water vapor barrier benefits.<br /> Ready or not ready, nanotechnology is taking us towards that plastic-free world. https://lup.lub.lu.se/student-papers/record/7442427/file/7442450.pdf application/pdf 2931351 no 2015 eng affordable CNC extraction high quality CNC sustainable packaging FT-IR TEM XRD contact angle transparency haze optical properties food packaging bio-packaging bio-coating plastics PET film polyethylene terephthalate Kraft CNC Kraft pulp cotton CNC oxygen barrier nanocellulose crystals ammonium persulfate CNCs cellulose nanocrystals Chemistry 978-91-7623-392-4 https://lup.lub.lu.se/student-papers/record/7442427/file/7442454.docx application/vnd.openxmlformats-officedocument.wordprocessingml.document no Introduction One of the leading challenges presented in 21st century for packaging industry is to address the growing environmental problems related to non-renewable flexible packaging. This leads to new growing interest in bio-based materials, particularly cellulose nanocrystals (CNCs) (see figure 1), which have already shown good performance in improving anti-fog and oxygen & water vapor barrier properties when applied to flexible film. Current existing extraction methods include use of acids, enzymes and oxidizers, by mechanical means, or combinations of these to isolate CNCs from the cellulosic material. A fast and low-cost CNC extraction was explored in this research by using unbleached Kraft pulp as the cellulosic source and treatment with ammonium persulfate (APS) as sustainable method for extraction. APS extraction has recently been attracting attention due to its properties being ideal for CNC extraction, such as low long-term toxicity, high water solubility, and low cost compared to its sodium and potassium counterparts, as well as to other previous harsh extractive agents. Presence of CNCs and its properties were verified and investigated using fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and x-ray diffraction (XRD). CNCs were then used to coat PET plastic film and were subjected to contact angle measurement, oxygen permeability, transparence, and haze for comparison. PET film was chosen since it is one of the most common type of plastic being used in food packaging. Materials and Methods Characterization of kraft pulp material was performed together with InnovHub – Paper Division, who assisted in performing the experiments according to standards being used in the paper industry. For the CNC extraction, swelling preparation was initially performed, where 10g dry weight of Kraft pulp was placed in 1000 ml beaker, diluted in 1-layer of distilled water, and stirred using magnetic stirrer. Heater temperature was increased to 70°C for 30 minutes, then cooled down in a cold water bath to reach the room temperature of 25°C. 340.5 g of ammonium persulfate (APS) was added to the cooled Kraft pulp solution to reach 1.5M APS, and was then stirred for another 30 minutes to allow the powder to dissolve completely. APS Extraction of Kraft Pulp This extraction method was based on patent with publication number EP 2513149 A1 filed by Leung, et al. It made use of 1.5M APS and was heated for 16 h at 70°C with high stirring speed for the cellulose nanocrystals extraction to occur completely. The sample was then removed from the heater, and was centrifuged using deionized water at 15,000 RPM for 20 minutes to concentrate the cellulose. It was centrifuged several times until it increased the pH level from around 0.2 to 3 (approximately 6 times). pH correction was then performed to the Kraft CNC solution, increasing it to pH 8 to avoid aggregation of the crystals in acidic environment. It was then subjected to ultrasonicator (UP400S 400W, hielscher Co., Germany) at 0.7 cycles of 20 minutes at 70% output to distribute CNCs evenly in the suspension. The solution was vacuum filtered using Whatman glass microfiber filter (grade GF/F, 0.7 µm) to remove fibers that did not react fully with APS treatment, and other big cellulose agglomerates and large contaminants that might have been introduced during the process. The Kraft CNC suspension was subjected to lyophilization by using a freeze drying machine (LIO-10P) for 3 days to get white Kraft CNC powder. The powder was rediluted using deionized water (18MΩ cm, Millipore Milli-Q Purification System) to reach 2.5% Kraft CNC solution, ultrasonicated for 5 minutes (0.7 cycles at 70% output), and applied to corona-treated PET film (25x20 cm2) for 20 rounds of rolling on one side of the plastic for approximately 3 minutes, improving adhesion of the nanocrystals on the surface of PET film. Automatic film applicator (ref 1137, Sheen Instruments, Kingston, UK) was used to apply the Kraft CNC solution evenly on top of the PET. Two samples were created: sample 1 having applied only 1-layer of Kraft CNC, while sample 2 was made by directly applying another round of coating using the automatic film applicator immediately after drying the first layer. It was then dried using the blower and air-dried for 24 hours. Results & Discussion TEM was used to identify physical properties of Kraft CNCs extracted in nanoscale level. Figure 2. TEM image of Kraft CNCs (left) and cotton CNC (right) at 92,000 x magnification Upon observing the image, it must be noted that the CNCs obtained have two distinct shapes: spherical and rod-like (see figure 2). APS concentration can influence the shape of CNC, as shown by the experiment involving different concentrations applied to a lyocell fiber matrix. It yielded a mixture of rod-like and spherical CNCs for 0.5M APS, but produced 100% spherical CNCs at 1M APS. On the other hand, acid hydrolysis extraction of Kraft pulp have yielded only rod-like crystal structure. Table 1. Characterization of Kraft pulp raw material Raw material kappa number α-cellulose % β-cellulose % γ-cellulose % lignin % Ash Kraft pulp 35.48 86.8 0.37 13.57 7.87 0 The Kraft pulp sample obtained was carefully characterized to identify its kappa number, lignin, and α, β, γ cellulose contents (see table 1). Having a kappa number of 35.48 for the sample acquired is around the kappa number range of 30-35 for Kraft pulp that underwent conventional cooking. Having the lignin content of 7.87% shows that the Kraft pulp is subjected to an alkalinity of 20-25% in a span of 60-90 min. The high α cellulose in the resulting characterization experiment shows that previous processes have caused low degradation to the cellulose. Table 2. Coating thickness comparison of kraft 1-layer, kraft 2-layer and cotton Sample Thickness (nm) Uncoated PET 0 Kraft 1-layer coating 132.90 Kraft 2-layer coating 411.39 Cotton layer coating 660.00 The thickness values in Table 2 show that the cotton CNC coated PET film has the highest thickness, which can be explained by the total amount of CNC used in the solution. The wettability of different samples shows that PET coated with cotton CNC has the best anti-fog property due to its very low contact angle measurement, allowing the water to spread to the solid surface. It is closely followed by Kraft 2-layers, with Kraft 1-layer exhibiting the lowest wettability. The increased amount of carboxylated CNCs in 2-layer compared to 1-layer have improved its hydrophilic interaction with polar water, thereby lowering the contact angle. Cotton APS managed to have a high transparency, with its transparency value being close to the bare film. Kraft 1-layer and 2-layer have lower transparency values, even though both of them are thinner than cotton APS (see table 2), and lower percentage of CNCs applied in the coating (2.5% vs 7%). This can be due to the fact that in comparison to cotton linters, which has been bleached and contains >99% cellulose, the unbleached Kraft pulp as source is relatively unpure, hence ion impurities might have influenced the slight decrease in transparency. To further verify the optical property of the samples, a sample logo with a subtitle of font 6, and website URL with font 11, were used. PET coated films still do have the same level of readability for both font sizes as compared to the bare film. This shows that in application to production, using Kraft CNC coating (both 1-layer and 2-layer at 2.5%) has almost negligible influence to transparency. Table 3. Oxygen transmission rate values of Kraft 1-layer, Kraft 2-layer, cotton and bare PET Oxygen Transmission Rate (O2TR (cc m-2 24h-1) 23°C) %RH Kraft 1-layer Kraft 2-layer Cotton Bare* 0 74.95 30 0.10 0.10 0.10 40 6.72 3.94 4.2 50 15.428 7.78 8.30 82 Given the relatively thinner size of both Kraft single and double layers as compared to cotton as seen on table 2 (132.90 nm and 411.39 nm vs 660.00 nm, respectively), and using less amount of CNC in the solution (2.5% vs 7%), the result has shown that Kraft CNC has exhibited a good potential as bio-coating source to improve oxygen barrier properties for PET film (15.43 O2TR for Kraft 1-layer and 7.78 O2TR for Kraft 2-layer vs 82 O2TR for bare under measurements at 50% RH) (see table 3). Conclusions The experiment has exhibited that high quality CNCs can be extracted from unbleached Kraft pulp, an unpure cellulose material source, and can be utilized as a high quality bio-coating for PET to improve its packaging properties. Ammonium persulfate has proven to be an efficient extracting agent for unbleached Kraft pulp. Kraft pulp preparation, which includes swelling using distilled water at elevated temperature (70°C) for 30 minutes, cooling down, and mixing it with APS at room temperature for 30 minutes, were shown to be important steps to execute before proceeding with APS activation via heating. Kraft CNC was successfully applied on PET, and different parameters related to packaging were performed. Oxygen permeability is an important property particularly for food packaging due to its potential effects on quality and shelf life. Kraft 2-layer showed positive results in terms of oxygen permeability rate at 30% and 40% RH. This is comparable to CNC coatings extracted using acid hydrolysis and acquired from cotton linters, which contains > 99% alpha-cellulose. Optical properties were also tested, given the transparent flexible packaging’s importance to better market the products on the shelves by showing the actual product to consumers via see-through packaging, while keeping its protective barrier properties. Both Kraft 1-layer and 2-layer showed hydrophilic contact angles when in contact with water, denoting a good wettability and anti-fog property. However, more tests must be performed to verify its response when used in actual packaging. It must be highlighted that these results are based on 2.5% CNC re-dilution with distilled water after freeze drying using Kraft CNC extracted from the experiment, compared to 7% re-dilution of cotton CNC from acid hydrolysis. This re-diluted solution was used for coating application on PET film. This shows that Kraft CNC needed a lower amount of CNC concentration to achieve similar improvements observed from cotton CNC. Utilizing unbleached and semi-processed Kraft pulp as cheaper material to extract CNC, in comparison to the heavily-processed cotton linters, was proven to be possible. Given the results, it can therefore be concluded that CNC bio-coating sourced from unbleached Kraft pulp provided a high quality bio-coating for PET, improving its optical and permeability properties. It has also provided a better alternative for a low cost extracting process at a shorter time (against acid hydrolysis, which includes dialysis step that lasts for 3-4 days). Application of this type of bio-coating can lead to reduction of total packaging weight by utilizing thinner and lighter plastics since its barrier properties were already improved. This can eventually provide economic benefit to producers and environmental benefit such as reduced energy use during transport. 7442427 2015-06-23T16:46:31+02:00 2015-06-24T10:44:22+02:00 2015-06-24T10:44:22+02:00

oai:lup-student-papers.lub.lu.se:7444716 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Sinead Leavy author 7442457 Henry Ampah-Korsah supervisor Department of Chemistry v1000647 department Major intrinsic proteins (MIPs) are proteins that allow the passive transfer of uncharged molecules through a membrane. They have many subfamilies the least understood of which is “X” intrinsic proteins (XIPs). The X illustrates that they are functionally uncharacterized. XIPs have previously been shown to facilitate the transport of boric acid, hydrogen peroxide, urea and glycerol across the membrane. This project focused on the Nicotiana benthamiana XIP1;1. It contains an extraordinary long N-terminal region that previous studies show abolish the expression when truncated. The N-terminal region also contains a lot of serine and threonine residues. These residues are most commonly associated with phosphorylation, which is a post translational modification (PTM). This study created constructs of varying length that would eliminate some of these putative phosphorylation regions and potentially influence the expression of the construct in the expression host Pichia pastoris. P. pastoris is a eukaryote and therefore expected to carry out PTMs similar to higher organisms. Its alcohol oxidase 1 promoter can be induced with methanol to produce high quantities of a specific protein. The constructs were successfully overexpressed by this promoter in P. pastoris and were also shown to be sensitive to boric acid as shown in the boric acid growth toxicity assay. All constructs showed decreased growth when compared to the empty plasmid which indicates that the constructs were successfully translated and inserted into the plasma membrane of the yeast. Another conclusion was that the better performing transformants were found on selection plates with the highest zeocin concentration used. These would have incorporated a high gene copy number of the zeocin resistance selection marker and the construct into the P. pastoris genome, and results indicate that this increases protein expression. Water is the molecule of life. Every cell in our body needs the right water content to function properly. For this to occur water needs a way to enter or exit the cells. One major way for this to happen is by allowing water to pass through proteins that form channels for water in the membrane that delimits the cell. Specific membrane proteins called aquaporins or major intrinsic protein (MIPs) provide for this function. There are many different types of MIPs and they all share a structurally conserved architecture. However not all MIPs facilitate the transfer of water through the membrane. The protein I studied, XIP1;1 from the tobacco plant Nicotiana benthamiana, belong to the “X” intrinsic proteins (XIPs), a subfamily of MIPs, and does not facilitate the transfer of water. The X in XIPs means its function in plants is not known. The XIP selectivity filter is different to MIPs that transport water and previous studies have shown that XIPs can facilitate the transfer of boric acid, hydrogen peroxide, urea and other hydrophobic solutes across the membrane. <br /> A unique aspect of XIP1;1 is that it has a very long N-terminal region. This region is at the beginning of the protein and reside inside the cell. In earlier studies where almost all of this region has been deleted the production of the protein was much reduced. In the N-terminal region there are a lot of sites that could potentially be modified by the addition of a phosphate group. These modifications may structurally change a protein and thereby regulate its localization and function. The aim in this project was to create constructs of various lengths and to investigate the impact of these N-terminal deletions on the expression and function of XIP1;1 protein in the yeast Pichia pastoris. P. pastoris was used because it can be manipulated to produce a high quantity of a specific protein and this has successfully been employed for production of membrane proteins from both plants and animals. Another reason for using this yeast is because it is a eukaryote and it may therefore support similar additions of phosphate groups that potentially occur in plants. <br /> Once the correct constructs in P. pastoris were obtained they were tested, using a boric acid growth toxicity assay. Boric acid was used because it was seen in previous experiments to have a detrimental effect on the growth of yeast cells making closely related XIPs. The slower the growth, the more efficient transfer of boric acid across the membrane. Indeed, each construct grew at a different pace but they all grew slower than a control with no XIP gene. The results showed that the constructs were successfully produced and inserted into the yeast cell membrane. In contrast to yeast, plants need boron to sustain the integrity of the cell wall and boron deficiency is harmful to plants. A plausible physiological function of XIPs is to facilitate the uptake and transport of boric acid in plants. https://lup.lub.lu.se/student-papers/record/7444716/file/7471366.pdf application/pdf 1351675 yes 2015 eng proteinvetenskap XIP major intrinsic protein Nicotiana benthamiana Boric acid Pichia pastoris membrane MIP protein science Chemistry 7444716 2015-06-24T11:48:23+02:00 2015-07-02T14:48:34+02:00 2015-07-02T14:48:34+02:00

oai:lup-student-papers.lub.lu.se:7449223 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Lina Falk author 7449220 Dr Åsa Davidsson supervisor Tobias Hey supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Med anledning av de ökande utsläppskraven för avloppsreningsverk kommer ökade resurser i form av elektricitet och kemikalier att krävas om dagens teknologi ska användas även i fortsättningen. Följaktligen undersöks för tillfället mer effektiva metoder, vilka tillåter inte bara rening av avloppsvattnet utan även erbjuder en möjlighet att ta tillvara på de resurser som finns i avloppsvattnet. En resurs av särskilt intresse för den här studien är det organiska materialet, vilket kan användas för produktion av förnyelsebar energi.<br /> <br /> Ett innovativt kompakt avloppsreningskoncept utvärderas för närvarande i forskningsprojektet ”Den varma och rena staden”. En pilotanläggning har installerats på Källby avloppsreningsverk i Lund, bestående av ett trumfilter följt av ett membran för mikrofiltrering och ett biomimetiskt membran för osmos. Syftet med det nya konceptet är att det ska ersätta försedimenteringen och det aktiva slamsteget på ett konventionellt avloppsreningsverk. En av fördelarna med detta koncept är en ökad avskiljning av organiskt material från avloppsvattnet<br /> till sidoströmmarna som genereras. Genom ytterligare tillsats av fällningskemikalier, kan avskiljningsgraden för suspenderade partiklar och fosfor ökas ytterligare.<br /> <br /> I denna studie har sidoströmmarna som genereras av trumfiltret och<br /> mikrofiltreringsmembranet utvärderats med hänsyn till deras lämplighet för anaerob rötning. Genom satsvisa rötförsök har metanpotentialen för trumfilterslammet med och utan kemisktförbättrad förbehandling jämförts med den för det konventionellt genererade slammet på<br /> Källby avloppsreningsverk.<br /> <br /> Vidare, för att öka lösligheten av organiskt material och genom detta även<br /> biogasproduktionen har dessutom möjligheten att använda biologisk hydrolys som<br /> förbehandlingssteg innan den anaeroba rötningen utvärderats.<br /> <br /> Resultaten från de satsvisa rötförsöken med obehandlat respektive kemiskt förbehandlat<br /> trumfilterslam visade en högre metanpotential än det motsvarande konventionella<br /> blandslammet som för tillfället rötas i rötkamrarna på Källby avloppsreningsverk. En ännu<br /> högre metanpotential uppnåddes när biologisk hydrolys tillämpades som förbehandling av det<br /> råa respektive kemiskt förbehandlade trumfilterslammet. Förutom högre metanpotentialer för<br /> trumfilterslammet, påvisades även en snabbare metanproduktion för trumfilterslammet i<br /> början av de satsvisa rötförsöken.<br /> <br /> Vidare ledde användningen av biologisk hydrolys som förbehandlingssteg även till en ökad<br /> löslighet av de organiska materialet i slammet från den kompakta avloppsreningsprocessen.<br /> Specifikt ökade den uppmätta mängden av lättflyktiga fettsyror, vilket är en viktig komponent<br /> i produktionen av metan, och bidrog till en ökad metanpotential i de satsvisa rötförsöken.<br /> Dessutom visade sig, genom mätningar av slamvolymindexet, både trumfilterslammet och<br /> retentatet från membranet för mikrofiltrering möjligt att förtjocka även om ytterligare analyser<br /> och tester krävs för att fastställa vilken metod som är den mest lämpade. Ytterligare<br /> undersökningar krävs även för att utvärdera metanpotentialen för slammet som framställs från<br /> de olika konfigurationerna för den kompakta pilotanläggningen för rening av avloppsvatten. Due to increasingly stringent outlet demands from waste water treatment plants, more resources in the form of electricity and chemicals will be needed if today’s technology is to be used henceforth. Consequently, more efficient methods are being investigated, which allow not only for the waste water to be treated but also offer an opportunity to utilise the resources present within the waste water. A resource of particular interest for this study is the organic matter, which can be used for the production of renewable energy.<br /> <br /> An innovative compact waste water treatment concept is currently being evaluated in the research project “Den varma och rena staden” (The warm and clean city). A pilot plant has been installed at the Källby waste water treatment plant in Lund consisting of a drum filter followed by a microfiltration membrane and a biomimetic membrane for forward osmosis.<br /> The idea of this new concept is to replace the primary clarifier and activated sludge step of a conventional waste water treatment plant. One of the advantages of this concept is an augmented extraction of organic matter from the waste water to the side streams generated.<br /> By the additional use of chemically enhanced primary treatment the separation efficiency of suspended solids and phosphorus can be further enhanced.<br /> <br /> In the present study the side streams generated by the drum filter and the microfiltration membrane have been evaluated with regard to their suitability for anaerobic digestion. By means of biochemical methane potential tests, the methane potential of the drum filter sludge with and without chemically enhanced primary treatment was compared to that of the conventionally generated sludge at Källby waste water treatment plant.<br /> Furthermore, in order to increase the solubilisation of organic matter and by that the biogas production the potential of using biological hydrolysis as a pre-treatment step before the anaerobic digestion has been evaluated as well.<br /> <br /> The results from the biochemical methane potential tests using non-hydrolysed raw<br /> respectively chemically pre-treated drum filter sludge showed a higher methane potential than for the conventional mixed sludge currently fed to the anaerobic digesters at Källby waste water treatment plant. An even higher methane potential was achieved when using biological hydrolysis to pre-treat the raw respectively chemically pre-treated sludge. In addition to higher methane potentials for the drum filter sludge, a faster initial methane production was also seen for the drum filter sludge in the biochemical methane potential tests.<br /> <br /> Furthermore, the application of biological hydrolysis as a pre-treatment step led to an increased solubilisation of the organic matter in the sludge from the compact waste water treatment process. Especially the measured amount of volatile fatty acids, a necessary component used for the production of methane, increased and conduced to a higher methane potential in the biochemical methane potential tests.<br /> <br /> Moreover, both the drum filter sludge and the membrane retentate proved to be possible to thicken through measurements of the sludge volume index, although further analyses and tests are needed in order to determine the most suitable method. Further investigations are also required in order to evaluate the methane potential of the sludge generated for the other configurations of the compact waste water treatment pilot plant. https://lup.lub.lu.se/student-papers/record/7449223/file/7449597.pdf application/pdf 3079873 no 2015 eng biological sludge hydrolysis biogas biochemical methane potential tests compact waste water treatment drum filter anaerobic digestion microfiltration environmental engineering water engineering avloppsteknik vattenförsörjningsteknik Chemistry 7449223 2015-06-25T12:40:40+02:00 2015-06-25T15:42:09+02:00 2015-06-25T15:42:09+02:00

oai:lup-student-papers.lub.lu.se:7510728 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Malin Alsved author 7510726 Karin Hjerpe author 7510724 Johan Svensson Bonde supervisor Senior scientist Sokol Ndoni supervisor Pure and Applied Biochemistry v1000655 department Deepening our knowledge about bacterial infections is of high priority in the work against antimicrobial resistance. Many infections are as well polymicrobial, and the different bacterial species are able to affect each other by cell-cell communication. This is a phenomenon that in several cases is known to enhance the virulence and the severity of the infection. Therefore, new approaches to study bacterial interactions are needed.<br /> In this project we have designed a bacterial growth chamber with a porous membrane as a separating wall between two bacterial species. This gave us the ability to discriminate what molecules that can be exchanged between the bacterial cultures by choosing the membrane properties. The setup allows the two bacterial cultures to be spatially separated, yet chemically connected via diffusion through the growth medium and the porous membrane. Two different kinds of hydrophilic membranes were chosen for investigation of their performance as filters in this membrane setup for bacterial growth: a block copolymer based membrane with a pore size of 10 nm and commercially available Millipore membranes with two pore sizes of 220 and 450 nm respectively.<br /> The studied bacterial interaction is between Pseudomonasaeruginosa and Staphylococcus aureus, two commonly found bacterial species in the lungs of patients with Cystic Fibrosis and in chronic wounds. We could conclude that bacterial interspecies cell-cell communication through a membrane was possible in our setup. Further, a double membrane setup with a water phase in between the membranes, showed the same bacterial interaction. This last setup enabled molecular analysis of the water phase and thereby the signal molecules. Kan man tjuvlyssna på bakteriers kommunikation? - I infektioner finns ofta flera olika sorters bakterier och de kommunicerar med varandra. Detta kan förvärra infektionen och leda till antibiotikaresistens. Nya metoder behövs därför för att ta reda på mer om de signalmolekyler som bakterier använder för att kommunicera. https://lup.lub.lu.se/student-papers/record/7510728/file/7510729.pdf application/pdf 23434034 no 2015 eng tillämpad biokemi applied biochemistry Biology and Life Sciences Chemistry https://lup.lub.lu.se/student-papers/record/7510728/file/7510731.pdf application/pdf yes 7510728 2015-07-01T22:48:49+02:00 2015-07-02T11:51:07+02:00 2015-07-02T11:51:07+02:00

oai:lup-student-papers.lub.lu.se:7512736 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Alfred Carlsson author 7512734 Sven Lidin supervisor Centre for Analysis and Synthesis v1000651 department Binary alloys comprising of the rare earth metals along with ruthenium, RE-Ru, have been noted to display superconductivity at low temperatures. Furthermore the alloys display interesting magnetic properties such as anomalies in magnetization measurements below the magnetic ordering temperature. In order to understand how some compounds obtain these intrinsic properties it is vital to investigate the crystallography of the compounds. In this thesis the structure, LaRux, of compounds comprising praseodymium, neodymium or lanthanum in the 35-38 at. % Ruthenium region has been investigated with modern x-ray diffraction techniques. Other compounds, Er3Ru2 and Y44Ru25, in the 30-40 at. % Ru region has been noted to show evidence of possible superstructure and has also been examined with x-ray diffraction in order to establish the connection between the two related crystal structures and to fully understand the extent and nature of the structures. <br /> The structure of the incommensurately modulated two composite compound Er3Ru2 was solved using the current (3+1)d superspace approach from structure data which was collected with x-ray single-crystal diffraction. The structure solution, performed with the charge-flipping algorithm, resulted in the non-centrosymmetric super-space group X3 (00γ)0 with a = b = 13.893 (4) Å, c = 4.0005 (12) Å q = 1.572 c*.<br /> The possibility for superstructure descriptions for the Y44Ru25 and the LaRux compounds could also be concluded. The diffraction patterns of both compounds contained satellite reflections, indicating superstructure. Furthermore the Y44Ru25 structure could be solved well with two symmetry incompatible lattices further strengthening the possibility of superstructure. Therefore it could be concluded that these compounds most likely can be well described with the superspace description. The task of describing them in higher-dimensions was not completed in this thesis and is considered future work. Binära föreningar beståendes av sällsynta jordartsmetallerna och rutenium uppvisar intressanta egenskaper såsom superledande förmåga och intressanta magnetiska egenskaper. För att förstå varför vissa föreningar uppvisar sådana egenskaper är det essentiellt att studera föreningarnas kristallstruktur. I denna rapport undersöks föreningar, i 35-38 at. % Ru regionen, beståendes av praseodym, neodymium eller lantan med hjälp av röntgendiffraktionsanalys. Andra faser i 30-40 at. % Ru, specifikt Er3Ru2 och Y44Ru25, har uppvisat tecken som tyder på att dessa strukturer bättre kan beskrivas i högre dimensioner, s.k. super-rymden. Även dessa föreningar har undersökts med röntgendiffraktionsanalys för att kunna ge en ny beskrivning av dess kristallstruktur. <br /> Strukturen av den inkommensurat modulerade kompositstruktur föreningen Er3Ru2 löstes framgångsrikt med hjälp av den rådande (3+1)d formalismen. Strukturlösningen gjordes med hjälp av programmet Jana2006 som använde data genererad från röntgendiffraktometern. Struktur lösningen resulterande i super-rymdgruppen X3(00γ)0 med cellparametrarna a = b = 13,893 (4) Å, c = 4,0005 (12) Å q = 1,572 c*. <br /> Den högre dimensionella beskrivningen av de två andra föreningarna utfördes inte i detta arbete. Flera indikationer på att dessa föreningar kan beskrivas väl i högre dimensioner kunde dock påvisas. Diffraktionsmönstren för de båda föreningarna visade sig innehålla, förutom huvudreflektioner, satellitreflektioner vilket indikerar en superstruktur. Föreningen bestående av yttrium och rutenium kunde dessutom beskrivas väl av två symmetriinkompatibla gitter vilket är ytterligare en indikation för förekomsten av en superstruktur. This thesis has answered the question; are the Er3Ru2, Y44Ru25 and LaRux crystal structures aperiodic in three-dimensions and therefore better described in higher dimensions? The short answer to the question above is yes! All three crystal structures can most likely be better described in four dimensions. https://lup.lub.lu.se/student-papers/record/7512736/file/7512737.pdf application/pdf 1780524 no 2015 eng Crystallography Higher-Dimensional Crystal Structures Aperiodic Structures Er3Ru2 LaRux Y44Ru25 Superspace Rare Earth-Ruthenium Binary Rare Earth-Ruthenium Systems Chemistry https://lup.lub.lu.se/student-papers/record/7512736/file/7512739.pdf application/pdf no 7512736 2015-07-06T15:01:08+02:00 2015-08-18T11:25:51+02:00 2015-08-18T11:25:51+02:00

oai:lup-student-papers.lub.lu.se:7516536 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Mikael Leveau Novén author 7511506 Daniel Topgaard supervisor Stefanie Eriksson supervisor Biophysical Chemistry v1000649 department The diffusion characteristics of water can be measured by using NMR methods. Specifically, the diffusion profiles in samples containing domains of water barriers are of major importance to be able to describe in applications such as diffusion tensor imaging or diffusion MRI-sequences. These sequences can be used to study the internal structure of samples of complex diffusion profiles. The diffusion characteristics can be described by a diffusion tensor matrix which can be parameterised by the isotropic diffusion coefficient and the level of anisotropy. This thesis work aims to measure diffusion weighted NMR signals from a triple-stimulated spin-echo pulse sequence to simultaneously determine both the diffusion tensor characteristics and the orientation density function, ODF. Traditionally, obtaining the ODF is based on assuming a fixed diffusion tensor in a diffusion-weighted NMR experiment to describe the different signal attenuations along different directions as differences in the shape of the microscopic water domains. By the work presented in this report, it is proven by measurements on lyotropic liquid crystal systems that the shape of the diffusion tensor and the ODF indeed can be extracted from the same measurement. This is shown for samples having either prolate or oblate diffusion tensors. Mapping the inside: Study of water diffusion using NMR experiment<br /> <br /> This work shows how the internal structures of samples, which for instance could be cells or crystals, containing microscopic water channels and other structures where the water molecules can move in some directions but not in others can be determined in detail by looking at the magnetic properties of atomic nuclei. In order to see the structures in which the water molecules can move, two kinds of information about how the molecules move around are needed. First, the way in which the water molecules can move inside of the channels, i.e. the diffusion of water, must be known. Second, the difference in how the water molecules can move around depending on the direction within the sample must be known. Older ways of finding out the latter depends on guessing the former. The technique described in this work shows a way to determine both in the same measurement.<br /> <br /> When you measure temperature with a thermometer it is the motion of molecules that is measured. Every molecule in a liquid moves around freely and randomly while still bumping into other molecules. This motion of molecules is called diffusion. Nuclear magnetic resonance (NMR) spectroscopy is the study of how the magnetic properties of atomic nuclei change from the influences of magnetic fields. As all nuclei are found within molecules and the molecules move around, it is understandable that the NMR signal can change if the molecules move around. In my work, I have shown that a NMR method can be used to map the diffusion of water molecules inside samples that have thin channels or corridors that the water molecules can move around in. Similar methods are used to map diffusion of water in the neurons in the brain, which among other things can show how the neurons are connected. The new thing that I showcase in my report, is that it is possible to determine two important features of the sample; both how much the water diffusion only can occur in one direction and also which directions the channels and corridors are oriented in. Previously, it has not been possible to determine both based on the same measurement. This improvement is important as it helps to make the map of the channel orientations more reliable. In the future, this might be used to study samples which is has a complex microscopical environment where the water molecules move around in wide or narrow corridors, big halls, and across planes. One very important application of this could be to gain more understanding of both the types, conditions, and structure of cells and tissues of the brain if the experiment could be performed in a clinical MRI scanner. https://lup.lub.lu.se/student-papers/record/7516536/file/7516627.pdf application/pdf 14915161 no 2015 eng Diffusion NMR ODF NMR Diffusion biophysical chemistry biofysikalisk kemi Chemistry Technology and Engineering 7516536 2015-07-08T14:23:44+02:00 2015-10-08T16:27:22+02:00 2015-10-08T16:27:22+02:00

oai:lup-student-papers.lub.lu.se:7520418 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Dennis Bengtsson author 7520416 Sophie Manner supervisor Centre for Analysis and Synthesis v1000651 department Proteoglycans (PG) are comprised of a core protein with a varying number of glycosaminoglycan (GAG) chains attached. Both PGs and GAG chains are involved in biological processes such as cell growth and dif-ferentiation. Both their structure and the expression of enzymes involved in their biosynthesis differ between cancer cells and healthy cells. Heparan sulfate(HS) and chondroitin sulfate/dermatan sulfate (CS/DS) GAG chains are primarily involved in cellular signaling. The second step in HS and CS/DS GAG chain synthesis is galactosylation of the unusual carbohydrate xylose, catalyzed by the enzyme β-1,4-Galactosyltransferase 7 (β4GalT7). β-D-xylopyranosides with hydrophobic aglycons, modified at one hydroxyl group has previous-ly been shown to have both initiating and inhibitory effects on β4GalT7 catalyzed HS and CS/DS GAG chain biosynthesis. To gain more knowledge about both the biological and the pathobiological role of HS and CS/DS GAG chains, as well as to generate potential lead compunds for future drugs targeting diseases de-pendent on GAG chains, the development of new, more efficient β4GalT7 inhibitors is vital. Synthetic routes for three new β-D-xylopyranoside-based potential β4GalT7 inhibitors have been developed. The xylose moiety of each potential inhibitor has been modified at both the C-2, and the C-4 hydroxyl group, to produce epi-, methoxy-, and deoxy-analogs. When a synthetic protocol for a complete series of 2,4-modified fluoro-, epi-, methoxy-, and deoxy-2-naphtyl β-D-xylopyranosides has been developed, their inhibitory effects on β4GalT7 will be investigated. https://lup.lub.lu.se/student-papers/record/7520418/file/7520420.pdf application/pdf 1431804 LU/LTH access 2015 eng organisk kemi organic chemistry Chemistry https://lup.lub.lu.se/student-papers/record/7520418/file/7520422.pdf application/pdf LU/LTH access 7520418 2015-07-10T11:44:55+02:00 2015-10-15T16:31:31+02:00 2015-10-15T16:31:31+02:00

oai:lup-student-papers.lub.lu.se:7766479 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Axel Rüter author 7761010 Professor Lei Ye supervisor Pure and Applied Biochemistry v1000655 department Molecular imprinting technology is a field where polymer technology is<br /> utilised to synthesise high affinity particles, much like antibodies. This<br /> project has dealt with the imprinting of the neurotransmitter molecules serotonin<br /> and histamine. Serotonin polymers were synthesised using methacrylic<br /> acid and acrylamide as functional monomers relying on hydrogen bonding<br /> for the imprinting effect. None of the produced batches showed any sign of<br /> imprinting. Instead histamine polymers were successfully synthesised showing<br /> specific binding with the average binding affinity Kd = 0:61 mM and the<br /> approximate number of binding sites N = 50 μmolg The common ways of measuring different analyte concentrations in the human blood are often based on antibodies. These biomolecules possess the best chemical recognition known and can easily distinguish friend from foe. Their perfection does however come at a very high price. Molecularly imprinted polymers (MIP) are a way around this. Easily chemically produced and much cheaper, these artifical antibodies can be incorporated in simple electrochemical devices for fast and precise concentration measurements, hopefully revolutionising the field of medical analysis. https://lup.lub.lu.se/student-papers/record/7766479/file/7766483.pdf application/pdf 15157783 no 2015 eng serotonin histamine imprinting neurotransmitter MIP sensor voltammetry applied biochemistry Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/7766479/file/7766488.pdf application/pdf A popular science summary to the master's thesis "Neurotransmitter MIPs for the Potential Use in Amperometric Sensors", by Axel Rüter. no 7766479 2015-08-24T11:18:29+02:00 2015-09-07T09:50:37+02:00 2015-09-07T09:50:37+02:00

oai:lup-student-papers.lub.lu.se:7793285 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Marie Långberg author 7766766 Professor Reine Wallenberg supervisor Centre for Analysis and Synthesis v1000651 department This master thesis is a part of a larger interwork between SP, KTH and Alfa Laval funded by the SIO graphene programme, which end goal is to formulate an anti-corrosion coating based on graphene or graphene related materials (GRMs). The investigation is partly based on an article “Novel anticorrosion coatings prepared from polyaniline/graphene composites” from 2012 by Chang et al in combination of knowledge acquired during a previous EU project, www.steelcoatproject.com concerning polyaniline for anti-corrosion coatings. The purpose of this master thesis is to optimize the synthesis of the, PAni, and GRM nanocomposite. <br /> Two different primary products of graphene oxides were investigated; water dispersed graphene oxide monolayer, GOW and water dispersed ammonia functionalized graphene oxide, AGO. These investigations were made to be able to confirm the presence of single sheets, the hybridizations of carbon and particle appearance and sheet size.<br /> A polyaniline/AGO nanocomposite made at SP before the initiation of this master thesis containing 20 wt% AGO was analyzed by Raman spectroscopy, SEM, TEM and AFM. The reaction at which the SP nanocomposite was made was reviewed to find improvements. Agglomeration occurs when AGO is added to the reaction mixture of aniline monomers and hydrochloric acid. Improvements were investigated by analyzing the pH during the synthesis and the usage of ultrasonication. The later tests were made with an AGO load of 1 wt% and was analyzed by SEM and Raman spectroscopy. The synthesis using an ultrasonication step showed the best dispersion according to the visual appearance and the intensity ratio between sp2 and sp3 bonds in the Raman spectra. <br /> Conclusion of this work is that the GRM products contain single sheets of the size of 1-7 µm for GOW and 4-10 µm for AGO, with a sp3/sp2 ratio of around 1. The PAni/AGO should be ultra-sonicated to obtain a well dispersed solution of AGO and aniline monomers before the synthesis is started by addition of the initiator. To be able to prolong the lifetime of stainless steel in saline environments, coatings can be used as an extra barrier for corrosive substances. The purpose of this work was to optimize the polyaniline ammonium graphene oxide synthesis which should be used as barrier particles in polymer coatings. This project is a part of a larger cooperation between SP, KTH and Alfa Laval, preformed within the Strateic Innovation programme “Grafen” jointly founded by VINNOVA, Formas and Energimyndigheten. <br /> Graphene has excellent properties like effective heat transport and good barrier properties which both are good qualities for protective coatings for heat exchangers. However dispersions of graphene are hard to produce in a cheap and easy way and therefore were graphene oxide used instead. Graphene oxide is easier to disperse and also easier to react with polymers. The polymer used in this investigation was polyaniline. This polymer was used because of its transporting properties.<br /> The polyaniline, PAni, and graphene oxide with NH2 groups, AGO, nanocomposite process included mixing of hydrochloric acid together with AGO. However during this process an aggregate was formed when monomers of aniline was added to the mixture of hydrochloric acid and AGO. This was a problem since the dispersion of graphene oxide was not optimal and could impact on the reactions between polyaniline and the AGO sheets. The effect of the pH of the mixture was investigated for being one potential reason for the aggregate formation. The pH were measured for both the synthesis and the level of the dispersion of the AGO sheets in the pH ranging between 1-14. The result showed that AGO was easily dispersed in pH between 4-6. Adding AGO last, before the initiator, the substance that starts the reaction, should give a more suited pH. However the agglomeration persisted, leading to the conclusion that the agglomeration was not caused by the pH change. Instead an ultra-sonication step was introduced to the synthesis. By ultra-sonication of the mixture for ten minutes agglomeration dissolved. The products made with and without ultra-sonication step were analyzed by SEM and Raman spectroscopy which showed that the ultra- sonicated sample differed from the other. The ultra-sonicated sample seemed to be more flakelike structures. <br /> PAni/AGO cannot adhere to the stainless steel whiteout adhesion aids in the form of for example polymeric binders. For future work different types of adhesion aid needs to be studied, as well as a way to disperse the composite particles in a binder. The effect of having graphene oxide or the effect of reducing the graphene oxide, by removing oxygen from the graphene oxide sheets, for the anti- corrosion and heat transporting properties is also of interest of investigate further. https://lup.lub.lu.se/student-papers/record/7793285/file/7793286.pdf application/pdf 2485785 no 2015 eng Polyaniline graphene materials chemistry materialkemi Chemistry 7793285 2015-08-30T17:37:37+02:00 2015-10-07T12:13:28+02:00 2015-10-07T12:13:28+02:00

oai:lup-student-papers.lub.lu.se:7851914 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Emil Gustafsson author 7794029 Peter Schurtenberger supervisor Linda Månsson supervisor Feifei Peng supervisor Department of Chemistry v1000647 department The ability of thermoresponsive, amine-functionalized microgel particles to take part in microgelmicrogel inter-cross-linking has previously been reported in the literature, in connection to applications such as for example the formation of stimuli-responsive colloidal gels and colloidosomes [1]. This thesis deals with the synthesis of such thermoresponsive, cross-linkable microgels and their subsequent assembly into clusters using droplet-based microfluidics, with the goal of forming<br /> responsive colloidal molecules with well-defined valency. Such colloidal molecules can be used as model systems to study controlled self-assembly processes.<br /> <br /> In this project, monodisperse amine-functionalized poly(N-isopropylacrylamide) (PNIPAM) and poly(N-isopropylmethacrylamide) (PNIPMAM) microgels, cross-linkable with glutaraldehyde, were synthesized. In total, four microgel systems were produced and the microgels were subsequently characterized by dynamic and static light scattering (DLS and SLS), confocal laser scanning microscopy (CLSM) and electrophoretic mobility. The microgels were shown to exhibit thermoresponsive behavior with respect to size, charge density and interaction potential. In the presence of glutaraldehyde, dense microgel suspensions were converted to macrogels through microgel-microgel cross-linking. Upon heating the macrogels to above the microgels’ volume phase transition temperature (VPTT), they contracted, thus showing that the thermoresponsive behavior of the microgels was conferred to the macrogels. The obtained microgel systems were then used in droplet-based microfluidics to generate colloidal molecule-like clusters. However, the presence of clusters could not be confirmed, likely due to problems with extraction.<br /> <br /> [1] a) G. Huang, J. Gao, Z. Hu, J. V. St. John, B. C. Ponder and D. Moro. Controlled Drug Release from Hydrogel Nanoparticle Networks. J. Control. Release, 94:303-311, 2004. b) G. Huang and Z. Hu. Phase Behavior and Stabilization of Microgel Arrays. Macromol., 40:3749-3756, 2007. c) R. K. Shah, J.-W. Kim and D. A. Weitz. Monodisperse Stimuli-Responsive Colloidosomes by Self-Assembly of Microgels in Droplets. Langmuir, 26:1561-1565, 2010. Kolloider är partiklar i storleksordningen nm till μm. De är viktiga i biologiska system, där exempelvis proteiner är en typ av kolloid. Att studera kolloider ger oss därför insikt i hur till exempel proteiner byggs upp och interagerar. I detta fall försökte vi tillverka kolloidala molekyler, alltså kolloider som interagerar med varandra genom ett specifikt antal bindningar i väl definierade positioner och riktningar. För att skapa kolloidala molekyler användes mikrogeler som sammansattes till kluster, där antalet bindningar och dess riktning bestäms av antalet mikrogeler och dess position. Mikrogeler är kolloidala partiklar med temperaturberoende egenskaper. Under en viss kritisk temperatur är mikrogelerna stora och vattenälskande och på grund av detta absorberar de vatten. Över den kritiska temperaturen skyr mikrogelerna vatten och krymper ihop. Ändring i temperatur påverkar inte enbart mikrogelernas storlek utan också hur de interagerar<br /> med varandra; över den kritiska temperaturen tycker mikrogelerna om att interagera med varandra. Kolloidala molekyler som tillverkas av mikrogeler får mikrogelernas temperaturberoende egenskaper och således kan klustrens egenskaper också styras genom temperaturen.<br /> <br /> För att kunna skapa kluster av mikrogeler behöver mikrogelerna tillverkas så att möjlighet finns att binda ihop dem med varandra. Mikrogelerna tillverkades därför med amingrupper som fungerar som brofästen. Glutaraldehyd fäster vid amingrupperna och kunde då användas som<br /> bro mellan två mikrogeler. För att få mikrogelerna att komma tillräckligt nära varandra, både för att bilda kluster och för att bygga broar mellan dem, så bildade vi vattendroppar innehållande både mikrogeler och glutaraldehyd. Mikrogelerna tvingades närmare varandra i vattendropparna genom att dropparna krymptes. Klustren som bildas antar olika form beroende på hur många mikrogeler som deltar. <br /> <br /> Fyra olika mikrogeler tillverkades från två olika temperaturkänsliga polymerer, det vill säga långa kedjor av upprepade mindre enheter, och färgades med fluorescerande molekyler. Vi har kunnat visa att mikrogelerna kan bindas ihop genom att låta dem bilda tvärbundna nätverk, geler, från lösningar. Kluster av mikrogeler har inte kunnat isoleras efter droppkrympning, men detta är något som vi hoppas kunna göra i framtiden. https://lup.lub.lu.se/student-papers/record/7851914/file/7851950.pdf application/pdf 10473523 no 2015 eng Physical chemistry fysikalisk kemi Chemistry 7851914 2015-09-01T15:14:28+02:00 2015-09-16T08:01:52+02:00 2015-09-16T08:01:52+02:00

oai:lup-student-papers.lub.lu.se:8570789 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 David Sörell Jonsson author 8570785 Eva Unger supervisor Centre for Analysis and Synthesis v1000651 department Methyl ammonium lead halides (MAPbX3 , X=Cl-, Br-,I-), crystallizing in a perovskite structure, have in recent years been shown to be a promising material as a light harvesting material in solar cells. It has many interesting properties which makes it suitable for solar cell applications, such as near-optimal band gap and long electron-hole diffusion lengths, as well as the possibility of synthesizing the films from solution based methods. It is also possible to tune the band gap by making mixed compounds of MAPb(I1-xBrx)3 (0≤x≤1), which could make this compound suitable for tandem cell applications. In order to optimize these perovskites for tandem cells, there are many steps and properties that need investigation. In this work, band gap tuning and structural properties were investigated using both optical techniques such as UV-Vis and Photoluminescence, as well as X-Ray Diffraction. Furthermore, the effect of annealing was studied by making measurements before and after annealing. Also, theoretical calculations of tandem cells were done to find the optimal band gap for MAPb(I1-xBrx)3. <br /> Bang gap tuning was achieved for MAPb(I1-xBrx)3 and the most efficient composition was calculated to MAPbI1.05Br1.95. Studies of annealing showed that the band gap onset becomes sharper after annealing. Peaks in XRD also became narrower, indicating either more homogenous samples or larger crystallite size. <br /> When MAPb(I1-xBrx)3 is illuminated with light, a phase splitting occurs creating multiple band gaps. This may be a problem for tandem cells, since the optimal band gap is not stable. Due to the phase splitting, a 4-terminal solar cell may be the preferred choice since the efficiency calculations show that the efficiency is less prone to change as the band gap is varied. Developing stable MAPb(I1-xBrx)3 is necessary to produce efficient tandem solar cells. Metylammonium-bly-halider (MAPbX3 , X=Cl-, Br-,I-), som kristalliserar i en perovskitstruktur, har de senaste åren visat sig vara ett lovande material för solceller. Det har många intressanta egenskaper som gör det passande för solceller, såsom ett optimalt bandgap och lång elektron/hål-diffusionslängd, samt möjligheten att tillverkas genom lösningsbaserade metoder. Det är också möjligt att justera bandgapet genom att tillverka föreningar med både brom och jod, MAPb(I1-xBrx)3 (0≤x≤1), vilket gör det här materialet passande för tandemsolceller. För att optimera dessa föreningar för tandemsolceller är det många egenskaper som behöver undersökas. I det här arbetet har bandgapet samt strukturella egenskaper undersökts med både optiska metoder som UV-Vis och fotoluminiscens, samt röntgendiffraktion (XRD). Dessutom har uppvärmningssteget undersökts genom att utföra mätningar före och efter uppvärmning. Till sist har teoretiska beräkningar av tandemceller utförts för att hitta det optimala bandgapet för MAPb(I1-xBrx)3.<br /> Justering av bandgapet för MAPb(I1-xBrx)3 utfördes och den mest effektiva sammansättningen beräknades till MAPbI1.05Br1.95. Studier av uppvärmningen visade att bandgapets ansats blir skarpare efter uppvärmning. Dessutom blev topparna i XRD smalare, vilket tyder på att proven antingen blivit mer homogena eller att kristallstorleken ökat. <br /> När MAPb(I1-xBrx)3 belyses med ljus sker en fasseparation vilket skapar multipla bandgap. Denna egenskap är ett problem för tandemsolceller, eftersom att det optimala bandgapet inte tycks vara stabilt. På grund av fasseparationen är troligtvis en tandemcell med fyra terminal att föredra, eftersom att de teoretiska beräkningarna visar att verkningsgraden för en fyrterminal förändras mindre med bandgapet. Att utveckla stabila filmer av MAPb(I1-xBrx)3 är nödvändigt för att i framtiden kunna tillverka stabila tandemsolceller. https://lup.lub.lu.se/student-papers/record/8570789/file/8570817.pdf application/pdf 1563994 no 2016 eng materials chemistry materialkemi Chemistry 8570789 2016-01-28T13:31:48+01:00 2023-05-23T15:35:02+02:00 2016-02-24T12:13:19+01:00

oai:lup-student-papers.lub.lu.se:8627821 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Amanda Persson author 8627819 bitr. universitetslektor Baozhong Zhang supervisor Innovation director Nils Lagerwall supervisor Centre for Analysis and Synthesis v1000651 department The packaging market is starting to demand renewable materials to face out the fossil based materials mainly used today. This thesis investigate the possibility and advance to switch from conventional grades of polyethylene (PE) and polyethylene terephthalates (PET) towards bio-produced qualities of the same polymers.<br /> The work is divided into two parts starting with a carbon dioxide evaluation of the existing products benchmarked with an evaluation of these products with the two new polymer qualities. Following the two most interesting Flextrus’ products were produced with the new qualities and benchmarking analyses were performed to investigate if there was any difference between the grades.<br /> The two most interesting materials chosen for further investigation after the Carbon Footprint evaluation was Fibercote 50/25, a paper coated with a PET layer, and HiLite390/40, a laminated plastic sheet of PET and PE. At production there was some struggle with the Fibercote 50/25 which can have had an extensive impact on some of the tests.<br /> Over all there is no obvious difference between the materials. Concluded by the results the sealing temperature is lower for the Bio-HiLite 390/40. Possibly this is because of the lower melting temperatures of the bio-produced PE.<br /> In most of the tests the new qualities perform well enough to be used in the same combination as the conventional material and keep the standard of the product. This conclusion is after only one production and the tests should be repeated in further production to ensure these results. Idag börjar fler och fler notera vilken påverkan våra konsumtionsmönster har på världens miljöproblem. Hur vi använder våra resurser och vilka råvaror som används får mer och mer fokus inom många områden - inte minst inom förpackningar. Att använda miljövänligare material på ett mer resurseffektivt sätt har blivit ett sätt att förmedla en miljöprofil för ett företag eller en produkt. https://lup.lub.lu.se/student-papers/record/8627821/file/8627822.pdf application/pdf 3003220 no 2016 eng bio-produced biopolymer polymers Materials plastics bio-feedstock polymerteknologi polymer technology Chemistry https://lup.lub.lu.se/student-papers/record/8627821/file/8627824.pdf application/pdf no 8627821 2016-02-15T21:10:32+01:00 2016-02-19T16:15:58+01:00 2016-02-19T16:15:58+01:00

oai:lup-student-papers.lub.lu.se:8870685 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Christoffer Wallerek author 8870683 Kent Sörensen supervisor Centre for Analysis and Synthesis v1000651 department Polyurethane is a widely used polymer with a lot of different applications due to its versatility and<br /> often resilient properties. The polymeris often prepared as a two component system consisting of<br /> polyols and isocyanates and can be cured at relatively low temperatures. Even though the formed<br /> polymer is hazardless the isocyanate used in the manufacture is dangerous in itself, but even more so<br /> is the often used precursor phosgene. Large quantities of phosgene and isocyanates are handled in<br /> the production of isocyanates and pose a threat to the environment and the people working with the<br /> production, and to great extent the application works. There is however a relatively new and<br /> “greener” alternative to commercially available polyurethane which is based on cyclic carbonates<br /> and amines. This NIPU (Non-Isocyanate PolyUrethane) production and comparison to commercial PU<br /> are the main focus of this master thesis. From the available literature NIPU is commonly prepared<br /> from 5-membered cyclic carbonates.But via internal competence and research from Perstorp AB and<br /> from LundUniversity a possible way to prepare a more reactive 6-membered monomer cyclic<br /> carbonate to be cross-linked with amines were formed.<br /> As a primary objective a polymer with an acrylate skeleton and cyclic functionality would be crosslinked<br /> with isophorone-diamine and compared with a similar acrylate-polyol polymer cross-linked<br /> with isophoronediisocyanate (IPDI). If the primary objective would prove too difficult, a crosslinking<br /> between a di-cyclic carbonate (di-TMPC) and polyether amines (Jeffamines) should be evaluated as<br /> films. The synthesis and final products were to be analyzed with gas chromatography, FT-IR, GPC and<br /> standardized film evaluation methods.The monomer was to be prepared via acrylate-esterification of<br /> tri-methylol-propane (TMP), followed by carbonation with di-methyl-carbonate (DMC). The cyclic<br /> carbonate with acrylate functionality would then be polymerized before being cross-linked with<br /> amines to create a multifunctional polyurethane polymer.<br /> The esterification process started with TMP being ring-protected with acetone before being<br /> transesterified. Later, the acetone group was removed to allow for carbonation. The three first<br /> synthesis steps were relatively simple in their set-up and a product purity of 93.67 % were obtained.<br /> The carbonation proved more complicated and several approaches were tried. The most effective<br /> way for preparing the precursor for the cyclic product was an enzymatic approach with N435, an<br /> enzyme kindly provided from Novozyme. At a reaction time of 45 h at 60 ℃ an estimated mass<br /> content of 53% of single coupled monomer were achieved. The other methods included a higher<br /> temperature thermal reaction, hydroxide catalyzed, DBTDL catalyzed and enzymatic processes at<br /> lower temperatures. All other methods besides the enzymatic approach yielded no product or<br /> precursor mass content of over 10%. The primary objective were put on hold in favor of the<br /> secondary aim.<br /> The secondary approach encountered problems with solubility of the di-TMPC and the Jeffamines<br /> which resulted in the lack of the polymer reactions necessary for film evaluation. The two solvents<br /> (cyclohexanone and methylethylketone) used to try and overcome this problem did not solve the diTMPC<br /> effectively enough despite raised temperature and sufficient time. Several DSC-scans did<br /> however confirm some exothermic reactions occurring at room temperature and an almost<br /> instantaneous reactivity at the melting point of di-TMPC. FT-IR was used to confirm the presence of<br /> urethane bonding and the cyclic carbonate decomposition in a series of scans.<br /> There are still different monomers to be evaluated to compare system and physical data for the pure<br /> cyclic carbonate in the future. Det pågår ständigt en utveckling för att minska både risker för miljö och hälsa inom den kemiska industrin. Oftast handlar det om att förbättra existerande processer eller att helt enkelt hitta nya vägar till samma produkt och i grunden ligger forskning bakom framgångarna. https://lup.lub.lu.se/student-papers/record/8870685/file/8871413.pdf application/pdf 1650667 no 2016 eng Isocyanate polyurethane cyclic carbonate NIPU polymer PU polymer technology Technology and Engineering Chemistry 8870685 2016-04-04T20:18:42+02:00 2024-02-28T14:29:04+01:00 2024-02-28T14:29:04+01:00

oai:lup-student-papers.lub.lu.se:8870854 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Magnus Hedlund author 8870852 Staffan Hansen supervisor Rune Sjövall supervisor Centre for Analysis and Synthesis v1000651 department The electrochemical capacity of the nickel mass in the positive electrode when subjected to various conditions, and the relation to changes in the nickel hydroxide phases and crystallite size was studied in this thesis work.<br /> The various conditions being: two different electrolytes, KOH and KOH/LiOH, different temperature during charging and different charge times.<br /> The nickel mass was made into monopockets to subject it to these conditions and register the capacity of the mass in a computer, which was connected to the charging station.<br /> From the monopocket analysis it could be seen that for most samples the capacity increased with increasing charge time.<br /> When the monopocket tests were done, the testing electrodes were cut open to analyse them in an X-ray diffractometer (XRD) to see what nickel hydroxide phases were present in the samples.<br /> The analyses showed that the electrolyte with LiOH added to it was more prone to form γ-phase and generated smaller crystallite sizes than the electrolyte without this addition. <br /> When comparing the monopocket results and the results from the XRD, it could be seen that the samples with KOH as electrolyte that had lower capacity than expected also had larger amounts of γ-phase. This implies that there was some loss of contact in the active material due to the swelling connected with the γ-phase.<br /> When cycling the monopockets further than the standard three times, it was found that the samples that used pure KOH as electrolyte still had γ-phase residues left even after the twentieth cycle whilst the samples with LiOH added to the electrolyte had no γ-phase left. <br /> The temperature testing gave a bit inconclusive results but the electrolyte with LiOH additions was clearly superior during these tests, which was no surprise as it has been found to improve the performance of the positive electrode at higher temperatures. Examensarbetet undersökte den elektrokemiska kapaciteten för nickelmassan i den positiva elektroden när den blev utsatt för olika förhållande och dess relation till ändringar i nickelhydroxidfaser och kristallitstorlek.<br /> De olika förhållandena var: två olika elektrolyter, KOH och KOH/LiOH, olika temperaturer under laddning och olika laddningstider.<br /> Nickelmassan gjordes till enfickor, en liten testelektrod, för att utsätta den för de olika förhållandena och dess kapacitet blev registrerad på en dator, som var kopplad till laddningsstationen.<br /> Från enficksanalysen kunde man se att de flesta provernas kapacitet ökade med ökad laddningstid.<br /> När enfickstesterna var klara, klipptes testelektroderna upp för att kunna analysera dem i en röntgendiffraktometer för att se vilka nickelhydroxidfaser som fanns i proverna. Resultaten från röntgendiffraktometern användes även för att räkna ut kristallitstorleken.<br /> Analysen visade att elektrolyten med LiOH tillsatt var mer benägen att bilda γ-fas och genererade mindre kristallitstorlekar än vad elektrolyten utan denna tillsats gjorde.<br /> Vid jämförelse mellan enficksresultaten och resultaten från röntgendiffraktometern visade det sig att proverna med elektrolyten KOH som hade lägre kapacitet än förväntat också hade större mängder av γ-fas. Detta indikerar att det var en viss förlust av kontakt i det aktiva matrialet på grund av uppsvällningen kopplad till γ-fasen.<br /> När enfickorna kördes tjugo cykler istället för de tre cykler som var standard, upptäcktes det att proverna som använde ren KOH som elektrolyt hade rester av γ-fas kvar även efter den tjugonde cykeln medan proverna med LiOH tillsatt till elektrolyten inte hade någon γ-fas kvar.<br /> Temperaturförsöket gav ganska otydliga eller inkonsekventa resultat, men elektrolyten med LiOH tillsatsen var klart överlägsen under dessa försök, vilket inte var så konstigt då tidigare studier hade konstaterat att denna tillsats ökade prestandan av den positiva elektroden vid höga temperaturer. Även om resultaten var otydliga hade proverna en fallande kapacitet med ökad temperatur.<br /> <br /> Detta arbete genomfördes på och åt batteriföretaget SAFT i Oskarshamn för att få en inblick i hur deras batterier beter sig under olika förhållanden. Då det inte är säkert att batterierna förvaras i den miljö som SAFT rekommenderar är det bra att få reda på hur funktionen påverkas av t.ex. temperaturen. https://lup.lub.lu.se/student-papers/record/8870854/file/8870856.pdf application/pdf 3800374 no 2016 eng materials chemistry materialkemi Chemistry https://lup.lub.lu.se/student-papers/record/8870854/file/8870858.pdf application/pdf Popular summary of the master's thesis in Swedish. no 8870854 2016-04-08T14:30:48+02:00 2016-04-21T10:54:55+02:00 2016-04-21T10:54:55+02:00

oai:lup-student-papers.lub.lu.se:8871028 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Jonathan Dahlin author 8871026 Ingemar André supervisor Department of Chemistry v1000647 department Encapsulation systems have long been studied, and the designs have varied in both capsule material as well as the type of cargo. The intended use have ranged from nanoreactors to delivery systems.<br /> This work presents an encapsulation system consisting of protein capsule and a protein cargo. The capsule is a redesigned hepatitis B virus capsid protein, in which the luminal extension has been altered to bind the protein calmodulin instead of the viral genome. The cargo is consequently a calmodulin fused protein.<br /> It is shown that co-expression of the redesigned capsid protein together with a capsid protein lacking a luminal extension greatly aids the solubility and assembly of redesigned capsids. Furthermore it is shown that the approximate 1:1 ratio resulting from the co-expression is maintained throughout disassembly and reassembly of the capsids. Scientists have long been interested in so called encapsulation systems, i.e. the ability to enclose a certain molecule inside a shell or capsule composed of another type molecule. Many different types of capsules have been suggested, from lipids to DNA to proteins. The enclosed molecule, often referred to as the cargo, has also been quite varied, ranging from small organic molecules to nucleic acids and proteins. <br /> There&#39;s generally two main applications for these encapsulation systems, nanoreactors and delivery systems. For nanoreactors the idea would be to encapsulate one or several enzymes within the capsule and then study enzymatic properties or leverage the nature of the capsule achieve a greater environmental control. The idea for the delivery systems would be to encapsulate a molecule of interest such as a drug or piece of DNA, and use the capsule as a vehicle for delivery into living cells. The capsule could serve a dual purpose in both protecting the loaded cargo from the external environment as well as providing a targeting and entry mechanism into the cells. <br /> <br /> In this work an encapsulation system based on a protein capsule and a protein cargo is used. More specifically the protein capsule is based of the capsid protein from the Hepatitis B virus (HBV). In nature the HBV capsid protein bind to and form a capsid structure around the viral genome. The genome binding is carried out through binding interaction with a peptide extension extending into the interior or lumen of the capsid from the main capsid protein body. In this system the capsid protein have been redesigned by replacing this luminal genome binding peptide with a protein binding peptide. By fusing the intended cargo with a peptide binding protein it is possible to achieve specific encapsulation of the desired cargo. Furthermore, the peptide-protein pair have been chosen in such a way that their binding interaction can be modulated by the presence or absence of calcium ions, allowing the cargo to dissociate from the capsid wall after encapsulation. <br /> <br /> One of the key functions in an encapsulation system is the ability to form the surrounding shell (here capsid). However, even small changes in proteins can have great effects on their characteristics. It had previously been shown that removing the luminal genome binding peptide of the HBV capsid proteins still allowed the formation of functional capsids. But it was shown here that simply replacing the peptide with a protein binding peptide resulted in non-functional capsid formation.<br /> However, by simultaneously expressing both the redesigned capsid protein with the capsid protein lacking the luminal peptide functional capsids could be obtained. These functional capsids was composed of a roughly 1:1 mixture of the two protein variants, furthermore this mixed composition was maintained throughout disassembly and reassembly of the capsids. The current hypothesis is that the presence of proteins without a luminal peptide reduces clashing between the peptide extensions in the tight spaces of the capsid lumen. <br /> This concept of co-expression and clashing reduction is probably the most important take away message from this work, and could potentially be applied to some other systems where clashing between subunits is a problem. https://lup.lub.lu.se/student-papers/record/8871028/file/8871029.pdf application/pdf 2349258 2018-04-14 no 2016 eng Hepatitis B Virus Protein Design protein engineering HBV protein science proteinvetenskap Chemistry 8871028 2016-04-14T11:17:18+02:00 2018-04-14T03:44:16+02:00 2016-04-21T10:33:50+02:00

oai:lup-student-papers.lub.lu.se:8871997 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mar Coto Acosta author 8871995 Charlotta Turner supervisor Department of Chemistry v1000647 department Gastric ulcer is a common disorder in horses. A known potent inhibitor of gastric acid secretion is omeprazole. This thesis describes the study of omeprazole extraction followed by a high-performance liquid chromatography (HPLC) method for the quantification of omeprazole in enteric-coated pellets (raw material) and in oral paste (final drug product) for horses. The drug product is composed by a paste in which pellets are wrapped. The reason for this investigation is the absence of a proper methodology applicable to the pharmaceutical industry and the necessity to determine the trueness of the method. In the first place, HPLC was validated using a reference standard of omeprazole. The method showed results within acceptable criteria in comparison with the intervals established by the United States Pharmacopeia (USP) for analytical parameters such as linearity (r2=0.9998) and precision (RSD 0.38%). Secondly, the experimental design for the extraction method of omeprazole from pellets was performed by trying a range of extraction conditions, such as the use of magnetic stirring and different sonication times. Extraction of omeprazole method from oral paste was already developed but it needed to be studied deeper. However, when the chromatographic method was applied to raw materials and drug product, higher concentration values than expected were obtained (e.g. 230.66 μg/ml omeprazole in pellets instead of the 220 μg/ml expected). A reason for such high values could be related to systematic errors and the instability of the pellets. Dimensions of pellets, the coating thickness and/or the size of inert core of the pellets can vary and thereby be sources of possible variation. Trueness of the method remains unknown because there is a lack of knowledge about the real concentration value and further studies are needed. A new formulation to be administered in horses has been recently developed. This drug is called omeprazole and it was discovered to be successful for the treatment of gastric ulcers in horses, a common illness in race-horses. A high performance liquid chromatography (HPLC) quantification method was studied with the aim to validate a method for the determination of omeprazole in pharmaceutical samples. Due to the absence of an efficient extraction method of omeprazole, a sample preparation method was also studied. <br /> Chromatography is a well-known separation technique which is widely used in analytical laboratories. Analytical chromatography is done to separate particular substances. One type of chromatography technique is HPLC. In general terms, a mixture composed by different substances is injected into a liquid (mobile phase) that flows through the chromatography system (stationary phase); separation is achieved due to chemical and physical interactions between both phases. Depending on the compounds adsorption with the stationary phase, they will spend different times in the column; so compounds will elute according to their affinity.<br /> In this study, once the chromatographic method was evaluated for different analytical parameters, it was applied to drug formulations. From previous research, it is known the need of an efficient sample preparation. So, different lab techniques were tried to ensure the total extraction of omeprazole from the formulations previous to its HPLC quantification. <br /> Finally, some inconsistencies were found because higher values than established in the label claim were obtained. A possible reason for such differences could be related with physical instability of the samples and errors introduced during the different steps of the experiments. https://lup.lub.lu.se/student-papers/record/8871997/file/8871998.pdf application/pdf 910330 yes 2016 eng Extraction methods Omeprazole Horses Analytical Chemistry Anti-ulcer drugs HPLC Validation analytisk kemi Chemistry 8871997 2016-05-04T09:13:53+02:00 2016-05-27T15:46:53+02:00 2016-05-27T15:46:53+02:00

oai:lup-student-papers.lub.lu.se:8934672 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Aleksander Sjörén author 8934670 Valtýr Freyr Hlynsson supervisor Department of Chemistry v1000647 department Synthesis of linearly fused heptakis-Tröger’s base has been completed, following a 12 step reaction route. Additionally, characterizations of reaction intermediates have been completed, while sufficient amount of material of different reaction intermediates is available for the characterizations that remain. Tröger’s Base, with predetermined substitution pattern was formed, functionalization of the benzylic position in the diazocine bridge, with (R)-menthyl ester groups, made separation of diastereomeric Tröger’s base analogues possible. Route b, with a bulkier ester side chain, was progressed through, with desymmetrisation followed by condensation to obtain the tris-Tröger’s Base and eventually the heptakis-Tröger’s Base. At the end of this project full characterization of heptakis-Tröger’s Base and its reaction intermediates is significantly closer to being available. Atoms within a molecule are normally bound to each other through covalent bonds which can be described as the sharing of two electrons between the two atoms. The focus of supramolecular chemistry can in light of this be described as the study of two molecular components which are bound to each other through forces weaker than this. This binding can happen for example through hydrogen bonding, Π-Π interactions, metal coordination and van der Waals forces.<br /> An interesting molecule which might be useful in supramolecular chemistry is Tröger’s Base (TB). The unique structure of TB, which it owns to its two aromatic rings being fused to a bicyclic diazocine unit, projects it as an V-shaped structure with an electron rich cavity due to the two aromatic rings being positioned nearly perpendicular to each other. In addition to this, the two nitrogen’s of the bicyclic unit are linked to each other through a carbon bridge preventing inversion of the molecule. These properties of TB show great promise for a wide range of supramolecular applications.<br /> The focus of this thesis has been to synthesize a linearly fused oligo-TB in order to explore applications of such a construct. Particular applications as potential nanotube was envisioned for the linear heptakis-TB, which was the ultimate goal of the project. If this was to be achieved then one of the applications might be provided by the electron rich inside of the nanotube which might be good electron conductor in electrical devices.<br /> Synthesis followed procedures developed within the group, route was started with the formation of TB by condensation of appropriately substituted anilines to give TB with a predetermined substitution pattern. Functionalization of TB followed by a controlled condensation gave the tris-TB and eventually the desired heptakis-TB. https://lup.lub.lu.se/student-papers/record/8934672/file/8934673.pdf application/pdf 2565982 yes 2018 eng organic chemistry organisk kemi Chemistry 8934672 2018-02-01T13:36:45+01:00 2018-02-19T15:01:16+01:00 2018-02-19T15:01:16+01:00

oai:lup-student-papers.lub.lu.se:8935293 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Christopher Musonda author 8935291 Sophie Manner supervisor Department of Chemistry v1000647 department The aim of this thesis was to synthesize various β-D-ribopyranoside derivatives with different C-4 functional groups, using D-xylose as the starting material. The desired modifications were deoxygenation, fluorination, methylation and epimerization of the C-4 hydroxyl group. Methylation provided the best results with the final product being successfully synthesized. Deoxygenation was also achieved but the final de-protection step was not carried out. Epimerization was attempted using two different methods but without success, firstly probably due to the high energetic favorability of having the hydroxyl group in the equatorial position, and secondly due to harsh reaction conditions causing the cleavage of the hydroxyl group. Fluorination was not attempted. INTAG AV TRÄSOCKER SKA FÖREBYGGA CANCER<br /> Cancer är den näst största orsaken till död i industriländer idag. Det görs för tillfället oerhörda ekonomiska satsningar där bl.a. Cancerfonden delade ut 385 miljoner kronor för forskning inom området år 2016. Ett forskningsområde som fått mycket uppmärksamhet på senare tid är användandet av det trädbundna sockret, D-xylos (också kallat ’träsocker’), som en källa till anti-cancermedel. Sockret visar bra potential, mycket tack vare dess biologiska betydelse i däggdjur samt dess tillgänglighet i naturen. I detta projekt har olika modifieringar av sockret syntetiserats för att man eventuellt ska kunna undersöka dem för potentiella anti-cancer egenskaper.<br /> <br /> I cellen av däggdjur fungerar xylos som en länk mellan en proteinkärna och en kedja av andra kolhydrater i proteoglykaner (se figur 1). Proteoglykaner är essentiella för en lång rad av biologiska processer och dess uttryck är förknippat med varje steg av cancer utveckling, vilka inkluderar bl.a. tumörinflytande och tumörmetastas.<br /> <br /> Biosyntesen av proteoglykan initieras vanligen av att det interna enzymet xylostransferas tillför en xylos molekyl till proteinkärnan. Detta följs av att andra enzymer bygger på med ytterligare kolhydrater tills en kolhydratskedja bildas.<br /> <br /> Biosyntesen kan dock också ske genom att låta en aglykon-bärande xylos molekyl, en så kallad xylosid, penetrera cellmembranet vilket kommer att initiera byggandet av kolhydratskedjan (aglykonen fungerar som ersättare för protein kärnan). Kolhydraterna som sedan kommer att göra upp kedjan beror på strukturen av aglykonen och man har tidigare lyckats selektivt inhibera tumörväxt med 97 % i råttor genom att använda xylosiden XylNap.<br /> <br /> I detta examensarbete har syntesvägen för analoger av XylNap studerats. Modifikationerna har fokuserat på hydroxylgrupperna tillhörande C3 och C4 och har inkluderat epimerisering, deoxygenering och metylering. Den syntetiska processen har verifierats av TLC (Thin Layer Chromatography), NMR (Nuclear Magnetic Resonance) och HRMS (High Resolution Mass Spectrometry).<br /> <br /> Examensarbete har gett en bra insikt till hur det går till när man tar ett råmaterial och transformerar det till en substans för användning inom läkemedelsindustrin. Arbetet har också medfört en fördjupad kunskap av organisk kolhydrat syntes. Med en hel del lyckade modifikationer har genomförbarheten av forskningen också påvisats och med den omfattande tillgängligheten av xylos kommer intresset av forskningsområdet troligtvis bara fortsätta stiga. https://lup.lub.lu.se/student-papers/record/8935293/file/8935295.pdf application/pdf 1120403 no 2018 eng organic chemistry organisk kemi xylos träsocker proteoglykan Chemistry 8935293 2018-02-08T12:51:15+01:00 2019-02-26T10:49:58+01:00 2019-02-26T10:49:58+01:00

oai:lup-student-papers.lub.lu.se:8935990 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Edvard Torkelsson author 8935988 Ulf Nilsson supervisor Department of Chemistry v1000647 department Centre for Analysis and Synthesis v1000651 department Galectins are a family of proteins naturally occurring in humans involved in a broad variety of bodily functions, including regulation of immune response and inflammation. The most studied protein of the family, galectin-3, has repeatedly been proven to be involved in tumour progression, affecting both tumour survival and metastasis. Both in vitro and in vivo analyses have yielded information that emphasizes the importance of galectin-3 inhibition for development of cancer therapeutics. An established technique to study a substance’s biodistribution through the body is by positron emission tomography. By injecting a radiolabelled pharmaceutical, it is possible to study its biological properties, such as uptake, elimination, etc. Three precursors to radiolabelled galectin-3 inhibitors were synthesised successfully. Labelling reactions were performed by 18F-fluorination, followed by deprotection. Only one precursor, a boronic pinacol ester, was successfully labelled to form a radioactive galection-3 inhibitor, in a Cu-mediated reaction. The crude product was purified by preparative high performance liquid chromatography and the isolated product was transferred to a suitable solvent via a solid phase extraction to yield a radiochemical pure product that can be further used in man for positron emission tomography studies. Vart tar läkemedlet tar vägen?<br /> <br /> Genom att märka potentiella cancerläkemedel med en radioaktiv isotop är det möjligt att bestämma vad i kroppen läkemedlet befinner sig.<br /> <br /> Proteiner har en stor diversitet av funktioner i kroppen och är essentiella för människans överlevnad, både som byggnadsmaterial och katalysatorer för kemiska reaktioner, men också som regulatorer för olika funktioner i kroppen. Galektiner, är en familj av kolhydratbindande proteiner som är involverad i reglering av bland annat immunsystemet. Galektiner binder specifikt till sockerarten galaktos och tidigare forskning har visat att högre koncentrationer i blodet är kopplat till inflammation och cancer. När ett av dessa proteiner, galektin-3, har blockerats med hjälp av en konstgjord galaktosbaserad hämmare har man sett en reducering av cancertillväxt. Denna kunskap understryker betydelsen av vidare forskning av galektinhämmare som potentiellt läkemedel mot cancer.<br /> <br /> En stor mängd molekyler som hämmar galektin-3 har framställts tidigare och påvisat goda resultat i olika djurstudier. För att få fram information om hur dessa molekyler fördelar sig i kroppen kan man använda sig av en metod som heter positronemissionstomografi. Det är en metod där man märker en molekyl med en radioaktiv isotop som sedan injiceras. Det är sen möjligt med hjälp av denna teknik att skanna kroppen och observera var de radioaktiva molekylerna är positionerade. <br /> <br /> Arbetet för denna rapport har delats in i två delar där först delen involverade organisk kemi för att producera tre galektin-3-hämmare. I andra delen av projektet undersöktes det om det var möjligt att märka dessa molekyler med en radioaktiv fluorisotop och även att optimera denna inmärkning.<br /> <br /> Resultatet från detta examensarbete var lyckat. Alla tre galektin-3-hämmare producerades och en av dem märktes in med radioaktivt fluor. En produkt redo för injicering till djur togs fram och kan användas för framtida studier. https://lup.lub.lu.se/student-papers/record/8935990/file/8935998.pdf application/pdf 3723888 yes 2018 eng galectins inhibitors protein organic chemistry organisk kemi Chemistry 8935990 2018-02-16T11:15:21+01:00 2019-08-12T15:00:08+02:00 2018-03-12T11:22:22+01:00

oai:lup-student-papers.lub.lu.se:8936069 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Jonathan Carrara Aste author 8894804 Peter Spégel supervisor Department of Chemistry v1000647 department Instrumental analysis in metabolomics has proven to be a challenging topic due to metabolites having a wide spectrum of physiochemical properties and concentrations. The more conventional techniques in metabolomics include gas chromatography and liquid chromatography coupled with mass spectrometric (MS) detection. In most cases these techniques provide methods that are adequate for metabolomic research, however, certain classes of metabolites still impose a challenge. One such class are metabolites that are polar <br /> (here defined as 0 ≥LogP) and to date none of the common techniques have provided a satisfactory method for their analysis. Recently, enhanced-fluidity liquid chromatography (EFLC) that uses high percentages of modifier (&gt;50%) combined with liquified carbon dioxide (CO2) in the mobile phase has been utilized for the analysis of polar compounds.<br /> <br /> In this study, we aim at exploring the potential of EFLC with MS detection in metabolomics. We selected a number of polar metabolites for analysis in our EFLC setup and studied the impact on retention when varying pressure, column temperature, flow rate, modifier composition and modifier/CO2 ratio in the mobile phase. The intention was to then develop an EFLC method and compare the results with an established gas chromatography method coupled with MS detection based on linear range, precision, accuracy, limit of quantification and limit of detection.<br /> <br /> The established gas chromatography method could detect 44 metabolites in cultured insulinoma cells (INS-1 832/13), which we used as a model of a complex tissue. However, poor precision and accuracy coupled with high limits of quantification makes this method less than ideal for quantitative analysis at the desired concentrations. The EFLC system could detect 15 metabolites from a mixture of standards. Modifier composition (methanol mixed with 10 mM ammonium formate buffered to pH 3.0) and modifier/CO2 ratio in the mobile phase had the most significant impact on retention. A change in modifier composition was also shown to cause a more rapid decrease in retention for early eluting metabolites compared to later eluting metabolites. In addition, analysis of the same 15 metabolites using hydrophilic interaction liquid chromatography (HILIC) on the same column revealed a selectivity difference when compared to the EFLC system. Unfortunately, an EFLC method was not developed due to time constrains and a comparison with the gas chromatography method was not possible. Varje dag pågår parallellt ofantligt många kemiska reaktioner i vår kropp vars funktion är att bryta ner och bygga upp olika typer av molekyler. Ett samlingsnamn för de molekyler som både bryts ner och används som byggstenar i kroppen är metaboliter och disciplinen som fokuserar på studien av dessa metaboliter kallas för metabolomik. Metabolomik kan användas för att få en fördjupad förståelse för hur olika typer av dieter, läkemedel och sjukdomar påverkar vår kropp, vilket i sin tur leder till en bättre förståelse för de kemiska processerna som gör vårt vardagsliv möjligt. På sikt kan denna kunskapen tillämpas för att utveckla bättre behandlingar som bidra till ett förbättrat levnadsförhållande för alla.<br /> <br /> Metabolomik har många intressanta och spännande frågeställningar som kan ha en betydande inverkan på vår uppfattning om hur en organism fungerar, men att få svar på dessa frågor är ingen enkel uppgift. En av de större utmaningarna inom metabolomik är att hitta rätt instrument som ska användas för att studera de olika metaboliterna. Metaboliter har väldigt olika kemiska egenskaper, vilket är anledningen till att det i nuläget inte finns en metod som kan analysera alla metaboliter samtidigt. Vissa metaboliter har också visat sig vara mer problematiska att analysera än andra. Detta gäller exempelvis för metaboliter som är hydrofila och här finns utrymme för vidare studier. Begreppet ”hydrofil” innebär att en molekyl är löslig i vatten och är en kemisk egenskap som delas av många metaboliter. <br /> <br /> Vår forskning har fokuserat på att utveckla en ny metod (s.k. enhanced-fluidity liquid chromatography (EFLC)) för att bestämma koncentrationerna för en viss grupp av hydrofila metaboliter i cellprover och sedan jämföra den med en redan etablerad metod (baserad på gaskromatografi). Genom att utveckla en metod för gaskromatografi kunde vi detektera 45 olika metaboliter, men koncentrationerna för majoriteten av dessa metaboliter var för låga för att göra en koncentrationsbestämning i cellprover. Däremot om metoden skulle appliceras på andra typer av prover där metaboliter förkommer i högre koncentrationer (exempelvis plasma) så förväntas metoden fungera bättre, vilket i sin tur skulle leda till att vi kan bestämma koncentration på fler metaboliter.<br /> <br /> EFLC är en metod som använder koldioxid i vätskeform blandat med ett lösningsmedel (exempelvis metanol) för att analysera prover. I våra experiment använde vi en blandning av koldioxid, vatten och metanol vilket ledde till att vi kunde detektera 15 metaboliter. Detta visar på att EFLC kan användas för att analysera hydrofila metaboliter, men det låga antalet detekterade metaboliter jämfört med gaskromatografi medför att EFLC i nuläget inte presterar tillräckligt bra för att ersätta mer etablerade metoder inom metabolomik. Vidare stötte vi på komplikationer med att detektera våra metaboliter som i sin tur ledde till att det inte fanns tid att göra någon koncentrationsbestämmelse i cellprover med EFLC.<br /> <br /> Framöver skulle det vara intressant att undersöka om vi kan utöka antalet detekterade hydrofila metaboliter med EFLC samt att göra en koncentrationsbestämmelse i cellprover. Detta skulle undersökas genom att exempelvis byta detektor eller ändra på sammansättningen av lösningsmedlet som blandas med koldioxiden. Om vi lyckas med detta skulle vi kunna göra en rättvis jämförelse med gaskromatografi. Därmed finns det utrymme för vidare forskning kring applikationen av EFLC i metabolomik. 2018 eng Enhanced fluid liquid chromatography gas chromatography polar metabolites mass spectrometry metabolomics analytical chemistry analytisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/8936069/file/8936071.pdf application/pdf yes 8936069 2018-02-18T10:46:59+01:00 2018-03-12T11:34:38+01:00 2018-03-12T11:34:38+01:00

oai:lup-student-papers.lub.lu.se:8937996 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Lina Le author 8886635 Peter Jönsson supervisor Mohammad Arif Kamal supervisor Department of Chemistry v1000647 department Microparticles of various sizes carrying different surface modifications have numerous technological and biomedical applications, for example to create a larger target for a molecular receptor by binding multiply ligands to the surface of the microparticle. The aim of the present work is to study how to most efficiently couple protein molecules to the surface of such microparticles. In the current study I have focused on the coupling of Streptavidin-Alexa Flour 488 (SA-AF 488) to polystyrene microparticles (PSMs). The passive adsorption of SA-AF 488 onto PSMs with diameter 6 µm was first investigated at two different pH. It was found that maximal adsorption occurs when pH is in the neighbourhood of SA-AF’s isoelectric point. However, the protein adsorption on the PSMs was uneven for the passive adsorption. To obtain a more even protein adsorption I then investigated covalent coupling of the same protein on carboxyl-modified PSMs (PSM-COOH) as well as amine modified PSMs (PSM-NH2) with diameter 1 µm. This approach resulted in more even protein coverage on the PSMs and of the two covalently-coupled PSMs it was found that the PSM-COOH bound more proteins in comparison to PSM-NH2. The study shows that efficiently coupling of protein molecules can be achieved to microparticles, opening up for different proteins such as antibodies to be coupled to microspheres of various sizes. Mikropartiklar är mer än 100 gånger mindre än ett hårstrå. De brukar användas som behållare för läkemedel eller för att markera enskilda molekyler. För dessa ändamål måste ytan på mikropartiklarna modifieras med olika kemiska grupper. Jag har i detta arbete undersökt olika metoder för att binda in protein till mikropartiklar. Som modellsystem valdes mikropartiklar tillverkade av plasten polystyren och testet gick ut på att undersöka hur man kan koppla proteinet Streptavidin till dessa. Jag undersökte tre olika metoder: passiv bindning till omodifierade partiklar, kovalent bindning till karboxyl-modifierade partiklar och kovalent bindning till amin-modifierade partiklar. För den passiva bindningen undersöktes hur pH inverkar på inbindningen. Bäst inbindning erhölls då pH var kring 5 vilket motsvarar det pH där proteinets nettoladdning är noll. Hög proteintäckning uppnåddes, men optisk mikroskopi kunde avslöja att denna inbindning inte var jämn utan att Streptavidin ofta band i kluster på partiklarnas yta. <br /> I kovalent bindning bands Streptavidin kemiskt till de modifierade mikropartiklarna. Olika reaktionssteg skedde beroende på om ytan var modifierad med karboxylgrupper eller amingrupper. Här fick jag också hög proteintäckning på mikropartiklarna, men till skillnad mot den passiva inbindningen var täckningen här mycket jämnare. Av de bägge teknikerna gav karboxyl-modiferade mikropartiklar bäst inbindning. Slutligen undersöktes hur dessa mikropartiklar bäst skulle förvaras för att inte klumpa ihop sig eller binda till andra molekyler. En vanligt förekommande metod för det senare är att tillsätta en molekyl för att blockera alla oönskade bindningar. Betakasein användes för detta syfte, men det upptäcktes att denna molekyl band Streptavidin och fick partiklarna att aggregera mer. Att bara förvara partiklarna i normal buffertlösning eller att använda en annan molekyl (t.ex. glycin) än betakesein fungerade därför bäst.<br /> Sammanfattningsvis så har jag undersökt olika metoder för att binda in specifika molekyler till mikropartiklar. Av dessa är den passiva inbindningen den enklaste men den sämsta, då det är svårt att få en jämn molekylinbindning . För att få ytan att bli jämnt täckt med protein, så är kemisk bindning till karboxyl-modifierade mikropartiklar det bästa alternativet. https://lup.lub.lu.se/student-papers/record/8937996/file/8937997.pdf application/pdf 1639780 no 2018 eng physical chemistry fysikalisk kemi Chemistry 8937996 2018-03-23T16:28:00+01:00 2018-11-06T13:01:27+01:00 2018-11-06T13:01:27+01:00

oai:lup-student-papers.lub.lu.se:8938293 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH1 Sarah Danielsson author 8938291 Mikael Nolin supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department The aim of this thesis work was to create a model describing the crystallization process of sodium formate and to calibrate this model to real process data. Sodium formate is a by-product formed during the production of Trimethylolpropane (TMP). The model used is based on the population balance equation and include crystallization mechanisms such as particle nucleation, growth and agglomeration. The model created will describe the particle size distribution of sodium formate crystals and the crystals will be divided into different classes according to size. The program used for the simulation is Scilab 5.5.2.<br /> The particle size distribution is expressed in volume%. After calibration, the created model differ some from real process data. The number of crystals of the smaller ones is too low and the large crystals are too many. Also the width of the distribution is too small. The best simulation, namely the one with the smallest deviation from real process data, was when the crystals where divided into 10 size-classes. The deviation/class where then ±5.8 volume units. A proposal for further work is to extend the model and add a term describing breakage of crystals. This will lead to more small crystals, less of the bigger ones and a wider distribution. Only one particle size distribution experiment has been done and to be sure that this distribution agrees with the distribution in the TMP-crystallizer, more experiment needs to be executed. För en kemisk industri är lönsamhet av största vikt, vilket uppnås via effektivisering av tillverkningsprocessen och ökad försäljning. I TMP-fabriken har man nu nått maximal produktionskapacitet genom att undersöka specifika driftparametrars inverkan på produktionshastigheten. För att komma vidare och kunna öka produktionshastigheten ytterligare måste varje steg utvärderas, modelleras och optimeras. <br /> I ett samarbete med Lunds Tekniska Högskola ska hela TMP-processen byggas upp och simuleras i simuleringsprogrammet Aspen. Detta specifika arbete har innefattat konstruktion av en modell som beskriver kristallisationsprocessen, ett delsteg i TMP-processen. Syftet med kristallisationssteget är att bilda kristaller av natriumformiat, en bi-produkt vid TMP-tillverkningen. Natriumformiat-kristallerna separeras sedan från TMP-lösningen genom centrifugering. Kristallisationsmodellen ska implementeras i Aspen tillsammans med övriga delsteg i processen. Detta ger en förståelse för varje delsteg i processen och på så sätt kan produktionskapaciteten ökas. <br /> Den konstruerade kristallisationsmodellen bygger på en populationsbalans, vilken ofta används för att beskriva system bestående av partiklar. För att kunna lösa populationsbalansen måste en förenkling göras. Förenklingen innebär att kristallerna delas in i olika klasser med avseende på storlek. Då erhålls ett antal Ordinära Differentialekvationer (ODE) som beskriver storleksfördelningen hos kristallerna. Detta gör att modellen går att lösa. Modellen inkluderar tre fenomen som sker under en kristalliseringsprocess: bildning av kristallkärnor, tillväxt av kristaller och agglomeration, som betyder att vissa kristaller slås ihop och bildar större kristaller. <br /> Modellen har byggts upp och simulerats i Scilab 5.5.2, vilket är ett gratisprogram som kan användas till numeriska beräkningar. Modellen innehåller ett antal variabler vars värde är okänt och svåra att bestämma. Genom att kalibrera modellen mot mätdata från fabriken med hjälp av en inbyggd optimeringsmetod i Scilab kan värde på dessa parametrar skattas.<br /> Resultatet, volymdistributionen av kristaller med avseende på storlek, har ett normalfördelat utseende. Jämfört med mätdata från fabriken ger modellen för få små kristallerna medan antalet av de större kristallerna är för högt. Modellens storleksfördelning är inte heller tillräckligt bred jämfört med mätdata. Det har undersökts hur de olika kristallisationsfenomenen påverkar resultatet och fördelningen. Fördelningen kan förskjutas i höger- och vänsterled (fler stora kristaller eller fler små kristaller) men bredden på fördelningen kan inte ändras nämnvärt. Slutsatsen är att den konstruerade modellen avviker från storleksfördelningen erhållen från experimentella försök. Möjliga orsaker till detta är att modellen inte beskriver sönderdelning av kristaller, ett fenomen som sker under kristallisationsprocessen. Detta resulterar i fler små kristaller, färre stora och en bredare fördelning. En annan möjlig orsak är att kristaller går sönder under analys av provet från kristallisatorn. Detta skulle betyda att mätdata ger fler små kristaller än vad som egentligen finns i kristallisatorn. Agglomerat som bildats från att kristaller slagits samman kan vara svaga och starka. Det finns en stor risk att svaga agglomerat inte håller samman under provanalysen och sönderdelas till mindre kristaller. För att öka modellens tillförlitlighet måste den förfinas samtidigt som mer mätdata måste samlas in. Dagens modell ger dock en indikation på kristallernas storleksfördelning. https://lup.lub.lu.se/student-papers/record/8938293/file/8938294.pdf application/pdf 1472146 no 2018 swe crystallization kristallisation modellering scilab chemical engineering kemiteknik Chemistry Technology and Engineering 8938293 2018-04-03T10:58:47+02:00 2018-05-15T13:03:58+02:00 2018-05-15T13:03:58+02:00

oai:lup-student-papers.lub.lu.se:8938867 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Öyvind Nörregård author 8938865 Researcher Christian Hulteberg supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Through hydrogenation of glucose to sorbitol followed by hydrogenolysis of sorbitol to glycerol a pathway to produce bio propane from lignocellulosic material has been confirmed. <br /> A wide range of catalyst was tested, in an autoclave batch reactor, to scout the activity of catalysts already proven active, according to previous literature, as well as catalysts not mentioned in literature for the specific reaction. Catalysts well known for both the hydrogenation of glucose and the hydrogenolysis of sorbitol are catalyst including either nickel or ruthenium as the active metal.<br /> The most active system was found to be Ni supported on γ-Al2O3 for both the hydrogenation and the hydrogenolysis. For the unknown process step, the hydrogenolysis, the selectivity was considerably high, 44%. This was though found after almost the triple operating time compared to certain literature with still low conversion rates of 36%, which was explained by the mild conditions and the low catalyst to sorbitol ratio 0.5 wt.-%.<br /> Other unexpected findings was the negative effect of a basic promoter for most systems and also the regenerating effect of sorbitol when adding hydrogen to the system which introduces further possibilities in research; studying tentatively the effect of hydrocracking derived from the high reactivity, specifically for the acidic catalyst, and if the retro-aldol is a crucial step, only obtained before the adding of hydrogen. Glycerol has flooded the market for almost two decades, as the result of the large increase in the production of biodiesel, in which glycerol is a stoichiometric by-product. But with new research, a pathway to produce bio-based propane from glycerol has been developed. To keep the glycerol price low and as well to state an economically feasible process route, a pathway to produce glycerol from glucose (from lignocellulosic materials) has been proposed. By hydrogenation of glucose, obtained from processed lignocellulosic materials, sorbitol can be produced. This is done in large scale commercial processes and can be performed productively, with high selectivity towards sorbitol. Further hydrogenolysis of sorbitol has proven primarily one of the most suitable ways to end up with the requested product. The backbone carbon structure of six carbon atoms makes it easy to imagine a split between the two middle carbons resulting in two glycerol molecules. Though the fairly easy process route, large difficulties were found in acquiring an economically feasible product yield.<br /> A wide range of catalyst was tested, in an autoclave batch reactor, to scout the activity of catalysts already proven active, according to previous literature, as well as catalysts not mentioned in literature for the specific reaction. Catalysts well known for both the hydrogenation of glucose and the hydrogenolysis of sorbitol are catalyst including either nickel or ruthenium as the active metal. <br /> The just mentioned active metals supported on γ-Al2O3 was proven to have high conversion rates as well as high selectivity in the hydrogenation of glucose. With catalyst loadings of 0.5% in weight and active metal concentrations lower or comparable to literature, highly active hydrogenation systems were found with both types of catalysts. For the unknown system of sorbitol hydrogenolysis, the case was different. The most active system was found to be Ni supported on γ-Al2O3 for which the selectivity was considerably high, 44%. This was though found after almost the triple operating time compared to certain literature with still low conversion rates of 36%.<br /> Unexpected results were found in the addition of basic promoter which lowered the activity for the nickel catalyst which according to literature would increase the activity of the system. The increase in activity was only found for the catalyst using ruthenium as active metal. Other remarkable findings were the high conversion of sorbitol before the system was put to operating conditions. This together with the regenerating sorbitol concentration with the adding of hydrogen to the system, leads one to think that the start-up procedure before introducing hydrogen may be a crucial step for achieving a more sought for product distribution. This introduces further possibilities in the research area, studying tentatively the effect of hydrocracking derived from the high reactivity, specifically for the acidic catalyst, and if the retro-aldol is a crucial step, only obtained before the adding of hydrogen. https://lup.lub.lu.se/student-papers/record/8938867/file/8938868.pdf application/pdf 2777024 no 2018 swe Catalysis chemical engineering kemiteknik Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/8938867/file/8938870.pdf application/pdf no 8938867 2018-04-18T15:00:05+02:00 2018-06-04T16:12:41+02:00 2018-06-04T16:12:41+02:00

oai:lup-student-papers.lub.lu.se:8940819 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Rawya Hussein author 8884252 Susanna Horsefield supervisor Department of Chemistry v1000647 department Mammals express thirteen different isoforms of the membrane-bound water channel aquaporin in a tissue-dependent manner. From a medical point of view, two of the most studied isoforms are aquaporin (AQP0), also known as major intrinsic protein and aquaporin 2 (AQP2). AQP0 is exclusively expressed in the mammalian eye lens and responsible for the transport of water across lens fiber cell membranes to maintain lens clarity. The water transport via AQP0 is modulated by CaM, a small protein composed of N and C- terminal calcium (Ca2+) binding domains that connected by an internal flexible linker. AQP2 is expressed in the kidney collecting duct, where it plays a critical role in water reabsorption from urine. AQP2 apical membrane abundance is regulated by trafficking in response to vasopressin, in a phosphorylation-dependent manner. Part of this process involves interacting with lysosomal trafficking regulator interacting protein-5 (LIP5), a small cytosolic protein with a molecular weight of 42 kDa. This interaction, which has been shown to be dependent on AQP2 phosphorylation, facilitates AQP2 lysosomal degradation and therefore balance the abundance of AQP2 in the body. In this project, the main purpose was to develop methods for chemical cross-linking of the AQP0-CaM and AQP2-LIP5 complexes in order to study the structural details of how human aquaporin’s interact with regulatory proteins. For this purpose, human AQP0, AQP2, LIP5 and CaM were overproduced and purified, and cross-linking experiments was set up using two different cross-linkers. For both complexes, successful cross-linking could be verified using Western blot. In addition, co-crystallization attempts of the AQP0 C- terminal peptide and CaM was explored, resulting in small crystals that will be further investigated. The faulty interaction between integral membrane protein and regulatory proteins can lead to several diseases. Therefore, studies of these interactions help us understand and answer essential questions on the development and outcome of these disease states. In this project, we investigated two water channels, aquaporin 0 (AQP0) and aquaporin 2 (AQP2) and how they are regulated by calmodulin (CaM) and lysosomal trafficking regulator interacting protein-5 (LIP5), respectively. The aim was to structurally characterize the complexes of these proteins. To reach this aim, AQP0, AQP2, LIP5 and CaM were produced and their ability for interaction was tested using chemical cross-linking and crystallization. The results suggest cross-linking can be used to stabilize the complexes of AQP0 and CaM and AQP2 and LIP5. Furthermore, small crystals were obtained of the complex between the AQP0 C-terminus and CaM. https://lup.lub.lu.se/student-papers/record/8940819/file/8940822.pdf application/pdf 17093158 no 2018 eng biochemistry biokemi Chemistry 8940819 2018-05-22T08:26:04+02:00 2018-06-20T16:04:36+02:00 2018-06-20T16:04:36+02:00

oai:lup-student-papers.lub.lu.se:8942975 2025-07-29T13:03:30Z AgricultureVeterinaryMedForestry PhysicsChemistryMaths Technology

studentPublicationsH2 Erik Lorin author 8942002 MSc Anton Sellberg supervisor Tomas Skoglund supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department In this master thesis project, the formation of fouling on heat exchanger surfaces in dairy processing and mainly the influence of air was examined. Based on prior experimental findings regarding the influence of air bubbles in combination with calculations based on solubility properties of air in milk, a hypothesis was stated. Milk can enter the processing system without any undissolved air, with altered equilibrium due to change in temperature and pressure the solubility can decrease. From this phenomenon, air bubbles can be created which are simultaneously filled with steam at the corresponding steam pressure. Assuming the steam is evaporated from the boundary layer of the bubble a local increase in TS would be present, creating a fouling footprint. The influence of dissolved air and processing pressure on the fouling rate was examined in the thesis and the reason behind the creation of fouling is assumed to be drying.<br /> <br /> A lab scale tubular heat exchanger UHT was used in the experiments and a part of the thesis is focused on the instrumentation of the machine. The results points in two directions. While processing milk entering with a high level of dissolved air, an increased process pressure led to a decreased initial fouling rate and prolonged induction period. The results from processing milk with low level of dissolved oxygen were inconclusive. Either a point of low enough oxygen level and high enough pressure was reached for nil creation of bubbles, or the milk properties were changed from the pre-processing which intended to lower the oxygen level. How come some milk can be stored outside of the refrigerator for several months without going bad? How is this milk processed and does the air content affect the processing? If these questions have stumbled upon your mind this is the article to point your eyes towards.<br /> <br /> Milk has not always been an as obvious choice for a nutritional beverage as it is considered today. Since it is almost an optimal environment for the growth of microorganisms, without proper processing several dangerous organisms can be found in milk. Raw milk has been known to contain pathogens like Salmonella, E. coli, Listeria and Campylobacter and historically, raw milk was a common source of spreading diseases like tuberculosis, typhus and scarlet fever.<br /> <br /> To kill the harmful substances milk is heated to a certain temperature for a certain time, called pasteurization. It was from the work performed by Louis Pasteur in the 19th century regarding the lethal effect heat has on microbes the process today commemorates his name. The kind of processing this thesis deals with is called Ultra High Temperature (pasteurization) which is performed in the temperature range of 135-140 °C for a couple of seconds. UHT milk is defined as commercially sterile meaning that the product is free from microbes that can grow in the conditions it is meant to be stored. The product is packed in sterile packages in a sterile environment and can be stored in ambient temperature (25-40 °C depending on location) up to a couple of months. Of course, once the product is opened it spoils in a matter of days just as regular milk.<br /> <br /> When heating the milk, a build-up is created on the hot pipes, called fouling, similar to the burnt milk seen in your pan when you forget to stir your béchamel sauce continuously. Fouling consists of fat, proteins and minerals, all originating from the milk. Fouling is money down the drain in the dairy industry since the process must be shut down regularly for cleaning, you lose product to the fouling and the processed milk quality can be worse when fouling is created. There is much to be gained if the phenomenon could be limited only slightly.<br /> <br /> Many factors affect the formation of fouling such as temperature difference between the milk and the heating side, the milk quality and composition and the pressure in the heat exchanger. Air content has long been a recognized factor leading to an increased fouling rate, but no one knows exactly why. This thesis examined the influence of air in milk. When the milk is heated in the process it cannot carry as much oxygen and thus are bubbles created in the process. These bubbles are then filled with steam which dries the product on the hot pipes and the fouling formation starts.<br /> <br /> From the experimental work performed on a small scale UHT in this thesis it was shown that the fouling rate was slower if the pressure in the process was increased. It was also shown that the period before the fouling starts to form was longer with an increased process pressure. If more experiments are performed in bigger scale maybe the fouling can be controlled in a wider sense which would save money for the dairy industry.<br /> <br /> The report also includes the experimental setup created to be able to examine the formation of fouling including advanced monitoring devices such as differential pressure transmitters and oxygen sensors. https://lup.lub.lu.se/student-papers/record/8942975/file/8943569.pdf application/pdf 2930412 no 2018 eng Fouling Dairy UHT Bubble Bubble induced fouling Drying THE Dairy Processing Processing Bubble Nucleation Differential Pressure Oxygen sensors chemical engineering kemiteknik Agriculture and Food Sciences Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/8942975/file/8943378.pdf application/pdf yes 8942975 2018-05-28T18:35:42+02:00 2018-06-04T16:05:26+02:00 2018-06-04T16:05:26+02:00

oai:lup-student-papers.lub.lu.se:8944118 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Charlotte Lindgren author 8944116 Irene Rodriguez Meizoso supervisor Department of Chemistry v1000647 department Potato protein is an industrial side product with highly desirable properties which can be utilized if the toxic glycoalkaloids can be removed in a gentle way which doesn’t damage the protein. The challenge within this project is to find an extraction technique efficient enough to remove the toxic glycoalkaloids, but still mild enough to preserve the protein from denaturation. Supercritical CO2 extraction in combination with co-solvents and gas-expanded liquid extraction is mild techniques known to be efficient for extraction of glycoalkaloid-like compounds from plant material, which indicates in a potential use within this project. The aim of this project is to screen different co-solvents in combination with CO2 for evaluation of the technique in terms of glycoalkaloid removal and protein re-solubility of native potato protein. First, several solvents were evaluated with Solid Liquid Extraction to screen for the highest glycoalkaloid removal from the potato protein, and the best performing solvents were further evaluated in combination with CO2. Second, temperature, time and co-solvent composition were evaluated with ethanol respectively methanol in water mixtures with a Box Behnken design to estimate the most suitable conditions for extraction of glycoalkaloids from potato protein and re-solubility of the treated potato protein. The amount of co-solvent with respect to CO2 was here 30%, which resulted in a CO2-expanded liquid rather than a supercritical fluid. Co-solvent composition was found to be the factor with the highest impact on both glycoalkaloid yield and protein re-solubility. Extraction with ethanol in water as co-solvent resulted in glycoalkaloid yields from 0 to 20 434 ppm with the highest yield obtained with 80% ethanol in water, while the re-solubility of protein was between 0 and 96.9% with the highest result obtained with 95% ethanol in water. Extraction with methanol in water as co-solvent resulted in glycoalkaloid yields from 748 to 21 111 ppm, with the highest yield obtained with 80% methanol in water, and the re-solubility was between 0 and 12.4% with the highest result obtained with 95% methanol in water. The results described in this study lead to the conclusion that the technique used was found to be less suitable for cleaning the potato protein from the toxic glycoalkaloids and more suitable to recover the toxic glycoalkaloids for other purposes. Från giftiga potatisar till användbara proteiner<br /> <br /> Potatis är en av världens mest odlade grödor. Den innehåller både kolhydrater och proteiner och har ett högt näringsvärde. Det talas ofta om att det är viktigt att få i sig proteiner, men sällan om proteinets emulgerande, konsistengivande och skummande egenskaper. Dessa egenskaper är högt värderade inom livsmedelsindustrin. <br /> Traditionell odling har lett till att vissa potatissorter har högt innehåll av stärkelse, därför är potatis en viktig råvara i stärkelseindustrin. En sidoprodukt från stärkelseframställningen är en fruktsaft som innehåller potatisprotein. I denna vätska finns även det giftiga ämnet Solanin som genom att bidra till en bitter smak skyddar potatisen mot angrepp från djur och insekter. Det är samma ämne som gör att potatis blir giftiga och inte ska ätas om de förvarats ljust och blivit gröna. Solaninförgiftning kan orsaka magsmärtor och i värsta fall leda till dödsfall. Det är därför viktigt att ta bort Solanin från fruktsaften om proteinet ska kunna användas som livsmedel. <br /> Industrin har idag metoder för att ta bort Solaninet, men det är tuffa metoder som skadar proteinerna. Behandlingen gör att proteinerna ändrar form vilket innebär att egenskaperna som industrin värderar högt går förlorade. Om Solanin kan avlägsnas, samtidigt som proteinets egenskaper förblir intakta, kommer potatisproteinets värde och användningsområden att öka. <br /> Examensarbetets målsättning var att studera hur koldioxidexpanderade vätskor fungerar för extraktion av solanin från proteiner och att undersöka i vilken grad extraktionen påverkas av temperatur och tid. Det visade sig att valet av vätskan för extraktionen av Solaninet är viktig. Temperaturen och tiden verkar däremot inte påverka resultaten i någon större utsträckning. I studien testades även hur mycket proteinerna påverkades av behandlingen. Här visade det sig också att valet av vätskan för extraktionen var viktig. <br /> Examensarbetet visade på svårigheten att hitta en metod som är både effektiv för att ta bort Solanin och samtidigt bevara proteinet. Metoden som tog bort mest Solanin påverkade proteinernas form i så hög grad att det inte fanns några oförstörda proteiner kvar. Detta leder till slutsatsen att tekniken med de förhållanden som användes i detta arbete inte är tillräckligt effektiv eller mild nog för att ta bort det skadliga Solaninet samtidigt som proteinet bevaras oskadat. 2018 eng Co-solvent Glycoalkaloid Potato protein CO2-expanded liquid extraction (CXLE) Supercritical fluid extraction (SFE) analytical chemistry analytisk kemi Chemistry 8944118 2018-06-02T09:46:59+02:00 2018-06-20T14:03:55+02:00 2018-06-20T14:03:55+02:00

oai:lup-student-papers.lub.lu.se:8973518 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Cedric Koolen author 8973516 Peter Schurtenberger supervisor Antara Pal supervisor Department of Chemistry v1000647 department We present an experimental investigation of the dynamics of near-to-sphere colloidal ellipsoids in which we deploy a recently developed technique differential dynamic microscopy (DDM). Inherently opaque systems as well as progressively dense dispersions exhibit multiple scattering and as conventional techniques such as dynamic light scattering (DLS) suffer from this effect, studies probing their dynamics are limited. We show that with DDM samples of at least two orders of magnitude higher volume fractions can be analyzed than is possible with DLS. We have combined the obtained results with rheometry and analyzed the onset of the glass transition in these colloidal dispersion, additionally. We report a glass transition at a volume fraction of ~0.64. Dynamics on the colloidal length scale is ubiquitous in nature. Of particular interest is the dynamics of systems approaching a glass or a kinetically arrested state. Despite the enormous effort devoted by researchers over the past few decades to investigate the nature of the glass transition, there remain a number of open questions concerning the effects of shape anisotropy on self and collective dynamics at high packing densities. The lack of suitable model systems and the failure of classical techniques for investigating dense and often highly turbid suspensions near an arrest transition has immensely contributed towards the limited experimental information available up until now. In the present article we are able to provide a model system along with a suitable technique that can be used to investigate the collective dynamics of anisotropic particles in the semi-concentrated regime.<br /> <br /> Using the recently developed technique Differential Dynamic Microscopy (DDM), we have demonstrated that it is possible to explore the collective dynamics of well-defined colloidal ellipsoids over a concentration range no accessible to more conventional techniques. This manuscript demonstrates that DDM can now be used as a versatile technique to overcome the impediment encountered with most classical methods. We believe that DDM has the potential to result in a paradigm shift in the investigation of dynamic properties of a wide variety of synthetic and biological systems and will help in uncovering new physics that has eluded researchers due to the aforementioned technical difficulties. 2019 eng Collodial ellipsoids differential dynamic microscopy DDM Physical chemistry Chemistry 8973518 2019-03-26T11:52:56+01:00 2023-06-28T13:26:36+02:00 2023-06-28T13:26:36+02:00

oai:lup-student-papers.lub.lu.se:8973986 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Amanda Willas author 8973984 Ingemar André supervisor Department of Chemistry v1000647 department All viruses are composed of both genetic material and a capsid. The capsid is composed by identical protein subunits and the purpose is protection of the genetic material, in this case RNA. This project is about cowpea chlorotic mottle virus, also called CCMV, which is a plant virus and the disassembly and reassembly mechanisms of the capsid are investigated to understand how the capsid proteins associate to create capsids. These mechanisms are suitable to use as a model system to study protein self-assembly. <br /> The capsid is able to disassembly and removes the genetic material. The capsid proteins can then assembly to an empty capsid without any genetic material. <br /> The goal with this project is to develop a method to recombinant express CCMV and isolate dimers that are appropriate for assembly.<br /> Previous research has tried to take advantages of a binding his-tag to facilitate the purification. These experiments have been unsuccessful. For that reason, this project doesn´t use a his-tag. <br /> Plasmids containing the gene of interest were recombinant expressed in E.coli and purified with ammonium sulphate precipitation followed by gel filtration. Dynamic light scattering and mass spectrometry were performed on fractions from the gel filtration. <br /> The solution conditions were changed to control assembly of capsid proteins. Dimers were isolated and experiments with a 50/50 mix of dimers and assembly buffer with different pH and incubation times were performed to create capsids. A 50/50 mix of dimers and assembly buffer with pH 4.5 and incubation for 30 minutes probably created capsids. <br /> After the expression was the protein found in the soluble part of the clarified lysate. Previous research has found the protein in the inclusion bodies. <br /> Further experiments should try to optimize the purification and also the solution conditions. The assembly-competent CCMV dimers can be recombinant expressed and isolated and thus useful in further biophysical experiments. Virus är icke levande organismer som infekterar levande celler och förökar sig med hjälp av cellernas maskineri. De kan infektera alla typer av liv och de är totalt beroende av en värdcell. Alla virus innehåller genetiskt material samt en så kallad viruskapsid. Denna kapsid kan ha olika struktur och består av identiska proteinenheter. Kapsidens uppgift är att skydda det genetiska materialet. Detta projekt handlar om cowpea chlorotic mottle virus, även kallat CCMV, som är ett växtvirus med ikosaedrisk struktur vars associerings- och disassocieringsmekanismer fungerar som ett lämpligt modellsystem för att studera hur olika proteinenheter sätts ihop för att skapa en kapsid. Detta är ett passande modellsystem för att kapsiden kan disassociera och avlägsna det genetiska materialet för att sedan under specifika förhållanden associera tillbaka till den ursprungliga kapsiden. <br /> Projektet har gått ut på att uttrycka CCMV genom rekombinant protein produktion. Proteinuttryck görs ofta i bakteriesystem eftersom bakterier både är lätta att odla och de växer snabbt. Dessutom producerar de ofta höga utbyten av rekombinant protein. <br /> Escherichia coli, mer känd som E.coli, är en bakterieart och i detta projekt utnyttjas två olika slags E.coli celler. <br /> Under projektet isolerades proteinenheter och det undersöktes under vilka förhållande som dessa proteinenheter associerar och skapar kapsider. Experimenten visade att med en associeringsbuffert och surt pH kunde troligen kapsider skapas. <br /> Sammanfattningsvis är målet med projektet alltså att utveckla en metod för att rekombinant uttrycka CCMV följt av isolering av associeringskompententa dimerer. https://lup.lub.lu.se/student-papers/record/8973986/file/8973987.pdf application/pdf 13981124 no 2019 eng Biokemi Biochemistry Viruskapsid Viruscaspid CCMV Chemistry 8973986 2019-04-03T20:44:14+02:00 2019-07-04T13:31:20+02:00 2019-07-04T13:31:20+02:00

oai:lup-student-papers.lub.lu.se:8974384 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ludvig Gunnarsson author 8974283 Abdelrazek Mousa supervisor Department of Chemistry v1000647 department Transition metal complexes can activate otherwise unreactive C-H bonds to form C-C bonds, which is of great use for the synthetic chemist. One type of organometallic framework that has gained fame in the last decade is the pincer complex because of its stability, and how easily its steric and electronic properties can be altered. Palladium is one of the transition metals commonly used in pincer complexes but is a very rare and expensive metal. Its less valuable analogue nickel shares similar activity with palladium in Kumada coupling. Nitrogen donor groups are hard donors, making it possible to stabilize nickel Ni(III) species, and hence being able to do radical reactions such as Kharasch addition. Nickel is also abundant and inexpensive, making it a very interesting alternative. In this work the synthesis of different NCN´ pincer Ni(II) complexes was tried, only N-(propan-2-yl)-N-{[3-(pyridin-2 yl)phenyl]methyl}propan-2-amine was successfully synthesized and characterized, but with an unsuccessful cyclometalation. The importance of organometallic chemistry and its reactions can be reflected in the three Nobel prizes in chemistry that this field has been awarded in the last twenty years. Organometallic chemistry has given the synthetic chemist a completely new toolbox to create new molecules. Transition metals, such as iron, nickel and silver, give the organometallic molecules the special properties to perform reactions that pure organic chemistry cannot.<br /> <br /> Organometallic molecules are often utilized as catalysts. The requirement for a molecule to be a catalyst is that it needs to increase the rate of reaction without itself being consumed. The catalyst provides the framework needed for catalysis to happen. An example of this are proteins where their protein structure creates an active pocket where the reaction can take place. An alternative reaction pathway of lower energy compared to the usual route is provided by the catalyst, increasing the reaction rate. A good parable is to see the energy levels of the catalysed and uncatalyzed reactions as hills; the more energy required higher the hill. A smaller hill requires less energy to climb and will be done faster than if one would try to climb the larger hill.<br /> <br /> There are many different types of catalysts, but one kind that is getting a rise in attention the last decade is the pincer complex. A metal atom is kept in place by surrounding atoms, connected in a chelated fashion. This means that the ligand creates a “jaw” that locks the metal in place, making it more stable and reactive in a productive way. Pincer ligand metal complexes are of interest because of their stability, as well as the simple ways of adjusting both its steric and electronic properties by changing the nature of the donor groups.<br /> <br /> Catalysts provide higher yield, consume less solvent and require lower temperatures to perform the same reactions and these are just a few pros of using these organometallic molecules. Today catalysts are used to produce a wide variety of products that we use in our everyday life, such as plastic, pharmaceuticals and soap, to name a few.<br /> <br /> In this work, we have tried to synthesize pincer complexes with nickel as the transition metal. Nickel share similarities with the extremely valuable palladium metal. However, nickel is more abundant and less expensive than its more valuable analogue, and this makes it a very attractive alternative for palladium catalysed reactions. 2019 eng Oorganisk kemi Inorganic chemistry Pincer complex NCN Nickel Chemistry 8974384 2019-04-11T11:08:09+02:00 2023-06-28T11:47:02+02:00 2023-06-28T11:47:02+02:00

oai:lup-student-papers.lub.lu.se:8974603 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Bernard Rosencrantz author 8974537 bitr. universitetslektor Baozhong Zhang supervisor Centre for Analysis and Synthesis v1000651 department Från ett presspulver och ett nytt bindemedelssystem har en ny sammansättning för metallformsprutning utvecklats. Kraven som ställts på nya sammansättningen var att de ingående komponenterna ska vara homogent fördelade och att sammansättningen ska ha de rätta reologiska egenskaperna. Presspulvret bestod huvudsakligen av volframkarbid, kobolt och polyetylenglykol.<br /> Presspulvret blandades med ytterligare nio organiska komponenter i en sigmabladsblandare för att framställa den nya sammansättningen. Genom försöksplanering kunde en statistisk analys av hur de organiska komponenterna påverkade den nya sammansättningen reologiskt och blandningsmässigt.<br /> En experimentanalys utfördes för att försäkra att inga farliga reaktioner förekom under tillblandningen av den nya sammansättningen. Dem nio organiska komponenterna som tillsattes bestämdes under en förstudie som utfördes av samma författare som för detta examensarbete under sommaren 2018. Förstudien var baserad på patent, vetenskapliga artiklar, böcker och kunskap från handledare på Seco Tools.<br /> För reologiska mätningar användes både en kapillär- och en rotationsreometer. Homogeniteten utvärderades med hjälp av en pyknometer och ett elektronmikroskop.<br /> De reologiska egenskaperna påverkades till största del av den mängden polyetyleneglykol och förhållandet mellan mängden organiska ämnen och mängden presspulver. Antioxidanter, ytaktiva medel och ”backbone” polymeren visade sig vara det som påverkade homogeniteten för de nya sammansättningarna.<br /> Totalt så producerade 41 unika sammansättningar varav fyra hade de rätta reologiska egenskaperna för att metallformsprutas. De fyra sammansättningarna metallformsprutades och sintrades. Från Seco Tools presspulver och ett nytt bindemedelssystem har en ny sammansättning för metallformsprutning utvecklats. Kraven som ställts på nya sammansättningen var att de ingående komponenterna ska vara homogent fördelade och att sammansättningen ska ha de rätta reologiska egenskaperna. Presspulvret bestod huvudsakligen av volframkarbid, kobolt och polyetylenglykol. För att effektivisera och minimera kostnader för processer där tillskärning av metall är viktigt, har en ny sammansättning utvecklats för metallformsprutning.<br /> <br /> Då en bil produceras krävs flera olika delar med väldigt precisa dimensioner; ett exempel på detta är motorn och dess delar. Motorn kommer ursprungligen från flera bitar av metall och för att få till de rätta dimensionerna krävs det väldigt precis skärmetoder för metall; För dessa skärmetoder används ofta skär som är producerade från hårdmetall. En hårdmetall är en metall som är väldigt slitstark och är vanligtvis ett billigare alternativ till diamant. Vid tillskärning av metall väljer man en hårdmetall som är mer slitstark än den metallen som ska skäras till och på grund av skillnaden i hårdhet kommer skäret av hårdmetall att bibehålla sin form under tillskärning. Hårdmetallskär används nästan inom alla industrier där metall finns tillgängligt, de absolut vanligaste är gruv-, olje- och transportmedelsindustrin.<br /> <br /> För att minimera produktionskostnader och maximera kvalitén hos ett hårdmetallborr har en relativt ny produktionsmetod börjat användas: metallformsprutning. Metallformsprutning har sitt ursprung i formsprutning, vilket är en metod för att producera komplexa komponenter av plast väldigt snabbt. Metallformsprutning kan producera stora eller små volymer, komplex eller enkla geometrier samt forma skäret i ett enkelt steg. Metallformsprutning görs med en sammansättning som består av metall och polymer varpå man avdriver polymeren.<br /> Seco Tools, som är ett företag beläget i Fagersta (Västmanland), är en av de största producenterna av hårdmetallskär i världen. Detta görs till största del med en teknik som heter pressning men med denna teknik kan man endast tillverka geometrisk primitiva skär, vilket har lett till att Seco Tools har intresserat sig mer för metallformsprutning<br /> Syftet med examensarbetet var utveckla en ny sammansättning för metallformsprutning och med en ny sammansättning tror Seco Tools att man kan substituera stora delar av deras pressning med metallformsprutning; Detta tros kunna leda till mer komplexa skär vilket skulle kunna öka livslängden hos ett skär men också sänka priset eftersom man kan producera stora volymer med hjälp av metallformsprutning<br /> Från examensarbetet hittades fyra sammansättningar med bra egenskaper för metallformsprutning. Detta har lett till att Seco Tools kommer fortsätta med resultaten från detta projekt för att vidareutveckla deras metallformsprutning. https://lup.lub.lu.se/student-papers/record/8974603/file/8974604.pdf application/pdf 8111580 yes 2019 eng Technology and Engineering Chemistry 8974603 2019-04-17T09:13:22+02:00 2019-05-03T11:28:01+02:00 2019-05-03T11:28:01+02:00

oai:lup-student-papers.lub.lu.se:8975098 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Jonathan Ekstrand author 8879025 João Pedro de Almeida Martins supervisor Department of Chemistry v1000647 department MRI can be used as an non-invasive method to map the brain. By correlating diffusion with relaxation it is possible to separate different tissue kinds such as white matter, grey matter and free water. <br /> <br /> In this work we look at how to bin the data to best separate the tissues. By modifying the bin limits in Diso, Dperp / Dparallel, \DDelta and R2 it will be shown that there is not a single optimal design for the bins. Instead the strength of this method is that by modifying the bins it is possible to highlight tissue that for example have a lower R2 than the surrounding tissue. Med hjälp av MRT så är det möjligt att undersöka en hjärna utan att behöva använda skadlig strålning. Genom att korrelera vattenmolekylers diffusion med dess R2 värde så är det möjligt att separera olika sorters vävnad. Detta då dessa parametrar beror på den kemiska sammansättningen samt strukturen på omgivningen. Men för att kunna separera vävnaderna och visualisera dem så måste datapunkterna som motsvarar en viss typ av vävnad sorteras tillsammans. Detta görs genom att datan sorteras in i tre stycken ”lådor” var vi hoppas på att fånga vit materia, grå materia samt fritt vatten. <br /> <br /> Genom att manipulera storlekarna på dessa lådor så är det möjligt att markera vissa datapunkter som sticker ut från dess omgivning i en specifik dimension. Det visar sig även att det inte finns en enda optimal design på lådorna utan denna metods styrka finns i att kunna ändra på lådorna och analysera datapunkter som skiljer sig i en dimension från vävnad av samma slag runtomkring. 2019 eng Physical chemistry fysikalisk kemi Chemistry 8975098 2019-05-06T18:55:42+02:00 2019-05-20T10:35:12+02:00 2019-05-20T10:35:12+02:00

oai:lup-student-papers.lub.lu.se:8976661 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Daphne le author 8902732 Profession Tommy Nylander supervisor Department of Chemistry v1000647 department Transport in and through biological membranes that consist of lipid bilayers has a crucial role in many applications in the food or pharmaceutical industries. How to deliver an enzyme through the membranes without damaging the enzymatic activity or the &quot;shelf-life&quot; of the enzyme has been of large interest since 1970 [29-30].<br /> In this work, we have shown that a thin lipid sponge phase (L3) layer can be formed on adiamond crystal of an attenuated total reflectance (ATR) accessory for Fourier transform infrared (FTIR).The lipid system used was composed of diglycerolmonooleate (DGMO), glycerol monooleate - Capmul GMO-50 (GMO-50) and the nanoparticle stabilizer polysorbate 80 (P80) in ethanol (EtOH).<br /> In this coated lipid layer, the enzyme beta-galactosidase (beta-gal) could be immobilized and characterized by the catalysis of lactose. Beta-galactosidase is an important enzyme in the food industry that is used to hydrolyze lactose to glucose and galactose for making lactose-free milk or other dairy products that are important for lactose intolerant peoples. <br /> We investigated by ATR-FTIR the catalytic response of the enzyme in lipid layers coated at different spinning times on the crystals and different concentrations of enzyme.<br /> The FTIR signals that are related to the catalytic process of beta-gal were identified at561 cm-1 and 582 cm-1 in the Infrared spectrum. The obtained signal belonged to the produced glucose. Furthermore, to understand the effect of spin-coating and enzyme activity as well as the best condition in term of maximizing the glucose formation- and lipid signals decrease rates for the system and technique, we designed a factorial experiment combining different spinning times (drop-casting, 20and 300 s) and enzyme dilution factors (10, 50 and 100 times). The optimal condition for the highest catalytic rate and lowest disturbance of the lipid signal was further used to investigate the re-usability of the encapsulated enzyme. No conclusions about the re-usability of the encapsulated enzyme could not be drawn from the experiment due to the unreliable collected data. Transporten i och genom de biologiska membranerna är väldigt viktig och har många applikationer i mat- och läkemedel industrier. Dessa membranerna består av dubbel-lager av lipid molekyler. Genom att blanda två olika sorter av lipiderna diglycerolmonooleate (DGMO) och glycerol monooleate (GMO-50) med nano-partikelstabilisatorpolysorbate 80 (P80) i överskott av vatten skapar det en lipidblandning med porer i som kallas för ”sponge-fas”. En tidigare studie av Valldeperas visar att de porerna kan fungera som ”bäraren” för enzymet beta-galaktosidas med syftet för att minska nedbrytning av enzymet genom membranerna. Hur som helst, det saknar fortfarande en förståelse för hur enzymet fungerar i lipidblandningen och om enzymet ändrar struktur på lipidblandningen. <br /> <br /> Beta-galaktosidas är ett vanligt enzym som används för att bryta ner laktos till glukos och galaktos. Enzymet är viktig för produktionen av laktos-fritt mjölk och andra mejeriprodukter. Denna funktion ska användas för att studera strukturen av lipidblandningen i närvaran av β-gal. Enzymet ska blandas in i lipidformuleringen innan en tunn lager av mixen skapas med hjälp av ”spin-coating” tekniken. Olika kombinationer av ”spinning” tid och enzymets koncentrationmåste testas för att få fram den optimala förhållande vad gällande maxglukosmängd bildad och reaktionshastigheten. <br /> <br /> I detta projekt har mätningar av aktivitet av enzymet, beta-galaktosidas,som kapslas in i lipids porerna gjorts med spektroskopiska mätmetoden, FTIR-ATR (Fourier Transform Infared Spectroscopy-Attenuated Total Reflection) som mäter vibrationerna av molekyler när en röntgenstrålning passerar genom dom. Mätningarna visar att aktiviteten av enzymet kan tämmas av FTIR-ATR och enzymet är fortfarande aktivt även när det är kapslat av lipidblandningen. Signifikanta signaler av produkten glukos kan också detekteras efter två timmars reaktionenstid. Tyvärr,glukos bildad hastigheten kan inte förutsägas med bara två faktorerna ”spinning tid” och ”enzymets koncentration”, ytterligare faktorer behövs för att kunna fatta en konkret slutsats om hastigheten. 2019 eng Lipid sponge phase (L3) DGMO/GMO-50/P80 beta-galactosidase enzymatic activity spin-coating ATR-FTIR physical chemistry fysikalisk kemi Chemistry 8976661 2019-05-23T02:10:23+02:00 2019-07-04T13:29:57+02:00 2019-07-04T13:29:57+02:00

oai:lup-student-papers.lub.lu.se:8979507 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Susanne Brixland author 8979445 Researcher Christian Hulteberg supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Climate change is one of humanities greatest challenges; the greenhouse gases in the atmosphere are still increasing. There is not one solution that will fix this problem several different products, raw material and technologies are required to take the steps towards a renewable society. Biomethanol and substitute natural gas, are two fossil free energy carrier, they can both be produced through gasification.<br /> <br /> Biomethanol is produced in an energy consuming process were the limited conversion rate, creates a need to recycle and thereby compress a large recycle feed. This thesis objective is to investigate if a co-production of substitute natural gas and biomethanol can be a feasible process, using mature technology. Simulations of the processes is performed in ASPEN plus. Three different cases were set up.<br /> <br /> In case 1 the produced syngas from the gasifier is cleaned using cyclone, OLGA, Rectisol and a guard bed. A shift is used to get the correct ratio between CO and H2.The gas is then compressed further before entering the methanol synthesis. The flashed off gas is then lead to a methanation step and further down to a gas upgrading step, while the liquid stream is lead to distillation. This way producing both substitute natural gas and biomethanol is produced.<br /> <br /> In case 2 the produced syngas from the gasifier is reformed and then cleaned using cyclone, OLGA, Rectisol and a guard bed. A shift is used to get the correct ratio between CO and H2.The gas is then compressed further before entering the methanol synthesis. The flashed off gas is recycled back to the methanol reactor inlet after being compress up to 75 bar again. The liquid stream is lead to distillation, biomethanol being the only product.<br /> <br /> In case 3 the produced syngas from the gasifier is cleaned using cyclone, OLGA, Rectisol and a guard bed. A shift is used to get the correct ratio between CO and H2.The gas is then compressed further before entering the methanol synthesis. The flashed off gas is recycled back to the methanol reactor inlet after being compress up to 75 bar again. The liquid stream is lead to distillation. The purge stream is lead through a gas turbine, before entering a furnace to create high and medium pressure steam, which is used to produce electricity in turbines.<br /> <br /> The simulation results shows that case 2 has the highest thermal efficiency, 0.63, followed by case 1, 0.47 and case 3, 0.21. <br /> <br /> The feasibility study shows that case 1 and 2 are feasible with present value method. The discount rate is set to 10% and the plants economical life time, is assumed to be 30 years. Case 2 is showed to be the most feasible investment, during this conditions and assumptions. Case 3 showed a negative present value.<br /> <br /> This thesis indicates that the theory of co-production being more feasible then a stand-alone biomethanol plant is not the case during these conditions. Klimatförändringar är en av mänsklighetens stora utmaningar, över hela världen obbar forskare och företag på att ta fram nya tekniker och innovationer för att bidra till en fosilfri framtid. https://lup.lub.lu.se/student-papers/record/8979507/file/8979516.pdf application/pdf 10259927 no 2019 eng biomethanol SNG substitute natural gas co-production gasification gasifier biomass syngas chemical engineering kemiteknik Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/8979507/file/8979522.pdf application/pdf no 8979507 2019-06-04T17:48:05+02:00 2019-07-04T11:05:09+02:00 2019-07-04T11:05:09+02:00

oai:lup-student-papers.lub.lu.se:8979818 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Niklas Gunnarsson author 8979797 Ola Wendt supervisor Professor Mikael Calner supervisor Department of Chemistry v1000647 department Exploitation of alum shale is a controversial subject in Sweden due to the history of pollution of the environment and groundwater, from past mining industries. The extraction of vanadium from alum shale is no different. Nevertheless the metal is a valuable resource used in tools, building, industries and aerospace materials. A look to the future reveals that vanadium may play a role in renewable energy. Vanadium redox flow batteries can store large amount of energy utilizing the many oxidation state of vanadium. This could solve the problem of energy storage many sources of renewable energy faces. This project is devoted to give a better understanding of how vanadium is bound and accumulated in the Cambrian Alum Shale Formation of southern Sweden, with the hope that this knowledge can help find an environmental friendly process to extract vanadium from alum shale in the future. In this project a drill core penetrating the Alum Shale Formation at Kinnekulle, has been analyzed with x-ray fluorescence spectroscopy, x-ray powder diffraction, x-ray photoelectron spectroscopy, IR-spectroscopy and a total organic carbon analysis. The aim is to identify the chemical state and evaluate possible correlations between vanadium, trace elements, organic carbon and minerals. The drill core was found to be enriched in several trace elements, such as vanadium, barium, molybdenum, uranium, lead, copper and nickel, compared to Clarke values of black shale. Illite, the suspected main carrier of vanadium, had a very low signal in the x-ray powder diffraction and organic matter is proposed as a major carrier of vanadium. The level of anoxia in the waters at the time of sedimentation showed a rise in dissolved oxygen at 1,02 m, which could be the cause of the lower amount of vanadium in the top-most section of the drill core. Alunskiffer är en svart lersten av kambrisk-tidig ordovicisk ålder som har en vid utbredning i Sverige och angränsande områden. Bergarten är rik på organiskt kol från ofullständig nedbrytning av marina mikroskopiska organismer som inlagrades i sedimentet på syrefria havsbottnar. Miljön gjorde det även gynnsamt för en del spårmetaller att deponeras, bland annat Uran, Nickel, Molybden och Vanadin. Vanadin och gruvnäring med alunskiffer är känt för att skapa kontroverser. Orsaken är risken för att giftiga ämnen släpps ut i miljön, grundvatten och påverkar det närliggande landskapet vid utvinning.<br /> <br /> Vanadin har främst använts i legeringar av specialiserat, värmetåligt stål i industrier, flygplan och rymdteknik. Metallen är unik eftersom den har flera naturligt förekommande oxidationstillstånd; dvs. variation i antalet elektroner tillhörande atomen. Denna egenskap har gett vanadin nya framtidsutsikter som en del i en grönare energiproduktion. De flera oxidationstillstånden är fördelaktiga i så kallade redox flow-batterier. Batterierna kan effektivt lagra stora mängder energi i stora tankar som battericeller. De är även stabila då de tål att laddas ur och ses dessutom som säkrare än till exempel litiumbatterier.<br /> <br /> Hur vanadin ackumuleras i sedimentet är en komplicerad process. Vanadin förekommer upplöst i vatten och ett cirkulerande flöde krävs för att transportera metallen till sedimentationsområdet. Vanadin kan adsorbera eller tas upp av metalloxider och biota som deponeras i sedimentet. Vanadin bildar starka komplex med det organiska kolet. Med tiden bryts komplexen och en del vanadin stannar genom inbindning till lermineralens gitterstruktur. I denna struktur kan vanadin<br /> vara kvar även under diagenesen, då sedimentet omvandlas till skiffer under högt tryck och temperatur, för att slutligen återfinnas i mineral som illit.<br /> <br /> I detta projekt har vanadin analyserats i en borrkärna med alunskiffer från Kinnekulle. Olika röntgenbaserade metoder har använts för att ge en bild av hur vanadinet sitter strukturellt i skiffern. Möjligen kan detta leda till bättre förståelse för hur vanadin kan utvinnas med minimal miljöpåverkan. https://lup.lub.lu.se/student-papers/record/8979818/file/8979836.pdf application/pdf 3986293 no 2019 eng Alum Shale Formation Alum shale Kinnekulle Vanadium Inorganic chemistry Oorganisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/8979818/file/8979839.pdf application/pdf no https://lup.lub.lu.se/student-papers/record/8979818/file/8979843.pdf application/pdf no 8979818 2019-06-05T13:13:55+02:00 2019-08-19T13:46:02+02:00 2019-08-19T13:46:02+02:00

oai:lup-student-papers.lub.lu.se:8982480 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH1 Lei Ortigosa author 8982478 Tinna Pálmadóttir supervisor Department of Chemistry v1000647 department The aggregation of α-synuclein into fibrils has been long proven to be closely related to the toxicity leading to Parkinson’s disease. In this process, medium-sized intermediates called oligomers are formed, a heterogeneous group of aggregates formed by a small number of monomers. While fibrils have been proven to cause little to no toxicity, oligomers have been demonstrated to induce cell death. This has pointed at oligomers as the possible key in understanding the relationship between protein and disease. However, its concentration during aggregation process in comparison to monomers and fibrils has made its analysis a difficult task. Photo induced crosslinking of unmodified proteins (PICUP) is a method that has been previously used for oligomer analysis. By crosslinking oligomers together, their stability is ensured, and they can be subjected to methods that couldn’t be used otherwise, making it possible to perform population analysis on. However, the method doesn’t have a unified protocol nor a set instrument in the market as of yet. The main goal of this research was to optimize the PICUP method by creating a more reproducible instrument of easy access to other research groups, as well as optimizing conditions such as reagents or light exposure time. Finally, the reaction was used to evaluate the oligomer population distribution throughout the aggregation of α-synuclein. The results proved the newly created instrument and the optimized conditions to be optimal for oligomer analysis, opening the gate to a big range of future experiments which will help us unravel the mysteries behind the aggregation process and its connection with cellular toxicity. Proteins are one of the most essential components of life. From controlling division or transporting “cargo” inside a cell, to coordinating the movement of a multicellular organism, proteins are responsible for most of the “active” parts of life. In order to keep us working, cells constantly produce big amounts of the specific protein we need in each part of our body. However, some of those protein’s functions have yet to be completely understood. Sometimes a protein is found because of its connection to a disease before we learn what it actually does. That’s the case for α-synuclein, a small protein produced in the area called substantia nigra in our brain. This protein was first discovered in some inclusion bodies called Lewy bodies, which could be found on Parkinson’s patients. Ever since then, the relationship between protein and disease has been thoroughly investigated.<br /> One of the biggest discoveries in that field has been the fact that the protein aggregating into big fibril structures has been linked to its toxicity. In that aggregation process, the protein units (monomers) cluster together forming many different sized aggregates. Oligomers, medium-sized aggregates consisting of 2 to around 20 units of proteins, have recently been proven to cause cell death. However, its concentration when compared to pure monomers or the big fibrils is very low. Due to this, many techniques have failed to analyze oligomers. Photo induced crosslinking of unmodified proteins (PICUP) is a very promising method which can be used for oligomer analysis. In this reaction, when light is shone on a protein-containing sample, units forming the oligomer bind together tightly, allowing us to perform methods to analyze them which we couldn’t otherwise use. However, this method hasn’t been standardized and optimized, to the point of there not even being an available instrument in the market to perform the technique. <br /> The main goal of this project was to develop an instrument to perform PICUP, and then proceed to optimize conditions of the reaction, such as testing different reagents or different durations for the light to shine on the reaction. Finally, when these conditions were optimized, the technique was used to analyze how the population of oligomers changes throughout the α-synuclein aggregation process. This didn’t only prove the instrument and the optimization to be a very useful tool in analyzing oligomers, but it threw more light into an important aspect of aggregation. All in all, the project has proven PICUP to be a very useful technique to help solve the many questions we have yet to answer in order to understand the connection between the protein and Parkinson’s disease. 2019 eng α-synuclein Parkinson's disease Crosslinking protein science proteinvetenskap Biology and Life Sciences Chemistry 8982480 2019-06-12T13:16:38+02:00 2019-07-04T13:33:09+02:00 2019-07-04T13:33:09+02:00

oai:lup-student-papers.lub.lu.se:8887260 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Hannes Nederstedt author 8887108 Zhecheng Shao supervisor Centre for Analysis and Synthesis v1000651 department Lithium-ion batteries are a common type of light-weight, rechargeable batteries. There are safety concerns because these batteries typically use an organic solvent electrolyte which presents fire hazards. By using dry polymer electrolytes, the fire hazards can be eliminated. The single-ion conductor is a type of polymer electrolyte in which the ion-containing group has been covalently bonded with the polymer structure, thereby immobilising the anion. This eliminates problems present in common liquid electrolytes, such as dendritic growth in the battery that can lead to short circuiting. <br /> <br /> The purpose of this Master thesis was to synthesise and characterise single-ion conductors. The polymers were random copolymers with a poly(ethylene oxide) backbone. The ion-containing repeating units contained a side chain with one quaternary ammonium cation and two sulfonate anions. The non-ionic repeating units carried a triethylene glycol monomethyl ether side chain. Copolymerisation by anionic and cationic ring-opening mechanism failed. Instead poly(epichlorohydrin) was synthesised using an anionic ring-opening mechanism followed by several post-polymer reactions to yield the target polymers. These polymers did not form a melt at sufficiently low temperatures (below 140 °C) in order to make samples for conductivity measurements. Instead blends between homopolymer only containing ionic repeating units and <br /> poly(ethylene glycol-ran-propylene glycol) were made and the conductivity of these blends were measured. The highest measured conductivity was 3.3∙10-6 S/cm at 90 °C for a blend with an EO/Li ratio of 8. This conductivity, while similar to other single-ion conductors, is too low for the blends to be used for battery applications. <br /> <br /> Suggestion for future work include the preparation of polymers with sulfonate groups that are more rigidly bonded to the polymer to inhibit the tight coordination of lithium ions by the polymer, thereby improving the conductivity. Copolymers with large amount of non-ionic repeating units should be synthesised to further decrease their glass transition temperature and make measurements by impedance spectroscopy possible. Batterier finns överallt, t.ex. i mobiltelefoner, bärbara datorer och surfplattor. I och med klimatförändringarna i världen så ökar intresset för miljösmarta bilar som t.ex. elbilar vilket medför att nya användningsområden för batterier skapas. Litiumjonbatterier är en typ av lätta, återuppladdningsbara och energirika batterier som skulle kunna användas för att möta de krav på nya batterier som uppstår. I mitt arbete har jag arbetat med att framställa och testa en typ av polymerer som kan användas som komponent i litiumjonbatterier för att kunna göra dessa batterier säkrare och därmed mer användbara.<br /> <br /> Alla batterier har en pluspol och en minuspol där kemiska reaktioner sker som producerar ström. För att detta ska ske under kontrollerade former och för att man ska kunna ta ut någon ström, krävs det att polerna hålls åtskilda av en så kallad elektrolyt som kan transportera joner (laddade atomer) mellan polerna men stoppa strömmen från att ledas inuti batteriet och hålla plus- och minuspolen åtskilda. Vi vill alla ha bättre batterier som är mindre och lättare, har längre batteritid och kortare uppladdningstid. Litiumjonbatteriet är en ganska ny typ av återuppladdningsbart batteri som började säljas av Sony 1991. Denna typ av batteri utnyttjar litium för att lagra kemisk energi som kan göras om till elektrisk energi och kan lagra mycket energi per kilogram batteri. Ett problem med litiumjonbatteriet är att det använder litiumsalt (ett salt inom kemin innebär en förening mellan positiva och negativa joner) upplöst i brandfarliga vätskor som elektrolyt. Brandsäkerheten begränsar i vilken utsträckning man kan använda litiumjonbatterier, speciellt i samband med elbilar. Genom att istället använda litiumsalt upplöst i polymerer (stora molekyler som är uppbyggda av flera mindre molekyler) så kan brandriskerna kopplade till dessa batterier elimineras. På det här viset så blir litiumjonbatterier mycket säkrare och lättare att använda. Polymerelektrolyter kan även medföra att batterierna blir lättare och kan användas längre. Idag så är fortfarande polymerelektrolyter för dåliga på att leda joner och mer forskning krävs innan de kan börja användas kommersiellt. <br /> <br /> Endast speciella polymerer fungerar som elektrolyter. Exempelvis kan inte polyeten som används till plastpåsar användas. Vanligaste typen är en polymer med mycket syreatomer i sin struktur som kan transportera litium mellan polerna. I mitt arbete har jag framställt polymerer med mycket syre i sin struktur för att lösa upp salter och transportera litiumjoner och jag har bundit in negativa joner i polymerstrukturen som kan bilda ett salt med positiva litiumjoner. Genom att ha de negativa jonerna bundna till polymerstrukturen försvinner andra problem med vanliga elektrolyter. Till exempel så kan det börja växa litiummetallgrenar mellan polerna i ett batteri som använder vanlig elektrolyt men detta problem finns inte med de polymerer jag har framställt. Den här typen av polymerelektrolyt brukar kallas singel-litiumjonledare eftersom endast de positiva litiumjonerna leds genom elektrolyten. Dessa polymerer har jag sedan undersökt för att se om jag fått fram rätt produkt, sen har jag värmt upp dem för att se när de börjar smälta och när de bryts ner av värmen. Jag har testat hur bra polymererna är på att leda joner och kommit fram till att ledningsförmågan fortfarande är för låg för att vara användbar. Det är känt att polymerer av just den strukturen jag framställt vanligtvis har för låg ledningsförmåga för att vara direkt användbara i batterier. Baserat på mina resultat har jag kommit med förslag hur man kan forska vidare och framställa polymerer med högre ledningsförmåga för att i framtiden kunna börja använda dessa elektrolyter kommersiellt. https://lup.lub.lu.se/student-papers/record/8887260/file/8887261.pdf application/pdf 1771779 2017-07-31 no 2016 eng single ion conductors electrolytes polymers lithium ion batteries polymer technology polymerteknologi Chemistry Technology and Engineering 8887260 2016-07-14T15:21:24+02:00 2017-07-31T04:09:57+02:00 2016-08-22T14:37:03+02:00

oai:lup-student-papers.lub.lu.se:8887320 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Lina Le author 8886635 Kaibo Zheng supervisor Department of Chemistry v1000647 department Monodisperse colloidal quantum dots of fully inorganic cesium lead bromide CsPbBr3 are synthesised at two distinguished temperatures (120 and 180oC) using inexpensive commercial precursors. The stability of these quantum dots is studied under three different conditions by measuring absorption as well as photoluminescence as functions of time. For both kinds of quantum dots, the light affect their stability while temperature is not an important factor. Quantum dots with low synthesis temperature does not have a clear cubic phase compared to the ones with higher synthesis temperature. Another property that we think might happen for only low temperature synthesised quantum dots is forming of bigger quantum dots through a shrinking-expanding process. Kolloidal nanokristaller är små kristaller (2-20 nm) som bildar till ett ordnat nätverk. Kolloidal nanokristaller kallas också för nanokristall quantum dots (QDs). Cesium bly bromid CsPbBr3 är inorganisk quantum dots med hög stabilitet. Vårt syfte är att bekräfta om CsPbBr3 quantum dots är stabila under olika förhållande. Cesium bly bromid QDs syntetiseras vid 120o och 180oC. För varje serie preparerar vi tre prover. De tre proverna sparas i följande konditioner: utan ljus, vid låg temperatur samt utan ljus och med ljus. Vi har observerat att ljuset är den viktigaste faktor som påverkar stabilitet av QDs. Quantum dots som syntetiseras vid lägre temperaturen visar otydligt det kubiska mönstret. Ett förslag för att förklara hur de QDs med låg syntes temperatur ändrar är att några QDs krymper medan andra expanderar. https://lup.lub.lu.se/student-papers/record/8887320/file/8887322.pdf application/pdf 1878496 no 2016 eng kemisk fysik chemical physics Chemistry 8887320 2016-07-15T15:40:40+02:00 2016-08-15T20:51:32+02:00 2016-08-15T20:51:32+02:00

oai:lup-student-papers.lub.lu.se:8887712 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Helena Mateos author 4780502 Emma Sparr supervisor Jenny Andersson supervisor Department of Chemistry v1000647 department In this study, we have investigated some mechanisms used in nature to protect membranes and other self-assembled biomolecular structures against changes in hydration. One common mechanism used by many living organisms is the accumulation of small polar solutes with low vapor pressure that stabilize the cell membranes in cases of osmotic stress.1 These molecules are known as osmolytes. Among other mechanisms, plants also synthesize dehydrin proteins, which are found in vegetative tissues, and that are believed to protect membranes from conditions like desiccation or cold stress.2 To elucidate the molecular mechanism of dehydrins, the effect of Lti30 protein on the swelling of a lipid lamellar system was studied by adding different water contents to samples with and without the protein present. On the other hand, the effect that Lti30 and two osmolytes, urea and trimethylamine N-oxide (TMAO), have on the phase transition of a lipid model system under dehydration conditions was studied by exposing the lipid systems to water at different relative humidities. Our results show that Lti30 interacts with the lipid membranes preventing them from swelling at high water contents. In the case of the lipid model system under dehydration conditions, Lti30 does not have any effect in the phase transition of the lipids but it increases the swelling of the phases. Urea has the effect of stabilizing the fluid lipid bilayers at low water activities, where otherwise a phase transition to a solid state would occur. Moreover, the swelling of the fluid lipid bilayers increases significantly in the presence of urea. Adding TMAO to the lipid model system has the effect of stabilizing the reverse structures by shifting the phase transition to higher water contents. Nature has many mechanisms to protect living organisms from dehydration. Two of these mechanisms that are present in plants, are the accumulation of osmolytes, and the production of dehydrin proteins. Osmolytes are small substances that help balancing the volume of a cell, maintaining a good humidity.1 Proteins are large, complex molecules that have many different roles in living organisms. They are required for the function, regulation and structure of the body’s organs and tissues.2 Both osmolytes and dehydrins are believed to protect cell membranes against dehydration. <br /> The cells of all living beings are confined and compartmentalized by membranes. The structural bases of cell membranes are lipid molecules, which are composed of two parts, one that likes to be in contact with water, and one that does not. Due to the nature of some lipids they can form closed structures that separate inner and outer aqueous spaces.2<br /> However, little is known about the molecular mechanism either osmolytes or dehydrin proteins. In the present study, the mechanism of a specific dehydrin, named Lti30, and two osmolytes, urea and trimethylamine N-oxide (TMAO), is investigated by preparing lipid model systems with different rates of hydration in the presence or absence of these molecules. Our results show that Lti30 interacts with the lipid membranes preventing them from swelling at high water contents. However, when subjecting the system to dehydration conditions, Lti30 does not show any effect in protecting lipid membranes from injuries. On the other hand, urea shows a stabilizing effect of the lipid bilayers at dehydration conditions while TMAO shows the opposite effect, destabilizing the lipid membranes under study. 2016 eng Phospholipids Osmotic Pressure Osmosis Magnetic Resonance Spectroscopy Proteins physical chemistry Cell Membrane Dehydrin Urea: chemistry X-Ray Diffraction fysikalisk kemi Chemistry 8887712 2016-08-01T17:51:50+02:00 2016-08-30T11:12:10+02:00 2016-08-30T11:12:10+02:00

oai:lup-student-papers.lub.lu.se:8888277 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ragnar Hansson author 8888275 Ingemar André supervisor Department of Chemistry v1000647 department Studies of virus capsids opens up new opportunities to develop different kind of cargo systems, but also the understanding of the transportation and the releasing of different kinds of cargo molecules. Virus capsids is a protein shell of a virus that encapsulates different types of infecting nucleic acid sequences in their native forms. One of these capsids is the Hepatitis B virus capsid that in nature carries the viral DNA for the hepatitis B disease. The core antigen in this capsid is build up by α-subunit dimer and in vitro these dimers can spontaneously self-assemble into a nanocapsid under right conditions. A previously invented system have shown the possibility to regulate the load and release of encapsulated cargo molecules instead of permanently fusing the protein to the α-subunit in the nanocontainer.[1] Successful modifications of this cargo system could in the future lead to better efficiency in drug transportation, gene therapy and other kind of treatments. In this work insulin is the target molecule that wants to be encapsulated because this could lead up to transportation of the insulin into cells and also to generate slow release of insulin out of the capsid.<br /> The aim of this project was to exchange the protein sequence in the C-terminal of one of the α-subunits so that it in turn under right conditions could encapsulate insulin. This was made by designing a gene that contained single chain insulin on the C-terminal of one of the α-subunits. The theory is that this insulin togheter with five other insulin subunits forms a hexamer complex when Zn2+ ions are present, which upon self-assembly will make the hexamer complex on the inside of the capsid.<br /> The aim was also to ease the purification of the protein capsids by introducing a polyhistidine-tag (his-tag) to the N-terminal of the subunits. This was made by designing a primer that contained the polyhistidine fragment, a small linker and then a primer which was able to stick to the designed insulin fragment to make it possible to amplify it by PCR. Since struggling with difficulties of low amplification results a touchdown PCR was investigated to increase the amplification yield.<br /> This work has shown that touchdown PCR was a more efficient method than regular PCR for amplification of the designed primers in this work. Unfortunately, no conclusions of the theoretically constructed insulin system or the polyhistidine introduction can be drawn due to unsuccessful ligation and further studies needs to be carried out. Insulin är ett litet blodsockerreglerande peptidhormon som bildas i bukspottskörteln och utsöndras i kroppen för att reglera glukosnivåerna, exempelvis efter förtäring. Detta synnerligen viktiga peptidhormon produceras inte i tillräcklig skala hos personer med sjukdomen diabetes. Tekniker för att ge personer har tidigare blivit upptäckt, men ytterliggare forskning kan bli implementerade för att öka effektiviteten ytterliggare. Därför är det intressant att studera och upptäcka nya sätt att optimera leveransen av proteinet till kroppen. Bland annat genom långsam utsöndring av insulinet och dessutom att leverera det över cellers dubbla lipidskikt, vilket inte är möjligt genom dagens standardbehandling.<br /> Tidigare studier har visat att viruskapsider av diverse slag kan bli modifierade för att bära på olika typer av transportmolekyler. En av dessa är hepatit B viruskapsiden vars ena komponent, kallad HBcAg, ansvarar av själva enkapsuleringen av den skadliga DNA-sekvensen och återfinns innanför kapsidens lapidlager som återfinns ytterst på kapsiden och vars syfte är att tränga in genom cellers dubbla lipidlager så att det skadliga DNA som finns inuti kapsiden kan frisläppas inuti cellen. Proteinuttrycket av Hepatit B genen kan göras så att den endast kodar för HBcAg, vilket har öppnat upp för nya möjligheter att enkapsulera olika typer av transportmolekyler, och inte minst proteiner.<br /> Studier har tidigare visat att dom 149 första aminosyrorna i HBcAg är kritiska för självsammansättningen vilket gör att dom resterande aminosyrorna kan bli modifierade till system som är av intresse. Denna studie bygger på ett tidigare upptäckt transporteringssystem där en extra peptidbit efter HBcAg var datormodulerad så att en α-helix uttrycktes efter dom 149 första aminosyrorna. Denna α-helix gjorde det möjligt för signalproteinet Calmodulin (CaM) i närvaro av Ca2+-joner blev inbundet runt om den modulerade helixen. När sedan kelatorn EDTA tillsates så bildades det ett kelatkomplex med Ca2+-jonerna vilket medförde att Calmodulinet släppte från helixen. Denna typ av reglerande frisättning bygger upp nya förutsättningar och tanken är att applicera detta system på andra typer av proteinsekvenser.<br /> Syftet med denna studie är att utveckla det tidigare systemet så att kapsiden istället enkapsulerar insulin. Efter dom 149 första aminosyrorna är istället enkelkedjigt insulin infört som tillsammans med fem andra enkelkjedjor av insulin samt i närvaro av Zn2+-joner bildar en hexamer. Frisläppningen är precis som i den tidigare studien tänkt att vara reglerad med hjälp av en kelator. Syftet var även att införa en polyhistidin-tag i systemet för att enklare kunna rena fram kapsiderna med hjälp av affinitetskomatografi.<br /> Trots upprepade försök lyckades inte insulingenen bli ligerad in i sin tänkta plasmid. Polyhistidin-taggen som användes för att amplifiera det tidigare systemet simultant med ligeringen gav inte heller något givande resultat. Ytterliggare studier behövs göras för att påvisa om det tänkta systemet fungerar i praktiken eller inte. Däremot lyckades arbetet påvisa att den nyligen utvecklade metoden touchdown-PCR gav ett bättre utbyte av polyhistidin-fragmentet jämfört med traditionell PCR. https://lup.lub.lu.se/student-papers/record/8888277/file/8888278.pdf application/pdf 2258008 yes 2016 eng Virus B Container HBcAg Insulin Encapsulation Chemistry 8888277 2016-08-14T22:36:34+02:00 2017-07-04T07:26:42+02:00 2017-07-04T07:26:42+02:00

oai:lup-student-papers.lub.lu.se:8891603 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Federico Valerio author 8891600 Ulf Nilsson supervisor Department of Chemistry v1000647 department Malaria is an infectious disease caused by the protozoan of the genus Plasmodium. It is a major problem in third-world countries, with hundreds of millions of infections and millions of fatalities annually. The extreme challenge in malaria management is the resistance of parasites to traditional chemotherapies like chloroquine and artemisinin.<br /> Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) was claimed to be one of the hottest malaria drug targets under investigation. PfDHDOH is an enzyme involved in the fourth key step of de novo pyrimidine biosynthesis. This way offer potential as targets for drug design, because, unlike the host, the parasite lacks pyrimidine salvage pathway.<br /> In search for new Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) inhibitors as antimalarial drugs, compounds bearing 5-hydroxy/methoxy-4-aminocoumarin scaffold were developed at Lund University. The compounds with 5-methoxy-4-aminocoumarin structures were synthetized from resorcinol and should be act as a prodrugs, further test on microsomes are necessary to determinate that. The 5-hydroxy-4-aminocompound was obtained through a melting reaction between 4,5-dihydroxycoumarin and the desired amine. All compounds will be tested on PfDHODH by Gothenburg University. Malaria is an infectious disease caused by five species of the genus Plasmodium (P. falciparum, P. vivax,<br /> P. ovale, P. malariae and P. knowlesi) that is transmitted by infected female Anopheles mosquito. The<br /> mosquito bite introduces the parasite into a host’s blood and those parasites travel to the liver where they<br /> multiply before infecting and destroying red blood cells causing anaemia. Plasmodium falciparum is the<br /> deadliest parasite and is responsible for majority of all Malaria cases that occurs mainly in Sub-Saharan<br /> Africa. A vaccine is still not available and malaria treatment depends on chemotherapeutics. It is important<br /> to find new targets and new antimalarial drugs versus Plasmodium parasite because it develops resistance<br /> against all classes of antimalarial medicines.<br /> Dihydroorotate dehydrogenase (DHODH) is the enzyme that catalyzes the fourth step of de novo pyrimidine<br /> biosynthesis. It is an interesting target because unlike the humane, the parasite has not pyrimidine salvage<br /> pathway and if PfDHODH is inhibited, it will not be able to synthesize DNA so it is growth will be stopped.<br /> In this project we synthetized new 4-amino-5-hydroxy-coumarin and 4-amino-5-methoxy-coumarin<br /> derivatives in search for new Plasmodium falciparum dihydroorotate dehydrogenase inhibitors.<br /> Figure 1. 4-Amino-5-hydroxy-coumarin and 4-amino-5-methoxy-coumarin structures synthesized.<br /> In conclusion we synthetized six compounds which will be tested on the PfDHODH.<br /> Supervisor: Prof. Ulf J. Nilsson and PhD student Maria Luisa Verteramo<br /> Degree project 30 credits, KEMP31, Organic Chemistry (2016)<br /> CAS - Centre for Analysis and Synthesis, Lund University https://lup.lub.lu.se/student-papers/record/8891603/file/8891619.pdf application/pdf 1720006 no 2016 eng PfDHODH coumarins synthesis medicinal chemistry inhibitors Malaria organic chemistry organisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/8891603/file/8894733.pdf application/pdf no 8891603 2016-09-13T14:36:23+02:00 2016-11-14T16:11:22+01:00 2016-11-14T16:11:22+01:00

oai:lup-student-papers.lub.lu.se:8892262 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Jonas Tuvesson author 8892260 dr Per Björk supervisor Department of Chemistry v1000647 department In this study a method for small scale purification of the protein RAGE (receptor for advanced glycation endproducts) was developed and soluble RAGE was purified from bovine and mice tissue. In healthy animals RAGE is expressed in measurable levels only in lungs and therefore lungs have been used. The tissue was homogenized and thereafter RAGE was purified using Concanavaline A (Con A)-Sepharose, Heparin-Sepharose and ion-exchange chromatography. The purified proteins were identified and characterized by electrophoresis, Western blotting and mass spectrometry. Also one RAGE ligand, S100A9, could be purified, from the flow through from the Con A-Sepharose column. Binding activity and functionality of the proteins were tested using surface plasmon resonance (SPR). Three different RAGE purifications were performed, resulting in 0.3 to 1 mg of soluble RAGE with a purity of 88 to 96%. SPR analysis revealed species-specific binding of antibodies, and binding of the RAGE ligand S100A9 demonstrated a highly conserved functionality. The developed purification protocol constitutes a valuable tool for understanding RAGE and its ligands. Vid t.ex. höga blodsockervärden kan socker binda in till proteiner och bilda försockrade proteiner s.k. advanced glycation endproducts (AGE). AGE proteiner anses vara en viktig faktor i åldrande och i nedbrytande sjukdomar som diabetes och Alzheimers sjukdom. Ligander är molekyler som binder till specifika receptorer på cellytan och därigenom skickar signaler in i cellen. Receptorn för AGE proteiner (RAGE) har fått sitt namn just efter förmågan att binda AGE. Det har dock visat sig att RAGE har många andra ligander och att många av dessa associeras till autoimmuna sjukdomar och cancer. RAGE finns dels som en full-längds receptor integrerad i cellmembranet och dels som en löslig receptor. Den lösliga receptorn saknar transmembrandelen men binder ligander på samma sätt som full-längds RAGE. För att kunna undersöka RAGE och dess ligander behöver RAGE renas fram. Vanligtvis görs detta från genetiskt modifierade celler, men som ett komplement till detta kan biologiskt aktiva proteiner renas fram från lämplig vävnad. Eftersom lungor är den enda vävnad med ständigt uttryck av RAGE har lösligt RAGE i denna studie renats fram från tre olika lungvävnader: lungor från kor, lungor från tumörbärande möss och lungor från friska möss. Lungvävnaden har först sönderdelas(homogeniserats) och därefter centrifugerats. Vid centrifugeringen separeras membranbundet RAGE från det som finns i den lösliga delen av cellen. Lösligt RAGE har därefter renats fram ur vätskan med hjälp av kromatografiska metoder. Vid kromatografi separerar man olika ämnen, t.ex. proteiner, från varandra. Därefter har proteinerna undersöks med hjälp av olika biokemiska analysmetoder. De tre reningarna resulterade i 0.3 mg till 1 mg lösligt RAGE med en renhet på 88 till 96%. Bindningsanalys visade att den biologiska aktiviteten var intakt och att funktionen har bevarats mer eller mindre oförändrad över artgränserna genom evolutionen. Det här utvecklade protokollet för att rena upp RAGE ur vävnad är betydelsefullt för studier av RAGE och dess ligander. 2016 eng Purification from tissue S100A9 Receptor for advanced glycation endproducts biochemistry biokemi Chemistry 8892262 2016-09-22T11:02:30+02:00 2016-11-08T08:55:52+01:00 2016-11-08T08:55:52+01:00

oai:lup-student-papers.lub.lu.se:8892457 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Niklas Ortenlöf author 5463871 Emanuel Magnus Smeds Gram supervisor Department of Chemistry v1000647 department Cofactors are essential for the growth of bacterial pathogens also inside a human host and one source of cofactors are proteins in blood. Pathogens can use surface proteins to bind and extract cofactors from these blood proteins. Here, using protein modeling of these proteins in complex with bacterial protein combined with bacterial growth assays with blood proteins from different species, we demonstrate that a certain bacterium preferably utilizes the one of the peptide chains of a specific blood protein for its growth. We also mapped a putative binding region in this blood protein. Moreover, redox status of these proteins appears to affect the growth of this bacterium in a dose-response manner. Unexpectedly, the key bacterial surface receptor is not essential for bacterial growth in presence of high concentrations of the blood protein. In conclusion, these results will be important in the design of novel therapies against bacterial pathogens. 2016 eng protein science proteinvetenskap Chemistry https://lup.lub.lu.se/student-papers/record/8892457/file/8892459.pdf application/pdf yes 8892457 2016-09-26T14:26:32+02:00 2017-07-13T11:24:43+02:00 2017-07-13T11:24:43+02:00

oai:lup-student-papers.lub.lu.se:8892918 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Fredrik Brorström author 5048770 Irene Rodriguez Meizoso supervisor Department of Chemistry v1000647 department Stevia is a natural sweetener with increasing use in known products, for instance Coca Cola Company launched a new brand called &quot;Life&quot; were they use Stevia as a sweetener. In this work, we have attempted to separate and analyze the different compounds that give the sweet taste, known as steviol glycosides, by ion-exchange chromatography with pulsed amperometric detection. The known methods for separating rebaudiosides often use HPLC and thereby often use polar interaction to separate the compounds. No research has been found where High-Performance Anion Exchange Chromatography with Pulsed Amperometric Detector (HPAEC-PAD) is used to separate the steviol glycosides, or as some of them are called, rebaudiosides. In this work the sugar moieties, attached to a non-polar diterpene as aglycone, were ionized in highly alkaline mobile phase and separated on a CarboPac PA20 column. This use of the sugar moieties for separation have not been used before and proved to give a good separation. The resin of this column is non-polar and interacted with the diterpene part of the rebaudiosides, there for acetonitrile was added to the mobile phase to counteract the hydrophobic interaction between these two parts. The exploratory experiments showed that acetonitrile does reduce the hydrophobic interaction and that the rebaudioside A, used as standard, does also have ionic interaction with the column and could be eluted with 200 mM NaOH, gradient of 0-200 mM NaOAc and 10 % ACN. A commercial product with stevioside and rebaudioside A are run under same conditions and achieves a good separation, thereby opening for further investigation of the separation of steviol glycosides with anion exchange chromatography. Good taste, bad taste - The quest for the prefect natural sweetener <br /> <br /> Have you ever noticed how light products differ in taste from the real thing? Well, I have noticed that sometimes there is an off taste or maybe a strange after taste. Not too long ago the Coca Cola Company launched a new brand called &quot;Life&quot;. With the green logo they want to make us aware of its natural contains. It is actually a plant called Stevia and Cane sugar they use. Cane sugar is, well normal sugar, however Stevia has a very sweet taste, actually 30 - 300 times sweeter, but low on calories. Great, so let us just use Stevia then! Well it of course it is not that simple, nothing ever is... You see, when you extract the sweet compound you basically make a cup of tea. Just imagine your water heater being a machine large as a moving box, but costing a lot more, and your teabag being a metal cylinder build to withstand high pressures. So you add your dried Stevia leafs into the cylinder and add hot water under high pressure and let it sit for a while. Then you get something that looks a lot like tea, however I call it Stevia extract. So in this extract I have a lot of things that I don&#39;t want like colour, small particle from the leaves and much more. But I only want to have the sweet thing! These contamination, as I call them, can be removed with organic solvents such as ethanol, you know Vodka, Gin, hangover, and filters. Ok so now the contaminations are gone, now I can add it to the Coca Cola? Well, you see there is not one but several compounds that are sweet in Stevia. They are called steviol glycosides, which you actually can see if you look at product containing Stevia or maybe rebaudiosides which is another name for some of them (The plants Latin name is Stevia Rebaudiana). So why can I not take all of them? sweet is sweet right? Not really, actually these compound are sweet but some of them have bitter taste and some have liquorice taste. So what I need to do is to separate them from each other, because I only want the one with the best resemblance to normal sugar. Now we are at the tricky bit, these compounds are very similar which is a problem when trying to separate them. What I have tried to do is to use ion-exchange chromatography. So what is that, well ions are basically molecules that have a charge, positive + or negative - and as you know + likes - . I can make the steviol glycosides negative by adding them to a very basic solution. Ok so now I have negative steviol glycosides and the thing is that they have different amount of negative charge depending on their small differences in structure. That&#39;s great but how does ion-exchange work? I use a cylinder with small positively charged particles that are permanently bond to the sides of the cylinder. Then I add my negatively charged rebaudiosides to this cylinder, or column as I call it, and guess what the steviol glycosides find a positive match in the column! So now they are stuck! But now I want them come out and not all together. Then I introduce a new negatively charged ion, let us call them bullies, that the positive parts in the column likes much better. I start sending them in small numbers and gradually increase their numbers. This will make the rebaudiosides with the weakest charge break up, how sad, with their positive charge and as the number of bullies increase even the stronger rebaudiosides have to give up. But I am happy the rebaudiosides didn&#39;t just give up, because now they left the column one at a time so I could pick which one I wanted and needed to get the best sweet taste.<br /> SWEET! 2016 eng Ion-Exchange Chromatography Steviol Glycosides KEMX11 Stevia tillämpningskurs Pulsed Amperometric Detector Chemistry 8892918 2016-10-04T15:19:45+02:00 2016-11-06T11:34:13+01:00 2016-11-06T11:34:13+01:00

oai:lup-student-papers.lub.lu.se:8893401 2025-07-29T13:03:30Z Medicine PhysicsChemistryMaths Technology

studentPublicationsH2 Niklas Warlin author 8893393 Axel Furevi author 8893396 Kristoffer Peterson supervisor Sophie Manner supervisor Ulf Nilsson supervisor Department of Chemistry v1000647 department Centre for Analysis and Synthesis v1000651 department Sialic acids are monosaccharides commonly located towards the end of the glycans in the human cell membrane. Therefore, sialic acids are in direct contact with the surroundings of the cell and are important antigens involved in the identification of human cells for the immune system. Some pathogenic bacteria have developed mechanisms for absorbing this sugar, and can use it to glycosylate their lipopolysaccharides, masking them from the human immune system. As this mechanism is essential for the survival of the bacteria in the human host, preventing it may result in a new mechanism of action for antibiotics. <br /> By synthesizing sialic acid analogues and later testing their affinity for the sialic acid membrane protein - a sodium solute symporter (SSS) protein, new sialic acid derivatives with stronger affinity towards the active site could be constructed. We have been focusing on the synthesis of thiosialic acid derivatives of α and β stereoisomers for the sialic acid Neu5Ac, as well as different amides in the C5 position. A synthetic pathway for modifications at position C3 is also suggested. <br /> The affinity for the smallest of the β-thiosialic acid, 2-thioethyl-5-acetamido-3,5-dideoxyD-glycero-β-D-galacto-2-nonulopyranosylonic acid, was tested using ITC and showed no binding interaction towards the SSS protein. So far, none of the amides have been tested due to purification issues. Models of the active site show promise for modifications at the C3 and C4 position, and these positions should be the focus of future analogues. Sialic acid is a type of sugar present in the human body. Certain bacteria use sialic acid to hide themselves from our immune system by displaying it on their cell surface. By synthesizing sialic acid based compounds, this mechanism could be blocked generating a potential new type of antibiotics to save humanity from multi resistant bacteria. https://lup.lub.lu.se/student-papers/record/8893401/file/8893410.pdf application/pdf 9296472 yes 2016 eng multiresistant bacteria Sialic acid sialic acid derivatives organisk kemi antibiotics organic chemistry Chemistry Medicine and Health Sciences Technology and Engineering https://lup.lub.lu.se/student-papers/record/8893401/file/8893409.pdf application/pdf Sialic acid is a type of sugar present in the human body. Certain bacteria use sialic acid to hide themselves from our immune system by displaying it on their cell surface. By synthesizing sialic acid based compounds, this mechanism could be blocked generating a potential new type of antibiotics to save humanity from multi resistant bacteria. yes 8893401 2016-10-12T14:04:41+02:00 2016-12-22T09:43:06+01:00 2016-12-22T09:43:06+01:00

oai:lup-student-papers.lub.lu.se:8893837 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Anders Kronander author 8893833 Mats Galbe supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department In this study, different membranes were tested for their use in a vanadium redox flow battery (VRB). The membranes were first tested under charge-discharge operation of the VRB over four charge-discharge cycles at different current densities (20 mAcm-2, 40 mA cm-2 and 60 mAcm-2) and the corresponding cell performance was evaluated in terms of total energy efficiency (EE), coulombic efficiency (CE) and voltage efficiency (VE). <br /> <br /> The anion exchange Fumasep® series FAP-450 as well as the cation exchange series, Fumapem®, F-930 by Fumatech™ (located in Baden-Württemberg, Germany) and the GN-115, GN-212, GN-212C (all from General Energy and New Materials Co Ltd,. Nanjing, China) and the VB1 (supplied by V-Fuel Pty Ltd) were all evaluated during charge-discharge operation. It was found that the F930 membrane outperformed all other membranes at all current densities tested in this study with a peak average EE of 89,6% at 500 mA (20 mAcm-2) and CE of 98,8% at 1500 mA (60 mAcm-2). The second best at charge-discharge evaluation was the FAP450 with an overall EE of 81,0%. <br /> <br /> In order to further quantify any differences between the membranes, these membranes were tested for permeability rates at constant temperature for all vanadium ions present in a VRB without influence of any current. The diffusion coefficients through the FAP-450 and the F930, VB2 (same as VB1 but thicker) and the GN-115 membrane were determined for the following ions V(II), V(III), V(IV) and V(V). It was found that the VB2 had the lowest measured permeability rates for the V(II), V(III) and V(IV) ions. Furthermore, the FAP450 membrane was the membrane with the second best diffusion coefficients which was consistent with the high coulombic efficiencies observed in the laboratory scale VRB cell. <br /> <br /> To predict the overall capacity loss during long term operation, the battery was simulated in MATLAB™ using mathematical models developed at UNSW Australia for 60 cycles (without electrolyte remixing). It was found that the FAP450 performed better than the F930 and the GN-115 membrane based on experimentally determined diffusion coefficients. The self-discharge reactions led to almost 0% capacity loss after about 60 cycles for the FAP450 membrane. For the F930, which had about 10 times higher diffusion coefficients compared to the FAP450, about 90% capacity was lost over the same number of cycles. The GN-115 membrane, which had higher diffusion coefficients than the F930 gave better results at simulations and had lost about 50% of the capacity after 60 cycles. This is believed to be due to the F930 having a factor of 20 difference between the diffusion coefficients which leads to a buildup of vanadium ions on one side of the cell and a deficit of the other. As the F930 had overall smaller diffusion coefficients compared to the GN115, it was unexpected that the latter would prove better than the F930 at extended use. It can thus be concluded that not only do the diffusion coefficients have to be low, they also have to be the same order of magnitude for all the different ions to prevent severe capacity drop. <br /> <br /> As the vanadium electrolytes may irreversibly precipitate at low respectively high temperatures it is imperative to understand how non-electrochemical, exothermic side reactions as well as surrounding temperatures interact with the electrolytes. Therefore, thermal modelling was also undertaken using the MATLAB model developed at UNSW. It was found that higher permeability rates gave much higher temperatures in the cell stacks and the electrolyte tanks. After 5 days, the electrolyte temperature in the tanks of the VRB using the F930 was about 30°C and increasing while the stacks reached temperatures of as high as 38°C and increasing. The FAP450, which had lower permeability rates than the F930, reached a stack temperature of only a few more degrees than the tank temperature due to the low influence of exothermic self-discharge reactions inside the cell stack. By comparison, previous thermodynamic simulation studies using Nafion showed that the temperature of the stack increased to about 40°C which indicates that external cooling should be considered when the pumps are turned off and the battery is at standby. <br /> <br /> The GN-115 membrane from General Energy © gave good results in the VRB cycling tests as well as for permeability rates and was therefore further evaluated by immersion in 1 M V(5), 2,5 M H2SO4 for 7 weeks in order to test its chemical resistance to the oxidizing V(5) solution. It displayed a 26% increase in thickness and about 6% increase in length and width. The weight increased by about 10%. This indicates that the pore size of the membrane might have changed during immersion which could influence the performance of the membrane in VRBs. Framtidens energilagring banar väg åt förnyelsebar elenergi<br /> <br /> Andelen förnyelsebar elenergi på marknaden ökar ständigt. En negativ aspekt med dessa källor är att vi inte kan kontrollera när energin skall vara tillgänglig – vindkraften behöver vind och solkraften behöver strålande sol. För att överkomma dessa motsättningar och göra energin mer tillförlitlig behöver vind och solenergi kompletteras med enheter för storskalig energilagring för att täcka energibehovet även när det inte är strålande sol och när vinden inte blåser. <br /> <br /> Självklart kan vi använda oss av fossila bränslen (och kärnkraft) när vår vind och solkraft inte genererar tillräckligt, men med ökad oro för växthuseffekten och påverkade ekosystem som en följd av en explosionsartad användning av just dessa bränslen är målsättningen att minska användningen dramatiskt. <br /> <br /> Hur kan vi lagra energi? <br /> <br /> Ur ett förnyelsebart perspektiv (alltså utanför den energi som finns lagrad i stenkol och andra fossila bränslen) utgör vattenkraft 98% av den totala lagringskapaciteten världen över. I Sverige står vattenkraften för ungefär 50% av vårt totala behov av elenergi. Vattenkraft är tillförlitligt, storskaligt och bidrar inte till några utsläpp av växthusgaser, men kräver synnerligen gynnsamma naturliga förhållanden för att kunna bli aktuell. Dessutom är vattenkraften till stor del utbyggd till maximal kapacitet världen över och kommer inte på tal i platta länder, såsom för Belgien och Nederländerna, där en annan typ av energilagring krävs för att etablera användningen av vind och solkraft ytterligare. Lösningen kan ligga i en ny typ av lagringsenheter, så kallade flödesbatterier, som kan återanvändas i miljontals cykler utan att degenereras och slitas ut. Dessutom har flödesbatterierna, teoretiskt sett, ingen begränsning i kapacitet och kan därmed täcka en mängd olika behov.<br /> <br /> Flödesbatterier<br /> <br /> Flödesbatterier lagrar elektrisk energi som kemiskt bunden energi vid uppladdning och förvandlar kemisk energi till elektrisk energi vid urladdning. Inuti batteriet är elektrolyterna lösta i svavelsyra och vatten och pumpas omkring i systemet, vilket gett upphov till namnet. För att utöka kapaciteten ökas mängden elektrolyt. Det finns olika typer av flödesbatterier som baseras på olika aktiva ämnen, men några av de främsta, ur energieffektivitet och miljöhänseende, är de som baseras på metallen vanadin. Metallen har speciella kemiska egenskaper som gör att dessa typer av batterier kan användas under väldigt lång tid vilket, i kombination med att elektrolyten inte är giftig, ger miljövänliga egenskaper. <br /> <br /> Andra batterier, som sådana baserade på litium eller bly, består ofta av ämnen som är giftiga och miljöfarliga plus att det kan föreligga risk för explosioner vid antändning. Vidare tappar dessa batterier ofta kapacitet efter ett antal cykler, vilket är en av många anledningar till att vi inte lagrar stora mängder energi i den typen av batterier i våra hus och hem. Flödesbatterierna tappar inte kapacitet utan kan enkelt återställas fullständigt och kan således användas under mycket lång tid.<br /> <br /> Anledningen till att flödesbatterier ännu inte slagit igenom är på grund av kostnaden som till stor del beror på membranet som skiljer elektrolyterna från varandra. Genom detta examensarbete undersöktes därför potentiella, billigare membran med hjälp av experiment och datoriserade simuleringar. Genom dessa studier isolerades två lovande kandidater för vidare användning i batteriet som kan komma att sänka kostnaderna rejält. https://lup.lub.lu.se/student-papers/record/8893837/file/8893839.pdf application/pdf 3613180 no 2016 eng thermodynamics Thermal Simulation Energy storage solutions Modelling VRB Vanadium Battery chemical engineering kemiteknik Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/8893837/file/8894716.pdf application/pdf Populärvetenskaplig artikel tillhörande examensarbetet. no 8893837 2016-10-21T10:42:24+02:00 2016-11-15T14:14:55+01:00 2016-11-15T14:14:55+01:00

