Global ETD Search

1	Gelbildning av vassleprotein / Gelation of Whey Protein Mörtberg, Rasmus January 2019 (has links) Vassleproteiner har kemiska egenskaper som gör att de, under rätt förhållanden, kan bilda geler. Det här gör vassleproteiner mycket intressanta eftersom de då kan användas i olika livsmedel för att ge önskad konsistens. Dessutom är vassleproteiner billiga och lätt att få tag på vilket gör de extra intressanta att undersöka. Får man mer information om hur dessa geler bildas kan man på ett relativt billigt sätt framställa dem för användning i livsmedel. De förhållanden som bäst gynnar gelbildning av vassleproteiner undersöktes. De faktorer som testades var proteinkoncentration, vikt% seeds, temperatur, pH och salthalt. För att undersöka detta utfördes flera försök med varierande nivåer av dessa variabler. Först gjordes försök med varierande nivåer av proteinkoncentration samt vikts% seeds samtidigt som övriga variabler hölls konstanta. Därefter utfördes försöken med varierande nivåer på de övriga variablerna (temperatur, pH och salthalt) en i taget. Försöken med varierande nivåer av dessa variabler undersöktes för flera olika proteinkoncentrationer samt vikt% seeds. I detta projekt har seeds använts för att ge proteinerna en startpunkt för att bilda de nätverk som gelen utgörs av. Som seeds användes fibrillfragment av samma typ som de fibriller som bildar gelen. Resultaten visade att för att få en så kort gelningstid som möjligt bör provlösningen ha hög temperatur (i detta projekt 90 ̊C), hög salthalt (100 mM) och lågt pH (pH 1,5). Provlösningen bör även ha en hög proteinkoncentration (80 mg/ml) samt en hög vikts% seeds (10%). När samtliga variabler sattes till den optimala nivån sjunker gelningstiderna ytterligare. / Whey protein have chemical properties that allows them to gel, under the right conditions. This makes whey protein very intresting since it makes it possible to use it in different food products to give them the right texture. Whey protein is also cheap and easy to get hold of which makes them even more intresting to study. If you can get more information on how these gels form you can, in a relatively cheap way, produce this gel that can be use in food products. This project investigated under which circumstances whey protein gelation is best benefitted. The different variables that were tested were protein concentration, weight% seeds, temperature, pH and ionic strength. In this project fibrils of the same type as the ones that forms the gel where used as seeds. The function of the seeds is to give the proteins a starting point at which to start forming the networks that the gel consists of. To investigate this many experiments with varying levels of these variables where made. First experiments with varying levels of protein concentration and weight% seeds were made while the other factors were put on a steady level. Then experiments with varying levels of the other variables (temperature, pH and ionic strength), one at a time. The experiments with varying levels on these variables were made with varied protein concentration and weght% seeds. Interaction effects between the different variables was studied by varying several of these variables at the same time. The results showed that to have as short of a gelling time as possible the solution should have a high temperature (