oai:lup-student-papers.lub.lu.se:8893998 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Marwaa Ahmad author 8871341 Claes von Wachenfeldt supervisor Department of Chemistry v1000647 department Gram-positive bacteria e.g. Streptomyces coelicolor [8], Bacillus subtilis [43] and Staphylococcus aureus [40] contain a novel sensor for the nicotinamide adenine dinucleotide (NAD) redox balance that functions as a transcriptional repressor called Rex (redox). Rex plays a key role in regulating genes in energy metabolism. It also modulates transcription of important genes for cellular redox homeostasis including genes for alternative metabolic pathways and oxidative stress responses [42]. The current Rex structures have provided novel insights into dinucleotide regulation of gene expression. However, to obtain a deep and complete understanding, additional Rex structural forms are required. In this project wild type and mutant variants of Rex from Streptococcus agalactiae were expressed in Escherichia coli. The wild type Rex (with or without a His6-tag) was purified, and the affinity to NADH was measured with a novel technique called MicroScale Thermophoresis (MST). To test the effect of mutation on the dissociation constant (Kd) of Rex for NADH binding, the following mutations were investigated; His6-Rex-triple mutant (S158A, E160A and S180T) and two single mutations; His6-Rex-R24S and His6-Rex-D130R. MST analysis revealed that the Kd value for Rex/NADH binding was ~5 µM while, the measured Kd for His6-Rex/NADH binding was ~50 µM. The difference in the measured Kd values might be due to an effect of the His6-tag. Bacteria have a fantastic ability to adapt to environmental changes. They can synthesize a wide variety of proteins, which can control different situations. One situation is when bacteria encounter stress. Stress is a chemical or physical environmental change that can affect important cellular physiological processes or can cause macromolecular damage. Bacteria respond by cellular stress responses to increase the tolerance towards stress and adapt to it. Pathogenic bacteria are under constant stress when they are facing the host defense response. Understanding mechanisms of bacterial stress responses could help us in finding new antimicrobial targets and new ways to control infectious diseases. Gram-positive bacteria contain a novel sensor for the nicotinamide adenine dinucleotide (NAD) reduction-oxidation balance in the cell, called Rex (redox). Rex plays a key role in regulating genes in energy metabolism and oxidative stress responses. To fully understand how this protein works we need detailed information on structure and function relationships of Rex. In this study, Rex from the pathogenic bacterium Streptococcus agalactiae was produced in Escherichia coli. The wild type and modified variants of Rex was purified and the effect of specific mutations were studied. This work lay the ground for future studies on Rex to provide an understanding of Rex structure and function properties. https://lup.lub.lu.se/student-papers/record/8893998/file/8894000.pdf application/pdf 3670244 no 2016 eng Rex protein Microscale thermophoresis (MST) dissociation constant (Kd) protein science proteinvetenskap Biology and Life Sciences Chemistry 8893998 2016-10-25T11:21:53+02:00 2019-02-26T10:54:45+01:00 2019-02-26T10:54:45+01:00

oai:lup-student-papers.lub.lu.se:8894505 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Thelma Sikombe author 5052044 Associate Professor Ingegerd Sjoholm supervisor Doctor Eden Tareke supervisor Food Technology and Nutrition (M.Sc.) v1000294 department The baobab is among the commonly consumed wild fruits found in the semi-arid regions of sub-Saharan Africa. It has a wide application in food systems and folk medicine and has an advantage of surviving even in harsh environmental conditions.<br /> While the fruit pulp is packed with a lot of essential nutrients and has gained much interest in recent past on the international market as a healthy ‘superfood’. The seed kernels are rich in proteins and essential fats, and thus, a suitable alternative energy source for rural communities where diets are usually deficient in these nutrients.<br /> This study was designed to determine the nutritional composition of the baobab fruit pulp and the seed kernels as there is only scanty data available in the species of the fruit found in Zambia. It is assumed that the nutritional characteristics of the fruits vary depending on their origin, hence, three species of baobab fruits from Zambia, Malawi and Eritrea, were investigated. <br /> The fruit pulp was separated from the seeds using a blender. The seed kernels were obtained from the seeds manually by rubbing the seeds between fingers following 5 minutes of boiling and 15 hours soaking. The results indicated varying amounts of ascorbic acid in the pulp, ranging from 20 to 260 mg/100g (p&lt;0.05). The colour saturation of the pulp was distinctively different (p&lt;0.05) among the samples and was inversely correlated to the ascorbic acid content. High phenolic content (3796 – 4447 GAE mg/100g) was recorded in the fruit pulp with the Malawian fruit being significantly below the other two. Dietary fibres ranged from 52.2 – 71.5 g/100g, relatively low amounts of the crude protein (2.2 – 2.6 mg/100g) and crude fat (0.1 – 0.4 mg/100g) were found in the pulp. Apart from the dietary fibre content no major differences were observed in the proximate and mineral content of the pulp. <br /> The seed kernels were mostly high in crude protein and fat content, with a high energy content of 512 – 530 kcal/100g. A greater contribution of the energy content was provided by the fat, 50.1 – 54.9%E and protein, 31.2 – 33.2%E. The kernels phenolic content was low in relation to the pulp (1380 – 1767 GAE mg/100g) but varied significantly among the samples (p&lt;0.05). The nutritional composition of the seed kernels indicate that they can be an alternative source of protein and essential fats where the diet is deficient in these nutrients.<br /> The results also indicated that moderate consumption of the baobab fruit pulp and kernels can meet much of the recommended daily allowance (RDA) for individuals. For instance, 40 g of fruit pulp can provide 260 and 120% of the recommended intakes of ascorbic acid for a child aged between 4-8 years and a pregnant woman between 19 -50 years old respectively. The same amount of pulp can provide over 100 and about 75% RDA of dietary fibre to an adult female and male respectively. While 40g of seed kernels will provide more than 100% of the RDA of protein to children between 1-3 years old. This data represents useful information to encourage adequate consumption of baobab fruit and promote utilization in food production. Africa is blessed with a great variety of wild edible foods, among them is the baobab tree. It is commonly found in the semi-arid regions of sub-Saharan African including Zambia, Malawi and Eritrea. The oldest baobab tree is said to be over 1000 years. One of the distinctive features<br /> of the baobab tree is its massively large sized trunk, that can hold up to several litres of water and thus, able to survive the harsh conditions including prolonged drought; and the naturally dry fruit pulp. It is a multipurpose tree that has found its application as a food and a cure for<br /> certain ailments hence the term ‘tree of life’ is commonly used to by many local people. The fruit pulp and seed kernels are some of food components of importance from the baobab tree.<br /> They contain sufficient nutrients that are essential for human health and maintenance. <br /> Experts suggest that our daily intake of fibers should contain at least 20–30% of soluble fibers and baobab pulp contains more than 50% dietary fiber, of which over 70% are soluble fibers which contain a lot of health benefits. The health benefits of dietary fibers include good bowel<br /> movement, reduction of blood cholesterol and glucose levels, thus its fibre could be used in foods for people with type II diabetes. Besides, fibre is an excellent texture enhancer that gives good rheological properties to jams, yoghurts, ice cream and candies.<br /> The pulp is also a good source of vitamin C, with amounts ranging from 10 to 260 mg/100g and more than four times that of oranges. Other health promoting constituents of the baobab fruit include polyphenols. The presence of vitamin C and polyphenols is credited for the good antioxidant properties of the baobab pulp. Antioxidants offer a good defence mechanism<br /> against certain chronic diseases such as, inflammation, certain types of cancers and cardiovascular diseases. Furthermore, absorption of non-heme iron (plant based iron) is improved with the presence of vitamin C. Therefore, incorporating baobab pulp into cereal based food preparations could positively influence the iron status of people.<br /> On the other hand the seed kernels are a rich source of proteins (&gt;40%) and fats (@ 30%). If adequately utilised, they can make a significant contribution to improve people’s nutrition status especially in times of drought.<br /> Wild fruit collection and trading is an important cultural and social economic practice in the daily lives of many rural communities in Africa when fruits are in season. With recent EU authorisation of the pulp as a novel food, baobab has received so much interest on the international market and thus more potential for increased incomes for the local people.<br /> The data generated from this study could be useful in optimizing the utilization of resources by local communities as well as foster the production of foods with the baobab fruit as a base or an ingredient in functional foods. https://lup.lub.lu.se/student-papers/record/8894505/file/8894692.pdf application/pdf 1185098 LU/LTH access 2016 eng dietary fibre phenolic utilization fat kernels pulp food engineering livsmedelsteknik Technology and Engineering Chemistry 8894505 2016-11-02T11:52:18+01:00 2016-11-17T06:49:08+01:00 2016-11-14T16:07:08+01:00

oai:lup-student-papers.lub.lu.se:8894627 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Alexander Rex author 8894625 Jan-Olle Malm supervisor Centre for Analysis and Synthesis v1000651 department This study has investigated the possibilities of coating additive manufactured titanium dental prosthesis structures. Different coating alternatives were evaluated with the regards of esthetics, function and implementation possibilities. The coatings were applied on test samples and the adhesion between the printed titanium structures and the coating as well as to resin veneering applied on top was tested. The coating methods that were evaluated were anodization, plasma electrolytic oxidation, physical vapor deposition, sol-gel as well as a conventional opaque resin coating. <br /> A so called Charpy test was conducted to evaluate if the different coatings affected the material strength, however the method proved unsatisfactory to study any differences caused by the coatings. The surface roughness was also tested for coated and non-coated samples. The possibility of implementing the coating at Dentsply were investigated by evaluating economic and technical aspects of the different coating methods. The shear bond test showed that the conventional method of opaque manual coating resulted in the highest bond strength, with anodization and plasma electrolytic oxidation being the second best.<br /> This study concluded that producing a large scale automated industrial method for coating titanium prosthetics before resin veneering poses several challenges. Although this thesis has put ground work into screening different available coatings, more development is needed in order to present an implementable solution. Coating of 3D Printed Titanium Prosthesis<br /> You might not have thought a lot about how dental prostheses are created, but once you need it certainly you would like one with the best possible quality and price! This thesis has investigated how to improve a coating process of these prostheses. <br /> This research has been about creating an improved coating for 3D printed dental titanium prostheses. The modern 3D printing process used to create these prostheses creates new possibilities for the manufacturer but also new challenges. This master’s thesis project was done in Belgium at a dental company called Dentsply Implants, giving access to valuable insight both in the process and product during the time there!<br /> The goal was to create a coating that was more efficient to produce whilst also being as functional as the one used today. The purpose of the coating is to achieve a good color and to help bonding between the titanium prosthesis and a top layer called resin that is applied in order for the prostheses to look like teeth and gum. This task proved quite a challenge since each prosthesis is unique and has a very complex geometry. <br /> Four different coatings were chosen to try out. For all of these the bonding was tested between the titanium and the resin as well as for the coating used in the process today. Possibilities to use these coatings in the process were also studied and calculations on the cost of implementing these coatings were also done. <br /> The results showed that the coating used today was still optimal when looking at the test results, and thus it was concluded that further development would be needed in order to improve the coating of the 3D printed tooth prostheses. To summarize this work can be used as a base to further develop dental prosthesis coatings, to improve efficiency and standards for these products. https://lup.lub.lu.se/student-papers/record/8894627/file/8894629.pdf application/pdf 3359753 no 2016 eng materials chemistry materialkemi Chemistry https://lup.lub.lu.se/student-papers/record/8894627/file/8894631.pdf application/pdf yes 8894627 2016-11-04T11:07:36+01:00 2016-11-22T14:23:07+01:00 2016-11-22T14:23:07+01:00

oai:lup-student-papers.lub.lu.se:8894677 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Cristiana Buzolin author 8894674 Irene Rodriguez Meizoso supervisor Department of Chemistry v1000647 department Understanding the dissolution kinetics is important in the experimental determination of solubility, the efficiency of extractions, the rate of reactions and in general any heterogeneous process. Despite the extensive use of supercritical fluids, studies regarding the dissolution kinetics of compounds in supercritical carbon dioxide (scCO2) using analytical methods are limited in the literature. So far, only one work can be found where acetaminophen was used as model compound and in-situ Infrared spectroscopy was used to investigate the dissolution kinetics for two different temperatures at the same pressure. A more common approach involving scCO2 as a solvent is the study of the kinetic of reactions, such as catalyzed organic reactions and polymerizations by the common in-situ spectroscopy techniques (IR, UV-Vis and Raman).<br /> In this work, the dissolution kinetic behaviour of limonene in scCO2 was studied at different combinations of pressure and temperature by in-situ Raman spectroscopy. The experiments were carried out inside a high-pressure constant-volume view cell. The instrumental setup consisted of a pressurized system and a linear Raman optical system, where a continuous-wave laser at 3.5 W and a wavelength of 532 nm were used. A peak correspondent to a C=C stretching mode from limonene (583-584 nm) was monitored with time, where the height is directly proportional to the amount solubilized in carbon dioxide (CO2). <br /> The experiments were carried out at temperature of 45 ºC and 55 ºC and pressure ranging from 84 to 163 bar. The time of the experiments ranged between 100 and 420 minutes. The time to reach complete dissolution varies significantly with pressure and temperature (from 30 min up to 4 hours). Curve fitting of the processed data showed that the solubility kinetics can be described by a first order exponential model. Dissolution rate values of the fitted curves showed that the rate of dissolution becomes slower with increase of pressure and temperature, in contradiction to conventional dissolution theory for liquid solvents. Experiments to evaluate the stirrer effect on the dissolution showed that for the lowest pressures tested at 45 °C and 55 °C (respectively 84 and 95 bar) stirring accelerates the process significantly, while for higher pressures stirring does not make a difference. These results are an indication that different mechanisms may govern dissolution kinetics, depending on the region of pressure and temperature studied. Thus, the results constitute the first step towards a theoretical understanding of the mechanisms of dissolution kinetics of solutes in supercritical fluids. Carbon dioxide (CO2) is a colourless and odourless gas present in all living organisms and the entire atmosphere on Earth. The molecule is formed by one carbon and two oxygen atoms. It is an essential molecule for plants to make the photosynthesis process, which produces the oxygen we breathe. It is also the main product of plant and animal respiration and burning process such as forest fires and volcanic eruptions.1 Levels of carbon dioxide would be well-regulated in the atmosphere if human interference did not exist. Nowadays, increasing levels of the gas as a result of mankind’s activities are intensifying the greenhouse effect, a natural phenomenon essential for making Earth’s atmosphere warm enough to support life, and therefore making carbon dioxide to be seen as a global issue. <br /> In the chemistry field, on the other hand, carbon dioxide is not seen as a threat but a solution. At a certain pressure and temperature (74 bar and 31ºC), that is above our surrounding conditions but still quite mild for chemical applications, CO2 can reach a state called supercritical and become a fluid. Beyond these values, CO2 present improved properties than as a gas, allowing it to work as a solvent. This means that some substances can be dissolved in it to a certain extent. Compared to toxic organic solvents commonly used in chemistry, such as hexane, CO2 is non-toxic, non-flammable, cheaper, abundant, renewable and therefore a better option.Examples of industrial applications with CO2 as a supercritical fluid involve extraction processes, such as removal of caffeine from coffee (decaffeination), particle size control of active pharmaceuticals ingredients (in order to improve its deliver in the human body), surfaces cleaning and textile dyeing. <br /> In the scientific area, very little is known about how fast substances are completely dissolved in supercritical CO2 (scCO2) with time, which are called kinetic studies. Pressure and temperature changes can also affect the dissolution speed. Understand such a system can help chemical processes by determining the best conditions to save time, control amount of substance used and improve yield, all relevant for an industry, since money is involved.<br /> One such study concerns the use of high pressure and temperature. The mixture of substance+scCO2 is commonly placed inside a sealed vessel to keep the conditions. Now imagine how hard it would be if a small amount of this mixture had to be taken out of the vessel to be analyzed without affecting the pressure and temperature. To overcome this problem, there is technique called in situ, that is analyzing the mixture directly inside the vessel. In the present work, in-situ Raman spectroscopy technique will be used. Spectroscopy is any study that involves the interaction of a matter with light. In the case of Raman, the light source is a laser, like the ones used as pointers, but at a much higher power. Basically, a powerful laser will be pointed to the mixture and through interactions undetectable by the naked eye, the energy of the laser will be split into lower energies, same is to say that the light will be scattered. This scattering is very specific for each substance and it is seen in form of peaks in a spectrum, which can be called the ID or fingerprint of your substance in the Raman. <br /> In this work dissolution kinetics of limonene in scCO2 was studied at different combinations of pressure and temperature inside a vessel by in-situ Raman spectroscopy. The curve fitting of the processed data showed that the solubility kinetics can be described by a first order exponential equation. Dissolution rate values of the fitted curves showed that the kinetic of solubility is faster at lower pressures and temperatures. https://lup.lub.lu.se/student-papers/record/8894677/file/8894678.pdf application/pdf 2088836 no 2016 eng limonene Raman spectroscopy supercritical carbon dioxide dissolution kinetics solubility analytical chemistry analytisk kemi Chemistry 8894677 2016-11-07T10:56:06+01:00 2016-11-15T13:59:17+01:00 2016-11-15T13:59:17+01:00

oai:lup-student-papers.lub.lu.se:8894806 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Jonathan Carrara Aste author 8894804 Peter Spégel supervisor Department of Chemistry v1000647 department Previous studies have shown that increased incorporation of odd chain saturated fatty acids (OCFAs) into plasma phospholipids is associated with a lower future risk of developing type 2 diabetes and that decreased levels of OCFAs are linked to increased insulin resistance. Since the β-cell plays a pivotal role in the progression of type 2 diabetes it is of interest to investigate if elevated levels of OCFAs affects the β-cells lipid content.<br /> <br /> To facilitate these studies, we also investigated the impact of well plate size and different liquid chromatography-mass spectrometry (LC-MS) systems on the performance of our lipid profiling method. The well plate size was investigated to determine if growth conditions were similar on each plate size by examining the relative increase in lipid response in the LC-MS system from control samples cultured on 24-, 12- and 6-well plates. In addition, possible saturation effects in the LC-MS system when increasing the number of cultured cells was also investigated. Different LC-MS systems were also investigated with respect to detectability, saturation effects and repeatability when analysing the extracted lipid mixtures.<br /> <br /> INS-1 832/13* cells were grown until 80 % plate coverage and then treated with either palmitic acid, stearic acid or margaric acid at different concentrations for 24 hours. A control containing no fatty acids was also included in the experiment. After 24 hours the cells were harvested and the lipids extracted using a two-phase liquid-liquid extraction protocol. The lipid content was then analysed with ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) and nanoflow liquid chromatography(nLC)-chip cube MS. Unfortunately, the similarity in growth conditions on different well plate sizes could not be determined, however, preliminary results from screening experiments suggest that increased well plate size leads to a higher signal intensity in LC-MS systems and that culturing cells on the tested well plate sizes does not saturate the nLC-MS system. In addition, it was not possible to determine the detectability, saturation effects and repeatability in nLC-chip cube system compared to UHPLC-MS due to a lack of repeated measurements imposed by time constraints. However, there was an indication that the nLC-chip cube system shows improved detection limits compared to UHPLC-MS. Statistical evaluation of the results indicate that margaric acid was efficiently incorporated into the lipidome, as suggested by increased levels of LPC (17:0), LPE(17:0) and PC(35:1). Thus, our results support the hypothesis that OCFAs affect lipid content in β-cells, but if this effect is significant in humans and if it’s important in type 2 diabetes remains to be elucidated.<br /> <br /> *Rat insulinoma derived clonal β-cells Diabetes mellitus är en av vår tids största folksjukdomar och påverkar miljontals människor runtom i världen. World health organization (WHO) uppskattade att ungefär 422 miljoner vuxna led av diabetes 2014 och att diabetes orsakade 1,5 miljoner dödsfall 2012. I Sverige beräknas ca 1 miljon människor lida av diabetes eller vara i riskzonen för att utveckla diabetes. Antalet människor som berörs att diabetes globalt har ökat sedan 1980-talet och beräknas fortsätta att öka, vilket kommer ställa höga krav på samhället i framtiden. Därmed kan grundforskning spela en central roll i hur samhället ska hantera denna utmaning genom att vidare undersöka de exakta processer som leder till utvecklingen av diabetes, vilket vi i dagsläget vet väldigt lite om. Detta kan exempelvis leda till bättre metoder för att detektera diabetes hos patienter i ett tidigare skede och nya mediciner.<br /> <br /> Diabetes mellitus omfattar en grupp av sjukdomar som kännetecknas av onormalt höga blodsockerhalter. Kroppen reglerar blodsockerhalten genom insulin och glukagon, som produceras och utsöndras från bukspottkörteln. Insulin utsöndras från β-celler och har som funktion att sänka blodsockerhalten när den är för hög, medan glukagon utsöndras från α-celler och har som uppgift att höja blodsockerhalten när den är för låg. Typ 2 diabetes är den vanligaste typen av diabetes och orsakas framförallt av att β-cellerna inte svarar med en tillräckligt hög produktion av insulin när blodsockerhalten höjs samt att vävnaders förmåga att utnyttja den insulin som utsöndrats är nedsatt, ett tillstånd som kallas för insulinresistens. Det senare leder till att blodsockerhalten förblir hög även om det finns gott om insulin i blodet.<br /> <br /> De exakta processerna på molekylär nivå som leder till utvecklingen av insulinresistens och typ 2 diabetes är för närvarande okända. Tidigare studier har visat att en lägre nivå av uddakolsfettsyror i blodet kan relateras till insulinresistens och att en ökad inkorporering av dessa fettsyror i fosfolipider kan kopplas till en minskad framtida risk att utveckla typ 2 diabetes. Fosfolipider omfattar en grupp av fetter som tillsammans med kolesterol bygger upp cellens membranstruktur. Därmed finns det ett intresse att studera om produktionen av fosfolipider i β-celler ändrar sig i närvaro av uddakolsfettsyror.<br /> <br /> Den potentiella effekten som uddakolsfettsyror har på produktion av fosfolipider i β-celler undersöktes genom att jämföra hur mängden av olika fosfolipider i cellen ändrar sig när man tillsätter olika fettsyror i cellens omgivning. Därmed tillsattes uddakolsfettyran margarinsyra till en grupp med celler medan andra grupper av celler behandlades med fettsyror som inte var uddakolsfettsyror. En kontrollgrupp användes också, i vilken cellerna inte behandlades med några fettsyror. Under en viss bestämd tid fick cellerna ta upp fettsyror från omgivningen innan cellerna skördas och deras lipidinnehåll undersöks.<br /> <br /> Då lipidinnehållet undersöks måste man ta hänsyn till att vissa lipider förekommer i högre koncentration än andra i cellerna som skördas. Detta kan leda till att vissa lipider har tillräckligt hög koncentration för att detekteras av vårt instrument medan andra lipider har för låg koncentration. Ett enkelt sätt att göra de mer sällsynta lipiderna detekterbara är att öka antalet celler, vilket leder till att mängden lipider i vårt prov blir större eftersom mer celler skördas. Att öka den totala mängden lipider kan också vara riskabelt då vårt instrument kan överbelastas till följd av ett prov med en för hög koncentration av lipider. Därmed gäller det att hitta antalet celler som ger maximal detekterbarheten av sällsynta lipider samtidigt som koncentrationen lipider inte överskrider det gränsvärdet som ges av vårt instrument. Detta undersöktes genom att sätta upp ett experiment där prover som innehåller olika mängder celler skördades. Därefter undersöktes om koncentration av lipider i de olika proverna hade en överbelastad effekt på instrumentet. Ytterligare ett sätt att öka detekterbarheten av sällsynta lipider är att byta till ett annat instrument. Därmed utförde vi också ett experiment där vi jämförde detekterbarheten av sällsynta lipider i ett prov som analyserades av två olika instrument (nanoflow liquid chromatography-mass spectrometry (nLC-MS) och ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS)).<br /> <br /> Från det undersökta lipidinnehållet kunde totalt 28 olika typer av fosfolipider identifieras. Resultaten visade att fosfolipidnivåerna påverkas när man tillsätter fettsyror i β-cellens omgivning och att denna påverkan är beroende på vilken fettsyra som tillsätts. Vi har således visat att uddakolsfettsyror har en unik påverkar på produktionen av fosfolipider i β-cellen. Ytterligare studier krävs för att utröna om detta sker i någon större utsträckning i vår kropp och om det har någon signifikant relation till β-cellens funktion och typ 2 diabetes. Slutligen kunde vi också notera att lipidinnehållet från de olika proverna inte ledde till att vårt instrument överbelastades, vilket öppnar upp möjligheten för ökad detekterbarhet av sällsynta lipider genom att öka antalet celler till de mängder som vi utförde mätningar på. Tyvärr kunde vi inte dra några slutsatser om skillnader i detekterbarhet mellan de två undersökta instrumenten på grund av tidsbrist. https://lup.lub.lu.se/student-papers/record/8894806/file/8894807.pdf application/pdf 1759480 yes 2016 eng analytisk kemi analytical chemistry β-cell Type 2 diabetes Odd chain saturated fatty acid Stearic acid Margaric acid Palmitic acid Chemistry 8894806 2016-11-09T16:07:43+01:00 2016-11-15T14:07:12+01:00 2016-11-15T14:07:12+01:00

oai:lup-student-papers.lub.lu.se:8895706 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Sebastian Clementson author 8895704 Associate Professor Daniel Strand supervisor Department of Chemistry v1000647 department Centre for Analysis and Synthesis v1000651 department Abstract (1)<br /> Carbohydrates are a class of biomolecules that play important roles within the cellular biochemistry. Functionalized carbohydrates are building blocks in our DNA in addition to being major components of the cell’s signaling molecules called proteoglycans and glycosaminoglycans. Certain carbohydrates with aromatic side chains have been shown to inhibit the biosynthesis of these signaling molecules by acting as a substrate for the enzyme β-1,4-galactosyltransferase 7 (β4GalT7). These inhibition properties make the aryl modified carbohydrates attractive tools for cancer therapy due to the fact that the signaling molecules are key factors in tumor development and metastasis. It is therefore in our interest to develop facile methods of synthesizing carbohydrates with β4GalT7-inhibitory properties in the search for potent anti-tumor drugs.<br /> <br /> Abstract (2)<br /> A major cause of kidney failure is resultant from damage to small blood vessels within the kidney as a result of diabetes and/or other imbalances in the blood sugar. Diabetes is a rapidly increasing public health issue and it is therefore an ever-emerging necessity of finding new substances with the potential of treating such conditions. Compounds originating from nature are an indispensable source of new drugs as ~50% of all drugs marketed worldwide in the period 1981-2007 originate from natural sources. The synthesis of natural products is also a platform upon which new chemical transformations are discovered and utilized. The fungi derived terpenoid Lingzhiol, possesses both an intriguing chemical architecture and a unique biological activity. Lingzhiol has been discovered and characterized as a compound, which inhibits a biochemical pathway that leads to kidney failure, and it is therefore in our interest to apply our recently developed synthetic methodologies with the aim of synthesizing this complex molecule. Populärvetenskaplig sammanfattning (1)<br /> En stor del av världens befolkning dabbas av cancer någon gång under deras livstid. Cancerceller har en förmåga att bli resistenta mot de cellgifter som används som behandling. Det finns därför en stor efterfrågan av nya substanser som kan hjälpa oss att förstå de fundamentala orsakerna till olika typer av cancer och eventuellt fungera som botemedel. Kolhydrater är en klass av biomolekyler som spelar en central roll i våra cellers maskineri. Kolhydrater är en viktig byggsten i vår arvsmassa och har en betydande funktion för hur celler växer och kommunicerar med varandra. Cancerceller har ibland en annorlunda uppsättning av de kolhydrater som är involverade i signalering jämfört med vanliga friska celler. Det är därför av stort intresse att försöka kontrollera cancercellernas förmåga att tillverka kolhydratbaserade signalsubstanser. Syntetisk modifierade varianter av kolhydraten xylos har en förmåga att inhibera den biologiska syntesen av signalsubstanser i cancerceller. Den här avhandlingen har för avsikt att syntetisera sådana xylossubstanser utan att använda någon kolhydrat som startmaterial. Dessa substanser är sedan tänkta att fungera som verktyg för att förstå de mekanismer som ligger till grund för bröstcancer. Eventuellt kan de också utgöra en startpunkt för framtida läkemedel mot den här sjukdomen.<br /> <br /> Populärvetenskaplig sammanfattning (2)<br /> Njursvikt är ett vanligt förekommande symptom till följd av diabetes och/eller andra obalanser i blodsockernivån. Diabetes är en kraftigt ökande sjukdom världen över, och det är följaktligen av stort intresse att hitta nya läkemedel som kan behandla de symptomer som uppstår vid insjuknande. En av de största källorna till läkemedel är så kallade naturprodukter. Naturprodukter med medicinskt relevanta egenskaper är ofta sekundära metaboliter som härstammar från levande organismer. Dessa molekyler tjänar ideligen ett syfte hos sin värdorganism och har således utvecklats under tusentals år av evolution. Naturprodukter kan vara allt ifrån ett antibiotikum från en bakterie, till ett pigment hos en sjöstjärna. Ofta har de här molekylerna komplexa strukturer och unika biologiska aktiviteter, vilket gör dem till ideala startpunkter för utvecklandet av läkemedel. Naturprodukten Lingzhiol härstammar från en kinesisk svamp och har en förmåga att avsevärt lindra en av orsakerna till njursvikt. Ett av målen med den här avhandlingen är därför att syntetisera Lingzhiol genom att använda sig av syntetiska metoder som vi själva har utvecklat. https://lup.lub.lu.se/student-papers/record/8895706/file/8895712.pdf application/pdf 5560418 yes 2016 eng organic chemistry organisk kemi Chemistry 8895706 2016-12-05T15:02:19+01:00 2016-12-13T11:26:40+01:00 2016-12-13T11:26:40+01:00

oai:lup-student-papers.lub.lu.se:8895770 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Eric Fagerberg author 8895768 Pär Söderhjelm supervisor Biophysical Chemistry v1000649 department Previously, a method for computing binding free energies between different poses of a ligand bound to a protein using alchemical perturbation was developed. The methodology is to perturb the ligand into a smaller version, common to both poses, from which the difference in free energy between poses can be computed. Here, the method is further improved by finding low-error setups for the method, by investigating different kinds of restraints put on the system during simulation and different kinds of parameters for the soft-core potential. The best low-error setup found was using a 1-1-48 soft-core potential with a water barrier and positional restraints for all the non-hydrogen atoms in the system. Instability was detected for one of the poses, this was investigated. The key to having a stable pose seems to be to understand the effect on stability of changing the Ryckaert-Bellemans parameters for a single rotatable bond. Det finns utmaningar med datormodeller av läkemedel som binder till proteiner på olika sätt. Genom att göra modellen mer overklig kan osäkerheten i resultatet bli mindre. https://lup.lub.lu.se/student-papers/record/8895770/file/8895771.pdf application/pdf 906244 no 2016 eng biophysical chemistry biofysikalisk kemi Chemistry Technology and Engineering Biology and Life Sciences https://lup.lub.lu.se/student-papers/record/8895770/file/8895773.pdf application/pdf no 8895770 2016-12-06T20:33:35+01:00 2017-03-03T15:03:47+01:00 2016-12-16T14:24:01+01:00

oai:lup-student-papers.lub.lu.se:8895834 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Jonas Tuvesson author 8892260 Bengt Johansson Lindbom supervisor Department of Chemistry v1000647 department The aim of this study was to test how the affinity of monoclonal antibodies, raised against a vaccine candidate, influences the results obtained in a quantitative antigen-specific enzyme-linked immunosorbent assay (ELISA). The vaccine candidate is a fusion protein consisting of the N-terminal parts of two bacterial cell surface proteins, Rib and Alpha-C. To determine binding protein (Rib or Alpha C) the plates were coated with Rib-N and Alpha C-N separately. The quantity of antibodies was determined in U/ml against a mouse serum standard. By dividing the values obtained for each monoclonal antibody in this antigen specific ELISA with the concentration of IgG for each of the hybridoma supernatants, the specific activity of each monoclonal antibody was determined and expressed as units (U)/µg monoclonal antibody.<br /> Kinetic parameters and affinity constants were then determined for the 5 Rib-N specific and 5 of the Alp-N specific antibodies by surface plasmon resonance (SPR), using a Biacore 3000 instrument. The monoclonal antibodies were captured by an anti-mouse antibody and the vaccine candidate was injected over the captured monoclonal antibody in different concentrations.<br /> The results showed that the same quantity of different monoclonal antibodies gave different results when quantified by the antigen specific ELISA. Furthermore, the results indicate that differences in affinity for the antigen explain the difference observed between the antibodies in the quantitative ELISA analysis. These results also show that studies like this are of importance for the understanding of what is measured in an ELISA. Vid vaccinering aktiveras kroppens immunförsvar mot den sjukdom som man vaccineras mot. Kroppen bildar antikroppar mot antigenet som finns i vaccinet och då skapas ett skydd mot sjukdomen. Antikropparna som bildas binder till olika ställen på antigenet, men varje enskild antikropp binder specifikt till ett ställe. De bildade antikropparna är polyklonala vilket innebär att de kommer från olika B-celler. Med hybridomteknik kan man odla fram antikroppar med samma specifika inbindningsställe. De kallas då monoklonala antikroppar och kommer från samma B-cell. <br /> Innan vaccinet är godkänt att användas på människor görs olika studier. I dessa studier vill man bland annat mäta hur mycket antikroppar som bildas i kroppen vid vaccinering och helst vill man få svaret i en enhet som tillåter jämförelser mellan olika studier eller olika metoder. En sådan enhet kan t.ex. vara gram antikroppar per liter serum (g/L).<br /> För att mäta hur mycket antikroppar som bildas används ofta en metod som på engelska heter enzyme-linked immunosorbent assay, vilket förkortas ELISA. I botten på brunnarna i en microtiterplatta sätter man fast antigenet. Man tillsätter det serum som man vill testa och om det finns specifika antikroppar i serumet kommer dessa att binda till antigenet. De antigen-specifika serumantikropparna kan därmed detekteras och kvantifieras. För att mäta mängden bildade antikroppar i en jämförbar storlek, till exempel g/L, jämförs proverna med en standard med känd koncentration.<br /> Bindningen mellan en antikropp och dess antigen är en reversibel reaktion. Det innebär att bindning mellan antikroppen och antigenet kan bildas för att sedan släppa igen. Efter ett tag har jämvikt uppstått. Då är mängden bundet antigen-antikropp konstant i förhållande till fritt antigen och fri antikropp. Detta förhållande beskrivs av associations konstanten KA. Ju mer komplex som finns vid jämvikt desto större värde på KA. KA varierar mellan olika antikroppar och är ett mått på affiniteten (styrkan i bindningen) mellan en antikropp och dess antigen.<br /> I denna studie har jag undersökt hur ett antal vaccin-specifika monoklonala antikroppars affinitet påverkar resultatet i en kvantitativ ELISA utvecklad för att mäta koncentrationen av vaccin-specifika antikroppar i humant serum. Antikropparna har således kvantifierats i en antigen specifik ELISA d.v.s. en ELISA med antigenet (vaccinet) i botten som beskrivits ovan. Resultaten i Units per ml (U/ml) har beräknats utifrån en standard och därefter dividerats med den faktiska koncentrationen av monoklonala antikroppar i respektive prov. Det sistnämnda värdet har erhållits genom ytterligare en ELISA analys som mäter den totala koncentrationen av IgG antikroppar oberoende av dessas specificitet. Genom att kombinera resultaten från dessa två olika ELISA analyser har jag därmed erhållit ett mått för hur stort utslag ett mikrogram av respektive monoklonal antikropp ger i den antigen-specifika ELISA analysen (specifik aktivitet; utryckt som U/µg monoklonal antikropp). Antikropparnas affinitet för vaccinet har därefter bestämts med hjälp av Biacore analys och plottats mot deras specifika aktivitet i ELISA.<br /> Resultaten visar att de monoklonala antikropparnas specifika aktivitet varierar avsevärt i den vaccin-specifika ELISA analysen. Resultaten indikerar också att denna variation delvis kan förklaras av antikropparnas olika affinitet för vaccinet. 2016 eng Biacore Monoclonal antibodies ELISA Vaccin biochemistry biokemi Chemistry 8895834 2016-12-08T09:00:39+01:00 2017-01-11T10:07:50+01:00 2017-01-11T10:07:50+01:00

oai:lup-student-papers.lub.lu.se:8895927 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Leila Allahgholi author 8895835 Viktoria Bågenholm supervisor Department of Chemistry v1000647 department Hemicelluloses account for 25-30% of total wood dry weight. Mannan-based polysaccharides are the major component of softwood hemicelluloses. They are characterized by their β-1,4-glycosidic linked backbone composed of mannose or a combination of mannose and glucose residues. The backbone can be substituted by α-1,6-linked galactose residues. β-mannanases cleave the internal β-1,4-glycosidic bonds in the backbone of mannans. They are produced by bacteria, fungi, plants and animals. Bacteroides ovatus is a gram negative bacteria capable of growing in human gut and degrading β-mannan based dietary fibers. In this thesis, two GH26 β-mannanases (BoMan26A and BoMan26B) from Bacteroides ovatus were over- expressed and successfully purified via Ni-NTA affinity chromatography. Enzyme kinetics of BoMan26B was determined using low viscosity locust bean gum. Michaelis-Menten kinetic parameters were found to be 21.2 ±4.8 mg/ml for KM and 260 ± 27 s-1 for kcat. Moreover, the effect of calcium ions on BoMan26B activity was investigated. Results show that in the presence of 1 mM CaCl2 the enzyme activity did not change considerably but the enzyme stability was increased significantly at 37°C. Furthermore, the hydrolysis of digalactosyl- mannopentaose (G2M5) by BoMan26B was attempted to be analyzed by HPAEC-PAD but hydrolysis products could not be detected. Finally, potential occurrence of processivity of BoMan26A and BoMan26B was studied via a new viscometric analysis using a GH5 β-mannanase from Trichoderma reesei (TrMan5A) as a reference enzyme. The product profiles of TrMan5A from hydrolysis of LBG together with the rapid decrease in viscosity suggested that this enzyme is an endo-acting β-mannanase in accordance with previous suggestions. BoMan26A reduced the viscosity of LBG in a similar trend as BoMan26B. The results of viscosity assay for TrMan5A demonstrated a considerable difference compared to the other two enzymes, indicating that BoMan26A and BoMan26B are processive. Polysaccharides are biodegradable and composed of sugars linked together by glycosidic bonds to form a polymer chain. They are available in our food and utilized in our body as a potential energy source.<br /> Hemicelluloses are plant cell wall polysaccharides, derived from the sugars xylose, galactose, mannose and glucose. Mannan-based hemicelluloses have applications in food and pharmaceutical industries. For instance, Locust Bean Gum (LBG) is a galactomannan, which has a backbone composed of mannose residues with galactose side chains, and is widely utilized as a food thickener and stabilizing agent.<br /> Hemicelluloses cannot be digested without help of bacteria that live in the human intestine. Usually, gut bacteria secrete enzymes to help the human for complete digestion of complex dietary fibres. For example, Bacteroides ovatus is a common bacterium in the human gut which utilizes a wide variety of plant cell wall polysaccharides by synthesizing enzymes called glycoside hydrolases. Two of these enzymes are β-mannanases, which play an important role in mannan degradation in the human gut.<br /> Glycoside hydrolases can have three different modes of action: endo, exo and processive. Endo-acting enzymes cleave the internal glycoside linkages, causing a significant decrease in the viscosity of the substrate, while exo- acting enzymes cleave the terminal glycoside bonds and hardly decrease the viscosity of the substrate. Processive enzymes bind to the polymer chain and cleave a series of glycosidic linkages before its dissociation so reduce the viscosity of LBG at an intermediate level between the exo- and endo- acting enzymes. <br /> In this project, the two β-mannanses from Bacteroides ovatus (with the name of BoMan26A and BoMan26B) were studied. The results for viscosity measurements indicate the processivity of the enzymes. Finally, the dominant product of LBG hydrolysis by the enzymes was shown to be mannobiose (a molecule consisting of two mannose units) which was another indication of the processivity of the enzymes, since it is known from previous studies that some processive enzymes produce dimers as a dominant product. https://lup.lub.lu.se/student-papers/record/8895927/file/8895931.pdf application/pdf 2037415 yes 2016 eng processivity Enzyme kinetics β-mannanase BoMan26B biochemistry biokemi Chemistry https://lup.lub.lu.se/student-papers/record/8895927/file/8895930.pdf application/pdf yes 8895927 2016-12-10T12:26:58+01:00 2017-02-03T13:38:39+01:00 2017-02-03T13:38:39+01:00

oai:lup-student-papers.lub.lu.se:8896111 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Marwaa Ahmad author 8871341 Johan Svensson Bonde supervisor Department of Chemistry v1000647 department ‘Smiling in your brother’s face is an act of charity’; said prophet Muhammad (ALLAH’s peace and blessings be with him). Amelogenin (Amg) is one of the most important proteins that are responsible for perfect tooth formation giving us that beautiful smile. <br /> Amelogenin has multifunctional characteristics like wound healing, cells proliferation induction, anti-inflammatory, anti-infectious and signaling properties in living organisms. Its high tendency to aggregate and self-assemble into nanospheric structures is employed biologically to control important physiological processes, like bio-mineralization, and induction of specific cellular responses. <br /> Having a distinct solubility profile, being soluble at high acidic and high alkaline pH, while it aggregates at physiologic pH in the form of nanospheres, Amg can be purified in a fairly simple one step acid-heat treatment purification method. <br /> In the current study, Amg nanospheres were examined for their binding capability to cellulosic materials. Amg wild type (rh174) and Amg fused with cellulose-binding domain (rh174_CBD), were successfully produced in E. coli and purified to homogeneity in high levels (~ 95% of total protein), (~ 107,7 and 195,25 mg/l culture) for purified rh174 and rh174_CBD, respectively. The purified proteins were characterized by (SDS-PAGE) and showed homogeneity indicating efficiency of the purification step. DLS was also performed at pH 10 with 0.5 mg/ml and resulted in highly homogenous, successfully assembled, uniform nanospheres with ~ 35 ± 2 nm hydrodynamic radius, which reflects their stability under these conditions. Then different Amg variants were tested for their binding capability to cellulose. The results showed superior affinity of rh174_CBD to cellulose despite the highly alkaline conditions. The immobilization yield of rh174_CBD reached up to ~ 99.4 % and a binding capacity up to 7 mg/g cellulose. ‘Smiling in your brother’s face is an act of charity’; said prophet Muhammad (ALLAH’s peace and blessings be with him). Scientists have approved how important a smile is, as a personal characteristic, in social communication for human being. Proteins are a group of molecules that function as constructive workers, and restrictive managers of any physiological process in any living micro/ macro organism. Amelogenin (Amg) is one of the most important proteins that are responsible for perfect tooth formation, and give us that beautiful smile. Formation of inorganic crystal structures by living organism in tooth bio mineralization is a substantial scientific puzzle. The ability of cells to form highly defined polymorphic crystal structures, while the living cells need precise molecular control and efficient mechanisms is nothing but magnificent. Amg has not only a critical role in correct enamel formation, but also has multifunctional characteristics of wound healing, anti-inflammatory, anti-infectious and signaling properties in living organisms, which make it a vital protein in biomedical research. Moreover, new advances in Amg production methodology have made it a promising tool for developing new materials, thus enriching this field of research. Amg has a natural characteristic of pH dependent self-assembly into several nanospheric structures. Nanoparticles made from recombinant proteins, can have many important applications in biotechnology, but most of them actually could not be used in industry due to low stability and/or low availability. On the other hand, the simple production of self-assembled Amg nanospheres can overcome these drawbacks. Amg nanospheres can be constructed from pure Amg or from an Amg fusion protein, with a diameter of ~30-40 nm (for recombinant Amg). The fused domain can be for example cellulose binding domain or another protein or peptide with a significant application or function that can be added to the system. The current study provides the evidence of Amelogenin nanoparticles high affinity for binding to cellulosic materials under simply controlled conditions. This study has suggested potential use in drug delivery systems applications and in textiles surface modification in industry. Consequently, more applications can be explored and more advances can be achieved. By labeling Amg with fluorescent dye, binding can also be examined and monitored using the fluorescence microscopy. https://lup.lub.lu.se/student-papers/record/8896111/file/8896112.pdf application/pdf 1854265 yes 2016 eng cellulose binding domain Amelogenin nano spheres protein science proteinvetenskap Chemistry 8896111 2016-12-15T15:30:14+01:00 2017-01-12T08:30:50+01:00 2017-01-11T10:05:35+01:00

oai:lup-student-papers.lub.lu.se:8896522 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Chirarat Koetchatturat author 8896520 Johan Svensson Bonde supervisor Pure and Applied Biochemistry v1000655 department Cancer figure among the leading causes of morbidity and mortality worldwide. Finding a treatment to defeat cancer is a challenging task but immunotherapy that aims to improve the patient´s own immune system seems to be a promising therapeutic approach. Cancer cells can develop different mechanisms to evade the immune system. One such resistance mechanism is the expression of PD-L1 protein on the surface of cancer cells. PD-L1 binds to the inhibitory immune checkpoint receptor PD-1 on T cells and this interaction has an inhibitory effect on the T cells. Also certain tumor-infiltrating immune cells such as macrophages overexpress PD-L1 and contribute to immune suppression. Blockade of the PD-1/PD-L1 pathway using monoclonal antibodies is one way of preventing suppression of immune responses caused by cancer cells allowing the immune system to fight cancer more efficiently and successfully. In this study monoclonal antibodies against PD-L1 were isolated. As a first step cell-bound and soluble target antigens, both human and mouse PD-L1, were prepared and quality controlled. Pools of antibodies were then isolated from a phage display based human antibody library using three cycles of selection. Antibodies were subsequently screened to characterize the binding specificity of individual clones by conventional ELISA and flow cytometry. Unique antibody clones were identified by DNA sequencing. A total of 101 unique antibodies that bind specifically to human and/or mouse PD-L1 were successfully isolated. 88 of these antibodies bind to PD-L1 when expressed on cells whereas the remaining 13 bind only to the soluble protein. The isolated panel of antibodies can be used for future functional studies in vitro and in vivo aiming to identify therapeutic drug candidates. Cancer is a group of diseases with over 100 different types. Cancer is characterized as abnormal cells that divide without control and potentially spread to the surrounding tissues. In healthy individuals, old and damaged cells die in a process called programmed cell death. New cells replace old by normal cell division. Cancer cells in contrast are able to ignore signals from the body telling them to stop dividing and/or undergo programmed cell death. <br /> The immune system is the defense system of the body. It protects the body from attacks by foreign microorganisms like bacteria, viruses, and fungi but also searches for abnormal human cells and kills them. The body most often kills cancer cells before they get the chance to grow into tumors, but occasionally cancer cells evade the immune system in different ways. A method of treating cancer is immunotherapy, which recently has gained much attention for its effective results. Immunotherapy basically boosts the immune system and m akes it more efficient. One important player in immunotherapy is the monoclonal antibody, which can be used in different ways for defeating cancer cells: 1) Antibodies attach to cancer cells which help the immune system to spot cancers more easily, 2) Antibodies carry drugs or radiation for specific delivery to cancer cells, 3) Antibodies block signals telling cancer cells to divide, 4) Antibodies modify the activity of cells in the immune system.<br /> This report describes the work to find possible antibody candidates from the fourth group. https://lup.lub.lu.se/student-papers/record/8896522/file/8896526.pdf application/pdf 4920976 yes 2017 eng immunotherapy cancer antibodies applied biochemistry tillämpad biokemi Biology and Life Sciences Chemistry 8896522 2017-01-01T16:22:05+01:00 2017-01-09T10:57:56+01:00 2017-01-09T10:57:56+01:00

oai:lup-student-papers.lub.lu.se:9074175 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Albin Olsson author 9074173 Johan Wennerberg supervisor Centre for Analysis and Synthesis v1000651 department Large amounts of organic solvents are used within the field of chemistry and nearly everything is being discarded and is not reused. A way to reduce the environmental impact that this leads to is to use a safe and natural solvent that is easy to access, like water. In this project, Diels-Alder and Michael reactions were carried out in an aqueous medium with rare earth triflates and alanine as catalytic system. Most of the Diels-Alder reactions were slow, and a good reaction rate was only reached in one of the reactions. The Michael reactions with methyl 2-nitroacetate as Michael donor were much faster, and all the performed reactions worked with high to moderate reaction rates. The Michael adducts were then used to demonstrate a short and convenient pyrrole synthesis route that with some optimisations of work up and purification could be a good alternative to the more conventional pyrrole synthesis methods used in industry and science today. Inom vetenskapsområdet organisk kemi kopplas molekyler ihop med varandra med hjälp av<br /> kemiska reaktioner. Molekylerna som ska reagera med varandra behöver i de flesta fall<br /> befinna sig i ett specifikt medium för att komma i tillräckligt bra kontakt för att kopplas ihop till en produkt. Dessa medium är olika typer av lösningsmedel, till exempel metanol, etanol eller något annat flytande kemiskt ämne. Stora mängder lösningsmedel används idag inom kemisk forskning och industri och nästan allt blir farligt avfall. Tillverkningen av lösningsmedel och hanterandet av avfallet ger upphov till mycket koldioxidutsläpp och har en negativ påverkan på klimatet. Många lösningsmedel är dessutom giftiga och utgör en direkt fara för människor och djur om de skulle hamna i naturen. Ur denna vetskap har området grön kemi vuxit fram, en inriktning inom kemin vars syfte är att minimera kemiska processers negativa påverkan på miljö och hälsa.<br /> <br /> I detta projekt har kemiska reaktioner utförts i vatten, det minst giftiga lösningsmedlet av dem alla. Det är dock inte alla reaktioner som fungerar särskilt bra i vatten och vid sådana tillfällen kan det vara bra att använda en katalysator. En katalysator är ett ämne (eller en blandning av ämnen) som blandas tillsammans med reagenterna för att skynda på reaktionen<br /> eller för att göra reaktionen möjlig att genomföra över huvud taget. De katalysatorer som här har använts har bestått av triflater (salter av sällsynta jordartsmetaller) och aminosyran alanin. Den katalytiska effekten kommer från metallatomen i systemet och den sällsynta jordartsmetall som främst har använts har varit ytterbium. Ytterbium har fått sitt namn från den svenska byn Ytterby, i vars gruva ytterligare åtta sällsynta jordartsmetaller har påträffats.<br /> <br /> De huvudsakliga reaktionerna som har utförts i detta projekt har varit Diels-Alder och Michael reaktioner, två kemiska reaktionstyper som är viktiga för att bilda kemiska bindningar mellan kolatomer. Projektets resultat visar att den använda metoden fungerar mycket bra på vissa typer av reaktioner men inte på alla. Vidare studier skulle kunna förbättra metodens effektivitet genom att optimera parametrar som temperatur på reaktion, mängd katalysator, mängdförhållande mellan reaktionens ingående reagenter med mera. https://lup.lub.lu.se/student-papers/record/9074175/file/9074179.pdf application/pdf 7085059 no 2022 eng Water Green Chemistry Synthesis Organic Chemistry Chemistry 9074175 2022-01-31T13:37:11+01:00 2022-02-02T14:57:37+01:00 2022-02-02T14:57:37+01:00

oai:lup-student-papers.lub.lu.se:9075211 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Eric Nielsen author 9075209 Niklas Andersson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department The aim of this project is to transfer and implement a monoclonal antibody purification process that is traditionally done on an ÄKTAxpress to another machine called the ÄKTA pure. This is due to the fact that the ÄKTAxpress is being discontinued by the manufacturer and a replace-ment machine is needed for the time being. The project will include developing some new meth-ods that might also highlight the industry’s need for more advanced methods when an eventual replacement machine will reach the market. <br /> The purification process consists of firstly affinity chromatography followed by size exclusion chromatography. The implementation of this purification process was done with the help of ex-ternal Python-based control system Orbit. <br /> The implementation went well and the chromatograms produced showed clearly the load, wash and elution stages of the respective columns. Three pumps were used to load and wash the seri-ally connected columns. Some new methods that were created using Orbit was concentration-based pooling and sample change depending on sample volume. While testing the system during longer runs, the process yields were constant and therefore the system was considered quite robust. <br /> Another proof of concept implementation of the purification process was developed that used parallel flow paths with the aim to shorten overall process time. Instead of using three pumps to load and wash all columns, two pumps were connected to the affinity column and one to the size exclusion column. Using a special kind of valve, these two flow paths were connected to allow loading the size exclusion column from the eluate of the affinity column. This did indeed in-crease the process productivity by roughly 30%. <br /> The ÄKTA pure has a larger sample loading capacity per machine than the ÄKTAxpress. In addition, it also has a larger fraction collector. With the possibility to run the process both serial-ly and in parallel, it is concluded that the ÄKTA pure is more than capable to replace the ÄKTAxpress. Småskalig plattform för upprening av monoklonala antikroppar<br /> <br /> Utvecklingen av en uppreningsplatform för antikroppar visar en 30% ökning i produk-tivitet med hjälp av parallella flödesbanor. Det är nu också möjligt att upprena ännu fler prov per körning än tidigare. <br /> <br /> Utvecklingen av nya antikroppar blir allt mer viktigare i dagens samhälle för att kunna förbättra vår analytiska och diagnostiska förmåga. Innan dessa nya antikroppar kommer vidare till den kliniska fasen där de kan godkännas för marknaden, måste de utvärderas och bli testade. För att detta ska bli möjligt, måste man producera en liten mängd antikroppar. Detta görs med hjälp av en uppreningsprocess som ska helst vara snabb, billig och pålitlig eftersom risken finns att just en antikroppsvariant inte blir godkänd och då vill man inte slösa allt för mycket resurser.<br /> Reningsprocessen här utgörs av två steg, först affinitetskromatografi följt av gelfiltrering. Affi-nitetskromatografsteget fångar upp antikropparna från en lösning och gelfiltreringen filtrerar de uppfångade antikropparna med avseende på storlek. Processen körs på särskilda kromatografi-system, och nästa år, 2023, utgår faktiskt ett av de vanligaste kromatografisystem som kallas ÄKTAXPRESS. Då behövs iallafall ett kortsiktigt ersättningssystem tills ett nytt system har utvecklats, och här finns det en unik chans i att belysa industrins framtida behov.<br /> <br /> I detta examensarbete överfördes och implementerades denna uppreningsprocess på ett annat kromatografisystem, ÄKTA PURE, som är väldigt anpassningsbart och då kunde att nya meto-der utvecklas med hjälp av det Python-baserade styrsystemet Orbit. Resultatet var framgångsrikt och det visade sig att det nya systemet kunde köra samma uppreningsprocess som ÄKTAX-PRESS. Här utvecklades bland annat nya metoder för att kunna upprena betydligt fler prover per körning samt smartare interaktioner mellan de två processtegen.<br /> <br /> Utöver detta, utvecklades ytterligare ett koncept på ÄKTA PURE som kunde köra vissa delar av processen i parallella flödesbanor så att man kunde minska körningstiden och på så sätt öka produktiviteten. Detta koncept belyste potentialen med att köra vissa steg parallellt då ett prak-tiskt exempel visade en 30% ökning av produktiviteten. En sådan ökning av produktivitet är förmånligt vid stora produktionsbehov av antikroppar. https://lup.lub.lu.se/student-papers/record/9075211/file/9075212.pdf application/pdf 2198113 no 2022 eng PURIFICATION MONOCLONAL ANTIBODIES ÄKTA PURE ÄKTA XPRESS Chemistry 9075211 2022-02-11T10:44:00+01:00 2022-02-11T13:17:06+01:00 2022-02-11T13:17:06+01:00

oai:lup-student-papers.lub.lu.se:9075438 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Moa Märs author 9075436 Charlotta Turner supervisor Department of Chemistry v1000647 department Introduction: The environment underwater preserves wooden artifacts well when the oxygen level is reduced thus the decay rate slows down. To prevent destruction in waterlogged wood after collecting, a treatment method is required.<br /> Aim: The study aims to present and discuss different kinds of preservation methods for archaeological wooden artifacts.<br /> Methodology: Mainly the website web-of-science was used in this study. Different kinds of experimental studies were used for references. Example of keywords for this study: degradation, waterlogged, preservation, archaeological, chromatography<br /> For long-lasting preservation were polyethylene glycine (PEG), carbohydrates, and 3D digital imaging the methods that were presented and discussed. For sample storage preservation before chemical analysis were oxygen absorber, inert gases, and EDTA-2Na the candidates.<br /> Conclusions: Long-lasting preservation methods such as PEG are already used in different kinds of industries. Preservation before chemical analysis showed that inert gases and the oxygen absorber are effective methods for keeping fresh produce away from degradation.<br /> Further work: Further research of inert gases and oxygen absorbers as sample storage before chemical analysis is a new area worthy of study. To take this research to the next level, an experimental study on these methods would be preferred. Arkeologiskt trä ses oftast i museumsammanhang, där beskrivs historia om skepp och andra föremål som tagits upp på land efter att en gång ha sjunkit till havets botten. Långt under vattenytan, där syretillgången är begränsad, bevaras träföremålen väl. Detta på grund av att nedbrytningsorganismer är beroende av syre. När det sedan tas upp på land, börjar föremålen förmultna snabbt och förstörs. För att förhindra detta är det viktigt med en behandlingsmetod efter att ha samlat in föremålen. För ett museumändammål är det viktigt att konserveringsmetoden stabiliserar träet så mycket som möjligt och att det ger ett estetiskt utseende. För att kemiskt analysera ett föremål krävs det att behandlingsmetoden inte reagerar med träet, då det skulle kunna orsaka svårigheter i ett tänkt experiment. Detta betyder alltså att det krävs olika behandlingsmetoder för museum ändamål och för lagring av prov inför kemisk analys. Denna teoretiska studie diskuterar och presenterar olika typer av konserveringsmetoder för både långvariga ändamål och för kortare lagringsperioder. I denna studie användes främst sökmotorn web-of-science för att få fram tidigare forskning och experiment som gjorts på arkeologiskt trä eller färska varor. De långvariga metoderna som diskuteras i studien är konservering med olika kolhydrater, 3D bilder, och konservering med PEG. Dessa metoder är redan etablerade i olika branscher. Arbetet visade att effektiva konserveringsmetoder inför kemisk analys är atmosfärer av inerta gaser och syreabsorbenter. Dessa metoder håller varor som exempelvis mat färska och förhindrar förmultning. Problemet är att metoderna inte har etablerats på arkeologiskt trä. Att detta var en teoretisk studie är något man bör ha i åtanke, och för att ta denna forskning vidare skulle en experimentell studie av dessa metoder föredras. 2022 eng Analytical chemistry Preservation Waterlogged wood Archaeological chemistry Chemistry 9075438 2022-02-16T11:17:03+01:00 2022-03-15T09:40:31+01:00 2022-03-15T09:40:31+01:00

oai:lup-student-papers.lub.lu.se:9078600 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Vera Karlin author 9078598 Daniel Varela supervisor Ingemar André supervisor Department of Chemistry v1000647 department Determining how proteins interact with each other to form complexes is very important for understanding both disease and cellular functions, but experimentally determining the structures of these complexes is both tedious and slow, which is why a great number of protein-protein docking algorithms have been developed to predict them. To this day, conformational changes in protein backbones have been one of the largest challenges when making docking predictions. The recently developed docking algorithm EvoDOCK aims to resolve this challenge by making use of a memetic algorithm that combines an evolutionary algorithm with Monte Carlo optimisations while also performing swaps of the backbone structures with conformer ensembles to simulate flexibility. In this thesis, a docking benchmark evaluating the performance of EvoDOCK against a standard Monte Carlo optimization based algorithm was constructed and performed along with evaluations of the algorithm’s backbone flexibility strategy. The results showed an improvement of prediction quality for EvoDOCK as measured by iRMSD, DockQ and CAPRI for most of the benchmark complexes, with slightly better results when using a more exploratory set of evolutionary parameters. However, the predictions were more computationally costly than the standard method and only made efficient use of a small part of the backbone ensemble libraries, although showing clear room for optimisations and improvements of the methodology. Det är sen länge känt att de proteiner som utför cellernas funktioner mestadels inte är oberoende och enskilda, utan sitter ihop i proteinkomplex. Förståelsen om hur dessa komplex ser ut och sitter ihop är väsentlig för att till exempel kunna avgöra deras funktion eller förstå hur strukturändringar från sjukdomar och mutationer kan påverka dem. Bestämning av strukturerna på proteinkomplex brukar göras experimentellt, vilket ofta är en långsam och utdragen process som är otillräcklig för att kunna kartlägga den stora mängden av interaktioner som finns. För att lösa problemet har en mängd algoritmer för så kallad proteindockning utvecklats med syftet att försöka förutspå proteinkomplexens strukturer. Dockningsalgoritmer har lyckats skapa modeller av komplex med god precision, men har svårigheter när det kommer till proteiner med flexibla ryggrader, som har olika form när de är i obundet respektive bundet tillstånd. <br /> EvoDOCK är en variant på en evolutionär algoritm som dessutom använder sig av optimeringar med Monte Carlo, en metod baserad på många små slumpmässiga förändringar. Algoritmen hanterar flexibilitet med hjälp av byten av proteinernas ryggrader med förgenererade bibliotek av strukturer som försöker imitera de möjliga strukturförändringar som kan uppstå vid bindning. I denna rapport utfördes ett benchmark, det vill säga en mätning av EvoDOCKs dockningsförmåga i jämförelse med en standard Monte Carlo-baserad algoritm för 10 komplex som klassifierats som svåra.<br /> Resultaten visade på att EvoDOCK hade en bättre förmåga att skapa modeller mer lika de verkliga komplexen i majoriteten av testerna, där de modellerna som använde sig av parametrar som var mer åt det utforskande hållet hade generellt sett större framgångar. Prestandan var å andra sidan lägre då algoritmen ofta tog dubbelt eller trippelt så lång tid som standardalgoritmen. Den dåliga prestandan skulle dock enkelt kunna förbättras genom att skapa färre dockingsmodeller eller byta ut ryggraderna mindre frekvent, vilka båda visats ha n negativliten negativ påverkan på själva kvaliteten av modellerna. Det visade sig även att stora delar av strukturbiblioteken ej kom till användning, dock även här med tydliga möjligheter för förbättring.<br /> Allt som allt tyder EvoDOCKs framgångar på att forskningen tagit sig ett steg närmre knäckandet av de flexibla proteinkomplexens gåta. Med många förbättringsområden kvar finns det även mycket goda förutsättningar för ännu större framtida framsteg. https://lup.lub.lu.se/student-papers/record/9078600/file/9078602.pdf application/pdf 4005178 no 2022 eng biochemistry EvoDOCK algorithm protein iRMSD DockQ CAPRI Chemistry 9078600 2022-04-20T12:50:20+02:00 2022-06-09T09:08:57+02:00 2022-06-09T09:08:57+02:00

oai:lup-student-papers.lub.lu.se:9079090 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Veronika Tolevska author 8960162 Urban Johanson supervisor Department of Chemistry v1000647 department Transient Receptor Potential Ankyrin 1 (TRPA1) is a nonspecific cation channel activated by a wide range of stimuli. The polymodal receptor resides in the cell membrane of sensory neurons and plays a key role in nociceptive pain transmission. Environmental irritants such as allyl isothiocyanate, an electrophile found in wasabi, activate TRPA1. In this work, the goal was to lay the basis for structure, and so function and mechanism, studies of Hylobius abietis TRPA1 (HaTRPA1). The large pine weevil, H. abietis, feeds on the bark of conifer seedlings in European plantations, opposing the re-establishment of forests. A natural repellent could be developed targeting HaTRPA1, i.e., by developing agonists of solely HaTRPA1. <br /> <br /> Membrane proteins can be solubilized in aqueous solution by reconstitution in nanodiscs. A nanodisc is a construct of a membrane scaffold protein (MSP) and lipids, which encircles the protein of interest. In this study, MSP2N2 and phospholipids (POPC, POPE and POPG) were used. The reconstitution of HaTRPA1 in MSP2N2 nanodiscs was studied by size exclusion chromatography. The chromatogram showed a separation of two peaks, possibly of empty nanodiscs and nanodiscs containing HaTRPA1. The sample of HaTRPA1 in MSP2N2 nanodiscs was studied by negative stain and single particle cryogenic electron microscopy. The imaging, and dynamic light scattering, of HaTRPA1 in MSP2N2 nanodiscs suggested particles with a size of approximately 25 nm. A truncated form of HaTRPA1 was studied, which lacked most of its peripheral part. Therefore, no clear protrusion from the disc was visible by imaging, and the presence of HaTRPA1 in nanodiscs could not be confirmed further. The amount of purified HaTRPA1 was insufficient, and thus the repeatability of the reconstitution experiment was not ensured. The expression of HaTRPA1 should be improved prior to advancements of structure studies. En människa gråter av nyhackad lök, hostar av rök och känner en brännande känsla i munnen av att äta wasabi. Det som ligger till grund för detta är Transient Receptor Potential Ankyrin 1 (TRPA1), en receptor i cellmembranet av nervceller. Ett stort antal irriterande ämnen, som allylisotiocyanat i wasabi, aktiverar TRPA1. I sin aktiva konformation, sänder TRPA1 ut en signal som omvandlas av nervsystemet till en känsla av smärta. Därigenom upptäcks skadliga eller potentiellt skadliga stimuli. En bredare förståelse av receptorns funktion och reglering är av intresse. Inom läkemedelsindustrin, till exempel, ses inaktivering av TRPA1 som en möjlig strategi för smärtbehandling. En substans som inaktiverar receptorn, en antagonist, kan utvecklas som läkemedel. För att lyckas med det, behöver strukturen av TRPA1 klarläggas.<br /> <br /> Snytbaggen, Hylobius abietis, är ett hot för nyplanterade barrskogar i Europa. Snytbaggen livnär sig på barrträdens bark, vilket leder till ringbarkning och en påföljande dödlighet hos barrträdsplantor. För att motverka skada på nyplanterade skogar, används i dagsläget insekticider och vax. Insekticider är allmänt kända för att innehålla giftiga ämnen som är skadliga för både människa och miljö. Ett naturligt alternativ på bekämpning kan vara en aktivering av HaTRPA1. I detta projekt var syftet att lägga grunden för strukturella studier av HaTRPA1. <br /> <br /> Inför strukturella studier av ett membranprotein, behöver proteinet vara stabilt i lösning. För att uppnå stabilitet kan proteinet sättas i en nanodisk. Detta är en konstruktion av membrane scaffold protein (MSP) och lipider, som efterliknar det naturliga cellmembranet. I varje nanodisk ligger scaffoldproteinet som ett bälte utefter kanten av en rund skiva som utgörs av ett dubbelt lager av lipidmolekyler. I dessa lipider är membranproteinet tänkt att placeras och hitta sin naturliga form. Uttryck och upprening av MSP2N2, en typ av MSP som stabiliserar nanodiskar av lagom storlek för HaTRPA1, genomfördes med framgång. Insättning av HaTRPA1 i nanodiskar utfördes genom att blanda HaTRPA1, MSP2N2 och olika lipider. Separation baserat på storlek och analys av bildade komplex visade att formeringen av nanodiskar innehållande HaTRPA1 lyckades. Mätningar av HaTRPA1 i MSP2N2-nanodiskar, med dynamisk ljusspridning, visade en diameter på 25 nm. Även bilder från elektronmikroskopin, både kryo (Cryo-EM) och negativ färgning, visade en partikelstorlek på 25 nm. För vidare strukturstudier behöver uttryck och upprening av HaTRPA1 optimeras för att säkerställa att bildningen av nanodiskar med HaTRPA1 kan förfinas och upprepas under olika förhållanden. https://lup.lub.lu.se/student-papers/record/9079090/file/9079557.pdf application/pdf 4346573 yes 2022 eng Nanodisc TRPA1 MSP2N2 biochemistry Chemistry 9079090 2022-05-09T07:21:30+02:00 2023-06-28T13:50:39+02:00 2023-06-28T13:50:39+02:00

oai:lup-student-papers.lub.lu.se:9079984 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Thi Hoai Thu Trinh author 9078673 Solmaz Hajizadeh supervisor Department of Chemistry v1000647 department Dye affinity chromatography is one of the chromatography techniques which uses dye as a ligand for protein purification. In this study, single-layer poly(acrylamide-allyl glycidyl ether) cryogel was prepared, which contains free epoxy groups at sub-zero temperature. The double-layer was prepared inside a primary single-layer cryogel to form a secondary network inside the gel. Cibacron Blue F3GA was immobilized onto single and double-layer cryogels by covalently binding with the epoxy groups. Bovine serum albumin (BSA) adsorption on the formed dye affinity single and double-layer cryogels was investigated. It was found that the kinetic model and adsorption isotherms follow the Pseudo-second-order and Freundlich model, respectively. The data showed that the binding capacity of double-layer cryogel decreased compared to single-layer cryogel due to lower surface area. However, the mechanical stability of the double-layer cryogel (based on Young&#39;s modulus) is higher than that of the corresponding single-layer cryogel. Both single and double-layer cryogels could be reused more than ten times in adsorption/elution cycles without losing their binding capacity. The physical and chemical properties of the cryogels were characterized by scanning electron microscopy, confocal microscopy, krypton adsorption, fourier transform infrared (FT-IR) spectroscopy, and texture analysis. Seperation and purification of the biological molecules from the complex mixture of many substances is a keystone phase of modern process biotechnology. The cost of current bioseparation methods is high in large scale manufacturing and the demand to obtain highly purified biomolecules like proteins is more and more increasing. These two critical points stimulate scientists to research and develop new polymeric materials to be used in bioseperation. <br /> Supermacroporous cryogels have drawn significant attention in the bioseparation applications due to the porous structure, efficient permeability, and the possibility to form them from the biodegradable materials. Cryogels are synthesized by freezing polymerization techniques at temperature of -12 ºC. The solution containing monomers, cross-linkers, initiators is frozen and then consists of the ice crystals and non-frozen liquid between the ice crystals. The polymerization reaction occurs in this non-frozen liquid and the ice crystals grow during freezing. After thawing of the ice crystals, permanent macroporous structures with interconnected channels is formed. <br /> Cryogel column is widely used in affinity chromatography for purification. However, the efficient mass transfer and high flow rate properties of cryogels are the reasons for the reduction of surface area of the network, thefore decreasing the binding capacity for small-sized molecules. One of other biggest limitations of cryogels is their mechanical weakness due to their low-density structure.<br /> With the aim to further improve the surface area and mechanical stability of cryogels, double-layer cryogels were synthesized inside the primary network of cryogels using the cryogelation method. The secondary layer of cryogels was absorbed in the pore walls and was formed inside and on the surface of the primary walls. <br /> In this work, the comparison of binding capacity towards bovine serum albumin (BSA) and mechanical stability between single-layer and double-layer cryogels was studied. The results show that the mechanical stability of double-layer cryogels increased up to 7-compared to the single-layer cryogels. However, the binding capacity of double-layer cryogel is lower than that of single-layer cryogel due to lower surface area. Both single and double-layer cryogels could be reused more than ten times in adsorption/elution cycles without losing their binding capacity.<br /> In conclusion, although cryogels still have some limitations in biotechnology applications, which are neccessary paid atention in the future work, they are attractive for scientist in many areas of chemistry, biology, biotechnology and bioengineering due to their cheap materials and reusibility. https://lup.lub.lu.se/student-papers/record/9079984/file/9079985.PDF application/pdf 2558597 no 2022 eng dye-affinity chromatography single-layer cryogels double-layer cryogels protein purification bovine serum albumin biochemistry Chemistry 9079984 2022-05-20T21:58:11+02:00 2022-06-02T14:34:04+02:00 2022-06-02T14:34:04+02:00

oai:lup-student-papers.lub.lu.se:9081631 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Erik Wiktorsson author 9081629 Researcher Christian Hulteberg supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Several channeled emissions at the Sysav water treatment plant for hazardous waste as of December 2021 exceed permitted levels of unknown volatile organic compounds (VOCs) stated in the European Parliament councils’ directives 2010/75/EU. <br /> A range of possible treatment methods are briefly discussed before zeolite adsorption, and thermal regeneration followed by catalytic combustion is decided to be the method of greatest feasibility and is the subject of further investigation. <br /> The zeolite suggested is faujasite zeolite of high silica content (Faujasite (Y) HY901) due to its large pore sizes and hydrophobic nature. <br /> The catalyst suggested is a manganese oxide (Mn3O4) due to its lower cost than that of noble-metal catalysts, as catalyst poisons present may result in rapid deterioration of the catalyst. <br /> A process flow chart is presented, which includes two parallel zeolite beds that operate in shifts, followed by catalytic combustion. Heat recovery is possible, and a heat exchanger is implemented after combustion to heat the regenerative air flow.<br /> The process is modeled as steady-state, and results include general dimensions as well as capital and operational costs. Calculated with the software EconExpert, the resulting capital costs as estimated are 12,-800,000 SEK. Operational costs are approximately 200,-000 SEK/year after two years. <br /> For future work, it is of crucial importance to determine what VOCs are present for accurate modeling and predictions. Flyktiga organiska ämnen (Volatile organic compounds, eller VOCs) är en<br /> samlingsbeteckning som omfattar alla kolväten vars kokpunkt understiger 250 °C och uppgår<br /> till cirka 2000 ämnen. Dessa ämnen förekommer brett inom all kemisk industri och är ofta<br /> resultatet av flyktiga lösningsmedel som sprider sig i luften. Vid längre mänsklig exponering<br /> av VOCs kan en myriad av hälsokomplikationer uppstå, och det är därför viktigt att hålla<br /> koncentrationer och utsläpp av dessa så låga som möjligt. Syftet med denna rapport är att<br /> utreda för vilken metod som är bäst lämpad att implementera på vattenreningen vid Sysavs<br /> avdelning för farligt avfall, där koncentrationerna vid flera tillfällen i december 2021<br /> överskred tillåtna halter. https://lup.lub.lu.se/student-papers/record/9081631/file/9081653.pdf application/pdf 924996 no 2022 eng VOC Zeolite Catalytic combustion Sysav Chemical Engineering Chemistry Technology and Engineering 9081631 2022-05-27T15:08:04+02:00 2022-06-08T14:19:38+02:00 2022-06-08T14:19:38+02:00

oai:lup-student-papers.lub.lu.se:9081840 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Alice Nildén author 9079706 Tommy Nylander supervisor Department of Chemistry v1000647 department The aim of this study is to reveal how the oil-in-water interface of triolein emulsions in aqueous solutions is affected by the lipase activity when using five different surfactants as emulsifiers. For this purpose Dynamic Light Scattering (DLS) and Small Angle X-ray Scattering (SAXS) were applied. Lipases are enzymes that catalyses the hydrolysis of ester bonds of lipids, i.e lipolysis, and act at the interface between water and oil. Surfactants, along with energy from sonication, can be used to create a stable oil in water emulsion that will significantly increase the interface surface area accessible to the lipase. Surfactant and lipase need to be compatible to not reduce enzyme activity due to lipase denaturation and/or by preventing the lipase to adsorb to the water oil interface. Two different types of Thermomyces languinosa lipase (TLL), wildtype and mutant that has very low catalytic activity, were used along with the five different surfactants as well as at two different pH’s of the Tris Buffer that affect the degree protonation of the fatty acid products and hence their solubility.<br /> <br /> Three of the surfactants used, the biosurfactant Rhamnolipid, Model detergent B and J, proved to be a good surfactant where TLL maintained some activity, which was reflected in the observed increase in particle size by DLS and structural changes observed by SAXS. Also, the results showed some pH effects, where less effects are shown at higher pH when oleate rather than the protonated fatty acid is formed. The Sodium Dodecyl Sulfate, SDS, didn’t seem to be compatible with TLL at either pH, which is likely due to the exclusion of lipase from the interface. The other environmentally friendly biosurfactants called Sophorolipid proved to be a surfactant that only allowed enzyme at a higher pH. This might have to do with the pH sensitivity of the Sophorolipid. Lipids are a large and diverse group of organic compounds serving as building blocks that gives structural support, function, signalling and energy storing of living cells. Acylglycerides are a subgroup of lipids where triglyceride are the most common one in edible fats and therefore used in this study. Triglycerides or oil are amphiphilic which means that they consist of a large “water fearing” and very small “water loving” part called the hydrophobic and hydrophilic part. Triglycerides in the presence of a solvent such as water tends to self-assemble aggregate to minimize exposure of its hydrophobic part with the aqueous solution. This creates an interface between the lipids and the aqueous phase important in digestion of lipids catalysed by lipase activated when close to the interface. Surfactants, which are compounds with hydrophobic part and larger hydrophilic part than triglycerides adsorb at the water-oil interface and decrease the surface tension and makes it easier to form oil in water emulsions. Five different surfactants are used in this study at pH 7 or pH 8,5 along with two different types of enzymes, one active and one inactive variant of the Thermomyces langinosa lipase (TLL).<br /> <br /> The digestion of triglyceride with lipase results into components such as glycerol, fatty acids, di- and monoglycerides that can accumulate at the interface. Interfacial processes are therefore important to understand biological processes and to develop environmentally friendly industrial processes and ways of cleaning. The aim is to reduce the amount of chemicals with sustainably produced and environmentally friendlier, biodegradable options i.e biosurfactants. The two biosurfactants used in this study are named Rhamnolipid and Sophorolipid. <br /> <br /> To reveal the effect of the digestion of triglycerides catalysed by the presence of Thermomyces langinosa lipase together with different surfactants, the structure and size of oil in water emulsions have been done with scattering techniques such as Dynamic Light Scattering (DLS) and Small Angle X-ray Scattering (SAXS). DLS is a technique used in order to determine the average size and size distribution of particles or aggregates in a sample. The DLS measurements indicated a general change and increase of size of emulsion soprlets with the active enzyme for the samples prepared with a majority of the surfactants. SAXS is a technique used to investigate the structural changes as well as average size and shape by analysing scattering that occurs when X-rays passing through a sample. The SAXS results proved that the samples with active enzyme showed structural changes that arise from an increase of products from lipid digestion. Preliminary modelling of the data suggests that these changes involve formation of a shell surrounding the lipid droplets with the majority of surfactants. The results from both techniques showed that TLL proved to be a suitable lipase with all the surfactants at some or both pH-value except with surfactant Sodium Dodecyl Sulfate (SDS). Regarding the exchange to a biosurfactant, only Rhamnolipid proved to be suitable to allow for lipid digestion at both pH-values. https://lup.lub.lu.se/student-papers/record/9081840/file/9081842.pdf application/pdf 2120869 LU/LTH access 2022 eng DLS Lipase Lipids SAXS Surfactants Physical Chemistry Chemistry 9081840 2022-05-30T10:05:23+02:00 2022-06-23T10:52:35+02:00 2022-06-23T10:52:35+02:00

oai:lup-student-papers.lub.lu.se:9082232 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Andras Szanthoffer author 9082230 Tamás Turányi supervisor Department of Chemistry v1000647 department Nowadays, due to the global climate change, it is extremely important to find alternative fuels to reduce the utilization of fossil fuels and the emission of air pollutants such as carbon dioxide (CO2), hydrocarbon pollutants, and soot. Ammonia (NH3) is a promising carbon free fuel candidate that can store and transport renewable hydrogen (H2) energy.<br /> Ammonia has several advantages over hydrogen in practical applications, but the combustion characteristics of NH3 are different from traditional hydrocarbon fuels. A possible solution to improve the disadvantageous combustion properties of ammonia is to blend it with other fuels. For this purpose, two of the most usually used co fuels are hydrogen and syngas (H2/CO).<br /> This study reports a collection of currently available chemical kinetic mechanisms from the literature that can be applied for modeling the combustion of NH3/H2 and NH3/syngas fuel mixtures. An indirect experimental data collection is also presented which can be used for testing the performance of these combustion mechanisms.<br /> In this work, 19 detailed reaction mechanisms were investigated that had been published in the last 13 years. Their performance was quantitatively assessed based on how well they can reproduce the results of indirect experiments. Almost 5000 experimental data points were utilized in the mechanism comparison including ignition delay times measured in shock tubes, concentration measurements in jet stirred and flow reactors, and laminar burning velocity measurements. Based on the results, it can be concluded that there are significant differences between the performances of the different models, and the performance of a mechanism may also vary significantly with the type of experiments. <br /> Local sensitivity analysis was carried out on the best performing mechanisms to identify the kinetic and thermodynamic parameters to which model outputs are most sensitive. Even though the investigated models are different, sensitivity analysis identified largely the same set of important reactions and thermodynamic data in these mechanisms.<br /> Results presented in this work may serve as a good basis for further mechanism development for the combustion of NH3/H2 and NH3/syngas fuel mixtures. In recent years, one of the most frequently heard terms in media has been global climate change because it raises concerns about the future of humanity. One cause of this phenomenon is the so-called greenhouse effect, which is due to the presence of greenhouse gases (GHGs) in the atmosphere. There are many GHGs, but based on quantity, the most important anthropogenic GHG is carbon dioxide (CO2), whose main anthropogenic source is the combustion of biomass and fossil fuels.<br /> Combustion of fossil fuels is the primary way of energy production nowadays. These processes take place in industry, heating of households, transportation, etc. The main fuel used in combustion devices is a hydrocarbon or a mixture of hydrocarbons, such as methane, gasoline, diesel, or kerosene. During the combustion of these fuels, not only CO2 is released into the atmosphere, but also various carbonaceous air pollutants including carbon monoxide (CO), hydrocarbon pollutants, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and soot, which are harmful to human health.<br /> Due to these reasons, it is crucial to find alternative carbon-free fuels that can be used efficiently for energy production. A promising candidate for this purpose is ammonia (NH3). Some of the advantageous characteristics of ammonia are that it can be produced using renewable energy sources in an entirely carbon-free process, and there exists an already established and reliable infrastructure for its storage and transportation. However, NH3 also has disadvantageous combustion properties as compared to conventional fossil fuels such as its low heat of combustion and high ignition energy, which must be improved to utilize ammonia as a fuel in practical combustion processes.<br /> To design new NH3-based engines or power plants, detailed knowledge is necessary about the processes that take place during ammonia combustion. The rates of the occurring chemical reactions have to be described quantitatively, that is, accurate chemical kinetic mechanisms are needed for the combustion of ammonia under conditions relevant to industrial applications. <br /> Several readily useable models exist in the literature that may be utilized for this purpose. This study aims to compare the performances of several such reaction mechanisms based on how accurately they can reproduce the results of experimental measurements. From the results, it can be concluded that none of the mechanisms can describe the investigated systems satisfactorily under all circumstances. From this, it follows that further mechanism development is needed to improve the predictive capabilities of the models. The study also reveals more detailed information about some selected models, which gives more insight into the chemistry of ammonia combustion, and most importantly, it can be used in future research to construct a reaction mechanism that can describe these systems better than any existing model. https://lup.lub.lu.se/student-papers/record/9082232/file/9082992.pdf application/pdf 4686171 no 2022 eng Ammonia combustion Detailed chemical kinetic mechanisms Quantitative mechanism comparison Local sensitivity analysis Chemical Physics Chemistry 9082232 2022-05-31T15:46:30+02:00 2022-06-02T16:04:41+02:00 2022-06-02T16:04:41+02:00

oai:lup-student-papers.lub.lu.se:8991126 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Joel Klarén author 8991124 Lisa de Groot supervisor Department of Chemistry v1000647 department Functionalization of a TB analogue through a six step synthesis has been performed, collecting valuable material for further synthesis towards a heptakis TB analogue and characterization of intermediates.<br /> Previous work in the Wärnmark group has produced this heptakis TB analogue and this project focused on following the worked out procedure and improving it where possible. The synthesis started from two aniline derivatives that were modified and condensed to a first TB analogue. The following steps were functionalizations of this molecule and finally formation of two diastereomers that were separated using column chromatography, allowing linear condensation in a controlled fashion later on. This work included many different reactions, such as condensations, TMS protection, Buchwald-Hartwig amination, and electrophilic aromatic substitution. The field of supramolecular chemistry is the study of intramolecular forces, or how molecules interact and bind to each other with weak bonds, different from covalent bonds which are usually what comes to mind when the word “chemical bond” is mentioned. Examples of such weak bonds are hydrogen bonds and van der Waals forces.<br /> An interesting molecule in this aspect is Tröger’s base (TB), which is a V-shaped molecule consisting of two aromatic rings fused together with a diazocine ring. The shape of TB gives it an electron-rich cavity which might give the molecule interesting properties in catalysis, speeding up desired reactions for example. The Wärnmark group has performed linear condensation of several TB analogs to create two different heptakis TB analogues which can form a zigzag or a tubular structure. These structures may prove useful in catalysis or as molecular receptors.<br /> This work has followed the procedures developed by earlier work in the group, functionalizing a TB analogue, preparing for a final linear fusion to the heptakis TB. Starting from an aniline derivative, condensation yielded a TB analogue which was then modified and functionalized in a series of reactions. https://lup.lub.lu.se/student-papers/record/8991126/file/8991127.pdf application/pdf 1989123 yes 2019 eng Tröger's Base Supramolecular chemistry Organic synthesis Organic chemistry Organisk kemi Chemistry 8991126 2019-07-29T11:08:16+02:00 2019-08-19T13:31:26+02:00 2019-08-19T13:31:26+02:00

oai:lup-student-papers.lub.lu.se:8991128 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Floriane Baussière author 8990991 Mujtaba Hassan supervisor Department of Chemistry v1000647 department Galectins are an old fifteen-member protein family. Every galectin has one or two highly conserved carbohydrate recognition domains (CRDs) through which it binds their mutual ligand galactose. They are involved in various pathways such as signaling, autophagy and immune response. However, they also contribute to pathological functions including fibrosis, metastasis, cardiovascular diseases and diabetes. Among this protein family, galectin-8 is known to promote tumor progression and lymphangiogenesis. For this reason, synthesis of novel galectin-8 inhibitors with drug lead abilities is needed as it might help cure those diseases.<br /> <br /> As shown by an earlier study, 3-O quinoline methyl -D-galactopyranoside derivatives were discovered to have promising galectin-8N inhibitor potential. To investigate it further, analogues of the most promising compound - methyl 3-O-((7-carboxy)quinolin-2-yl)-methyl)--D-galactopyranoside - were synthesized during this project by functionalizing the carboxylic acid on position 7 of the quinoline. The inhibition capacities of the amide and urea derivatives against galectin-8N measured by fluorescence polarization assay indicated that the affinity dropped compared to the compound of reference. However, the benzylamide derivative displayed a higher selectivity for galectin-8N than the original molecule.<br /> <br /> Subsequently, the galactopyranoside was substituted by D-galactal. The inhibition capacities of the galactal-derived quinoline compounds were measured and compared with their corresponding methyl -D-galactopyranoside analogues. It resulted that D-galactal has a better natural affinity and selectivity for galectin-8N than methyl -D-galactopyranoside. However, due to the presence of impurities in the samples, the binding data from the galactal compounds could only be considered as indication and not hard data. Non the less, the benzylamine galactal derivative showed promising affinity and an acute selectivity for galectin-8N. Therefore, it became the new compound of interest.<br /> <br /> The crystal structure of methyl 3-O-((7-carboxy)quinolin-2-yl)-methoxy)--D-galactopyranoside was determined with a resolution of 1.56 Å and indicated that the carboxylate on position 7 of the quinoline favored the interaction with the binding-site by forming water-bridged hydrogen bonds with the amino acids Arg52 and Gln54. The crystal structure of 3-O-((7-carboxy)quinolin-2-yl)-methyl)-D-galactal was also determined by X-ray crystallography but the data refinement wasn’t finalized in time to be included in this thesis. Getting the crystal structure of the benzylamine galactal derivative would give interesting insights on the binding properties. “Biology is the most powerful technology ever created. DNA is software, proteins are hardware, cells are factories.”<br /> - Arvind Gupta <br /> <br /> What are proteins and why are they so important? A protein is a folded chain of building blocks called amino acids. All building blocks have the same structure except for one subpart that vary from one amino acid to another. In total, they are twenty different amino acids. Most proteins are approximately 400 amino acids long but their size varies greatly depending on their function. Thus there are a lot of possible amino acids combinations which means there are a lot of different proteins.<br /> <br /> Proteins are responsible for almost everything that happens in the body, from transporting molecules from one place to another to speeding chemical reactions up through building structures or releasing signals. Therefore, they are fundamental. However, due to their implication in every mechanism and the complexity of our system, they can cause various diseases when ill-regulated. Therefore, a great amount of work is put in research to find ways to block proteins.<br /> <br /> In order to activate a protein, a small molecule - called ligand - has to attach itself on a particular part of the surface of the protein - called binding pocket -. Each protein’s binding pocket is specific which is why different proteins respond to different ligands. One way of blocking a protein is to introduce a new small molecule resembling the ligand - called inhibitor - that will bind strongly to the protein without activating it. If the protein’s binding site is occupied by the inhibitor, the ligand can’t be attached and the protein won’t be expressed. Thus inhibitors are good drugs as they are highly selective for their particular proteins which is a must since only the protein involved in the targeted disease has to be shut down.<br /> <br /> The research in our group is focused on galectins, a small family of proteins. Galectins are widely spread in the body and take part in many central biological functions such as sending signals and regulating the interactions between cells. However, they are sometimes involved in biological disorders such as cardiac diseases, fibrosis and tumor spreading. Thus they are important drug targets.<br /> <br /> There are fifteen different types of galectins. All of them bind a sugar called galactose. The aim of this project was to develop new inhibitors for galectin-8 which is a protein known to be involved in organ graft rejection and diverse types of cancer. An earlier research showed that adding a specific chemical group, called quinoline, to the left side of the natural ligand made it a relatively good inhibitor. Based on these results, the synthesis strategy of this project was to modify the chemical group on the left-hand side of the quinoline to try to improve the affinity even further. During the project, it was discovered that replacing the galactose by another sugar named galactal improved both the affinity and selectivity of the compounds for galectin-8. These promising results will help develop the next generation of galectin-8 inhibitors.<br /> <br /> In conclusion, new galectin-8N inhibitors were synthesized with insightful results. However, further optimization is needed to make even better inhibitors. 2019 eng organic chemistry organisk kemi Chemistry 8991128 2019-07-29T11:51:40+02:00 2019-08-19T13:51:29+02:00 2019-08-19T13:51:29+02:00

oai:lup-student-papers.lub.lu.se:8991195 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Veronika Chadimová author 8991193 Ulf Nilsson supervisor Department of Chemistry v1000647 department Galectins are family of cytosolic proteins that function as both positive and negative modulators of various cell processes. Galectin-3 has an altered expression pattern in pathophysiological processes, such as cancer or chronic inflammation, which makes it an interesting target for pharmaceutical research. The treatment of galectin-3 ill-regulation was shown effective in serious conditions like idiopathic pulmonary fibrosis. This project aimed to combine the structural factors of protein and galectin inhibitors with interactions and their corresponding thermodynamic parameters. That would lead to better understanding of the protein-ligand binding and its future utilization for thermodynamic optimization in drug design.<br /> A set of galectin-3 inhibitors based on 3,4-dichlorophenyl α-thiogalactoside was designed and synthesised to determine the thermodynamic fingerprint of halogen bond found between ligand halogen and carbonyl of G182 of galectin-3C. The thermodynamic parameters were measured by isothermal titration calorimetry (ITC), contextualised by X-ray crystal structure study and compared to K¬¬D values received by competitive fluorescence polarization assay. Results correspond well to theoretical properties expected from the halogen bond, as seen on the congruence between enthalpy and halogen polarizability. Second set of compounds was designed to investigate another interaction of interest, chalcogen-π interaction of W181 in galectin-3C and anomeric chalcogen substituent of inhibitor. Several synthetic strategies for preparation of deactivated phenyl α-selenogalactoside were examined and the successfully synthesised compound showed promising binding affinities on competitive fluorescence polarization assay. The thermodynamic profile of the system is going to be further investigated by isothermal titration calorimetry. All of us will get to a situation, when our body needs help with fighting a disease, at some point of our life. It can be as banal as taking aspirin to relieve from flu or more serious as antibiotics during bacterial infections, oncological treatment for various types of cancer and drugs for other kinds of life-threatening conditions. After the great development of pharmaceutical research from 20th century to these days, we are able to cure more and more diagnoses, but as we improve our arsenal of medicines, the diseases are also evolving. It can be exemplified on rising antibiotic resistance, which is partly caused by our misuse of antibiotics, or on influenza viruses, such as bird flu. It is of importance to develop more drugs to reflect the new challenges as well as to minimize the side effects for patients. <br /> The discovery and development of a new drug is very time-consuming and expensive process, often taking more than decade from identifying the active substance to delivering it on the market and costs around 800 million dollars per compound. An effective collaboration among the pharmaceutical industry and academic research is crucial to tackle the complex conditions like neurodegenerative diseases or multiple genotypes cancer, especially in attempts to make the drug development faster and more cost-efficient. Another big issue is the attrition during clinical trials, the risk of failure is high for reasons including low efficacy or safety. Identifying these and coupling them to factors that can be screened during the drug discovery phase, would lead to dramatic cuts on time and financial demands. Significant improvements can be made by optimising the thermodynamic parameters of binding at early stage and those can be investigated for example by isothermal titration calorimetry.<br /> The method was tested on model system of galectin-3 in complex with its ligand – a compound that binds to the receptor. Galectins are proteins found abundantly in cytosol, their expression is specific for each tissue. Galectin-3 is found in inflammation sites and certain kinds of cancer, therefore the research on its interactions and their thermodynamic fingerprint is valuable for general medicinal chemistry and drug discovery. 2019 eng medicinal chemistry galectin-3 halogen bond chalcogen-π interaction organic chemistry organisk kemi Chemistry 8991195 2019-07-30T13:31:10+02:00 2019-08-19T13:52:56+02:00 2019-08-19T13:52:56+02:00

oai:lup-student-papers.lub.lu.se:8991204 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Samuel Persson author 8921483 Kenneth Wärnmark supervisor Department of Chemistry v1000647 department Syntheses of novel homo- and heteroleptic iron(II) N-heterocyclic carbene complexes have been pursued. The heteroleptic complexes contain donor-acceptor structures meant to enhance their sensitization activity when operating as a part in a dye sensitized solar cell by slowing down charge recombination.<br /> Syntheses of two related heteroleptic complexes were completed but require additional characterization. Another heteroleptic, donor-acceptor complex with a more extensive p- system has been designed and the synthesis of said complex was started but not finished. I takt med att det globala samhället blir större och större och mer och mer utvecklat, kräver mänskligheten mer energi. Idag kommer mycket energi runt om i världen från kol, olja och naturgas, så kallade icke-förnybara energikällor. Dessa är begränsade resurser som kommer att ta slut om vi använder dem ens i närheten av den utsträckning vi gör idag. Dessutom bidrar deras användning till en ökad växthuseffekt. Detta gör att vi behöver nya och förnybara sätt att alstra energi på. En potentiellt nära obegränsad energikälla är solen. Solstrålarna som når jorden på en timme bär med sig lika mycket energi som hela mänskligheten gör av med på ett helt år.1 Det svåra är att ta tillvara på all denna energin. För att göra detta har vi redan en rad olika solfångarteknologier. Dessa tekniker har dock problemen att de ofta är dyra eller ineffektiva. Ett alternativ skulle kunna vara att man försöker använda sig av molekyler som kan fånga energi helt av sig själva.<br /> Alla molekyler byggs upp av atomer runt vilka elektroner flyger runt. Beroende på hur molekylen ser ut och vilken sorts atomer som finns i den så finns det ett antal speciella nivåer som elektronerna kan befinna sig på, som stegen i en trappa. Det får bara plats några få elektroner på varje trappsteg. Elektroner har i sin natur att rulla neråt i trappan så om det finns plats på ett trappsteg på lägre steg än en elektron befinner sig på, kommer den snart att rulla ner och lägga sig i utrymmet på det lägre steget. Så länge molekylen får vara ostörd kommer elektronerna därför rada upp sig, snyggt och prydligt, först på det lägsta steget och sedan uppåt i trappan tills det inte finns några elektroner kvar fylla på med.<br /> En ljusstråle som kommer till molekylen har med sig energi. Om det är tillräckligt med energi och trappstegen inte är för höga kan en elektron ta energin och använda den för att klättra ett steg eller två uppåt i trappan. Oftast är detta en elektron som redan är långt upp i trappan eftersom trappstegen brukar bli lägre ju längre upp man kommer. När elektronen har klättrat upp så har den dock problem. Den har ju lämnat efter sig en tom plats på ett lägre steg i trappan som den nu har en tendens att rulla tillbaka ner till igen. Om ingen annan utväg skulle uppenbara sig så är det precis det som händer och energin det tog att klättra upp i trappan kommer inte till nån användning.<br /> Men andra saker kan hända. Andra molekyler som kanske finns i närheten har också helt egna elektrontrappor. Kanske har dessa trappsteg med plats som är lägre än steget vår klättrande elektron är på. Om det inte allt för krångligt kan elektronen bestämma sig för att rulla över och ner till platsen i den andra trappan. Om man vill bygga en solfångare med en sådana här molekyler kan man till och med gör så att elektronen måste genom en elledning för att komma över till den andra trappan. Elektroner som går genom en ledning är elektrisk ström och när elektronen byter trappa så skapas alltså elektricitet.<br /> Allt detta är dock lättare sagt än gjort. I många molekyler är trappstegen alldeles för höga för att ens det allra energirikaste ljuset ska vara nog för att elektronerna ska lyckas klättra ett enda trappsteg. Detta gör att molekylerna måste designas på speciella sätt för att få trappor med tillräckligt låga trappsteg. Men även om man lyckas få elektronerna uppåt i trappan är utmaningarna inte över. Oftast är det mycket enklare att bara rulla ner för den egna trappan än att byta till en annan. Därför måste molekyldesignen också innefatta placeringen av hinder för att rulla ner i trappan. Samtidigt ska det helst göras enklare att ta sig över till en annan molekyls trappa för att övertala elektronerna att ta den vägen som alstrar ström.<br /> Att få allt detta att funka utan att använda dyra metaller är fortfarande svårt. I mitt arbete har jag hjälpt till med försök att använda järn för att få allt detta att funka. Järn har helt okej trappstegshöjd men det är för lätt att rulla ner för trappan. Med hjälp att speciella strukturer runt järn är förhoppningen att bromsa farten neråt. Samtidigt ska molekylen förlängas med andra speciellt designade strukturer som ska hjälpa elektronen över till en elledning och över i en annan molekyls trappa. https://lup.lub.lu.se/student-papers/record/8991204/file/8991205.pdf application/pdf 2325279 yes 2019 eng organisk kemi organic chemistry solar harvesting iron carbene dye sensitized solar cells Chemistry 8991204 2019-07-30T17:16:32+02:00 2019-08-19T13:49:13+02:00 2019-08-19T13:49:13+02:00

oai:lup-student-papers.lub.lu.se:8991223 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Rita Franzén author 8991221 Tommy Nylander supervisor Department of Chemistry v1000647 department The aim of this thesis was to reveal how nano-sized extracellular vesicles (EVs) isolated from human breast milk and Aascaris suum, parasitic worm incubation media interacts with hydrophilic, hydrophobic and DOPC surfaces and colloidally characterize EVs and EV fluids by determining their hydrodynamic radius and zeta potential. <br /> Dynamic Light Scattering (DLS) was used to determine the size and zeta potential of EVs from Human breast milk (three different samples) and Ascaris suum incubation media. The results show that pellet from the milk and also EV depleted substrate were consisted of particles / aggregates with the largest Hydrodynamic radius. Pellet from milk sample had the largest polydispersity index, indicating a heterogeneous origin of the sample due the fact that pellet contained proteins / fat / cells in addition to EV´s. All of these samples were not sterile due to which bacterial growth and contamination could occur. Zeta potential for all milk and Ascaris suum samples was low but for the stability of EV&#39;s steric stabilization has a more significant aspect.<br /> In Quartz Crystal Microbalance with Dissipation, attractive interactions between EVs with Hydrophilic and Hydrophobic surfaces could be observed due to the negative frequency shifts typically found in adsorption. A thin viscoelastic film was formed on these surfaces. EVs were shown to have no interactions with the DOPC surface since in some case not any or very small changes in frequencies were observed. Extracellulära vesiklar (EV) är membranbundna vesiklar som utsöndras från de flesta celler och släpps ut i biologiska vätskor. De är 30 - 5000 nm i diameter stora och innehåller biologiska molekyler som RNA, lipider och proteiner. De spelar en nyckelroll för kommunikationen mellan cellerna, så kallad, intercellulär kommunikation. EV är ett utmärkt medel för långdistans kommunikation mellan celler. Då transporteras de bland annat genom blodomloppets relativt långa avstånd till sina målceller. EV är även involverade i många fysiologiska och patologiska tillstånd. Med hjälp av informationen som transporteras i EV lasten kan vår hälsa främjas eller sjukdom alstras. EV är intressanta som biomarkörer vid diagnos, prognos, för övervakning av sjukdom samt för läkemedelstransporten. Trots sin stora potential, EV mätningar introducerar många utmaningar på grund av deras extra små och olika storlekar (polydispersitet), lågt brytningsindex och varierande densitet. För att kunna analysera EV krävs sortering till en homogent delmängd vilket ger renare prover, högre reproducerbarhet eller avkastning, mindre tidskrävande samt billigare tillverkningsmetoder av EV. Mikro- och nanoteknologiska verktyg som kan separera EV i storleksordning och få mer homogena prover stiger i antal och det kommer att öka vår förståelse för EV inom nära framtid. <br /> Interaktioner som studerades var EV och EV-vätskors samverkan med hydrofila, hydrofoba och DOPC (enkel modell av ett cellmembran) ytor. Det vill säga EVs bindningsegenskaper till dessa ytor. Detta gjordes genom att isolera EV från mänsklig bröstmjölk samt från parasitens Ascaris suum inkubations media och sedan analysera dessa med hjälp av en teknik som kallas Quartz Crystal Microbalance med dissipation. Resultaten visade att EV hade en viss interaktion men hydrofila (vattenälskande) och hydrofoba (vattenavvisnde / fetta) ytor. Ett tunt och mjukt (viskoelastisk) lager uppmättes av instrumentet. Interaktioner av EV med båda ytorna kunde bero på att EV membrankomponenter bestod av båda hydrofila ( som lipid membran huvud samt andra hydrofila komponenter) och hydrofoba (fettsyrasvansar och andra hydrofoba ämnen) komponenter. Vid mätning på DOPC ytan, EV visade inte några interaktioner. Detta kunde bero på att DOPC lager var för tunt men är trots det ganska oklart. <br /> Utöver EVs interaktioner med olika ytor undersöktes även EVs kolloidala egenskaper i form av deras Hydrodynamiska radii, det vill säga storlek av EV partiklarna och zeta-potentialen som är laddning (positiv eller negativ) som finns runt om partikel (EV). Dessa kolloidala egenskaper påverkar EVs interaktioner med ytan. Detta analyserades med hjälp av en metod som kallas dynamisk ljusspridning (DLS). Resultaten visade att EV-vätskor har en ganska ojämn storleksfördelning så länge de inte är renade på proteiner/ celler/ lipider. Deras zeta potential är relativt låg, då alla mätningar där den uppmättes vara mindre än minus tio. För ett elektrostatiskt stabilt system (system med laddningsrepulsion) skall zeta potentialen vara runt +/- 30. Trots att zeta potentialen indikerar ett väldigt instabilt kolloidalt system, som tenderar att snabbt klumpa ihop sig till större kluster (aggregat), är dess betydelse mindre viktig. Detta eftersom partiklarna kan stabiliseras steriskt, det vill säga med hjälp av andra partiklar än EV som finns i vätskor. https://lup.lub.lu.se/student-papers/record/8991223/file/8991231.pdf application/pdf 2200925 yes 2019 eng Physical Chemistry extracellular vesicles colloidal characterization fysikalisk kemi Chemistry 8991223 2019-07-31T10:52:53+02:00 2019-08-12T12:06:07+02:00 2019-08-12T12:06:07+02:00

oai:lup-student-papers.lub.lu.se:8991307 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Helin Hamarashid author 8991305 Susanna Törnroth-Horsefield supervisor Department of Chemistry v1000647 department More than 400 million people in the world have type 2 diabetes, making it one of<br /> the most common diseases internationally according to the World Health Organization.<br /> Thiazolidinediones (TZDs) is used to treat type 2 diabetes since it increases<br /> the sensitivity of insulin in peripheral tissues. The knowledge about the mechanism<br /> how TZD works is limited which has resulted in patients getting serious side effects<br /> upon receiving treatment. The target of TZD has recently been identified as the<br /> mitochondrial pyruvate carrier complex (MPC) but studies have not yet provided<br /> detailed knowledge about the structure and functional mechanisms of the complex.<br /> By determining the structure and function of the complex, designing a de novo TZD<br /> would be possible. The purpose of this study is to solve the crystal structure of the<br /> MPC 4 from Pinus patula as a candidate of the pyruvate carrier complex family. The<br /> sequence containing the protein was designed and commercially obtained with the<br /> positioning of the poly Histidine-Tag (His-Tag) in the C-terminus. Expression of the<br /> protein was obtained through transformation into the expression host of Escherichia<br /> Coli BL21(DE3) and the yeast host of P. pastoris for comparison and determination of<br /> the best host organism. When sufficient amount of protein was produced an optimized<br /> purification protocol for the proteins was implemented to acquire pure protein<br /> using immobilized metal affinity chromatography (IMAC) and size exclusion<br /> chromatography (SEC). To keep the protein stable and soluble for further analysis a<br /> suitable detergent was found to be DDM which was used throughout the purification<br /> process. From Western Blot (WB) analysis it was shown that the expression of<br /> the protein was successfull in both bacteria and yeast, however during purification<br /> only low concentration of the protein was obtained. Through Sodium Dodecyl Sulfate<br /> Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis after the IMAC and<br /> SEC the samples did not seem to be pure. For future studies optimization of both<br /> expression and purification is needed to obtain a higher concentration of the protein<br /> that is pure. Växtprotein - lösningen för bekämpning av typ 2 diabetes?<br /> <br /> Mer än 400 miljoner människor i världen lider av diabetes typ 2 vilket gör det till en avde vanligaste folkhälsosjukdommarna enligt World Health Organisation (WHO). Thiazolidinediones (TZDs) används vid behandling av typ 2 diabetes då det höjer känsligheten för insulin. Kunskap om mekanismen kring TZD har tidigare varit begränsad vilket resulterat i att patienter fått allvarliga biverkningar vid behandling. Proteinet som TDZ påverkar blev nyligen identifierat som mitokondrie pyruvat bärar komplexet (MPC). Genom att ta reda på strukturen och funktionen av klomplexet kan utveckling av ett mer specifikt läkemedel utan biverkningar för patienter vara möjlig. Bärarproteiner är nödvändiga för transport av molekyler i biologiska system. MPC är ett membranprotein som är lokaliserat i mitokondriens innermembran. Uppgiften är att transportera pyruvat från cellen in till mitokondrien. Studier har hittills inte kunnat påvisa detaljerad information om strukturen och funktionen hos proteinet. Syftet med denna studie är att påbörja en utredning av MPC komplexet genom att använda MPC 4 från växten Pinus patula. Kloning och uttryck av MPC 4 från Pinus patula i bakterie samt jäst och därefter olika försök till upprening av proteinet kommer att behandlas i denna studie. Följande frågeställningar uppstod: Vilken organism uttrycker proteinet bäst? Vilken metod är optimal för upprening av proteinet? Vilken struktur har proteinet? För att kunna besvara frågorna tillämpades metoderna: kloning, uttryck av proteinet och upprening. Genen stoppades in i en bakterie som kan producera väldigt mycket av proteinet och är ett system som är lätt att jobba med. Sedan sattes produkten in i en bakterie som är bra på att uttrycka ett speciellt protein. Uttryck av proteinet i bakterierna skedde genom att sätta bakterierna innehållande proteinet i en näringsberikad lösning och låta dem växa i 37°C. Därefter tillsattes ett ämne för att aktivera överuttryck av proteinet vilket ger höga koncentrationer av det önskade proteinet. Sedan skördades bakterierna genom centrifugering och bakterierna utan näringslösning sparades för vidare analys. Vid uttryck av proteinet i jäst aktiverades överuttryck genom ett utbyte av näringslösning som jästen växer i. Från att växa i en glycerolberikad miljö till att växa i en miljö där metanol är närvarande. Detta aktiverar en del av jästen som tillåter nedbrytning av metanol vilket resulterar i överproduktion av det önskade proteinet. Två olika sammansättningar av proteinet undersöktes där det ena var anpassat till bakterier och det andra till jäst. Det visade sig att resultatet av proteinet i bakterie och jäst inte hade stora skillnader, kloningen av proteinet i jäst utfördes av Dr. Tamim Al Jubair medan kloning av proteinet i bakterien samt uttrycket hos både bakterien och jästen utfördes av författaren. Uttryck av proteinet lyckades, men dessvärre var det inte rent till den grad som behövs för fortsatt analys. Efter olika uppreningsförsök av proteinet var det fortfarande inte rent. Orsaker till att uppreningen av proteinet inte lyckades kan vara många men förmodligen ligger problemet i konstruktionen vilket lyckligtvis går att ändra på inför fortsatta studier. Vid framtida studier bör därför olika konstruktioner testas för att undvika detta samt få en högre koncentration av proteinet. Funktionen av proteinet bör testas och strukturbestämning genom kristallografi. Om strukturen kan lösas kan forskare förhoppningsvis tillverka en ny TZD medicin utan biverkningar för patienter med typ 2 diabetes 2019 eng Biochemistry Diabetes MPC TZD Plant Yeast Bacteria Protein science Proteinvetenskap Chemistry 8991307 2019-08-02T09:45:27+02:00 2019-08-19T13:55:45+02:00 2019-08-19T13:55:45+02:00

oai:lup-student-papers.lub.lu.se:8991376 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Aleksander Sjörén author 8934670 Valtýr Freyr Hlynsson supervisor Department of Chemistry v1000647 department The route towards linearly fused heptakis-Tröger’s base was followed using a 12 step synthesis route. Hope remains that the final compound will be purified to a satisfactory level within the near future. Additionally, characterizations of reaction intermediates has been completed, up to monoprotected tris-Tröger’s base which has been submitted for its final characterizations. A specifically designed Tröger’s Base analogue was synthesized by functionalizing the benzylic position in the diazocine bridge, with (R)-menthyl ester groups, to make successful separation of previously enantiomeric Tröger’s base analogues possible. Tröger’s Base analogue, containing the bulkier ester side chain, was progressed through, to allow condensation to the tris-Tröger’s Base with a limited set of possible stereo-outcomes, and eventually the heptakis-Tröger’s Base. At the end of this project heptakis-Tröger’s Base is closer to<br /> being successfully purified and characterized and its reaction intermediates has nearly been fully<br /> characterized. The search for new breakthroughs is a never ending quest. No matter which field of science you look at there is always a new discovery around the corner, some envisioned and some stumbled upon. The focus of this thesis is one of the envisioned ones. Imagine if you could place the active substance of a pharmaceutical inside of a small vessel and transport it to a targeted part of a biological system. This would surely increase the potency of most existing drugs<br /> on the market. As tool to accomplish this we had an interesting building block, discovered more than a century ago, Tröger’s base. Recent breakthroughs within the Tröger’s base chemistry had given us hope that maybe one day we would be able to utilize its v-shaped structure to produce a small nano capsule. The focus of this thesis was to continue on this project, started by previous researcher within the group, investigate the possibility of forming these tubes. It was also to be considered what could be done with our molecule if nanotubes was not to be achieved, what other kinds of application we could find for our<br /> structure? As a final part, importance was put into characterizing every intermediate building block along the way, and to improve on already existing chemistry. https://lup.lub.lu.se/student-papers/record/8991376/file/8991380.pdf application/pdf 2182984 yes 2019 eng Organic chemistry Tröger's base Diazocine bridge Chemistry 8991376 2019-08-05T13:53:30+02:00 2023-06-28T15:24:18+02:00 2023-06-28T15:24:18+02:00

oai:lup-student-papers.lub.lu.se:8991929 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ivana Filipcev author 8991927 Susanna Törnroth-Horsefield supervisor Department of Chemistry v1000647 department As the consumption of energy increase in today’s world, the need for new fuel sources is of central importance. In order to be considered viable in the long run, the new energy sources must provide high efficiency and low environmental impact. The search for alternative fuels and energy extraction methods have become increasingly focused on finding ways to mimic systems found within nature. Oxidoreductases are a group of enzymes characterized by electron transfer reactions performed in numerous biological processes. These enzymes have showed great potentially to act as electrode-coupled catalysts in biofuel cells, which allows utilization of many new biofuels at low production costs and minimal environmental impact. But the complex nature of enzymes imposes restrictions for our exploitation of their electrochemical potential. The coupling between enzyme and electrode is one of the main issues for our intended purpose, most oxidoreductases depend on molecules to transfer the electrons from enzyme active site to the electrode, which results in low current- and power densities. <br /> <br /> Fructose dehydrogenase (FDH) is a membrane bound heterotrimeric flavoprotein-cytochrome c complex that catalyzes the oxidation of D-fructose into 5-keto-D-fructose through a covalently bond flavin adenine dinucleotide (FAD) cofactor. It is one of few enzymes capable of conducting effective direct electron transfer (DET) from substrate to electrode, thereby it possess advantages such as higher substrate specificity and elimination of voltage losses connected to mediated electron transfer. Although FDH has been extensively studied over the past decades, the full mechanism of the DET mechanism has not been possible to elucidate in absence of the tree-dimensional structure. At present, the structural information is of utmost importance for further development. Structural information enables genetic engineering directed toward specific properties and thereby improve the electrode-coupled enzyme catalysis. Moreover it could open up possibilities to design artificial analogues with desired properties held by FDH.<br /> <br /> This project covered the initial work of the protein crystallization procedure. The purity and stability of the initial protein sample was assessed with size exclusion chromatography, followed by SDS-PAGE. The buffer composition was assessed and optimized by Differential scanning fluorimetry (DSF) to provide the protein highest possible stability. Crystals were produced in initial screening, and proved reproduceable in the initial crystallization conditions. Further optimization of these conditions generated larger crystals. None of the obtained crystals diffracted when exposed to x-ray beam. Teknologins snabba utveckling och de omfattande förändringar som det inneburit för människans levnadssätt är både fascinerande och skrämmande. Allt eftersom tekniken utvecklats har vi kommit att bli mer beroende av elektroniska hjälpmedel, vilket ställt det moderna samhället inför utmaningen att finna nya energikällor och långsiktigt hållbara strategier att utvinna dem på. De senaste decennierna har elektronisk utrustning miniatyriserats och i allt större utsträckning övergått till att vara portabel, vilket gjort att en större variation av bränslen behövs för att tillgodose nya nischade användningsområden. Förmågan att tillvarata och omvandla energi är en grundläggande förutsättning för allt liv. Årtusenden av evolution har försett biologiska processer med sofistikerade mekanismer för högeffektiv energiomvandling, där komplexa proteiner som kallas enzymer utgör en avgörande roll genom att påskynda de kemiska reaktionerna. Mekanismerna bakom reaktionerna som sker med hjälp av enzymer studerats noga i hopp om att kunna efterlikna naturens tillvägagångssätt och därigenom lyckas extrahera energi från nya energikällor. <br /> <br /> Fruktos dehydrogenas (FDH) är ett enzym som har särskilt tilltalande karaktärsdrag i denna kontext. FDH hör till enzymklassen oxidoreduktaser vars huvudsakliga funktion är att överföra elektroner mellan molekyler, dessa elektronöverföringar motsvarar de reaktioner som utförs av metallkatalysatorer i konventionella bränsleceller. Därför är oxidoreduktaser kapabla att tjäna som biokatalysatorer och driva bränsleceller, vilket innebär att en stor variation av sockerarter och alkoholer kan användas som primär energikälla för att producera elektricitet. Men dessvärre är det svårt att få enzymer att prestera enligt önskan, det beror bland annat på att det är svårt att koppla enzymer direkt till elektroder så att elektroner kan överföras tillräckligt effektivt. FDH hör till ett fåtal enzymer som har förmågan att överföra elektroner till elektroden direkt och därmed prestera med hög elektrokemisk kapacitet vid tillämpning i bränsleceller. Mekanismen som den här typen av direkt elektronöverföring sker genom är av yttersta intresse för att förbättra den elektrokemiska kommunikationen mellan enzymer och elektroder. Trots att FDH har studerats omfattande under många år har den fullständiga mekanismen inte gått att kartlägga utan att känna till den tredimensionella molekylärstrukturen.<br /> <br /> Detaljrik strukturbestämning av proteiner kan göras genom en metod som kallas röntgenkristallografi. Principen bakom metoden är att skapa en kristallstruktur, där proteinmolekyler måste vara placerade i ett välordnat mönster, därefter bestrålas den med röntgenstrålar för att ta fram rådata som vidarebearbetas matematiskt och utfaller i atomernas exakta tredimensionella positioner. Detta projekt omfattade det initiala arbetet i kristalliseringsprocessen av FDH. Proteiner är oerhört känsliga och tenderar att falla sönder när de berövas sin biologiska atmosfär, därför var utgjordes de första stegen i projektet av analys, utvärdering och optimering av miljöbetingelser för att stabilisera FDH i högsta möjliga mån. Kristaller erhölls vid det initiala kristalliseringsförsöket och kunde därefter replikeras och optimerades, vilket resulterade i större kristaller. De erhållna kristallerna bestrålades med röntgenstrålar men genererade dessvärre ingen diffraktion. https://lup.lub.lu.se/student-papers/record/8991929/file/8991931.pdf application/pdf 3731374 yes 2019 eng biochemistry biokemi crystallization fructose dehydrogenase Chemistry 8991929 2019-08-14T10:44:27+02:00 2019-09-12T08:48:29+02:00 2019-09-12T08:48:29+02:00

oai:lup-student-papers.lub.lu.se:8992445 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Josefine Hansson author 8992443 Proffessor Ola Wendt supervisor Department of Chemistry v1000647 department The formation of [PCN-Ni-OAc] from reaction of [PCN-Ni-Me] with CO2 was followed by 1H NMR to determine the kinetics of the reaction. The second order rate constant was calculated, and the entropy and enthalpy of activation was obtained. <br /> The PCN-ligand were synthesised followed known synthetic routs. The crystal structure of the [PCN-Ni-I] complex was also obtained. A POCN- ligand was also synthesised from known synthetic route but metalation of this was not obtained. Labelled 13C benzoic acid were synthesised for measurements of solubility of CO2 in toluene-d8 but complications stopped these measurements. Mängden koldioxid i atmosfären är ett av de största diskussionsämnena när det kommer till miljöförstöring i dagens samhälle. Koldioxid i sig är en gas som är svår att utföra kemiska reaktioner med eftersom den är mycket oreaktiv. Den består av ett kol och två syre som är hårt bundna till kolet med dubbelbindningar. För att kunna reagera måste någon av dessa bindningar brytas vilket kräver energi. I många kemiska reaktioner är det intressant att kunna binda in nya kol till olika molekyler för att skapa nya ämnen. Koldioxid är väldigt bra källa för kol men då måste denna först aktiveras så den kan reagera. <br /> Om en katalysator tillförs till en reaktion så kan reaktioner som inte skulle hända av sig själva ske. Detta beror ofta på att energin som måste tillföras för att bindningar ska brytas i en molekyl är alldeles för hög och en katalysator sänker denna energin. Man kan tänka sig ett berg, istället för att klättra över detta kan man med katalysatorns hjälp gå igenom det vilket är mycket lättare och kräver mindre energi. Katalysatorn förbrukas inte vilket gör att bara en liten mängd behövs.<br /> I denna forskning framställdes ett metallkomplex med en stor PCN-ligand som binder till en nickelatom. Denna ligand är en stor organisk molekyl som skyddar tre av nickels fyra inbindningsställen. Alla olika grundämnen har ett specifikt antal bindningar dessa kan göra. Metallernas antal bindningar beror på hur många elektroner de har. I detta fallet har nickel fyra inbindningsställen. Reaktionen kan därför bara ske på ett ställe på nickelatomen. Liganden ändrar även hur mycket elektrontäthet det finns på nickelatomen, vilket påverkar dess reaktivitet. Först har en metylgrupp (Ett kol med tre väte) bundit in till nickelatomen. Därefter sätts en koldioxidmolekyl in mellan metylen och nickelatomen vilket bildar en molekyl som nu består av två kol i en kedja. Kol kedjor är viktiga inom kemin. Denna insättning kan man följa genom NMR vilket visar de olika väteatomerna i molekylen. Allt eftersom reaktionen fortskrider kan man se hur vissa signaler från väteatomer försvinner och nya kommer fram. Från detta kan man sen räkna ut hur fort reaktionen går och även på vilket sätt just denna reaktionen sker. 2019 eng Inorganic chemistry Oorganisk kemi Chemistry 8992445 2019-08-19T10:52:13+02:00 2019-09-12T14:25:19+02:00 2019-09-12T14:25:19+02:00

oai:lup-student-papers.lub.lu.se:8992586 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Julian David Rivera Ramirez author 8992584 Christer Larsson supervisor Applied Microbiology v1000654 department Biotechnology v1000653 department Probiotics are living microorganisms which could induce a potential health benefit to the host when consumed in adequate amounts. Among the different probiotics in the market, Lactobacillus reuteri strain DSM 17938 is a microaerophilic and heterofermentative organism that is able to tolerate high oxygen conditions compared with another L. reuteri and lactic acid bacteria strains. This study investigated the enzymatic and metabolic responses to oxidative stress by L. reuteri DSM 17938 and its effects on the enzymatic activities, the metabolism and survivability of the cells. Cultivation under aerobic conditions at different levels of aeration, 0%, 33%, 66% and 100% of air at 0.5 L/L/min, did not trigger a significant increase on the concentration of hydrogen peroxide (H2O2) accumulated that could affect generating an inhibitory effect. Specific enzymes activities were evaluated for NAD(P)H oxidases, NAD(P)H peroxidases and glutathione peroxidase; characteristic enzymes associated with the enzymatic oxidative stress mechanisms. A ten to thirty-fold increase in the activity of the NAD(P)H oxidases, NAD(P)H peroxidases, and glutathione peroxidase, proportional on the level of oxygen supplied to the system after a threshold of 33% of air at a rate of 0.5 L/L/min. The enzyme assays suggest that the lack of accumulation of H2O2 in the media was absorbed by the NAD(P)H peroxidases and glutathione peroxidase which were constitutively-active under anaerobic conditions but with a higher induction at higher aeration rates in contrast to NAD(P)H oxidase. The different levels of aeration were sufficient for a significant reduction in end-products typically found during anaerobic growth, ethanol and lactate, and an increase of the concentration acetate. At different levels of oxygen, NAD(P)H is mainly regenerated by the NA(P)DH oxidase - peroxidases system rather than through the production of ethanol and lactate allowing L. reuteri to produce an extra ATP by the production of acetate. These observations indicated that a coupled NAD(P)H oxidase – NAD(P)H peroxidase – glutathione peroxidase system was the main oxidative stress resistance mechanism in L. reuteri DSM 17938, and was regulated by oxygen availability. The response to how an oxygen-sensitive bacterium is able to thrive in environments with high oxygen concentrations<br /> <br /> Probiotics are living microorganisms that could induce health benefits to the host as the improvement of nutrients bioavailability or the treatment of different intestinal disorders (e.g. constipation, diarrhea) when they are consumed in adequate amounts. Considering these potential health beneficial effects, probiotics have been increasingly incorporated during the last two decades to several supplements and food products. Among the different probiotics on the market, Lactobacillus reuteri strain DSM 17938 is a probiotic bacterium that is able to tolerate high oxygen concentrations compared with other probiotic bacteria. This distinctive feature represents an advantage on the production and storage of L. reuteri DSM 17938, as in general, probiotic manufacturers face difficulties in preserving the viability of probiotics in their final matrix (e.g. food products) as most of the probiotics cannot resist oxygen (strict anaerobes) or only tolerate it at low concentrations. However, it is not clear what mechanisms allows this bacterium to thrive and resist high concentrations of oxygen in comparison with other strains, even of the same species. Therefore, the main objective of this study was to elucidate the chemical transformations catalyzed by enzymes inside the probiotic (enzymatic mechanisms) which allows it to tolerate high concentrations of oxygen and their effect in the metabolism. <br /> <br /> The production of the probiotic at four oxygen concentrations (0%, 7%, 14% and 21% of oxygen) showed that the strain was able to tolerate these conditions, as there was not hydrogen peroxide production (H2O2), a harmful molecule for the organism, under none of the conditions evaluated. In contrast, most of the probiotic strains produce high concentrations of this molecule at low concentrations of oxygen, which inhibits their growth. Moreover, the investigation found that the increase of the oxygen concentration on the media increased the production of the enzymes NAD(P)H oxidases, NAD(P)H peroxidases, and glutathione peroxidase in a proportional way with respect to the oxygen concentration. These results indicate that the lack of hydrogen peroxide production is due to, at least in part, the action of the identified enzymes. On the other hand, the analysis of the metabolic end-products showed a reduction in the concentrations of ethanol and lactate produced by the probiotic, at high oxygen levels, while the concentration of acetate increased. These findings are remarkably important, as other investigations has found this change as a clear indicator that the strain is utilizing oxygen in its metabolism. In conclusion, the findings of this study indicate the system composed by the enzymes NAD(P)H oxidase, NAD(P)H peroxidase and glutathione peroxidase is the main mechanism used by the strain L. reuteri DSM 17938 to tolerate and thrive in the presence of high concentrations of oxygen. https://lup.lub.lu.se/student-papers/record/8992586/file/8992665.pdf application/pdf 3827019 2020-12-24 no 2019 eng Applied microbiology Teknisk mikrobiologi Biology and Life Sciences Chemistry https://lup.lub.lu.se/student-papers/record/8992586/file/8992594.docx application/zip Popular summary yes 8992586 2019-08-20T18:44:59+02:00 2020-12-24T03:40:28+01:00 2019-09-12T10:30:14+02:00

oai:lup-student-papers.lub.lu.se:8992591 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Caterina Rovegno author 8992589 Universitetslektor Ulf Ellervik supervisor Department of Chemistry v1000647 department The development and the use of anibiotics since the second half of XX century really affected the approach on treatment and prevention of infectious diseases. Despite a lot of resources and energies has been invested on the research, antibiotics resistance is a growing phenomenon in the last years.<br /> Today this problem has become a real public health priority worldwide, not only for the important clinical implications, but also for the economic fallout of antibiotic-resistant bacteria infections, due to the additional cost required for the use of drugs and more expensive procedures, for lengthening hospital stays and for any disability.<br /> Furthermore, the appearance of pathogens resistant to multiple antibiotics (multidrug resistance) further reduces the possibility of effective treatment.<br /> The problem of antibiotic resistance is complex because it is based on multiple factors: the increased use of these drugs (including inappropriate use), the spread of hospital infections by antibiotic-resistant microorganisms (and the limited control of these infections), an increase in international travel and therefore a greater diffusion of the strains. The continuous use of antibiotics increases the selective pressure favoring the emergence, multiplication and spread of resistant strains.<br /> <br /> The project on which I worked on is trying to find an alternative approach to fight bacteria avoiding the use of antibiotics.<br /> Sialic acid, in fact, is a very abundant sugar on our cells surfaces and it is involved in many biological processes. Most of the bacteria are not provided with sialic acid and they are use to steel it from other cells using many kind of transport protein and use it to elude human immune system and delaying the immune response.<br /> The aim of the rearch is to find molecules that have a very high affinity for the binding site, higher than sialic acids itself. Reaching this goal it could be possible to inhibit the sialic acid&#39;s bacterial transport protein and and prevent them from camouflaging with the cells of the host organism and elude the immune response.<br /> This approach could be basically an alternative way to counteract the bacteria infections avoiding the use of antibiotics. Antibiotika är en av de viktigaste upptäckterna under 1900-talet. Med antibiotika blev det möjligt att bekämpa och förhindra bakteriella infektioner. Ett växande och svårlöst problem är antibiotikaresistans. <br /> Detta projekt syftar till att hitta alternativ till klassisk antibiotika. Vi har arbetat med sialinsyra, en kolhydrat som återfinns på cellytan. De flesta bakterier tillverkar inte själva sialinsyra utan tar istället upp kolhydraten med hjälp av transportproteiner. Bakterierna använder sialinsyra för att maskera sig och därmed undkomma immunförsvaret. Vi har därför arbetat med att ta fram inhibitorer till dessa transportproteiner. 2019 eng Organic chemistry Organisk kemi Chemistry 8992591 2019-08-20T18:51:18+02:00 2019-09-12T13:40:25+02:00 2019-09-12T13:40:25+02:00

oai:lup-student-papers.lub.lu.se:8993348 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Axl Eriksson author 8993112 Prof. Ulf Ryde supervisor Department of Chemistry v1000647 department A protein’s function is directly related to its structure, which is in a water medium where it is affected by hydrogen bonds and the hydrophobic effect. These interactions are in turn dependent on the water molecules’ orientations around the protein. Therefore, it is vital to have correct orientations for the water molecules. Such information can be obtained by neutron crystallography. However, even in such structures, the correct orientation of water requires a manual evaluation and possible re-orientation of each water molecule. This is a tedious and time-consuming procedure since proteins typically contain hundreds of water molecules in their lattice and can have several sub-units. Therefore, we have here tried to develop a method that reliably automatizes the orienting of the water molecules in a simple and relatively fast way. As test cases, we used the proteins galectin-3C, rubredoxin and pyrophosphatase. We evaluated the water molecules&#39; orientations both quantitatively, with RSCC values, and qualitatively, by studying the orientations in density maps. We have optimized the refinement by varying the optimization methods and refinement parameters, thus finding the settings that yielded the best results in terms of time and performance. In particular, we have constructed two scripts that identify and re-orient inadequately oriented water molecules. Ultimately, we performed the refinement and re-orienting using only neutron data. We show that our approach yields improved orientations of the water molecules for all three proteins, in a shorter time than a manual orientation. Vid läkemedelsutveckling används proteiner vars funktion är beroende på hur det är veckat (dess konformation). Denna veckning påverkas i sin tur av vätebindningar från vatten, som bildar vätskemiljön i kroppen där medicinen ska verka och styrkan av vätebindningar påverkas i sin tur av vattenmolekylernas orientering kring proteinet. För att kunna förutse proteinets funktion i kroppen är det därför viktigt att känna till vattenmolekylernas orientering i förhållande till proteinet. Efter att ha bildat en kristall av proteinet och utfört t.ex neutronkristallografi, kan man ta reda på detta genom att utföra en kristallografisk förfining. I denna förfining orienteras vattenmolekylerna automatiskt baserat på en modell och kärntäthetskartorna från neutrondatan. Men detta steg är inte perfekt och kräver därför en manuell omorientering av felaktigt orienterade vattenmolekyler. Detta brukar ta lång tid och kräver mycket arbete eftersom proteinstrukturer kan innehålla flera hundra vattenmolekyler och kan bestå av flera subenheter. Eftersom omorienteringen görs manuellt, kan resultaten vara lite partiska och därmed finns inte heller någon tydlig gräns på vad som gör en vattenmolekyls orientering bra eller dålig. Därför vill vi utveckla en objektiv metod som på ett pålitligt sätt automatiserar orienteringen av vattenmolekyler på ett snabbt och enkelt sätt. För att göra metoden så objektiv som möjligt införde vi real-space correlation coefficient (RSCC) som en numerisk validering på vattenmolekylerna. Som testproteiner använde vi galectin-3C, rubredoxin och pyrofosfatas. Vi har optimerat förfiningen genom att variera optimeringsmetoden och parametrarna. Sedan jämförde vi RSCC med vår manuella studie av de modellerade vattenmolekylerna. När vi hittat den optimerade förfiningsmetoden gjorde vi ett program som automatisk roterade dåligt orienterade vattenmolekyler baserat på deras RSCC. Vår metod gav förbättrad orientering bland vattenmolekylerna hos alla tre proteiner och på kortare tid än en manuell orientering. https://lup.lub.lu.se/student-papers/record/8993348/file/8993355.pdf application/pdf 2204962 no 2019 eng Teoretisk kemi Theoretical chemistry Crystallography Neutron crystallography X-ray crystallography Phenix.refine Method development Model improvement Chemistry 8993348 2019-08-29T10:55:50+02:00 2019-09-12T14:36:25+02:00 2019-09-12T14:36:25+02:00

oai:lup-student-papers.lub.lu.se:8994117 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Sabitan Alharbi author 8973940 Alexey Polukeev supervisor Department of Chemistry v1000647 department Supported Iridium pincer complexes were used to study gas-phase isopropanol <br /> dehydrogenation under continuous flow system at temperatures 200-260 °C with different flow rates. First supported catalyst was [Ir(C2H4)(p-tBu2PO-tBu4POCOP)] supported by covalent bonding to silica, the second one was [Ir(HCl)(p-HO2C- tBu4POCOP)] supported by adsorption <br /> to γ-Alumina. The highest activity of catalyst 1 was 11906 TON (TOF 1963 h-1) with 26% conversion and [Ir(C2H4)(p-tBu2PO-tBu4POCOP)] was supported by covalent bonding to silica <br /> show higher activity and stability compare with catalyst 2 up to 24525 TON (TOF 3901 h-1) <br /> with 90% conversion The development of using transition metal in organic synthesis has had an important impact on organic synthesis and lead to the discovery of new reactions. Heck reaction who won the Noble prize stands as the prototypical example to illustrate how this field important in academia and industry. Catalyst is known as a substance that speeds up a chemical reaction but does not consumed by the reaction, and transition metal complexes have been used as a catalyst in many field such as pharmaconutrients, clean fuel and solar cell. <br /> <br /> In general, an organometallic catalyst consists of two parts metal and ligand, the metal center bind to the ligand. The ligand is an organic or inorganic molecule attached to a metal atom by coordinate bonding, which is responsible for the electronic and steric properties of the organometallic catalyst, these complexes have been used as catalyst which highly efficient and has been employed in numerous industrial processes, Among the organometallic catalysts, the iridium metal group complexes have been used for dehydrogenation and transfer dehydrogenation reactions, dehydrogenation is a chemical reaction that involves the removal of hydrogen H2 from organic molecules and is the reverse of hydrogenation. <br /> <br /> In this respect, alcohols dehydrogenation produces hydrogen, which is considered as an efficient energy carrier and has the highest energy content of any standard fuel by weight, also using hydrogen dramatically reduces pollution. Another benefit of alcohols dehydrogenation is produced aldehyde from primary alcohols and ketone from secondary alcohols, so dehydrogenation of alcohol yield carbonyl compounds, which are considered an important intermediate in organic synthesis. Another benefit is that alcohols dehydrogenation is known as a green oxidation procedure, which can minimize waste formation. <br /> <br /> Iridium catalyst is considered an active catalyst for dehydrogenation of alcohols, so the thesis aimed to synthesized iridium catalyst and study dehydrogenation of isopropanol under continuous flow system, continuous flow process when the reactant and the product are charged and discharged simultaneously. Continuous flow processing is considered in crucial general feature in making the organic synthesis more economical and environmentally friendly resulted in a growing research area in both academic and industrial. 2019 eng Dehydrogenation Iridium pincer complexes Pincer catalyst Inorganic chemistry Oorganisk kemi Chemistry 8994117 2019-09-04T11:23:00+02:00 2019-09-12T15:35:44+02:00 2019-09-12T15:35:44+02:00

oai:lup-student-papers.lub.lu.se:8994588 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Isabella Gimskog author 8994536 Tommy Cedervall supervisor Pure and Applied Biochemistry v1000655 department Computational Chemistry v1000659 department The breakdown of plastics in our oceans is one of our times biggest challenges. What happens when these plastics are broken down into pieces too small to see is still a mystery. Nanoplastics is a relatively new area of research and much more studies need to be done before we can get a perspective of how big the problem is. To be able to study these plastics we need a way to attain nanoplastic samples from our oceans. This thesis aims to act as a first step in suggesting a method to isolate eventual nanoplastics accumulated in fish. This thesis investigates the possibility to find nanoplastic particles in the gills and digestive tract of food fish from the Mediterranean sea.<br /> During the last few years microplastics has gone from being an almost unknown word to being a hot topic frequently discussed in media and possibly one of the worst environmental threats of our time. But what happens when the microplastics break down? The answer we all would wish for is that they disappear or become useful matter for the ecosystem again. This might unfortunately not be the case as plastics never break down fully but are just fragmented into smaller and smaller pieces and we might stand before an even more incomprehensible threat. Nanoplastics.<br /> Nanoplastics are usually defined as plastic particles with at least one dimension under 100nm and they are still much of a mystery in how they are formed and how they affect the ecosystem in which they are present. It can be hard to comprehend the difference between micro- and nanoplastics but as microplastics are usually defined as plastic pieces smaller than 5mm, the difference in scale is like comparing a Olympic size swimming pool to a single drop of water. They are so small that they are not restricted to the pathways we are used to and previous research shows that they can even cross the brain-blood-barrier in fish.<br /> Nanoplastics is a new area of research and it is of great importance that we learn more, fast. This thesis aims to be a first step in finding a way to detect existence of nanoplastics in the fish we eat and thereby in our oceans. The work analyses the the particles from the digestive tract and gills of fish below the size of 1,2 μm. The findings indicate that there are nanoplastics present in the fish and that these plastics are possible to isolate.<br /> The report also includes mechanical breakdown of microplastics found in the same fish and of a polystyrene coffee cup lid. All experiments show that nanoplastics are released in the break down process.<br /> The hope is that this report can act as a starting point and a guide to anyone who is curious about nanoplastics and wish to isolate them from complex samples. https://lup.lub.lu.se/student-papers/record/8994588/file/8994590.pdf application/pdf 8493821 no 2019 eng nanoplastics microplastics Mediterranean fish isolation applied biochemistry tillämpad biokemi Chemistry Biology and Life Sciences Earth and Environmental Sciences Technology and Engineering 8994588 2019-09-10T09:08:13+02:00 2020-06-12T14:05:35+02:00 2020-06-12T14:05:35+02:00

oai:lup-student-papers.lub.lu.se:8995597 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Johan Söderblom author 8995595 Anita Hoang supervisor Kirill Popov supervisor Department of Chemistry v1000647 department Ortho-amides have shown to be an important intermediate in the total synthesis of the cytotoxic indole alkaloid, dehaloperphoroamidine. The potential of this functional group lead to further investigation of its reactivity. Background, known reactions with ortho-amides and A 7-steps synthesis route of a general ortho-amide from tryptamine are presented here. Lack of time resulted in that the synthesis was never completed but 3 of the steps were carried out successfully with a moderate yield. Människan använde sig tidigt av växter för att behandla sjukdomar utan att veta vilket specifikt ämne i växten som verkade, hon tycktes sig enbart se en behandling av sjukdomen eller på symptomen av denna. Vid läkemedelsutveckling så har naturen varit en oändlig källa till inspiration och potenta kemiska föreningar. Antingen är de rena naturprodukter eller kemiska derivat som genomgått en liten ändring. <br /> <br /> Biologiskt aktiva molekyler som ger organismer en fördel att överleva och kunna reproducera sig, så som signalsubstanser, feromoner eller försvarssubstanser är exempel på naturprodukter. Ett känt exempel är acetylsalicylsyra som finns i Aspirin, som är ett kemiskt derivat av naturprodukten salicylsyra som finns naturligt i bla. salix och spirea. <br /> <br /> I de flesta fall är det mer ekonomiskt och mindre tidskrävande att isolera en naturprodukt från en organism istället för att tillverka den syntetiskt på labb. Men i de fall där organismen inte producerar den aktiva biologiska substansen i större mängd eller bara under specifika förhållanden får syntetisering av ämnet göras på labb. Ju kortare och effektivare totalsyntesen av ämnet är desto större vinning i ekonomi, miljö, tid och resurser. <br /> <br /> Detta projekt inriktar sig på ett specifikt steg i en totalsyntes av dehaloperophoramidine som är en naturprodukt från sjöpung. Det steget involverar en ortho-amide som här har studerats vidare. En syntesplan för en generell ortho-amide har tagits fram och syntetiserats delvis. Den kan användas för att studera dess reaktivitet, dvs. hur och hur fort den reagerar med andra molekyler. https://lup.lub.lu.se/student-papers/record/8995597/file/9131018.pdf application/pdf 443522 LU/LTH access 2019 eng Organic chemistry Organisk syntes total synthesis totalsyntes Ortho-amide perophoramidine dehaloperophoramidine Chemistry 8995597 2019-09-24T09:46:38+02:00 2023-06-28T11:44:32+02:00 2023-06-28T11:44:32+02:00

oai:lup-student-papers.lub.lu.se:8997448 2025-07-29T13:03:30Z AgricultureVeterinaryMedForestry PhysicsChemistryMaths

studentPublicationsH2 Gao Wenjia author 8997446 Björn Bergenståhl supervisor Ida-Marie Andersson supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Spray-dried milk serum protein concentrate powders could be applied either as ingredients in dairy applications or delivery materials in pharmaceutical and biotechnology industry. Yet, one of the critical challenges is that lumps are easily to form when the powders is added into water. Surface rheology of solutions from redissolved protein powders is suggested to be an important part in increasing the systematic knowledge about this phenomenon. The objective of this thesis is to compare milk SPC aggregates with unheated milk SPC on the adsorption behaviors to the given air-water interface. Surface rheology (surface tension, surface pressure and dilational rheology) of solutions from redissolved protein powders were measured and the spray drying parameters were fixed. The total solids, that is the total weight percentage of proteins and lactose, is with constant value 22.5%. The ratio of milk SPC aggregates to unheated milk SPC is 1, 4/1, 9/1, 19/1 and 0 of the system before the spray drying. Bulk protein concentrations, with designed values of 10%, 7%, 2%, 1% and 0.2%, on the surface rheology of solutions from redissolving protein powders are also under investigation. <br /> <br /> It is found that ratios of milk SPC aggregates to unheated milk SPC do not significantly influence static surface tensions statistically. While, the bulk protein concentrations significantly influence static surface tensions. Despite this, through dynamic surface tension measurements, the lowest surface tension value is given by protein powders with unheated milk SPC only. The induction regime of solutions with unheated milk SPC is shorter than that with milk SPC aggregates. Yet, the adsorption rate show that protein aggregates could decrease the surface tension more constantly. <br /> <br /> Regarding the elasticity of adsorbed protein films, the formation of a gel-like protein film is shown at the bulk protein concentration 6.15% and above while unheated milk SPC is mixed with milk SPC aggregates. Milk SPC aggregates from protein powders may be the main contributor to a stiff adsorbed protein films. And unheated milk SPC could play as the blocking polymer during the interfacial polymerization. This is based on the result that an increase in modulus of elasticity with the measurement time shows at the bulk protein concentration as low as 1.76% of solutions from protein powders with milk SPC aggregates only. While, if proteins of solutions from redissolved protein powders were the mixing of unheated milk SPC with milk SPC aggregates, similar trends requires the bulk protein concentration as high as 9.5%. Milk Serum protein concentrate, namely milk SPC, is produced by filtering milk without fat. It does not contain caseins after the filtration. The application of protein powders from milk SPC is widespread, cause proteins included in milk SPC are similar as byproducts from cheese manufacturing. Spray drying is a method to dry milk SPC and produce milk SPC powders. Through spray drying, the milk SPC liquid is fed into the chamber filled with hot air. The liquid is atomized into a lot of small droplets. The water of the liquid evaporates quickly by contacting with the hot air. Powders are collected afterwards. Properties of protein powders depend on powder compositions and spray drying parameters, such as inlet air volume, inlet and outlet temperatures. For instance, lumps are easily form when powders are added into the water. <br /> <br /> This thesis studies this type of system, including milk SPC and denatured milk SPC, as well as lactose. Heating milk SPC under 85 °C for 20min, milk SPC is denatured. Different from natural milk SPC state, sub-structures of denatured milk SPC change, and render different properties, such as solubility. One example of protein denaturation is heating egg proteins during cooking. This thesis is to compare denatured milk SPC and unheated milk SPC on the diffusion of proteins to the droplet surface. The diffusion is connected to the surface activity of proteins. The surface activity is the ability of milk SPC and denatured milk SPC to lower surface tensions at phases. Surface tension is the force to hold the shape of a droplet. One typical example is the water droplet and the water surface tension is the force to give its sphere shape. Surface elasticity is also studied. Surface elasticity is the ability of the droplet to stretch the original shape and recover from deformation, that is, the stiffness of the droplet surface. <br /> <br /> The aim of the thesis was to look at the surface rheology values of diluted solutions from redissolved protein powders. How the surface rheology was influenced by diluting the system with lactose in different ratios and the addition of denatured milk SPC was studied.<br /> <br /> The method to measure the surface rheology is Pendant drop method. For the surface tension values, the droplet forms automatically and the surface tension was calculated by the software based on the droplet image. The surface elasticity value was given by oscillating pendant drop method. The droplet is under regular compression and expansion and the area of the droplet is changing within the measurement. <br /> <br /> Results show that unheated milk SPC from solutions is more surface active than denatured milk SPC. However, the ratio of unheated milk SPC to denatured milk SPC does not affect surface tensions of diluted solutions with lactose from redissolved protein powders significantly. Regarding the layer on the droplet surface, its stiffness depends on how much proteins in the solution and whether proteins are unheated SPC or denatured SPC. The formation of gel-like layer happened with the existence of denatured milk SPC at a lower protein concentration than that of the industrial scale. And the fraction of hollowed protein particles could be related to a stiff protein film as a result. However, no decisive conclusion is available about the impact of the lactose in the system on the surface rheology. https://lup.lub.lu.se/student-papers/record/8997448/file/8997449.pdf application/pdf 5964758 LU/LTH access 2019 eng Food technology Livsmedelsteknologi Agriculture and Food Sciences Chemistry 8997448 2019-11-05T20:53:56+01:00 2019-12-20T14:05:39+01:00 2019-12-20T13:53:14+01:00

oai:lup-student-papers.lub.lu.se:8998164 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Amanda Eriksson Skog author 8958471 Marie Skepö supervisor Dr. Yuri Gerelli supervisor Department of Chemistry v1000647 department In this project, three smaller projects were conducted, all utilizing the surface sensitive technique QCM-D, and for two of them neutron reflectometry was used as well. In two of the projects, adsorption of the intrinsically disordered peptides, Histatin 5 and Keif, to lipid bilayers was studies, whereas in the last project a protocol for forming bilayers of natural lipids using the vesicle fusion method was developed. Results for Histatin 5 and the variants of it shows that the adsorption depends on the number of histidines in the chain, as well as the electrostatics within the bilayer. A less charged bilayer show less adsorption. The overall electrostatics in the system is also crucial for adsorption. When the salt concentration was set to 500 mM, all adsorption was washed away. For the interactions of Keif, a small dependence of concentration of magnesium was found, at low concentration of magnesium the peptide adsorption to all studied substrates (both membranes and surfaces) was less reversible compared to other concentrations of magnesium. Lastly, a protocol to deposit natural lipids using vesicle fusion was obtain, but it needs to be refined to obtain bilayers of higher quality. Proteiner är något som många förknippar med mat, exempelvis kött och ägg. Proteiner finns också i kroppen och har där många olika uppgifter, bland annat att bygga upp muskler. Det finns en intressant grupp proteiner som har en oordnad struktur (intrinsically disordered proteins), vilket innebär att de inte har en ordnad tredimensionell struktur, utan kan anta flera olika konformationer. Det kan vara hela proteinkedjan som är oordnad, alternativt en eller flera delar av den. Dessa oordnade proteiner har visats vara viktiga inom biologi, där det bland annat finns oordnade proteiner som är inblandade i sjukdomar såsom Alzheimers och Parkinsons sjukdom. Det finns även oordnade proteiner som skyddar oss mot angrepp, till exempel Histatin 5, en oordnad salivpeptid som är ett första skydd mot torsk. I den här studien har det studerats hur Histatin 5 interagerar med ett membran och bildar en ”kudde” under membranet och lyfter upp det från underlaget. Mätningar har gjorts på olika muterade peptidkedjor där antalet histidiner har varierats. Histidin är en aminosyra som kan vara antingen oladdad eller positivt laddad beroende på pH-värdet i lösningen. En mutant med slumpmässig ordning på aminosyrorna har också studerats och metoderna som använts är QCM-D samt neutronreflektometri. Resultaten visar att antalet histidiner i kedjan har betydelse för hur mycket som adsorberar till membranet.<br /> I projektet har även Keif studerats med QCM-D och neutronreflektometri. Keif är en oordnad peptid och en del av ett magnesiumtransportprotein hos bakterier som sitter inbundet i ett membran. Därför studerades Keifs interaktion med membran och hur interaktionen påverkades av hur mycket magnesium som fanns i systemet. Resultatet visade att Keif adsorberar med minst reversibilitet till alla i studien undersökta ytor och membran vid låga koncentrationer av magnesium.<br /> I den sista delen av projektet var målet att hitta en metod för att bilda ett membran av naturliga lipider på en yta med vesikelfusionsmetoden. Det är en av de enklaste metoderna för att skapa membran, då vesiklar injiceras till en yta och sedan sköljs med en buffert för att skapa osmotisk chock. För att få naturliga lipider att adsorbera till en laddad yta behövs en hög koncentration salt i systemet för att skärma den elektrostatiska repulsionen. Naturliga membran består till stor del av negativt laddade lipider. De bildar därför väldigt stabila vesiklar, vilket gör det svårt att spräcka dem med osmotisk chock. Två olika metoder togs fram, en för hydrogenerade lipider och en för deutererade lipider. Båda metoderna kräver optimering för att erhålla högre kvalitet på membranen. https://lup.lub.lu.se/student-papers/record/8998164/file/8998165.pdf application/pdf 5489800 yes 2019 eng Fysikalisk kemi Physical chemistry Chemistry 8998164 2019-11-26T09:02:47+01:00 2019-12-20T10:37:38+01:00 2019-12-20T10:37:38+01:00

oai:lup-student-papers.lub.lu.se:8998615 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Markus Lilja author 8998613 Researcher Christian Hulteberg supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department One of the main challenge’s society faces today is climate change caused by CO2 due to the de-pendence on fossil fuels. To combat the increasing CO2 levels there is a need to develop renewable fuels. One such fuel could potentially be derived from lignin.<br /> <br /> In this thesis, lignin derived from a pulp and paper mill was first treated and cleaned. The lignin was then processed by catalytic hydroprocessing. By varying time as well as the amount of H2 within the decided central composite design, the future direction of further could be discovered. For each experiment there was a comparison test conducted (blank) without lignin conducted in order to examine the effect of the lignin. The resulting products were analysed by GC-Fid through compari-son to biodiesel as well as commercial gasoline. Afterwards mass balances were used to analyse the yields. <br /> <br /> The results of the experiments indicated that the set interval of parameters or equipment were not optimal for lignin. Since they resulted in a large amount of coke formation, especially in the cases of more severe treatment. For future research the results seem to point towards the use of higher content of H2 coupled with shorter reaction time.<br /> <br /> However, different catalysts, equipment setups as well as lower temperatures will need to be evalu-ated for lignin fuel optimization. By using lignin, which is a biproduct of the pulp and paper industry, there is hope of reducing the worlds dependency on fossil fuels. In this work, lignin was broken down by hydrogen and heat to produce fuel. The results suggest higher amounts of hydrogen at lower temperatures as the direction of further work.<br /> <br /> One of the largest challenges that is discussed today, is that of climate change. According to the United nations [1], “Climate Change is the defining issue of our time and we are at a defining moment. From shifting weather patterns that threaten food production, to rising sea levels that increase the risk of catastrophic flooding, the impacts of climate change are global in scope and unprecedented in scale. Without drastic action today, adapting to these impacts in the future will be more difficult and costly”. Climate change is mainly caused by the burning of fossil fuels, which today covers a lot of the world’s energy demand. By burning fossil fuel, CO2 is released into the atmosphere, which has been stored in the earth’s crust for millions of years. The increased CO2 in the atmosphere then traps more of the sun’s energy, which leads to increased temperatures around the globe. To prevent further increase in temperature, while continuing to enable our way of life, there is a need to find renewable sources of fuels. <br /> <br /> Such renewable fuels could be made from wood, which takes us to the remarkable molecule of lignin. Lignin makes up roughly a third of all the contents of wood. Interestingly, other than being a renewable source, it is already being produced in huge quantities around the world, since in the making of paper, it needs to be removed. This means that lignin is available in huge quantities, which if converted to fuel, would enable large quantities of fossil fuels being left in the ground. Before lignin can be used for fuel, it needs to be broken down into smaller molecules of the right size. For this sake, lignin was treated by H2 at high temperatures and the products were evaluated. <br /> <br /> The results showed that the selected duration of experiments and/or possibly the temperature was set to high. This was shown by the unwanted gas and coke content, which increased the longer the experiments took. Furthermore, it was also shown that higher H2 pressure led to less gas and coke being formed from lignin. Nonetheless, the results showed fuel being made from lignin, which was seen in the experiments with the lowest duration and at the highest H2 pressure. This means that future experiments should be done in those directions. However, during experimentation and evaluation, several issues arose with the method and equipment, which could affect the results. For example, the heater couldn’t sometimes keep the temperature up, there were large variations in results of repeated experiments, many leaks were detected, and it took a long time heat up and cooldown the reactor. This means that a different experimental setup might be desirable in future experiments.<br /> <br /> The conclusion that can be drawn is that lignin is an exciting field with lots of potential, and we might be one step closer to a world that is free of fossil fuels. However, there is much more work that needs to be done in the field of making fuel from lignin. https://lup.lub.lu.se/student-papers/record/8998615/file/8998617.pdf application/pdf 3299252 no 2019 eng Lignin hydrotreating kemiteknik chemical engineering Chemistry Technology and Engineering 8998615 2019-12-11T14:05:44+01:00 2020-02-17T14:30:39+01:00 2020-02-17T14:30:39+01:00

oai:lup-student-papers.lub.lu.se:8998802 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Linnéa Gunnarsson author 8998690 Adrian Sanchez-Fernandez supervisor Tommy Nylander supervisor Department of Chemistry v1000647 department Deep eutectic solvents (DES) are designer solvents comprised of a quaternary ammonium salt and a hydrogen bond donor that are mixed at a 1:2 molar ratio. They are a green, biodegradable alternative to ionic liquids (ILs) that replace organic solvents in many applications. However, the high viscosity of these solvents limits their areas of use, but this can be overcome through addition of water. The characteristics of DES with additions of water has been investigated and it is believed that smaller additions can be achieved without altering the nanostructure of the DES. Vesicle formation is possible in DES, but the interactions between the lipid bilayer and the eutectic are not yet fully understood. The solvophobic effect that drives vesicle formation is likely affected by the theoretically high ionic charge of the DES. Drawing from previous research, a characterisation of vesicles in DES was attempted to contribute to the field. Vesicles made from DOPG and DOPC lipids were assembled in solutions of both 1:2 choline chloride/urea (reline) and 1:2 choline chloride/glycerol (glyceline) DES, with different additions of water. The resulting vesicles were analysed using dynamic light scattering (DLS), accompanied by a study of their bilayers using small angle X-ray scattering (SAXS). The results indicated that vesicles formed in different eutectic mixtures were of different sizes and displayed structural differences in their lipid bilayer. The type of lipid used, the DES, as well as the hydration level of the solvent were all influential factors. The differences encountered were hypothesised to result from interactions between the lipid headgroups and the DES constituents. När lipider löses i vatten kan de spontant arrangera sig för att anta formen av en vesikel. En vesikel består av ett cirkulärt dubbelskikt, ett bilager, av lipider där lösningsmedlet befinner sig på insidan och utsidan. Lipiderna har drivits av interaktioner med lösningsmedlet till att vända sina hydrofoba – ej vattenlösliga – delar från vattnet vilket resulterar i formationen av bilagret, där enbart de vattenlösliga delarna av lipiderna är i kontakt med vatten. Bilagret i vesiklar har samma struktur som cellmembranet i kroppens celler.<br /> Vesiklar kan också bildas när lipider löses i deep eutectic solvents (DES). De är en relativt ny klass av polära lösningsmedel som påminner om vatten då de är polära och deras beståndsdelar interagerar med vätebindningar. Eftersom flera processer som vanligen sker i vattenlösningar även går att utföra i eutektiska lösningsmedel blir det intressant att undersöka hur dessa påverkas av det nya lösningsmedlet.<br /> Eutektiska lösningsmedel är intressanta ur ett miljöperspektiv då de har låg toxicitet och kan ersätta organiska lösningsmedel som är svåra att bryta ner. De består vanligtvis av en vätedonerande komponent och ett ammoniumsalt; men beståndsdelarna kan väljas så att lösningsmedlet får egenskaper som passar för specifika applikationer. En svårighet i användningen av eutektiska lösningsmedel är att de har hög densitet och därmed är mycket viskösa. Den höga viskositeten kan däremot minskas genom addition av vatten. Om små mängder vatten tillsätts bibehålls strukturen som ger lösningsmedlet sina unika egenskaper; men desto mer vatten som tillsätts desto mer förfaller lösningsmedlets struktur.<br /> Trots att det har bevisats att lipider kan arrangera sig till vesiklar i eutektiska lösningsmedel är det fortfarande oklart hur det påverkar vesikelns struktur. En teori är att attraktiva krafter kan uppstå mellan lipiders huvudgrupper och lösningsmedlets komponenter, och att dessa kommer att påverkas av andelen vatten i lösningsmedlet. Genom att lösa lipider i eutektiska lösningsmedel med olika tillsatser av vatten kunde storleken och formen på vesiklarna studeras. Vesiklarnas storlek och bilagrets karaktär analyserades med hjälp av spridningstekniker (DLS och SAXS).<br /> Resultaten indikerade att lipider bildar vesiklar av olika storlek beroende på andelen vatten i det eutektiska lösningsmedlet. Strukturella skillnader kunde också påvisas mellan vesiklarnas bilager, vilket stärkte teorin om att det förekommer interaktioner mellan lipidernas huvudgrupper och det eutektiska lösningsmedlets komponenter. https://lup.lub.lu.se/student-papers/record/8998802/file/8998803.pdf application/pdf 2365234 LU/LTH access 2019 eng physical chemistry fysikalisk kemi DES Deep eutectic solvents Deep eutectic solvent lipid lipids bilayer DOPC DOPG ionic liquids viscosity vesicle vesicles formation choline chloride glycerol urea glyceline reline DLS SAXS dynamic light scattering small angle X-ray scattering light microscopy scattering Chemistry 8998802 2019-12-17T17:48:55+01:00 2020-04-30T14:53:31+02:00 2020-04-30T14:53:31+02:00

oai:lup-student-papers.lub.lu.se:9001386 2025-07-29T13:03:30Z Medicine PhysicsChemistryMaths Technology

studentPublicationsH2 Sofia Classon author 9001371 Nelida Leiva Eriksson supervisor Dennis Eriksson supervisor Eskil Åhlin supervisor Pure and Applied Biochemistry v1000655 department Computational Chemistry v1000659 department Iron deficiency is the most common nutritional disorder in the world. It is the only nutrient deficiency that is not exclusively prevalent in non-industrialized nations but also in all industrialized countries. Despite this, the treatment for the disease is inefficient, long and associated with side effects such as constipation and nausea. In recent years several studies have highlighted the difference in bioavailability between iron salts and iron present in a heme-group. Heme iron has a higher bioavailability than iron salts which enable lower concentrations to satisfy the iron demand in deficient patients. Today meat is the most common source of heme iron but it is also present in plants to some extent. However, due to livestock production’s major contribution to climate change and the unfavorable health consequences associated with meat consumption, meat is not an optimal vehicle. In this regard, a way to reduce the frequency rate of iron deficiency and invent a product with shorter treatment periods, reduced side effects and reduced environmental impact this report focused on investigating the potential market for a heme-based iron produced through genetic engineering. Women was found to be the optimal target segment since they showed the highest prevalence of iron deficiency and were more prone to exclude meat from their diets. This segment favored food products before iron supplements. Regarding what legal framework that would apply to a food product or an ingredient produced using genetic engineering, more details would be needed. Three frameworks were however found as potential candidates for the EU market; Genetically Modified Organism, Novel Ingredient and Food additive. Järnbrist är idag ett växande problem, i både utvecklings- och industrialiserade länder, och uttrycker sig oftast genom att den drabbade individen känner sig trött och svag. Om sjukdomen däremot inte behandlas kan konsekvenserna bli större. Järn är nämligen en viktig komponent för produktion av röda blodkroppar, det vill säga blod, och fungerar som en syre-transportör till kroppens alla energidrivande processer. Det är därför en individ med lite järn ofta löper stor risk att få blodbrist samt känner sig orklös. <br /> <br /> Kroppen återvinner järn från de röda blodkropparna men det är inte tillräckligt för att tillfredsställa det dagliga behovet och därför är det viktigt att få i sig järn via kosten. Kvinnor och personer med högre blodförluster, snabbt växande individer eller vegetarianer har ett större järnbehov och måste därför vara extra noggranna att deras behov tillfredsställs. I dagsläget rekommenderas individer att till exempel äta järn-rik kost såsom broccoli och bönor och kan även få järntabletter utskrivna. Nackdelen med de här alternativen är att de består av järn i saltform vilket kroppen har svårare att ta upp och tillgodogöra sig. Tabletterna måste därför ha höga järnkoncentrationer för att den faktiska mängd som kroppen kan tillgodogöra sig och använda ska vara tillräcklig. Detta skapar irritationer i tarmen vilka gör att individen ofta kan känna sig illamående eller drabbas av förstoppning samt andra bieffekter. Behandlingsperioden med järnsalter är dessutom lång vilket gör att alla inte fullföljer behandlingen. <br /> <br /> Nya studier har visat att järn som befinner sig i den form som den gör i hemoglobin, i blod, tas upp signifikant bättre. Där återfinns järn i en protetisk grupp kallad heme. Heme-baserat järn finns även i andra makromolekyler såsom i myoglobin i våra muskler. Det här arbetet har därför fokuserat på att studera det marknadsbehov en sådan produkt kan tänkas mötas. Potentiella konsumenter, för- och nackdelar med befintliga järnprodukter, regulatoriska ramverk samt sociodemografiska trender och kulturella aspekter som kan tänkas påverka. I arbetet valdes kvinnor som den mest passande målgruppen för en ny heme-produkt. Kvinnor visade sig ha en större tendens till att drabbas av järnbrist, huvudsakligen på grund av de blodförluster som är kopplade till menstruation och graviditet. Gravida kvinnor med järnbrist löper dessutom större risk att föda barn med intellektuella dysfunktioner. I den marknadsundersökning som gjordes i det här arbetet föredrog segmentet en matprodukt rik på heme-baserat järn framför ett tillskott. När de regulatoriska ramverken för en sådan produkt undersöktes hittades tre ramverk som kan tänkas tillämpas; Genetiskt modifierade organismer (GMO), en ny ingrediens eller livsmedelstillskott. En större analys kring detta behövs göras. Gällande marknadens acceptans av GMO ansågs det fortfarande vara kontroversiellt trots att trender tyder på en ökad användning. Fler och fler lantbruksföretag börjar en GMO-baserad, process för att möjliggöra en stor produktion men samtidigt ha en lägre miljöpåverkan. 2020 eng Anaemia Iron Blood Applied biochemistry Tillämpad biokemi Chemistry Technology and Engineering Medicine and Health Sciences 9001386 2020-01-15T16:54:48+01:00 2020-02-03T13:19:19+01:00 2020-02-03T13:19:19+01:00

oai:lup-student-papers.lub.lu.se:9002175 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Moritz Schuldt author 9001875 Ola Wendt supervisor Department of Chemistry v1000647 department Different homogenous and heterogenous catalysts, including different noble metals on silica or carbon and methyltrioxorhenium (MTO), were screened for their catalytic activity in the deoxydehydration of mucic and tartaric acid. A method for the determination of yields by NMR was developed and the reaction conditions, e.g. solvent composition and acidic catalyst, were optimized for tartaric acid.<br /> These optimized conditions were then applied to mucic acid, but this gave only low yields, therefore the use of MTO and a separate hydrogenation step was attempted and gave better results. The hydrogenation step was then further optimized to employ lower temperatures and catalyst loadings. For this step both Pt on carbon and an Iridium pincer complex were screened as potential catalysts. In recent years environmental problems and polution have gained much importance in the public´s eye. Especially the emission of greenhouse gases such as carbon dioxide and nitrous oxides from different sources, before all from industry and transport, have moved into focus here. This is why the topic of reducing these emissions has gained so much traction in scientific publications. Another aspect, that has seen a similar trend and which is also closely linked to the environmental discussion, is the issue of sustainability. As the resources of our planet are limited, we must find ways to reduce our use of them to an amount that can be replenished in the same timeframe. This is certainly an issue regarding our fossil fuel-based transportation, but it is also an issue for the chemical industry, which is dependent on the use of natural oil, a not renewable and therefore not very sustainable raw material. The focus of green chemistry is to tackle these problems at their root by reducing emissions as well as by trying to find ways to use e.g. plants and thereby regrowing resources for these processes.<br /> The main problem with the use of plant-based feedstocks, is that they need to be broken down to be used in these processes. This breakdown happens in complex chemical reactions and effective catalysts need to be developed for this to work. A catalyst is used in chemical reactions to speed them up, because otherwise they would take very long. As a consequence catalysts make it possible to use these reactions in an industrial process.<br /> The focus of this work is the development of a catalyst that is needed to turn sugar beet residues into a chemical that is needed in very large amounts for the production of certain plastic types. The currently used industrial process for the production of this chemical has two major environmental disadvantages. It not only uses oil as starting point, but also produces large amounts of a greenhouse gas.<br /> Another process, we tried to improve, is the breakdown of a chemical, obtained from grapes, into another chemical, that can be used as feedstock for a variety of different chemical processes, which result in different widely used chemicals.<br /> For the two processes described above, different types of catalysts, that are known to work in these types of breakdowns, have been tested and their effectiveness was determined for our reactions. We also did experiments on improving those catalysts and the conditions under which they can be used. 2019 eng deoxygenation mucic acid tartaric acid Chemistry 9002175 2020-01-21T18:24:18+01:00 2020-02-17T13:17:41+01:00 2020-02-17T13:17:41+01:00

oai:lup-student-papers.lub.lu.se:9003878 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Aleksandra Ilic author 9003007 Ola Wendt supervisor Department of Chemistry v1000647 department Alkanes offer great and barely utilised potential for usage as raw materials in large-scale chemical processes. Their lack of reactivity, however, warrants methods of manipulating and transforming them in an efficient and mild way, which can potentially be realised by employing homogeneous catalysis using pincer complexes. A reliable procedure for the synthesis and diastereomer-separation of 2-methyl-1,3-cyclohexanediol was established, paving the way for the preparation of three novel cyclohexyl-based POCOP-pincer ligands, which have been characterised via 1H-, 31P{1H}- and 13C{1H}-NMR spectroscopy. These systems had been proposed as candidates for the ultimate goal of scission of unstrained, unactivated C(sp3)-C(sp3) bonds in an intermolecular reaction. Therefore, their cyclometallation behaviour was thoroughly studied under varying conditions employing i.a. different metallating agents. The results of these investigations revealed a trend of facile metal-induced ligand decomposition occurring with two of the ligands accompanied by a distinct lack of cyclometallation in all tested systems, clearly indicating an underlying issue, wherein bidentate coordination appears to not be feasible. While the desired bond cleavage has not been achieved, these studies provided an increased understanding of the general aspects of cyclometallation and ligand stability/flexibility as well as the influence these factors exert on each other. Further mechanistic investigations were initiated as to elucidate the potential of the proposed concept, affording novel insight into differences in reactivity between these POCOP-systems and their PCP-analogues. Catalysts are substances, which are known to be at the root of many large-scale chemical processes, due to their ability to either facilitate specific steps in the reaction sequence or by altogether rendering certain transformations possible, which would not have occurred otherwise, by lowering the required energy input and increasing the overall-rate of the reaction. Among such chemical processes which employ catalysts are well-known representatives such as the Monsanto process for acetic acid production, the Wacker process for large-scale synthesis of aldehydes, the Müller-Rochow process for the generation of chlorosilanes, which are further used for the production of silicones as well as various catalysts that are being used in polymerisation reactions leading to synthesis of ubiquitous plastic materials. <br /> In recent decades a process known as “C-C bond activation” has been granted increasingly more attention in research. C-C activation is a term that describes the scission of a carbon-carbon bond in a molecule that often involves a catalyst based on a metal compound that induces this breakage. Having cleaved such a bond, a variety of subsequent transformations of the molecule can occur, providing grounds for achieving a great versatility of substances based on one molecule. <br /> One very impactful application of the C-C bond activation could be the manipulation of so-called “alkanes”. Alkanes are a substance class that is mainly afforded from crude oil and are isolated and purified through refining processes.<br /> These products serve mainly as the constituents for different fuel types and lubricants. These applications do not warrant complex transformations of the alkanes, which are generally used as received after isolation, with solely long-chain compounds being transformed into their shorter-chain analogues, due to their limited utility of the former. <br /> Their sheer abundance however would make them convenient candidates for usage as starting materials in large-scale chemical processes, with C-C bond activation providing an efficient way to overcome difficulties in transforming them into other chemical substances. Furthermore, this route could provide less energy-consuming methods for controlled degradation of long-chained products, while simultaneously rendering the targeted and controlled transformations of these compounds possible.<br /> Recent studies in this field have offered promising insight into the reaction behaviour of alkyl-groups in so-called PCP-pincer complexes, which contain an organic molecule harbouring phosphorus-groups bound to a metal centre. These findings have given rise to the herein conducted project work, wherein a system analogous to that PCP-pincer complex, known as a POCOP-pincer complex, was proposed as a possible candidate for investigation of intermolecular C-C bond cleavage in this class of compounds, which would afford the very first example of such a reaction being successfully conducted. Thus, the required molecules used as ligands were synthesised and their reaction behaviour was thoroughly studied in the context of the desired activation, providing insight into whether this particular approach could prove promising in the future. 2020 eng C-C bond activation POCOP pincer cyclometallation inorganic chemistry organometallic chemistry Chemistry 9003878 2020-01-31T09:19:36+01:00 2020-02-25T12:50:12+01:00 2020-02-25T12:50:12+01:00

oai:lup-student-papers.lub.lu.se:9004317 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Fardous el-Sakka author 9004205 Haiyue Gong supervisor Pure and Applied Biochemistry v1000655 department Computational Chemistry v1000659 department The vision of protein purification is to be both efficient and environmentally friendly with the ability of reusage. This project has been focused on designing and synthesizing a functional composite material that can be used for protein purification. The material consists of silica particles coated with polydopamine, an affordable and easy synthesized material that can be reused. The ability of reusage is due to a dynamic bonding between polydopamine and azide modified boronic acid. The azide modified boronic acid is in turn bound to N-propargyl iminodiacetic acid which is a component with a triple bond able to bind a transition metal ion. <br /> <br /> This study has been able to prove that a histidine tagged lactate dehydrogenase (LDH) have an ability to bind to the transition metal on the synthesized material with an average of 40 mg protein per gram particles without any unspecific binding. No affinity has been showed to non-His-tagged protein. The ability of protein binding to the material has also been proved by measuring the enzyme activity of His-LDH where the specific enzyme activity increased for the eluted proteins compared to the crude protein sample. The silica with coated polydopamine have also been proved to be reusable by replacing the bonding between polydopamine and azide modified boronic acid using fructose molecules. These finding suggest that this material may be promising for protein purification in the future. Proteins are macromolecules with different functions in the human body. The process of characterization of proteins is important to study their function and structure but also to determine their amino acid sequence. This is important in the field of example drug development as more knowledge of the protein structure allows for more accurate and efficient treatments. For this to be carried out the proteins needs to be separated from a mixture of other components, for example other proteins. This process is called protein purification. <br /> In this work a material was designed and synthesized to be used for protein purification. https://lup.lub.lu.se/student-papers/record/9004317/file/9004319.pdf application/pdf 1292139 LU/LTH access 2020 eng Applied biochemistry Tillämpad biokemi Chemistry 9004317 2020-02-05T21:58:41+01:00 2020-06-12T13:56:54+02:00 2020-06-12T13:56:54+02:00

oai:lup-student-papers.lub.lu.se:9004771 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anna Eriksson author 9004769 Associate Professor Søren Rasmussen supervisor Department of Chemistry v1000647 department G protein coupled receptors (GPCRs) is the largest superfamily of membrane proteins and convert a multitude of extracellular signals and turn them into intracellular responses by binding and activating just a few G proteins. The mechanism for activation is very conserved and is likely to be similar for all GPCRs and G proteins, but how a vast amount of GPCRs selectively couple to specific G proteins is still unknown. Structural comparison of GPCR coupled to Gs and Gi1 respectively show similarities but also differences in conformational changes and interactions with G proteins upon activation. To this date we do not have structures of one GPCR coupled to different G proteins, structures that would be a corner piece in the puzzle of GPCR-G protein selectivity. The aim of this project is to solve the structure of β2AR coupled to a modified Gi1 with Cryo-EM in hope of better understanding of GPCR-G protein selectivity. Proteins were expressed using the baculovirus expression vector system and purified with various chromatographic methods. A complex was formed and isolated by SEC and then vitrified for data collection with Cryo-EM. As of now we have no finished structure due to problems during vitrification, but there are high hopes of succeeding with this in the future. G protein kopplade receptorer (GPCRs) är en grupp proteiner som sitter tvärsigenom cellernas membran med delar på både utsidan och insidan. Som namnet förtäljer så kopplar dessa receptorer till en annan sorts proteiner, G proteiner, och dessa hittas på insidan av cellen. Tillsammans översätter dom extracellulära signaler till intracellulära vilket till slut resulterar i specifika fysiologiska effekter. Vad effekten blir beror på vilket G protein som aktiveras och i vilken cell det händer. För att en GPCR ska aktiveras och i sin tur aktivera ett G protein behöver en så kallad ligand, vilket ofta är en liten extracellulär signalmolekyl, binda till receptorn på utsidan av cellen. Detta ändrar strukturen på receptorn vilket i sin tur resulterar i att den kan binda till G proteinet. <br /> GPCRs utgör en familj med väldigt stor mångfald och i det mänskliga genomet finns det ca 800 gener som kodar för dom. G proteiner däremot finns det inte lika många av. Hur dessa interagerar med varandra är komplext och en sorts G protein kan aktiveras av flera olika GPCRs. En sorts GPCR aktiverar en sorts G protein, så kallad primärt G protein, men kan även aktivera ett (eller flera) sekundärt G protein. Hur GPCRs och G proteiner känner igen varandra är fortfarande något av ett mysterium. <br /> Funktionen av ett protein är starkt kopplat till dess struktur. GPCRs har varit notoriskt svåra att bestämma strukturen på, och ännu svårare har det varit att bestämma den när den är bunden till ett G protein. Framsteg inom metoden Cryo-EM de senare åren har underlättat strukturbestämning av GPCR-G protein komplex, men trots dessa framsteg finns det fortfarande inga strukturer av GPCR kopplat till ett sekundärt G protein. Detta är en viktig pusselbit för att lösa mysteriet hur dom känner igen varandra. <br /> Att lösa detta mysterium är av vikt, dels för en grundläggande förståelse av reglering av livsviktiga fysiologiska processer, men även för utvecklingen av nya och bättre läkemedel. En stor del av läkemedlen på marknaden fungerar som ligander till GPCRs med målet att påverka dom fysiologiska effekter skapade av GPCR-G protein interaktioner. <br /> β2AR är en GPCR som bland annat har adrenalin som naturlig ligand och när det binder till denna receptor i släta muskelceller orsakar det relaxation, något som utnyttjas i bland annat astmamedicin då relaxationen i lungbronkiolerna gör luftvägarna större och underlättar andningen. β2AR är en väl studerad GPCR och har fungerat som något av en modell för den här gruppen proteiner. Strukturen av β2AR i komplex med dess primära G protein var en av det första strukturerna av GPCR-G protein komplex och förhoppningen är att vi med detta arbete ska åstadkomma den första strukturen av β2AR bundet till sitt sekundära G protein i hopp om att få större klarhet i mysteriet hur dessa protein känner igen varandra. https://lup.lub.lu.se/student-papers/record/9004771/file/9004772.pdf application/pdf 2190109 yes 2020 eng Protein science GPCR β2AR G protein Structural Biology Cryo-EM Proteinvetenskap Chemistry 9004771 2020-02-11T09:51:39+01:00 2020-04-17T14:39:29+02:00 2020-04-17T14:39:29+02:00

oai:lup-student-papers.lub.lu.se:9005358 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Alexander Braune author 9005353 Simon Kaufhold supervisor Department of Chemistry v1000647 department The aim of this study was the investigation of the photocatalytic properties of Iron{phenyl[tris(3-methylimidazole-2-ylidine)]borate}2 ([Fe(phtmeimb)2]+) by optimising reactions previously established with ruthenium-based catalysts in good yields. For the first time in several decades of research on photochemistry of iron complexes a Fe complex has been made ([Fe(phtmeimb)2]+) that has photophysical properties that are at least in some regards comparable to [Ru(bpy)3]2+, such as charge transfer excited states of high energy and nanosecond lifetime Therefore, we investigated photoredox catalysis with this complex. We investigated the photocatalytic performance of [Fe(phtmeimb)2]+ in aza-Henry and [2+2] cycloaddition reactions. Then optimisation was conducted to make [Fe(phtmeimb)2]+ viable in reactions where currently [Ru(bpy)3]2+ is used as a photocatalyst. For this the commercial photoreactor Photoredox Box from HepatoChem with 450 nm and 525 nm lamps was used and attempts were made to repeat the conditions of the literature reactions and secondly alter the reaction conditions so that [Fe(phtmeimb)2]+ becomes viable. The experiments were predominantly followed by NMR analysis with internal standard. <br /> Initial results from the [2+2] cycloaddition reactions suggest that the reductive pathway is not accessible by [Fe(phtmeimb)2]+ and further investigation should be made on the oxidative pathway. The aza-Henry reactions initially showed some promise. Although, after further control, it could not come close to the performance of [Ru(bpy)3]2+. However, it was found that the addition of a counterion (NH4PF6) showed increased yields in the reactions where [Fe(phtmeimb)2]+ was used. [Fe(phtmeimb)2]+ cannot replace [Ru(bpy)3]2+ as a photocatalyst (PC) so far and more research should be done to further enhance the photophysical properties of iron complexes. Photocatalysts – what are they?<br /> <br /> Most of us have heard of catalysts in one way or the other. One of the most prevalent catalysts that come to most people’s mind is the one in cars. Here, harmful gases formed in the combustion engine get transformed into less harmful substances before they are released to the environment. So how does this work? To keep it simple one might envision a trail over a mountain during a trek in the wilds. We start at our dangerous compound (A) and move over the mountain, requiring energy, and then arrive at our destination (B) which is the less harmful substances. A catalyst, in this instance, would lower the amount of energy it takes for us to cross from A to B. How this energy is reduced varies from catalytic system to system. Using the analogy of the mountain again: reducing the energy required to move from A to B could be done by reducing the height of the mountain (reducing the energy of activation between A and B). This is just one example in how a catalyst might work. Photochemistry might not be as prevalent in the minds of the masses and a short introduction is in order. Photochemistry deals with the chemistry involved with light, photons. It is a broad area that encompasses, among other thing, solar cells and chemical reactions driven by the energy from photons. One similar reaction that might come to mind is natural photosynthesis. Here a chromophore (in this case chlorophyll) initiates a charge transfer that drives chemical reactions at specialised catalytic units. A chromophore is a molecule or part of a molecule that can absorb photons. In some cases, a chromophore can function as a photocatalyst directly. So, what then, is a photocatalyst? Simply put, it is a molecule that catalyses a reaction (A to B) by the help of the energy of photons. Photons hit the photocatalyst which thereby gets excited. Simplified, this means that the energy of the molecule is increased until it decays back to the ground state. One decay path is the transfer of this energy to another system that could not have received this energy directly from the photons themselves. So how is a photocatalyst created?<br /> <br /> When creating a photocatalyst in a lab we focus on the chromophore and try to synthesise one that absorbs light energy, preferably in the visible spectrum, and can transmit this energy. A lot of research has already been conducted with ruthenium based photocatalysts as these have beneficial properties. One of the drawbacks of ruthenium is that it is a rare transition metal and hence not cheap or available for large scale projects. How can the cost be decreased while the scalability is improved? During the last couple of years researchers have investigated the properties of other, more abundant metal complexes. Our group has focused on iron chemistry and has reached milestones in the development of molecules that might be used to produce dye-sensitised solar cells, among other things. We are currently investigating said molecules ability to act as photocatalysts in a range of chemical reactions where ruthenium complexes have been used previously. The aim of this study is to map out the photocatalytic properties of one of the molecules synthesised in our lab that has recently been published. This will be done by synthesising the photocatalyst and substrates used during the reactions and optimising the reaction conditions. <br /> <br /> Preliminary results show that photocatalysis with iron complexes is not as straightforward as with standard photocatalysts. But the study shows that there might be a way to mediate these shortcomings. https://lup.lub.lu.se/student-papers/record/9005358/file/9005359.pdf application/pdf 1786828 yes 2020 eng Aza-Henry [2+2] Cycloadditions Iron based photocatalyst Photochemistry Organic chemistry Organisk kemi Chemistry 9005358 2020-02-19T14:43:37+01:00 2020-03-02T10:04:42+01:00 2020-03-02T10:04:42+01:00

oai:lup-student-papers.lub.lu.se:9005391 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Amanda Eriksson Skog author 8958471 Marie Skepö supervisor Mathematical Statistics v1000668 department Common departments, the faculties of Science and Engineering 000007000 department Department of Chemistry v1000647 department In this study, the two peptides Aβ40 and Aβ42, which are related to Alzheimer’s disease, was studied. The aim was to study them in bulk solution, to understand if, and in that case how, the two peptides differ in structure and aggregation be- haviours. To investigate the structure, all-atom moleuclar dynamics simulations were used, whereas the aggregation was studied using coarse-grained Monte Carlo simulations. Scattering curves obtained from both methods were compared with Small Angle X-ray Scattering data provided by Professor Hugh I. Kim. The obtained results showed no difference in aggregation between the two peptides. However, when increasing the ionic strenght of the solution, aggregation increased in both systems. The structure analysis showed minor differences between the pep- tides, where Aβ42 was shown to have some more β-type secondary structure ele- ments, however, both peptides were shown to consist mainly of coils, bends, and turns. The comparison of the scattering curves showed that the peptides produces in the coarse-grained Monte Carlo simulations was to compact compared to the re- sults obtained with all-atom molecular dynamics, as well as the experimental SAXS data. However, when comparing the latter two, the results overlapped nicely. Alzheimers sjukdom är den vanligaste orsaken till demens och omkring 100 000 svenskar beräknas lida av sjukdomen. Runt om i världen beräknas ungefär 50 miljoner människor lida av Alzheimers sjukdom. En peptid som är inblandad i sjukdomen är Amyloidβ som kan vara olika lång beroende på vilka APP-sekretas som klyver Amyloid-βproteinprekursor. I den här studien har de peptider med 40 (Amyloidβ40), respektive 42 aminosyror (Amyloidβ42) studerats.<br /> <br /> Amyloidβ-peptider aggregerar lätt, och bildar då plack eller fibriller bland nervcellerna i hjärnan, vilket skadar nervcellerna. Hos unga och friska individer kan kroppen lätt bryta ner dessa skadliga peptider så att nivån av dem i hjärnan inte är för hög, men hos äldre och/eller sjuka individer är nedbrytningen av peptiderna försämrad, och kan då lättare aggregera. Det finns också indikationer på att den längre peptiden, Amyloidβ42, driver på aggregeringen mer än den kortare.<br /> <br /> I den här studien undersöktes därför Amyloidβ40 och Amyloidβ42 i lösning för att undersöka om det finns några skillnader mellan hur de aggregerar, samt om det finns några strukturella skillnader mellan dem. För att göra detta har datorsimuleringar använts. För att studera aggergeringen av peptiderna har grovkorniga Monte Carlo simuleringar och all-atom molecular dynamics simuleringar har använts för att undersöka strukturen av peptiderna. Data från ljusspridningsexperiment erhållna från Professor Hugh I. Kim vid Korea University, Sydkorea, har använts i jämförelse med spridningskurvor erhållna från simuleringarna.<br /> <br /> Resultaten från de grovkorniga Monte Carlo simuleringarna visade ingen skillnad i aggregering mellan de två peptiderna, men hurvida det beror på att det inte är någon skillnad, eller om modellen inte var detaljerad nog för att fånga skillnaderna behöver undersökas vidare. Strukturanalyserna från all-atom molecular dynamics simuleringarna visade en liten skillnad mellan peptiderna, där Amyloidβ42 visades innehålla något mer av sekundärstrukturerna β-sheets och β-bryggor. Båda peptiderna visades dock ha mest oordnad struktur (coil och bends) och vändningar (turn), där den senare också kan räknas som en oordnad struktur. I jämförelsen mellan spridningskurvorna visades den grovkorniga Monte Carlo modellen ge för kompakta strukturer i jämförelse med resultaten från molecular dynamics simuleringarna. I jämförelsen mellan kurvorna från molecular dynamics simuleringarna med de experimentella ljusspridningsresultaten visades det att resultaten stämmer väl överrens. https://lup.lub.lu.se/student-papers/record/9005391/file/9005392.pdf application/pdf 2520756 yes 2020 eng IDP Amyloid beta Monte Carlo simulations molecular dynamic simulations Chemistry 9005391 2020-02-20T08:39:43+01:00 2020-03-06T14:16:05+01:00 2020-03-06T14:16:05+01:00

oai:lup-student-papers.lub.lu.se:9005987 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Erika Miegel author 9005959 Peter Spégel supervisor Centre for Analysis and Synthesis v1000651 department Adenosine tetraphosphate, or Ap4A, is a nucleotide with very interesting proposed biological effects. Previous studies have indicated that blood glucose levels in mammals might increase in the presence of Ap4A, and that Ap4A might antagonize pancreatic<br /> ATP channels. In order to study these effects further, a reliable method of separating Ap4A from other nucleotides in biological samples is required. This is made difficult by the high polarity and the high structural resemblance of different nucleotides. The<br /> aim of this study was to develop a method for separation of Ap4A from ATP and AMP on the Agilent Poroshell 120 HILIC-Z column, using conditions compatible with mass spectrometry.<br /> <br /> A method previously employed to separate simple nucleotides, using 10 mM ammonium acetate buffer at pH 9, a column temperature of 25℃, a flow rate of 300 µL/min, and a re-equilibration time of 33.3 minutes was used as a starting point. [1] In order<br /> to investigate the retention mechanism of the separation, an array of parameters (column temperature, mobile phase flow rate, re-equilibration time, buffer concentration, and mobile phase pH) were varied one by one while all the other parameters were held constant.<br /> <br /> Out of all evaluated parameters, increasing the buffer concentration to 20 mM was the only adjustment that had a positive effect on the separation. In this method two peaks were observed; one corresponding to ATP + AMP and the other corresponding to Ap4A, with a resolution of about 1.3. Furthermore, it was found that reproducible results could be achieved with a re-equilibration time as short as 8.3 minutes. På den ryske botanikern Mikhail Semyonovich Tsvets gravsten står det &quot;Han uppfann kromatografin, separerade molekyler men förenade folk&quot;. Hans metod för att separera molekyler används än idag - till exempel i detta arbete.<br /> <br /> Tsvets försöksuppställning bestod av en glascylinder fylld med kolsyrad kalk, samt en lösning som innehöll olika färgpigment från växter. En stund efter att han hällt pigmentblandningen i den kalkfyllda cylindern visade det sig att de olika färgerna hade delat upp sig som på bilden. Pigmenten hade nämligen olika kemiska egenskaper och hann därför rinna olika långt genom cylindern innan de fastnade i kalken. Tsvet kallade sin teknik för kromatografi efter grekiskans färgskrift. Idag utförs kromatografi med avancerade apparater under högt tryck, och kalk används inte längre som packningsmaterial, men principen är fortfarande densamma. <br /> <br /> Ibland kan ämnen med väldigt olika biologiska funktioner ha liknande kemiska egenskaper. Olika nukleotider, som till exempel adenosintrifosfat (ATP), är sådana molekyler. ATP minns du säkert som kroppens energivaluta, men det finns även mindre välkända nukleotider, exempelvis diadenosintetrafosfat (Ap4A). Ap4A liknar ATP i sin kemiska struktur, men tros till skillnad från ATP påverka utvecklingen av diabetes. För att undersöka denna molekyl måste man först separera den från andra nukleotider med hjälp av kromatografi, men eftersom kromatografi bygger på molekylers olika egenskaper är detta en utmaning. I mitt arbete har jag använt en speciell kromatografisk metod som kallas för HILIC - ungefär hydrofil kromatografi - för att utnyttja små skillander mellan olika nukleotider för att separera dem. Efter mycket arbete och en gnutta kromatografisk magi i labbet lyckades jag - nästan. https://lup.lub.lu.se/student-papers/record/9005987/file/9005988.pdf application/pdf 638157 no 2020 eng analytical chemistry HPLC HILIC chromatography technical analytical chemistry teknisk analytisk kemi Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/9005987/file/9005990.pdf application/pdf no 9005987 2020-03-02T22:10:50+01:00 2020-03-26T08:42:30+01:00 2020-03-26T08:42:30+01:00

oai:lup-student-papers.lub.lu.se:9006040 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mona Koder Hamid author 9006038 Marie Skepö supervisor Maria Jansson supervisor Department of Chemistry v1000647 department Clays are negatively charged nanoplatelets with a layered silicate structure. It has been<br /> observed from small angle X-ray scattering measurements, and coarse-grained molecular<br /> dynamics simulations (CG-MD) that clay nanoplatelets are able to form stacks, known<br /> as tactoids, in the presence of divalent or multivalent counterions [8, 5]. In this thesis, the<br /> interactions between clay nanoplatelets and counterions of varying valency was studied<br /> by the use of atomistic MD, which are of higher resolution than CG-MD. The particular<br /> systems studied here are the clay mineral montmorillonite (MMT) with sodium or calcium<br /> as counterions, as well as the addition of deca-arginine (Arg10), which is a cationic<br /> antimicrobial peptide (CAMP). Experimental studies and CG-MD, have shown that<br /> clays are able to sequester CAMPs within tactoids, thus indicating that it can be used<br /> as drug delivery vehicles for CAMPs [5]. The aim of this thesis was to investigate<br /> whether atomistic MD can be applied to study freely moving clay nanoplatelets and<br /> their interactions with CAMPs, to aid in the acquisition of knowledge of such systems.<br /> For this purpose the thesis is comprised of three studies of increasing complexity, simu-<br /> lating MMT systems with atomistic MD using the force field CLAYFF with the SPCE<br /> water model. In the first study, the distribution of sodium and calcium ions in the inter-<br /> layer between MMT surfaces was studied, where a qualitative agreement was found with<br /> previous studies. In the second study, two freely moving MMT nanoplatelets were simu-<br /> lated in the presence of either sodium or calcium ions. It was seen that the platelets had<br /> attractive edge-to-face interactions regardless of the cation valency, however attractive<br /> face-to-face interactions only occurred at high calcium content, above 100 mM, for the<br /> platelets that were initially placed in close proximity. Lastly, in the third study, systems<br /> of MMT and Arg10 were studied. The Arg10 chains were modelled with the CHARMM<br /> force field, and two water models were used, SPCE and TIP3P. The number of Arg10<br /> chains that adsorb to the platelets increased with concentration until saturation occurred,<br /> where the total charge of the Arg10 chains exceeded the platelet charge, resulting in over-<br /> charging, in agreement with experiments and CG-MD [5]. In addition, it is seen that<br /> individual Arg10 chains are able to interact with multiple platelets simultaneously, which<br /> may lead to intercalation within tactoids. However, atomistic MD of multiple platelets<br /> with Arg10, did not exhibit tactoidal formation. Therefore, the process behind tactoidal<br /> formation is likely more complex than what CG-MD suggests. Although, the simula-<br /> tions here indicate that atomistic MD may capture tactoidal formation given the right<br /> circumstances, such as the initial configuration. Further research is required to receive<br /> conclusive results of these systems, however, this thesis has shown that atomistic MD<br /> is a promising method for studying clay minerals and CAMPs, and may elucidate the<br /> complex interactions involved, which is difficult to capture with experiments and not<br /> available at atomistic resolution with CG-MD. Lera har vi alla kommit i kontakt med på ett eller annat sätt, men det vi kanske inte<br /> vetat om är att lera har flera fantastiska egenskaper som gör att det kan användas i<br /> många olika applikationer. De som sysslat med keramik är bekanta med att lera blir<br /> mjukt och formbart när det är blandat med vatten, men kan sedan hårdna när det<br /> värms och torkas, och då behålla den form den formats till. Det är denna egenskap<br /> som är själva definitionen av lera. Lera har även andra viktiga egenskaper som gör att<br /> det kan används i andra syften än inom keramik och bygge. Lera består av negativt<br /> laddade plattor av nanostorlek. Då lika laddning repellerar, så tenderar torr lera att ta<br /> upp vatten och svälla så att vattenlager kan sätta sig mellan plattorna och då minska<br /> deras repulsion. Dessutom, så adsorberar gärna positivt laddade joner och molekyler<br /> till ytan av lerplattorna för att neutralisera deras laddning. Flera farliga tungmetaller<br /> är positivt laddade, och därför används lera för att ta upp dessa metaller i rening av<br /> bland annat vatten. Lera används även för att förvara farligt radioaktivt avfall då dessa<br /> farliga ämnena också tenderar att fastna mellan lerplattor. På grund av leras spännande<br /> egenskaper finns ännu fler applikationer än de ovan nämnda, till exempel används lera<br /> som en komponent i plast och papper, och även i kosmetika och färgmedel. Lera är<br /> ett hett forskningsområde då lera är billigt och miljövänligt, och det finns möjlighet att<br /> användas i ännu fler applikationer.<br /> Det kan vara svårt att studera lera med experiment, och därför studeras det även till<br /> stor utsträckning med datorsimuleringar. En typ av datorsimuleringar är så kallade<br /> molekylär dynamiska (MD) simuleringar. https://lup.lub.lu.se/student-papers/record/9006040/file/9006041.pdf application/pdf 1614832 no 2020 eng clay molecular dynamics simulations physical chemistry fysikalisk kemi theoretical chemistry teoretisk kemi Chemistry 9006040 2020-03-03T21:40:25+01:00 2020-04-30T15:15:57+02:00 2020-04-30T15:15:57+02:00

oai:lup-student-papers.lub.lu.se:9008193 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Sofi Gummesson author 8958923 Thomas Brimert supervisor Department of Chemistry v1000647 department Overconsumption and abuse of alcohol are common causes of disabilities and disease. In some cases, it can even lead to premature death. To detect alcohol abuse and overconsumption of alcohol, medical history, patient symptoms and different biomarkers can be used.<br /> In this thesis the alcohol specific phosphatidylethanol (PEth) biomarker has been of interest. PEth is the collective name for a group of glycerolphospolipid homologues which are only created in the presence of ethanol in the body. To be able to detect and quantify the amount of PEth in a patient a reference molecule is needed. Through High Performance Liquid Chromatography (HPLC) a prepared blood sample, from the patient, and the reference molecule can be analysed. The commercially available reference molecule is a deuterium labelled PEth 16:0/18:1. Since PEth 16:0/18:1 has been shown to be the most common PEth homologue in patients it is therefore used as a reference molecule. <br /> Herein a new reference molecule to PEth with carbon-13 labelling has been suggested and synthesised. The synthesised carbon-13 PEth molecule has been evaluated at the university hospital in Lund (Anders Blomgren, Department of Clinical Chemistry, University Hospital of Lund), to compare if the new reference molecule is a better alternative than the commercially available one. Alcohol is a socially accepted drug in the western world and is something most of us encounter at social gatherings. Like most types of drugs, alcohol can lead to an addiction which has serious health problems and may lead to premature death. To be able to detect prolonged exposure to alcohol and alcohol abuse medical history, patient symptoms and biomarkers can be used.<br /> Biomarkers are measurable indicators which can be found in the body and can be used in medicine to indicate a state of disease. When investigating a patient long term exposure to alcohol biomarkers are becoming more frequently used as they are very reliable. There is one biomarker which has been of special interest since it is specific to alcohol, it is only present in the body if the person has consumed alcohol, called Phosphatedylethanol or PEth for short. By analysing a patient blood sample and comparing it to a reference molecule, a compound similar to the biomarker, the amount of biomarker can be distinguished and a diagnosis of the patient can be made. As biomarkers are being used more frequently new reference molecules are needed which are reliable and accurate. <br /> Herein a chemical synthesis of a new reference molecule for PEth, a carbon-13PEth reference, is described as well as improvements of the synthesis. The compound has been evaluated at the University hospital in Lund (Anders Blomgren, Department of Clinical Chemisty, University Hospital of Lund) to see if the carbon-13 labelled reference molecule is a more accurate reference molecule than the commercially available one. https://lup.lub.lu.se/student-papers/record/9008193/file/9008194.pdf application/pdf 1850498 yes 2020 eng Organic chemistry Organisk kemi Chemistry 9008193 2020-04-22T11:14:53+02:00 2020-07-06T13:56:36+02:00 2020-07-06T13:56:36+02:00

oai:lup-student-papers.lub.lu.se:9008213 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ludvig Gunnarsson author 8974283 Alexander Dahlqvist supervisor Department of Chemistry v1000647 department Introducing an N-sulfonylamidine substituent in galactose increased the selectivity for galectin-9N, a protein involved in functions of the immune system, and is believed to have roles in autoimmune diseases and cancer. In this work, a fast method for regioselective monoalkylation of galactose by microwave irradiation was developed, and eight potential galectin-9N inhibitors were synthesized. Molecular dynamics simulations proposed interactions deep into the binding pocket between the N-sulfonylamidine moiety and Asn48 and Asn137; two residues which are thought to be essential for selective binding to the N terminal of galectin-9. Evaluation of six of the eight novel N-sulfonylamidine galactoside derivatives showed selective, high-affinity binding to galectin-9N over galectin-1 and galectin-3. One of the N-sulfonylamidine galactoside derivatives were highly selective and stood out in the assays. Due to the molecules&#39; inherent high hydrophobicity, they were poorly soluble in water solutions and precipitated during binding affinity testing, and the correct binding affinity could not be determined. The improved affinity and selectivity of the novel N-sulfonylamidine galactoside derivatives provide important information for the development of novel galectin-9N inhibitors. Carbohydrates are not only used as an energy source in the body. The cell surface is covered in different sugar molecules, and one of these is galactose, to which the proteins called galectins bind with their carbohydrate-binding domain. To this day, fifteen different galectins have been discovered in vertebrates, and they bind to similar, but different galactose containing carbohydrates. The different galectins govern different cellular functions, like cell division and cell death, to name a few. When the galectins bind to their sugar of choice on the cell surface, they can, for example, initiate cell signaling in or between cells or cross-link to other proteins.<br /> <br /> The aim of this work was to synthesize artificial galactose derivatives that will bind stronger than the naturally occurring carbohydrates and only bind to one type of galectin proteins, galectin-9N. This protein has functions in the immune system, and diseases, such as arthritis and cancer, have been addressed to this protein. By creating inhibitors to galectin-9N, it may be possible to ease or even cure diseases caused by this protein.<br /> <br /> In this work, eight different inhibitors were synthesized, and a fast method for alkylation of galactose molecules was developed. This reaction usually takes everything from five to twenty hours to perform, but with the use of heating by a microwave reactor, the reaction time is significantly decreased to less than an hour. The binding to galectin-1, -3, and -9N by six of the eight synthesized inhibitors were evaluated. All inhibitors showed considerable binding to galectin-9N, and weak binding to galectin-1 and -3, and was, therefore, more selective than previously developed inhibitors. This selectivity is important only to affect one type of galectins to minimize side effects. 2020 eng Organic chemistry Medicinal chemistry Galectin-9N Organisk kemi Chemistry 9008213 2020-04-23T11:54:00+02:00 2020-05-14T11:14:19+02:00 2020-05-14T11:14:19+02:00

oai:lup-student-papers.lub.lu.se:9008770 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Elin Wenker author 9008768 Cecilia Dahlgren supervisor Department of Chemistry v1000647 department In this project the effect different water qualities had on water-based paint products were investigated. Tap water was used as a control and deionised and distilled water were used to determine whether the water purity had an impact on the quality of the finished paint products. <br /> One intermediate and five finished products were used to investigate the effect of water purity. The intermediate was used in all finished products in the project. The quality of these paint products were determined by measuring density, pH, viscosity, solid content, gloss, colour and tint strength. Each finished product were produced in five batches for each water quality and then the controls specified for each product were performed on each batch to check the quality. <br /> In conclusion the results did not show any notable correlations between water purity and the quality of the finished products. However since tap water has varying quality over time it could still be relevant for the company to continue looking into the effect of water purity. I detta examensarbete har man undersökt hur olika renheter på vatten påverkar kvaliteten på vattenbaserade färgprodukter. Man har använt sig av två olika renade vatten och kranvatten som kontroll. De renade vatten som användes var avjoniserat vatten och destillerat vatten. Avjoniserat vatten renas genom filtrering och destillerat vatten renas genom kokning och uppsamling av vattenångan. <br /> Kvaliteten på färg kontrolleras genom viskositet, glans, densitet, torrhalt, kulör, brytstyrka och pH. Viskositet beskriver hur trögflytande en vätska är. Detta är viktigt för appliceringen av färgen. Glans beskriver hur mycket ljus som reflekteras av den torkade färgproduktens yta. Då olika kunder använder färgen till olika ändamål, så har de behov av olika glans på sina färgprodukter. Densitet beskriver hur tung en vätska är per volym. Torrhalt beskriver hur stor andel fasta partiklar mot vätska en färgprodukt innehåller. Kulören beskriver nyansen som färgprodukten har. Brytstyrka beskriver hur stora de fasta partiklarna i en färgprodukt är. Detta är viktigt då det påverkar kulör när kunder nyanserar färgen själva. pH beskriver hur sur/basisk en produkt är. <br /> Färg är uppbyggt av flera olika substanser. Grunden består av antingen bindemedel, vatten eller båda. Förtjockare används för att uppnå rätt viskositet. Pigment av olika slag används för att få rätt kulör. Titandioxid används för att få vit kulör. Olika additiv och lösningsmedel används för att få rätt yta och torktid.<br /> I projektet valde man att undersöka ett halvfabrikat och fem slutprodukter. Halvfabrikatet var en vitpasta, som användes i alla slutprodukter man kollade på. En vitpasta är en vit bas som man använder för att pigmentera produkter. Att använda halvfabrikat underlättar för produktionen och säkrar kvalitén hos slutprodukter. Slutprodukterna tillverkades med alla tre olika renheter på vatten för att undersöka om man kunde se något samband mellan kvalité och vattnet. <br /> Sammanfattningsvis kunde man inte se något samband mellan vattnets renhet och färgprodukternas kvalité. Men i kranvatten tillsätts olika ämnen under året för att minska mängden bakterier och justera pH. Detta innebär att kranvatten har olika renhet beroende på vilken tid på året man kollar. Därför kan det förbättra kvalitén på färgprodukter över tid om man använder ett renat vatten i industrin, men man skulle behöva utföra fler tester över längre tid för att ta reda på om detta är fallet. https://lup.lub.lu.se/student-papers/record/9008770/file/9008773.pdf application/pdf 932447 yes 2020 eng Paint quality water purity Sherwin Williams AB water-based paint physical chemistry fysikalisk kemi Chemistry 9008770 2020-05-11T15:10:31+02:00 2020-05-19T08:14:23+02:00 2020-05-19T08:14:23+02:00

oai:lup-student-papers.lub.lu.se:9009011 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Tiago Bozzola author 9009009 Ulf Nilsson supervisor Department of Chemistry v1000647 department According to the World Health Organization (WHO), antibiotic resistance is a serious threat to our society. Infections with multi-resistant bacteria are causing increased mortality and social costs. Few new drugs are in the pipeline and no prospective of significantly improving the situation seems to be present. <br /> Sialic acids are a wide family of acidic sugars found in the terminal position of glycan chains. Due to their terminal position and abundance in glycoconjugates, sialic acids are responsible for a wide range of physiological and pathological processes such as cell interaction, communication and information transfer. Bacteria are not able to biosynthesize sialic acid and thus utilize host-derived sialic acid for different purposes. In the first place, bacteria catabolize sialic acid as a convenient source of carbon and nitrogen. Additionally, some pathogenic bacteria have developed mechanisms to glycosylate their lipopolysaccharides (LPS), masking them from the human immune system. This immune-evasion mechanism is called “molecular mimicry”.<br /> A recent collaboration has led to the characterisation of a bacterial sialic acid transporter, a sodium solute symporter (SSS) protein. The aim of the collaboration is the development of sialic acid derivatives with high affinity for the SSS protein and other sialic acid transporters. Inhibiting the sialic acid uptake was proved to block bacterial growth and reduce bacterial resistance to human serum. Sialic acid uptake inhibitors may be a brand-new type of antibiotic agents and thus be new tools in the antibiotic resistance fight. <br /> In this thesis, I focused on the synthesis of 9-C and 3-OH N-acetyl neuraminic acid derivatives, the most abundant sialic acid. The work on position 9 led to the synthesis of five derivatives, characterized by the presence of different functional groups to establish a Structure-Activity Relation (SAR) approach. This work produced the first sialic acid derivative able to bind the SSS protein with higher affinity compared to natural ligands. Furthermore, a synthetic path to develop 3-OH derivatives was tested and found highly reliable, even though no final compound was isolated. According to the World Health Organization (WHO), antibiotic resistance is a serious threat to our society. Infections with multi-resistant bacteria are causing increased mortality and social costs. Few new drugs are in the pipeline and no prospective of significantly improving the situation seems to be present. <br /> Sialic acids are a wide family of acidic sugars and are responsible for a wide range of physiological and pathological processes such as cell interaction, communication and information transfer. Bacteria are not able to biosynthesize sialic acid and thus utilize host-derived sialic acid for different purposes. In the first place, bacteria catabolize sialic acid as a convenient source of carbon and nitrogen. Additionally, some pathogenic bacteria have developed the ability to use host sialic acid to avoid the human immune system, in a mechanism called “molecular mimicry”.<br /> In this thesis, I have worked on the synthesis of sialic acid derivatives. The aim is to fight the utilisation of sialic acid by bacteria, thus developing molecules with potential antibacterial properties. https://lup.lub.lu.se/student-papers/record/9009011/file/9009013.pdf application/pdf 8012970 yes 2018 eng Sialic acid medicinal chemistry antibiotics organic chemistry organisk kemi Chemistry 9009011 2020-05-15T10:42:56+02:00 2020-05-19T08:21:59+02:00 2020-05-19T08:21:59+02:00

oai:lup-student-papers.lub.lu.se:9099880 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Simone Facchini author 9099878 Dong Pan supervisor Department of Chemistry v1000647 department In a world where the problem of energy resources, pollution and all aspects related to these issues becomes more and more dominant, a greater commitment is needed in the search for solutions. The goal of this project is to make a contribution to the research and development of new materials to reduce the environmental impact in some fields. First of all, we tried to synthesize and prepare an isatin-based membrane which has the potential for use in separating industrial gases. Furthermore, ion exchange membranes, specifically hydroxide exchange membranes (HEMs) derived from the same material were developed for fuel cells (HEMFC) applications. These materials are essential for energy conversion and storage. The most difficult challenge is to guarantee their thermal stability and stability in corrosive environments such as alkali without losing efficiency. In recent years the polyhydroxyalkylation catalysed with superacids, e.g. TFSA, has become increasingly studied. This reaction is exploited for the synthesis of the compounds of this thesis. After a preliminary optimization of the reaction conditions it was concluded that, due to the rigidity and excessive reactivity of the monomers, it was not possible to obtain the isatin-based membrane to evaluate the gas separation properties. The synthesis of precursor materials for HEMs was successful. Instead of isatin, 1-(4-bromobutyl)indoline-2,3-dione (BID) was used as a substitute. A characterization of the polymers was carried out using NMR, TGA and DSC analyses, and subsequently the membranes were functionalized with different ammonium-based cations. Unfortunately, this last step was not successful due to the appearance of side reactions. Future studies on the mechanism and kinetics of the reaction may solve this obstacle. It is no secret that one of the biggest problems of modern times is climate change. This topic has been avoided for many generations and in recent years all industries and the world of marketing have begun to move and raise awareness on this issue. There is already much evidence that links the connection between man-caused damage to the environment and increasingly frequent natural disasters. The increase in temperature due to the accumulation of carbon dioxide in the atmosphere has not only impacted the climate but also the life cycle of the animals. Related to that it is estimated that some species have been forced to change the place where they generally resided and move closer near inhabited centres, bringing new contacts and the onset of new diseases. The solution being adopted is the search for renewable energy sources such as solar, hydrogen and bio fuels, and the development of new technologies green-energy based. However, compounds such as membranes, capable of energy converting economically and efficiently, must support these technologies.<br /> One of the most energy-intensive industrial processes is the selective separation of the components of a gas or a liquid gas stream. The classic methods such as extraction, distillation and absorption are essential and not very green. For this reason, an alternative solution was sought. The separation of gas mixtures employing polymeric membranes has been commercially utilized since the late 1970s. While the ability to separate gas mixtures was recognized much earlier, the commercial reality has only recently generated a significant amount of academic and industrial research activity. Membrane separation has many advantages such as low energy consumption, economy and versatility. Another area of emerging importance for these materials is the recapture of CO2 from industrial processes. For these reasons, we have in this work tried to design an isatin-based membrane for this purpose. There are various problems in the synthesis mechanism that did not allow control over the product structure. What was supposed to be a flexible film turned out to be fragile and of low quality and therefore unusable as it was initially thought.<br /> The other field that this work was aimed at is that of fuel cells. Briefly, these are electrochemical devices that allows to obtain electrical energy directly from certain substances, typically from hydrogen, without any thermal combustion process-taking place. Between the anode and cathode there must be a means of connection between the two parts. Generally, this connection is composed of a liquid, but many polymeric membranes that can replace them are being studied. In our specific case, we are talking about anion exchange membranes (AEM), consisting of a neutral polymeric backbone to which positively charged chemical groups are attached. These, generally quaternary ammonium salts (QA), are responsible for the transport of anions, and therefore of the current, inside the batteries or fuel cells. In this project, a less reactive isatin derivative was synthesized and polymerized. The membrane precursor had the same problem found in the first part of the study. In addition, this time a side reaction prevented the functionalization of the polymer. The usage of this polymer need a more in-depth analysis of the reaction mechanism.<br /> To summarize, the work focus on two main topics, the synthesis of a gas separation membrane and an AEM. The successful optimization of the reaction conditions led to obtaining the polymeric compounds. The quality of the isatin polymer films were brittle and not enough to provide films for gas separation characterizations. The functionalization reaction of the polymer for AEMs was unsuccessful. The thermal and structure characterization using TGA and NMR analysis had provided a likely explanation about the reasons of the problems encountered. https://lup.lub.lu.se/student-papers/record/9099880/file/9099888.pdf application/pdf 3097385 2023-09-01 no 2022 eng organic chemistry membranes isatin polymers Chemistry 9099880 2022-09-12T09:46:15+02:00 2023-09-01T03:45:17+02:00 2022-09-13T14:37:55+02:00

oai:lup-student-papers.lub.lu.se:9100198 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Simon Edin author 9024313 Anna Lidskog supervisor Department of Chemistry v1000647 department Hydrogen bonding based self-assembly is prevalent throughout nature dictating the folding of proteins and DNA. Hydrogen bonding has been utilized for self-assembly of small monomers into aggregates of varying size and shape. Potential applications of these aggregates could be creation of ion channels, formation of inclusion complex for delivery of drugs or capture of hazardous material in water supplies. In this project, two monomers based on an enantiopure C2-symmetric bicyclic cleft compound with varying hydrogen bonding motifs and solubilizing groups were successfully synthesized. One of the monomers contains alkyl solubilizing groups and have previously been shown to self-assemble into tetrameric cyclic, polymeric tubular or capsule aggregates depending on solvent conditions. The other monomer contains a polyethylene glycol-substituted solubilizing groups and hydrogen bonding motifs which should allow for tetrameric and pentameric cyclic self-assembly. The different solubilizing groups were introduced to allow for comparison of solubility and self-assembly behavior of the monomers, with the ultimate goal of increasing the water solubility of the monomers and thus enabling biological applications. The focus on this project was the synthesis of the two monomers, and self-assembly studies were beyond the scope of this project. The syntheses consisted of two eight-step synthetical pathways. All new compounds were characterized by HRMS, OR, IR, 1H NMR and 13C NMR spectroscopy, and elemental analysis. Supramolekulär kemi är ett fält inom kemi där samlingar av molekyler som hålls ihop av olika ickebindande interaktioner mellan molekylerna studeras. Dessa bindingar kan ses som två legobitar som sätts ihop, där legobitarna är molekylerna och det ickebindinade interaktionerna är passformen som håller dem på plats. Legobitarna kan tas isär med mindre kraft än vad det krävs för att dela en bit lego. En av dessa ickebindande interaktioner är vätebindingar som är relativt starka och riktade interactioner mellan ett väte bundet till en heteroatom och en annan heteroatom. I denna rapport har vi satt vätebindande delar på molekyler för att kunna bygga olika former i lösning (aggregat). Tidigare forskning från Wärnmark gruppen har visat att aggregaten kan bilda ringar av fyra eller fem molekyler, dessa ringar kan under rätt förhållande bygga rör genom att de staplas på varandra. Ett annat exempel av de möjliga aggregaten skulle vara så kallade inklusionskomplex där en gästmolekyl omsluts av flera av dessa molekyler för att bilda en kapsel. Dessa kapslar kan få molekyler som normalt sätt har dålig löslighet att lösa sig, lite som hur tvål bildar stora bubblor runt fett för att få det vattenlösligt. Tidigare molekyler har haft dålig vattenlöslighet och därför har en av de molekyler ändrats för att ge högre vattenlöslighet. En ökad löslighet i vatten skulle kunna tillåta användning i biologiska system för till exempel inklusionskomplex runt läkemedel för att öka lösligheten av svårlösta läkemedel eller göra så kallade jonkanaler. En jonkanal är ett rör genom ett cellmembran som joner kan passera igenom. Detta rör skulle kunna bildas av flera staplade ringar som i tidigare exempel. https://lup.lub.lu.se/student-papers/record/9100198/file/9100359.pdf application/pdf 2832333 yes 2022 eng Organic chemistry supramolecular chemistry H-bond self-assembly monomer Chemistry 9100198 2022-09-14T22:51:59+02:00 2022-09-20T10:57:25+02:00 2022-09-20T10:57:25+02:00

oai:lup-student-papers.lub.lu.se:9100729 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Noemi Ferrante Carrante author 9100727 Emma Sparr supervisor Department of Chemistry v1000647 department α-Synuclein is an intrinsically disordered protein implied in still not-well-known healthy function and also found as the main component of aggregates in Lewy bodies and Lewy neurites, hallmarks of the Parkinson’s disease. In both of cases, the interaction with lipid membranes is crucial. In this study we propose the investigation of the interaction between α-Synuclein and model systems made of DOPC:DOPS (7:3 molar ratio) in a wide range of condition in order to evaluate the cooperativity of α-Synuclein in lipid membranes binding. Cooperativity is a widespread concept in biochemistry since it is related to many metabolic pathways, signaling and transport processes. In a cooperative event the binding of one molecule onto a surface enhances the affinity of the next binding event on the same surface, resulting in a non-random distribution. Cooperative binding of α-Synuclein in lipid membranes was already found for the same system in MES buffer at pH 5.5. Here we systematically changed parameters such as pH, ionic strength and amino acidic sequence in order to evaluate the cooperativity, by means of confocal laser scanning microscopy, circular dichroism and fluorescence cross correlation spectroscopy. Both small unilamellar vesicles as well as giant unilamellar vesicles were used as model systems. The binding was observed for all the conditions investigated and, in addition, for some of them fluorescence cross correlation spectroscopy and confocal microscopy proof a positive cooperative binding in excess of vesicles. All biochemical reactions in our bodies are finely controlled in order to guarantee its healthy function. When this does not happen, pathologies can occur. Proteins and lipids are the building blocks of our body so that a mis-regulation in their interaction can lead to the onset of severe diseases.<br /> In this study the focus was given to α-Synuclein and its interaction with model systems act to mime lipid membranes. α-Synuclein is a neuronal protein localized in vivo in synapses where signaling, of electrical or chemical nature, happens. Although the role of α-Synuclein is not fully understood, it has been hypothesized that this protein may take part to the synaptic plasticity, to neurotransmitter release and to other important event implied in the maintenance of cells health. On the other hand, excess of α-Synuclein cause the formation of insoluble aggregates which are hallmarks of aberrant neurodegenerative disease. Parkinson’s disease is characterized by the presence of Lewy Bodies and Lewy Neurites which are mainly composed of α-Synuclein as well as lipids.<br /> In this work, we investigated the interaction between α-Synuclein and lipid membranes in a wide range of condition. In addition, this study was born in the wake of precedent findings made on the same system in fixed conditions. Here we systematically varied physical chemical conditions such as pH, ionic strength, and amino acidic sequence. We have found that the binding of α-Synuclein with lipid membranes is cooperative under some conditions just as it has been proven in precedent studies in different conditions.<br /> Cooperativity is a common key-word in the biological world. Many different biochemical pathways are characterized by this mood of binding. In a cooperative event we expect that the binding of the first molecule enhance the affinity of binding of another molecule on the same surface. Translating this to our system, in such conditions, we expect some vesicles to be completely empty and others full of protein.<br /> We believe that this study can be a good starting point to positively contribute to a deeper understanding of mechanism behind both the healthy and the pathologic function of α-Synuclein. 2022 eng Physical Chemistry a-synuclein Cooperativity Chemistry 9100729 2022-09-22T14:35:43+02:00 2022-09-26T11:14:44+02:00 2022-09-26T11:14:44+02:00

oai:lup-student-papers.lub.lu.se:9101146 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Hedvig Ekfors Elvin author 9101144 Martin Ek supervisor Karin Blume supervisor Niklas Mårtensson supervisor Søren Echwald supervisor Centre for Analysis and Synthesis v1000651 department Introduction: GaP nanowires were functionalized using silane-PEG-NH2 and compared with cellulose acetate, PAcrAm™-g-(PMOXA, amine, silane) and a non-functionalized reference sample. Functionalization would allow strong, covalent anchoring of antibodies instead of adsorption.<br /> <br /> Aim: The thesis work focused on deciding on, and optimizing, a protocol for nanowire surface modification of the three mentioned functional compounds.<br /> <br /> Methods: The different surface treatments were qualitatively compared using optical microscopy. The fluorescence of the different samples was analyzed using a full-factorial DOE of four concentrations of each functionalization incubated in four different concentrated antibody solutions. The functionalizations&#39; success and the protocol alterations&#39; impact were validated using SEM and TEM imaging.<br /> <br /> Results: The functionalized samples had considerable drying effects following the initial treatments, visible in the optical microscope and SEM. All protocols were altered to allow slow drying, by covering the Petri dishes with a lid, resulting in significantly decreased drying effects. The detected fluorescent signal was higher for the silanized samples compared to the other functionalities and the reference. However, all functionalized samples without antibodies did reveal an exceedingly high signal, indicating cross-contamination. Further TEM examination of the different samples revealed that none of the functionalized nanowires had any additional compound on their surfaces. This indicates unsuccessful surface treatments for all functional compounds or functionalization of a small fraction of the sample, thus requiring a more extensive TEM analysis.<br /> <br /> Conclusion: The surface treatment protocols were improved by implementing slow drying. However, a more extensive TEM examination is required to quantify the extent of the different surface modifications. Furthermore, repeats of the final protocol are required to validate the possible signal-enhancement observed for the silanized nanowires. There are 104,000 people in the UK, aged 0-40, who are living with a life-limiting or life-threatening disease.[1] There are 300-400 million people in the world living with a rare disease, with 50% of them being untreated for decades. These diseases may be life-limiting or life-threatening, and almost always reduce the quality of life.[2, 3] Imagine a medical test that could detect these conditions at early stages, potentially saving many lives[4] and increasing the quality of life because the right treatment is provided. One newly developed immunological test, a.k.a. immunoassay, can according to Aligned Bio AB detect biomolecule concentrations 20 times lower than medical tests (e.g. ELISA) used today. These tests bind fluorescently labelled antibodies, antigens or biomarkers to signal-enhancing nanowires. The aim of my thesis was to come up with a protocol for surface functionalization of nanowires and investigate the potential signal effects.<br /> <br /> Samples containing GaP nanowires grown in parallel rows and columns had already shown astonishing signal-enhancing properties when bound to fluorescently labelled biomolecules. All GaP nanowire samples were covered with a thin SiO2 layer, as this compound is commonly used for immunoassays because they readily bind to biomolecules such as antibodies.[5] The thesis work investigated the effect of surface modification of GaP/SiO2 nanowires. The hope was for these modifications, or functionalizations would create a strong covalent linkage between the investigated antibody and the nanowire surfaces. Theoretically, this would allow harsher washing procedures and utilize a stable bond in order to prolong the shelf life. A harsher washing procedure may decrease the background noise which would result in a decreased limit of detection (LOD). A lower LOD allows the detection of smaller biomolecule concentrations. A longer shelf life stabilizes the nanowire samples, preventing the nanowire-biomolecule complex from breaking down before analysis. [5, 6, 7]<br /> <br /> The compounds used to modify the nanowire surfaces were silane-PEG-NH2 and compared with cellulose acetate, PAcrAm™-g-(PMOXA, amine, silane). These were chosen because of their ability to covalently bind to SiO2 and the fluorescently-labelled antibody used. These compounds also have antifouling properties, meaning that their chemical composition prevents unwanted molecules from binding.[6, 7] A nonfunctionalized sample was also used, where antibodies were adsorbed directly onto the nanowires. The protocol for functionalizing nanowire surfaces was based on literature done on flat surfaces. The protocol for PAcrAm™ was based on recommendations from the manufacturer because it is relatively new on the market and without many relevant references in the literature.<br /> <br /> The main issue with all functionalization processes was the drying effects that appeared on all samples in optical microscope and scanning electron microscope (SEM). Drying effects indicate that uneven evaporation of the solvent occurred, thus creating an uneven film thickness formed around the nanowires. The protocol, therefore, had to be altered in order to increase the diffusion and allow slow drying. This was done by incubating the samples on see-saw shakers and drying the samples inside a Petri dish with lid on. This decreased the drying effects significantly. Furthermore, the detected fluorescent signal was higher for the silanized samples compared to the other functionalities and the reference. However, the control sample for all functionalized samples, which did not contain any fluorescing antibodies, did reveal a considerably high signal. The most likely reason behind this high signal is cross-contamination, invalidating all fluorescent results for the functionalized samples. Further transmission electron microscope (TEM) examination of the different samples revealed that none of the functionalized nanowires had any additional compound on their surfaces. These results reveal unsuccessful surface treatments for all functional compounds. The lack of functionalization compounds on the nanowire surfaces could also be a result of functionalization of a small fraction of the nanowires on each sample. A more extensive TEM analysis is therefore required to analyze a larger number of nanowires.<br /> <br /> References<br /> 1 How many children and young people are affected by a life-limiting or life-threatening condition? [homepage on the Internet]. Together for Short Lives; [updated 2018 Jan; cited 2022 Sep 1]. Available from: https://www.togetherforshortlives.org.uk/app/uploads/2018/01/ProRes-How-<br /> Many-Children-Young-People-Affected-By-A-Life-Limiting-or-Life-Threatening-Condition-Factsheet.pdf.<br /> 2 Horizon - the EU Research and Innovation Magazine [homepage on the Internet]. European Commission;[updated 2022 Feb 2; cited 2022 Apr 26]. Expanding research into rare diseases. Available from: https://ec.europa.eu/research-and-innovation/en/horizon-magazine/expandingresearch-rare-diseases.<br /> 3 Marwaha S, Knowles JW, Ashley EA. A guide for the diagnosis of rare and undiagnosed disease: beyond the exome. Genome Medicine. 2022;14:2–23. Available from: https://doi.org/10.1186/s13073-022-01026-w.<br /> 4 Harvard Health Publishing [homepage on the Internet]. Robert H. Shmerling; [updated 2021 Jan 28; cited 2022 Apr 26]. Are early detection and treatment always best?. Available from: https://www.health.harvard.edu/blog/are-early-detection-and-treatmentalways-best-2021012821816.<br /> 5 Verardo D, Lindberg FW, Anttu N, Niman CS, Lard M, Dabkowska AP, et al. Nanowires for Biosensing: Lightguiding of Fluorescence as a Function of Diameter and Wavelength. Nano Lett. 2018;18:47964802. Available from: http://dx.doi.org/10.1021/acs.nanolett.8b01360.<br /> 6 Migliorini E, Weidenhaupt M, Picart C. Practical guide to characterize biomolecule adsorption on solid surfaces (Review). Biointerphases. 2018;13:06D303. Available from: https://doi.org/10.1116/1.5045122.<br /> 7 Suwatthanarak T, Thiodorus IA, Tanaka M, Shimada T, Takeshita D, Yasui T, et al. Microfluidic-based capture and release of cancer- derived exosomes via peptide–nanowire hybrid interface. Lab Chip. 2021;21:597–607. Available from: http://dx.doi.org/10.1039/d0lc00899k. https://lup.lub.lu.se/student-papers/record/9101146/file/9101173.pdf application/pdf 125222317 no 2022 eng Functionalization Nanowires Silanization Surface Chemistry Materials Chemistry Chemistry 9101146 2022-09-30T09:18:03+02:00 2022-10-11T14:54:12+02:00 2022-10-11T14:54:12+02:00

oai:lup-student-papers.lub.lu.se:9101260 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Emanuela De Carlo author 9099750 Peter Jönsson supervisor Department of Chemistry v1000647 department One of the main contributors in the immune system are T cells. The exact molecular mechanisms behind T cell activation are not yet fully understood but it starts through the contact between the T cell and an infected cell. In order to study such interaction, supported lipid bilayers (SLBs) are used to mimic cell membranes and to reduce its complexity but still retaining the fundamental property of lateral mobility. The project was based on two different systems for adhering T cells to SLBs which do not make use of specific adhesion proteins that are not easily available commercially: (i) SLBs with RGD moiety and (ii) SLBs with biotinylated antibodies bound to the SLB via biotin-streptavidin binding.<br /> Jurkat E6-1 cells transfected with the rat CD48 were found to not bind the SLB with RGD moiety because of low levels of integrin expression. This system, however, could be used for the adhesion of different cell lines, as the mobility of the lipids ensured the formation of a homogeneous and fluid SLB that mimicked the cell membrane. For SLB with antibodies, the immobile fraction of streptavidin (SA) in the SLB increased from 15 to 80% upon addition of antibodies suggesting the binding and a possible cross-linking of SA with antibodies. Using an SLB with SA and anti-rCD48, Jurkat’s adhesion fraction was 75% when a concentration of 800ng/mL of SA was used and 41% with a lower concentration (150 ng/mL). With the latter concentration, it was also possible to visualize the recruitment of anti-rCD48 within the contact area.<br /> This system was not able to activate T-cells significantly, yielding a suitable platform for T cell adhesion without employing not purified protein ligands. We are continually exposed to pathogens, such as bacteria and virus which can causes diseases. Our body’s defense mechanism is called immune system which consists of different cells that can distinguish between healthy cells and infected cells, killing the latter or activating mechanisms that lead to their elimination. One specific type of immune cells is called T cells. Their surface presents an important receptor (TCR), molecule that recognize and bind specific molecules, and other proteins that play a fundamental rule in the formation of a cell-cell contact. T cells are activated when TCRs recognize and bind molecules of pathogens that are presented by a second receptor called major histocompatibility complex (MHC) on other cells called antigen presenting cells (APC).<br /> The molecular mechanisms of T cell activation are complex and not yet fully understood. The initial process involves phenomena occurring on the surface of the T cell and the infected cell; through a series of cascading processes, the activation of the cell occurs. With the purpose of facilitating such studies that this work focused on build generic system that had the ability to adhere T cells onto a supported lipid bilayer. Supported lipid bilayers (SLBs) are models used to mimic the cell membrane; they consist of two layers of lipids linked together through particular interactions that are deposited onto a solid support (e.g. glass). To mimic cell membranes, the lipids that make up the SLB should be mobile, that is, they should move laterally within the bilayer. Therefore, for all systems devised, the mobility of the SLB was analyzed.<br /> For adhesion to occur, the SLB must contain molecules that can be recognized by other T-cell molecules, for example, by TCR, adhesion proteins or other receptors.<br /> Therefore, the first system devised saw an SLB containing 3 amino acids that are recognized and bound by integrins, proteins found on the surface of T cells. This type of system did not lead to T- cell adhesion on the SLB because of the small amount of integrins present on the surface of the cells I studied.<br /> Another system was an SLB decorated with antibodies, molecules that have the ability to specifically bind other targets. Hence antibodies with the ability to bind TCR and other T-cell proteins were used, resulting in a good percentage of adhered cells.<br /> For the latter system, its ability to activate cells had also been analyzed. The system composed of antibodies specific for a protein not involved in activation had a low ability to activate cells. For this reason, the system could be a suitable platform for adhesion of T cell and used for future studies on activation. 2022 eng T-cells supported lipid bilayers biochemistry Chemistry 9101260 2022-10-03T21:47:56+02:00 2022-10-04T11:37:54+02:00 2022-10-04T11:37:54+02:00

oai:lup-student-papers.lub.lu.se:9102373 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Erik Friberg author 9102371 Niklas Andersson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department The purification process of monoclonal antibodies (mAbs) for therapeutic drugs is expensive, especially the chromatography step in which the mAbs are separated from other proteins and cells present in the feed. The antibodies are separated from the feed using affinity chromatography, where only the antibodies interact with active sites within the column, whereas the rest passes through the column without stopping. The antibodies leave the column when their chemical environment is changed, and the column is cleaned thoroughly with strong chemicals. <br /> The chemicals are essential in the cleaning process to ensure that there is no contamination between cycles or that there are any antibodies left. The chemicals are however slightly damaging the column, and after many cycles of loading with mAbs, eluting the mAbs and then cleaning, the capacity of the column is reduced. <br /> In this master thesis, periodic counter-current chromatography is modelled and simulated in python with columns that exhibit degradation. Two different controllers and a flow trajectory method is applied, to varying degrees, in different cases to investigate if they can counteract some of the problems that emerge due to the column degradation. <br /> To evaluate the effectiveness of the controllers and the flow trajectory, the performance process variables productivity, yield, and resin utilization were used. <br /> The best case used both controllers, the flow trajectory and had a productivity at 0.18 mg mAb per ml resin and minute, a minimum yield of 94.7% and a maximum resin utilization of 62.5 mg mAb per maximum amount adsorbed mAb at feed concentration. Uppreningsprocessen av monoklonala antikroppar (mAbs) är dyr, speciellt det kromatografisteg där antikropparna separeras från andra protein och celler i lösningen från tidigare steg i processen. Antikropparna separeras från lösningen med hjälp av affinitetskromatografi, där det endast är antikropparna som interagerar med innehåller i kolonnen och stannar kvar, medan resten passerar obehindrat. Antikropparna lämnar kolonnen när den kemiska omgivningen förändras och samlas upp, och kolonnen rengörs med starka kemikalier. <br /> De starka rengöringskemikalierna är nödvändiga för att säkerställa att den inte sker någon kontaminering mellan cykler och att det inte sitter kvar några antikroppar. Kemikalierna skadar dock kolonnens innehåll något, och efter många cykler av antikroppupprening och rengöring, har kapaciteten hos kolonnen minskat.<br /> I detta examensarbete har periodisk motströmskromatografi (PCC) modellerats och simulerats i programvaran Python tillsammans med kolonner som uppvisar degradering. Det används två olika regulatorer och flödestrajektoria, i varierande grad, i olika försök för att undersöka om de kan motarbeta de problem som skapas av degraderingen hos kolonnerna. Om kolonnerna, trots degradering, kan användas effektivt under längre tid till låg kapacitet återstår, är det möjligt att producera den upprenade antikroppen till ett lägre pris. <br /> För att undersöka effektiviteten hos kontrollerna och av flödestrajektorian, kommer processprestandan utvärderas med hjälp av variablerna produktivitet, utbyte och utnyttjandegrad. <br /> Det bästa fallet använde sig av båda kontrollerna, av flödestrajektorian och hade en produktivitet på 0.18 mg mAb per ml resin och minut, ett utbyte på 94.7% och en maximal utnyttjandegrad på 62.5 mg mAb per maximal mängd adsorberad mAb för flödeskoncentrationen. Antibodies are proteins that our bodies produce to protect us from infections. However, it is also possible to produce antibodies artificially in an industrial setting. These antibodies can then be used in a wide variety of research and clinical settings and their potential uses are evolving rapidly.<br /> Artificially produced antibodies are typically produced by cells contained in large bioreactors under conditions where the cells are allowed to multiply. Cells containing antibodies are then continuously harvested. However, they typically need to be further purified after harvest. This can be done using a technique called affinity chromatography. In affinity chromatography, the harvested antibodies, including impurities such as other cell proteins, are fed to a column containing sites that capture the antibodies. After the impurities have been washed away, the antibodies get released from the column through a process of adjusting pH and salt concentrations. The column then needs to be chemically cleaned before it is ready to process more antibodies. Although necessary, the chemical cleaning process damages the column and decreases a column’s ability to capture antibodies over time. It is therefore of interest to find ways in which the process can be run where the impact of the capacity reduction is minimal.<br /> In this project, a so-called periodic counter-current chromatography (PCC) set-up was utilized to investigate ways to counteract the effects of column degradation. A mathematical model of a PCC system with three columns was created, and multiple simulations were performed in different cases to counteract the effects of column degradation.<br /> Two different flowrate controllers and a flowrate trajectory were used in these cases. The flowrate controllers were each set to be fast, slow, or inactive, in different configurations. Each configuration was run twice. Once with flowrate trajectories and once without. The simulations were compared to each other using the processes performance variables productivity, yield and column utilization. <br /> The best case had a productivity of 0.18 mg mAb per ml resin and minute, a yield of 94.7% and resin utilization of 62.5 mg mAb per maximum amount adsorbed mAb at feed concentration. This case was chosen for its high productivity (in the range 0.11 – 0.20), acceptable yield (ranges from 88 – 100%), and good resin utilization (in range 40.2 – 77.5). Antikroppar är proteiner som produceras av våra kroppar för att skydda oss från infektioner. Det är däremot möjligt att producera dessa antikroppar artificiellt. Dessa antikroppar kan sedan användas i en mängd olika forsknings- och kliniska miljöer och deras potentiella användningsområden utvecklas snabbt.<br /> Artificiellt producerade antikroppar produceras vanligtvis av celler i stora bioreaktorer under förhållanden där cellerna tillåts föröka sig. Celler som innehåller antikroppar skördas sedan kontinuerligt. Men de behöver vanligtvis renas ytterligare efter skörd. Detta kan göras med en teknik som kallas affinitetskromatografi. Vid användandet av affinitetskromatografi matas de skördade antikropparna, inklusive föroreningar såsom andra cellproteiner, till en kolonn som innehåller platser som fångar antikropparna. Orenheterna spolas bort och efter justerat pH och salt koncentration släpper antikropparna från de aktiva platserna och fångas upp vid hög koncentration. Kolonnen spolas och renas kemiskt innan den är redo att rena upp mer antikroppar. Den kemiska rengöringen är viktigt men den skadar kolonnen vilket med upprepade cykler leder till en minskad kapacitet hos kolonnen. Det är därför av intresse att hitta sätt som processen kan köras på där påverkan av kapacitetsminskningen blir minimal.<br /> I detta examensarbete användes en set-up kallad periodisk motströmskromatografi (PCC) för att undersöka hur effekterna av kolonndegraderingen kunde motverkas. En matematisk modell av ett PCC-system med tre kolonner skapades och flertalet simulationer utfördes för olika fall där kolonndegraderingens effekter motverkades.<br /> I dessa olika fall användes det två flödesregulatorer och en flödestrajektoria. Flödesregulatorerna var snabba, långsamma eller inaktiva, i olika konfigurationer. Varje konfiguration utfördes två gånger. En gång med flödestrajektoria och en gång utan. Simulationernas processprestanda jämfördes mot varandra med hjälp av variablerna produktivitet, utbyte och utnyttjandegrad.<br /> Det bästa fallet hade en produktivitet på 0.18 mg mAb per ml resin och minut, ett utbyte på 94,7% och en maximal utnyttjandegrad på 62.5 mg mAb per maximal mängd adsorberad mAb för flödeskoncentrationen. Detta fall valdes på grund av sin höga produktivitet (bland resultat inom spannet 0.11 – 0.20), sitt acceptabla utbyte (inom spannet 88 – 100%) och sin goda utnyttjandegrad (i spannet 40.2 – 77.5). https://lup.lub.lu.se/student-papers/record/9102373/file/9102378.pdf application/pdf 1945818 no 2022 eng Counter-current chromatography PCC Monoclonal antibodies Affinity chromatography Process control Chemical engineering Process simulation Chemistry 9102373 2022-10-27T14:03:07+02:00 2022-11-22T10:49:14+01:00 2022-11-22T10:49:14+01:00

oai:lup-student-papers.lub.lu.se:9102461 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Federico Balgera author 9043320 Ricardo Ferreira supervisor Department of Chemistry v1000647 department The efficiency of gold complexes featuring di- or tri-pyridine scaffolds in inhibiting human aquaporins have been previously investigated. They have returned promising results in cancer treatment and have been suggested to be potentially applied against malaria too. ([Au(bipy) Cl_2]+)., ([Au(phen)Cl_2]+) and ([Au(terpy)Cl]2+) in all their possible forms in solution, were computationally studied using Molecular Dynamics (MD) to investigate whether they could inhibit the permeation of glycerol and/or water in the malaria parasite Plasmodium falciparum through its single aquaglyceroprotein. The target was chosen due to its similarity with other aquaporins that are known to be inhibited by these complexes, and showed conserved interactions with residues lining the pore. In particular, the model suggested how both the chloride and the hydroxide complexes of [Au(terpy)Cl]2+ ,together with [([Au(phen)Cl_2]+ ,yield the most efficient inhibition of the channel. These predictions were proven via in vitro assays, thus demonstrating the validity of the computational method. [Au(terpy)Cl]2+ gave the most efficient reduction in parasitemia, with and IC50 of 0.37 μM (FCR3, chloroquine resistant strain), and [([Au(phen)Cl_2]+ had to be administered in higher concentration to return the desired effect (IC50 of 2.60 μM FCR3 resistant strain).<br /> Therefore, the compounds were proven to be active even in the absence of combination with chloroquine. These results are thus promising for the development of a novel approach to treat malaria. Malaria accounts for hundreds of thousand of deaths every year, mostly in the poorest regions of the globe and especially in sub-Saharan Africa. The difficult socio-economic conditions of the area contribute to the complications of stemming the parasite diffusion and overcoming resistance to known drugs and therefore, to treatment issues. Such a situation requires to be tackled from multiple points of view, from improving general sanitary conditions to developing new compounds and/or finding new exploitable targets. Currently, five strains of the parasite responsible for this disease in humans are known and they show different infectiousness and mortality. They also respond differently to treatments, but the current medicines are efficient against them all, albeit to different extents. This study focuses on the deadliest strain, accounting for nearly 80 % of the deaths, namely Plasmodium falciparum. Parasites such as this one are treated by the administration of a combination of several drugs, that aim to slow down proliferation or kill the undesired pathogen, and therefore have different targets. <br /> In the present study, some gold complexes, previously known to the medical community, have been investigated, focusing on the possibility to inhibit a membrane protein that is fundamental to the parasite life-cycle. Such gold-based complexes have already been noticed to inhibit some human transmembrane channel proteins belonging to the class of aquaglyceroproteins, which are responsible for osmotic balance and glycerol uptake functions that are necessary for the synthesis of cell membranes during multiplication phases. Such proteins have received particular interest due to the fact that they appear to be over-expressed over cancer cell membranes, as this kind of cells requires more nutrients because of their high growth rate. The inhibition of these protein channels has been linked to malaria treatment as it seems to be potentially effective in slowing down the parasite proliferation because the parasite exploits our very own membrane proteins for its personal glycerol intake. Despite that, our bodies require human aquaporins to be functioning for their own sake; therefore inhibition of these aquaporins would perhaps slow down the parasite proliferation, but it would also return some more or less serious side-effects. <br /> The novelty of this study consists in targeting not the human aquaporins, but the single parasite aquaglyceroprotein. This way, our cells could continue taking up glycerol for their correct functioning, while selectively depriving the parasite cells. Nevertheless, for the compounds to be fully selective towards PfAQP (Plasmodium falciparum aquaglyceroporin), additional modifications might need to be exploited. On the other hand, targeting the parasite protein to find out whether it can be inhibited by these complexes in the first place is the first step in this direction.<br /> Starting from a computational approach, the drug candidates under investigation are expected to block the entrance of glycerol through the pore and, therefore, be considered worth to be tested on the parasite in vitro. The tests on live parasite showed that the results are in line with the observed activities: Auterpy ([Au(terpy)Cl]2+) gave the best inhibition efficiency, followed by Auphen ([Au(phen)Cl_2]+) and Aubipy ([Au(bipy) Cl_2]+). Therefore, all tested compounds are promising building blocks for targeting PfAQP, alone or in combination with known antimalarials, such as chloroquine. 2022 eng Malaria Plasmodium falciparum gold complexes biochemistry Chemistry 9102461 2022-10-29T19:05:09+02:00 2022-11-04T10:48:37+01:00 2022-11-04T10:48:37+01:00

oai:lup-student-papers.lub.lu.se:9102688 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Simon Hans Lilje author 9102686 Joachim Björklund supervisor Department of Chemistry v1000647 department In this project, a regioselective method to deprotect and acylate the amide on C5 of sialic acid<br /> is explored. Sialic acid is one of the most complex monosaccharides and is an important ligand<br /> in many higher organisms in intercellular cell communication. The most prominent example is<br /> related to the immune system. Sialic acids are attached as the terminal carbohydrate on cell<br /> surface glycans, which is one of the unique patterns, used to distinguish between enemy and<br /> friend. Most pathogens need to take up sialic acid from their host, either to use it as an additional<br /> energy source or to incorporate it in their cell surface glycans to mimic the host cells. This<br /> mechanism leading to disguise is called molecular mimicry. The long-term aim is to find sialic<br /> acid derivatives to clog the transporters of the pathogens, resulting in a better immune response.<br /> Synthesising derivatives of sialic acid isn’t trivial due to its carboxylic acid function next to the<br /> anomeric hydroxyl group, four additional hydroxyl groups and an amide. This multitude of<br /> functional groups requires elaborate protection group strategies, which make it possible to<br /> address functional groups regioselectively. The simplest protecting strategy for sialic acid is the<br /> esterification of the carboxylic acid and per acetylation of all the hydroxyl groups. The problem<br /> was to remove just one of these acetyl groups. The new method, which is explored in this project<br /> enables the removal of the acetamide from C5 of sialic acid, enabling an easy and fast amidation<br /> of C5, saving four steps compared to the current synthetic pathway. However, side reactions<br /> made the synthesis of new compounds more difficult than expected, so just a few new<br /> compounds were observed in NMR and three were isolated. All in all, the reaction conditions,<br /> especially for the amidation and the processing of the reactions have to be optimized before<br /> simple synthesis is possible via this route. https://lup.lub.lu.se/student-papers/record/9102688/file/9102689.pdf application/pdf 3713731 no 2022 eng acylation amide antibacterial drugs regioselective deprotection sialic acid organic chemistry Chemistry 9102688 2022-11-03T18:54:07+01:00 2022-11-04T10:53:13+01:00 2022-11-04T10:53:13+01:00

oai:lup-student-papers.lub.lu.se:9103463 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Markus Leihed author 9037766 Yong Li supervisor Department of Chemistry v1000647 department Malaria is a massive global health crisis that is most prevalent in tropical regions of Africa, Asia, and Latin America. The World Health Organization (WHO) estimated in 2013 that 3.3 billion people were at risk of being infected by the disease, resulting in around 200 million cases with more than 500 000 of these cases leading to lethal outcome. Africa was by far the most affected by the disease with an estimated 90 % of all malaria deaths occurring in the sub-Saharan areas of the continent. According to the World Malaria Report from 2021, an estimated 241 million cases and 627 000 deaths was reported globally in 2020. This indicates that deaths caused by the disease has risen to levels last seen in the beginning of the last decade. Malaria is caused by a blood infection from the protozoan (single-celled eukaryotes) Plasmodium parasites, transmitted between humans through female Anopheles mosquitos. There are five species of Plasmodium parasites that infect humans, those are Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium knowlesi, and Plasmodium ovale. It is generally from infections by P.falciparum that lethal conditions emerge, such as severe anaemia and dysfunction of vital organs, i.e. liver, kidneys, lungs, and the brain. Symptoms of these conditions are paroxysmal fevers, nausea, body and headaches, to name a few. Chloroquine was the most prominent drug in the WHO Global Eradication Programme, that began in 1955 and saved millions of people dying from malaria infection. The first backlash came in 1957 when the first case reports of chloroquine resistance in P.falciparum appeared from the border region of Thailand and Cambodia, along with Colombia. Africa had its first cases of chloroquine resistance in 1978 and it soon spread throughout the continent and the rest of the world where malaria infections were endemic. The introduction of organometallic compounds to overcome chloroquine resistance came in 1997 when Biot and associates synthesised and tested the antimalarial activity of ferroquine. This chloroquine analogue was the first organometallic complex to be subjected to clinical trials and exhibited effectiveness against chloroquine resistant strains of P.falciparum. This project is a reach into the ongoing endeavour to overcome chloroquine resistance in P.falciparum and to extend the numerous collection of chloroquine-related organometallic complexes synthesised in the Nordlander group. Nordlander and co-workers have a number of such complexes showing similar and in some cases higher effectiveness than chloroquine against chloroquine resistant P.falciparum. In contrast to the sandwich complex ferroquine, the Nordlander group has been testing the effectiveness of half-sandwich complexes of chromium, iridium, osmium, rhodium, and ruthenium. This project entails the synthesis of 7-trifluoromethyl and 6-fluoro salicylaldimine ligands and their iridium, rhodium, and ruthenium half-sandwich complexes along with 7-trifluoromethyl, 7-chloro, and 6-fluoro pyridinmethanimine ligands and their manganese and rhenium tricarbonyl complexes. Malaria är en sjukdom som orsakas av parasiter av plasmodium släktet och överförs mellan människor av myggor. Då myggan biter en malariasmittad människa och förtär dess blod så innehåller detta blod parasiter som i senare sprids ifrån myggans mage och vidare till dess salivkörtlar. När myggan vid ett senare tillfälle biter en frisk människa, överförs parasiten från salivkörtlarna till människans blodomlopp och vidare till levern där parasiten blir kvar mellan 2-10 dagar innan den sprids till de röda blodkropparna. När parasiten spridit sig till de röda blodkropparna, uppkommer symptom i form av periodiska och aggressiva febertoppar, illamående, skakningar, och i de värsta fall kan dessa symptom leda till att den smittade avlider. Sjukdomsförloppet kan vara i flera månader om det inte behandlas och ställer därför höga krav på att verksamma och kostnadseffektiva läkemedel finns att tillgå. Malaria är en sjukdom som funnits i århundraden och har beskrivits som en av de dödligaste och mest ihållande sjukdomarna historiskt sett. Världshälsoorganisationen rapporterade 241 miljoner sjukdomsfall under 2020, varav 627 000 resulterade i dödlig utgång. I decennier har hundratusentals dödsoffer rapporterats årligen medan forskningen världen över ständigt försöker motarbeta denna utvecklingen.<br /> Malariamediciner är ingen modern uppkomst, redan på 1600-talet upptäckte jesuitpräster i Sydamerika att barken från Cinchonaträdet hade lindrande effekt på febersjuka individer. Ungefär 200 år senare isolerade två franska kemister det aktiva ämnet i barken, kinin. Stora plantager anlades av Nederländarna i Indonesien för att framställa kinin som länge var det ledande läkemedlet mot malaria. Engelsmännen behandlade sina malariasjuka soldater med en tonic innehållandes kinin, varpå soldaterna blandade ut denna tonic med gin för mer välsmakande ändamål och därmed var den berömda drinken gin &amp; tonic uppkommen. Än idag smaksätts tonicvatten med väldigt låga koncentrationer av kinin. Forskning på nya effektiva läkemedel och malariaparasitens biologi är ständigt pågående, men dessvärre är parasitens evolution hack i häl med de framsteg som görs. I 30-talets Tyskland tog man fram ett läkemedel som skulle komma att<br /> revolutionera kampen mot malaria och rädda miljontals människoliv, klorokin. Läkemedlet togs i användning 1946 och blev snabbt standard i behandling mot malaria, faktum är att klorokin användes så flitigt att parasiter utvecklade resistans mot läkemedlet redan 10 år efter det tagits i bruk. Detta bakslag påverkade i största grad högt sjukdomsdrabbade områden så som tropiska Afrika och Sydostasien och är än idag ett stort problem. Även andra läkemedel som använts mot malaria har skapat resistans i parasiter och är en av anledningarna till att forskningen ständigt strävar med att vara i framkant med detta problem. När malariaparasiten invaderar dom röda<br /> blodkropparna så börjar den bryta ner ett protein som kallas för hemoglobin. Hemoglobin består av stora kluster av aminosyror som parasiten använder till att föröka sig, men det består också av en heme-grupp som är giftigt för parasiten då det inte är bundet till proteinet. Parasiten tar dessa heme-grupper och formar hemozoin-kristaller som däremot inte är giftiga för parasiten. Klorokin ansamlas i parasitens magsäck där den binder till heme-grupper som i sin tur ackumuleras och efterhand dödar parasiten. Vad det är som orsakar klorokinresistans är fortfarande under debatt men den mest troliga teorin är att parasiten uppvisar mutationer i ett protein som gör att klorokin inte kan ansamlas i dess magsäck. En ljuspunkt kom 1997 då ämnet ferrokin togs fram av franska forskare och visade sig ha utmärkt effektivitet mot klorokinresistenta parasiter. Detta öppnade ett nytt forskningsfält där nya metallorganiska läkemedel mot malaria började ta form och utvecklas. I detta projektet har 21 nya metallorganiska molekyler framtagits med syftet att potentiellt kunna bekämpa klorokinresistans och i förlängningen kunna bota malaria. https://lup.lub.lu.se/student-papers/record/9103463/file/9103464.pdf application/pdf 2327412 yes 2022 eng Malaria chloroquine resistance sandwich complex ferroquine half-sandwich metal complexes chemical physics Chemistry 9103463 2022-11-23T19:45:57+01:00 2022-11-29T12:08:33+01:00 2022-11-29T12:08:33+01:00

oai:lup-student-papers.lub.lu.se:9103613 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Johannes Lidberg author 9103611 Marcus Wilhelmsson supervisor Department of Chemistry v1000647 department Through recent years, RNA has rapidly gone from mainly being known as a passive information-carrying molecule within the central dogma of molecular biology to becoming the active ingredient in multiple therapeutics, such as in vaccines and potential drugs against cancer. However, one of the main challenges with RNA as a therapeutic is efficient delivery to cells. Understanding the mechanism through which RNA enters cells is therefore crucial to develop more effective RNA therapeutics. New methods to accurately study RNA in cells are becoming increasingly important to fully understand these processes. Fluorescence is one such method commonly used to analyse RNA in cellulo. Since natural nucleotides are virtually non-fluorescent, fluorescent labels have to be introduced to enable analysis. tCO is a fluorescent cytosine analogue causing little perturbance to the RNA’s structure and function. This thesis explores a novel way of enzymatically labelling RNA with tCO using terminal deoxynucleotidyl transferase (TdT), a DNA polymerase capable of template-independent 3′-extension of nucleic acids.<br /> <br /> RNA coding for enhanced green fluorescent protein (eGFP) was produced through in vitro transcription. These strands were then extended using the TdT enzyme to add a mixture of natural nucleotide triphosphates (NTPs) and tCO-triphosphate (tCOTP) to their 3′-ends. Reactions using varying tCOTP /canonical NTPs-ratios, different cofactors, as well as different cofactor concentrations were performed to study their effect on the labelling performance. The RNA extension was evaluated using gel electrophoresis, as well as UV-vis absorption, excitation, and emission spectroscopy.<br /> <br /> tCO was successfully added to the 3′-ends of the RNA. The efficiency of the labelling seemed to be dependent on the available tCOTP amount, the used cofactor, the cofactor concentration, and the RNA sequence. Altogether, TdT labelling of RNA was demonstrated as a feasible way of labelling long, functional RNAs with tCO. Every living cell making up the human body carries a copy of the genome. This is essentially the recipe for how to make a human. The recipe is written as long strands of the four letters A, C, G, and T, collectively known as nucleotides, spelling out genes as long strands of DNA. Genes get read by the cell and copies are made in the form of ribonucleic acids (RNAs) with the letter T replaced with U. The RNA can then be translated by the protein factory of the cell, the ribosome, into a functioning protein, able to perform the actions needed by the cell. This is the central dogma of molecular biology. A big field of research today is how to use RNA in new medical therapies, as was done for the vaccines used against the Covid-19 virus. However, delivering therapeutic RNA to cells remains a challenge. New techniques to study RNA in cells are therefore becoming increasingly important. One such technique is the use of fluorescence. Fluorophores are molecules that, when exposed to photons of the right energy level, emit new photons with lower energy which can be detected. The process where a fluorophore emits a photon is called fluorescence and allows for highly sensitive analysis. As the RNA building blocks are virtually non-fluorescent themselves, fluorescent labels have to be attached to the RNA to enable analysis.<br /> <br /> This thesis explores the use of the enzyme terminal nucleotide transferase (TdT) to label the ends of long RNA strands using the fluorescent label tCO. Conventional fluorescent labels are generally large and bulky, leading to possible adverse effects on the structure and function of the labelled RNA. tCO is a fluorescent label that has been designed to replace and act as the natural C nucleotide within the RNA sequence, making it a less perturbing label for studying the native behaviour of RNA with fluorescence. To attach tCO to RNA, the enzyme TdT is used. TdT is an enzyme that has the unique ability to extend nucleic acids, such as RNA, by taking the precursors to nucleotides, nucleoside triphosphates (tCO-triphosphate in the case of tCO), and adding them to one of the RNA ends. To work, TdT requires a metal ion present in the reaction called the cofactor. Reactions using different reaction conditions were performed to study their effect on the incorporation of tCO.<br /> <br /> TdT was successfully used in this thesis to label RNA using tCO. The amount of incorporated tCO was shown to be dependent on the amount of available tCO triphosphate, the cofactor used, and the concentration of the cofactor. RNA sequence also seemed to affect the incorporation of tCO. The number of tCOs attached to the RNA strands was considerably less than what has previously been done with shorter RNA. https://lup.lub.lu.se/student-papers/record/9103613/file/9103617.pdf application/pdf 918081 no 2022 eng Physical biochemistry Fluorescence In vitro transcription RNA Terminal deoxynucleotidyl transferase Nucleobase analogue Chemistry 9103613 2022-11-28T15:04:15+01:00 2022-12-06T14:11:00+01:00 2022-12-06T14:11:00+01:00

oai:lup-student-papers.lub.lu.se:9104120 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 David Carlsén author 9104118 Magnus Genrup supervisor Simon Wakter supervisor Balder Hagert supervisor Department of Energy Sciences v1000205 department The steel industry is with its high emissions an important sector to transform from fossil-fueled to fossil-free. In recent years, the technology development has accelerated quickly regarding iron ore reduction using hydrogen produced from electrolysis within the EL-DRP-EAF steel production route. However, it is problematic that the energy supply for the majority of the efforts made within the green transition, steel production included, is to come from electricity. In this study it is investigated if it is possible to reduce the primary energy demand of the EL-DRP-EAF route by using direct heat integration of hot SMR steam into the process. A beneficial design of such a system is proposed and later on modeled in order to find out how much SMR steam that is needed to produce 1 ton of DRI. It is found that the primary energy demand can be reduced compared to other systems, with direct heat integration of hot SMR steam as what makes the difference. Though, the result is sensitive to somewhat unsimilar assumptions and system boundaries of the compared modelings. Lastly, scaling of the system result is performed based on the Swedish DRI production rate. As the energy demand is vast, the suggestion is made that the nearby located SMRs could be used for direct heat integration only, whilst the remaining energy demand in the form of electricity could be taken from the grid. That would allow for a mix of energy sources and still lead to the reduction in energy demand. There is a lot going on right now regarding transitioning the high-emitting steel industry from fossil-fueled to fossil-free. However, when transitioned the electricity demand of steel production will be vast. This study finds out that the energy demand of fossil-free steel production can be reduced if integrating Small Modular Reactors into the production process.<br /> <br /> Fossil-free steel production uses hydrogen instead of coal to transform the iron ore to iron. Thereby, the emissions become water instead of carbon dioxide. The technology development has accelerated quickly in recent years and the process is now close to becoming reality in a large scale. But, to be able to call the process fossil-free it is crucial that the hydrogen is produced in an electrolysis running on fossil-free electricity. It is problematic that the energy supply for the majority of the efforts made within the green transition, steel production included, is to come from electricity. That makes this study very interesting, as a reduced energy demand of fossil-free steel production would increase its chances of becoming reality in a larger scale across the world. Since the steel industry today constitutes 7 % of the world´s greenhouse gas emissions, a large scale transition of it would make a great impact in cutting worldwide emissions.<br /> <br /> It is already known that operating the fossil-free steel production process with a high temperature electrolysis can reduce the energy demand of steel production by 21 % compared to operating it with a low temperature electrolysis, due to the possibilities of introducing waste heat integration and by-product utilization into the high temperature electrolysis. This project finds out that the energy demand can be further reduced, by 36 % compared to the operation on low temperature electrolysis, if operating on high temperature electrolysis and integrating the steam produced from SMRs directly into the process. The SMR steam is directly sent into the electrolysis (to be turned into hydrogen and oxygen), it is used for heating in several parts of the steel production process and to produce the electricity needed to run the electrolysis. What is beneficial about the direct heat integration is that the energy does not have to go from hot SMR steam, to electricity, to heat again and in that way losing overall efficiency.<br /> <br /> The heat demand of the steel industry is vast and constant. This study has shown that SMRs are very suitable to supply the steel industry with energy in the form of heat, hydrogen and electricity, resulting in nice overall energy efficiency advantages. https://lup.lub.lu.se/student-papers/record/9104120/file/9104125.pdf application/pdf 1095270 no 2022 eng Small Modular Reactor SMR Xe-100 Pink Hydrogen Electrolysis SOEC Steel Iron DRI DRP Energy Industry Transition Technology and Engineering Chemistry Earth and Environmental Sciences 0282-1990 LUTMDN/TMHP-22/5509-SE 9104120 2022-12-20T13:39:41+01:00 2022-12-20T14:22:38+01:00 2022-12-20T14:22:38+01:00

oai:lup-student-papers.lub.lu.se:9106448 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Lisa Mazzeo author 9106446 Urban Johanson supervisor Department of Chemistry v1000647 department Animals monitor environmental ques by translating them into electrical signals through a depolarization of the electric potential over the cell membrane of nerve cells. A way to initiate the depolarization is through activation of receptors that are ion channels. These channels can facilitate the diffusion ions across membranes driven by the differences in concentration and electrical charge on each side of the membrane. TRP is a family of ion channels present in cell membranes. In particular, TRPA1 is an ion channel on the plasma membrane of eukaryotes and it is activated by harmful chemical substances which are causing pain and itch. However, this peculiar ion channel in malaria mosquitoes (Anopheles gambiae; Ag) is crucial for its host seeking behavior, as it operates on environmental temperature gradients. Therefore, to simplify detection and thus facilitate further studies on AgTRPA1, clones encoding sequences of AgTRPA1 fused with a green fluorescent protein (GFP) will be constructed in this project. A PCR product encoding the GFP-tag with following His-tag at its C-terminal amplified from the plasmid pPICZA- eGFP will be cut with the restriction enzymes Esp3I and BamHI. Furthermore, the DNA fragment encoding the GFP-tag will later be ligated into plasmids encoding full length and truncated versions of AgTRPA1, cut open by NotI and BamHI, and then be transformed into competent Escherichia coli cells. The resulting plasmids will then be prepared from the isolated transformants, verified by restriction enzyme digestion and then sent to sequencing. Overall, the project proceeded according to expectations. As a result, three clones could successfully be verified by sequence data. The data confirmed a properly ligated fragment encoding the GFP-tag in frame with the encoding sequence of AgTRPA1 and an intact BamHI site. To continue this project, the next step will be to put these promising sequences inside the yeast Pichia pastoris, express, isolate and hopefully determine the structure of AgTRPA1. The final goal is to create a molecule that works as a repellent that activates only AgTRPA1 without affecting the human orthologous receptor. TRPA1, är en smärtreceptor på cellmembran vilken aktiveras av skadliga kemiska ämnen, som t.ex. allylisotiocyanater från senap, pepparrot och wasabi och därav kallas TRPA1 även för wasabi-receptorn. Smärta och klåda är tydliga symptom på högre aktivitet hos receptorn. Malariamyggan (Anopheles gambiae), använder denna receptor för att känna av skillnader i miljötemperaturer och receptorn spelar därav stor roll för myggan när den söker byte. I denna studie har grönt fluorescerande protein (GFP) inkorporerats med malariamyggans TRPA1. Tre kloner av GFP-fusioner med malariamyggans TRPA1 har framgångsrikt kunnat verifieras med sekvensdata, två fullängdsplasmider och en trunkerad plasmid. Genom att följa fluorescensen kan de kloner som har högst halt av fusionsproteinet lättare identifieras och dess upprening optimeras. Nästa steg i projektet kommer vara att tillverka proteinet i jästen Pichia pastoris, som används för att producera proteiner i stora mängder. Slutgiltligt mål i framtiden är att få bättre förståelse för hur proteinet fungerar i myggan och om det är möjligt att bekämpa sjukdomar som myggan sprider genom att designa en molekyl som fungerar som en repellent som aktiverar myggans receptor utan att påverka den motsvarande smärtreceptor i människa. https://lup.lub.lu.se/student-papers/record/9106448/file/9106454.pdf application/pdf 4596673 yes 2023 swe Biochemistry TRP AgTRPA1 GFP Chemistry 9106448 2023-01-11T15:46:53+01:00 2023-01-12T08:01:52+01:00 2023-01-12T08:01:52+01:00

oai:lup-student-papers.lub.lu.se:9106715 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Virginia Martín Cristóbal author 9106713 Herwig Schüler supervisor Department of Chemistry v1000647 department PARP16/ARTD15 is an intracellular mono-ADP-ribosyltransferase that catalyzes auto- and heteromodification by transfer of a single ADP-ribose moiety. It belongs to the ADP-ribosyltransferase (ART) superfamily. ADP-ribosylation of amino acids on protein targets is critical in the regulation of cellular pathways in eukaryotes, especially involved in physiological functions, cell stress responses and disease. It has been discovered that PARP16 plays an important role in the Unfolded Protein Response (UPR) as the main activator of 2 endoplasmic reticulum (ER) stress sensors, PERK and IRE1α kinases. In addition, it was also found that these kinases phosphorylate PARP16. The aim of this project is to investigate the phosphorylation of PARP16 by the kinases and whether that implies alterations of its activity. To answer this question, we coexpressed Tyrosine-kinases with YopH and Serine/Threonine-kinases with Lambda from an Addgene genetic library. The kinases were purified by a 2-step elution protocol using Ni-NTA beads and imidazole. Although the samples showed signs of phosphatase contamination, we found conditions in which we could assess the phosphorylation activity of the kinases. Finally, phosphorylation and ADP-ribosylation assays were performed with PARP16 and our kinases. The results showed clear phosphorylation of PARP16 and a variation of its ADP-ribosylation activity in the presence of the modification. This discovery opens up new questions about the biological effects that the phosphorylation of PARP16 can have, especially in cancers and protein folding diseases. Therefore, these findings can be critical for therapeutic inhibition and treatment. Further investigation should address questions such as what residues from PARP16 are modified and how phosphorylation by PERK and IRE1α affect the ADP-ribosylation activity of PARP16. This report covers an investigation on protein modification and enzymatic activity. Our protein of interest is known as PARP16/ARTD15 and belongs to a protein superfamily that modifies other proteins by adding ADP-ribose using NAD+ as a substrate (ADP-ribosylation). The proteins from this superfamily are involved in several physiological functions, cell stress responses, and even disease. Therefore, they have been recently identified as important therapeutic targets for cancer and for the modulation of the immune system.<br /> PARPs present various characteristic and essential features in their structure and sequence critical for their ADP-ribosylation activity. In particular, we could highlight their catalytic domain that contains a signature histidine, tyrosine and glutamate (H-Y-E) motif. However, the catalytic domain of PARP16 is composed of H-Y-Y in the catalytic triad and is only capable of performing auto and trans mono-ADP-ribosylation, unlike other PARPs that have poly-ADP-ribosylation activity.<br /> PARP16 has been found to have an important role in the Unfolded Protein Response (UPR) since it is required for activation of two ER stress sensors, PERK and IRE1α. These are so-called kinases and play critical roles in disease development related with protein folding and cancer. Additionally, the same study showed that these two proteins modify PARP16 by adding phosphate residues (phosphorylation).<br /> Aiming to understand this biological mechanism, and due to difficulties to produce PERK and IRE1α, we designed various experiments in which we expressed, purified, and tested several kinases from an Addgene genetic library called ``an open library of human kinase domain constructs for Automated Bacterial expression´´. It contained 72 kinases and 2 phosphatases. The phosphatases are of great relevance because they allow a non-toxic overexpression of the kinases.<br /> The experimentation began with the coexpression of the phosphatases and kinases followed by purification of the kinases with Ni-NTA beads. Next, we tested the autophosphorylation activity and transphosphorylation activity to PARP16 of the kinases in presence of ATP. This showed that the kinases were active and we identified several kinases that phosphorylated PARP16. After the results of both assays, ADP-ribosylation assays were designed in order to investigate the effects that phosphorylation has on the catalytic activity of PARP16. The results showed a variation of the ADP-ribosylation activity of PARP16. It is remarkable that 2 of the 4 kinases tested in this last assay have the same specificity as PERK and IRE1α and reduce the activity of PARP16.<br /> This discovery can be key to develop therapies to prevent or treat cancer and genetic disease development. However, further investigation is indispensable to elucidate which residues of PARP16 are modified by the kinases and how PERK and IRE1α behave in the presence of PARP16. https://lup.lub.lu.se/student-papers/record/9106715/file/9106725.pdf application/pdf 1827801 no 2023 eng ADP-ribosylation Kinases PARP16 Phosphorylation UPR biochemistry Biochemistry Chemistry 9106715 2023-01-13T11:48:46+01:00 2023-01-26T09:26:59+01:00 2023-01-26T09:26:59+01:00

oai:lup-student-papers.lub.lu.se:9107176 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Agnes Berggren author 9107174 Lintang Hizbullah supervisor Department of Chemistry v1000647 department Malaria is a life-threatening disease, but widespread antimalarial drug resistance has become a major obstacle when it comes to malaria treatment. Derivatives of existing drugs are potential drug candidates that can overcome this resistance and in recent years metal derivatives of chloroquine (CQ) have been of interest for their potential antimalarial activity. Three new organometallic complexes of Cr(0) have been synthesised and characterized in this project by reacting chromium hexacarbonyl with three different bidentate chloroquine analogue ligands. This was done with the purpose of later analysing if the complexes can evade the major obstacle of CQ resistance. Malaria är en dödlig infektionssjukdom som kännetecknas av feber, huvudvärk, muskelvärk och kräkningar och år 2020 uppskattade WHO antalet dödsfall i malaria till 627 000, varav 96 % av fallen skedde i subsahariska Afrika. Sjukdomen orsakas av encelliga parasiter av släktet Plasmodium. Arterna som smittar människor är P. falciparum, P. vivax, P. malariae, P. ovale samt P. knowlesi, varav P. vivax och P. falciparum är de vanligast förekommande och P. falciparum är den dödligaste. Malariaparasitens livscykel involverar två värdar; människor och myggor av släktet Anopheles. Människor kan endast smittas genom att bli bitna av infekterade myggor och då sprids först parasiten till levern där de förökar sig för att sedan spridas till de röda blodcellerna. Det är i detta stadie som malariasymptomen uppstår. Därefter fortsätter parasiten att fortplanta sig, dels asexuellt för att spridas till andra röda blodceller, dels sexuellt för att kunna infektera en mygga vid ett myggbett. I de röda blodcellerna bryter parasiten ned hemoglobin för att använda aminosyrorna som näring. En biprodukt av degraderingen är hemgruppen som är giftig genom att bland annat bilda oxidativa fria radikaler och inhibera enzymer. Parasiten hanterar detta genom att kristallisera hemgrupperna till hemozoin, vilken inte är giftig för parasiten. <br /> Malaria kan ha funnits i upp till 130 miljoner år och har exempelvis beskrivits på mesopotamiska lerplattor och av grekiska filosofen Platon. Idag finns det en stor mängd olika malarialäkemedel men ett problem som har uppstått är den utbredda resistensen mot de etablerade läkemedlen. Detta, tillsammans med färre biverkningar och militära behov såsom tillförsel av malarialäkemedel till soldater i endemiska områden, har under lång tid drivit framtagandet av nya malarialäkemedel. Kinin, i form av barken på Cinchona-trädet, användes av jesuiter redan på 1600-talet och användes trots sina biverkningar under en lång tid. Klorokin upptäcktes under 1930-talet i Tyskland och visade sig ha färre biverkningar och högre effektivitet än tidigare malariamediciner. Klorokin verkar genom att interagera med hemgrupperna så att dessa inte kan bilda hemozoin och därför förblir giftig för malariaparasiten. Sedan klorokin introducerades har dock resistens mot läkemedlet uppstått i stora delar av världen. Ett sätt att undvika resistensen är att ändra delar av de kända malarialäkemedlen så att de är tillräckligt lika för att behålla sin funktion men tillräckligt olika för att inte ”kännas igen” så att resistensen återuppstår. Det är detta det här arbetet går ut på.<br /> Metallorganisk kemi handlar om ämnen där kol i organiska molekyler, det vill säga molekyler som till stor del består av kol, väte och syre, är direkt bundet till en metall. Detta medför nya egenskaper och har på senare tid utnyttjats för att utveckla nya läkemedel. Genom att lägga till ett s k ”sandwich-komplex” i klorokins sidokedja har man kunnat framställa ferrokin. Ett sandwich-komplex innebär att en metallatom, i det här fallet järn, är bundet mellan två ”ringar” av kolatomer likt en sandwich. Malarialäkemedlen utgår ofta från klorokin och adderar olika element till dess sidokedja. Metallen i ett malarialäkemedel kan antingen binda till sidokedjan via en ”ring” i exempelvis ett sandwich-komplex (en kovalent förankring till ”ringen”) eller direkt till metallen (en förankring genom koordination av en ligand).<br /> I det här arbetet har tre metallorganiska komplex med krom framställts genom att direkt binda metallkomplex till klorokin-liknande molekyler. Detta gjordes för att senare kunna jämföra dem med kända malarialäkemedel i effektivitet hos resistenta malariaparasiter. https://lup.lub.lu.se/student-papers/record/9107176/file/9107181.pdf application/pdf 1212158 yes 2023 eng inorganic chemistry malaria chromium(0) Chemistry 9107176 2023-01-16T17:36:49+01:00 2023-01-26T10:51:19+01:00 2023-01-26T10:51:19+01:00

oai:lup-student-papers.lub.lu.se:9107930 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Maria Chaudhry author 9107928 Peter Spégel supervisor Centre for Analysis and Synthesis v1000651 department Antibiotic resistance is currently a very serious and pressing issue. Grave consequences are predicted in the future if the rate of resistance development continues as today. In relation to this there are many contaminants in our environment and the grade of effects of these contaminants on antibiotic resistance is still very much unknown. The aim of this study is to give an overview on this subject and to find out if these unknown contaminants influence antibiotic resistance in the environment. A brief review on the technique used in the field to analyse these contaminants will also be given. The databases used in this literature review were LUBsearch and google scholar. Peer-reviewed publications published after 2020 regarding this topic were examined. According to the literature reviewed the contaminants that influence antibiotic resistance in the environment are as following: metals, biocides, pesticides, microplastics, and gasoline and diesel exhaust particles. But also, various physical environmental aspects influence the antibiotic resistance in the environment. The ones mentioned in this study are temperature and climate warming, antibiotic resistance genes (ARG), biochar, minerals, and earthworms. Some of the mechanisms behind the obtained antibiotic resistance attained by the bacteria due to the contaminants were cross-resistance, effecting the efflux pumps, horizontal gene transfer of ARGs and induced stress and pressure on the bacteria. There are still many knowledge gaps regarding antibiotic resistance in the environment. But it is quite clear that contaminants influence the antibiotic resistance in the environment. Therefore, more comprehensive studies are needed about these topics in every environmental niche so that global precautions can be taken. The public should also be made more aware of this. Future studies of the mechanism of bacteria and natural environment may give an insight to how antibiotic resistance in the environment can be prevented. Kan kemiska föroreningar leda till ökad resistens hos bakterier?<br /> I dagens samhälle kan de flesta känna en trygghet kring utvecklingen av moderna mediciner som gör att allt fler sjukdomar kan botas jämfört med innan. Varje år kan det kännas som att mänskligheten gör framsteg vad gäller den medicinska utvecklingen. Dock är det inte så att det bara görs framsteg kring läkemedel utan vissa läkemedel kommer att börja förlora sin påverkan. Det handlar om antibiotikaläkemedel. Antibiotikaresistensen ökar och det finns inte tillräckligt med studier kring vad som leder till en ökning och vad som kan göras för att minska effekten av antibiotikaresistensen. Vidare behövs det även forskning kring vilka behandlingar som kan ersätta antibiotika medicinen för att minska den förutspådda framtida dödligheten på grund av antibiotikaresistensen. Det finns många föroreningar i vår miljö och graden av dessa föroreningars effekter på antibiotikaresistens är fortfarande väldigt oklar. Syftet med denna litteraturstudie är att ge en översikt över detta ämne och undersöka om dessa okända föroreningar påverkar antibiotikaresistens i miljön. Studie kommer även att lyfta fram tekniken som används inom fältet för att analysera dessa föroreningar. Denna litteraturstudie har genomförts genom att analysera studier avseende antibiotikaresistens i den naturliga miljön. Vad som framkommer av den granskade litteraturen är att de föroreningar som påverkar antibiotikaresistens i miljön är följande: metaller, biocider, mikroplaster samt bensin- och dieselavgaspartiklar. Dock påverkas också olika fysiska miljöaspekter antibiotikaresistensen i miljön. De som nämns i denna studie är temperatur, biokol, antibiotikaresistenta gener (ARG), mineraler och daggmaskar. Det finns fortfarande många kunskapsluckor om antibiotikaresistens i miljön. Men det är tydligt att föroreningar påverkar antibiotikaresistensen i miljön. https://lup.lub.lu.se/student-papers/record/9107930/file/9122317.pdf application/pdf 505349 yes 2023 eng Antibiotic resistance bacteria contaminants environment analytical chemistry Chemistry 9107930 2023-01-19T09:26:58+01:00 2023-06-09T09:27:29+02:00 2023-06-09T09:27:29+02:00

oai:lup-student-papers.lub.lu.se:9111521 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Neus Arbós Labal author 9111516 Eric Anguera Aixalà supervisor Department of Chemistry v1000647 department Tröger’s Base analogues have been widely used as scaffolds in supramolecular systems due to their structure, rigidity, and chirality. This project aims to synthesize two diastereomer Tröger’s Base analogues that could be used as building blocks for a linearly fused heptakis-Tröger’s Base. Initially, two haloaniline moieties were condensed into a halogenated Tröger’s Base analogue, which was then functionalized with amino groups in the aromatic rings and menthyl side chains at the benzylic positions of the diazocine bridge. The addition of new controlled stereogenic centres in the benzylic positions generated two diastereomers, which were separated using chromatography and will provide two possible routes for the synthesis of heptakis-TB. Popular Science Summary: A brick for molecular buildings <br /> <br /> This project is in the field of supramolecular chemistry, which was summarized by Nobel Prize winner Jean Marie Lehn as “chemistry beyond the molecule”. Supramolecular chemistry goes beyond the study of single molecules and reactions and focuses on how different molecules interact and arrange themselves in bigger and intricate systems without changing their individual structure. <br /> <br /> A relevant molecule used in supramolecular chemistry is Tröger’s Base. This molecule is rigid, with a fixed and well-known shape that makes it useful as a building block in structures with a controlled geometry. The goal of this project is to synthesize an analogue of Tröger’s Base that could later be condensed to form a 7-membered chain with a C-like shape. <br /> <br /> Since the goal structure would be C-shaped, other molecules could be stored in the empty space in the middle, for example drugs. Therefore, this structure could serve as a cavity where the drugs would be protected, so they could travel through the body safely. In addition, the building blocks that could be condensed to create the C-shaped cavity have also been designed so that cells would recognize the structure, allowing for the drugs to be delivered.<br /> <br /> The focus of this project has been the synthesis of the building blocks for the cavity: starting from a very simple molecule, new parts have been added until the goal structure was obtained. The process can be viewed as if one was building a lego, using chemical reactions to stick the pieces together until the desired shape is obtained. Since the final structure needs to be a very specific one, these parts need to be added very carefully and one by one, making sure the result of each step is the expected one. <br /> <br /> After 6 synthesis steps from the starting material, the desired building blocks were obtained, allowing for further investigation towards the building of the final C-shaped product in the future. 2023 eng Organic synthesis supramolecular chemistry Tröger's Base heptakis-Tröger's Base Chemistry 9111521 2023-02-27T11:18:38+01:00 2023-03-02T10:53:57+01:00 2023-03-02T10:53:57+01:00

oai:lup-student-papers.lub.lu.se:9112319 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mohamad Abd Elwadood author 9112317 Peter Spégel supervisor Margareta Sandahl supervisor Department of Chemistry v1000647 department Fatty acids-based herbicides are considered to be a green alternative to synthesized weed control products. However, the environmentally sustainable effect of those herbicides needs more investigation to be confirmed. The aim of this work was to develop a chemical analysis method that enables identification of short-chain fatty acids (SCFA´s) and medium-chain fatty acids (MCFA´s) in a commercial fatty acid-based herbicide product, and to set up extraction and gas chromatography (GC) methods that can be used to detect the exposure to the product in environmental matrices. Fatty acids (FA´s) were extracted from the herbicide by liquid-liquid extraction (LLE) using n-heptane as organic solvent. FA´s were extracted from soils spiked with the herbicide; on a supercritical fluid extraction (SFE) system using extraction solvent consisting of 90% supercritical carbon dioxide (SC-CO2) and 10% methanol (MeOH) (v/v). The extracted FA´s were derivatized under acidic conditions into fatty acid methyl esters (FAME´s) to be analysed on gas chromatography-flame ionization detector (GC-FID) system and gas chromatography-mass spectrometry (GC-MS) system. Standard solutions of known FAME´s were used to construct retention index (RI) models and internal calibration models to identify and quantify FAME´s in the samples. The herbicide product was found to contain octanoic acid, pelargonic acid, decanoic acid, and 2-methyoctanoic acid. R2 values of the calibration curves ranged between 0.992 and 0.996. Repeatabilities for the peak areas and retention times had RSD% values varied between 1.32 -7.69 and 0.011-0.783, respectively. Recoveries (R%) of pelargonic acid in the spiked soils were estimated to vary between 8% and 128%; showing that more work could be required to investigate the optimum parameters for SFE extraction method. Herbicide products are widely used as weed-controlling agents by both professionals and individuals. The formulas of some of those products contain chemicals that may have harmful impacts on the environment, which incentivized governments and health authorities to ban some of those herbicides. Researchers and producers were also encouraged to synthesize and examine weed-controlling agents that are greener and more environmentally sustainable. Some products of the modern generation of herbicides depend mainly on fatty acids and natural oils to achieve their mode of action as weed-controlling agents. Nonanoic acid, also known by its trivial name as pelargonic acid, is widely used as the main ingredient in the so-called bio-herbicides. However, the friendly environmental impact of those bio-herbicides is yet to be investigated. Research and studies that could achieve that goal, implicitly, shall include analytical methods to extract, detect and quantify those products in environmental matrices. The aim of this work was to identify the fatty acid composition in a commercial fatty acid-based herbicide product and to detect it in environmental matrices.<br /> Soils collected from different locations were spiked with different amounts of the herbicide in order to mimic the exposure to the herbicide in nature. The extractions of FA´s from the soil were performed using extraction solvent consisting of SC-CO2 and methanol as a co-solvent to tune the polarity of the extraction solvent in order to create optimal solubility conditions for the extraction of the FA´s from the soils. Qualitative and quantitative analysis’s were performed on GC-FID system and GC-MS system. The free FA´s used to construct the models as well as lipids in the extractions were derivatized under acidic conditions and then analyzed in their FAME´s form. The qualitative analysis was performed by constructing retention index models for the FAME´s to detect and identify the corresponding FA´s in the herbicide and the soils. The quantitative analysis was performed by constructing internal calibration models for the FAME´s. <br /> The herbicide was found to contain octanoic acid, pelargonic acid, 2-methyl octanoic acid, and decanoic acid, with pelargonic acid and 2-methyl octanoic acid having the highest abundance, respectively. The constructed internal calibration models showed acceptable R2 values that ranged between 0.992 and 0.996. The performance of the analysis showed good precision where repeatabilities for the peak areas and retention times with RSD% values ranged from 1.32 to 7.69 and from 0.011 to 0.783, respectively. Validation of the extraction process of FA´s from the spiked soils was estimated quantitatively in terms of recovery percentage for the concentrations of pelargonic acid. Recoveries of pelargonic acid in the spiked soils were below the acceptable criterion in five spiked samples with values: 8%, 22%, 62%, 66 %, and one sample with 129%, while three spiked samples were within the acceptable range, two samples with 79% and one sample with 100%. The low obtained recoveries may indicate that a better extraction method can be considered in future work in order to achieve optimal extraction conditions. https://lup.lub.lu.se/student-papers/record/9112319/file/9112320.pdf application/pdf 2386649 no 2023 eng Analytical Chemistry Fatty Acids Gas Chromatography Green Herbicides Retention Index Flame Ionization Detector Mass Spectrometry Supercritical Carbon Dioxide Extraction. Chemistry 9112319 2023-03-13T19:23:09+01:00 2023-03-16T13:22:23+01:00 2023-03-16T13:22:23+01:00

oai:lup-student-papers.lub.lu.se:9112918 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Filip Hallböök author 9112916 Sara Blomberg supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department To be able to face the challenges brought on by climate change there is an urgent need to reduce the<br /> heavy dependence on fossil fuels. Bio-oil is one such renewable and carbon-neutral replacement that<br /> has shown promising potential. A key step in making bio-oil commercially feasible is improvements<br /> of the upgrading processes of the bio-oil. One such upgrading process is catalytic hydrodeoxygenation<br /> (HDO), which has been developed using mainly molybdenum sulfide (MoS2) catalysts. One method to<br /> further develop the process is to improve the catalyst performance by the addition of promoters. Nickel<br /> and cobalt has commonly been used as promoters for MoS2 catalysts, but there is potential for further<br /> improvement of the catalysts by addition of noble metals as promoters.<br /> In this study the promoting effects of adding the noble metals iridium, palladium and platinum using two<br /> different impregnation methods were investigated. This was done by studying the reduction characteristic<br /> of the new catalysts using Temperature Programmed Reduction (TPR), together with chemical characterization using Scanning Electron Microscopy - Energy Dispersive Spectroscopy (SEM-EDX). All the<br /> studied noble metals induced a significant change of the reduction characteristics of the catalysts, by<br /> lowering the reduction temperature of the Ni-Mo oxide. Two different promoting mechanisms could be<br /> identified. The addition of iridium resulted in a separate reduction of IrO2 with a subsequent promoting<br /> of Ni-Mo oxide, while the addition of platinum and palladium gave rise to simultaneous reduction of the<br /> noble metal and the surrounding Ni-Mo oxide. One possible mechanism for the promoting by iridium<br /> is hydrogen spillover. The differing behaviours of palladium and platinum could indicate a different behavior, for example the ability to be dissolved in the Ni-Mo oxide structure, creating nucleation sites for<br /> the reduction process. The formulation method used was found to have the largest effect on the iridium<br /> catalysts, where co-impregnation improved the promoting abilities. No significant changes were found<br /> for palladium and platinum. Overall this study has found promising results in the use of noble metals as<br /> promoter for Ni-Mo catalysts, and further studies are warranted. Klimatförändringar är en av vår tids stora utmaningar. För att kunna möta dessa finns det ett brådskande behov av att minska vart stora beroende av fossila bränslen. En lovande råvara för produktion av förnyelsebara och koldioxidneutrala bränslen är bioolja. Bioolja kan användas som ett substitut för råolja i raffinaderier och produceras från biomassa, vilket innebär att den kan agera som ett förnyelsebart substitut. Bioolja kan produceras med en process som kallas for pyrolys där exempelvis träflis eller annan biomassa snabbt hättas upp och förångas. De resulterande ångorna kyls sedan ner och har då en sammansättning som kan liknas med råolja, vilket främst innehåller kol- och väteföreningar som är grunden för de bränslen som används idag. Bioolja producerad från biomassa har dock en betydande skillnad, en hög halt av kemiska föreningar med syre. Detta är en konsekvens av den kemiska sammansättningen av biomassan biooljan producerats från och detta påverkar bränsle-egenskaperna hos oljan negativt. På grund av detta behöver biooljan uppgraderas innan den kan användas. Ett av det viktigaste stegen kallas för katalytisk hydrodeoxygenering (HDO) där syreatomerna i oljan selektivt tas bort. <br /> <br /> Som namnet antyder är detta en katalytisk process vilket innebär att en så kallad katalysator krävs för att processen ska fungera. Katalysatorer bestar ofta av metaller som hjälper reaktionen att fortgå ofta vid en lägre temperatur och med färre biprodukter. Den katalysator som mest framgångsrikt har använts i HDO-processen är baserad på nickel och molybdensulfid. I denna katalysator är molybden är den aktiva komponenten som underlättar reaktionen, medan nickel agerar som en så kallad promoter, det vill säga ett ämne som underlättar reaktionen utan att vara direkt involverad. Ett viktigt steg i att göra denna process mer effektiv och ekonomiskt gångbar är vidareutveckling av dessa katalysatorer. <br /> <br /> I denna studie undersöktes effekterna av att tillsätta små mängder av ett tredje ämne, en ädelmetall, till dessa katalysatorer. Mer specifikt undersöktes ädelmetallerna platina, palladium och iridium. Tanken med tillsatsen av små mängder av dessa metaller är att undersöka om det finns synergistiska effekter tillsammans med nickel och molybden. For att se om dessa finns undersöktes metallernas reduktionsegenskaper. Detta gjordes genom en metod som kallas for Temperatur-Programmerad Reduktion (TPR), där katalysatorerna utsätts för ett flöde av vätgas medan temperaturen ökar. Genom att studera hur reduktionen av katalysatorn förändras när man tillsätter ädelmetallerna kan slutsatser dras kring dessa synergistiska effekter. Två tillverkningsmetoder av katalysatorerna undersöktes också, där tillsatsordningen av ädelmetallen ändrades för att undersöka om detta påverkar hur katalysatorn beläggs med ädelmetallen. Alla tre ädelmetaller hade en stor inverkan på reduktionen av molybden och nickel. De studerade ädelmetaller uppvisade alla en synergistisk effekt, men effekten av att tillsätta iridium skiljde sig från platina och palladium. För iridium kunde en övergång till metalliskt iridium observeras innan nickel och molybden reducerades medan for platina och palladium skedde detta samtidigt. Detta tyder på att den synergistiska mekanismen är annorlunda för iridium. Sammanfattningsvis visar denna studie på att tillsatsen av de undersökta ädelmetallerna ledde till enklare reduktion av den resterande katalysatorn. https://lup.lub.lu.se/student-papers/record/9112918/file/9113039.pdf application/pdf 2675210 no 2023 eng Catalysis Hydrodeoxygenation TPR NiMo-catalysts Chemical engineering Chemistry 9112918 2023-03-27T14:17:21+02:00 2023-05-04T09:20:30+02:00 2023-05-04T09:20:30+02:00

oai:lup-student-papers.lub.lu.se:9112997 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Iga Wawerek author 9112995 Per Bengtsson supervisor Department of Chemistry v1000647 department Abstract <br /> <br /> Introduction: this study is about optimization and application of a new liquid chromatography tandem mass spectrometry method with reversed phase instead of HILIC column for analysis of methylmalonate. <br /> <br /> Background: methylmalonate cannot be broken down if there is a low level of cobalamin. Therefore, the investigation of lack of cobalamin is supplemented with, among other things, methylmalonate analyzes. The analyzes are performed with LC-MS/MS instruments where an effective separation is required. <br /> <br /> Aim(s): this study aims to optimize a new analysis method at LC-MS/MS for greater chromatographic separation of methylmalonate with reversed phase, as the current method is insufficient and has been discontinued. <br /> <br /> Methods: optimization of parameters such as gradients of mobile phases, collision energy, temperature and flow established the rest of the study. Patient samples were then analyzed for validation of the new method. Linearity test of dilution series was made to examine up to which levels the method is linear within, test to determine the lowest detectable level of analyte, carry over test to minimize contamination and evaluation of signal/noise. <br /> <br /> Results: concentrations of 40 µM gives a carryover of less than 0.03 µM, which is the lowest level of quantification. Comparison of methylmalonate between the theoretical values on the y-axis and the obtained values on the x-axis gave an explanatory rate (R2) of 99.94% and a strong correlation. The regression shows that the relationship is linear, and the linear function was calculated as y=0.6229x + 0.182. A Passing-Bablok regression analysis was made to compare the old method with the new which resulted in a strong linear relationship without neither systematic nor proportional differences. <br /> <br /> Conclusion: comparison of the new optimized method with the old one has resulted in a good precision and agreement with each other, which would allow to be using this method for the analysis of methylmalonate. <br /> <br /> Keywords: Liquid chromatography, methylmalonate, tandem mass spectrometry Populärvetenskaplig sammanfattning <br /> <br /> Vid kemiska analyser på laboratorium är det ofta nödvändigt att separera olika molekyler i en blandning med hjälp av vätskekromatografi. Vätskekromatografi är en separationsmetod där man använder sig av tvåfassystem. Masspektrometri är en teknik där joner separeras i gasfas baserat på deras massa i förhållande till laddning (m/z). En kombination utav dessa metoder kallas vätskekromatografi- tandem masspektrometri (LC-MS/MS). Genom att kombinera dessa två metoder kan man få en bättre och noggrannare separation och identifiering av olika molekylslag, till exempel molekylen metylmalonat (MMA) som är en markör för brist på vitamin B12. <br /> <br /> I det här arbetet utfördes ett metodbyte och tillämpning av en ny analysmetod för LC-MS/MS för att kunna analysera molekylen metylmalonat (MMA) bättre. Man ville uppnå en bättre kromatografisk separation av metylmalonat med omvändfas, eftersom den nuvarande metoden var otillräcklig och har lagts ner. Undersökningsfrågorna som behandlades i arbetet var: <br /> <br /> Vilka parametrar i MS-systemet är de mest kritiska? <br /> <br /> Hur är inomdags- och mellandags-variationen med den nya metoden? <br /> <br /> I vilken utsträckning smittar provet nästa prov? <br /> <br /> Finns det något linjärt samband mellan prover i en spädningsserie? <br /> <br /> Metodjämförelse för att ta reda på om det finns systematiska och proportioonella skillnader mellan HILIC och omvändfas. <br /> <br /> Optimering av parametrar som gradienter av mobilfaser, kollisionsenergi, temperatur och flöde la grunden för resten av studien. Patientprover analyserades sedan för validering av den nya metoden. Linjäritetstest av utspädningsserier gjordes för att undersöka upp till vilka nivåer metoden är linjär inom, bestämma den lägsta detekterbara nivån av analyten, smittest för att minimera kontaminering och utvärdering av signal/brus. <br /> <br /> Resultatet av smittester med koncentrationer upp till 40 µM ger en överföring på mindre än 0,03 µM, vilket är den lägsta kvantifieringsnivån. Jämförelse av metylmalonat mellan de teoretiska värdena på y-axeln och de erhållna värdena på x-axeln gav en förklaringsgrad (R2) på 99,94 % och en stark korrelation. Regressionen visar att sambandet är linjärt, och den linjära funktionen beräknades som y=0,6229x + 0,182. En Passing-Bablok regressionsanalys gjordes för att jämföra den gamla metoden med den nya vilket resulterade i ett starkt linjärt samband utan vare sig systematiska eller proportionella skillnader. <br /> <br /> Jämförelse av den nya optimerade metoden med den gamla har resulterat i en god precision och överensstämmelse med varandra, vilket skulle göra det möjligt att använda denna metod för analys av metylmalonat. 2023 swe Analytical chemistry Liquid chromatography methylmalonate tandem mass spectrometry Chemistry 9112997 2023-03-29T12:15:28+02:00 2023-04-04T13:07:06+02:00 2023-04-04T13:07:06+02:00

oai:lup-student-papers.lub.lu.se:9113585 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Aidas Urbonavicius author 9031831 Kimberly Dick Thelander supervisor Robin Sjökvist supervisor Mikelis Marnauza supervisor Centre for Analysis and Synthesis v1000651 department III-V semiconductor material based nanowires have been extensively<br /> studied and shown to be a very exciting building block for future<br /> electronics. Material systems such as GaSb show a lot of promise<br /> in optoelectric and thermoelectric generation applications because of<br /> its high electron mobility and small bandgap. Although there is a lot<br /> of research about III-V nanowires, a gap in understanding antimony<br /> based nanowire growth is present. The surfactant effect of Sb makes<br /> growth of antimony based nanoowires challenging. The aim of this<br /> master thesis is to investigate direct nucleation of GaSb from both<br /> Au and Sn seed particles which would help to develop a method for<br /> direct nucleation. The study is carried out in an environmental transmission<br /> electron microscope which enables the nucleation of GaSb to<br /> be studied and recorded in-situ. Au seeded nucleation occurred at<br /> high amounts of Ga present in the particle, above 90 at.%, whilst it<br /> is shown that Sn seeded nucleation is possible for a very broad range<br /> of seed particle compositions, between 12 at.% and 70 at.%. The Au<br /> seeded nanowires were much bigger than the Sn seeded, 100 to 200 nm<br /> and 25 to 50 nm respectively, which is related to the Ga amount in the<br /> seed particle. This shows that Sn seeded GaSb direct nucleation gives<br /> much more promise if the nanowires would be integrated into electrical<br /> devices where smaller diameter nanowires are needed. For Au<br /> seeded GaSb nanowires twin planes were observed in the zinc blende<br /> crystal structure which indicated a possibility of polytypism in GaSb<br /> nanowires which has not been reported yet. The observation of polytypism<br /> in GaSb is the first step to crystal phase engineering in GaSb<br /> nanowires which could be crucial in applications such as nanowire<br /> quantum dot devices. This thesis serves as a guideline and a starting<br /> point for further GaSb direct nucleation, nanowire growth and crystal<br /> structure studies. Under de senaste 30 åren har all elektronik fått allt mindre storlek. Detta beror på att man har lyckats skala ned de komponenter som bygger upp dagens elektronik till nanoskalan. En av de allra viktigaste strukturerna som har bidragit till den här utvecklingen är nanotrådar, som är i storlek av en miljarddels meter. Nanotrådar är små avlånga strukturer som är kristallina och kan användas att bygga upp elektriska komponenter så som transistorer. Istället för att säga &quot;framställa nanotrådar&quot; brukar man istället använda frasen &quot;växa nanotrådar&quot;. Det beror på att nanotråden växer nerifrån upp och väldigt ofta har en så kallad &quot;fröpartikel&quot;, som liknar hur en växt växer. För att börja växa nanotrådar använder man oftast en metallisk fröpartikel som utgångspunkt. Beroende på vilket material partikeln består av så kan man växa olika nanotrådar vid olika temperaturer och miljöer. I mitt projekt har jag undersökt hur olika material på partikelfröet påverkar växten av nanotrådar.<br /> <br /> Nanotrådar består av halvledarmaterial vilket innebär att deras egenskaper är som en kombination av en isolator och en ledare. Det är därför halvledare är så viktiga och användbara för elektriska komponenter då deras strömledande förmåga kan kontrolleras. Atomerna i en nanotråd sitter i väldefinierade positioner som bygger upp en kristallstruktur. Man kan jämföra atomerna i kristallen med pingisbollar i en låda. Det finns flera olika sätt att placera pingisbollarna i lådan. Man kan bara slänga in dem eller lägga i dem en och en. Naturen är väldig effektiv och vill alltid minska mängden energi den ska spendera och vill fylla ut volymen på det mest effektiva sättet. Därför, enligt naturen, ska pingisbollar sättas in på det sättet som gör att vi får maximalt antal bollar i lådan. Samma princip gäller för atomerna i kristallen som strukturerar sig på så sätt att volymen fylls ut på det mest effektiva sättet. Men om man tillför energi, till exempel genom att öka temperaturen, kan atomerna börja röra på sig och istället bygga upp någon annan struktur. Det leder till att nanotrådar kan finnas i flera olika kristallstrukturer.<br /> <br /> Det finns flera olika metoder för att växa nanotrådar, och en av de vanligaste är att använda metalliska partiklar som en startpunkt. För att nanotråden ska kunna bildas måste man tillföra material som oftast är i gasform. Materialet då samlas in i partikeln och det kan då börja bilda en kristall under den. I och med kristallen byggs upp under partikeln, så kommer den resulterande nanotråden ha partikeln på toppen. Guld är bland de vanligaste metallerna att använda för dessa partikelfrön, men det finns flera alternativ så som silver eller tenn. Partikeln fungerar som en samlingspunkt för material som då kan bilda en nanotråd. Utöver det vet man inte exakt varför olika partiklarna är &quot;bättre&quot; än andra, men det finns olika teorier.<br /> <br /> Man kan fråga sig &quot;Hur kan man veta/se vad som händer när nanotråden växer om de är så små?&quot;. De flesta känner igen ljusmikroskopet som används inom nästan alla vetenskapliga fält för att undersöka allt som är för litet för våra ögon. Ljusmikroskopet är dock inte tillräckligt bra för att undersöka grejer på nanoskalan. Några smarta forskare har kommit på att istället för att använda ljus som består av fotoner, så kan man använda elektroner och uppfann då elektronmikroskopet. Elektronmikroskopen är mycket mer komplicerade än ljusmikroskopen, men det allra viktigaste som man ska veta är att det ger oss möjlighet att undersöka pyttesmå föremål, såsom nanotrådar.<br /> Inom mitt examensarbete så använde jag ett väldigt speciellt elektronmikroskop som inte endast tillåter undersökning av små strukturer, men också ger möjlighet att växa dem! Det är väldigt användbart, för vanligen växer man nanotrådar i en stängd kammare där man inte vet riktigt vad som händer och kan endast analysera resultaten i efterhand. Därför kunde jag undersöka hur nanotrådar växer och identifiera olika problem och fenomen som uppstår under nanotrådens växtprocess.<br /> <br /> Men en väldigt betydelsefull fråga kvarstår: varför är nanotrådar så viktiga? Det finns flera olika anledningar, men en av de största är att det är något nytt! Nanotrådstekniken är relativt ny och det finns redan några användningsområden såsom solceller. Det finns hur mycket forskning som helst som föreslår flera olika nya material med nya egenskaper som kan användas för att växa nanotrådar och hur dessa kan användas för väldigt spännande appliceringar. Det är bara en tidsfråga innan de kan realiseras i verkligheten. Allt från att göra elektriska komponenter ännu mindre till andra ännu outforskade forskningsfält. Kort och gott ser framtiden för nanotrådar väldigt ljus ut. https://lup.lub.lu.se/student-papers/record/9113585/file/9121695.pdf application/pdf 46182494 no 2023 eng ETEM Nucleation GaSb Nanowires Materials chemistry Technology and Engineering Chemistry 9113585 2023-04-18T13:06:15+02:00 2023-06-28T10:56:25+02:00 2023-06-28T10:56:25+02:00

oai:lup-student-papers.lub.lu.se:9113890 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Serdar Unal author 9057693 Researcher Christian Hulteberg supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Kraftliner is the unbleached pulp used in the outermost layer of corrugated cardboard. Like other types of paper, it is produced from wood chips as a raw material. Kraftliner is known for its high tensile strength, tear resistance, compressive strength, etc., making it suitable for packaging material for heavy objects. When paper is exposed to moisture, there is usually a dimensional change within the fiber structure as it is a porous material. Thus, paper can absorb water from the environment and swell, called hygro-expansion. When exposed to moisture, corrugated cardboard boxes used for high-quality boxes, packaging, and protective layers in transport packaging suffer as well. By boiling wood chips to different kappa numbers (lignin content) and reducing the hemicellulose content in some of the pulp samples, the influence of the chemical composition on the tensile strength, compressive strength, and hygroexpansion of the number of produced sheets was experimentally determined. A fiber test was also performed to compare fiber properties and identify any relationships between them. Tensile strength, compressive strength, and hygroexpansion were found to increase with increased sheet density. Removal of hemicellulose was shown to decrease tensile strength by up to 72% and increase hygroexpansion by up to 17%, but did not significantly affect compressive strength. Finally, the effect of lignin&#39;s chromophore groups on the brightness of the sheets was also studied, which resulted in a significant decrease of about 15-18% when removing the chromophores. https://lup.lub.lu.se/student-papers/record/9113890/file/9113957.pdf application/pdf 5893277 no 2023 eng Chemical Engineering Hygroexpansion Pulp Kraftliner Tensile strength Iso-brightness Chemistry 9113890 2023-05-02T15:50:57+02:00 2023-05-04T14:15:21+02:00 2023-05-04T14:15:21+02:00

oai:lup-student-papers.lub.lu.se:9114571 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mattias Tan author 9056195 Nitish Kumar Garg supervisor Department of Chemistry v1000647 department Both C-N and C-C bond formation reactions are fundamental part of synthetic chemistry and have been widely studied for the past several decades and will most likely continue to do so in the future. In this project, I report a base catalyzed transition metal-free C-N and C-C bond formation reactions from abundant and green substrates with sustainable chemistry in mind. Previous methods uses either halides, transition metal or series of oxidation and reduction steps to produce similar C-N and C-C bonds. These methods except excluding transition metal-based catalyst are both atom inefficient, toxic or produces a lot of wastes. The transition metal-based catalyst method was later developed to overcome these drawbacks and utilizes hydrogen borrowing methodology. The borrowing-hydrogen methodology is much more atom efficient and less toxic as it only produces water as byproduct. The only drawback with this method is the usage of transition metal catalyst as well as to synthesize these catalysts which could be costly and toxic. <br /> <br /> In this work, the reactions are less toxic, usage of abundant and greener substrates, more sustainable/greener with water as only byproduct, atom efficient and transition metal-catalyst free. The reaction for N-alkylation (C-N bond formation) was carried out with primary amine such as aniline and primary alcohol as benzyl alcohol with catalytic amount of KOtBu as base with toluene as solvent in closed air at 140ᵒC for 18h. For β-alkylation (C-C bond formation) the reaction was carried out with benzyl alcohol as primary alcohol and 1-phenyl ethanol as secondary alcohol with catalytic amount of KOH as base with toluene as solvent in closed air at 120ᵒC for 18 h shown in scheme 1. The methodologies utilize hydrogen transfer and the product from these reactions were successfully synthesized in 98% yield with only water as a byproduct. The reaction methods were then explored with various derivatives of the standard reaction substrates to investigate the scope of these reactions. The reactions were shown to be successful with various derivative of products which makes the reactions excellent atom efficient, cost effective, greener, and more sustainable methods for C-N and C-C bond formations. The importance of carbon-carbon (C-C) and carbon-nitrogen (C-N) bond formation in pharmaceutical industry as well in general synthetic chemistry is fundamental and essential in many everyday products. Many drug that we take from time to time and for some, every day, in order to keep ourselves healthy are based on these methods for development of various drugs shown in Figure 1.<br /> <br /> The bond formation methods are not just to make a bond between two atoms but also a tool to introduce various molecule groups to another molecule. These methods expand the complexity of the molecule which produces different products with desired effects such as the drug molecules mentioned.<br /> Knowing the importance of the C-N and C-C bonds formation, many methods have been developed for the past decades and are still in focus to further improve the efficiency but also with sustainability in mind. Traditionally, making a C-N bond, it was common to use halides (Br, Cl, F) as part of the production process to form the desired C-N bond. Although it is a useful method, this method unfortunately has some large disadvantages where one of them is by generating a lot of waste in form of byproducts. The reactions also involve the use of toxic chemicals (Br, Cl, F) which is far from ideal when striving for greener and more sustainable methods. The N-alkylation (C-N bond formation) was then further improved by using transition metal-based catalyst which resulted in less toxic chemicals being used as well as greatly reducing the amount of byproducts with only water instead, making the reaction much more efficient and sustainable. The previously toxic chemicals (halides) are instead replaced with alcohols and amines which is much less toxic and more sustainable, although the reaction requires higher temperature (often 100ᵒC and higher) it is still considered better alternative. The reaction method was then even further improved by replacing the transition metal-catalyst with other organic chemicals such as nitrile and pyridine as a catalyst or activation molecule with the only drawback being, more waste generated than with transition metal-catalyst.<br /> The situation is similar with β-alkylation (C-C bond formation) as it was traditionally produced by multi step synthesis. These series of reaction steps are less efficient due to the formation of byproducts in each step and generated a lot of waste. The reaction was then also improved by introducing transition metal-based catalysts to the reaction which utilizes a strategy called borrowing-hydrogen (BH) similar to N-alkylation, where the role of the metal was to catalyze the transferring of the hydrogens from the starting material into the product. The reaction uses primary and secondary alcohols which is a great improvement in green and sustainable chemistry as they are abundant and less toxic. <br /> The methods are both atom efficient and less toxic compared to the previous mentioned method as it also only releases water as byproduct. As good as the reaction methods are, the reactions have a drawback which is the usage of transition metal-catalyst as it can be toxic and costly. This was later overcome by having the reaction run without the transition metal but using larger amount of base (stoichiometric) compared to catalytic amount of base with transition metal catalyst. <br /> The aim of this project is therefor, to further improve and push the boundaries of C-N and C-C bond formation methodologies with sustainability and green chemistry in mind. This is done by developing and optimizing transition metal-catalyst free reactions but retaining most of advantages. In this project the methods are aimed to further reduce the amount of waste generated while still using less toxic and abundant chemicals. The reactions methods in this project do not require any activation agents or other chemicals to catalyze but the base itself. The reactions are thus less sensitive to air because of the absence of transition metal-catalyst but instead essential for the reaction to work. The reactions are also explored with various chemicals to synthesize different products to study the scope of the reaction methods. 2023 eng C-N bond formation C-C bond formation Transition metal-catalyst free Base catalysed Sustainability Green chemistry Borrowing hydrogen Analytical chemistry Chemistry https://lup.lub.lu.se/student-papers/record/9114571/file/9114573.pdf application/pdf Abstract and popular science scheme and figure no 9114571 2023-05-15T19:41:05+02:00 2023-05-22T10:46:34+02:00 2023-05-22T10:46:34+02:00

oai:lup-student-papers.lub.lu.se:9115258 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Saga Vesterbacka author 9115255 bitr. universitetslektor Baozhong Zhang supervisor Centre for Analysis and Synthesis v1000651 department Plastic recycling is a very relevant topic from both environmental and economic viewpoints. Chemical plastic recycling is a logical solution to the plastic problems, which shows the potential to reduce plastic waste and carbon emissions from burning the plastics. <br /> One strategy of chemically recycling plastic is to incorporate sensitive bonds into polymer chains, which can be selectively degraded under specific conditions. In this study, selective acetal hydrolysis of two poly(acetal-esters)s containing spiroacetal linkage was performed under different conditions regarding temperature, concentrations of acid, and additional solvents. More specifically, polymers with spiroacetal groups have been hydrolyzed, which include: Akestra 90, Akestra 110, PHVT-5 and PHVT-20. The experiments have been mainly analyzed with NMR spectroscopy. The results show that both Akestra 90 and Akestra 110 are very resistant to hydrolysis. However, PHVT-5 and PHVT-20 could be completely hydrolyzed. There was then an attempt to re-polymerize the oligomer of PHVT-5 which led the polymer to be polymerized to 79 %. Plast är ett material som vi alla stöter på i vår vardag. Du kommer ha svårt att inte stöta på plast åtskilliga gånger under dagen i vårt moderna samhälle och efterfrågan för plast runt jorden ökar år efter år. Problemet är att när vi behöver slänga vårt plastavfall så är återvinnigsmöjligheterna idag inte så stora globalt sett. Mycket hamnar i naturen och i havet vilket är hemskt för miljö och ett enormt slöseri av outnyttjade resurser. Det vanligaste sättet att hantera plastavfall är att lägga det på soptippen och lämna plasten där länge eftersom plast tar evigheter att brytas ner. Fast plastavfall är skräp så har den ett värde i sig om man kan elda upp det och utnyttja energin eller återvinna den. Det är på ett sätt bra om man kan få ut energi av att förbränna plast men mindre bra att det släpper ut växthusgaser som värmer upp vår planet och andra farliga avgaser. Det bästa är dock om man kan återvinna plasten men det är tyvärr det alternativ som väljs mest sällan idag. Anledningen till att man inte väljer att återvinna plast är att den återvunna plasten brukar ha sämre egenskaper än ny plast och ofta till ett högre pris. Därför behövs det mer forskning på bättre processer för återvinning som kan förbättra den återvunna plastens egenskaper och helst på ett så miljövänlig och ekonomiskt sätt som möjligt.<br /> Ett sätt att återvinna plast är kemisk återvinning där man bryter ner plasten till molekyler och sedan återanvänder dem. Syftet med det arbete som jag har utfört under mitt examensarbete har varit att selektivt bryta ner bindningar i plaster till mindre beståndsdelar som jag kan sen använda för att bygga upp plasten igen. Bindningarna kan brytas genom att reagera med vatten om reaktionen är katalyserad med stark syra. Jag har provat att hydrolysera både en kommersiell polymer som heter Akestra och en biopolymer syntetiserad på kemicentrum av Smita Mankar. Akestra visade sig vara väldigt resistent mot hydrolys och gick inte särskilt bra att bryta ner men jag lyckades däremot hydrolysera biopolymeren helt och hållet till 100%. Det gick även delvis att bygga upp den nedbrutna bioplasten igen men mer forskning krävs för att 100% procent av bioplasten ska bli återuppbyggd. En annan möjlig forskningsväg att gå är att försöka bygga upp de nedbrutna plastmolekylerna med en annan molekyl för att utveckla ett nytt material vilket kan tillföra ett ökat värde för materialet. Detta forskningsområde är väldigt relevant för att lösa problemet med ackumuleringen av plast på vår planet. https://lup.lub.lu.se/student-papers/record/9115258/file/9115259.pdf application/pdf 809733 no 2023 eng Poly(actetal-ester)s Chemical plastic recycling Hydrolysis Acidic degradation Akestra PHVT Re-polymerization Polymer technology Chemistry https://lup.lub.lu.se/student-papers/record/9115258/file/9115261.pdf application/pdf no 9115258 2023-05-22T14:51:19+02:00 2023-05-29T11:55:07+02:00 2023-05-29T11:55:07+02:00

oai:lup-student-papers.lub.lu.se:9117022 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Constantinos Chatzicharalampous author 9116105 Herwig Schüler supervisor Department of Chemistry v1000647 department PARP14, a member of the PARP family that can modify target proteins with ADP-ribose has stimulated the interest of researchers as it is involved in a variety of diseases including cancer. While some structural and activity characterization has been conducted, it has not been yet expressed and purified as a single molecule, instead it was examined in small constructs that include several of its domains separately. It contains multiple domains, the RNA recognition motif (RRM), three tandem macrodomains, a WWE and an ART catalytic domain (ADP-ribosylation). In this study a suspected region of the protein that could be responsible for aggregation and contamination generation, was substituted (using Gibson-assembly cloning), by a soluble SUMO-tag to express PARP14 as a single molecule, excluding the region starting from RRM until the N-terminal macrodomain. The SUMO-PARP14 was also studied from structure and activity perspective to approximate the characterization of the wild-type PARP14. The protein purification steps utilized were Immobilized Metal Affinity Chromatography, Anion exchange chromatography and Size Exclusion Chromatography. Negative staining was used to visually assess the protein structure in solution to confirm that it is suitable to be observed using cryo-EM in the future. Western blots and the MacroGreen plate assays were used to test whether SUMO-PARP14 preserves the ART activity, by monitoring the signal generated from ADP-ribosylated targets after treatment with an HRP-Streptavidin and an ADP-ribose binding macrodomain-GFP, respectively. SARS-CoV-2-NSP3-MAC1 inhibitory compounds were also tested against PARP14 macrodomain 1 due to structural homology, to determine if there is inhibition so that they could be used as ligands in the future for cryo-EM or crystallography. The methods used for the drug assessment were Western blot and Differential Scanning Fluorimetry. Ultimately, SUMO-PARP14 was successfully expressed with low signs of aggregation and contamination, and it was decided that it can be used after purification optimizations in cryo-EM. The protein retains the wild-type ART catalytic and macrodomain 1 (M1) glycohydrolytic activity (which was firstly experimentally confirmed in this study). As a confirmation that structural homologues of PARP14 M1 have glycohydrolytic capacity, PARP9 M1 which is its closest phylogenetic homologue, was assessed and determined that also has the same activity. Further, all compounds tested against PARP14 M1 were found to destabilize the protein structure observed through Tm shifts. Concluding, SUMO-PARP14 is a suitable construct to approximate the structure and activity of wild-type PARP14 as it can be highly pure with no significant aggregation present. The interest of this study is on a family of proteins called PARPs (Poly (ADP-ribose) polymerases) with focus on a member of this family, PARP14. PARP14 attaches a molecule called ADP-ribose (Adenosine Diphosphate-ribose) to other proteins in a cell (this action is called ADP-ribosylation), altering its properties. PARP14 is responsible for immune system regulation and was also identified to be present in a variety of cancers and inflammatory diseases, thus there is a public health interest to study this protein. In previous studies conducted in our laboratory, attempts to isolate, and purify the entire PARP14 molecule from bacterial cells, lead to protein aggregation and contamination of the sample. The goal of this study was to use biochemical approaches enabling researchers to prevent these issues from occurring and in parallel to be able to characterize the structure and activity (ADP-ribosylation) of PARP14. The tactic followed was to substitute a region in the protein, that was suspected to cause issues with purification, with a soluble protein sequence, called SUMO (Small Ubiquitin Like Modifier), to test whether the aggregation and contamination issues disappear. In parallel, the ADP-ribosylation activity was studied using assays that detect ADP-ribose presence on proteins. <br /> <br /> The study results show that the SUMO insertion in PARP14 significantly reduced the presence of aggregation and contaminants and that the new protein, called SUMO-PARP14, preserves the ADP-ribosylation activity. In addition, it was experimentally confirmed for the first time in literature, that another domain that it contains, called macrodomain 1, can remove ADP-ribose from proteins, thus reversing its own ADP-ribosylation effect. Concluding, SUMO-PARP14 can be used in the future to find approximately the structure of the original PARP14 protein and its interactions with other cell contents such as DNA, RNA and proteins, while also providing the opportunity to study in more extent its ADP-ribosylation addition and removal properties. https://lup.lub.lu.se/student-papers/record/9117022/file/9117025.pdf application/pdf 2472939 LU/LTH access 2023 eng ADP-ribosylation Biochemistry Glycohydrolase Macrodomain MacroGreen PARP Chemistry 9117022 2023-05-26T15:53:45+02:00 2023-05-31T09:47:31+02:00 2023-05-31T09:47:31+02:00

oai:lup-student-papers.lub.lu.se:9117138 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Fatlinda Gashi author 9031589 Charlotta Turner supervisor Department of Chemistry v1000647 department Supercritical fluid extraction method was optimized and applied to extract seed oil from baobab seed (Adansonia digitata L.). A full-factorial design was used to investigate the interaction influence of density and temperature in the range of 0.6-0.8 g/ml 40 to 77 °C, respectively, on the extracted amount of oil from crushed seeds. The results showed that density has a significant influence on the extracted amount of oil. The best extraction condition using neat CO2 was found at 0.8 g/ml and 77 °C, yielding 9-11w/w % ± 1.2w/w % oil. An extraction kinetics study revealed both a solubility-controlled extraction, as well as a desorption/diffusion-controlled extraction. GC analysis revealed that palmitic acid, oleic acid and linoleic acid were the most abundant in the baobab seed oil after derivatization. Pressurized liquid extraction was optimized and applied to extract phenolic compounds from baobab seed (Adansonia digitata L.). A full-factorial design was used to evaluate the percentage of water in ethanol (10, 30, 50%) and volumetric ratio between CO2 (0, 5, 10% CO2) and the extracting solvent. The optimized setting from both SFE and PLE were used to run sequential extraction with SFE followed by PLE using the same instrument. It showed promising results with repeatable extractions. Baobabträdet är ett inhemskt träd i Afrika där bladen, fruktköttet och fröna från baobabfrukten är källor till kolhydrater, fibrer, fetter, proteiner och vitaminer, och konsumtion av dessa är vanlig i lokala samhällen. Efterfrågan på produkter tillverkade av baobabfrukt har ökat för konsumentvaror på de europeiska och amerikanska marknaderna och ett sådant område är den kosmetiska industrin där kärnolja från baobabfrukt kan användas som en ingrediens i formulering. <br /> <br /> Hur kan då olja utvinnas på ett effektivt sätt som ger högt utbyte och korta utvinningstider? En teknik med potential att erbjuda detta är superkritisk vätskeextraktion och med denna studie vill man utveckla en extraktionsmetod baserad på superkritisk vätskeextraktion (SFE). Därutöver vore det av intresse att undersöka om ytterligare extraktion kan utföras på de avfettade baobab kärnorna genom att i en sekvens med SFE följa upp med trycksatt vätskeextraktion (PLE) på samma instrument. Detta för att extrahera mer polära ämnen exempelvis fenoler. För att bekräfta oljeextraktionen görs en fettsyraprofileringsanalys av den erhållna oljan med GC-FID och GC-MS, och den totala fenol mängden analyseras med HPLC. <br /> <br /> SFE är en extraktionsmetod som använder superkritiska vätskor som är enfasvätskor där temperaturen och trycket befinner sig över den kritiska punkten. Superkritisk koldioxid är en vanlig superkritisk vätska som används vid extraktion och den vätske-liknande densiteten och gas-liknande viskositeten hos den superkritiska vätskan ger hög diffusivitet, vilket resulterar i en snabbare massöverföring. En superkritisk vätska har stor kompressabilitet som innebär att densiteten kan ändras genom att ändra på tryck och temperatur i extraktionen vilket resulterar i ändrad lösningsmedelskraft för den superkritiska vätskan. PLE är en extraktionsmetod där exempelvis vatten och etanol används som lösningsmedel och baseras på att lösningsmedlet ska befinna sig i flytande form över dess kokpunkt, vilket görs genom att utsätta vätskan för höga temperaturer och tryck. https://lup.lub.lu.se/student-papers/record/9117138/file/9117140.pdf application/pdf 1000327 yes 2023 eng analytical chemistry baobab seed extraction optimization fatty acid composition supercritical carbon dioxide extraction pressurized liquid extraction sequential extraction Chemistry 9117138 2023-05-28T13:38:40+02:00 2023-05-30T14:44:42+02:00 2023-05-30T14:44:42+02:00

oai:lup-student-papers.lub.lu.se:9117646 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Simon Gripvall author 9049075 Susanna Törnroth-Horsefield supervisor Department of Chemistry v1000647 department The metabolism of pyruvate in the cell is abnormally regulated in several human diseases, such as type-II diabetes, cancer and neurodegenerative disorders, in which the human mitochondrial pyruvate carrier (HuMPC) sits at a pivotal point. It transports pyruvate across the inner mitochondrial membrane and consists of two proteins, MPC1 and MPC2, and is a potential drug target against these diseases. There is currently no three-dimensional structure at atomic resolution nor unambiguity of the biological oligomeric composition of this pyruvate transporting complex, although many studies advocate for a heterodimer of MPC1/2 being the main functional unit. In this study, the pyruvate transport activity of HuMPC complexes was investigated as well as the presence of a MPC1/2 heterocomplex. The pyruvate transport activity of human MPC1 alone, MPC2 alone and MPC1/2 mixed together was investigated with a proteoliposome assay based on the enzymatic activity of lactate dehydrogenase (LDH). In addition, the presence of the MPC1/2 complex in proteoliposomes was examined with nano-differential scanning fluorimetry, as well as with cross-linking trials for further analyses with mass spectrometry. Pure HuMPC protein was obtained by affinity chromatography from solubilised Pichia pastoris membranes. Here it was demonstrated that MPC2 and MPC1/2 displayed higher pyruvate transport activity compared to MPC1. Moreover, the nano-DSF measurement did not give any concrete evidence of the presence of the MPC1/2 heterocomplex. The mass spectrometric analyses did not identify any cross-links between MPC1 and MPC2 in the MPC1/2 proteoliposomes but more peptides of MPC2 than MPC1 could be identified. In conclusion, the true pyruvate transporting complex of HuMPC still remains unclear based on these results, as well as the existence of the MPC1/2 heterocomplex, which requires further investigation. In cancer, type-II diabetes and neurological disorders, the way important molecules are interconverted into one another inside human cells is abnormally altered. An example of such a molecule is pyruvate. It is a central intermediary molecule in the processing of glucose that is present in the food we eat so we can generate energy for several important processes in the cell. A critical step in the continued processing of pyruvate is its transportation from the cytosol into the mitochondria. The protein responsible for this transportation is called the mitochondrial pyruvate carrier (MPC) and in humans, it consists of two different proteins (MPC1 and MPC2) cooperating and forming a complex to perform its function. It has been proposed that the MPC complex can serve as a potential drug target against the abovementioned diseases. Up until this point, there is no detailed information of how this protein is built up at a molecular level, which is required for efficient production of drugs. Moreover, it is also unclear of how many MPC1 and MPC2 proteins the MPC complex is composed of and which of three MPC complexes, MPC1 alone, MPC2 alone and MPC1/2 together is the main functional unit. The aim of this study is to investigate which of these three possible MPC complexes has the highest ability to transport pyruvate in a cell membrane resembling environment, called proteoliposomes, which are vesicles of lipid molecules in which the protein is imbedded in. The existence of a MPC1/2 complex, which several studies point towards is the main functional unit, was also examined with temperature stability tests based on the decomposition of the protein and with experiments in which one attempted to attach the two proteins together, called cross-linking. The detailed appearance of the MPC complex at a molecular level was supposed to be investigated as well, but due to lack of time this was not performed. To obtain these MPC1 and MPC2 proteins, cell membranes containing these proteins were extracted from yeast cells followed by isolation of the proteins with chromatographic methods based on their binding properties. It turned out that both MPC2 alone and MPC1/2 were able to actively transport pyruvate into these proteoliposomes, while MPC1 alone did not. In addition, the attempt to prove the existence of the MPC1/2 complex with the temperature stability tests as well as the attempt of cross-linking MPC1 and MPC2 together were both unsuccessful. In conclusion, although both MPC2 alone and MPC1/2 were able to transport pyruvate, it is still unclear which one of these two different species has the highest pyruvate transporting ability. Moreover, the unsuccessful attempt of the temperature stability tests as well as the cross-linking leaves the presence of the MPC1/2 heterocomplex still unknown and needs to be further investigated. https://lup.lub.lu.se/student-papers/record/9117646/file/9117651.pdf application/pdf 1505155 no 2023 eng biochemistry complex MPC proteoliposomes pyruvate transport Chemistry 9117646 2023-05-30T16:32:24+02:00 2023-06-01T08:46:16+02:00 2023-06-01T08:46:16+02:00

oai:lup-student-papers.lub.lu.se:9118805 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Elin Olsson author 9118803 Herwig Schüler supervisor Department of Chemistry v1000647 department Poly (ADP-Ribose) Polymerase 14 (PARP14) is an ADP-ribosyltransferase, an enzyme whose catalytic activity is to transfer ADP ribose (ADPr) to a target molecule, utilizing its substrate NAD+. PARP14 has been discovered to partake in the development of different kinds of cancers such as multiple myeloma, B-cell lymphoma and sarcoma, which has led to the interest of using PARP14 as a drug target for cancer treatment by inhibiting its activity. The challenge is to find an inhibitor that not only inhibits the enzyme at low concentrations, but also is selective to PARP14. The aim with this study is to evaluate new synthetized compounds that potentially could inhibit PARP14, and to determine their IC50 values. The methods used for this are different adaptations of the MacroGreen assay, which make use of a fluorescent tag that binds to ADPr and thus enables to quantify the amount of modified protein over time as well as how the activity decreases when a compound is introduced. The results show that the compound with the highest inhibition efficiency has an IC50 value of 0.68 µM, which is, compared to the literature, a very potent inhibitor, but not as potent as one already existing (0.16 µM). The conclusions that can be made from this are that the compounds whose IC50 values are determined, are highly efficient inhibiting PARP14, but they are yet to be tested for their selectivity. In our everyday life we make use of some kind of communication to interact with each other. Think of it as the indicator of a car, letting you know if the driver is intending to turn right or left. Or when someone wants your attention from a distance and they wave their arms and shout your name. Signaling is all around us, present in different kinds of way and always with a purpose – letting us know something. If we scale this down from the big world around us, and instead look at a cellular level, signaling is present in all organisms. Indeed, without signals, nothing in our bodies would work.<br /> <br /> Our bodies are made up of many different types of cells. New cells arise from cell division, where a mother cell is divided into two new daughter cells. The daughter cells then grow and divide again into two new daughter cells, and so on. However, when something is wrong with the cell beyond repair, it is programmed to die – a process called apoptosis. Special types of cells can evade apoptosis, and therefor continue to divide and increase in numbers for longer periods of time. These are the cancer cells. Nonetheless, there are still ways for these cells to die, one of which is cell death following DNA damage that is not repaired.<br /> <br /> The enzyme that is studied in this report, Poly ADP-Ribose Polymerase 14 (PARP14), has been found to be part of the development of certain cancer types, for example multiple myeloma. It cleaves a molecule, Nicotinamide Adenine Dinucleotide (NAD+), and transfers a part of it onto a target molecule. This is seen as a signal by other molecules in the cell that something is needed to be done with the targeted molecule. When the target is damaged DNA, the signal perceived is to recruit DNA repairing molecules to the site of damage. However, in cancer cells this is not a desired response, since the consequence of this signaling is that the DNA is repaired and the cancer cell continues to live. Herein lays the interest, as well as the aim of the study, to find a molecule that is able to inhibit the activity of PARP14, which would hinder the DNA repair and thus leading to death of the cancer cell. <br /> <br /> This study evaluated synthetized compounds that could be potential inhibitors of PARP14, by assessing how much they decrease the activity of the enzyme. This was done using an enzymatic assay called MacroGreen, which enables comparing between a non-inhibited enzyme to an inhibited enzyme. The results showed that some of the compounds tested are able to inhibit PARP14 at low concentrations, but not as efficiently as some compounds already existing in the literature. 2023 eng ADP ribosylation Biochemistry Cancer Inhibition MacroGreen PARP14 Chemistry 9118805 2023-06-02T12:02:04+02:00 2023-06-08T12:29:25+02:00 2023-06-08T12:29:25+02:00

oai:lup-student-papers.lub.lu.se:9118991 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Elin Edström author 9118987 Urban Johanson supervisor Department of Chemistry v1000647 department Introduction: The topic of this project was the expression and purification of Transient Receptor Potential Ankyrin 1 (TRPA1) from Anopheles gambiae, both the full length protein and a truncated version.<br /> Background: The structure of AgTRPA1 has not previously been determined, a step towards the determination is to express and purify the protein. Particular challenges working with AgTRPA1 are that it is a membrane protein which is notorious for being expressed at a low level and the need of detergent to get the protein solubilized.<br /> Aim: The aim with this project was to transform a plasmid containing the protein sequence into the yeast Pichia pastoris where it would be expressed. The protein was then purified using a his-tag and followed with a GFP-tag.<br /> Methods: Electroporation was used to transform the yeast, the expression of protein was screened with the fluorescence of GFP. A jackpot clone was grown in a fermenter and cells were lysed with a bead beater, the protein was solubilized with foscholine-14 and purified with Immobilized metal affinity chromatography, reverse IMAC and size exclusion chromatography.<br /> Results: The truncated version of AgTRPA1 was successfully expressed and purified with the method mentioned above. Expression of the full length protein could not be confirmed due to lack of time and therefore the purification method could not be tested on this version. Purification with the his-tag was an effective method and the GFP-tag made it possible to follow the protein through the entire process.<br /> Conclusion: From this project, it was concluded that the truncated version of the protein was easier to transform into the cell compared to the full length. Only the expression of the truncated protein could be confirmed. The purification of the truncated protein was successful and a high amount was purified. TRPA1 from malaria mosquito<br /> <br /> In the membrane of the cell there are proteins embedded that works as channels between the outside and inside of the cell. These proteins are used to communicate the environment outside of the cell to the inside of the cell. One protein like this is the so called wasabi receptor which has the more technical name Transient Receptor Potential ion channel with ankyrin repeats (TRPA1). This type of protein can be found in a number of organisms, but in this project the focus is on TRPA1 from the African malaria mosquito. There are substances, e.g. in wasabi, which can bind to this protein and activate a pain response. To design a substance that generates the pain response specifically in the mosquito, the protein structure needs to be known. This means that with knowledge of this protein a repellent for the mosquito can be designed. <br /> For this project, the goal was to achieve a pure protein sample. To study this protein, it first had to be produced, which was done by introducing the DNA sequence for the protein into a fast growing organism such as a yeast. To visualise the protein throughout the process, the sequence for a green fluorescent protein was added to the protein sequence so that the protein would emit green light when illuminated with blue light. This fluorescent light was used to evaluate which yeast colonies that produces the highest amount of the protein. A colony was chosen to grow in big scale and the cells were broken and the TRPA1 was purified from the other parts of the cells.<br /> The results from this project were that the full length protein was hard to introduce into the yeast and it was produced at a low level. However, a shortened version of the protein was successfully introduced and produced in large quantities, therefore the purification was done on this version. To conclude this project, the method chosen worked for the shorter version of the protein, but more time is needed in order to determine if the same method can be used for the full length protein. https://lup.lub.lu.se/student-papers/record/9118991/file/9119008.pdf application/pdf 16717941 yes 2023 eng AgTRPA1 Biochemistry GFP-tag His-tag Pichia pastoris Chemistry 9118991 2023-06-02T15:25:39+02:00 2023-06-08T11:28:00+02:00 2023-06-08T11:28:00+02:00

oai:lup-student-papers.lub.lu.se:9063100 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ujala Mahmud author 9063084 Yong Li supervisor Department of Chemistry v1000647 department New half-sandwich complexes of pentamethylcyclopentadienyl-rhodium, iridium, and p-cymene-ruthenium have been synthesized and characterized. All metal complexes contain ligands based on a 4-chloroquinoline framework analogous to the antimalarial drug chloroquine. The first reaction in the preparation of a new ligand is a nucleophilic substitution at the chloro position of 4-chloro-7-fluoroquinoline by a Schiff base condensation. The salicylaldimine ligand derivatives are synthesized by a Schiff base condensation from N1-(7-fluoroquinolin-4-yl)ethane-1,2-diamine and determined 2-hydroxy-benzaldehydes in ethanol which leads to the formation of HLSAL(H), HLSAL(F), HLSAL(Cl), HLSAL(Br), and HLSAL(I) ligands. Furthermore, these ligands will then be used to coordinate with the metal dimers [Ir(Cp*)Cl2]2, [Rh(Cp*)Cl2]2, and [Ru(p-cymene)Cl2]2 to synthesize the different metal complexes. Due to the startingmaterial 4-chloro-7-fluoroquinoline not reacting with various ligands along with the metal complexes, no metal complexes could be obtained. Instead, another starting material was utilized for further examination. Malaria är en tropisk sjukdom som orsakas av en encellig parasit av släktet Plasmodium och sprids till människor via infekterade myggor. Smittan uppstår genom stick från honmyggor av Anopheles-släktet. Efter sticket, tar sig parasiten till levern och sedan till de röda blodkropparna som efter ett tag spricker. Därefter kommer parasiten ut i blodet tillsammans med andra nedbrytningsprodukter vilka är toxiska. Malariainfektionen leder till feber, frossa och kräkningar. Det finns fyra olika arter av Plasmodium-parasiter som smittar människor, vilket är Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae och Plasmodium ovale. Parasiten P. falciparum är den dödligaste utav alla; ungefär 20 procent av alla fall smittade med denna parasit leder till döden i avsaknad av behandling. Ett stort problem är att många av malariaparasiterna har uppnått resistens mot de mest effektiva och användbara läkemedlen. Klorokin-, är ett antimalaria-läkemedel som upptäcktes 1934 av Hans Andersag, en tysk forskare. Läkemedlet är effektivt mot den asexuella formen av malariasjukdomen i de röda blödkropparna. Klorokin används då den är billig, effektiv och har relativt milda biverkningar. Detta har lett till en stor förbrukning av läkemedlet, vilket betyder att nästintill alla malariaparasiter har blivit immuna mot klorokin, d v s. att parasiten har råkat muteras på något sätt och härigenom blivit immun mot klorokin. För att resistens inte ska växa fram snabbt, används flera läkemedel samtidigt, då kan andra läkemedel i blandningen döda patogenen ifall resistens uppstår mot ett av läkemedlen. När en läkemedelresistens uppstår kan en kemiskt modifikation av läkemedelsmolekylen vara en enkel lösning för att få fram ett nytt läkemedel. Denna metod har fungerat för klorokin-, bl a med hjälp av att inkludera en metallorganisk sandwich-förening i den molekylära strukturen för klorokin. På detta sätt skapades läkemedlet ferrokin, vilket är mycket effektivt även mot klorokinresistenta malariaparasiter. Sandwich-föreningar är ämnen med en metallatom som är fastbunden till två ringar av kolatomer därpå ligger dessa två ringar plant mot metallatomen. I fallet ferrokin användes järn som metall. Det finns också så kallade till halv-sandwich-föreningar vilket betyder att metallatomen endast är fastbunden till en ring av kolatomer. Detta innebär att flertal ämnen kan binda sig till metallen ty bara ena sidan av metallen är bunden till kolringen. Förut har klorokinliknande halv-sandwichföreningar blivit syntetiserade och istället för en järnatom har rutenium, osmium, rhodium och iridium använts för att se dess förmåga att döda malariaparasiter. Det visade sig att ingen av de ovannämda föreningarna var i synnerhet gynnsam på att döda malariaparasiter mer än de klorokinliknande ämnena utan metaller. I detta projekt användes metallatomerna rutenium, rhodium och iridium i halv-sandwichföreningar. Istället för en kloratom på den aktiva delen användes en fluoratom för att se dess effektivitet samt vad detta har för någon inflytande på malariaparasiten. https://lup.lub.lu.se/student-papers/record/9063100/file/9063101.pdf application/pdf 823399 no 2021 eng Malaria Plasmodium Ruthenium Iridium Rhodium Inorganic chemistry Chemistry 9063100 2021-08-16T13:45:51+02:00 2023-06-28T13:24:57+02:00 2023-06-28T13:24:57+02:00

oai:lup-student-papers.lub.lu.se:9063573 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Robin Ekberg author 9063571 Universitetslektor Ulf Ellervik supervisor Department of Chemistry v1000647 department The enzyme dermatan sulfate epimerase 1 is one of the enzymes involved in the biosynthesis of the glycosaminoglycan dermatan sulfate. The expression of dermatan sulfate has been linked to several severe pathological conditions including breast, lung, and oesophagus cancer. The change in expression alters i.e., the tumorigenesis, cell viability, and adhesion. By altering the activity of dermatan sulfate epimerase 1, new treatments could be possible. This could be done by finding an inhibitor of the enzyme. This project mainly focuses on finding a synthetic route towards a starting material. This starting material, glucopyranuronic azide, can then be used in the synthesis of potential inhibitors of dermatan sulfate epimerase 1 through “click chemistry&quot;.<br /> To find potential molecules that can be added to glucopyranuronic azide, molecular dynamics is used. Molecular dynamics gives an indication whether a molecule can interact with the enzyme in the active site. From these simulations, two molecules are presented as potential candidates. These molecules show high stability in the active site of dermatan sulfate epimerase 1. Sockermolekyler, eller mer korrekt kolhydrater, spelar en mycket större roll för livet än att enbart förse våra celler med energi. Ytan av våra mänskliga celler är nämligen försedda med långa kedjor av diverse kolhydrater. Dessa makromolekyler har era viktiga funktioner för cellerna. De ger bland annat stöd i, och smörjer våra leder. De är även involverade i cellers kommunikation med varandra i det som kallas den extracellulära matrix, det området utanför och mellan våra celler. Att förstå hur dessa kolhydrater syntetiseras i kroppen är av största vikt, eftersom man har sett samband mellan ett antal sjukdomar och hur dessa kolhydrater uttrycks i cellerna. En sådan kolhydrat är dermatansulfat. Hur denna kolhydrat syntetiseras i kroppen är inte helt känt än idag men ett av de enzymer som är inblandade i syntesen, dermatansulfatepimeras 1 karaktäriserades 1975 av forskare vid Lunds universitet.<br /> Detta projekt fokuserar på att syntetisera av ett derivat av glukoronsyra som skulle kunna inhibera, alltså stoppa aktiviteten hos dermatansulfatepimeras 1. För att ta reda på hur man skall förändra glukoronsyra används en typ av beräkningsprogram, så kallad molekyldynamik. Genom denna molekyldynamik kan man ta reda på om en molekyl är stabil i det aktiva sätet på enzymet. Detta ger en fingervisning på hur man kan förändra glukoronsyra för att få den bästa inbindningen och potentiellt inhibitionen av enzymet. 2021 eng Organic chemistry Glucuronic acid Enzyme inhibitors Organisk kemi Organisk syntes Molecular dynamics Chemistry 9063573 2021-08-23T09:47:46+02:00 2021-08-23T12:18:11+02:00 2021-08-23T12:18:11+02:00

oai:lup-student-papers.lub.lu.se:9065780 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Shazalatun Binte Huda Epi author 9026583 Charlotta Turner supervisor Fiona Maungo Nermark supervisor Department of Chemistry v1000647 department This work aimed to optimize a multiclass reverse-phase HPLC-DAD chromatographic method and SPE method for the quantification of eight antibiotics in wastewater. Cefalexin, Levofloxacin, Nitrofurantoin, Doxycycline, Nalidixic Acid, Oxacillin sodium salt, and Cloxacillin sodium salt were separated with a C6-Phenyl (100 x 2 mm, 3.00 μm particle size) column within 10 minutes. Gradient elution was performed using mobile phase A: acetonitrile, H2O + ammonium acetate (2mM), formic acid (3/97/0.05, v/v/v) and B Acetonitrile, H2O + ammonium acetate (2mM), formic acid (95/5/0.05, v/v/v). The flow rate was 3.00 mLmin−1, and the injection volume was 3μL. Detection was carried out at wavelength 230 nm using a photodiode array detector. The LOQs ranged from 0.8 to 3.7 μg/mL except for doxycycline and cloxacillin which were 5.3 and 8.1 μg/mL respectively. SPE cartridges and sample pH values were tested both for cleaning and pre-concentrating purposes. It was found that Waters Oasis HLB SPE cartridges were most effective in recovering target compounds from water samples. Furthermore, acidifying samples prior to SPE did not enhance the recovery of the compounds (except Doxycycline and T-HCl). The recovery range was 12% (Cloxacillin) to 166 % (T-HCl). The developed method was not applied to the real sample. In the modern world, antibiotic resistance is a serious concern. That is why it is essential to identify and quantify antibiotics in different environmental recipients, for example, water sources. Nonetheless, analyzing environmental water samples is not an easy task as it involves complex mixtures of plastics, pathogens, nutrients, chemicals such as antibiotics, pesticides, heavy metals, etc. Sometimes they can also exist at low concentrations. Thus, sample pre-treatment, such as sampling, storage, and cleaning of samples, is essential before antibiotic analysis. Solid-phase extraction is one of the most used sample preparation procedures for extracting samples from water. In this extraction technique, a solid packing material is used for cleaning samples. Many commercial solid packing materials are selected based on the chemical properties of the compound. In the next step, the sample needs to be analyzed appropriately. A chromatographic analysis method is one of those methods that is used for separating or analyzing chemical mixtures. The reverse-phase liquid chromatography (RP-HPLC) is one of the chromatography techniques used for separating compounds that are hydrophobic or have less polarity. Since antibiotics are hydrophobic or less polar, RP-HPLC was chosen to analyze them. Mobile and stationary phases are essential components of chromatography.<br /> A stationary phase does not move, whereas a mobile phase is one that moves. When compounds move through the stationary phase, they interact with the stationary phase. Compounds that have a lower attraction with stationary phase will elute first, and the higher attraction will elute later, which are detected by the detector. In RP-HPLC, a partitioning mechanism causes separation through an adsorptive process. Solute molecules are partitioned (i.e. equilibrium is established) between the mobile and stationary phases. When many compounds are mixed, it is difficult to separate them properly. Many terms come into play to separate those compounds properly, e.g., solvent type of flowing them through the stationary phase, pH of the solvent, temperature, etc. Successful separation requires the optimization of all terms together. 2021 eng Antibiotics C6-phenyl column Gradient elution Recovery Solid-phase extraction: Analytical chemistry Chemistry 9065780 2021-09-21T01:27:51+02:00 2021-10-01T10:12:02+02:00 2021-09-22T15:59:29+02:00

oai:lup-student-papers.lub.lu.se:9068724 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Christian Greback author 8995264 Manish Singh supervisor Senior Lecturer Cedric Dicko supervisor Department of Chemistry v1000647 department In this report, we wish to test the hypothesis that zinc oxide (ZnO), usually only catalytic in the presence of light, can become catalytic when combined with polypyrrole and silk fiber in the absence of light. To template the synthesis of zinc oxide (sonication) and polypyrrole (oxidative polymerisation), we used four different silk fibers (Mulberry, Eri, Muga, and Tasar silks). We assessed the influence of silk type, sonication time, and pyrrole added with a factorial design. We found that neither of these factors played a significant role in the non-photocatalytic degradation of Methylene Blue (MB) nor Methyl Orange (MO). We tentatively explained our results by the fact that ZnO might not have formed on the fibers. Syftet med detta arbete var att testa hypotesen att zinkoxid tillsammans med en polymer (en stor molekyl bestående utav många upprepade, mindre molekyler) av pyrrol på silkesfiber kan verka katalytiskt, det vill säga sänka aktiveringsenergin för en viss eller vissa reaktioner utan att själv konsumeras. Med andra ord så var målet att producera hybridsilkesfiber som är katalytiska utan ljus.<br /> Silke är ett material som är väldigt slitstarkt samt biologiskt nedbrytbart. Silkesfiber från spindlar hade kunnat utnyttjas, men eftersom spindlar inte kan avlas så ansågs silke från silkesmaskar vara mer gynnsamt. Mulberry-silke, den mest förekommande formen av silkesfiber, består bland annat av proteinet sericin. Sericin har antibakteriella egenskaper och absorberar vätska väldigt bra. Silkesfiber har dessutom oerhört bra optisk genomskinlighet, vilket givit det god användning som bland annat ett tillägg till solceller.<br /> <br /> Grätzelsolceller är en typ av mycket flexibla solceller där metalloxider såsom zinkoxid utnyttjats mycket flitigt. Zinkoxid användes specifikt på grund av sin exceptionellt höga energiskillnad mellan HOMO (det av elektroner högsta ockuperade molekylorbitalet) och LUMO (det lägsta ockuperade molekylorbitalet). På sistone så har metalloxider även visats vara effektiva material för nedbrytning av kolbaserade vattenföroreningar då de träffas av ljus. Detta är av relevans inom textilindustrin, vars avloppsvatten innehåller stora mängder färgämnen. Exempel på sådana ämnen är Metylenblå och Metylorange, vilka båda är väldigt stabila molekyler som inte kan brytas ner via vedertagna nedbrytningsmetoder. Metylorange är dessutom ett så kallat azo-färgämne, vilket är giftigt för vattenlevande organismer. Ett problem när det kommer till zinkoxid är dock att ren zinkoxid inte verkar fotokatalytiskt (katalytiskt under ljus) - för detta krävs att det omvandlas till zinkoxid-nanopartiklar.<br /> <br /> Även konduktiva (strömledande) polymerer verkar katalytiskt under ljus, vilket har utnyttjats inom vattenbehandling. Den konduktiva polymeren polypyrrol är ett exempel på en sådan polymer, vilken är en billig och flexibel molekyl. Därtill så kan polypyrrol kombineras med zinkoxid för att förbättra den fotokatalytiska aktiviteten.<br /> <br /> Dessa molekyler bildades tillsammans på fyra olika typer av silkesfiber från silkesmaskar (Mulberry, Eri, Muga, och Tasar-silke). För att lägga till zinkoxid på dessa silkesfiber utnyttjades sonikering, som är en metod där energi i form av ljud används för att bland annat skapa nanopartiklar, och oftast tillämpas via någon form av bad. När pyrrolen skulle adderas så användes metoden oxidativ polymerisering, där de mindre molekylerna som utgör polymeren vanligtvis tenderar att innehålla kol samt donera elektroner.<br /> <br /> Vad som upptäcktes var att hybridsilkesfiber inte bildats, och att vår hypotes om att polypyrrol assisterar zinkoxid silkesfiber i den ljusfria nedbrytningen av Metylenblå eller Metylorange utan ljus inte stämmer. Preliminärt så har de erhållna resultaten förklarats av att zinkoxid-nanopartiklar inte bildats på silkesfibern, eventuellt att zinkhydroxid i stället bildats. I framtiden så föreslås att testa andra typer av silkesfiber (eftersom varje typ har relativt varierande egenskaper), eller att försöka bryta ned andra färgämnen än Metylenblått och Metylorange. 2021 eng Biochemistry Silk Polymer Metal Oxide Catalysis Dye Chemistry 9068724 2021-12-01T18:20:57+01:00 2021-12-09T10:35:30+01:00 2021-12-09T10:35:30+01:00

oai:lup-student-papers.lub.lu.se:9069025 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Emil Steen author 8984638 Margareta Sandahl supervisor Charlotta Turner supervisor Department of Chemistry v1000647 department Introduction: Knowing the viscosity of carbon dioxide expanded solvents is important in extraction and chromatography processes due to its effect on mass transfer. <br /> <br /> Background: Rather few studies on viscosity of carbon dioxide expanded ethanol at different pressures, temperatures, and molar ratios exist. <br /> <br /> Aim(s): Building a system and validating a method to determine the viscosity of supercritical carbon dioxide and carbon dioxide expanded ethanol.<br /> <br /> Methods: A method based on the Hagen-Poiseuille equation is used. Fluid is pumped through a tube and the pressure at the beginning and end of the tube is measured. From the difference in pressure the viscosity can be calculated.<br /> <br /> Results: Viscosity of carbon dioxide expanded ethanol was determined at 250 bar and 40 °C; 150 bar and 60 °C; and at 250 bar and 60 °C; using carbon dioxide molar ratios of 0.1, 0.3 and 0.5, respectively. Viscosity of pure ethanol and pure supercritical carbon dioxide were also determined. The difference between the viscosity values of pure ethanol estimated in this study and reported in the literature was between -5 and -23 % (higher difference due to slightly different temperature used in literature). Corresponding data for supercritical carbon dioxide was between 2 and 14 % but with a larger relative standard deviation of between 24 and 42 % (compared to 7 % for pure ethanol). <br /> <br /> Conclusion: The experimental setup has a fairly large difference between the determined viscosity and literature viscosity. The experimental method does however show promising results for the future if only smaller modifications are performed, such as installing new pressure sensors. Measuring viscosity<br /> Carbon dioxide is a gas at ambient conditions that is mostly associated with global warming and something living animals are breathing out. This carbon dioxide gas can also be used in analytical chemistry. If carbon dioxide is put under enough pressure and heat, we get a supercritical fluid. You can think of a supercritical fluid as something in-between a liquid and a gas, with density like a liquid and viscosity like a gas. This supercritical carbon dioxide can be used in separation processes, such as chromatography and extraction. In this work the viscosity of neat supercritical carbon dioxide and carbon dioxide mixed with ethanol have been determined. Think of the change in viscosity the next time you are about to deep-fry something. When you pour the oil in the pan it is viscous and as you heat it up it flows more easily. Or think of honey, in the store you can buy two types of honey. One that is not freely flowing and requires a knife to spread it and a more easily flowing honey in a squeeze bottle. Viscosity of fluids is an important parameter in chromatography and extraction processes, as fluids are used to transport chemical substances from and/or through solid materials. If the fluid viscosity is lowered the transport process is more efficient and the flow resistance is reduced. Rather few have determined the viscosity of carbon dioxide mixed with ethanol, and this is the aim of this work. Mixing carbon dioxide into the ethanol lowers the viscosity, compared to pure ethanol.<br /> <br /> In this work an experimental setup is built that can determine the viscosity of supercritical carbon dioxide and carbon dioxide mixed with ethanol. The method used in this work is based on that a fluid is pumped inside a tube, and that there will be a pressure difference at the beginning and end of the tube. This pressure difference is due to the viscosity of the fluid. By measuring the pressure difference and knowing the velocity of the pumped fluid the viscosity can be calculated. In this work the viscosity is determined at 40 °C and 60 °C at pressures of 150 bar and 250 bar and at different ratios of carbon dioxide to ethanol. 2021 eng Carbon dioxide Ethanol Hagen-Poiseuille Pressure Viscosity Analytical chemistry Chemistry 9069025 2021-12-11T14:06:05+01:00 2022-01-11T09:31:17+01:00 2022-01-11T09:31:17+01:00

oai:lup-student-papers.lub.lu.se:9069242 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Simon Edin author 9024313 associate professor Ola Wendt supervisor Department of Chemistry v1000647 department Röntgenkristallografi är en metod för att strukturbestämma kristaller vilket först användes under 1900-talet av William och Lawrence Braggs. Strukturbestämningen möjliggörs utav att ljus som passerar genom kristaller böjs eller delvis absorberas och ger ett diffraktionsmönster. Om ljuset är av en sådan våglängd så den kan passera mellan atomerna i kristallen, kommer ett diffraktionsmönster med information om elektrontäthet att bildas. Om detta upprepas från ett flertal vinklar kan det kombineras till en 3d karta med information om elektrontätheten. Elektrontätheten kan sedan användas för att beräkna positionen av atomerna i kristallen samt deras bindningar. 2021 eng Crystallography Single crystal X-ray crystallography Crystallization Chemistry 9069242 2021-12-18T15:29:54+01:00 2022-01-24T16:00:46+01:00 2022-01-24T16:00:46+01:00

oai:lup-student-papers.lub.lu.se:9069297 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Fredrik Sjövall author 9068533 Mujtaba Hassan supervisor Centre for Analysis and Synthesis v1000651 department The family of proteins called galectins, are a group of carbohydrate-binding proteins. This allows them to take part in cell signalling by binding to glycoproteins on cell surfaces. Galectin-9 has been identified as a TIM3 ligand. TIM3 is a protein found on T-cells, which are used by the immune system to destroy for example cancer cells. When galectin-9 binds TIM3 it starts a reaction chain which turns off and kills T-cells, which allows for unhindered tumour growth. As galectins bind to carbohydrates, chemically modified sugars can be used as galectin inhibitors. Mannose has shown promise as a scaffold for galectin-9N inhibitors. In this project, the goal was to synthesize a substituted C-6 1,2,4-triazole with a β-pyrazole benzyl amide on the C-1 position as previous research suggests this will give a good binding affinity towards galectin-9N. In the end, the complete total synthesis was not achieved within the time frame of the project. However, both sub-goals, separately synthesising the 1,2,4-triazole and the β-pyrazole addition were successful, and the total synthesis will likely be completed and the compounds will be tested in the near future. Galektiner är en grupp proteiner som finns i de flesta djur och celltyper. Gemensamt är att de binder till kolhydrater. De flesta cellmembran är täckta av glykoproteiner, det vill säga proteiner med en kolhydratssvans längst ut. Till den, kan galektiner binda, vilket kan användas för att signalera och kommunicera mellan celler. Galektiner har visats vara aktiva i en rad olika sjukdomar så som cancer, fibros, diabetes och COVID-19. <br /> <br /> En av medlemmarna i gruppen är galektin 9. För att förstå varför just det är intressant behöver vi först titta på Immunoterapi, ett ämne som tilldelades nobelpriset i medicin 2018. Pristagarna, Allison och Honjo, upptäckte två olika membranproteiner på T-celler, en typ av cell som ingår i immunförsvaret, som reglerar aktiviteten för de. De fick namnen CTLA-4 och PD-1. När kroppen utvecklar cancer, kommer immunförsvaret skicka T-celler för att angripa cancern. Men cancern kan försvara sig själv genom att binda till CTLA-4 eller PD-1, vilket i princip stänger av och dödar T-cellerna. Både Allison och Honjo utvecklade antikroppsbehandlingar, det vill säga protein som binder till receptorerna utan att stänga av T-cellerna, men som samtidigt hindrar cancern från att binda till dem. I många fall är immunoterapin lyckad, men i en del fall fungerar den inte, därför att cancern angriper ett annat av T-cellernas membranprotein, TIM3, istället. Det som händer är att galektin 9 utsöndras från cancercellerna och binder till TIM3. Det ger samma effekt som för CTLA-4 och PD-1, att T-cellerna stängs av och dör. <br /> <br /> I det här arbetet har vi försökt göra en hämmare till Galektin-9, en organisk molekyl som binder till galektin 9 och hindrar den från att binda till TIM3. Eftersom galektiner binder till kolhydrater naturligt, har vi använt oss av ett socker, mannos, som grund för hämmaren. För andra galektiner har man använt sockret galaktos i stället, men det har visat sig att mannos är selektivt för galektin 9 medan galaktos är generell ligand för flertalet galektiner. https://lup.lub.lu.se/student-papers/record/9069297/file/9069298.pdf application/pdf 2833174 yes 2021 eng Organic chemistry Medicinal chemistry Galectins Synthesis Chemistry 9069297 2021-12-21T11:13:32+01:00 2022-01-11T12:00:24+01:00 2022-01-11T12:00:24+01:00

oai:lup-student-papers.lub.lu.se:9069427 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Linnéa Stahre author 9069275 Kamal Hossain supervisor Department of Chemistry v1000647 department Malaria is a disease that affects about 228 million persons every year. It is a deadly disease caused by a Plasmodium parasite, spread by female Anopheles mosquitos. Today there is no cure, but it can be treated with medicine and taken in prevention. Unfortunately, the parasite is getting resistant to the drugs on the market. <br /> The most common drug is chloroquine which was discovered in 1934 and has been used ever since. Chloroquine forms complexes with hematin in the food vacuole of the parasite, and the complexes are poisonous to the parasite. It is believed that the resistance is caused by a mutation that makes it possible for chloroquine to leave the food vacuole. To overcome this, an alteration to the chloroquine molecule has been done by adding ferrocene, making ferroquine. Ferroquine is under clinical trials that look promising. Because of this it has become of interest to synthesize other complexes that use as metal together with a ligand that resembles chloroquine.<br /> The purpose of this bachelor’s project was to synthesize new half-sandwich complexes that could potentially be anti-malarial active agents. This was done in two parts, synthesis of ligands and then the complexes. All the ligands contain a potentially bidentat Schiff-base unit and are supposed to coordinate with metals in two places, forming complexes. In this project the ligands that were used had a shorter link between the Schiff-base than the ones that has been published by members of the group. <br /> The metals used for the complexes were molybdenum, iron, rhodium and iridium. For both rhodium and iridium related complexes have been successfully synthesized by members of the Nordlander group, unlike molybdenum and iron. The synthetic routes have therefore been inspired by previous complexes with rhodium and iridium. <br /> This report describes the synthetic routes to the ligands L1, L2 and L3, the complexes (1)-(9) as well as for two monomers. Three more complexes were synthesized but due to unsatisfactory results they will not be discussed in this report. I det här arbetet har målet varit att syntetisera ett flertal olika metallbaserade kemiska föreningar som skulle kunna användas som antimalariamediciner i framtiden. Föreningarna har syntetiserats utifrån tidigare vetskap om mediciner och problem med resistens. Tyvärr erhölls inte resultaten som förväntats i arbetet men ger vägledning inför framtida försök. <br /> Malaria är en sjukdom som är utspridd över stora delar av världen och orsakade ca och 228 miljoner fall, varav ca 405 000 dödsfall, under 2018. Sjukdomen sprids när myggor bärande en malariaparasit suger blod från människan. Parasiten bryter ned röda blodkroppar vilket oftast ger influensaliknande symtom som huvudvärk, feber och illamående men kan även leda till anemi, respiratoriska problem eller döden.<br /> I dagsläget finns inget botemedel mot malaria men det finns mediciner som kan motverka, behandla eller förebygga sjukdomen. En sådan medicin är klorokin som upptäcktes redan 1934 och har sedan dess används flitigt. Detta har tyvärr lett till att parasiten har utvecklat resistens och nya mediciner är av stort intresse.<br /> En ny medicin som just nu genomgår klinisk prövning är läkemedlet ferrokin. Ferrokin är en kemisk förening, ett komplex, där klorokin har länkats med ferrocen, ett kemiskt ämne innehållande järn. Förhoppningen är att detta läkemedel ska överkomma resistensen. Då de kliniska studierna går bra har ferrokin öppnat ett intresse för andra metallbaserade komplex.<br /> I den forskningsgrupp där studien utfördes, har man experimenterat med olika typer av metaller tillsammans med klorokinliknade molekyler, ligander, och skapat nya komplex. Gruppen har lyckats syntetisera flera metallbaserade komplex som skulle kunna vara framgångsrika. Dessa komplex har använts som inspiration under arbetet. <br /> Projektet har bestått av två delar där den ena delen var att syntetisera nya ligander och den andra var att syntetisera komplex med liganderna. Liganderna, totalt tre olika, som syntetiserats har varit kortare än tidigare och gett positiva resultat. Flera försök att syntetisera dessa komplex av dessa ligander tillsammans med metallerna molybden, järn, iridium samt rodium utfördes. De syntetiska vägar som har används för komplexen tycks tyvärr inte ha lyckats då tveksamma eller rent av negativa resultat erhölls. https://lup.lub.lu.se/student-papers/record/9069427/file/9069428.pdf application/pdf 675498 yes 2021 eng malaria half-sandwich complexes ligands molybdenum iron rhodium iridium chemical physics Chemistry 9069427 2021-12-28T12:29:24+01:00 2022-06-09T09:15:19+02:00 2022-06-09T09:15:19+02:00

oai:lup-student-papers.lub.lu.se:9069524 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Simon Enbom author 9069522 Pär Söderhjelm supervisor Yulian Gavrilov supervisor Biophysical Chemistry v1000649 department Aromatic ring flips are a classic example of a dynamic process in proteins. Discovered decades ago, methodological limitations hindered progress at the time. Ring flips have gained new interest and experimentalists can measure the flip rate and thermodynamic quantities associated with it. Molecular Dynamics (MD) simulations provide atomic resolution data and can complement the experimental work since it allows us to 1) compare theoretical and experimental values, 2) distinguish between local and global activation volumes and 3) elucidate the ring flip mechanism. Ring flips are slow processes and an enhanced sampling technique is necessary to sample them in reasonable computational times. Metadynamics, an enhanced sampling technique, works by applying a bias potential which “fills up” energy minima for a system coordinate, often called Collective Variable (CV) and while the dynamics are inherently non-physical, rare events can be sampled, thus creating extended ensembles. I have calculated the local activation volumes for buried residues in Bovine Pancreatic Trypsin Inhibitor(BPTI) in metadynamics trajectories and found qualitative agreement with experimental studies, showing that there is a positive activation volume associated with flips. I have also calculated the compressiblity of the transition state ‡κ=5.40*10−4 bar−1, developed an indirect CV that can force ring flips if biased and showed that solvation may be associated with flip kinetics. Protein är inte bara &quot;det man ska äta mycket av om man är fysiskt aktiv&quot;. Det är en klass av molekyler som spelar en roll i alla biologiska funktioner som vi känner till. Allt från muskelaktivitet till igenkännandet av signalsubstanser i hjärnan. Proteiner är tillsammans med DNA och RNA livets hörnstenar och att förstå dem skulle drastiskt förbättra förutsättningarna för att utveckla säkra och effektiva läkemedel.<br /> <br /> Proteiner är stora, långa molekyler bestående av hoppusslade kemiska enheter som kallas aminosyror. De får sin funktion i stor utsträckning från sin tredimensionella struktur och hur den ändrar sig på molekylär nivå. På detta sätt kan man likna dem vid olika typer av mänskligt skapade maskiner, men på molekylär skala är spelreglerna annorlunda. I allmänhet har vi god förståelse för de principer och lagar som gäller för mänskligt skapade maskiner, men så är inte fallet för protein.<br /> <br /> Ett mål inom proteinforskningen är därför att förstå proteinernas rörelser, deras dynamik. Proteiners dynamik är dels associerad med dess funktion, exempelvis enzymatisk katalys, men det finns också rörelser som saknar direkt koppling till den utförda funktionen, vilka kan vara svåra att rationalisera.<br /> <br /> I detta arbete har jag med hjälp av simuleringsverktyg försökt att förstå en känd dynamisk process som kallas aromatisk ringvändning, eller &quot;aromatic ring flip&quot; på engelska. Dessa aromatiska ringar är ofta tätt packade i proteinernas mitt och för att de ska kunna vända sig krävs att utrymme skapas kring dem. Detta kräver energi och kan jämföras med hur en dörr blir tung att öppna om man ställer något i vägen för den. I projektet undersöks hur mycket volym som behöver skapas och hur denna är tryckberoende. https://lup.lub.lu.se/student-papers/record/9069524/file/9069525.pdf application/pdf 6629840 no 2022 eng Biophysical Chemistry Molecular Dynamics Protein Dynamics Activation Volume Aromatic Ring Flips BPTI Biology and Life Sciences Chemistry Technology and Engineering 9069524 2022-01-02T12:30:34+01:00 2022-02-11T13:26:43+01:00 2022-02-11T13:26:43+01:00

oai:lup-student-papers.lub.lu.se:9072357 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Isolde Zuleta Sjögren author 9072355 Daniel Willén supervisor Department of Chemistry v1000647 department All around in our bodies – inside and on top of cells, as well as in the extracellular matrix (ECM) – complex carbohydrate chains known as glycosaminoglycans (GAGs) are to be found. While some of their properties are known, many functions and biosynthetic pathways remain undiscovered. Heparin is one of the GAGs whose function in the body is not completely known, however, it has been used as an anticoagulant since the 1930s after the discovery that it inhibits the blood clotting cascade in multiple steps, primarily by enhancing the effects of antithrombin (AT), a factor Xa inhibitor. Nowadays, heparin makes out the biggest part of a 13.8-billion-dollar industry, with most of it originating from China. Heparin is not synthesized but extracted from pig’s intestines, and to satisfy the yearly demand hundreds of millions of animals are needed. Other anticoagulants are present on the market, but nothing has significantly challenged heparin yet. In 2019, a study from Tykesson et al. discovered that recombinant dermatan sulfate GAGs (more specifically 2,4-sulfated) exhibit anticoagulant effects like heparin by a strong interaction with the thrombin inhibitor heparin cofactor II (HCII). <br /> In this project we hypothesize that HCII binds recDS-2,4 because of the specific pattern of charges and that such a pattern can also be achieved by a fully O-sulfated polyserine. Synthesis of persulfated compounds is challenging because of the charge density and polarity of the product, which complicates traditional work-up. In this project, a tri- and pentaserine synthesized by solid-phase peptide synthesis (SPPS) are used as targets for sulfation. The sulfation strategy was using trimethylsilyl chlorosulfonate, with the expectation that this would avoid the problem with anionic crowding, as well as produce a non-polar molecule that could be worked up by flash chromatography. The reagent was first investigated on benzyl β-L-arabinose with good result: all three hydroxyl groups were sulfated despite steric crowding and the product could easily be purified due to its highly apolar nature – however, it did not seem to be stable when deprotected. The sulfation on the polyserine chains did not give any detectable product – a lack of starting material forcing the reactions to be done on a small scale, probably combined with a low yield, seemed likely to be the main reasons for this. Since the sulfation reagent remains promising due to its ability to fully sulfate benzyl β-L-arabinose, a fully sulfated polyserine should be possible to synthesize in the future with some optimizations of the reaction and can then be tested for inhibiting properties on the blood clotting cascade. Kolhydrater är livsviktiga för människor och djur av fler anledningar än för att generera energi; överallt i kroppen –på cellmembran, inuti, och utanför celler – hittas långa kolhydratkedjor som kallas glukosaminoglykaner. Dessa kedjor bär många negativa laddningar, till stor del i form av sulfatgrupper, och kan vara självständiga eller kovalent bundna till ett protein – det senare fallet inkluderar proteoglykaner, där ungefär 50% av massan utgörs av linjära glukosaminoglykaner.Trots att dessa kolhydratkedjor är frekvent förekommande i kroppen är området i stora drag outforskat. <br /> En typ av glukosaminoglykan är heparin, vilken tack vare sina antikoagulerande egenskaper används som intravenöst blodförtunnande medel sedan 30-talet och är ledande på marknaden. Heparin har dock sina nackdelar, bland annat på grund av att det inte produceras syntetiskt, utan utvinns från grisar, till största del i Kina. Mellan 2007–2008 cirkulerade förorenat heparin på marknaden vilket resulterade i nästan 100 dödsfall där den bakomliggande orsaken tros vara Kinas bristfälliga regleringar kring djurhållningen i livsmedel- och hälsoindustrin. <br /> Forskning kring en annan glukosaminoglykan, dermatansulfat, ledde till upptäckten att även den (med ett visst mönster av sulfatgrupper) uppvisade blodförtunnande egenskaper likt heparin, vilket ledde till hypotesen att en molekyl med sulfatgrupper på samma positioner som dermatansulfat också skulle kunna verka antikoagulerande. Molekylen som teoretiskt sett passade in på denna beskrivning var en kedja av aminosyran serin, med en sulfatgrupp på varje serindel. <br /> Fokus i detta projekt har varit att skapa den sulfaterade serinkedjan för att sedan undersöka dess effekt på blodkoagulationen; då sulfatering i praktiken för med sig en hel del svårigheter kan detta vara lättare sagt än gjort. Sulfatering testades först på en sockermolekyl, vilket gav lovande resultat, men fungerade inte lika bra på serinkedjan; möjligen var det alldeles för lite produkt som skapades för att ge ett tydligt resultat. Serinkedjan var även något förorenad, vilket störde analysen. Då sulfaterings-strategin fungerade på sockermolekylen är det möjligt att det även kan göra det på serinkedjan, men reaktionen bör då ske i en större skala, och eventuella föroreningar bör avlägsnas i förväg. Endast en mycket liten mängd produkt krävs för vidare testning, så länge den är detekterbar och fri från föroreningar, med de förbättringar som nämnts kan teorin om den antikoagulerande molekylen testas inom en snar framtid. 2022 eng Organisk kemi Kolhydrat Heparin Chemistry 9072357 2022-01-19T10:58:10+01:00 2022-01-19T14:06:41+01:00 2022-01-19T14:05:26+01:00

oai:lup-student-papers.lub.lu.se:9072402 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Klara Peltomaa author 9072400 Suresh Rayavarapu supervisor Department of Chemistry v1000647 department Tröger’s base is a V-shaped bicyclic aliphatic unit with a 1,5-diazocine bridge. Its unique shape and structure create a hydrophobic pocket and give it its chirality. This makes Tröger’s base a valuable molecule in different fields with many different applications. Tröger’s base has proven to be a useful molecule in supramolecular chemistry due to its unique properties. In this Tröger&#39;s base project the aim is to synthesize a linear fused Tröger’s base analogue, the heptakis Tröger’s base analogue in a thirty-step synthesis. In this thesis project a linear Tröger’s base analogue, diastereomers of Tröger’s base analogues have been synthesized through a six-step synthesis collecting valuable material for further synthesis. In the beginning, aniline derivatives were halogenated and condensed to form a Tröger’s base analogue. In the end, two diastereomers were synthesized through a deprotonation following an attack on a carbonyl carbon. The synthesis also includes reactions as dehalogenation, Pd-catalyzed amination, and amine protection. After this thesis project, Tröger’s base analogues are available for further synthesis. Syntetisera molekyler kan beskrivas som att bygga lego. Anvisningar följs för att gå från en legobit till exempelvis ett lego hus. Bit efter bit adderas för att nå den önskade produkten. Syntetisera molekyler fungerar på liknande sätt, molekyler läggs ihop för att bilda en större molekyl. I kemivärlden går det inte alltid att bara addera molekyler för att nå den önskade produkten. Detta då reaktionen påverkas av olika faktorer som exempelvis temperatur. Specifika molekylerna måste därför adderas vid specifika tillstånd för att en önskad reaktion ska fungera. Tänk på det som att lägga ett pussel. Alla pusselbitar passar inte med varandra eller på alla ställen utan måste placeras på rätt ställe och med rätt andra pusselbitar för att pusslet ska kunna byggas. En bild används för att leta reda på vart en specifik pusselbit passar. I detta projekt har en specifik molekyl syntetiserats tillsammans med dess analogier, Tröger’s bas som ses i figuren nedan. Instruktioner har följts och Tröger’s bas har syntetiserats efter addition av andra specifika molekyler vid specifika tillstånd i syftet av vidare syntetisering.<br /> <br /> Denna specifika molekyl har unika egenskaper och har studerats mycket under åren. Som syns i figuren nedan är molekylen V formad. Denna egenskap är en anledning till varför denna molekyl har många olika användningsområden, exempelvis vid packning av molekyler. Den kan fungera som en pincett som packar andra molekyler. Tröger’s bas används också som receptorer, en molekyl som tar emot och skickar vidare signaler. Som hur en TV fungerar. Den tar emot signaler från fjärrkontrollen att byta kanal.<br /> <br /> <br /> <br /> Strukturen av Tröger’s bas 3D struktur av Tröger’s bas. 7<br /> Alla dessa ovannämnda applikationer är baserade på supramolekylär kemi som oftast beskrivs som ‘’kemi bortom molekylen’’. Molekyler har beskrivits som lego bitar eller pusselbitar för att generera en större molekyl. Inom supramolekylär kemi används molekyler i stället som färdiga produkter. En produkt som kan användas för olika ändamål men ändå behållas intakta. Till exempel en kniv är en färdig produkt men används för att dela andra föremål, förändra andra produkter. Detta är hur supramolekylär kemi fungerar. Molekyler som inte förändras utan fungerar som en färdig produkt och kan förändra eller assistera andra föreningar, exempelvis i de ovan nämnda tillämpningarna. Detta projekts syfte är att syntetisera analogier av Tröger’s bas för att använda inom supramolekylär kemi. 2022 eng Organisk kemi Organisk syntes Trögers bas Chemistry 9072402 2022-01-19T13:21:06+01:00 2022-02-14T10:45:53+01:00 2022-02-14T10:45:53+01:00

oai:lup-student-papers.lub.lu.se:9119597 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Miriana Carmela Chincoli author 9119594 Marija Dubackic supervisor Department of Chemistry v1000647 department N-(9-fluorenylmethoxycarbonyl)-diphenylalanine (Fmoc-FF) is a combination of two phenylalanine amino acids connected by a peptide bond and protected by a Fmoc group. This dipeptide exhibits unique self-assembly properties, forming a variety of structures such as nanofibers, nanotubes, and hydrogels. The aim of this project is to investigate the structure and phase behaviour of self-assembled Fmoc-FF.<br /> To achieve this goal, two sets of samples were prepared in water at pH 10, the value at which hydrogel formation occurs above a concentration threshold of 0.5wt%. The samples were prepared using two different bases: sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAH). The method employed for sample preparation differs from what has been reported in literature up to this point.<br /> The samples were examined and analysed using various experimental techniques. The monomer solubility of Fmoc-FF in the two different solutions was determined by Static Light Scattering and it was found that the monomer solubility of one set was four times greater than the other.<br /> Two distinct structures were revealed in the two sets of samples by employing X-Ray Scattering technique. The presence of fibres and ribbons was detected in the NaOH-treated samples, while only fibres were observed in the TBAH-treated samples. These findings were further corroborated by Cryo-Transmission Electron Microscopy, which also unveiled the presence of twisted ribbons and an overlapping mesh of fibres as the concentration of the dipeptide increased. The phase behaviour of the samples was investigated by examining their birefringence at different temperatures using Cross Polarization. Considering the wide application of this dipeptide across various scientific fields, studying its structure and behaviour under different conditions is of great importance and can provide inspiration for future applications. The main objective of this research project was to investigate the structure and phase behaviour of a self-assembled dipeptide known for its exceptional self-assembly capabilities, enabling the formation of diverse structures such as nanofibers, nanotubes, and hydrogels. Peptides are chain molecules composed of amino acids just as proteins, but generally shorter. In this case only two amino acids.<br /> Two sets of samples were prepared using different bases, sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAH), in water at a pH of 10, revealing interesting insights. It was discovered that the samples treated with NaOH showed four times higher monomer solubility of the dipeptide compared to the samples treated with TBAH. Further investigation revealed distinct structures in the two set of sample. The NaOH-treated samples exhibited long fibers, with radius of 3 nm coexisting with ribbons having a radius of 12 nm and axial ratio about 3. The TBAH-treated samples exclusively showed long fibers with radius of 1.9 nm. Microscopic imaging techniques confirmed the presence of twisted ribbons and overlapping mesh-like structures of fibers, particularly at higher concentrations of the dipeptide. The fibers and ribbons form a transient network so that the samples form hydrogels.<br /> This study introduced a new method for preparing Fmoc-FF fibers and hydrogels, shedding new light on the structural aspects and properties of this self-assembling dipeptide. By advancing our understanding of Fmoc-FF&#39;s behaviour under different conditions, these findings hold significant potential for diverse applications in various scientific disciplines. 2023 eng Aqueous Phase Behaviour Fmoc-FF Peptide Structure Self-Assembly Physical Chemistry Chemistry 9119597 2023-06-04T19:45:26+02:00 2023-06-14T09:47:51+02:00 2023-06-14T09:47:51+02:00

oai:lup-student-papers.lub.lu.se:9120395 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Emil Jakobsson author 9120393 Eric Anguera Aixalà supervisor Centre for Analysis and Synthesis v1000651 department Tröger’s Base (TB) is a bicyclic compound containing a methanodiazocine group between two aromatic rings. The methylene bridge forces the molecule to have a bent formation; thus, the aromatic rings are close to 90 degrees relative to each other, resulting in a rigid concave aromatic cavity. These unique properties make TB a great candidate as a molecular cleft compound and a good structure as a molecular receptor towards unfunctionalised molecules. The Tröger’s Base framework has therefore been found to be a useful building block in supramolecular chemistry. The Tröger’s Base project aims to complete a total synthesis of a linearly fused heptakis Tröger’s Base analogue. As a part of this project, the goals of this master thesis are to acylate the benzylic position of a TB analogue and to separate the resulting diastereomers with dry column vacuum chromatography. In order to achieve these two goals, six synthesis steps have been performed, starting from a commercially available aniline analogue. The aniline analogue was halogenated, followed by a condensation reaction to form the first TB analogue. After four more synthesis steps, including dehalogenation, Pd-catalyzed amination, amine protection, and acylation, where the benzylic position of a TB analogue finally functionalised. Afterwards, one of the diastereomers was successfully separated from the mix of diastereomers with a dry vacuum column using silica. As a result, this thesis work has shown it possible to acylate a TB analogue at the benzylic position and shown that the resulting mix of diastereomers is separable by dry column vacuum chromatography. In addition, the work has given valuable TB analogues, which can be used in further synthesis in the Tröger’s Base project. Supramolecular chemistry focuses on the forces between molecules and how molecules interact to form complex systems of molecules. Supramolecular systems can be designed for specific purposes, such as transporting specific molecules or speeding up a particular chemical reaction. One molecule that has shown exciting properties within this field is Tröger’s Base (TB). This molecule has a V-shaped structure, resulting in a cavity in which hydrophobic molecules can interact. TB also possesses a rigid structure and therefore does not tend to alter its shape, making this molecule an excellent building block for making supramolecular systems. <br /> <br /> In this project, called the Tröger’s Base project, the goal is to synthesize a large analogue of TB consisting of seven TB bridges, a heptakis Tröger’s Base analogue. This molecule is envisioned to function as a host molecule, in other words, to bind to smaller molecules reversibly. This could be useful in medicinal applications, like drug delivery. By synthesizing this molecule, the supramolecular properties and the potential applications of the molecule could be discovered. <br /> <br /> As a part of this project, the focus of this work has been to form a TB analogue needed as a building block for the heptakis TB analogue. The procedure for obtaining this TB analogue can be described as doing multiple reactions; starting with a simple molecule on which new pieces are added under specific conditions until the final structure is formed. In addition, much work has been done to separate the diastereomers of this TB analogue which are formed in the final reaction step. Diastereomers of a compound can be described as molecules that differ in molecular configuration; in other words, having different arrangement of atoms but are made of the same set of atoms. In many cases, it is desirable to have the diastereomers separated, this because they have different chemical and physiological properties. Therefore, a method called chromatography has been used to investigate if these diastereomers can be separated. Chromatography is a separation method in which a column is packed with a stationary (solid) phase together with the product and rinsed with a mobile (liquid) phase. Due to diastereomers having differences in the affinity to the stationary and the mobile phase, the diastereomers will elute from the column at different times and can therefore be collected separately. <br /> <br /> As a result, six synthesis steps have been completed, and one of the two diastereomers has been separated from the mix of diastereomers. The outcome from these results is that it has been shown possible to make this TB analogue with the implemented method. Also, the result from the chromatography shows that the mix of TB diastereomers is separable by using dry column vacuum chromatography. These findings are valuable for further TB research. In addition, this work has resulted in useful TB analogues that can be used as building blocks for obtaining the heptakis TB analogue in the future. https://lup.lub.lu.se/student-papers/record/9120395/file/9120414.pdf application/pdf 2281237 no 2023 eng Tröger's Base Synthesis Chromatography Supramolecular chemistry Diastereomers Organic chemistry Chemistry https://lup.lub.lu.se/student-papers/record/9120395/file/9120421.pdf application/pdf no 9120395 2023-06-06T11:16:15+02:00 2023-06-09T09:07:08+02:00 2023-06-09T09:07:08+02:00

oai:lup-student-papers.lub.lu.se:9121093 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Kemal Jahic author 9121091 Eric Anguera Aixalà supervisor Department of Chemistry v1000647 department Due to its chemical properties, Tröger’s base is frequently used in supramolecular systems. This project aims to create two diastereomers of Tröger’s base, which potentially could be utilized to generate heptakis-Tröger’s base. The initial step is to synthesize a Tröger’s base analog consist on a condensation reaction between two substituted anilines. This reaction fuses them to produce a Tröger’s base analog. The synthesized Tröger’s base analog is further functionalized to achieve two amines to the aromatic ring. A new stereocenter in the benzylic position after acetylation on the benzylic position, which gives rise to two diasteromers, because there also are sterocenters on the nitrogen’s too. The resulting diastereomers can be separated through dry vacuum column chromatography and potentially be used in two different synthetic routes to produce heptakis- Tröger’s bases, which could potentially have uses in supramolecular chemistry. Det här projektet fokuserar främst på området för supramolekylär kemi, vilket innebär ”kemin bortom molekylerna”. Det handlar om hur två olika molekyler kan interagera med varandra för att bilda ett system som är energimässigt fördelaktigt. Dessa molekyler interagerar med så kallade intermolekylära krafter, vilka är krafter som verkar mellan olika molekyler. Dessa krafter kan liknas vid positiva och negativa laddningar, och de ger upphov till struktur, liknande hur plus och minus genererar ström, medan intermolekylära krafter representerar själva strömmen och plus- och minusladdningarna motsvarar molekylerna själva.<br /> <br /> Trögers bas är en spännande molekyl inom supramolekylär kemi på grund av dess V-formade struktur med två aromatiska ringar och en diazocinbrygga, vilket ger den intressanta egenskaper. En sådan egenskap är dess kiralitet, vilket betyder att molekylen skiljer sig från sin spegelbild. Trögers bas har en distinkt geometri som kan appliceras inom olika områden av kemin, särskilt i situationer som kräver hög belastning och begränsad rörlighet, såsom molekylär rekognition <br /> <br /> Inom Wärnmarksgruppen har Trögers basmolekyler syntetiserats genom linjära kondensationsreaktioner, vilket resulterat i två diastereomerer som kan följa olika reaktionsvägar, vilket leder till distinkta geometriska arrangemang. Dessa strukturer har potentiella tillämpningar inom supramolekylär kemi över olika grenar, inklusive läkemedelstransport och katalys. Arbetet som utförs följer etablerade protokoll inom gruppen för att nå den önskade molekylen. Utgående från ett specifikt utgångsmaterial syntetiseras Trögers bas, följt av efterföljande reaktioner för att funktionalisera molekylen ytterligare,vilket i slutändan erhåller den önskade slutprodukten 2023 eng Organic chemistry Total synthesis Supramolecular chemistry Dry vacuum column chromatography Chemistry 9121093 2023-06-07T12:39:33+02:00 2023-06-09T09:36:06+02:00 2023-06-09T09:36:06+02:00

oai:lup-student-papers.lub.lu.se:9121236 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Tilda Jigsved author 9121233 Ronja Gillberg Strandberg author 9121231 Martin Ek supervisor Centre for Analysis and Synthesis v1000651 department As for now, there is a need for more information and understanding about how variations in 316L steel affect the deformation of sheet steel to produce steel pieces. Therefore, this project aims to present the material&#39;s variation regarding chemical composition, mechanical properties and coil dimensions. Furthermore, experiments are conducted to evaluate the quality of deformed steel pieces and identify any effect resulting from variation in the steel material. In this project, the steel has been analysed in LOM and EBSD to investigate its microstructure. Other analytical methods used are ICP-OES, XRF and combustion to detect the chemical composition of the steel. Lastly, several different deformations experiments were conducted to evaluate the effect of variations in the steel on the finished deformation and size of the steel pieces. The results showed no significant differences in the microstructure of the steel or the deformation or size of the produced steel pieces depending on the subsuppliers. Moreover, it revealed no differences within coils regarding coil thickness or in the deformation or size of the produced steel pieces. It also showed that steel with higher yield strength and thickness gives a lower deformation value, but the deformed steel piece&#39;s length and width were unaffected. Using a higher force will result in a steel piece with more extensive deformation and a smaller range without introducing more defects. Dwell time did not affect the results of the deformation or size of the steel piece. The first known production of steel dates back 4000 years ago in the form of ironware in the region of today&#39;s Turkey. Since then, steel usage has exploded and is today the most essential engineering and construction material. It is still used today because it is an essential material in society, and the constant development of the materials makes it fit for modern functions. This study aims to deepen the understanding of steel&#39;s behaviour to optimise its full potential and establish its future usage. More precisely, the study has focused on the effect of 316L steel variations on the forming of steel pieces and has the goal of giving recommendations to the production of how the settings in the deformation machine may compensate for the variations.<br /> <br /> Many factors have to be considered before having a complete understanding and control over how a steel piece is deformed. The outcome of the deformed piece can be affected by the type of machine, deformation tools or setting used. However, even more interesting, the steel&#39;s properties will impact the steel&#39;s forming. To produce steel products with high quality, an understanding of the properties of the steel and how variations of these may affect the finished product is crucial. This is because, without this knowledge, the outcome of the deformation may vary between different steel, leading to irregular production. <br /> <br /> The different variations that have been studied are the yield strength, microstructure and composition of the steel, along with the thickness of the steel coil. We could conclude from the results that steel with higher yield strength and thickness generally gave steel pieces with lower deformation. Beyond this, the usage of higher forces is also seen to be beneficial to all steels since it gives a lower range of deformation, leading to more uniform steel pieces without introducing more defects. Another exciting discovery was the variation in grain size between the studied steels. We could see that this steel property appears influential since the steel with a significantly smaller grain size also behaved differently than all other steels in the production. <br /> <br /> The recommendation that can be made to the production from this study is to use a higher force if a lower range of deformation is desired. Furthermore, the settings in the deformation machine can compensate for steel with high thickness and yield strength by using a higher force to achieve the same deformation as steel with low values.<br /> <br /> This study has only covered some variables that can affect the deformation of steel. Understanding the most influential properties when deforming it needs to be further analysed. It is vital to continue the development and increase the understanding of the material to ensure the usage of steel. Who knows, 4000 years into the future, steel is still one of our most essential materials? https://lup.lub.lu.se/student-papers/record/9121236/file/9121246.pdf application/pdf 19162175 yes 2023 eng deformation steel 316L materials chemistry Chemistry 9121236 2023-06-07T15:13:19+02:00 2023-07-11T08:39:35+02:00 2023-07-11T08:39:35+02:00

oai:lup-student-papers.lub.lu.se:9121750 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Azemina Bajramova author 9055295 Peter Spégel supervisor Mynta Norberg supervisor Department of Chemistry v1000647 department Introduction: Antibiotic resistance is rising globally, increasing the demand on new antibacterial substances.<br /> Background: Studies suggest that lignin exhibits antibacterial properties, however this property is unexploited commercially. The valorization of lignin is difficult due to its complex and variable structure. <br /> Aims: This study aims therefore to fractionate lignosulfonate lignin (LSL) into chemically well-defined fractions with elevated antibacterial properties. The influence of quaternary ammonium groups with long alkyl chains on antibacterial activity is also investigated.<br /> Methods: LSL was fractionated using a ternary solvent system consisting of pressurized carbon dioxide, ethanol, and water. The fractions were analyzed using nuclear magnetic resonance (NMR) and ion mobility high resolution mass spectrometry (IM-HRMS). The effect of solvent composition on extraction selectivity was investigated with a simplex-like design of experiment. Each NMR spectra was divided into 99 different intervals, and the peak area in each interval was correlated to solvent composition using the reduced cubic Scheffe model. The fractions were derivatized via the Mannich and Menshutkin reactions which introduce tertiary amines and alkyl groups, respectively. A variant of the Etest and the microdilution broth assay were used to screen antibacterial susceptibility and determine minimum inhibitory concentrations (MIC).<br /> Results: The obtained extracts varied in composition regarding type of functional groups and oligomer length. 83 out of the 99 regression models were valid giving tools for correlating extraction selectivity in terms of functional groups to solvent composition. Analysis of the derivatized fractions suggest that the reactions were unsuccessful. Antibacterial susceptibility testing suggest that the antibacterial effect is elevated in fractions extracted with intermediate polar solvent compositions, yielding antibacterial fractions with MIC values of 2500 µg/mL.<br /> Conclusion: Antibacterial LSL fractions were obtained using intermediate polar solvent compositions, although with low potency compared to commercial antibiotics. More research should be dedicated towards optimizing introduction of quaternary ammonium groups on LSL. Interest in replacing fossil-based polymers is growing, due to fossil feedstocks being nonrenewable and having a negative impact on the environment. A more sustainable alternative is lignin which is an important component of plants and is therefore bio-based and renewable. Lignin is produced as a side-product in the paper and pulp industry, and has historically mostly been burned as a source of heat. An interesting property of lignin is its antibacterial activity, which has not been thoroughly investigated. However, due to the prevalence of antibiotic resistance, the need for new antibacterial substances has increased. One reason to why lignin has been an under-utilized resource is that it has complex molecular structure. It is composed of many different building blocks that can be linked to each other in different ways to form larger structures. This makes it difficult to produce useful lignin-based polymers, but some heterogeneity is necessary to make it difficult for the bacteria to develop resistance. The aim of this project was therefore to separate the lignin sample obtained from industry into fractions that have a less complicated chemical composition, and then test if the antibacterial activity is enhanced in the fractions. This was performed by fractionating the lignin sample using different combinations of three solvents: liquid carbon dioxide, ethanol, and water. The obtained fractions were analyzed using techniques that give information about their composition and mass. The fractions were also chemically modified to alter their structure with the aim to improve antibacterial activity. Both the chemically modified and non-chemically modified fractions were then applied on bacteria to observe if they will affect their growth. In total, seven different fractions were obtained with differing composition regarding molecular structure and number of lignin building blocks linked together. The results suggested that the chemical modification did not improve the antibacterial activity of the lignin. However, the tests on the bacteria showed that the fractions separated with intermediate polar solvent mixtures had enhanced antibacterial activity compared to the original lignin sample. These fractions differed from the other fractions mainly regarding number of lignin building blocks linked together. However, the antibacterial activity was not that high compared to commercial antibiotics. In conclusion, it is possible to fractionate lignin obtained from the industry into fractions with increased antibacterial activity, but more work is needed to establish lignin-based antibiotics or materials with antibacterial properties as a viable alternative. https://lup.lub.lu.se/student-papers/record/9121750/file/9121775.pdf application/pdf 1934208 yes 2023 eng Antibacterial activity Lignosulfonate lignin Simplex Supercritical fluid extraction Quaternary ammonium groups Analytical chemistry Chemistry 9121750 2023-06-08T12:33:43+02:00 2023-06-09T10:14:54+02:00 2023-06-09T10:14:54+02:00

oai:lup-student-papers.lub.lu.se:9123343 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mona Fathi author 9057879 Simon Palmer supervisor Department of Chemistry v1000647 department Abstract<br /> Introduction: A great decline of wild pollinators has been observed, the decline is believed to be a result of many stressors, whereas pesticide usage being one of them. Wild pollinator insects are significantly important to maintain and preserve food production and biodiversity. <br /> <br /> Background: Pesticides are used to protect and enhance crop yield, by targeting insect and fungi pests. Imidacloprid (IMI) and acetamiprid (ACE) are both neonicotinoids with same mode of action. Tebuconazole (TEB) is a fungicide, that might exhibit synergistic effect when combined with a neonicotinoid. Studies done one effects of the combinations are limited, and strictly only involving bee pollinators. Furthermore, the metabolomic effect of pesticides as well as the sample handling and sample treatment procedure is not thoroughly investigated. <br /> Aim(s): This study aims to investigate how different pre-treatments as immobilization techniques affect the metabolomics in flies. It also aims to investigate how the metabolism of the hover fly is altered by the pesticides IMI, ACE and TEB, alone, in binary and in ternary mixtures. <br /> <br /> Methods: Two different immobilization techniques were evaluated; carbon dioxide or ice and compared to when no anaesthesia was used. After each treatment the fly was either dissected in room temperature or in cold. The same experiment was performed with acetamiprid orally exposed and control flies. Lastly, a design of experiment approach using face centred composite design was implemented for the single, binary, and ternary exposed mixtures of the three pesticides. A simple extraction procedure was used where the brains were homogenized with a ball mill, followed by freezing, centrifuged, dried and derivatization. The sample was analysed using gas chromatography-mass spectrometry in SIM mode. <br /> <br /> Results: The different pre-treatment showed different accumulation and restricted metabolite. When no anaesthesia was used, an accumulation of GABA and cysteine was observed indicating oxidative stress. CO2 and cold anaesthesia exhibited a shift in energy demand. When exposed to acetamiprid, the three immobilization techniques resulted in the same reaction suggesting that the anaesthesia may not affect when exposing to a pesticide. The effect of three pesticides IMI, ACE and TEB, displayed the highest effect of ACE. IMI exhibited low effects suggesting a low dose used. TEB showed an up-regulation of cell membrane metabolite, suggesting possibly the fungicide affecting the cell membrane not only in fungi but also in insects. Interaction terms exhibited a synergistic effect. Quadratic effects was significant for almost all pesticides suggesting a non-linear relationship for the regulation of the metabolites. <br /> <br /> Conclusion: The three pre-treatment exhibited different result. Acetamiprid exposure resulted in the same outcome for all methods. Model selections were performed and demonstrated. ACE displayed the highest effect, IMI showed low effect, TEB showed an effect but on fewer metabolites. Interaction terms showed a synergistic effect and quadratic effects was displayed as significant for many metabolites. Popular Scientific Summary <br /> Pollinators like bees, flies, moths, and birds are responsible for 35% of the world food production. Unfortunately, in recent years a decline of pollinators has been observed. The decline is believed to be influenced by pesticides. Pesticides are chemicals used on crops and plants to protect from diseases, fungi, weeds, and harmful insects. A lot of research on pesticide effects are focused on bee-pollinators, despite the wild insect pollinators being at greater risk. Wild insect pollinators are not well managed and controlled like bees, which makes them more at danger. On top of that, almost no research has been done on the molecular level and the studies done lack the evaluation of sample handling and pre-treatment. <br /> To analyze pesticide effect on non-bee pollinators, this study aims to analyze molecules in the brain defined as metabolites, in the non-bee pollinator the hover fly Eristalis tenax. The purpose of this study is also to examine how different immobilization techniques affect the metabolite in the brain, and if this effect is changed when the flies are exposed to pesticide. Immobilization techniques are used to handle insects because some insects possess toxins or can sting. But also, to make it easier to handle the insects, since insects could fly or move. In addition, three different pesticides; imidacloprid, acetamiprid and tebuconazole were analyzed based on their single and combined metabolomic effect. The metabolites were analyzed with gas chromatography where they get separated by a column and analyzed with a mass spectrometer.<br /> When no immobilization technique was used, metabolites that expresses stress was affected, meaning that the flies were experiencing fear. The ice and carbon dioxide treatment showed an increased demand for energy, to compromise for the heat loss due to freezing and to compensate for oxygen reduction. When exposed to acetamiprid, the three immobilization techniques showed similar responses, which could mean that the pesticide treatment resulted in such a huge reaction that the immobilization technique did not affect. It was also shown that the flies was actively trying to reduce the toxicity of acetamiprid by producing more metabolite that are involved in the metabolism of toxins. Metabolites involved in energy production was also affected, which could be a result of more energy is needed to recover from the exposure. And lastly, acetamiprid displayed the highest effect, imidacloprid showed low effect, tebuconazole showed an effect but on fewer metabolites. Interaction terms showed a synergistic effect and quadratic effects was displayed as significant for many metabolites. 2023 eng metabolomics insect brain tissue GC-MS pesticides analytical chemistry Chemistry 9123343 2023-06-11T19:43:18+02:00 2024-02-09T08:58:48+01:00 2023-06-13T11:11:43+02:00

oai:lup-student-papers.lub.lu.se:9123425 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Sakina Khwaja author 9024835 Joachim Björklund supervisor Department of Chemistry v1000647 department Sialic acids are prominent on the cell surfaces of mammalian cells and partake in modulating cellular mechanisms. N-acetyl neuraminic acid (Neu5Ac) is one of the most prominent sialic acids on mammalian cells. Bacterial pathogens can acquire Neu5Ac from the environment and display them on their cell surfaces, in a process known as molecular mimicry, thus evading the immune system. Many pathogens also utilize Neu5Ac for metabolic purposes.<br /> <br /> Proteus mirabilis and Staphylococcus aureus are associated with a wide range of infectious diseases and they acquire Neu5Ac via a sialic acid transporter (SiaT). The SiaT of the two bacterial pathogens shares homology. Thus there is an interest in inhibiting the sialic acid transporter to suppress bacterial growth. Previous work has focused on the modification of other positions of Neu5Ac.<br /> <br /> In this thesis, the aim was to investigate different synthetic modifications on C7 of Neu5Ac. Neu5Ac is not a trivial carbohydrate, it possesses multiple functional groups such as a carboxylic acid, an acetamide, and a glycerol side chain. Hence protecting groups in the form of a methyl ester and a thioglycoside were employed to selectively convert the glycerol side chain to an aldehyde. The C7 aldehyde was then subjected to various reactions such as epoxidation, olefinations, and azide formation all with varying degrees of success. The deprotection of the thioglycoside was optimized by conducting the reaction in the absence of<br /> light. Carbohydrates are an ambiguous group of molecules and are often associated with being either a vital or harmful source of nutrition. Contrary to popular belief, carbohydrates play a pivotal role in the defense system of our bodies. The outermost part of our cells is decorated with a dense layer of glycoconjugates that are important in modulating communication between the cell and the surrounding environment. The most prominent carbohydrate on the terminal position of the glycoconjugates is sialic acid. Sialic acids help the immune system differentiate between endogenous (self) and exogenous (other) substances. Bacterial pathogens can acquire sialic acids from the environment and decorate their cell surfaces with<br /> it in a phenomenon known as ‘molecular mimicry’ thus disguising themselves as endogenous cells. This allows the pathogens to evade the immune system of the host.<br /> <br /> According to WHO (the World Health Organization), the increase of antibiotic resistance amongst bacterial pathogens is a major threat as it is becoming more difficult to treat infectious diseases. Pathogens that use molecular mimicry can acquire sialic acids with the help of specific sialic acid transporters found in their cell membranes. The interest lies in inhibiting the specific transport proteins with a suitable sialic acid analog.<br /> <br /> This thesis aimed to investigate possible synthetic modifications on one of the most prominent sialic acids in nature, N-acetylneuraminic acid (Neu5Ac). This carbohydrate consists of a nine-carbon backbone with different functional groups, rendering it challenging to work with. The main focus was to synthesize different analogs of Neu5Ac, with modifications on the seventh position. 2023 eng Carbohydrates Neuraminic acid Organic Chemistry Sialic Acids Chemistry 9123425 2023-06-12T08:22:27+02:00 2023-06-14T10:18:32+02:00 2023-06-14T10:18:32+02:00

oai:lup-student-papers.lub.lu.se:9123452 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Niklas Tan author 9123449 Jesper Schwarz supervisor Department of Chemistry v1000647 department In recent decades problem of using the finite resource, fossil fuels, as an energy source have caught more and more public attention. The usage of it produces side-products which in long term harms our environment. To combat the usage of such destructive resources, a more sustainable way of creation of energy needs to be implemented, to which scientist have set their eyes on solar cells.<br /> Currently for the third generation of solar cells, DSSC (dye-sensitize solar cells), use ruthenium complexes for its high efficiency. But due to the metal’s scarcity, cost, and toxicity it has very limited usage. To make it more industrial friendly, another metal must replace ruthenium. Iron being ruthenium’s 3d-metal analogue can potentially to replace it, but due to the short living energy state LMCT (ligand to metal charge transfer) poses a problem for iron complexes. To combat it NHC (N-heterocyclic carbene) is being used to extend the lifetime of LMCT.<br /> NHC complexes is quite a new area or chemistry, with very few complexes have been created and explored of their photochemistry. Some iron NHC complex, which was synthesised and explored by Wärnmark and co-workers showed promising photochemistry and applications. My research explores the synthetic pathways of some of those complexes to further advance it towards to potentially be attached to a DSSC. Title: Popular science abstract: Synthesizing each step towards a possible “greener” future<br /> <br /> In the modern society there is a drive to not stagnate and always strive towards a brighter future. This drive has made the lives of countless of people better, but without the knowledge of the importance of implementing a sustainable way to work with the resources “given” to us, will lead to major problems in the future. In a society which is growing rapidly, which also brings a rise in resource consumption, there are currently not enough resources available on earth to sustain our over consuming habits. To sustain our current lifestyle and population, we would need the equivalent of 1,75 earths 1. Some most important resources used are finite, such as fossil fuels.<br /> Energy is currently what our society relies heavily on and is the backbone for our society to function. But the current worldwide way to create energy is to use oil (fossil fuels), coal, nuclear energy, and natural gases to create energy, but these methods are not sustainable and are harmful for the environment. The usage of fossil fuels leads to the production of greenhouse (CO2, CH4, N2O, etc.) gases, which in turn keeps the heat longer on earth. The anthropogenic greenhouse gas release gives a rise in temperature and will in the long run create a lot of problems for all communities around the world. The usage of nuclear energy creates a lot of radioactive waste which needs to be disposed safely and currently are just locked up under ground and have the risk of leakage of radioactive materials into our soils and waters.<br /> Seeing how this is currently a big problem, maybe even the biggest problem in this generation. A quote by Paul McCartney sums up what many people have in mind “There must be a better way to make the things we want, a way that doesn’t spoil the sky, or the rain or the land.”. <br /> One huge energy source that can be utilized is the energy emitted from the sun. The sun emits more energy to earth than what the whole human civilization consumes for a whole year. This energy ball is giving out free energy, if one can utilize it. The sun creates energy and is unaffected by whether we harvest its energy and is therefore a sustainable source of energy. Knowing this has led many to try to come up with a way to use its energy. Intrigued by nature’s own solar harvesting system, photosynthesis, the plants that utilize the solar energy, can covert the solar energy, CO2 and water to turn it into glucose, which it can utilize during nighttime for cellular respiration. <br /> There are currently technologies which try to combat the problem such as solar cells, but due to its cost to either maintain or manufacture is too expensive it will act as a barrier to put it into everyday usage. There are some that are not too expensive but will run into the problem of efficiency of said technology. To solve these problems, some component in the solar cells needs to be exchanged into a more inexpensive material, this has led to a possibility of changing out the core component, ruthenium, in the dye in solar cells from a ruthenium complex to iron complex, which is the most earth abundant metal and much cheaper than ruthenium. With a cheaper cost, it may allow for a large-scale application. <br /> Iron NHC (N-heterocyclic carbene) complexes have not only proven to be a possible candidate for solar cells, but have displayed its excellence in catalysis, which had led to hydrogen production 2, 3.<br /> This is where I come in, by testing out different synthetic pathways towards modified ligands, the iron complex may be able to be enhanced and possibly unlocking its potential to bond with other molecules to ultimately be able to be put in solar cells. 2023 eng Iron carbene Metal organic chemistry N-heterocyclic carbene complex Synthesis Chemistry 9123452 2023-06-12T09:50:39+02:00 2023-06-20T11:49:59+02:00 2023-06-20T11:49:59+02:00

oai:lup-student-papers.lub.lu.se:9123808 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Saher Alissa author 9123805 Joachim Björklund supervisor Department of Chemistry v1000647 department The one-step conversion of unprotected sugars to sugar intermediates invented by the Shin-ichiro Shoda group at Tohoku University in Japan by using 2-chloro-1,3-dimethyl-imidazolinium chloride (DMC) as a dehydrative condensing agent is a relatively new way to synthesize carbohydrate derivatives. A great effort has been done to investigate the minimum requirement of bases, the suitable dehydrative condensing agent that can be used to promote the reaction, and the effect of different bases on the yield and the α/β ratio of the products. This work aims to investigate the effect of different nucleophiles in the one-step conversion of the unprotected monosaccharides glucose (Glc), mannose (Man), and N-acetyl-D-glucosamine (GlcNAc) to glycosyl compounds. The reactions carried out have been followed by thin-layer chromatography (TLC) and liquid chromatography-mass spectrometry (LC-MS). The isolated products were analyzed by nuclear magnetic resonance (NMR). More analysis is needed to confirm that the conversion has happened. The one-step procedure is a promising way to synthesize different glycosyl compounds that can be extended to cover other nucleophiles and other sugars. De flesta är medvetna om kolhydraters betydelse som näringsämnen och energikälla, men vad många förmodligen inte känner till är att kolhydrater är viktiga byggstenar i kroppen då de binder till olika proteiner och lipider och bildar så kallade glykoproteiner och glykolipider som finns bland annat i våra cellmembran. En viktig klass av kolhydrater är glykosider som består av en sockerdel som kallas för glykon och en annan del som består av något annat och som kallas för aglykon. Glykosider är naturligt förekommande molekyler som finns som pigment i olika växter och frukter, fungerar som byggstenar till nukleinsyror i alla organismer och utgör en stor del av läkemedel som till exempel aspirin och streptomycin. <br /> <br /> Då glykosider är väldigt viktiga har en hel del forskning ägnats åt att syntetisera dom med olika sockertyper som startmaterial. Dock behöver kolhydrater skyddas om man vill göra en selektiv substitution av startmaterialet på grund av reaktiva hydroxylgrupper. Detta är mycket tidskrävande och resulterar i ett lågt utbyte av den önskade produkten vilket gör hela processen ineffektiv. Detta problem har länge funnits och man har alltid behövt använda sig av skyddsgrupper i syntesen av glykosider och andra typer av kolhydrater.<br /> <br /> Mitt projekt handlar om att utreda frågan om det går att glykolysera den anomera positionen utan att använda skyddsgrupper genom att använda en ett-stegprocedur som det nyligen har rapporterats om och prova olika nukelofiler i den proceduren. En nukelofil är en elektronrik molekyl som har lätt att reagera med en positivt laddad molekyl. Alla nukleofiler som provades under projektet har bevisats fungera med hjälp av TLC och LC-MS. Dock behövs det mer analys av de isolerade produkterna innan man kan dra den slutsatsen då produkterna inte helt har kunnat identifieras med hjälp av NMR-spektroskopi. Den här reaktionsvägen är en mycket lovande teknik att syntetisera glykosider som antingen kan vara önskvärda mål eller som kan fungera som socker intermediärer inom läkemedelskemin och kan därför ersätta den traditionella reaktionsvägen som involverar många steg av skyddande och oskyddande av hydroxylgrupperna. 2023 eng Anomeric position carbohydrates DMC glycosides one-step conversion organic chemistry unprotected sugars Chemistry 9123808 2023-06-12T14:26:38+02:00 2023-06-20T11:51:16+02:00 2023-06-20T11:51:16+02:00

oai:lup-student-papers.lub.lu.se:9123823 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Erik Brännström Rehn author 9123820 Tommy Cedervall supervisor Department of Chemistry v1000647 department Plastic pollution is an urgent environmental problem. Plastic can break down in nature into<br /> micro- and nanoplastics, and the impacts of these, and especially nanoplastics on the<br /> environment are not fully understood. Particles have been shown to accumulate in tissues<br /> of animals, where they are believed to cause cell damage. In this project, LDPE was broken<br /> down, filtered to obtain nanoplastics, separated according to size and exposed to D. magna.<br /> The aim was to determine if LDPE nanoplastics would affect the survival and reproduction<br /> of D. magna, and thereby conclude whether they are an environmental problem. Without<br /> the addition of food, the nanoplastics showed no toxic effects compared to control, and some<br /> even exhibited a higher rate of survival. In the long term experiment with food addition, the<br /> smallest particle fraction was shown to be toxic and to negatively impact the reproduction<br /> of D. magna. Therefore, it can be deduced that the breakdown of LDPE into nanoplastics<br /> in nature may lead to further environmental challenges. Små partiklar från nedbrytning av plasten polyeten kan leda till<br /> ytterligare miljöutmaningar<br /> Plast produceras idag i stor omfattning och en stor del av plasten som används<br /> hamnar i naturen. När plasten bryts ned till mindre partiklar av bland annat<br /> mekaniska påfrestningar och UV ljus, kan dessa ta sig in i vävnader hos djur och<br /> människor och orsaka skada. I vilken utsträckning dessa partiklar påverkar vår<br /> miljö och hälsa är inte helt klarlagt. Partiklar från olika plaster och olika storlekar<br /> av partiklarna har varierande potential att göra skada.<br /> Lågdensitetspolyeten (LDPE) är en mjuk plast som består av en kolkedja med förgreningar,<br /> vilket gör den mindre tätpackad och därmed lättare än dess motpart högdensitetspolyeten, som<br /> saknar förgreningar. LDPE används i många olika produkter som bland annat beläggningar på<br /> mjölkförpackningar, plastfolien och plastpåsar. År 2021 uppskattas LDPE ha stått för 14.7%<br /> av den totala plastproduktionen i Europa och är därmed viktig att undersöka.<br /> I det här projektet bröts plastfilm från LDPE ned till mindre partiklar med en stavmixer i vatten<br /> och delades upp efter storlek. Sedan delades de olika proverna upp i provburkar med<br /> vattenloppor och därefter jämfördes deras överlevnad och fortplantning med vattenloppor i<br /> vanligt vatten. Målet med detta var att kunna avgöra om plastpartiklarna skadade<br /> vattenlopporna, och därmed om plastpartiklarna kan orsaka miljöproblem.<br /> När försöken genomfördes utan mat till vattenlopporna i sju dagar, så levde vattenlopporna i<br /> vatten med plastpartiklar längre än vattenlopporna i vanligt vatten. Vilket misstänks vara på<br /> grund av att bakterier växer på partiklarna, som vattenlopporna kan livnära sig på. Trenden var<br /> omvänd då försöken genomfördes med mat och över en längre tidsperiod, där visade sig de<br /> minsta plastpartiklarna skada både överlevnad och fortplantning hos vattenlopporna. Därmed<br /> är slutsatsen att nedbrytningspartiklar från LDPE kan ge upphov till miljöproblem. 2023 eng Daphnia magna LDPE nanoplastics toxicity reproduction Chemistry 9123823 2023-06-12T14:30:30+02:00 2023-06-20T11:52:10+02:00 2023-06-20T11:52:10+02:00

oai:lup-student-papers.lub.lu.se:9124198 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Hannah Lund author 9124196 Joachim Björklund supervisor Department of Chemistry v1000647 department The threat of resistant bacteria is an increasing issue that has emphasized the need for therapeutic strategies. One possible drug candidate is the carbohydrate sialic acid, which adorns almost every cell surface on mammalian cells. These so-called glycans (defined as carbohydrate-based polysaccharides) are involved in key cell functions, including cell-to-cell recognition in eukaryotes. Because of their importance in a cell’s overall health, irregularities may lead to human disease. For example, bacteria have developed the skill to import sialic acid onto their surface glycoconjugates which mask them from getting spotted by the human immune defense. <br /> This project aims to create a molecular library of sialic acid derivatives, that could potentially disrupt bacteria’s ability to perform masking. The strategy used is to synthesize sialic acid derivatives by modifying position 7 in the molecule.<br /> A powerful precursor that could potentially be used for the metathesis reaction was generated in the project. Furthermore, a methodology in which alkenes can be introduced at C-7 was optimized. 2023 eng molecular library biochemistry sialic acid Chemistry 9124198 2023-06-13T07:57:30+02:00 2023-07-14T10:40:46+02:00 2023-07-14T10:40:46+02:00

oai:lup-student-papers.lub.lu.se:9124499 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Zhuoying Deng author 9124497 Dr. Roya Sardari supervisor Andrius Jasilionis supervisor Biotechnology (MSc) v1000284 department Biotechnology (M.Sc.Eng.) v1000285 department The main aim of this master project is to find out whether strain Geobacillus 7349 can produce biosurfactant during their growth by extraction and characterization of the product. The other goal is to optimize the cultivation condition of the strain. This work presents an evaluation of batch and fed-batch cultivation techniques for production of Geobacillus 7349 in shake flask, using DRM medium. The growth condition of the strain was monitored by cell density (OD) measurement, cell dry weight measurement, along with glucose consumption characterized by HPAEC-PAD. Batch cultivation results in a high cell density (OD600 ≥ 5) after around 14 hours of cultivation and a high concentration of biosurfactant being produced. To extract the biosurfactant from the culture broth, liquid-liquid extraction is an effective method. In both batch and fed-batch cultivations, the production of biosurfactant was detectable in both exponential and stationary phase, by the usage of high-performance liquid chromatography (HPLC), which means the cells were active in producing biosurfactant during these phases. And the fed-batch cultivation supplemented with fresh feed solution containing MgCl2, NH4Cl, and NaCl can increase the cell density threshold and prolong the lifespan of cell generation. To conclude, the project demonstrates the production of biosurfactant from strain Geobacillus 7349 by fermentation and the importance of the process design and nutrient source for bacterial growth. Hopefully, these findings can be used to scale up the fermentation process of Geobacillus 7349 from lab scale to trial scale, in order to have a more substantial biosurfactant production. Surfactant is widely used in many industrial fields such as petroleum, food, pharmaceuticals and so on as detergent, solubilizers or emulsifying agents. Currently, most of the surfactants are chemical petroleum based due to low cost but they are often toxic, irritant and non-biodegradable. Furthermore, petroleum for chemical synthesis of surfactant isn’t renewable. People are trying to reduce their dependence on fossil fuels and move forward to a more renewable source. And biosurfactants which are produced by microorganisms as secondary metabolites, typically bacteria and yeast, become environmental friendly alternatives, as they are usually more biodegradable and less toxic than petroleum derived ones (Jyoti Sharma 2021). Biosurfactant can be divided into various categories. Among them, rhamnolipids are the most popularly researched one in recent years. However, production of rhamnolipids by microbial fermentation is usually very costly, due to the high substrate cost and high production cost. The carbon sources used for production are preferably cheap, such as glucose in our case. In addition, reducing the cost of downstream processing is another essential strategy to reduce the production cost. The extraction of rhamnolipids can make up 80% of the total production cost. The complexity of the extraction depends on the selected strain and the produced culture mixture and it shouldn’t be over complicated.<br /> There’re quite a few strains producing rhamnolipids, nowadays. In this project, Geobacillus 7349 is the strain used to investigate the possibility of producing biosurfactant. Geobacillus, is gram-positive, rod shaped, aerobic species that is isolated from hot spring in Iceland. It can grow within a temperature range of 30 to 75 °C (Burgess, Flint et al. 2017). And it is naturally selected, without making any genetic modification. In this report, the cultivation of Geobacillus 7349 in a defined medium and the extraction and characterization of the product are the two main concerns. On one hand, it’s important to define the culture condition of the strain. On the other hand, it’s vital to extract and characterize our product, in order to know what is produced. The results can help with the further development of the production process of biosurfactant by Geobacillus 7349 in larger scale. https://lup.lub.lu.se/student-papers/record/9124499/file/9124888.pdf application/pdf 1431696 no 2023 eng biosurfactant rhamnolipids HPLC HPAEC-PAD bacteria growth downstream purification liquid-liquid extraction biotechnology Chemistry 9124499 2023-06-13T14:21:02+02:00 2023-06-14T10:05:33+02:00 2023-06-14T10:05:33+02:00

oai:lup-student-papers.lub.lu.se:9126273 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Owais Khalil author 9120829 Tommy Nylander supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Drug delivery with lipid nanoparticles, especially sponge phase lipid nanoparticles (LNP), has been well studied because of its ability for drug encapsulation and transferring the drug through the cell membrane. The sponge phase LNP formulation could be affected by the molecular structure of the lipid, the temperature, pH, dilution, the buffer, and the addition of a stabiliser. This project aimed to replace the sonication method with microfluidics because the sonication damages the sample by using ultrasound waves. However, in microfluidics more parameters were involved in the formulation, the total flow rate, and the lipid/buffer flow ratio. In this study, a mixture of mono-, di- and triglycerides and polysorbate 80 were used to investigate the formulation of sponge phase LNP by a microfluidic device. The effect of flow rate, flow ratio, stabilizer concentration, buffer and pH were studied to optimise the sponge phase LNP formulation method. Protein encapsulation was also tested to see how it would affect the size and structure of the LNPs. <br /> The formulation method used a T-crossed channel chip where the channel has a rectangular shape, 140x200 µm, with three inputs and one output. A statistical experimental design by the software Design Expert was done to plan the project and decide the different sample preparation conditions. The effect of the buffer was studied by comparing the formulation in milli-Q water, tris(hydroxymethyl)aminomethane (TRIS) buffer at pH=7.2 and pH=8.9, and in phosphate buffer (PB) at pH=7.0. The protein encapsulation was tested with different protein concentrations. The size and the zeta potential of the LNP were measured by dynamic light scattering (DLS), and the structure of the LNP was determined by small-angle X-ray scattering (SAXS). In addition, some samples have been imaged in transmission electron microscope (cryo-TEM).<br /> The size measurements of the LNP were fitted into a model that describes the effect of the parameters, total flow rate, and final lipid concentration that depended on the flow ratio and the concentration of the P80 as a stabiliser. According to the model, a high flow rate decreased the particle size, a high P80 concentration helped form smaller particles and a larger flow ratio led to lower lipid concentration and smaller particles. However, the pH also influenced the size where pH=7 helped form smaller particles than pH=8.9. Furthermore, TRIS and phosphate buffer formed smaller particles than milli-Q water and had clearer signals for the sponge phase. Even the encapsulation showed to influence the size and the phase of the LNP. High protein concentration disturbed the formulation of the sponge phase and led to bigger particles. Despite all, the microfluidic method showed its ability to form sponge phase LNP with different big sizes. Läkemedelstransportering med lipidnanopartiklar (LNP), särskilt svampfas lipidnanopartiklar,<br /> har varit intressanta på grund av dess möjlighet att inkapsla läkemedel och överföra<br /> läkemedlet genom cellmembranet. Svampfas LNP formuleringen kan påverkas av lipidens<br /> molekylära struktur, temperaturen, pH-värdet, utspädningen, bufferten och existerandet av<br /> en stabilisator. Projektets syfte var att ersätta ultraljudsformuleringsmetoden med<br /> mikrofluidik, eftersom ultraljud skulle skada provet genom de inskickade energifulla<br /> ultraljudsvågor. I mikrofluidik system var fler parametrar involverade i formuleringen, den<br /> totala flödeshastigheten och lipid/buffertflödesförhållandet. I denna studie undersöktes<br /> blandningar av olika monooleat lipider och polysorbat 80 för att formulera svampfas LNP med<br /> hjälp av en mikrofluidik system. Effekten av flödeshastighet, flödesförhållande,<br /> stabilisatorkoncentration, buffert och pH studerades för att optimera LNP-<br /> formuleringsmetoden med svampfas. Proteininkapsling testades också för att se hur det<br /> skulle påverka storleken och strukturen på LNP.<br /> Formuleringsmetoden använde ett T-korsat kanalchip där kanalen har en rektangulär form,<br /> 140x200 μm, med tre ingångar och en utgång. En statistisk experimentell design av<br /> programvaran Design Expert gjordes för att planera projektet och bestämma de olika<br /> provberedningsvillkoren. Genom resultatet studerades effekten av bufferten genom att<br /> jämföra formuleringen i milli-Q vatten, tris(hydroximetyl)aminometan (TRIS) buffert vid<br /> pH=7,2 och pH=8,9, och i fosfatbuffert (PB) vid pH=7,0. Proteininkapslingen testades med<br /> olika proteinkoncentrationer. Storleken och zetapotentialen för LNP mättes med dynamisk<br /> ljusspridning (DLS), och fasen för LNP bestämdes med liten vinkelröntgenspridning (SAXS).<br /> Dessutom har några prover avbildats i transmissionselektronmikroskop (cryo-TEM).<br /> Storleksmätningarna av LNP monterades in i en modell som beskrev effekten av<br /> parametrarna, total flödeshastighet, slutlig lipidkoncentration som berodde på<br /> flödesförhållandet och koncentrationen av P80 som stabilisator. Enligt modellen minskade en<br /> hög flödeshastighet partikelstorleken, en hög P80-koncentration hjälpte till att bilda mindre<br /> partiklar, och ett mer signifikant flödesförhållande led till lägre lipidkoncentration och mindre<br /> partiklar. pH påverkade också storleken där pH=7 hjälpte till att bilda mindre LNP jämfört med<br /> pH=8,9. Dessutom bildade TRIS och fosfatbuffert mindre LNP än milli-Q-vatten och de hade<br /> tydligare signaler för svampfasen i SAXS mättningarna. Även proteininkapslingen visade sig<br /> påverka storleken och fasen av LNP. Hög proteinkoncentration störde formuleringen av<br /> svampfasen och ledde till större partiklar. Trots allt visade mikrofluidik metoden sin förmåga<br /> att bilda svampfas LNP med olika stora storlekar. https://lup.lub.lu.se/student-papers/record/9126273/file/9128774.pdf application/pdf 2771597 no 2023 eng Sponge phase lipid nanoparticles microfluidics SAXS cryo-TEM DLS chemical engineering Chemistry 9126273 2023-06-16T16:49:05+02:00 2023-06-22T11:10:39+02:00 2023-06-22T11:10:39+02:00

oai:lup-student-papers.lub.lu.se:9126442 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Parahat Shovkedov author 9126440 Ann-Charlotte Almstrand supervisor Department of Chemistry v1000647 department Introduction: Identification and quantification of OxPCs and LPCs in the lung surfactant with non-invasive sampling techniques and validated analytical methods are of great importance in terms of exploring biomarkers of oxidative stress in lung and other lung related diseases. <br /> Background: Although there are some well-structured analytical methods for the detection and quantification of OxPCs, there is no standardized method and no consensus on the best way. In general, quantification of OxPCs and LPCs in the pulmonary surfactant is challenging especially due to the lack of well-developed sampling technique. Particles in exhaled air (PExA), a non-invasive sampling method, is a promising candidate to close this gap. <br /> Aims: The aims of the present research were to study the auto-oxidation of POPC to improve the sampling and the sample preparation technique, to improve and validate an RP-UHPLC-MS/MS method, and to apply the analytical method for the absolute quantification of PONPC and LPC 16:0 in PEx. <br /> Methods: Auto-oxidation of POPC was evaluated based on the change in the levels of POPC and PONPC with air-exposure of POPC spiked on the sample membrane. In addition, influence of time and temperature on auto-oxidation during the extraction step was studied. <br /> The improved in-house RP-UHPLC-MS/MS method was validated in terms of matrix effect, precision, accuracy, recovery, and carry-over. Data acquisition was achieved by MRM mode using an ESI probe in negative polarity. Absolute quantification of PONPC and LPC 16:0 was performed in PEx samples from healthy individuals (n=8), where two of them were smokers.<br /> Results: Auto-oxidation of POPC was observed during sample collection, storage, preparation, and extraction. The auto-oxidation was reduced by decreasing air-exposure time during sample collection and preparation, and by lowering the extraction temperature and time.<br /> The proposed RP-UHPLC-MS/MS method was found to be precise and accurate (in terms of within-run precision and accuracy) for the absolute quantification of PONPC and LPC 16:0 when the calibration and the analysis was performed in a PTFE matrix. The extraction recovery was found to be high, and no analyte carry-over over was found with regards to the analytical pathway. <br /> Conclusion: The analytical method was successful for the absolute quantification of PONPC and LPC 16:0 in PEx, but the absolute quantity of endogenous PONPC in PEx could not be determined due to the auto-oxidation of POPC during sample collection and preparation. Recently, identification and quantification of oxidized phosphatidylcholines (OxPCs) and lysophosphatidylcholines (LPCs) in lung surfactant is gaining more attention since they are considered potential biomarkers of oxidative stress in lung diseases. Particles in exhaled air (PExA), which provides collection of non-volatile particles originated from the airway with specific breathing technique, is a convenient sampling method for lipid analysis. PExA method is non-invasive and relatively simple, and demands less extraction procedures, making it attractive for clinical and research oriented large population studies. However, the compatibility of PExA method for determination of OxPCs in PEx needs to be studied since auto-oxidation of unsaturated phospholipids can give erroneous results by overestimating the levels of OxPCs. <br /> The aims of the present research were to improve the PEx sample collection and preparation technique with regards to the auto-oxidation, to improve and validate an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method, and to apply the analytical method for absolute quantification of the most abundant OxPC and LPC, namely 1-palmitoyl-2-(9`-oxo-nonanoyl)-sn-glycero-3-phosphocholine (PONPC) and 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocoline (LPC 16:0), respectively, in PEx. <br /> The experimental studies showed that auto-oxidation of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) during collection, handling and extraction of PEx samples is an important issue that needs to be addressed for quantification of endogenous PONPC accurately. The studies conducted on POPC air-exposure showed that measures such as decreasing air-exposure time during sample collection and preparation, and reducing the extraction temperature and time helped to minimize the auto-oxidation. The proposed UHPLC-MS/MS method was found to be precise and accurate (in terms of within-run precision and accuracy) for the quantification of PONPC and LPC 16:0 when the calibration was performed in the matrix with the membrane used for PEx collection. The analytical method was successful for the absolute quantification of PONPC and LPC 16:0 in PEx obtained from healthy individuals (n=8, smokers and non-smokers), but the absolute quantity of endogenous PONPC in PEx could not be determined due to the auto-oxidation of POPC during sample collection. It is believed that the present study will provide researchers with an effective bioanalytical tool that enables investigation of biomarkers of airway inflammation and other lung diseases. However, further improvement of sample collection conditions addressing auto-oxidation during sampling is necessary. 2023 eng auto-oxidation lysophosphatidylcholine oxidized phosphatidylcholine PExA validation analytical chemistry Chemistry 9126442 2023-06-17T08:56:10+02:00 2023-06-20T11:53:39+02:00 2023-06-20T11:53:39+02:00

oai:lup-student-papers.lub.lu.se:9128105 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ruben Hansson author 9128096 Johan Wennerberg supervisor Department of Chemistry v1000647 department The effect that organic solvents have on the environment and the intrinsic risk that come with using them should be limited. By replacing organic solvents with less harmful solvents, such as water, and with more effective catalysts can risks intrinsic to organic solvents be minimized or eliminated. The focus of this project is testing if Michael addition using transition metal salt catalysts with Zr or Hf are viable. Several conditions were tested to determine the optimal conditions. With limited time for testing conditions were the best result found to not use solvent. Tests performed gave insight into the limitations of the catalyst. Limitations such as solidification, unwanted side product and what methods are not applicable for quantification. This has given insight into what conditions and methods that should be avoided or circumvented can be used for future studies. Behovet av lösningsmedel som kan byta ut farliga organiska eller fossil-baserade lösningsmedel har uppstått för att minimera utsläpp av farliga restprodukter. En lösning till detta behov är att istället använda vatten. Vad man har hittat är att vissa rektioner i vatten kan sker snabbare än i organiska lösningsmedel. Att byta ut lösningsmedel är inte den enda lösningen på att minimera slöseri i kemi. En annan aveny är att använda effektivare katalysatorer för att göra rektioner effektivare, kunde användas flera gånger om och kanske även i vatten. Flera katalysatorer som innehåller ”rare earth metals” har redan visat sig vara lovande och har optimerats för att binda samman molekyler. Vad detta projekt vill undersöka är mer lättillgängliga ”transition metal” katalysatorer och se om det fungerar lika bra eller bättre än de redan testade katalysatorerna. Efter flera tester med att höja och sänka temperatur och byta ut i vilket lösningsmedel rektionen sker i kom vi fram till att det testade ”transition metal” katalysatorerna inte fungerade lika bra som de ”rare earth metals” katalysatorerna. Det testade katalysatorerna kunde inte återanvändas och kunde inte utföra rektionerna lika effektivt som det redan optimerade. En överraskning var att det mest lovande reaktioner som gjordes inte hade någon katalysator alls. Att testa olika rektioner utan katalysator kan vara minder spännande än att testa nya metall katalysatorer, men det är nyttigt för att se om en katalysator hjälper eller hindrar reaktioner från att ske. Slutsatsen vi kom fram till var att det behövs fler tester för att hitta optimala förhållanden för det testade ”transiton metal” katalysatorerna så de kan fungera lika bra som det redan optimerade ”rare earth metal” katalysatorerna. https://lup.lub.lu.se/student-papers/record/9128105/file/9128108.pdf application/pdf 534954 no 2023 eng Green chemistry transition metal rare earth metal Michael addition Yb Zr Hf analytical chemistry Chemistry 9128105 2023-06-20T15:56:36+02:00 2023-06-22T10:57:50+02:00 2023-06-22T10:57:50+02:00

oai:lup-student-papers.lub.lu.se:9128119 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Samer Karim author 9128117 Alice Spangenberg supervisor Department of Chemistry v1000647 department Four pincer-ligated iridium complexes, 1-4, featuring substituents with different electronic properties on meta and para positions on the aromatic backbone were synthesized for the purpose of comparing their efficiency as catalysts in the acceptorless dehydrogenation of 1-phenylethanol. Previous studies have already revealed that turnover frequencies were higher in more dilute catalyst solutions, but the interesting new observation in this project is that this also applies to these four complexes. We obtained concentration- and temperature-dependent plot by conducting an initial rate experiment over a 15-minute period. These were then used to determine the reaction orders and activation parameters for these four catalysts. Regarding the reaction orders for the four catalysts, the catalyst dependence is non-proportional. With higher catalyst concentrations a diminishing return occurs. This could be due to hydrogen in the solution, which could affect the catalyst performance. The low enthalpy barrier for the four catalysts shows that minimal bond breaking occurs in the rate-determining step which aligns with the mass transfer of hydrogen. This means that the efficiency of hydrogen leaving the solution can have an impact on the reaction. Based on the experiment over an extended period, both complexes 1 and 2 were very effective in the acceptorless dehydrogenation of 1-phenylethanol and could achieve complete conversion, whereas the catalysts 3 and 4, lose their effectiveness over extended periods. På grund av klimatkrisen och de minskade resurserna av fossila bränslen, accelereras sökandet efter gröna och förnybara energikällor. Vätgas är en av de bästa ersättningarna för fossila bränslen eftersom det enda biprodukten vi får vid förbränning är vatten. Dock är dess användning begränsad på grund av utmaningarna med att lagra och transportera vätgas. Den nya och framväxande teknologin för att lagra och transportera vätgas i flytande material, där de lätt kan extraheras, kallas flytande organiska vätgasbärare (LOHC). För att extrahera vätgas från dessa LOHC används vanligtvis iridiumbaserade katalysatorer. För att förbättra de katalytiska egenskaperna hos dessa katalysatorer behöver vi en djupare förståelse av denna process. Därför valde vi fyra komplex som skiljer sig åt i de elektroniska egenskaperna hos liganden och studerade skillnaden i reaktiviteten mellan dem. Resultaten visar att en specifik typ av elektrondragande ligand förbättrar aktiviteten, medan andra resulterar i ogynnsamma effekter. Dessutom gynnas reaktionen för extraktion av vätgas av en effektiv borttagning av bildad vätgas från reaktionssystemet. Denna studie ger en grundläggande förståelse av dessa processer, men ytterligare arbete behövs för att få mer kunskap. 2023 eng Acceptorless dehydrogenation of alcohols (AAD) Hydrogen mass transfer rate POCOP pincer ligands POCOP pincer iridium complexes Turnover frequencies (TOFs) Analytical chemistry Chemistry 9128119 2023-06-20T16:14:12+02:00 2023-06-22T11:00:14+02:00 2023-06-22T11:00:14+02:00

oai:lup-student-papers.lub.lu.se:8908901 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Fredrik Persson author 8908898 Johan Svensson Bonde supervisor Pure and Applied Biochemistry v1000655 department Amelogenin is an enamel matrix protein which participates in the formation of dental enamel, the hardest tissue in the human body. The protein participates in this process by orienting the mineral crystals which make up the enamel and several proteolytic products from amelogenin also affect the dental enamel during its maturation. The protein is mostly hydrophobic with a hydrophilic region at the C-terminal and is regarded as an intrinsically disordered protein (IDP) due to its lack of secondary and tertiary structure. In addition to being an IDP the protein is capable of self-aggregating in order to create larger structures. One of these structures is the nanosphere. The formation of these spheres is highly pH-dependant and affects the solubility of the protein with the protein being in its monomer form under acidic conditions and in the aggregate form under alkaline conditions. These nanospheres are of great interest to the scientific community since it has been shown that by producing fusion proteins containing amelogenin it is possible to create nanospheres with a wide range of abilities. The purpose of this project is to synthesize fusion proteins with amelogenin and a cysteine residue bound together by a linker in order to determine if it is possible to create fusion proteins with similar properties as the wild type protein while also being capable of specifically binding molecules to the cysteine residue. Furthermore the feasibility of a model where maleimide derivatives are used as a way to bind molecules with different properties to the nanosphere will be investigated. This project has shown that it is possible to create amelogenin+ cysteine fusion proteins with similar properties as the wild type protein if a reducing agent is present. The need for a reducing agent is due to formation of disulphide bridges between cysteines on different nanospheres which causes excessive aggregation. In addition to the properties of the wild type amelogenin the availability of the cysteine residues for reactions has been shown. The feasibility of the maleimide derivative model is still unknown due to the unsuitable derivative used in this study. Further research is needed for the characterization of the proteins and finding a suitable molecule to test the maleimide derivative model. Amelogenin is a protein that can be produced by several species, including humans and is capable of gathering together in water to form microscopic aggregates called nanospheres. In this master thesis the DNA sequence of amelogenin was altered so that different fusion proteins were created. These fusion proteins differ from normal amelogenin in that the fusion protein aggregates have thiols, chemical molecules consisting of sulphur and hydrogen on the aggregate surface. The thiols is a result of the fusion proteins containing a specific amino acid called cysteine. Amino acids are molecules that cells use to produce proteins and cysteine is often used by cells to give proteins stability. This stability is a result of the thiols on the cysteines being able to react with one another if they are close enough and create a strong bond called a disulphide bridge.<br /> The purpose of this study was to produce and purify different fusion proteins consisting of amelogenin and cysteines and then compare some of the properties of the fusion proteins with ordinary amelogenin. After this a model was tested where a group of molecules called maleimide derivatives can be used to alter the properties of the fusion protein nanospheres. Maleimide derivatives were used in this model since they react specifically with thiols under the right conditions.<br /> When the proteins had been produced and purified five experiments were performed. First an SDS-PAGE was performed with both non-purified and pure protein samples where the samples were injected into a gel and analysed in order to see if the proteins had been produced and if they were pure. After that the solubility and aggregation of the fusion proteins were compared with amelogenin. The solubility was tested with solubility profiles where protein samples in water at different pH were prepared and analysed with the same type of gel as in SDS-PAGE. The aggregation was tried with DLS which is an experiment where a sample is analysed with a laser and depending on how the sample affects the scattering of the light from the laser the size of the aggregates in the sample can be determined. Thereafter the reactivity of the thiols on the nanospheres were tested by measuring how much light each protein absorbs in a specific reaction. Finally the possibility of using maleimide derivatives to alter the properties of fusion protein nanospheres was tested by using a derivative that fluoresces when it binds to thiols.<br /> <br /> The experiments showed that the fusion proteins could be produced and purified. Regarding the properties of the new proteins the solubility and aggregation experiments indicated that the nanospheres formed unwanted disulphide bridges between each other resulting in larger aggregates. These disulphide bridges could be broken with a reducing agent resulting in the fusion proteins having similar solubility and aggregation as amelogenin. The third property that was tested was thiol reactivity and the absorbance measurements showed that almost all fusion proteins had reactive cysteines. The exception was one protein that was likely less water soluble than the others which affected the measurement. In the end the maleimide derivative model was tested with the fluorescent molecule but unfortunately the derivative was unspecific and likely reacted with the nanospheres in unwanted ways since the molecule reacted with nanospheres made up of normal amelogenin which does not contain thiols.<br /> <br /> Even though this study has answered many questions about the fusion proteins made in this study there is a need for more research regarding the properties of the proteins. For example there is a need to find more suitable maleimide derivatives in order to test if they can be used to alter the properties of nanospheres<br /> To conclude it can be said that the project has been successful in producing and purifying the desired proteins. Additionally the performed experiments showed that the fusion proteins had similar properties as common amelogenin if a reducing agent is present and that the thiols on the aggregate surface are reactive. Unfortunately it is still unclear whether maleimide derivatives can be used to modify nanospheres since the molecule chosen for this study was unspecific in its binding. https://lup.lub.lu.se/student-papers/record/8908901/file/8908902.pdf application/pdf 840099 yes 2017 eng fusion protein cysteine nanosphere amelogenin self-aggregation maleimide derivatives applied biochemistry tillämpad biokemi Biology and Life Sciences Technology and Engineering Chemistry 8908901 2017-05-25T13:34:48+02:00 2017-09-18T14:14:23+02:00 2017-09-18T14:14:23+02:00

oai:lup-student-papers.lub.lu.se:8909485 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Klara Hammarstrand author 8909483 Ulf Nilsson supervisor Centre for Analysis and Synthesis v1000651 department Department of Chemistry v1000647 department This master thesis project focuses on establishing a synthetic method with the prospect of developing new antibacterial agents. Due to the increment of resistant strains of bacteria throughout the world, this area of research is well motivated.<br /> The nine-carbon sugar - sialic acid - is a highly prevalent communication molecule on human cell surfaces. It signals that the cells are endogenous and not harmful. This signalling mechanism is mimicked by exogenous cells - bacteria -, masking them as human cells and thus resisting the host’s innate immune response. As a result the bacterial strain can grow uncontrolled leading to an infection in the human body. Therefore, it seems that a disruption of their protective mechanism, with means of sialic acid, poses an excellent antibacterial target.<br /> This work has focused on finding a pathway to be able to modify position C-4 of sialic acid. A couple of different approaches have been tried out leading to one successful way to conduct the desired modification. It was concluded that a complete protective strategy was required where all hydroxyl groups were protected except for OH-4. Eventually, a sialic acid derivative with a substituent at C-4, consisting of a triazole ring and a para-substituted fluorophenol, was identified by MS. Since the discovery of penicillin in the 1940’s, mankind have been spared deaths caused by bacterial infections. Up until today we rely on the curing benefits of antibiotics. This is a security we will lose within a short period of time, as in the recent years, more and more resistant bacteria have been detected. The development of resistant bacterial strains is on one hand a result of evolutionary adaption but foremost a result of overuse of antibiotics. Before us stands an unpleasant picture of a healthcare with no weapons in the fight against bacterial diseases. To change this picture, we need to change the way we use antibiotics and we need to find novel antibiotics. The work of this thesis focuses on the latter. https://lup.lub.lu.se/student-papers/record/8909485/file/8909487.pdf application/pdf 2364546 no 2017 eng KOK820 organic chemistry medicinal chemistry drug development method development antibiotics organic synthesis Chemistry 8909485 2017-05-29T19:25:58+02:00 2017-06-07T12:10:41+02:00 2017-06-07T12:10:41+02:00

oai:lup-student-papers.lub.lu.se:8909860 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Rebecca Frankel author 5473636 Tommy Cedervall supervisor Department of Chemistry v1000647 department The use and production of polymeric plastic products have increased immensely since the 1960s, and with it, the correlated presence of plastics in the aquatic environment. Through different biotic and abiotic processes, the plastics will be degraded to smaller pieces, eventually down to the micro- and nanoscale as well. Previously known about these nanoparticles is their ability to enter cells dependent on the size of the particles – with possibly lethal outcome -, as well as their interaction with organic matter which may cause agglomeration. Unbeknownst before is the effect of this agglomeration to the toxicity of the particles. We have induced the aggregation of amine-functionalized polystyrene nanoparticles (50 nm) using immunoglobulin G, studied the formed aggregates through absorbance at 400 nm, Dynamic Light Scattering, Nanoparticle Tracking Analysis, and Differential Centrifugation Sedimentation, as well as investigated the toxicity of free particles (50 nm, 200 nm, 500 nm) versus the aggregates to the freshwater zooplankton species Daphnia magna. The results show aggregation dependent on substrate concentrations and buffer pH. Furthermore, both the 50 nm particles and the aggregates made of 50 nm particles with IgG showed an acute (24 h) lethal effect to the D. magna, which was not observed for the larger particles. It can be speculated that the aggregates, when entering the D. magna, break down into its smaller, toxic subunits; however, the size analysis of the samples afterwards was inconclusive as particles of similar size could also be detected in control treatments and so would require further investigation. Samhällets plastproduktion och –konsumtion har ökat markant sedan 1960-talet, vilket även har resulterat i den korrelerade ökade närvaron av plast i bland annat vattenmiljöer. Dagligen kommer information om de problem plasten orsakar, då exempelvis valar och sälar trasslar in sig i övergivna fisknät eller genom förtäring av plaster till sist dör av svält och undernäring. Genom olika biotiska och abiotiska processer kommer plasten dessutom att brytas ned till mindre bitar, till slut ned på mikro- och nanoskalan, vilket medför risker för mindre organismer som inte tar skada av den större plasten. I detta arbete har jag framförallt arbetat med nanopartiklar, och som namnet antyder är dessa partiklar väldigt små: för att jämföra så är en nanopartikel för ett saltkorn som vad en punkt efter denna mening är för en fotbollsplan. Att nanopartiklar tas upp av celler baserat på partikelns storlek – ibland med letalt resultat – är tidigare känt; likaså känt är partiklarnas förmåga att klumpa ihop sig när de kommer i kontakt med olika ”klister”molekyler såsom vissa protein, och således bilda aggregat av större storlek. Det är dock tidigare okänt vilken inverkan denna aggregering har på nanopartiklars toxiska effekt. Mitt arbete har gått ut på att inducera aggregeringen av aminmodifierade polystyrenpartiklar (50 nm) genom proteinet immunoglobulin G, och sedan studera storleksfördelningen av aggregaten genom olika analysmetoder (absorbans vid 400 nm, Dynamic Light Scattering, Nanoparticle Tracking Analysis, och Differential Centrifugation Sedimentation) samt undersöka toxiciteten av fria partiklar (50 nm, 200 nm, 500 nm) jämfört med aggregaten gentemot zooplankton (Daphnia magna). Resultaten visar att aggregeringen är beroende av substratkoncentrationer och buffer pH; vidare så uppvisade både 50 nm partiklarna och aggregaten (skapade med 50 nm partiklar och IgG) en akut (24h) dödlig effekt på D. magna, vilket de större partiklarna inte gjorde. Det kan spekuleras att aggregaten, när de tas upp av D. magna, bryts ned till sina mindre, toxiska enheter; ytterligare studier behövs dock för att påvisa detta, då storleksanalysen efteråt var ofullständig på grund av att partiklar av likartad storlek kunde observeras även i kontrollexperimenten. 2017 eng Aggregation Toxicity Nanoparticles biochemistry biokemi Chemistry 8909860 2017-05-31T14:56:55+02:00 2017-07-13T11:20:46+02:00 2017-07-13T11:20:46+02:00

oai:lup-student-papers.lub.lu.se:8911963 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Emil Gustafsson author 7794029 Malin Zackrisson Oskolkova supervisor Department of Chemistry v1000647 department In this work, lactoferrin was studied as a function of pH, starting at a low pH of 5.5 with 5 mM salt, in terms of interactions and dynamics with small angle X-ray scattering (SAXS), static and dynamic light scattering (SLS and DLS). Under these conditions lactoferrin was expected and found to have a strong electrostatic repulsion and behaved similar to an isotropic colloid. The glass transition was under these conditions determined to occur at a volume fraction of 0.32. Any effect of high protein concentration on lactoferrins secondary structure was investigated by circular dichroism (CD) and concentrations close to the glass transition (440 mg/mL) and no effect on secondary structure was found. <br /> <br /> At pH where patch-patch attractions are dominating, attractions were investigated by measuring second virial coefficients and collective diffusion. On approaching the isoelectric point, lactoferrins patch attraction was found to be stronger as well as active over a wider range with respect to ionic strength. At pH 9, the expected repulsion at low ionic strength is gone and attractions decreased as a function of ionic strength. This behavior can, in part, be attributed to a Kirkwood-Schumaker interaction, expected to occur for proteins with high capacitance and close to the isoelectric point which is the case here. In addition, investigation of stripe-like nanostructures under patchy conditions were imaged using fluorescence microscopy. Proteiner är stora biomolekyler som finns i alla levande organismer. De är uppbyggda av ett antal byggstenar, så kallade aminosyror med varierande egenskaper, och de utför många uppgifter som är essentiella för att liv skall kunna finnas. Hur proteiner interagerar med varandra och sin omgivning styr deras beteende vilket i sin tur är relaterat till deras funktion. Att förstå dessa interaktioner är av stor vikt för att förstå proteiners komplicerade beteende. Proteiner har i regel en ojämn interaktionsyta, där olika områden på ytan interagerar med omgivningen på olika sätt. För att kunna få ökad förståelse för hur sådana interaktioner fungerar så har modellproteinet laktoferrin, som har två interaktionsområden, studerats. En mindre del av laktoferrins yta, en så kallad patch, har en attraktiv interaktion med motsvarande del på en annan laktoferrin molekyl. Resterande del av proteinet har istället en frånstötande, repulsiv, interaktion och dessa två konkurrerar med varandra. Vid låga salthalter är den repulsiva interaktionen starkare men vid tillsats av mer salt så blir attraktionen istället dominant. När salt tillsätts bortom denna punkt blir även attraktionen allt svagare och vid höga salthalter försvinner den helt. Patchen leder till att kluster av två laktoferrin molekyler bildas när koncentrationen av laktoferrin ökas.<br /> <br /> Laktoferrins patch attraktion studerades för att få djupare insikt i vad som styr styrkan på attraktionen och hur denna kan kontrolleras. För att göra detta etablerades först en referens under förhållanden där patchen inte är aktiv, det vill säga vid lågt pH och låg salthalt, där laktoferrin karaktäriserades. Attraktionen slogs sedan på genom att öka pH och salthalt och interaktionsstyrkan kvantifierades under olika pH och salthalt. När pH ökas, minskar det totala antalet laddningar på proteinets yta vilket leder till en svagare repulsiv interaktion och i gengäld ökas attraktionen. Vid högre pH är dessutom är attraktionen starkare vid högre salthalter och när pH blir tillräckligt högt är attraktionen dominant redan vid de lägsta salthalterna. Det noterades också att attraktionen blir starkare vid högre temperatur men att färre laktoferrin kluster bildas. Under förhållanden där attraktionen dominerar bildades också låg koncentration av avlånga strukturer, eller strimmor, av laktoferrin.<br /> <br /> Med information om hur styrkan på attraktionen kan modifieras hoppas vi kunna öka styrkan på attraktionen och därmed öka mängden av de strukturer som bildas. Vid högre koncentration blir de lättare att studera och kan därför noggrannare undersökas. https://lup.lub.lu.se/student-papers/record/8911963/file/8911979.pdf application/pdf 941802 LU/LTH access 2017 eng Chemistry 8911963 2017-06-07T13:46:38+02:00 2017-06-26T10:36:26+02:00 2017-06-26T10:36:26+02:00

oai:lup-student-papers.lub.lu.se:8911971 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Caroline Olsson author 8911969 Susanna Horsefield supervisor Department of Chemistry v1000647 department Aquaporin 2 (AQP2) acts as a water channel in the apical membrane of principal renal cells in the collecting ducts of the kidney. Upregulation is controlled by stimulation of these cells with vasopressin. Downregulation of the presence of AQP2 in the membrane occurs through ubiquitination and then sorting of the protein via the ESCRT-I, -II and –III complexes into the Multivesicular bodies (MVBs). It then interacts with the soluble protein LIP5 and LIP5 facilitated VPS4 ATPase translocates it into inner vesicles of the MVBs. From there it can either be targeted for lysosomal degradation or released as exosomes into the urine. This project was aimed at investigated the binding between AQP2 and LIP5. The first step was to express the LIP5 in e. coli and purifying the protein. Affinity analysis of the binding between the two proteins was then performed with both fluorescence anisotropy and microscale thermophoresis (MST). Binding between the proteins was observed and the obtained results indicate that the N-terminal domain of LIP5 might be most important for the binding to AQP2. It was also suggested by the results from MST that the amino acid residue K71 is particularly important for the binding. Further work should be performed to further study the binding between AQP2 and LIP5. Har du tänkt på att du behöver kissa oftare än vanligt när du har druckit öl? Eller när du druckit te eller kaffe? Detta beror på ett hormon som heter vasopressin och som produceras i hypofysen. Vassopressin är en slags signal till njurarna att återvinna mer vatten från urinen. Koffein och alkohol påverkar hypofysen så att den producerar mindre vasopressin vilket gör så att mer vatten hamnar i urinen och vi måste springa till toaletten stup i kvarten.<br /> <br /> Hur kan då vasopressin påverka vattenåterviningen? För själva återvinnandet står ett protein som kallas Aquaporin 2, AQP2, (ja det finns massa olika aquaporiner och de sitter på lite olika ställen i kroppen). I njurarna filtreras ungefär 180 L vatten varje dag för att kroppen ska bli av med ämnen den inte vill ha. För att vi inte ska bli av med allt detta vattnet genom att kissa behöver en hel del av vattnet tas upp igen. Det är det AQP2 gör. Aquaporinerna är kanaler som sitter i cellens membran och bara släpper igenom vissa molekyler, te.x. bara vatten. Membranen är som väggar som vattnet inte kan ta sig genom utan en aquaporin som fungerar som en sluss eller en dörr för vattenmolekylerna så att de kan ta sig till andra sidan. Vasopressin i blodet gör så att njurcellerna sätter in AQP2 i sina membran. För att vi inte ska samla på oss allt för mycket vatten i kroppen och för att vi ska kunna kissa ut avfall och föroreningar, går AQP2 tillbaks in i njurcellen när den gjort sitt jobb i membranet.<br /> <br /> Detta kandidatarbete handlar om en tredje molekyl, proteinet LIP5, som binder till AQP2 för att signalera till cellen att AQP2-molekylen är uttjänt och ska brytas ner i lysosomen. Lysosomen är en organell, en del innuti cellen, som tar hand om saker som cellen vill göra sig av med. Detta inkluderar bland annat förbrukade celldelar eller proteiner, som till exempel AQP2. LIP5, som detta arbete handlar mest om är alltså en signal till cellen att AQP2-molekylen den binder till har gjort sitt och inte kan återanvändas fler gånger i membranet. Mer konkret har detta arbete gått ut på att dels producera och rena fram LIP5 och dels att undersöka mer exakt hur LIP5 och AQP2 binder till varandra.<br /> <br /> För att kunna studera LIP5 har den producerats genom att man har låtit den uttryckas i Escherichia coli, en typ av bakterie även känd som E. coli. Interaktionen mellan LIP5 och AQP2 undersöktes sedan med två olika metoder. En modell i datorn användes för att bestämma enstaka aminosyror, byggstenarna som proteiner består av, som kunde muteras för att avgöra hur viktiga de är för bindningen. Samma metoder användes på det naturliga proteinet, som man brukar kalla vildtyp, en avkortad variant av det naturliga proteinet och på en mutant som skiljer med en aminosyra.<br /> <br /> Experimenten visade att det muterade proteinet hade svagare interaktion med AQP2 än vildtypen. Även det avkortade proteinet band svagare än viltypen men starkare än mutanten. Detta kan betyda att det är den del som fanns i det avkortade proteinet, N-terminaldomänen (ND), som är viktigast för interaktionen med AQP2. Även mutationen som gjordes är i samma domän och att den band svagare kan betyda att just den muterade aminosyran är viktig för att LIP5 ska kunna binda till AQP2. 2017 eng Affinity analysis biochemistry LIP5 AQP2 biokemi Chemistry 8911971 2017-06-07T13:58:53+02:00 2017-07-13T11:18:46+02:00 2017-07-13T11:18:46+02:00

oai:lup-student-papers.lub.lu.se:8913239 2025-07-29T13:03:30Z Medicine PhysicsChemistryMaths SocialBehaviourLaw

studentPublicationsM1 William Osmani author 8913237 Ia Rosenlind supervisor Food Technology and Nutrition (M.Sc.) v1000294 department I dagens livsmedelsbutiker ser man allt fler produkter märkta med närings- och hälsopåståenden. Functional foods är en miljardmarknad där man tydligt ser en årlig tillväxt för dessa livsmedelsprodukter. I början av år 2017 konstaterades att majoriteten av de svenska aktörerna inom olivoljebranschen väljer att använda sig av livsmedelsverkets nyckelhålsmärkning, vilket indikerar till konsumenterna att olivoljan är ett nyttigt fett och bra för hälsan. Detta kan tolkas som att även olivoljetillverkare ser potential att marknadsföra sina produkter som nyttiga och följa den trend som pågår.<br /> Studiens syfte är att undersöka hur de svenska aktörerna inom branschen resonerar allmänt kring hälsopåståenden samt specifikt gällande olivoljans polyfenoler och utvärdera hur olivoljekvalitet regleras. Arbetet har även som mål att undersöka hur polyfenol halterna varierar i olivolja och möjligheten att använda det godkända hälsopåståendet som lyder ”Olivoljans polyfenoler bidrar till att skydda blodfetter mot oxidativ stress”. Kravet är att olivoljan ska innehålla minst 5 mg hydroxityrosol och dess derivat per 20g olivolja.<br /> För att uppnå studiens syfte har 15 olivoljor i olika prisklasser och kvalitetér inhandlats där bestämning av totalfenoler varit i fokus genom Folin- Ciocalteu metoden. Utöver det har även 2 olivoljeprover skickats till ett externt laboratorium för analys av fenolämnet hydroxityrosol och dess derivat. Genom att skicka en enkät till de svenska aktörerna inom olivoljebranschen gavs en bättre bild på hur aktörerna resonerar kring användning av hälsopåståenden allmänt och specifikt av hälsopåståendet gällande olivoljans polyfenoler.<br /> Provresultaten från Folinmetoden visade att olivoljor av extra jungfrukvalitet innehåller betydligt mer polyfenolämnen än övriga olivoljekvalitéer. De externa proverna visade koncentrationer på över 400 mg/kg hydroxityrosol och dess derivat, vilket möjliggör en användning av hälsopåståendet om olivoljans polyfenoler. De koncentrationer som mättes med hjälp av Folin metoden visade betydligt högre värden än de externa analyserna, vilket innebär att Folinmetoden är en allt för osäker metod vid analys av specifika polyfenolämnen.<br /> Det som framkom av enkätundersökningen gällande hälsopåståendet om olivoljans polyfenoler var att majoriteten av deltagarna var överens om att det beror på att hälsobudskapet inte är kommunikativt nog för att användas som marknadsföring. Flera ansåg att hälsopåståendet kan ha motsatt effekt och mer informations krävs till konsumenterna för att de ska kunna ta till sig det. En annan viktig faktor som framkom var att alla partier av oliver behöver analyseras vilket ur ett ekonomiskt perspektiv blir kostsamt. Detta medför att företagarna har många kriterier att uppfylla när de märker sina produkter och som regleras av flera grundförordningar. Om ett företag bestämmer sig för att använda hälsopåståendet tillkommer fler förordningar de måste anpassa sig till och då kanske företagarna behöver ställa sig frågan om det är värt besväret samt om det finns ekonomisk vinning i det? https://lup.lub.lu.se/student-papers/record/8913239/file/8913373.pdf application/pdf 1153650 yes 2017 swe Functional foods Hydroxityrosol EG-förordning 2568/1991 EG-1924/2006 EU-förordning 432/2012 EU-förordning 1308/2013 EU-förordning 29/2012 Folin-Ciocalteu Hälsopåståenden olivolja Polyfenoler i olivolja livsmedelsteknik Chemistry Medicine and Health Sciences Law and Political Science 8913239 2017-06-09T12:04:34+02:00 2017-06-29T08:58:32+02:00 2017-06-29T08:58:32+02:00

oai:lup-student-papers.lub.lu.se:8913611 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Björn Pålsson author 8913609 Hans-Erik Åkerlund supervisor Department of Chemistry v1000647 department Photosynthetic organisms harvest and convert light energy into chemical energy and utilize it in their metabolism. The light is captured through pigments called chlorophylls and carotenoids, present in the thylakoid membranes inside the chloroplast. In addition to acting as auxiliary light harvesters, the carotenoids also act as antioxidants by 1) preventing the formation of reactive oxygen species (ROS) and 2) quenching formed ROS before it can cause damage to the cell. <br /> ROS are reactive species, radicals and non-radicals, containing oxygen. They are naturally generated e.g. in the electron transport chains of chloroplasts and mitochondria and act as indicators of stress in the cell. Too high ROS concentration for a prolonged period of time is lethal to the cell due to their high reactivity.<br /> One way carotenoids are involved in preventing ROS formation is the non-photochemical quenching (NPQ) of excited singlet chlorophyll (1Chl*): the energy is transferred from 1Chl* to the carotenoid and is then dissipated to the solvent through vibrations and rotations. This prevents the conversion of 1Chl* into triplet state chlorophyll (3Chl*) which gives rise to ROS. Plants regulate the amount of carotenoids available to NPQ through the xanthophyll cycle: At high light intensity, the carotenoid violaxanthin is de-epoxidized into zeaxanthin, which more effectively participate in NPQ. The reaction is catalysed by violaxanthin de-epoxidase (VDE). <br /> The closest relative of VDE is the not yet officially named protein nick-named ‘violaxanthin de-epoxidase related protein’ (VDE-R). It is present in the same context as VDE but its function is of yet unknown. <br /> In this study, methods of bleaching photosynthetic pigments from Spinacia oleracea (spinach) using copper(II) phosphate (Cu3(PO4)2), UV light and hydrogen peroxide (H¬¬2O2) were investigated in order to identify experimental conditions under which it is possible to determine whether or not VDE-R is involved in repairing damaged photosynthetic pigments. Also the effect of VDE-R on unbleached thylakoids was briefly investigated. <br /> The relative amount of pigments were determined using HPLC (high performance liquid chromatography) and UV-Vis spectroscopy.<br /> It was concluded that the bleaching was most effective when H2O2, UV light and Cu2+ all were present rather than only one or two components. No connection between added VDE-R and the amount of major thylakoid pigments was observed, regardless of whether NADPH, FMN, ascorbic acid and Mg2+ were present or not. <br /> The function of VDE-R is still highly unclear and further studies are needed. Fotosyntetiserande växter, alger och bakterier fångar in och omvandlar solenergi till kemisk energi. Själva ljusinfångningen involverar olika pigment, varav de mest kända är de gröna klorofyllmolekylerna som förekommer i olika varianter (varav två varianter kallade klorofyll A respektive B förekommer hos högre växter). De ljusinfångande pigmenten inkluderar även de mer mångtaliga karotenoiderna, exempelvis β-karoten som ger morot dess orangea färg, vilka tillåter att mer varierande våglängder kan användas i fotosyntesen. Karotenoiderna skyddar även cellen från reaktiva syreföreningar som uppstår i samband med olika typer av stress, d.v.s. då miljöbetingelserna avviker för mycket från vad som är optimalt för organismen. Ett exempel på detta är för starkt ljus. Om ljusstyrkan överstiger vad cellen förmår använda i fotosyntesen finns det risk att en del av ljusenergin istället resulterar i att reaktiva syreföreningar uppstår. För att förhindra skada kan karotenoiderna avleda den ”extra energin” på ett säkert sätt i en process som kallas ”icke-fotokemisk utsläckning” (på engelska ”Non-photochemical quenching”, NPQ), alternativt reagera direkt med syreföreningarna och på så sätt ”offra sig” för resten av cellen. Den icke-fotokemiska utsläckningen är associerad med ett enzym kallat violaxantin-deepoxidas (eng. ”violaxanthin de-epoxidase”, VDE) som aktiveras vid starkt ljus och omvandlar en karotenoid kallad violaxantin till zeaxantin, vilken är effektivare på att avleda ljusenergin på ett säkert sätt. <br /> <br /> VDE:s närmaste släkting (ännu inte officiellt namngiven) förekommer i samma sammanhang som VDE men dess funktion är ännu okänd. Det är möjligt, med tanke på proteinernas släktskap och förekomst, att släktingen också har en funktion som involverar skydd mot stress och karotenoidpigment. <br /> I denna studie undersöktes i första hand olika metoder för hur fotosyntes-pigment kan blekas och i andra hand huruvida det fanns något samband mellan halten pigment och det besläktade proteinet med hjälp av tylakoider, innanmätet av kloroplasterna (de organeller i cellen där fotosyntesen sker och där fotosyntes-pigmenten finns), från Spinacia oleracea (spenat). Metoderna som användes var spektroskopi och HPLC (”high performance liquid chromatography”) samt protein utvunnet och delvis renat från genmodifierade bakterier. <br /> Det visade sig att effektiv blekning åstadkoms genom att tylakoiderna genomgick en behandling av kopparjoner, väteperoxid (H2O2) och UV-ljus och att behandling med väteperoxid och kopparjoner (med eller utan UV-ljus) resulterade i att ett ”nytt” pigment detekterades. Det ”nya” pigmentet absorberade ljus av samma våglängder som klorofyll A, men molekylen var mer hydrofil än klorofyll A. Däremot upptäcktes inget samband mellan pigment och tillsats av det aktuella proteinet, varför vidare studier krävs för att avgöra VDE-släktingens funktion. https://lup.lub.lu.se/student-papers/record/8913611/file/8924181.pdf application/pdf 1392524 yes 2017 eng biokemi biochemistry Spinacia Oleracea Photosynthetic pigments Reactive oxygen species Fenton chemistry Violaxanthin de-epoxidase related enzyme thylakoids Chemistry https://lup.lub.lu.se/student-papers/record/8913611/file/8913622.pdf application/pdf yes 8913611 2017-06-10T10:24:12+02:00 2017-08-30T14:46:19+02:00 2017-08-30T14:46:19+02:00

oai:lup-student-papers.lub.lu.se:8913760 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Alexandra Bäckström author 8911128 David Bryder supervisor Amol Ugale supervisor Eva Erlandsson supervisor Pure and Applied Biochemistry v1000655 department Advances in our understanding of hematopoietic stem cells (HSCs) have enabled the establishment of differentiation pathways throughout the hematopoietic hierarchy. To further explore the molecular cues governing cell fate options, there is a need to manipulate gene function in a controllable manner. Gene manipulation systems based on CRISPR activation (CRISPRa) or interference (CRISPRi) could be used to achieve this requirement. Here, we have generated doxycycline-inducible CRISPRa and CRISPRi mouse models. To functionally validate these systems, we aimed to induce or repress the chosen genes C/EBPβ and Notch1, respectively. An initial requirement to this end was to obtain functional high titer lentiviruses that could be used to deliver guide RNAs (gRNAs) to cells from the mouse lines, and work was conducted to optimize the production of lentiviruses. Furthermore, we demonstrate the ability to induce the CRISPRa system. However, initial experiments show difficulties in C/EBPβ mediated transdifferentiation of B cells from the CRISPRa mouse model. Thus, further detailed validations are necessary to address the potential problems. A bacterial immune system called CRISPR can be modified to overexpress or repress any gene of interest, which makes it possible to study why some blood cells develop normally while others become diseased. https://lup.lub.lu.se/student-papers/record/8913760/file/8913761.pdf application/pdf 1313148 no 2017 eng Applied biochemistry tillämpad biokemi Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/8913760/file/8913764.pdf application/pdf Popular Scientific Summary no 8913760 2017-06-11T13:17:24+02:00 2017-09-14T15:41:17+02:00 2017-09-14T15:41:17+02:00

oai:lup-student-papers.lub.lu.se:8913767 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Fanny Jernberg author 8913765 Dimitra Zacharaki supervisor Stefan Scheding supervisor Pure and Applied Biochemistry v1000655 department Bone marrow mesenchymal stromal cells (BM-MSCs) are critical for hematopoiesis and have been largely explored for potential stem cell therapies in a variety of diseases. This will inescapably create the need for long term storage via cryopreservation. Nevertheless, the effect of cryopreservation on primary human BM-MSCs remains largely unknown. We demonstrated that the surface marker expression pattern of the MSCs was maintained post cryopreservation. However, the viability and CFU-F capacity of the cells were reduced. Furthermore, we showed that there was an increase in the frequency of CD271+ cells post cryopreservation suggesting that MSCs survive freezing better than other cell types of the mononuclear cell fraction. In addition, we investigated the phenotype of healthy MSC in different age groups and found that the expression of several MSC surface markers, such as CD271 and CD51, increase over time. Although the study has provided additional insight, there is still a needed for further research before we can fully understand the human MSC phenotype and development. Mesenchymal stromal cells (MSCs) are shown to have different characteristics depending on a person’s age. MSCs are also often frozen for storage but this makes it more difficult for the cells to survive afterwards. https://lup.lub.lu.se/student-papers/record/8913767/file/8913770.pdf application/pdf 1519843 LU/LTH access 2017 eng applied biochemistry tillämpad biokemi Biology and Life Sciences Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/8913767/file/8913777.pdf application/pdf yes 8913767 2017-06-11T13:24:32+02:00 2017-09-18T13:43:28+02:00 2017-09-18T13:43:28+02:00

oai:lup-student-papers.lub.lu.se:8913814 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Nanna Sjöstrand author 8913812 PhD Ken G Andersson supervisor Johan Svensson Bonde supervisor Pure and Applied Biochemistry v1000655 department Antibodies have for long time dominated the field of affinity proteins in example imaging and therapeutics, due to their high specificity and affinity. However, they have some major drawbacks such as high molecular weight, complex structure leading to instability and high production cost. Therefore, other types of affinity proteins have been engineered, for example the Affibody molecule which is a small stable three helical protein. One method used to isolate Affibody molecule binders to targets, is to create a large Escherichia coli (E. coli) library with surface displayed Affibody molecules and select binders using FACS (Fluorescence Activated Cell Sorting). To characterize isolated binders from FACS today takes time, subcloning of the proteins of interest is needed before downstream analysis is possible. In this master thesis project it was examined whether transpeptidase eSrtA, a transpeptidase opening up a new world of conjugations difficult to create with other methods, could conjugate three different N- terminal triglycine molecules (functional groups) to E. coli surface displayed Affibody molecules with eSrtA recognition site, LPETG, and release the conjugate from the cell surface. The conjugated N-terminal triglycine molecule is a functional group, enabling direct downstream analysis of the Affibody molecule. eSrtA was recombinant expressed for reaction with two substrates, N-terminal triglycine molecules and surface displayed LPETG-tagged Affibody molecules. It was concluded that transpeptidation by eSrtA was successful and resulted in a surface released Affibody molecule conjugated to a functional group. The surface modification of the released conjugated Affibody molecule did not affect its binding capacities and it proved to work in common characterization methods. Since subcloning and then labelling could be avoided, the method developed in this master thesis would facilitate and accelerate the process from having isolated binders from a library to perform protein characterization of the released conjugates using the functional group. A new fast and simplified method to find future drugs<br /> <br /> Has anyone around you ever suffered from cancer or Alzheimer’s? If so, you know how tough the treatment is, or in worse case there is no treatment. In the future you could get a more effective drug that causes less adverse effects, or a marker that points out where the disease is. But what is this future drug and more importantly, how do you find it?<br /> <br /> The future drug is a small protein. Proteins are building blocks of the human body and are created by putting amino acids, there are 20 essential, together. In this project a new method was developed in order to easily find small proteins that could be used as drugs or markers for diseases. The small protein binds specifically to a certain target, just like antibodies. Antibodies are large proteins that defend your body against foreign substances. They do not bind any other molecule except the one they are programmed to bind. But how can they be used as drugs?<br /> <br /> When suffering from a disease, there is something wrong in your body. When having cancer, some of your own cells grow more than usual and you get a tumor. The tumor cells are different from normal cells, they have a special reporter that instructs the cells to grow or not, just like parents telling you what to do. When suffering from Alzheimer’s, molecules in your brain start to stick together. This is something they should not do and it disrupts functions in the brain. Let’s call the special reporters or the sticky molecules disease-markers. <br /> <br /> Medicines used today affect the entire body, which results in side effects. If you instead could have a drug that binds only the disease-marker, the rest of your body would not be affected. By binding the disease-marker, you could force the cancer cell to stop growing or stop the molecules in the brain from sticking together. Another method is to have something binding only the disease-marker, linked with a molecule that shines very bright. It could bind to the disease-marker and with the shining molecule inform the doctor where the cancer cells or the molecules sticking together are. That marker of diseases could lead to a better treatment. Now the antibodies come into the picture, since they bind the programmed molecule very specifically. However, they are not optimal to use as drugs, and therefore special variants of them have been created. One is the small protein. But how do you find a small protein that only binds to the disease-marker? <br /> <br /> In this project, a new method to faster and easier find small proteins binding disease-markers was developed from an existing method. The existing method starts with gene manipulation of bacteria, telling the bacteria to produce the small protein and store it on their surface. The bacteria therefore serve as a producer and carrier of the small protein. Secondly, you generate millions of bacteria that all have a unique small protein on their surface. All bacteria with small proteins bound on their surface are then mixed with the disease-marker and a machine picks out the small proteins that can bind to it. The tricky thing now is that the small protein must be separated from the bacteria. You need to separate them to know more about the small protein before it can be used as a drug. The method used now to separate them, takes a lot of time and work, something that we wanted to avoid. <br /> <br /> We have developed a method to superfast separate the small protein from the bacteria. We have used something that could resemble a scissor and glue kit. It directly cuts away the small protein from the bacteria after they are picked out by the machine. At the same time, a new molecule is glued on. The glued on molecule simplifies the analysis of the small protein. Thereby, we have created a faster and more simple way for researchers to find new small proteins and at the same time improve their analysis process. Researchers could therefore use this short cut to save time and energy when trying to find new drugs or markers for diseases. https://lup.lub.lu.se/student-papers/record/8913814/file/8913819.pdf application/pdf 3693147 yes 2017 eng Sortase surface display Affibody molecules E. coli library conjugation and surface release applied biochemistry tillämpad biokemi Chemistry Technology and Engineering Biology and Life Sciences 8913814 2017-06-11T17:46:05+02:00 2017-09-19T14:46:11+02:00 2017-09-19T14:46:11+02:00

oai:lup-student-papers.lub.lu.se:8913938 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Carl Eric Onema author 8913931 Peter Jönsson supervisor Victoria Junghans supervisor Department of Chemistry v1000647 department The immune system is a very complex system, aimed to protect the body from the many dangers that loom around us. A well-functioning immune system can fight of most invaders, remove foreign particles that entered our bodies, and take care of dead cells.<br /> <br /> The aim in this work is seeing how the protein CD45 (also known as PTPRC, protein tyrosine phosphatase, receptor type, C) is affected by salt concentration, more exactly how it is oriented on a lipid bilayer. CD45 have been observed to be essential for proper activation of T cells, but exactly how this is achieved on a molecular level is not known. Since the protein interact with its environment, its orientation may play an important role for the sensitivity and function of CD45.<br /> <br /> In order to investigate this, a combination of total internal reflection fluorescence microscopy, FRAP (fluorescence recovery after photobleaching) and hydrodynamic trapping have been used. The protein was attached to a supported lipid bilayer (SLB), which is a common cell membrane mimic. The orientation of the protein, i.e. its effective height, on the bilayer was measured using hydrodynamic trapping at different concentrations of sodium chloride at a physiological pH of 7.4. The diffusion of the protein across the SLB was also studied at different salt concentrations. The investigation implied a difference in the height of the proteins with it standing higher above the bilayer with increased salt concentration. This finding is important since it has consequences for how CD45 should be modelled on cell membrane mimics such as SLBs as well as on live cells. Många av dem mest spektakulära händelserna som sker i vår värld kan inte ses med blotta ögat. Vid varje andetag sker miljontals reaktioner, saltkoncentrationen i cellerna regleras, signaler skickas genom kroppens nervsystem, och receptorer plockar upp signalmolekyler likt hur post skickas till brevlådan och läses av oss i hemmet.<br /> <br /> Immunförsvaret är en otroligt viktig del av vår kropp som dagligen handskas med olika inkräktare som tar sig in i kroppen. Det ser till att sålla bort det som inte ska vara i kroppen likt hur reklamen sållas bort när det står ”ingen reklam” fastklistrat på brevlådan, eller så som spamfiltret i din e-post gör att mail med skadliga länkar hamnar i skräpposten.<br /> <br /> Tänk dig nu att du ska hantera posten som kommer till hela ditt kvarter, eller låt säga att du ska hantera brevflödet som skickas till 100 personer, och det gäller att du sållar bort den oönskade reklamen. Du kan göra det själv, eller ta hjälp utav andra men när du gör detta måste du förse dem du tar hjälp av med energi och se till att de går hem igen när de inte finns något att göra så de inte blir rastlösa och börjar löpa amok! Lite så fungerar det med immunförsvaret. Det måste kunna svara i rätt proportioner, annars väntar problem.<br /> <br /> I detta arbetet undersöktes en aspekt i immunförsvarets led som hanterar regleringen och initialiseringen av T-celler, B-celler samt andra typer av blodceller och går under namnet CD45. Protein har olika områden, aktiva säten, där reaktioner sker. Intresset för arbetet låg i att se hur en del av proteinet, CD45 D1-D4, orienterade sig i olika saltkoncentrationer med hjälp av en metod kallad ”Hydrodynamic Trapping”, en generell proteinfälla som utan direkt kontakt med proteinet samlar upp dem vid en punkt på en konstgjord cellyta kallad ”supported lipid bilayer”.<br /> <br /> CD45 är ett protein som enbart finns på blodceller och på immunceller återfinns proteinet i ofantliga mängder. CD45 har i uppgift att slå på och av immuncellernas aktivitet då vissa immunceller kan vara för starka även för vår egen kropp. Att veta hur detta protein fungerar är av stor betydelse då immunförsvaret har stor betydelse för att vi ska kunna leva ett friskt liv. https://lup.lub.lu.se/student-papers/record/8913938/file/8914003.pdf application/pdf 2127693 no 2017 eng Physical chemistry Fysikalisk kemi Chemistry 8913938 2017-06-12T09:35:23+02:00 2017-06-26T10:37:55+02:00 2017-06-26T10:37:55+02:00

oai:lup-student-papers.lub.lu.se:8914192 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Tym de Wild author 8914190 Peter Schurtenberger supervisor Department of Chemistry v1000647 department In this report the preparation of colloidal molecules through electrostatically driven self-assembly of spherical, thermoresponsive microgel building blocks is investigated. Colloidal<br /> molecules are of interest to the scientific community because, unlike spherical colloids, they account for anisotropic interactions that can also be found in atomic molecules. The added<br /> benet of using thermoresponsive microgel building blocks is that each microgel particle in the colloidal molecule can be used as an interaction site by tuning the interaction potential, from<br /> repulsive to attractive, by changing the temperature and the ionic strength. The thermoresponsive behaviour of the colloidal molecules, moreover, make them promising building blocks<br /> for the construction of complex 3D structures and phases with temperature-dependent properties. In this project, two methods for assembling the microgel building blocks into colloidal<br /> molecules were developed and both resulted in the formation of colloidal molecules. These colloidal molecule-like clusters consisted of a central core particle surrounded by either two, three,<br /> or four oppositely charged satellite particles to give colloidal molecules resembling carbon dioxide, borane, and methane, respectively. Following the assembly, the clusters were cross-linked<br /> using an EDC-NHS coupling reaction and the size distribution of clusters was determined using an analytical centrifuge. Guided by previous works, the possibility of using rate-zonal<br /> centrifugation for separation of clusters with different sizes was investigated. As well as synthesising clusters with one type of satellite, a second goal was to make patchy colloidal molecules<br /> with two different microgel satellite particles with different thermoresponsive behaviour - this is to be able to evoke patch-specific interactions. However, a strong preferential adsorption<br /> of the more highly charged satellites made it impossible to achieve simultaneous adsorption of two satellites. Finally, efforts were undertaken to replace the spherical satellite particles<br /> with cap-shaped particles to evoke, besides thermoresponsiveness, also shape-complimentary interactions. Despite numerous efforts to improve the synthesis method, no cap particles were<br /> obtained and were therefore not used as satellites. Spherical colloids are widely used as model systems for atoms and molecules, which is due to the fact that they all obey the same laws of physics. Colloids are particles in-between 10 and 1000 nm in size, which is about one hundred times smaller than the thickness of a human hair. Colloids can be suspended in a liquid or in a gas, and some examples of colloidal systems are milk and smoke that contain fat droplets in water and sot particles in air. Studying real atoms and molecules requires sophisticated equipment located at large-scale facilities, which is often costly to use. Even though colloids are very small in comparison to things we use every day, their large size compared to atoms and molecules allows us to study their behaviour by means of microscopy.<br /> <br /> In this project a new type of model colloid is investigated. This model colloid consists of multiple spherical colloids that have been assembled into a cluster that mimics the shape of a molecule; the resulting assembly is referred to as a colloidal molecule. Because colloidal molecules, just like real atoms and molecules, are not fully symmetric with respect to shape and interactions, they are viewed as more realistic models compared to the previously described colloidal spheres. The scientific community is therefore curious to learn more about their behaviour and interactions. Moreover, studying colloidal molecules may lead to important advances in the preparation of new materials with interesting and useful properties, due to their non-spherical shape that affects the way they pack together. <br /> <br /> This study deals with the preparation of colloidal molecules using spherical, temperature-sensitive microgel colloids as building blocks. Microgels are cross-linked polymer particles that are suspended in water and are positively or negatively charged based on the synthesis conditions. To prepare colloidal molecules, we exploit the fact that microgel particles of opposite<br /> charges are attracted to each other. A central particle that is negatively charged can be decorated with positively charged particles (or vice versa), where two positive particles around a negative particle will give a linear geometry, resembling a carbon dioxide molecule, and three particles will give a trigonal planar geometry, as seen in borane. The geometry of the colloidal molecules is set by the size ratio between the centre and outer particles. Aside from microgels, other colloids can be used as building blocks to make colloidal<br /> molecules. The benet of using microgels is the temperature-tuneable interactions that these particles offer. At room temperature the microgels are highly water-swollen, but as the temperature increases they drastically de-swell by expelling water at a critical temperature, known as the volume phase transition temperature (VPTT). This volume transition occurs as a response to the polymer transitioning from a &quot;water-loving&quot; to a &quot;water-avoiding&quot; state where polymer-polymer interactions are preferred over polymer-water interactions. As this &quot;polymer loving&quot; regime is entered, the microgel-microgel interaction behaviour changes from repulsive to attractive.<br /> <br /> In summary, using oppositely charged, temperature-sensitive microgels as building blocks, and temperature as an external stimulus, we can prepare colloidal molecules where each individual microgel serves as an interaction site that is able to make a bond to a corresponding site on another colloidal molecule above the VPTT. https://lup.lub.lu.se/student-papers/record/8914192/file/8914288.pdf application/pdf 143935716 yes 2017 eng KEMR37 Physical chemistry Hydrogel microgel Chemistry 8914192 2017-06-12T14:17:49+02:00 2017-06-26T10:31:45+02:00 2017-06-26T10:31:45+02:00

oai:lup-student-papers.lub.lu.se:8915936 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ignacio Arribas Díez author 8911236 Peter James supervisor Department of Chemistry v1000647 department The study of post-translational modification has driven scientist to have a better understanding of protein function, activity and behavior in the metabolism that could later be useful for developing new drugs and treatments targeting key proteins in diseases, like cancer or neuronal disorders. In this project we tried to optimize the Acyl-Biotin Exhange of proteins coming from Chinese Hamster Ovary cells to purify the ones with fatty acids bound to their cysteines, also known as palmitoylated proteins. We managed to obtain a small amount of them after changing the composition of the buffers and reducing the complexity of the mixture by subcellular fractionation. We also tested alternative chemicals for protein digestion that cleave at PTM sites like phosphorylation and glycosylation: S-Ethyl trifluorothioacetate and pentafluoropropionic acid. These chemicals were tested on different conditions and compared with CNBr+Tryp digestion, where we were able to find optimal conditions for protein cleavage with pentafluropropionic acid and designed an especial glass system for gas-phase digestion with S-Ethyl trifluorothioacetate. Proteins have an essential role in biology. They perform numerous functions in the organism: from sending the signals from the brain, to breaking down the nutrients we eat and many more. They are made out of chains composed of building blocks called amino acids and their constructors are the ribosomes. But not all protein are completely functional once they’ve been produced, some of them require certain changes. These rearrangements are called post-translational modifications (PTMs) and they usually involve linking other molecules, like sugars or fats, to the proteins.<br /> In this project we focused on the study of methods for studying PTMs than could help us understand them and helps us in the fight against diseases like cancer or neuronal disorders.<br /> We worked on a purification protocol named Acyl-Biotin Exchange (ABE) for obtaining proteins that have fats attached to them, named palmitoylated proteins (pps). We also tested two different molecules that are able to cut proteins at specific amino acids that are related to other modifications: pentafluoropropionic acid (PFPA) and S-ethyl trifluorothioacetate (SeT). In the future these chemicals could help localize were the PTMs are in the protein. We can see this by mass spectrometry analysis, which measures the mass of the fragments produced by the molecules and can give us the exact arrangement of the sequence, identifying the protein it belongs to.<br /> We were able to obtain some palmitoylated proteins after we tested different components of the cells by separate instead of all together: a less complex sample helps the ABE to be more efficient at capturing pps. We also managed to find the best conditions for PFPA to cut proteins and discovered that in combination with another protein cutting agent, trypsin, we are able to identify many more proteins from complex mixtures. As for SeT, we designed a glass system that creates the conditions necessary for it to work, as it is a liquid that needs to transform into gas to be able to cleave proteins. The glass system seems to recreate the conditions for SeT to be transformed into a gas, but we could not obtain proper cleavage of the proteins at the end. 2017 eng trifluorothioacetate pentafluoropropionic digestion chemical palmitoylation acyl biotin exchange protein science proteinvetenskap Chemistry 8915936 2017-06-15T11:46:28+02:00 2017-07-13T11:27:28+02:00 2017-07-13T11:27:28+02:00

oai:lup-student-papers.lub.lu.se:9028563 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Nicolas Velásquez González author 8959320 Jens Uhlig supervisor Meiyuan Guo supervisor Department of Chemistry v1000647 department The structural properties in the ground and the excited states of the hexa-coordinated iron carbene molecule FeIII(phtmeimb)2PF6 were investigated by ultrafast time-resolved X-ray absorption spectroscopy (XAS)techniques. Namely X-ray absorption near edge structure (XANES) and Extended X-ray Absorption FineStructure (EXAFS). Data from a time-resolved pump-probe synchrotron radiation experiment was treatedand analyzed. Moreover, we developed an analysis work-flow that made it suitable to operate with a reduced number of parameters. After which the data was modeled from a variety of starting points. We found that an anisotropic geometry in the ground state, and a close to isotropic geometry in the excitedstate best described our data. In the ground state, the axial ligands distort visibly more than the equatorial counterparts, showing signs of a Jahn-Teller distortion, characteristic of low-spin d5 transition metal complexes. In the excited state the molecule loses its distorted character relaxing into a more symmetric geometry. One interesting feature observed was that the nitrogen atoms of the second shell of the molecule displayed higher degree of axial elongation compared to the carbon atoms of the first shell, thus distort-ing the ligand. This distortion is of great interest for further simulations, as it indicates the location of the charges and emphasizes the electronic influence of the ligand onto the molecular orbitals. Ett av vetenskapens största mål är att få rena och skalbara energikällor. Om detta ska ha en positiv effekt på<br /> klimatförändringar måste det utföras effektivt och förhoppningsvis så fort så möjligt. Flera övergångsmetallkomplexer, exempelvis andra- och tredje raden övergångsmetaller har tidigare framgångsrikt använts<br /> för ändamål såsom fotokatalys och andra artificiella ljusskördesystem. Dessa övergångsmetaller är dock<br /> knappa och därför har sökandet efter mer lättillgängliga källor intensifierats. En av upptäckterna i denna<br /> sökning är föreningar med den ständigt närvarande första raden övergångsmetall järn. Till skillnad från<br /> dess tyngre kusiner, saknar emellertid järn med pyridilligander och besläktade föreningar en eftertraktad<br /> egenskap, det vill säga en relativt långlivad och hög energiladdningsöverföringstillstånd.<br /> <br /> För att kringgå begränsningarna har en ny typ av koordinationsföreningar utvecklats. N-heterocykliska<br /> karbener uppvisar mycket bättre fotokemiska och fotofysikaliska egenskaper jämfört med deras flerpyridilföregångare, med potentialen att konkurrera med de redan etablerade ruteniumbaserade föreningarna.<br /> Hittills har många järnkarbenkomplexer syntetiserats och studerats genom optisk spektroskopi, vilket ger<br /> omfattande och ovärderlig information om exempelvis exciterad tillståndsdynamik, men få har karakteriserats i både grund- och exciterade tillstånd med röntgen-spektroskopitekniker.<br /> <br /> Synkrotronstrålningens experimentella tekniker har möjliggjort det för forskare att få information som<br /> sannolikt inte kommer att förvärvas genom optiska metoder. En sådan teknik är ultrasnabb XAS med<br /> hård röntgenstrålning som när den är kopplad till en pump-probe uppsättning kan ge oss en strukturell<br /> ögonblicksbild av molekylen som studerats i en specifik miljö. Genom detta kan utredaren observera hur<br /> molekylens struktur och elektroniska egenskaper kopplas i det exciterade tillståndet, om så önskas.<br /> <br /> Traditionella spektroskopiexperiment i kombination med EXAFS, XANES och kvantkemiska beräkningar<br /> kan ge forskarna en fullständig bild av hur metallen och dess omgivande ligander interagerar, vilket banar<br /> vägen för en större förståelse och möjligen förutsägelse av ännu mer intressanta föreningar. Tidupplösta<br /> tekniker på andra sidan är mycket svårare att anvånda på grund av sämre kvalitet när det gäller det tidsupplösta spektrumet. En ny analysteknik har utvecklats och använts, vilken dessutom kan svara på den<br /> viktiga frågan om hur vi kan uttveckla nya molekyler. 2020 eng chemistry chemical physics iron carbenes solar energy x-ray spectroscopy ultrafast EXAFS XANES Chemistry 9028563 2020-09-08T11:00:48+02:00 2023-06-28T15:48:04+02:00 2023-06-28T15:48:04+02:00

oai:lup-student-papers.lub.lu.se:9028788 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Hugo Selling author 9028786 Patric Jannasch supervisor Centre for Analysis and Synthesis v1000651 department Alkaline exchange membrane fuel cells (AEMFC) is an interesting and attractive alternative to proton exchange membrane fuel cells (PEMFC) due to the potential use of non-precious catalysts which can reduce the overall cost of the fuel cell.<br /> An important component of the AEMFC is the anion conducting membrane. This membrane needs to possess several important properties such as a high hydroxide conductivity and sufficient stability at elevated temperatures for a prolonged time.<br /> The membrane material is a polymer which structure affects the properties. Extensive research has been made in the last decade in order to find a material that posses all the required properties.<br /> In this work, polymers with an all-carbon based backbone and incorporated piperidinium ions, poly(p-terphenyl piperidnium), are synthesized and studied with regards to the structure of the piperidinium ion. Two different polymers were synthesized via superacid catalyzed polycondensations of p-terphenyl, with either 4-piperidone or N -methyl-4-piperidone. These polymers were then functionalized via Menshutkin reactions with alkyl and benzylic halides of different sizes and structures. Seven polymers were successfully synthesized. Three more were attempted, but unsuccessful due to sterical restrictions in the functionalization step, e.g. a limit with regard to the size of the alkylhalide used. Three of the successfully synthesized polymers poly(p-terphenyl N -methyl-N -isobutyl-piperidinium), poly(pterphenyl N -methyl-N -cyclohexylmethyl-piperidinium) and poly(p-terphenyl N - methyl-N -benzyl-piperidinium) were evaluated as hydroxide exchange membranes.<br /> The evaluated polymers displayed OH− conductivities of over 100 mS cm−1 but poor alkaline stability and high water uptake. The properties that the evaluated polymers displayed related to the size and structure of the extender group. En av de största utmaningarna världen står inför är omställningen från icke-förnyelsebara till förnyelsebara energikällor. Vissa av de förnyelsebara energikällorna, såsom vind- och solkraft har dock ett problem, nämligen att energin från dessa källor är svåra att lagra. När det blåser mycket eller solen lyser starkt produceras ibland mer energi (elektricitet) än vad som förbrukas, och då går denna elektricitet till spillo. När det däremot är vindstilla eller svag sol så produceras kanske mindre elektricitet än vad som behövs. Vi behöver därför komma på nya innovativa tekniska lösningar för att kunna lagra denna energi. En potential lösning är att omvandla den genererade elektriciteten från dessa energikällor till vätgas. Denna vätgas kan lagras för att sedan, när energin behövs, återigen omvandlas till <br /> elektricitet. Denna omvandling kan ske i en så kallad bränslecell. <br /> <br /> En bränslecell är en elektrokemisk anordning, vilken kan liknas vid ett batteri. Bränslecellen omvandlar vätgas tillsammans med syre till elektricitet och vatten. Detta sker genom kemiska reaktioner i olika ändar av bränslecellen, precis som att det sker kemiska reaktioner vid plus och minuspolen i ett vanligt batteri. I dessa reaktioner bildas joner och elektroner, vilka båda är små laddade partiklar. Det är elektronerna som ger upphov till den elektriska strömmen, men för att kunna utvinna elektricitet behöver jonerna och elektronerna separeras i bränslecellen. Detta uppnås genom att en komponent i bränslecellen endast släpper igenom joner medan en annan endast släpper igenom elektronerna. Komponenten i bränslecellen som leder joner kallas elektrolyt. Beroende på vad för material elektrolyten är gjord av så kommer den att leda olika typer av joner. Detta i sin tur påverkar vilka reaktioner som sker i bränslecellen, vilket ytterligare leder till olika krav på materialen som bränslecellen är uppbyggd av. Kort och gott har materialen bränslecellen är uppbyggd av stor betydelse. <br /> <br /> Bränsleceller har flera användningsområden men det mest välkända är nog bilar. I bilar används bränslecellen för att driva en elektrisk motor och det finns bränslecellsdrivna bilar redan idag. Bränslecellerna som används dessa bilar har dock problem, vilket bl.a. är deras pris. En av de största anledningarna till det höga priset är användandet av den sällsynta och dyra metallen platina. Användandet av platina <br /> ökar kostnaden för bränslecellen avsevärt. I dessa typer av bränsleceller är elektrolyten ett ett så kallat membran, som släpper igenom positivt laddade joner (protoner). Genom att byta ut membranet som leder protoner till ett membran som leder en annan sorts joner så kan man också byta ut platina till något billigare. <br /> <br /> Att byta ut membranet är inte speciellt lätt eftersom man då ändrar vilka reaktioner som sker men även vad för kemisk miljö som uppstår i bränslecellen. Membranen har Hera krav på sig som behöver uppfyllas, såsom att jonerna lätt måste kunna ta sig igenom membranet. Membranet får inte heller gå sönder p.g.a. den temperatur eller miljö som råder i cellen. Allt detta påverkas av den molekylära strukturen på <br /> det material som membranet består av. Genom forskning försöker man komma på en molekylär struktur som uppfyller alla dessa krav. <br /> <br /> I detta arbete tillverkades membran med olika molekylär struktur. Membranen undersöktes sedan för att se hur väl de uppfyllde de olika kraven och hur den molekylära strukturen påverkade de önskade egenskaperna. Detta arbete är viktigt för att i framtiden kunna utveckla bättre och billigare bränsleceller. Vi behöver kunna lagra och använda mer förnyelsebar energi som en del av ett mer hållbart och miljövänligt <br /> samhälle. https://lup.lub.lu.se/student-papers/record/9028788/file/9028791.pdf application/pdf 7207114 no 2020 eng Fuel cells Alkaline exchange membrane fuel cells Anion exchange membrane fuel cells Polymer technology Polymerteknologi Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/9028788/file/9028793.pdf application/pdf no 9028788 2020-09-09T16:51:17+02:00 2020-09-16T11:16:17+02:00 2020-09-16T11:16:17+02:00

oai:lup-student-papers.lub.lu.se:9028898 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Zahraa Majhool author 8973591 Susanna Törnroth-Horsefield supervisor Department of Chemistry v1000647 department Around 60 million people around the world are struggling with a traumatic brain or spinal cord injury. The swelling of the brain or spinal cord happen when the water content in the CNS increase due, infection, tumor growth or brain edema. AQP4 is a membrane water channel which mediates the water flux across the blood brain barrier (BBB) and blood spinal-cord barrier (BSCB). We believe that protein-protein interactions play crucial roles in regulating human Aquaporin’s by gating or trafficking, but the mechanism of how protein-protein interaction mediate water transport across the membrane remain poorly characterized. It has been suggested that AQP4 protein could be regulated by protein calmodulin through complicated and poorly characterized mechanism. It has been suggested that protein AQP4 is regulated by trafficking mechanism, through directly binding of CaM to AQP4. <br /> In order to demonstrate this hypothesis, AQP4 was purified from P.pastoris cells and incorporated into nanodiscs. Activated CaM will be added to the nanodisc to study the binding mode between CaM and AQP4. The purified nanodisc, used for further analysis using Cryo-EM technology. By this technique we proved that AQP4 can bind to two calmodulin protein directly. Cells are the basic building blocks of all living organisms. There are organisms that are composed of a single cell, such as a bacterium or yeast, and some others could be composed of trillions of different cells such as animals or plants. If you look at the structure of these tiny cells using the microscope, you will figure out that these cells have many different parts and each part have different function. All these parts are essential for cell functioning. One of these parts is called the plasma membrane. It is made up of a lipid bilayer which separates the interior of the cells from the outside environment. This plasma membrane regulates the transportation of different material in and out of the cells, which means that this membrane is embedded tightly with lots of different channels and receptors. Water is an essential component of all living organisms and regulated water transportation is crucial for proper cell functioning. Aquaporin (AQP) is a small transmembrane water channel which facilitates water transport across the membrane. This channel is an open channel and needs to be regulated to function properly. This regulation could be happen upon a triggers such as, protein-protein interactions or other small molecules to force the AQPs to close or open the pore. It has been suggested that tumor cells express the AQPs and there is a direct relation <br /> between histological tumors and the number of AQPs expressed in the membrane compared to normal tissues. This make the AQPs interesting proteins to be investigated to understand how they function and how they could be regulated after discovering their structure. Until now 13 different AQP have been discovered, each being expressed in different tissues. AQP4 is one type of human AQP which is mostly expressed in astrocytes and which mediates the water flux across the BBB and BSCB. In this project we overexpressed AQP4 and used it to find if this protein could be regulated by the protein calmodulin. This was done by incorporating AQP4 into nanodiscs and using these nanodiscs for complex formation of AQP4-CaM. This complex formation was confirmed by Cryo-EM to show that calmodulin could bind to AQP4 with a ratio of 1:2 (AQP4:CaM). https://lup.lub.lu.se/student-papers/record/9028898/file/9028899.pdf application/pdf 1530005 no 2020 eng aquaporin4"protein-protein interaction"calmodulin" biochemistry molecular biology biokemi molekylärbiologi Chemistry 9028898 2020-09-10T21:25:01+02:00 2020-11-09T09:23:05+01:00 2020-11-09T09:23:05+01:00

oai:lup-student-papers.lub.lu.se:9029616 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Lars Eicholt author 9029614 Johan Svensson Bonde supervisor Pure and Applied Biochemistry v1000655 department The world population is continuously growing and will have to be fed. To keep pace with the increasing demand, multiple innovations have been implemented in agriculture during the last decades. The main bottleneck remains the global photosynthetic productivity. The efficiency of photosynthesis is limited, inter alia, by the fixation of CO2 via Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). The poor discrimination of RuBisCO between CO2 and O2 leads to the process of photorespiration, and subsequently to carbon and nitrogen loss. During oxygenic photosynthesis light is converted into energy and used to fix CO2 in the Calvin-Benson cycle via RuBisCO. RuBisCO acts here as a carboxylase, adding CO2 to one molecule of ribulose-1,5-bisphosphate and producing two molecules of 3-phosphoglycerate. In photorespiration RuBisCO takes instead of CO2 a molecule of O2 and, acting as an oxygenase, generates 2-phosphoglycolate which is recycled back into the Calvin-Benson Cycle. This recycling process releases CO2 and nitrogen and costs chemical energy. One approach to solve this limitation of carbon fixation is to develop synthetic photorespiration bypass pathways that release no CO2. Several different options of bypasses were proposed in silico (Trudeau et al., 2018) and the overall aim is to follow with a proof of concept in vitro and then to establish an efficient bypass in vivo. The proposed bypasses rely on pre-existing enzymatic activities but also on enzymatic activities that are not known in nature yet. The aim of this project was to engineer a D-ribulose-1-phosphate 5-kinase for the proposed ribulose-1-phosphate shunt (Figure 1) via rational design of the promiscuous activity of a phosphoribulokinase that natively phosphorylates ribulose-5-phosphate. World population is growing but the production of crops is limited due to several factors. One is that cropland is limited and will further decrease due to climate change. Another factor is the limited efficiency of plants. It is commonly known that plants convert CO2 to oxygen via photosynthesis. However, sometimes plants, especially crops, take oxygen instead. When this is the case, the plant accumulates and releases CO2 and other toxic chemicals to the environment and wastes energy. The energy that would otherwise be used to let the plant grow. This process is called photorespiration which is a metabolic pathway composed of several different chemical reactions in the plant´s cells. It is considered as one of the natural bottlenecks of photosynthesis efficiency. Solving this problem of photorespiration would increase the efficiency of plants and could provide food to the growing world population and the millions already malnourished. One proposal is to bypass photorespiration with other chemical reactions utilising different enzymes. The bypass this project is based on needs an enzymatic reaction that is not known in nature yet. The conversion of ribulose 1-phosphate to ribulose 1,5-bisphosphate. There are several enzymes known in nature that form ribulose 1,5-bisphosphate from ribulose 5-phosphate. A number of these enzymes were screened for additional ability to convert ribulose 1-phosphate. This is called “promiscuous activity” since the enzyme has a main function and a less efficient side function. One candidate enzyme was found, and models of its ancestors were done. One ancestor had higher activity and was the starting point for further optimisation via mutations. While the target activity was increased, it is likely not sufficient enough to be implemented into a functioning bypass of photorespiration. https://lup.lub.lu.se/student-papers/record/9029616/file/9029617.pdf application/pdf 11307379 yes 2020 eng Photorespiration Enzyme Engineering Rational Design Food Security Metabolic Engineering Applied biochemistry Tillämpad biokemi Chemistry 9029616 2020-09-19T15:50:05+02:00 2020-09-25T17:05:35+02:00 2020-09-25T17:05:35+02:00

oai:lup-student-papers.lub.lu.se:9029959 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Lisa Bywall author 9029957 Sofie Cederlund author 9029962 Mats Galbe supervisor Linda Zellner supervisor Jenny Klevås supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Flexible Polyvinyl chloride (PVC) is a plastic material commonly used in today’s society and a fundamental material for a lot of sectors. It has advantages over other polymers such as energy-efficient production, flame retardancy, durability and cost-effective. The one important component in flexible PVC that gives it is flexible properties is the plasticizer. The most common plasticizers used are ortho-phthalates. Concerns about some ortho-phthalates toxicity to humans and other living organism has induced a movement away from using ortho-phthalates as a plasticizer.<br /> The chemical company Perstorp AB has developed a non-phthalate plasticizer called Pevalen, which is a general-purpose plasticizer intended for close-to-human applications of flexible PVC. Pevalen has shown to have favorable qualities both for processing and in the final application and has a low toxicity profile.<br /> This thesis work includes the status of the plasticizer market, regional differences between Eu-rope, USA and China and market requirements for the following of close to human flexible PVC applications; coated fabrics, flooring, wall covering, pool liner and food contact material. These requirements have then been compared to internal work and knowledge at Perstorp regarding Pevalen. To find opportunities for the plasticizer to be successful in each segment and identify possible needs to further complement with strengthening technical information and data. <br /> The market analysis showed that the plasticizer market is very price driven and constantly looking for ways to reduce costs. The most used plasticizers are still the ortho-phthalates due to low production cost and high availability. There is a movement away from using ortho-phthalates with DOTP being the most used non-phthalate plasticizer. Use of DOTP is increasing rapidly on the market and considered the main competitor to Pevalen among the non-phthalates.<br /> Europe is at the forefront of moving away from phthalates and are increasingly interested in the environmental impact and the toxicity of plasticizers. The USA focuses on non-phthalates but is not are so much concerned about sustainable and environmentally friendly products. China is still mainly using ortho-phthalates, but DOTP is increasing. Production speed is one of the most important things here since the market is very competitive, so they are willing to try new plasticizers that can increase productivity. <br /> For a new plasticizer to compete on the market, it has been found crucial that either the product reduces cost by performing better during the process, that the plasticizer is more efficient, or thirdly that the plasticizer has valuable properties that reduce the need for expensive additives or specialty plasticizers.<br /> The analyze of the application segments showed that flooring and wall coverings have similar key requirements; low VOC, abrasion resistance, dimensional stability, chemical resistance, fire retardancy and low smoke generation. Their application market is hard to enter due to it being very price concerned as well as having high production rates. For food contact materials, the following key requirements have been found important: high flexibility, cleanability, abrasion resistance, migration resistance and chemical resistance. This market is very regulated with stringent requirements. Coated fabrics are considered a promising industry for Pevalen since it gives the material a very soft touch, has low toxicity, low VOC, and good UV-stability which are all factors of high importance in this field. The positive aspects of Pevalen positive aspects are highly valuable in this industry.<br /> Perstorp has done quite an extensive research and laboratory work. However, there are a few gaps, such as abrasion resistance, chemical resistance, and dimensional stability linked to the selected applications that can complement this data. It is also important to always compare with relevant benchmark plasticizers when performing a test. Overall, Pevalen has shown good results in the properties that are important for the researched segments but needs to push more on the cost reducing properties. Världen är i ständig miljö- och hälsofrämjande utveckling, där ny forskning och upptäckter hela tiden driver marknadskrav och bidrar till restriktioner. Plastindustrin har länge varit under luppen, till stor del för fossila råvaror och nedskräpning, men även då vissa plastmaterial innehåller ifrågasatta tillsatser. <br /> Flexibel Polyvinylklorid (PVC) är en typ av plast som används mycket i dagens samhälle på grund av att det är ett material som håller länge och kan användas till många olika typer av applikationer, allt från hårda PVC rör till flexibelt konstläder. En mjukgörare tillsätts för att PVC ska få sina flexibla egenskaper, där ftalater länge varit de dominerade mjukgörarna på marknaden. De senaste årtiondena har oro för ftalaters toxicitet för människor och andra levande organismer gjort att man succesivt börjat gå ifrån att använda ftalater som mjukgörare och istället hitta andra icke-ftalater som kan ersätta dessa med likvärdiga resultat. <br /> Målet med detta examensarbete har varit att analysera mjukgörarmarknaden och finna de svårigheter och möjligheter som finns för en icke-ftalat att kunna konkurrera. Detta har gjorts med fokus på ett fåtal slutapplikationer ämnande för nära kontakt med människor, där det sätts höga krav på toxicitet och slitstyrka. Regionsskillnader mellan Europa, USA och Kina har även studerats. Detta examensarbete omfattar marknadens nuvarande status och marknadskrav för följande flexibla PVC-tillämpningar; bestruket tyg, golvbeklädnad, väggbeklädnad, pooldukar och material i kontakt med livsmedel.<br /> Kemiföretaget Perstorp AB har utvecklat en icke-ftalatmjukgörare under produktnamnet Pevalen, som är en mjukgörare avsedd för applikationer av flexibel PVC som kommer i nära kontakt med människor. Marknadens krav har sedan jämförts med internt arbete och kunskap på Perstorp, gällande Pevalen. Målet har sedan varit att hitta möjligheter för mjukgöraren att lyckas i varje segment och identifiera möjliga behov för att ytterligare komplettera med teknisk information och data.<br /> Marknadsanalysen visade att mjukgörarmarknaden är mycket prisdriven och ständigt söker möjligheter att minska kostnaderna. De mest använda mjukgörarna är fortfarande ftalater, mycket på grund av låg produktionskostnad och hög tillgänglighet. Det finns drivkraft att gå ifrån användandet av ftalater och använda icke-ftalater istället. Dioktyltereftalat är den mest använda icke-ftalat mjukgöraren och anses vara den främsta konkurrenten till Pevalen bland icke-ftalater.<br /> Både USA och Europa driver ett aktivt arbete för att använda icke-ftalater, Europa är också alltmer intresserade av biobaserade och miljövänliga mjukgörare. Kina däremot använder fortfarande huvudsakligen ftalater även om det har börjat röra sig mot icke-ftalater, men marknaden är villiga att prova nya mjukgörare som kan öka produktiviteten. Analysen av applikationssegmenten visade att liknande nyckelkrav var väldigt fördelaktiga inom de flesta områden: lågt utsläpp av VOC, slitstyrka, dimensionsstabilitet, kemikalieresistens, brandhämmande egenskaper och låg rökutveckling. <br /> För att en mjukgörare ska kunna konkurrera på marknaden, har det visat sig avgörande att antingen produkten minskar kostnaderna genom att antingen göra så tillverkningsprocessen går snabbare eller kräver mindre energi, eller att mjukgöraren är effektivare och att därmed en mindre mängd krävs, eller slutligen, att mjukgöraren har värdefulla egenskaper som minskar behovet av dyra tillsatser eller special-mjukgörare. <br /> Perstorp har gjort ett ganska omfattande forsknings- och laborationsarbete om Pevalen. Pevalens positiva egenskaper är mycket värdefulla i denna bransch och det finns god möjlighet att konkurrera med hjälp av dessa. Det finns några luckor men sammantaget har Pevalen visat goda resultat i de egenskaper som visats vara viktiga för de undersökta segmenten, men man behöver marknadsföra de kostnadsreducerande egenskaperna mera. https://lup.lub.lu.se/student-papers/record/9029959/file/9030218.pdf application/pdf 1088540 no 2020 eng PVC plasticizer plasticiser industry flexible PVC polyvinylchloride vinyl flooring chemical engineering kemiteknik Chemistry 9029959 2020-09-25T13:28:29+02:00 2020-11-09T10:54:35+01:00 2020-11-09T10:54:35+01:00

oai:lup-student-papers.lub.lu.se:9030056 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Hassan Mourad author 9030008 Ebbe Nordlander supervisor Chuanshuai Li supervisor Department of Chemistry v1000647 department This work constitutes the results from a one year master thesis research project (Sep, 2019 to Aug, 2020). Metal-Organic Frameworks (MOFs) have been used for encapsulation of homogeneous catalysts to generate heterogeneous catalysts. This work describes the incorporation of the non-heme iron complex [(Fe(II)N4Py)]2+ and two molybdenum−sulfur clusters (MOS) into the pores of UiO-type MOFs via absorption from solution ([Fe(II)(N4Py)]@UiO-66, MOS@UiO-66, and MOS@UiO-66-NH2 respectively). The new materials have been characterized by powder X-ray diffraction (PXRD). <br /> The reactivities of UiO-66 and [Fe(II)(N4Py)]@UiO-66 in hydrogen atom transfer (HAT) reactions shows that both exhibit reactivity when compared to the analogous N4Py complexes. The [Fe(II)(N4Py)]@UiO-66 MOF shows a high reactivity compared to the UiO-66. The photochemical hydrogen evolution from UiO-66 and UiO-66-NH2 with incorporated MOS catalysts, in conjunction with a ruthenium photosensitizer and an ascorbate donor have been tested. The results show the ability of MOS@MOF to produce hydrogen. Denna avhandling beskriver studier av hur metallkomplex som fungerar som katalysatorer i lösning kan absorberas i s k metall-organiska nätverksstrukturer (metal-organic frameworks = MOFs). MOFs är porösa kristallina material som har en bred funktion i såväl laboratorium som industri. Genom sådan absorption kan det lösliga komplexet inkorporeras i håligheter i nätverket; det lösliga komplexet befinner sig då i ett fast ämne (pulver). När en katalysator befinner sig i samma fas (t ex lösning) som de molekyler som reagerar/omvandlas med hjälp av katalysatorn, kallar man katalysatorn för en homogen katalysator. När katalysatorn och reaktanter befinner sig i olika faser, kallar man katalysatorn för en heterogen katalysator. Med hjälp av den typ av absorption som beskrivs ovan, kan man alltså omvandla en homogen katalysator till en heterogen katalysator, under förutsättning att katalysatorkomplexet fortfarande fungerar när det är absorberat i nätverket. Fördelen med en sådan omvandling kan vara att katalysatorn stabiliseras inuti nätverket och därför kan användas i flera katalytiska cykler än den homogena varianten. Detta kan vara en stor fördel när den homogena katalysatorn är ett ljus-, luft- och/eller värmekänsligt komplex. En ytterligare fördel med en heterogen katalysator (i fast fas) är att den lätt kan separeras från en lösning m hj a filtrering. En möjlig ytterligare fördel är att MOF-nätverket kan diskriminera mellan olika reaktanter baserat på storleken på porerna i nätvetket. Detta kan brukas inom katalysforskning och i ett förlängt perspektiv, industriell katalys. Genom att heterogena katalysatorer lätt återanvänds genom filtrering från en reaktionslösning, kan de betraktas som ”gröna” katalysatorer.<br /> <br /> De katalysatorer som har studerats är ett järn(II)-komplex och två molybden-svavelkluster (MOS). Järn-komplexet fungerar som en modell för det aktiva sätet i vissa oxygenas-enzymer som innehåller en järnjon, och som katalyserar ett brett spektrum av oxidationsreaktioner med biologisk relevans. De molybden-svavelkluster som har studerats fungerar som fotokatalysatorer som kan producera väte under synligt ljus. Forskningen som beskrivs i denna avhandling syftar till att kapsla in de tre katalysatorerna på ett så enkelt och ekonomiskt sätt som möjligt. Olika MOFs har blivit testade. Användande av de billiga MOFarna som benämns UiO-66 och UiO-66-NH2 ledde till anmärkningsvärt goda resultat. <br /> <br /> Järnkomplexet (katalysatorn) brukar bl a användas till väteatomabstraktion. Här används väteperoxid som oxidationsmedel för att skapa ett Fe(IV) oxo-komplex som i sin tur kan abstrahera ett väte i en stökiometrisk reaktion, d v s en väteatom överförs från en molekyl (ett kolväte) till järn-oxokomplexet. För att bekräfta att järnkomplexet fortfarande finns och fungerar inuti porerna av UiO-66, har samma reaktionsbetingelser använts med de nya materialen. Resultaten visar att järnkomplexet fungerar även när det är absorberat inuti ett MOF. Vidare visar också MOFet förmåga att stabilisera järnkomplexets mellanprodukter. <br /> <br /> Avhandlingen behandlar också reaktiviteten för de två inkapslade molybden-svavelklusterna i MOFarna. Reaktiviteten har undersökts i en blandning av metanol och vatten. Askorbinsyra användes som elektrondonator och ett rutenium-komplex som antennmolekyl som omvandlar inkommande ljus till en elektrokemisk potential. De nya materialen har visats fungera i sådan fotokatalytisk produktion av väte. 2020 eng Chemical physics Kemisk fysik Chemistry 9030056 2020-09-28T13:21:38+02:00 2020-11-09T09:07:40+01:00 2020-11-09T09:07:40+01:00

oai:lup-student-papers.lub.lu.se:9031380 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Andras Karajos author 9031378 bitr. universitetslektor Baozhong Zhang supervisor Niklas Warlin supervisor Department of Chemistry v1000647 department Amidst global warming, perturbed ecosystems and an ever-diminishing fossil feedstock, a paradigm shift toward renewable and sustainable plastics have emerged. Significant advances have been made in the past decade and several green polymers have entered the market. Much attention has been focused on the catalytic conversion of lignin, as it represents the largest source of renewable platform chemicals to generate sustainable substitutes to petroleum-based polymers.<br /> This work explores the use of sugar and lignin-based building blocks in synthesis of bio-based monomers with versatile side groups in order to prepare diverse polymers with novel characteristics.<br /> Three different dialdehydes and their corresponding reduced diols were prepared by a base catalysed nucleophilic substitution and reduction with NaBH4 from sugar based 5-CMF and lignin based 4-hydroxy benzaldehyde, vanillin and syringaldehyde. The reaction of vanillin-CMF dialdehyde with pentaerythritol was investigated under acidic condition to produce spirocyclic polyacetals. The thermal instability of the monomer in the acidic environment prohibited the polyacetal formation and resulted in humin formation instead. Copolymerization of the corresponding reduced diol with bio-based 1,6-hexanediol and dimethyl terephthalate by melt polymerization yielded a series of polyesters with 9-34% content of the rigid monomer. Higher amount of incorporation resulted in an increase of the glass transition temperature and decreased melting points. The copolymer containing 9.1% of the rigid diol was semi-crystalline, while the polymers with higher content of the new diol (20-, 29-, 34%) were amorphous. The heat-sensitivity of the new diol resulted in colorization of the products. The idea of sustainable development and wholesome consumption is a cornerstone of today’s academia and firmly integrated in many commercial enterprises and consumer mindsets. The concepts, however, are very much reflective of a 21st century world view and many business sectors lag behind. In particular, we are dependent on non-renewable carbon sources for our energy and plastic material. This year, fossil fuels carry circa 80% of our total global primary energy demand and plastics are ubiquities world-wide. While the harnessing of fossil carbon allowed the west to industrialise at such a rapid pace, it did not turn out to be the eternal source of utility that was once thought. Non-renewable carbon is a strictly finite resource. Even if new reserves are found, the formation rate is only a fraction of the necessary depletion rate to cover energy demands of modern-day life. Expert calculation estimates a complete depletion of coal, natural gas and oil within the coming 50-100 years. Moreover, and perhaps most importantly, the use of carbon for energy concerns produces large amount of greenhouse gases. This has had disastrous consequences for the environment and humans. The process of generating energy through burning hydrocarbons is today directly or indirectly responsible for a total loss of 3.3% of the global GDP in damages and approximately 4.5 million deaths - mostly due to a rapidly changing environment. In a similar fashion, plastics, a cornerstone of our modern-day life, has shown not to be without its faults. A great majority of all plastics made today stem from fossil carbon and it has been discovered in the past few decades to have a severe environmental impact. As recycling has historically been next to nothing, most plastics have ended up in landfills or the ocean. This has been due to the fact that none of the plastics made of non-renewable carbons are completely degradable. Circa 80% of all litter that accumulates on land and in the waters are plastics. Ignoring the purely aesthetic considerations, plastics have been known to leech toxic additives, entangle animals and readily sorb and transport highly damaging persistent organic pollutants. Needless to say, it is imperative that renewable sources of energy and plastics are developed soon, for the sake of our environment and the continuation of modern-day life. <br /> Polymers are substances or materials, which are made by connecting small molecules (monomers), usually one or two different into a really long, large molecule. Natural polymers are cellulose, starch and lignin, while examples for synthetic polymers are Teflon, nylon or PET. An important property of polymers is glass transition temperature. Below this thermal point the polymers are more brittle, while that temperature the polymer becomes more rubber-like. For example, PET has glass transition temperature around 70 °C. That means if we would pour a really hot tea in our bottle, it would become more rubber-like, and bend. Increase of this property also affects the plastic’s physical appearance, processability and recyclability. A common technique to improve the glass transition temperature is to incorporate a more rigid molecule into the commercial polymer. Using this approach cups from modified PET can be filled with almost boiling water was synthetized by Perstorp (Akestra).<br /> In present work six new monomers were prepared from sugar and lignin (cell wall of wood and bark) based molecules to produce novel polymers. The first group of molecules unfortunately turned out to be inadequate, due to their thermal instability, while one of the monomers from the other group were successfully raised into a commercial polymer with up to 34% monomer content, after optimization of the reaction. The reaction successfully improved the glass transition temperature of the resulting copolymer and the desired effect was achieved. The monomers low heat stability unfortunately made the polymerization difficult to execute in high quality. However, after further optimization, the monomers can be effective tools to improve commercial polymers. https://lup.lub.lu.se/student-papers/record/9031380/file/9031381.pdf application/pdf 5064788 yes 2020 eng polymer green chemistry biobased sugar lignin glass transition temperature sustainable fossil based analytical chemistry Chemistry 9031380 2020-10-27T11:00:38+01:00 2023-06-28T13:31:05+02:00 2023-06-28T13:31:05+02:00

oai:lup-student-papers.lub.lu.se:9031591 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Fatlinda Gashi author 9031589 Tommy Nylander supervisor Department of Chemistry v1000647 department The purpose of this thesis was to investigate how extracellular vesicles extracted from cows milk interacts with the surfaces hydrophilic surface, DOPC bilayer surface, 95% DOPC and 5% DOTAP mixture bilayer surface and 1:1 ratio of DOPC and DOTAP mixture bilayer surface, and colloidally characterize EVs by determining the hydrodynamic radius and zeta potential. To determine the size and zeta potential of six different samples of milk vesicles, Dynamic Light Scattering (DLS) was used. The results showed that all samples had vesicles with a hydrodynamic radius sized within the range for exosomes. The vesicles that were first isolated and then subjected to either acidification or chelating agents, had larger sized vesicles than when the vesicles were purified in the reversed order. The polydispersity index showed relatively heterogeneous samples. The zeta potential for all samples was around -10 mV, which is a lower value and would imply less steric stabilisation. The interaction between a surface and vesicle was observed with Quartz Crystal Microbalance with Dissipation (QCM-D). It showed that the samples had the most interaction with the 1:1 ratio of DOPC and DOTAP mixture bilayer and the hydrophilic surface. This was seen from the negative shift in frequency which would indicate adsorption to the surface. The interaction with these surfaces is believed to be a result of electrostatic interactions between lipid and vesicle. The shift in dissipation was also high which would indicate viscoelastic layers were formed when adsorbed to the surface. The DOPC surface and the 95% DOPC and 5% DOTAP mixture surface gave little to no interaction with the vesicles which could be seen in the small or no shift in frequency and dissipation. Extracellulära vesiklar (EVs) är en typ av vesiklar som finns i olika typer och storlekar som utsöndras från en cell. En vesikel består av en omslutning där det yttersta lagret utgörs av ett dubbellager av lipider. Storleken varierar mellan 20-5000 nm i diameter, och en funktion som vesiklar har är att möjliggöra kommunikation mellan olika celler. Vesikeln bär då på information såsom DNA, RNA, aminosyror och liknande. EVs uppvisar stor potential för användning inom läkemedelsbranschen genom deras förmåga att transportera och kommunicera med andra celler. Rena EVs är kostsamma att tillverka och kräver tid och resurser eftersom de är små, men forskning görs för att finna ett sätt att tillverka rena homogena vesiklar i större skala, som är mindre tidskrävande och kostar mindre. <br /> <br /> Det som studerades var EVs kolloidala egenskaper och dess interaktioner med fyra olika typer av ytor och dessa var en hydrofil yta samt tre olika sammansättningar av bilager bestående av lipiderna DOPC och DOTAP. Sammansättningen för första typen av bilager bestod av DOPC, den andra typen var en 95% DOPC 5% DOTAP yta och den sista ytan bestod av 50% DOPC 50% DOTAP. Det var sex olika prover av vesiklar upprenade från mjölk som undersöktes. Interaktionerna mellan vesikel och yta undersöktes med ett instrument som kallas för Quartz Crystal Microbalance med dissipation (QCM-D) Detta instrument visade att störst interaktion uppstod med 50% DOPC och 50% DOTAP yta, men även med hydrofil yta. De två andra ytorna visade inte på någon märkvärd interaktion. Interaktionen tros bero på elektrostatiska krafter mellan positiva polära delar i lipid ytan med negativa delar i vesikeln. De kolloidala egenskaperna undersöktes med Dynamic light scattering (DLS) och med detta instrument kunde man undersöka hydrodynamisk radie som ger storleken, polydispersity index (PdI) som anger hur stor variation i storlek det finns och zeta potentialen som ger laddningen på vesikelns yta och dess stabilitet. Storleken på vesiklarna uppmättes till värden som sträcker sig mellan 90-110 nm med ett polydisperisty index under 0.3 för de flesta storlekar, vilket tyder på heterogena prover där storleken inte varierar stort. Zeta potentialen uppmättes till ett lägre negativt värde (-10 mV) för vesiklarna vilket innebär mindre sterisk stabilitet. https://lup.lub.lu.se/student-papers/record/9031591/file/9031592.pdf application/pdf 1605964 yes 2020 eng Physical Chemistry Fysikalisk kemi Extracellular Vesicles Cows Milk Acidification Chelating Agents Bilayer Surface Bilayer Mixture Bilayer Lipids Lipid DOPC DOTAP Hydrophilic surface Hydrophilic Quartz Crystal Microbalance with Dissipation QCM-D Dynamic Light Scattering DLS Chemistry 9031591 2020-11-03T19:09:09+01:00 2020-11-11T10:32:16+01:00 2020-11-11T10:32:16+01:00

oai:lup-student-papers.lub.lu.se:9031905 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Giorgia Brandoni author 9031903 bitr. universitetslektor Baozhong Zhang supervisor Department of Chemistry v1000647 department Utvecklingen av anjonbytarmembran som kombinerar långvarig termokemisk stabilitet, hög hydroxidjonledningsförmåga med adekvata mekaniska egenskaper för alkaliskt elektrokemiskt system, är för närvarande ett brett forskningsområde. I det aktuella arbetet undersöker vi radikalpolymerisationen av allylamin, särskilt i organiska lösningsmedel, som uppnåddes genom direkt polymerisering av den protonerade monomeren i dimetylsulfoxid (DMSO), dimetylformamid (DMF) och N-metylpyrrolidon (NMP), varvid polyallylaminen (PAH). Dessutom gjöts vattenolösliga membran baserat på blandningar av polybensimidazol (PBI) och polyallyltrimetylammonium (PAT), den kvaterniserade formen av PAH, eftersom ammoniumimidazolatkomplex bildas efter en alkalisk behandling. Membranen uppvisade god termisk stabilitet med en sönderdelningstemperatur på 234 °C. När det gäller PAT: s alkaliska stabilitet behöver det fortfarande undersökas ytterligare i detta skede för att förstås fullt ut. Mellan de två blandningarna nådde den som innehöll 30 viktprocent PAT, benämnd PBI-PAT-30, den högsta jonledningsförmågan, upp till 8 mS/cm vid 80 ℃ uppmätt under helt hydratiserade förhållanden och 17 viktprocent vattenupptag vid 80 ℃. Studien visar möjligheten för allylamin att användas som komponent i katjoniska polymerer som används i anjonbytarmembran. Emellertid behöver blandningsmembranen fortfarande ytterligare optimering för att förbättra deras egenskaper. The development of anion-exchange membranes that combine long-term thermochemical stability, high hydroxide ion conductivity with adequate mechanical properties for alkaline electrochemical system, is currently a wide research area. In the present work, we investigate the radical polymerization of allylamine, especially in organic solvents, which was achieved by directly polymerizing the protonated monomer in dimethyl sulfoxide (DMSO), dimethylformamide (DMF) and N-methylpyrrolidone (NMP), obtaining the polyallylamine (PAH). In addition, water insoluble membranes were cast based on blends of polybenzimidazole (PBI) and polyallyltrimethylammonium (PAT), the quaternized form the PAH, as ammonium-imidazolate complexes are formed after an alkaline treatment. The membranes showed good thermal stability with a decomposition temperature of 234 ℃. As regards the alkaline stability of PAT, it still needs further investigation at this stage to be fully understood. Between the two blends, the one containing 30 wt % PAT, named PBI-PAT-30, reached the highest ion conductivity, up to 8 mS/cm at 80 ℃ measured in fully hydrated conditions and 17 wt% of water uptake at 80 ℃. The study demonstrates the feasibility of the allylamine to be used as component in cationic polymers used in anion-exchange membranes. However, the blend membranes still need further optimization to improve their properties. Nel corso degli ultimi decenni, è diventato sempre più chiaro come i combustibili fossili non possano essere più l’unica fonte di energia disponibile per soddisfare la globale domanda energetica. Il cambiamento climatico e l’inquinamento ambientale che stiamo sperimentando ne sono la prova e rappresentano la forza trainante per la transizione energetica richiesta a livello mondiale. A questo scopo, vasti studi e sforzi si sono focalizzati sullo sviluppo di nuovi metodi per passare dai combustibili fossili a fonti energetiche rinnovabili e più sostenibili. Tra queste tecnologie ci sono tutti quei dispositivi di accumulo e conversione di energia, come le batterie e le celle a combustibile, i quali per esempio sono fondamentali per poter usare efficacemente fonti energetiche intermittenti (quali energia solare ed eolica). L’obiettivo preposto non è facile da raggiungere, specialmente visto che queste alternative devono essere non solo energeticamente efficienti ma allo stesso tempo anche competitivi a livello di costi.<br /> Le membrane a scambio ionico (IEMs) sono vastamente utilizzate in questi dispositivi elettrochimici come separatori. Le IEMs sono costituite da polielettroliti e nelle fuel cells, il loro scopo è quello di mediare il trasporto degli ioni da un elettrodo all’altro e di prevenire il crossover dei gas. In base alla natura dello ione trasportato, le membrane a scambio ionico sono classificate in membrane a scambio cationico o anionico (AEMs). Nello specifico, il focus di questo progetto è stato rivolto verso lo sviluppo di quelle AEMs in cui lo ione scambiato è lo ione idrossido.<br /> Durante questo lavoro di ricerca, la polimerizzazione radicalica dell’allilammina è stata investigata, con l’obiettivo di ottenere polimeri adatti a questo tipo di membrane. Esse devono avere stabilità termochimica a lunga durata, alta conduttività ionica e al contempo buone proprietà meccaniche. Naturalmente, le loro proprietà influenzano fortemente le performance e la durata delle pile a combustibile in cui sono utilizzate. Pertanto, nella ricerca di fonti energetiche innovative e più sostenibili, migliorando in primo luogo il materiale stesso usato nelle fuel cells, sarà possibile aumentare la competitività di questi dispositivi elettrochimici sul mercato. In the last few decades, it has become increasingly clear how fossil fuels can no longer be the only source of energy available to meet the growing global energy demand. Climate change and local air pollution that we are experiencing are the proof of this and they are among the key driving forces for the energy transition worldwide. For this purpose, extensive studies and efforts have been focused on developing new methods to switch from fossil fuel to more renewable and environmentally friendly source of energy. Among these technologies are storage and conversion devices like batteries and fuel cells, which for example are fundamental to efficiently use intermittent primary sources of energy (e.g. wind and solar power). Clearly, the goal is not an easy one to meet, considering that these alternative methods should be not only energetically efficient but also cost competitive at the same time.<br /> Ion exchange membranes (IEMs) are vastly employed in these electrochemical devices as separators. IEMs consist of polyelectrolytes and in fuel cells, their purpose is to mediate the transportation of the ions between the electrodes and to prevent the cross-over of gasses as well. Based on the nature of the conducted ions, the IEMs are classified either as an anion-exchange membrane (AEM) or as a cation-exchange membrane. More specifically, the focus of this project has been mainly directed toward the development of AEMs, where the conducted ion is the hydroxide. <br /> During this research work, the radical polymerization of the allylamine was investigated in order to obtain polymers suitable for this type of membranes. They should have long-term thermochemical stability, high ion conductivity and good mechanical properties at the same time. Naturally, their properties highly affect the performances and lifetime of the fuel cell itself. Therefore, in the quest for innovative and more sustainable source of energy, by improving the material used in the cells in the first place, it will be possible to better the competitiveness of these electrochemical device on the market. https://lup.lub.lu.se/student-papers/record/9031905/file/9031906.pdf application/pdf 1134291 LU/LTH access 2020 eng anion-exchange membranes polymer electrolytes alkaline fuel cells hydroxide ion conductivity organic chemistry organisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/9031905/file/9031910.pdf application/pdf LU/LTH access 9031905 2020-11-12T15:42:39+01:00 2020-11-27T09:34:40+01:00 2020-11-27T09:34:40+01:00

oai:lup-student-papers.lub.lu.se:9032242 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Roman Lord author 9032069 Peter Spégel supervisor Danny Mollerup Sørensen supervisor Centre for Analysis and Synthesis v1000651 department There is a need for harmonisation of stability study designs of monoclonal antibodies. Monoclonal antibodies (mAbs) are widely used in treatments for various diseases. Like all drugs, their quality must be verified through stability studies. The ICH guidelines give general recommendations regarding stability studies of antibodies, and specifications should often be determined on a case-by-case basis. More detailed requirements may need to be defined to make better designed stability studies for mAbs. This report aims to produce a broader understanding of the parameters that should be included in mAb stability studies and give a proposal for a comprehensive stability study design. The information for this report was obtained through literature studies including amongst other the ICH guidelines and several newly published articles regarding size-exclusion chromatography and its application in stability studies. The results showed that the existing guidelines regarding stability studies of biopharmaceutical are very general. Therefore, stability test focusing on the physicochemical stability of mAbs in clinical settings are often missed. This additional stability test can increase the understanding of the analyte and may facilitate the work of health personnel. Even though it is difficult to make a study design that fit all types of mAbs, there are opportunities for improvement in the guidelines as they are today in order to make a more comprehensive stability study design. In conclusion, there is a need for development in stability study designs regarding mAbs. To create more comprehensive stability studies new recommendation may have to be added that may contribute to a harmonisation of the stability study designs Antibodies do not only exist in our body, but they can also be manufactured in laboratories and cell-factories. Monoclonal antibodies (mAbs) are the type of antibodies that are used in for drug development. Their high selectivity makes them very useful in cancer treatments, but they can be used for the treatment of a large repertoire of diseases such as rheumatoid arthritis and multiple sclerosis to mention a few. <br /> <br /> It is of great importance that the drugs that reach the market are thoroughly controlled. They should fulfil the required quality standards set by The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) or by regional authorities such as the United States Pharmacopeial Convention (USP) and the European Medicines Agency (EMA). To control an antibody’s quality, stability studies are performed. These studies should be well designed and cover all stability issues that may arise. Because, if some parameters are missed, they could lead to severe consequences for the patient, or even death. <br /> <br /> Clear standards for study designs may help to avoid unnecessary consequences by contributing to well-designed stability studies. Recently, a study found that many companies do not perform sufficiently thorough stability studies regarding mAbs. Most studies focus only on fulfilling the stated regulations by the authorities. Tests for stability in a clinical setting, such as accidental shaking of the container, short term temperature changes during transportation or accidental breaking of sterility, are often missed. <br /> <br /> The objective of this work was therefore firstly, to define what is required today for a stability study based on guidelines and recent literature. Secondly, to propose an example of what a comprehensive, well-designed stability study for mAbs should include, based on the studied literature. <br /> <br /> It was found that there is a need for standardised comprehensive stability study designs for mAbs. Also, it is important to understand the characteristics of the studied protein to be able to perform better studies. In order to create more comprehensive stability studies new recommendation may have to be added to the guidelines, which may contribute to a harmonisation of the stability study designs. https://lup.lub.lu.se/student-papers/record/9032242/file/9032243.pdf application/pdf 797459 no 2020 eng Biopharmaceuticals mAbs SEC stability study design technical analytical chemistry teknisk analytisk kemi Technology and Engineering Chemistry 9032242 2020-11-22T15:59:10+01:00 2020-12-18T17:01:20+01:00 2020-12-18T17:01:20+01:00

oai:lup-student-papers.lub.lu.se:9032484 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Markus Schulze author 9032482 Ulf Nilsson supervisor Department of Chemistry v1000647 department Galectins are a 15-member family of β-D-galactose binding proteins that are interesting targets in drug development, since they are linked to various inflammatory diseases, fibrosis and cancer. Efforts to find galactose derived high-affinity inhibitors that are selective towards members of the galectin-family have increased in the last decade. On top of that Galectin-3 has been shown to be a suitable model protein for thermodynamic affinity studies. Galactosides carrying C1 naphthamidomethyl and C3 phenyltriazolyl moieties have reportedly shown high affinity and selectivity towards galectin-3. Based on this knowledge we want to develop a new class of macrocyclic inhibitors featuring these structural elements. Apart from that, the influence of macrocyclization on binding thermodynamics is aimed to be a future subject of study, particularly in the context of conformational entropy. This project work is a contribution to the synthesis of a macrocyclic inhibitor. By means of a fluorescence polarization assay it was discovered that a precursor of the target macrocycle shows an increased affinity to galectin-3, compared to previously reported C1 naphthamidomethyl carrying inhibitors. Galectins are a specific class of proteins that occur in the cells of our bodies. They can bind to carbohydrates such as the sugar galactose. Galactose is a so-called monosaccharide that makes up half of the disaccharide lactose, which is part of milk. Galectin-proteins participate in numerous cell-processes, for example the regulation of cell death and responses of the immune system. Furthermore, they are linked to diseases such as heart disease or cancer. This makes them an interesting research subject for the development of medical drugs. <br /> By chemically modifying sugars such as galactose we can enhance their binding on galectins and eventually block these proteins. This blocking of dedicated proteins in the body is a principle of many drugs. It ideally results in a positive therapeutic effect with only few side effects. To find such modified sugar-molecules that bind well to the galectins it is necessary to understand in detail how these sugars and proteins interact. This can be done by conducting so called interaction-studies, that show us in detail which parts of the proteins and sugar molecules interact with each other. Experiments like these also give us information how spontaneous or “voluntary” these interactions are.<br /> Macrocycles are organic ring-shaped molecules, that contain 12 or more ring atoms. Some drugs that are used broadly today, for instance certain antibiotics are macrocyclic compounds. Many of them are orally available, so they can be administered to patients in the form of pills. This is a generally beneficial feature of a drug or drug candidate. Their large and flexible ring-structure gives macrocycles special chemical and biophysical properties. This allows them to bind to shallow protein surfaces or binding pockets. The protein pocket where galectins bind and recognize sugars is such a flat and shallow groove. A macrocycle could therefore be suitable to fit into the binding pocket of the galectin-proteins.<br /> This project work is a contribution to a chemical synthesis of a galactose-based macrocycle that could be used for further binding studies on galectins in the future. A precursor of this macrocycle was newly synthesized during the project. It was discovered, that it binds well to one of the members of the galectin protein family. 2020 eng Medicinal Chemistry Galectins Macrocycles Organic Synthesis Medicinsk kemi Chemistry 9032484 2020-12-01T14:00:53+01:00 2020-12-11T14:12:57+01:00 2020-12-11T14:12:57+01:00

oai:lup-student-papers.lub.lu.se:9032500 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Laleh Tavakoli author 9032498 Kamrul Hasan supervisor Department of Chemistry v1000647 department Computational Chemistry v1000659 department The results of studies have shown that the several applications such as microbial electrochemical system (MES), bio-electrochemical systems (BESs) and production of beneficial chemicals are due to electrochemical connection among electrodes and microorganisms. The following two factors are important in choosing the microbe mediated electrochemical biosensors: I) Binding of bacterial cells on the electrode, II) Efficient electron transfer (EET) between the electrode and the cells by a mediator.<br /> In this study, gram-negative bacterium Shewanella oneidensis MR-1 was used in MES due to its unique characteristic features such as metal ion-reducing bacterium and direct ET capability. Osmium redox polymers (ORPs) were acted as efficient electron transfer (EET) mediators to direct the electrochemical flow of biomaterials to electrods.<br /> In the present study, the effect of the formal potential (E0&#39;) of three flexible osmium redox polymers was investigated: [Os(4,4&#39;-dimethoxy-2,2&#39;-bipyridine)2(PVI)Cl]+ ([Os-DMOPVI]); [Os(4,4&#39;-dimethyl-2,2&#39;-bipyridine)2(PVI)Cl]+ ([Os-DMPVI]); and [Os(4,4&#39;-dichloro-2,2&#39;- bipyridine)2(PVI)Cl]+ ([Os-DCPVI]). The electron donating or withdrawing ability of the functional group on the bipyridyl ligands coordinated to the osmium redox center can greatly affect the Os (II/III) redox potential.<br /> Our results demonstrated that out of the three polymers, Os-DMPVI with E0&#39; of +121 mV vs Ag|AgCl|KCl(sat.) had the greatest ability to produce electrical energy in the presence of lactate as a substrate because of the methyl functional group. Os-DMPVI polymer modified graphite electrode connected with S. oneidensis MR-1 exhibited a current density of 13.62 μA cm2 with a significant decrease in the start-up time for electrocatalysis. A great deal of microbial electrochemical system (MES) and microbial biosensors are the results of electrochemical connection between microorganisms and electrodes.<br /> In the present thesis, the extracellular electron transfer (EET) from a biomaterial is studied. Shewanella oneidensis MR-1 was used in MES due to its unique charateristic Features: I) Metal ion reducing bacterium, II) Direct electron transfer ET competence.<br /> The efficiency of ET was increased by using the covered Osmium redox polymers (ORPs) as an efficient ET mediator.<br /> We have shown in our results that current density could be increased by this bacterium. In addition, a major decrease in the start-up time for electrocatalysis was observed. The extracellular electron transfer abilities of electrogens combined with such polymers could increase electrocatalysis.<br /> In this thesis we have studied the effect of the formal potential (E0&#39;) of three flexible osmium redox polymers with efficient electron shuttling properties combined with the polymeric structure. The efficiency of electrical wiring from gram-negative bacterium; S. oneidensis MR-1 was investigated on these three different polymers.<br /> Os-DMPVI had the greatest ability to produce electrical energy in the presence of lactate. Our results showed that S. oneidensis MR-1 presents a good mediator to be wired to the osmium redox polymers with methyl functional group over the graphite electrode surface. https://lup.lub.lu.se/student-papers/record/9032500/file/9032710.pdf application/pdf 1501413 2020-12-09 no 2021 eng Analytical Chemistry Bio-Analytical Chemistry Electrochemistry Bacteria Osmium redox polymers Shewanella Oneidensis MR-1 electrode Microbial electrosynthesis Electron transfer Chemistry https://lup.lub.lu.se/student-papers/record/9032500/file/9032715.jpeg image/jpeg no 9032500 2020-12-02T10:03:46+01:00 2021-05-05T11:42:01+02:00 2021-05-05T11:42:01+02:00

oai:lup-student-papers.lub.lu.se:9033305 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Gustav Berndtson Klette author 9033303 Sara Linse supervisor Martin Lundqvist supervisor Biophysical Chemistry v1000649 department Prefibrillar oligomers are thought to be the “culprit” behind the cytotoxicity of islet amyloid polypeptide (IAPP) to pancreatic islet β-cells. The oligomers are generated in the process of IAPP’s conformational change into amyloid fibrils. The depletion of islet β-cells has been connected to type II diabetes. Knowledge of how to stop IAPP from switching into the cytotoxic oligomer form is of the utmost importance. The microscopic process secondary nucleation has previously been identified as the reaction mechanism step responsible for the numerous production of these oligomers. Three large phage display libraries were analyzed to find fibril-specific protein binders that can inhibit secondary nucleation. Protein binders, specific against IAPP, were selected from phage display libraries during three rounds of selection. Fibril-specific binders were isolated from monomer-specific members with IAPP coupled to silica nanoparticles. The binders were ranked by their affinity using surface plasmon resonance. The protein binders with the highest affinity against IAPP were sequenced and afterwards produced in soluble form. These soluble proteins were analyzed to find members that can inhibit the fibril-catalyzed secondary nucleation reaction step during a kinetics analysis. Two scFv were found to inhibit both primary and secondary nucleation in a dual effect. This method had previously been used to find secondary nucleation inhibiting proteins for amyloid β peptide involved in Alzheimer’s disease. Based on these results, the method used in both these cases might be instrumental in developing protein inhibitors in other amyloidogenic protein diseases where toxic oligomers are responsible. Den bakomliggande orsaken till att islet amyloid polypeptide (IAPP) är cytotoxisk mot β-celler från bukspottkörteln tros vara prefibrillära oligomerer. Oligomererna skapas då IAPP ändrar konformation till amyloidfibriller. Förlusten av β-celler från cellklusterna har kopplats till typ II-diabetes. Ytterligare kunskap om hur man hindrar IAPP från att växla till den giftiga oligomerformen är oerhört betydelsefullt. En mikroskopisk process som kallas sekundärnukleering har tidigare identifierats som det reaktionsmekanismsteget som är ansvarigt att producera dessa oligomerer. För att försöka hitta fibrilspecifika proteinbindare som kan hämma sekundärnukleering, undersöktes tre stora fagdisplaybibliotek. Proteinbindare som var specifika mot IAPP, valdes ut från fagdisplaybiblioteken under tre urvalsrundor. Fibrilspecifika medlemmar separerades från monomerspecifika genom att koppla IAPP till kiseldioxidnanopartiklar. Ytplasmonresonans användes därefter för att rangordna proteinbindarna efter deras affinitet mot IAPP. Proteinbindarna med den högsta affiniteten mot IAPP, sekvenserades och framställdes sedan i löslig form. I en kinetisk analys så undersöktes dessa lösliga proteiner för att hitta medlemmar som kan hämma sekundärnukleering. Två scFv visade en dubbel effekt av att hämma både primär- och sekundärnukleering. Denna metod för att hitta proteinbindarna har tidigare använts för att hitta proteiner som kan hämma sekundärnukleering hos amyloid β-peptide, involverad i Alzheimers sjukdom. Eftersom metoden nu lyckats användas i båda dessa fall kan den vara avgörande för att utveckla proteinhämmare för andra amyloidrelaterade proteinsjukdomar där giftiga oligomerer är ansvariga. IAPP är ett litet protein som utsöndras tillsammans med insulin i bukspottkörteln. Detta protein kan omvandla sig under felvikning och hopklumpning till en annan struktur som tros spela en avgörande roll i typ 2-diabetes. Den här studien har hittat två små proteiner som till synes kan hämma ett giftigt mellansteg i IAPP:s utveckling till denna struktur.<br /> Typ 2-diabetes är en långsamt tickande bomb som kan leda till en för tidig död. Det blir alltmer förekommande i världen och inget botemedel finns än i sikte. Bakom diabetesgåtan är en misstänkt bov ett litet protein vid namn IAPP. IAPP kan i vissa fall ändra konformation och klumpa ihop sig i trådlika strukturer. Man kan tänka sig att denna struktur är uppbyggd av starka men böjliga biologiska byggklossar som stapplande ovanpå varandra. Varje kloss är ett IAPP protein som antagit denna konformation. På ytan av dessa trådar kan det växa ”oligomerer” som är ett mellansteg till nya trådar. Det är detta mellansteg som dödar de celler som producerar insulin och man tror därför dessa oligomerer ligger bakom utbredningen av typ 2-diabetes.<br /> Den minsta beståndsdelen av oligomerer kan använda trådarnas yta som språngbräda för att växa som kulor på ett snöre till oligomerer. Detta snöre kan sen brytas av och ändra konfirmation till en ny tråd. Processen där oligomerer växer på trådarnas yta kallas sekundärnukleering och den vill man såklart hindra. Det finns därför ett behov av biologiska molekyler som kan fästa sig på trådarnas yta och hindra oligomererna från att växa. Ett av avhandlingens syfte var att hitta hämmare till dels de andra stegen som bildar trådarna men helst sekundärnukleering med en speciell metod.<br /> Två antikroppsfragment hittades som verkar kunna hämma sekundärnukleering av i realtid växande IAPP i laboratoriemiljö. Dessa fragment hittades i ett urval av miljarder andra smått olika proteiner. Urvalsprocessen gick till så att IAPP fästes på små nanopartiklar. Sen ”kastade” man successivt alla miljarder proteiner på dem och ser vad som fortfarande fäster kvar på IAPP när man tvättat. De proteiner som binder till IAPP, odlas sedan i bakterier och visas på ytan av bakteriofager, små ofarliga viruspartiklar, i en metod som kallas ”fagdisplay” Denna metod har tidigare hittat proteiner som hämmar sekundärnukleering av ett annat protein som är involverad i Alzheimers.<br /> Denna metod har fungerat för att hitta proteinbindare som hämmar sekundärnukleering av två olika proteiner och att visa detta var ett annat av avhandlingens syfte. Därför finns det stora chanser att den kan användas för att hitta proteinhämmare i andra sjukdomar där dessa oligomerer är ansvariga. Forskningen i denna avhandling kan potentiellt hjälpa med att öka förståelsen av mekanismen inom produktionen av dessa oligomerer. Genom att studera proteinbindare som är framtagna med denna metod kan man kanske få idéer om hur man ska designa ett potentiellt diabetesbotemedel. https://lup.lub.lu.se/student-papers/record/9033305/file/9033306.pdf application/pdf 4762245 yes 2020 eng Diabetes Phage Display Antibody IAPP S100G Amyloid fibril formation Inhibitor Drug development Biophysical chemistry Biofysikalisk kemi Technology and Engineering Chemistry 9033305 2020-12-25T12:46:41+01:00 2021-01-19T08:13:34+01:00 2021-01-19T08:13:34+01:00

oai:lup-student-papers.lub.lu.se:9037098 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Anna-Malin Hallberg author 9037096 Professor Lei Ye supervisor PhD Rasmus Gustafsson supervisor Pure and Applied Biochemistry v1000655 department Computational Chemistry v1000659 department Biological pharmaceuticals are the answer to many severe diseases of today’s society. Some of these are protein-based drugs and can be produced from human blood plasma. In order to guarantee the safety of patients, absence of any pathogens needs to be ensured. Such a pathogen is HIV-1, which holds high mutation rate and a large variation in its genome.<br /> The aim of this project was to develop novel primers and probes for detection of a wide range of subtypes of HIV-1, using the TaqMan qPCR detection system. Three targets within conserved parts of the genome were selected in the regions of LTR5´, Pol and LTR3´. The primers and probes were optimized regarding concentrations, salt content and compatibility. <br /> The sensitivity of detection showed promising results with a value as low as 8.18 IU. The selectivity did not result as preferred, with the best combination of primers and probe possible to detect 7 out of 8 subtypes of the most common genotype, M. If combining the primers and probes of all targets suggested here, detection of all tested subtypes was possible. <br /> Summarizing the results, the primers and probe targeting the Pol region shows promising data. Optimization regarding the sequences of the Pol primers and probe and additional evaluation of compatibility between all targets need to be studied, in order to see, if the method can meet the standards and further be implemented into the experimental routine for HIV-1 detection. Popular science summary – The potential of better detection of HIV<br /> Viruses have become a global health issue and people are constantly dying from their effects, both in rich and poor countries. This has awakened a new dimension in the urgency and interest of finding new methods of identifying infected people in order to help, treat and stop the spread of infection in the society. In order to make the world a better place for all with a better life quality. <br /> More than 700 000 people died last year of the effects of HIV, and millions are living with the disease causing a poor life quality, worldwide. In order to be able to stop the spread of infection more accurate methods of detecting the virus are necessary. Containing the spread of the illness is paramount, and by making the contagious individuals aware of their infection, the spread will be easier to control as well as the infected individual can get treatment faster. However, many viruses of this kind cannot be cured, proper inhibitor medicines are available. Many of these treatments today have shown promising results with best effect upon usage in early stages of infection. Viruses mutate frequently, in order to avoid the immune system. This makes them a hard target, since they are changing their genetic code constantly. The numbers of infected cells can differ between individuals and in the stage of infection, which puts high standards on detection methods. Two aspects of virus detection are especially important; the possibility of detecting the virus with high specificity, able to distinguish the HIV infected cells from others, and with high sensitivity, capable of finding every infected cell even in low numbers is of great importance. <br /> The work done during the project has shown interesting results of HIV detection. A method using genetic nucleotide sequences has been developed. The developed genetic sequences verifying the starting point of replication in DNA, called primers. Additionally, with a complementary nucleotide sequence to the DNA template, dyed with signal giving elements attached, called probes. The results suggest a detection method with high sensitivity, able to find viruses in very low concentrations within blood. In addition to, good ability of specificity, with as many as 7 out of 8 types of the most common kind of HIV, with the use of 4 replicates. In total the most promising method developed managed to find HIV in 19 out of 24 samples evaluated with prominent signals. These results indicate a highly promising method. At this stage it needs further development in order to meet the standards of European Medical Agency and Food and Drug Administration, as well as being even more precise in specificity. <br /> Substantial theoretical knowledge of HIV and insights in possibilities of detection of the virus has been the foundation to success in the project. Different parameters such as suitable components, time, temperature, target sequences in the genetical code of the virus has been evaluated and optimized in order to develop a most positive method. Both with high specificity and low sensitivity. The aim of using the method in routine analysis is not completely reached, but the method is on the right track to fulfil the demands of it. <br /> The research and development of new detection methods for viruses such as HIV is of great importance to the society. Infected individuals need to know about their disease and being able to get proper treatment as well as not pass the virus further on to their fellow humans. The methods can also be used to certify that donated blood is absent from pathogens. If so, the blood can be donated to those in need or used to produce biological and protein-based pharmaceuticals for severe diseases. https://lup.lub.lu.se/student-papers/record/9037098/file/9037099.pdf application/pdf 3603548 no 2021 eng HIV PCR primers probes virus detection blood plasma pathogen biological pharmaceutical protein-based pharmaceutical genotype subtype RT qPCR extraction TaqMa RNA virus cross-dimer applied biochemistry tillämpad biokemi Biology and Life Sciences Technology and Engineering Chemistry 9037098 2021-01-20T20:49:27+01:00 2021-01-22T11:26:08+01:00 2021-01-22T11:26:08+01:00

oai:lup-student-papers.lub.lu.se:8873900 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH3 Mohamed Esmael author 8873902 Ali Majid author 8873904 Professor Marie Wahlgren supervisor Food Technology and Nutrition (M.Sc.) v1000294 department The aim of this study was to optimize a function starch-ethyl cellulose film for targeting the therapeutically active substance to the colon in the disease state for patients suffering from inflammatory bowel diseases. This study includes: <br /> • The preparation of the polymeric films and the investigation of the characterization (for example mechanical properties, water uptake, dry mass loss, and microscopy analysis) for these prepared film coatings. • Coating of the pellets with 3-1 as well as 3-2 and the study of the release through the coated pellets. • The study of the film formulation factors such as (formulation temperature, amount of the TEC, and polymer blends ratio) and their impact on the properties of the final prepared film as well as on the drug release from the coated pellets at healthy as well as disease state before and after upon exposure to: § Gastric fluid with pepsin § Intestinal fluid with and without pancreatin § Colonic fluid at different PH (6.8, 5.6, and 2.8) with different concentration of bacterial amylase. Utveckling och optimering av en läkemedelsförmulerings teknik för kolon <br /> De besvärliga symptomen såsom Diarré och blod i avföringen är mesta tydliga tecken för Kolons sjukdomar Inflammatory bowel disease (IBD). Därför utvecklingen av ett läkemedel som botar, lindrar, behandlar, eller förebygga sjukdomen är jätte viktigt för både patienterna och läkemedelsindustrierna. Minsta biverkningar och bekväm leveransrutt är de mest önskade egenskaper för det ideala läkemedlet. Orala läkemedel som t.ex. suspensioner, tabletter och lösningar som riktar sig mot kolon måste ha en specifik formulering teknik som kallas (filmbeläggning). Filmbeläggning som täcker aktiva substanser bör ha förmåga att skydda och förhindra lösningen av aktiva substanser som är benägna att lösas i övre delen av mag-tarmkanalen. Denna typ av formulering kan utvecklas med hjälp av beläggning av aktiva substanser med vanliga och billiga polymersblandningar såsom stärkelse och cellulosa. Dessa polymerer, speciellt cellulosa tål sura miljön d.v.s. låg pH -värdet samt matsmältningsenzymer i den övre delen av mag-tarmkanalen. Olika polymersblandning förhållande av stärkelse-cellulosa kan användas för att belägga tabletter eller piller med specialutrustning som kallas (fluidized bed). Dessa polymerer kan användas för att kontrollera frisättning av aktiv substans i tarmen beroende av polymer blandningsförhållande d.v.s. stärkelse- cellulosa. Många studier har redan genomförts på många typer av polymerer, polymer blandning, mjukgörande substans halt samt med olika blandningsförhållande. Resultatet från dessa studier har bevisat att polymerstyp och blandningsförhållande har stor betydelse för frisättning av en aktiv substans som leder till minskning av dosseringsintag av läkemedel som i sin tur öka patients bekvämhet, speciellt hos äldre och barn. Vår studie fokuserades på utveckling, analys och optimering av filmbeläggning. Olika analyser för filmbeläggningar med två olika polymer blandningsförhållande 3-1 och 3-2 etylcellulosa- stärkelse genomfördes i friska samt som sjukdomstillstånd. Analyserna har omfattat mekaniska egenskaper, vattenupptagning, torr massa förlust och mikroskopi analys. Dessutom studerades frisättning av en aktiv substans. Dessa analyser genomfördes i magsaft med pepsin, tunntarms vätska med pankreatin. Analysen i kolonsvätska genomfördes med olika koncentration av amylas enzymen och pH-värde. <br /> <br /> Resultatet har visat att filmbeläggning av polymersblandning 3-1 etylcellusa-stärkelse med 25 % mjukgörande substans trietylcitrat (TEC) beräknas enligt den totala torrvikten för båda polymererna. Med 60 ⁰C som en filmbildnings temperatur resulterar i funktionsfilm med de acceptabla mekaniska egenskaperna och vattenupptag samt torrvikt förlust. Dessutom den 3-1 filmbeläggning blandningsförhållande ger kontrollerade frisättning av aktiv substans i kolonen samt bevisat mer motstånd mot sura miljön d.v.s. låg pH -värdet samt matsmältningsenzymer i den övre delen av mag-tarmkanalen. <br /> Slutligen den typen av formuleringsteknik kan utformas praktiskt ekonomisk samt med hög kvalitet. Mer forskning och analys behövs för att garantera vilka faktorer som kan förbättra och minska kostnad är viktigt för läkemedelsindustrier. https://lup.lub.lu.se/student-papers/record/8873900/file/8873901.pdf application/pdf 15757816 2017-12-01 no 2016 eng starch colon delivery pharmaceutical technology läkemedelsteknologi Chemistry 8873900 2016-05-24T10:50:49+02:00 2017-12-01T04:10:01+01:00 2016-05-27T15:41:22+02:00

oai:lup-student-papers.lub.lu.se:8875134 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ardian Salihu author 8875103 Prof Lo Gorton supervisor Department of Chemistry v1000647 department Orientation of Myriococcum thermophilum Cellobiose Dehydrogenase (MtCDH) immobilized on spectroscopic graphite electrodes has been investigated electrochemically through flow injection analysis in order to obtain more information about the DET efficiency of this enzyme. The effect of applied potential and the long term stability of the modified electrodes were determined, as well as the bioelectrocatalytic current response with lactose as substrate was investigated by amperometric flow injection measurements in both direct and mediated electron transfer mode, with 1,4-benzoquinone as mediator. The effect of immobilization method on enzyme orientation was tested, and the assumption regarding orientation of MtCDH was accomplished by involving papain as restriction enzyme for cutting CDH molecules both in solution and on graphite electrodes. In this work the enzyme called Myriococcum thermophilum Cellobiose Dehydrogenase (MtCDH) was investigated by chemical methods with a final intention to contribute on building up a device which will be used by the aid of this enzyme to measure the substrate called lactose, which is an important component in milk and many other products. But, before going in details why lactose is such an important component to be controlled, a few important words about enzymes in general, what they are, what they do, their specificity, how they work, and which things affect their activity will be mention as follows, as well as, a few facts particularly will be mention about Myriococcum thermophilum Cellobiose Dehydrogenase (MtCDH), the enzyme that I worked with in this thesis. <br /> Enzymes are special types of proteins. Like all proteins, enzymes are made from strings of amino acids. The function of the enzyme is determined by the sequence of amino acids, types of amino acids, and the shape of the string. They are responsible for a lot of the work that is going on in cells. They act as catalysts in order to help produce and speed up chemical reactions. When a cell needs to get something done, it almost always uses an enzyme to speed things along. Enzymes are very specific. This means that each type of enzyme only reacts with the specific type of substance that it was made for. This is important so enzymes don&#39;t go around doing the wrong thing and causing chemical reactions where they are aren&#39;t supposed to. Enzymes have a special pocket on their surface called an &quot;active site.&quot; The molecule that they are supposed to react with fits neatly right into that pocket. The molecule or substance that the enzyme reacts with is called the &quot;substrate.&quot; The reaction takes place between the enzyme and the substrate at the active site. After the reaction is complete, the new molecule or substance is released by the enzyme. This new substance is called the &quot;product.&quot; The environment of the enzyme and the substrate can affect the speed of the reaction. In some cases the environment can cause the enzyme to stop working or even unravel. When an enzyme stops working we call it &quot;denatured.&quot; Here are some things that can affect enzyme activity: The temperature can affect the reaction rate. The higher the temperature, the faster the reaction will occur. However, at some point the temperature will become so high that the enzyme will denature and stop working. In many cases the pH level, or acidity, of the environment around the enzyme and substrate can affect the reaction rate. An extreme pH (high or low) will typically slow the reaction or even stop the reaction altogether. Concentration of the substrate or enzyme is another important factor. A higher concentration of substrate or enzyme can increase the reaction rate. On the other hand inhibitors are molecules that are specially made to stop the activity of enzymes. They may just slow down the reaction or stop it altogether. Some inhibitors bond with the enzyme causing it to change shape and not work correctly. The opposite of an inhibitor is an activator which can help to speed up the reaction. Enzymes don&#39;t get used up after they do their job. They can be used over and over. Enzymes are often used in industrial applications such as food processing, paper manufacturing, and detergents. There is an enzyme in human saliva called amylase that helps to break down starches as one chew. Enzymes also play an important role in breaking down our food so our bodies can use it. There are special enzymes to break down different types of foods. They are found in our saliva, stomach, pancreas, and small intestine and many other organisms as well.<br /> The enzyme I worked with as mentioned above is called Cellobiose Dehydrogenase (CDH), produced from the ascomycete fungus Myriococcum thermophilum (Mt). The natural function of this enzyme is to substract electrons from cellobiose sugar units and deliver them to another enzyme, which makes highly reactive radicals with the help of those electrons and oxygen. Those oxygen radicals help on wood degradation. <br /> In this thesis the CDH molecules were put on the surface of graphite electrode and instead of delivering the electrons to the radical producing protein as mention on the previous paragraph, the electrons were delivered directly to the graphite electrode and the amount of gained electrons were counted by measuring the electrical current, which is nothing else than a flow of electrons. <br /> The device build based on such components is called a biosensor. The adsorption of CDH on the graphite electrode surface was shown to be stable and operational for a long time. Enzyme kinetics performed in this work has shown that CDH has high specificity toward lactose sugar. The influence of the applied potential on the catalytic response was investigated and results show that very little potential (mV) is needed to be applied to get the maximal oxidation current. CDH also has shown efficient direct electron transfer properties at graphite electrode toward lactose substrate. Therefore, such and many other beneficial features that CDH possess make it a promising enzyme on development of biosensors. <br /> Regarding lactose sugar, it can be found in milk and dairy products such as cheese and yogurt, in bread and baked goods, processed breakfast cereals, instant potatoes, some soups and non-kosher lunch meats, candies, dressings and mixes for pancakes and biscuits etc. After eating such dairy products that contain this sugar, usually lactase, a digestive enzyme of the small intestine, helps to breakdown this complex sugar into two simple sugars, glucose and galactose. These simple sugars are then absorbed in the small intestine and ultimately reach the blood stream where they act as nutrients. In many cases because lactose is not digested properly in the small intestine of individuals who are lactose intolerant, it passes whole into the large intestine or colon and causes many harmful symptoms. <br /> Eating lactose-containing products will result in discomfort for many who are lactose intolerant and this was the whole intention of this investigation to contribute on building up a device which might control this component in different products. CDH show promising features to build up such a device but much more investigations remains to be done and I look forward to give my contribution. 2016 eng biosensor amperometric flow injection analysis cellobiose dehydrogenase MtCDH Myriococcum thermophilum direct electron transfer mediated electron transfer analytical chemistry analytisk kemi Chemistry 8875134 2016-05-27T11:43:24+02:00 2016-06-10T10:13:50+02:00 2016-06-10T10:13:50+02:00

oai:lup-student-papers.lub.lu.se:8925143 2025-07-29T13:03:30Z Medicine PhysicsChemistryMaths

studentPublicationsH1 Nada Abdulla author 8167925 Associate professor Ulrica Englund Johansson supervisor Department of Chemistry v1000647 department Abstract<br /> The retina is the inner most layer of the eye. It is responsible for conversion of light into an electrical signal that pass through the fibers of the optic nerve to the visual centers in the brain. Most of the neo-vascular retinal diseases lead to legal vision loss. Silver and gold nanoparticles have got a great interest in ocular research due to their anti-bacterial effects and their ability to inhibit retinal neovascularization and pass retinal blood barrier. Here we studied toxicological effects (apoptosis and microglial activation) of silver and gold nanoparticles, 20 and 80 nm in adult mouse retina after different times of intravitreal injection. Different staining methods were used, includingTUNEL staining, Iba1 and ED1 double immunostaining. Also, autometallography-based silver staining was used to detect Au and Ag nanoparticles (NPs). Most of the apoptotic cells were detected in the outer nuclear layer (ONL), AuNPs 20nm had the highest toxic effect followed by AuNPs, 80nm. It was also found AuNPs 20 nm cause the highest inflammation effect which cause degeneration of microglial cells at the late activation state. Small particles are everywhere!<br /> In our life style, we daily use many products like sun screen, anti -scratch frying pan, make up and pacifiers for babies. All of these products contain tiny small particles called nanoparticles. They are defined as sub 100 nm structures. There are different types of nanoparticles depending on the material source. Some nanoparticles are used as a vehicle to deliver drugs to cells (e.g. cancer cells). Due to their large surface area relative to their volume, they can carry large amount of drugs. Gold (Au) nanoparticles have many applications in the medical field especially in the cancer treatment, Silver (Ag) nanoparticles also got great attention as they have the ability to kill the bacteria. Besides having many treatment applications in the medical field, they also have side effects so it is a double-edged weapon. Many factors control these effects such as the particles’ size, type, concentration, the administration route, the nature of the target etc. One of the most sensitive organs that are exposed daily to these particles is the eye. Exposure to nanoparticles can have different side effects, such as cell death and inflammation. Therefore, we here studied effects of Ag- and Au nanoparticles on the retina in vivo, by analyzing cell death and inflammation using specific stainings. By studying the side effects of nanoparticles, more progress in the medical field will be carried out. In this study, we found that 20 nm Au nanoparticles had the highest toxic effect while no effect was found for Ag nanoparticles. 2017 eng Silver and Gold Nanoparticles Retina protein science proteinvetenskap Chemistry Medicine and Health Sciences 8925143 2017-09-08T19:55:05+02:00 2018-02-01T11:47:24+01:00 2018-02-01T11:47:24+01:00

oai:lup-student-papers.lub.lu.se:8925174 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Emma Welinder author 8925172 Johanna Nilsson author 8925178 Carlos Rodriguez Arza supervisor Centre for Analysis and Synthesis v1000651 department The main goal of this project was to investigate how the thermal stability of two different types of polyhydroxyalkanoates; poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) were affected when washing them with acid solution. Initially, four different acids were used: citric acid, hydrochloric acid, formic acid and acetic acid. Citric acid gave the best results for both biopolymers and was further investigated with respect to different concentrations and washing times to find the optimal parameters. <br /> Experiments where deionized water was used as the washing solution, and experiments where citric acid was mixed into the samples were also investigated. The analyzing techniques used to evaluate the results was thermogravimetric analyze, differential scanning calorimetry, rheometer and size exclusion chromatography. <br /> The degradation temperatures of as-received P(3HB) and P(3,4HB) powder were 279℃ and 247℃, respectively, determined with TGA. After the citric acid wash (1 mM, washing time 30 min), the degradation temperatures increased with 16℃ (296℃) for P(3HB) and with 48℃ (295℃) for P(3,4HB). Higher degradation temperatures could not be reached with higher concentrations or longer washing times. However, further investigation of P(3HB) showed that a concentration of only 0.05 mM and a washing time of 45 s was enough to raise the degradation temperature to 296℃. For P(3,4HB), a concentration of 1 mM and a washing time of 45 s was required to reach a degradation temperature of 295℃. <br /> By washing P(3HB) with deionized water for 30 minutes, the degradation temperature became 294℃, and for P(3,4HB) it became 271℃. Due to the high increase in degradation temperature, more washing times were investigated. For P(3HB), a washing time of only 45 s was enough to raise the degradation temperature to 294℃, and for P(3,4HB) 5 min was required to reach 271℃. <br /> When citric acid was mixed into the homopolymer, the degradation temperature decreased with 27℃, and for the copolymer the degradation temperature stayed the same. <br /> The increase in degradation temperature by washing the biopolymer powder indicates a significant increase in the thermal stability. Today, plastic materials play a very important role in our everyday life. Plastics are used in almost every manufacturing industry nowadays because their physical properties make them very useful in many different areas. They are very versatile and can therefore be manipulated to get a wide range of desirable properties. The major disadvantage with these plastics made by fossil sources is that they are non-degradable and thus, they accumulate in the environment at a rate of 25 million tons per year. Because of this, there is a strong desire for new polymers with degradability to replace the old plastics. A so-called biopolymer. https://lup.lub.lu.se/student-papers/record/8925174/file/8925175.pdf application/pdf 6019416 no 2017 eng polymer technology polymerteknologi Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/8925174/file/8925177.pdf application/pdf no 8925174 2017-09-10T10:48:51+02:00 2017-09-19T15:17:37+02:00 2017-09-19T15:17:37+02:00

oai:lup-student-papers.lub.lu.se:8925194 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Emil Axell author 8925192 Martin Lundqvist supervisor Department of Chemistry v1000647 department The small protein α-synuclein is strongly associated with Parkinson’s disease.<br /> This protein is found in inclusion bodies, named lewy bodies inside neurons of<br /> people suffering from the disease. α-synuclein is very abundant in the human<br /> brain, and its normal function is still elusive and unclear. The factors that<br /> trigger the accumulation and fibrillation of this protein into pathogenic inclusion<br /> bodies is of great interest in the quest of finding a cure for the disease. In this<br /> study the isothermal fibrillation of this protein from monomeric form (found in<br /> the brain of healthy people) into aggregated structures (found in people with<br /> the disease) was investigated using calorimetry. This yielded insights about<br /> the underlying thermodynamics that govern the onset and progression of the<br /> disease. This work shows that the process of fibrillation is endothermic (needs<br /> energy to proceed) under the investigated conditions and that calorimetry is<br /> a method that may be employed in the study of this protein. Attempts were<br /> made to investigate whether this protein had an effect on proton permeability<br /> across the membrane of small unilamellar vesicles, with a pH gradient between<br /> the interior and exterior of the vesicles. In doing so groundwork was laid for<br /> developing a vesicle leakage assay using the lytic peptide melittin and studying<br /> leakage through isothermal titration calorimetry. Under de senaste årtionden har människans förväntande levnadsålder ökat dramatiskt, som ett resultat av bland annat förbättrad levnadsstandard och utveckling inom medicin. Globala vaccinationsprogram har lett till att sjukdomar som tidigare varit stora hot mot folkhälsan nu mera nästan är utrotade. Ny kunskap om hur sjukdomar uppstår och utvecklar sig hos den drabbade individen, är mycket viktigt för att försöka förhindra och bota de drabbade av sjukdomen. Under dessa årtionden har även huvudorsakerna till vår bortgång ändrats. Bland de orsaker som ständigt blir större i kraft av att vår livslängd ökar är neurodegenerativa sjukdomar. I utvecklade länder är nu Alzheimers och Parkinsons sjukdom bland de 6 respektive 15 främsta anledningarna till att vi dör. Med en åldrande befolkning är det väntat att dessa sjukdomar kommer att klättra på listan, och att ännu fler människor kommer att drabbas. <br /> <br /> Denna studie har undersökt proteinet som tros vara syndabocken i Parkinsons sjukdom, proteinet heter α-synuclein. Alla människor har detta protein i sina hjärnceller. Vilken exakt funktion det fyller hos friska individer är ännu inte helt kartlagt, men det tros ha en funktion vid kommunikation mellan hjärnans celler. Denna kommunikation sker bland annat med signalsubstanser som är inkapslade i små membranblåsor. Hos individer med Parkinsons sjukdom har man sett ansamlingar av detta protein i deras hjärnor. Kunskap om hur detta protein ansamlas är mycket viktigt i kampen mot att en dag hitta ett botemedel som kan förhindra sjukdomen.<br /> <br /> Det som har undersökts är ”ansamlings-processen” av proteinet. Detta har gjorts genom att mäta den energi som krävdes eller avges under aggregeringen. Kunskap om den underliggande termodynamiken bakom denna aggregering kan hjälpa till att bättre förstå de komplexa molekylära orsakerna till att en individ insjuknar i Parkinsons. <br /> <br /> Interaktionen mellan proteinet och konstgjorda celler undersöktes också. Det som studerades var huruvida aggregeringen av proteinet kunde orsaka läckage av celler.<br /> <br /> Alla dessa undersökningar gjordes i olika typer av kalorimetrar, apparater som mäter energiändringar när en process äger rum. <br /> <br /> Studien har lyckats visa att aggregeringen av proteinet är en endoterm process (att processen kräver energi för att ske) under de betingelser där den studerats. Vidare har grundstenarna för en metod för att mäta läckage från modellceller blivit lagt. https://lup.lub.lu.se/student-papers/record/8925194/file/8925199.pdf application/pdf 1861611 2019-09-11 no 2017 eng Differential Scanning Calorimetry ITC Isothermal Titration Calorimetry Parkinson α-synuclein Alpha synuclein DSC Melittin Vesicles biochemistry biokemi Chemistry 8925194 2017-09-10T17:34:02+02:00 2019-09-11T03:47:56+02:00 2017-09-19T14:49:57+02:00

oai:lup-student-papers.lub.lu.se:8927277 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Nawel Betina author 8927096 Mariena van der Plas supervisor Department of Chemistry v1000647 department Wound healing is a process that ensures regeneration and repair of damaged tissue. This process can be interrupted, leading to chronic wounds, and one of the factors that can interrupt it is infection. The bacterium Pseudomonas aeruginosa is prevalent in chronic wounds, and as it is antibiotic resistant it makes chronic wounds infected with this pathogen a challenging clinical problem.<br /> For a better understanding of causes behind wound healing failure when a wound is infected by P. aeruginosa we studied elastase, which is one of several virulence factors of P. aeruginosa. This protein is secreted by most strains of this species and is characterized as zinc metalloprotease. The present study relies on the isolation and purification of elastase for investigations of a potential difference in the enzymatic activity of elastase between four different strains of P. aeruginosa, the PAO1 (wild type strain), PAOA1 (elastase A mutant), PAOB1 (elastase B mutant), and PAOA1B1 (elastase A and B double mutant). Also, to understand the interplay between elastase and the host by clarifying the interaction between elastase and both the immune and the coagulation systems.<br /> Results of the purity analysis, using tricine gels together with results of gelatin zymography show that the purification of active elastase B using fast protein liquid chromatography was successful. Our results from an azocasein assay together with the gelatin zymography of both P. aeruginosa conditioned medium and purified elastase show that elastase B dominates the elastolytic activity of P. aeruginosa. Interestingly, results of this study disagree with the hypothesis that elastase A can enhance the virulence of elastase B. Contrary, the present data suggest that elastase A represses virulence of both elastase B and the toxin pyocyanin. Skin is an organ, which acts as a physical barrier between the body and the environment. It provides protection against pathogen invasion by regulating skin immune system. A skin wound can be defined as any damage or disruption of the normal anatomical structure and function of the skin, and it can be classified into acute wounds that heal in an ordered pathway within a time frame of 30 days, and chronic wounds which take longer time to heal or even fail the healing process. <br /> The combination between the high prevalence of chronic wounds, their treatment costs, frequency of the bacterium Pseudomonas aeruginosa in chronic wounds, and its resistance to antibiotics, makes wounds infected with this bacterium a real issue for both patients and society. For this reason elastase, which is one of the most prominent protein degrading enzyme in disease produced by P. aeruginosa, is studied in this project. A better understanding of its degrading activity might help in finding new treatments of non-healing wounds.<br /> This study aims at isolating and purifying elastase, and then comparing the protein degrading activity of four different strains of P. aeruginosa: normal strain, an elastase A deficient mutant, an elastase B deficient mutant, and a mutant lacking both elastase A and B. A further objective is to elucidate and understand the role of elastase in interactions between the bacterium and the host.<br /> The results of purity assays combined with enzymatic activity assays confirm the successful isolation of purified active elastase B. In addition, our results show that elastase B dominates the elastase protein degrading activity of P. aeruginosa. Contradictory to previous studies, results reveal that, elastase A represses the activity of elastase B and the production of pyocyanin, which is a toxin excreted by the bacterium. 2017 eng Pseudomonas aeruginosa chronic wounds elastase enzymatic activity cytokines protein science proteinvetenskap Chemistry 8927277 2017-10-13T11:41:06+02:00 2017-10-31T09:34:42+01:00 2017-10-31T09:34:42+01:00

oai:lup-student-papers.lub.lu.se:8927706 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Dino Redzic author 8927704 Maitham Majeed supervisor Department of Chemistry v1000647 department Centre for Analysis and Synthesis v1000651 department C-H activation with transition metal catalysts is one the most intense areas of research today<br /> and new advancements aid in the production of bulk chemicals, simplifying synthetic routes<br /> and transforming inert substrates into functionalized ones. By attempting to synthesize two N-<br /> heterocyclic palladium complexes (1 and 2, complex 3 is received) heterogenous, ligand-<br /> directed halogenation of substrates 4 and 5 is evaluated to for activity, selectivity, time-profile<br /> recyclability, and heterogenity. Complex 1 was synthesized in low yield and further<br /> purification must be done going forward. The intermediate silver complex of complex 2 was<br /> synthesized. The bromination of substrate 5 was completely selective in low yield and more<br /> selective than the homogenous variant. Further, the time-profile indicated a single reaction<br /> pathway. The iodination and bromination of substrate 4 showed complete selectivity in<br /> moderate yield and better selectivity than the homogenous equivalent. The iodination was<br /> found to be recyclable up to 5 runs. Chemical catalysis is a hugely important tool used not only by our bodies in different biological processes but also by the synthetic chemist to perform transformations that would otherwise be impossible or very difficult. One important class of catalysts employ a transition metal, such as palladium, bound to a N-heterocyclic (NHC) ligand. The NHC ligand allows the chemist to modify the properties of the catalyst so that it can be used for a wide variety of purposes. Such catalysts can, moreover, be noncovalently bound to a support, such as graphene or carbon nanotubes, which makes the catalyst heterogenous and easily separable from the reaction mixture after the reaction is complete. By using these catalysts, the hope is that selective (only targeting one bond) and high-yielding conversion of C-H bonds into C-X (X usually N, O, C, halogen) can be achieved. C-H activation, as this is called, is a tricky but highly useful part of synthetic chemistry. <br /> <br /> This diploma work aims to synthesize two NHC-palladium catalysts and support them onto reduced graphene oxide (rGO). Further, a third presynthesized NHC-palladium complex will be supported on rGO and used in a number of catalytic reactions. The results show that one of these catalysts was succesfully synthesized, with some impurities, while strides were made on the path to synthesize the other. The third catalyst was used for a number of C-H activation reactions where a ligand on the substrate directs the C-H activation. The results show that when the catalyst was supported onto rGO the catalysis gave a lower yielding but much more selective conversion. Further, a time-profile of the catalysis was constructed, which showed typical behaviour. Finally, the recyclability of one of the catalytic reactions was performed and was shown to be effective up to 4 cycles. https://lup.lub.lu.se/student-papers/record/8927706/file/8928232.pdf application/pdf 2939794 LU/LTH access 2017 eng organometallic chemistry organic chemistry ligand-directed catalysis Chemistry 8927706 2017-10-23T11:49:24+02:00 2024-02-28T12:46:22+01:00 2024-02-28T12:46:22+01:00

oai:lup-student-papers.lub.lu.se:8927990 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Niels Kouwenhoven author 8927888 Associate Prof. Mikael Lund supervisor Peter Jönsson supervisor Department of Chemistry v1000647 department This paper seeks to express the chemical potential for proteins on a surface in terms of number surface densitiy. Generalized Van der Waals (GVdW) theory and Virial hard disk theory are explored and fitted to experimental data by varying the hard disk radius. <br /> Additionnally Metropolis Monte Carlo simulations are used to simulate the interactions between proteins. Simulations are done on freely rotating proteins with the center of mass constrained to a 2D plane and employing the Widom insertion method to calculate the chemical potential. The theory, derivation and discussion of GVdW, Virial and Widom insertion are examined in this paper. Finally an interactive tool is included, which dynamically plots GVdW potentials. This tool is available online, both as source code and as a public web interface. The surface of cells or the cell membrane contains proteins that are floating along the surface. How closely can you pack those proteins and how much energy would that cost? <br /> Proteins like to be spread out across the surface. The proteins are anchored to the cell membrane, but can move along the surface. In this way, they behave similarly to the particles in a gas, except that they can only move in two dimensions. <br /> <br /> One can indeed quite accurately model the proteins on a cell surface as a two-dimensional gas. Even the most basic theory of gases—which models molecules as hard marbles that bounce off each other when they get to close works quite well. Even though the shape, charges and other interactions of the molecules have been ignored, the hard marbles theory which only model the volume of the proteins correctly is able to make some decent rough predictions for the chemical potential, where the chemical potential is defined as the amount of energy it takes to add a single particle to the system.<br /> More than a century ago Dutch physicist Johannes van der Waals developed theories that describe the behavior of gases. The description of liquids and gases that he developed, is now called the “Van der Waals equation of state” and earned him the Nobel prize in physics in 1910. His theory is still relevant today and factors in two corrections to the ideal gas law: Firstly, molecules take up space, and their “excluded volume” limits the <br /> movability of the other molecules, which increases the pressure. Secondly, molecules attract each other, which lowers the pressure, which is expressed with a value called the “binding constant”. <br /> <br /> An alternative way to study the properties of a gas is to simulate it: put some virtual molecules in a virtual box and let the computer move and rotate them such that this virtual system is representative of a physical system. Then this virtual gas can be analyzed by several methods. For example, the chemical potential can be analyzed by via a sampling algorithm. The chemical potential is defined as the amount of energy it takes to add a single particle to the system. In the virtual gas you can do just that: add a particle to your system and calculate how the energy changes. Remove the particle and repeat the process a hundred times so you can calculate an average. <br /> <br /> This thesis treats proteins on a surface as gas molecules in a plane in order to find physical properties about them, such as the chemical potential. The moleculer were modeled as “hard marbles”, then interactions were introduced by calculating the “binding energy constant”, and even more details were taken into account by simulating the proteins entirely on a computer. https://lup.lub.lu.se/student-papers/record/8927990/file/8927991.pdf application/pdf 2370109 no 2017 eng Monte Carlo simulation 2D Van Der Waals nanochemistry nanokemi Chemistry 8927990 2017-10-31T18:44:05+01:00 2017-12-18T08:58:43+01:00 2017-12-18T08:58:43+01:00

oai:lup-student-papers.lub.lu.se:8928233 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Mathias Wiemann author 8922565 Mostafa Abdalkhalik supervisor Department of Chemistry v1000647 department Friedriech&#39;s ataxia is a serious neurological condition that is caused by a deficiency in the expression of the protein frataxin. This deficiency is caused by an extension of GAA repeats in the first intron of the frataxin-coding gene. The disease can have an onset as early as five years and by the time the patient has reached 20 years they often require a wheelchair and help to be able to have a functional life.<br /> The exact role of frataxin in humans is currently not fully understood but it has been suggested that it plays part in several iron pathways in the mitochondria, including iron-sulfur(Fe-S) cluster synthesis. Frataxin can oligomerize in the presence of iron and this study is focused on better understanding of the mechanisms of this process. The main focus of the study has been CyaY, a bacterial orthologue to human frataxin, that has a fold similar to that of its human counterpart. <br /> The main method of investigation was dynamic light scattering (DLS). The oligomerization process was studied over time to see how oligomerization proceeded dependant on iron concentration. The effects of hydrogen peroxide, and indirectly the availability of Fe3+, on the size of the oligomers was investigated. Experiments were also performed to study the potential role of the protonation state of the protein in oligomerization by carrying out oligomerization experiments at pH 4.8. The effect of formation of Fe3+ after incubation with Fe2+ under anaerobic conditions was also followed. Finally, initial experiments to try to gain a better understanding of the effects of iron chelators and their interaction with frataxin were carried out.<br /> In the study we show there is a difference in oligomerization behaviour depending on the iron-to-protein ratio, possibly due to filling the available iron-binding sites per monomer. Furthermore we show that the initial availability of Fe3+ have an effect on the size of the particles formed. Finally the study shows that oligomerization at pH 4.8 is severely repressed, although the reason for this repression is currently not clear since this could be due several different factors. Järn är essentiellt för livet som vi känner det idag. Det är en del i flera av de huvudsakliga energisystemen som finns i de flesta levande organismer. Men järn som är fritt i en cell kan orsaka enorma skador genom att det deltar i en process som bildar så kallade syreradikaler. Det finns därför en mängd olika proteiner som på olika sätt binder och reglerar järn.<br /> Fel med dessa proteiner kan leda till allvarliga sjukdomar. En av dessa sjukdomar är Friedreich&#39;s ataxi där de första symptomen kan göra sig kända så tidigt som vid fem års ålder. Sjukdomen utvecklas därefter och tjugo år gammal kan den drabbade vara behov av rullstol och assistans för att kunna klara sig. <br /> Sjukdomen beror på att ett järnbindande protein kallat frataxin inte uttrycks i tillräckligt stora mängder. Proteinets exakta funktion är inte helt utrett i nuläget men det verkar vara involverat i ett flertal olika processer där järn används som byggstenar för att skapa viktiga molekyler för kroppens funktioner.<br /> Frataxin har förmågan att gå ihop och bilda större protein-sammanslutningar i närvaro av järn. Dessa sammanslutningar kan potentiellt vara viktiga för att förstå proteinets funktion i kroppen. Detta arbete har därför fokuserat på förutsättningarna för att bilda dessa proteinsammanslutningar för att öka förståelsen om frataxin och potentiellt leda till nya insikter hur man kan behandla Friedreich´s ataxia. https://lup.lub.lu.se/student-papers/record/8928233/file/8928234.pdf application/pdf 1113478 yes 2017 eng Frataxin oligomerization iron protein science proteinvetenskap Chemistry 8928233 2017-11-07T15:39:39+01:00 2017-12-18T09:01:19+01:00 2017-12-18T09:01:19+01:00

oai:lup-student-papers.lub.lu.se:8928450 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Magdalena Riad author 8928447 Professor Mikael Akke supervisor Olof Stenström supervisor Biophysical Chemistry v1000649 department This master thesis consists of two parts, which both deal with NMR studies of the carbohydrate-binding domain of the protein galectin-3 (Gal3C). In the first part, 19F relaxation of two difluorinated diastereomeric ligands bound to Gal3C was analyzed with the model-free approach to extract information about the dynamics. The second part reports the assignments of the backbone amide 1H/15N resonances of Gal3C with a tetrafluorinated ligand bound. <br /> In the first part of the project, I investigated two diastereomeric ligands, denoted R and S, which contain two fluorine atoms, one at each end of the molecule. I modified in-house written Matlab code for model-free analysis of 19F relaxation data and ran simulations and fits. Synthetic relaxation parameters were calculated, for given values of the internal correlation time and the order parameter, to compare with experimental values. Then, these parameters were fitted to the experimental values and the relaxation parameters were back-calculated. The resulting fit was good only for one of the two fluorines of the ligands. Then, the order parameter and the chemical shift anisotropy were fitted which gave the opposite results, the other fluorine was fitted well. However, the result of the last fit was puzzling, indicating that the fluorine which is known to be more rigid, would be the more flexible one. <br /> In the second part, I carried out assignment NMR experiments such as 15N-HSQC and HNCACB on Gal3C with a tetrafluorinated ligand bound. The backbone assignments showed similarity with those obtained for complexes with congeneric ligands, as expected. However, compared to apo-Gal3C, several residues moved significantly in the spectrum, especially those located in the binding pocket and in loops. Förståelse av dynamiken i interaktionen mellan proteiner och olika molekyler kan underlätta designen av nya läkemedel mot till exempel cancer. Detta kan man studera i stora magneter med så kallad magnetresonansspektroskopi.<br /> <br /> I kroppen finns en proteinfamilj, Galektiner, som deltar i många biologiska processer. Ett av dessa protein, Galektin-3, är involverat i utvecklingen av cancer vilket gör att man är intresserad av att rikta läkemedel mot dem. För att bättre designa nya läkemedel kan kunskap om inbindningen av läkemedelsmolekylen till proteinet och om hur den rör sig när den är bunden vara till stor hjälp. Så hur tar vi reda det?<br /> Jo, med hjälp av magnetresonansspektroskopi (NMR)! <br /> <br /> Vissa atomkärnor, exempelvis 1H, 13C 19F, har en egenskap som kallas “spinn” vilket gör att de beter sig som små stavmagneter när de placeras i ett större magnetfält. Därför placeras protein-provet i en stor magnet när ett experiment ska utföras. Dessa små stavmagneter lägger sig i linje med det stora magnetfältet eftersom det är energimässigt mest gynnsamt. Riktningen på spinnen kan dock rubbas genom en radiofrekvens-puls vilket utnyttjas i experimentet. Signalen erhålls när spinnen tippats så att dess riktning avviker från det stora magnetfältet och därefter precesserar (pendlar i cirkelrörelse) kring detta. Samtidigt återgår spinnen till att ligga i linje med det stora magnetfältet i en process som kallas “relaxation” och som beror på molekylernas dynamik. Resultatet av ett NMR-experiment är ofta ett spektrum där signaler från spin av ett visst atomslag (t.ex. 1H) dyker upp på olika ställen beroende på dess kemiska miljö. Alltså kommer ett spektrum av bara proteinet Galektin-3 och ett spektrum av Galektin-3 med en bunden läkemedelsmolekyl se aningens olika ut. <br /> <br /> Fluor finns inte bara i vår tandkräm utan förekommer också ofta i läkemedelsmolekyler. Fluor kan studeras med hjälp av NMR och detta utnyttjades i det här projektet eftersom just de potentiella läkemedelsmolekyler som studerats har fluor-atomer i ändarna. <br /> <br /> Projektet bestod av två delar. I den första delen har jag dels använt en analys-metod där man i ett datorprogram passar vissa parametrar till experimentella NMR-data som beskriver relaxationen. Dessa parametrar ger en beskrivning av dynamiken hos det man undersöker och detta har tidigare gjorts för proteinet Galektin-3. Nu modifierade jag koden för att kunna studera läkemedelsmolekylens dynamik, genom dess fluor-atomer, när den är bunden till Galektin-3. <br /> Passningarna gav förbryllande resultat, vilket pekar på att fler studier behöver göras för att fullt förstå fluor-relaxationen. <br /> <br /> I den andra delen har jag utfört NMR-experiment på proteinet bundet till en läkemedelsmolekyl. När en molekyl binder in till proteinet ändras den kemiska miljön för proteinets byggstenar, aminosyrorna. Det spektrum som jag erhöll jämförde jag med ett spektrum av proteinet fritt från läkemedelsmolekyl. Dessa skiljde sig åt något och speciellt de signaler som tillhörde aminosyror som hamnade nära läkemedelsmolekylen ändrade sig. Sedan jämförde jag spektrumet med spektra av proteinet bundet till andra läkemedelsmolekyler som erhållits tidigare. Det visade sig att de liknade varandra vilket var väntat eftersom molekylernas strukturer var liknande. Den kemiska miljön rubbades alltså inte så mycket då. <br /> <br /> Detta projekt var ett led i att nå mer kunskap om inbindningen av läkemedelsmolekyler till proteinet Galektin-3 och om hur de rör sig när de är bundna. Forskningen fortsätter. https://lup.lub.lu.se/student-papers/record/8928450/file/8928456.pdf application/pdf 3145813 LU/LTH access 2017 eng Galectins Nuclear Magnetic Resonance NMR Biophysical Chemistry 19F relaxation relaxation Model-free analysis Biofysikalisk kemi Kärnmagnetisk resonans Technology and Engineering Chemistry Biology and Life Sciences https://lup.lub.lu.se/student-papers/record/8928450/file/8928458.pdf application/pdf LU/LTH access 8928450 2017-11-13T10:09:02+01:00 2017-12-18T09:08:05+01:00 2017-12-18T09:08:05+01:00

oai:lup-student-papers.lub.lu.se:8928833 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Magdalena Riad author 8928447 Professor Mikael Akke supervisor Olof Stenström supervisor Biophysical Chemistry v1000649 department This master thesis consists of two parts, which both deal with NMR studies of the carbohydrate-binding domain of the protein galectin-3 (Gal3C). In the first part, 19F relaxation of two difluorinated diastereomeric ligands bound to Gal3C was analyzed with the model-free approach to extract information about the dynamics. The second part reports the assignments of the backbone amide 1H/15N resonances of Gal3C with a tetrafluorinated ligand bound. <br /> In the first part of the project, I investigated two diastereomeric ligands, denoted R and S, which contain two fluorine atoms, one at each end of the molecule. I modified in-house written Matlab code for model-free analysis of 19F relaxation data and ran simulations and fits. Synthetic relaxation parameters were calculated, for given values of the internal correlation time and the order parameter, to compare with experimental values. Then, these parameters were fitted to the experimental values and the relaxation parameters were back-calculated. The resulting fit was good only for one of the two fluorines of the ligands. Then, the order parameter and the chemical shift anisotropy were fitted which gave the opposite results, the other fluorine was fitted well. However, the result of the last fit was puzzling, indicating that the fluorine which is known to be more rigid, would be the more flexible one. <br /> In the second part, I carried out assignment NMR experiments such as 15N-HSQC and HNCACB on Gal3C with a tetrafluorinated ligand bound. The backbone assignments showed similarity with those obtained for complexes with congeneric ligands, as expected. However, compared to apo-Gal3C, several residues moved significantly in the spectrum, especially those located in the binding pocket and in loops. Förståelse av dynamiken i interaktionen mellan proteiner och olika molekyler kan underlätta designen av nya läkemedel mot till exempel cancer. Detta kan man studera i stora magneter med så kallad magnetresonansspektroskopi.<br /> <br /> I kroppen finns en proteinfamilj, Galektiner, som deltar i många biologiska processer. Ett av dessa protein, Galektin-3, är involverat i utvecklingen av cancer vilket gör att man är intresserad av att rikta läkemedel mot dem. För att bättre designa nya läkemedel kan kunskap om inbindningen av läkemedelsmolekylen till proteinet och om hur den rör sig när den är bunden vara till stor hjälp. Så hur tar vi reda det?<br /> Jo, med hjälp av magnetresonansspektroskopi (NMR)! <br /> <br /> Vissa atomkärnor, exempelvis 1H, 13C 19F, har en egenskap som kallas “spinn” vilket gör att de beter sig som små stavmagneter när de placeras i ett större magnetfält. Därför placeras protein-provet i en stor magnet när ett experiment ska utföras. Dessa små stavmagneter lägger sig i linje med det stora magnetfältet eftersom det är energimässigt mest gynnsamt. Riktningen på spinnen kan dock rubbas genom en radiofrekvens-puls vilket utnyttjas i experimentet. Signalen erhålls när spinnen tippats så att dess riktning avviker från det stora magnetfältet och därefter precesserar (pendlar i cirkelrörelse) kring detta. Samtidigt återgår spinnen till att ligga i linje med det stora magnetfältet i en process som kallas “relaxation” och som beror på molekylernas dynamik. Resultatet av ett NMR-experiment är ofta ett spektrum där signaler från spin av ett visst atomslag (t.ex. 1H) dyker upp på olika ställen beroende på dess kemiska miljö. Alltså kommer ett spektrum av bara proteinet Galektin-3 och ett spektrum av Galektin-3 med en bunden läkemedelsmolekyl se aningens olika ut. <br /> <br /> Fluor finns inte bara i vår tandkräm utan förekommer också ofta i läkemedelsmolekyler. Fluor kan studeras med hjälp av NMR och detta utnyttjades i det här projektet eftersom just de potentiella läkemedelsmolekyler som studerats har fluor-atomer i ändarna. <br /> <br /> Projektet bestod av två delar. I den första delen har jag dels använt en analys-metod där man i ett datorprogram passar vissa parametrar till experimentella NMR-data som beskriver relaxationen. Dessa parametrar ger en beskrivning av dynamiken hos det man undersöker och detta har tidigare gjorts för proteinet Galektin-3. Nu modifierade jag koden för att kunna studera läkemedelsmolekylens dynamik, genom dess fluor-atomer, när den är bunden till Galektin-3. <br /> Passningarna gav förbryllande resultat, vilket pekar på att fler studier behöver göras för att fullt förstå fluor-relaxationen. <br /> <br /> I den andra delen har jag utfört NMR-experiment på proteinet bundet till en läkemedelsmolekyl. När en molekyl binder in till proteinet ändras den kemiska miljön för proteinets byggstenar, aminosyrorna. Det spektrum som jag erhöll jämförde jag med ett spektrum av proteinet fritt från läkemedelsmolekyl. Dessa skiljde sig åt något och speciellt de signaler som tillhörde aminosyror som hamnade nära läkemedelsmolekylen ändrade sig. Sedan jämförde jag spektrumet med spektra av proteinet bundet till andra läkemedelsmolekyler som erhållits tidigare. Det visade sig att de liknade varandra vilket var väntat eftersom molekylernas strukturer var liknande. Den kemiska miljön rubbades alltså inte så mycket då. <br /> <br /> Detta projekt var ett led i att nå mer kunskap om inbindningen av läkemedelsmolekyler till proteinet Galektin-3 och om hur de rör sig när de är bundna. Forskningen fortsätter. https://lup.lub.lu.se/student-papers/record/8928833/file/8928834.pdf application/pdf 11753126 LU/LTH access 2017 eng Galectins Nuclear Magnetic Resonance NMR Biophysical Chemistry 19F relaxation Model-free analysis Biofysikalisk kemi Kärnmagnetisk resonans Biology and Life Sciences Chemistry Technology and Engineering 8928833 2017-11-26T14:52:47+01:00 2017-12-18T10:03:24+01:00 2017-12-18T10:03:24+01:00

oai:lup-student-papers.lub.lu.se:8929241 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Klas Bratteby author 8929239 Ulf Nilsson supervisor Department of Chemistry v1000647 department Centre for Analysis and Synthesis v1000651 department Galectin-3 is a soluble protein in the body that has been shown involvement in biological<br /> processes such as tumour growth and metastasis as well as auto immune disease. Molecules<br /> developed by Ulf Nilsson’s research group have shown inhibitory effect in in vitro and in vivo<br /> studies towards galecin-3 but to get detailed information about distribution in vivo studies using<br /> PET should be performed. Precursors were developed and synthesized to obtain a product that<br /> could be radiolabelled with fluorine-18 and form a traceable galectin-3 inhibitor to see affinity<br /> and distribution in vivo. The synthesis was optimized to generate enough product to be able to<br /> perform several radiolabelling reactions. Three different precursors were tested with different<br /> radiolabelling methods and conditions to obtain a high enough radiochemical yield and then<br /> purify the formed product to be able to see if the method could be used to proceed to animal<br /> experiments. Out of the three the precursor to tracer 22 using a boronic pinacol ester leaving<br /> groups facilitated by a Cu(OTf)2(pyr)4 catalyst showed a high radiochemical yield and<br /> purification by preparative HPLC generated radiochemically pure product. Using the boronic<br /> pinacol ester precursor, radiolabelling it using the proposed method and purify it using<br /> preparative HPLC results in a product that can be taken to in vivo animal studies. Kan man spåra framtida läkemedel i kroppen med radioaktivt fluor?<br /> Hur fungerar egentligen olika läkemedel? De allra flesta kanske inte bryr sig, så länge det lindrar din huvudvärk eller tar hand om din infektion. Men när man ska ta fram nya läkemedel måste man tyvärr vara lite mer noggrann än så. Eftersom kostnaden för att gå från en flaska på kemilabbet till en burk på apoteket ofta är miljardbelopp och tiotals år av forskning och tester. En av de sakerna som är väldigt viktig är att veta hur läkemedlet beter sig när det kommer in i kroppen. Tar kroppen upp det som man vill eller skickas det direkt ut i urinen. Kan det ta sig till precis den tumören man vill bota eller sprider det ut sig lika mycket i hela kroppen? Det finns väldigt många olika metoder man kan använda sig av som att artificiellt simulera olika processer i kroppen i ett laboratorium eller använda sig av djurförsök. Men få av dessa metoder är lika effektiva eller precisa som att använda sig av positronemissionstomografi (PET).<br /> PET är en metod där man använder sig av en radioaktiv variant av fluor (fluor-18 isotopen) som man märker den molekylen man vill undersöka med. Man injicerar sedan en lösning med den radiomärkta molekylen i till exempel ett försöksdjur och analyserar den med en PET-kamera som kan läsa av radioaktiviteten. Det kombineras ofta med en skiktröntgen och då kan man avgöra den märkta molekylens exakta position i djuret man undersöker utan att djuret kommer till skada under undersökningen.<br /> I mitt projekt har jag undersökt om det går att märka in ett potentiellt framtida läkemedel mot cancer och/eller inflammatoriska sjukdomar med radioaktivt fluor. Molekylen blockerar, väldigt effektivt, ett protein som heter galektin-3 som har visat sig vara involverat i både cancer och inflammation.<br /> Första delen av projektet gick ut på att syntetisera en variant av läkemedlet som kan märkas med fluor på ett effektivt sätt. Tre stycken av dessa så kallade prekursorer sattes ihop i labbet med hjälp av organisk kemi. Sedan testades dessa tre molekyler i ett specialdesignat radiokemilabb för att se om det gick att hitta en reaktion som märker in dem med radioaktivt fluor. En av prekursorerna visade sig fungera bra i reaktionen och när den var inmärkt så testades olika sätt för att rena fram den radioaktiva produkten på bästa sätt.<br /> Sammanfattningsvis så visar mitt projekt att det går att syntetisera en variant på läkemedlet som går bra att märka in med radioaktivt fluor. Den inmärkta produkten går sedan att rena upp så pass väl att den kan injiceras i ett djur för att sedan analysera hur läkemedlet beter sig i försöksdjuret med hjälp av en PET-kamera. https://lup.lub.lu.se/student-papers/record/8929241/file/8929242.pdf application/pdf 8321336 yes 2017 eng Radiochemistry organic chemistry galectin organisk kemi Chemistry 8929241 2017-12-09T15:14:24+01:00 2017-12-18T10:39:34+01:00 2017-12-18T10:39:34+01:00

oai:lup-student-papers.lub.lu.se:8929295 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Erik Cheng author 8929293 Marie Wahlgren supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Detta examensarbete handlar om att undersöka stabiliteten hos Pickering emulsioner som består av myglyol olja, vatten, etanol och stärkelse. Emulsioner med olje- och etanol i vattenhalt upp till 60 % samt 70 % visade sig vara stabila upp till fyra månader vid rumstemperatur. Detta tyder på att Pickering emulsion är stabilt och kan användas för framtida alkohol baserade emulsioner. The aim of this work was to study ethanol based particle-stabilized emulsions, using a known phenomena called Pickering emulsions. The intended uses of the studied emulsions are towards skin formulations, but other applications could be used. The particles of interest were quinoa starch modified with skimmed milk powder and heat treated afterwards. Comparison between modified starch and native starch in stabilizing emulsions indicated that the modification was exceptional for stabilizing ethanol based emulsions. Various emulsions were studied to evaluate how the properties like ethanol and oil content affect the particle size and stability. It shows that emulsions with a continuous phase of 70% ethanol and oil content up to 60% showed reasonable particle size and stabilization persisted even after four months. The particle size of the system decreased with the starch to oil ratio while increased by the amount of oil or ethanol. In the end a minor sensory analysis showed that emulsification in ethanol based Pickering emulsion increased the cream properties of a sample and was the most preferred to use as a product. https://lup.lub.lu.se/student-papers/record/8929295/file/8929296.pdf application/pdf 3250612 yes 2017 eng Pickering emulsion Starch Ethanol based Pickering emulsion Pharmaceutical technology läkemedelsteknologi Chemistry https://lup.lub.lu.se/student-papers/record/8929295/file/8929298.pdf application/pdf yes 8929295 2017-12-11T13:00:13+01:00 2017-12-18T10:48:11+01:00 2017-12-18T10:48:11+01:00

oai:lup-student-papers.lub.lu.se:8933150 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Simon Fridolf author 8933135 Karin Schillén supervisor Department of Chemistry v1000647 department The co-assembly and temperature-dependent phase behavior of dilute aqueous solutions of a thermoresponsive cationic diblock copolymer and oppositely charged bile salts, sodium deoxycholate and sodium glycodexoycholate, or sodium dodecyl sulphate at different charge fractions in terms of negative charge were investigated by static- and dynamic light scattering (SLS/DLS), differential scanning calorimetry (DSC) and zeta potential measurements. The block copolymer was composed of poly(N-isopropyl acrylamide) (PNIPAAM) and poly((3-acrylamidopropyl) trimethylammonium chloride (PAMTPMA). PNIPAAM homopolymer mixed systems were also investigated. The phase behavior was found to be highly dependent on the lower critical solution temperature behavior of PNIPAAM as revealed by the endothermic transitions found by DSC and as reflected in the cloud point determinations using SLS. The DLS measurements performed at temperatures below the phase transition temperature showed that co-assembled structures with hydrodynamic radii ≈ 50-100 nm were formed. In the block copolymer case, they were charge neutral even at off-stoichiometric charge conditions and could thus be described as bile salt-copolymer coacervate complexes formed a result of the electrostatic interaction between the PAMPTMA blocks and the surfactants. In the homopolymer case, the co-assembly was instead governed by hydrophobic interactions pointing towards another type of aggregate structure. Upon increasing temperature larger aggregates developed and, depending on mixing ratio and surfactant, phase separation was observed. Några av de viktigaste molekylära strukturerna för livet på jorden är polymerer. Några exempel på dessa är deoxyribonukleinsyror (DNA) som bär den genetiska informationen nödvändig för att en organisk ska kunna utvecklas och fungera, och proteiner som utför andra komplexa och livsnödvändiga funktioner och utgör maskineriet för till exempel cellandning och ämnesomsättning. Det som DNA, proteiner och andra polymerer har genemsamt är att de är långa kedjor som är uppbyggda av individuella kemiska grupper som kallas monomerer och är sammanfogade genom kovalenta kemiska bindningar. I fallet med proteiner är monomerna aminosyror och deras individuella kemiska egenskaper tillsammans med hur de är ordnade i kedjan är avgörande för vilka strukturer de bildar tillsammans med andra kedjor och andra små molekyler – och är avgörande för deras funktion.<br /> <br /> För att förstå beteendet av, och för att skapa nya syntetiska (konstgjorda) polymerer för specifika ändamål bedrivs omfattande forskning. Både konventionella och nya syntetiska polymerer används redan eller har potential för många tillämpningar inom industri, forskning och medicin. För att ge dem specifika egenskaper är det möjligt att syntetisera s.k. copolymerer, där flera olika sorters monomerer kan organiseras på olika sätt, till exempel i en uppdelning i<br /> block av en sorts monomer i vilket fall polymeren benämns en block copolymer.<br /> <br /> Polymeren som undersöks i det här arbetet förkortas PNIPAAM65-b-PAMPTMA20 och är en block copolymer med en längre neutral hydrofil (vattenälskande) del som blir hydrofob (vattenhatande) vid högre temperatur, och en kortare positivt laddad hydrofil del vilket ger den intressanta egenskaper och ett komplext beteende i vatten. Molekyler som samtidigt har både hydrofila och hydrofoba delar kallas för amfifiler och i vatten bildar de vanligtvis spontanta strukturer som försöker tillfredställa båda delarna genom att samtidigt exponera eller gömma dem från vattenmolekyler. En potentiell tillämpning av PNIPAAM65-b-PAMPTMA20 är att<br /> transportera vatten-olösliga läkemedel i sin hydrofoba del och det som gör polymerer av denna typ extra lovande för denna tillämpning är dess låga giftighet och dess temperaturkänslighet (mer korrekt termoresponsibilitet) i närheten av kroppstemperatur, vilket ger möjligheten att släppa ut dess innehåll vid en specifik plats eller tidpunkt som kan vara viktig för tillämpningen.<br /> <br /> Gallsalter kallas ibland för kroppens tvättmedel och är små amfifila molekyler som finns i gallan hos däggdjur och andra ryggradsdjur och är ansvariga för att transportera vatten-olösliga ämnen som vitaminer och fettsyror i kroppen vilket är viktigt för metabolismen (ämnesomsättningen) av dessa. Gallsalter är negativt laddade och kan tänkas interagera med polymerer som PNIPAAM65-b-PAMPTMA20 och bilda specifika strukturer som påverkar varandras funktion, därför är det viktigt att undersöka den här sortens system. I det här arbetet undersöks dessa strukturer med hjälp av ljusspridnings- och kalorimetriska tekniker för att öka förståelsen för dessa system. 2018 eng physical chemistry thermoresponsive polymers PNIPAAM neutral-ionic block copolymers bile salts light scattering differential scanning calorimetry Chemistry 8933150 2018-01-19T13:31:35+01:00 2018-02-01T11:27:38+01:00 2018-02-01T11:27:38+01:00

oai:lup-student-papers.lub.lu.se:8933301 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ayesha Kanwal author 8931139 Magnus Johnson supervisor Department of Chemistry v1000647 department An efficient method for selective alpha-alkylation of ketones with alcohols was developed using<br /> 2-hydroxypyridine-based ligands coordinated by palladium as pre-catalysts. The reactions were<br /> performed without additional additives under mild reaction conditions. The method is<br /> environmentally friendly to build C-C bond as water is the only byproduct. This tandem reaction<br /> proceeds via dehydrogenation reaction, aldol condensation and hydrogenation processes using<br /> hydrogen borrowing from the alcohols. The pre-catalyst was characterized by NMR, IR and XRD.<br /> Time profile study investigated by NMR and GC. In certain parts of chemistry, it is important to be able to design organic molecules so that they<br /> have exactly same structure that you are looking for. C-C bond formation is very important<br /> reaction in synthesis of products such as pharmaceuticals, natural products, agrochemical and in<br /> the plastics industry. There are variety of organic reactions that can be used to couple and build<br /> molecules differently.<br /> Recently, there has been great interest in using alcohols as starting materials for C-C bond<br /> formation processes. As they are less toxic, cheap, environmentally friendly. Alcohols are readily<br /> available alkylating agents however they are unreactive as alkylating agents because hydroxy<br /> group cannot be easily replaced by nucleophilic reagents. The common ways to convert alcohols<br /> to carbonyl compounds is by using wide range of oxidizing agents in stoichiometric and over<br /> stoichiometric amount by using metal oxides or metal salts for oxidation. These procedures<br /> produce heavy metal waste that is not compatible with environmental regulations. Therefore,<br /> the search for environmentally friendly, selective, and efficient methods is a great challenge for<br /> chemists. Metal catalyzed dehydrogenation or oxidative dehydrogenation have been found an<br /> interesting alternative. Catalysis has become one of the cornerstones in organic synthesis, as it<br /> increases the rate of a chemical reaction, theoretically without being consumed itself. This occurs<br /> by lowering the activation energy compared to uncatalyzed reaction.<br /> Transition metal catalyzed cross coupling reaction between alcohols and ketones is attractive<br /> strategy for alpha alkylation of ketone. 2-Hydroxy pyridine ligands have been found to catalyze<br /> hydrogenation and dehydrogenation reactions. Therefore, the aim of the project is to prepare 2-<br /> hydroxy pyridine and quinoline ligands then coupled with palladium chloride to study<br /> hydrogenation and dehydrogenation reactions between alcohols and ketones. An advantage of<br /> this reaction is it follows borrowing hydrogen approach for α-alkylation of benzyl alcohol with<br /> acetophenone and produces water as only byproduct which is in accordance with green<br /> chemistry. The reaction is proceeding via hydrogen transfer strategy and alcohols are source of<br /> hydrogen.<br /> The reactions were performed without additional additives under mild reaction conditions using<br /> KOtBu, 1-Pd catalyst in toluene at 120oC for 48 hours under nitrogen in carousal. The reaction<br /> proceeds via dehydrogenation reaction, aldol condensation and hydrogenation processes using<br /> hydrogen borrowing approach. https://lup.lub.lu.se/student-papers/record/8933301/file/8933304.pdf application/pdf 2051136 no 2017 eng Hydrogen Borrowing in activation of alcohols Palladium in Catalysis hydrogenation and dehydrogenation reactions hydrogen borrowing concept for hydrogenation and dehydrogenation reactions 2-hydroxyquinoline Ligand 2-hydroxy pyridine ligands inorganic chemistry oorganisk kemi Chemistry 8933301 2018-01-20T17:14:47+01:00 2018-02-01T11:40:22+01:00 2018-02-01T11:40:22+01:00

oai:lup-student-papers.lub.lu.se:9014949 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 David Wahlqvist author 9012574 Martin Ek supervisor Centre for Analysis and Synthesis v1000651 department This thesis aims to explore how the reduction of iron oxide by hydrogen should be explored in an environmental transmission electron microscope (ETEM). This is done by performing a series of reduction attempts in the ETEM at nCHREM, Lund University, and exploring how the ETEM conditions are different from those used commercially. Various reduction parameters are explored, the presence of water vapour, the hydrogen pressure, the temperature, the effect of the electron beam, the presence of contaminants, and the effect of the silicon nitride film that the sample is mounted on. The reduction results are inconclusive since full reduction is not obtained without the presence of gallium in the reduction. It is indirectly shown that gallium can potentially aid in the reduction of iron oxides. It is concluded that ETEM studies of iron oxide reduction can be applied in industrial processes if some considerations are taken into account. Svårigheterna med att se reduktion av järnoxid med vätgas på atomnivå<br /> <br /> Jag har undersökt hur järnoxid omvandlas till järn med hjälp av vätgas. Detta gjordes i ett elektronmikroskop för att kunna följa hur atomstrukturen förändras under processens gång. I mikroskopet är dock trycket lågt och elektronstrålen tillför stora mängder energi. Jag undersökte dessa begränsningar med flera och visar i rapporten vad som krävs för lyckade studier i framtiden.<br /> <br /> Forskningen idag tittar på olika metoder att lagra energi, bland annat genom att använda järnpulver. Metoden innebär att energin lagras i järnpulver och när den behövs låter man järnpulvret oxidera, det rostar och omvandlas till järnoxid, vilket skapar värmeenergi. När det finns ett överskott av energi kan järnoxiden återigen reduceras till järnpulver. Men för detta behöver man förstå hur järnoxid reduceras och omvandlas till järn. <br /> <br /> I mitt examensarbete, &quot;Reduction of iron oxide by hydrogen studied using environmental transmission electron microscopy&quot; undersökte jag reaktionen där järnoxid bildar järn. Detta gjordes i en vätgasmiljö med varierande tryck mellan 0.1 Pa och 120 Pa (ca en miljondel och en tusendel av atmosfärstrycket) samt med temperaturer mellan 500 \degree C och 800 \degree C. Reaktionen kunde observeras vid höga tryck vid olika temperaturer, men inte vid lägre tryck. Jag såg även hur elektronstrålen och kontamineringar i provet påverkade processen. För att kunna utföra vidare studier krävs det att påverkan från elektronstrålen och effekten från kontamineringar minimeras.<br /> <br /> I energilagringsmetoder som använder järnpulver görs oxidationen enklast genom att utsätta järnet för syre, antingen i form av ren syrgas, vanlig luft eller vatten. Reduktionen har traditionellt gjorts med kolmonoxid, men då den reduktionen producerar koldioxid är det inte en lämplig väg att gå. Istället kan vätgas användas för att reducera järnoxiden, då produceras enbart vatten som restprodukt. Vätgas kan dock ha andra effekter på järnoxidprovet och för att kunna undersöka dessa effekter behöver vi veta hur provet beter sig under flera sådana reduktion/oxidation cykler. Detta kan bland annat göras genom att observera hur materialet och dess struktur förändras under reaktionens gång.<br /> <br /> Då vanlig ljusmikroskopi är otillräcklig för att kunna se så små mikrostrukturella förändringar som vi är ute efter, använde jag istället ett så kallat transmissionselektronmikroskop (TEM). Detta fungerar genom att en elektronstråle passerar genom ett prov och interagerar med det. Från dessa interaktioner kan en bild skapas där mikrostrukturer i provet kan ses. Om man tillsätter olika gaser in i TEM:et, som vanligtvis fungerar i vakuum, så kan det skapas en reducerande eller oxiderande atmosfär vilket möjliggör den ovan nämnda cykeln. Det finns dock en del begränsningar med TEM. Trycket måste hållas lågt, provet måste placeras på en yta som kan i sig ha påverkan på provet, det finns kontamineringar från andra metaller, och elektronstrålen tillför energi in i systemet. https://lup.lub.lu.se/student-papers/record/9014949/file/9015085.pdf application/pdf 19556222 no 2020 eng Transmission Electron Microscopy Electron Diffraction Iron Oxide Reduction Iron Environmental Transmission Electron Microscopy ETEM Materials chemistry Materialkemi Chemistry https://lup.lub.lu.se/student-papers/record/9014949/file/9015087.pdf application/pdf Popular summary in swedish for the master's thesis of David Wahlqvist no This thesis is funded by the Swedish Research Council (Vetenskapsrådet) 9014949 2020-06-09T11:25:24+02:00 2020-06-12T17:11:34+02:00 2020-06-12T17:11:34+02:00

oai:lup-student-papers.lub.lu.se:9015858 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Anna Heiling author 9015856 Marie-F Gorwa-Grauslund supervisor Celina Borgström supervisor Applied Microbiology v1000654 department Saccharomyces cerevisiae is a commonly used industrial organism which cannot consume xylose naturally. This is a problem since xylose is a major component in renewable resources, for instance lignocellulose. The Weimberg pathway is a pathway that converts xylose into α-ketoglutarate. It has been successfully integrated into S. cerevisiae, enabling it to utilize xylose. The successful strain had the genes xylB, xylD, xylX (from Caulobacter crescentus) and ksaD (from Corynebacterium glutamicum) integrated with one copy of xylB and four copies of each of the others. In addition, the strain had the iron regulon repressor gene, FRA2, deleted to enhance the activity of the XylD enzyme. <br /> <br /> In the present master thesis project, the aim was to find the optimal number of copies of the genes xylB, xylD, xylX and ksaD as well as what enzyme activities that are needed for the pathway to be functional. This was done by creating a pallet of strains that contained different copy numbers of the genes, using CRISPR/Cas9. Enzyme activity was measured before further analysis of biomass formation and metabolite production.<br /> <br /> It was found that TMB CB 016 (xylB, xylD, 4x(xylX, ksaD)) had an activity in the coupled assay, measuring the activity of XylD, XylX and KsaD together. However, due to the problems with the assay the results are unreliable and need to be further investigated. The constructed strains did not grow as well as the original strain with the functional Weimberg pathway, nor were any of them able to consume xylose. Trying to optimize the consumption of xylose in baker’s yeast<br /> <br /> Baker’s yeast can not consume xylose naturally, but the Weimberg pathway has made it possible. This master thesis focuses on optimization of the Weimberg pathway for an optimal xylose consumption. <br /> <br /> The world is becoming more sustainable. This includes the industries that are interested in using sustainable and renewable carbon sources in the production of chemicals. One of the promising renewable sources is called lignocellulose and it contains a high percentage of the sugar xylose. Baker’s yeast or Saccharomyces cerevisiae is a commonly used industrial organism, but it cannot consume xylose and instead prefers the sugar glucose. This means that if for example lignocellulose is used as the substrate, a major part of this cannot be used by the yeast. <br /> <br /> Therefore, it is of great interest to make baker’s yeast able to consume xylose. This has successfully been done by introducing the Weimberg pathway into the yeast. The pathway consists of four enzymes called XylB, XylD, XylX and KsaD. These enzymes convert xylose into a compound called α-ketoglutarate that can be converted into a variety of chemicals. Introducing the pathway into the yeast means that the yeast obtains genes that work as a template for producing the four enzymes. What is interesting now is to optimize the pathway to make the yeast consume xylose in the most effective way.<br /> <br /> In the present master thesis project the goal was to optimize the Weimberg pathway. This was achieved by looking at the number of copies of the genes coding for the four enzymes in the Weimberg pathway. A pallet of strains was constructed with different copy numbers of the genes. The strains were constructed using the engineering tool CRISPR/Cas9, which can make specific cuts in the genome and paste the gene of interest.<br /> <br /> Once the strains had been constructed enzyme activity was measured. The enzyme activity of the enzymes XylD, XylX and KsaD were measured together. It was shown that one strain had higher activity of these enzymes than the existing strain with a working Weimberg pathway. This was very promising since that would mean that the pathway most likely worked in this strain and possibly perform even better than the existing working strain.<br /> <br /> Unfortunately, the constructed strains grew poorly and none of them were able to consume any xylose. It is difficult to say if this is due to their poor growth or due to the Weimberg pathway not working (wrong copy numbers of the genes).<br /> More research is needed, starting with constructing strains with better growth. It is of special interest to investigate the strain that had higher enzyme activity than the existing working strain. Progress in this area may contribute to a more sustainable, efficient and profitable use of for example lignocellulose in the industry. https://lup.lub.lu.se/student-papers/record/9015858/file/9015867.pdf application/pdf 1525990 no 2020 eng Yeast Weimberg pathway xylose consumption Applied Microbiology Teknisk mikrobiologi Chemistry Technology and Engineering 9015858 2020-06-10T14:24:23+02:00 2020-06-12T17:15:44+02:00 2020-06-12T17:15:44+02:00

oai:lup-student-papers.lub.lu.se:9016821 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Viktor Geraldsson author 9016819 Anton Löfgren supervisor Matthias Josef Beier supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department To utilize sugars as a feedstock for renewable industries, the feedstock often needs to be very pure. This is due to ionic species contaminating the sugar feedstock being potent catalyst poisons in many cases. To remove ionic species from the sugar feedstock, it is dissolved and purified using packed ion-exchange columns. In this report, a lab-scale setup of a large scale ion-exchange setup was constructed. The system was then modelled using Matlab. The goal was to produce a lab-scale setup that in theory operates similarly to the large setup and develop a model that can predict the behaviour of the system. The feed sugar content was varied using glucose, the range of glucose concentrations tested were 0, 10, 30, and 50 wt% glucose. The feed linear flow velocity was also varied, the flows studied were 0.65, 1.3 and 2.6 m/h respectively. <br /> To simulate the kinetics of adsorption of ionic species to the resin, the equilibrium adsorption isotherm was measured experimentally. Both the temperature effect and the effect of different glucose concentrations in the liquid was studied. It was found that lower temperatures favoured the resin performance at higher glucose temperatures and higher glucose concentration had a negative effect on the resin performance. <br /> As the isotherm had been determined for the different glucose concentrations, experimental data of the lab-scale setup was compared to model simulations. The model shows promise in emulating the experimental setup. The experimental setup does however need more work to raise reproducibility of the setup which has been a major issue throughout. Skalning och modellering av en kromatografikolonn för rening av sockerlösningar. <br /> För att uppnå klimatmålen behöver fossila råvaror inom kemiindustrin bytas ut mot förnybara råvaror. Socker är en råvara med stor potential inom industrin, men är ofta förorenat med salter. Därför utforskas rening av sockerlösningar här.<br /> För att använda socker som förnybar råvara för kemiindustri behöver sockret ofta vara mycket rent. Detta är på grund av att salter och andra orenheter i sockret ofta är mycket starka katalysatorgift. För mycket salt i inflödet till en process kan därför förstöra katalysatorn och därmed hela processen. För att rena sockret från salter löses det upp och renas med jonbytarkromatografi. Jonbytarkromatografi som process fungerar genom att pumpa en förorenad vätska genom en kolonn. Kolonnen innehåller en bädd av fast packningsmaterial med speciella platser där föroreningarna kan fästas på. Packningsmaterialet tar då upp föroreningarna ur vätskan, men låter resten av vätskan passera och på så sätt kan man få en mycket ren vätska som produkt. <br /> I denna rapport konstruerades en labbskalad variant av en existerande storskalig jonbytarkolon. Processen simulerades även med hjälp av datorverktyg. Målet var att producera en enhet på labbskala som i teorin producerar jämförbara resultat som den storskaliga enheten och sedan utveckla en modell som kan förutspå hur systemet beter sig. Frågeställningen var följande: Kan en labbskalad variant av reningsprocessen konstrueras och kunde den ge rimliga resultat? Kan processen modelleras med datorverktyg och vilka effekter har olika parametrar på processens beteende? <br /> Fördelar med att ha en labbskalad variant av en processenhet gentemot att endast ha en storskalig process är flera. Mängden tid, arbete och resurser som krävs för att utföra tester minskar drastiskt med storleken på uppsättningen. Om man sedan går ett steg längre och bygger en simuleringsmodell av uppsättningen, så kan försök utföras på mycket kortare tid än möjligt i labbet och kostnaden per experiment är försumbar. Med en pålitlig modell kan man snabbt ta reda på hur en process ska drivas för bästa resultat. I denna studie undersöktes hur sockerinnehållet hos vätskan och flödeshastigheten genom kolonnen påverkade processens beteende. <br /> För att bygga en modell för systemet behövdes data för både hur packningsmaterialet och kolonnen beter sig. Packningsmaterialet tog upp färre föroreningar både med högre sockerhalt i vätskan och vid högre temperaturer. Även kolonnen visade sig prestera sämre vid högre sockerhalter hos vätskan. Med experimentella data kunde modellen utformas och resultat från experiment kunde återskapas med framgång. Kolonnen och modellen visade båda jämförbara resultat även om flödeshastighet och sockerhalt på vätskan varierades. https://lup.lub.lu.se/student-papers/record/9016821/file/9016825.pdf application/pdf 1500270 no 2020 eng Ion-exchange chromatography glucose purification modelling equilibrium isotherm Matlab chemical engineering kemiteknik Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/9016821/file/9016827.pdf application/pdf no 9016821 2020-06-11T20:39:21+02:00 2020-09-14T09:49:04+02:00 2020-09-14T09:49:04+02:00

oai:lup-student-papers.lub.lu.se:9018321 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 David Pålsson author 9018319 Tommy Nylander supervisor Polina Naidjonoka supervisor Mathematical Statistics v1000668 department Department of Chemistry v1000647 department Cubosomes are nanoparticles that are prepared by dispersing a liquid crystalline cubic phase. Typically, the cubosomes are stabilized by copolymers to prevent the colloids from aggregating. In this thesis galactoglucomannans (GGM) from softwood was evaluated as a stabilizer for monoolein cubosomes and triolein emulsions.<br /> Galactoglucomannans are the most abundant hemicellulose in softwood and have previously been tested as a stabilizer of emulsions, due to its similarities with commercially used stabiliser such as guar gum. The use of GGM as a stabilizer is a possible new use for materials from biorefineries. <br /> Here, triolein emulsions were prepared with two different GGM samples. The stability of the emulsions over 12 weeks were evaluated with DLS measurements. Cubosomes of monoolein stabilized with three different types of GGM was prepared and the obtained cubosomes were examined with SAXS and Cryo-TEM. The stability of the cubosomes were evaluated with zeta potential measurement and a six-week storage tests where the size development was measured by DLS. Ellipsometry was also performed on the cubosomes stabilized with GGM and cubosomes prepared without any stabilizer, and the results were compared. The cubosome stability in phosphate saline buffer over a four-hour period was also evaluated.<br /> The results showed that the emulsions stayed relatively stable over 12 weeks of storage, with some creaming. The SAXS showed that cubosomes with Pn3m structure were formed. The zeta potential and the stability measurements of the cubosomes showed that cubosomes were quite stable. The ellipsometry data and buffer stability measurement were not unambiguous, but from the combined results it was concluded that GGM could be used to stabilize cubosomes. The difference in stabilizing properties between the GGM samples used are discussed. Kubosomer är nanopartiklar där den inre strukturen är uppbyggd av ett dubbellager av fettmolekyler som omsluter en tredimensionell struktur av vattenkanaler. Denna unika struktur gör att nanopartiklarna kan lastas med hydrofoba, hydrofila och amfifila molekyler. Detta gör dem lovande för bland annat läkemedelsadministration. Kubosomer är i sig själva inte kolloidalt stabila utan aggregerar i en vattenlösning. För att motverka detta tillsätter man stabilisatorer. Dessa är ofta polymerer med en hydrofob och en hydrofil del. Den hydrofoba delen adsorberas på ytan av kubosomerna, medan de hydrofila delarna sticker ut i vattenlösningen. De hydrofila delarna hindrar kubosomerna från att komma för nära varandra och aggregera, vilket kallas steriskt stabilisering.<br /> Hemicellulosa är en grupp av polysackarider som tillsammans med cellulosa och lignin utgör de huvudsakliga komponenterna i trä. Den vanligaste typen av hemicellulosa i barrträd är galactoglucomannan (GGM). Flera polysackarider med liknande struktur som GGM används som stabiliserings- och förtjockningsmedel inom livsmedelsindustrin. Mest känd är troligen gummi arabicum. GGM har använts i ett par studier som stabiliseringsmedel av emulsioner.<br /> I detta arbete undersöktes huruvida GGM kan användas som stabilisator för emulsioner av triolein och vatten och för kubosomer av monoolein. Stabiliteten för emulsionerna och kubosomerna mättes med dynamisk ljusspridning (DLS). Kubosomerna undersöktes därutöver med Small Angle X-ray Scattering (SAXS) och cryogenic Transition Electron Microscopy (Cryo-TEM). Resultatet visade att det går att stabilisera emulsioner och kubosomer med GGM. Kubosomerna var stabila i en vattenlösning i minst sex veckor, medan emulsionerna visade tecken på gräddning och flockuering under de 12 veckor som stabiliteten undersöktes.<br /> Skillnader i stabiliserande förmåga mellan de prover av GGM som användes, samt möjligheten att lignin bundet till GGM förbättrar GGM som stabilisator för kubosomer diskuteras. https://lup.lub.lu.se/student-papers/record/9018321/file/9021337.pdf application/pdf 1892855 yes 2020 eng physical chemistry cubosomes emulsions galactoglucomannans fysikalisk kemi Chemistry 9018321 2020-06-15T13:19:24+02:00 2020-07-06T10:30:55+02:00 2020-07-06T10:30:55+02:00

oai:lup-student-papers.lub.lu.se:9018475 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Edit Jonsson author 9018473 Professor Per Uvdal supervisor Mathematical Statistics v1000668 department Department of Chemistry v1000647 department Melanin is a group of pigments present in almost all kingdoms of life. It has many interesting properties such as high fossilizing potential and the ability to chelate metals. The binding of metal ions is believed to have two major functions within biological systems: metal reservoir and metal scavenger. However, eumelanin’s chemical structure is still unknown and there is a knowledge gap regarding the enrichment and coordination of metals. Furthermore, due to the preservation of the pigment’s chemical properties over hundreds of millions of years, it is potentially possible to extract information about animals and their life via spectroscopic methods. In this study we investigated eumelanin extracted from Sepia officinalis doped with Cu(II)- and Zn(II)-ions, and the possible metal content in eumelanin from a Jurassic fossil (Loligosepia), with the aim to learn more about the structure and binding sites of copper and zinc. In order to shed light on the binding properties of metals in different kinds of eumelanin we applied x-ray absorption spectroscopy. Our results indicate that the present porphyrin-ring-based model of eumelanin, is insufficient and that divalent zinc has at least two binding sites. In addition, we concluded that synthetic eumelanin is not a good representative for natural eumelanin. Apart from this we found that copper was present in the ancient pigment and therefore the method can be applied to identify the presence of metals in fossils. Melaniner är en grupp pigment som förekommer hos en rad olika organismer tillhörande växter, djur och bakterier. Människor har melanin i huden, vilket skyddar mot solens farliga UV-strålning, men även i ögonen, hjärnan, inneröronen, håret, och i vissa organ. Melaniner kan delas upp i eumelanin, som har en brun till svart färg, och feomelanin, med en gul till röd färg. Det är bland annat andelen av eumelanin och feomelanin som avgör vilken hårfärg man har. <br /> <br /> Förutom att skydda mot farlig strålning så har melaniner också i uppgift att binda metalljoner som kan skada kroppen (tex koppar), och fungera som en reservoar för metaller som är viktiga i kroppen, (tex zink). Melaninet som finns hjärnan har bland annat i uppgift att reglera järnbalansen och tros ha en koppling till Parkinsons sjukdom. Hur de olika metalljonerna binder in till melanin är dock fortfarande okänt. <br /> <br /> Man vet fortfarande inte hur melaninernas molekylära strukturer ser ut, trots att de är så allmänt förekommande. Detta kommer sig av att de har en rad olika kemiska och fysikaliska egenskaper som gör det svårt att utföra mätningar på dem. Tidigare har forskare på teoretisk väg hittat ett förslag på en molekylär struktur för eumelanin, innehållande en så kallad porfyrin-liknande ring, bestående av fyra kväveatomerna. En annan väg som flertalet andra forskare tagit, för att lära sig mer om pigmentet, är att på syntetisk väg försöka tillverka eumelanin. Det har dock varit okänt hur väl naturligt och syntetiskt eumelanin stämmer överens. <br /> <br /> En tredje användbar metod är röntgenabsorption-spektroskopi. Där skjuts röntgen-strålar med olika energier på provet så att vissa elektroner exciteras. Eftersom elektronerna bara kan ha vissa energier kommer ljuset som absorberas motsvara skillnaderna i energinivåerna som elektronerna kan ha. Alltså kan man få veta mer om molekylen utifrån absorptionsspektrumet. Denna metod användes i vår studie för att lära oss mer om eumelanin, både om dess struktur och dess inbindning av metaller. <br /> <br /> Vi mätte på eumelanin i bläcket från bäckfiskarten sidensepia, och även på eumelanin där koppar- och zinkjoner tillsatts. Spektrumen från mätningarna jämfördes med referensmolekyler med en känd struktur, liknande förslaget innehållande en porfyrin-liknande ring. Från dessa mätningar kunde vi dra slutsatsen att den förslagna molekylstrukturen inte stämmer, samt att syntetiskt eumelanin inte är en bra modell för naturligt eumelanin. Dessutom visade mätningarna att zinkjoner bindas in på åtminstone två olika ställen i eumelanin varav ett är till syreatomer. Kopparjoner visade sig däremot binda till kolatomer. Dessa nya kunskaper kan ses som ett steg för att förstå den biologiska funktionen av eumelanin, vilket på sikt kan användas för att behandla melanin-relaterade sjukdomar, så som Parkinson. <br /> <br /> En annan mycket intressant egenskap hos melanin är att det har en hög fossiliseringspotential, vilket leder till att pigmentet kan behålla sina kemiska egenskaper under flera hundra miljoner år. Det kan jämföras med DNA som högst bevaras i några hundra tusen år. Mätningar på fossilt melanin kan därför användas för att få reda på mer om djur som levde för mycket länge sedan. Vi utförde mätningar på koppar i fossilt eumelanin från en 180 miljoner år gammal bläckfisk. Mätningarna visade att koppar är närvarande, och att det möjligtvis binder på samma sätt som i modernt eumelanin. Denna upptäckt öppnar för möjligheten att använda röntgenabsorptionsspektroskopi som metod för att ta reda på mer om metallinnehållet i fossilt melanin. Kunskaperna om detta skulle till exempel kunna användas för att lära sig om enskilda djurs levnadsätt, hitta släktskap mellan arter och förstå melaninets evolution bättre. Om mätningarna dessutom skulle utföras på fossiler från olika tidsåldrar finns det potential att förstå förändringar i jordens klimat bättre. 2020 eng Ancient melanin Eumelanin NEXAFS Pigment Soft x-ray spectroscopy Trace metals Chemical Physics Kemisk fysik Chemistry 9018475 2020-06-15T15:48:14+02:00 2020-06-18T13:04:14+02:00 2020-06-18T13:04:14+02:00

oai:lup-student-papers.lub.lu.se:9019015 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Sofia Lindström author 9019013 bitr. universitetslektor Baozhong Zhang supervisor Marcel Ollila supervisor Centre for Analysis and Synthesis v1000651 department The project’s main goal was to develop an understanding of how to gain a higher deep cure of UV-curable waterborne polyurethane dispersions for pigmented systems. Specifically, the project studied and concluded that radicals from oxidation of 1.3-4 wt-% of unsaturated fatty acids in the dry film can initiate radical polymerisation of acrylate groups.<br /> Polyester polyols containing 0, 5, 10 and 15 wt-% of either linseed or soybean fatty acids were synthesised, resulting in number average molecular weights between 1325-1470 g/mol measured with gel permeation chromatography. Varying combinations of the polyesters were used to make UV-curable acrylate functional polyurethane dispersions, which in turns were used to make coatings with 0.002-0.013 wt-% Mn(III)-acetylacetonate catalyst, 0.0095-0.03325 wt-% Dragon ligand (1,4,7-trimethyl-1,4,7-triazacyclononane), with and without pigments, and with and without photo initiators, depending on whether the coating was UV-cured or not. Both the oxidatively cured and the UV-cured coatings were held in 40°C, making the UV-cured coatings UV/oxidative dual-cured. Models of the measured chemical resistances to ethanol and coffee, the surface and deep cure, the pendulum hardness, the impact resistance, and the scratch resistance were created using a statistical software called Design-Expert 12.<br /> The conclusions are that around 10-15 wt-% of fatty acids, a mid-range to high wt-% of both catalyst and Dragon, in combination with oxidative curing alone give the highest curing degrees for the pigmented systems. No unequivocal difference was seen between linseed and soybean fatty acids. Although the curing degrees achieved are not high enough for high-performance applications, the project shows that radicals from oxidation reactions can give a second curing mechanism. Oxidative curing at higher temperatures than 40°C appears to give higher curing degrees, altogether indicating that sufficiently high deep cure might be achieved using this technique if the compositions are further adjusted in combination with using higher curing temperatures. How could a high performance be obtained in pigmented UV-curing coatings when the pigments absorb all or parts of the UV-radiation? A possible route investigated in this project is to combine oxidation of unsaturated fatty acids with the reactions found in UV-curing coatings.<br /> Coating materials are found on many different objects, for example floors, chairs, ceramics, airplanes, and cars. The coatings should therefore have different performances depending on the application of the objects. However, it can be said that the main purpose of a coating material is to produce a both protective and decorative film of an object, giving the object longer lifetime and better-looking surface. To produce this protective film of an object, the coating material must be cured in some way.<br /> A common industrial way to achieve curing of a coating material is to use UV-radiation to initiate the curing reactions of so-called acrylate groups. The acrylate groups are usually found in the polymers that the coating mainly consists of. During the curing reactions, the polymers are crosslinked, which means that they are reacting with each other to form a coherent network. Generally, a highly crosslinked polymer network gives a high performance of the coating. Clear and white coatings on objects with simple geometry are usually fully cured when subjected to UV-radiation. But this is unfortunately not the case for neither pigmented coatings nor for coatings applied on objects with shadowed zones that the UV-radiation cannot reach.<br /> As is commonly known, pigments absorb light and UV-radiation, giving poorly cured coatings and therefore poor performance too. This becomes a problem when a UV-curable coating must have a high performance while at the same time be pigmented. A kitchen cabinet door is an example of such application. The door must withstand not only everyday chemicals used, for example coffee and ethanol, but also other stress factors as for example scratches and impact forces. So, how do we overcome the problem with insufficient UV-curing?<br /> Oxidation of unsaturated fatty acids is used in air drying alkyd paints, for example the paint normally used for houses. An idea of how to achieve high curing of pigmented coatings is to combine air drying with UV-curing. If these two types of curing techniques could be combined, a moderate cured coating could be achieved instantly by subjection to UV-radiation while the rest of the curing could occur with time, continuously initiated by the oxidation of the fatty acids.<br /> This project investigated and concluded that oxidation of unsaturated fatty acids from linseed oil and soya beans can initiate the curing reactions of the acrylate groups found in the polymers of a coating material. Although the required high performances and high curing were not achieved, the project could be a first step towards further investigations of the potentials in combining the techniques used in UV-curing and in air drying. The project also opens up for using an additional curing technique by investigating the positive effect of drying at higher temperatures. https://lup.lub.lu.se/student-papers/record/9019015/file/9019018.pdf application/pdf 4150252 yes 2020 eng Polymer technology Polymerteknologi Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/9019015/file/9019023.pdf application/pdf no 9019015 2020-06-16T13:13:28+02:00 2020-06-18T13:03:19+02:00 2020-06-18T13:03:19+02:00

oai:lup-student-papers.lub.lu.se:9019067 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Pol Mestres author 9019062 Charlotta Turner supervisor Margareta Sandahl supervisor Barbara Socas Rodriguez supervisor Daniel Molins Delgado supervisor Department of Chemistry v1000647 department Introduction: This study is focused on the development and comparison of different extraction methods for vitamin D (VD) analysis in liver samples.<br /> Background: VD deficiency is related to several diseases, so it is crucial to correctly detect and quantify its concentration in the human body. Despite the existing methodologies for VD analysis, the selectivity and the sensitivity of the methods for its analysis in biological samples should be improved. Also, to the best of our knowledge, there is no method that allows determining both types of VD metabolites – alcohols and esters – at the same time, especially there is no method in the literature that lets the esters to be detected.<br /> Aim(s): The aim of this study is to compare different extraction methods to find the most reachable and the greenest option for the analysis of VD and a group of VD metabolites in liver samples and to optimize the conditions of their extraction.<br /> Methods: Folch method, ultra-high pressure supercritical fluid extraction (UHPSFE) and dispersive liquid-liquid microextraction (DLLME) will be tested and optimized by using statistical design of experiments (DoE) prior to analysis by ultra-high performance supercritical fluid chromatography – triple quadrupole tandem mass spectrometry (UHPSFC-QqQ-MS/MS). The most suitable methodology will be validated.<br /> Results: Folch method and DLLME were optimized obtaining a non-valid model for the DLLME and a good one for Folch extraction, but with non-significant recovery values for ester metabolites and low ones for vitamin forms. UHPSFE appears to be the most suitable methodology, according to initial experiments, but further experiments should be carried out to confirm it . A solubility test using different solvents and gravimetric experiments showed that matrix effects are important and that classical Folch method and 2-propanol seem to be the best<br /> options for extracting the target analytes.<br /> Conclusion: Folch, DLLME and UHSFE have been combined with UHPSFC-QqQ-MS/MS for the evaluation of ten VD analogues in liver samples. <br /> Results for ester metabolites and vitamin D3 and D2 are still not satisfactory and should be improved. More experiments should be done to find the most suitable approach for the analysis of the VD compounds. Comparison of different extraction methods for the analysis of vitamin D analogues in liver samples.<br /> Vitamin D (VD) deficiency is related to several diseases, so it is crucial to correctly detect and quantify its concentration in the human body. One of the most challenging parts in the analysis of VD in biological samples is to extract the compounds, due to the complexity of these kinds of samples, as well as the low levels of concentration at which VD analogues are present in it, that required the application of very sensitive and selective techniques. Despite the existing methodologies for VD analysis, the existing methods for its analysis in biological samples should be improved.<br /> The aim of this study is to compare different extraction methods to find the most suitable and the greenest option for the analysis of VD and its metabolites in liver samples. Finally, the parameters that can affect the extraction efficiency will be determined, studied and optimized.<br /> Different methods were tested and the expected results were not obtained, especially because of the low extraction yield achieves for some of evaluated compounds including the ester metabolites and VD2 and VD3. On account of that, a backward step was done and some experiments were performed to study the viability of VD compounds extraction by using<br /> different solvents. Classical Folch (i.e., a liquid-liquid extraction method using a mixture of chloroform with methanol and water), 2-propanol, acetone and acetonitrile were found as the most suitable options for extracting the target substances. Moreover, some gravimetric<br /> experiments were done in order to study how much fat was extracted from the liver alongside the VD compounds depending on the solvent used. This study was carried out taking into account the hypothesis that the more fat is extracted, the more analytes akin to fat would be<br /> extracted (these kinds of analytes were the ones that showed the worst results when extracting VD from liver samples). These experiments indicated that mixture of chloroform and methanol and 2-propanol are the best options for analyzing the desired compounds, as with these two<br /> solvents the highest amount of fat was extracted.<br /> More experiments should be done in order to find the most reachable approach to extract these compounds from the liver samples. However, this study constitutes the first step to recognize those parameters that have a remarkable effect on the extraction of vitamin analogues from such complex matrices. 2020 eng analytical chemistry green extraction techniques liver mass spectroscopy supercritical fluid chromatography vitamin D analytisk kemi Chemistry 9019067 2020-06-16T14:43:02+02:00 2020-06-18T17:21:05+02:00 2020-06-18T17:21:05+02:00

oai:lup-student-papers.lub.lu.se:9019180 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Sandra Larsson author 8957190 Emma Sparr supervisor Department of Chemistry v1000647 department Computational Chemistry v1000659 department The keratin structure and mobility of protein and lipid components in keratinous materials, and the changes in these properties upon hydration and addition of osmolytes affects the mechanical properties and permeation of skin, hair and nails. <br /> In this thesis, the effect of hydration and the addition of solvents and an osmolyte on the structure of keratin filaments and on the mobility of protein and lipids in nails and hair was studied. PT ssNMR was used to study the mobility of amino acid and lipid segments in hair and nails. No increase in the mobility of amino acid segments in either hair or nails was noted for any of the additives, including water. An increase in the mobility of lipid segments in both hair and nails was observed at additions of water or ethanol. SAXS and WAXS measurements showed structural changes in keratin filaments at hydration and addition of ethanol and acetone. The changes in molecular structure and dynamics in hair and nails were compared to experiments on SC and close similarities were found in the changes in lipid mobility and keratin structure. Hair and nail amino acids were determined to be more rigid than SC amino acids. Hud, hår och naglar är utåt sätt olika, men på en mikroskopisk nivå är likheterna stora. Det översta lagret av hud, som kallas stratum corneum, hår och naglar består av döda celler till mestadels fyllda av proteinet keratin. Keratinet i dessa celler bildar cylindriska strukturer; keratinfilament, som består av flera keratinkedjor. Denna uppbyggnad ger materialen både styrka och flexibilitet. Lipider, en typ av molekyler som är olösliga i vatten, finns också i hud, hår och naglar. Dessa finns mellan de keratinfyllda cellerna och framförallt i huden bildar de flera lager av många lipidmolekyler. Vatten och många andra molekyler har svårt att tränga igenom dessa lipidlagren vilka fungerar som en barriär så att vi människor inte ska ta in eller tappa för mycket vatten och så att vi inte ska ta in skadliga ämnen genom huden. De keratinfyllda cellerna fungerar också som ett hinder för olika molekyler att tränga igenom. I naglar och hår, som inte har en lika stor andel lipider som huden, är keratinbarriären kanske ett ännu viktigare hinder.<br /> <br /> I de flesta fall är det önskvärt för människan att det är svårt att tränga sig igenom huden, naglarna eller håret. Men när man vill leverera läkemedel genom naglar för att bota nagelsvamp, eller smörja huden med krämer för att motverka torrhet eller behandla eksem, måste man få molekylerna i läkemedlen att passera dessa hinder och tränga genom materialen till ställena de ska verka på. Då kan man använda sig av olika tekniker för att öka genomträngligheten av huden eller naglarna. Ett välbevisat trick för att göra detta är att blötlägga huden eller naglarna. När man får huden att ta in mer vatten ändras vissa mikroskopiska egenskaper i den. Strukturen av keratinfilamenten förändras och rörligheten av proteinerna och även lipiderna utanför cellerna ökar. Dessa förändringar sammanlagt tros förklara varför en ökad vattenhalt i huden ökar genomträngligheten av många läkemedel. I naglar är mekanismen för varför genomträngligheten ökar med vattenhelten inte utredd. Eftersom naglar är mycket likt uppbyggda huden är det troligt att detta sker på ett liknande sätt som i huden, och att även hår kan visa samma förändringar. I den här uppsatsen studeras keratinstrukturen och rörligheten av aminosyror och lipider i naglar och hår för att utreda vad som händer på mikroskopiska nivåer när man tillsätter vatten, och ett par andra vanliga ämnen som ofta kommer i kontakt med naglar i form av nagelborttagningsmedel (aceton) och handsprit (etanol). Resultaten av experimenten som utförs jämförs sedan med forskning som gjorts tidigare på hud.<br /> <br /> Från de undersökningar som gjordes på naglar och hår visade det sig att naglar och hår har många likheter till hud i hur de svarar på ökad vattenhalt. Det sker likanande förändringar i keratinstrukturen och rörligheten av lipiderna ökar. Däremot visade sig aminosyrorna vara betydligt mindre rörliga i både naglar och hår jämfört med huden, vilket troligen kan förklaras av de skillnader i keratinstrukturen som finns mellan hud, hår och naglar. 2020 eng physical chemistry keratin nails hair skin lipids NMR x-ray scattering infrared spectroscopy sorption fysikalisk kemi Chemistry 9019180 2020-06-16T17:13:29+02:00 2020-06-18T18:20:25+02:00 2020-06-18T18:20:25+02:00

oai:lup-student-papers.lub.lu.se:9019225 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Madeleine Andersson author 9019223 Marie Wahlgren supervisor Food Technology and Nutrition (M.Sc.) v1000294 department A great challenge during early development of medicinal antibodies is to determine the stability of the<br /> candidates. This is required to be able to select the candidates with the greatest developability. The<br /> stability of the candidates can be estimated using different orthogonal techniques and the aim of this<br /> investigation was thus to use orthogonal techniques for the investigation of conformational changes<br /> and aggregation of mAbs. The secondary aim was to obtain information concerning the effect that<br /> formulation components has on the stability of NIST mAb and which techniques that detects which<br /> conformational changes. The stability will be estimated for NIST mAb in liquid formulations where the<br /> mAb concentration, buffer type, tonicity, pH and storage time is altered. Differential scanning<br /> calorimetry (DSC), dynamic and static light scattering (DLS &amp; SLS), circular dichroism (CD) and intrinsic<br /> fluorescence are the methods used to estimate the stability in the different formulations.<br /> During the investigations it was noted that the instruments detect different conformational changes<br /> as they investigate different parts of the mAb and they received different peak temperatures of the<br /> conformational changes. Most instruments detect conformational changes in the span of 54-78°C. The<br /> order of the instruments that detected the first conformational change, from the lowest to the highest,<br /> was: DLS, CD, intrinsic fluorescence and DSC.<br /> Additionally, the effect of the addition of salt was investigated using the nanoDSC and the Zetasizer<br /> and it was noticed that it caused destabilization of the mAb in both cases. The effect of pH on the mAb<br /> was investigated using DSC, DLS, CD and fluorescence. The CD measurements shows a positive linear<br /> trend between stability and pH for the investigated solutions, and a slight wavelength shift was<br /> detected during the fluorescence measurements between pH 5.2 and 5.7. Yet, the trend was not as<br /> clear for the DSC and it was unclear if DLS could detect a stability change based on the received results.<br /> Lastly, there are no clear correlations between the buffer types and the mAb stability for any of the<br /> investigated methods. Thus, it can be concluded that the methods detect different formulation<br /> changes, yet it is difficult to determine which investigational method is the most applicable in early<br /> formulation development Antikroppar har ett brett användningsområde med stor potential men det är svårt att skapa stabila lösningar. Den strukturella stabiliteten är en viktig faktor när man väljer läkemedelskandidater, och i de tidiga utvecklingsstadierna görs prediktiva undersökningar för att ta reda på varje kandidats stabilitet och utvecklings-potential. Därmed är det av största intresse att utvärdera hur antikroppars stabilitet påverkas av olika vätskeformuleringar och hur de prediktiva undersökningar utvärderar stabiliteten.<br /> Användandet av antikroppar i läkemedelsbehandlingar har öppnat upp fantastiska möjligheter för att bota en bred variation av sjukdomar som antingen ej tidigare kunnat behandlats eller där de tidigare<br /> behandlingarna haft kraftiga biverkningar. Därmed har antikroppar en ljus framtid på läkemedels-marknaden och antalet godkända antikroppar har ökat stadigt under de senaste årtiondena. Det finns emellertid vissa svårigheter när det kommer till läkemedelsutvecklingen av antikroppar och ett stort hinder är antikropparnas stabilitet. En stabil antikropp krävs för att man ska kunna tillverka och transportera medicinen till patienten och det finns olika lösningar för att öka stabiliteten. Man kan till exempel tillsätta olika stabilisatorer till vätskelösningen som undersöker vilka stabilisatorer som passar den<br /> valda antikroppen så måste man bestämma vilken kandidat som har störst utvecklingspotential. Detta görs i ett tidigt stadie då man endast har en begränsad mängd av de olika kandidaterna och därmed görs prediktiva undersökningar för att ta reda på varje En antikropps stabilitet kan delas upp i två huvudgrupper, nämligen den fysiska och den kemiska stabiliteten, och denna text har fokuserat på en antikropps aggregationskänslighet i olika vätskelösningar. Det tillhör den fysiska stabiliteten och innebär att man undersöker hur lätt antikropparna i lösningen klumpar ihop sig med varandra och därmed ändrar form och möjligtvis tappar sin medicinska funktion. <br /> En schematisk bild av en antikropp kan ses i Figur 1 nedan och från den kan man se att den består av två lätta och två tunga kedjor. Man kan även se att antikroppen<br /> delas upp i två regioner, en som heter Fab och en som heter Fc. Fab regionen är den region som binder sig fast till patogenen eller smittämnet och Fc regionen binder till andra immunceller som tar hand om smittämnet. Figur 1. En schematisk representation av en antikropp där Fab och Fc regionerna är synliga. De tunga kedjorna är mörkblå och de lätta kedjorna är ljusblå. Fc regionen består av en CH2 och en CH3 region.<br /> En metod som heter differentiell svepkalorimetri (DSC) användes för att undersöka vid vilken temperatur Fab och Fc regionen ändrade form och det visade sig att antikroppar i en vätskelösning med bordssalt<br /> ändrade form vid än lägre temperatur än en lösning utan salt. Detta visar att salt i detta fall hade en negativ inverkan på antikroppens stabilitet. Lösningar med två olika typer av buffrar och tre olika pH-värden undersöktes även, men en lika tydlig trend som med saltet kunde inte ses. Det resonerades därmed att man möjligtvis kunde ändra dessa två förhållande beroende vilken region som var mest känslig för den valda antikroppen.<br /> En annan metod som heter dynamisk ljusspridning (DLS) användes för att undersöka vid vilken temperatur antikropparna började återfanns samma stabilitetstrend mellan salthalt och stabilitet som i DSCn. Emellertid återficks inga tydliga och entydiga svar mellan stabiliteten och lösningens pH, buffer eller förvaringstiden i kylskåp. En möjlig orsak till de tvetydiga resultaten kan bero på att metoden<br /> är aggregationskänslig och att mätcellen troligtvis blev smutsig under undersökningarna vilket skulle ha en inverkan på mätresultaten.<br /> Cirkulär dikroism (CD) är en tredje metod som användes för att komplettera undersökningsmetoderna och den kan mäta vilken 3D-struktur antikroppen har vid olika temperaturer. Dessa mätningar visade att<br /> antikroppen ändrade struktur vid en högre temperatur då lösningen hade ett högre pH. Dessutom tydde resultaten på att lösningens pH hade en inverkan på vilka delar av antikroppen som ändrade form.<br /> De två sista metoderna som undersöktes var statisk ljusspridning (SLS) och fluorescence. SLS liknar DLS och mäter också partikelstorleken men på ett lite annorlunda sätt. Emellertid kunde man inte se någon aggregation under de mätningarna, vilket möjligtvis kunde bero på att koncentrationen var för låg för att mäter ljusmängden som emitteras från fluorescerande delar av antikroppen och i detta fall undersöktes ljuset som emitterades från tryptofan, som är en aminosyra. Detta kan ge information om strukturförändringar och undersökningsresultaten tydde på att det skedde en strukturell föränding vid 64°C.<br /> Sammanfattningsvis, konstaterades det att metoderna som undersöktes kan användas för att bestämma en antikropps stabilitet i olika vätske-formuleringar, och att de strukturförändingarna som uppmättes skedde efter ca 58°C. Dessutom bekräftades det att salt har en negativ inverkan på korttidsstabiliteten av en antikropp och att korrelationen mellan en antikropps stabilitet och lösningens pH eller buffer är mer komplex. Slutligen kan man säga att läkemedelsindustrin har löst många av de stabilitetsutmaningar som proteinläkemedel har frambringat, och att antikroppar kommer vara den läkemedelstypen som leder oss in i en<br /> ny medicinsk era. https://lup.lub.lu.se/student-papers/record/9019225/file/9019228.pdf application/pdf 5237812 no 2020 eng Pharmaceutical technology Läkemedelsteknologi Biology and Life Sciences Chemistry Technology and Engineering 9019225 2020-06-16T20:06:14+02:00 2020-08-10T14:24:35+02:00 2020-08-10T14:24:35+02:00

oai:lup-student-papers.lub.lu.se:9019354 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Tea Torell author 8949320 Larissa Cunico supervisor Margareta Sandahl supervisor Charlotta Turner supervisor Department of Chemistry v1000647 department Introduction: The knowledge of the diffusion coefficient of a solute in neat carbon dioxide (CO2) and CO2 mixed with organic solvents is of importance as it correlates to the efficiency of chromatography and extraction processes.<br /> Background: Several studies have been found in literature for diffusion coefficients measurements of different solutes in neat carbon dioxide, but to our knowledge rather few can be found using CO2-expanded liquids/binary mixtures.<br /> Aim(s): The aim of this project was to modify and validate a home-built chromatography set-up by measuring the diffusion coefficient of toluene in neat CO2 and compare the obtained values with data available in literature. When the equipment set-up had been validated, the aim was to measure the diffusion coefficient of toluene in CO2-expanded liquids. The estimation of the viscosity for neat CO2 and CO2-expanded liquids using theoretical models was also evaluated.<br /> Methods: The Taylor dispersion method was used for the measurements of diffusion coefficients. It consists of injecting a quick pulse of solute into a laminar flow of solvent running through a long, hollow capillary. As the solute moves through the capillary, its peak broadens due to convection effects along the peak and molecular diffusion in the radial direction. <br /> Results: Four different flow rates were examined to see how the flow rate affected the magnitude of the diffusion, to which the conclusion was drawn that a too low flow rate does give a statistically significant impact on the diffusion coefficient. Three injection volumes were also examined, and it was determined that the magnitude of the diffusion coefficient was not affected by the injection volume in the range examined. The configuration of the detector (UV/Vis CCD) was also evaluated. The system was validated and compared to data available in literature, giving deviations between 15-30%, and well-known theoretical models were used to estimate the viscosity of the solvent, giving deviations between 5-33%, depending on what equation was used and the pressure/temperature conditions. Measurements of the diffusion coefficient and viscosity of toluene in 4% ethanol in CO2 were then done and compared to literature, giving the mean diffusion coefficient of 1.06*10-8m2/s showing deviations between 8.5-10% in regards to the viscosity depending on which equation was used. Finally, measurements of the diffusion coefficient of toluene in solvents of CO2 and ethanol and CO2 and ethyl lactate with different molar ratios were performed, showing how the viscosity of the solvent changes with the addition of CO2. <br /> Conclusion: Modifications were made to an already existing chromatographic set-up, in an attempt to measure diffusion coefficients of toluene which would align with values reported in literature, and then use these diffusion coefficients to estimate the viscosity of the solvent using theoretical equations. Even though the measured diffusion coefficients deviated from the literary values quite a lot, the deviations were less for the estimated values for the viscosity for neat CO2 and 4% of ethanol in CO2. Diffusion coefficient measurements of toluene was thereafter made in solvents with the molar ratio of 0.1, 0.3 and 0.5 CO2 in ethanol and ethyl lactate, and through exponential regression, the conclusion was drawn that the addition of CO2 affected the viscosity of ethyl lactate more than the viscosity of ethanol. When mixing juice, one takes concentrated, flavourful juice extract and blend it with water. The two liquids fuse, creating a homogenous mixture where the flavour and colour of the concentrated juice extract have been diluted in the water. Scientifically speaking, the molecules of the juice extract have spread out, or diffused, in the water and gone from a high concentration to a lower one. <br /> <br /> This phenomenon of diffusion has been studied in this work, except that the juice extract has been exchanged with toluene and the water with neat carbon dioxide or carbon dioxide mixed with an organic solvent. When mixed, carbon dioxide and organic solvents are however not in the normal gas or liquid phase in which we are used to find them, but in a subcritical phase which is achieved by adding a certain amount of pressure and heat to a solvent. In this subcritical phase, the solvent has a density similar to that of a liquid but the viscosity closer to a gas. The solvent can also be called carbon dioxide expanded liquid. The viscosity of solvents and diffusion coefficient of solutes are important properties to investigate, as mass transfer rates are crucial when designing, scaling up or optimizing extraction and chromatography processes.<br /> <br /> In this work, a home-built chromatography like set-up was modified to be able to measure diffusion coefficients of toluene in neat carbon dioxide which correlated to those already available in literature at two different temperatures (40 and 60 °C) and two different pressures (150 and 250 bar). When comparing the results with values reported in literature, they deviated between 15-30%. <br /> The measured diffusion coefficients were thereafter used to estimate the viscosity of the CO2, giving deviations between 8-13% for the modified versions of the Wilkes-Chang, Schiebel and Lusis-Ratcliff equation, and 5-7% for the Lai-Tan equation. The diffusion coefficient of toluene was thereafter measured in 4% ethanol in CO2, and the estimated viscosities was compared to literature, giving deviations between 8-10% depending on what equation was used. Finally, the diffusion coefficient of toluene was measured in solvents of 0.1, 0.3 and 0.5 of CO2 in ethanol and ethyl lactate under the same temperature and pressure conditions as before, and the viscosities were once again estimated. Using exponential regression, the conclusion was drawn that there is a larger impact on the viscosity of ethyl lactate with the addition of CO2 than there is for ethanol. 2020 eng Diffusion coefficients CO2-expanded liquids Carbon dioxide Taylor dispersion method Viscosity Analytical chemistry Analytisk kemi Chemistry 9019354 2020-06-17T03:38:40+02:00 2020-06-18T13:43:05+02:00 2020-06-18T13:43:05+02:00

oai:lup-student-papers.lub.lu.se:9019402 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Gemma Nilsson author 9019378 Associate professor Cecilia Emanuelsson supervisor Mathematical Statistics v1000668 department Department of Chemistry v1000647 department In order to maintain proteins’ functionality their native folding state must be preserved. Chaperones fold other proteins and DNAJ-chaperones may collaborate with Hsc70 chaperones to prevent aggregation of aggregation-prone peptides such as polyQ and Aβ42, which form fibrils in currently incurable diseases as Huntington’s and Alzheimer’s, respectively. Fibril formation of polyQ and Aβ42 is detected by ThT fluorescence measurements over time and halftime values (t​1/2 values) of fibril formation can be calculated and used to determine how chaperones can suppress fibril formation which is observed as increased t​1/2 value. Here we observed that there is an enhancement of the DNAJB6 suppression of fibril formation by Aβ42 in the trimeric chaperone system with DNAJB6, Hsc70, Hsp110 and ATP. The increased t​1/2 values observed with the trimeric chaperone system is dependent on ATP-hydrolysis since the effect was reversed (decreased t​1/2 values) in absence of Hsp110, the nucleotide-exchange factor. Moreover, the effects were different with ATP, ADP or a non-hydrolyzable ATP-analogue. A possible interpretation is that the observed enhancement here, for the first time with DNAJB6 in the trimeric chaperone system, is the result of a continuous capture of Aβ42 oligomers, which otherwise function as nuclei for fibril formation, and continuous release as Aβ42 oligomers under ATP-hydrolysis. Ett protein måste upprätthålla sin tredimensionella struktur för att bevara sin funktion. De flesta proteiner veckas inte spontant till sin fungerande konformation och med tiden veckas de ut. Därför behöver kroppens celler ett system som främjar korrekt veckning och ser till att de bevarar denna veckade form. Proteiner som har denna uppgift kallas chaperoner. Chaperoner binder till och veckar andra proteiner samt samverkar i ett komplext nätverk för att bibehålla cellers proteostas. Många chaperoner är så kallade Heat Shock Proteins (Hsps), däribland DNAJ-proteiner som främst binder till felveckade proteiner och Hsp70-proteiner som binder och veckar andra proteiner.<br /> Chaperoner förhindrar bland annat skadlig ackumulering av aggregationsbenägna peptider såsom polyQ and Aβ42. Aggregering och därpå fibrillering av polyQ och Aβ42 är associerade med Huntingtons respektive Alzheimers sjukdom, vilka båda är neurodegenerativa sjukdomar som angriper och orsakar skador på nervsystemet. I tidigare studier har man observerat att vissa Hsp70-proteiner samarbetar med DNAJ-proteiner för att dämpa sådan skadlig bildning av fibriller. Chaperonerna som användes i studien var Hsc70 (ett Hsp70-protein) och DNAJB1 (ett DNAJ-protein) samt Hsp110 som är en så kallad nucleotide exchange factor (NEF).<br /> I tidigare forskning på Lunds Universitet, vid avdelningen för biokemi och strukturbiologi, har det visat sig att DNAJB6, ett DNAJ-protein som är likt men ändå olikt DNAJB1, verkar vara specialiserat på att binda just de former av polyQ och Aβ42, som kallas oligomerer. Det är oligomererna som orsakar sjukdom. De binds starkt till en S/T-rik region i DNAJB6, vilket är en region som saknas i DNAJB1. Baserat på detta var syftet med vårt projekt att undersöka om DNAJB6, i likhet med DNAJB1, interagerar med ett system av Hsc70 och Hsp110. Är det så att DNAJB6 kan lämna över ett substrat, som polyQ eller Aβ42, till Hsc70?<br /> En förenkling av händelseförloppet då monomera peptider slutligen bildar fibriller kan beskrivas som en reaktion där monomerer initialt kolliderar och alltså bildar oligomerer. Dessa oligomerer är mycket skadliga för celler och sätter fart på reaktionen. Nästa fas kallas förlängning (elongation) eftersom fler monomerer nu binder in och oligomererna börjar då närma sig formen av en fibrill. När fibriller väl har bildats kan bildningen av ännu flera farliga oligomerer katalyseras på fibrillernas yta. Att fibrillerna själva fragmenteras ökar antalet fibriller ytterligare, vilket förvärrar situationen. Därför skulle det vara viktigt om DNAJB6 kan hindra och oskadliggöra de allra första oligomererna som bildas.<br /> För att undersöka hur chaperonerna fungerar användes en metod som kallas ThT-mätning. ThT är en fluorescerande molekyl och bildningen av fibriller mäts som ThT fluorescensmätning över tid. En ökning i fluorescensen tyder på bildning av fibriller tills ett maximal-värde uppnås. Ett värde beräknades för halva tiden innan maximal-värdet uppnås (ett t​1/2 värde). Chaperonernas förmåga av att dämpa fibrilleringen kan då mätas som ett ökat t​1/2​ värde.<br /> Vi observerade att DNAJB6 kan dämpa bildning av fibriller redan vid mycket låga mängder i förhållande till aggregationsbenägna peptider. Vid förhållandet 1:0.01 Aβ42 till DNAJB6 fanns en tydlig ökning av t​1/2 värdena. En annan observation var att värdena för t​1/2 ökar kraftigt vid tillsats av DNAJB6, Hsc70 och Hsp110, men i frånvaro av Hsp110 (och ATP) blir värdena för t​1/2 mycket lägre. Detta pekar på att det trimera chaperonesystemet bestående av DNAJB6, Hsc70 och Hsp110 är beroende av ATP hydrolys. Detta tyder på en interaktion mellan DNAJB6 och systemet av Hsc70/Hsp110/ATP där substratet kan överlämnas från DNAJB6 till Hsc70.<br /> Det dimera systemet av DNAJB6 och Hsc70 i närvaro av ATP gav noterbart låga värden, mycket lägre än när chaperonerna arbetade självständigt. Vår hypotes är att i avsaknad av ATP-hydrolys, det vill säga i frånvaro av Hsp110 och ATP, så lämnar DNAJB6 över de uppfångade oligomererna till Hsc70 som sedan släpper ut dem igen. Däremot när Hsp110 och ATP också är närvarande, sker ATP-hydrolys och Hsc70 löser då upp de skadliga oligomerer till ofarliga monomerer.<br /> Svaret på vår huvudsakliga fråga: ”Kan DNAJB6 lämna över substrat, som Aβ42, till Hsc70” är, kort sagt, ”ja”. Åtminstone med Aβ42 och åtminstone under de testade förhållandena. https://lup.lub.lu.se/student-papers/record/9019402/file/9019405.pdf application/pdf 1981544 no 2020 eng chaperones DNAJB6 Hsc70 Hsp110 ATP-hydrolysis Ab42 polyQ biochemistry biokemi Chemistry 9019402 2020-06-17T09:23:13+02:00 2020-06-18T15:42:15+02:00 2020-06-18T15:42:15+02:00

oai:lup-student-papers.lub.lu.se:8898233 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Josefine Karlsson author Kenneth Wärnmark supervisor Department of Chemistry v1000647 department This thesis describes the preparation of the previously unknown Tröger´s base mono- and bislactams from Tröger´s base and the transformation via olefination, stereoselective hydrogenation and reduction yielding Tröger´s base derivatives which features functional groups pointing into the interior of its cavity.<br /> <br /> The target molecules are two new chiral molecular cleft molecules which may be useful in supramolecular chemistry or as ligands in asymmetric catalysis due to the C2-symmetry, rigidity and sharply folded geometry with a nearly right angle between the planes of the aromatic rings.<br /> <br /> This thesis also describes the investigation of finding a higher yielding oxidation method since the reaction from Tröger´s base to Tröger´s base-bis-lactam did not proceed with good yield, and in addition the effort to obtain the two target molecules. Trögers bas upptäcktes först av Julius Tröger 1887, det är en symmetrisk molekyl med fyra stycken sexledade ringar som sitter ihop utan ringspänning. Molekylen är kiral (skiljer sig från sin spegelbild) tack vare de två kväveatomerna som hindras av bryggan mellan dem att röra sig, detta skapar en konkav form och en hydrofob (vattenskyende) ficka i molekylen med de två sexledade ringarna nästan vinkelrätt mot varandra. Dessa olika egenskaper gör molekyler baserade på Trögers bas väldigt attraktiva inom många olika områden inom kemi, och är därför intressant att studera. 2017 eng organic chemistry organisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/8898233/file/8898261.pdf application/pdf no 8898233 2017-01-09T09:24:39+01:00 2017-01-09T09:55:12+01:00 2017-01-09T09:55:12+01:00

oai:lup-student-papers.lub.lu.se:8901287 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Mar Coto Acosta author 8871995 Larissa Cunico supervisor Charlotta Turner supervisor Department of Chemistry v1000647 department Antioxidants are compounds present in plant, fruit, and vegetables, and they are known for their medicinal benefits such as anti-carcinogenic and anti-fungicidal activity. Most commonly used methods for extractions of such compounds are lengthy due to mass transfer limitations. This study proposes the use of carbon-dioxide expanded liquids (CXLs) as solvent to improve these limitations. Such solvents, considered as green solvents because of its inertness, odourless and low toxic properties, present tunable physical properties, such as low viscosity and high diffusivity rates. The solubility of CO2 in ethanol determines the volume expansion and, depends on temperature and pressure. Hence, the acquisition of solubility data of analyte in CXLs and the density of such mixtures will be valuable for an optimum extraction of antioxidant from complex solid samples. Aiming to study these properties, a system able to perform measurement of solubility and phase equilibria was developed. The equipment consists of a high pressure view cell connected in-line to a densitometer and a supercritical fluid chromatograph with a photodiode array detector. Validation of such equipment was performed with curcumin, a polyphenol extracted from Turmeric (Curcuma longa L.), 200 bar and 40 ºC in 92 % CO2 and 8 % ethanol, giving a solubility of 0.37 x 102 (molar fraction) , while in literature the observed value is 0.41 x 102 (molar fraction). Solubility measurements were successfully determined for curcumin at 200 bar, 35 ºC and at different content of ethanol in the mixture– from 50 to 90 %. Densities for such mixtures were also studied. Results have shown that the solubility of curcumin increases with the amount of ethanol as expected. Another polyphenol studies is quercetin, which it was found to be higher in solubility than curcumin. In general terms, the developed equipment has shown to be efficient for the established purpose. Further investigations are needed to confirm the range of applicability. How chemical properties can improve the extraction of antioxidants?<br /> Analytical chemistry is based on the study of the identification, extraction and separation of compounds of interest, so that the structure and composition of these compounds in a sample are obtained. Different types of samples are of interest for these studies. For instance, the healthy properties attributed to fruits and vegetables (i.e. antioxidant capacity) relies on the analytical determination of its composition. Nevertheless, no possible determination could be done if the compound of interest was not previously extracted from the matrix. An extraction process involves the isolation of a substance – referred as analyte – from a sample by using solvents, which have the ability to dissolve the referred substances. For example, coffee beans are the seeds of the coffee plant and they are subjected to extraction processes so we can have our daily cup of coffee. However, extractions are usually lengthy in time, and also costly, due to the amounts of energy and solvent used for it. Moreover, the chemical properties of an analyte (i.e. polarity dependence) make extractions even more challenging, meaning that many parameters must be controlled. Polyphenols are a type of antioxidants which are difficult to extract due to its polarity. Thus, a suitable solvent has to be selected for the extraction.<br /> In this thesis, an interesting and green technique for such processes is presented. This technique uses a so-called carbon dioxide–expanded liquids (CXLs) as extraction solvent. CXLs is a fluid state of carbon dioxide (CO2) above its critical pressure (74 bar) and critical temperature (31 ºC) to which a traditional organic liquid – ethanol in a range content of 50 to 90 % – is added to enhance its properties, like polarity. Therefore, CXL presents tunable physical properties. Consequently, it can be used for extracting polyphenols or any other medium-polar antioxidant compound. Prior to its application in extraction, the study of solvent – analyte interactions is needed. So, this information will be valuable to obtain higher extraction yields.<br /> Solubility plays a major role in the study of an extraction process. A simple example present in our daily basis can be used to exemplify the effect of temperature in extraction. If sugar dissolves better in water at higher temperatures, it is because is a favour temperature process. The same principle applies for extractions. Information of the solubility of analytes in CXLs will lead to extraction improvements. In this thesis, a home-made equipment was developed to acquire solubility measurements. The applicability of such system was tested with solubility measurements of curcumin, which is a polyphenol found in curry spice.<br /> Experimental data showed that the system was adequate for solubility measurements. Moreover, the system was valid as well to provide information about CXLs density values, which are also of high importance to study the solvent behaviour. The obtained results in this thesis validated the idea that high contents of ethanol in CO2, at relatively moderate pressures and temperatures, led to higher solubility values of the analyte in CXLs than in a system composed by pure CO2. https://lup.lub.lu.se/student-papers/record/8901287/file/8901288.pdf application/pdf 1710269 yes 2016 eng Carbon-dioxide expanded liquids (CXLs) Solubility Density Antioxidants analytical chemistry analytisk kemi Chemistry 8901287 2017-01-25T17:39:44+01:00 2017-02-03T13:40:33+01:00 2017-02-03T13:40:33+01:00

oai:lup-student-papers.lub.lu.se:8901384 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Adam Eliasson author 8901361 Krisztina Kovacs supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department To reach the goals set for the reduction of green house gas by the European Union the use of fossil fuels has to be reduced. To do this alternative fuels such as bioethanol have to substitute fossil fuels. Second generation bioethanol is produced from lignocellulosic substrates, such as forest and agricultural residues, whereas first generation bioethanol is obtained from material as sugar cane and corn containing sugar and starch. A possible raw material for production of ethanol from lignocellulosic biomass could be the stem of jerusalem artichoke. Lignocellulosic materials are recalcitrant, and therefore they need to be pretreated in order to make them more degradable. Steam pretreatment is the way of pretreatment most commonly used at commercial scale production of ethanol from lignocellulosic material. <br /> In this study, it was investigated if the stem of jerusalem artichoke is a suitable material to produce ethanol using steam pretreatment as method for pretreatment. Jerusalem artichoke stem was pretreated at 7 different conditions, and the pretreated material were subjected to enzymatic hydrolysis. Two differently pretreated material (pretreated at 200°C for 5 minutes and 10 minutes) were selected for simultaneous saccharification and fermentation. The main aim of this study was to get an as high conversion from the sugars in the raw material to ethanol as possible. <br /> The highest final ethanol yield that was received was 76% of the theoretical maximum for material treated at 200°C for 10 minutes. With this set of parameters, the corresponding overall glucan to glucose conversion was 81%. These results were approximately in the same range as those of other studies using jerusalem artichoke as raw material. The highest concentration of ethanol that was received was 10,7 g/l. This is low compared to 40 g/l which is usually considered to be what must be achieved. However, the parameters and procedure are not optimized and there is still room for improvements. Bioetanol producerat från blast av jordärtskocka.<br /> I tider av ökad vetskap om fossila bränslens påverkan på vår miljö har efterfrågan på nya sätt att producera alternativa drivmedel bara blivit större och större. Många av dagens biobränslen behöver stora arealer av jordbruksmark för att tillgodose produktionen med tillräckligt råmaterial. https://lup.lub.lu.se/student-papers/record/8901384/file/8901396.pdf application/pdf 8000920 no 2017 eng SSF Simultaneous Saccharification and Fermentation Lignocellulose Bioethanol Second generation Bioethanol Steam Explotion Jerusalem Artichoke Enzymatic Hydrolysis chemical engineering kemiteknik Technology and Engineering Chemistry 8901384 2017-01-26T11:55:05+01:00 2017-04-19T10:23:22+02:00 2017-04-19T10:23:22+02:00

oai:lup-student-papers.lub.lu.se:8903071 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Adam Kranas author 8516519 Susanna Horsefield supervisor Department of Chemistry v1000647 department Studies of aquaporin’s are broad study field in today’s science. In this master project the membrane protein aquaporin SoPIP2;1 has been studied. The aim of the project was to obtain protein crystals with Lipidic Cubic Phase (LCP) crystallization and study their diffraction. If the obtained resolution of the crystals were satisfying the molecular map also would be studied and that would reveal us a desired resolution on the structure. Different mutants and wildtype SoPIP2;1 has been purified in this laboratory work. The mutants studied were S188E and S115E. It was believed in previous studies that mutant S188E would possibly show the open structure of the channel and that was the aim in studies of both those mutants; to study the open structure of the channel. At the end of the project Calcium titration experiments has been made in order to study the calcium binding properties of the wildtype SoPIP2;1 protein. The results from crystal screening for various types of SoPIP2;1 that are presented above showed that the crystal that were studied in the X-ray diffraction were salt crystals. The conclusion drawn from this master work was that LCP needs more optimization for particular types of protein that are studied by that method. Struktur studier av vatten kanalen SoPIP2;1 från Spinach. <br /> <br /> Syfte för studier av denna jon kanal i detta masterprojekt var att studera kristaller från så kallade membranprotein aquaporin SoPIP2;1 och sedan bestämma dess molekylära struktur till en hög upplösning. Detta kan sedan utnyttjas i vidare forskning för just detta proteinet. <br /> Proteinet som studerades kommer från Spinach. Detta protein överproducerades i jästceller av Pichia Pastoris. Fermentering är namn på metoden som används för att överproducera det sökta proteinet i jästceller. Efter fermenterings processen en del av celler lyserades eller bröts upp med hjälp av så kallad Bead Beating metoden. Detta handlar om att celler med det sökta proteinet skakas drastisk i en buffertlösning som så kallade glass beads tillsätts till. Dessa glass beads slår sönder cellerna. När cellerna slåss sönder eller lyseras så använder man en metod att spinna ner det lyserade cellinnehållet. Cellmembraner flyter runt i lösning vid låg centrifugeringshastighet och det som är på botten är cell organeller och allt annat cellinnehåll. Nästa steg i denna framreningen av detta membranprotein var att tvätta bort detta cell membranlösning med UREA samt NaOH lösningar. Denna metoden gjordes i hög hastighets centrifugering och det nämns till ultracentrifugering. <br /> För att sedan få det sökta proteinet i ren form så gjordes två framrenings steg. Dessa heter Jon bytes kromatografi samt gel filtrarings kromatografi. Det första metoden separerar proteiner med hjälp av dess laddnings skillnad och den andra metoden hjälper och separara proteiner med hjälp av dess storlek skillnad. <br /> Det rena proteinet användes sedan till en så kallad Lipidic cubic phase (LCP) krystaliseringsexperiment. Detta experimentet teoretisk skulle ge möjlighet till proteinkristaller. Den metoden baseras på att cellmembranet som saknas när proteinet framrenas på ett sätt återskapas i denna LCP metoden. Detta återskapande görs med hjälp av en typ av lipid molekyl. När kristaller har producerats så studeras dessa med hjälp av så kallade X-ray diffraktion experiment som utförs i en så kallad synchotron. En ny synchotron laboratorie byggdes nyligen i lund och heter Max IV. <br /> Resultatet av detta masterprojekt visade tyvärr att dessa var inga proteinkristaller utan saltkristaller när dessa har testats i en synchotron i Hamburg. I slutet av detta masterarbete Calcium bindning till ovan nämnda proteinet gjordes. <br /> LCP metoden är i utveckligsstadiet och mängder av lösningar som används för denna metoden är mycket små. Felkällor är många i denna metod och kräver till exempel en krystaliserings robot för att sätta upp själva krystaliseringsexperimentet på en specifik platta. Vid brist av tid kunde inte denna metoden studeras utförligt men i framtiden kan LCP vara en metod som kommer hjälpa att producera kristaller för respektive membranprotein; om metoden utvecklas utförligt av forskare. 2017 eng proteinvetenskap protein science Chemistry https://lup.lub.lu.se/student-papers/record/8903071/file/8921469.pdf application/pdf no https://lup.lub.lu.se/student-papers/record/8903071/file/8921471.pdf application/pdf no 8903071 2017-02-13T11:03:07+01:00 2017-07-05T09:10:59+02:00 2017-07-05T09:10:59+02:00

oai:lup-student-papers.lub.lu.se:8903148 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Olivia Söderman author 8903146 Professor Ann-Sofi Jönsson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department In many places across the northern hemisphere, drinking water treatment plants (WTPs) need to avert the effects of deteriorating quality in surface water sources caused by increasing lev-els of natural organic matter (NOM). The two major factors responsible for this phenomenon, also called brownification, are the greenhouse effect and changes in soil acidification. Additional treatment steps needs to be investigated and implemented in order to ensure safe drinking water in the future. Membrane technology is a candidate that has proven to be effective in terms of organic matter removal as well as functioning as a microbiological barrier. The company responsible for producing drinking water in southern Sweden, Sydvatten, has experienced a change in raw water quality and as a consequence, an increasing demand for dosing coagulant chemicals in order to treat the incoming water. They want to investigate the possibility of introducing membrane filtration units as part of the treatment process. <br /> The efficiency of membranes are very site specific. This thesis is therefore executed with water from Lake Bolmen, which is the raw water source for the largest WTP owned by Sydvatten; Ringsjöverket. A comparative study of 12 different membranes was performed with the purpose of identifying a suitable membrane, or membranes, for removing organic matter. The membranes, ranging between tight nanofiltration to ultrafiltration, were all flat sheet membranes with the exception of one hollow fibre membrane. Screening tests with cross flow filtration were executed using a batch unit with the capacity of testing three membranes at once. An additional bench scale batch unit was used for the hollow fibre membrane. The test procedures were designed to accommodate the studying of flux, fouling and the effect of changing different operational parameters. Samples of the surface water and permeate were collected and analysed in terms of UVA254, total organic carbon (TOC) and colour to estimate the retention capabilities of the membranes. <br /> Initial screenings identified two promising membranes, Alfa Laval NF99HF and DOW FILMTEC(TM) NF270 (hereinafter &quot;NF270&quot;), both displayed a prominent flux trend combined with efficient removal of NOM with a TOC retention of approximately 94% and 95% respectively. However, the two membranes also showed signs of irreversible fouling which would affect the efficiency and lifetime of the membrane. Changing the transmembrane pressure (TMP) affected the membranes with larger pore sizes where the permeate quality decreased at higher pressures. For the tighter membranes, NF99HF and NF270 included, this effect was negligible and the TOC retention remained at the same level. After the initial screenings, spiral wound module tests were performed with the NF99HF membrane which achieved the same level of NOM separation. However, the fouling behaviour and the flux capacity somewhat contradicted previous results where the flux was halved and the cleaning managed to restore the permeate flux completely. <br /> The combined results from the different experiments showed that Alfa Laval NF99HF could potentially be suitable in terms of achieving a high flux without compromising the permeate quality. However, there are certain contingencies concerning flux and fouling behaviour as well as drawbacks such as the inability to treat the membrane with disinfectant chemicals containing chlorine which is an advantage from a hygienic perspective. Vilket membran lämpar sig bäst när det kommer till avskiljning av organiskt material från Bolmenvatten?<br /> Med vattendrag som blir brunare och brunare – hur ska våra dricksvattenverk klara av att säkra vårt vatten i framtiden? Svaret heter membranteknik! Vilket membran som passar bäst är däremot en svårare fråga att besvara och således också det som har undersökts i denna studie. https://lup.lub.lu.se/student-papers/record/8903148/file/8903156.pdf application/pdf 3017977 no 2017 eng natural organic matter ultrafiltration nanofiltration drinking water membrane technology water engineering environmental engineering vattenförsörjningsteknik avloppsteknik Chemistry 8903148 2017-02-14T11:53:41+01:00 2017-02-17T16:00:21+01:00 2017-02-17T16:00:21+01:00

oai:lup-student-papers.lub.lu.se:8903674 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Jeanette Karlsson author 8903273 Sven Lidin supervisor Centre for Analysis and Synthesis v1000651 department The stainless steel metal includes a large group of alloys and which one should choose for a process can be difficult to determine. Despite much research on corrosion, there is still disagreement on the impact of the corrosion resistance from passivation. This master thesis was assembled together with Tetra Pak to see the influence of passivation on stainless steels used in their processes. <br /> The goal of this master thesis was to understand whether the passivation of the two stainless steels gave a better protection against corrosion. This was supposed to be investigated at different temperatures and concentrations of chloride ions. A large part of the project however, became finding out the right method to measure with. Because of this, the master thesis has given large insight of how a project proceeds from start to finish and has brought knowledge in problem solving and planning. <br /> In this project, stainless steel types 304 and 316 were studied using polarization and OCP measurements. The stainless steels in half of the measurements had been passivated with citric acid. From the initial measurements it was clear that the OCP measurements required more time than the project could offer - after 12 hours it had still not reached a stable value and thus could not be used to draw any conclusions. One could nevertheless see tendencies for an increased protection by passivation in the beginning of the measurements, but after some time the values tended to reach stagnation. <br /> The polarisation measurements gave more varying results and appeared to be more sensitive against small differences in the system. From the polarisation measurements one could see that the pitting potential (Epit) ranged from 2.37E-6 mm/year to 1.44E-4 mm/year. The corrosion rate (Crate) with the estimated compositions of the steel varied between 149mV and 1235mV. The reliability of the measurements was questioned early in the process since the results differed from what was expected. The accuracy was later seen more clearly by comparing results from the same tests with each other. Since the temperature in this project differed greatly from the temperatures that are used in Tetra Pak’s processes, one cannot advise on whether to passivate or not. However, the report can lead to knowledge of methods to measure corrosion and knowledge of how materials are affected at lower temperatures. The report also contains advice on how the research should continue. Korrosion (rost) är ett stort forskningsområde som hunnit komma långt, men fortfarande finns det mycket kvar att lära. Detta kan man se enbart genom att reflektera över de nästan 100 miljarder kronor som korrosionsskador kostar samhället i Sverige årligen. Rostfritt stål har ett vilseledande namn då det faktiskt rostar i vissa miljöer. I detta projekt har korrosion av rostfritt stål undersökts i olika miljöer för att se skillnaden med och utan förbehandling. Förbehandlingen gör att det rostfria stålet får ett ökat skyddande lager. https://lup.lub.lu.se/student-papers/record/8903674/file/8903722.pdf application/pdf 1876688 no 2017 eng materials chemistry materialkemi Chemistry https://lup.lub.lu.se/student-papers/record/8903674/file/8903678.pdf application/pdf Populärvetenskaplig sammanfattning av examensarbete. no 8903674 2017-02-23T06:48:48+01:00 2017-02-24T12:48:09+01:00 2017-02-24T12:48:09+01:00

oai:lup-student-papers.lub.lu.se:8903956 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Emil Åberg author 8903954 Pär Söderhjelm supervisor Biophysical Chemistry v1000649 department A computational method is described and tested for prediction of ligand-binding poses between the human farnesoid X receptor and a set of 36 potential agonists, provided by the D3R Grand Challenge 2016. Using tools such as Molecular Docking, Molecular Dynamics, Reconnaissance metadynamics and cluster analysis, the method is an attempt to predict the binding pose without being biased by experimental data. When comparing the predicted poses with the crystal structures, more than half of the ligands were predicted accurately. It is shown that the accuracy of the Molecular Docking is very conformation dependent, as the flexibilty of two α-helices adjacent to the active site makes it difficult for docking to predict the correct pose. Molecular Dynamics are dependent on the predictions from docking, and the force field (GAFF) used for the ligands may be the reason for that only 3 of the accurately predicted poses were refined further. Reconnaissance metadynamics did not result in finding any better poses with the collective variables set used.<br /> <br /> More effort is needed to determine a better set of collective variables, which are able to take the flexibility of the α-helices and the positions of the side chains into consideration, as well as possibly enable Reconnaissance metadynamics to overcome the short-comings of docking. Många sjukdomar kan kopplas till en svag länk i en av kroppens kemiska reaktionskedjor. En sådan svag länk kan vara ett protein. Ibland går det att lösa problemet genom att ett läkemedel binder in till, likt en nyckel i ett nyckelhål, och stoppar proteinets funktion. Frågan är: vilken molekyl kan binda in till proteinet, och hur?<br /> <br /> Kunskap om hur en liten molekyl binder in till ett protein är viktigt för utvecklingen av framtida läkemedel. Med datorsimuleringar försöker man få insikt i och förutsäga hur dessa molekyler binder in (samt om de inte gör det). Beroende på hur noggrann simuleringen skall vara krävs det mer eller mindre tidsåtgång och datorkraft för att kunna utforska alla möjliga scenarion. Därför har tekniker som försöker att kringgå de långa simuleringstiderna som krävs för att utforska möjliga molekylstrukturer utvecklats. Tekniker som kan öka rörligheten på både protein och molekyler i hopp om att undersöka alla möjliga inbindningsstrukturer. Men för att dessa tekniker skall fungera gäller det att man väljer rätt parametrar.<br /> <br /> I detta arbete presenteras och testas en metod som är ett försök till att förutspå strukturen på ett antal molekyler när de bundit till ett protein. Kunskap om den ”korrekta” inbindningsstrukturen för molekylerna till proteinet var inte känd under simuleringsdelen av arbetet och därför fungerar arbetet även som ett blindtest av den presenterade metoden. Efter simuleringarna var slutförda blev de korrekta strukturerna tillgängliga och jämförda med de strukturprediktioner från metoden. ​ Lite mer än hälften av alla molekylers inbindningsstrukturer bestämdes korrekt med datorsimuleringar. Det visade sig att proteinets strukturändringar var en viktig faktor för att kunna förutsäga inbindningen. Därför måste nya eller fler parametrar till simuleringarna bestämmas som tar bättre hänsyn till strukturen av proteinet och dess rörlighet. https://lup.lub.lu.se/student-papers/record/8903956/file/8903957.pdf application/pdf 2360895 no 2017 eng GAFF FXR farnesoid X receptor MD computational enhanced sampling binding receptor ligand Simulations Reconnaissance Metadynamics Docking Molecular Dynamics Protein AMBER force fields structure prediction crystallography collective variables potential bias potential biophysical chemistry biofysikalisk kemi Chemistry Technology and Engineering Biology and Life Sciences 8903956 2017-03-01T12:45:18+01:00 2017-03-24T08:53:42+01:00 2017-03-24T08:53:42+01:00

oai:lup-student-papers.lub.lu.se:8904681 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anna Lidskog author 5364241 Sami Dawaigher supervisor Department of Chemistry v1000647 department Two novel pseudo-Cs-symmetric heterobimetallic bissalen complexes have been synthesized, one containing chromium and cobalt and the other containing chromium and manganese. The design is based on a previously unexploited method; breaking the symmetry of an achiral meso-ligand by insertion of two different metal ions. The synthesized complexes are expected to catalyze the asymmetric ring-opening of meso-epoxides by TMSN3 with high efficiency and enantioselectivity. <br /> <br /> The two pseudo-Cs-symmetric complexes were successfully synthesized following an eight-step synthetic route starting from tert-butylhydroquinone. The pseudo-Cs-symmetric complexes and their intermediates has been characterized by ESI-MS, IR, 1H NMR and 13C NMR. For the Cr-Co bissalen complex, the target complex was a Cr(III)-Co(II) complex. MS spectra indicate that the obtained complex is instead a Cr(III)-Co(III) complex with a fifth ligand on the cobalt. The identity of this fifth ligand is most likely a chloride ion but has not been confirmed. Elemental analysis to elucidate the exact element composition was attempted but no conclusive results were obtained. Kiralitet (från grekiskans cheiʹr ’hand’) är en symmetriegenskap som är viktig bland annat inom kemin. En kemisk förening kallas kiral om den skiljer sig från sin spegelbild. De två spegelbildsformerna (även kallade enantiomerer) förhåller sig till varandra som en högerhand till en vänsterhand – hur du än vrider och vänder på den ena kan du inte få den att överlappa med den andra. Två enantiomerer har samma fysikaliska egenskaper, t.ex. smält- och kokpunkt och densitet, men skiljer sig åt när de interagerar med andra kirala objekt (försökt till exempel sätta en högersko på en vänsterfot). <br /> <br /> Naturen innehåller en oändlig mängd kirala molekyler. Man kan tycka att båda formerna av en kiral molekyl borde vara lika vanligt förekommande, men det visar sig att naturen oftast bara använder den ena av de båda enantiomererna. Exempel på detta är aminosyror och sockerarter, kemiska föreningar som är viktiga byggstenar i enzymer och nukleinsyror, som nästan enbart förekommer som den ena enantiomeren. Eftersom människokroppen är uppbyggd av kirala molekyler utgör den en kiral omgivning, där två olika enantiomerer kan ha olika egenskaper. <br /> <br /> Många läkemedel består av kirala molekyler. Det är därför viktigt att kunna framställa de båda enantiomererna i ren form var för sig, då de kan ha helt olika effekt i cellen. Ett välkänt exempel på detta är läkemedlet talidomid, som såldes under 1960-talet under namnet Neurosedyn till gravida kvinnor mot illamående. Talidomid är en kiral molekyl men läkemedlet såldes som ett racemat, en blandning som innehåller lika delar av de båda enantiomererna. Tragiskt nog visade det sig att den ena enantiomeren hade en lugnande effekt, medan den andra gav upphov till fosterskador.<br /> <br /> Det finns flera olika metoder för framställning av kirala substanser i ren form. Katalytisk asymmetrisk syntes, där en kiral katalysator används för att styra syntesen så att produktion av den ena enantiomeren gynnas, är ett av de mest aktiva forskningsområdena inom modern kemi. Ett exempel på asymmetrisk syntes är den asymmetriska ringöppningen av epoxider, vilken kan katalyseras av en typ av kirala metall-salenkomplex. Efter att studier visat att två molekyler av komplexet är involverade i den katalytiska mekanismen har nya typer av komplex utvecklats där två salenenheter länkats samman och på så sätt gett en effektivare katalys.<br /> <br /> I det här arbetet har två stycken nya heterobimetalliska bissalenkomplex syntetiserats, ett med krom och kobolt och det andra med krom och mangan. Komplexen bygger på en tidigare outforskad designprincip, där symmetrin hos en meso-ligand bryts genom koordination av två olika metalljoner. De syntetiserade komplexen förväntas katalysera den asymmetriska ringöppningen av meso-epoxider av TMSN3 med hög effektivitet och enantioselektivitet. 2017 eng heterometallic complexes organisk kemi organic chemistry Chemistry 8904681 2017-03-16T15:59:12+01:00 2017-07-05T08:53:46+02:00 2017-07-05T08:53:46+02:00

oai:lup-student-papers.lub.lu.se:8905051 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Daphne le author 8902732 Assistant Professor Irene Rodrigues Meizoso supervisor Department of Chemistry v1000647 department Hydrogenation is a universal reaction, which is widely used in industry and academy. However, the reaction is not easy to be studied in extreme conditions such as high temperature and high pressure. On top of that, using Raman spectroscopy to observe the reaction is not so customary. Due to these aspects, the experiment was carried out. During the working process, the degradation reaction was also observed to try whether the technique could apply to all type reactions. Raman spectroscopy is a powerful method, which has a better resolution than such as infrared spectroscopy that can provide complete information about molecule structure of a compound. Therefore, the method is a suitable technique when several compounds studied. <br /> <br /> Our work was based on Raman spectroscopy in-situ to develop methods to study the kinetics of two chemical reactions: hydrogenation under high-pressure and degradation. The method was used to monitor the change in intensity of the significant peaks with time and it would be applicable to all substrates. <br /> <br /> Before the hydrogenation reaction under high-pressure was studied, several fluorescence-tests for acetonphenone (reactant), phenathroline and pyridon (ligands), iron (acac)3 (catalyst) dissolved in different solvents were acquired to make sure that significant signals of the reaction could be detected and monitored by Raman spectroscopy. The results showed that fluorescence came from two ligands: pyridon and phenanthroline. However, it was possible to detect the signal of the carbonyl group from reactant, acetonphenone. Based on the promising results, the reaction hydrogenation kinetics of acetonphenone into phenanthroline in ACN, in the presence of iron (acac)3, and K2CO3 under high pressure (100 bars) and high temperature (110°C) could be studied by in-situ Raman spectroscopy. Unfortunately, the seals of the studying high-pressure vessel were destroyed by the solvent and the experiment had to be stopped. <br /> <br /> The degradations of beta-carotene, ascorbic-acid and quercetin by exposure to light at room temperature were studied. At the wavelength 532 nm that used in the experiment, all three compounds emitted fluorescence. The relevant signal corresponding to the degradation of beta-carotene could be detected but not monitored due to fluorescence. Whereas, no signals from ascorbic acid and quercetin could be found because fluorescence caused a high base line and all the signals were overlapped by it. The experiments therefore could not be continued further. <br /> <br /> Due to fluorescence and the destroyed seals, the degradation and hydrogenation, respective could not be studied further. Raman spectroscopy is a suitable method for hydrogenation reaction because the obtained spectrum can show complete information of a compound. However, it does not work so efficiently in degradation reaction. Otherwise, the method would be developed and validated by using well-known hydrogenation and degradation reactions.<br /> <br /> Keywords: Raman spectroscopy, chemical kinetics, hydrogenation under high-pressure, degradation, beta-carotene, ascorbic acid, quercetin. När vi påstår att en reaktion är snabb, vad är det exakt vi menar? För att förenkla saken, en snabb reaktion betyder att omvandlingen från reaktant till produkt sker inom ett kort tidsintervall. En explosion är ett exempel på en snabb reaktion. Motsatt är en långsam reaktion som produkten genereras över en längre tidsperiod, exempelvis vid korrosion. Hastighet av reaktion kan studeras genom att kontrollera förändringen i koncentration av antingen reaktanten eller produkten med tiden. Beroende på vilken del av reaktionen som studeras, substratkonsumtion eller produktbildning, kan hastigheten av processen uppträda efter ett mönster. Detta kallas för kinetik. Målet är att med hjälp av Ramanspektroskopi utveckla en metod för att studera kinetiken av två kemiska reaktioner: hydrogenering av omättade föreningar och självnedbrytning av naturprodukter. I ett sådant arbete är det viktigt att kunna identifiera de karakteristiska signaler som skulle kunna användas för en kinetisk undersökning. En utmaning som fås under arbetsgången är att kunna bevisa om detektionsgränsen (LOD) och kvantifieringsgränsen (LOQ) i den använda tekniken är tillräckligt bra för att kunna utföra studien. De två gränserna påverkas av provtyp och Raman-instrument. Instrumenten består av en ljuskälla, här användes en grön laser med våglängden 532 nm, en detektor och en Charged Coupled Device (CCD) kamera. <br /> <br /> Första reaktionen som studerades var hydrogenering. Hydrogenering är en kemisk reaktion där väteatomer adderar till en förening som har dubbel eller trippel bindningar i närvaro av en katalysator. Hydrogenering är en viktig reaktion med applikationer både inom industri och akademi. I detta arbete studeras omvandlingen av reaktanten, acetonfenon till produkten, 1 - fenylethanol i närvaro av en komplex av katalysator i metall saltet, järn (accac)3 och en ligand. Reaktionen observeras vid 110℃, med trycket mellan 100 och 200 bar och i närvaro av vätgas (H2). Innan kinetiken av hela reaktionen undersöktes, utfördes tester med olika lösningsmedel och metalljoner för att optimera reaktionen. Den optimerade reaktionen användes vidare för att studera kinetiken i en högtrycksreaktor. Ett problem med materialet av trycksisoleringen uppstod vid reaktionsgång samt tiden som krävdes för att upphetta reaktionen till 110℃ var för lång.<br /> <br /> Andra reaktionen är molekylärnedbrytning. Beta-karoten (vitamin A), askorbinsyra (vitamin C) och quercetin är naturligt förekommande föreningar som har antioxidativa egenskaper. Under återvinningsprocessen från naturliga källor kan molekylerna brytas ner av ljus och luft. Syftet är att studera hur föreningarna bryts ner under belysning av en halogenlampa vid rumstemperatur. Experimenten utfördes under enkla förhållanden där proverna förvarades i transparenta vialer och utsattes för en vanlig halogenlampa. På grund av dessa betingelser blev resultatet inte som förväntat. Inga signifikanta signaler kunde detekteras i askorbinsyra och quercetin. En relevant signal av beta-karoten identifierades och kunde användas för att studera kinetiken. Experimenten kunde inte utvecklas vidare eftersom tiden för den fullständiga nedbrytningen skulle ta upp till 200 timmar. 2017 eng Raman spectroscopy chemical kinetics hydrogenation under high-pressure degradation beta-carotene ascorbic acid quercetin analytical chemistry analytisk kemi Chemistry 8905051 2017-03-25T19:57:44+01:00 2018-02-01T11:43:40+01:00 2018-02-01T11:43:40+01:00

oai:lup-student-papers.lub.lu.se:8905624 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Zoe Barakat author 8905622 Marie Wahlgren supervisor Food Technology and Nutrition (M.Sc.) v1000294 department No suitable contrast agent for bowel diagnostics exists on the market today. A solution may be a new potential food-based contrast agent called Lumentin, which is based on foaming egg white. To gain new knowledge about the contrast agent, the objectives of this project were to study the physiochemical properties of different egg white powders (A-F) that can be used to prepare Lumentin and their foam stabilities. These studies were performed using many different methods, including DSC, rheology measurements, surface tension measurements, and stability experiments. The physiochemical properties provided knowledge about the proteins in the egg white powders, leading to conclusions that powders with a longer heat treatment and hence more denatured proteins gives a more stable foam. The gained results showed that egg white powder A gives the most stable foam and should therefore be used for preparation of Lumentin. Inget lämpligt kontrastmedel för tarmdiagnostik finns på marknaden idag. En lösning<br /> på det här kan vara ett nytt potentiellt livsmedelsbaserat kontrastmedel som kallas för Lumentin. Lumentin är ett negativt kontrastmedel som är baserat på äggvita. https://lup.lub.lu.se/student-papers/record/8905624/file/8905625.pdf application/pdf 16313297 yes 2017 eng Pharmaceutical Technology Läkemedelsteknologi Chemistry https://lup.lub.lu.se/student-papers/record/8905624/file/8905628.pdf application/pdf yes 8905624 2017-04-10T11:53:49+02:00 2017-04-19T11:42:57+02:00 2017-04-19T11:42:57+02:00

oai:lup-student-papers.lub.lu.se:8905957 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Gustav Améen author 8905955 Tobias Essunger author Mikael Nolin supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department The production of TMP (Trimethylolpropane) is important for many applications, and is used as alkyds in paint and lubricants among others. The reactions producing TMP consist of two major reaction chains, Aldol condensation and Cannizzaro reaction. To get a deeper understanding and improve the running conditions the kinetic expressions for the reactions were examined. The aim of this paper was to produce kinetic data that would not deviate more than 10 % from the experimental values. In addition, an optimization over the reactor was made to find the best operational conditions based on the kinetic expressions. A system of reaction rates was constructed using a modified Arrhenius equation with an added reference temperature. To calibrate the model several experiments were used together with a single objective differential evolution algorithm. By running several calibrations with different conditions the best weighing and minimization unit were established. The result had a deviation of almost 15 % for TMP and around 20 % for Di-TMP (Di-Trimethylolpropane) while the other substances produced a higher deviation. The result did not fully meet the requirements but the deviation between TMP in the model and experimental data was no greater than 20 percent which was deemed acceptable. The optimization of the reactor showed that the productivity, per the approximated reaction parameters, could be increased by decreasing the batch time whilst still maintaining a high yield. Furthermore, a purer product could be produced, with a small productivity loss, if the temperatures over the reactor was decreased from 50 to about 30 degrees C. TMP, kort för Trimetylolpropan, är en kemisk komponent som används som byggsten för alkydproduktion inom färgindustri samt som komponent i syntetiska smörjmedel. Perstorp har under drygt 50 år producerat TMP för vidare försäljning till andra kemiska industrier. Under denna period har produktionskapaciteten ökat många gånger om. Denna produktivitetsökning har kommit som följd av ett ”trial and error” förfarande där olika driftsparametrar undersökts för att öka effektiviteten i reaktorn. Processen är nu så pass förfinad att det blivit allt svårare att förbättra produktiviteten genom att testa sig fram. Angreppssättet som testats i detta arbete är att istället sätta ihop en reaktionskinetisk modell som beskriver storleken på alla väsentliga reaktionshastigheter i reaktorn som funktion av driftsförhållandena.<br /> TMP-reaktorn består av ett komplicerat nätverk av olika reaktioner som i modellen beskrivs via Arrhenius ekvationer och första ordningens beroende av reaktant koncentrationerna för var reaktion. Systemet sattes upp så att det kunde köras med en Ordinary Differential Equation (ODE) lösare i SCILAB (ett beräkningsprogram som påminner mycket om MATLAB). Modellen resulterade i ett system där 28 okända parametrar var tvungna att skattas. Då data sparats från olika experiment som testat TMP-utbytet vid olika driftparametrar kunde systemet kalibreras mot dessa. Olyckligtvis var de tidigare experimenten inte konstruerade för att undersöka kinetik och således var i de flesta fall endast data från jämviktslägena sparade. <br /> Kalibreringen skedde med en Differential Evolutions (DE) algoritm som medhjälp av ett evolutionssystem med ”naturligt urval” och kombinationer av tidigare gissningar söker sig mot systemets optimala lösningar. De skattade parametervärdena kunde sedan förutspå TMP produktionen vid experiment som inte använts i kalibreringen med en precision på ±20%. Biprodukterna från reaktorn erhöll en mycket större procentuell avvikelse vilket påvisar att det finns svagheter i den kalibrerade modellen samt möjligtvis i de uppmätta koncentrationerna mot vilken kalibreringen skett.<br /> Den resulterande optimeringen visar på att det mycket väl kan vara så att den nuvarande processen kan erhålla större utbyte av TMP genom att sänka reaktorstemperaturen utan att förlänga reaktionstiderna. Tvärt om visar modellen på att den tid inom vilken reaktionsjämvikt inställt sig är betydligt kortare än vad idag används vid fabriken som batchtid för reaktorn. Vidare konstateras att modellering av reaktorn innebär ett stort steg framåt i förståelse för hur man på bästa sätt bedriver TMP-syntesen och att experiment som utformas för att bättre undersöka reaktionskinetiken borde utföras för att på bästa sätt skatta reaktionskonstanter. https://lup.lub.lu.se/student-papers/record/8905957/file/8906073.pdf application/pdf 2941301 no 2017 swe reactor modelling TMP kinetics Tri-methylol-propane chemical engineering kemiteknik Chemistry Technology and Engineering 8905957 2017-04-20T09:48:24+02:00 2017-04-25T13:19:25+02:00 2017-04-25T13:19:25+02:00

oai:lup-student-papers.lub.lu.se:8905976 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Julia Scheffel author 8905974 Johan Svensson Bonde supervisor Pure and Applied Biochemistry v1000655 department Antibodies have become immensely important reagents within biomolecular research and analysis as well as in medicine. Monoclonal antibodies are the largest class of biological drugs and with an increasing number of therapeutic antibodies approved for clinical use the need for efficient<br /> purification strategies is vast. Today, most antibodies are purified using affinity chromatography based on Protein A, an extensively researched protein. However, a major drawback of Protein A is the need for a low pH (2-3) to elute the antibodies from the purification column. Since acidic<br /> pH poses the risk of aggregation and even loss of function of the antibody, these harsh elution conditions have been avoided by the development of a Protein A based IgG binding protein domain Zmat8 with calcium dependent behavior. The antibodies can instead be purified by EDTA at pH<br /> 5.5, and in this master thesis project the protein domain Zmat8 is optimized by the development of multimeric variants. The multimeric variants were designed and cloned followed by production and purification of the proteins Zmat8MonoCys, Zmat8DiCys, Zmat8TriCys and Zmat8TetCys.<br /> They were immobilized onto a cysteine reactive matrix and tested as affinity chromatography ligands in an IgG-purification set up. The aim was to find a ligand with a higher binding capacity than the monomer that can purify larger amounts of IgG. Based on the purification tests, the amount of eluted IgG appears to increase with the length of the protein ligand and subside after<br /> Zmat8TriCys. Zmat8TriCys and Zmat8TetCys appear to cause the most efficient antibody purification with slightly more IgG eluted by Zmat8TriCys. Consequently, this master thesis project has optimized the novel protein domain Zmat8 by enabling more efficient antibody purification at mild elution conditions with significantly reduced risks of aggregation or loss of<br /> function compared to traditional Protein A affinity chromatography. Proteins that are built by several identical subunits are shown to be more efficient tools to isolate antibodies from a mixture of proteins compared to a protein with one single subunit. That is likely because the proteins of several subunits are large enough to catch and fish out more antibodies out of the mixture. https://lup.lub.lu.se/student-papers/record/8905976/file/8905979.pdf application/pdf 59356215 yes 2017 eng Calcium dependent Zmat8 Protein A Antibodies Purification Multimeric variants applied biochemistry tillämpad biokemi Chemistry Technology and Engineering https://lup.lub.lu.se/student-papers/record/8905976/file/8905978.pdf application/pdf yes 8905976 2017-04-20T14:33:09+02:00 2017-09-19T15:26:55+02:00 2017-09-19T15:26:55+02:00

oai:lup-student-papers.lub.lu.se:8906083 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Jesper Schwarz author 8906012 Lu Yu supervisor Prof Peter Somfai supervisor Department of Chemistry v1000647 department We have investigated the synthesis of anti-β-Hydroxy-α-amino Esters from the corresponding β-Keto-α-amino Esters. The coupling of Asymmetric Transfer Hydrogenation (ATH) with Dynamic Kinetic Resolution (DKR) allows us to control the relative and absolute stereochemistry of the product. The procedure uses a 1:2 mixture of formic acid and triethylamine as hydrogen source, and (S,S)-[RuDPAE(mesitylene)Cl] as catalyst. A substrate scope of different aryl-substituted olefin possessing β-Keto-α-amino Esters have been studied. This shows that the substituents influence the yield, but less the dr and er. High dr and er were obtained for all products. Om du tar dina två händer, så ser du att de är spegelbilder. Däremot är din vänsterhand inte identisk med din högerhand. De går inte att placera på varandra, utan måste läggas handflata mot handflata för att passa ihop. Detta kallas kiralitet. Kroppen är enda ner på molekylnivå kiral, det vill säga även de minsta byggstenarna i cellerna är kirala. När ett läkemedel designas vill man att det ska passa som handen i handsken, bokstavligt talat, på den molekyl det ska verka på. Detta leder till att man kanske bara vill tillverka den vänsterhänta läkemedelsmolekylen. Högst sannolikt så har den högerhänta läkemedelsmolekylen helt andra effekter på kroppen, som kanske inte är önskvärda.<br /> Produkten som tillverkas i det här arbetet kan finnas i totalt fyra olika varianter, som är spegelbilder av varandra två och två. Alla fyra molekylerna har dock exakt samma atomer och bindningar. Att vi kan få fyra olika varianter av samma molekyl beror på att vårt startmaterial består av båda spegelbilderna, det vill säga både vänsterhänta och högerhänta molekyler. Genom att använda en katalysator som också är kiral, kan vi styra reaktionen så att vi bara får den ena av de fyra varianterna av produkten. Katalysatorn funkar som en högerhandske som matchar den högerhänta startmolekylen bäst, vilket gör att den högerhänta startmolekylen reagerar fortast.<br /> Den kirala produkten som vi får ut kan sedan användas som byggsten när vi vill bygga större molekyler, t. ex. antibiotika eller läkemedel mot cancer. Om vi istället skulle ha använt alla fyra varianterna för att försöka bygga dessa läkemedel kanske de inte skulle ha någon effekt alls, eller en helt annan effekt. https://lup.lub.lu.se/student-papers/record/8906083/file/8906084.pdf application/pdf 1560971 yes 2017 eng ATH Dynamic Kinetic Resolution Asymmetric Transfer Hydrogenation DKR organic chemistry organisk kemi Chemistry 8906083 2017-04-24T13:37:48+02:00 2017-05-02T13:11:35+02:00 2017-05-02T13:11:35+02:00

oai:lup-student-papers.lub.lu.se:8907451 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Felix Lundkvist author 8905604 Dr Crispin Hetherington supervisor Dr Anwar Ahniyaz supervisor Centre for Analysis and Synthesis v1000651 department Morphology, structure and chemistry have been investigated for 17 different commercial graphenegrades,all labeled as different kinds of graphene powder. For objectivity reasons, all powders have been given names as Graphene A-Q instead of their real product names. Out of the 17 tested powders, only Graphene A and B showed consistent results of being graphene-like. All powders have been characterized by SEM. The SEM results showed large difference between the powders, some seemingly containing exfoliated graphite, and some containing nanosized carbon particles resembling carbon black. From these results the different grades were divided into 4 classes. Class 1 (Graphene A, B and C)and 2 (Graphene D,E, K, L, M and N) which held the overall best apparent quality were selected for further investigation. These powders were characterized using XPS, XRD and Raman spectroscopy. XPS<br /> results showed that all examined powders contained between 94-98.8 at% carbon, where the rest is mostly oxygen. All powders contained some amount of sulfur, probably left from the synthesis. XRD results showed that only Graphene A, B, C and partly D contained a graphene-like phase, the others contained a purely graphitic phase in powder form. Raman spectroscopy showed a wide range of defect density in the investigated powders, where Graphene D and E contained the least amount of disorder.<br /> Graphene A and B showed slightly more, but still showed good results. No powder gave a signal of being single-sheet graphene in the Raman spectroscopy. Graphene B was also investigated in TEM, where the presence of single- to few layer graphene could be confirmed. Out of 17 commercially available graphene powders only 2 or 3 seemed to contain actual graphene, according to characterization carried out in this project. These results reveal a market where customer cannot trust manufacturer, and where there is a great need for standardization and common nomenclature. https://lup.lub.lu.se/student-papers/record/8907451/file/8918058.pdf application/pdf 10737003 yes 2017 eng Graphene Graphene Oxide Graphene Quality Graphene Powder Graphene Barrier Graphene Characterization SEM Scanning Electron Microscope Scanning Electron Microscopy TEM Raman spectroscopy XPS XRD Chemistry https://lup.lub.lu.se/student-papers/record/8907451/file/8907463.pdf application/pdf Popular science summary of the report "Characterization of Commercial Graphene Powders". no 2017-06-01 8907451 2017-05-18T14:49:27+02:00 2017-06-21T16:19:38+02:00 2017-06-21T16:19:38+02:00

oai:lup-student-papers.lub.lu.se:8952458 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH3 Tommy Dam author 8950047 Peter Jönsson supervisor Biophysical Chemistry v1000649 department The aim of this MSc-project was to investigate whether it is possible to incorporate native cell membrane components from Jurkat T cells into supported lipid bilayers, SLBs, to produce a model membrane system better resembling the native cell membranes in T cells. The procedure of forming native-like SLBs (nSLB) was adapted from an existing protocol and is done through the deposition of hybrid vesicles onto a cleaned glass slide. The hybrid vesicles are composed of synthetic lipids (PEGylated lipids and POPC) and native cell membrane components from the Jurkat T cells. Upon contact with the substrate the hybrid vesicles rupture to form the nSLB. By using this experimental protocol naturally occurring cell membrane components, such as membrane proteins, can be transferred to the bilayer. Formation of the hybrid vesicles is done through bath sonication to fuse synthetic vesicles and native membrane vesicles (NMVs). First, the most optimal sonication parameters to ensure a good mixing of the two types of vesicles was evaluated. It was found that sonicating at 35°C 45 min gave a good mixing of NMVs and synthetic vesicles. These hybrid vesicles were next used to form the nSLB, which was characterized in detail. The diffusivity of lipids in the nSLB was measured using fluorescence recovery after photobleaching and found to be 1.00 µm2/s. This was 16 % lower compared to a similar SLB without native material and similar to the diffusivity measured by others for nSLBs, indicating that an nSLB has formed. The immobile fraction of lipids was 21% for the nSLB which was significantly higher than the 5% measures for an SLB without native material. This could be due to unruptured vesicles, which could also be observed in the fluorescence microscopy images. Antibodies targeted at different T-cell proteins were finally used to investigate how well these proteins had been incorporated in the nSLB and whether they were mobile. Both the proteins CD45 and TCR could be detected at a surface concentration &lt; 100 molecules/μm2 in this way. However, essentially all of the antibodies were immobile on the nSLB, which could be due to the proteins interacting with the underlying support or being confined to vesicles. This needs to be taken into consideration if using this as a model membrane system for T cells, but for experiments where the mobility is not of primary concern then the developed nSLB could make it possible to study the interaction with T-cell membrane proteins under more controlled conditions. The cell membrane plays an important part in many of the cell’s functions. It forms a boundary between the internal and external environment of the cell and governs the exchange of essential molecules, for the cell’s survival, with its surroundings. The behaviour of the membrane and the proteins present in it, greatly affects our immune system and health. In fact, a majority of drugs in the market target some protein integrated into the cell membrane. With the presence of certain proteins embedded into the membrane, the cells in the immune system are able to communicate with each other to fight back any pathogens posing a threat against the body. The T-cell is one such cell in the immune system which is central in forming an immune response against bacteria or viruses. <br /> Studying the cell membrane and the molecules therein can therefore seem to be an obvious endeavour but is quite difficult since it is so complex. For example, there are more than 600 lipid types in most cell membranes and the contribution from each cell membrane component can be hard to quantify. A popular alternative within research has been to instead use supported lipid bilayers (SLBs), a mimic of a real cell membrane formed on a solid support. Contrary to cell membranes, the SLB is comprised of only one or two lipid types and normally only have one type of membrane protein integrated into it. This makes it easier to study the function of individual proteins. Although this system has been of great use to study how membranes behave, it is in some instances too simple when compared to a live cell membrane. The main aim of this work has been to try and form SLBs which contain a larger fraction of lipids and membrane proteins that are naturally occurring in native cell membranes. Specifically, I tried to produce SLBs that resemble the cell membrane of the immune cells called T cells. <br /> This was done by forming structures called vesicles. These structures can be imagined as planar bilayer, a membrane, which closes in on itself to form a sphere. One of the main tasks was to try and incorporate components from a real T cell membrane into these vesicle structures. This was done by optimizing a technique called sonication. When the vesicles are deposited onto a solid support, they deform and rupture to form a patch of SLB. In a real cell membrane, the lipids and proteins are able to move around in the bilayer. It is therefore interesting to investigate how fast the components are moving in the more cell-like SLB compared to the traditional SLBs which doesn’t contain any components from real cell membranes. The results show that the lipids move a bit slower in the more cell-like SLB. Similar to how it is more difficult to move around in a more crowded room, the lipids move slower when facing more obstacles from the extra added components into bilayer from a real cell membrane. <br /> I further investigated how much the SLB resembled the T-cell membrane by using antibodies. Antibodies are proteins which only bind specifically to a certain protein. By using antibodies I could detect if the membrane proteins one would expect to find on the membrane of a T cell, are present on the newly formed SLB. A few proteins could be detected on the surface of the SLB. However, the proteins seem to be quite stationary and does not move around very well. This problem is multi-facetted can be because the proteins are very large and more massive objects require more energy to move around. An additional reason may be that the proteins are still part of vesicles which haven’t ruptured, in which case they are not able to move in the bilayer that has formed. <br /> In summation, this has been an investigation into whether it is possible to create a platform to better model the cell membrane of a T cell. An experimental protocol to produce a SLB, with cell membrane components, was formed. Although the membrane proteins seem to be largely stationary, the resulting SLB could still be used to study the binding mechanism of the proteins in the SLB which does not require proteins to move. This work forms a basis which could be further expanded upon to improve the produced cell-like SLB. The tool could then be used to further study how T cells interact with other cells in the immune system, giving more insights into how the body fights off diseases. Knowing more about this process could also optimize and improve some of the strategies, used by the pharmaceutical industry, developing drugs against a certain illness. https://lup.lub.lu.se/student-papers/record/8952458/file/8952459.pdf application/pdf 2687633 no 2018 eng T cells Model membrane systems Supported lipid bilayers SLB biophysical chemistry biofysikalisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/8952458/file/8952461.pdf application/pdf yes 8952458 2018-06-23T16:56:52+02:00 2018-06-26T10:02:23+02:00 2018-06-26T10:02:23+02:00

oai:lup-student-papers.lub.lu.se:8952639 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Linus Gustafsson author 8952635 Daniel Nilsson author Niklas Andersson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Automated information flow is an important way of optimizing the time used for analyzing<br /> processes. Other added benefits are that in a well-made automated system, the probability of<br /> human error diminishes because less liability is put on the person to manually transport and<br /> utilize the data. This notion of automation can be applied to the field of chromatography.<br /> <br /> This thesis investigates the possibility of integrating modelling softwares (Matlab and JModel-<br /> ica.org) into the control software of a chromatography system for an automated information<br /> flow. This integration can be utilized for automated calibration and optimization of the process<br /> which will save a lot of time and work with data handling.<br /> <br /> The software integration has proved successful and data can be passed from the control software<br /> to the modelling softwares automatically. The main control center is Python which controls the<br /> events and extracts data from the chromatography system as well as calling the modelling soft-<br /> ware with defined input parameters. Matlab has been utilized to make an Experiment – Cali-<br /> bration – Optimization (ECO) scheme and JModelica.org has been used to simulate the chro-<br /> matography process. The ECO scheme has not been fully automated, which is the next step to<br /> take where multiple experiments are conducted and the best result is chosen to proceed in the<br /> ECO scheme making it possible to automate. Automation: Optimering av din tid<br /> <br /> Tänk dig att du har fått en deadline på ditt nya projekt. Ditt arbete för projektet beror<br /> helt på din praktiska noggrannhet och tidsoptimering, samtidigt så ska du lämna in<br /> massvis med pappersarbete. Du har en tuff tid framför dig ifall du ska klara detta på egen<br /> hand inom tidsramen. Här kommer automatisering in i bilden. Det noggranna och<br /> tidskrävande arbetet som du behöver göra kan du hålla i ordning och göra smidigare ifall<br /> din process automatiseras. Detta ger dig mer tid över att utfärda pappersarbetet på ett<br /> bra sätt.<br /> <br /> Om vi återgår till vetenskapens värld så kan man applicera liknande tankebanor kring<br /> upprening av läkemedel. För att kunna förutspå hur en uppreningsprocess ska bete sig<br /> behöver processen modelleras i en dator. Informationsflödet mellan datorn och processen, även<br /> utbytet av information mellan mjukvaror i datorn, kan göras manuellt eller automatiserat.<br /> Automatiseras informationsflödet så kan hela informationsutbytet ske i ett steg till skillnad från<br /> vid manuellt utbyte där flera steg är ett måste. Denna automatisering kommer ej utan sina<br /> smärtor, men när den väl är implementerad så sparar den massvis med börda och tid för<br /> kommande arbete.<br /> <br /> I ett examensarbete från Lunds Universitet har Matlab och Python, två väldigt väl använda<br /> mjukvaror, kopplats samman genom en Application Programming Interface (API). Python<br /> hanterar det huvudsakliga informationsflödet där experimentella resultat importeras från<br /> uppreningsprocessen för att sedan användas tillsammans med Matlab för att få en bild av hur<br /> processen bör bete sig. I Matlab har en modell av uppreningsprocessen skapats och kräver<br /> endast att man nämner vilka betingelser som processen sker vid för att få en simulering av<br /> processen.<br /> <br /> Ett alternativt modelleringsprogram har även testats i examensarbetet vid namn JModelica.org<br /> som först utvecklades vid Lunds Universitet och som sedan tagits över av Modelon AB.<br /> Skillnaden mellan Matlab och JModelica.org är att JModelica.org är skapad specifikt för<br /> industriell simulering och optimering medan Matlab har en mer allmän anfallsvinkel.<br /> Dessa båda modelleringprogrammen har alltså en koppling till informationsflödet som sker från<br /> uppreningsprocessen och kan användas för att förutspå hur väl den modellerade processen<br /> kommer att fungera. På grund av det integrerade informationsflödet kan all simulering göras i<br /> ett steg och sparar mycket tid som annars går till spillo vid informationshantering.<br /> Förhoppningen är att kunna automatisera andra systems informationsflöde med denna teknik<br /> för att optimera personers tidsanvändning och för att minska den mänskliga faktorn vid<br /> experiment. https://lup.lub.lu.se/student-papers/record/8952639/file/8952662.pdf application/pdf 10608858 no 2018 eng Chromatography ÄKTA ÄKTA system Programming Matlab JModelica.org Modelling Calibration Optimization Python Orbit OPC Open OPC Unicorn Matlab API for Python Lysozyme Cytochrome C Ribonuclease A FMU ECO biopharmaceutical industry proteins purification of proteins ÄKTAexplorer JModelica Auto calibration Automation chemical engineering kemiteknik Chemistry Technology and Engineering 8952639 2018-06-25T10:57:53+02:00 2018-08-03T10:59:19+02:00 2018-08-03T10:59:19+02:00

oai:lup-student-papers.lub.lu.se:8952976 2025-07-29T13:03:30Z Medicine PhysicsChemistryMaths Technology

studentPublicationsH2 Alexandra Petersson author 8952681 Solmaz Hajizadeh supervisor Linda Elowsson supervisor Pure and Applied Biochemistry v1000655 department Computational Chemistry v1000659 department The demand of healthy functional lungs is increasing, requiring a greater need of knowledge about lung tissue regeneration and repair. Glycosaminoglycans (GAGs) – polysaccharide sidechains found on proteins in the extracellular matrix (ECM) – are believed to be involved in several processes in the lung including cell proliferation, cell differentiation and tissue regeneration. We have developed a macroporous hydrogel (cryogel) scaffold as a model system that can easily be modified with different types of GAGs to study their impact on cellular behavior. The synthetic scaffold offers a 3D environment mimicking the ECM with minimal interference in our analyses. Our aim is to find GAGs that promote lung tissue regeneration.<br /> <br /> The cryogels (Ø 0.5 cm x 1 cm) were produced using free radical polymerization at partly frozen condition with two main materials – Hydroxyethyl methacrylate and Acrylamide. The cryogels were sliced into 1 mm discs before modified with the desired GAG – Chondroitin sulfate (CS) or Chondroitin Dermatan sulfate (CS/DS). GAG attachment was confirmed by disaccharide analysis. The modified scaffolds were seeded with lung fibroblasts and cultured for 24 hours before gel structure and cell behavior were analyzed. Prior to modification, the non-modified scaffolds were evaluated for cell culture during 7 days. <br /> <br /> From our results we may conclude that the cryogel is a suitable model system for studying the impact of GAGs on lung fibroblasts. The cells were able to attach and spread on the material and the GAGs do affect cell behavior differently depending on the specific GAG and concentration used. Future work may include optimization of the cryogel as well as evaluating different combinations of GAGs and pulmonary cells to find cues promoting lung tissue regeneration. Vad gör vi när avgaser och cigarettrök förstört våra lungor? Vad gör vi när behovet av friska lungdonatorer blir för stort? Vi försöker tillverka lungor i labbet såklart! <br /> <br /> Våra lungor utsätts dagligen för avgaser och andra skadliga ämnen som finns i luften runt omkring oss. För det mesta kan kroppen reparera skadan på egen hand, men allteftersom påfrestningarna blir för stora höjs risken att misslyckas. Sjukdomar såsom kroniskt obstruktiv lungsjukdom (KOL) och idiopatisk lungfibros har ökat de senaste åren och den enda behandlingen i slutändan är att göra en lungtransplantation. Det finns dessvärre inte tillräckligt med friska donatorer och dessutom innebär transplantationer ofta andra problem såsom bortstötning av organet. Ett alternativ till transplantation tror forskare kan vara att ”odla” ny lungvävnad utanför kroppen – i labbet! https://lup.lub.lu.se/student-papers/record/8952976/file/8952981.pdf application/pdf 8198884 LU/LTH access 2018 eng tissue engineering medicine lung biology chemistry polymer glycosaminoglycans biotechnology engineering biochemistry applied biochemistry tillämpad biokemi Medicine and Health Sciences Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/8952976/file/8952986.pdf application/pdf no 8952976 2018-06-26T09:55:34+02:00 2018-06-27T12:45:03+02:00 2018-06-27T12:45:03+02:00

oai:lup-student-papers.lub.lu.se:8953109 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Lucas Lissner author 8928679 Åsa Håkansson supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Non-alcoholic beer is gaining more attention in the brewing industry due to the negative health and economic consequences of alcohol consumption, even smaller microbreweries are showing interest in the production of non-alcoholic beer. Producing non-alcoholic beer has been restricted to the large breweries due to the special equipment needed and the high investment costs, but by using biological methods the process can be adapted to a traditional brewing setup. This involves using the special maltose negative yeast strain Saccharomycodes ludwigii and changed mashing step. The pure strain DBVPG 3010 has shown promising results in a screening study, producing high levels of desirable sensory compounds to mask the off-flavors usually a consequence of limited fermentation. This yeast will be compared with the commercially available yeast S. ludwigii WSL-17. <br /> The aim of this master thesis is to develop a method for producing non-alcoholic beer customized for traditional brewery equipment and to test the produced beers in a sensory evaluation to judge the potential of the method. One of the primary objectives was to develop a method to produce a starter culture with adequate cell concentration and ensuring viability. <br /> The results show that a suitable starter culture can be made using malt extract fortified with fructose with a magnetic stirrer and calculating cell concentration with a microscope and Burker chamber with methylene blue straining. The sensory evaluation gave positive results, from both expert panel and difference test, indicating that S. ludwigii DBVPG 3010 has high potential in small scale non-alcoholic beer production. Användning av den maltosnegativa jäststammen Saccharomycodes ludwigii för tillverkning av alkoholfri öl, metodutveckling. <br /> I detta projekt har en metod utvecklats som ger mikrobryggerier möjligheten att tillverka alkoholfri öl.<br /> I takt med att fler blir medvetna om alkoholens negativa effekter, ökar intresset för alkoholfri öl, även hos väldigt små bryggeriet, så kallade mikrobryggerier. Då det krävs speciell utrustning och stora investeringar för att producera alkoholfri öl, har den stora majoriteten av mindre byggerier bara haft möjligheten att producera lättöl. <br /> Metoden utnyttjar en speciell jäststam, Saccharomycodes ludwigii, som till skillnad från vanlig öljäst inte kan omvandla maltos till etanol. Eftersom maltos är den dominerande sockerarten i vört (maltbaserad sockerlösning som jäses till öl) kan man reducera alkoholhalten ner till en femtedel bara genom användandet av jästen. Genom att designa ett recept med mindre total sockermängd kan den slutliga alkoholhalten i ölet reduceras till under 0.5%. Två av de större utmaningarna med att använda denna speciella jäst är att det kan vara svårt att få jästen att växa och jäsa ordentligt och att det slutliga ölet blir för sött på grund av maltos som finns kvar.<br /> Eftersom det är lite socker jästen kan använda för tillväxt är det viktigt att använda en starterkultur som har en tillräckligt hög cellkoncentration för en lyckad jäsning, det är också av vikt att ha en metod för att kunna kontrollera cellkoncentrationen och hur stor andel av cellerna som är levande. För att undvika att det slutliga ölet blir för sött kan man modifiera vissa av ölbryggningens steg, i detta projekt har mäskningen (här blandas vatten med krossad malt och sockret löses ut i vätskan under uphettning) modifierats för att minska bildningen av maltos. Istället främjar ändringen bildningen av längre kolhydratkedjor som är mindre söta än maltos och istället bidrar med smak och fyllighet till det slutliga ölet. <br /> Resultaten visar att en ölbryggare med relativt enkla metoder och utrustning kan producera en starterkultur med kontroll över cellkoncentration och aktivitet som sedan kan användas för att jäsa ett alkoholfritt öl med bra sensoriska egenskaper. https://lup.lub.lu.se/student-papers/record/8953109/file/8953111.pdf application/pdf 738105 no 2018 eng Non-alcoholic beer Saccharomycodes ludwigii Changed mashing food technology livsmedelsteknologi Chemistry Technology and Engineering 8953109 2018-06-26T14:55:18+02:00 2018-06-27T13:18:28+02:00 2018-06-27T13:18:28+02:00

oai:lup-student-papers.lub.lu.se:8953886 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Simon Fridolf author 8933135 Daniel Topgaard supervisor Department of Chemistry v1000647 department The 13C mobility and cross-β-sheet structure of lipid-protein co-assemblies formed by incubating ganglioside GM3-containing model membranes with the amyloid protein α-synuclein were investigated by solid-state NMR and wide-angle X-ray scattering (WAXS) at varying lipid-to-protein ratios and membrane compositions at body temperature. The POPCGM3 model membrane was characterized by PT ssNMR and X-ray scattering, and monitored during the co-assembly process using dynamic light scattering (DLS) and zeta potential measurements. The model lipid systems were shown by SAXS, 31P NMR and cryo-TEM to form several co-existing phases at 20 wt% lipids. The mobility of the lipid main acyl chain and GM3 headgroup was found to decrease after co-assembly, while the mobility of the α-synuclein C-terminal residues was affected by co-assembly in a non-monotonic way depending on the<br /> lipid-to-protein molar ratio. Selective GM3 uptake was indicated by PT ssNMR at an excess of 30 mol% GM3 vesicles. WAXS showed that the cross-β-structure is affected by lipid-protein co-assembly, which decreases the inter-strand distance. DLS and zeta potential measurements during the incubation process show that the zeta potential of SUVs decrease during the coassembly. Parkinsons sjukdom är den näst vanligaste neurologiska sjukdomen efter Alzheimers sjukdom och drabbar årligen runt 2000 personer i Sverige. Sjukdomen drabbar oftast personer över 55 år och ger problem med nedsatt rörelseförmåga, ofrivilliga skakningar och stelhet. Idag finns ingen behandling som botar Parkinsons, och det största hindret mot utvecklingen av en effektiv behandling är bristen på kunskap om de underliggande molekylära händelserna som ger upphov till sjukdomen.<br /> <br /> Orsaken till Parkinsons är inte klarlagd, men den är en såkallad amyloid sjukdom och kännetecknas av att proteiner som finns naturligt i hjärnan veckas felaktigt och bildar fibriller, som sedan klumpas ihop i stora aggregat kallade Lewykroppar. Lewykroppar har hittats i hjärnan hos Parkinsons- och demenspatienter och förknippas med nedbrytningen av nervceller som ger upphov till sjukdomssymptomen. För att förstå den molekylära uppkomsten och dess implikationer för sjukdomsförloppet är det därför värdefullt att undersöka hur den främsta byggstenen för dessa Lewykroppar: proteinet alfa-synuklein, interagerar med sin omgivning och hur det påverkar uppbyggnaden av Lewykroppar.<br /> <br /> En stor mängd forskning har fokuserat på hur alfa-synuklein interagerar med cellmembran (vars främsta byggsten är lipider), eftersom lipider har hittats i Lewykroppar. Det har visat sig att interaktionen mellan lipider och alfa-synuklein stimulerar både aggregeringsprocessen när proteinet binder till membranytan, och att själva strukturen av membranen kan skadas vilket kan få patologiska konsekvenser. En lipidklass som kallas gangliosider är vanliga i hjärnan och utgör 10-12% av lipidinnehållet hos nervcellernas membran. De består till del av en sockergrupp som sticker ut från cellmembranet och kan användas för att interagera med proteiner eller andra molekyler och anses ha en funktion inom cellsignalering. Gangliosiden GM3 har hittats ackumulerad i hjärnor från patienter med Parkinsons sjukdom och membran som innehåller GM3 har visats accelerara aggregering av alfa-synuklein. I en studie identifierades gangliosiderna GM1 och GM3 som komponenterna av membranet som är ansvariga för effekten på aggregeringshastigheten.<br /> <br /> Traditionellt sett så har lipid-protein interaktionen studeras ur ett persepektiv där membranet anses förblir intakt, men med tanke på att interaktionen mellan protein och membran även kan skada membranet när lipider tas upp när de byggs ihop till en nya struktur så studerar vi här processen som en sam-aggregering där hela systemet förblir dynamiskt. I det här arbetet undersöks först strukturen av ett modellmembran som innehåller gangliosiden GM3, och sedan de sam-aggregerade strukturerna av alfa-synuklein och membran med hjälp av fyra olika<br /> tekniker:<br /> Kärnmagnetisk resonans-spektroskopi, som här ger atomupplöst information om hur<br /> rörligheten och ordningen av både protein och lipider påverkas beroende på hur de sitter ihop och interagerar. <br /> Dynamisk ljus- och röntgenspridning, som ger information om storlek, form<br /> och avståndsförhållanden inom strukturerna. Zeta-potential mätningar, som ger den elektriska potentialen som uppstår utanför ytan av partiklar och membran i vattenlösning och påverkas av bl.a. lipidsammansättningen. https://lup.lub.lu.se/student-papers/record/8953886/file/8953888.pdf application/pdf 3192627 yes 2018 eng NMR alpha-synuclein lipid membranes physical chemistry fysikalisk kemi Chemistry 8953886 2018-06-29T14:32:26+02:00 2018-08-05T10:08:38+02:00 2018-08-05T10:08:38+02:00

oai:lup-student-papers.lub.lu.se:8954384 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Rui An author 8952408 Kaibo Zheng supervisor Department of Chemistry v1000647 department All-inorganic CsPbI3 perovskite quantum dots (QDs) have attracted intense attention for the application in photovoltaics and optoelectronic applications due to their phase stability and great photoluminescence (PL) properties. However, the their photostability is still to be investigated in detail. In this thesis work, we studied the photostability of the CsPbI3 QDs suspended in hexane and found light illumination would induce photodegradation of CsPbI3 QDs. The steady-state spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and transient-absorption spectroscopy (TA) verified that light illumination would lead to the collapse of the CsPbI3 QDs’surface and the emergence of Pb0, which is a trapped state leading to the quench of PL and dramatic decrease of quantum yield. Our work provides some insight of the photodegradation process in CsPbI3 QDs and could lead to the optimization of such QDs towards device applications. Nowadays, we demand a huge amount of energy due to population growth and rising living standards. A substantial portion of our energy consumption is from fossil fuels (i.e. coal, oil and natural gas), that would lead to environmental pollution and global warming which are serious problems. As a suitable alternative, solar energy is renewable, clean, and cheap. It is a key to find high-performance materials to harvest and use solar energy efficiently.<br /> Many materials have been investigated towards solar cell applications. In this thesis, we are giong to study one particular type of material, lead halide perovskites. In recent years, they have attracted intense attention in various photovoltaics and optoelectronic applications such as solar cells and light-emitting diodes (LEDs) due to their great photophysical properties. While the photophysical properties in lead halide perovskite materials are very important to improve the performance of the materials and devices, to understand their photostability is also a key to realize mass application. In this thesis, we studied the photostability of one lead halide perovskite material, the CsPbI3 quantum dots (QDs are very small semiconductor particles, usually under 20 nanometres in size, 1 nm = 10−9 m) because of their high efficiency in solar cells. We also investigated the photodegradation process, i.e. what would happen and how the QDs would change upon light illumination. We find that upon illumination, some lead would emerge on the surface of the QDs, that would significantly lower its photoluminescent properties. This knowledge may be useful for optimization of such QDs towards device applications. https://lup.lub.lu.se/student-papers/record/8954384/file/8955314.pdf application/pdf 2817574 yes 2018 eng Light illumination trap state blue-shift emission quantum yield drop surface collapse photodegradation mechanism chemical physics kemisk fysik Chemistry 8954384 2018-07-04T12:38:14+02:00 2018-09-25T11:18:26+02:00 2018-09-25T11:18:26+02:00

oai:lup-student-papers.lub.lu.se:8954663 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Sofie Önnemar author 8954661 Rohit Kumar supervisor Department of Chemistry v1000647 department The enzyme Ribonucleotide Reductase (RNR) reduces ribonucleotides (NTPs) to deoxyribonucleotides (dNTPs), which are then used as building blocks in the synthesis of DNA. In this thesis are reported the expression and purification of a mutant version of Chlamydia trachomatis Ribonucleotide Reductase protein R1 , called Chlamydia trachomatis Ribonucleotide Reductase protein R1 Δ248. The R1 subunit of the “normal” version has an extended amino terminus in its primary sequence, and the R2 subunit has instead of a tyrosine, a phenylalanine. The mutant however, lacks the first 248 amino acids and therefore has a shorter amino terminus than the “normal” version. This causes it to only contain one ATP-cone instead of three, as in the normal version.[1] Results from the purification and Dynamic Light Scattering analysis suggest that even though the extended amino terminus is not vital for enzyme activity, it’s necessary for the binding of dATP. dATP-Sepharose chromatography shows that the method is not efficient in purifying this protein. The lack of ATP-cones is discussed as the reason for this occurrence. Results from the Hydrophobic Interaction Chromatography shows the protein&#39;s characteristics of high hydrophobicity, and produces the protein in a satisfactory amount. Målet med detta arbete var att rena fram proteinet Chlamydia trachomatis ribonucleotide reductase R1 Δ248. För att göra detta effektivt, med en så liten förlust av proteinet som möjligt under processen, så krävs kunskap om proteinets egenskaper. Med vetskapen att denna mutant, som saknar de första 248 aminosyrorna jämfört med den icke-muterade varianten, enbart har en ATP-kon medan den icke-muterande har tre stycken, så bör renings metoder baserade på ATP/dATP-inbindning vara undermåliga. I ATP-konerna sker själva aktiveringen samt inhiberingen av proteinets aktivitet genom att binda in antingen ATP, som ger ett aktivt enzym, eller dATP, som inaktiverar enzymet.<br /> Metoder använda i detta projekt för att rena fram proteinet består av dATP-Sepharose Chromatography och Hydrophobic Interaction Chromatography (HIC). dATP-Sepharose metoden baseras på proteinernas förmåga att binda in dATP, d.v.s. ju bättre inbindningen av ATP till proteinet är, desto bättre är reningsresultatet, då större mängd av vårt protein binder till kolonn-mediet och kan elueras. HIC baseras istället på proteinernas hydrofobicitet, d.v.s ju högre salt koncentrationen på lösningen innehållande proteinet har, desto starkare interaktion mellan proteiner och kolonnens medium. Dessa elueras sedan med en linjär gradient m.h.a. en buffert innehållande samma typ av salt, där de proteinerna med lägst hydrofobicitet elueras först. <br /> Resultatet av dATP-Sepharose kromatografin gav en låg proteinmängd, p.g.a. att proteinet enbart har en ATP-kon, och därmed binder ATP ineffektivt. Detta innebär att majoriteten av proteinet vi är intresserade av i lösningen, rinner igenom kolonnen istället för att binda in. <br /> Resultatet för HIC metoden gav en betydligt större mängd protein, vilket påvisar proteinets höga hydrofobicitet egenskap, och var i slutändan en effektiv reningsmetod. Om mer tid hade funnits hade möjligheten till en fördjupad studie av proteinets egenskaper kunnat genomföras. 2018 eng biochemistry biokemi Chemistry 8954663 2018-07-08T14:16:10+02:00 2018-08-13T12:09:00+02:00 2018-08-13T12:09:00+02:00

oai:lup-student-papers.lub.lu.se:8955361 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Yu Rui author 8955359 Margareta Sandahl supervisor Department of Chemistry v1000647 department Water is not a popular solvent for SFC because it usually causes peak distortion. In a previous study in the lab it was shown that a water/organic solvent ratio of 9:1 in sample diluent actually produced sharper peak shape compared with the ratio of 1:9. The aim of the current study is thus to do a systematic study of the effect of water in the sample diluent on the retention behaviors of the analytes and their peak shapes. Seven compounds with different physico-chemical properties were separated on eight SFC columns using sample diluents with different ratios of water in acetonitrile. Three injection volumes were tested at each ratio of water to organic solvent. The obtained results showed that the water effects on analyte retention and peak shape were compound and column dependent. As a conclusion, water in the sample solvent is quite compatible with a Diol column but very unfavourable with an HSS C18 SB column. Compared with the commonly utilized sample diluent, this observation suggests that the usage of high amount of water may favour the analysis of certain compound types, and this may lead to a wider application of SFC to analyse polar and ionizable compounds which are not soluble in conventional SFC sample diluents. Supercritical fluid chromatography is a very environment-friendly analytical technique since it utilizes mainly carbon dioxide during sample analysis. However, in the real application of this technique, the samples being analyzed usually need to be dissolved in organic solvent, which leads to a difficulty of analyzing polar and ionizable compounds due to the poor solubility of the analytes in the sample diluent.<br /> Water is not considered as a good solvent in supercritical fluid chromatography because the usage of water in the sample diluent usually causes peak distortion. However, in one of our previous works, it had been observed that water used in the sample diluent had helped the formation of nicer peak. As a result, this current study focused on a systematic study regarding the effect of water in sample diluent on the performance of supercritical fluid chromatography. Seven analytes were analyzed on four different types of columns, and sample diluent containing four different ratios of water in a polar organic solvent were tested. The results showed, similar as what our previous work had observed, water facilitated the formation of nicer peaks, and this effect was column and analyte dependent. The hypothesis is that the water in the sample diluent may induce a water layer inside the Diol and Silica columns with polar stationary phases, which favored the analysis of compounds with larger polar surface areas (sulfanilamide and cortisone). In conclusion, using water in sample diluent is not always bad but it could be applied to improve the performance of supercritical fluid chromatography on certain cases. 2018 eng peak shape retention sample solvent effect supercritical fluid chromatography analytical chemistry analytisk kemi Chemistry 8955361 2018-08-01T13:31:42+02:00 2018-09-25T11:21:15+02:00 2018-09-25T11:21:15+02:00

oai:lup-student-papers.lub.lu.se:8956910 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Jan Romano de Gea author 8956908 Daniel Strand supervisor Department of Chemistry v1000647 department Enantioselective synthesis is an important research topic with applications in drug development. Asymmetrical catalysis is one of the available ways of producing enantioenriched products. <br /> C2-Symmetric dibenzo[a,e]cyclooctenes or dbCOTs are a family of versatile chiral ligands for transition metals. They display great efficiency and enantioselectivity in 1,2- and 1,4- additions reactions. <br /> In this work, a two-step synthesis to 5,11-R2dbCOT, initially reported in 1962 and improved by the Strand group, is presented. Methods and chemicals not widely available at that time have been used, aiming for better yields in an already efficient synthesis. It also offers a simpler, faster, milder, safer, cheaper and scalable pathway to the ligands, with minor drawbacks compared to the state of the art synthesis.<br /> Four dbCOT analogues have been synthesised and three of them have been evaluated, following the reactions by quantitative 1H NMR (qNMR). Several factors: thermal/photochemical conditions, fluoride sources, reagents, stoichiometries, concentrations and reaction temperatures have been tested and optimised. Optimal conditions have been identified for 5,6-Ph2dbCOT and 5,6-Ph2dnCOT.<br /> 5,6-Ph2dbCOT was isolated by crystallisation from warm heptane yielding 48%, which represents an important increase of 65% compared to the originally reported yield (29%) and 35% from unpublished work previously performed in the group (38%). This paves the way to an important cost reduction, a more sustainable pathway to the desired ligand, and the production capacity of covering the ligand necessity. Like your hands, some molecules exist as non-superimposable mirror-images, called enantiomers. These two enantiomers will have different properties and behave differently in chiral environments of the body. One famous example of a molecule whose two enantiomers exhibited different properties is thalidomide. It was used in the late 50’s to alleviate morning sickness in pregnant women (one enantiomer had pharmaceutical applications) but caused malformations to the foetus (the other one was teratogenic).<br /> The compounds in this research also have two enantiomers. They have a special ability: when one enantiomer of the compound reacts with another molecules, it produces one enantiomer of the product. As you can imagine, this is of great interest to scientists as, with our compounds, you can form selectively the enantiomer with useful properties. <br /> In this study, we are optimising the way we prepare these compounds to make the process cheaper, faster, safer and more environmentally friendly. We try to produce them in big amounts, so other chemists can synthesise the active components in the drugs that will heal us in the future. https://lup.lub.lu.se/student-papers/record/8956910/file/8956911.pdf application/pdf 16870160 yes 2018 eng Organic Chemistry Ligand Synthesis Asymmetric Catalysis Organisk kemi Chemistry 8956910 2018-08-26T17:45:49+02:00 2018-11-06T13:22:10+01:00 2018-11-06T13:22:10+01:00

oai:lup-student-papers.lub.lu.se:8957192 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Sandra Larsson author 8957190 Jan Forsman supervisor Department of Chemistry v1000647 department Thermoresponsive polymers with a lower critical solution temperature, LCST, have attracted interest in the development of new ``smart materials&#39;&#39;, which change properties in response to external stimuli. Polymers with an LCST near physiological temperatures are especially relevant in biomedical applications, most notably perhaps in drug delivery systems.<br /> <br /> The aim of this work is to investigate polymer solutions with an LCST using a coarse-grained model where the monomers of the polymer chains exist in one of two states; one solvophilic and one solvophobic state, where the degeneracy of the solvophobic state is higher than that of the solvophilic. Metropolis Monte Carlo simulations were performed on both single-chain and multiple-chain systems, and on chain lengths varying between 20 and 400 monomers. Simulations on single-chain systems showed a collapse for chains with 40 or more monomers, while the investigated multiple-chain systems of all chain lengths aggregated. Due to fluctuations in the temperature at which the collapse occurred, as well as inconsistencies between simulations performed by decreasing and increasing the temperature, further investigations are needed to determine the limitations of the model and its usefulness in describing polymer solution behaviour. Polymerer är långa kedjor av upprepade segment och finns både som naturliga polymerer (proteiner, DNA, gummi, och cellulosa) och som syntetiskt framställda polymerer (plaster, nylon, etc.). Många polymerer är känsliga för ändringar i deras miljö och termoresponsiva polymerer, som har studerats i detta arbete, ändrar egenskaper drastiskt vid ändringar i temperaturen. Vid en viss kritisk temperatur, som är specifik för den enskilda polymeren, går dessa polymerer från att vara utsträckta kedjor, lösliga i medlet de befinner sig i, till att kollapsa och bilda tätpackade kluster som kan fällas ut från lösningen. <br /> <br /> Termoresponsiva polymerer är intressanta att studera på grund av deras applikationer som &quot;smarta material&quot;. De kan till exempel användas inom transportsystem för läkemedel som en del av läkemedelskapseln, då de skulle kunna reagera på temperaturen i omgivningen för att veta när kapseln har kommit rätt och frisätta läkemedlet på en lämplig plats i kroppen. <br /> <br /> Datorsimuleringar med dessa typer av polymerer kan ge en större inblick i hur och varför polymererna kollapsar, samt hur olika egenskaper av polymeren och hur yttre faktorer påverkar temperaturen polymererna kollapsar vid. Simuleringar av större polymersystem, med många och långa kedjor är mycket tidskrävande och det är därför önskvärt att kunna beskriva polymerernas beteenden vid olika temperaturer med en enklare modell. I detta arbete har därför en enklare modell användts för att studera polymerlösningar. Både enstaka polymerer och större system med flera polymerkedjor har studerats och det har undersökts om det går att se en direkt koppling mellan kollapsen av en kedja och aggregeringen av ett helt system till ett hoppackat kluster. Simuleringarna har visat att modellen kan beskriva den plötsliga kollaps av polymerer som sker vid en viss temperatur både för enstaka polymerer och för flera polymerer. Det fanns dock en variation i när denna kollaps skedde för båda systemen och därför kunde inte en specifik temperatur för aggregeringen bestämmas. Det fanns även stora skillnader i förhållandena vid vilka en kollaps kunde ses för simuleringar där temperaturen ökades jämfört med sänktes. Detta är något som hade behövt undersökas nogrannare för att ta reda på modellens begränsningar i att beskriva det undersökta fenomenet. https://lup.lub.lu.se/student-papers/record/8957192/file/8957194.pdf application/pdf 1009453 no 2018 eng Monte Carlo simulations polymer solutions lower critical solution temperature thermoresponsive polymers LCST theoretical chemistry teoretisk kemi Chemistry 8957192 2018-08-29T09:42:58+02:00 2018-09-12T11:24:01+02:00 2018-09-12T11:24:01+02:00

oai:lup-student-papers.lub.lu.se:8957566 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Cindy Phan author 8957331 Tommy Nylander supervisor Department of Chemistry v1000647 department Lipid liquid crystals (LLC) have been studied widely because of their broad application in both food- and pharmaceutical industry. Inverse bicontinuous cubic phase of LLC have been of particular interest as it has three-dimensional structure and has been proven to be able to incorporate and deliver substances (e.g. topical drug delivery). There is a growing interest to prepare hybrid responsive lipid and polymer system. This study concerns how starch particles influence an LLC system. The system consists of capmul glycerol monooleate (GMO-50) and diglycerol monooleate (DGMO) and are mixed with different water concentration and weight percentage of native or modified starch particles. These has been proven, from small angle x-ray scattering and Cryo-TEM imaging, to form inverse bicontinuous cubic phases. At lower temperatures and water concentration, the system favorably forms gyroid type of bicontinuous cubic phase with space group Ia3d. At high temperatures and water concentrations, the system instead forms cubic crystal symmetry of space group Pn3m. Even at high concentration of starch particles, the system is favoring space group Pn3m. This tells that starch particles regulates the hydration and determines which one of the two crystal symmetries are formed. Further studies should be made in order to fully understand the lipid system with starch. Nevertheless, with this study it has proven new possibilities of using starch for materials based on lipid-polymer responsive layers. Leverering av substanser inom både livsmedels- och läkemedelsindustrin är viktig. Detta för att de aktiva ämnena måste nå dess verkningsställe utan att brytas ned eller påverkas av yttre faktorer. Av dessa anledningar har det har blivit mer populärt att studera nya aggregat, som skall möjliggöra för mer produktiva, effektiva och stabila levereringar från en utgångsplats till målet. Genom att studera olika tillsatser, som i detta fallet är stärkelse, kan levereringarna styras vilket bland annat öppnar upp nya vägar av läkemedelsleverering i kroppen. <br /> <br /> Stärkelse är en polymer som består av långa molekylkedjor. Det förekommer naturligt i växter och konsumeras av människor genom råvaror som till exempel potatis. Dess ofarliga förekomst i naturen och dess tillgänglighet är två faktorer till varför det anses vara en bra polymer till att utnyttja för reglering av lipidsystem. <br /> <br /> Lipider är fettliknande molekyler som består av en vattengillande (polär) och en ickevattengillande del (opolär). När lipider befinner sig i vattenhaltig miljö arrangeras de så att den polära delen interagerar med vatten, medan den opolära delen dras och interagerar med andra lipiders opolära del. Dessa kan på så vis packas ihop och bilda olika strukturer. Beroende på lipidernas egenskaper, så samordnas de på olika sätt. Cellen – som är den minsta byggstenen i levande organismer - har ett membran som består av lipider. Dessa har genom tidiga studier visat sig kunna bilda en struktur som en kub, så kallad kubisk fas, som har tredimensionell struktur. Den kubiska fasen har en inre vattenhaltig miljö som möjliggör inkapsling av ämnen. Tanken med att föra in stärkelse bland lipidsystem, är bland annat för att kunna reglera frisläpp av aktiva substanser som har kapslats in för transportering. Genom att använda stärkelse tillsammans med lipidsystemet, blir det möjligt att styra frigivningen. Lipiderna som användes var en blandning av glycerol monooleate, diglycerider, triglycerdier och diglycerol monooleate. Dessa provblandningars struktur studerades med hjälp av röntgenbestrålning (small angle x-ray scattering) där man kunde se att kubisk fas bildades genom att studera spridningen av röntgenstrålarna. Beroende på temperatur, stärkelse- eller vattenkoncentrationen, så bildades det olika kubiska faser. Detta systemet observerades även genom elektronmikroskopi, där systemets struktur kunde ses som bilder. <br /> <br /> Denna studie visar att man genom att sätta till stärkelsepartiklar kan kontrollera hydreringen i ett lipid- och vattensystem som kan avgöra hur lipider i ett system samordnas till olika strukturer. Detta öppnar upp nya dörrar för levereringssystem inom både livsmedels- och läkemedelsindustrin. https://lup.lub.lu.se/student-papers/record/8957566/file/8957567.pdf application/pdf 1037688 no 2018 eng physical chemistry fysikalisk kemi lipid liquid crystals starch cubic phase Chemistry 8957566 2018-08-31T23:00:56+02:00 2018-09-12T11:08:29+02:00 2018-09-12T11:08:29+02:00

oai:lup-student-papers.lub.lu.se:8957597 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ragnar Hansson author 8888275 Rohit Kumar supervisor Department of Chemistry v1000647 department Ribonucleotide reductases (RNRs) are important enzymes that convert the building blocks of RNA (NTPs) into building blocks of DNA (dNTPs). dNTPs are used for synthesis of DNA as well as repair of mutated and damaged DNA. These cellular processes are critical to an organism. That is why these processes are found in various organisms. Since these processes are so essential, their allosteric regulation is tightly controlled to maintain the conversions. They are divided into three main classes that are mainly determined by the different radical mechanisms of these enzymes. Investigations of RNRs from different organisms have led to structural insights such as crystal structures. This has made deeper understanding of these important enzyme’s allosteric regulation, catalytical mechanisms and how they are related to each other from an evolutionary perspective. The structural understanding of these enzymes could also lead to drug discoveries since they are essential, which makes them to be good candidates as target proteins.<br /> The most common RNR is built up of two proteins that together catalyze the reaction. One domain is the so called large subunit α2 (historically also known as R1) where the main catalysis takes place and the other is the so called small subunit β2 (historically also known as R2) where the free radical formation takes place.<br /> In the first part of this work the subunits NrdD (large) and NrdG (small) from class III RNR from Pseudomonas aeruginosa were investigated. These two proteins have previously resulted in insoluble inclusion bodies and in this work they were attached by solubility tags found in the three vectors pETM41/pETM50/pETM60. The constructs were then expressed to see if the proteins were soluble or not. Further studies need to be done to determine whether the solubility tags from the three different vectors improved the solubility or not.<br /> In the second part of this work, the aerobic RNR class I enzyme from Chlamydia trachomatis was purified and later investigated by electron microscopy (EM) and cryo-electron microscopy (Cryo-EM) in a step to get a deeper insight in their structure and function. The results from the EM looked promising, although the Cryo-EM data needs to be analyzed to draw any conclusions. DLS-analysis and crystallization trials remain to be done in the future in pursuit of solving this structure. Ribonukleotidreduktaser (RNR) är livsviktiga enzymer som är involverade i nästan alla levande organismer. Enzymernas uppgift är att omvandla ribonukleotider (NTPer) till deoxyribonukleotider (dNTPer), byggstenar som är essentiella för såväl DNA-syntes som DNA-reparation. Enzymernas aktivitet baseras på en radikal-mekanism som skiljer sig, vilket gör att RNRerna är uppdelade i tre olika klasser. Utöver detta är enzymerna ibland även uppdelade i underklasser men dessa skiljelinjer är ibland en definitionsfråga som inte alltid är antingen svart eller vit.<br /> Dessa livsviktiga enzymer gör att karakterisering av dem är viktigt. Dels för att öka förståelsen över deras aktivitet, men också för att förstå korrelationen mellan olika organismer och hur evolutionen påverkat utvecklingen från början till nu. Detta kan i sin tur leda till att man kan förstå enzymernas involvering I olika typer av sjukdomar och därifrån genomföra olika mikrobiologiska modifieringar och analyser vars upptäckter förhoppningsvis kan användas för att upptäcka läkemedel.<br /> I första delen av detta arbete så studerades RNR klass III proteinerna NrdD och NrdG från bakterien Pseudomonas aeruginosa. Tidigare försök att studera dessa två proteiner har genererat svårlösliga inklusionskroppar vilket gjort att man försökt klona in generna som uttrycker dessa två proteiner i plasmider som före det inklonade proteinet uttrycker proteiner som är kända för att öka lösligheten för proteiner vars uttryck uppvisar liknande tendenser som i detta fall. I arbetet användes tre olika plasmider (pETM41/pETM50/petM60) som alla tre har olika taggar som alla är kända för att öka lösligheten. Dessa tre plasmider innehåller även alla tre His-taggar framför sina respektive löslighetstaggar som gör det enkelt att rena fram det önskvärda proteinet i fråga med hjälp av affinitetskromatografiupprening. Fem av dessa sex kloningar fungerade, men däremot inte det sjätte trots upprepade försök. Bara en utav de fem lyckade kloningarna genererade överexpression, vilket betyder att de fyra misslyckade överexpressionerna måste testas fler gånger.<br /> I den andra delen delen av detta arbete så upprenades aeroba RNR klass I proteiner från Chlamydia trachomatis som sedan undersöktes med hjälp av elektronmikroskopi (EM) och kryoelektronmikroskopi (CryoEM). EM undersökningarna såg lovande ut, däremot fanns det tyvärr ingen tid att analysera data från CryoEM undersökningen. Tidsbristen gjorde även att undersökningar med dynamisk ljusspridning (DLS) och kristalliseringsförsök tyvärr uteblev. https://lup.lub.lu.se/student-papers/record/8957597/file/8957598.pdf application/pdf 3642898 yes 2018 eng Ribonucleotide Reductases RNR RNRs Cryo-EM dNTPs DLS biochemistry biokemi Chemistry 8957597 2018-09-01T15:58:09+02:00 2018-09-12T11:19:04+02:00 2018-09-12T11:19:04+02:00

oai:lup-student-papers.lub.lu.se:8958473 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Amanda Eriksson Skog author 8958471 Marie Skepö supervisor Department of Chemistry v1000647 department The aim of this thesis was to study how the structure and the electrostatic interactions within the chain of α-casein are affected by phosphorylations and the ionic strength of the buffer. To do so, Small Angle X-ray Scattering measurements together with Circular Dichorism measurements were used to experimentally determine the stucture of α-casein. The theoretical model was then adjusted to fit the experimental results by adding an angular potential to restrict the flexibility of the chain. How the α-casein chain was affected by changes in ionic strength was then investigated with Monte Carlo simulations in the program MOLSIM. The results showed that the conformational entropy of the α-casein chain increased with increasing ionic strength. The results for α-casein were compared with the results of dephosphorylated α-casein, which showed that the phosphorylations are important for the electrostatic interactions within the chain. Dephosphorylated α-casein displays a less prominent change in Full Width Half Maximum (FWHM) of the probability distribution of the radius of gyration than the phosphorylated α-casein does. This was used to indicate the changes in conformational entropy of the chains, and hence, the restrictions due to electrostatic interactions within the chains when changing the ionic strength of the buffer. I människokroppen sker hela tiden viktiga processer, flera av dem på cellnivå. Dessa cellulära processer innefattar bland annat celldelning, där nya celler skapas, reparation av DNA, samt när cellerna upptar näring från maten vi äter. En viktig reaktion för att dessa processer ska fungera är fosforylering av molekyler. Det innebär att en fosforylgrupp sätts fast på en molekyl. Detta är extra viktigt för proteiner, då det påverkar dess funktion. Eftersom fosforyleringar är viktiga i många biologiska processer är det viktigt att förstå hur dessa påverkar proteinerna.<br /> Kaseiner är en grupp proteiner som finns i mjölk. De består främst av tre proteiner, α-, β-, och κ-kasein (alfa, beta, kappa), som förekommer i följande förhållande: 50:40:10. Kaseinerna är fosforylerade till olika grad. Alla tre av dessa proteiner tillhör en grupp proteiner som kallas intrinsically disordered proteins, dvs oordnade proteiner. Dessa proteiner har en oordnad tredimensionell struktur, antingen är hela proteinkedjan oordnad, eller endast en del av den. Att de är oordnade innebär att de inte antar någon specifik konformation, utan beter sig mer som en flexibel kedja. Det har även visat sig att dessa oordnade proteiner har en viktig roll inom biologin, bland annat är de inblandade i cellsignalering, samt att det finns oordnade proteiner som är inblandade i sjukdomar, såsom Alzheimers sjukdom och Parkinsons sjukdom.<br /> Målet med den här studien var att undersöka hur strukturen samt växelverkan inom kedjan för α-kasein beror på hurvida proteinet är fosforylerat eller inte, samt hur det påverkas av saltkoncentrationen av lösningen den befinner sig i. Detta har gjorts med hjälp av datorsimuleringar samt två experimentella metoder, SAXS (Small Angle X-ray Scattering) och CD (Circular Dichroism). Information om sekundärstrukturen, alltså olika sätt aminosyrorna interagerar på, erhölls från CD-mätningarna. Resultaten från SAXS-mätningarna gav information som användes till att anpassa simuleringsmodellen, då α-kasein faktiskt har lite struktur och därför inte beter sig helt som en flexibel kedja. Simuleringsresultaten visade att fosforyleringar spelar en stor roll för både strukturen och de elektrostatiska interaktionerna för α-kasein. https://lup.lub.lu.se/student-papers/record/8958473/file/8958474.pdf application/pdf 7208948 yes 2018 eng IDP protein theoretical chemistry teoretisk kemi Chemistry 8958473 2018-09-11T15:47:10+02:00 2019-02-26T10:43:45+01:00 2019-02-26T10:43:45+01:00

oai:lup-student-papers.lub.lu.se:8958925 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Sofi Gummesson author 8958923 Ulf Nilsson supervisor Department of Chemistry v1000647 department Galectins are a family of carbohydrate recognition proteins involved in modulation of cell signaling and cell adhesion. galectin-9 especially is involved in regulation of the immune response. In this work, galectin-9N inhibitors have been designed, synthesized and evaluated. The aim was to synthesize compounds with higher affinity than currently known compounds. Three compounds were synthesized with different substituents at the alpha position of the anomeric carbon. Substituent patterns employed in this study were phenyl, methyl phenyl and fluoro phenyl. Affinities of compounds were evaluated in a fluorescence polarization assay. The compound with best affinity was the galectin-9N inhibitor with fluoro phenyl as the substituent, with affinity of 5. The polar interaction between the binding pocket and the inhibitor is believed to be the reason for the good affinity. Galektiner är en proteinfamilj som har visats vara aktiv i cancerceller. Proteinet har bland annat funktioner så som utveckling och spridning av cancerceller. För att förhindra proteinets inblandning i cancercellen kan man introducera en inhibitor, som hindrar aktiviteten hos proteinet. Genom att inhibitorn placerar sig i den position där substratet naturligt skulle binda.<br /> Inhibitorn tävlar med det naturliga substratet. För att inhibitorn ska vara så effektiv som möjligt är det viktigt att den binder så starkt som möjligt för att konkurrera ut det naturliga substratet.<br /> I mitt projekt utvecklades tre molekyler som skulle förhindra galektin-9Ns aktivitet, ett protein ur galektin-familjen. Galektin-9N är viktig för immunförsvaret och har bland annat funktioner så som programmerad celldöd (apoptos) och förflyttning av cellen mot eller ifrån en ökad koncentration av ett kemiskt ämne (kemo taxis). Syntesen utgick från galaktos-molekylen och byggdes upp till en mer avancerad struktur som var designad för att binda till galektin-9N. Målet var att se om de nya molekylerna band starkare till den avsiktliga positionen än tidigare studerade molekyler gjort. https://lup.lub.lu.se/student-papers/record/8958925/file/8958929.pdf application/pdf 904580 no 2018 eng organic chemistry organisk kemi Chemistry 8958925 2018-09-17T15:41:58+02:00 2019-02-26T10:28:09+01:00 2019-02-26T10:28:09+01:00

oai:lup-student-papers.lub.lu.se:8959325 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Nicolas Velásquez González author 8959320 Prof. Emma Sparr supervisor Department of Chemistry v1000647 department The structure and dynamics of isolated Stratum Corneum lipids in different temperatures and hydration conditions was investigated using natural abundance 13 C NMR and X-ray scattering.<br /> In order to isolate the lipids a new extraction method was tested. The novel aspect of this method was its ability to extract more lipids from SC. This new method (referred to as Method II in-text) was further modified. The resulting method (Method III) was chosen as the method to follow during this project. These two methods were also compared (using 13 C NMR) to an extraction method used in a pre-study. The lipids obtained through Method III were characterized with polarization transfer solid-state NMR and wide/small angle x-ray scattering.<br /> NMR studies showed that a greater amount of lipids in a rigid state were being extracted with the new extraction method. These studies also showed that hydration has a clear effect on lipid mobility at temperatures of 32 ˚C. In the dry state there is low mobility, while upon full<br /> hydration, a fraction of lipids are in a mobile state coexist with solid lipids. SAXS studies showed that SC lipids form two types of lamellar phases, one with a lamellar repeat distance of ~144 Å in dry and hydrated conditions, while another with a repeat distance of ~71Å in dry<br /> conditions and ~68 Å in hydrated conditions. In the solid fraction of SC lipids, the hydrophobic chain adopts hexagonal packing, as detected with WAXS. The largest organ in our bodies is the skin. It forms a protective barrier against exogenous substances and dehydration. The barrier function is attributed to the Stratum Corneum (SC), which is the outermost layer of the skin epidermis. The main components of the SC are proteins<br /> called corneocytes (dead cells containing mainly keratin and water) and lipids. These lipids form an intercellular matrix wherein the corneocytes are embedded. This lipid matrix, which is highly ordered, consists chiefly of ceramides (CERs), free fatty acids (FFAs) and cholesterol<br /> (CHOL), in an almost equimolar ratio. Knowing how the barrier function behaves, for instance in the presence of compounds such as drugs, is extremely desirable. To do this, we studied and characterized lipids extracted from porcine SC, whose properties are highly similar to those of<br /> human SC. Their molecular mobility and structure was investigated in different conditions, such as temperature and relative humidity. Structurally, the lipids arrange themselves in periodical layers referred to as lamellae and are stacked parallel to the surface of the skin. Two<br /> periodicity phases have been detected, long and short. The lamellar phases also possess density, which is how tight the chains are packed together. Variations in lipid composition, temperature and hydration conditions, will alter the lipid phase behavior.<br /> Powerful techniques used to characterize extracted lipids are 13 C polarization transfer solid-state NMR (PT ss-NMR) and Small/Wide X-ray scattering (S/WAXS). Both providing high resolution and sensitivity, necessary to study the microscopic properties of the intercellular lipid<br /> matrix and subsequently the skin barrier function. https://lup.lub.lu.se/student-papers/record/8959325/file/8959326.pdf application/pdf 4291618 no 2018 eng stratum corneum skin barrier lipids physical chemistry fysikalisk kemi Chemistry 8959325 2018-09-24T19:09:48+02:00 2018-11-06T13:45:55+01:00 2018-11-06T13:45:55+01:00

oai:lup-student-papers.lub.lu.se:8959582 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Martin Müller author 8959520 Senior lecturer Mats Galbe supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department In this thesis project, properties and factors that are involved in the fractionation of wood when using deep eutectic solvents (DES) have been investigated. The project is based on an earlier project that was conducted at RISE Processum in Örnsköldsvik and the results from that is the foundation for trials in this project. <br /> In that first project, five different DES were used (Oxalic acid, Lactic acid, Urea, Acetic acid and Formic acid), all based on Choline chloride. Two of these DES showed good fractionation and light colour, properties considered as promising attributes for the cellulose fraction. The two DES were acetic acid: Choline chloride and Lactic acid: Choline chloride.<br /> The main goals of this project were to find parameters that produce a pulp with qualities close to recycled pulp fibres. In the preceding project, a mean fibre length of 0.98 mm [1] was obtained. The DES treatment procedure used was a system of acetic acid and Choline chloride with treatment conditions at 170°C for 1h. <br /> In this project, a multivariate experimental structure was set up, focusing on four factors: temperature, time, wood content and the composition of the DES. These factors are considered important in a sustainable process design, if the concept is to be taken further. From these experiments, the conditions that produced a cellulose fraction with good visual qualities, such as light colour and low amounts shive were selected and further analysed. The multivariate experiments generated a model for how the cellulose and lignin were distributed when various conditions were applied, this served as an estimation tool for further optimization of the reaction conditions and more extensive analysis of selected samples.<br /> Effects on the fractionation using impregnation were also investigated, this gave in general a lower amount of cellulose fraction with a 16.5 wt% decrease when the impregnation was complete. It is believed that this is a result of higher lignin extraction and higher fractionation of the larger sawdust. Upscaling of the selected experiments from the multivariate analysis was performed. This generated a fibre fraction that showed same visual properties as the small-scale experiments, which would be a good fractionation and light colours. <br /> To generate further knowledge about the composition and material quality, analysis of fibre- and paper properties was performed. An analysis of the molecular composition in the different fractions were also performed. With an HPLC the structural carbohydrates in cellulose and hemicellulose could be identified, as well as the lignin. The analysis showed that the material had a longer fibre length, compared to the preceding project.<br /> The density is high for obtained material, with strength properties comparable to OCC quality which do have lower density. Milling the pulp is often used to both increase density and strength properties. Föreställ dig att du blandar två fasta ämnen, t.ex. salt och socker, och att det då bildas en vätska. Det känns spontant onaturligt, men inom kemin finns många exempel på sådana, så kallade eutektiska lösningar som nu blir allt vanligare inom en rad olika forskningsområden. <br /> I detta projekt undersöktes en metod för att använda just ett eutektiskt lösningsmedel för att behandla sågspån, med det specifika målet att få fram en träfiber med bevarade egenskaper som är lämpliga för att användas till produktion av wellpapp. <br /> Idag finns ett ökande intresse för att finna nya metoder för att producera pappersmassa genom nya metoder. Eftersom massabruken idag är kontinuerliga processer med väldigt stora produktionsvolymer, vilket krävs för att dem ska vara lönsamma. Det skulle ta tid och kosta pengar att stoppa produktionen för att byta råvara från t.ex. träflis som är anpassade för massaproduktion till sågspån. I detta fall är det dessutom tal om att byta till en råvara som producerar en produkt av lägre kvalitét och därför söker man efter en alternativ metod för att producera massa ifrån sågspån.<br /> En eutektisk lösning består av molekyler som lätt binder till varandra genom vätebindningar. Dessa blandas i ett visst förhållande vid en specificerad temperatur. Vid denna punkt, den eutektiska punkten, bildas en vätska klar som vatten, men ofta med tjockare konsistens. Det finns många olika komponenter som kan användas för att bilda en eutektisk vätska, vilket leder till att dessa lösningsmedel är väldigt mångsidiga. De har redan funnit användningsområden i allt ifrån nya sortersbatteri, koldioxidrening, utvinning av metaller och även för att separera ved i sina beståndsdelar, så kallad fraktionering. Ofta är målet att ersätta ett organiskt lösningsmedel som kommer ifrån fossila källor, mot ett grönare alternativ som t.ex. en eutektiska lösnin. <br /> Det första steget i processen att göra papper är att utvinna träfiber från ved eller sågspån. För att komma åt träfibrerna i sågspånen måste den struktur som bygger upp veden brytas ner; de viktigare komponenterna i denna struktur är cellulosa, hemicellulosa och lignin. Nedbrytning av veden görs idag i sura eller basiska lösningar via en kokprocess. Ofta är målet i papperstillverkningen att göra ett papper som är starkt och håller ihop. Pappersstyrkan hänger mycket ihop med hur mycket lignin som man har lyckats separera bort från pappersmassan under tillverkningen. I tidigare studier har man observerat att vissa eutektiska lösningar löser lignin selektivt. Det skulle innebära att man på ett mer effektivt sätt kan separera ut ligninet från det material som skulle gå till att göra wellpappen. Det är en av anledningarna till att detta koncept kan bli framgångsrikt i just pappersindustrin. En annan anledning är att många eutektiska lösningar skapas ifrån biomolekyler, såsom mjölksyra och kolinklorid som använts i detta projekt. Dessa ämnen betraktas som ”gröna alternativ” till organiska lösningsmedel. Det gör att de eutektiska lösningarna har stora möjligheter att vara ett mer hållbart och miljövänligt alternativ än konventionella processer.<br /> Undersökningarna som har gjorts i detta projekt har haft som mål att hitta lämpliga förhållanden för värmebehandlingen under fraktioneringen av sågspån, men även att ta reda på vad man kan göra för att öka fraktioneringen och mängden lignin som man tar bort ifrån massan. Resultaten ifrån projektet blev en pappersmassa som kunde jämföras i styrka med den massa som idag används för att producera wellpapp. Resultaten visar dock att densiteten av massan som tagits fram är väldigt mycket högre än vad den borde vara innan man börjar bearbeta massan för att höja styrkan, samt att längden på fibrerna är kortare än i wellpapp. Detta gör att kvalitén på massan inte riktigt lever upp till det som massan ska användas till. I detta avseende finns det mer att jobba på för att utveckla och optimera konceptet med eutektiska lösningar som lösningsmedel. <br /> Att få fram en metod som kan komplettera processerna i de stora massabruken och producera användbara produkter från en restråvara som sågspån är av stor vikt i en cirkulär ekonomi. Det skulle t.ex. innebära att mer av den skog som fälls utnyttjas till samhällsnyttiga produkter. Det gäller inte bara till papper och kartong; det pågår även mycket forskning för hur man kan utnyttja lignin och hemicellulosa, till exempel för att göra biobränslen och olika sorters biomaterial. Konceptet med eutektiska lösningar skulle kunna öka mängden lignin och hemicellulosa på marknaden och därmed öka konkurrensen med fossila produkter av liknande sort, vilket är en viktig del i omställningen till ett förnybart samhälle för en hållbar framtid. https://lup.lub.lu.se/student-papers/record/8959582/file/8959584.pdf application/pdf 3308137 yes 2018 eng Fractionation Deep eutectic solvent Sawdust chemical engineering kemiteknik Chemistry 8959582 2018-09-28T12:58:53+02:00 2018-11-26T14:39:57+01:00 2018-11-26T14:39:57+01:00

oai:lup-student-papers.lub.lu.se:8959698 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Shuai Bai author 8959696 Lars Nilsson supervisor Food Technology and Nutrition (M.Sc.) v1000294 department The presence of Nano particles in food is a topic that have gain much attention lately. The aim of this study is to investigate the aggregation behavior of nano silica under in vitro gastrointestinal conditions using asymmetric flow field flow fractionation (AF4) coupled with several detectors. Major part of this work is to find a suitable condition for the experiments. With measurements of Z-potential and utilizing the DLVO theory a suitable condition for the experiment is developed. To avoid membrane interaction a relatively high surface energy membrane (Regenerated cellulose) is most suitable. The carrier liquid should have a low ionic strength and a pH away from the iso electric point to contribute to a greater electrostatic repulsion. These actions lead to less membrane interaction as well as ensuring the carrier liquid does not interfere with the aggregation. <br /> Parameters in the gastrointestinal environment like the ionic strength, pH, presence of proteins and Bile salts are altered individually during experiments, to examine the effect of each parameter. Under gastric conditions the high ionic strength and low pH gives the silica particles a poor electrostatic repulsion causing the particles to aggregate. The enzymes present in the gastric conditions is insufficient to cover the particles and might causes bridging. The ionic strength and pH conditions of the intestinal fluids cause a small electrostatic repulsion but not enough to entirely prevent aggregation, instead the large number of mixed enzymes will initiate aggregation by protein-protein interaction. The aggregation of silica particles is greatly reduced when bile salt is introduced to the fluid. Bile salt will act as a surfactant stabilizing the suspension. https://lup.lub.lu.se/student-papers/record/8959698/file/8959704.pdf application/pdf 1203698 no 2018 eng Silica nanoparticles in vitro digestion Aggregation Asymmetrical flow field flow fractionation DLVO membrane interaction food technology livsmedelsteknologi Chemistry 8959698 2018-10-01T14:07:11+02:00 2018-11-26T15:53:41+01:00 2018-11-26T15:53:41+01:00

oai:lup-student-papers.lub.lu.se:8960164 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Veronika Tolevska author 8960162 Tommy Nylander supervisor Department of Chemistry v1000647 department The triglyceride/ aqueous interface has an important role in many processes, e.g. lipase activity. Lipase is responsible for the degradation of triglycerides to smaller components, such as fatty acids. The enzyme attracts interest in industrial applications of the catalytic behavior it possesses, such as in food and pharmaceutical industries. Thus, understanding the interface which is controlling its activity, is of importance. The emulsification and the interface of triolein and water is investigated in terms of water inclusion and Thermomyces lanuginosa lipase (TLL) activity, to gain information about the workings of the interface and TLL relation. Based on measurements of the thickness change of a triolein film over time, using spectroscopic ellipsometry (SE), the water uptake in the triolein phase appears to increase when active or inactive TLL is present in the aqueous solution. The presence of TLL was further investigated with small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS), which suggested a longer repeat distance of triolein molecules when active TLL is present than if it is not. This suggests bigger aggregates are formed with more water uptake, when the triolein molecules are degraded. The obtained scattering data is preliminary. The information gained from SE unfolds a portion of the molecular interactions between TLL and the lipid/aqueous interface, by indicating different trends of thickness variations of triolein, when active TLL or inactive TLL is present. Den gåtfulla gränsytan mellan lipid och vatten<br /> <br /> Lipider är amfifila, vilket betyder att de består av en hydrofil och en hydrofob del. Vid kontakt med vatten arrangerar de sig i strukturer för att undvika oönskad interaktion. Den gränsyta som uppstår mellan vatten och lipider är intressant, eftersom den spelar en viktig roll i många processer, såsom nedbrytning av lipider med så kallade lipaser. Trots detta, finns det fortfarande en saknad förståelse för hur gränsytan fungerar och ser ut. <br /> <br /> Vid lipid/ vattengränsytan aktiveras enzymet lipas. Bara när det interagerar med gränsytan, kan enzymet hydrolysera triglycerider till di-, monoglycerider, glycerol och fettsyror. Hur detta sker och kan effektiviseras är av intresse, då lipaser attraherar industrier, så som mat- och läkemedelsindustrin, för dess mångfaldiga katalytiska förmåga. <br /> <br /> I detta arbete har strukturstudier gjorts av triolein/ vattengränsytan när Thermomyces lanuginosa lipas (TLL) är närvarande, med spektroskopisk ellipsometri och röntgenspridning vid små och stora vinklar. Ellipsometrimätningarna tyder på att trioleinfasen ökar i tjocklek över tid, när den exponeras för vatten. Dessutom ökar tjockleken när aktivt vildtyp-TLL eller inaktivt TLL finns i vattenlösningen. Men trenden för ökningen är olika för båda situationer. Den slutsats som kan tas är att lipas har en påverkan av vattenintaget i lipidfasen, och att påverkan ser olika ut för olika lipastyper. Tidigare studier indikerar att inaktivt TLL minskar lipidtjockleken vilket är i kontrast till vad som visas i denna studie. Orsakerna till denna diskrepans diskuteras. https://lup.lub.lu.se/student-papers/record/8960164/file/8960165.pdf application/pdf 3052778 no 2018 eng Spectroscopic ellipsometry SAXS lipase activity interfacial activation triolein/ aqueous interface physical chemistry fysikalisk kemi Chemistry 8960164 2018-10-12T01:14:11+02:00 2019-02-26T10:30:37+01:00 2019-02-26T10:30:37+01:00

oai:lup-student-papers.lub.lu.se:8962860 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Hugo Öhrneman author 8962767 Tommy Cedervall supervisor Department of Chemistry v1000647 department Plastics play a central role in todays society and its use will only increase. When certain plastics are broken down to a nanometre size they become toxic to some aquatic life. Such plastic particles often undergo aggregation, especially in the aquatic environment. It is therefore of interest to study how different types of aggregation affects the physical characteristics as well as the toxicity of these particles.<br /> <br /> In this report 53nm polystyrene spheres are linked together with covalent bonds using the linkers BS3 and DTSSP, which can be used effectively with a fairly simple protocol and few reagents. Both BS3 and DTSSP are effective linkers and their concentration can effectively control the size of the aggregates. These aggregates have a fractal shape and have a tendency to entangle. Additionally coating of particles/aggregates with albumin was a very effective way to protect them from further aggregation, both spontaneously and when introduced into tap water, this is promising since it allows to study of relatively monodisperse particles in the aquatic environment. This study also shows that these albumin treated particles are significantly more toxic to D. magna than the equivalent non-treated particles.<br /> <br /> The toxicity of the aggregates decreases when the size is increased, which could be an effect of the lowered surface area of the aggregates. Importantly the aggregates were toxic at sizes were large single particles showed practically no toxicity, as demonstrated by previous studies. This supports the idea that the size of the particles are not as important as the shape and curvature of the particle, and that aggregation perhaps only lowers the exposure of this toxic surface. Plast är en central del av det moderna samhället och har otaliga användningsområden. En av konsekvenserna av detta är att det nu finns 4900 miljoner ton plast i naturen. Denna plast bryts långsamt ner tills partiklarna är på nanometer-nivån, dvs. en miljondel av en millimeter. Vissa plaster i denna storlek är giftiga för akvatiskt djurliv och transporteras upp i näringskedjan. I denna rapport undersöks hur dessa partiklars egenskaper förändras när man binder ihop dem. Vidare undersöks även hur partikelstorleken påverkar toxiciteten på djurplanktonet D. magna. Det visar sig att toxiciteten bibehålls, men sänks när storleken ökas. Om man istället stabiliserar partiklarna med proteinet albumin så blir de betydligt giftigare. Detta är ett allvarligt problem och något som borde uppmärksammas mer i vetenskapen och även i vardagen. https://lup.lub.lu.se/student-papers/record/8962860/file/8962861.pdf application/pdf 24123745 LU/LTH access 2018 eng Nanoparticles Polystyrene Toxicity Daphnia magna Covalent bond Aggregation physical chemistry fysikalisk kemi Chemistry 8962860 2018-11-06T11:52:57+01:00 2018-11-26T14:52:29+01:00 2018-11-26T14:52:29+01:00

oai:lup-student-papers.lub.lu.se:9040288 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Louise Kalander author 9040286 Marie Skepö supervisor Eric Fagerberg supervisor Biophysical Chemistry v1000649 department In this study a coarse-grained model of intrinsically disordered proteins (IDPs) is evaluated to determine whether the model is suitable to use for analyzing the structure and dynamics of IDPs. IDPs are proteins that lack a stable tertiary structure which gives them a flexible structure. The aim with this study is to find a model that is appropriate to use for analyzing dynamics events of IDPs. To evaluate if the model is appropriate to use, the structural characteristics of the protein are examined to verify that the generated results are consistent with previous studies. With a good model it will be possible to achieve a deeper understanding about these proteins, which is of considerable importance since IDPs are involved in several vital biological processes in eukaryotes. <br /> In this study, a specific model, primarily described by Das et al [1], is evaluated whether it can be used as a suitable model. To evaluate the model, the results from different simulations, with the IDP Histatin 5 [2] used as the model protein, will be compared and analyzed. Running several simulations with different set-ups of parameters from the original model will give a deeper understanding of how these parameters affect the conformation and flexibility of the IDP, and thus give the ability to improve the model. The simulations were performed by using the molecular dynamics package GROMACS [3]. To evaluate if the model is appropriate to use for analyzing the structure and dynamics of IDPs, the results from the different simulations are compared with protein contact maps and experimental data from small angle X-ray scattering.<br /> The results from a reference simulation, a simulation where there were as few changes as possible from the original model, indicates that the simulated Histatin 5 resembles a globular protein rather than an IDP that would have been the desired result. The conclusion can be drawn that the original model is not suitable to use for examining dynamic events of IDPs, but additional simulations have to be performed since some deviations made from the original model could have affected the results and thus the conclusion.<br /> Four simulations with different set-ups of the parameters from the original model are performed in this study. The results from these simulations indicate that there are clear differences in the behavior of the simulated proteins compared to the protein simulated in the reference simulation. Most of the parameter changes made in this study gave a satisfactory result, where the properties of the simulated protein are more similar to an IDP than to a globular protein. This study is only a first step in the process of finding a suitable model to be able to examine both the structure and the dynamics of IDPs. The work has to be continued in order to find an appropriate model for this purpose and there are several simulations that could be performed to continue this study. https://lup.lub.lu.se/student-papers/record/9040288/file/9040407.pdf application/pdf 1185774 no 2021 eng IDP Intrinsically disordered proteins Histatin 5 Simulation Biophysical chemistry Chemistry 9040288 2021-02-11T16:22:20+01:00 2021-08-16T11:36:21+02:00 2021-08-16T11:36:21+02:00

oai:lup-student-papers.lub.lu.se:9040413 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ellen Öberg author 9040411 Dr Ola Wallberg supervisor Tony Persson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Produktionen av kemikalier på Perstorp AB genererar kontaminerat avloppsvatten som renas i industriparkens egna avloppsreningsverk innan de kan återanvändas till processen igen. Industriparken i Perstorp har villkor från avloppsreningsverket på hur mycket vatten som fabrikerna får släppa ut till avloppsreningsverket. Det finns fortfarande kapacitet kvar innan villkoret uppnås, men marginalerna ser ut att minska i framtiden för varje kapacitetsökning som sker på företaget. Målet med examensarbetet har därför varit att komma fram till kortsiktiga och långsiktiga förslag för att minimera mängd avloppsvatten och optimera vattenförbrukningen. <br /> <br /> Arbetet har bestått av tre delar. Första delen var att studera processerna med hjälp av piping and instrumentation diagram (PID) för Pentafabriken samt Neofabriken på Perstorp AB för att kunna skapa massbalanser av vattenförbrukningen samt uppkomst av avloppsvatten. I andra delen undersöktes kortsiktiga optimeringar av den befintliga utrustningen i Pentafabriken. Baserat på massbalansen så undersöktes två olika fall där kondensat och filtrat som annars direkt går till avloppsreningsverket eventuellt istället kunde recirkuleras i processen. På det sättet kan man ersätta en källa som använder renvatten och samtidigt avlasta avloppsreningsverket genom att minimera mängd avloppsvatten. Sista delen var att studera innehållet i tre strömmar som gick till avloppsreningsverket och med hjälp av en litteraturstudie som handlade om olika vattenreningsmetoder, komma fram till förslag på långsiktiga optimeringar där man kan rena strömmarna för att sedan återanvända i processen. <br /> <br /> Resultatet av examensarbetet blev att både kortsiktiga och långsiktiga förslag presenterades för att effektivisera vattenförbrukningen. Detta har gynnat företaget både ur ett ekonomiskt men även hållbart perspektiv. The production of chemicals at Perstorp AB generates contaminated wastewater that is treated in the industrial park’s own sewage treatment plant before it can be reused in the process again. The industrial park has conditions from the sewage treatment plant on how much water the factories may discharge. There is capacity left before the condition is reached, but the margins look to decrease in the future for each capacity increase that takes place at the company. The aim of this report has been to be able to present short-term and long-term suggestions to minimize the amount of wastewater and optimize water consumption. <br /> <br /> The work has consisted of three parts. The first part was to study the processes with the help of piping and instrumentation diagrams for the Penta factory and Neo factory at Perstorp AB in order to create mass balances of water consumption and generation of wastewater. In the second part, short-term optimizations of the existing equipment in the Penta factory were examined. Based on the mass balance, two different cases were investigated where condensate and filtrate that otherwise go directly to the sewage treatment plant instead could be recycled in the process. In this way, you can replace a source that uses clean water and at the same time relieve the sewage treatment plant by minimizing the amount of wastewater. The last part was to study the contents of three streams that went to the sewage treatment plant and together with the literature study about different water treatment methods, come up with suggestions for long-term optimizations where you can purify the streams and then reuse in the process. <br /> <br /> The result of this study was that both short-term and long-term suggestions were presented to make the water consumption more efficient. This has benefited the company both economic but also in a sustainable perspective. Vattenbrist är ett växande problem världen över. Efterfrågan på vatten ökar samtidigt som tillgången minskar på grund av klimatförändringarna. I examensarbetet har vattenanvändningen på två fabriker på Perstorp AB undersökts för att komma fram till kortsiktiga och långsiktiga optimeringar för att effektivisera vattenanvändningen. https://lup.lub.lu.se/student-papers/record/9040413/file/9040415.pdf application/pdf 1570065 yes 2021 swe Kemiteknik Vattenoptimering Vattenrening Processoptimering Processdesign Chemistry 9040413 2021-02-15T06:40:32+01:00 2021-02-24T15:39:49+01:00 2021-02-24T15:39:49+01:00

oai:lup-student-papers.lub.lu.se:9040520 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Emelie Andersson author 8951068 Ulf Nilsson supervisor Department of Chemistry v1000647 department Sialic acids are a large family of acidic sugars. One of the most abundant is N-acetylneuraminic acid. Sialic acids are found at the terminal position of glycan chains of all cell types. Their wide distribution makes them have a broad set of biological functions, for example cell to cell interaction and communication.<br /> Bacteria can utilize sialic acid for two purposes; 1) as a source of carbon, nitrogen and energy, and 2) for immune evasion to avoid the host’s immune response. Only a few bacteria have developed biosynthetic pathways to independently produce sialic acid, while the majority of them relies on host-derived sialic acid. <br /> Bacteria have developed different transport systems to import sialic acid. One of them is the sialic acid transporter (SiaT) which belongs to the sodium solute symporter (SSS) family. The members of the SSS family cotransport sialic acid with sodium, using the sodium gradient as driving force. <br /> Inside bacteria, sialic acid undergoes two different paths: catabolism or being involved in immune evasion mechanisms. Bacteria using molecular mimicry, utilizes sialic acid to escape the host immune system, since sialic acids are common for mediating a large set of recognition functions. Bacteria sialylate their lipopolysaccharides to avoid recognition, they are mistaken for being the host’s own cells and thereby escaping the host’s immune response. <br /> Despite some synthetic and pharmacokinetic challenges, for example instability of some derivatives and side reactions, sialic acid is an interesting starting point in the development of new antibacterial drug leads since it is involved in several functions. <br /> There has already been some work done with sialic acid on this topic. My objective was to continue that research by modifying the 4 th position of sialic acid by building a large linker onto it that would have a large fluorescent molecule at the end. The aim of the linker is to prevent sialic acid to enter the bacteria, thereby preventing molecular mimicry and immune evasion. This might be helpful in the research for new antibacterial drugs that are based on inhibition of sialic acid uptake. <br /> In my project work, I designed and carried out a pathway towards a compound that potentially would have the properties desired for inhibition of the SiaT protein. The pathway consisted of selective 4-OH alkylation of sialic acid to 3-nitrobenzyl and 3-bromobenzyl ethers. Then exchange of bromine to alkyne and eventually 1,3-dipolar cycloaddition with azide. Many of the steps were optimized during the time and finally, two potential compounds were generated whose binding affinity are ready for being tested. Kolhydrater kan användas som en energikälla i kroppen, men de kan även användas för mycket mer än så. I alla organismer finns celler vars ytor är täckta av olika sockermolekyler vilka är avgörande för cellernas överlevnad samt kommunikation med andra celler. Ett exempel på ett sådant socker är sialinsyra; en syrlig kolhydrat med en nio kol lång kolkedja.<br /> Patogener, exempelvis en del bakterier, kan utnyttja vissa sockermolekyler som är vanliga på cellytor för att maskera sig så att de smälter in bland värdens egna celler. Genom att använda speciella transportproteiner kan de importera sockermolekyler från sin omgivning så att de sedan kan dekorera sin egen cellyta med dessa. På detta sätt kan bakterier undvika värdens immunrespons, fortsätta sprida sig och orsaka infektioner. Detta fenomen kan orsaka antibiotikaresistens, vilket är ett globalt hot. <br /> Genom att blockera de transportproteiner som ansvarar för upptag av sialinsyra, skulle bakterier förlora förmågan att gömma sig för immunresponsen. Därför är det av intresse att designa en molekyl som kan binda till dessa transportproteiner och blockera dem likt en vinkork. Tidigare har det inte gjorts så mycket forskning inom just detta området. <br /> Målet med detta arbete var att skapa en molekyl som potentiellt skulle kunna besitta dessa blockerande förmågor. Utgångspunkten var att bygga på en lång länk på den fjärde positionen i sialinsyra och sedan sätta på en stor molekyl i slutet av den.<br /> I projektet designades en syntesväg mot en molekyl med blockerande egenskaper. Denna innehöll en uppsättning av flera olika reaktionstyper som genomfördes. Många av stegen optimerades under tiden och slutligen genererades två potentiella föreningar som är redo för att bli testade. https://lup.lub.lu.se/student-papers/record/9040520/file/9040521.pdf application/pdf 6106136 yes 2021 eng sialic acid medicinal chemistry carbohydrate organic chemistry antibacterial drugs organic synthesis antibiotic resistance Chemistry 9040520 2021-02-15T20:03:16+01:00 2021-03-01T08:33:51+01:00 2021-03-01T08:33:51+01:00

oai:lup-student-papers.lub.lu.se:9040765 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Ignacio Martínez Casasús author 9040763 Chemical Physics (S) Donatas Zigmantas supervisor Department of Chemistry v1000647 department Chlorophylls comprise one of the most important families of molecules for the photosynthetic process. Chlorophyll-like molecules have been classically interpreted under the Gouterman model, being thought to feature two independent transitions, Qy(S1) and Qx(S2). Recent studies on the matter provided a new interpretation, assuming these states to feature strong vibronic coupling and to be inseparably mixed. Experimental study of vibronic mixing can be done with non-linear spectroscopy techniques that can create and record superpositions of states, the so-called &quot;coherences&quot;. These coherences, when excited via vibronically coupled transitions, represent a direct observation of vibronic mixing phenomena. Polarization-controlled two-dimensional electronic spectroscopy is performed on chlorophyll a at cryogenic (77 K) temperature, followed by a complex analysis to the oscillatory signals, unveiling vibronic coupling in the most common member of the chlorophyll family. Life needs energy to function, and living beings have developed different mechanisms to obtain it. Heterotrophic organisms, such as human beings, can nourish themselves with organic matter to get it. However, for autotrophic organisms, this task is not as straightforward, since they must generate their own complex organic compounds from inorganic matter. To do this, they incorporate a complex biological machinery in their cells. Like a power plant, they harvest sunlight as a source of energy, and they use it to generate, from carbon dioxide and water, chemical energy stored in the form of sugars, producing also oxygen in the process. For millions of years, plants, algae and some bacteria have been carrying out this process, generating their own molecular fuel.<br /> <br /> The way in which these organisms conduct photosynthesis is very diverse, since the biochemical machineries they employ for this purpose is different. Nevertheless, they have one common feature: the presence of photosynthetic pigments known as chlorophylls inside their cells, in the thylakoid membranes. These are responsible for absorbing sunlight, and for transmitting it to the rest of the machinery for the production of chemical energy. Generally, these chlorophylls absorb light in the visible region of the spectrum. This is also the responsible for the vivid colours that these organisms have, such as the green of leaves.<br /> <br /> Therefore, the study of these photosynthetic pigments is fundamental to the understanding of how these natural power plants function. Such studies have several complications associated to them, since the first steps in the processes of sunlight absorption occur on an ultra-fast time scale, in which energy is transferred from one pigment to another. This time scale is generally in the femtosecond to picosecond range, which is around 10 to the power of -15 or 10 to the power of -12 seconds.<br /> <br /> To capture processes that happen so quickly, we need equally fast &quot;cameras&quot;. A similar problem was encountered in the late 19th century, when some members of high society were trying to understand how the gallop of race horses worked. The animal&#39;s gallop was so fast that the human eye could not pick up what exactly the rapid movement of its legs looked like. Therefore, it was not known if the animal ever got completely off the ground, or if it always had one foot on it. Eadweard Muybridge, with the help of multiple cameras and high-speed automatic triggers, was able to recreate the sequence of the horse&#39;s gallop, demonstrating that it did indeed get completely off the ground, and resolving, in this way, the long standing question.<br /> <br /> In our laboratory, the concept used is similar. Even though the process to be studied was extremely rapid, we were able to capture it by employing also really fast triggers, which consisted of short laser pulses. Their duration was in the range of just 15 femtoseconds. Therefore, by employing them, it was possible to research how these chlorophylls interacted with light in such a short time. Specifically, for this purpose, we used a technique known as &quot;Two-Dimensional Electronic Spectroscopy&quot; (2DES).<br /> <br /> In the experiments developed, the objective consisted on the study of the electronic structure of chlorophyll a (Chl a). It is the most common of the chlorophylls, as it is present in each and every organism that carries out oxygenic photosynthesis. In particular, we seek to understand the relationship between the two main energy transitions that occur in Chl a in the visible region, which are traditionally denoted as Qy and Qx.<br /> <br /> The earlier studies of their electronic structure had been carried out from the so-called &quot;Gouterman model&quot; perspective. This was originally applied to porphyrins in general, but was later applied to chlorophylls, since they exhibit a porphyrinic head in addition to a long phytol tail. This model proposed that the two transitions, Qy and Qx, were independent, with orientations perpendicular to each other. Thus, it did not consider any special coupling or mixing between them.<br /> <br /> However, recent studies on the matter, pointed out that these states could be intimately coupled, by means of a phenomenon known as &quot;vibronic mixing&quot;. Although there were evidences of the presence of vibronic mixing in chlorophylls, it was not until 2019, that this phenomenon was directly witnessed for the first time. It was observed in the chlorophyll c1, a chlorophyll present in a certain group of marine algae, such as those of the Chromista kingdom.<br /> <br /> The way we were able to demonstrate the existence of this vibronic coupling is by detecting a series of signals known as quantum beats. Our ultrafast laser pulses interacted with the Chl a, producing a set of electronic transitions and, through these, superpositions of states called &quot;coherences&quot;. In our experiments, these coherences manifested as oscillations (quantum beats), which serve as a probe of how the energetic states of a molecule interact with each other.<br /> <br /> In order to selectively study the coherences of special interest, a &quot;polarization control&quot; has been used. With it, a multitude of unwanted signals that could arise in the experiments were suppressed, leaving, among the remaining signals, those that have a special relationship with the vibronic mixing phenomenon.<br /> <br /> The result of the experiments turned out to be positive, identifying a multitude of coherences whose origin must involve transitions between vibronically mixed states. Therefore, we can conclude that the coupling between the Qy and Qx states is present in Chl a, in accordance with the most recent studies mentioned above. Moreover, due to the previous findings, and the fact that Chl a is the most common among chlorophylls, it is expected to be present, not only in this chlorophyll, but in every other member of the chlorophylls family.<br /> <br /> Vibronic mixing phenomenon is, so far, a scarcely explored phenomenon in chlorophylls, and there is still uncertainty as to which extent this &quot;vibronic mixing&quot; may be involved in the photosynthetic process. The scope of its importance is yet to be discovered. Nonetheless, these results open the way to an understanding of chlorophylls from a new perspective that, from now on, will consider the vibronic mixing as a fundamental property when studying the properties of chlorophylls in regard to its photosynthetic functions. https://lup.lub.lu.se/student-papers/record/9040765/file/9040766.pdf application/pdf 6046023 no 2021 eng Two-dimensional spectroscopy Ultrafast spectroscopy Chlorophyll a Chlorophylls Photosynthesis Light harvesting Vibronic mixing Quantum coherence Chemical physics Chemistry 9040765 2021-02-19T00:40:03+01:00 2021-03-01T08:30:48+01:00 2021-03-01T08:30:48+01:00

oai:lup-student-papers.lub.lu.se:9041040 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Alexander Braune author 9005353 Mukul Mahanti supervisor Department of Chemistry v1000647 department Galectins are in the centre of an intricate communications system within the cells and designing inhibitory ligands for them has proved useful in discerning the expression and retardation of various diseases. Galectins traditionally bind via carbohydrate recognition domains to carbohydrate ligands. Currently, only limited research has been conducted in regard of finding suitable glycomimetic ligands where the saccharides are removed completely. In this thesis, molecular dynamics simulations were conducted, synthetic routes to selected 5-heterocylic compounds were developed, and experimental binding affinities for galectin-3 were determined. The aim was to find a ligand that exhibits low dissociation constant values and to further elucidate the binding site to ligand interactions. To this end, computational analysis and fluorescence polarization were conducted and multiple synthetic routes were evaluated. The synthetic routes involved cycloadditions, SN2, reducitons and finkelstein. In the end, four compounds were analysed. The experiment showed that the 5-heterocyclic compounds behaves differently than the phenyl counterpart in regard to the binding site interactions. The experimental results show that the ligand might benefit from being rigidified by a tautomerisation effect and further information regarding the necessity of a hydrogen bond forming between the ligand and protein has been gained. Hence, a new hypothesised scaffold for drug design in regard to galectin-3 has been synthesised. This scaffold is devoid of hydroxyl groups and can be further optimised and other high affinity molecules might be retrofitted with this scaffold in mind. However, more experiments need to be made with this new scaffold and its actual binding affinity and mode of binding as the affinity tests were unable to completely solvate the ligand. If the ligand sits in the binding site or interact allosterically should also be investigated. To explain galectins, a simplistic analogy will be used comparing them to how humans communicate. Human communication is built on words but when we communicate, the words we choose stem from our vocal cords, comes out of our mouths and travels to the listeners ears. When cells communicate, both within themselves and their surroundings, the vocal cords could be compared to the Golgi apparatus. Here, “words” get chosen depending on the recipient and what needs to be said. The words in this case being proteins which are meant to facilitate some kind of cell reaction and are in turn dependent on the chemical composition of the cell. The Golgi apparatus labels proteins with, for example, sugars. Then the marked proteins travel to the “mouth”: galectins, which can be on the outside of the cell, but not exclusively. The galectins thereby have different proteins bound to them determined by the inner working of the cells, flagging the content of the cells for the ears of other cells and even the blood stream.<br /> <br /> This analogy falls short as the galectins and Golgi apparatus have a far more complex role than described. The same type of galectin can be both the “ears” and “mouth” of the cell. The galectins do not only interact with proteins from the cell but also with invading lifeforms like viruses and bacteria. A lot of known diseases stem from the virus or bacteria using the flagging system of galectins as a point of entry and/or proliferation. Galectins are also responsible for the ordering of certain proteins into motile areas on the cell surface called rafts.<br /> <br /> This thesis is built around synthesising molecules which mimic the sugars with which the proteins bind to the galectins. By binding these molecules to the galectin, certain functions of the galectins can be hindered. Since the organism is so complex a medicinal chemist should think about Absorption, Diffusion, Metabolism and Excretion (ADME) of the molecule as well. This, however, is beyond the scope of this thesis as we mainly aim at finding molecules that bind well to the target (galectin) which will give us information on how the molecule binds to the galectin. <br /> <br /> Using computers to simulate the interaction can be helpful but should not be leaned on solely as experimental data can tell a different story. Simulations can help decide which compounds should be synthesised and experimental data can tell us which of them work. From here, creating an actual drug is still far away as the molecule need to be optimised with ADME in mind and then, finally, clinical trials can be made. <br /> <br /> But even if the molecule never becomes a drug, it can still give valuable information on where to go next. In this project a new scaffold for the drug has been discovered. This new scaffold is devoid of the groups which galectins normally interact with. This might be a good step in the direction of making drugs which are able to penetrate the brain. Although, more research and experiments must be made to confirm this and further optimize the structure of the drug. https://lup.lub.lu.se/student-papers/record/9041040/file/9041041.docx application/zip 14604987 yes 2021 eng Medicinal Chemistry Galectins Computational chemistry Synthesis. Chemistry 9041040 2021-02-25T15:20:34+01:00 2021-03-01T08:14:33+01:00 2021-03-01T08:14:33+01:00

oai:lup-student-papers.lub.lu.se:9041166 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Max Lumetzberger author 9041164 Ulf Nilsson supervisor Department of Chemistry v1000647 department Antimicrobial resistance is according to the World Health Organization (WHO) one of the most rapidly growing threats to world health. According to a recently published WHOreport, drug resistant microbials could be responsible for up to 10 million annual deaths by the year 2050 unless drastic measures are taken such as decreasing misuse and developing new antibiotics. This work explores the possibility of using modified structures of the sugar<br /> named Neu5Ac, more commonly referred to as just sialic acid, in hopes of creating a new type of antibiotic.<br /> Sialic acids are commonly found on the outside of human cells. Besides being used as an energy and atom source, a large range of pathogenic bacteria such as P.mirabilis and S.aureus utilize sialic acids to evade the host’s immune system.<br /> This is achieved through something that is called molecular mimicry. By obtaining these sugars from glycoconjugates on human cells, they can transport them into their own cells through specific transporter-proteins and reattach them onto their own surface. This masks them from the immune system of the host and allows the bacteria to proliferate.<br /> In a recent article from 2018 published In Nature communications, Wahlgren et al.characterized one of these sialic acid transporters, a sodium solute symporter (SSS) protein named Sialic Acid Transporter (SiaT). This gave a massive insight into the geometry of the active site. In light of this newfound knowledge, members of the Ulf Nilsson group have set out to modify sialic acid to increase the affinity for SiaT with the ambition of creating potent inhibitors.<br /> This work specifically focuses on modifying the 4-C position of sialic acid with the approach of forming new C-C bonds instead of previously made C-O-C bonds in hopes of creating high affinity compounds and increasing the SAR knowledge of the region.<br /> Although new C-C bonds were created selectively using a rather unusual approach of cerium chemistry, the target compounds have within the timeframe of this project not been reached. It is however likely that the obstacles that remain to overcome could be solved<br /> soon. Antimicrobial resistance is according to the World Health Organization (WHO) one of the most rapidly growing threats to world health. According to a recently published WHO report, drug resistant microbials could be responsible for up to 10 million annual deaths by the year 2050 unless drastic measures are taken such as decreasing misuse and developing new antibiotics.<br /> This work explores the possibility of changing the structure of a sugar named sialic acid, in hopes of creating a new type of antibiotic.<br /> <br /> Sialic acids are commonly found on the outside of human cells. Besides being used as an energy and atom source, a large range of harmful bacteria utilize sialic acids to evade the host’s immune system.<br /> <br /> This is achieved through something that is called molecular mimicry. By obtaining these sugars from the surface of human cells, they can transport them into their own cells through specific transporter-proteins and reattach them onto their own surface. This masks them from the immune system of the host and allows the bacteria to grow.<br /> <br /> In this project two new molecules that mimic sialic acid and could potentially block the uptake of sialic acid were made starting from the natural sugar. 2021 eng Organic chemistry Organic synthesis Sialic Acid Carbohydrates Chemistry 9041166 2021-03-01T16:20:31+01:00 2021-03-02T15:21:05+01:00 2021-03-02T15:21:05+01:00

oai:lup-student-papers.lub.lu.se:9041303 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Julia Ramon author 9031314 Valtýr Freyr Hlynsson supervisor Department of Chemistry v1000647 department Tröger’s base molecule has a unique V-shaped cavity and a chiral structure. These molecules can be fused together in a linear fashion to create either tubular structure or zigzag structure. Different fields can be benefited from the applications of these molecules.<br /> <br /> Previous studies carried out in the Wärnmark group led to 30-step synthesis route to get a linearly fused heptakis-Tröger’s Base analogue. The aim of this project was to reply the synthetic route and to improve it where possible. Through a nine-step reaction route, a linear fused tris-Tröger’s base analogue has been synthesized, collecting valuable material for further synthesis of the Tröger’s Base (TB) analogue and the characterizations of the TB intermediates.<br /> <br /> The synthesis started from two aniline derivatives, which modified and condensed led to a Tröger’s Base analogue. In the end, two diastereomers were formed and separated through column chromatography, and followed by a deprotection of the amine groups of one of them. The whole covered synthesis included different steps and reactions, like condensations (as mentioned), amine protection with TMS groups, Pd-catalysed reactions, aminations, and electrophilic aromatic substitution. After this project, a large amount of products are available and the studies for the improvement of all the steps possible can be continued. Supramolecular chemistry, or as it is known as chemistry beyond the molecule, can be described as the field that studies interactions, weak and non-covalent, between two or more molecules. When we think about this type of interactions, we often think about two components that are bound to each other: the smallest one “substrate” is the one bound to the biggest one “receptor”. <br /> <br /> One of the valuable structural motifs for supramolecular applications is the Tröger’s Base (TB), a molecule that has a rigid, V-shaped structure with two aromatic rings that are forming a hydrophobic and concave cavity in the molecule, usually used as a building block for compounds that end working as ligands. <br /> <br /> The main work during this project has been following and replying the already written (on previous studies in the Wärnmark group) synthetic route, to be able to get the linearly fused heptakis-Tröger’s Base analogue. Also, an important part of this work has been trying to improve some steps of the synthesis, when possible and characterize the intermediates. Due to the period we were able to work in the lab, only nine of the 30-steps of the reaction route have been done, but a linear fused Tris-Tröger’s base analogue has been synthesized. <br /> <br /> The whole covered synthesis included different steps and reactions, like condensations (as mentioned), amine protection with TMS groups, Pd-catalysed reactions, aminations, and electrophilic aromatic substitution. https://lup.lub.lu.se/student-papers/record/9041303/file/9041319.pdf application/pdf 1415113 yes 2021 eng Tröger's Base organic chemistry synthesis Chemistry 9041303 2021-03-04T12:48:20+01:00 2021-03-29T14:44:46+02:00 2021-03-29T14:44:46+02:00

oai:lup-student-papers.lub.lu.se:9042974 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Cecilia Meuller author 9042972 phD Dániel Papp supervisor Margareta Sandahl supervisor Centre for Analysis and Synthesis v1000651 department The valorization of lignin offers sustainable and renewable products and materials. For that reason lignin needs to be further analyzed although the various challenges this process implicates. The major obstacles in this field are lignin’s chemical heterogeneity, all the modifications in lignin’s chemical structure owing to its extraction method and purification process and the lack of appropriate standards that match lignin’s structure. However, significant breakthroughs have been made in this area of research and have yielded more knowledge on lignin’s chemical composition remaining the molecular weight (MW) distribution as a task. This present work aims to study the characterization of the high MW of Kraft lignin using Size Exclusion Chromatography (SEC) and polystyrene standards (PS) and finding the best separations conditions such as temperature, flow rate and an eluent that can give a good resolution. The yielded molecular weight distribution for lignin was estimated to be in the ranges of 5000-1000 g/mol and 580-370 g/mol at approximately 30°, THF 1 mL/min. Lignin is the second most abundant polymer found on earth after cellulose. This polymer constitutes a main component in the cell wall of the plants and works as a mechanical backbone providing shape, stability and rigidity. In addition, due to lignin’s chemical composition offers a wide range of applications as biodegradable plastics, textile, lubricants, composites, pesticides and many other products. Lignin has the potential to be a great substitute for petroleum based fuel and materials. Therefore, more knowledge on lignin’s properties is needed. One important property that the research community is trying to determinate is lignin’s molecular weight (MW) which implicates a big challenge. Because the chemical composition of lignin is highly complex and varies owing to its botanical origin. Moreover, lignin’s structure become substantially modified during its extraction and purification. Being Kraft lignin the type of lignin gained from the Kraft pulping process in the paper industry. Different analytical methods have been used for this purpose and we have more knowledge on lignin’s structure and its constituents but there is no gold standard method that can be used to elucidate the MW.<br /> In the present study we aim to characterize the MW distribution of lignin using Size Exclusion Chromatography (SEC). This analytical technique is used because it is an unquestionable powerful method for polymer studies and it works over a wide range of high molecular weights. This method is based on the separation of the sample molecules according to their size or the volume that they occupied as dissolved molecules. The sample solution passes through a column filled with porous packing material, called the stationary phase and the fluid that carries on all sample molecules is called the mobile phase. Because the sample molecules have different sizes, some of them are able to enter the pores while other just flush out with the mobile phase. In this manner the separation is effectively performed. Since there are some factors that affect the separation it is important to take those in account. This work was aimed to study the type of solvent, temperature, flow rates, calibration standards and the interactions that may occur between the sample and phases. The results in this investigation have shown that Tetrahydrofuran (THF) is a good solvent for the separation of Kraft lignin samples, working best at 1.0 mL/min in 30°C, giving a molecular weight distribution 5000-1000 mg/mol and 580-370 mg/mol. https://lup.lub.lu.se/student-papers/record/9042974/file/9042977.pdf application/pdf 1637468 yes 2021 eng Kraft lignin molecular weight polystyrene standard Size Exclusion Chromatography and THF technical analytical chemistry Chemistry 9042974 2021-04-12T11:13:56+02:00 2021-04-15T10:56:44+02:00 2021-04-15T10:56:44+02:00

oai:lup-student-papers.lub.lu.se:9043861 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Linnea Sternefält author 9043859 Marie Wahlgren supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Powders are widely used in pharmaceutical applications and understanding their nature is an important aspect of making successful formulations. Powder flowability describes the behaviour of powders and can be measured using several different methods. This study looks at the techniques: angle of repose and tapped density, comparing them to each other and looking at how consistent they are with changing variables, such as container size, powder mass, and number of taps for the tapped density tests. Tests were performed using several different powders, such as different forms of sodium bicarbonate and lactose. Results show a dependence of powder flowability on particle size of the powders involved. Granulated lactose exhibited great flowability through all the tests. Container size is<br /> shown to have little to no effect on the results, while the number of taps has a big influence on the tapped density results. Good flowing powders have overall coherent results, while poor flowing powders are affected by changes in experiment design to a greater degree. Angle of repose and tapped density measurements can give rough estimates for powder flowability, but do run the risk of inconsistent results based on the physical parameters of the experiment. Pulver används inom många moment i läkemedelsbranschen, däribland tillverkning av tabletter och dylika processer. Att förstå och kunna anpassa sig till hur pulver beter sig, “flyter”, genom till exempel en tabletteringsmaskin leder till ökad kontroll över tabletternas innehåll och minskad variation mellan individuella tabletter. Vi kallar denna egenskap hos pulvers för deras “flytbarhet”. I vardagligt tal kan det beskrivas som den egenskap som avgör hur lätt det är att hälla över ett pulver från en behållare till en annan. Alla som någon gång bakat vet säkert att det är stor skillnad mellan strösocker och vetemjöl. För att mäta pulvers flytbarhet finns flera metoder, såsom att mäta rasvinkel eller kompressionsindex. Rasvinkelmätningar går ut på att mäta vinkeln av den hög som pulvret bildar efter att det har fått falla genom en tratt. Kompressionsindex tittar på hur volymen av pulvret ändras efter att det pressats samman. Denna rapport jämför dessa mätmetoder, och tittar på hur resultaten varierar under olika förhållanden, såsom vattenhalten i pulvret eller mängden pulver som används. Experimenten indikerar att pulvrets partikelstorlek har stor inverkan på dess flytbarhet. Om man kan styra över storleken på pulverkornen så leder det till bättre flytbarhet och, i en maskin, till ökad kontroll över pulvret. Resultaten i rapporten pekar också på svårigheterna med att hitta en standardiserad mätmetod för pulverflytbarhet: mätningar av rasvinkel eller kompressionsindex kan ge en grov indikering på hur bra pulvret flyter, men är beroende på experimentella parametrar som är svåra att replikera från ett labb till ett annat, utan identisk utrustning. Inverkan av mängden pulver som används i mätningarna pekar också på svårigheten med att standardisera en mätmetod, då inte alla pulver finns eller kan finnas tillgängliga i lika stora mängder. https://lup.lub.lu.se/student-papers/record/9043861/file/9043878.pdf application/pdf 1261097 no 2021 eng powder technology pharmaceutical technology engineering Chemistry 9043861 2021-05-10T13:54:33+02:00 2021-10-12T09:36:15+02:00 2021-10-12T09:36:15+02:00

oai:lup-student-papers.lub.lu.se:9044494 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Lintang Hizbullah author 9044492 Chuanshuai Li supervisor Department of Chemistry v1000647 department The reactions of [Fe2(CO)6(µ-sdt)] (1) (sdt = SCH2SCH2S) with diphosphine ligands have been investigated. New diiron complexes that can serve as model complexes for the active sites of [FeFe]-hydrogenases were obtained from these reactions. Treatment of 1 with the dppm (bis(diphenylphosphino)methane) and the dcpm (bis(dicyclohexylphosphino)methane) ligands affords the diphosphine-bridged products [Fe2(CO)4(µ-sdt)(µ-dppm)] (2) and [Fe2(CO)4(µ-sdt)(µ-dcpm)] (3), respectively. The complex [Fe2(CO)4(µ-sdt)(κ2-dppv)] (4) with a chelating diphosphine was obtained by reacting 1 with dppv (cis-1,2-bis(diphenylphosphino)ethene). Reaction of 1 with dppe (1,2-bis(diphenylphosphino)ethane) produces [{Fe2(CO)4(µ-sdt)}2(µ-κ1-dppe)] (5) in which the diphosphine forms an intermolecular bridge between two diiron cluster fragments. Three products were obtained when dppf (1,1′-bis(diphenylphosphine)ferrocenyl) was introduced to complex 1; they were [Fe2(CO)4(µ-sdt)( κ1-dppfO)] (6), [{Fe2(CO)4(µ-sdt)}2(µ-κ1-κ1-dppf)] (7), and [Fe2(CO)4(µ-sdt)(µ-dppf)] (8) with complex 8 being produced in highest yield. Single crystal X-ray diffraction analysis was performed on compounds 2, 3, and 8. All structures reveal the adoption of an anti-arrangement of the dithiolate bridges, while the diphosphines occupy dibasal positions. Infra-red spectroscopy indicates that the mono-substituted complexes 5, 6, and 7 are inert to protonation by HBF4.Et2O, but complexes 2, 3 and 4 show shifts of their (C-O) resonances that indicate that protons bind to the metal clusters. Addition of the one-electron oxidant [Cp2Fe]PF6 does not lead to any discernable shift in the IR resonances. The redox chemistry of the complexes was investigated by cyclic voltammetry, and the abilities of the complexes to catalyze electrochemical proton reduction were examined. Forecast on the energy consumption indicates a surge demand globally within next decade. Concurrently, fossil fuel plays pivotal role as energy source and industry component which contributes to our present problems. Several alternatives have been investigated, one of the promising candidates is hydrogen. It has energy output as much as oil produce, emit water as byproduct, and sustainably abundance in a form of gas and water. Hydrogen also industrially applicable as raw material for producing fertilizer, refining petroleum process, metal purification by reduction, etc. The invented process that effectively produce hydrogen is by using platinum catalyst which is a noble metal. Thus, an endeavor to hydrogen economy is a fascinating goal. On the other hand, nature has been harvesting hydrogen using active enzyme for millennia, on one of which consist of [FeFe]-hydrogenase cluster in its active site. Iron as the metal core of the component is far more abundant than platinum emphasizing the scale up of the facility is possible industrially. In this study, several novel diiron carbonyl clusters have been synthesized to bio mimic such a structure and revealed the potential in hydrogen production electrochemically. Structure characterization is proven by IR and NMR spectroscopy, and its electrochemical properties are identified by cyclic voltammetry. The complexes exhibit proton reduction activity, via electron donation from metal to the proton that attracted to the metal followed by another reduction to the second proton. 2021 eng Diiron hydrogenase diphosphines derivatives proton reduction electrocatalytic inorganic chemistry Chemistry https://lup.lub.lu.se/student-papers/record/9044494/file/9044498.pdf application/pdf no https://lup.lub.lu.se/student-papers/record/9044494/file/9044500.pdf application/pdf no 9044494 2021-05-19T09:03:28+02:00 2021-05-21T12:18:54+02:00 2021-05-21T09:07:50+02:00

oai:lup-student-papers.lub.lu.se:8965219 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Atef Mannaa author Ebbe Nordlander supervisor Chemical Physics v1000658 department Triruthenium dodecacarbonyl was reacted with the non chiral ligand PSSP as well as chiral ferrocenyl diphosphines of the Josiphos (J008, J006 and J015) and Walphos (W009) families to give [Ru3(CO)10(µ-1,2-P-P)], (P-P = W009 1, J008 2, J006 3, J015 4 and PSSP 5. The X-ray structure of 3 shows that a Ru-Ru edge is bridged by a diphosphine ligand in an equatorial coordination mode. The corresponding clusters with the ligand in a chelating coordination mode were also obtained as minor products. The tetraruthenium cluster [H2Ru4(CO)13] was reacted with chiral diphosphine ligands of the Josiphos family (J007 and J015). Four products were isolated: [H2Ru4(CO)11(µ-1,2-J007)] 6 and [H2Ru4(CO)11(µ-1,2-J015)] 7, in which the diphosphine coordinates in a bridging mode, as well as [H2Ru4(CO)11(µ-1,1-J007)] 8 and [H2Ru4(CO)11(µ-1,1-J015)] 9, where the diphosphine coordinates in a chelating mode. Clusters 6 and 7 were found to give high conversion and good enantiomeric excess for the hydrogenation of tiglic acid. IR spectroscopy indicates that 6 is a precursor to the active catalyst, while 8 may be an active catalyst. https://lup.lub.lu.se/student-papers/record/8965219/file/8965231.pdf application/pdf 673709 no 2010 eng inorganic chemistry oorganisk kemi Chemistry 8965219 2019-01-08T08:43:50+01:00 2019-01-08T08:56:10+01:00 2019-01-08T08:56:10+01:00

oai:lup-student-papers.lub.lu.se:8965431 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Hong Jiang author 8964934 Daniel Topgaard supervisor Department of Chemistry v1000647 department Diffusion magnetic resonance imaging (dMRI) is a non-invasive method that provides micrometer or millimeter-scale tissue structural information. In order to further advance this technique to obtain more detailed microstructural information of biological tissues, developing new diffusion MRI method becomes a necessity. <br /> For the past few years, the multidimensional diffusion MRI technique has been developed to advance clinical research by providing non-invasive techniques that enable exploration of pathological cellular changes, e.g. multiple sclerosis, cancer, Alzheimer’s disease and traumatic brain injury.<br /> Phantom, as a specially designed object which mimics brain physiological conditions, is normally composed of water, polymer, surfactant and hydrocarbons with tunable relaxation and diffusion property. The main purpose of this project is to design a lamellar liquid crystal phantom as a mean to validate multidimensional dMRI. The specific aim is to design a lamellar liquid crystal with transvers relaxation time (T2) as long as possible. The chemicals that we used are sodium octanoate (as surfactant) and 1-Deconal (as oil). As solution, we used a mixture of 90% Millipore-Q water and 10% heavy water. My work is basically described as follows. First, we mixed liquid crystals with different chemical compositions and then observed the samples by utilizing the polarized light microscopy. Second, we tested the samples by performing some NMR experiments. Specifically l measured deuterium NMR spectra and its transverse relaxation time T2, and then recorded NMR diffusion imaging for these samples. We know that biological tissues contain hundreds of thousands of microscopic domains of water. For different microstructure, the corresponding water mobility is different. By probing the effects of structure on water diffusion, the structure information of biological tissue can been obtained. This method is called diffusion magnetic resonance imaging (dMRI). dMRI is a non-invasive method that can give tissue structural information on micrometer-scale.<br /> For the conventional dMRI, the spatial resolution of the images is limited that mean we obtain microscopic structures information has too lower revolution. In order to obtain more details information of biological tissues, new dMRI methods were developing in recent years. Our (Topgaard’s) group has a long history of developing new dMRI methods and utilizing them to study tissue microstructure of living human brain tissues. These methods are supposed to provide structural information at an unprecedented precise level.<br /> In order to validate measurements of new diffusion MRI methods, developing phantoms are very necessary. Phantoms are special materials that mimic pathological conditions of biological tissues. Phantoms are utilized to optimize and validate measurements of new diffusion MRI methods. My thesis project is to design a lamellar liquid crystal phantom as a first step to validate new dMRI methods. Prior to my study, a phantom with diffusion properties corresponding to brain white matter was developed in our group. My work will follow the same line, but aiming to make a different phantom that mimic the microstructure of brain tumor tissue or epidermoid cyst. 2019 eng Diffusion MRI phantom NMR tensor anisotropic nanochemistry nanokemi Chemistry 8965431 2019-01-08T15:10:03+01:00 2019-02-25T09:04:21+01:00 2019-02-25T09:04:21+01:00

oai:lup-student-papers.lub.lu.se:8966213 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Elsa Hallin author 8965122 bitr. universitetslektor Baozhong Zhang supervisor Centre for Analysis and Synthesis v1000651 department Inom lackindustrin har LED-lampor (från engelskans ”light emitting diode”), utvecklats som ett miljövänligt alternativ till de konventionellt använda kvicksilverlamporna. De konventionella lamporna avger breda spektra av UV-ljus och kan därför härda lacker med ett flertal olika fotoinitiatorer. Jämfört med de konventionella avger LED-lampor mindre energi och de avger endast UV-ljus vid enskilda våglängder. Därför måste fotoinitiatorerna som används effektivt absorbera vid de enskilda våglängderna som LED-lampan avger, vilket begränsar antalet användbara fotoinitiatorer.<br /> Detta projekt hade två mål där det första målet var att utvärdera olika fotoinitiatorer för användning i en UV-härdad polyuretandispersion (UV-PUD) som härdats av antingen LED- eller kvicksilverlampa. Då UV-PUD:en är en dispersion måste fotoinitiatorerna även vara möjliga att dispergera i vattenbaserade system. För att bedöma fotoinitiatorernas kompatibilitet med det vattenbaserade systemet och den valda härdningsmetoden utvärderades flera egenskaper hos de slutgiltiga lackerna. Härdningsgraden mättes med FTIR-ATR (från engelskans ”fourier-transform infrared spectroscopy with attenuated total reflectance”), lackens gulning mättes med en spektrofotometer och lackens kemikalieresistensen testades genom exponering av kaffe och alkohol.<br /> Flera av de studerade fotoinitiatorerna gav lacker med tillräcklig härdning och hög kemisk resistans när de härdas med konventionell kvicksilverlampan. När lackerna härdades med LED gav däremot ingen av de utvärderade fotoinitiatorerna de önskade egenskaperna. En möjlig förklaring till detta kan vara en dålig passning mellan LED-lampans avgivna våglängder och de våglängder som de utvärderade fotoinitiatorerna absorberade.<br /> Projektets andra mål var att bedöma hur tillsatsen av ljusstabilisatorer (LS) påverkar UV-PUD-lacker. LS:er är tillsatser som skyddar lacker emot nedbrytning av UV-ljus. I detta projekt användes två sorter, HALS (från engelskans ”hindered amine light stabilizer”) och UV-absorptionsmedel (UVA). LS:er påverkar absorptionen av UV-ljus och kan därmed konkurrera med fotoinitiatorernas absorbering och initiering. Därför kan tillsatsen av LSer minska härdningen av lacken och påverka dess slutgiltiga egenskaper. För att utvärdera hur lacker påverkades av detta studerades ändringen i härdning och gulning före och efter accelererad solljus-exponering i en väderkammare. Resultaten visade en minskning av gulning och härdning vid tillsats av LS samt tecken på en synergistisk effekt mellan HALS och UVA. Light emitting diodes (LEDs) are an environmentally friendly alternative to the conventional medium pressure mercury (MPMs) lamps used in the coating industry. However, LEDs emit at defined wavelengths and have a lower energy output than the MPM lamps. Therefore, the used photoinitiators (PIs) must absorb the defined wavelengths of the LED efficiently. The first aim of this project was to evaluate PIs for use in a UV-curable polyurethane dispersion (UV-PUD) cured by either LED or a conventional MPM. This means the used PIs must be dispersible in waterborne (WB) systems. To assess the properties of the coatings, and thereby the PIs compatibility to the WB system and the used UV lamp, Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) was used for determining cure. Evaluation of yellowing of the coating was done by a spectrophotometer. The chemical resistance of the coating was tested by exposure to coffee and alcohol.<br /> Several of the assessed PIs could produce coatings with sufficient cure and high chemical resistance when cured by conventional oven and could therefore be recommend for further development. When cured by LED, none of the evaluated PIs provided coatings with the desired properties, possibly due to the mismatched emission and absorption wavelengths.<br /> The second aim of this project was to assess the effect of the addition of Light Stabilizers (LS) on UV-PUD coatings. LS such as hindered amine light stabilizers (HALS) and UV-absorbers (UVA), are additives that protects against photodegradation. LS affect the absorption of UV-light and may compete with the absorption of the PI and thereby hinder the initiation and crosslinking process of the coating.<br /> Using a weathering chamber, the samples were subjected to accelerated sunlight exposure (ASE) to evaluate how yellowing and curing of coatings were affected by the addition of LS. Results show a decrease in yellowing and curing upon addition of LS as well as evidence of a synergistic effect between the HALS and UVA. Att vi behöver gå mot ett mer hållbart samhälle blir allt tydligare. Användningen av fossila bränslen och överkonsumtionen av kläder och elektronik börjar märkas. Inte minst genom årets alla bränder, men även genom klimatförändringar där extremväder blir allt vanligare. Konsumenter och politiker har börjat ställa krav på kemiföretag för att dessa ska minska sin klimatpåverkan. Inom färg- och lackindustrin har skiftningar mot miljövänligare alternativ pågått ett tag, men är långt ifrån klara. Ett exempel på detta är utvecklingen av vattenbaserade, UV-ljus härdande lacker som används i industriell målning. Dessa lacker härdas, alltså torkar på kemisk väg, med hjälp av UV-ljus och har utvecklats som ett alternativ till oljebaserade härdande lacker. Användningen av vattenbaserade lacker bidrar till en minskning av användning och utsläpp av skadliga och miljöfarliga kemikalier så som lösningsmedel.<br /> Ytterligare ett sätt för färg och lackindustrin att minska sin klimatpåverkan är att utveckla system som kräver mindre energi vid applicering. Dagens industrier har jättelika ugnar och lampor för att härda sina lacker. Ett miljövänligt alternativ i denna processen är LED-lampor som används för att ge det UV-ljus som behövs för att härda lackerna. Redan idag används LED-lampor till mindre applikationer av till exempel nagellack eller inom tandvård. Inom industriell applicering av färg- och lack används istället LED-lamporna som ett energieffektivare alternativ till de vanliga kvicksilverlamporna som används idag. Att kombinera LED och vattenbaserad lack är inte etablerat i industrin ännu. Detta på grund av de speciella krav kombinationen sätter på kemikalierna i lacken, vilket gör det svårt att anpassa lackerna till LED. Dessa krav innebär bland annat att fotoinitiator, alltså själva molekylen som startar härdningen, har ljusupptag som matchar med LEDs avgivna ljus. Vattenbaserade lacker kräver dessutom att vattenlösliga kemikalier används. Fotoinitiatorn måste därför fungera med LED och vara vattenlöslig.<br /> Ett annat sätt att minska miljöpåverkan är genom att öka lackens hållbarhet. Detta kan leda till mindre konsumtion och på så sätt göra produkten miljövänligare. Hållbarheten hos en lack kan ökas på flera sätt, bland annat genom att förhindra slitage och färgförändringar. Den vanligaste färgförändringen är gulning av lacken eller träet, som bland annat orsakas av solens strålar. Du har antagligen sett exempel på gulning i din eller bekantas bostad. Det kan till exempel synas på föremål som stått i fönster länge eller på trägolv där man flyttat på möbler som stått på samma plats länge. Då har golvet en helt annan kulör där möbeln stått. För att förhindra gulning kan speciella ämnen, så kallade ljusstabilisatorer, tillsättas till lacker. Dessa fungerar som en solkräm för lacken och skyddar mot solens skadliga ljus. Men att tillsätta ljusstabilisatorer kan också påverka härdningen av lacken. Vilken kan ge lacken sämre hållbarhet mot skav eller avskrap.<br /> I detta projekt hittades inga tillräckligt bra lösningar för härdning med LED. När de vattenbaserade lackerna härdades med den vanliga kvicksilverlampan hade de bra egenskaper. Men när de härdades med LED hade ingen av lackerna alla de efterfrågade egenskaperna. Att tillsätta ljusstabilisatorer till lackerna var däremot effektiv, det minskade gulningen. Dessvärre påverkade ljusstabilisatorerna även härdningen.<br /> Detta projekt utforskade alltså möjligheten att härda vattenbaserade lacker med hjälp av LED. Dessutom undersöktes också om ljusstabilisatorer minskade gulningen av lacken. Tyvärr så hittades ingen bra fotoinitiator som var både vattenlöslig och fungerade i LED. Däremot kan de prövade fotoinitiatorerna uteslutas från att användas och på så sätt underlätta framtida undersökningar. Att tillsätta ljusstabilisatorer till lacker gav däremot lovande resultat och om deras negativa påverkan på härdningen kan minskas eller förhindras kan de hjälpa till att skydda framtiden lacker mot gulning.<br /> Utvecklingen av miljövänligare lacker och tillverkningsmetoder går dock vidare. Det utvecklas ständigt nya LED som kan avge mer anpassat ljus med mer energi. Dessutom upptäcks det nya fotoinitiatorer som kan vara både effektivare och bättre anpassade för användning i LED.<br /> Nyckelord: Fotoinitiator, UV-LED, Vattenbaserad lack, UV-härdning, Ljusstabilisatorer https://lup.lub.lu.se/student-papers/record/8966213/file/8966221.pdf application/pdf 1885791 yes 2019 eng UV-PUD Light stabilizers UV-LED Photoinitiator Coatings polymer technology polymerteknologi Chemistry Technology and Engineering 8966213 2019-01-10T11:31:39+01:00 2019-02-07T09:28:18+01:00 2019-02-07T09:28:18+01:00

oai:lup-student-papers.lub.lu.se:8966794 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Shehed Allafta author 8966792 Hanna Wacklin supervisor Department of Chemistry v1000647 department Supported lipid bilayers are a popular in situ artificial bilayer model where a lipid solution is deposited on a surface. Usually the supported lipid bilayers consist of only 2-3 lipids and the problem with that is that they do not represent the biological membrane very well. In this project Pichia pastoris lipids were used to form supported lipid bilayers at different pH, temperature and different concentrations of both NaCl and CaCl2 to study the parameters that effect the formation and the quality of supported lipid bilayers. <br /> <br /> The supported lipid bilayers were formed in situ in QCM-D on a silica surface. From the results it was clear that Na+ and Ca2+ were essential to form a supported lipid bilayer and a lower pH was more favorable. Interestingly, the lipids did not need to be above all their<br /> melting points for the vesicles to rupture, fuse together and form a supported lipid bilayer. Människans kropp består av miljontals celler och alla dessa celler har ett cellmembran som skyddar cellens interiör från dess omgivning. Cellmembranet sköter även transporten utifrån och in till cellen. För att få en förståelse över cellmembranets funktion så används olika konstgjorda lipid bilager som modeller. I dag kan man enkelt skapa konstgjorda bilager modeller som består av 2-3 fosfolipider men dessa bilager representerar inte det biologiska membranet på ett verkligt sätt. För att skapa konstgjorda bilager som mer liknar det biologiska membranet så kan naturliga lipid extrakt från cell kulturer, som till exempel jäst användas.<br /> <br /> När en bilager modell väl har formats så kan det användas för att studera hur bl.a. läkemedel och proteiner interagerar med bilagern och på så vis få en bättre förståelse hur dessa läkemedel/proteiner kommer att interagera med det biologiska cellmembranet.<br /> <br /> I detta projekt studerades lipider från Pichia pastoris jäst för att skapa bilager modeller vid olika pH, temperaturer och Ca2+, Na+ koncentrationer för få en överblick på faktorer som påverkar bildningen av dessa bilager modeller. Från resultatet var det tydligt att Ca2+ och Na+ var nödvändiga för att skapa bilager modeller och att dem formades lättare vid låga pH. 2019 eng physical chemistry supported lipid bilayer lipids QCM-D fysikalisk kemi Chemistry 8966794 2019-01-15T22:23:09+01:00 2019-02-25T09:06:52+01:00 2019-02-25T09:06:52+01:00

oai:lup-student-papers.lub.lu.se:8967509 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Erik Vu author 8963775 bitr. universitetslektor Baozhong Zhang supervisor Centre for Analysis and Synthesis v1000651 department Knowledge on how polymeric materials changes or is affected when exposed to<br /> products is of interest and importance for many commercial applications. Understanding the product interaction on packaging materials is the key to preventing errors and increasing the quality of products. At Tetra Pak®, product packaging is created to make food and drink safe and accessible everywhere. Therefore, packaging solutions for products must be constantly developed and improved in order to meet customer needs. Today’s packaging contains many different polymeric materials and it does not look like it will change in the near future. Therefore, it is of importance to find an experimental working method to test and perform simulations, that are as close as possible to real behaviour of the material. <br /> <br /> In this thesis, several experimental methods have been used to study the interaction between different products on low density polyethylene. Methods such<br /> as Wide-Angle X-ray Scattering (WAXS), tensile tests, thickness measurement,<br /> product uptake and Differential Scanning Calorimetry (DSC) have been used to<br /> study the interaction with products at Tetra Pak® and LTH. From the experimental<br /> tests, it was difficult to observe large difference in crystallinity and mechanical properties in the short period of the experiment. However, large differences could be seen in the thickness variation, which may be important to look into in the future as it may have a major impact on test results. The packaging industry is a huge and growing sector but is facing pressure from manufactures and customers to look good, reduce cost and energy use. Therefore, to have a good package requires ones to understand how packaging materials react to everyday uses and interactions with food and products. The goal of this thesis is to understand how the most common polymer material reacts to dierent everyday food at dierent exposure time. A combination of mechanical and thermal properties of the polymer are rst studied and, with the obtained knowledge, experimental tests are the performed in an experimental environment as close to real environment as possible.<br /> To study food interactions with polymer, many experimental methods were used.Weight measurements on the polymer before and after exposure of food was one method to try to study and explain food interactions in the larger scale. But, to understand the interactions in the smaller scale, we used a technique that directed a beam of X-ray radiation on the polymer which gave information on the atomic scale. A thermal method where we quickly heat and cool the polymer, were used to understand how temperature aects the polymers properties after exposure to food.<br /> We also pull apart samples of polymers by tensile test to study how the whole polymer sample reacts to mechanical stress after exposure to food. Thereafter, electron microscopy was used to obtain high quality images of broken polymer samples on a very small scale. Lastly, thickness measurements were nally performed to study exactly how thick the polymer sheets were in reality.<br /> This thesis has shown that the polymer pick up and absorb the food, which should aect the properties of the polymer. But from the experiments we have not seen any big changes in properties of the exposed polymers. This means that it is unlikely that food interaction occurs at the atomic scale, as we originally expected. Therefore, in the future it would be interesting to look into larger length scale than have been studied in this thesis. Lastly, the thickness measurement showed large thickness variations in the supplied polymer, and this is believed to give an error<br /> on all the tensile tests. Therefore a way to reduce thickness dierences is needed to fully understand the interaction between product and polymers. https://lup.lub.lu.se/student-papers/record/8967509/file/8969189.pdf application/pdf 13793498 no 2019 eng polymer technology polymerteknologi Technology and Engineering Chemistry 8967509 2019-01-22T15:36:50+01:00 2019-02-22T15:26:47+01:00 2019-02-22T15:26:47+01:00

oai:lup-student-papers.lub.lu.se:8968835 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Amélie Fuentes author 8968833 Victoria Junghans supervisor Department of Chemistry v1000647 department T cells play an important role in the immune system where T cell receptors (TCR) identify foreign pathogens bound to major histocompability complex (MHC) molecules on antigen presenting cells (APCs). The detection of an antigen causes the T cell to trigger, which is an activation of the cell that results in a cellular immune response. This triggering process is not fully understood and studying the T cells in vivo is difficult due to the sheer amount of interactions between the hundreds of different proteins on the cell surface. This is circumvented by studying the cells in vitro on a supported lipid bilayer (SLB) which resembles a cell membrane of an opposing cell. In this thesis the interactions between T cells and bilayers of different lipid compositions were studied, where all different surfaces produced triggered cells. Surprisingly, the antibody OKT3 had the lowest number of triggering cells whereas the bilayers with 1%, 2% and 5% of the lipid DGS-NTA produced the highest number of triggering cells independent of the percentage. However, the OKT3 coated surface caused the quickest triggering whereas the other surfaces had slower but similar triggering times. The interaction between cells and membrane proteins are studied by binding membrane proteins to an SLB and adding cells. Next in this thesis, the T cell protein rat CD2 was non-covalently bound to an SLB, where the detachment of the protein was measured over time in different buffer mixtures to observe whether the buffers had an effect on the bound protein. The RPMI media had the highest influence on the detachment of protein. The FBS component of RPMI media stopped rat CD2 from binding to the bilayer but did not influence the detachment of the proteins that successfully bound to the bilayer. In the last experiment the interaction between T cells and rat CD2 bound to an SLB was studied. It was known that the cells would trigger when binding to the CD2 but not how much of the protein is needed for triggering. The protein accumulated under the cell after binding to non-native rat CD48 on the cell surface. The cells were triggered both before and after visible protein accumulations on the bilayer and therefore it could not be concluded whether a certain level of protein accumulation was necessary for the cells to trigger. När vi drabbas utav bakteriella infektioner agerar immunförsvaret kvickt för att utrota dessa elakingar som orsakar sjukdomar. De kanske mest kända försvararna är de vita blodkropparna, olika celler som upptäcker och utrotar hot. T-cellen, vars namn kommer från engelskans Thymus (brässen, ett litet organ i bröstkorgen) är delvis ansvariga för upptäckandet av hoten. T-cellen har en receptor kallad TCR som identifierar hoten och binder till den infekterade cellen. När en T-cell upptäcker en infekterad cell sker det en mängd interna reaktioner i cellen som leder till aktivering av hela försvarsarmén. Den huvudsakliga händelsen är att TCR får en massa fosfatmolekyler på sig som signalerar om att ett hot är upptäckt. Denna signalering kallas för triggning av cellen och är inte helt förstådd än, men är av stort intresse för forskning kring autoimmuna sjukdomar där friska celler identifieras som infekterade. Det finns olika modeller som föreslår hur för triggning fungerar, varav Kinetic Segregation (KS) modellen som anses vara korrekt i denna tes. Det finns ett stort protein som plockar bort fosfatgrupper från TCR och hindrar triggning, och när T-cellen binder till en infekterad cell antas det att proteinet puttas bort vilket låter cellen triggas. Detta har visats experimentellt i en studie av Chang et al (2016) där man band ihop T-celler till ett låtsascellmembran med två små proteiner och såg att cellerna triggades. Låtsasmembranet består av ett bilager (dubbelt lager) av fettliknande molekyler kallade lipider som härmar cellytor. <br /> <br /> I och med att bilager används vanligen för att studera cellers interaktioner med proteiner så var det av intresse att testa om olika bilager kunde orsaka triggning av T-celler. I detta projekt användes lipiderna POPC och DGS-NTA, varav den sistnämnda kan binda till andra molekyler. Koncentrationerna som testades var 1%, 2% och 5% DGS-NTA. Dessa tre bilager orsakade lika mycket triggning oavsett koncentration. Andel triggade celler kunde variera mycket från dag till dag, vilket troligtvis berodde på att cellerna är olika friska beroende på när de t.ex. blir matade. I nästa del av projektet upprepades en version av Chang et al experiment med proteinet CD2 bundet till ett 5% DGS-NTA bilager för att testa huruvida mängden CD2 under T-cellerna spelade roll för när cellerna skulle triggas. Vad som observerades var att cellerna triggades oavsett mängd CD2 under cellerna och något sammanband kunde inte hittas. En viktig detalj med proteinet CD2 är att det är inte permanent bundet utan kan lossna från bilagret. Om proteinet lossnar under experiment när man studerar interaktioner mellan cell och protein kan resultatet påverkas. I den tredje delen av projektet testades hur mycket CD2 som lossnade från ett 5% DGS-NTA bilager i olika bufferlösningar, varav två av dessa innehöll näringsämnen som salter och socker som cellerna lever av. Cellmedium som innehöll alla näringsämnen orsakade sju gånger större förlust av proteiner från bilagret än bufferten utan näringsämnen. Den tredje buffertlösningen innehöll en komponent utav cellmediet, där den som väntat hindrade proteinerna från att binda till bilagret, däremot kunde inte någon förlust av proteiner mätas. Detta var oväntat med tanke på att de hindrade CD2 från att binda till bilagret och bör på samma sätt ha orsakat proteinerna att lossna. <br /> <br /> Sammanfattningsvis så kunde det observeras att lipidbilager triggade T-celler lika mycket, cellmedia orsakade stor förlust av proteiner bundna till bilager samt att något sammanband mellan mängd CD2 och triggande celler kunde ej hittas. Detta resultat gav inte mer information om hur triggning fungerar, men det visade att det spelar ingen roll vilken koncentration på bilagret man har när man studerar interaktioner mellan celler och proteiner. https://lup.lub.lu.se/student-papers/record/8968835/file/8968836.pdf application/pdf 1051119 LU/LTH access 2019 eng Physical chemistry Biophysics T cell Supported lipid bilayer membrane protein fysikalisk kemi Chemistry 8968835 2019-01-30T10:31:24+01:00 2019-02-28T08:29:24+01:00 2019-02-28T08:29:24+01:00

oai:lup-student-papers.lub.lu.se:8969709 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Nadia Abdalla author 8969707 Dr Åsa Davidsson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department After the sewage wastewater is collected from different households and directed to the treatment plants, it goes through several processes, which are physical, chemical and biological. The different processes remove the contaminant, and produce a semi-solid material named sludge. Sludge has a huge amount of liquid. Disposing this sludge with no further treatment is a very costly procedure and presents an environmental hazard. Further treatment of the sludge reduces the liquid volume, and furthermore reduce the transportation cost.<br /> However, different techniques are evolving nowadays in large scale, but further investigation is needed of the sludge dewatering properties on the small scale. These laboratory scale methods reliability compared to full scale is a milestone due to lack of knowledge in this area.<br /> In this thesis work, attempts were applied to find methods for dewatering the sludge on lab scale, and then evaluate these different methods based on different criteria. The thesis was divided into two part: literature reviewing and laboratory work. From the literature, seven sludge dewatering methods were found: electro-dewatering, dewatering by osmosis, network strength, ultra-high-pressure filtration (UPF), capillary suction time (CST), centrifuge and lastly pressure filtration test. The first four methods were evaluated based on the information found in the literature. The criteria used for evaluating the methods were: time required and how comparable the obtained results are to large scale. The network strength method required around 24 hours until obtaining the results. The method concept was new and gave abundant data about the sludge dewatering properties. For this reason, network strength is considered an interesting method for further studies. <br /> The lab work included three methods found in the literature, which were CST, centrifuge and pressure filtration test (PFT). The sludge was firstly conditioned using two type of polymers from Kemira. Then lab-scale dewatering methods were applied. The results were obtained from both CST and centrifuge. The pressure filtration test (PFT) faced some technical difficulties regarding filtrating the sludge sample. The three methods were evaluated based on certain criteria.<br /> The criteria used for evaluating the methods used in the lab were: time required, space requirement, simplicity, and the reliability of the results. Based on the evaluation, CST test had a very simple methodology compared with others and consumed less time (few minutes). However, the centrifugation studied the solid content in the supernatant and dry solid content in the obtained sludge cake. These two are important parameters in studying efficiency of the sludge dewaterability.<br /> At last, the aim of this thesis work was accomplished. The different methods were evaluated based on certain criteria. The CST test could be recommended due to its simplicity, short time required to conduct the test, easiness and direct obtaining of the results. Wastewater is collected from different household then channeled to the treatment plant where it goes through physical, biological and chemical treatment. Then a by-product is produced from these different process called sludge, which requires further treatment before final disposal. <br /> The sludge undergoes thickening, conditioning and dewatering processes before the final disposal. In the thickening stage, the solids of the sludge are concentrated and the water volume is reduced. The conditioning phase is a process of breaking out the jelly-like layer in the sludge by using chemicals (polymers) or various means. The following step is the dewatering of the sludge.<br /> Sludge dewatering is basically separating the solid and liquid components to minimize the waste. It is important to note that sludge dewatering does not treat the sludge, it only separate the two states for further separate treatment and easier final disposal. Besides that, reducing the volume of sludge corresponds to a reduction of transportation and final disposal costs. <br /> Different technologies are used nowadays for sludge dewatering but to maximize and increase the dewatering efficiency, it is imperative to have more researches studying the composed sludge dewatering properties and evaluate the used method in a small scale. Furthermore, compare this used methods with the results obtained from large scale. <br /> The methodology used for this work are both literature reviewing and conducted experiments in the laboratory. From the literature reviewing, four methods were found which are Electro-dewatering, Osmosis pressure for dewatering, Ultra high pressure and Network strength methods. These methods were then evaluated using different criteria : the time used to conduct the experiment and how comparable the obtained results with the full scale results. The evaluation was based on the available data found in the scientific reports of these methods.<br /> The laboratory work consisted of conducting three methods which are Capillary Suction Time (CST), Centrifuge and Pressure filtration test (PFT). The Capillary suction time method is not a sludge dewatering method but it provides information regarding the ease of separating the water portion from the solid one in the sludge. The Centrifuge performance on the other hand depends on different parameters; intensity, time, type of sludge and the used polymer. The pressure filtration test (PFT) principle is applying pressure on the sludge sample to extract the water from the sludge. <br /> The capillary suction time was measured for the different doses for the two polymers type. As for the centrifuge, different time durations were used with a constant speed to study the effect of the centrifugation timing on the sludge dewaterability. The method were then evaluated based on simplicity of implementation, time required to conduct the experiment, area used in the laboratory and how comparable the results are to the large scale results. <br /> The results and conclusions achieved in this study are tangible proof and indicator to conduct more research in this area. A better understanding of this will lead to improve the way we handle the sludge today and the waste management. https://lup.lub.lu.se/student-papers/record/8969709/file/8969711.pdf application/pdf 4067744 no 2019 eng sludge dewatering sewage sludge laboratory scale sludge treatment dewatering sludge dewatering sewage sludge CST capillary suction time test centrifuge lab-centrifuge rheology polymers conditioning sludge conditioning centrifuge on lab scale evaluation of lab experiments CST evaluation mechanical de-watering evaluation sludge dewatering at lab lab scale dewatering process sludge dewatering methods at lab Chemical engineering Lab centrifuge Capillary Suction Time (CST) Mechanical sludge dewatering evaluation Polymers conditioning of sludge sewage sludge dewatering methods for sludge dewatering at lab water engineering environmental engineering vattenförsörjningsteknik avloppsteknik Chemistry This thesis study discusses several methods used for sludge dewatering at lab scale and evaluating these different methods. Further work is recommended for more in-depth understanding on this subject. 8969709 2019-02-07T21:50:28+01:00 2019-02-22T15:13:21+01:00 2019-02-22T15:13:21+01:00

oai:lup-student-papers.lub.lu.se:8969772 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Vilhelm Ekberg author 8872140 Valera Veryazov supervisor Department of Chemistry v1000647 department While many crystals, both natural and artificial, grow isotropically, there are examples of crystals growing anisotropically. The aim of this theoretical study was to confirm the growth modes displayed by three different crystals, representing 3D, 2D and 1D structures. This was done by using energetic calculations with both molecular mechanics, with ReaxFF$_{ \textrm {SiO}}$ as the force field, and semi-empirical methods, with PM6 as the method. To start with, the 3D structure was represented by CaO, and both the ReaxFF$_{\textrm{SiO}}$ and PM6 results confirmed the isotropic growth mode of this rock salt structure. As for the 2D structure, nanoplatelets of calcium silicate hydrate (C-S-H), which make up the bulk phase in concrete, were investigated. These were modelled as C-S-H clusters with approximate cylinder shapes and adjustable chemical bonds and compositions. The ReaxFF$_{\textrm{SiO}}$ calculations showed that the energetic gain was higher when the radius was increased than when the height was increased. This was in agreement with the platelet shape of real C-S-H nanoparticles. However, the high computational costs of semi-empirical methods meant that the PM6 results did not represent a large enough cylinder size span to confirm the ReaxFF$_{ \textrm {SiO}}$ results. Lastly, the 1D structure was represented in the form of calcium oxalate monohydrate (COM), which may form elongated shapes such as raphides and styloids. Due to the ReaxFF$_{\textrm{SiO}}$ force field not being optimized for COM crystals, only PM6 calculations were performed. However, the computational demands of semi-empirical methods again limited the number of PM6 data points considerably. Therefore, it could not be concluded if the 1D growth mode was the most energetically favourable. Kristaller av olika former och storlekar finns överallt omkring oss. Medan de flesta kristaller föredrar att växa lika mycket i alla riktningar, som bordssalt (natriumklorid) och diamant, finns det kristaller som bara föredrar att växa i vissa specifika riktningar. Som exempel på det sistnämnda, s.k. anisotropisk tillväxt, finns det kristaller som växer endimensionellt och bildar nålliknande former eller de som bildar tvådimensionella plattor. Syftet med denna studie var just att undersöka varför olika kristaller växer på det sätt de gör.<br /> <br /> Att modellera hur kristaller växer är mycket svårt, och det finns många parametrar som antingen får kristaller att växa eller att falla sönder. Det finns analogier för de komplicerade parametrar som dikterar kristalltillväxt, exempelvis de komplexa biologiska och kemiska faktorer som styr hur träd växer, eller de ekonomiska och ingenjörsmässiga utmaningar som präglar bygget av skyskrapor. I denna studie valde vi att enbart skapa teoretiska modeller av olika kristaller, anta att de är stabila, och därefter beräkna den totala atomära interaktionsenergin för olika kristallstorlekar. <br /> <br /> Vi studerade tre olika kristaller, vilka växer som bulk, plättar och nålar; de kan anses representera kristaller som växer i 3D, 2D och 1D, respektive. Vi använde olika sätt för att modellera expansionen av dessa kristaller, i ett försök att förstå mekanismen bakom anisotropisk kristalltillväxt. Först och främst genomfördes beräkningar för kalciumoxid (3D tillväxt), en förening som väldigt mycket liknar bordssalt (natriumklorid). Kalciumoxid är ett mycket enkelt system växer lika mycket i alla riktningar, och beräkningarna bekräftade detta.<br /> <br /> Huvudfokus låg på betong (2D tillväxt) och tidigare studier har visat att de mikroskopiska betongpartiklarna bildar plättar. Det är den slumpmässiga och kaosartade strukturen hos de mikroskopiska betongpartiklarna som ger betong dess karaktäretiskt slitstarka karaktär. Som bekant är det just p.g.a. styrkan som betong återfinns i broar, dammar, höghus och allt däremellan. I ett datorprogram skapades det cylindriska betongpartiklar med hundratals upp till tiotusentals atomer; cylindrar ansågs kunna efterlikna formen hos verkliga betongpartiklar. Energiberäkningarna visade på tendenser att det var mer fördelaktigt för cylindrarna att öka radien snarare än höjden. Detta hade kunnat vara en förklaring, eller en del av en förklaring, till varför riktiga betongpartiklar är platta. Dessvärre, p.g.a. begränsad beräkningskapacitet hos datorerna, var antalet datapunkter så pass lite att tendenserna inte kunde bekräftas slutgiltigt. <br /> <br /> Vi tittade även på teoretiska modeller av rafider (1D tillväxt), ett slags långsmala kristaller som finns i växter, där de bl.a. upprätthåller jonbalansen och skyddar mot växtätare, men även i drygt 70 procent av alla njurstenar. Men även här ställde den begränsade beräkningskapaciteten till det, och de få datapunkter som erhölls räckte inte till för att dra några klara slutsatser om varför rafider växer som de gör. https://lup.lub.lu.se/student-papers/record/8969772/file/8969776.pdf application/pdf 15873204 no 2019 eng anisotropic crystal growth COM C-S-H PM6 ReaxFF$_{\textrm{SiO}}$ organizing molecular matter nanochemistry nanokemi Chemistry 8969772 2019-02-08T14:04:03+01:00 2019-02-26T10:23:32+01:00 2019-02-26T10:23:32+01:00

oai:lup-student-papers.lub.lu.se:8970251 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Linnea Lindh author 8970133 Pavel Chabera supervisor Dr. Petter Persson supervisor Centre for Analysis and Synthesis v1000651 department In the hunt for fossile-free energy-harvesting techniques, solar cells constitute one of the most promising techniques. Today, silicon-based solar cells are the dominant technique on the market but even the Silicon solar cell has limitations which means that there is a motivation for developing new solutions. One of those techniques is the dye-sensitized solar cell. Just as in photosynthesis, the solar cell contains a dye molecule that when absorbing the light from the sun can separate an electron from an electron hole. The electron is injected into titania and from there extracted as current. In this Master&#39;s thesis, two new dye molecules called FeCAB26 and FeCABCN2 have been investigated by spectroscopic methods (absorption spectroscopy, emission spectroscopy and transient absorption spectroscopy), quantum-chemical calculations and electrical measurements with the purpose to investigate the potential for usage as sensitizers in dye-sensitized solar cells. The molecules are iron-carbene-complexes, synthesized by colleges at Lund University, which are at the frontier of this research field since many traditionally used sensitizers have been ruthenium-complexes.<br /> <br /> Both molecules were able to sensitize films of titania and absorb light in the visible part of the spectrum. Quantum-chemical calculations indicated that the molecules did excite an electron from metal-centred orbitals to ligand-centred orbitals upon absorption of light. The molecules did also inject electrons into<br /> titania via the excited metal-to-ligand charge transfer state. The excited states had lifetimes of 21 ps and 36 ps for the different molecules. When the dye molecules were used as sensitizers in solar cells, a photocurrent was measured upon illumination in a solar simulator for the molecule FeCABCN2. Without<br /> having optimized the fabrication process, the efficiency of the best solar cell was 0.13 %. This shows a proof of concept that FeCABCN2 could work as a sensitizer in DSSCs. The optical characterization of both molecules will contribute to the development of iron-carbene-complexes as dye molecules to be used for applications in a broader context than just solar cells. I jakten på förnyelsebara energikällor är solceller en av de mest lovande teknikerna. Idag dominerar kisel-solcellen marknaden men även den har begränsningar och därför är det motiverat att utveckla andra sorters solceller. En solcellsteknik på utvecklingsstadiet som försöker efterlikna fotosyntesen är<br /> Grätzelsolcellen. Precis som i fotosyntesen är det en färgämnesmolekyl i solcellen som ska absorbera solens ljus och separera en elektron från ett elektronhål genom att elektronen skickas från färgämnesmolekylen till en titandioxid-elektrod och därifrån extraheras som elektrisk ström. I detta masterarbete har två nya färgämnesmolekyler kallade FeCAB26 och FeCABCN2 undersökts genom en rad spektroskopiska (absorptionsspektroskopi, emissionsspektroskopi, tidsupplöst laserspektroskopi), beräkningskemiska och<br /> elektriska mätmetoder med målet att bestämma deras fotofysiska egenskaper och bedöma dugligheten för bruk i Grätzelsolceller. Färgämnesmolekylerna är båda järnkarben-komplex, syntetiserade av kollegor vid Lunds universitet, vilka är i framkanten av forskningen inom detta fält där många metallbaserade färgämnesmolekyler annars varit rutenium-komplex.<br /> <br /> Båda molekylerna visade sig fästa till titandioxidytor och absorbera ljus i det synliga våglängdsområdet. De kvantkemiska beräkningarna indikerade att färgämnesmolekylerna vid absorption av ljus exciterade en elektron i en metall-centrerad orbital till ligand-centrerade orbitaler. De exciterade tillstånden hade livstider på 21 ps respektive 36 ps. Färgämnesmolekylerna visade sig även injicera elektroner i titandioxiden vid belysning. När färgämnesmolekylerna införlivades i solceller, så kunde en elektrisk ström mätas under belysning i solsimulator för FeCABCN2. Utan att ha optimerat tillverkningsprocessen var effekten för de bästa solcellerna med FeCABCN2 runt 0,13 %. Som ett första steg visar detta att FeCABCN2-färgämnet principiellt sett fungerar, även om fortsatt utveckling mot bättre solceller av denna typ kräver omfattande fortsatt forskning. Karaktäriseringen av båda molekylernas optiska egenskaper bidrar även till den fortsatta utvecklingen av järnkarben-komplex som färgämnesmolekyler mer generellt. Solar energy is a renewable energy source harvested by solar cells. But even if there are functioning solar cells on the market, the hunt for even better ones are engaging many scientists. This project has contributed in the development of a solar cell inspired by nature, that is using simple compounds to form the versatile solar cell of tomorrow: a solar cell that is environmentally friendly, can have different colours and can be made bendable. https://lup.lub.lu.se/student-papers/record/8970251/file/8970254.pdf application/pdf 61550217 no 2019 eng Dye-sensitized solar cells Grätzel cells solar cells of the future solar cells of tomorrow spectroscopy time-resolved spectroscopy materials chemistry materialkemi Chemistry https://lup.lub.lu.se/student-papers/record/8970251/file/8970253.pdf application/pdf Popular scientific article to the Master's Thesis Iron-Based Dye-Sensitized Solar Cells - From Theory to Working Solar Cell by Linnea Lindh no 8970251 2019-02-13T12:52:17+01:00 2019-02-22T15:21:03+01:00 2019-02-22T15:21:03+01:00

oai:lup-student-papers.lub.lu.se:8971945 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Symantha Zandelin author 8958870 Katharina Herzog supervisor Department of Chemistry v1000647 department Determining fatty acid composition within different lipid classes is a time-consuming process. Generally, normal phase chromatography is used to separate lipids by lipid class, based on differences in polarity. Fractions of this separation are then collected and derivatized into fatty acid methyl esters (FAMES), followed by analysis with gas chromatography and flame ionization detection (GC-FID). The introduction of electrospray ionization (ESI) and other<br /> soft-ionization methods however have eliminated the need for derivatization as the analyte can be ionized in solution. The use of ESI in conjunction with QTOF-MS is now an established method in determining lipid composition. <br /> <br /> This study focuses on the use of ultrahigh performance supercritical fluid chromatography (UHPSFC) in combination with quadrupole time of flight mass spectrometry (QTOF-MS) as an alternative to normal phase chromatography. Although UHPSFC is not yet widely used within lipidomics, interest has been shown in its development for a number of reasons. Compatibility with ESI-MS means that samples can be analysed with a single method, providing an advantage over the time-consuming process of normal-phase chromatography and GC-FID. In addition, carbon dioxide serves as a non-toxic mobile phase characterized by a low critical temperature and pressure that provide efficient chromatography.<br /> <br /> The goal of this project was to quantify a broad range of fatty acids within as many phospholipid classes as possible in approximately 10 min of analysis time. Approaches for quantification using internal standards and monoisotopic signal correction methods were investigated for four phospholipid subclasses. Attempts were also made to minimize dynamic ionization suppression although further measurements are required in this area. Internal standards were introduced to the make-up fluid in an effort to handle remaining dynamic ionization suppression. Due to mechanical and experimental set-backs, the method has only been validated for two of the four phospholipids of interest. The study therefore includes<br /> considerations for future measurements. Tackling the diversity of Lipids <br /> Lipids are a structurally and functionally diverse group of biomolecules comprised of several classes. They serve in energy storage and membrane structure, as well as functioning as signal substances and precursors for second messengers. Lipidomics is the emerging field which investigates lipid function on the cellular level. Biological samples are analysed to determine which lipid species are present and at what quantities. This quantitative and qualitative<br /> information aids in the understanding of lipid metabolism, which has been found to play a key role in diseases like diabetes and cancer.<br /> <br /> Because of the diversity within and between lipid classes, developing methods which can give quick and accurate results has proved tedious. One of the greatest bottlenecks faced is the processing of data, as many steps are involved in the transformation of raw data into accurate and quantitative results. The lipids must first be identified through the method of choice, and then quantified by comparison with lipid species of known concentration.<br /> <br /> In this project, a method was developed based on ultrahigh performance supercritical fluid chromatography (UHPSFC) coupled to quadrupole time of flight mass spectrometry (QTOF-MS) for the analysis of a class of lipids known as phospholipids. In particular, the fatty acid acyl chains which phospholipids are composed of will be examined. UHPSFC is used to separate the lipid classes, which generates individual peaks that can be assigned to a particular lipid. After separation with UHPSFC, the lipids are analysed and detected according to their<br /> mass.<br /> <br /> In this study, a method was developed and optimized to quantify a number of phospholipids. Due to mechanical set-backs and time constraints, a number of inquiries remain. Additional measurements are required before truly quantitative data can be produced. 2019 eng Analytical chemistry Ultrahigh performance supercritical fluid chromatography Lipidomics Analytisk kemi Chemistry 8971945 2019-02-25T06:04:45+01:00 2019-02-26T11:11:19+01:00 2019-02-26T11:11:19+01:00

oai:lup-student-papers.lub.lu.se:8972685 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Tomas Szakacs author 8972624 Ulf Nilsson supervisor Food Technology and Nutrition (M.Sc.) v1000294 department The main purpose of this master thesis was to test a novel approach of finding leads for new pharmaceuticals, by using Solid Phase Peptide Synthesis (SPPS) in combination with Weak Affinity Chromatography (WAC). Put in a more concrete way, the objective was to find a lead for a better human neutrophil elastase inhibitor. The plan was to take advantage of the fact that the tripeptide Valine-Proline-Valine is a known binder to elastase, and synthesis peptide libraries of tripeptides and test the binding affinity using WAC. Unfortunately, the in-house method of binding the protein onto the WAC-column was not compatible with human elastase, so porcine elastase was used instead. A hit for a new lead was possibly discovered, but the data are inconclusive as the reference binder did not show any binding in the assay, raising the suspicious of denatured protein. To validate the method, the same setup, but with a different protein, porcine trypsin and reference binder Threonine-Arginine-Glutamine was also evaluated. According to the results tripeptides with Ac-X-Glutamine-Valine-NH2 showed potential to have inhibitory effect, but the design of the additional libraries focusing on this sequence showed negative results. Any future experiments should test amino acids with saturated carbon side chains in position X, as all amino acids in this position for the first trypsin WAC run were of that type. Undersökning av en ny metod att söka efter inhibitorer <br /> Vad görs när immunsystemet, systemet byggt för att skydda oss, attackerar oss istället? I dagsläget finns inte så mycket man kan göra. Jag har därför undersökt en ny metod för att hitta ämnen som ska kunna hindra det trasiga immunsystemet från att skada!<br /> Framsteg inom medicinen är bland de viktigaste som kan göras för mänsklighetens fortlevnad. Ett specifikt område inom medicin där det är relativt snålt med detta är immunsystemet. Men immunsystemet är väl bra som det är ju? Mja, visst, när allt funkar som det ska. Ibland slår immunsystemet slint och börjar attackera kroppen, då behövs det läkemedel som tillfälligt kan hindra, med ett finare ord, inhibera, därav ordet inhibitor, de delar som gör skada.<br /> En viktig del av immunsystemet är de vita blodcellerna, de är kroppens försvarare mot olika främmande saker, exempelvis bakterier eller virus som vill bryta sig in i kroppen. Enzymet som valdes att testa vår metod på, det vill säga försöka hitta en inhibitor till, heter neutrofilelastas. <br /> Enzymer är katalysatorer, dvs. påskyndare. Enzymer består av en kedja av aminosyror, där en aminosyra kan ses som byggstenen för enzymer. Tänk på aminosyrorna som pärlor på ett ihopknycklat pärlhalsband, och enzymet som det ihopknycklade halsbandet. Någonstans på detta halsband, finns ett aktivt centrum, där reaktioner skyndas på. En inhibitors syfte är att blockera aktiva centrumet så att enzymet inte kan öka hastigheten på reaktioner, vilket även kan betyda att reaktionen inte kommer ske alls.<br /> Den vita blodcellen som heter neutrofil sprutar ut enzymet neutrofilelastaset när den hittar något i kroppen den inte gillar. Neutrofilelastaset tuggar då endast sönder den främmande saken, i alla fall vanligtvis. Två saker kan ske som gör neutrofilelastaset farligt för kroppen:<br /> 1. Kroppens ”stoppmekanism”, det som signalerar att jobbet är färdigt och det är dags att återgå till det normala, är ur funktion. <br /> 2. Den lokala koncentrationen av bakterie/virus etc. är låg.<br /> När något av ovanstående händer kan neutrofilelastaset börja attackera kroppen istället, särskilt lungorna. Neutrofilelastas kan orsaka kroniskt obstruktiv lungsjukdom (KOL).<br /> Under fem månaders tid testade jag därför en ny metod för att försöka få fram en inhibitor. Tyvärr hittades ingen inhibitor, varken till neutrofilelastaset eller trypsin som denna metod också undersöktes på. Däremot tror jag ändå på metoden trots att det inte lyckades med just dessa två protein. <br /> Metoden gick ut på att massproducera aminosyrekedjor, dvs pärlhalsbandsbitar, med tre aminosyror per kedja. Mellan 15 till 24 unika aminosyrakedjor var lösta i 13 olika lösningar, vilket gav ca 200 kedjor totalt, och dessa testades med Weak Affinity Chromatography (WAC).<br /> I WAC, något förenklat, har man två packade rör. Det ena röret är bara en kontroll och i det andra binder man fast sitt enzym. Man pumpar sen alla sina lösningar genom de båda rören. Man jämför sedan, med en referens som man vet sätter sig i enzymets aktiva centrum, hur länge kedjorna befunnit sig i rören. Om någon av kedjorna befinner sig längre tid i enzymröret än referensen har man potentiellt hittat startskottet till en ny inhibitor! https://lup.lub.lu.se/student-papers/record/8972685/file/8972687.pdf application/pdf 2915710 no 2019 eng pharmaceutical technology läkemedelsteknologi Chemistry Technology and Engineering 8972685 2019-03-11T12:25:25+01:00 2019-04-11T14:31:34+02:00 2019-04-11T14:31:34+02:00

oai:lup-student-papers.lub.lu.se:8972869 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Simon Birgersson author 8972690 Professor Mikael Akke supervisor Olof Stenström supervisor Biophysical Chemistry v1000649 department DMSO sees common application as a solvent for studies of synthetic molecules in biological systems, in fields such as drug design. Despite this, the possibility and nature of solvent interactions with both synthetic ligand and their target macromolecules is widely unexamined. DMSO could potentially have significant effect on binding characteristics due to conformational changes of protein structure. In this thesis, I have studied the effects of DMSO on the binding of a synthetic ligand to the carbohydrate recognition domain of galectin-3C using isothermal titration calorimetry (ITC) and NMR relaxation dispersion experiments. ITC reports on the thermodynamics of binding, whereas NMR relaxation dispersion reports on the kinetics of binding. ITC results displayed an increase in calculated KD from 5.588 μM to 13.02 μM with the addition of 10 % (v/v) DMSO, as well as an increase in free energy from −30.28 kJ/mol to −28.1665 kJ/mol. NMR relaxation dispersion studies showed that the chemical exchange rate of binding site residues decreased as well. Kinetic on- and off-rates were determined from the chemical exchange rate. Notably the on-rate was affected by DMSO ~10% more than the off-rate, indicating that the reduced binding affinity is primarily caused by a reduced frequency of protein-ligand encounters. DMSO är ett vanligt lösningsmedel för studier av syntetiska molekyler i biologiska system, bl.a. inom läkemedelsutveckling. Trots detta är lösningsmedlets interaktioner med dessa syntetiska molekyler och deras målprotein inte tillräckligt undersökta. DMSO kan påverka proteinerna struktur eller ha någon annan inverkan<br /> inbindningen. I detta arbete har denna möjliga effekt studerats för inbindningen av den syntetiska molekylen KP0440 och en kapad version av proteinet Galectin-3 som endast innefattar the kolhydratsbindande domänet. Detta utförs med hjälp av ITC och CPMG relaxations-dispersionsexperiment för att utvärdera inverkan på både termodynamiska och kinetiska parametrar över en spädningsserie DMSO från 0 % till 10 % volymprocent. Resultaten från ITC visade en ~60% försvagad inbindning vid tillsättning av 10 % DMSO och en mer gynnsam entropi för liganden fritt i lösningen<br /> än jämfört med i bundet tillstånd när DMSO var tillsatt. CPMG-studierna visade att det kemiska utbytet mellan bundet och obundet tillstånd minskade med DMSO på ett liknande vis som hos ITC-resultaten. Kinetiska på- och avhastigheter räknade ut utifrån kemiska utbyteskonstanten, och av intresse var att minskningen var större för påhastigheten relativt till av-hastigheten vilket skulle innebära att DMSO:s inverkan skulle mest bero på den minskade frekvensen av mötet mellan protein och ligand i lösningen. Protein är livets arbetshästar. Nästan varje liten sak som händer i kroppen, från synen, till matsmältningen, till allt annat sker med hjälp av proteiner. Galectin-3 är ett protein i människokroppen som binder till socker. Man tror att galectin-3 är inblandat i många sjukdomar, men är allra mest inblandad i cancerutveckling. Därför är det väldigt intressant att studera olika sätt att utveckla läkemedel som binder till detta protein. Med hjälp av olika tekniker kan man studera på mikroskopisk nivå hur det här proteinet ser ut och hur mycket den tycker om att reagera med olika möjliga syntetiska molekyler. Men när man studerar dessa olika molekyler är det viktigt att allting beter sig som man förväntar sig att det kommer att göra när det sker på riktigt i människokroppen, men detta kan vara svårare än man tror. Mitt examensarbete har handlat om att undersöka om ett speciellt ämne dimetylsulfoxid, eller DMSO, har någon inverkan på själva resultatet av en typisk sådan här studie. DMSO hjälper till att få ämnen som vanligtvis inte kan lösa sig i vatten att göra det, vilket kan vara väldigt hjälpsamt när man vill undersöka nya konstiga molekyler. Enligt<br /> nya rön har det visat sig att detta lösningsmedel kan påverka proteinet, vilket inte alls är bra! Men hur ska man undersöka något så litet som hur ett protein kläms ihop av en molekyl som är ännu mindre? När man studerar saker på mikroskopisk skala fungerar det sällan att försöka få fram bilder, utan man får istället försöka att få en uppfattning genom att studera andra saker. En av metoderna som jag använt heter ITC, där mäter man den oerhört lilla värme som släpps fri eller tas upp när man tillsätter en av delarna i en reaktion till den andra. Med hjälp av denna energi kan man uppskatta hur mycket proteinet vill binda sockermolekylen vilket är väldigt bra om man vill ta fram en ny molekyl. Den andra metoden jag använde heter NMR, som istället mäter magnetismen i molekylerna för att få reda på om dem. NMR fungerar som magnetröntgen ungefär, fast man försöker få en bild av små molekyler istället för insidan av människokroppen. Det häftiga med detta är att man kan undersöka händelser som händer över tid! Med detta kan man till exempel se hur ett protein ändrar på sig när det binder till en sockermolekyl, och vad som händer sen när sockret släpper igen. De här är metoder som kan användas för enormt många olika saker, och därför tycker jag det är viktigt att man vet vad det är man undersöker när man utför dem. I mitt projekt visade resultaten att det faktiskt fanns en effekt, mest relaterat till att lösningen blev mer trögflytande med DMSO i vilket gör det svårare för sockermolekylerna att ta sig fram igenom lösningen, lite som att försöka simma i en gröt! Detta är alltså något man måste ha i åtanke när man designar framtida läkemedel, som kan till exempel tillåta oss att bekämpa cancer utan skadlig kemoterapi. https://lup.lub.lu.se/student-papers/record/8972869/file/8972871.pdf application/pdf 744951 no 2019 eng Galectins Nuclear Magnetic Resonance NMR Biophysical Chemistry Relaxation CPMG ITC Biofysikalisk Kemi Kärnmagnetisk resonans Technology and Engineering Chemistry Biology and Life Sciences https://lup.lub.lu.se/student-papers/record/8972869/file/8972873.pdf application/pdf no 8972869 2019-03-13T10:40:42+01:00 2019-04-11T14:21:58+02:00 2019-04-11T14:21:58+02:00

oai:lup-student-papers.lub.lu.se:8946255 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Lisa de Groot author 8946253 Valtýr Freyr Hlynsson supervisor Department of Chemistry v1000647 department The Tröger’s base molecule has a unique V-shaped cavity and can be fused together in a linear fashion to create either tubular structures or zigzag structures. These structures could be applicable in for example catalysis. The Tröger’s base scaffold is easily functionalised with different side-groups and therefore has a wide range of applications.<br /> Previous research in the Wärnmark group had led to a thirteen-step synthesis from 4-bromo-3-methylaniline to a linearly fused heptakis-TB analogue with methoxy side-groups. The aim of this project was to repeat this synthetic route and to improve it where possible. Also, characterisations of the synthesised compounds have been provided. <br /> This research covers the first nine steps of the synthesis and includes a wide range of reactions, such as electrophilic aromatic substitutions, condensations, a Buchwald-Hartwig amination, a TMS and TFAA protection, and formation and separation of diastereomers. Supramolecular chemistry can be described as the field that studies weak, non-covalent, interactions between molecules. We often think of a bigger ‘host’ molecule that allows easy reversible coordination of smaller molecules it interacts with.<br /> A molecule that has been envisioned for such supramolecular chemistry is Tröger’s base, which has a unique V-shaped structure and if several of these V-shaped molecules are connected together, we can think of applications such as catalysis. A catalyst is a molecule that helps the reaction to proceed faster by, for example stabilising their intermediates or bringing the molecular components closer together. Such catalysis, where different molecules end up in the V-shaped cavities and therefore get brought closer together to help the reaction between the components, we can call bi-molecular catalysis. Of course, many more interesting applications could also be possible.<br /> In the Wärnmark group, research has been performed on the linear fusion of Tröger’s base analogues, where it was seen that when fusing these V-shaped molecules together, either a tubular structure or a zigzag shaped compound is formed. The particular compounds studied in this project show the formation of a zigzag shaped linearly fused Tröger’s base analogue. A previously designed and performed synthesis was partially repeated in this project, with the ultimate goal to produce a linearly fused Tröger’s base analogue consisting of 7 sub-units through a multi-step synthesis, which means different reactions are performed to get from one intermediate to the next. https://lup.lub.lu.se/student-papers/record/8946255/file/8946694.pdf application/pdf 2674133 yes 2018 eng organic chemistry organisk kemi Chemistry 8946255 2018-06-07T11:50:27+02:00 2018-06-20T16:09:44+02:00 2018-06-20T16:09:44+02:00

oai:lup-student-papers.lub.lu.se:8947886 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Hans Paajanen author 8946242 bitr. universitetslektor Baozhong Zhang supervisor Centre for Analysis and Synthesis v1000651 department One way to make a UV curable ink is to mix a pigment dispersion with monomers, oligomers,<br /> photoinitiators and additives. Creating a pigment dispersion is in many cases the first processing<br /> step of making a UV curable ink and is of large importance. To process pigment dispersions<br /> of Pigment red 2 and Pigment red 122 a premixing step with a dissolver is used followed<br /> by a grinding step employing a three-roll mill. The components for the dispersions are<br /> a monomer/oligomer blend of acrylates, pigment and a dispersing agent. The optimal monomer/oligomer<br /> blend of acrylates were determined by the Daniel flow point method. When<br /> processing using a three-roll mill the process time becomes of great importance, alongside<br /> with the final viscosity of the dispersion. Each dispersion was passed three times over the<br /> three-roll mill and the passing times were recorded to get the processing time. To find a correlation<br /> between processing time and viscosity a design of experiment was conducted for the<br /> two different pigments. The design of experiment model was of the extreme vertices design<br /> type which allows setting upper and lower boundaries for the input variables. From the design<br /> of experiment an expected viscosity and processing time could be estimated. For Pigment red<br /> 2 the model suggested a processing time of 14.47 grams/min and a viscosity of 44.58 Pa*s.<br /> The actual processing time came out as 16.46 grams/min with a viscosity of 49.10 Pa*s. For<br /> Pigment red 122 the estimated processing time was 24.35 grams/min with a viscosity of 43.04<br /> Pa*s. The results were a processing time of 22.98 grams/min with a viscosity of 43.80 Pa*s.<br /> The use of the Daniel flow point method combined with design of experiment allows for an<br /> efficient way of screening new pigments and monomer/oligomer optimums for UV curable<br /> inks. Printing inks cured by ultraviolet light (UV) can be found in many places of our everyday life.<br /> These printing inks are found on very many packaging and label applications, such as beer<br /> bottles, milk cartons and bottles of soap. These type of inks first hit the market in the early<br /> 1960’s and have since then seen a steady growth. Because of this steady growth and wide<br /> application range there are several demands that need to be met by a printing ink.<br /> One of the most important demands on the printing ink is the type of color that the ink shows.<br /> As one of the large applications for UV printing inks is packaging, the color should in many<br /> cases be very bright and intense to attract the shopping customers. Besides the intensity and<br /> shade of the printing ink, it is important that the printing ink gives a label with high durability.<br /> This high durability is often characterized by that the print on the label does not change due to<br /> twisting of the label, spilling liquids on the label, or that the product sits on the shelf for a<br /> long time. All of these different types of demands put a high pressure on the formulation of<br /> the printing inks, and especially a high pressure on the<br /> pigment in the ink.<br /> Because of the pressure on the printing inks and especially<br /> on the pigment, there needs to be a way to check if a new<br /> pigment is suitable for packaging and label applications. In<br /> many cases, it is the pigment that is the most important<br /> factor for deciding if a printing ink has a high durability or<br /> not. In my study I have been trying to develop a method<br /> for the investigation of new pigments for UV-curable<br /> printing inks. More specifically, I have been looking at<br /> two different types of pigment, one that shows a shade of<br /> warm-red and another that shows a shade of rhodamine<br /> red. The reason for why new pigments are needed is in<br /> many cases related to cost, and trying to be cost<br /> competitive on the market.<br /> When looking at these two types of pigments, there are more things to keep in mind besides<br /> the durability of the pigment in the printing ink. One of these things is to investigate the flow<br /> behavior the pigment has in its concentrated state. This concentrated state is known as a<br /> pigment dispersion. In comparison, the example of a juice concentrate comes very handy. A<br /> juice concentrate you dilute in water to obtain the drinkable juice. For a pigment dispersion,<br /> the same type of dilution is made to obtain a printing ink. However, the dilution step for the<br /> pigment dispersion has several components and does not contain any water. The flow<br /> behavior in the concentrated state is very important for the printing ink, but also for the<br /> production workers. If the concentrated state has a free flowing behavior, meaning that you<br /> can easy pour it out from a bucket, it becomes easier to handle in production, as well as giving<br /> a better flow property for the printing ink.<br /> The goal of my study has been to employ the method how to investigate new pigments, and<br /> then implement it on the warm-red and rhodamine red pigment to create new pigmentdispersions. The results were successful and the new pigment dispersion will in a near future<br /> be produced on a larger scale in the production Flint Group has in Trelleborg. Eventually<br /> these new pigment dispersions will end up in printing inks, which will be used on the<br /> different types of packaging that are used on a daily basis in very many households. https://lup.lub.lu.se/student-papers/record/8947886/file/8947897.pdf application/pdf 2479880 no 2018 eng polymer technology polymerteknologi Chemistry 8947886 2018-06-11T12:57:41+02:00 2018-06-18T14:07:55+02:00 2018-06-18T14:07:55+02:00

oai:lup-student-papers.lub.lu.se:8947963 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Mynta Norberg author 8947961 Larissa Cunico supervisor Department of Chemistry v1000647 department CO2-expanded liquids (CXLs) are a class of solvent systems that have shown great promise as a green and effective medium in synthesis, catalysis, extractions, and analytical separation methods. Unfortunately, not much information is available on the polarity and miscible compositions of CXL systems, information which is crucial for selecting the right solvent system for a particular application. Here, the relative static permittivity (εr) of a set of binary and ternary CXLs at 35◦C and 80 bars was measured, along with visually determined miscibility limits of glycerol in 10:90, 30:70, and 50:50 CO2:ethanol (by molar fraction), and glycerol and water in 10:90, 30:70, and 50:50 CO2:ethyl lactate. A novel technique for the measurement of εr was validated and applied to binary and ternary CXLs, and an additive model for approximating εr of solvent mixtures was applied to CXL systems and evaluated. Glycerol remained miscible over a large range of molar fractions in all ratios of CO2:ethanol and CO2:ethyl lactate. Water remained miscible over an even larger range of molar fractions in all ratios of CO2:ethyl lactate. The additive model was adequate for approximating εr values of the CO2+ethanol+glycerol system, but not for the systems containing ethyl lactate. The compositional dependence of εr was remarkably nonlinear for all studied ratios of CO2:ethyl lactate in the CO2+ethyl lactate+water system. Lösningsmedel är vätskor i vilka nästan all kemi utspelar sig, såsom tillverk- ningen av kemiska ämnen (t.ex. mediciner), extraktioner av ämnen, eller separationer av olika ämnen. Inom framförallt läkemedelsindustrin används enorma mängder lösningsmedel, vilket är ett stort problem eftersom nästan alla vanliga lösningsmedel är giftiga, miljöfarliga, och brandfarliga. Så kallade gröna lösningsmedel, exempelvis vatten eller etanol (vanlig alkohol), räcker inte alltid till eftersom de inte har alla de olika egenskaperna som kemister och kemiindustrin behöver. Forskare har därför börjat leta efter nya alterna- tiv, i hopp om att hitta mer hållbara sätt att t.ex. tillverka mediciner på. Ett sådant alternativ som utforskas i detta arbete är så kallade koldioxidexpan- derade lösningsmedel. Koldioxid är normalt en gas, men under höga tryck så omvandlas det till en väldigt lättflytande vätska. Genom att spruta in sådan flytande koldioxid i ett lösningsmedel i en sluten, trycksatt behållare så får vi en blandning med egenskaper som kan finjusteras beroende på vad vi vill använda den till. En viktig sådan egenskap som går att kontrollera är polaritet, vilket är vad som avgör vad som kan lösas upp i ens lösningsmedel (t.ex. löser sig vatten i sprit, men inte i fett). Flytande koldioxid är väldigt likt fett, det löser sig inte bra i polära lösningsmedel som vatten, och bland- ningen skär sig. Samtidigt vill kemister ha vätskeblandningar som flyter lika lätt som flytande koldioxid, men löser upp ämnen på samma sätt som vatten. I det här arbetet blandades därför polära, vattenlika lösningsmedel med ännu ett lösningsmedel, som är likt både fett och vatten, innan den flytande koldioxiden sprutades in. Detta gjorde att blandningarna höll ihop mycket bättre, och det mättes sedan i experiment hur polära de här blandningarna var med hjälp av ett nydesignat chip ifrån en samarbetspartner på Uppsala Universitet. Eftersom sådana här så kallade koldioxidexpanderade lösnings- medel inte har forskats så mycket på ännu så jämfördes också resultaten med en matematisk modell som används för att snabbt och lätt räkna ut hur po- lär en blandning av lösningsmedel är. Blandningarna som utforskades i det här arbetet var mycket mer polära än de som utforskats i tidigare studier, och den matematiska modellen som testades fungerade väldigt bra i vissa fall, men sämre i andra. https://lup.lub.lu.se/student-papers/record/8947963/file/8947968.pdf application/pdf 623267 yes 2018 eng green analytical chemistry co2 carbon dioxide expanded liquid solvent ethyl lactate water glycerol ethanol analytisk kemi Chemistry 8947963 2018-06-11T14:02:19+02:00 2018-06-20T16:13:24+02:00 2018-06-20T16:13:24+02:00

oai:lup-student-papers.lub.lu.se:8949100 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Christoffer Weber author 8949098 Prof Peter Somfai supervisor Centre for Analysis and Synthesis v1000651 department Polymers of N-substituted glycine (NSG) or as they are also called, peptoids, <br /> have shown potential in biomedical applications due to proteolytic resistance, among other interesting properties.<br /> In this thesis project, two synthetic routes have been performed and evaluated to <br /> achieve a better understanding of large-scale syntheses of peptoids as a bioinert coating for nanoparticles. The primary focus has been on a solution-phase synthesis where the monomer, N-(3,6,9-trioxadecyl)glycine, has been synthesized via an oxidation of a primary alcohol to aldehyde followed by reductive amination. A “submonomer” approach, where the peptoid is grown on a resin in an iterative process of nucleophilic displacements and acylations, has also been performed but with a 3-methoxypropyl side chain. Begränsningar med polyetylenglykol (PEG) som ytbeläggningen av proteiner och nanopartiklar i biologiska tillämpningar, har ökat intresset för peptoider. Peptoider har framställts med både en fastfassyntes och en syntes i lösningsmedel. Vad är mest lämpligt för storskalig framställning? https://lup.lub.lu.se/student-papers/record/8949100/file/8949131.pdf application/pdf 3535794 no 2018 eng Peptoid Antifouling Polymer coating Organic chemistry Organisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/8949100/file/8949134.pdf application/pdf Begränsningar med polyetylenglykol (PEG) som ytbeläggningen av proteiner och nanopartiklar i biologiska tillämpningar, har ökat intresset för peptoider. Peptoider har framställts med både en fastfassyntes och en syntes i lösningsmedel. Vad är mest lämpligt för storskalig framställning? no 8949100 2018-06-13T15:48:48+02:00 2018-06-25T09:02:01+02:00 2018-06-25T09:02:01+02:00

oai:lup-student-papers.lub.lu.se:8949322 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Tea Torell author 8949320 Susanna Horsefield supervisor Department of Chemistry v1000647 department AQP4 is a protein in the brain which regulate the diffusion of water in and out of cells. Through studies using AQP4 null mice, a correlation between the regulation of AQP4 and the survival rate of cerebral edemas has been noted. Due to the fact that there are three different kinds of cerebral edemas, and that they require different kinds of regulation of AQP4 in order to lessen the problem, the regulation of AQP4 is of upmost relevance. <br /> Through previous studies, it has been made clear that Calmodulin (CaM) affects the water permeability of the cell by regulating the amount of AQP4 available in the membrane. In Susanna Törnroth Horsefield’s group, it has also been proven that CaM interacts directly with AQP4 through the C-terminus of AQP4. <br /> In this study, the possible inhibition of the interaction between AQP4 and CaM through the FDA-approved drug Trifluoperazine (TFP) was examined using Microscale Thermophoresis (MST), as well as the interaction between just the C-terminus of AQP4 and CaM. In addition, the crystallization of the full length AQP4 was attempted, since the previous crystallization of AQP4 has excluded the C- and N-termini because of their flexibility, which makes the crystallization harder to achieve.<br /> In the first studies where varying concentrations of TFP was added to constant concentrations of AQP4 and CaM, no inhibition could be seen. Several attempts were made in order to investigate the reason for this. Finally, when the solvent of the TFP was altered from Dimetylsulfoxid (DMSO) to water and TFP concentrations was kept constant at 10 mM while varying the concentration of AQP4, an inhibition could be detected. In future studies, a TFP dilution series will be tested, with an addition of a constant volume of AQP4 and CaM, where the concentration of AQP4 would be closer to the Kd value (Kd=[AQP4][CaM]/[AQP4*CaM] ) than in previous examinations.<br /> Through the studies between the C-terminus of AQP4 and CaM, no clear binding curve could be seen. The result behind this could to be that the C-terminus is too small for MST to detect the complex formation. In future studies, a fluorescence-marked peptide could be used instead of CaM, in order to see if the size for the marked component would increase when the complex is formed, which would be clearer to see in the MST. <br /> The crystallization of the full length AQP4 was achieved using a precipitant containing 0.1 M Tris pH 8.0, 44% v/v PEG and 0.2 M CaCl2 but have not yet been optimized. The obtained crystals had a resolution of 14 Å, which is too low to get any clear information in regards to the structure of the protein. In further studies, more experimental setups with conditions similar to the one which gave crystals would be tested, as well as further examination of the previously setup of additive screening. I dagens I-länder är neurologiska sjukdomar en av de främsta orsakerna bakom dödsfall. Enligt statistik från ”Disabled World” påverkas upp till 1 miljard människor världen över av någon form av neurologisk sjukdom, vilket inkluderar allt från epilepsi och migrän till Alzheimer och stroke. <br /> Till följd av detta är medicin för att såväl förhindra som att motverka skador från neurologiska sjukdomar en prioritering inom forskarvärlden. För att kunna bota en sjukdom måste man först förstå vad det är som blir fel i kroppen, samt vad som kan göras för att motverka det. <br /> Ett specifikt fall på en orsak på en neurologisk sjukdom är hjärnödem, också känt som ansamlingar av vatten vid hjärnan vilket kan leda till stroke, trauma, inflammation och tumörer. Via forskning kring hjärnödem har det framkommit att reglering av ett protein i hjärnan, vid namn aquaporin 4, kan ha en positiv påverkan på hjärnödem genom att påverka mängden vatten som tas in i hjärnans celler.<br /> I denna rapport undersöks möjligheten av reglering av aquaporin 4 med hjälp av en redan existerande medicin vid namn Trifluoperazine (TFP), samtidigt som strukturen hos aquaporin 4 försöker kartläggas med hjälp av röntgen kristallografi, eftersom kunskap kring ett proteins struktur och uppbyggnad är viktigt för att känna till dess egenskaper. 2018 eng biochemistry biokemi Chemistry 8949322 2018-06-14T09:39:23+02:00 2018-06-21T11:54:01+02:00 2018-06-21T11:54:01+02:00

oai:lup-student-papers.lub.lu.se:8949696 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Erika Pehrsson author 8949693 Urban Johanson supervisor Department of Chemistry v1000647 department The Transient Receptor Potential, TRP, family is a group of non-selective ion channels which can be activated by harmful stimuli such as temperature, chemicals and mechanical stimuli. The channels play a crucial role in many physiological processes and it is therefore of great interest to know more about these proteins. The TRPA1 is one of many TRP channels, and a better knowledge of its function could lead to a development of repellents against insects such the pine weevil, a beetle which is causing problems by ring barking trees and thereby making it a challenge to establishing new forest at clearings. The sequence of the TRPA1 gene in pine weevil is not completely established and to expand the known sequence PCR was used to amplify fragments of the gene. By sequencing of PCR products it was possible to confirm parts of the coding sequence and also to verify four intron positions that were previously only predicted. A new strategy to facilitate crystallization of the human TRPA1 protein was tried out. It was hypothesized that removal of putatively unordered parts of the protein, possibly including the N-terminal carrying the His-tag, by a trypsin digestion would make it more stable and easier to crystallize. To be able to localize the TRPA1 lacking the His-tag, a TRPA1 antibody was tested and proved to work. The trypsin digestion proved successful and is recommended in further work aiming at a crystal structure of the human TRPA1 protein. En människa utsätts varje dag för smärta, vilken kan ha orsakats av exempelvis tryck, värme, kyla eller någon sorts kemikalier. Smärtan är nödvändigt för att kroppen ska förstå att den befinner sig i en skadlig situation. Så fort vi utsätts för ett hårt tryck, en extrem temperatur eller farliga kemikalier detekteras detta av speciella receptorer i nervtrådar som skickar vidare signaler till hjärnan där det tolkas som smärta och ger oss möjlighet att undvika den skadliga situationen. <br /> <br /> Proteiner är de molekyler som bygger upp och ansvarar för de olika funktionerna i vår kroppar på molekylär nivå. TRP kanalerna är en typ av proteiner som fungerar som smärtreceptorer och är inblandade i många livsnödvändiga processer så som signalering och transport, både under normala förhållanden och i många sjukdomsrelaterade processer. TRPA1, även kallad wasabi-receptorn, är en av många TRP kanaler vilka också har en motsvarighet i insekter. Genom att jämföra TRPA1 från människa med insekternas version kan vi få en bättre förståelse av hur dessa proteiner fungerar. Detta kan även leda till utvecklingen av repellenter mot insekter såsom snytbaggen, en skalbagge som ringbarkar skogsplantor och därför utgör ett problem vid etablering av ny skog efter avverkning. Därför är det mycket viktigt att utveckla förståelsen av dessa proteiner, både vad gäller genen som kodar för proteinet och hur proteinet ser ut i 3D. <br /> <br /> En gen är uppbyggt av exoner (huvudsakligen proteinkodande dela) och introner (delar som inte kodar för protein). När ett protein ska tillverkas klipps intronerna bort så bara exonerna blir kvar. Dessa utgör ”receptet” för proteinet och kallas den kodande sekvensen. Hela TRPA1 genen i snytbagge är inte känd, speciellt inte delar rörande intronerna. I ena delen av detta projekt låg fokus på att utöka den kända sekvensen med hjälp av en teknik som kallas PCR (Polymerase Chain Reaction) där man skapar många kopior av en specifik region av DNA:t. Dessa DNA fragment kan senare undersökas och sekvenseras. I mitt arbete kunde jag bekräfta delar av den kodande sekvensen och fick även fram tidigare okänd sekvens från icke kodande regioner (introner). Detta kommer att underlätta framtida undersökningar av de olika genvarianter (alleler) som finns i olika individer av snytbagge. <br /> <br /> Om man vill förstå hur ett specifikt protein fungerar är det till stor hjälp om man vet hur den molekylära strukturen ser ut i 3D. Problemet är att proteiner är för små för att studera i vanligt mikroskop. Man får därför ta till andra metoder, där kristallisering är en vanlig metod. Man försöker då få proteinet att bilda kristaller där proteinet sitter i välordnade repetiva enheter med precis en och samma form. Kristallen belyses med Röntgen strålar och utifrån hur dessa sprids kan man räkna ut 3D strukturen av proteinet. För att få ett bra resultat krävs det att proteinet är stabilt och inte antar en massa olika alternativa 3D former. I detta projektet var syftet att skapa en mer stabil form av det humana TRPA1 proteinet genom att klippa av rörliga delar med enzymet trypsin. I detta pilotprojekt kunde vi visa att det fungerar att klippa av delar av proteinet, vilka troligen utgörs av flexibla regioner. I en uppskalad version kan detta nu, efter att trypsin tagits bort, användas för att prova om det går lättare att få välordnade kristaller av TRPA1 och därmed en mer detaljrik bild av dess 3D struktur. https://lup.lub.lu.se/student-papers/record/8949696/file/8951359.pdf application/pdf 8969203 yes 2018 eng biochemistry biokemi Chemistry 8949696 2018-06-14T17:25:12+02:00 2018-06-21T14:44:47+02:00 2018-06-21T14:44:47+02:00

oai:lup-student-papers.lub.lu.se:8949779 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Maria Alejandra Silva Quintero author 8900278 Ebbe Nordlander supervisor Department of Chemistry v1000647 department Malaria is a disease that is transmitted by mosquitoes; it has been transmitedaffecting humanity for more than 10.000 years, it affects between 700 000 and 2.7million people per year and it can be deadly, therefore there is a large and increasinginterest in developing a cure against it.<br /> <br /> Quinine, the first antimalarial, was isolated from the chinchona tree in 1632. Thiscompound was widely used in the form of tonic water, but afterwards, a decrease ofits antimalarial effectivity was observed and in 1910 it was concluded that thissituation was because the parasite that causes malaria had developed a resistanceagainst the quinine.<br /> <br /> This situation inspired the scientific community to find new options to fight thesickness. In 1934, chloroquine was developed by German scientists and was themost used antimalarial until the 1950&#39;s, when parasitic resistance again occurred.Other medicaments like mefloquine and arteminisin have been developed but theresistance problem still exists thus maintaining interest in the development of for newtreatments.<br /> The success of the anticancer medicine cisplatin and other metal-based drugs hasincreased interest in inorganic medicinal chemistry. Therefore scientists came to theidea of coupling a known antimalarial with a organometallic species thus creatingorganometallic antimalarial complexes that are not only effective but the parasitedoes not develop resistance against it. Studies of ferroquine, a chloroquinolinederivative coupled with a ferrocene molecule, showed fantastic results and it is inphase IIb of medical trials.<br /> <br /> Chloroquine derivatives may be coupled with metals like ruthenium, iron, iridium andrhodium, and the first studies showed similar results (increased antimalarial activitywithout the resistance) to those from the ferroquine studies, indicating the greatfuture and potential of these compounds. This chemistry is still on in the developmentphase.<br /> <br /> This project is involved with the development of organometallic antimalarialcompounds. Specifically ruthenium-chloroquine complexes coupled with a water-soluble phosphine molecule (PTA) were targeted in order to create antimalarialcomplexes with good aqueous solubility, which may be of importance to, theirantimalarial effectivity Malaria är en sjukdom som överförs av myggor; det har överförts påverka mänskligheten i mer än 10 000 år, det påverkar mellan 700 000 och 2,7 miljoner människor per år och det kan vara dödligt, därför finns det ett stort och ökat intresse för att utveckla en bot mot den. <br /> Quinin, den första antimalarialen, isolerades från chinchona-trädet år 1632. Denna förening användes i stor utsträckning i form av tonisk vatten, men efteråt observerade man en minskning av dess antimalarial effektivitet och år 1910 drogs slutsatsen att denna situation berodde på att parasit som orsakar malaria hade utvecklat ett motstånd mot quinin. <br /> Denna situation inspirerade det vetenskapliga samfundet att hitta nya alternativ för att bekämpa sjukdomen. År 1934 utvecklades klorokin av tyska forskare och var den mest använda antimalarialen till 1950-talet, när parasitmotståndet upprepades. Andra läkemedel som mefloquin och arteminisin har utvecklats men resistansproblemet finns fortfarande och därmed bibehåller intresse för utveckling av nya behandlingar. <br /> Framgången av anticancermedicin cisplatin och andra metallbaserade läkemedel har ökat intresse för oorganisk medicinsk kemi. Därför kom forskare till idén om att koppla en känd antimalariell med en organometallisk art och därigenom skapa organometalliska antimalariella komplex som inte bara är effektiva, utan parasiten utvecklar inte motstånd mot den. Studier av ferroquin, ett kloroquinolinderivat kopplat till en ferrocenmolekyl, visade fantastiska resultat och ligger i fas IIb av medicinska prövningar. <br /> Kloroquinderivaten kan kopplas med metaller som rutenium, järn, iridium och rodium, och de första studierna visade liknande resultat (ökad antimalariell aktivitet utan motstånd) mot de från ferroquinstudierna, vilket indikerar den stora framtiden och potentialen hos dessa föreningar. Denna kemi finns fortfarande i utvecklingsfasen. https://lup.lub.lu.se/student-papers/record/8949779/file/8949788.pdf application/pdf 4753201 no 2017 eng Chemistry 8949779 2018-06-14T21:19:50+02:00 2018-09-25T11:31:21+02:00 2018-09-25T11:31:21+02:00

oai:lup-student-papers.lub.lu.se:8949808 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH3 Marcus Malmsjö author 8949554 Professor Lars J Nilsson supervisor Ellen Palm supervisor Environmental and Energy Systems Studies v1000256 department This thesis provides an understanding and overview of the opportunities and challenges to enable a sustainable use of individual polybags used in the retail-industry. This was done by conducting a qualitative analysis including literature reviews, semi-structured interviews and e-mail correspondence. A common material choice for individual polybags is the fossil-based LDPE plastic and this packaging solution contributes to an increase in fossil-based plastic waste. Sustainable materials and solutions that can be implemented for individual polybags are therefore important, and these should be applicable in a circular economy. Caution should be taken regarding bioplastics, which often is interpreted as a “green” material choice. A clear communication and labelling regarding bioplastics is required to enable a sustainable use. Materials as bio-based LDPE and recycled LDPE can be used as sustainable material alternatives for the conventional individual polybag. Solutions that reduces the use of material or packaging solution should be prioritized, and this can be done by thinner polybags, smaller polybags or by using folding and tying techniques that possibly could eliminate the use entirely. Mechanical recycling is the preferred end-of-life option for individual polybags and closed loop recycling by re-take and collection systems could be applied as a sustainable solution. In China a paper-based material alternative should be looked into for individual polybags used for e-commerce, where the companies has no control over the package. This is due to that China has an underdeveloped waste management system and is a large contributor of plastic leakage into nature. When this material is evaluated it is of importance to discuss trade-offs concerning energy- and water consumption, pollution, end-of-life options and littering. Den här avhandlingen ger en förståelse och överblick av möjligheterna och utmaningarna för en hållbar användning av individuella polybags i detaljhandeln. Detta genomfördes genom en kvalitativ analys som inkluderade litteraturstudier, semi-strukturerade intervjuer och e-mejl korrespondens. Ett material som används vanligtvis för individuella polybags är fossil-baserad LDPE plast och denna förpackningslösning bidrar till en ökning av fossil-baserat plastavfall. Hållbara material och lösningar som kan bli implementerade för individuella polybags är därför viktiga, och dessa ska kunna vara applicerbara i en cirkulär ekonomi. Försiktighet ska tas angående bioplaster, som ofta är sedda som ett ”grönt” materialval. En tydlig kommunikation och märkning angående bioplaster behövs för att kunna användas på ett hållbart sätt. Material som bio-baserad LDPE och återvunnen LDPE kan användas som hållbara material alternativ till den konventionella individuella polybagen. Lösningar som reducerar användandet av material och själva förpackningslösningen ska prioriteras, och det kan göras genom tunnare polybags, mindre polybags, eller använda vikning- och knyt tekniker som skulle kunna eliminera användandet helt. Mekanisk återvinning ska föredras för individuella polybags när denna ses som avfall, och återvinning i slutna loopar genom återtagande och samlande är hållbara lösningar som skulle kunna implementeras. I Kina borde ett pappers-baserat material alternativ undersökas för individuella polybags som används för online-handel, där företagen inte har kontroll över plastavfallet. Detta på grund av att Kina har ett underutvecklat avfallssystem och är en stor bidragande faktor till läckage av plast i naturen. När detta material undersöks är det viktigt att diskutera eventuella avvägningar angående energi- och vattenanvändning, föroreningar, avfalls alternativ och nedskräpning. Hållbara material och lösningar till individuella polybags<br /> <br /> En oljebaserad plastförpackning som används inom detaljhandeln och som ökar i användning är den individuella polybagen. Material gjorda från förnyelsebar biomassa och återvunnen plast är två exempel som skulle kunna ersätta det material som används idag.<br /> <br /> Företag inom detaljhandeln jobbar för en mer hållbar industri och förpackningar är en del av detta. Individuella polybags är en förpackning som används inom detaljhandeln för att transportera kläder över hela världen och skyddar kläderna så att de anländer hela och rena. Denna förpackning är gjord av plast som är oljebaserad; plasten är dessutom inte nedbrytbar och om den hamnar i naturen så kommer den sannolikt att vara kvar där i flera decennier. Med den ökande användningen av online-handel så kommer denna förpackning att generera ännu mer oljebaserad plastavfall. Ett problem med plast idag är att plast återvinns i liten utsträckning och tas hand om med andra avfallsmetoder som inte är lika bra från ett miljöperspektiv. Nedskräpningen av plast diskuteras frekvent idag och att plasten då till slut hamnar i våra hav. Detta återspeglas i uppskattningen att om nedskräpningen av plast fortsätter som det gör idag så kommer det finnas mer plast än fisk i haven år 2050. Nedskräpning av plast och återvinning av plast kan skilja sig mellan länder, speciellt mellan länder som har stora skillnader i hur utvecklat deras avfallssystem är. Därför kan det vara intressant att se på om man ska tillämpa ett annat material i Kina jämfört med Sverige. Genom att använda hållbara material och lösningar till den individuella polybagen så kan man skapa en mer hållbar industri inom detaljhandeln och upplysa om de aspekter som bör tas i beaktning för en hållbar förpackningsindustri.<br /> För att realisera hållbara förpackningar kan man till exempel använda material från biobaserade råvaror, nedbrytbara material eller återvunnet material. Bioplaster är ett material som ofta ses som ett hållbart alternativ till den vanliga oljebaserade plasten som används idag. Inom bioplaster finns det flera olika material som har olika egenskaper och då även bör tas hand om på olika sätt när det ses som avfall. En bioplast kan delas upp i tre grupper: biobaserad och icke nedbrytbar, biobaserad och nedbrytbar, samt oljebaserad och nedbrytbar. Detta resulterar i att bioplast-området kan ses som förvirrande i samhället och för företag. En annan aspekt som är viktig är att materialen ska hållas inom ett slutet cirkulärt system och bibehålla sitt värde så länge som möjligt. Detta kan göras genom att använda sig av ett effektivt återtagande och samlingssystem för förpackningen, som sedan kan återvinnas till nya individuella polybags i ett slutet kretslopp. Med detta sagt så ska lösningar som kan reducera mängden material prioriteras. Detta skulle kunna göras genom att till exempel implementera vikningstekniker som ger mindre dimensioner av plagget och som då kräver en mindre förpackning som resulterar i minskad materialanvändning. <br /> Genom att använda en kvalitativ analys med intervjuer och litteratur så visar detta examensarbete att det finns två potentiella hållbara materialalternativ till den plast som används för den individuella polybagen idag: en biobaserad plast som har samma kemiska struktur och egenskaper, samt återvunnen plast som även den har samma kemiska struktur och egenskaper. I ett land som har ett underutvecklat avfallssystem och stort läckage av plast i naturen som Kina, så bör ett pappersbaserat material användas då det är nedbrytbart i naturen. Med detta sagt så ska nedskräpning aldrig uppmuntras! Avslutande så bör man se över hur man kan använda så lite material som möjligt men också hur man kan skapa ett slutet cirkulärt system för förpackningen. https://lup.lub.lu.se/student-papers/record/8949808/file/8949809.pdf application/pdf 2569175 no 2018 eng Individual polybags sustainability circular economy plastic bioplastic packaging retail-industry plastic recycling waste management China Technology and Engineering Earth and Environmental Sciences Chemistry 1102-3651 ISRN LUTFD2/TFEM--18/5133--SE + (1-70) https://lup.lub.lu.se/student-papers/record/8949808/file/8951340.pdf application/pdf no 8949808 2018-06-14T22:03:35+02:00 2018-06-20T10:20:44+02:00 2018-06-20T10:20:44+02:00

oai:lup-student-papers.lub.lu.se:8950023 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Hanna Malmquist author 8950021 Sophie Manner supervisor Department of Chemistry v1000647 department Almost everyone is aware of the big problem with increasing antibiotic resistance among bacteria and the importance and need of developing new antibiotics. This bachelor thesis is a part of one such project with the aim to find new possible antibiotics. A promising candidate is a derivative of the sialic acids. The sialic acids are important molecules in the human body where it from the cell membrane is responsible for a lot of the communication between cells. One of its many messages is between the human cells and the immune system where it signalizing that they are human and not harmful. This is something many bacteria has choose to take advantage of by developing a method to absorb this molecule and place it at their own cell membrane, and in that way hinder the immune system from recognize them as bacteria. Thus, this process is an interesting target for new antibiotics and by inhibiting the involved transport protein at the bacteria we can stop this process. Therefore this project has been part of a larger study where the aim is to find and synthesize a sialic acid derivative that can bind more strongly to the involved protein than the natural ligand. Previous studies have resulted in one promising candidate, the sialic acid derivative where the OH-group at carbon 9 has been replaced by an amino group. With the intention to study this molecule more my focus has been to synthesize this molecule again. The synthesis has been quite problematic and has not resulted in the intended amine. However, it has led to some improvements of the synthetic pathway as well as new insights in the reactions, for example that protecting groups might be needed. Sialinsyra är en viktig molekyl i den mänskliga kroppen. Den deltar bland annat i kommunikationen mellan cellerna eftersom den är placerad på cellmembranet hos de mänskliga cellerna. Av alla dessa meddelande som den kan sända ut är det ett speciellt som flera bakterier har valt att utnyttja. Detta meddelande talar nämligen om för kroppens immunförsvar att denna cell med sialinsyra är mänsklig och ofarlig, något som såklart ses som gynnsamt för bakterierna. Genom olika processer har bakterierna därför utvecklat strategier för att ta upp dessa molekyler och sätta dem på deras egna cellmembran och på så vis lura immunförsvaret att inte bryta ner dem. Och i dagens samhälle då stora problem råder med antibiotika resistens och nya antibiotika måste framställas, kan forskning inom detta område vara ett steg i rätt riktning. Genom att undersöka möjligheten att stänga av dessa processer som bakterierna använder för att överföra sialinsyran kan vi hindra bakterierna från att ”kamouflera sig” som mänskliga celler och därav kan immunförsvaret själv bryta ner dem. Detta är grunden till det projekt jag har arbetat med där jag utvecklat metoder för att framställa en modifierad sialinsyra molekyl som eventuellt kan binda till de protein som deltar vid transporten av sialinsyra molekyler hos flera bakterier och på så viss hindra denna process, och efter fortsatt forskning skulle detta i framtiden eventuellt kunna leda till en ny form av antibiotika.<br /> <br /> Tidigare studier har visat att en viss modifikation på sialinsyran ger en molekyl som binder starkt till det involverade proteinet hos bakterierna och därför kan vara en lovande läkemedelskandidat för att stoppa denna process. Målet med mitt projekt har därför varit att syntetisera mer av denna molekyl för att kunna göra ytterligare tester. Tyvärr kom jag aldrig hela vägen. Sialinsyra molekylen har nämligen en del egenskaper som gör den lite svår att arbeta med och framställa. Därför har mitt fokus istället varit på att förbättra de olika stegen i syntesen, vilket har lett till en del nya insikter och idéer för att till slut kunna framställa den. https://lup.lub.lu.se/student-papers/record/8950023/file/8950050.pdf application/pdf 1636728 no 2018 eng organic chemistry sialic acids antibiotics organic synthesis organisk kemi Chemistry 8950023 2018-06-15T11:47:35+02:00 2018-06-21T12:07:06+02:00 2018-06-21T12:07:06+02:00

oai:lup-student-papers.lub.lu.se:8950795 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Klara Kylhammar author 8950793 Frank Lipnizki supervisor Adjunct Professor, KTH Jinying Yan supervisor Hans Karlsson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Biomass-fired combined heat and power (CHP) plants in Sweden are usually equipped with a flue gas condenser, where the flue gas is sprayed with water which absorbs contaminants and makes the flue gas meet emission restrictions. This results in a contaminated condensate that has to be treated to be discharged or re-used in the plant. This can be done in various ways, but at the moment the interest in this area is focused on membrane technology to avoid unnecessary use of chemicals. To be able to draw conclusions on which parameters that affects the flue gas condensate quality, and thus what affects the condensate treatment system in a CHP plant, case studies has been performed on two CHP plants owned by Vattenfall, located in Jordbro (Stockholm) and Idbäcken (Nyköping). <br /> <br /> In this study, both measurement of the content of the process streams in the condensate treatment system at Jordbro, and simulation of the condensate treatment with reverse osmosis (RO) in the softwares Matlab and Winflows, were performed. The condensate treatment system in Jordbro was recently installed and was estimated to meet the presented state-of-the-art performance. The investigation indicated that the old equipment still in operation at Jordbro could be redundant since the treatment in these units did not significantly improve the condensate quality. <br /> <br /> The results from the Jordbro RO condensate treatment system were used to investigate how a similar system could be implemented in Idbäcken. The aim was to study if the Idbäcken condensate treatment system could be less chemical dependent, and if the production of condensate that can be re-used in e.g. the district heating network, could be increased. The implementation study was done in Matlab and Winflows, and was considered successful. The simulations indicated that the current treatment units: the ion-exchanger, the softening and NH3 membrane, could be redundant if implementing a RO condensate treatment system similar to the one in Jordbro. <br /> <br /> It was also shown that at optimal operating conditions, the inlet concentration does not significantly affect the quality of the purified condensate. It was also indicated that the preceding flue gas cleaning and flue gas condensation set-up affects the condensate quality more than the level of contaminants in the incinerated fuel in a CHP plant. Reduced Environmental Impact of Flue Gases Through Membrane Technology:<br /> <br /> Heat and electricity are generated in a net-CO2 neutral way in biomass- fired combined heat and power (CHP) plants. Contaminants in the flue gas are absorbed in water, the flue gas condensate, which can be purified and re- used, if treated with membrane technology. <br /> <br /> Biomass is used as fuel to generate heat for the production of high quality steam for electricity generation in the CHP plants studied in this work. The combusted biomass also results in a high temperature flue gas which is net-CO2 neutral due to the renewable energy source, but contains contaminants that are restricted to be emitted from the process. To make sure that the quality of the flue gas meets the restrictions, the flue gas is treated in different stages.<br /> <br /> The final flue gas treatment before emission is called flue gas condensation (FGC). This means that water is sprayed on the flue gas to absorb the contaminants and thereby form a hot condensate that can be heat exchanged to the district heating network. The flue gas is thus cleaned with the FGC technique but the unwanted contaminants, such as salts (sodium chloride), heavy metals and ammonia, are transferred to the condensate. To be able to re-use the formed condensate, the condensate has to be treated.<br /> <br /> The treatment of the condensate can be done in various ways but at the moment the interest in this area is focused on membrane technology, to avoid unnecessary use of chemicals. The membrane technology can be described as that the condensate is pumped through a semipermeable membrane creating one purified stream that has gone through the membrane and one stream containing the retained contaminants. Solutes as small as salts can be retained, depending on the membrane.<br /> <br /> Two CHP facilities owned by Vattenfall were studied, one in Jordbro (Stockholm) and one in Idbäcken (Nyköping). The Jordbro plant has recently updated their FGC equipment and installed a membrane based condensate treatment system which needed to be evaluated. The Idbäcken plant operates an older FGC set-up and has a condensate treatment system consuming a considerable amount of chemicals and discharges condensate continuously to a recipient. The aim of the project was therefore to investigate the performance of the recently installed condensate treatment system in Jordbro and then to give suggestions to Idbäcken on how to develop their condensate treatment to a similar set-up. This was to reduce the chemical usage and increase the re-usage of the condensate in Idbäcken. The impact that flue gas treatment has on the condensate quality was also estimated. <br /> <br /> By an experimental investigation in Jordbro, the condensate treatment was considered as living up to standards and it was indicated that the old equipment still in operation could be redundant since these units did not improve the condensate quality significantly. The Jordbro condensate treatment system was successfully implemented in Idbäcken through simulations in the computer softwares Matlab and Winflows. It was shown that, in addition to that more purified condensate could be produced, that some of the currently operating unit operations in Idbäcken could be considered as redundant for the process. On an overall perspective, the study thereby showed that the inlet condensate quality did not significantly affect the performance of the membrane process and that the flue gas treatment has a larger impact on the formed FGC condensate than the level of contaminants in the combusted fuel. https://lup.lub.lu.se/student-papers/record/8950795/file/8950938.pdf application/pdf 2669621 yes 2018 eng CHP Plants Flue Gas Condensation Membrane Technology Condensate Treatment Reverse Osmosis Matlab Winflows Chemical engineering Kemiteknik Chemistry https://lup.lub.lu.se/student-papers/record/8950795/file/8950916.pdf application/pdf LU/LTH access 8950795 2018-06-18T12:41:24+02:00 2018-06-21T10:46:51+02:00 2018-06-21T10:46:51+02:00

oai:lup-student-papers.lub.lu.se:8951071 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Emelie Andersson author 8951068 Sara Linse supervisor Mattias Törnquist supervisor Thom Leiding supervisor Department of Chemistry v1000647 department To optimize precision and accuracy of small dispensed volumes, a dispenser was built. A 96-well plate was loaded with four replicates of a linear pyranine dilution series to test the accuracy and precision of the dispenser machine. Three dilution series of pyranine (100-0 percent, 10-0 percent and 1-0 percent) were made. The results showed that the dispenser has very good accuracy and precision. The dispenser was then used in an enzyme kinetic experiment with alcohol dehydrogenase to reveal kinetic properties of this enzyme. A dilution series of the substrate ethanol was loaded onto a new 96-well plate to generate a Michaelis Menten curve. The kinetic parameters for the ethanol concentration 0,2 M and 0,1 M were as follows: KM 10,5 mM and KM 7,48 mM, kcat 1,06 s-1 and kcat 0,39 s-1. Reproducerbarhet av experimentella resultat är centralt inom vetenskapliga metoder och ett standardsystem av enheter underlättar detta. Vetenskap använder ofta större och mindre måttenheter än de som används vardagligt. Det är svårt att behålla precision och noggrannhet när det kommer till att överföra väldigt små volymer, något man ofta gör i kemi. Mitt arbete har gått ut på att validera en dispensermaskins precision samt noggrannhet och sedan att med hjälp av denna undersöka kinetiska parametrar hos enzymet alkohol dehydrogenas. Resultaten visade att dispensermaskinen hade god reproducerbarhet med små spädningsserier. Genom att studera enzymets reaktionsförlopp, plottat som en så kallad Michaelis Menten kurva, kunde flera kinetiska parametrar bestämmas. https://lup.lub.lu.se/student-papers/record/8951071/file/8951076.pdf application/pdf 3328973 2018-06-19 no 2018 eng enzyme kinetics dispenser machine Gradis alcohol dehydrogenase biochemistry biokemi Chemistry 8951071 2018-06-18T22:41:30+02:00 2018-06-21T11:57:36+02:00 2018-06-21T11:57:36+02:00

oai:lup-student-papers.lub.lu.se:8951126 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Oliver Bogojevic author 8951124 Senior Lecturer Cedric Dicko supervisor Anna Leung supervisor Pure and Applied Biochemistry v1000655 department Computational Chemistry v1000659 department This thesis covers established procedures for the successful and attempted immobilization of lipases and phospholipases to various hydrophobic support materials, utilizing a rotating bed reactor, magnetic stirrer and tube-rotator. The design of a robust platform was established with great instrumental knowledge and proper conditioning for the creation of efficient immobilizations and activity assays. Influencing factors as substrate amount, pH, temperature, solvent selection, solubility, RPM, Co-factors, support material, protein loading and water activity have all been considered and assessed, although not thoroughly evaluated due to the purpose of solely finding an efficient and working system for immobilization. The success of the immobilization experiments has primarily been validated utilizing the NanoDrop- instrument, for protein concentration estimations, and a variety of activity assays. The activity assays are performed utilizing both already commercially immobilized lipases and self-immobilized (in-house) lipases and phospholipases. The conversion rate, established from the activity assays were analyzed utilizing Gas Chromatography Flame Ionization Detector (GC-FID), Nuclear Magnetic Resonance (NMR) and Thin Layer Chromatography (TLC). Lipase from Rhizopus oryzae (ROL) was successfully immobilized, with the proper conditions and working procedures, via adsorption to various hydrophobic support materials. ROL effected a 94% conversion of the lauric acid in the esterification reaction of lauric acid to propyl laurate, and a maintained catalytic activity of 99% after two cycles. No confirmed immobilization of the sn2- specific phospholipase A2 from Porcine pancreas (PLA2) could be presented during the thesis, although a deeper knowledge for the reaction settings and conditions were acquired, resulting in promising opportunities for future development. Användandet av nya strategier för immobilisering av enzymer (proteiner) möjliggör<br /> för stora framsteg inom neutron forskning. Genom noggranna tester upprättades väl<br /> valda villkor för användandet av enzymer, med ambitionen att effektivisera<br /> framställning av så kallade ”tunga molekyler”. Något som i sin tur är värdefullt för att förstå hur celler är strukturerade samt signalerar och interagerar med varandra. https://lup.lub.lu.se/student-papers/record/8951126/file/8951127.pdf application/pdf 5988137 yes 2018 eng Applied Chemistry Lipases Phospholipases Rhizopus oryzae Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/8951126/file/8951130.pdf application/pdf yes 8951126 2018-06-19T09:27:37+02:00 2022-06-30T10:50:41+02:00 2022-06-30T10:50:41+02:00

oai:lup-student-papers.lub.lu.se:8951211 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Frida Terne author 8951174 Ola Wendt supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Carbetocin is an uncharged cyclic therapeutic peptide with a tendency to aggregate in solution. Aggregation is undesirable since it, for example, can lead to loss of pharmaceutical effects. To gain a better understanding of peptide aggregation, along with a potential to develop better drug formulations, aggregation of carbetocin was studied. In focus were soluble aggregates in contrast to phase-separated aggregates. The behavior of these soluble aggregates was studied with NMR spectroscopy. NMR diffusometry and 1 H NMR spectroscopy were used as the main analytic methods. Aqueous solutions of carbetocin at different concentrations alone, and with added sodium dodecyl sulfate (SDS) and pentaethylene glycol monododecyl ether (C12E5) were analyzed using these methods. The peptide has an increased self-aggregation in solution at higher peptide concentrations, with a distinct increase in aggregation at around 15-20 mM carbetocin. Hydrophobic interactions and hydrogen bonding are suggested to be the major attractive forces in the aggregation mechanism based on that the chemical shifts of hydrophobic and hydrogen-bonding sites in carbetocin show significant changes at higher peptide concentrations. Surfactants significantly affect the aggregation behavior of carbetocin and co-aggregates are formed. To fully understand the aggregation behavior of carbetocin and other peptides, more research has to be conducted. Visst vore det bra om färre kvinnor dör som följd av komplikationer vid förlossning, eller att ett nytt läkemedel mot depression kommer ut på marknaden? Med mer insikt om ett biologiskt läkemedels fysikaliska stabilitet kan detta bli verklighet. I detta mastersarbete har det biologiska läkemedlet carbetocin studerats med avseende på just detta. <br /> Vanliga läkemedel som vi är vana vid att ta i tablettform består oftast av små molekyler. Det finns dock vissa sjukdomar och tillstånd som inte kan behandlas med dessa små oftast kemiskt framställda molekyler, då finns det (kanske) biologiska läkemedel att tillgå. Biologiska läkemedel är läkemedel av biologisk härkomst, ett exempel på detta är peptidbaserade läkemedel. En peptid är biologisk molekyl som består av aminosyror, en kemisk enhet som bygger upp alla proteiner. En peptid består av färre aminosyror och saknar den 3D-struktur som proteiner har, men i grunden är de lika. Carbetocin är en peptid som används för att behandla onormal mängd blödning efter förlossning. Carbetocin är en modifierad variant av hormonet oxytocin vilket bland annat ”orsakar” sammandragningar av livmodern vid förlossning. Carbetocin är den peptid som har studerats i detta projekt. <br /> På grund av att carbetocin och andra peptider har ett biologiskt ursprung fungerar de på ett annorlunda sätt än traditionella läkemedel. Ett problem är hantering och förvaring, att de måste hålla sig stabila innan de ges till en patient. Med stabilitet menas här att läkemedlet behåller sin terapeutiska effekt och inte blir skadlig för patienten. Ett stabilitetsproblem som ofta dyker upp för peptider (och proteiner) är aggregering. Aggregering är när partiklar (eller molekyler i det här fallet) interagerar och bildar en större partikel (eller ett aggregat av molekyler). Fokusen för detta arbete var att studera och försöka förstå hur carbetocin aggregerar. <br /> För att studera detta fenomen, användes NMR spektroskopi vilket är en teknik som bygger på samma grundprinciper som en MR-kamera. Med denna teknik kan egenskaper kring enstaka atomer i en molekyl analyseras. Genom att studera carbetocin tillsammans med olika tillsatser, fick vi fram att aggregeringen är väldigt koncentrations- och temperaturberoende och vilka delar i peptiden som spelar en stor roll i aggregeringen och därav vilka mekanismer som sannolikt ligger bakom aggregeringen. Det kan vara så att det krävs en viss minimi-koncentration av carbetocin för att aggregering ska uppstå, under vilken aggregeringen är knappt märkbar och att så kallade tensider har en stor påverkan på aggregeringsbeteendet.<br /> Med detta bidrag till en djupare förståelse av carbetocins stabilitet, kan förhoppningsvis läkemedel med nya tillsatser forskas fram som gör läkemedlet bättre och mer tillgängligt för kvinnor som behöver det. Denna förståelse kan i förlängningen också leda till nya läkemedelstillsatser som gör det möjligt att ha en högre peptidkoncentration. En applikation av detta är att använda carbetocin som ett depressionsdämpande läkemedel vilket det enligt forskning finns en möjlighet till men att det då krävs en högre koncentration av peptiden jämfört med när man behandlar förlossningsproblem. Generellt, ger en djupare förståelse för läkemedlets aktiva ingrediens (peptiden i detta fall) större möjligheter att utveckla ett bättre och mer effektivt läkemedel. https://lup.lub.lu.se/student-papers/record/8951211/file/8951213.pdf application/pdf 4107219 no 2018 eng Pharmaceutical Technology läkemedelsteknologi Chemistry 8951211 2018-06-19T11:54:43+02:00 2018-06-21T11:11:44+02:00 2018-06-20T14:23:11+02:00

oai:lup-student-papers.lub.lu.se:8951413 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Erika Andersson author 8950051 Ulf Olsson supervisor Centre for Analysis and Synthesis v1000651 department Regenerated cellulose fibres can become a sustainable alternative to cotton and polyester in textile applications. One method of producing such is dissolution of cellulose in an ionic liquid (IL) and regeneration through air-gap spinning. In this master thesis, the dissolution state of cellulose in the ionic liquid 1-ethyl-3-methylimidazolium acetate (EmimAc) together with dimethyl sulfoxide (DMSO) has been studied through concentration series and diffusion nuclear magnetic resonance (NMR). It was shown that a stoichiometric relation of 3 or higher between the IL and anhydroglucose unit (AGU) is needed for complete dissolution and that one acetate ion bind to each AGU. In pure EmimAc, a structure of anions and cations is proposed to form around the polymer chain. The structure of the cellulose chains in solution was studied through small-angle x-ray scattering (SAXS) showing stiff cylinders with repulsive interactions. Rheological measurements were performed to evaluate spinnability of the solutions. Fibres were produced using air-gap spinning and the titer, tenacity, elongation at break and birefringence obtained at two different draw ratios (DR=4 and 6) and using two different coagulation mediums (water and isopropanol) were investigated. The level of crystallinity and internal fibre structure was evaluated using wide-angle x-ray scattering (WAXS) and SAXS. Fibres coagulated in water showed higher tenacity and a higher level of crystallinity but little dependence on the DR could be shown. An internal structure of 20 nm thick crystalline lamella in an amorphous matrix is proposed. From tree to textile – cellulose dissolution and fibre spinning<br /> I will make a guess: The clothes you are wearing are made of polyester or cotton, the two main textile fibres in use today. They are both related to several problems concerning sustainability but there are options on the way. This thesis investigates the dissolution of cellulose from wood and the spinning of textile fibres from this kind of liquid solution. It was shown to be a promising technique with many possibilities for future development.<br /> <br /> The world’s population is increasing and with it the need for a sustainable and renewable society. Textile and clothing is an essential part of our everyday life and which materials we use can have a large effect on our environment. Polyester is produced from oil and is therefore an unsustainable alternative. Cotton is a natural fibre but the production consumes huge amounts of water and land and harmful pesticides are often used. Also, we seem to have reached the limit of how much cotton that can be produced per year and there is a need to develop alternative fibres with similar properties.<br /> <br /> One such alternative is regenerated cellulose fibres. Two types are already produced on industrial scale: viscose and lyocell, but more environmentally friendly production methods using less dangerous chemicals are needed. Cellulose is the most abundant biopolymer on earth, but it does not melt as most polymers do and therefore has to be dissolved to be processed. Special solvents are needed for this and in this thesis dissolution in the ionic liquid EmimAc is investigated. Ionic liquids are salts that are in liquid form at temperatures below 100°C. In solution the cellulose was shown to take the form of a stiff cylinder, only bending in segments of around 20 glucose units. This is thought to be because of a structure created around the chain consisting of alternating positive and negative ions coming from the EmimAc.<br /> <br /> Fibres could successfully be spun from the cellulose/EmimAc solutions using a technique called air-gap spinning where the solution is extruded and stretched in an air-gap before being coagulated in a suitable medium. The coagulation medium is thought to affect the crystallinity of the fibre and thereby the mechanical properties. Here, fibres coagulated in water showed higher crystallinity than fibres coagulated in the alcohol isopropanol. Evaluation of the mechanical properties showed that the water fibres had potential of reaching strength comparable to viscose, lyocell and cotton. The main problem is that they have to be made thinner and still maintain these properties.<br /> <br /> A structure which differs from what is commonly assumed for regenerated cellulose fibres was proposed. This constitutes crystalline lamella with a thickness of 20 nm ordered along the length of the fibre and surrounded by an amorphous matrix, as opposed to the common model which instead contains different amounts of needle-shaped micro-voids.<br /> <br /> The main characterisation technique used in this work was x-ray scattering. It involves exposing a sample to a narrow x-ray beam that will be scattered by the particles in the sample and create a pattern on a detector. From this pattern, properties such as size, shape and interactions of the particles in the sample can be determined. https://lup.lub.lu.se/student-papers/record/8951413/file/8951425.pdf application/pdf 7584143 no 2018 eng Cellulose scattering ionic liquid dissolution regenerated cellulose fibre structure-property relationship materials chemistry materialkemi Chemistry Technology and Engineering 8951413 2018-06-19T17:12:05+02:00 2018-06-21T14:43:03+02:00 2018-06-21T14:43:03+02:00

oai:lup-student-papers.lub.lu.se:9163474 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH1 Angelica Nash author 9086269 Susanna Horsefield supervisor Department of Chemistry v1000647 department In all living organisms, proteins which transport water and other small solutes across the membrane exist and are known as aquaporins. Aquaporins consist out of four monomers, forming a homo-tetramer with a substrate conducting channel in each monomer. Aquaporins can be regulated by either gating or trafficking, which allows the cell to control the permeability of the membrane. Aquaporin 5 is one of the aquaporins which is believed to be regulated by trafficking, partly due to sequence homology to aquaporin 2, which is a well-studied membrane protein and known to be regulated by trafficking. Interactions with other proteins play an important role in the regulatory process of aquaporins and further studies and knowledge regarding their regulatory processes are of great interest, since aquaporins are involved in several pathophysiological conditions such as cancer, obesity, nephrogenic diabetes insipidus (NDI) and Sjögren’s syndrome.<br /> <br /> Two proteins suggested to be involved in the trafficking machinery of aquaporin 5, are CLIP2 and β-catenin. CLIP2 and β-catenin are both located in the cytoplasm of the cell and previous studies have indications of interactions between CLIP2 and β-catenin and aquaporin 5. The goal of this study is to investigate whether there is an interaction and at some extent investigate what part of the protein that are interacting. This is done with two techniques, far Western Blot and Microscale Thermophoresis (MST), which both are methods used for protein-protein interaction investigation. Furthermore, the structure of CLIP2 is investigated with crystallization, and co-crystallization between CLIP2 and aquaporin 5 C-termini peptide.<br /> <br /> The results from the MST measurements indicates an interaction between aquaporin 5 and CLIP2, where the dissociation constant (Kd) was determined to 97.4 ± 13.8 nM, while far Western Blot indicated the interaction, but the experiment was not reproducible. Further analysis is done on CLIP2 with only one domain present at a time (out of two). This shows no interaction with aquaporin 5, suggesting that it has no or very low affinity when only one domain is present. MST analysis between aquaporin 5 C-termini peptide and CLIP2, an indication of binding can be seen, but with much lower affinity. Regarding β-catenin and aquaporin 5, no interaction is seen in either analysis method. Protein crystals is seen for both crystallization attempts, of CLIP2 and CLIP2 with aquaporin 5 C-termini peptide, making way for further structural analysis. An Investigation of Binding between a Water Channel Protein and Cytoplasmic Proteins <br /> <br /> Water is vital for all living organisms. In human cells there are proteins which are specialized in transporting water in and out of the cells over the cell membrane, driven by an osmotic gradient. The proteins responsible for water transportation in cells are known as aquaporins. Earlier studies have shown that aquaporins play a major role in several pathophysiological diseases, where regulation and alteration can be of great interest for further medical development or fundamental knowledge in further research regarding these proteins. Aquaporins are known to be regulated by two different pathways: gating or trafficking. Gating is mainly regulated by conformational changes, while trafficking regulates aquaporins by triggers from the environment, including other proteins in the trafficking machinery. In this study, the focus is on one of the thirteen human aquaporins: aquaporin 5. This protein has a very high sequence similarity to aquaporin 2, which is a well-studied protein, known to be regulated by trafficking. Studies have suggested that aquaporin 5 may also be regulated by trafficking, where other proteins in the cytoplasm are involved in the translocation of aquaporin 5 to the plasma membrane. CLIP2 and β-catenin are two of the proteins which are believed to be involved in the translocation of aquaporin 5, suggested to interact with aquaporin 5 in its trafficking mechanism.<br /> <br /> The aim of my thesis is to investigate the suggested interaction between aquaporin 5 and the cytoplasmic proteins CLIP2 and β-catenin. This is done by several purification steps, leading up to two analytical methods: far Western Blot and Microscale Thermophoresis (MST). Furthermore, the structure of CLIP2 is investigated by protein crystallization and co-crystallization with aquaporin 5 peptide. The findings indicate that there is an interaction between aquaporin 5 and CLIP2, which is seen with Microscale Thermophoresis and indicated with far Western Blot. Further analysis is done on CLIP2 with only one of its two domains present which does not show any indication of binding, suggesting that both domains are required for the binding with aquaporin 5 to occur. Analysis with only the C-termini peptide of aquaporin 5 and CLIP2 is also done, showing interaction but with much lower affinity. No protein-protein interaction is seen between aquaporin 5 and β-catenin with either MST or far Western Blot. Considering crystallization, protein crystals is seen for both attempts which is a useful starting point for further analysis of the protein structures. https://lup.lub.lu.se/student-papers/record/9163474/file/9164041.pdf application/pdf 17992572 LU/LTH access 2024 eng Aquaporin 5 β-catenin CLIP2 protein-protein interactions trafficking biochemistry Chemistry 9163474 2024-06-13T20:06:18+02:00 2024-06-20T14:34:25+02:00 2024-06-20T14:34:25+02:00

oai:lup-student-papers.lub.lu.se:9163481 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Sophie Friman author 9163479 Hanna Svensson author 9163498 Stephen Burleigh supervisor Maria Petersson supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Biotechnology (MSc) v1000284 department Biotechnology (M.Sc.Eng.) v1000285 department This degree project aims to develop standard methods for determination of the size distribution in different samples using laser diffraction, as well as to create methodologies for development of new methods for unknown samples.<br /> <br /> The size distribution is crucial to understand for pharmaceutical products since it affects properties such as the stability and bioavailability of the product. A way to measure the size distribution is to use laser diffraction. Laser diffraction is a technique in which laser beams are directed through a sample flow. When the laser beam hits a particle in the sample flow, the light scatters at different angles and intensities depending on the size and shape of the particle. The scattered light is then detected and translated into a size distribution, in this degree project by using the Mie theory. <br /> <br /> Different parameters suspected to affect the size distribution when using laser diffraction were analysed and evaluated for both emulsion- and powder samples. Due to the small droplet- and particle sizes, the sample preparation technique was believed to have a great impact on the size distribution. Other than this, the parameters pump speed, sonication intensity, obscuration and delay time were evaluated.<br /> <br /> The pump speed as well as the sonication time and intensity were found to affect the size distribution the most, while the delay time had a slight effect, and the obscuration barely affected the size distribution. It was further found that the powder samples were less sensitive than the emulsions and hence could withstand more energy in terms of higher pump speeds and sonication intensities. This also contributed to different optimal dispersing techniques during sample preparation; the powders were dispersed by sonication while the emulsions were dispersed by stirring on a magnetic stirrer plate. Other than this, the temperature was found to greatly impact the size distribution of the emulsions. In short, it was concluded that the pump speed and sonication intensity affected the size distribution the most, and that the emulsions should be treated with less energy than powders to maintain a representative sample. Metodutveckling för Mätning av Dropp- och Partikelstorleksfördelning med hjälp av Laserdiffraktion<br /> Partiklar finns i princip överallt runtomkring oss, och har en stor betydelse inom många industrier. Partikelstorleken i målarfärg avgör dess kvalitet, partiklar i miljön påverkar vår hälsa, och partikelstorleken i läkemedel påverkar dess effektivitet och stabilitet, för att nämna några exempel. Fokus för detta examensarbete har varit att bestämma partikelstorleken i olika läkemedel, såsom emulsioner och torra pulver. <br /> <br /> Två olika typer av emulsioner analyserades; hudkräm och hudlotion. I dessa emulsioner har en oljefas blandats i en vattenfas, likt beredningen av majonnäs. Oljefasen bildar då små oljedroppar i vattenfasen, eftersom olja inte löser sig i vatten. Droppstorleken av oljedropparna är viktig att känna till då den påverkar formuleringens egenskaper, såsom hur den känns på huden och hur snabbt den absorberas. Utöver emulsionerna analyserades två pulver; laktos och mometasonfuroat. Laktos kan användas i inhalationsprodukter medan mometasonfuroat kan användas som antiinflammatorisk komponent i exempelvis hudkrämer. Det är viktigt att veta partikelstorleken för inhalationsprodukter eftersom de måste vara tillräckligt små för att ta sig ner i lungorna i stället för att exempelvis andas ut, medan partikelstorleken för det antiinflammatoriska pulvret påverkar huruvida det kan tränga igenom huden.<br /> <br /> Vid mätningar av partikelstorlek är det väsentligt att förstå att partikelstorleken i en formulering inte har ett specifikt värde, utan snarare är en distribution av olika partikelstorlekar. Exempelvis kan det påstås att partikelstorleken är 5 µm, men i verkligheten kan partiklarnas storlek variera från 3 till 7 µm. För att bestämma distributionen är laserdiffraktion en passande teknik. Principen bakom laserdiffraktion är att en laserstråle riktas mot ett prov beståendes av tusentals partiklar, varpå laserstrålen kommer att ändra riktning när den träffar en partikel. Små partiklar är mer krökta och ändrar därför riktningen på lasern mer än vad stora partiklar gör. Ändringen av laserns riktning detekteras sedan, utifrån vilken distributionen beräknas baserat på alla tusentals partiklar. <br /> <br /> Inställningarna som används under mätningarna behöver optimeras, eftersom olika sorters prov är olika tåliga och därmed kan utsättas för olika mängder energi utan att förstöras. Exempelvis är emulsioner normalt sett mer känsliga än pulver, vilket gör att proven behöver behandlas olika. Dessutom är det viktigt att partiklarna som analyseras inte sitter ihop i klumpar, i så kallade aggregat, eftersom dessa då kommer att uppfattas som en enda stor partikel. För att motverka detta behövs olika mycket energi appliceras på de olika proven, exempelvis i form av ultraljud och pumphastighet. Under examensarbetet har det därför undersökts hur mycket energi, och vilken energikälla, som behövs för att minska antalet aggregat och därmed få ett mer tillförlitligt resultat. Även andra inställningar som kan påverka resultatet, såsom fördröjning innan mätningen startas, provkoncentration, och hur provet bereds, har undersökts. Sammanfattningsvis resulterade undersökningarna i att både pumphastighet och ultraljud hade stor påverkan på både emulsioner och pulver, medan fördröjningstid och koncentration inte hade lika stor påverkan. Dessutom resulterade undersökningarna i att emulsioner behöver beredas på ett annorlunda sätt jämfört med pulvren, då emulsioner är mer känsliga och därför inte kan behandlas med lika mycket energi under beredningen. https://lup.lub.lu.se/student-papers/record/9163481/file/9163496.pdf application/pdf 5013827 no 2024 eng Laser Diffraction Size Distribution Emulsions Powders Method Development Pharmaceutical Formulation Technology and Engineering Chemistry Biology and Life Sciences 9163481 2024-06-13T20:10:47+02:00 2024-06-17T12:18:09+02:00 2024-06-17T12:18:09+02:00

oai:lup-student-papers.lub.lu.se:9163585 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Tove Rasmusson author 9057169 Susanna Törnroth-Horsefield supervisor Department of Chemistry v1000647 department Introduction: The aim of this project is to study if the predicted model of the interaction between aquaporin-5 (AQP5) and CLIP2 is accurate by introducing single point mutations in the predicted interaction site of CLIP2 and see if it affects the interaction or not. <br /> Background: Aquaporins are essential membrane proteins for many biological processes. The regulation of aquaporins is crucial for cell functioning and survival. Aquaporins are regulated by other proteins and that is why there is an interest in studying interactions between aquaporins and other proteins. Defects in regulation of aquaporins can cause several diseases, such as Sjogren’s syndrome. This report will focus on aquaporin-5 and CLIP2, which is a protein recently discovered to interact with and regulate AQP5. A binding model has been predicted and to be able to confirm or reject this model, the protein interaction needs to be studied in vitro. <br /> Aim(s): How do mutations in the predicted interaction site of CLIP2 affect its interaction with aquaporin-5?<br /> Methods: To generate the mutations in CLIP2, a two-stage PCR method was used. The mutated plasmids were cloned into BL21, where the protein was expressed in large scale before being purified using IMAC and SEC. AQP5 expressed in Pichia pastoris was purified using IEC and SEC. The interaction between each CLIP2 mutant and AQP5 was measured using microscale thermophoresis (MST). <br /> Results: The introduction of mutations in the DNA, expression and purification of the final mutated proteins were successful. The purification of AQP5 was unsuccessful, however, the final measurements in MST could still be executed by using another AQP5 batch. <br /> Conclusion: The lack of binding or weakening of binding, which was observed for every mutant, supports the predicted binding model stating that the four mutated amino acids are involved in the interaction between AQP5 and CLIP2. <br /> Keywords: Aquaporin-5, CLIP2, microscale thermophoresis, mutagenesis PCR. Människokroppen består av en otalig mängd celler, där varje enskild cell är omsluten av ett så kallat membran. Likt ett äpple där skalet omsluter och skyddar fruktköttet skyddar membranet cellen. En cell kan inte överleva utan ett membran. Förutom membranet är cellen också beroende av en fungerande transport av vatten och andra näringsämnen över membranet. För att kunna transportera ämnen över membranet finns det proteiner som sitter tvärsöver membranet och bildar kanaler genom membranet genom vilka olika ämnen kan flöda in eller ut ur cellen. Olika typer av proteiner används beroende på vad som ska transporteras. För transport av vatten används en typ av proteiner som kallas för aquaporiner. Aquaporiner kan aktiveras eller inaktiveras beroende på om vatten behöver transporteras eller inte. Det finns flera faktorer som bidrar till att en aquaporin aktiveras eller inaktiveras, varav ett sätt är om ett annat protein binder till aquaporinen. Ett protein består av en kedja av sammanlänkade aminosyror och när två proteiner interagerar med varandra så innebär det att några av aminosyrorna i de båda proteinkedjorna binder till varandra. <br /> I detta projekt kommer bindningen mellan en typ av aquaporin, aquaporin-5 (AQP5), och proteinet CLIP2 att studeras. Idag finns det många datorprogram som kan förutspå hur bindningar mellan proteiner ser ut utifrån proteinernas egenskaper och hur bindningar mellan strukturellt liknande proteiner ser ut. Utifrån detta har man kunnat förutspå hur bindningen mellan CLIP2 och AQP5 ser ut, det vill säga vilka aminosyror som interagerar med varandra, men för att vara säker på att bindningsmodellen stämmer måste det bekräftas experimentellt. I detta projekt har fyra varianter av CLIP2 producerats, där varje version skiljer sig från det naturliga CLIP2 proteinet med bara en aminosyra. Med hjälp av en metod som heter PCR har en aminosyra muterats, det vill säga bytts ut, mot en annan aminosyra för att kunna avgöra om den aminosyran som togs bort haft någon betydelse för bindningen. Om aminosyran är viktig kommer det att visa sig genom att CLIP2 inte längre kan binda till AQP5 eller att bindningen blir mycket svagare. Detta kan detekteras med hjälp av en metod som heter MST. <br /> Resultaten visade att CLIP2 fortfarande kan binda till aquaporinen, även fast att en mutation introducerats, men att bindningen är betydligt mycket svagare. För en av de fyra undersökta mutationerna kunde proteinet inte längre binda alls till aquaporinen. Detta resultat pekar på att den förutspådda bindningsmodellen sannolikt stämmer bra överens med hur proteinerna interagerar i verkligheten. 2024 eng biochemistry aquaporin-5 CLIP2 microscale thermophoresis mutagenesis PCR Chemistry 9163585 2024-06-13T23:10:53+02:00 2024-06-20T14:40:08+02:00 2024-06-20T14:40:08+02:00

oai:lup-student-papers.lub.lu.se:9163676 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Baaba Dadson author 9163661 Associate professor Henrik Stålbrand supervisor Department of Chemistry v1000647 department α-Galactosidases from Aspergillus nidulans (AglC) and Penicillium subrubescens (PsGal36-2527) are exo-acting enzymes that can be found in the Glycoside Hydrolase (GH) 36 phylogenetic cluster with eukaryotic α-galactosidases. In utilizing enzymes for industrial applications, finding enzymes with a broad range of substrate specificities and high catalytic efficiencies is quite challenging. It has become important to discover and produce novel enzymes such as the ones from GH36 family. This study seeks to recombinantly produce and characterize fungal GH36 α-galactosidase in terms of its stability and catalytic potential on different substrates. The expression of the enzyme was induced by growing Pichia pastoris transformants expressing AglC and PsGal36-2527 in Buffered Methanol-Complex Medium (BMMY). His-tag Affinity Chromatography was used to purify the expressed AglC followed by a purity analysis on SDS-PAGE and MALDI-TOF. Enzyme activity assays were done to obtain specific activity and other kinetic parameters using the artificial substrate para-Nitrophenyl-α-D-Galactopyranoside (pNPαGal). Enzyme activity assay and SDS-PAGE revealed success in the production of AglC with high purity. AglC showed optimum activity at pH 5.5 and temperature 40°C but had relatively low affinity to pNPαGal compared to previous studies. However, no enzyme activity was observed for PsGal36-2527 nor was it detected on SDS-PAGE. The expressed AglC was secreted with very little contamination. However, its relatively lower affinity to pNPαGal could be due to loss of enzyme activity over a long period of storage. Null activity of PsGal36-2527 in the supernatant and cell lysate suggests that the PsGal36-2527 was misfolded or degraded. Achieving Sustainability with Plant-Degrading Enzymes<br /> According to the World Economic Forum, plants contribute to a significant amount of the total biomass generated on earth. Plant biomass may include wood, straw and energy plants such as sugarcane. They can be used to generate renewable materials and energy such as transport fuel, biochemicals and heat to generate power. <br /> It is important to understand the structure of plants to extract useful parts of the plant. This can be achieved with the aid of carbohydrate-degrading enzymes such as glycoside hydrolases. Enzymes are biomolecules that speed up chemical reactions. Glycoside hydrolases catalyze the breakdown of carbohydrate structures into simpler sugar structures and units. Some industrial applications of such enzymes include the production of food stabilizers, prebiotics and detergents.<br /> In this study, we are interested in producing a type of glycoside hydrolase known as α-galactosidases. This enzyme catalyses the release of terminally linked galactose units from carbohydrate structures. We are specifically interested in α-galactosidases from fungal sources. Using genetic engineering techniques, the enzyme was expressed in a different fungal host. The activity of the expressed enzyme was determined using a synthetic substrate which includes the structure of galactose linked to another compound that allows the quantification of the substrate. This activity assay was used to determine the stability and kinetic characteristics of the enzyme. The results showed a success in the production of the enzyme with high purity. It also catalysed the breakdown of the substrate and showed good stability at temperatures below 60°C. However, its kinetic parameters showed a relatively lower affinity to the substrate compared to other recombinantly expressed α-galactosidases in previous studies. 2024 eng Biochemistry α-Galactosidase Galactomannan Glycoside Hydrolase Recombinant expression Pichia pastoris Chemistry 9163676 2024-06-14T09:53:00+02:00 2024-06-18T11:27:59+02:00 2024-06-18T11:27:59+02:00

oai:lup-student-papers.lub.lu.se:9164453 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Felicia Breimer author 9164450 Johan Wennerberg supervisor Hanna Andersson supervisor Centre for Analysis and Synthesis v1000651 department Chagas disease, also known as American Trypanosomiasis, is a parasitic infection caused by the triatomine bugs, commonly referred to as kissing bugs. It is the deadliest parasitic disease in South America but has spread beyond this region due to migration and climate change. Approximately 70 million people are at risk of infection, and there is no cure for the chronic phase of the disease. In previous research, waltherione F served as the starting point for drug development, leading to the identification of a lead candidate, DNDI0003974327, referred to as compound 4 in this paper, with an IC50 value of 2.7 µM Although this lead candidate shows promising properties, further modifications are necessary to enhance its biological activity. A major challenge in this process is the lack of a known target for the drug, which requires phenotypic screening. Our approach involved computational chemistry to develop a proposed pharmacophore model, which guided the creation of a synthetic plan. This plan aimed to modify the 3-methoxy position of the lead candidate in accordance with the pharmacophore model, resulting in a six-step synthetic protocol. Three of the new derivatives, compounds 16, 21 and 22, achieved IC50 values of 2.6, 1.7 and 3.7 µM, respectively. The SI values for the compounds also exceeded the threshold of 10, ensures a decent level of T. cruzi parasites being killed at a concentration that does not affect the rat myoblasts cells used in the screening. These compounds have similar stability profiles but have significantly lower solubility compared to the current lead candidate. However, their IC50 values are not below 1 µM, indicating that further development is necessary for effective treatment of Chagas disease. Despite the need for optimization, valuable insights have been gained about the target, particularly regarding positive interactions for biological activity with chlorobenzene substituents. I dagens samhälle präglas vår samtid av nyheter om krigsdrabbade områden och naturkatastrofer, vilket är två orsaker till att migrationen runt om i världen ökar. Människor förlorar sina hem och vissa är på ständig flykt. Detta är ett fruktansvärt öde som också bidrar till spridningen av sjukdomar som tidigare varit begränsade till vissa kontinenter. <br /> <br /> Chagas sjukdom, även känd som amerikansk trypanosomiasis, är den dödligaste parasitsjukdomen i Sydamerika. Studier visar att den har spridit sig utanför regionen på grund av ökad migration och klimatförändringar. Idag uppskattar man att 6,5 miljoner människor är infekterade av Chagas sjukdom och att 70 miljoner människor riskerar att bli smittade. Chagas sjukdom omfattar två olika faser: en akut fas och en kronisk fas. För den akuta fasen finns idag två läkemedel på marknaden, men deras användning är begränsad på grund av svåra biverkningar. För den kroniska fasen finns det ingen behandling. I tidigare forskning användes waltherione F som utgångspunkt för läkemedelsutveckling, vilket ledde till en mer aktiv substans. Trots att denna substans visar lovande resultat, krävs ytterligare modifieringar för att förbättra dess biologiska aktivitet. En stor utmaning i denna process är avsaknaden av ett känt mål för läkemedlet, vilket kräver fenotypisk screening. Vårt tillvägagångssätt involverade beräkningskemi för att utveckla en modell, som vägledde skapandet av en syntesplan. Denna plan syftade till att modifiera en position i molekylen i enlighet med modellen, vilket resulterade i en sexstegs syntes med olika kemiska reaktioner. Totalt syntetiserades 19 nya substanser som testades för löslighet, stabilitet och biologisk aktivitet. Sammanfattningsvis visade de analytiska testerna låg löslighet för samtliga substanser, med undantag för huvudkandidaten och en substans med en hydroxylgrupp på substituenten. Tre av de nya substanserna, 16, 21 och 22, uppnådde IC50-värden, dvs hur effektiv bindningen är och vilken mängd som behövs, på 2,6, 1,7 respektive 3,7 µM. Dessa föreningar har liknande stabilitetsprofiler men betydligt lägre löslighet jämfört med den nuvarande huvudkandidaten. Deras IC50-värden är dock inte under 1 µM, vilket indikerar att ytterligare utveckling är nödvändig för en effektiv behandling av Chagas sjukdom. Trots behovet av optimering, har värdefulla insikter uppnåtts om modellen, särskilt när det gäller positiva interaktioner för biologisk aktivitet med substituenter med klorbensen. https://lup.lub.lu.se/student-papers/record/9164453/file/9164476.pdf application/pdf 4602784 yes 2024 eng organic chemistry chagas disease chlorobenzene substituents chronic Chemistry 9164453 2024-06-17T11:49:12+02:00 2024-08-29T09:10:49+02:00 2024-08-29T09:10:49+02:00

oai:lup-student-papers.lub.lu.se:9164989 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Isabelle Bäckström author 9148658 Ingemar André supervisor Department of Chemistry v1000647 department Understanding the pH sensitivity of proteins and enzymes across intracellular compartments is crucial for fundamental research. Lizatović et al. [1] aimed to design a peptide incorporating a specific amino acid to form a hexamer structure and lacking it to form a pentamer structure. Unexpectedly, two distinct structures emerged based on pH. At pH 6, a hexamer structure formed, albeit with a surprising arrangement, while at pH 8, a pentamer structure appeared despite the presence of the specific amino acid. This peptide came to be abbreviated as pHios (pH-induced oligomerization switch).<br /> <br /> The pH-induced oligomerization switch prompts several questions: is it feasible to use the designed peptide to regulate the structure and function of other proteins within a tightly controlled pH range? This would involve fusing pHios with the desired protein to exploit its pH-induced oligomerization capability to modulate the structure and activity of the fused protein. Can new sequences with similar properties be rationally designed? Will slight alterations to the designed sequence still maintain functionality?<br /> <br /> Experimental methods, including size exclusion chromatography (SEC) to assess protein size changes, and circular dichroism (CD) to study secondary structure alterations, were employed on redesigned sequences of the wild-type (WT) peptide at varying pH levels. Results indicate limited tolerance to sequence modifications, although cautious interpretation is warranted due to suboptimal fitting and low concentrations. Certain sequences exhibit differing stability at pH 6 or pH 8. The fusion of pHios to the target protein faced expression challenges, highlighting the need for optimized protein expression protocols. pH power: exploring the impact of protein shape and activity<br /> <br /> A cell is the smallest living unit in all organisms. It works like a tiny factory, producing energy, storing information, and performing essential functions to sustain life. Cells consist of different compartments with varying pH levels. Proteins, essential molecules inside these compartments, perform numerous vital functions and are composed of chains of building blocks (amino acids), similar to beads on a necklace.<br /> <br /> Researchers have previously worked on designing a small protein intended to have a specific shape, where long helical threads coil around each other. In nature, such structures typically have 3, 4, or 5 threads, but the researchers attempted to create one with 6. The design intended to result in 6 threads with a specific amino acid present, and 5 threads without it. However, the outcome was different from expectations. Two distinct structures were observed depending on pH. At pH 6, a structure with 6 threads formed, but their arrangement was unexpected. At pH 8, a structure with 5 threads appeared, despite the specific amino acid being present.<br /> <br /> The discovery led to new questions: can the designed protein and its pH-dependent structural changes be used to modify the shape and activity of another protein? By attaching the designed protein to the target, could we control its activity by forcing it into the desired structure at a specific pH? Another question is how “perfect” this designed system is. Can small modifications to its building blocks still maintain its functionality? To investigate this, two experimental methods are used. One method aims to determine how the size of the protein’s changes. The other method studies how their shapes change.<br /> <br /> If the designed protein can alter other protein’s structure and function via pH, it could open up many possibilities. For example, genes in our bodies serve as blueprints for how the body should be built and function, and faulty genes can lead to illness. By leveraging the designed protein and the variation in pH across different cell compartments to control the opening of specialized containers made up of protein molecules, we can use them as vehicles to deliver the components needed to repair the faulty genes.<br /> <br /> Our study found that the system doesn’t adapt well to small changes in its building blocks. Some redesigned proteins were more stable at pH 6, while others preferred pH 8. When we tried to combine the designed protein with a target protein, we had trouble producing it, highlighting the need for better protein production methods. https://lup.lub.lu.se/student-papers/record/9164989/file/9164994.pdf application/pdf 1764300 yes 2024 eng Biochemistry Oligomerization pH Chemistry 9164989 2024-06-17T19:16:58+02:00 2024-06-20T14:33:09+02:00 2024-06-20T14:33:09+02:00

oai:lup-student-papers.lub.lu.se:9165173 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Jan Planelles Samper author 9165171 Dr. Petter Persson supervisor Department of Chemistry v1000647 department In this work we study some potential light-harvesting iron complexes. Transient Absorption Spectra (TA ) has been used to determine the lifetime of the different excited states. The issue with this technique is that it is difficult to define the exact contribution of each excited state to the Transient Absorption Spectra. The aim of this work is to use DFT methods to calculate the ground and excited states absorption spectra of some iron complexes and see if it matches with the experimental transient absorption spectra. DFT and TDDFT with B3LYP and B3LYP* were used to optimize and calculate the excited states of some of the promising Fe(II) complexes for photochemical reactions. It has been seen how TDDFT provides a similar result for the spectra of ground state but the excited states were usually not accurate. Further work would need to be done in order to find the right functionals. For years, efforts have been being made to make an energy transition towards renewable energies. One of them is solar energy such as solar panels. The sun provides energy that can be transformed into electrical energy, however, there is one problem: some of the metals used to make these plates are scarce in the Earth’s crust. For this reason, scientists are looking for new materials made of more abundant metals, such as iron. To study these new materials, various techniques are used. One of these techniques is based on exciting a molecule energetically, as the sun would, to reach an excited state and see what happens when the molecule in this state gives itself a little more energy. The problem lies in the fact that experimentally it is difficult to break down and identify each of the different behaviors of the molecule involved. This is where the field of computational chemistry comes in: it allows us to study the molecule in each of its individual states. We want to break down the results obtained by scientists through experiments without having to enter a laboratory or have to synthesize any molecule. In this work, simulations are used, to study individually those states that we think the molecule enters when it comes into contact with sunlight and to compare the results with those obtained in a laboratory. Several molecules containing iron, which have shown to be promising in the field of solar energy, have been studied. Despite having shown similarities with the experiments, computational tools still need to be improved to obtain results like the experimental ones. When this is possible, it will not be necessary to go to a laboratory to find out which materials would be useful for solar panels, but only a computer will be needed. https://lup.lub.lu.se/student-papers/record/9165173/file/9165174.pdf application/pdf 9486323 yes 2024 eng Theoretical Chemistry Photochemistry Transient Absorption Spectra Chemistry 9165173 2024-06-18T08:40:54+02:00 2024-06-20T14:37:15+02:00 2024-06-20T14:37:15+02:00

oai:lup-student-papers.lub.lu.se:9165576 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Karolina Matulewska author 9161303 Sara Linse supervisor Oskar Hansson supervisor Department of Chemistry v1000647 department Background: Parkinson’s disease (PD) is the second most common neurodegenerative disease, and it is linked with aggregation of α-synuclein protein. PD can be diagnosed using real-time quaking induced conversion (RT-QuIC) assay. RT-QuIC, despite its effectiveness, is not really understood in terms of the mechanisms driving it.<br /> Aim(s): The aim of the project was to reproduce RT-QuIC protocol developed in prof. Piero Parchi’s lab and to understand the effect of different parameters in its efficiency and reproducibility.<br /> Methods: CSF samples from healthy and sick individuals were analysed in RT-QuIC setup with varying conditions. <br /> Results: We reproduced the RT-QuIC protocol and compared the impact of monomer preparation, the protein’s sequence, and shaking on the outcome. <br /> Conclusion: <br /> Our data show that RT-QuIC can be successfully used to diagnose PD and can be reproduced. Additionally, we introduce the half-time of aggregation as an additional criterion that could be used for differentiating samples. Parkinson’s disease (PD) is the second most common neurodegenerative disorder worldwide. It impacts not only 6 million patients but also their relatives and society as a whole. Therefore, understanding the molecular basis of PD means a great deal for both patients and taxpayers.<br /> A molecular outcome of Parkinson’s disease is the appearance of fibrillar plaques in the brain made of an amyloid protein – α-synuclein. The middle part of it is folded into a helical structure that is responsible for forming the core of fibrils that then pile into a plaque. Two terminal regions of α-synuclein are intrinsically disordered which means that they don’t fold in any specific structure but rather float freely. One of the ends (C-terminus) creates a fuzzy coat around a fibril and the other (N-terminus) provides a binding site for lipid particles. That function is crucial as α-synuclein can be transported outside the brain by being bound to extracellular vesicles, small lipid bobbles that cross the brain-blood barrier. Thanks to that it has been possible to find α-synuclein in various body fluids such as saliva, blood, cerebrospinal fluid (CSF) but also skin and olfactory mucosa.<br /> Diagnosis of synucleinopathies is still a challenge. Usually, doctors recognize PD based on the clinical symptoms such as tremors, slowness of movement, and rigidity but also non-motor symptoms such as dementia, fatigue, and cognitive and mood disorders. However, once the symptoms have occurred, the disease is already highly developed, medications slowing down the symptoms are less effective and differentiating from different diseases harder. Therefore, a diagnostic tool that could catch PD before its clinical onset would dramatically improve patients’ quality of life as well as it could help develop new therapeutics. So far, few methods have been developed to do so. One of them is positron emission tomography (PET) which allows us to directly image specific disease markers in the brain. Even though it is very powerful it has also its flaws such as high costs, radiation, and low availability. Hence, methods based on biomarkers from body fluids have recently gained the interest of researchers. Blood tests could be the most convenient way to detect PD. However, despite recent very promising findings, they haven’t been so far developed in a way that they could be clinically used. CSF-based tests have dominated so far. One of those tests, real-time quaking-induced conversion (RT-QuIC), is the focus of this thesis. RT-QuIC uses α-synuclein ability to aggregate differently depending on the conditions. We can follow fibrils appearing using a fluorescent dye called thioflavin T (ThT). CSF obtained from patients contains so-called seeds, fibrils that can accelerate aggregation of α-synuclein monomers. As it turns out, monomeric α-synuclein seeded with CSF from sick patients aggregate giving much higher fluorescence signal than when seeded with CSF of a healthy person. The measurement takes place in a shaking fluorescence-detecting reader.<br /> Despite its relative simplicity, a few challenges arise in the RT-QuIC protocol. Mainly, reproducing results across different laboratories. Here, we tried to reproduce RT-QuIC from a pioneering lab in Bologna and to understand the mechanisms driving the method. 2024 eng RT-QuIC biomarkers alpha-synuclein polymorphism amyloids biochemistry Chemistry 9165576 2024-06-18T19:42:55+02:00 2024-06-20T14:44:06+02:00 2024-06-20T14:44:06+02:00

oai:lup-student-papers.lub.lu.se:9166203 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Rezan Okutan author 9165935 Researcher Christian Hulteberg supervisor PhD Maitham Majeed supervisor PhD Sonia García supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department In the Formox-process, methanol is converted to formaldehyde via partial oxidation on a heterogeneous iron-molybdate catalyst. To an extent, the formed formaldehyde (FA) is over-oxidized into carbon monoxide (CO) which cannot be recycled into FA. As CO affects the environment negatively and decreases the process economy, internal attempts have previously been made to decrease the CO formation of the process. This project has been conducted with the intent to decrease the CO formation of the process by at least 0.5 percentage points from today’s roughly 4.5%. <br /> <br /> In this project, CO reduction of the Formox-process has been attempted by investigating two different pathways; with the first being addition of a readily combustible material known as a Pore Former in various amounts to increase the porosity of the catalyst, as well as doping the catalyst with a metal oxide to act as a hardener. Changes to the mixing method of these ingredients has also been investigated. Analysis of the produced catalyst pellets showed that after these changes, the catalyst is either too fragile to be tested at a pilot scale, or exhibit too low porosity to be deemed promising for further study. <br /> <br /> The other method that was tested involved replicating a washing step of the catalyst that is currently done in large-scale production. A washing liquid with a lower number of ions compared to the one being currently used was tested and compared to commercial references. Three samples with different washing liquids were produced and tested at a pilot scale, and the sample washed with process water showed an increased FA yield and a decreased byproduct yield compared to the commercial reference. However, the samples also exhibited an increased CO yield. These results potentially indicate a shift in the nature of the active sites of the catalyst from acidic to basic, but further testing must be done to determine the exact nature of the changes that have been made. Overall, the results provide a good basis for further study. De flesta associerar förmodligen ordet katalysator med bilkatalysatorer där smutsiga avgaser från fordon renas genom att gasen får reagera med syre och därmed bilda mindre skadliga produkter. Så kallade heterogena katalysatorer är ofta metalloxider och de används i många industrier för att möjliggöra kemiska reaktioner. Ett sådant exempel är Formox-processen, där en katalysator bestående av järnmolybdat används för att förena syre och metanol under bildningen av formaldehyd. Reaktionen sker inne i porer i denna ihåliga, pelletsformade, katalysator, och skulle dessa porer vara för små kan den bildade formaldehyden fångas i porerna och enkelt reagera med mer syre under bildning av kolmonoxid och koldioxid. Då dessa ämnen är välkända växthusgaser, och ämnena inte kan återcirkuleras och reagera till formaldehyd igen, finns det en stor drivkraft att försöka öka storleken på porerna i katalysatorn, vilket har varit syftet med denna studie. Projektet gjordes i samarbete med Johnson Mattheys R&amp;D-avdelning i Perstorp under första hälften av 2024. <br /> <br /> Två olika metoder har testats; dels har ett ämne tillsats katalysatorn som lätt kan brännas bort under hög temperatur i en ugn. Tanken var att när ämnet bränns bort kommer den efterlämna hål i strukturen och därmed ge större porer. Analyser av dessa katalysatorer visade emellertid att strukturen nu blir väldigt bräcklig, vilket skulle leda till problem vid förvaring och transport av katalysatorn. Därmed genomgick inte dessa prover ytterligare tester. <br /> <br /> Utöver detta testades det även att tvätta katalysatorerna med avjoniserat vatten i stället för vatten med högre koncentration av joner, vilket motsvarar den nuvarande tvättningen i produktionen. Här var tanken att tvättning med det avjoniserade vattnet skulle leda till en mindre mängd joner som sätter sig i porerna och utgör ett fysiskt hinder för formaldehyden på dess väg ut ur porerna. Pilotförsök av de tvättade katalysatorpartiklarna visade emellertid att mängden CO som bildades ökade för samtliga prover, samtidigt som bildningen av andra biprodukter minskade. Detta kan möjligen hänföras till ett skifte i karaktären hos de aktiva sätena i katalysatorn, från sura till basiska, men vidare studier behöver bedrivas för att säkerställa detta. https://lup.lub.lu.se/student-papers/record/9166203/file/9166206.pdf application/pdf 2171602 2024-06-25 no 2024 eng Heterogeneous Catalysis Chemical Engineering Formaldehyde Chemistry Technology and Engineering 9166203 2024-06-19T19:29:35+02:00 2024-06-25T03:42:52+02:00 2024-06-20T14:01:18+02:00

oai:lup-student-papers.lub.lu.se:9166672 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Maria Kulesh author 9166670 Roberto Mastio supervisor Department of Chemistry v1000647 department This project is part of a larger effort to design bacterial sialic acid inhibitors based on sialic acid, Neu5Ac. The emergence of antimicrobial resistance is a major concern for the public health and causes a significant number of deaths globally each year. There is an urgent need to discover novel antibacterials to still be able to cure infections in the future.<br /> This project explores a strategy based on sialic acid - a 9-carbon sugar found on the terminal positions of the carbohydrate chains covering the cell surfaces. Several pathogens may utilize sialic acid for molecular mimicry or as an energy source. The idea is to block the sialic acid transport into the cell, thus preventing the bacteria from colonizing and infecting the host.<br /> Previous work has been focused on modifying the 4-OH, 5-NHAc and 9-OH positions of sialic acid, but little is yet known about the role of the glycerol tail for protein binding. This project aimed to expand the compound library, by replacing the glycerol tail with other moieties, with the goal of improving binding affinity.<br /> To achieve this, the glycerol tail was transformed into an aldehyde and new moieties were successfully installed via different linkers. A new class of compounds – 1,7-bicyclic lactams was accidentally discovered in the process.<br /> The project resulted in a collection of sialic acid analogues based on reductive amination of the C7-aldehyde, but their effect on binding affinity remains to be explored. I duellen mellan människor och bakterier har båda ett par ess i rockärmen. Människan har utvecklat läkemedel som hämmar bakteriens förmåga till att föröka sig och sprida infektionen vidare. Bakterien i sin tur har utvecklat knep för att komma undan. Under de senare åren hör vi allt oftare om antibiotikaresistens, det vill säga infektioner som inte längre svarar på vanlig behandling och vi behöver därför utveckla nya strategier för att kunna bota dem.<br /> Detta projekt syftar till att framställa ny antibiotika utifrån sialinsyra – ett socker som man kan hitta på cellernas ytor. Sockret utgör en slags QR-kod, som kan användas för att känna av och kommunicera med andra celler i omgivningen. En del bakterier kan förklä sig med sockret, likt ulvar i fårakläder, för att lura kroppens försvar eller använda sockret som energikälla.<br /> Tanken är att förhindra att bakterierna tillgodogör sig sialinsyra genom att sätta en kork på sockertransporten in i bakterien och därmed sätta en käpp i hjulen för en ny infektion. En sådan kork behöver ha rätt form och storlek för att vara effektiv.<br /> I detta arbete framställde vi ett flertal sialinsyreanaloger, det vill säga varianter av sialinsyra. Dessa kommer senare kunna testas för att se ifall de kan blockera sialinsyretransporten in i bakterien. 2024 eng AMR bacterial transporter drug design organic chemistry sialic acid Chemistry 9166672 2024-06-20T14:32:58+02:00 2024-06-27T08:35:13+02:00 2024-06-27T08:35:13+02:00

oai:lup-student-papers.lub.lu.se:9166746 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Hadiqa Inam author 9166744 Associate professor Henrik Stålbrand supervisor Department of Chemistry v1000647 department This study investigated the enzyme BoGal36A, produced by the gut bacterium Bacteroides ovatus. BoGal36A is an alpha-galactosidase, an enzyme that breaks down complex sugars. Unlike most alpha-galactosidases from the GH36 family, BoGal36A appears to cleave internal glycosidic bonds. In this study, the wild-type BoGal36A and mutant W297F was expressed in E. coli BL21 (DE3) cells and purified subsequently using His-tag affinity chromatography. The proteins were analysed qualitatively using SDS-PAGE and quantitatively using nanodrop and para-nitrophenol alpha-galactosidase assay. Bioinformatics analysis for the protein predicted BoGal36A to be a stable, hydrophilic protein. The wild-type BoGal36A exhibited significantly higher specific activity (229.5 U/mg) whereas the mutant showed a specific activity of 2.86 U/mg. The W297F mutation likely affects the enzyme&#39;s structure and function due to the change in amino acid properties. X-ray crystallography or computational modeling could provide detailed structural information on how the mutation affects BoGal36A and give insights into the substrate specificity. Further research is needed to understand the unique catalytic activity of BoGal36A in the gut environment. Understanding BoGal36A&#39;s function could also contribute to improved methods for promoting the growth of Bacteroides ovatus in the gut, potentially leading to better human health. This study investigated an enzyme called BoGal36A and its variant called W297F which is produced by the human gut bacterium Bacteroides ovatus. This enzyme helps people digest complex sugars that we consume in our diet. How? To address some of it, this study was conducted using a combination of scientific techniques. Unlike most other members of the family that BoGal36A belongs to, BoGal36A seems to be a special case because it has shown its ability to cleave the glycosidic bonds inside the sugar molecules instead of just cleaving the bonds at the terminals. In this study, the wild-type BoGal36A and mutant W297F were obtained from growing E. coli BL21 (DE3) cells and using the His-tag which is a repeat of Histidine amino acids that the Ni+2 prefers. This is why nickel ion beads were used in a complex system to obtain the relatively pure enzyme. The results of the study show that the enzyme in its wild-type is much more active than the mutant protein which indicates that the difference in the structure and sequence of both proteins is important in its activity and role for sugar preference. More information about the structure and function of this enzyme can be helpful in promoting people’s gut health. https://lup.lub.lu.se/student-papers/record/9166746/file/9166761.pdf application/pdf 571267 yes 2024 eng biochemistry alpha galactosidase bacteroides ovatus GH36A glycoside hydrolase BoGal36A expression purification Chemistry 9166746 2024-06-20T16:05:15+02:00 2024-06-24T11:37:33+02:00 2024-06-24T11:37:33+02:00

oai:lup-student-papers.lub.lu.se:9167162 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ebba Jönsson author 9167160 Roberto Mastio supervisor Department of Chemistry v1000647 department Glycosaminoglycans comprise linear polysaccharide containing repeated disaccharide units. When one of the disaccharide units of chondroitin sulfate, glucuronic acid, gets epimerized by dermatan epimerase 1 to iduronic acid, dermatan sulfate is formed. Dermatan sulfate is essential in tumorigenesis, due to increased flexibility in the chain and enables interaction with certain proteins such as cytokines, growth factors and angiogenic factors. Current studies suggest that an over-representation of iduronic acid or elevated expression levels of dermatan sulfate epimerase 1 are associated with tumor growth in breast cancer. Inhibiting DS-Epi1 may alter DS expression, affecting conditions like connective tissue disorders like EDS and breast cancer. This project aims to create an effective inhibitor to dermatan sulfate epimerase 1 using glucuronic acid derivatives with hydrophobic groups on C4 to improve interaction with the enzyme. Kolhydrater är en grupp av biomolekyler som omfattar sockerarter, både enstaka och sammankopplade i kedjor. Förutom att förse våra celler med energi har kolhydrater en rad viktiga funktioner, från att vara involverade i kommunikationen mellan celler till cellulär uppbyggnad. Syntesen av kolhydrater i våra celler behöver undersökas ytterligare eftersom det finns samband mellan ett antal sjukdomar och syndrom som uppstår när uttrycket av vissa kolhydrater blir felaktigt. Ett exempel är uttrycket av kolhydratkedjan kondroitin/dermatan sulfat till följd av felaktigt uttryck av enzymer i biosyntesen. Detta får som konsekvens att kolhydratkedjan blir mer flexibel vilket kan resultera i olika vävnadssjukdomar eller bidra till cancerutveckling. Syftet med detta projekt är att syntetisera ett derivat av glukuronsyra som skulle kunna inhibera, det vill säga stoppa aktiviteten hos dermatansulfatepimeras 1, vilken orsakar konverteringen av kolhydratkedjan kondroitin till dermatan sulfat. Tidigare har betydelsen av karboxylsyran på glukuronsyra studerats medan detta projekt syftar till att se hur en hydrofob sidogrupp påverkar interaktionen med enzymet. Detta möjliggör jämförelser med tidigare data rörande en potentiell förbättrad inhibitor till enzymet dermatan sulfat epimeras 1. 2024 eng Organic chemistry Glucuronic acid Enzyme inhibitors Organisk kemi Organisk syntes Chemistry 9167162 2024-06-22T11:41:53+02:00 2024-06-27T11:51:08+02:00 2024-06-27T11:51:08+02:00

oai:lup-student-papers.lub.lu.se:9167772 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH3 Elsa Ekström author 9167770 Sara Linse supervisor Max Lindberg supervisor Kalyani Sanagavarapu supervisor Biophysical Chemistry v1000649 department Amyloid beta (Aβ) proteins are a group of proteins able to form fibrillar aggregates that are linked to the adverse neurological effects seen in Alzheimer’s disease [11]. The molecular mechanisms that lead to the Aβ aggregation are complex processes, and efforts to understand them are being made by investigating the kinetics and thermodynamic properties of the protein. The solubility of the protein is a central thermodynamic property governing the equilibrium between the non-aggregated forms and the aggregated forms [10]. To study the solubility, it is necessary to be able to study both aggregated and non-aggregated states. One method to study the non-aggregated state is with an enzyme-linked immunosorbent assay (ELISA). The aim of this project was to develop an ELISA for the monomeric form of the Aβ42 peptide. The method was based on a previous ELISA described in Hellstrand et al.(2009) [8]. The goals of the method development was for the ELISA to be sensitive and to be selective for the Aβ42 monomer. With the method, an Aβ42 aggregation kinetics experiment described in Hellstrand et al. (2009) was reproduced. The method was developed for Aβ42 in a buffer environment, but the assay was also tested with Aβ42 in an environment of cerebrospinal fluid (CSF).<br /> <br /> The method development was successful and the method showed satisfactory sensitivity and selectivity. Standard curves with linear regions between 1 and ∼30 nM Aβ42 were obtained. The limit of detection and limit of quantification of the method were shown to be in the low single-digit nanomolar range. The results from the aggregation kinetics experiment and the experiment described in the Hellstrand et al. (2009) paper varied slightly, possibly because of the ELISA being saturated or because of different fibril formations being achieved. The CSF experiments showed that unprocessed CSF has an interfering effect on the assay. https://lup.lub.lu.se/student-papers/record/9167772/file/9167991.pdf application/pdf 2102071 no 2024 eng amyloid beta amyloid beta 42 alzheimer's disease ELISA enzyme-linked immunosorbent assay amyloid beta 42 solubility amyloid beta aggregation biophysical chemistry Biology and Life Sciences Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/9167772/file/9167821.pdf application/pdf no 9167772 2024-06-24T15:28:03+02:00 2024-08-08T13:23:23+02:00 2024-08-08T13:23:23+02:00

oai:lup-student-papers.lub.lu.se:9167894 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Lucas Andersson author 9167891 Roberto Mastio supervisor Department of Chemistry v1000647 department The enzyme dermatan sulfate epimerase 1 epimerizes glucuronic acid on chondroitin sulfate into iduronic acid giving dermatan sulfate resulting in increased flexibility of the glycosaminoglycan. The increased flexibility results in changed interactions with some proteins such as growth factors, cytokines, and angiogenic factors, and recent studies suggest that it also plays an important role in the process of tumorgenesis. The over-representation of iduronic acid, or elevated levels of the enzyme is believed to be related with tumor growth primarily in breast cancer cells. By inhibiting dermatan sulfate epimerase 1 the over-representation of dermatan sulfate can be adjusted and the aim for this project is to find a suitable glucuronic acid derivative for further investigations of such an inhibitor. Previous projects have been focused on changing the C1 sidechain while this project is aiming to further investigate the inhibitory effects of substrate with new sidechain at the C4 position. Människan livnär sig på bland annat kolhydrater, dessa är essentiella för kroppen och utöver att förse oss med energi är de även viktiga i cellulär uppbyggnad och cellulär kommunikation. Kolhydrater fungerar som bränsle många av kroppens viktigaste funktioner, såsom centrala nervsystemet, vita blodkroppar och celler i hjärnan. Detta arbete fokuserar på polysackariden kondroitin/dermatansulfat där flexibiliteten av denna kedja påverkas av förhållandet mellan dessa två former. Den ökade flexibiliteten skapar bättre interaktioner med andra proteiner vilket kan påverka tillväxt av tumörer eller ge upphov till vävnadssjukdomar. Enzymet dermatan sulfat epimeras 1 konverterar kondroitinsulfat till dermatansulfat och felaktig enzymatisk aktivitet av detta enzym ligger till grund för de oönskade effekterna nämnda ovan. Detta projekt går ut på att undersöka en möjlig inhibitor till enzymet dermatan sulfat epimeras 1 för att kunna motverka cancer och vävnadssjukdomar. Tidigare försök har visat att en inhibitor som utgår från glukos har haft starkast effekt och arbetet har utgått från denna molekyl. Medan tidigare försök fokuserat på nya grupper i position C1 har detta arbete fokuserat på position C4. 2024 eng Organic chemistry Glycosaminoglycan Inhibiting Dermatan Sulfate Epimerase 1 Chemistry 9167894 2024-06-24T17:36:26+02:00 2024-06-27T08:34:39+02:00 2024-06-27T08:34:39+02:00

oai:lup-student-papers.lub.lu.se:9168591 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Anette Hansen author 9168589 Christina Wegeberg supervisor Dr. Petter Persson supervisor Department of Chemistry v1000647 department First-row transition metal complexes are considered a more sustainable and cheaper alternative to ruthenium in photoredox-active complexes. However, the fast excited state relaxation of complexes based on first-row transition metals hinders direct replacement of Ru(II) with its 3d6 counterparts Mn(I) and Fe(II). Diisocyanide ligands have previously been used to achieve photostable 3d6 complexes while also improving MLCT lifetimes in Cr(0) and Mn(I) complexes. In the current project, the impact of ligand optimisation on the excited states of Mn(I) and Fe(II) complexes is studied through a new diisocyanide ligand with an electron deficient backbone. Steady-state and transient absorption spectroscopy, infrared spectroscopy and cyclic voltammetry indicate that the MLCT energy decreases as a result of LUMO stabilisation without impacting the excited state dynamics of the complexes. However, the new tris(diisocyanide) 3d6 complexes photodissociate under irradiation into their MLCT bands. Inspired by the promising properties of Fe(III)-carbene complexes, the LMCT transition in a 3d5 Mn(II) tris(diisocyanide) complex was also explored. Mn(II)-isocyanide complexes are known to be unstable in solution, which was also the key finding in this work. In summary, this project provides valuable insight into the design of first-row transition metal isocyanide complexes and their photostability. Sunlight is a widely available and renewable source of energy. Therefore, there is a large interest in utilising sunlight in various processes including solar cells and photocatalysis. Transition metal complexes can absorb light, which gives them their oftentimes strong colours. Furthermore, the absorption of sunlight allows practical application of such complexes as photosensitisers in dye-sensitised solar cells and photocatalysis. Especially ruthenium complexes are known to be very well-performing for the aforementioned purposes but, unfortunately, ruthenium is a scarce metal on Earth. From both a sustainability and a cost point of view, it is therefore sensible to replace ruthenium with more abundant transition metals.<br /> The transition metal manganese is nearly one million times more abundant than ruthenium. In previous research, manganese-isocyanide complexes have shown potential as photosensitisers. My aim is to continue this exploration and try to optimise the properties of manganese-isocyanide complexes as photosensitisers. Iron is even more abundant than manganese, but iron-isocyanide complexes are less explored and understood. In this project, I also synthesised iron-isocyanide complexes and gained new insight about them. <br /> The manganese and iron complexes I have synthesised are not terrific photosensitisers – in fact they fall apart when light is shone on them. Therefore, the new complexes have no practical applications as photosensitisers, but they have given valuable and fundamental knowledge about what considerations that should be made when designing more sustainable transition metal complexes in the future. 2024 eng Fe(II) isocyanide Mn(I) Mn(II) photosensitiser photodissociation chemical physics Chemistry 9168591 2024-06-26T09:23:04+02:00 2024-06-27T08:37:01+02:00 2024-06-27T08:37:01+02:00

oai:lup-student-papers.lub.lu.se:9169251 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ahmed Aadl Alsalehe author 9169249 Lintang Hizbullah supervisor Department of Chemistry v1000647 department The malaria parasite causes the deadly malaria disease that claims thousands of lives every year. While antimalarial drugs such as chloroquine and artemisinin exist, there is a continuous race to overcome the resistance developed by malaria parasites against drugs. Four new chromium complexes have been synthesized and characterized. The complexes contain quinoline structures with four different substituents at the 6- or 7-position with resemblance of quinoline part of the drug chloroquine. The complexation step was the coordination of the ligands with chromium hexacarbonyl to synthesize different metal complexes. All complexes have been characterized by 1H-NMR, UV-Vis, and FTIR spectroscopies.The malaria parasite causes the deadly malaria disease that claims thousands of lives every year. While antimalarial drugs such as chloroquine and artemisinin exist, there is a continuous race to overcome the resistance developed by malaria parasites against drugs. Four new chromium complexes have been synthesized and characterized. The complexes contain quinoline structures with four different substituents at the 6- or 7-position with resemblance of quinoline part of the drug chloroquine. The complexation step was the coordination of the ligands with chromium hexacarbonyl to synthesize different metal complexes. All complexes have been characterized by 1H-NMR, UV-Vis, and FTIR spectroscopies. Malaria is a deadly disease caused by malaria parasite. The parasite lives its life cycle between humans and mosquitoes. In 2022, the world health organization estimated that there were 249 million malaria cases and approximately 608 000 malaria deaths. This disease claims the lives of thousands of people every year. Scientists and researchers have been searching for treatments for this deadly disease since ancient times. One of the most important drugs discovered to treat malaria disease was chloroquine. Despite the effectivity of chloroquine, some of the malaria parasites have developed resistance to it. <br /> In this study, four new compounds were synthesized to overcome this resistance. The new compounds were examined by different chemical and physical methods to conform their structure. 2024 eng Inorganic chemistry Anti malaria drug Chromium complexes Ligand synthesis Organic chemistry Chemistry 9169251 2024-06-28T00:17:50+02:00 2024-07-03T08:58:24+02:00 2024-07-03T08:56:24+02:00

oai:lup-student-papers.lub.lu.se:9169991 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Ida Odefalk author 9169988 Professor Mikael Akke supervisor Angus J.Robertson supervisor Department of Chemistry v1000647 department This study aims to present a protocol for pH determination in biomolecular NMR samples by evaluating the pH dependence of chemical shifts in the most commonly reported buffer molecules in the BioMagResBank (BMRB). Whilst there exists multiple methods and protocols for intrinsic NMR pH determination and various molecules have been proposed as pH indicators, there is no method to determine the actual pH of an older NMR sample/spectrum. Hence, this study studies commonly used bio-buffer molecules and evaluates MES, HEPES, bis-TRIS-propane and bis-TRIS as pH indicators by performing NMR titration experiments to create a protocol that is applicable to older data were these molecules are included. All molecules proved to have some pH dependent 1H chemical shift perturbations in the total pH range of 4.7 to 10.0. The data was fitted to a modified version of the Henderson Hasselbach equation. To receive a result that can be intrinsically referenced, two peaks were paired up as the δobs variable and the parameters were calculated for each pair of signals. The fitting resulted in the calculation of parameters δHA and δA for part of the 1H chemical shifts of the MES molecule, all 1H chemical shifts of the HEPES molecule and part of the 1H chemical shifts of the bis-TRIS-propane molecule. However, it was found that the bis-TRIS molecule was not suitable as a pH indicator, at least not in this internal chemical shift difference approach. NMR (nuclear magnetic resonance) spektroskopi, är en omfattande teknik som har många applikationer inom kemin. Det kan användas inom organisk kemi som stöd och underlag till strukturbestämning av molekyler, men framför allt finns det många tillämpningar inom biokemi och molekylärbiologi där tekniken utnyttjas; NMR är mycket användbart för att studera biomolekylers strukturer och biologiska processer. <br /> Det fysiologiska pH-värdet i kroppen är 7,4 och många biokemiska processer är väldigt känsliga för små pH förändringar. När biokemiska processer studeras är det därför viktigt att veta exakt vad provet som studeras har för pH, vilket inte alltid är konstant. Sammansättningen av ett prov kan variera vid interaktioner mellan analyter och ofta undersöks någon process, så som aggregering av proteiner, detta påverkar provets pH. Att därför enbart veta provets pH innan mätning är inte tillräckligt – särskilt inte eftersom ett NMR experiment ibland kan sträcka sig över dagar och ibland upp till flera veckor. <br /> I denna undersökning utvecklas därför ett protokoll som möjliggör bestämning av pH med hjälp av enklare NMR experiment. Genom att genomföra en så kallad NMR titrering, där korta NMR experiment utfördes på samma prov vid flera olika pH-värden, kan en korrelation mellan pH och kemiskt skift bestämmas. Denna korrelation beskrivs med hjälp av den så kallade Henderson Hasselbach ekvationen. <br /> Detta har genomförts tidigare och ett antal molekyler har presenterats som lämpliga pH indikatorer, men i denna undersökning analyseras vanligt förekommande buffer molekyler som framtida pH indikatorer. En stor fördel med att utvärdera dessa vanligt använda molekyler är att de redan finns i många prover – både i nya och gamla mätningar – vilket innebär att resultatet är applicerbart även på äldre resultat från tidigare mätningar. <br /> Fyra molekyler undersöktes; MES, HEPES, bis-TRIS-propan och bis-TRIS. De tre förstnämnda visades vara lämpliga pH indikatorer, då pH hade en tydlig påverkan på deras respektive kemiska skift. Den erhållna datan från samtliga molekyler passades till Henderson Hasselbach ekvationen och korrelationen mellan pH och kemiskt skift bestämdes. 2024 eng biomolecular NMR buffer molecules NMR spectroscopy pH measurement Chemistry 9169991 2024-07-03T07:48:15+02:00 2024-07-03T10:45:43+02:00 2024-07-03T10:45:43+02:00

oai:lup-student-papers.lub.lu.se:9170986 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Martin Sandberg author 9170984 Eric Anguera Aixalà supervisor Department of Chemistry v1000647 department This project aims to use the Tröger’s base molecule to synthesize a linearly heptakis-Tröger’s base. The furthest this project reached was the synthesis of the linearly fused tris-Tröger’s base analogue. To reach this compound, nine synthesis steps were preformed starting with an aniline analogue. The aniline was first halogenated and then condensed into the first Tröger’s base analogue. This was followed by a dehalogenation, amination, amine protection, alkylation of the benzylic position and lastly separation of two diastereomers by dry column vacuum chromatography. After this point, two more reactions are preformed including a deprotection and protection reaction before the final condensation reaction was preformed to yield the linearly fused tris-Tröger’s base analogue. Supramolecular chemistry can be thought of as the chemistry that studies how molecules interact with each other to form large and complex structures. These large molecular structures can be made so that they have specific desired properties or shapes that can be utilized for a specific purpose, such as transporting smaller molecules around our bodies. To make a supramolecule, a good starting block is needed and one of these is the Tröger’s base molecule. This specific molecule is suitable because of its unique structure that resembles a V shape, gives rise to a cavity in which molecules that possess specific properties can be attached to. In this project the Tröger’s base molecule has been used as a starting block to make a final molecule consisting of two of these molecules connected in a straight chain, a linearly fused tris-Tröger’s base analogue. <br /> <br /> This project has followed the synthetic pathway previously developed by the Wärnmark group. The first part of this project consisted of making several modifications of the Tröger’s base molecule in such a way that the two diastereomer of Tröger’s base could be separated and so that multiple of these molecules could be connected in a straight chain. Diastereomer are two molecules that are made up of the same atoms and connected in identical ways but arranged differently in 3D-space. The second part thus consisted of connecting two of these modified molecules in a chain. 2024 eng Organic chemistry Tröger's base Supramolecular Chemistry Dry column vacuum chromatography Chemistry 9170986 2024-07-28T16:11:13+02:00 2024-08-12T12:34:19+02:00 2024-08-12T12:34:19+02:00

oai:lup-student-papers.lub.lu.se:9170996 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Christian Wertheimer author 9170993 Jesper Schwarz supervisor Department of Chemistry v1000647 department Iron is one of the most versatile transition metals on the planet, and it is the fourth most plentiful element in the crust on earth. It is among numerous things, endogenously, vital to the human organism, and exogenously, safe to handle. When combined with ligands to form a complex, it exhibits qualities that of catalysing light into viable energy, which can be harnessed to sustain different electrical apparatuses. To evolve this capability so that it reaches the highest potential is a major goal. Järn är en metall som finns i överflöd på vår jord. Den är säker, är ett av de mest använda grundämnena genom den mänskliga historien och finns naturligt inom varje människa. När den kombineras med andra atomer kallade ligander för att bilda ett så kallat komplex, kan den ifall den får lov att absorbera ljus, uppvisa fotokatalytiska egenskaper. Detta innebär att den omvandlar det inkommande ljuset till energi som kan appliceras till olika elektriska apparater. För att maximera den utgående energin måste de exciterade tillstånden förlängas. 2024 eng Organic chemistry Hydrogenation N-heterocyclic carbene Chemistry 9170996 2024-07-29T15:26:26+02:00 2024-08-12T12:35:45+02:00 2024-08-12T12:35:45+02:00

oai:lup-student-papers.lub.lu.se:9055297 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Azemina Bajramova author 9055295 Peter Spégel supervisor Department of Chemistry v1000647 department Introduction: Superfruits have been promoted as nutrient-rich food that can improve your health, however, many scientists argue that the validation of the term is based on exaggeration of the limited studies that are available.<br /> <br /> Background: The chemical composition of a food is complex and there are many substances that can affect the human body. One such group of substances are fatty acids (FAs), which have been observed to contribute to both positive and negative health effects. This field is in need of more research on the FA composition of different fruits and of more comparative research between superfruits and more “common fruits”.<br /> <br /> Aim: The aim of this study is to quantitatively and qualitatively investigate the FA composition of three common fruits (bananas, apples, and strawberries) and three superberries (goji berries, white mulberries, and cranberries), and to compare their FA composition in order to detect any existing differences.<br /> <br /> Methods: The samples were prepared by freeze-drying, lipid extraction, and derivatization into fatty acid methyl esters (FAMEs). The FAMEs were then analysed with gas chromatography coupled to a flame ionization detector (GC-FID). Two different GC-columns were used in order to be able to detect all possible FAs. External calibration was used for the quantitative determination and the polyunsaturated fatty acid per saturated fatty acid (PUFA/SFA) and omega-6/omega-3 (ω-6/ω-3) ratios were used to compare samples.<br /> <br /> Results: The average total FA concentration ranged between 1.6 and 19.3 mg/g dry sample in the analysed samples. In general, most samples contained favourable FA compositions, with PUFAs as the major group, and preferable PUFA/SFA and ω-6/ω-3 ratios.<br /> <br /> Conclusions: In conclusion, there was no statistically significant difference (P &gt; 0.05) of the FA composition between more common fruits and superfruits. However, individual berries in both groups have been shown to contain fatty acid compositions that are of more nutritional value than others. A group of fruits and berries that have gained a lot of popularity in recent years are superfruits and superberries. They are described as “nutrient-rich food considered to be especially beneficial for health and well-being” in the Oxford English Dictionary. However, there is no legal definition. Research has suggested that superfruits and superberries can be good sources of some important nutrients, which is one argument that marketers use when selling exotic superfruits and berries, usually at a higher price. However, some scientists argue that the term superfruit actually is a marketing term and that marketers are exaggerating the limited research that is available. The aim of this project is therefore to determine the fatty acid composition and concentration in three common fruits and berries (apple, banana, and strawberry) and three superberries (goji berry, cranberry, and white mulberry). Another aim is to compare their fatty acid composition and to see if there is any difference that can support the claims marketers make. Common fatty acid classes are saturated, monounsaturated, and polyunsaturated fatty acids. The human body can synthesise fatty acids, except some essential fatty acids like linoleic acid and α-linolenic acid, which are omega-6 and omega-3 fatty acids, respectively. They need to be obtained from the diet, which is why they are called essential fatty acids. The ratio between omega-6 and omega-3 fatty acids has been associated with future risk of different diseases and can be used as a measure of which food has a better fatty acid composition. A ratio around 1:1 has been suggested to be the most beneficial for humans. The ratio between polyunsaturated and saturated fatty acids can also be used as a measure of the nutritional value of the fatty acid composition, where a high ratio is better. The fatty acid composition was determined with a gas chromatograph coupled to a detector. The gas chromatograph separates compounds based on boiling point and how polar they are. The samples were, however, first prepared by extracting the lipids and then converting them to a more volatile form. After identification of fatty acids and calculation of concentrations, it could be observed that most of the fruits and berries had a high ratio between polyunsaturated fatty acids and saturated fatty acids and that the omega-6/omega-3 ratio was between 1:1 to 5:1 in most cases. However, no differences in the fatty acid composition could be observed between the groups superberries and common fruits, although some individual fruits and berries in both groups showed better ratios than others. Overall, strawberry was observed to have a more favourable fatty acid composition when considering both ratios. The results led to the conclusion that there is no difference of the fatty acid composition between superberries and more common fruits and berries. https://lup.lub.lu.se/student-papers/record/9055297/file/9055303.pdf application/pdf 4282691 yes 2021 eng Analytical chemistry Comparative study Fatty acids Health impact Quantification Superfruits Chemistry 9055297 2021-06-16T11:21:11+02:00 2021-06-16T12:01:56+02:00 2021-06-16T12:01:56+02:00

oai:lup-student-papers.lub.lu.se:9055883 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Isak Svenningsson author 9055880 Balazs Franko supervisor Biotechnology (MSc) v1000284 department The use of biopolymers instead of traditional fossil fuel based and non-biodegradable polymers is seen as a positive step forward towards a more environmentally friendly future. This project investigates a granule product that is used in a dishwashing system with the aim of gaining knowledge about how it is affected by the storage in between uses and its biodegradability. The product is based on a known biodegradable polymer which is partially biobased. Experimental tests were performed to explore the effect of different pH values, in the pH range of foods, to give insight into how the granules could optimally be stored in between uses. Furthermore, biodegradation screenings were performed to investigate disposal options for the granules after they have been used. The results showed that a neutral pH value, 7, is preferred over a low pH, 3, during storage to minimize negative effects on the granules. Results from the biodegradation tests showed that the product is more degradable under aerobic conditions (in aerated soil and compost) than under anaerobic conditions (in anaerobic sludge). This could be further explored when looking into disposal options for the granules, but the relatively slow rate of degradation may be an obstacle. Att vissa plaster kan brytas ned med hjälp av mikroorganismer och deras enzymer i jord, kompost och andra biologiskt aktiva miljöer är det långt ifrån alla som vet. Dessa plaster, en del av de så kallade biopolymererna, kan brytas ned till väldigt små delar som organismerna sedan kan dra nytta av genom att de får i sig bland annat energi och kolväten för att fortsätta leva, växa och förökas. I denna studie, där man tittade på hur både biologiskt aktiva miljöer samt vattenlösningar med olika pH-värden påverkade en granulprodukt, visades en viktminskning hos vissa av de undersökta granulerna på omkring 12 % efter 60 dagar både i jord och kompost. Detta kan jämföras med endast 2.5 % i syrefritt slam från ett reningsverk vilket pekar på att syre, som fanns tillgängligt i jorden och komposten, är en viktig komponent i den omgivande miljön för att bryta ned granulerna.<br /> <br /> Granulerna är ca. 3 mm stora och används i ett diskmaskinssystem där de slår loss matrester från grovdisk. De är baserade på bland annat polybuten adipat-co-tereftalat, en biologiskt nedbrytbar biopolymer som är delvis baserad på förnybara resurser, och kalciumkarbonat. I dagsläget slängs granulerna till förbränning efter slutanvändning vilket gjorde att man ville undersöka om de kan göras av med på något annat sätt, till exempel komposteras, som är mer miljövänligt. Trots att resultaten visade att de faktiskt bröts ned i kompost och jord sågs det att nedbrytningen tar väldigt lång tid, vilket inte är optimalt. Det hade varit önskvärt att produkten bryts ned snabbare, men detta är svårt att få till när man samtidigt vill ha en produkt som inte ska slitas för mycket under sin användning. Vanligtvis behövs även certifikat för att produkter ska få komposteras industriellt, och dessa kräver att produkten ska brytas ner snabbare än vad som påvisades i denna studie. Det undersöktes även hur granulerna påverkades av vattenlösningar med olika pH-värden för att få information om hur granulerna bäst kan lagras mellan användningar. När granulerna tas ut från disksystemet för att lagras mellan användningar kan matrester finnas kvar vilket kan påverka pH-värdet på granulernas omgivning. pH-värden för mat ligger vanligtvis mellan 3-7 men utstickare såsom citronjuice och äggvitor kan ha pH-värden på 2-3 respektive 8-9, vilket<br /> utgjorde grunden till vilka pH-värden som testades i studien (3, 5, 7 &amp; 9). Resultaten, som visade att granulerna var lite mer resistenta mot vattenlösningar med neutrala än låga pH-värden, pekar på att man bör undvika förhållanden med låga pH-värden vid denna lagring. Studier som dessa är bra för att ta reda på hur man bäst kan behandla och ta vara på produkter som används i situationer där de kan påverkas negativt, för att därefter designa omgivningarna så att produktens livslängd kan förlängas. Trots att just denna produkt troligtvis inte kan komposteras på en industriell skala ses biopolymerer som är, helt eller delvis, baserade på förnybara resurser som ett steg framåt mot en mer miljövänlig framtid. Om fler polymerprodukter baseras på polymerer som är biologiskt nedbrytbara och/eller baserade på förnybara resurser kan detta vara ett positivt steg framåt i kampen mot planetens växande avfallshögar med sopor, sinande fossila resurser och förödande utsläpp av växthusgaser. https://lup.lub.lu.se/student-papers/record/9055883/file/9055907.pdf application/pdf 6946719 no 2021 eng polymerteknik biopolymer bioteknik Technology and Engineering Biology and Life Sciences Chemistry 9055883 2021-06-17T11:06:34+02:00 2021-06-29T10:02:33+02:00 2021-06-29T10:02:33+02:00

oai:lup-student-papers.lub.lu.se:9056197 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Mattias Tan author 9056195 Nitish Kumar Garg supervisor Department of Chemistry v1000647 department Due to problems associated with the use of fossil fuels, new, sustainable methods are needed to synthesize biofuels and chemicals from readily available biomass. In this project, we report a method to quantitatively convert biomass derived chemicals into value-added chemicals and biofuels using hydrosilylation. Cost effective silanes, such as PMHS and TMDS, which are biproducts in silicone industries, were used as reducing agents together with B(C6F5)3, which is a commercially available catalyst. This metal-free reaction method is carried out in room temperature under mild conditions and analyzed with gas chromatography and NMR spectroscopy. Biomass derived chemicals such as levulinic acid (LA), γ-valerolactone (GVL), 2-methyltetrahydrofuran (2-MTHF), alkyl levulinates, 2-pentanol (2-POH) and valeric acid (VA) are defunctionalized into chemicals with reduced oxygen content. These chemicals, GVL, 2-MTHF, 2-POH, 1,4-pentanediol (1,4-PeD) and pentane/pentene, were successfully synthesized in a high yield. We discovered that a complete deoxygenation of biomass derived chemicals to pentane/pentene could be done in one-step hydrosilylation and even possible under 1h. This synthetic pathway has not been explored before and opens a new sustainable way to produce biofuel chemicals from biomass derived chemicals. As this is still a new reaction pathway, it still needs to be optimized and explored further with different biomass derived compounds. For centuries, humans have used fossil fuel and the growing consumption has caused many problems. The combustion of fossil fuel releases excess CO2 into the atmosphere and contributes to global warming. In addition, fossil fuel is a limited supply. The carbon from fossil fuel comes from animals and plants decaying for several million years and accumulates underground as crude oil, natural gas and coal, which we extract for fuel production. The combustion releases the accumulated carbon from underground and introduce it to the natural carbon cycle. Because of this ever-growing issue, sustainable ways of producing chemicals and biofuel are in focus. Instead of using chemicals that are limited and contribute to increased CO2 in the atmosphere, a renewable resource such as biomass, which is carbon neutral, would be a good solution and substitution for fossil fuel. From biomass we can extract polymers and convert it to many useful chemicals and biofuel.<br /> From biomass the lignocellulose is extracted for its ability to reduce to chemicals with less oxygen content. The lignocellulose is made up of carbohydrate polymers such as cellulose and hemicellulose, but also of aromatic polymers like lignin. These polymers are then broken down to less complex molecules like glucose and fructose, which then can be converted to different platform chemicals (chemicals which are used to produce many value-added chemicals) like levulinic acid, which is 1 of the top 12 chemicals used as building blocks for different chemicals (figure 1).<br /> <br /> Figure 1. Cellulose which is extracted from biomass and is converted to platform chemicals like levulinic acid.<br /> <br /> From levulinic acid, many chemicals can be synthesized and the main method for doing so is using hydrogenation. Chemicals like γ-valerolactone (GVL), 2-methyltetrahydrofuran (2-MTHF) and alkyl levulinates can be used as biofuels, 2-pentanol (2-POH) is used as solvent, 1,4-pentanediol (1,4-PeD) is used as plasticizer for rubber, cosmetic and electrical equipment, to name a few. The use of hydrogenation involves high pressure of H2 and high temperature together with noble metals, such as iridium and ruthenium, as catalyst. This method has some drawbacks such as the high temperature, high pressure, and the use of noble metals. Another method called hydrosilylation, which has been rarely used to defunctionalize biomass chemicals, uses silanes as reduction agent. The advantages with hydrosilylation are that it can be done under mild condition, without noble metal catalyst and could be used as substitution to hydrogenation. <br /> <br /> The aim of this project is to explore hydrosilylation of biomass derived chemicals, like levulinic acid and levulinates, into value-added chemicals and biofuel. This also includes other biomass derived chemicals like γ-valerolactone (GVL), 2-methyltetrahydrofuran (2-MTHF), 2-pentanol (2-POH) and valeric acid (VA). The hydrosilylation is done with polymethylhydrosiloxane (PMHS), tetramethyldisiloxane (TMDS) and triethylsilane (Et3SiH) as reduction agent and a metal free catalyst, B(C6F5)3. The silanes used are air stable and both PMHS and TMDS are biproducts from the silicone industry, which makes them cheap. The reactions are carried out under mild conditions. The products of aim are GVL, 2-MTHF, 2-POH, 1,4-pentanediol and hydrocarbons like pentane/pentene. 2021 eng Hydrosilylation Biomass derived chemicals Value-added chemicals Inorganic chemistry Chemistry https://lup.lub.lu.se/student-papers/record/9056197/file/9056207.docx application/zip no 9056197 2021-06-17T18:54:16+02:00 2021-06-28T11:50:23+02:00 2021-06-28T11:50:23+02:00

oai:lup-student-papers.lub.lu.se:9056417 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Agnes Hermansson author 9056414 Niklas Andersson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Chromatography is a separation technique frequently used in the purication of<br /> medicinal drugs. In studies and project at the department of chemical engineering at Lund University a large amount of data have been generated through the use of their research software Orbit and their ÄKTA chromatography system. Methods have been developed for visualization of this data but there is currently no good way to have an overview of the data in their database. The aim of this master thesis was to developed a graphical user interface (GUI) in order to provide an overview of historical data generated in earlier projects as well as develop new methods for<br /> visualization and analysis. The nal version of the GUI consists of four main parts: 1) A list widget with the possibility to sort and work with data, 2) A search bar for querying a particular set of data, 3) Tabs, nine in total, with windows for plotting, 4) Push buttons for plotting data and clearing the plot windows. A pop-up window with an overview of a run can be generated by double-clicking an item in the lefthand list of the GUI. A simpler design was also considered during this project but was discarded as it became more dicult to sort between runs. The nal version of the GUI is, in large part, ready to be used but further improvements in terms of general stability needs to be considered for optimal functionality. Three new plot methods for visualizing total pool area and volume as well as a method for cycle<br /> analysis in periodic counter-current chromatography (PCC) were developed. The<br /> cycle plots gave results of varying quality; some runs showed a regular cycle patterns whereas none could be found in others. In particular, the plots for total pool area and volume could give a misleading impression due to a few large jumps in volume or area between runs, making it looks like there is little or no variation between the lower values. A New Way of Interacting with Chromatography Data<br /> <br /> With no easy way of getting a bird&#39;s eye view of the experimental data generated in previous chromatography projects at the department of chemical engineering at Lund University. This master thesis ventured out to put together a tool to x this issue. A graphical user interface (GUI) was developed with the aim of compiling the earlier work done in the area of chromatography at the institution into a single tool. By extracting chromatography data from the MongoDB database the user is able to<br /> look at historical data as well as data being uploaded in real-time (by updating the GUI). The nal product is able to manage sets of data, plotting the same data in a variety of ways, as well as searching the database. Additionally, three new methods for visualizing the experimental data was created in order to provide the user with more options of analysis. The idea behind developing this GUI was to make it easier and quicker to visualize and analyse large amounts of data in the form of plots, tables and gures. This GUI also tackles the problem of not knowing how to code yourself, i.e. using a GUI requires absolutely no prior knowledge of any programming language in order to use it. Previously, the only way only way to look at the plots available in the GUI was to either run a script of code or create the methods yourself. At the moment of writing, the ability to analyze and process data through the GUI is literally just a few keystrokes away. Furthermore, the relevance of creating a GUI is also evident when it comes to research. Now, researchers can focus on the task of analysing data instead of trying to invent ways to visualize it since the GUI already provides the user with this. It is quicker to work with large amounts of data using the GUI, freeing up time for other areas of focus. Hopefully, this will come in handy in that it frees up time for other areas of research. Visualizing and analyzing data is a very important research task and should not be regarded lightly, but any tools that can automate routine parts of this work are always a convenient addition. The GUI was developed using the framework PyQt5, the NoSQL database MongoDB as well as the research software Orbit which has been developed for controlling chromatography systems at the department of chemical engineering at Lund University. https://lup.lub.lu.se/student-papers/record/9056417/file/9056420.pdf application/pdf 2045717 no 2021 eng GUI graphical user interface PyQt5 Orbit Chromatography data visualization chemical engineering Chemistry 9056417 2021-06-18T10:05:10+02:00 2021-07-06T10:14:05+02:00 2021-07-06T10:14:05+02:00

oai:lup-student-papers.lub.lu.se:9056857 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH3 Gabriella Björkengren author 9056855 Pär Söderhjelm supervisor Associate Professor Günther H.J. Peters supervisor PhD student Suk Kyu Ko supervisor Biophysical Chemistry v1000649 department The purpose of this project was to investigate protein stabilization by formulation excipients during the process of freeze-drying using Molecular Dynamics (MD) simulation. A recombinant therapeutic protein, Reteplase, was used as a model and the study focused on a comparative analysis of two excipients, arginine and tranexamic acid (TXA), as included in commercially available formulations of Reteplase. The simulation of freeze-drying was divided into five consecutive steps based on the conditions applied to the system: room temperature, freezing, primary drying, secondary drying and reconstitution at room temperature. Protein conformational changes and the existence of aggregation-prone regions (APRs) were investigated, as to assess the conformational stability during freeze-drying. The relevant stabilization mechanisms were analyzed with respect to protein-excipient interactions and the nature of preferential interaction. The study found a modest degree of conformational instability of Reteplase, which was mainly attributed to the tertiary structure level and effectively reduced in the presence of either arginine or TXA. In this regard, arginine was effective at a lower concentration than TXA. The stabilization mechanism was associated with preferential binding to exposed protein residues, mainly mediated via ionic interactions. A higher strength of interaction was observed for TXA, which was suggested as a consequence of its high accessibility to the protein surface and its chemical character, which enables multiple types of interactions. A correlation was suggested between the stabilization of certain APRs and selective protein-excipient interactions. The results from a parallel study of another protein, Granulocyte Colony-Stimulating Factor (G-CSF), was used provide basic level support for the impact of protein surface charge on the proposed modes of stabilization. The conformational space of Reteplase was explored through the application of cluster analysis to Accelerated Molecular Dynamics (aMD) simulation, which provided further support for the good stability of secondary structure elements. The colloidal stability of Reteplase was investigated in a preliminary small-scale study using Coarse-grained (CG) MD simulation. Initial results suggest a tendency of arginine to reduce the strength of unique proteinprotein interactions, as to prevent the experimentally observed aggregation-propensity of Reteplase. Freeze-drying is a widely used approach to improve long-term stability of protein-based biopharmaceuticals. The process involves multiple challenges and proper formulation design is a key component in product development to overcome these issues. Small molecule excipients have a vital function in protection of the protein. A thorough investigation of the relevant stabilization mechanisms is essential for optimization of screening procedures. Within these frames, computational modelling is an important tool to provide the necessary molecular level insight. https://lup.lub.lu.se/student-papers/record/9056857/file/9056860.pdf application/pdf 39090378 no 2021 eng Biophysical chemistry protein stability molecular dynamics simulation Chemistry https://lup.lub.lu.se/student-papers/record/9056857/file/9056862.pdf application/pdf no 9056857 2021-06-20T23:14:55+02:00 2021-06-28T11:57:52+02:00 2021-06-28T11:57:52+02:00

oai:lup-student-papers.lub.lu.se:9056921 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Axl Eriksson author 8993112 Jens Uhlig supervisor Department of Chemistry v1000647 department The interest in energy sources has shifted over the years toward sustainable energy, which has popularized the research in solar cells (among other energy sources). One of the key topics in solar cell research is the power conversion efficiency, and to understand how this can be improved one must understand the photo-induced dynamics of the solar cell material. In this thesis, we modeled the conduction band dynamics in CZTS kesterite nanoparticles using TA – data from a previous experiment. The modeling was performed using the optimization functions in the plot_func project. We managed to create a model of 6 states and 7 processes, assigned the states to time-and wavelength region in the spectra. Based on our results combined with results from literature, we also identified these states and processes. Of these 7 processes, we modeled one as Auger recombination which has not been observed directly before, to the author’s knowledge. Due to confinement effects, the Auger recombination could be written as a second order process (instead of a third order) allowing us to only consider the electron concentration. The same could be said about the recombination from the bottom of the conduction band, reducing it into a first order reaction instead of a second order. We also modeled shallow and deep trap states and tried to model the filling of these, and calculated the number of charge carriers in deep-and shallow trap states. The trap-assisted recombination from shallow traps was also reduced to a first order process probably due to localization of electrons in these states. To reliably model the main processes in CZTS kesterite with only TA – data is quite an achievement if done successfully, as it reduces the number of required measurements, and we see this attempt as a first step towards this goal. Green and renewable energy sources have over the years seen an increased interest in research, where solar cells have received special attention. Solar cells consist of several layers, or parts, with different functions and this thesis focuses on the material that makes up the so-called active layer. The active layer is where sunlight is absorbed, exciting electrons to then generate a current to the other layers. Therefore, it is important for the active layer to have a high absorption and power conversion efficiency (efficiency to generate electrons with the energy of the sunlight).<br /> <br /> To improve this efficiency, we need to first understand what actually happens in the active layer when light is absorbed. Generating a current is one process, that we want, but other processes<br /> that we do not want, occur too. To gain this understanding, we rely on experimental data from transient absorption (TA) measurements, from which we can see the generation of electrons and the processes these participate in. As the processes occur, the absorption of light in the material changes in strength and in wavelength, and since different processes occur at different speeds, the absorption difference signal will appear at different wavelength-and time regions that consist of different strengths.<br /> <br /> With the knowledge of signal strength, wavelength-and time region we can use the data from the TA – measurement to create a model, a representation, of what happens in the active layer. This way, we point out the sources (processes) of any reduction in power conversion efficiency. In this master thesis, we use TA – data to model the processes in Cu2ZnSnS4 (CZTS) of the kesterite structure. With this model, we manage to observe 7 different processes involving 6 different states that we assign to a wavelength-and time region in the spectra. Gröna och förnybara energikällor har under åren sett ökad uppmärksamhet inom forskning och utveckling, där solceller har fått särskild uppmärksamhet. Solceller består av flera lager, eller komponenter, med olika funktioner och den här tesen fokuserar på material som bygger upp det aktiva lagret. Det aktiva lagret är det som absorberar solljus vilket exciterar elektroner till att bilda en elektrisk ström till de andra lagren. Därför är det viktigt att det aktiva lagret har en hög absorption och effektivitet med att omvandla solljus till en elektrisk ström.<br /> <br /> För att förbättra denna effekt, behöver vi först förstå vad som händer i det aktiva lagret när ljus absorberas. Att bilda en elektrisk ström är en process, som vi vill ha, men det sker även andra processer som vi inte vill ha. För att få denna förståelse, använder vi experimentell data från transient absorptionsmätningar som låter oss se hur solljuset genererar elektroner och vilka processer dessa elektroner deltar i. Allt eftersom processer sker, absorptionen av ljus ändras i styrka och våglängd, och eftersom olika processer sker olika fort ser vi signalen för ändring i absorption vid olika våglängds-och tids regioner som också har olika styrkor.<br /> <br /> Med kunskapen om signalstyrka, våglängds-och tidsregion kan vi använda datan från transient absorptionsmätningarna till att skapa en modell, en representation, av vad som händer i det aktiva lagret. På det här sättet, ser vi vilka processer som orsakar minskningen i effektivitet. I det här masterarbetet, använder vi transient absorptionsdata till att modellera processerna i Cu2ZnSnS4 (CZTS) av kesteritstrukturen. Med den här modellen lyckas vi identifiera 7 olika processer som involverar 6 olika tillstånd som vi tilldelar en våglängds-och tidsregion i spektrumen. 2021 eng CZTS kesterite transient absorption dynamics chemical physics Chemistry 9056921 2021-06-21T09:31:09+02:00 2021-06-30T10:32:09+02:00 2021-06-30T10:32:09+02:00

oai:lup-student-papers.lub.lu.se:9056991 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Yi Wang author 9056882 Anne Nilsson supervisor Juscelino Tovar supervisor Mohammad Mukul Hossain supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Consumers are becoming interested in oats as a healthy food. Several studies have investigated the impact of oats components on human metabolism. The purpose of this project is to study the influence of oat polar lipids on human cardiometabolic variables, which focused on four cardiometabolic variables, these were postprandial responses of glucose, insulin, cortisol, and subjective appetite variables. A randomized cross-over human study in 20 healthy subjects was conducted, in which subjects were assigned to consume test or reference breakfasts in random order. Test breakfasts consisted of white wheat bread (WWB) with spreads consisted of oat lipids containing 15 g polar lipids (OL), rapeseed oils (Raps), and a mixture of oat lipids (8.3 g) and rapeseeds oil (Mix). A plain WWB without lipids was included as a reference breakfast. All test breakfast contained similar amounts of lipids. Cardiometabolic test variables were determined at different times postprandially. The results showed that OL resulted in the lowest increase in concentrations of glucose and insulin after breakfast. The effect of oat polar lipids on cortisol wasn&#39;t statistically significant, however, this could be due to too few test subjects included in the study. Three appetite related variables: fullness, hunger, and desire to eat, were also measured. OL resulted in the lowest ratings of hunger and desire to eat. It is concluded that oat polar lipids are effective in decreasing postprandial blood glucose and insulin concentrations. At the same time, OL also has a beneficial effect on appetite variables, indicated by increasing satiety and decreasing hunger. The results provide information regarding oat polar lipids as possible new bioactive compounds with preventive potential against obesity and type 2 diabetes. People’s health is negatively affected due to excessive consumption of processed foods and a sedentary lifestyle, which result in an increase of the proportion of people suffering from metabolic syndromes, as well as the risk of cardiometabolic related diseases. Dietary intervention is one of the most economical and convenient methods to reduce the risk of illness, since diet is an indispensable part of daily life. Oils are a common and essential part of the daily diet, so it is feasible to keep health by eating healthier oils, such as oat polar lipids. Oat polar lipids are extracted from oats. It has great potential to become an emerging healthy food, there is not much research on the effects of oat lipids on the human body. Therefore, the aim of this project was to study the influence of oat polar lipids on human cardiometabolic variables, including four sections: postprandial glucose response, insulin, cortisol, and subjective appetite variables. <br /> A human study in 20 healthy subjects was conducted for investigation. Three test breakfasts (oat polar lipids, rapeseed oils and the mixture of oat polar lipids and rapeseed oils) and a reference breakfast (white wheat bread) were prepared for them. The human study lasted 330 minutes. At 8:00 am, the subjects came to the laboratory at fasting state. Firstly, fasting blood glucose was measured through fingertip blood collection and extra blood samples were collected for insulin and cortisol analysis. After that, they got one of the test breakfasts or the reference, which was consumed in around 12 min. Then their blood glucose was tested repeatedly, and blood samples were collected. After 210 minutes, the subjects ate a standardized lunch (meatball sandwich). Then the measurement of blood glucose and collection of blood samples were continued until the end of the test day. At the same time, the subjects needed to fill out the appetite survey based on their true feelings, which contains three variables: fullness, hunger and desire to eat. <br /> The results showed that the effect of oat polar lipids in lowering blood glucose was significantly better than the other oils and it also increased satiety and reduced hunger compared with other test products. Therefore, can be recommended to people with metabolic syndrome can supplement their diet with oat polar lipids, which will help them relieve symptoms. Healthy people can also be recommended to consume oat polar lipids to reduce the risk of obesity and cardiovascular disease and other related diseases. However, people have to be aware of that irrespective of the type of oil, any oil that is consumed in excess may result in weight gain. https://lup.lub.lu.se/student-papers/record/9056991/file/9056998.pdf application/pdf 3112776 2021-10-01 no 2021 eng oat polar lipids bio-actives metabolic diseases applied nutrition food chemistry Chemistry 9056991 2021-06-21T10:50:17+02:00 2021-10-01T03:41:07+02:00 2021-06-29T10:31:40+02:00

oai:lup-student-papers.lub.lu.se:9057173 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Tove Rasmusson author 9057169 Charlotta Turner supervisor Arwa Mustafa supervisor Department of Chemistry v1000647 department Introduction: In this work, oil from Baobab seeds was extracted and analysed in order to determine how much oil the seeds contain and the fatty acid composition of the seeds. <br /> <br /> Background: A lot of seeds go to waste when either producing drinks of Baobab fruit or simply eating the fruit raw. Thus, it would be favourable if it was possible to produce a product based on the left-over seeds, suitably on the oil they contain. Currently there is a knowledge gap concerning how much oil Baobab seeds contain and also what the fatty acid composition of the oil is. The challenge in the field is to optimize the extraction of Baobab oil to achieve the highest possible yield in order to develop the supercritical carbon dioxide extraction for usage at an analytical scale. <br /> <br /> Aim(s): How much oil does the seeds contain? What is the fatty acid composition of the Baobab seeds? <br /> <br /> Methods: The lipids were extracted from the Baobab seeds through supercritical fluid extraction, SFE. The extraction was optimized by varying the density and temperature to achieve the highest possible yield. Gravimetry was used to determine the extracted amount. A central composite design, CCD, was used as experimental design. A derivatization step was performed to convert the extracted oil to fatty acid methyl esters, FAMEs. The FAMEs were analysed with a gas chromatography/flame ionization detector, GC/FID, with the aim of determining the fatty acid composition. <br /> <br /> Results: The result of the extraction optimization showed that a higher temperature and a higher density generated a higher yield. Highest yield of 6.6 weight % was obtained at 48 ºC and 0.9 g/ml. The GC/FID analysis showed that the Baobab oil contained a wide variety of both saturated and unsaturated fatty acids.<br /> <br /> Conclusion: Within the range of the SFE optimization a maximum of around 6 % of oil could be extracted from the seeds. The fatty acids that could be found in the oil were the following: stearic, arachidic, behenic, lignoceric, margaric, pentadecyclic, α-linolenic and linoleic acid. Baobab är ett träd som främst växer i Afrika, men även förekommer i östra Indien, Sydamerika och Australien. På träden, som kan bli upp till 20 meter höga, växer frukten Baobab. I vardagligt tal brukar frukten benämnas som apbröd, detta eftersom babianerna gärna äter sig mätta på frukten. Det är inte bara babianer som tycker om frukten, utan även människor. Frukten är näringsrik då den innehåller mycket kostfiber, mineraler och antioxidanter. Dessutom finns det andra användningsområden för resten av trädet, exempelvis kan löven ätas, råa eller tillagade, eller torkas och malas till pulver som kan användas som redning. Kärnorna i frukten kan ätas råa eller rostade, alternativt kan fruktens olja utvinnas, alltså extraheras, och användas i kosmetika. De senaste åren har produktion av dryck baserat på Baobabfrukten startats upp i Sverige. Vid tillverkning av drycken utnyttjas endast fruktköttet, vilket betyder att en stor mängd fruktkärnor blir över. Både ur miljösynpunkt och ekonomisk synpunkt hade det varit optimalt om det gick att tillverka en produkt baserad på de överblivna kärnorna och framförallt då på oljan de innehåller. Syftet med arbetet är att få svar på följande två frågor. Hur mycket olja innehåller Baobabkärnorna? Hur ser sammansättningen av fettsyror ut för Baobabkärnorna? <br /> <br /> Oljan har extraherats i en process där koldioxid pumpas igenom kärnorna, som blivit mortlade till ett pulver, vid särskilda temperaturer och tryck. Vid temperaturer över 31 grader och tryck över 73.8 bar är koldioxiden inte längre en gas, utan en superkritisk vätska. En superkritisk vätska är inte en vätska som det låter som, men inte heller en gas. En superkritisk vätska har en densitet likt en vätska men också en viskositet likt en gas. Dessa egenskaper är gynnsamma vid extraktioner och är det som har utnyttjas här. Denna typ av extraktion, en så kallad superkritisk vätskeextraktion, är en bra extraktionsprocess ur miljösynpunkt då inga farliga kemikalier används och då koldioxiden kan återvinnas. I arbetet gjordes en optimering av extraktionen, vilket innebär att temperaturen och trycket varierades för att se vad som gav mest olja. Resultatet visade att högre tryck och högre temperaturer var gynnsamt då det gav störst mängd extraherad olja per gram kärnor. Vid högsta temperatur och tryck kunde cirka 6 viktprocent olja extraheras ur kärnorna. <br /> <br /> Efter att oljan extraherats analyserades oljan för att se vilka fettsyror oljan består av, alltså vilken fettsyrasammansättning oljan har. Oljan injicerades i en gaskromatograf, där fettsyrorna kunde separeras baserat på bland annat deras olika kokpunkter. Resultatet visade att oljan innehöll både mättade och omättade fettsyror. https://lup.lub.lu.se/student-papers/record/9057173/file/9057192.pdf application/pdf 5031888 yes 2021 eng Analytical chemistry Baobab seeds Fatty acid composition Gas chromatography/flame ionization detector Supercritical carbon dioxide extraction. Chemistry 9057173 2021-06-21T13:41:17+02:00 2021-06-29T10:00:26+02:00 2021-06-29T10:00:26+02:00

oai:lup-student-papers.lub.lu.se:9057435 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM1 Amane Kandas author 9057433 Margareta Sandahl supervisor Centre for Analysis and Synthesis v1000651 department The topic of this study is to develop and validate an analysis method of nicotine nasal spray produced at McNeil AB. When developing the analysis method, several parameters were determined in advance to make the method more similar to other analysis methods at the company, making it more practical. However, other parameters were adjusted with the aim to improve the resolution and to fulfil the updated cGMP requirements, where category I, II and IV according to USP &lt;1225&gt; were of interest.<br /> The research questions to be answered during this project are; (1) what conditions that leads to the highest resolution, (2) Does these conditions fulfil the cGMP requirements, and (3) if the new method is greener than the currently used method. The aims have been fulfilled by initially varying the temperature, flow, pH and mobile phase gradient by using UHPLC, followed by a full validation where various performance characteristics were studied. Different sequences for the performance characteristics were used for calculations and comparison with the requirements that needed to be fulfilled. <br /> The developed method improved the resolution between the analytes as well as the complexity was decreased. All regulatory requirements were achieved except for the robustness. However, the sample solution was only stable for 45 hours, where the aim was to have a longer stability. Thereby, further investigation should be done on the stability. Also, column equivalence did not fulfil the requirement. The new analysis method was significantly greener, with more than 40 times less consumed solvent. <br /> <br /> Conclusion: The developed method showed good results and will be a good implementation for the company, yet further investigations should be done before sending the validation report for approval. Nicotine nasal spray is produced at McNeil AB, with the aim to help people stop smoking, and thereby decrease the deaths caused by smoking. Since nicotine nasal spray is considered as a pharmaceutical product, the analysis of the product needs to fulfil regulatory requirements. Currently used method was issued in the 20th century, which due to an update in the regulatory requirements, also need to be updated. When developing an analysis method of a pharmaceutical product, a validation of the new method is essential to investigate if the requirements are fulfilled. <br /> The method used today was developed year 2019, however this method needed further development before implementation. The aim of this project is to develop this last-mentioned analysis method of nicotine nasal spray, and thereafter to perform a validation by examining various parameters. The analysis method was performed by using ultrahigh-performance liquid chromatography, a commonly used analytical technique. Analytes that were studied were nicotine, which is the active pharmaceutical ingredient, preservatives, and degradants from nicotine. The goal was to find the chromatographic conditions that lead to the best resolution, and to obtain a method that fulfil the regulatory requirements. Also, the new method was aimed to be greener than currently used method. <br /> Overall, this project has been successful where all research questions have been answered. The parameters that were investigated were temperature, flow, pH and gradient of the mobile phase. By using the identified conditions, the new method became greener with a decreased consumption of solvent with more than 40 times. Parameters that were investigated during the validation were: linearity, quantification limit, accuracy, carryover, stability, robustness, precision, specificity, and method equivalence. Also, column equivalence and filter study were investigated. Further investigation should be done regarding the stability and column equivalence, whereas other parameters showed acceptable results. Some advantages of the new method compared to the present method, beyond the less consumed solvent, is the improved accuracy, repeatability, and efficiency, as well as the decreased complexity. Finally, by using the same set-up as other analytical methods at the company, the new method is more practical. https://lup.lub.lu.se/student-papers/record/9057435/file/9057812.pdf application/pdf 1309316 no 2021 eng Nicotine Nicotine nasal spray Ultrahigh-performance liquid chromatography Development Validation Technical analytical chemistry Chemistry 9057435 2021-06-21T20:23:47+02:00 2021-06-28T15:17:02+02:00 2021-06-28T15:17:02+02:00

oai:lup-student-papers.lub.lu.se:9057645 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Noemi Ströhagen author 9045518 Doc. Derek Logan supervisor Department of Chemistry v1000647 department The project’s focus is on the protein galectin-8N and crystallizing it with lactose and a novel ligand, MH1. The question for the project comes from previous work that shows that galectin-8N has an empty pocket on the surface of the protein. A novel ligand was designed to improve the affinity to the protein through potential interactions between the chlorophenyl group in the ligand and a pocket on the surface of the protein containing amino acids Arg66 and Tyr148. First, proven conditions for crystallization of galectin-8N were attempted without any harvestable crystals being produced. Four commercial crystallization screens were then made to map out new galectin-8N crystallization conditions. These were the commercial screens JCSG+ and PACT, which are complementary, and then two commercial Morpheus screens (first in complex with lactose and the second in complex with the ligand, MH1). An optimization of the crystal hits of JCSG+ was also done. From the first Morpheus screen, crystals in complex with lactose were obtained. Data to 1.2 Å were collected from these crystals at the BioMAX beamline of MAX IV. This structure was solved by molecular replacement with Phaser and refined in phenix.refine. A new space group for galectin-8N in complex with lactose was found, I41. In the second Morpheus screen, co-crystallization with the ligand created well-diffracting crystals which at best had a resolution of 1.3 Å. This structure was also solved by molecular replacement with Phaser and refined in phenix.refine. The crystal was then examined in PyMOL for ligand interactions of MH1. It had overall good electron density and the ligand was in one conformation with full occupancy. The ligand interaction was with amino acids Arg66, Arg52, Arg76, Asn86, Gly149, Glu96, His72 and Trp93. The proposed additional interactions of the ligand with the protein were confirmed, as the Arg66 side chain interacted with the chlorophenyl group and Tyr148 has a ring system that interacts with the phenyl ring at a 90° angle. This gives room for further work with understanding ligand interaction and improving affinity for the N-terminal domain of galectin-8. The first step of drug development is to understand what the cause of the illness is. Then the following question is how the progression of the illness can be stopped and possibly how it can be detected early. Oftentimes what needs to be found is an inhibitor, which is a ligand that binds to the protein causing the illness and stops it from functioning. <br /> <br /> An important aspect is to find a ligand that binds strongly and only to the specific protein. To find a ligand that binds in this way, often several different ligands are studied structurally to understand how the interaction looks like between the protein and the ligand. There is a chance of improvement of the affinity and specificity between each ligand based on the structural and biochemical information obtained from the previous ligands studied. In this project, one ligand’s interaction with a disease-causing protein was mapped out. <br /> <br /> The protein studied is galectin-8N, a member of the family of galectins. These proteins are interesting because they are involved in a multitude of illnesses in humans including cancer, fibrosis, and heart problems. Galectins are a family of 15 proteins and 10 of these are found in humans. They are highly similar in structure and bind to the same type of galactose-containing carbohydrate groups attached to certain types of proteins. <br /> <br /> Galectin-8 is a protein that is interesting to study because it is present in several different tissues in the human body: lungs, liver, kidney, brain and cardiac muscle. Galectin-8 is involved in carcinogenesis (formation of cancer) and cancer within the digestive, reproductive, urinary and hematological systems. <br /> <br /> The aim of the project was to crystallize part of galectin-8 called galectin-8N with lactose and a novel synthetic ligand, collect data, and generate a structure to be able to study the interactions between the protein and the ligands. The ligand studied in this project was the latest ligand in a line of ligands with improved selectivity and affinity to galectin-8N. There was a hypothesis from a previous studied ligand that showed that there was a new potential binding pocket and that the two amino acids, Tyr148 and Arg66, in galectin-8N are thought to interact with the ligand. <br /> <br /> The crystallization part was done by conducting four screens (tests of conditions that commonly crystalize). The first three screens were with galectin-8N in complex with lactose and in the last galectin-8N was in complex with the novel ligand. After crystallization, a data collection at MAX IV was conducted using the beamline BioMAX. After that a structure was generated. <br /> <br /> The lactose-galectin-8N complex has an already known structure and the structure determined was a confirmation of previous research. The more interesting part was when galectin-8N and the novel ligand were in complex and showed a new potential binding site. The complex also had several promising interactions between the ligand and protein. The ligand interacted with the amino acids Tyr148 and Arg66 as expected in the hypothesis. <br /> <br /> To conclude, this project gives a deeper understanding for further development of drugs connected to galectin-8N. That gives the opportunity to explore new ligands based on the using the new binding pocket and the two new interactions of the amino acids Tyr148 and Arg66. It leaves room for more studies of the ligand interaction with the protein, to improve ligands selectivity and affinity for galectin-8N to further drug development. 2021 eng galectin-8N ligand complex crystalization screen JCSG+ PACT premier Morpheus biochemistry Chemistry 9057645 2021-06-22T10:34:42+02:00 2021-06-28T16:31:59+02:00 2021-06-28T16:31:59+02:00

oai:lup-student-papers.lub.lu.se:9057720 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Zeinab Hojeij author 9057714 Professor Margareta Sandahl supervisor Centre for Analysis and Synthesis v1000651 department Introduction: Validation of a new test method to determine nicotine from chewing gum extracts with ultra high-performance liquid chromatography.<br /> <br /> Background: In Quality Control-laboratories, the methods that are regularly used are consistently developed in order to conduct effective analysis procedures. The aim of all of these developments is to simplify the analysis as much as possible and make the methods robust and efficient to maintain preciseness since they will be used continuously. Methods that do not fulfil all the requirements are usually replaced with new methods that are intended for this purpose. The two methods that are used to determine nicotine in chewing gum extracts do not fulfil the requirements for specificity and robustness, therefore a new method<br /> that fulfil all the requirements was developed. The validation criteria and requirements were conducted from the validation SOP (Standard Operating Procedure) that is regulated with ICH (International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use) and USP (United States Pharmacopoeia) regulations.<br /> <br /> Aim(s): The aim is to validate and develop the new method TMD-0000877 that is intended to be robust and selective for all the chewing gum formulations.<br /> <br /> Methods: The instruments used in the older methods (named A and B) are based on HPLCanalysis where the latter method uses a column with a very low performance that results in peaks with low resolutions. Method B is only selective for two formulations, and the remaining formulations are analysed with method A. The new method uses an UHPLC (Ultra High-Performance Liquid Chromatography system) and is considered to be selective for all the 17 formulations. The validation experiment consists of testing different parameters such as robustness, specificity, precision, robustness, linearity, accuracy, method equivalency, and filter study. In order to assess the robustness, a 3-factorial DOE (Design of Experiment) was<br /> done by randomly varying analysis parameters (flow, pH and temperature) giving a total of nine runs. All data were numerically calculated with Excel and Minitab.<br /> <br /> Results: All the parameters fulfilled the requirements and most importantly the new method TMD-0000877 was selective for all the formulations since no interference under the nicotine peak was obtained. The robustness experiment gave contingent results since no significant difference was obtained for all the formulations. The only formulation that diverged was Spearmint 4 mg since a significant difference in analysis parameters was shown when the temperature is increased, due to a temperature sensitive colouring agent in the formulation that interfered with the nicotine peak, resulting in low resolution values. Although the robustness experiment fulfilled the requirements since all runs conducted a %RSD (Relative<br /> Standard Deviation) ≤ 5.<br /> <br /> Conclusion: The validation was successful, and all the tested parameters fulfilled the requirements. The method will be in use when the validation report is approved by McNeil AB and the countries demanding the method. A new method for determining nicotine in the chewing gum formulation used at the Quality-Control labs at McNeil AB, was developed and validated. The aim of this project was to replace several older methods with a robust and selective method for all the chewing gum formulations. The analysis instruments used for determining nicotine are liquid chromatography, which is a process for separating components by pumping a solvent mixture at high pressure through a solid silica particle-packed column in order to separate and determine compounds. The chewing gum formulation consists of a total of 17 flavours and strengths, and the sample preparation method included dissolving and chewing the gums in media in a chewing apparatus.<br /> The aim of this project was to develop and validate the new test method using validation approaches dedicated for the pharmaceutical industry. The validation consisted of testing different parameters that explained the robustness of the method, specificity, precision, linearity, method equivalency, filter study, accuracy, and solution stability. The requirements for each parameter were taken from the validation SOP (Standard Operating Procedure) that belongs to the company.<br /> The results obtained from the experiments showed that the method fulfilled all the requirements, was selective for all the formulations and was robust. Since all the other validation parameters also fulfilled the criteria, the method will be applicable when the validation report is written and approved. https://lup.lub.lu.se/student-papers/record/9057720/file/9057722.pdf application/pdf 1018584 yes 2021 eng Chewing gum Nicorette® Nicotine Ultra High-Performance Liquid Chromatography Validation Technical analytical chemistry Chemistry 9057720 2021-06-22T12:07:45+02:00 2021-06-28T16:03:44+02:00 2021-06-28T16:03:44+02:00

oai:lup-student-papers.lub.lu.se:9057796 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsM2 Teodor Olsson author 9057794 Professor Susanna Törnroth-Horsefield supervisor Department of Chemistry v1000647 department En människas kropp är alltid i behov av en balanserad mängd vätska för att fungera optimalt. Majoriteten av vätskan inuti en människa består vatten och kroppens celler har därmed en typ av proteiner specialiserade på att balansera vattennivå. Proteinerna kallas aquaporiner och sitter placerade inuti cellernas membran där de främjar flödet av vatten mellan cellens insida och utsida. Andra typer av proteiner reglerar vattenflödet genom att reglera aquaporinerna igenom transporten av aquaporiner till och från cellmembranet utifrån kroppens vätskebehov. Om mängden aktiva aquaporiner på cellernas membran inte är balanserade blir kroppens vätskebalans förskjutet vilket yttrar sig formen av sjukdomar. En sjukdom relaterad till aquaporiner är Nephrogenic diabetes insipidus som orsakar att vattnet i urinet inte återabsorberas ordentligt av njurens celler och förloras i väldiga mängder av urin. Aquaporin 2 är en typ av aquaporin som finns i njurens celler och är delaktig till att koncentrera urinen. Ezrin är ett protein som är delaktig inom transporten av proteiner till och från cell membran och kan tänkas vara viktig inom regleringen av just aquaporin 2. Detta projekt har undersökt om aquaporin 2 interagerar med proteinet Ezrin och i så fall hur proteinerna interagerar med varandra.<br /> <br /> Tidigare forskning har funnit att Ezrin interagerar med aquaporin 2 och att interaktionen har en effekt på mängden aquaporin 2 närvarande i cellers membran. Den tidigare forskningen har använt mass spektrofotometrisk analys av co-Immunoprecipitation komplex för att erhålla sina resultat. I detta projekt har istället microscale thermophoresis (MST) använts för att studera interaktionerna. I MST utsätts proteinerna för en temperaturgradient och deras förflyttning i gradienten ändras om proteinerna interagerar med varandra vilket mäts genom fluorescens.<br /> <br /> Aquaporin 2 överproducerades inom jästceller och renades upp från cellerna. De upprenade aquaporinerna blandades med två olika former av Ezrin färgad med fluorescerande färg, Ezrin med alla delar av proteinet och Ezrin med bara den delen av proteinet som kallas FERM. Interaktionen mellan Ezrinerna och aquaporin 2 studerades genom MST vilket visade en interaktion för båda formerna av Ezrin med aquaporin 2. Styrkan hos bindningen för båda formerna av Ezrin med aquaporin 2 kunde inte tillförlitligt tolkas.<br /> <br /> Resultaten ger insikt i mekanismerna för reglering av aquaporin 2 och vilka proteiner som påverkar regleringen samt hur. Kunskapen om mekanismen kan användas för utvecklingen av mediciner som imiterar eller binder till relevanta proteiner för att bibehålla en fungerande reglering av aquaporin 2. https://lup.lub.lu.se/student-papers/record/9057796/file/9057806.pdf application/pdf 6607015 LU/LTH access 2021 eng Aquaporins Aquaporin 2 biochemistry AQP2 membrane-protein Ezrin trafficking MST Microscale Thermophoresis binding-affinity binding interaction FERM-domain Biology and Life Sciences Chemistry 9057796 2021-06-22T14:32:39+02:00 2021-06-28T15:57:18+02:00 2021-06-28T15:57:18+02:00

oai:lup-student-papers.lub.lu.se:9057881 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Mona Fathi author 9057879 Margareta Sandahl supervisor Department of Chemistry v1000647 department Introduction:<br /> Narasin is a feed additive for animals to treat the parasitic disease Coccidiosis. The antibiotic is deadly to humans when consumed in large amounts. Studies has shown that Narasin can transfer on Vancomycin resistant E. Faecium (VRE). Vancomycin is an antibiotic used to treat bacterial infections in humans. The resistance could be passed on to humans from the chicken and contribute to yet another resistance issue. <br /> <br /> Background: <br /> Many studies on Narasin in feed has been done but very little work has been done on chicken tissue and in particular Swedish chicken. Moreover, when working with tissues quite often a cell disrupter or tissumeizer is used. In this report a bead mill will be used and evaluated in terms of recovery and repeatability. <br /> <br /> Aim(s): <br /> The aim of this study is to determine the amount of Narasin in Swedish chicken tissue using a bead mill instead of a cell disrupter in the sample preparation step.<br /> <br /> Methods: <br /> Parts of the method was done according to Tracey L. Cash et al report with small deviations. A bead mill was utilized instead of a cell disrupter and a vortex instead of a mechanical shaker. Chicken was purchased from a local store in Malmo. The tissue was homogenized with a blender. The samples were vortexed, centrifuged and cleaned using solid phase extraction. The analyte was analyzed using reversed-phase liquid chromatography with post-column derivatization for selective detection at 520 nm. <br /> <br /> Results: <br /> The result showed a LOD on 0,13 ppm and LOQ 0.43 ppm. The amount of Narasin in Swedish chicken tissue couldn’t be detected with this method. Regarding the use of a bead mill on three spiked chicken tissue samples showed a mean recovery at 57% and a standard deviation on 5. The repeatability of the three spiked samples showed a value on 8.72 %. <br /> <br /> Conclusion: <br /> In conclusion Narasin couldn’t be detected in Swedish chicken tissue with this method. The usage of a bead mill resulted in an acceptable recovery in accordance with the report done by Tracey L. Cash et al, where the acceptable value of spiked samples should be between 60% and 110%. Narasin detection in Swedish Chicken tissue <br /> In our everyday life chicken is considered a basic food component. The chicken industry is, and have been expanding drastically, which has forced the industry to take actions to preserve the expansion. Different additives are given to the animals to promote the expanding industry. The main purpose with the additives is fast growth and healthy chickens. Narasin is a drug used to prevent the sever disease, Coccidiosis. The illness has devastating effect on animals and has death as consequence. However, Narasin is an antibiotic and has proven to preserve and spread Vancomycin resistant E. Faecium (VRE) in chickens. Vancomycin is an antibiotic used to treat human infections and is classified by World health organization, as a significant antimicrobial for medicine. Nevertheless, a major resistance has been documented in hospitals where Vancomycin is widely used. This makes Vancomycin resistant E. Faecium a severe issue worldwide. The fact that Narasin preserve the spread of VRE in chickens, which humans then consume is worrisome. <br /> <br /> High amounts of Narasin have been proven to be very harmful for humans. An accidental consumption of high amounts of Monesin, which is chemically very similar to Narasin, left humans with symptoms as vomiting, muscle weakness, respiratory failure and eventually death. Hence, the European union has put up a regulation for the maximum residue limit of Narasin in chicken tissue, to control and protect humans and animals. This regulation is taken very serious and regular controls is conducted to preserve that. In Norway, a step further was taken and all use of Narasin was banned since 2016. Instead of feed additives a vaccination program was conducted. <br /> <br /> The purpose of this study is to investigate the amount of Narasin in Swedish chicken tissue, but also to evaluate the use of a bead mill in the extraction procedure. A bead mill is used to ground solid materials into a finer component. The bead mill was used to grind the chicken tissue with a solvent. The purpose of this technique is to break down the cells so that intracellular fluid becomes available to be dissolved in added solvent. This procedure is usually not used to extract Narasin from tissue. Therefore, there are a knowledge gap that this report aimed to investigate. <br /> <br /> The method that was performed followed a validated method for determining Narasin in chicken tissue. Chicken tissue was purchased and minced with a blender then bead milled and cleaned in a series of steps. To analyze the Narasin a liquid chromatography was used with a derivatization. Narasin can’t be detected with UV/Vis since the compound doesn’t absorb light in the visible region. For that reason, an additional compound is added that react with Narasin. The reaction produces a chemical that is detected. Three samples were spiked with a known concentration Narasin. This method is used to detect how much of the Narasin is lost in the clean-up procedure. <br /> <br /> The result in this study showed that the amount of Narasin in Swedish chicken tissue is too low to be detected with the method used. Because of that, the amount couldn’t be detected. The use of bead mill showed a low recovery. Which means that a lot of the Narasin put was lost in the cleaning-up process. The amount of Narasin in Swedish chicken tissue couldn’t be detected with this method. It also couldn’t be determined if the amount proceeded the maximum residue limit sat by the European union. 2021 eng Ball mill Chicken Derivatization HPLC Narasin Analytical chemistry Chemistry 9057881 2021-06-22T16:24:46+02:00 2021-06-28T14:02:50+02:00 2021-06-28T14:02:50+02:00

oai:lup-student-papers.lub.lu.se:9057918 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Vendela Gustafsson author 9057916 Charlotta Turner supervisor Department of Chemistry v1000647 department Introduction: This study was performed to optimize extraction of lead, copper and zinc from seaweed using pressurized hot water, to investigate the selectivity and extractability of the extraction. <br /> <br /> Background: Pressurized hot water extraction is an environmentally sustainable method in comparison to more common extraction methods, such as distillation or solvent extraction, used with plant material. Extraction of metals in seaweed using pressurized hot water is unusual and information about this is limited. <br /> <br /> Aim: The aim of this study is to find the extraction variables where selective extractions (where the extraction for one metal is efficient but the other metals are inefficient) for all the metals are performed and where high extractability is reached.<br /> <br /> Methods: The pressurized hot water extraction is performed at varying temperatures, between 60-180 °C, with and without additives, such as formic acid and different extraction times, between 1 to 9 static cycles with 10 minutes on each cycle. The extractions will then be analysed using atomic absorption spectroscopy, the measured absorbances will be compared to a concentration curve made from standards with known concentrations. <br /> <br /> Results: All the measurements of lead were negative. The extractions were contaminated by copper and zinc, influencing the measurements. The highest amount of zinc was extracted using 180 oC, with addition of 2,5 % formic acid and 9 extraction cycles.<br /> <br /> Conclusion: There were no lead found in the extract, therefor nothing can be said about the extractability or the selectivity of the extraction of lead. Due to contamination no conclusions can be formed about the extractability or selectivity of copper. An increase of temperature positively influenced the extraction of zinc, addition of formic acid also positively influenced the extraction. The extraction time did not influence the extraction of zinc as much as the other two experimental variables, but it had a slight positive influence. Why should you eat seaweed? Previous research has suggested it is good for both health and environment. Even so it is important to know that seaweed is good at absorbing toxic substances that may be harmful if we ingest too much of them. To prevent sickness, we need to know if the seaweeds contain the toxic substances. In this report seaweeds from Norway are analysed to see if they have high amounts of metals such as lead, zinc and copper, making them toxic. Lead is a toxic metal while copper and zinc are essential but can be harmful if too much is ingested.<br /> The metals need to be extracted and then analysed. And it is important to optimize extraction methods of the toxic metals and other substances. The extraction will be performed using different experimental variables. It can be difficult to extract the wanted metals, but other minerals and healthy polyphenols (antioxidants) may easily be extracted, therefor removing heathy substances and not the harmful ones. The optimization is needed to increase the selectivity of the extraction.<br /> Extraction methods usually require large volumes of toxic solvents and/or solvents that are bad for the environment. However, pressurized hot water is not toxic and we have plenty of it making it an environmentally sustainable option. To get an accurate picture of how much metal the seaweed contains the extraction also needs to be optimized to retrieve as much of the metals as possible. This was done by changing different variables of the extraction. <br /> The experiment was designed to perform 16 extractions using different combinations of the extraction variables. The temperature was set to go from 60 oC to 120 oC and at the highest 180 oC, the extraction time was 10, 50 and 90 minutes. The solvent was water mixed with acid, and extractions were performed with 2,5% and 5% formic acid as well as with only water. <br /> No lead was detected after extraction using pressurized hot water. Copper was not successfully extracted; the samples were contaminated. The most zinc was extracted at 180 oC, with addition of 2,5 % formic acid and 90 minutes extraction time. The extraction of zinc is more efficient at higher temperatures and with addition of acid. The extraction time did not influence the extraction as much as the other two experimental variables. A nutritional value of the seaweed could not be determined. https://lup.lub.lu.se/student-papers/record/9057918/file/9057925.pdf application/pdf 1343890 yes 2021 eng Atomic Absorption Spectroscopy Pressurized hot water extraction Seaweed Toxic metals Analytical Chemistry Chemistry 9057918 2021-06-22T18:03:44+02:00 2021-07-01T09:04:29+02:00 2021-07-01T09:04:29+02:00

oai:lup-student-papers.lub.lu.se:9057947 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Daniel Shahne author 9057945 Mahdi Khataei supervisor Department of Chemistry v1000647 department Introduction: A new method for separation and determination of Glyphosate and Glufosinate alongside their respective major metabolites aminomethylphosphonic acid and 3-(methylphosphinico)propionic acid was found then tested in spiked soil and surface water.<br /> <br /> Background: Most methods today require derivatization for determination and separation of these compounds. Methods without derivatization rely on expensive mass spectrometers for determination.<br /> <br /> Aim(s): Use a hydrophilic interaction column for achieving separation without derivatization and test an evaporative light scattering detector for determination. Pre-concentration also tested and optimized.<br /> <br /> Methods: Traditional one variable at a time approach was used for optimizing the pre-concentration and detector, while design of experiments software was used for optimizing the separation (using UPLC). The traditional method was used for maximizing (in most cases) peak areas and recoveries. The software design was used for checking interactions between mobile phase pH, buffer concentration and water percentage, in addition to optimization of these parameters. For this two responses was used with one being the number of peaks and the other being the retention time of the second analyte.<br /> <br /> Results: Optimization was done and interactions (and lack of) between variables found. Lack of proper clean-up for the real-world samples resulted in aminomethylphosphonic acid being impossible to detect in either matrix. These impurites were likely non-charged compounds. Glyphosate was only detected in the surface water sample with a LOQ close to legal limits. 3-(methylphosphinico)propionic acid and Glufosinate were well separated and detectable in both matrixes.<br /> <br /> Conclusion: The evaporative light scattering detector can detect all the analytes. For real samples there needs to be better clean-up. An interaction that was ignored in the DoE model between formic acid and the buffer ammonium formate needs to be studied in future work. Glyphosate, aminomethylphosphonic acid (AMPA), Glufosinate and 3-(methylphosphinico)propionic acid (3-MPPA) are substances that accumulate in soil as a result of using certain herbicides containing Glyphosate and Glufosinate (the other two are their respective breakdown products). Not only that but these are also amongst the most used herbicides globally. Modifying and improving already existing methods is a staple of analytical chemistry and its partly what i’m doing here alongside some novel studies. Although there are studies for some combinations of the four analytes in soil using similar methods to mine, there are none with all four simply because it has not been done yet. <br /> <br /> In this study a less typically used way of detecting them was used. These Evaporative Light Scattering Detectors (ELSD) are a good choise for analytes like mine that do not respond to much more common methods of detection. They are also very inexpensive compared to the mass spectrometry detectors commonly used in methods similar to the one in this study. To separate the compounds and thus be able to individually detect them a special technique (column) intended for very water-soluble compounds was used. These hydrophilic interaction liquid chromatography (HILIC) columns have additional benefits.<br /> <br /> An additional goal was to achieve this method without chemically modifying the analytes during analysis (derivatization) as it saves time, money and is more environmentally sustainable. It also has the benefit of reducing errors as is allways the case when reducing steps in any method. Usually, derivatization is required for these substances due to their properties making analysis difficult, particularly at the usual very low amounts they are found in contaminated soil and water. While underivatized separation is difficult with common columns like C18 and these derivatizations are primarily done to enhance detection, it also makes separation possible on those common columns. One benefit of HILIC columns is that derivatization can be skipped. ELSD should in theory (and as found in the study) respond to all the analytes. <br /> <br /> The results were that this method can be used for Glufosinate and 3-MPPA, with difficulties for Glyphosate. For AMPA its currently unusable until a method of removing certain impurities is found in future work. https://lup.lub.lu.se/student-papers/record/9057947/file/9057953.pdf application/pdf 2892066 yes 2021 eng Glyphosate herbicides extraction zwitterionic hydrophilic interaction liquid chromatography analytical chemistry Chemistry 9057947 2021-06-22T18:59:51+02:00 2021-06-28T15:59:25+02:00 2021-06-28T15:59:25+02:00

oai:lup-student-papers.lub.lu.se:9058162 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Joachim Björklund author 8987599 Roberto Mastio supervisor Department of Chemistry v1000647 department Sialic acids are nine-carbon carbohydrates that are present and essential in nearly all mammalian cells. Sialic acids have many functions such as molecular recognition, cell adhesion, and markers for pathogens. Some pathogens can take advantage of mammalian sialic acids and disguise themselves as host cells in a phenomenon that is called pathogenic mimicry. By doing this, the bacteria and virus infect a host unnoticed as no immune response will recognize the threat. It is well known that P. Mirabilis and S. Aureus uses mimicry by harvesting host sialic acid as they cannot synthesize the sialic acid themselves. Furthermore, it has been shown that SARS-CoV-2 uses sialic acid as a co-factor when binding to the ACE2 receptor of humans. By exploiting the structure of sialic acid, we will synthesize an antagonist to these bacteria and viruses, thus functioning as an antibiotic or antiviral agent. This project will focus on the synthesis of C5 amine analogs of Neu5Ac to develop a library and increase the understanding and knowledge of how SARS-CoV-2 infects humans as well as finding an antibiotic inhibitor towards pathogenic bacteria. Sialinsyra är en kolhydrat som finns i och på nästan alla däggdjursceller och fyller många funktioner. En viktig funktion är att agera som kommunikatör mellan celler. Många virus och bakterier använder sig av sialinsyra för att hitta rätt cell att infektera medan andra använder sialinsyra som en mantel för att gömma sig för immunförsvaret. Detta kan användas som ett verktyg för att utveckla medicin mot dessa infektiösa bakterier och virus då vi vet att de kommer attraheras av sialinsyror. Genom att göra små förändringar av sialinsyran så kan man stoppa bakteriens funktion att kunna ta upp sialinsyra och där med kan den inte förklä sig. Vårt mål med detta projekt är att hitta en modifierad sialinsyra som kan stoppa dessa funktioner från att fungera. 2021 eng Carbohydrate Sialic acid SARS-CoV-2 ACE2 SiaT transporter 5C amide C5 amide Neu5Ac Organic chemistry Chemistry 9058162 2021-06-23T11:10:46+02:00 2021-07-01T15:49:50+02:00 2021-07-01T15:49:50+02:00

oai:lup-student-papers.lub.lu.se:9058212 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsM1 Emelie Wiklund author 9058210 Anton Järild author 9058227 Martin Ek supervisor Centre for Analysis and Synthesis v1000651 department Spallation sources such as European Spallation Source (ESS) produces neutrons by bombarding high-energy protons onto the target wheel. To determine the location of the proton beam a Proton Beam Imaging (PBI) system will be installed. The PBI system at ESS relies on the properties of a luminescent coating that is sprayed onto the target wheel and the proton beam window. In this study, luminescent materials for the PBI system are investigated and evaluated on their luminescent properties using photoluminescence spectroscopy. The material in focus is the Cr-doped alumina, which has been investigated in two parts. Sprayed coatings, made from an existing precursor, are investigated to understand how the luminescent behavior of Cr-doped alumina is affected by various factors in the ESS environment. Thereafter, a new Cr-doped alumina precursor is developed and optimized to produce a coating with superior properties.<br /> <br /> The existing precursor from the sprayed sample consists of a mixture of alumina and chromia that reacts during spraying to form Cr-doped alumina. This study compared the luminescent properties of two spraying techniques: plasma-spray and flame-spray. The results show that plasma spraying produces brighter coatings than flame spraying due to lower presence of the undesired η-alumina phase in the finished coating. The coating thickness optimization showed that 100 μm gave the brightest coating. Pure chromia was found in all the sprayed samples, which indicates that full incorporation of chromia into alumina has been unsuccessful.<br /> <br /> In this study, a new Cr-doped alumina precursor is proposed in which the powder is sintered prior to thermal spraying. Pre-sintering of the precursor material is suggested to produce a more controlled, homogeneous and complete incorporation of the trivalent chromium ions into the alumina matrix, hence producing a coating with superior luminescent properties. Pink, bright luminescent Cr-doped alumina powders were successfully prepared via two synthesis routes, the solid-state and solution-based synthesis, and compared based on their luminescent properties after heat treatment at different temperatures. The solution-based samples exhibited superior luminescence at temperatures of 1100 °C and 1300 °C, which is due to earlier transition into the η and α-alumina phase. Sintering powders at 1550 °C gave equally bright materials from both syntheses. The optimal doping concentration of trivalent chromium ions was 1 wt% of chromia. To spray the precursors, the particle size needs to be in the range of 5-60 μm to give satisfactory results. Therefore, the effect of ball milling on luminescence was studied. It was discovered that high-energy ball milling reduced the luminescence intensity significantly due to the violent crushing of the alumina crystals. Grinding the particles with a mortar and pestle could reduce the particle size sufficiently without the material losing its luminescent properties. <br /> <br /> For the last part of this study, two alternative materials for the PBI system were investigated: Ti-doped alumina and Ce-doped YAG. The Ti-doped alumina powder showed no luminescent properties and the study continued with Ce-doped YAG. This material was successfully produced, which created a yellow powder that exhibited a broad emission from the green to yellow region upon blue light excitation. A doping concentration screening that was performed revealed that 1.6 mol% gave the brightest material. Protonstrålning används för att generera neutroner på ESS; en effektiv metod som kommer ge ESS världsledande prestanda, men som medför utmaningar. Den högenergetiska protonstrålen kan inte ses med blotta ögat och kan potentiellt skada instrument, vilket leder till att övervaka protonstrålen blir svårt, men kritiskt. Lösningen är ett självlysande material som skapar en bild av var protonstrålen träffar.<br /> <br /> Det sameuropeiska forskningsprojektet European Spallation Source (ESS) byggs för närvarande i Lund och förväntas bli färdigställt år 2023. Forskningsanläggningen kommer då att använda neutroner för att studera material på atomär nivå för att bryta ny mark inom biologi, kemi, fysik, geologi och medicin. För att skapa en neutronpuls på ESS kommer en roterande målskiva gjord av volfram att bli bestrålad av en högenergetisk protonstråle. Protonerna träffar målskivan med 94 % av ljusets hastighet, vilket gör att protonerna tränger in i materialet och slår ut neutroner från volframkärnorna. På grund av dess oerhörda energi kan protonstrålen, om den är fel inställd och belyser oönskade områden, skada dyr utrustning som även kan bli en säkerhetsrisk. Därför är det av oerhörd vikt att övervaka och säkerställa protonstrålens status i alla lägen. Eftersom protoner inte är synliga med blotta ögat har ESS planerat att installera ett avbildningssystem av protonstrålen. Principen är att spraya en tunn ytbeläggning av ett självlysande material på målskivan. När protonstrålen penetrerar det självlysande materialet genereras fotoner. Dessa fotoner detekteras av kamerasystem för att skapa en avbildning i realtid av protonstrålen med millimeterprecision. Den påfrestande miljön av det högteknologiska ändamålet sätter höga krav på den luminescerande ytbeläggningen. Därför har ESS påbörjat ett samarbete med ett flertal forskningsinstitut för att utveckla ett lämpligt material innan ESS sätts i drift. <br /> <br /> Detta examensarbete har undersökt och optimerat luminescerande material för protonstråleavbildning. Materialen som har behandlats i studien är dopade, kristallina material. Dopning är en process där en liten andel av ett främmande ämne avsiktligt introduceras i en struktur för att ändra materialets egenskaper. En följd av doping kan vara att ett material får självlysande, eller &#39;luminescerande&#39;, egenskaper. Materialet i huvudfokus i denna studie har varit krom-dopat aluminiumoxid, även känt som rubin, vilket är ett material som tidigare har studerats för detta ändamål. Av listan på krav valdes ett antal ut att utvärdera under denna studie, varav ljusstyrka var en av dem.<br /> <br /> Först undersöktes färdigsprayade ytbeläggningar av krom-dopat aluminiumoxid. Dessa hade tillverkats av ett pulver inköpt från en materialleverantör i U.S.A. Pulvret bestod av kromoxid och aluminiumoxid som, när det sprayas reagerar och bildar kromdopat aluminiumoxid. Resultat från diverse analysmetoder visade att kromoxiden inte hade lösts upp fullständigt i aluminiumoxiden, vilket antydde på att det inköpta pulvret inte var optimerat och att materialet kunde uppnå bättre egenskaper. ESS önskar att kunna producera ett eget pulver med optimala luminescerande egenskaper vilket motiverade utveckling av ett nytt pulver av krom-dopat aluminiumoxid. <br /> <br /> Därför utvärderades två nya syntesmetoder för att producera pulver med luminescerande egenskaper. Genom att värmebehandla pulvret innan sprayning genomförs en fulländad och kontrollerad doping. Resultaten visade att båda syntesmetoderna skapade krom-dopat aluminiumoxidpulver med starkt luminescerande egenskaper. Efter tillräckligt hög värmebehandling omvandlades pulvret från grön till rosa, vilket tydde på dopningen hade genomförts och att rätt kristallstruktur av aluminiumoxiden var uppnådd. Ljusstyrkan hos materialet ökade med temperaturen på värmehandlingen, vilket berodde på ökad dopningsgrad och även omvandling till mer gynnsamma kristallstrukturer. Kristallstorleken visade sig påverka luminiscensen då större kristaller gav starkare luminescerande förmåga och att vissa malningsstekniker därför dämpar luminiscensstyrkan i produkten. Efter optimering kunde det nya pulvret produceras i stor-skala för testsprayning. <br /> <br /> Denna studie har bidragit till att ESS är ännu ett steg närmare att ha ett fungerande luminiscernade material innan ESS är i drift och första protonerna når målskivan. https://lup.lub.lu.se/student-papers/record/9058212/file/9058311.pdf application/pdf 20110306 no 2021 eng Chemical Engineering Luminescent materials Cr-doped Alumina Proton Beam Imaging System ESS Chemistry Technology and Engineering 9058212 2021-06-23T12:11:14+02:00 2021-06-28T12:50:42+02:00 2021-06-28T12:50:42+02:00

oai:lup-student-papers.lub.lu.se:9058701 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Caroline Almqvist author 9058747 Pernilla Larsson author 9058687 bitr. universitetslektor Baozhong Zhang supervisor Jonas Rothén supervisor Centre for Analysis and Synthesis v1000651 department Poly(vinyl chloride) has a long history of use in the flooring industry. Throughout the years, several environmental and health issues have arisen concerning the production, usage and disposal of PVC. Forbo Flooring Systems is a company striving to provide environmentally friendly products for their customers, and therefore has an investigation of alternative polymers to PVC been initiated. The aim of this study is to investigate the environmental effects of the production of alternative polymers to PVC. The study consists of two main parts: <br /> <br /> • A literature research in which potential alternative polymers were selected for further investigation based on qualities required in flooring applications. <br /> • A life cycle assessment where the alternative polymers environmental impacts were evaluated using S-PVC as benchmark.<br /> <br /> In the literature study, four alternative polymers were found: modified poly(phenylene ether) (mPPE), epoxidized linseed oil (ELO), ethylene methacrylic acid (EMAA) and ethylene vinyl acetate (EVA). The LCA results showed that PVC had the lowest environmental impact of the five different polymers. In the LCA study a dominance and a sensitivity analysis were also performed. The results of the dominance analysis were applied in the sensitivity analysis to evaluate the influence of the origin of the raw material and the energy. The sensitivity analysis revealed that the exchange of fossil-based to bio-based raw materials decreased the global warming potential of the polymer production but had an increase in other impact categories. It also determined that the exchange of generic European to Swedish electricity had a positive effect on the environment. The conclusion was reached that the production of PVC has a lower environmental impact than the investigated polymers. However, when bio-based raw materials and Swedish electricity was used for mPPE (PS), EMAA and EVA, the GWP was lower than for PVC. This indicates that the polymers have the potential to be an environmentally preferable alternative to PVC. PVC: an environmental villain or a “green” solution? <br /> PVC has long had a bad reputation of being toxic to humans and to the environment. It has been called “the poison plastic” and “the most environmentally damaging of all plastics”. In this Master thesis it is revealed that PVC is in many ways, the most environmentally friendly alternative among the studied plastics.<br /> <br /> PVC is a very common plastic used in many different applications. One of them is flooring systems, often referred to as vinyl flooring. Because of the bad reputation of PVC, an increasing demand for PVC-free plastic floorings has been noted. The flooring company Forbo Flooring Systems has therefore initiated this study. The aim of the study was to investigate other plastics that has a potential to be used in floorings instead of PVC, with the hopes of decreasing the environmental impact of their plastic flooring products. Four potential alternative plastics has been chosen based on a literature study. These are mPPE (PS), ELO, EMAA and EVA. The advantage of these is that they do not contain any chlorine, compared to PVC, which has a negative impact on the climate. <br /> <br /> In order to evaluate the environmental impact of these plastics, a life cycle assessment (LCA) has been performed on PVC and four alternative plastics. LCA is a tool used to evaluate the environmental impact of a product throughout its lifetime. By gathering data of all the processes connected to the product and then compile all the emissions and the recourse uses, a total environmental load can be calculated. This environmental load is then translated to environmental impact by a so-called LCIA method. This is done by translating all the emissions associated with a certain environmental issue to a standard unit. For example, many are familiar with that CO2 is a greenhouse gas that increase the global warming, but also that methane is a far worse (about 25 times) greenhouse gas than CO2. The LCIA method translates all emissions that has an impact on global warming to CO2 equivalences. In this study 11 impact categories have been chosen.<br /> <br /> It was shown that the environmental impact was lower for PVC than it was for the other plastics in most categories, including CO2 emissions. In a sensitivity analysis performed, some of the fossil-based materials used to make the plastics were substituted to materials made from bio-based resources. That led to reduced CO2 emissions for all five plastics. Interestingly enough, PVC still outperforms all the other plastics. Another thing that was found was that the origin of the electricity used also affected the environmental impact greatly. Especially for the plastics with energy demanding production processes. Swedish electricity is much more environmentally friendly than the average European electricity! <br /> <br /> When a flooring system is produced, other materials such as additives and fillers are needed. However, this study has not taken this into account, only the plastic has been accounted for. This means that when a flooring system is made it is possible that the environmental impact is lower for the non-PVC floorings than it is for PVC. But, according to the results in this study it seems like PVC is the better choice in flooring applications at current moment. Maybe PVC has an undeserved bad reputation? https://lup.lub.lu.se/student-papers/record/9058701/file/9058786.pdf application/pdf 3250991 no 2021 eng PVC Flooring Life Cycle Assessment LCA Polymer technology Earth and Environmental Sciences Chemistry Technology and Engineering 9058701 2021-06-24T11:22:02+02:00 2021-06-28T12:53:29+02:00 2021-06-28T12:53:29+02:00

oai:lup-student-papers.lub.lu.se:9059038 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH3 Maxine Gripberg author 9059036 Daniel Topgaard supervisor Biophysical Chemistry v1000649 department With viral infections becoming an ever-increasing health problem in the world, the study of viral proteins is a cornerstone for understanding and preventing future pandemics. The following work shows the purification and structural characterization of the Influenza A M2 proton channel through solid-state NMR (ssNMR). Despite previously published structures of the M2 proton channel, the method of purification has not been well detailed and requires further optimization in order to produce samples to study at Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP). A truncated version of M2 containing residues 18-60 was studied in this work, which is referred to as M2[18-60]. Purification of labeled and unlabeled M2[18-60] expressed at 22°C and 30°C degrees were performed with varied results. It was found that the expression of M2[18-60] produced the highest yield when expressed in M9 minimal media and that the temperature during expression has no significant impact on the purification results. In addition, there was no difference in purification yield of M2[18-60] using a C3 or C4 column. Both labeled and unlabeled M2[18-60] was able to be reconstituted into liposomes. The acquired 2D 13C-13C correlation spectrum confirmed that presence of M2[18- 60] generated by the previous purification steps. The stability of the M2 protein was confirmed through overlay of previously published assigned spectra of a M2 S31N mutant. Further optimizations of the methods used in this work will be important in order to produce samples of M2[18-60] for future investigations into the design of antiviral drug candidates, ssNMR analysis of binding sites of M2-targeting drugs and assay development. Virusinfektioner har utan tvekan blivit det största hälsoproblemet i världen. I skrivande stund når antalet COVID-19 infektioner i världen upp emot 151 800 000 vilket gör att behovet av vacciner och antivirala läkemedel är viktigare nu än någonsin tidigare. Influensa A är ytligare ett virus som orsakar överdödlighet, trotts att många klarar sig lindrigt vid infektion. För att kunna förhindra eller bromsa influensainfektioner kan antivirala läkemedel användas innan ett vaccin har hunnit producerats. Startpunkten för utvecklingen av antivirala läkemedel är oftast strukturbestämning av virusets proteiner, vilket detta examensarbete lägger grund till. <br /> <br /> Antivirala läkemedel kan förhindra eller bromsa influensainfektioner genom att inhibera funktionerna av virusets proteiner. Det finns många proteiner som virus producerar som är viktiga för virusets förmåga att infektera celler och replikera sig. Ett av dessa proteiner heter Matrix 2 (M2). Detta lilla protein består av fyra identiska komponenter, varav varje komponent består av 97 aminosyror. M2 har som funktion att både frisätta virusgenomet, och se till att virusets hemaglutininer behåller sin struktur under viral replikation. Tidigare har det antivirala läkemedlet amantadine använts för att behandla influensainfektioner, men på grund utav mutationer av aminosyrorna i M2 proteinet blev influensa A virus resistenta mot amantadine. <br /> <br /> Trotts att M2 har kunnat mutera och bli resistent mot amantadine finns det ännu hopp om att hitta nya antivirala läkemedel som inhiberar M2. För att kunna upptäcka nya läkemedel måste strukturen på M2 bestämmas, vilket kan göras med fast-fas NMR. Denna teknik bygger på visualisering av atomer vars atomkärna är NMR-aktiva. Dessa atomer är tillexempel 1H, 13C och 15N. Genom att stråla ett prov av NMR-aktiva atomer med radiofrekvent strålning kan man se hur olika atomer inom proteinet interagerar med varandra. Detta kan ge insikt i vilka atomer som ligger nära varandra och därmed kan strukturen på proteinet bestämmas. <br /> <br /> För att kunna analysera M2 med hjälp av fast-fas NMR måste M2 uttryckas, separeras och urskiljas. I detta examensarbete uttrycktes M2 i E. coli, som agerar som proteinfabrik. M2 uttrycktes i två olika medier samt vid 22°C och 30°C. För att sedan kunna separera och urskilja M2 från andra proteiner användes olika separations och klyvnings metoder. Två olika kolumner användes för att separera proteiner beroende på deras hydrofobicitet, och till slut kunde proteiner urskiljas beroende på deras storlek. Det visade sig att separationen och urskiljningen av M2 var mycket svår då tidigare publikationer inte publicerat deras metodik i detalj. Optimeringar av metoderna gjordes för att till slut kunna producera ett protein som kunde analyseras i fast-fas NMR. Resultatet av fast-fas NMR visade att M2 kunde uttryckas, separeras och urskiljas men att separationsmetoderna behövde optimeras ytterligare.<br /> <br /> Resultaten och optimeringarna som publiceras i detta examensarbete lägger grunden för framtida analyser av M2. Förhoppningen är att kunna använda metoderna kring separation och urskiljning av M2 för att utöka kunskapen av strukturen av M2 och på så sätt upptäcka nya antivirala läkemedel. https://lup.lub.lu.se/student-papers/record/9059038/file/9059039.pdf application/pdf 10828455 no 2021 eng Solid-state NMR Influenza A M2 proton channel Biophysical chemistry Biology and Life Sciences Technology and Engineering Chemistry 9059038 2021-06-25T12:09:11+02:00 2021-07-05T09:31:21+02:00 2021-07-01T15:32:26+02:00

oai:lup-student-papers.lub.lu.se:9060229 2026-02-02T09:51:45Z PhysicsChemistryMaths

studentPublicationsH2 Aina Mc Evoy author 8988708 Tommy Nylander supervisor Justas Barauskas supervisor Department of Chemistry v1000647 department Computational Chemistry v1000659 department Lipids in the presence of a solvent can through the process of self-assembly form a number of phases referred to as Lipid Liquid Crystalline (LLC) phases. The inverse hexagonal, inverse bicontinuous cubic phases and sponge phase are examples of LLC structures that have been studied and used in drug delivery settings or food applications. For this project the focal point will be the sponge (L3) phase. This structure is formed in the presence of water and contains a network of hydrophilic water channels and continuous hydrophobic bilayer structures, similar to the inverse bicontinuous cubic LLC phase. However, the sponge phase tends to have a greater flexibility and fluid nature compared to the inverse bicontinuous cubic phase allowing for improved swelling properties. Where water channel diameters of 12 nm for the sponge phase compared to 8.4 nm for the inverse bicontinuous cubic phase have been observed for similar systems. These structural features could allow the lipid sponge phase to accommodate larger molecules. The water channel and bilayers of the structure construct the polar and apolar regions of the structure respectively. The presence of these two regions together with the ability to swell are greatly sought after properties in drug delivery structures. It has previously been observed that the glycerides: Capmul glycerol monooleate (GMO-50) and diglycerol monooleate (DGMO), when mixed within a certain range of ratios form a sponge phase when hydrated. It was also found that the addition of an emulsifier Polysorbate 80 (P80) expands this sponge forming range. In this thesis the effect of the zwitterionic phospholipid dioleoylphosphatidylcholine (DOPC) on sponge phases will be investigated. The incorporation of charges from the zwitterionic head group of DOPC to the system may be of interest when it comes to drug uptake and releasing mechanisms. Specifically the thesis investigates the effect of adding DOPC to GMO-50/DGMO and GMO-50/DGMO/P80 mixtures that are in or around their sponge phase forming ratios. Also the thesis investigates the possibility of replacing DGMO with DOPC without affecting the original phase present. The phases formed by these various mixtures were identified by visual inspection with cross polarised light as well as by small angle X-ray scattering (SAXS) measurements. It was found that the GMO-50/DGMO/P80/water sponge forming system tolerated the inclusion of DOPC to a greater extent compared to the GMO-50/DGMO/water system. This was observed for both the addition of DOPC as well as the replacement of DGMO with DOPC. However, where DGMO had been fully replaced by DOPC none of the systems studied formed a pure sponge phase at 25°C. The temperature dependencies of the formed phases were also investigated for the hydrated GMO-50/DGMO/DOPC(/P80) systems, showing different behaviours depending on the DOPC concentration in the system. Lipids are the building blocks for many biological systems, such as cell membranes. Some lipids are described as being amphiphilic meaning that they consist of both water-loving (hydrophilic) and water-disliking (hy- drophobic) parts. The hydrophobic part comprises one or more hydrocarbon tails or chains and the hy- drophilic part comprises the head group. In the presence of a solvent, such as water, due to the amphiphilic nature of the lipids they try find the optimum physical formation for that environment, in order to minimise the exposure of the hydrophobic part of the lipid to water. This process or ordering event is called lipid self-assembly, and is dependant on many factors such as the characteristics of the lipid as well as environmen- tal factors. The self-assembly may result in the formation of structures or so called Lipid liquid crystalline phases. Some of these structures are used for drug delivery where the structure contains a medical substance which is carried to its target. Some Lipid liquid crystalline phases form structures with hydrophobic regions and hydrophilic compartments, which is desirable as the structure can incorporate both hydrophobic and hy- drophilic medical substances. In this project the main focus will be on one particular Lipid liquid crystalline phase, namely the sponge phase. This phase has the property of both having hydrophobic and hydrophilic continuous networks, but also a flexibility which allows for swelling of the system. Larger water channels are useful for the purpose of drug delivery, as larger substances can also be incorporated. In this study the sponge phase consisting of a mixture of two and three lipid compounds that have previously been shown to form sponge phases at certain ratios once hydrated. The lipids used were the glycerides: Capmul glycerol monooleate (GMO-50) and diglycerol monooleate (DGMO) both in the presence and absence of an emulsifier Polysorbate 80 (P80) which is commonly used in drug and food applications. In this project these systems will be further investigated and modified by the addition of another lipid namely dioleoylphosphatidylcholine (DOPC) and also by replacement of DGMO with DOPC. DOPC compared to DGMO has the property of having two hydrocarbon tails as opposed to one and a zwitterionic head group. The latter means that it has a locally positive and negative charged head group, which could possibly contribute beneficial drug delivery properties. Through this study it was found that the presence of P80 enhances the retention of the sponge phase as the relative proportion of lipids (GMO-50/DGMO/DOPC) changed. However, fully replacing the DGMO portion of a lipid ratio with DOPC, at 25°C, altered the phase formed and did not reproduce the phase of the original system. 2021 eng Lipid liquid crystalline phases Sponge phases DOPC SAXS Theoretical chemistry Chemistry 9060229 2021-07-01T08:19:40+02:00 2026-02-02T10:51:45+01:00 2021-07-01T15:33:26+02:00

oai:lup-student-papers.lub.lu.se:9060809 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH3 Cecilia Håkansson author 9060803 Sara Linse supervisor Thom Leiding supervisor Biophysical Chemistry v1000649 department In this work spectroscopic methods have been used to determine the effect of fluorophores on protein affinity. Fluorophores are used in many different contexts to mark proteins, genes or antibodies. By marking a construct with a fluorophore, it is possible to follow the localization and function in a biological system, but it is not often investigated how the bound fluorophore could affect the marked construct. To gain some understanding of how marking a protein with a fluorophore might affect the protein properties, the small Ca2+ binding protein calbindin was used. The protein consists of two parts, called EF-hands, with great affinity for each other. The two EF-hands are split up with one fluorophore covalently bound to each EF-hand. There are two different fluorophores which can be positioned on either of the two EF-hands which results in four different constructs and two construct pairs. The two fluorophores have a convenient spectral overlap which allows for excitation energy to travel within the molecules from one fluorophore (donor) to the other fluorophore (acceptor) when they are close enough to each other. When the EF-hands are bound to each other the fluorophores are within range for the excitation energy to travel from donor to acceptor. By measuring the fluorescence decrease from the donor fluorophore when increasing the concentration of the acceptor fluorophore, it is possible to determine equilibrium dissociation constants (KD) of the system. This method can be used at lower protein concentrations on the nM scale, compared to isothermal calorimetry titrations where protein concentrations on the µM scale is needed, whereas SPR is performed on a surface which introduces other artifacts. Using low protein concentrations is convenient since the EF-hands affinity is high and measures very low KD values. From this work, KD values fitted to the experimental data for protein concentrations varying from 3-40 nM were in the range of 0.2-2 nM, whereas the KD values obtained for 80 nM titrations were around 30 nM. One of the construct pairs also had a relatively larger decrease in fluorescence compared to the other construct pair, indicating that the positioning of the fluorophores might affect the distance of the fluorophores. There are many diseases taking countless lives every day, and for many of these diseases we do not know exactly what is happening and why we get ill. The diseases are a result of biological functions going off the rails and malfunctioning mysteriously. By being able to follow a certain biological process without interfering with it, many of the unknown mysteries can be unrolled. But how do we know if we are interfering with a process when we don’t know how it functions to begin with?<br /> <br /> I have been working with a protein which can be found in our bodies called calbindin. Proteins are long chain-like structures which can be folded in different ways depending on the elements of the chain, and<br /> they are responsible for all our body functions. This specific protein can bind Calcium ions, which are metal ions very important for our body to function properly. There are two parts of the protein which each<br /> can bind one calcium ion. The most interesting property of calbindin is, however, that these two parts very strongly want to be together. If they are split up, they will find each other and bind together strongly. This is a characteristic which is very interesting and could be used in many different contexts, that is, if we can follow their binding.<br /> <br /> Calbindin is a quite small protein with a short chain, and to follow its functions, much larger proteins, with more than a 5x longer chain are attached to it. These larger proteins have an<br /> ability to emit specific light which makes it possible to follow them. The calbindin protein is split up between its two parts and two different light emitting proteins are added, one for each part<br /> of calbindin. By doing this we can determine, depending on the light emitted from the larger proteins, if the parts of calbindin are bound together or alone. The question here is whether the larger,<br /> light emitting proteins will be in the way when the two parts of calbindin tries to bind together.<br /> <br /> My results are that even with much larger light emitting proteins added to the small calbindin protein, the two parts of calbindin can bind together very well. This indicates that the larger proteins are not that much in the way. It is, however, difficult to know how well the calbindin parts would bind together without the larger light emitting proteins, since the other methods to follow the binding have their own sources of error. A conclusion is therefore that, in this case, the larger light emitting proteins do not seem to interfere much with the function of the protein. This information can be used as an assurance when using light emitting proteins to follow biological processes, however, one should not attach new structures to follow a biological process without paying attention to the effect it might have. https://lup.lub.lu.se/student-papers/record/9060809/file/9060810.pdf application/pdf 1625377 LU/LTH access 2021 eng Biophysical chemistry FRET EF-hand complementation S100G Protein affinity Fluorophores Technology and Engineering Biology and Life Sciences Chemistry 9060809 2021-07-04T20:15:24+02:00 2021-07-05T15:01:36+02:00 2021-07-05T15:01:36+02:00

oai:lup-student-papers.lub.lu.se:9061036 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Erik Golovtchenko author 9061032 Tommy Cedervall supervisor Martin Lundqvist supervisor Department of Chemistry v1000647 department In nature, for example through mechanical degradation (e.g., plastic waste in the sea) and through the exposure to UV-radiation, plastics can degrade to microplastics and eventually to even smaller plastic nanoparticles. Studies performed under laboratory conditions have shown that plastic nanoparticles can accumulate in the liver and the brain of fishes, hence plastic nanoparticles can cause brain damage to the fish. However, to my knowledge, there are no significant or published studies performed on the effect of polyethylene nanoparticles. Several studies have also shown that proteins can “dress” the surface area of some plastic nanoparticles, resulting in a formation of a protein corona around the particles. However, it has been criticised, that many studies are performed with a high surface area of particles, in proportion to how many macromolecular biological molecules that can “dress” them. Therefore, the present study aims towards understanding what proteins that “dress” polyethylene, respectively, polystyrene nanoparticles in bovine blood serum. The nanoparticles were downgraded from their bulk materials in this study with a kitchen blender in Milli-Q water. The size and stability of nanoparticles were determined used Nano Tracking Analysis, Dynamic Light Scattering and Zeta potential. <br /> <br /> Samples were prepared by incubating adult or fetal bovine serum with the prepared polyethylene or polystyrene nanoparticle solution. Control samples were made by incubating adult or fetal bovine serum with Milli-Q water. All samples were then centrifuged, and pellets were washed 2 times. The washed pellets were analysed with gel electrophoresis. The gels were stained with Coomassie Blue or silver-stain and bands cut out for mass spectrometry analysis.<br /> <br /> The present study showed that samples containing polyethylene gave a couple of bands differing from their control samples on gels stained with Coomassie Blue and silver-stain. Samples containing polystyrene gave only one band that differed from their control samples, visible only on a silver-stained gel. Additionally, the bands were analysed with mass spectrometry. Serum albumin and apolipoprotein A-1 were abundant in almost all analysed bands. However, there were particular proteins differing in the samples with nanoparticles. Finally, the present study gives suggestions for future improvements, e.g., optimisation of sample preparation to achieve a smaller surface area of particles in proportion to biological macromolecules that can adsorb, using more sensitive detection methods and analysing the difference between qualities among serums. 2021 eng Nanoscience Biochemistry Nanoplastics Chemistry https://lup.lub.lu.se/student-papers/record/9061036/file/9061045.pdf application/pdf no 9061036 2021-07-06T11:14:18+02:00 2021-08-19T09:37:43+02:00 2021-08-19T09:37:43+02:00

oai:lup-student-papers.lub.lu.se:9061037 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Alice Spangenberg author 9061033 Kaushik Chakrabarti supervisor Department of Chemistry v1000647 department As concerns grow ever larger about the negative effects of CO2 emissions, the use of hydrogen gas as an alternative to fossil fuels is becoming a more attractive objective. This however, requires practical ways of storing and transporting a highly flammable gas and is generally not compatible with much of the existing infrastructure. One proposed solution to this problem is implementation of liquid organic hydrogen carriers (LOHCs)- liquids which can be hydrogenated and dehydrogenated, and as such function as liquid storage systems for hydrogen gas. Many organic liquids, such as nitrogen containing heterocyclic compounds, have been suggested as possible candidates for this purpose but despite its practical benefits, this method of hydrogen storage requires efficient catalysis for the loading and unloading steps. <br /> <br /> In this work, three immobilised iridium pincer complexes are explored for the catalytic dehydrogenation of 4-methylpiperidine in continuous flow. The catalysts were made heterogeneous by linking para- and meta-substituents on the pincer ligand to the surfaces of metal oxides. One of these catalysts is a previously known silica supported complex which shows activity for dehydrogenation of linear alkanes in flow. The other two catalysts are related complexes displaying different aromatic substituents and supported on an alumina surface. The effect of flow rate and temperature on catalyst activity were also explored in order to replicate the challenges these systems may face as part of larger infrastructure. 4-methylpiperidine was found to easily undergo one dehydrogenation over the N-C bond, however the reactivity over the C-C bonds was considerably lower. The two complexes supported by COO-Al linking to alumina displayed higher activity compared to the previously known complex supported by O-Si linking to silica. It was also found that the catalyst with two meta-carboxylate groups displayed higher activity than the analogous para-substituted one. Both alumina supported catalysts displayed good stability at high temperatures, with the di-carboxylate catalyst still being active after 32 h at 350 degrees Celsius and obtaining a TON of 66900. I dagens samhälle finns det en stor drivkraft att verka för mer hållbara alternativ till de fossila material som varit allmänt förekommande i flera områden av bland annat energiproduktion. Den begränsade mängden kombinerat med de klimatförändrande effekterna av växthusgasutsläpp skapar inte bara en efterfrågan utan gör det ytterst nödvändigt att hitta nya vägar för samhällsutveckling. En sektor som ofta nämns i samband med utsläpp av växthusgaser är transport, där vätgas har lyfts fram som ett renare alternativ till bensin. Vätgas kan användas i så kallade bränsleceller, där vätgas och syre från luften transformeras till vatten och elektricitet. Även om detta är att föredra över en process som genererar t.ex. koldioxid finns det ett antal komplikationer i nyttjandet av denna energikälla, framförallt transport och lagring av stora mängder brandfarlig vätgas. För att vätgas ska kunna användas som bränsle likt de flytande drivmedlen som förekommer idag har en metod föreslagits där en katalysator lastar på (hydrogenering) och av (dehydrogenering) väte från molekyler i en vätska. På så sätt kan all hantering av bränslet göras i vätskeform, och vätgasen frisläppas när det behövs. Dessa vätskor går under samlingsnamnet liquid organic hydrogen carriers (LOHC), och är ofta någon form av kolväteföreningar. Framförallt avlastningssteget har dock visat sig medföra vissa svårigheter och kräver ofta höga temperaturer för att genomföras. Därför har nya typer av LOHC föreslagits, så som aminer och alkoholer. <br /> <br /> I detta arbete har området LOHCs undersökts utifrån effektiv katalys för dehydrogenering i flöde, där flödet av LOHC ämnar replikera vårt nuvarande nyttjande av bränsle. När katalysatorerna fästs i metaloxider kan de enkelt separeras från vätskan och vätgasen. Den cykliska aminen 4-metylpiperidin användes här som LOHC och en skillnad i katalytisk aktivitet beroende på vilken metaloxid som användes och hur många kemiska grupper på katalysatorn som potentiellt kunde fästa iakttogs. Katalysatorn med två aluminiumoxidförankrande grupper gav snabbare dehydrogenering jämfört med katalysatorn med endast en förankrande grupp. Dessa var båda bättre än en tredje katalysator med en kiseloxidförankrande grupp. Alla tre var annars identiska, med iridium som det katalytiskt aktiva centret. Hur mycket av vätskan som dehydrogenerades var starkt kopplat till flödeshastigheten, då ett snabbt flöde innebär en kortare tid spenderad med katalysatorn. Vid lägre flödeshastigheter och högre temperaturer var närmare 40% av vätskan åtminstone delvis dehydrogenerad, medan mindre total vätgas producerades då mindre av aminen processades. Båda aluminiumoxidförankrade katalysatorer var relativt stabila även vid höga temperaturer, och den dubbelt förankrade katalysatorn var fortfarande delvis aktiv efter flödesreaktion under 32 h i 350 grader. Resultaten är lovande, men påvisar ett problem i användandet av LOHCs, vilket är balansen mellan en rimlig mängd vätska att använda för att extrahera den nödvändiga mängden vätgas. En hög flödeshastighet kan producera betydligt större mängder vätgas, men den procentuella mängden av vätskan som dehydrogeneras sjunker samtidigt. Det är även bara en bråkdel av molekylerna som dehydrogeneras fullständigt, något som är önskvärt för att minimera mängden LOHC som behövs. Både katalysator och LOHC har betydelse för fortsatt förbättring av dessa resultat, och det är möjligt att dessa katalysatorer skulle kunna prestera ännu bättre med ett annat val av LOHC. 2021 eng organic chemistry catalysis pincer complex iridium LOHC dehydrogenation Chemistry 9061037 2021-07-06T11:14:23+02:00 2021-07-07T09:36:28+02:00 2021-07-07T09:36:28+02:00

oai:lup-student-papers.lub.lu.se:9062580 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Linn Nilsson author 9062577 Yong Li supervisor Department of Chemistry v1000647 department Introduction: To synthesize a half-sandwich rhodium complex that could be a possible drug targeting malaria.<br /> Background: Resistance to the most successful drug chloroquine is widespread and new possible agents are required to ensure future disease treatment. To introduce organometallic half-sandwich complexes opens up possibilities to modify the drug and to overcome resistance.<br /> Aim: Can a half-sandwich rhodium complex be synthesized with a certain electron withdrawing group and a certain sidechain?<br /> Methods: A synthetic protocol was followed including a 2-step ligand synthesis followed by coordination with a rhodium metal dimer to obtain the final half-sandwich complex.<br /> Results: The salicylaldimine ligand was synthesized with success and purity confirmed by 1H-NMR. The half-sandwich complex was also confirmed by 1H-NMR to have been successfully obtained.<br /> Conclusion: The half-sandwich rhodium complex was synthesized with success but no biological activity testing was performed. Malaria är den sjukdom som leder till näst mest dödsfall i världen. Varje år resulterar den i 1.0 till 2.5 miljoner dödsfall och 500 miljoner insjuknanden. Malaria orsakas av parasiten Plasmodium som sprids till människors blodomlopp via myggbett. Där genomgår den olika reproduktionssteg och ligger gömd för människans immunförsvar i de röda blodcellerna där den bryter ner hemoglobin för att få näring. Det bildas då ett giftigt restavfall för parasiten, men som den tar hand om genom att sätta ihop de giftiga resterna i en lång kedja. Det är just denna process som de flesta malarialäkemedel jobbar mot, så att den giftiga miljön kvarstår och parasiten således dör. Det första effektiva botemedlet mot Malaria upptäcktes i Sydamerika, nämligen barken från cinchona-trädet och togs till Europa på 1600-talet. Dess aktiva substans isolerades på 1800-talet och namngavs kinin. Resistens mot kinin rapporterades på 1900-talet och nya läkemedel behövde hittas. På 1930-talet upptäcktes det hittills mest framgångsrika malarialäkemedlet klorokin. Både kinin och klorokin tillhör gruppen kinolin-malarialäkemedel som har vissa speciella egenskaper för att just kunna upprätthålla den giftiga miljön mot parasiten i de röda blodcellerna: en särskild ringenhet, en elektrondragande grupp och en basisk sidogrupp. Då det ständigt uppstår läkemedelsresistens måste nya läkemedel hittas och det är främst den basiska sidogruppen som det görs modifikationer i för att få fram en ny molekyl som inte parasiten känner igen. Att använda metaller i sidokedjan har visat sig ha god effekt mot klorokinresistens med ferrokin som exempel. Ferrokin, som är ett sandwich komplex, skapades på 1990-talet och var det första metallorganiske läkemedlet att genomgå kliniska tester. Ett sandwich komplex innebär att en metallatom befinner sig mellan två plan av parallella organiska (kolinnehållande) ringar. I ett halv-sandwich komplex å andra sidan byts ena organiska ringen ut mot något annat och då bildas ännu fler möjligheter till att modifiera sidokedjan.<br /> I detta kandidatarbete skapades just ett halv-sandwich komplex med metallen rodium.<br /> Tidigare har halv-sandwich komplex av bland annat rutenium, krom, renium, mangan, osmium, rodium och iridium skapats tillsammans med olika sidokedjor men med samma elektrondragande grupp, en kloratom i en viss position. I detta kandidatarbete har den elektrondragande gruppen bytts ut mot en annan, från en kloratom till en kolatom med tre fluoratomer på. Genom att skapa olika kombinationer av metaller, sidokedjor och elektrondragande grupper kan ett bibliotek byggas i kampen mot läkemedelsresistensen. 2021 eng Antimalarial treatment Drug resistance Half-sandwich complexes Inorganic chemistry Quinoline chemistry Chemistry 9062580 2021-08-10T09:01:00+02:00 2021-08-16T11:51:32+02:00 2021-08-16T11:51:32+02:00

oai:lup-student-papers.lub.lu.se:8983760 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Richard Olofsson author 8982362 Helena Svensson supervisor Meher Sanku supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department A rather hot subject in today’s society is global warming. Both technical progresses and global agreements between nations are much needed to counter this ever growing world problem. In this report a novel CO2-capture system, using the sterically hindered amine 2-amino-2-methyl-1-propanol (AMP) and N-methyl-2-pyrrolidone (NMP) as an organic solvent, is investigated by process simulation in the software Aspen Plus™ using the property method “Non Random Two Liquid” (NRTL). Expected chemical reactions occurring within the system are ionic. Since the property method of NRTL is in general not suitable for ionic reactions the main aim of this study is to examine if acceptable assumptions can be made to simplify the process, making NRTL a viable option as chosen property method. To do so a full working industrial model of a CO2-capture system was not needed and so the process was simplified to a flash vessel.<br /> Binary interaction for the process were described with NRTL-pair-parameters and Henrys theorem, the latter one accounts for non condensable gases such as CO2. These parameters were regressed from experimental data from various studies of Karlsson, Sanku and Svensson. Pure component parameters were either obtained from literature or estimated using various software’s from molecular structure. Several methods to describe chemical reactions and precipitation products, namely an AMP-carbamate, were evaluated and suitable ones were tested in the process simulations. Det talas allt oftare om stigande världshav, tropiska stormar och klimatflyktingar. Vi vet alla att vi måste minska våra CO2-utsläpp för att överleva följderna av den globala uppvärmningen. Om det ändå fanns<br /> något sätt att samla upp all CO2 från luften så hade kanske den globala uppvärmningen varit ett minne blott…. Men hör här, denna teknik finns redan idag!<br /> Tekniken kallas CO2-absorptionsteknik med aminen 2-amino-2-methyl-propanol (AMP) och denna studerades i examensarbetet. Tekniken möjliggör att CO2 kan avskiljas från industriella avgaser och fria luften. Denna CO2 kan sedan återanvändas som t.ex. drivgas i sprayflaskor eller som mat till alger som i sin tur kan tillverka biobränsle. https://lup.lub.lu.se/student-papers/record/8983760/file/8983762.pdf application/pdf 1216953 no 2019 swe Kemiteknik Chemical engineering Technology and Engineering Chemistry https://lup.lub.lu.se/student-papers/record/8983760/file/8983764.pdf application/pdf no 8983760 2019-06-14T11:56:26+02:00 2019-07-04T13:08:49+02:00 2019-07-04T13:08:49+02:00

oai:lup-student-papers.lub.lu.se:8983803 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Björn Pålsson author 8913609 Javier Linares-Pastén supervisor Department of Chemistry v1000647 department The many advantageous abilities of plastics have made them omnipresent in today’s society. However, the low cost of production, light weight, durability and insolubility in water combined with inadequate waste handling have led to a vast and increasing accumulation of plastics in nature, approximated to be over 6 300 million tons (Geyer, Jambeck and Law, 2017, ‘Production, use, and fate of all plastics ever made’, Science Advances, 3(7), pp. 1-5). In addition to being unsustainable and environmentally hazardous, this is an enormous waste of resources. Thus, new recycling methods which are economically favourable compared to de novo production and which don’t require any hazardous chemicals or large amounts of energy are being sought among organisms which are able to degrade what was previously considered biologically non-degradable plastics. One such organism is the bacteria Ideonella sakaiensis which is able to use PET (for instance used in soda bottles) as its source of carbon and energy using a PET-degrading enzyme known as PETase (Yoshida et al., 2016, ‘A bacterium that degrades and assimilates poly(ethylene terephthalate)’, Science, 351(6278, pp. 1196-1199). In this thesis, the first glance at a number of novel PETase-homologs as well as a lipase is presented, including the results of their expression, melting point and hydrolysis of para-nitrophenyl esters. Nothing conclusive can be stated regarding the plastic degrading abilities (or lack thereof) of the proteins, but the results may provide some insights beneficial to future studies. Med ordet ’plast’ avses i vardagligt bruk typiskt helt eller delvis syntetiskt framställda polymerer (långa kedjor av upprepande mindre enheter), ofta tillverkade av ursprungligen fossilt råmaterial. Tack vare det stora omfång av önskvärda egenskaper som plaster generellt besitter, däribland uthållighet mot biologisk och kemisk nedbrytning samt låga produktionskostnader, har plaster blivit allstädes närvarande i, och utgör en förutsättning och ett kännetecken för, det moderna samhället. <br /> Plasters beständighet leder dock till att de i praktiken inte bryts ned i naturen utan istället ansamlas och påverkar jordens ekosystem. Denna ackumulering innebär inte bara en rent fysisk nedskräpning av plastskräp som djur kan försöka äta eller trassla in sig i utan tycks även påverka på en cellulär nivå: Små plastbitar (så kallade mikroplaster eller nanoplaster) adsorberar och bär med sig olika organiska miljögifter, olika hälsovådliga tillsatser till plaster (flamskyddsmedel, mjukgörare, m.m. som i flera fall har visat sig kunna störa det endokrina systemet hos människor) läcker med tiden ut och de spjälkningsprodukter som kan bildas genom den långsamma nedbrytningen av plast kan vara hälsovådliga. <br /> Återvinning av plast har nackdelarna att den ej är ekonomiskt lönsam jämfört med nyproduktion och att den återvunna plasten typiskt är av lägre kvalité än den nytillverkade plasten medan förbränning, vilket förvisso löser nedskräpningsproblemet och erbjuder en form av energiåtervinning, släpper ut växthusgaser (och beroende på plasten eventuellt andra icke önskvärda ämnen så som HCl från PVC). <br /> Därför är det av intresse att identifiera organismer (och specifika enzym) som förmår bryta ned plast för att därigenom kunna utveckla biologiskt baserade återvinningsmetoder. Nyligen identifierades en bakterie, Ideonella sakaiensis, vilken kan utnyttja PET-plast som kol- och energikälla. Det enzym som påskyndar själva spjälkningen av plastens ryggrad (bryter ned polymeren tillmindre enheter) kartlades och fick namnet ’PETas’. <br /> I denna uppsats redovisas resultaten av en första undersökning av ett antal okända proteiner vilka utifrån sina likheter med PETas förmodades möjligen kunna spjälka plast. Även ett lipas undersöktes då de bindningar som lipaser klyver i fett (esterbindningar) återfinns hos vissa plaster (så som PET). Resultaten för bland annat genuttryck, smältpunktsanalys och hydrolys av para-nitrofenolestrar redovisas. Inga definitiva slutsatser kunde dras angående proteinernas plast-spjälkande förmågor men förhoppningsvis kan resultaten vara till gangn för framtida studier därkring. https://lup.lub.lu.se/student-papers/record/8983803/file/8983816.pdf application/pdf 2481947 no 2019 eng PETase PET plastic degrading enzyme biotic degradation plastic degrading organisms biochemistry biokemi Biology and Life Sciences Chemistry 8983803 2019-06-14T12:53:13+02:00 2019-07-04T13:27:32+02:00 2019-07-04T13:27:32+02:00

oai:lup-student-papers.lub.lu.se:8984749 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Emil Steen author 8984638 Margareta Sandahl supervisor Department of Chemistry v1000647 department Introduction: Knowing diffusion coefficients in supercritical carbon dioxide is important from an efficient process in chromatography and extraction.<br /> <br /> Background: Several papers have estimated diffusion coefficients in pure supercritical carbon dioxide, but rather few have investigated the effect of adding a cosolvent.<br /> <br /> Aim(s): Building and validating a system for estimating diffusion coefficients in supercritical carbon dioxide and in supercritical carbon dioxide with a cosolvent.<br /> <br /> Methods: Taylor dispersion technique using a long hollow capillary. <br /> <br /> Results: Diffusion coefficients of toluene was estimated at 40 °C and 60 °C at the pressures 158 bar and 180 bar. The diffusion coefficients were estimated to be between 6.4*10-9 (± 2.0*10-9) and 8.2*10-9 (± 3.4*10-9) m2/s. The diffusion coefficients varied inside a series of injections. Ethanol was not added into the carbon dioxide due to time limitations. <br /> <br /> Conclusion: The large variance in the estimations of diffusion coefficient means that no conclusion of the effects of pressure and temperature could be made. From high concentration to low concentration<br /> Imagine dropping a single drop of red food colouring in the middle of a glass of water. The red colour spreads slowly from the middle of the glass out to its sides. Eventually the whole glass is filled with a red solution. Or when you are in your kitchen cooking food, the fragrance is the most pronounced right at the stove. But slowly the aroma is spreading into all the rooms in your house, and soon the whole family comes rushing to the kitchen starving. At the source, when the red drop just mixed into the water glass or at the stove, the concentration of colour and aroma is the highest. But as time goes, the colour and aroma spread out to places of lower concentration, the rest of the water glass or the rest of your house. Both colour and aroma consist out of different molecules. The spreading of these molecules is due to something called diffusion and occurs every time there is a difference in concentration between two points. <br /> <br /> The aim of this study is to measure molecular diffusion but not in media like water in your water glass or in the air you breathe, but in a medium that is called supercritical carbon dioxide. If we take carbon dioxide gas, released by cars for example, purify it from other substances that are also abundant in exhaust from cars and put it under pressure we get carbon dioxide as a liquid. It is even possible to make solid carbon dioxide by applying pressure and lowering the temperature, something we call dry ice (which can be used in movies to create a dense fog when mixed with water). If we increase the pressure and temperature of the carbon dioxide enough, we get something that behaves both like a liquid and a gas, called supercritical carbon dioxide (a supercritical fluid). <br /> <br /> We can use this supercritical carbon dioxide to separate or extract different compounds from a sample, called supercritical fluid chromatography and supercritical fluid extraction. Think of the red drop being dropped into viscous honey instead of water, and the increase in time for the same spreading. The aim of this study is to estimate diffusion in supercritical carbon dioxide, under various temperature and pressure conditions, meaning different viscosities. <br /> <br /> In this study, diffusion rates were estimated in supercritical carbon dioxide at 40 °C and 60 °C at two different pressures, 158 bar and 180 bar. 2019 eng Supercritical carbon dioxide Diffusion Viscosity Taylor Toluene Analytical chemistry Analytisk kemi Chemistry 8984749 2019-06-17T13:04:52+02:00 2019-07-04T13:24:02+02:00 2019-07-04T13:24:02+02:00

oai:lup-student-papers.lub.lu.se:8984809 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Caroline Olsson author 8911969 Associate Professor Ingemar André supervisor Department of Chemistry v1000647 department Lumazine Synthase forms pentamers, C5 in some organism and icodahedra, Ih in other. The aim of this project is to investigate which evolutionary steps could have led the pentamers to assembly into icosahedral capsids. Therefore prevoius work has been performed to reconstruct ancestral sequences for the pentameric and icosahedral forms of Lumazine Synthase. The icosahedral sequence had been expressed and shown to give insoluble expression. The work in this thesis has therefore been done to, firstly, try to purify and refold the protein from inclusion bodies and secondly, try to improve the sequence to give soluble expression.<br /> <br /> Expression of the protein resulted in the protein in inclusion bodies. The protein could be purified from the inclusion bodies by guanidine·HCl extraction and size exclusion chromatography. However it was not possible to refold the protein into native structure by dialysis to remove the denturant, guanidine·HCl.<br /> <br /> To improve the sequence to give stable expression, a stability assay system was used in combination with random mutagenesis of the sequence. The stability assay system consist of two reporter proteins, red fluorescent tagRFP and green fluorescent sf -GFP. Expression of the protein is monitored by red fluorescence by tag RFP fused to the protein and the stability of the expressed protein is monitored by sf -GFP expressed under the control of stress activated DnaK promoter. The random mutagen- esis was performed by error prone PCR to produce fragments spanning the sequence of Lumazine Synthase. The created fragments were then used as megaprimers to amplify the whole plasmid containing the protein with tagRFP and the stability assay system. Proteiner är de små byggstenar som bygger upp nästan allt omkring oss. Proteiner bygger upp våra kroppar och utför olika funktioner som är livsviktiga för alla djur, växter och andra organismer. Byggstenarna kan ha olika former och utseende och de har olika funktioner. Det finns proteiner som hjälper till att bryta ner maten vi äter, proteiner som bygger upp våra muskler och massor av andra proteiner som hjälper till med olika kemiska reaktioner. Proteinerna består av långa kedjor av aminosyror som sitter ihop i en viss ordning, en viss sekvens. Genom evolutionens gång har proteinernas sekvenser förändrats och utvecklats till de varianter som finns i olika organismer idag. Många proteiner är lite annorlunda beroende på vilken organism man undersöker.<br /> <br /> Det protein som detta arbete undersöker heter Lumazine Synthase och det bildar tre olika varianter i olika organsimer. I svampar och arkéer bildar 5 proteinenheter, som sitter i en cirkel tillsammans, så kallade pentamerer av proteinet. I de flesta bakterier bildar 12 stycken pentamerer tillsammans en sfärisk struktur. Ungefär som rutorna på en fotboll sitter de 12 pentamererna sida vid sida och bildar en rund kapsel. I vissa organismer sitter två pentamerer ihop som en sandwich. Det är intressant att det bara är i vissa organismer som enheterna bildar kapslar medan de i andra organismer bara bildar pentamerer eller dubbla pentamerer. Därför vill man undersöka hur det kan ha gått till när evolutionen har gjort så att det finns dessa varianter. Det måste ha skett några förändringar i strukturen som gjorde att pentamererna kunde sitta ihop i varandra och bilda kapslar. Därför har man räknat ut vilken sekvens den första Lumazine Synthase som bildade en kapsel kan ha haft.<br /> <br /> Det som ställde till med ett problem var att sekvensen man räknat fram inte lyckades bilda ett stabilt protein. Därför ville man försöka ändra på sekvensen litegrann för att få ett lite mer stabilt protein. Detta kan man göra genom att driva en slags evolution på liten skala genom att göra slumpmässiga förändringar i aminosyrasekvensen och sen välja ut varianter som fungerar bättre. Tanken är då att någon av de slumpmässiga förändringarna ska ge en variant som bildar ett mer stabilt protein vilket man sen kan använda för att undersöka vidare. https://lup.lub.lu.se/student-papers/record/8984809/file/8984815.pdf application/pdf 9425319 no 2019 eng Icosahedra Assembly Lumazine Synthase Fluorescence-Activated Cell Sorting FACS Directed evolution Random mutagenesis Stability Structure Biochemistry Biokemi Chemistry Biology and Life Sciences 8984809 2019-06-17T14:48:39+02:00 2019-07-04T15:57:50+02:00 2019-07-04T15:57:50+02:00

oai:lup-student-papers.lub.lu.se:8984918 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Guillem Onyos de Plandolit Ruiz author 8984914 Tommy Nylander supervisor Department of Chemistry v1000647 department Biomedical application of nanoparticles is largely associated to their fate in biological media which, in fact, is related to their surface properties. Surface functionalitzation plays a key role in determining biodegradation, cytotoxicity and biodistribution through interactions which may be meditated by the macromolecules occurring in biological media. This project is focused on the effect of different buffers on lysozyme adsorption on flat silica surfaces and hydrophobized silica surfaces as well as mesoporous silica nanoparticles functionalized with amino groups (MSN-NH2). In order to know the adsorption amount of lysozyme we used ellipsometry, where each buffer has been studied independently at two different buffer concentrations at the same pH. The effect of different buffers can be related to specific ion effect described interaction of buffers and salts induces relevant effects on the charged interfaces (Hofmeister effect), and thus lysozyme loading.<br /> Lysozyme adsorption on silica and hydrophobized silica as well mesoporous silica at pH 7.15 was found to be buffer specific. The BES buffer seems to present a unique characteristic behavior which does not allow desorption. TRIS buffer shows the highest lysozyme adsorption amounts, while citrate and phosphate buffer usually show quite similar results.<br /> The sequential addition of MSN-NH2 causes more extensive desorption of lysozyme from the flat surface as observed with ellipsometry. Large effects of the buffer are also observed. The competitive adsorption to the particles, i. e. lysozyme protein corona formation, is likely to promote detachment from the silica surface The use of improved pharmaceutical formulations, which release the drug at the targeted cancerous tissue only, would reduce undesired side effects of the chemotherapeutics. Thus, nanoparticles are often helpful in order to reduce those side effects in biological media due to their surface properties. Surface functionalitzation plays a key role in in determining biodegradation, cytotoxicity and biodistribution through interactions which may be meditated by the macromolecules occurring in biological media. <br /> This project is focused on the effect of different buffers on lysozyme adsorption on flat silica surfaces and hydrophobized silica surfaces as well as mesoporous silica nanoparticles functionalized with amino groups (MSN-NH2).<br /> In order to know the adsorption amount of lysozyme we used ellipsometry, where each buffer has been studied independently at two different buffer concentrations at the same pH. The effect of different buffers can be related to specific ion effect described interaction of buffers and salts induces relevant effects on the charged interfaces (Hofmeister effect), and thus lysozyme loading.<br /> Lysozyme adsorption on mesoporous silica at pH 7.15 was found to be buffer specific. <br /> The sequential addition of MSN-NH2 causes more extensive desorption of lysozyme from the flat surface as observed with ellipsometry. Large effects of the buffer are also observed. The competitive adsorption to the particles, i. e. lysozyme protein corona formation, is likely to promote detachment from the silica surface. <br /> Lysozyme adsorption relies upon buffer salts electrostatics considerations on MSNs surfaces; citrate and phosphate molecular structures grant an akind lysozyme loading performance while BES and TRIS present an utterly diverse performance.<br /> Conclusevly, these nanoparticles would allow to conduct further studies on targeting cancerous cells as their surface properties could be used in biological media. https://lup.lub.lu.se/student-papers/record/8984918/file/8984920.pdf application/pdf 2784780 no 2019 eng Ellipsometry mesoporous silica nanoparticles surfaces physical chemistry fysikalisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/8984918/file/8985192.pdf application/pdf Popular Science LU/LTH access Thesis 8984918 2019-06-17T17:09:08+02:00 2019-07-04T13:47:17+02:00 2019-07-04T13:47:17+02:00

oai:lup-student-papers.lub.lu.se:8987215 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM1 Maria Häggström author 8987213 Jimmy Lodel author 8987218 Olena Prykhodko supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Food Science 011300190 department Enligt studier har ananasens enzym bromelain en positiv effekt på hälsan, exempelvis anticancereffekt samt en gynnsam verkan för matsmältningen. Bromelain har även visat sig vara inflammationsdämpande samt att det ökar proteinupptaget hos äldre. I nuläget finns ingen produkt på den svenska marknaden inom functional food med tillsatt bromelain. Functional food är en produkt som intas som ett vanligt livsmedel men med bevisade goda hälsoeffekter.<br /> Syftet med detta examensarbete var att med hjälp av laborationer undersöka om det skedde en förändring av bromelainaktiviteten vid olika processer i tillverkningen av olika ananasprodukter. Fortsättningsvis ville vi se om produkternas olika hållbarhetstid hade någon inverkan på resultatet.<br /> Bromelainaktiviteten mättes med kasein som substrat på ett antal produkter, som finns i en vanlig svensk livsmedelsbutik. En del av dessa var rena ananasprodukter, i andra var ananas en ingrediens. Vid jämförelse med juice från färsk ananas, visade det sig att de pastöriserade och tryckbehandlade produkterna hade en lägre bromelainaktivitet. Juice gjord av frysta ananasbitar resulterade i aningen högre aktivitet än den som gjordes på färsk ananas. Tre juiceproducenter ombads svara på frågor gällande enzymer och dess effekter samt synen på functional food. According to numerous of published studies, the pineapple enzyme bromelain has a positive effect on human health. This includes an anti-cancerous effect as well as a beneficial influence on digestion. Bromelain has also been shown to have anti-inflammatory properties and to increase protein uptake in elderly. At present time, there are no products at the Swedish Functional food market that has bromelain added to it. Functional food is a product that is eaten as normal food, but with proven beneficial health effects. <br /> The aim of this thesis was to experimentally determine if there was any change in the enzymatic activity at different processes in the manufacture of different products containing pineapple. Furthermore, the objective was also to investigate if the shelf life of the different products had any impact on the results. <br /> The activity of bromelain was measured using casein as a substrate on a number of products, those that can be found in a general Swedish grocery store. Some of these were pure pineapple products such as juice, in others pineapple was one of the ingredients.<br /> As a result, we found that the pasteurized and pressure treated products had a lower bromelain activity in comparison with juice from fresh pineapple. Juice made from frozen bits of pineapple resulted in slightly higher activity than that made on fresh pineapple. Three juice producers were asked to answer questions concerning enzymes in the products and their effects on human health, as well as the view on Functional food. https://lup.lub.lu.se/student-papers/record/8987215/file/8987217.pdf application/pdf 825472 no 2019 swe Bromelain enzym antiinflammatoriskt enzyme anti-inflammatory livsmedelsteknik Chemistry 8987215 2019-06-23T17:18:32+02:00 2019-07-29T15:33:19+02:00 2019-07-29T15:33:19+02:00

oai:lup-student-papers.lub.lu.se:8987446 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Erica Ahl author 8987444 Ingemar André supervisor Department of Chemistry v1000647 department Virus capsids shows promise within a wide variety of applications. However, the current lack of understanding about their self-assembly limits their usefulness. A study of the amino acids relevant for their assembly would be of great use by giving insight to the mechanic behind it. Since the number of proteins involved in each capsid is so big, there is a need for a reporter system enabling easy assaying of the stability between different mutations of the protein. A system proposed allows simultaneous monitoring of both the production and stability of the capsid forming protein in vivo. The production monitoring part is created by linking a fluorescent gene to the protein gene, creating a fusion protein with a measurable signal. In this project a production monitoring system is created where only a small proportion of the translation leads to the fusion protein. This in order to minimize the destabilizing effect of the fluorophore on the protein’s capsid forming ability, while still allowing a signal that can be converted into amount of protein produced. This is achieved by digestion ligation where a frameshift sequence is placed between the two genes. The frameshift sequence directs how much of non-fusion to fusion protein is expressed during translation. Viruses are the cause of a large variety of diseases, some currently cureless, like HIV, and some harmless but persistent, like the common cold. One of the things giving the viruses such perseverance is the protective protein coat, called capsid, that encapsulate their genomic material. This capsid packs, protects and delivers the genomic material to the cell intended for infection. <br /> The capsids are complex and the proteins forming the capsids will spontaneously assemble into their capsid formation when in contact with each other. The mechanism behind this self-assembly is poorly understood. If knowledge about the driving forces behind this assembly could be widened this would be useful in cases where the virus eludes the body’s own immune system by hiding within capsids, as is the case with HIV. Virus capsids would be a good target for antiviral drugs seeing as the drugs existing today often targets the virus after it has entered the cell, harming the host cell in the process. <br /> Furthermore, additional knowledge of the capsids would make it possible to manipulate and use them for other purposes. We could modify the protein to encapsulate molecules other than the virus’s genomic material and steer the cell targeting of the capsid. With this level of control very specific drug delivery could be obtained, for example if anticancer drugs could be delivered by targeting only the cancer cells, this would mean a much less harmful treatment than the alternatives currently available. <br /> This is only a small fraction of the possibilities that extended knowledge could lead to. There is a large field of research being made with the purpose of utilizing the capsids unique properties for various purposes. There has been attempts to replicate this self-assembly found in nature, but so far none of the engineered capsids have come close to the sophisticated structures found in virus capsids. <br /> In this group the aim is to build a library of knowledge about one specific virus capsid, the Hepatitis B virus capsid. This library is intended to expand the knowledge of capsid self-assembly by mapping which parts of the Hepatitis B virus’s capsid forming protein is relevant in its assembly. This is accomplished by making small changes in the protein and comparing the stability between the resulting capsids. <br /> One of the problems when studying capsid formation is the large number of proteins that makes up each capsid. In the case of the Hepatitis B virus each capsid consists of either 180 or 240 proteins, this results in a large amount of data when studying these proteins. Therefore, this group is also working towards creating a system, allowing for fast and easy monitoring of these large quantities as they are produced within a cell. The principle of the system is to have one signal reporter, in the form of a fluorescent protein, that is related to the amount of protein the cell expresses and another signal reporter that will indicate how well the protein forms capsids. <br /> In my project I focused on the production measuring part of this system. The easiest way to directly measure the production of a protein is to have the signal reporter directly linked to the protein. However, this alteration to the protein will most likely affect the capsid forming ability of the protein. For the production signal to be of use when compared to the stability signal this interference must be minimised. The system I created makes it so that only a small percentage of the protein expressed will be linked to a reporter, allowing for most of the protein to be unaffected. With this the production signal can still be used to calculate the amount of protein that contributes to the stability signal.<br /> This project is one small step in the direction towards better understanding the mechanics behind capsid assembly. 2019 eng biochemistry biokemi Virus capsid frameshifting Chemistry 8987446 2019-06-24T13:12:53+02:00 2019-07-04T16:24:28+02:00 2019-07-04T16:24:28+02:00

oai:lup-student-papers.lub.lu.se:8987542 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths Technology

studentPublicationsH2 Katarzyna Bengtsson author 8987540 Dr/ Universitetslektor Ed van Niel supervisor Applied Microbiology v1000654 department Biotechnology v1000653 department Under anaerobic condition the specific growth rate of Lactobacillus reuteri DSM 17938 on different sugars, was analyzed using spectrophotometry. Electron acceptor (fructose) supported cells to cope with poor energy recovery by re-oxidising the NADH, thus enabling ATP formation thru acetate production, while fermenting glucose via the phosphoketolase pathway (PKP) and simultaneously operating via Embden-Meyerhof pathway (EMP). The specific growth rate on glucose, maltose and sucrose was improved unquestionably in the presence of fructose. <br /> <br /> Analysis of the fermentation products showed in the fermentations without fructose produced relatively more ethanol than in all other cases studied so far with L. reuteri DSM 17938. It indicated that the enzyme pyruvate dehydrogenase (PDH) is active. It can be hypothesized that the particular growth environment (SD4 without electron acceptor) caused intracellular conditions that activated PDH. Comparison with the literature revealed that this enzyme is highly regulated on metabolic level by a number of metabolites.<br /> <br /> In short, this study displayed that the environmental conditions (anaerobic, pH 5.5) together with medium composition (SD4) had an effect of the fluxes through the two central carbon pathways in L. reuteri DSM 17938, which had no apparent effect on the energy and redox fluxes. Due to that ethanol could be produced via each pathway it made it impossible to estimate the flux in each pathway. Therefore, two extreme cases, regarding the variation in the cofactor formation flux ratio, RJ (ratio between the redox formation flux (JNADH+NADPH), and the energy carrier formation flux (JATP)), were investigated: PDH not active (SD4 media with e- acceptor) and PDH active (SD4 media without e- acceptor). The real case is somewhere between the two cases. Thus the results need verification and further experiments. <br /> Additionally the data obtained from osmotic potential measurements reflected the product formed during the fermentation and showed linear correlation between osmotic potential and optical density. L.reuteri DSM 17938 is a bacterium isolated from breast milk and it is known being beneficial for the human gut. In the commercial production the bacterium is grown in the fermentation tank and than used in tablets. The knowledge of the bacterium behavior is a key for a good growth and subsequently good product. <br /> <br /> Sugar, medium composition and oxygen are impotent components for the bacterial growth. Sugar is the carbon source and oxygen is needed to gain energy. This study investigates changes in the metabolic pathways of L.reuteri when grown on different sugars and specific medium. Sugars such as glucose, maltose and sucrose are used and also combined with fructose. As we grow the bacteria in the tank without oxygen the fructose helps the bacterium obtain energy, fructose is en electron acceptor.<br /> <br /> Using the spectrophotometer measurements we can estimate bacterial growth, how much and how fast our organism grow. Using the chromatography we can identify and calculate amount of the product produced by L. reuteri. Amount of products such as acetate, ethanol and lactate. Results from these two methods, growth velocity and amount of product produced, allow to predict the metabolic pathways taken by bacterium. Usually two pathways can be taken: one producing just lactate (homofermentation) and the other producing acetate and ethanol (heterofermentation). <br /> <br /> Results from these study show that the environmental conditions together with medium composition had an effect on product produced thus the metabolic pathways taken by L. reuteri. Analysis of the fermentation products showed in the fermentations without fructose produced relatively more ethanol than in all other cases studied so far with L. reuteri DSM 17938. It indicated that the enzyme pyruvate dehydrogenase (PDH) is active. It can be hypothesized that the new metabolic pathway was taken connecting homo and heterofermentative pathways. <br /> Particular growth environment (medium without electron acceptor) caused intracellular conditions that activated PDH. Comparison with the literature revealed that this enzyme is highly regulated on metabolic level by a number of metabolites. https://lup.lub.lu.se/student-papers/record/8987542/file/8987557.pdf application/pdf 3164151 no 2019 eng Energy redox fluxes Lactobacillus reuteri DSM 17938 different sugars applied microbiology teknisk mikrobiologi Biology and Life Sciences Chemistry Technology and Engineering 8987542 2019-06-24T15:52:23+02:00 2019-07-04T14:40:47+02:00 2019-07-04T14:40:47+02:00

oai:lup-student-papers.lub.lu.se:8987551 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Roberto Mastio author 8987549 Universitetslektor Ulf Ellervik supervisor Daniel Willén supervisor Department of Chemistry v1000647 department Carbohydrates are found everywhere. They are the main component in the macromolecules glycosaminoglycans, chains of carbohydrates that make up our cartilage but also play important roles in cancer cell proliferation. Xylose is a carbohydrate which initiates the biosynthesis of these chains by acting as a substrate for the enzyme β4GalT7. Some of these GAG chains become toxic for certain cells. The mechanism for the biosynthesis of glycosaminoglycans can be investigated by attaching a fluorescent probe called Pacific blue to xylose and following its path through biosynthesis. To do this, the synthesised products must be able to still act as substrates for β4GalT7 and also to permeate the hydrophobic walls of a cell. Three new compounds where synthesised and their ability to act as substrates to β4GalT7 was investigated. As the compounds are substrates for β4GalT7, further tests on live cells will now be performed. Kemi och kemikalier är något som är inblandat i vårt dagliga liv mycket mer än vi alla tror. När man hör ordet ”kemikalie”, tänker de flesta på något med ett långt konstigt namn, något onaturligt eller farligt. Men allt är kemikalier och bara för att något har ett svårt namn, betyder det inte att det är farligt. Ett exempel är (2R,3S,4R,5R)-2,3,4,5,6-Pentahydroxyhexanal, eller i folkmun ”glukos” som är en kolhydrat.<br /> <br /> Kolhydrater finns i vår mat och ger vår kropp energi. Det finns dock flera kolhydrater, ”Xylos” är ett annat exempel och den har en viktig biologisk roll som ett ”ankare” för biosyntesen av så kallade ”glykosaminoglykaner”, långa kedjor av kolhydrater kopplade till proteiner på cellernas ytor. Dessa kedjor har många viktiga funktioner, de är till exempel en viktig beståndsdel av brosk, inblandade vid nybildning av blodkärl, blodets koagulation och även för celldelningen. Exakt hur dessa kedjor bildas, var de tar vägen i cellen och deras reglering är komplicerat. Ett sätt att försöka ta reda på detta, är genom att koppla xylos till en fluorescerande molekyl vid namn Pacific blue. <br /> <br /> Genom att syntetisera xylos med Pacific blue kopplat till ville vi skapa en molekyl som fortfarande producerar glykosaminoglykaner i kroppen, men som går att se när den bestrålas med UV-ljus. På så sätt kanske en del av gåtorna kring hur glykosaminoglykanerna bildas, var de tar vägen och deras reglering gå att ta reda på.<br /> <br /> Vi syntetiserade tre olika fluoroscerande xylosmolekyler med variation i länken mellan xylos och Pacific blue, men även en analog med svavel istället för syre i kolhydraten. Dessa visade vid ett preliminärt enzymtest ha goda egenskaper som ”ankare” och kan möjligtvis initiera biosyntesen av glykosaminoglykaner. 2019 eng Glycosaminoglycan Proteoglycan Pacific blue Fluorescence organic chemistry organisk kemi Chemistry 8987551 2019-06-24T15:59:53+02:00 2019-07-04T15:55:17+02:00 2019-07-04T15:55:17+02:00

oai:lup-student-papers.lub.lu.se:8987552 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Sofia Dahlqvist author 8981982 Peter Spégel supervisor Department of Chemistry v1000647 department Introduction: This study evaluated lipid identification using mass spectrometry.<br /> <br /> Background: Three main modes of acquisition are used in mass spectrometry of lipids; data-independent acquisition (DIA), data-dependent acquisition (DDA) and targeted acquisition. DIA is the most including one, yielding a complete but complex data set, while targeted is the least including one, basing acquisition on a predefined list. It has not been established which of these methods is able to identify the most lipids, which is a general goal in lipidomics. Furthermore, a local method for analyzing DIA data does not exist.<br /> <br /> Aim(s): The aim of this study was to compare how DIA, DDA and targeted acquisition perform in high-throughput lipid identification and to establish a method for DIA analysis by comparing data-driven and targeted peak picking.<br /> <br /> Methods: DIA (MSe), DDA and targeted acquisition mode was used on a Xevo G2 QTOF (Waters, USA) quadrupole time-of-flight mass spectrometer coupled to ultra-high performance liquid chromatography (UHPLC/QTOF-MS). The software MS-DIAL (RIKEN, Japan) and MRMPROBS (RIKEN, Japan) were used for data-driven and targeted peak picking of DIA data, respectively. Standard settings were used for all methods. The DIA method that identified the most lipids was compared to DDA and targeted acquisition. Comparisons were based on the number of lipids identified from a predefined list containing 34 lipids in negative mode and 23 lipids in positive mode, adding up to a total of 35 individual lipids.<br /> <br /> Results: Data-driven peak picking of DIA data was able to identify 15 lipids, while targeted peak picking identified 26 lipids. DDA did not yield any usable data, but targeted acquisition produced MS/MS spectra for 17 of the lipids from the list.<br /> <br /> Conclusion: When analyzing DIA data, targeted peak picking was more effective than data-driven peak picking, and more lipids were identified with DIA than with targeted acquisition. Further studies are necessary to confirm these findings. How to identify lipids in a sample<br /> <br /> Lipids are molecules that do not interact appreciably with water, they are also called fats, and oil is an example of a mixture consisting of lipids. In the body there are thousands of different lipids serving many different functions. One example is as fat depots, but cell membranes, the shell around each cell, also consist of lipids. Lipids are involved in sending signals, both within a cell and throughout the entire body. By determining which lipids are present in a tissue such as blood, you can discover low or high levels that can be the result of a disease or injury. In this study, I have compared three methods to identify lipids in a sample to see which method finds the most lipids.<br /> <br /> Lipids can be measured with a technique called mass spectrometry, and quadrupole time-of-flight mass spectrometry was used in this study. It is a procedure in which you insert the sample into a machine which converts the molecules into ions, accelerate them through an electrical field, and measure how long time it takes for the molecules to travel through a chamber. The time is related to the size of the molecule, so the machine is essentially a scale for molecules. In addition to this, if you collide the molecules with a gas, they will fragment before the chamber and you can find out how much separate parts of the molecule weighs. With information about the mass of the entire molecule and its parts, you can figure out which lipid it is.<br /> <br /> The three methods compared in this study were one where all lipids in a sample are fragmented, a second in which only the most abundant lipids are fragmented, and a third where a list specifies which lipids to fragment. For the first method, I also tested two different data analysis methods; one where a software does all data processing and gives you a list of lipids, and one where you have to enter a predefined list of lipids and fragments into the software before analysis and the software looks for a match.<br /> <br /> The results showed that you can identify the most lipids by measuring with the method that fragment all lipids, and then use a software that identifies lipids based on a predefined list. 2019 eng Analytical chemistry Data-dependent acquisition Data-independent acquisition Lipid identification Mass spectrometry Targeted acquisition Chemistry 8987552 2019-06-24T16:01:22+02:00 2019-07-04T14:38:17+02:00 2019-07-04T14:38:17+02:00

oai:lup-student-papers.lub.lu.se:8987601 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Joachim Björklund author 8987599 Ebbe Nordlander supervisor Rosely Peralta supervisor Department of Chemistry v1000647 department It is well known that Carbon monoxide is a toxic and hazardous gas, but during recent years it has been proven that using a controlled concentration, carbon monoxide can in fact be used as a therapeutic agent, and can contribute to decrease malaria, treat cardiovascular and lung diseases and potentially even treat cancer, among other things. The main problem in using carbon monoxide directly is the fact that it is not trivial to control the volume of gas inhaled, compromising its use as a therapeutic agent. Much effort has been made to synthesize molecules that can release carbon monoxide, so-called CORMs. The release of the carbon monoxide present in these molecules can occur in different ways: a) exchanging the carbon monoxide with solvent (e.g. water). Although this is an easy and controlled method to release a known quantity of carbon monoxide, it is not possible to guarantee the time and tissue the CO is released. b) triggering the release of carbon monoxide, for example by light exposure (Photo-CORMs). This can be an efficient method, since metal carbonyls are well known as photosensitive systems. <br /> Two Photo-CORMs complexes, Re(aaz)(CO)3]Cl (aaz = 6-amino-6-methylperhydro-1,4-diazepine) and [Re(tacn)(CO)3]Cl (tacn = 1,4,7-triazacyclononane), were synthesized, fully characterized and tested for their ability to release carbon monoxide when exposed to light radiation. By determining the change in oxidation potential through square wave electrochemistry, as well as UV- and IR-spectra, there was enough proof to conclude that the complexes release at least 2 equivalents of carbon monoxide per Photo-CORM when radiated by UV light. <br /> Four new complexes, containing photosensitizers were also synthesized and characterized [Ru(Me2bpy)2Cl2] (bpy = 2,2’-bipyridine) , [Ru(phen)2Cl2] (phen = 1,10-phenanthroline), [Cu(Me2-bpy)2]BF4 (4,4’-dimethyl-2,2’-bipyridine) and [Fe(η5-C5H4CHO)(η6-C6H6)]PF6 ((η5-C5H4CHO)(η6-C6H6) = η6-benzene,η5-cyclopentadienyl). All the four complexes absorb IR radiation and excite the Photo-CORM through triplet energy transfer. The IR spectroscopy showed that all photosensitizers were formed, since there were displacements of the bands and formation of new bands. Det är väl känt att kolmonoxid (CO) är en giftig och hälsofarlig gas som är luktlös, färglös och smaklös vilket gör den svår att detektera utan analytisk utrustning. Men under senaste åren så har forskning bevisat att i små doser så kan kolmonoxid användas som en terapeutisk substans för att lindra malaria, cancer, lung-, hjärt- och kärlsjukdomar men även reducera mängden inflammatoriska substanser i kroppen. Hur får man då in kolmonoxiden i kroppen? Det mest självklara valet är att andas in gasen i små mängder men där uppstår ett problem, då man inte kan kontrollera vart i kroppen kolmonoxiden kommer att distribueras. Istället så kan man då använda så kallade CORMs (Carbon monoxide releasing molecules) för att kunna kontrollera mängden, och distributionen av kolmonoxid i patientens kropp. Dessa CORMs består av ett metall-center (i detta fall rhenium) med kolmonoxid bundet direkt till metallen med diverse ligander bundna till metallen för att ändra hur CORM:en beter sig.<br /> I detta arbete så syntetiserades ett par photo-CORMs, alltså en molekyl som släpper ifrån sig kolmonoxid genom ljusstrålning, för att testa dess effektivitet i att släppa kolmonoxid i lösning. Det gjordes med UV-strålning då CORM:en endast reagerar med UV-strålning. Experimenten var lyckade och kolmonoxid släpptes i lösning och kunde detekteras med hjälp av IR, UV-vis spektroskopi och elektrokemi.<br /> Det är inte alltid gynnsamt att använda UV-strålning då det är farligt för celler, och har en dålig penetrationsförmåga. Det är mycket mer gynnande att använda IR-strålning, men det går inte att ändra beteendet på en CORM så drastiskt så då syntetiserades några PS (Photosensitizers) för att lösa det problemet. En photosensitizer är en molekyl som tar emot elektromagnetisk strålning som exciterar sina elektroner, och överför sedan den exciterade energin till en annan molekyl genom kollision, bland annat. Syntetiseringen av ett par rutenium, järn och koppar komplex var lyckade, men hann aldrig testas i lösning med CORMs, så effektiviteten är ännu okänd. https://lup.lub.lu.se/student-papers/record/8987601/file/8987603.pdf application/pdf 1153760 no 2019 eng Inorganic Chemistry Bioinorganic Chemistry CORM Photo-CORM Photosensitizers Synthesis Characterization Oorganisk kemi Chemistry 8987601 2019-06-24T18:46:01+02:00 2019-07-04T14:36:36+02:00 2019-07-04T14:36:36+02:00

oai:lup-student-papers.lub.lu.se:8987912 2025-07-29T13:03:30Z PhysicsChemistryMaths Technology

studentPublicationsH2 Johanna Hjalte author 8987908 Dan Lundberg supervisor Ola Wendt supervisor Andreas Hugerth supervisor Food Technology and Nutrition (M.Sc.) v1000294 department The aggregation propensity of four GnRH analogues, namely D-Phe6-GnRH, ozarelix, cetrorelix and degarelix has been studied with 1H NMR spectroscopy in 100 % H2O, while tracking changes in pH. A method was developed to study aggregation propensities by variations in absolute integral values over time and with concentration. The method provided an intuitive visual comparison of the aggregation propensities of the peptides and also a rough estimation of the fraction of peptides that were not involved in aggregates. This could be applied in early stages of development of peptide therapeutics when ranking or choosing an appropriate candidate. <br /> <br /> Ozarelix, cetrorelix and degarelix have a single positive charge at the studied concentrations and they all show signs of aggregation. The counterion, acetate, is involved in the aggregates of ozarelix and cetrorelix but not for degarelix. The pH values for cetrorelix and ozarelix increased with concentration, this suggests that aggregates that incorporate acetate also incorporate a proton from the solution. D-Phe6-GnRH is the only peptide studied that has a Histidine residue. The pH values of the D-Phe6-GnRH solutions at the concentrations studied coincide with the pKa of Histidine. Thus, D-Phe6-GnRH has a higher cationic charge than the other peptides of this study and that could explain why D-Phe6-GnRH does not aggregate. Studie av aggregeringstendenser hos en homolog serie peptider med NMR-spektroskopi <br /> <br /> Examensarbetet utvärderar tillämpningen av 1H NMR-spektroskopi med vattenundertryckning vid en första undersökning av aggregeringsbeteende hos fyra närbesläktade läkemedelsmolekyler.<br /> <br /> Utveckling av peptidläkemedel står inför många svårigheter. För det första är de är relativt nya på marknaden. Läkemedelsutvecklare har därför en begränsad mängd publicerat material att använda som guide. Peptider har en komplicerad dynamik som påverkas av sin miljö. De har dessutom kort halveringstid i kroppen. <br /> <br /> Vad som händer med ett peptidläkemedel i kroppen kommer bero på dess formulering, om det ges som spruta eller tablett t.ex. Peptider är mycket känsliga för salter och lösningsmedel. Det finns därför en risk att formuleringen kan inducera aggregering. Aggregering är när molekyler bildar strukturer utan att kemiskt binda till varandra, ett fenomen som kan leda till både nytta och skada. Det finns många typer av aggregat vilket gör att detta kan få flera olika konsekvenser. I utvecklingen av ett nytt läkemedel är det viktigt att förstå hur den aktiva substansen och eventuella sidoprodukter som aggregat, beter sig i olika miljöer. Detta för att undvika farliga konsekvenser i kroppen. <br /> <br /> En formulering anpassas efter peptidens egenskaper, men det är också viktigt att formuleringen är användbar för patienter. Den vanligaste formuleringen för peptidläkemedel är i form av en spruta. Degarelix är ett exempel på en peptid med en smart lösning som innebär en mer bekväm dosering för patienter. Degarelix används som aktiv substans mot prostatacancer. Degarelix blir injicerat i underhudsfettet och aggregerar för att bilda en depå. Läkemedlet löser sig från depån allt eftersom, något som innebär att färre injiceringar för patienten. En dos degarelix förnyas efter 28 dagar medan en närbesläktad peptid bryts efter bara några timmar i kroppen. <br /> <br /> Ett exempel på skadlig aggregering sker när ett specifikt protein i kroppen viker om sig till en struktur som underlättar aggregering. Aggregaten i detta fall blir långa trådar som bildar plack i hjärnan och leder till Alzheimers sjukdom. Mycket forskning kretsar kring denna typ av aggregat. <br /> <br /> I utvecklingen av framtida läkemedel skulle det underlätta med en simpel metod som kan påvisa aggregering för att utesluta skadligt beteende men också påvisa användbara aggregat. Till denna studie valdes fyra peptider (inklusive degarelix) av liknande strukturer som tidigare påvisat olika aggregeringsbeteenden. Detta för att se om en undersökning med NMR-spektroskopi kunde validera och eventuellt ge en ny inblick i deras olika beteenden. <br /> <br /> Majoriteten av analyserna utfördes i rent vatten, detta är ovanligt för analyser med NMR. Vanligtvis används ett deutererat lösningsmedel, som tungt vatten, eftersom det ger direkt jämförbara resultat. Tidigare försök har dock påvisat att tungt vatten påverkar aggregeringstendenser hos peptider. Därför utvecklades en metod där data från körningar i rent vatten kunde jämföras. <br /> <br /> Resultaten var i linje med tidigare resultat och andelen peptider som var involverade i aggregat kunde uppskattas inom grova marginaler. Dessutom påvisades nya intressanta aspekter som beteende över tid och huruvida aggregaten involverade peptidens motjon (alla peptider var ett salt). Sammanfattningsvis pekar detta på att den nya metoden visar god potential för att jämföra aggregerings tendenser inom en serie peptider och att den kan användas för att välja peptidkandidater i ett tidigt skede av utvecklingsprocessen. https://lup.lub.lu.se/student-papers/record/8987912/file/8987926.pdf application/pdf 2009734 yes 2019 eng aggregation peptides proton NMR pharmaceutical technology läkemedelsteknologi Chemistry Technology and Engineering 8987912 2019-06-25T13:04:30+02:00 2019-07-04T16:54:49+02:00 2019-07-04T16:54:49+02:00

oai:lup-student-papers.lub.lu.se:8988015 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Greta Bürger author 8987507 Dr Åsa Davidsson supervisor Chemical Engineering (M.Sc.Eng.) v1000299 department Many regions around the world suffer from occasional or permanent droughts. Recent years have shown that although Sweden is not a water scarce country, it is vulnerable to dry peri- ods. As drinking water is applied in not only households, but within agriculture and indus- tries, this thesis explores the opportunities to achieve an improved management of water re- sources, by investigating the possibilities to reuse treated wastewater.<br /> By collaborating with water associations and industries around Sweden, a categorization of the main water consuming applications within industries was established. These were found to be cooling water, boiler feed, the washing of vehicles and water for recreational purposes. The reuse within agriculture and directly at the wastewater treatment plant were also investi- gated although mainly through literature.<br /> It was found that a large interest in the topic is present within the industries and the environ- mental incitement is strong. It was though also communicated that the environmental benefits alone will not be motivation enough, the economical incitement dominates, since drinking water is easily accessible at a relatively low cost.<br /> Further, this study proposes processes, which could be installed in the wastewater treatment plant, to achieve the water qualities required by the industries. The proposed processes in- clude activated carbon, reverse osmosis, nano-, micro- and ultrafiltration, ozonation and the disinfection processes ultraviolet light and chlorination. The instalment of nanofiltration showed a reduction or elimination of most substances, relevant for the categories for imple- mentation. The remaining processes have abilities to reduce or eliminate some substances and it was further investigated if a combination of processes could be beneficial.<br /> For a more holistic approach, the legal aspects and costs were looked into, with the conclusion that clarifying definitions about treated wastewater are needed, as it has the possibility not to be seen as waste, but as a bi-product of the treatment process. Depending on the classification, the possibilities of reusing treated wastewater change.<br /> The range of costs is large, depending on mainly the process which needs to be installed at the treatment plant and the connecting pipe systems, since local differences may have large ef- fects.<br /> In conclusion, the reuse of treated wastewater does have potential and with the interest and motivation by industries, it seems like a promising option for the future of water. Drinking water is currently used for many applications, which do not require as high of a qual- ity. At the same time, treated wastewater is discharged into the environment without being fur- ther used. To connect those two topics, this thesis, in collaboration with VA SYD, explores the possibilities for a more conscious water usage.<br /> The reuse of treated wastewater has been done in several countries around the world. These regions suffer from occasional or permanent droughts, and recent years have shown that even northern Europe can experience water shortages. Sweden does not suffer from water scarcity, but reoccurring droughts, have caused for discussions around the usage of drinking water.<br /> With the help from seven other water associations around Sweden, this thesis looked into, if industries have the possibility and motivation, to use another type of water than drinking water, with a focus on treated wastewater. It was found, that there is a great interest and industries are eager to rethink their water usage. As not all processes in industries have the same water quality requirements, it was further looked into, how these differ. The seven main water reuse possi- bilities are cooling water, recreational purposes, cleaning of vehicles, boiler water, food indus- try and process water, wastewater treatment plants and agriculture. As wastewater treatment plants are not designed for the reuse of treated wastewater, additional processes need to be installed to achieve the required qualities. Since wastewater is defined as waste, so is treated wastewater. In order to be able to reuse the water, an end-of-waste procedure could be a solution to re-classify wastewater as a bi-product of an industry. This would enable the water to be reused for other purposes, instead of being discharged into the environment.<br /> The costs to go through with a wastewater reuse project, depend on the location of reuse and the required water quality. To install processes and connect the wastewater treatment plant with the industry can range greatly, due to regional, local and individual circumstances. Industries work towards environmentally benefitting solutions but without an economical benefit of reus- ing treated wastewater, it seems unlikely for them to contribute to the investment. Drinking water is comparably cheap and easily available in Sweden and for industries to invest in the project, more benefits need to become clear.<br /> Concluding, it was found that industries in Sweden have noticed the water issues and the dry summers during the past years. This has contributed to more awareness and environmental thinking around their water usage. As processes exist to fulfill the quality requirements of the industries, the reuse of wastewater could become a valuable option in the future. https://lup.lub.lu.se/student-papers/record/8988015/file/8988022.pdf application/pdf 2524037 no 2019 eng Wastewater Reuse Symbiosis water engineering environmental engineering vattenförsörjningsteknik avloppsteknik Chemistry 8988015 2019-06-25T16:16:54+02:00 2019-07-04T16:46:31+02:00 2019-07-04T16:46:31+02:00

oai:lup-student-papers.lub.lu.se:8988147 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Nikol Labecka author 8885015 Emma Sparr supervisor Enamul Mojumdar supervisor Department of Chemistry v1000647 department Stratum corneum (SC) is the outer most layer of the epidermis recognized as the main barrier of the skin. The most important function of SC is to regulate water loss to the outer environment and prevent the chemical as well as microbial invasion. This exceptional ability of SC is attributed to its composition and architecture which resembles an actual brick and mortar wall. The structure and composition of this brick wall can be altered with genetic disorders or exposure to environmental factors and result in enhanced permeability of the skin barrier. In case of Psoriasis, an already impaired SC barrier is further exposed to chemical and irradiation treatments with purpose to reduce pathogenesis of the disease. To understand the effect of such treatments on the skin barrier function, one need to evaluate alteration in the structure and mobility of SC components on molecular level. <br /> <br /> In this work, the alteration in SC structure and molecular mobility after UVB exposure and chemical treatment with hydrocortisone, salicylic acid and UCA are evaluated by employment of 13C solid-state NMR, WAXS scattering and AT-FTIR. The hydrocortisone and salicylic acid are first in line substances used in treatment of several skin conditions where UCA is a naturally occurring chromophore in the skin. We show that these molecules affect the mobility of SC components differently, where Salicylic acid and UCA increase the mobility of lipids and proteins where hydrocortisone has an opposite effect. The mobility of SC components after UVB treatment was observed to decreases. However, no significant structural changes in both UVB and chemically treated SC samples were observed. Finally, microscopic changes were correlated to the macroscopic changes regarding water swelling. It was shown that the untreated SC samples had larger water uptake in comparison with UVB and chemically treated SC samples. An attempt to evaluate the effect and interference between combinational UVB and chemical treatments on SC layer was also performed. We showed that the chemical treatment with salicylic acid has a stronger effect on molecular mobility of SC in comparison with UVB treatment. UV/Vis spectroscopy was employed on chemically treated SC samples to evaluate the interference between combinational UVB and chemical treatments employed for Psoriasis patients. We show that the natural occurring photoprotective barrier (in the UVB range) of the skin is enhanced after UCA and salicylic acid treatments where no changes are observed after hydrocortisone treatment. <br /> <br /> The results of this thesis shows that UVB and chemical treatments impose microscopic and macroscopic changes in SC which can be correlated and provide widely useful information about the behaviour of the skin barrier. Kroppens största organ utgörs av huden, en töjbar och mjuk vävnad vars viktigaste uppgift är att skydda oss från omvärlden. Hudens yttersta lager, hornlagret eller Stratum Corneum på latin, utgör den viktigaste barriären mot yttre fiender som skadliga virus, bakterier och giftiga kemikalier. Hornlagrets barriäregenskaper beror på dess sammansättning och uppbyggnad, som kan liknas med en tegelstensmur. Den största komponenten utgörs av döda hudceller dvs. tegelstenar som är omgivna av ett fetthölje motsvarande cement. Likt en tegelmur, kan hornlagrets konstruktion brista. Ärftliga sjukdomar och yttre faktorer kan försvaga huden barriären mot omvärlden genom att förändra hornlagrets sammansättning och uppbyggnad.<br /> <br /> Psoriasis är en kronisk sjukdom som orsakar inflammation i huden med utslag i form av plackbildning. Behandling av sjukdomens framfart innebär en livslång användning av kortisonsalvor, i många fall kombinerat med en UVB-ljusbehandling. Denna typ av behandlingar härmar plackbildningen genom att härma tillväxten av hudceller men kan i sin tur orsaka molekylära förändringar i tegelmurkonstruktionen. Denna typ av förändringar samt deras påverkan på hornlagrets egenskaper utgör utgångspunkten för detta arbete. Det är även av intresse att undersöka hur kemiska behandlingar med exempelvis kortisonsteroider och mjukgörandemedel kan interferera med UVB-ljusbehandlingen. <br /> <br /> I detta arbete har molekylära förändringar i hornlagret undersökts med hjälp av kärnmagnetisk resonans (NMR) och röntgenljusspridning (X-ray spridning) efter kemiskbehandling med hydrokortison, salicylsyra och urokansyra (UCA). De två förstnämnda molekylerna är relevanta för psoriasisbehandling medan UCA är en naturligt förekommande UVB-filter i huden. Resultaten visade att olika ämne påverkar rörligheten av hornlagrets komponenter (proteiner och fetter) på olika sätt. Både syrorna ökade den molekylära rörligheten i hornlagret (särskild i fetthöljet) medan hydrokortison visade en omvänd effekt. Det fanns även indikationer på att hornlagrets makroskopiska egenskaper som vattenkapacitet var lägre efter kemikaliebehandlingarna. Molekylära förändringar i hornlagret undersöktes även efter en ljusbehandling med UVB där rörligheten av respektive komponenter var lägre än in det obehandlade hornlagret. Inga strukturförändringar i hornlagrets komponenter var observerad efter ljusbehandlingen. I detta arbete utfördes även en kombinationsbehandling med kemikalier och UVB-ljus. Det visades att UCA respektive salicylsyra behandlat hornlager absorberade en högre mängd av UVB-ljus vilken i sin tur kan försvaga effekten av UVB-ljusbehandlingen för psoriasis patienter. Hydrokortison hade ingen effekt på UVB-ljusabsorptionen i hornlagret. Det visades även att salicylsyrabehandling i kombination med UVB exponering har en komplementärade effekt på den molekylära rörligheten i hornlagret. <br /> <br /> Detta arbete demonstrerar hur svårt det är att bestämma olika kemikaliers molekylära påverkan på hudens viktigaste barriär, samt hur viktigt det är med karakteriseringen för att utveckla och förbättra effekten av olika behandlingar. https://lup.lub.lu.se/student-papers/record/8988147/file/8988156.pdf application/pdf 6612862 yes 2019 eng Stratum Corneum UVB chemical treatment molecular dynamics fluidity structure keratin ssNMR X-ray scattering psoriasis physical chemistry fysikalisk kemi Chemistry https://lup.lub.lu.se/student-papers/record/8988147/file/8988159.pdf application/pdf no 8988147 2019-06-25T21:55:54+02:00 2019-07-04T16:02:15+02:00 2019-07-04T16:02:15+02:00

oai:lup-student-papers.lub.lu.se:8988311 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsL3 Miguel López author 8988309 Daniel Strand supervisor Department of Chemistry v1000647 department Natural products are an important source of novel structure and biological activity and often form the basis for the development of new medicines and pesticides. Organic synthesis plays and important in this process from addressing supply to providing access to novel structures through semi-synthesis.<br /> <br /> The [5.5.5.6]dioxafenestrane family of compounds, which feature four fused rings are attractive, and often challenging targets for synthesis. Some members of this family have displayed interesting biological activity but if they are to be fully explored, new synthetic methods towards these complex and varied molecules are needed.<br /> <br /> Challenges observed in the first-generation synthesis of one such compound are addressed in this work. A faster, milder, more efficient and scalable approach has been developed, allowing supply issues in the broader synthesis to be addressed. Preliminary insights into absolute stereocontrol are also presented. With a growing global population, the need for new medicines and adequate food production are increasingly important considerations. Pesticides are widely used to increase the yields of the crops, and as a result the demand for more effective, selective and environmentally friendly pesticides is constantly growing. Natural molecules are often the inspiration for new pesticides and medicines.<br /> <br /> The [5.5.5.6]dioxafenestranes are a family of small complex molecules which possess an intriguing chemical structure and display promising biological activity. New chemical tools are needed to make these and related compounds, if their properties are to be fully explored.<br /> <br /> The chemical synthesis of key intermediates in the synthesis of a [5.5.5.6]dioxafenestrane has been investigated and improved. A faster, milder, more efficient and scalable approach has been developed, allowing large quantities of important compounds to be made quickly. https://lup.lub.lu.se/student-papers/record/8988311/file/8988324.pdf application/pdf 2985411 yes 2019 eng Organic Chemistry Organisk Kemi Total Synthesis Chemistry 8988311 2019-06-26T11:59:33+02:00 2019-07-04T16:09:29+02:00 2019-07-04T16:09:29+02:00

oai:lup-student-papers.lub.lu.se:8988390 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Carl Eric Onema author 8913931 Kenneth Wärnmark supervisor Lisa de Groot supervisor Valtýr Freyr Hlynsson supervisor Department of Chemistry v1000647 department 4-Bromo-3-methylaniline was used as the starting block to synthesise a Tröger’s base analogue with the aim of fusing the final monomer into a nanotube. The intermediates were to be characterised using 1H-NMR, 13C-NMR, infrared-, high resolution mass spectrometry, elemental analysis, and X-ray crystallography amongst other. At the end, 356 mg of N-((5R,6S,11R,12S)-8-amino-6,12-bis(methoxymethyl)-1,7-dimethyl-6H,12H-5,11-methano-dibenzo[b,f][1,5]diazocin-2-yl)-2,2,2-trifluoroacetamide, the target monomer used for fusing the Tröger’s base analogue into a potential nanotube, were synthesised and characterized by 13C-NMR and melting point analysis. Kemi är en viktig del i våra dagliga liv och den är fylld med många invecklade processer och mekanismer.<br /> <br /> Några av oss kanske kommer ihåg tumregeln ”lika löser lika” från kemiundervisningen. Detta påstående stämmer i de flesta sammanhangen inom kemin och kan i vissa fall leda till problem om vi till exempel hade haft smutsig tvätt och enbart hade använt vatten vid rengöringen.<br /> <br /> När vi använder vatten i våra tvättmaskiner, vilket som sagt inte är det bästa medlet att lösa upp smuts och fett på våra kläder, introducerar vi ofta molekyler som kallas tensider via vårt tvättmedel för att hjälpa till. Men det finns gånger då tillägg av tensider för att öka ett ämnes löslighet i vatten är en dålig idé och där andra alternativ behövs. Ett sådant fall är när vi vill sätta in medicin i våra kroppar.<br /> <br /> Varje levande människa består av flera billioner celler, och celler har ett membran som består av ett dubbelskikt av lipider och är oftast en fettsyra, i detta fall en fosfolipid. Lipider hittar vi också i de vegetabiliska oljor vi använder och vi känner alla till att olja inte är lösligt i vatten. Liknande paralleller kan dras för många medicinskt aktiva ämnen och vårt blod, som till 50% består av vatten, vilket leder till att dessa hydrofoba medicinska molekyler behöver hjälp för att transporteras via blodet.<br /> <br /> Ett sätt att tillåta transporten av aktiva substanser är att omsluta dem i ”värdmolekyler”. Med hjälp av lämpliga nanorör skulle ämnen som har goda medicinska egenskaper, men saknar löslighet i blod, kunna administreras i en rad olika behandlingar istället för att ”gå in i (cell)väggen” och hamna på fel ställe.<br /> <br /> I detta arbete byggs nanorör baserade på den näst intill rätvinkliga, V-formade Trögersbasen som inspirationskälla, och genom fusion av enskilda block (monomerer) binds dessa ihop, med hopp om att skapa ett användbart nanorör för transport av läkemedel och kanske även andra intressanta applikationer inom transport och signalering. Chemistry is an important part of our daily lives, and it is filled with plenty of intricate processes and mechanisms.<br /> <br /> Some of use might recall from our chemistry classes that the more a compound and a solvent are alike, the more likely the compound is to be dissolved in the solvent. This statement holds true in many situations found throughout chemistry and may unfortunately lead to issues when dealing with, say dirty laundry.<br /> <br /> As we use water in our laundry machines, which isn’t the best at dissolving dirt and oils present on our clothes, molecules called surfactants are often introduced to help cleaning the clothes. But there are times in which adding surfactants to increase solubility of compounds is a bad idea and alternatives need to be found. One such example is when we want to introduce medicine into the human body.<br /> <br /> Every living person consists of trillions of cells, and cells have a wall consisting of a lipid bilayer. A lipid is a fatty acid, which is what our vegetable oils are made of, and we can observe that water and oil don’t mix. The same can be said for many potential medicinal substances and with our blood being about 50% water, there is a need to help these molecules move in our blood.<br /> One way of doing this is to encase the compound of interest in a host in order to allow it to move in a so-called nanotube. With the aid of suitable nanotubes substances possessing great medicinal properties, but poor solubilities, may be administrated in various treatments instead of ending up stranded against the wrong cell wall…<br /> <br /> In this work, nanotubes are built using molecules based on the near 90º, V-shaped Tröger’s base as a source of inspiration and, by fusing four of them together, hope to form a nanotube useful for transporting medicine and other interesting applications involving transport. 2019 eng organic chemistry organisk kemi synthesis syntes fusion Tröger's base total synthesis supramolecular chemistry guest-host interactions Chemistry https://lup.lub.lu.se/student-papers/record/8988390/file/8988402.pdf application/pdf Popular science of "Synthesising analogues of Tröger’s base for multiple linear fusion" no https://lup.lub.lu.se/student-papers/record/8988390/file/8988404.pdf application/pdf Popular science of Synthesising analogues of Tröger’s base for multiple linear fusion in English no 8988390 2019-06-26T15:14:12+02:00 2019-07-04T16:23:13+02:00 2019-07-04T16:23:13+02:00

oai:lup-student-papers.lub.lu.se:8988710 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Aina Mc Evoy author 8988708 Erik Hedegård supervisor Department of Chemistry v1000647 department In this thesis the enzyme Lytic polysaccharide monooxygenase (LPMO) is investigated. The LPMOs have captured the interest of the biofuel industry due to their ability to boost the breakdown of cellulose. Researchers have progressed in mapping out the mechanism behind this oxidative reaction. However, there are still many uncertainties concerning the intermediates involved and the role of certain amino acids close to the LPMO active site. In this thesis we investigate the formation of three intermediates formed by deprotonation of the tyrosine (Tyr164), denoted [CuOH-TyrO]^(+), (1b), [CuOH_2-TyrO]^(2+), (2b), and [CuOH_2-TyrO]^(+), (3b), to test weather these intermediates are energetically and structurally feasible.Tyr164 is located close to the copper in the active site. It is uncertain What the role of this amino acid plays in the reaction mechanism. One suggestion is that Tyr164 is deprotonated. A combination of quantum and molecular mechanics (QM/MM) was used. We employed density functional theory (DFT) and also investigated the effect of different functionals on computed energies. Additionally UV-Vis spectra for [CuOH-TyrO]^(+) (1b) were calculated using time-dependent density functional theory (TD-DFT). We investigated how the calculated spectra depend on the size of the system specified, and how the calculated UV-Vis spectra compare to experimental observations of the same intermediate. A spin density analysis was also carried out to suggest possible oxidation states of the copper component of the intermediates. The thesis found that all investigated intermediates were energetically feasible. We also showed that the system size affected the calculated UV-Vis spectrum in that a variation could be seen, but the spectra were qualitatively the same. Analysis of the computed spectra showed good agreement with experimental observations. The results support that the hypothesis that all three intermediates examined are feasible in the deprotonation pathway of Tyr164 in LPMOs. Further investigation of the involvement of the deprotonation of Tyr164 is warranted. I dagens samhälle är ett hållbart alternativ till fossiltbränsle högt efterfrågat. Biobränsle är ett alternativ, men om detta alternativ ska vara optimalt, måste det härstamma från ett billigt och lättillgängligt material, som t.ex. cellulosa. Cellulosa finns i bl.a. växtcellväggar och är uppbyggd av sockerenheter (glykos) i en väldigt stabil struktur vilket är en bra egenskap när den sitter i växtcellväggen. Dessvärre i vårt syfte att extrahera energi blir det lite svårare. Man har hittat att vissa bakterier och svampar har egenskapen att bryta ner cellolusa. Efter närmare undersökning visar det sig att de använder sig av enzymet \textit{Lytic polysaccharide monooxygenase (LPMO)}. Just hur detta enzymet gör och vad som får processen att fungera undersöks noggrannare. För att kunna härma denna process på bästa sätt på en industriell skala krävs det att man vet mer om hela reaktionen. I denna uppsatsen kommer möjliga strukturer av enzymet att undersökas och för att se om dessa bidrar till enzymets funktion. I enzymets aktiva säte finns aminosyroran tyrosin (Tyr164). Närmare bestämt kommer denna tyrosinens (Tyr164) roll i reaktionen att undersökas. Kvantmekaniska beräkningar utfördes för att erhålla enzymets struktur samt energin på enzymet. Energin agerar som en indikator på om de föreslagna intermediated är 1. trolig att existera, 2. möjlig att bildas. Ytterligare försöktes ett oxidationstillstånd för koppar jonen i aktiva sätet att identifieras, även ett UV-Vis spektra replikerande experimentella spektra beräknades. Energiberäkningarna som utfördes visade att de investigerade strukturerna skulle kunna existera. Det beräknade UV-Vis spektrat visade även resultat liknande de som erhållits från experimentella mätningar. Dessa observationer stödjer att vidare undersökning av tyrosinens roll i reaktionen kan vara av intresse. 2019 eng Theoretical chemistry Teoretisk kemi QM/MM LPMO Chemistry 8988710 2019-06-27T13:57:49+02:00 2019-07-04T16:25:52+02:00 2019-07-04T16:25:52+02:00

oai:lup-student-papers.lub.lu.se:8988893 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Emma Johansson author 8988891 Johan Svensson Bonde supervisor Pure and Applied Biochemistry v1000655 department Computational Chemistry v1000659 department Skin integrity is something that matters to a lot of people since it makes up a protective barrier but also contributes to a beautiful appearance. To maintain skin integrity there is a wide range of skin care products on the market to choose from. However, lately one particular product group called &quot;cosmeceuticals” have increased. Cosmeceuticals contain biologically active substances among which recombinant growth factors are commonly seen. Recombinant proteins have already been used for a long time in pharmaceuticals where they are under much stricter regulations than in cosmetics. This means that neither the purity or the effectiveness, nor the concentration of the growth factors in cosmeceuticals are meeting the requirements of cosmetics. Thus, there is a risk that consumers will be misled or, in even worse cases, have adverse effects.<br /> In this master’s thesis five different cosmeceutical products containing recombinant growth factors were studied with the aim of detecting and characterizing protein. Different methods of sample preparation were performed to detect protein with electrophoresis followed by characterization with chromatography and two-dimensional fluorescence difference gel electrophoresis.<br /> The obtained results showed that only one out of five products contained protein. This could mean that no protein was included in a majority of the products, although in future experiments additional analysis with higher sensitivity should be carried out to confirm this. Considering the protein that was found, it was not only the growth factor FGF, claimed to be there, but mainly another one that shared a lot of properties with bovine serum albumin. Hence, there seems to be reason to question the quality of cosmeceuticals and<br /> it would be advisable to establish stricter regulations. Att ha välbevarad, vacker hy är något som många människor eftersträvar. Frågan är vilka medel folk är beredda att ta till för att uppnå detta och hur långt tillverkarna vågar gå i sina försök att tillfredsställa konsumenterna. <br /> På senaste tiden har en ny typ av skönhetsprodukter dykt upp på marknaden. Produkter som vid första anblick ser ut som vilka ansiktskrämer och serum som helst. Tar man sig en närmare titt ser man dock att de påstås innehålla biologiskt aktiva ingredienser såsom mänskliga tillväxtfaktorer. Tillväxtfaktorer är proteiner som normalt finns i huden hos alla människor och hjälper till att kontrollera bland annat celldelning och celltillväxt. Dessa egenskaper har man utnyttjat under en längre tid inom läkemedelsbranschen där tillväxtfaktorer har inkluderats med goda resultat. På senare tid däremot, har forskare inte bara sett botande egenskaper hos dessa protein utan även en skönhetsfrämjande effekt som skulle kunna ge föryngrad och vackrare hud om de inkluderades i ansiktskrämer eller dylikt. <br /> Det må låta lovande, men läkemedelsindustrin och kosmetikaindustrin har några väsentliga skillnader som inte bör förbises. Nya läkemedel som kommer ut på marknaden har genomgått en strikt process och regleras av lagar och regler som ska se till så att alla produkter är säkra och saknar allvarliga biverkningar. När det kommer till kosmetika däremot, är regelverket betydligt mildare och det saknas liknande krav på produktkvaliteten. Det är där skon klämmer. Det finns alltså nya kosmetiska produkter på marknaden med samma ingredienser som i läkemedel men som inte regleras till närmelsevis lika hårt. <br /> I det här examensarbetet har fem olika hudvårdsprodukter som sägs innehålla en utav de två tillväxtfaktorerna, EGF och FGF, undersökts. Detta gjordes i syfte att komma fram till huruvida dessa protein verkligen har inkluderats, hur stor koncentrationen i så fall är, samt för att få en bild utav produkternas renhet. Flertalet experiment utfördes för att kunna detektera protein vilket resulterade i oväntade svårigheter. Efter mängder av olika försök med varierande metoder kunde nämligen protein endast upptäckas i en utav produkterna. Slutsatsen kunde dras att det antingen saknades protein eller att det förekom i extremt låg dos. Detta borde bekräftas med känsligare analysmetoder i framtida experiment för att säkerhetsställa att de biologiskt aktiva hudvårdsprodukterna inte är en marknadsföringsbluff. Hursomhelst, den enda produkten som påvisade närvaro av en tillväxtfaktor kunde vidare analyseras. Olika egenskaper såsom storlek, koncentration, laddning och hydrofobicitet undersöktes och dokumenterades. Det visade sig att FGF som hävdats ingå i produkten fanns där, men desto mer protein utgjordes av en helt annan sort, nämligen serum albuminer - blodproteiner. <br /> Vidare studier borde göras utav användandet av tillväxtfaktorer i skönhetsprodukter. För att det som konsument ska vara värt att lägga stora summor pengar på hudvårdsprodukter med påstådda effekter, ska det gå att säkerhetsställa vad som faktiskt ingår i produkterna och huruvida några risker tillkommer vid användandet. https://lup.lub.lu.se/student-papers/record/8988893/file/8988910.pdf application/pdf 1618946 no 2019 eng Cosmeceuticals applied biochemistry protein protein analysis tillämpad biokemi Chemistry 8988893 2019-06-28T09:24:59+02:00 2019-07-04T16:30:24+02:00 2019-07-04T16:30:24+02:00

oai:lup-student-papers.lub.lu.se:8989188 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Sofie Andresen author 8923995 Ulrika Schagerlöf supervisor Peter Spégel supervisor Department of Chemistry v1000647 department Parkinson’s disease (PD) is the most common neurodegenerative disorder after Alzheimer’s disease and today more than 6 million people are living with PD world-wide (2018). PD is characterized by muscle stiffness, shaking at rest, and postural imbalance. The symptoms are caused by a decreased dopamine (DA) level in the brain due to a gradual loss of DA producing neurons.<br /> The cause and trigger of the disease is unknown but is believed to be a combination of both environmental and genetic factors. No treatment that can cure or slow down the disease progression is available; there are on the other hand treatments for symptom relief. Gene therapy is one potential treatment option for symptoms relief in PD. In gene therapy, genetic material is introduced into cells in the brain using viral vectors with the goal of restoring DA production. <br /> In this study gene material for two important enzymes in the dopamine production has been injected into the brain of rats using viral vectors. The two enzymes are Tyrosine hydroxylase (TH) and GTP cyclohydrolase 1 (GCH1). A destabilization domain was added to regulate the activity of the enzymes. All proteins coupled to the domain are degraded in the absence of trimethoprim (TMP), thus enabling regulation and fine tuning of the enzyme activity in the brain. <br /> The dopamine and serotonin in the brain, as well as their precursors and metabolites were monitored using HPLC-ECD. The result showed a restored production in the non-regulated group and the GCH1 regulated group but not in the TH regulated ones. The TMP concentration in brain was monitored using HPLC-MS and found to be lower than expected. Further studies have to be done in order to optimize the conditions and fine tuning the regulation of the constructs. Parkinsons sjukdom är den näst vanligaste neurologiska sjukdomen efter Alzheimers sjukdom och idag lever ungefär 24000 personer med Parkinsons sjukdom i Sverige. Vanliga symptom är skakningar i vila, muskelstelhet samt försämrad rörelseförmåga. Symptomen uppkommer till följd av en sänkt koncentration av dopamin i hjärnan. Till en början är motorsymptomen lindriga men förvärras med tiden då fler dopamin producerande nervceller i hjärnan dör. <br /> Det finns idag ingen behandling som stoppar sjukdomsförloppet utan dopamintillverkande nervceller forsätter att brytas ner och förstöras trots medicinering. Behandlingen fokuserar istället på att lindra sjukdomssymptom genom att på olika sätt återställa dopamin-nivån i hjärnan. Levodopa, förstaidet till dopamin, används för öka dopamin-nivån i hjärnan hos Parkinsonspatienter. Levodopa tas upp av hjärnan och omvandlats där till dopamin. Efter en tids behandling uppkommer ofta svåra bieffekter vilka tros uppstå på grund av en fluktuerande dopamin-nivå. <br /> Genterapi är en potentiell och förhoppningsvis i framtiden möjlig behandling av Parkinsons sjukdom. Oftast används en djur modell för att testa ut behandlingsmetoder. I genterapi introduceras genmaterial i utvalda celler hos djuret för att komplettera eller reparera en gen. Överföringen av genmaterialet sker med hjälp av inaktiverade viruspartiklar. I denna studie introducerades genetiskt material för två enzymer involverade i produktionen av dopamin: tyrosin hydroxylas och GTP-cyklohydrolas. Reglering av enzymaktiviteten har möjlig gjorts att koppla en destabiliseringsdomän till ett av enzymen. Enzym kopplade till destabiliseringsdomänen bryts ner i frånvaro av en antibiotika som heter trimetoprim och enzymaktiviteten kunde på så sätt regleras genom tillsats av trimetoprim. <br /> Resultaten visade att regleringen med hjälp av trimetoprim inte fungerade optimalt och detta tros bero på en för låg dos av trimetoprim i hjärnan. Ytterligare experiment måste därför göras för att optimera trimetoprim-dosen. https://lup.lub.lu.se/student-papers/record/8989188/file/8989209.pdf application/pdf 1653907 no 2019 eng Parkinson's disease Gene therapy Tyrosine hydroxylase Biochemistry Chemistry 8989188 2019-06-30T17:29:25+02:00 2023-06-28T15:18:07+02:00 2023-06-28T15:18:07+02:00

oai:lup-student-papers.lub.lu.se:9155309 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Hannah Olsson author 9155293 Herwig Schüler supervisor Department of Chemistry v1000647 department Introduction: PARP-14 is a human enzyme that use NAD+ to perform ADP-ribosylation on targets, which serves as a signalling system. The enzyme is important in for instance DNA repair and immunity, as well as regulating other PARPs in the enzyme family.<br /> Background: There are several features of PARP-14 that needs to be further studied, such as its connection to some diseases and cancers. It is of great interest to find a selective inhibitor against the enzyme to enable further studies as well as of therapeutic relevance.<br /> Aim: The purpose of this study is to test two inhibitors, nr. 49 and 45, against PARP-14 with the intention of them exhibiting suicide inhibition. <br /> Methods: Firstly, the catalytic domain of PARP-14 encoded by a plasmid was transformed to competent Escherichia coli which produced the protein. The cells were lysed, and the protein was purified by IMAC and SEC FPLC, to analyze the purity SDS-PAGE was used. The PARP-14 enzymatic activity was then tested with its substrate by detecting ADPr activity by Western Blotting. Different conditions of the inhibitors incubated with PARP-14 was tested and compared to the normal activity of PARP-14. The substances were tested for suicide inhibition by trying to outcompete them by adding a great excess of NAD+.<br /> Results: The transformation of bacteria and protein production as successful, and after purification by IMAC and SEC the protein exhibited ADPr activity on Western blot. Both substance 49 and 45 displayed inhibitory effects on PARP-14 activity, and compound 49 had a greater effect at high concentration. When testing for suicide inhibition, there was an observable decrease in PARP-14 activity, and this was the greatest for pH 9, then 8,2 and the least at pH 7,5 after an overnight incubation.<br /> Conclusion: The substances effectively decrease the activity of the enzyme and shows great potential in being suicide inhibitors of PARP-14. The definition of life and its boundaries is difficult to limit, but what is certain is that chemical reactions are fundamental for all life. Inside our bodies, an abundance of reactions take place, and these are catalysed by enzymes. The focus of this study is on the human enzyme PARP-14, which serves an important role in fighting illness as well as protecting our genetic code. This enzyme is also observed to be involved in some diseases and certain types of blood and liver cancer, and it has potential in being a medical target. Cancer is one malady that is of great interest in modern drug research. A close relative to PARP-14; PARP-1, is already an approved target in treatment of breast and ovarian cancer. PARP-14 is also observed to be involved in some cancers, but the full purpose of this enzyme in the cell is still obscure and need to be further studied. When using inhibitors against enzymes, their activity is blocked, and this is convenient when studying their purpose, since their inhibition result in an absence of a function. Further studies of the PARP-family are of great interest, and selective inhibitors are of importance to conduct this.<br /> <br /> The aim of this study was to test two potential inhibitors of PARP-14. An ambition was also that these inhibitors when in contact with the enzyme, get bound to enzyme’s reactive site, not able to leave. This is called a suicide inhibition, since it results in the enzyme becoming permanently inactive, as if committing suicide.<br /> <br /> The substances, nr 49 and 45, were synthesized and provided by prof. Dana Ferraris, which have produced inhibitors against PARP-14 before with known inhibitory effect, although no suicide inhibitors. To be able to test the new compounds, the PARP-14 protein was produced by bacteria, which were decomposed, and the protein of interest was collected by purification methods. The purified protein was then tested for enzymatic activity to verify that the protein was functional. The protein could then be tested with and without inhibitors, at different conditions, to see if the inhibitors had a desirable effect on PARP-14. If the enzymatic activity of PARP-14 is lower with the inhibitor present compared to not, this indicates on inhibition. To investigate if the inhibitors also exhibited suicide inhibition, methods were used to try to outcompete them. When this method is used, the real substrate of the enzyme is added in a great access over inhibitor. If the inhibitor is irreversible bound to the enzyme, this will block the real substrate from interacting with the enzyme. <br /> <br /> The protein was successfully produced and after two essential purification steps it was verified that it exhibited activity. The inhibitors were then tested, and they proved to be inhibiting PARP-14 effectively. They also displayed suicide inhibitory effects, since when trying to outcompete them, a decreased PARP-14 activity persisted. This effect was the greatest after overnight incubation and at a pH well above the physiological of 7,4. 2024 eng ADP-ribosylation biochemistry PARP-14 Suicide inhibition Chemistry 9155309 2024-05-29T14:58:35+02:00 2024-05-30T14:07:01+02:00 2024-05-30T14:07:01+02:00

oai:lup-student-papers.lub.lu.se:9155816 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Jaume Adrover Forteza author 9155217 Jonas Carlstedt supervisor Marie Wahlgren supervisor Tommy Nylander supervisor Food Technology and Nutrition (M.Sc.) v1000294 department α-Olefin Sulfonate surfactants offer a greener alternative to traditional sulphated surfactants thanks to their higher biodegradability. Their similar molecular structures should, in theory, allow them to be used in the same range of applications as the sulphonated counterpart. However, the newer alternative also comes with novel challenges. While the thickening of a formulation with a sulphated surfactant can be achieved by salt addition, novel sulphonated surfactants require the introducing co-surfactants to the formulation. Previous studies at CR resulted in the design of a purification process that enhanced the viscosity build up capacity of the surfactant was achieved. <br /> In this master thesis work this method was applied and tested. Through techniques such as HPLC-MS and NMR the content of the surfactant was unveiled, revealing that the technical grade surfactant was a mixture of different compounds. Among them, the most possible culprit for hindering the thickening capacities those holding an alcohol group in carbons distancing from the head group. Additionally, the surfactant-water system was further characterized utilizing SAXS and DLS, leading to the elaboration of a phase diagram. The acquired knowledge will help formulators incorporate the greener alternative in their products, and guide manufacturers on how to make a surfactant with enhanced properties. This master thesis work was carried out as a joint project between Lund University and CR Competence AB. The research focused on characterizing and tackling the challenges found in a promising green surfactant.<br /> Surfactants are everywhere in our daily lives, they are found in food, personal care, pharmaceuticals, oil industry, etc. The studied green surfactant, α-Olefin Sulfonate (AOS), is more easily biodegraded and could theoretically be used to substitute traditional sulphated ones, making a leap towards a more sustainable future. However, its usage is being held by its incapacity to build up viscosity by simple salt addition like the sulphated surfactants. In contrast, when AOS is used in formulation, it required the addition of other surfactants to achieve the same properties.<br /> In the thesis, a purification method was used to enhance the properties of AOS. When testing the purified AOS against the commercial AOS, much better results were obtained. Implying that the problematics came from the impurities present in the AOS, rather than the surfactant itself.<br /> Through a combination of analytical techniques, the major components of the technical grade AOS and the most likely culprit of the hindrance, were found. The culprit was a by-product generated from the synthesis of AOS. That molecule modified how the surfactant self-assembled and gave rise to the problematics. <br /> Additionally, the surfactant was tested in multiple formulations including varying salt concentration and the presence of a co-surfactant. Also, those formulations were further characterised to gain a deeper understanding of its physical-chemical properties. <br /> The knowledge gained through this work will help formulators incorporate the greener alternative to their products. Moreover, it aids producers understand the root of the problem and hints at how to manufacture a better product. Overall, this thesis is a small step towards a more environmentally friendly future. https://lup.lub.lu.se/student-papers/record/9155816/file/9163692.pdf application/pdf 3656290 no 2024 eng Physical Chemistry Micelle Elongated micelles α-Olefin Sulfonate alfa-olefin sulfonate AOS surfactant surfactants green HPLC NMR SAXS DLS viscosity Critical packing parameter CPP birefringence CMC tensiometer surface tension. Chemistry https://lup.lub.lu.se/student-papers/record/9155816/file/9155827.pdf application/pdf no 9155816 2024-05-30T16:41:04+02:00 2024-06-14T10:27:32+02:00 2024-06-11T08:29:33+02:00

oai:lup-student-papers.lub.lu.se:9158025 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Emma Lundberg author 9158023 Ingemar André supervisor Department of Chemistry v1000647 department Conformational changes are essential for the function of many proteins and is determined by the sequence of amino acids and interactions between them. With computational protein design, new de novo proteins with the ability to undergo conformational changes have been designed. Also, proteins that are one amino acid apart and predicted to have two different conformational states, with the ability to change to the other one can be designed. The aims of this work was to express, purify and characterise two de novo computer-generated proteins, that are one mutation apart and could undergo conformational changes between two structures upon heating. Another aim was to mutate sequences for proteins on a trajectory. To succeed with the aims, Golden Gate Assembly was used to introduce the gene of the proteins in a plasmid. Next the protein was expressed and then analysed with mass spectroscopy, Circular Dichroism (CD) spectroscopy, Nuclear Magnetic Resonance (NMR) and crystallography. Mutations were also done. The results showed that the proteins can undergo conformational change upon heating and that the changes are partially reversible. The results also showed that mutations to the plasmid are possible. The conclusions could be drawn that the two proteins have differences in secondary structure, and that conformational changes happen in response to increased temperature. No conclusions about conformation of mutated proteins were drawn. Proteins are important for all life on earth. They help the body to digest food, move and keep the shape of the cells. Many proteins can change their shape, which can give them a function. These changes can for example happen if a specific molecule binds to the protein, if the charge around the protein changes or even if mechanical forces are used, for instance if you put a hand on your arm. Some proteins can even change their shape if the temperature changes. Because the function of a protein can be dependent of the changes of shape, research is done to try and design proteins with specific shape or ability to change shape. With the help of a computer and different machine learning models, proteins that do not exist in nature can be designed. This is what has been done for the two proteins that have been analysed in this work. <br /> <br /> All proteins are built in a sequence, from a bank of 20 smaller building blocks called amino acids. The amino acids have unique characteristics. Some like water, some does not, some have a positive charge, some have a negative charge and some of them have a ring structure that provides them with certain characteristics. The proteins in this work have 150 amino acids each, are designed by a computer and change shape when the temperature increases. The sequences of the building blocks are identical, except for one amino acid that has been changed into another. The computer predicted that this small change would have a big impact on the shape of the protein. In this work, this has been analysed. <br /> <br /> The small changes in amino acid sequence, called mutations, are a driving force in the evolution of proteins. These have however mostly been used to explain small changes in the proteins, and not big changes like shape. If small mutations in amino acid sequence can alter the shape of proteins was also analysed in this work. <br /> <br /> To do this, the amino acid sequence was ordered and put in bacteria who could create the protein. Then the protein was purified and analysed with different methods. From this, it was concluded that the proteins do change shape when the temperature increases, and the analysed shapes are like the predicted shape to some extent. The method used to change the amino acid sequence did also work. https://lup.lub.lu.se/student-papers/record/9158025/file/9158031.pdf application/pdf 2611496 yes 2024 eng biochemistry computational protein design conformational change protein characterisation protein evolution protein expression protein purification Chemistry 9158025 2024-06-04T12:36:00+02:00 2024-06-11T11:01:08+02:00 2024-06-11T11:01:08+02:00

oai:lup-student-papers.lub.lu.se:9158039 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Alice Nildén author 9079706 Tommy Nylander supervisor Department of Chemistry v1000647 department Computational Chemistry v1000659 department The thesis focuses on optimizing microfluidic methodology to create lipid sponge phase nanoparticles (L3NPs) for myoglobin encapsulation, while investigating buffer and pH effect on particle characteristics. Traditional LNP production methods like ultrasonication are time consuming and requires large material quantities. Microfluidic techniques offer a more precise and cost effective alternative but requires optimization due to equipment and cost constrains. The study aims to optimize microfluidic techniques for L3NP production, investigating influence of microfluidic parameters, buffer composition, and pH on particle size and phase using dioleoyl phosphatidylcholine, glycerol monooleate (Capmul GMO-50) and Polysorbate 80 in buffer.<br /> The microfluidic technique for lipid nanoparticle formation uses three pumps and a T.cross channel chip (dimensions 200μm x 200μm x 87mm) with three inlets and one outlet, monitored by an optical microscope. Flow rates and lipid+surfactant (L&amp;S) to solvent ratio were varied, and dispersion are prepared using different DOPC/GMO-50/P80 amounts. Hydrodynamic size and polydispersity index are examined using Dynamic Light Scattering, structure and particle morphology via Small Angle X-ray Scattering. Cryo-TEM was performed to visualize the particles and their structures. <br /> This study demonstrates that microfluidic and formulation parameters significantly affected L3NP size and phase. Optimal conditions include a 250 μl/min flow rate, 1:4 flow ratio L&amp;S:solvent, increasing lipid and surfactant concentration and a DOPC/GMO-50/P80 ratio of 28/42/30 in 20 mM TRIS buffer at pH 7.4 and 5 mM CaCl buffer at pH 8.5. This study proved that nanoparticle size increased with a majority of the buffers, while TRIS and CaCl were chosen due to the low PDI, observed in DLS. Myoglobin encapsulation minimally impacts size and structure, but may affect the intra-particle interactions. <br /> The results demonstrate that microfluidic techniques effectively create L3NPs for myoglobin encapsulation under specific conditions, confirmed by using Cryo-EM. Conditions include the importance to alter the DOPC/GMO-50 ratio to prevent phase separation, the necessity for P80 for nanoparticle colloidal stability and using a flow ratio of higher solvent content. These results confirm that by adjusting microfluidic and formulation parameters, buffer and pH, it is possible to optimize particle size and phase for myoglobin encapsulation, with L3NPs bilayer form factor and internal structure unaffected implying no change in intra-particle interactions. Lipids, known as fats and oils, play essential roles in the body. Lipid nanoparticles (LNPs) are small lipid in the nanometric scale and can be made in the lab and designed to deliver drugs or genetic material in the body, protecting their cargo until it reaches the target. Ingredients like DOPC, GMO-50, and P80 are used to form LNPs in this study: both DOPC and GMO-50 served as main building block, while GMO-50 also aids stabilization and delivery, and P80 maintains the integrity of LNPs by colloidal stability. LNPs are created by first dissolving the ingredients in a organic solvent, such as ethanol. This solution is mixed with water or buffer under controlled conditions. In this method the particles are build up during mixing in contrast to stirring or the usage of high-frequency sound waves (ultrasonication) which is based on the principle to divide larger clusters (aggregates) into smaller once. These methods, known as conventional, are straightforward but limited in controlling particle size and distribution, often resulting in variability between batches. In this study we have used microfluidic techniques, often used since it entails with better control over particle properties and composition suitable for reproduction but are also known for its rapid and efficient nanoparticle production. Microfluidics, which is a small plumbing system with tiny channels, allows improved precise control over LNP properties by adjusting the rate and ratio of fluid mixing with help of pumps that controls the flow of liquids from syringes. By altering the composition of lipid, surfactants and stabilizers (DOPC, GMO-50 and P80, also referred to as lipid-mixture) and introducing different charges from the buffer, LNP properties and pH stability can be optimized. These adjustments are made to find the optimal method to prepare the LNPs for the intended cargo to enclose, the protein myoglobin. Myoglobin is a protein that stores and releases oxygen in muscles. Once energy is requires, during training for example, myoglobin releases oxygen to produce energy required for exercise. <br /> In this study we’re using two different scattering techniques: Dynamic Light Scattering (DLS) which gives information about size and size distribution while Small Angle X-ray Scattering (SAXS) is used to examine the structure of the LNPs. <br /> This study proved that altering DOPC and GMO-50 content play a crucial role in LNP formation and maintenance. An increase of DOPC and decrease of GMO-50 were suitable to prevent phase separation between water and lipid-mixture. P80 seemed to have an effect on size and size distribution while the structure seemed unaffected. The fluid mixing were seen optimal when all three pumps used were pumping fluid in a rate of 250 μl/min in total, in a ratio of 1:4 of Lipid-mixture:water. A higher water content were seen to lower size distribution. Size generally increased with most buffers, with TRIS and CaCl chosen for their low size distribution. Myoglobin introduction, enclosed by the LNPs, didn’t alter LNPs structure or size but could affect how particles interact with each other. https://lup.lub.lu.se/student-papers/record/9158039/file/9158068.pdf application/pdf 9574171 LU/LTH access 2024 eng Lipid nanoparticles Lipid sponge phase Microfluidics Myoglobin Protein encapsulation Physical chemistry Chemistry 9158039 2024-06-04T13:07:46+02:00 2024-06-11T10:58:42+02:00 2024-06-11T10:58:42+02:00

oai:lup-student-papers.lub.lu.se:9158180 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsM2 Amanda Lundberg author 9158178 Tobias Juhlin supervisor Petros Tesfai supervisor Department of Chemistry v1000647 department A study has been created to develop a method quantifying the active pharmaceutical ingredient (API) nicotine in tablets with near infrared (NIR) spectroscopy using chemometrics. The current technique, liquid chromatography (UHPLC), used to determine the nicotine content in tablets is time consuming and require sample preparation. NIR spectroscopy is non-destructive and the implementation of NIR spectroscopy can lead to increased productivity which makes it an attractive alternative. To perform an analysis on the NIR instrument a multivariate calibration model needs to be developed. A partial least square (PLS) method has been developed using cross-validation for 2 and 4 mg nicotine tablets. A total of 660 samples containing 70-130% nicotine for 2 mg and 4 mg tablets were used to create the model. Several pre-processing methods and spectral regions were evaluated to obtain the best model. An analysis of 50 samples was preformed using the best model created and the results were showed a small difference between the NIR predicted values and the reference method. According to the company’s internal requirements the method developed is fit for analysis. This study is a step-forward in the implementation of NIR spectroscopy for analysis of nicotine content in tablets. Den här studien har skapats för att effektivisera analysen av tabletter innehållande den aktiva substansen nikotin på Kenvue. Nuvarande teknik för att analysera nikotinhalten i 2 och 4 mg tabletter är vätskekromatografi (UHPLC), en tidskrävande teknik som kräver provupparbetning. Near infrared (NIR) spektroskopi är en snabb analysteknik som är icke-destruktiv och kräver ingen provupparbetning vilket gör den till ett attraktivt alternativ. NIR spektroskopi är mer miljövänligt då inga lösningsmedel behövs och implementering av NIR spektroskopi kan leda ökad produktivitet i labbet. För att övergå till NIR spektroskopi behöver en metod utvecklas med hjälp av olika matematiska modeller. 660 prov med nikotinkoncentrationen 70-130% av 2 och 4 mg tabletter användes för att skapa modellen. Modellen optimerades genom att förbehandla datan samt att utvärdera olika områden av spektrumet. När den bästa modellen hade skapats testades modellen genom att analysera 50 prov av 2 mg tabletter. NIR metoden gav lovande resultat och en liten skillnad visades mellan NIR metodens predikterade värden och referensmetoden. Metoden som utvecklades når upp till företagets krav på analysmetoder och är därför lämplig för analys. https://lup.lub.lu.se/student-papers/record/9158180/file/9158183.pdf application/pdf 1221249 yes 2024 eng analytical chemistry NIR nicotine Chemistry 9158180 2024-06-04T15:08:30+02:00 2024-06-14T14:12:13+02:00 2024-06-14T14:12:13+02:00

oai:lup-student-papers.lub.lu.se:9159056 2025-07-29T13:03:30Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Wilhelm Hansson Wennersten author 9159054 Urban Johanson supervisor Department of Chemistry v1000647 department TRPA1, also known as the wasabi receptor, is a non-selective cation ion channel that plays an essential role in the detection of noxious substances and irritants. Hylobius abietis, the pine weevil, is a pest that causes substantial damage to the forestry industry. The structure of the pine weevils TRPA1 (HaTRPA1) is so far unknown. If the structure were to be determined, an agonist could be developed, which could be used as a repellent against the pine weevil. Membrane proteins are naturally expressed at lower levels and can be highly unstable in certain conditions. Heterologous expression and different protocols must often be attempted and evaluated to produce a high-yield, stable membrane protein sample. The aim of this study is to optimize and evaluate different protocols to express and purify HaTRPA1, including using a truncated version of HaTRPA1 and a cleavable green fluorescent protein tag.<br /> <br /> HaTRPA1 was expressed through large-scale fermentation in Pichia pastoris. The cells were broken, and the membrane was isolated and washed. The protein was solubilized using Fos-choline 14, purified using Immobilized metal ion affinity chromatography (IMAC), cleavage with the tobacco etch virus protease, reverse IMAC, and separated using size exclusion chromatography. Steps throughout the expression and purification were evaluated using SDS-PAGE. The protocols were attempted for two constructs of HaTRPA1, the full-length construct and a truncated version labelled C2. The results showed that degradation was the major issue with the expression and purification of HaTRPA1. Both the full-length construct and the truncated C2 showed substantial degradation. A decrease in degradation was observed when the induction time during expression was reduced. Implementing a urea wash in the membrane preparation was beneficial in reducing the amount of degradation.<br /> <br /> The conclusion of this paper was that there is little difference in stability between the two constructs of HaTRPA1. To prevent degradation, a shorter induction time should be implemented during fermentation. Have you ever put too much wasabi on a piece of sushi? The painful sensation you feel that causes instant regret is generated by the so-called Transient Receptor Potential Channel, subfamily A, member 1 (TRPA1). The protein TRPA1 plays an essential role in detecting irritants and noxious substances, like our dear friend wasabi. While wasabi may be harmless, there are many substances that can be highly damaging, and our bodies need a way to tell us to stay away from them. Therefore, once TRPA1 is activated by a noxious substance, a signal is sent to our nervous system to generate a painful sensation. While human TRPA1 has been the subject of many studies, it is also worth studying TRPA1 in other organisms.<br /> <br /> Hylobius abietis, or the pine weevil, is a major pest in the commercial forest industry. It eats the bark of seedlings causing them to die. The pine weevil is responsible for millions of euros in damages each year. Currently, the fight against the pine weevil has involved plenty of harmful insecticides, and with a greater focus on environmentally friendly forestry, there is an interest in other alternatives. If the 3D structure of H. abietis TRPA1 was resolved, it would be possible to develop an activator of TRPA1 that would trigger a similar response in the pine weevil as our overindulgence in wasabi caused.<br /> <br /> This study attempted different conditions and protocols to produce a substantial amount of TRPA1 from the pine weevil for structural studies. Two different constructs were studied: the full-length construct and a truncated version. Both constructs of the protein were tagged with a green fluorescent protein to enable tracking of the protein throughout the purification and expression. The protein was expressed in the yeast species Pichia pastoris. Afterwards, the protein was solubilized and purified under different conditions to find the optimal protocol. https://lup.lub.lu.se/student-papers/record/9159056/file/9159066.pdf application/pdf 1815970 no 2024 eng Degradation Fermentation GFP TRPA1 Biochemistry Biology and Life Sciences Chemistry 9159056 2024-06-05T15:29:44+02:00 2024-06-11T10:47:04+02:00 2024-06-11T10:47:04+02:00

oai:lup-student-papers.lub.lu.se:9159851 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Abrar Snowbar author 9086220 Sophie Manner supervisor Fredrik Sjövall supervisor Centre for Analysis and Synthesis v1000651 department Galectins are glycan-binding proteins that can reprogram the function of many cell types. They are involved in different positive and negative physiological functions in the human body including inflammation and autophagy. Thus, they have been suggested as therapeutic targets for tumour progression and they have been proposed as biomarkers for diagnosis. Galectins bind to the carbohydrates on the cell surface and extracellular matrix with high affinity, especially glycoconjugates containing galactose. Galectin-3 is the focus of this work which is an important type of galectin that has gained a lot of attention recently. Galectin-3 triggers the positive immune response to fight pathogens in our cells but meanwhile, its over-expression is linked to fibrosis and cancer. Designing a drug target to inhibit galectin-3 has become a new target for medicinal chemists. However, the challenge is the binding sites of galectins that are polar and shallow. In this study, new compounds have been synthesised and studied. The compounds are based on triazole attached to 3,4,5-trifluorophenyl or thiophene and to an OH group in turn linked to another ring structure (5-membered heterocycles). The aim was to synthesise compounds with low molecular weight and low polarity to enhance the binding affinity to galectin-3 to make them cross the blood-brain barrier for brain tumour targets. Surprisingly, the compounds showed a higher affinity to galectin-1 than galectin-3. Therefore, it would be interesting to develop this molecule for better binding affinity to galectin-1 as it is also involved in tumour progression. Galektiner är små proteiner som finns i vår kropp och de förekommer antingen intracellulärt och i cytoplasman eller extracellulärt. De binder till kolhydrater på cellytan med hög affinitet, speciellt de som innehåller galaktos och det avgör dess viktiga roll i de<br /> olika fysiologiska processerna i kroppen. De är involverade i modulering av cellulära processer såsom programmerad celldöd när cellen är skadad. Hittills har 15 galektiner upptäckts i olika celltyper, var och en är galektin-3 som är huvudfokus för detta projekt. Den är en av de vanligaste typerna och spelar en viktig roll med att förstärka immunsvar mot bakterier och andra organism som kan orsaka sjukdomar. Däremot har forskning visat att galektin-3 bidrar till många olika sjukdomar såsom cancer och ärrbildning när det uttrycks i hög koncentration. Nya läkemedels-projekt har fokuserat på att utveckla molekyler som kan binda till galektin-3 och hämma dess funktion vid sjukdomstillstånd. Det finns redan molekyler som testas i kliniska studier och visar en bra affinitet till galectin-3. Dessa molekyler är dock polära och stora och har därmed svårt att nå hjärnan för att hämma proteinet vid sjukdomen. En av de molekyler som visar bra affinitet till galektin-3 är galaktosderivata, vilket är baserad på att klyva ut galaktosen behålla den delen av galaktos som huvudsakligen binder till proteinet som sedan kopplas ihop med en molekyl för modifiering för extra affinitet. Dessa molekyler är fortfarande för stora och polära för att kunna ta sig in till nervsystemet. Denna hypotes utgör<br /> utgångspunkten för detta projekt där galaktosen tas bort och en små del av det behållas och modifierades med olika kemiska grupper för en ökad affinitet till galektin-3. Resultatet visade att hypotesen inte stämmer för galektin-3 men molekyler som synteserades visade bättre affinitet för galektin-1. https://lup.lub.lu.se/student-papers/record/9159851/file/9159861.pdf application/pdf 4363752 yes 2024 eng galectins organic chemistry molecular weight Chemistry 9159851 2024-06-07T12:16:55+02:00 2024-08-29T08:57:29+02:00 2024-08-29T08:57:29+02:00

oai:lup-student-papers.lub.lu.se:9160409 2025-07-29T13:03:30Z AgricultureVeterinaryMedForestry PhysicsChemistryMaths

studentPublicationsM2 Fabian Borg author 9066668 Viktor Dahlberg author 9160420 Jeanette Purhagen supervisor Åsa Håkansson supervisor Livsmedelsteknik (kandidat) v1001414 department Food Science 011300190 department Hampapresskaka är en restprodukt som uppstår vid produktion av hampfröolja. Intresset för<br /> denna restprodukt har successivt ökat i takt med att forskningsvärlden letar efter nya hållbara<br /> proteinsubstitut. En metod som används för att isolera proteinet i hampapresskaka är pH-skift<br /> extraktion. Tidigare studier har redan undersökt vilka parametrar som ger det optimala utbytet<br /> av protein mellan material och protein-isolat.<br /> <br /> Ett urval av hampapresskaka med tre olika odlingsursprung gjordes inför försöken för att se<br /> om några skillnader kunde observeras i resultaten baserat på ursprunget. Extraktioner i<br /> laboratorieskala baserade på optimala parametrar utfördes sedan på de tre urvalen med en<br /> implementering av förbehandlingar. Genom en förbehandling av råmaterialet bestående av<br /> ultraljud och fermentering var syftet att ytterligare optimera befintlig extraktionsprocess.<br /> <br /> Resultaten har visat att genom ultraljudsbehandling av råmaterialet kan det procentuella<br /> utbytet ökas vid pH-skift extraktion. En ökning på 7,9% kunde observeras vid försök utförda<br /> på ett av urvalen. Fermentering har vid samtliga försök minskat det procentuella utbytet.<br /> Däremot har dessa resultat bidragit med diskussionsunderlag för framtida forskning.<br /> <br /> Några definitiva slutsatser kopplade till ursprunget har inte kunnat dras, utan har enbart<br /> använts som diskussionsunderlag. Inga definitiva slutsatser har kunnat dras av<br /> extraktionsresultaten utan bör i stället användas som framtida forskningsunderlag. Hemp press cake is a by-product that forms during the production of hempseed oil. Interest in<br /> this by-product has gradually increased as the research community seeks sustainable protein<br /> substitutes. A method used to isolate the protein in hemp press cake is pH-shift extraction.<br /> Studies prior to this have already investigated the parameters that yield the optimal protein<br /> yield between material and protein isolate.<br /> <br /> A selection of hemp press cake from three different cultivation origins was made before the<br /> experiments to see if any differences could be observed in the results based on the origin.<br /> Extractions on a laboratory scale based on optimal parameters were then carried out on the<br /> three selections with an implementation of pre-treatments. Through pre-treatment of the raw<br /> material consisting of ultrasound and fermentation, the aim was to further optimize the<br /> existing extraction method.<br /> <br /> The results have shown that through ultrasound treatment of the raw material, the percentage<br /> yield can be increased during pH-shift extraction. An increase of 7,9 % was observed in<br /> experiments conducted on one of the selections. Fermentation decreased the percentage yield<br /> in all experiments. However, these results have provided discussion material for future<br /> research.<br /> <br /> No definitive conclusions related to the origin could be drawn, instead it has been used for<br /> hypothetical discussions. For the process of extraction, no definitive conclusions could be<br /> drawn. Instead, these results should be used as a basis for future research. https://lup.lub.lu.se/student-papers/record/9160409/file/9160419.pdf application/pdf 1095905 no 2024 swe Hampa Ultraljud Fermentering L.Plantarum 299v Extraktion pH-skift Livsmedelsteknik Chemistry Agriculture and Food Sciences 9160409 2024-06-09T13:18:20+02:00 2024-06-11T09:53:00+02:00 2024-06-11T09:53:00+02:00

oai:lup-student-papers.lub.lu.se:9160977 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Ida Linn Silfors author 9160975 bitr. universitetslektor Baozhong Zhang supervisor Maria Petersson supervisor Katarina Jonasson supervisor Centre for Analysis and Synthesis v1000651 department In recent years, there has been a surge in attention towards biodegradable polymer films, driven by the growing environmental awareness concerning the harmful effects of petroleumbased plastics. The maize protein zein, a by-product from wet milling processes, has shown potential to work as hydrophobic coating. The aim of this study has therefore been to find the most promising process conditions for zein-based liquid barrier coatings, including dissolution, application method, film formation and drying conditions, to achieve maximum barrier efficiency.<br /> <br /> Different concentrations of zein were dissolved in various concentrations of ethanol. In some solutions, a plasticizer, either oleic acid (OA) or linoleic acid (LA) was added. The solutions were then coated, using a blade coater, onto printing paper. Several parameters were explored in this study, including the solution´s application temperature, the number of coated layers,the coating´s drying temperature and drying time. Additionally, the significance of the<br /> solution´s storage time and the conditioning time (23°C and 50% Relative humidity) for the finished coatings were investigated.<br /> <br /> The most promising liquid barrier properties were found for the coating consisting of 10% (g/g EtOH) zein, 30% (g/g zein) OA, and 96% (v/v) EtOH, with the process conditions of; 3 layers with 1h air-drying in between each layer and where the solution has been stored for 8 days before reheated and applied onto the substrate. The coating received a 47% decrease in water uptake compared to reference/ uncoated paper. However, the coatings with 10% (g/gEtOH) zein does not appear to be particularly robust as some of them experience water leakage, suggesting that 20% zein should be used instead for future attempts. <br /> <br /> SEM imaging revealed that coatings without a plasticizer displayed sharp cracks, indicating that zein becomes brittle in the absence of a plasticizer. In contrast, coatings with OA exhibited smooth and even surfaces on top of the paper fibers and without any distinct pits.<br /> <br /> In this study it became evident that the liquid barrier properties of the coatings were significantly improved by the addition of plasticizer, where coatings with oleic acid yielded lower water uptake than coatings with linoleic acid. It was further found that the ethanol concentration affects both the solution´s rheology and the final coating´s barrier properties. An ethanol concentration of 96% proved to yield the most effective barrier. Rheological changes were also observed when the solution was cooled down to room temperature. However, the storage time of the solution as well as the conditioning time of the coating showed to have no significant effect on the barrier properties. Lastly, air drying yielded a better barrier than drying the coating in oven at 60°C. <br /> <br /> From this study it has become evident that the biopolymer zein shows great potential to work as a liquid barrier within a cellulose material. Continued research of these zein-based polymer coatings is highly recommended. Under de senaste åren har plaster och deras hälso- och klimatpåverkan blivit mer uppmärksammat, vilket har drivit utvecklingen av nya hållbara material. Biobaserad och biologiskt nedbrytbar plast betraktas ofta som ett hållbart material och därför bedrivs omfattande forskning kring naturligt förekommande molekyler, såsom proteiner, cellulosa och stärkelse.<br /> <br /> Pappersförpackningar som ska omsluta en vätska är beroende av någon sorts barriär för att hålla tätt vilket ställer krav på på de hydrofoba (vattenavstötande) egenskaperna. Det naturliga majsproteinet zein är en restprodukt av masjstärkelseproduktionen och har uppvisat potential till att fungera som barriär i förpackningssammanhang. Eftersom zein är en hälsosäker substans samt uppvisar vattenavstötande egenskaper är den passande att använda som vätskebarriär i förpackningsmaterial för livsmedel. Syftet med denna studie var därför att undersöka vilka processvillkor som ger bäst vätskebarriäregenskaper för zeinbaserade beläggningar på papper.<br /> <br /> Olika koncentrationer av zein löstes upp i varierade etanolkoncentrationer och i några av lösningarna tillsattes även en mjukgörare, antingen oljesyra eller linolsyra. Lösningarna applicerades därefter på kopieringspapper med hjälp av en bänkbestrykare. De parametrar som testades var appliceringstemperaturen på lösningen, antal lager som applicerades samt torktemperatuen och torktiden på beläggningarna. Dessutom undersöktes hur stor påverkan förvaringstiden av lösningen samt de färdiga beläggningarna hade på barriäregenskaperna.<br /> <br /> Beläggningarnas vattenbarriäregenskaper analyserades och från resultaten framgick att bäst vätskebarriäregenskaper uppnåddes då beläggningen innehöll tre lager av 10% (g/ g etanol) zein, 30% (g/g zein) oljesyra samt 96% (v/v) etanol, där lösningen förvarats i 8 dagar innan den värmts upp och applicerats, och där beläggningen därefter torkats 1h i rumstemperatur mellan varje lager.<br /> <br /> I de mikroskopiska analyserna framgick att beläggningar utan mjukgörare uppvisade skarpa sprickor, vilket tydligör mjukgörarens betydelse. Beläggnignar som innehöll oljesyra hade jämna ytor utan några tydliga gropar i strukturen. https://lup.lub.lu.se/student-papers/record/9160977/file/9161007.pdf application/pdf 2923692 no 2024 eng Zein biopolymer film formation food packaging polymer technology Chemistry https://lup.lub.lu.se/student-papers/record/9160977/file/9161017.pdf application/pdf no 9160977 2024-06-10T13:00:11+02:00 2024-06-13T10:12:06+02:00 2024-06-13T10:12:06+02:00

oai:lup-student-papers.lub.lu.se:9161043 2025-07-29T13:03:30Z PhysicsChemistryMaths

studentPublicationsH2 Johanna Åberg author 9160604 Stephen Burleigh supervisor Jesper Østergaard supervisor Food Technology and Nutrition (M.Sc.) v1000294 department Biotechnology (MSc) v1000284 department Biotechnology (M.Sc.Eng.) v1000285 department Studying dissolution of oral drug substances is crucial throughout the drug development process. Current methods are time consuming and require large quantities of both the drug and dissolution media. Thus, exploring new methods is highly desirable. UV imaging, an analytical technique based on real-time absorbance measurements, can be used in early drug discovery to study drug dissolution and has significant potential to overcome these obstacles. This work aimed to develop a UV imaging setup to study the dissolution of two drug compounds, salicylic acid and sodium salicylate, and to investigate the possibility of determining microenvironmental pH during dissolution. IDR (intrinsic dissolution rate) values were determined for both compounds in different dissolution mediums and images from the experiments were analyzed. The results demonstrated that UV imaging could distinguish between the dissolution profiles of the two compounds and that dissolution was highly dependent on the pH of the dissolution medium. By preparing solutions of salicylic acid and sodium salicylate of different pH and measuring absorbance, it was concluded that these compounds could serve as their own pH probes. The two-wavelength spectrophotometric method to determine pH was investigated using both the UV imaging system SDi2 and a spectrophotometer. This method was subsequently applied to calculate microenvironmental pH during the dissolution of the drug compounds. This novel approach requires further studies but holds significant potential for future applications. Att studera upplösning av orala läkemedel är avgörande för att förstå deras biotillgänglighet och terapeutiska effekt. Då dagens metoder för att studera upplösning är tidskrävande och kräver stora mängder av läkemedel och media så finns det ett stort behov av att fram nya metoder. En potentiell metod är UV-Vis imaging som kan användas för att studera upplösning av läkemedel i realtid. Detta projekt har utforskat denna teknik samt utvecklat en metod för att studera pH-förändringar i mikro-miljön under upplösning av utvalda läkemedel. Detta har genererat väldigt intressanta och unika resultat och metoden har stor potential inför framtiden<br /> <br /> Upplösning av orala läkemedel påverkas av flera olika faktorer, men bestäms huvudsakligen av affiniteten mellan läkemedlet och upplösningsmediet. Intrinsic dissolution rate, (IDR), är en form av upplösningshastighet som ofta används för att karakterisera läkemedel. IDR definieras som mängden läkemedel som löser sig per tidsenhet och area. Ett vanligt problem inom läkemedelformulering är svårlöslighet, och ett tillvägagångsätt för att förbättra detta hos joniserbara läkemedel är saltbildning. Lösligheten hos dessa läkemedel är ofta starkt beroende av pH i det omgivna mediet, vilket gör det intressant att studera pH förändringar vid upplösning av läkemedel och deras salter. <br /> <br /> UV-Vis imaging är en analytisk metod för att studera upplösning av små mängder läkemedel i realtid. Genom att föra in sitt prov in en cell där upplösningsmedium flödar och mäta UV absorbansen genom cellen så kan information om händelser vid ytan av läkemedlet och koncentrationen av läkemedlet i upplösningsmediet erhållas. IDR kan beräknas och bilder från experiment kan studeras. I detta projekt har dessutom en spektrofotometrisk metod använts, där absorbansen mäts vid två olika våglängder för att beräkna pH vid upplösningsexperiment. Denna metod för att beräkna pH är helt ny och har tidigare endast använts för pH-bestämning av havsvatten. Ett tillgängligt UV-imaging-instrument, Sirius SDi2, har använts i detta projekt.<br /> <br /> Resultaten visade att UV-imaging kunde skilja mellan de två föreningarnas upplösningsprofiler och att upplösningen var starkt beroende av upplösningsmediets pH. Natriumsalicylat hade en signifikant högre upplösningshastighet i jämförelse med salicylsyra vilket var väntat. Genom att förbereda lösningar av salicylsyra och natriumsalicylat med kända pH-värden och mäta absorbansen, drogs slutsatsen att dessa föreningar kunde fungera som sina egna pH-indikatorer. Den spektrofotometriska metoden för att bestämma pH undersöktes med både UV-Vis imaging instrumentet SDi2 och en spektrofotometer. Denna metod tillämpades sedan för att beräkna mikro-miljö pH under upplösning av salicylsyra at natriumsalicylat. Metoden fungerade bra för att bestämma intermediära pH-värden men stor osäkerhet observerades vid höga och låga pH-värden. Denna nya metod kräver ytterligare studier men har stor potential för framtida tillämpningar. https://lup.lub.lu.se/student-papers/record/9161043/file/9161063.pdf application/pdf 6303927 no 2024 eng UV-Vis imaging dissolution salicylic acid pH pharmaceutical formulation Chemistry 9161043 2024-06-10T13:48:57+02:00 2024-06-11T11:23:31+02:00 2024-06-11T11:23:31+02:00

oai:lup-student-papers.lub.lu.se:9161395 2025-12-31T02:43:58Z LifeEarthScience PhysicsChemistryMaths

studentPublicationsH2 Milad Mohammadi author 9160379 Roya Sardari supervisor Biotechnology (MSc) v1000284 department Biotechnology (M.Sc.Eng.) v1000285 department In this study the thermophilic marine bacterium Rhodothermus marinus DSM 16675 was exploited for the production of biosurfactants. Different strategies employing batch, or a combination of batch and fed-batch cultivations were investigated. These cultivations were performed both on complex and defined media. The extracted crude biosurfactants were then analyzed with different methods such as FTIR, HPLC and mass spectrometry. The identified biosurfactants were saturated and unsaturated fatty acids with lengths ranging from C16:0 to C18:0. The LC-MS analysis on these samples revealed peaks at different retention times consisting of the same fatty acid precursor ion which is suggested to be due to different branching on the carbon chain. Furthermore, it was found that the exopolysaccharide (EPS) produced by this microorganism has emulsifying properties. The critical micelle concentration (CMC) of the crude EPS was calculated at 0.75 ± 0.01 g/L using advanced fluorometric method and curcumin as fluorescent probe. Moreover, the produced EPS was able to stabilize the water-in-oil emulsion at a concentration of 10 g/L with an emulsification index (% E24) of 59.3 ± 2.5 %. The reported EPS has the potential application in oil industry, but further experiments are required to fully utilize the properties of this emulsifier. Nowadays we can find surfactants in many products that we daily use. Surfactants are compounds that can react both with water and fatty compounds such as vegetable oils and mix them together. This property gives rise to many potential applications from detergents to oil industry. Currently, most of the surfactants that are in use are derived from fossil fuel and consequently extensive research has been conducted to find more sustainable sources to produce these compounds. One such source are microorganisms such as bacteria. It has been suggested that bacteria produce surfactants during their growth to be able to utilize a variety of food sources as well as to increase their mobility. These surfactants that are produced by bacteria are called biosurfactants.<br /> This research was focused on producing biosurfactants from a bacteria that was isolated from a hot spring where it thrived at high temperatures. More specifically, different parameters such as the concentration of nutrients were changed to see their effect on the production of biosurfactants. Different tests were done to see the composition of the biosurfactants as their structure influence their potential application. Consequently, two different types of biosurfactants were identified in this study but further analysis is required to unlock their full potential for industrial applications. https://lup.lub.lu.se/student-papers/record/9161395/file/9161404.pdf application/pdf 4025758 2025-12-31 no 2024 eng Rhodothermus marinus biosurfactant exopolysaccharide fermentation fatty acids HPAEC-PAD HPLC MS biotechnology Biology and Life Sciences Chemistry 9161395 2024-06-10T21:28:42+02:00 2025-12-31T03:43:58+01:00 2024-06-12T09:37:38+02:00 PhysicsChemistryMaths!!!mods!500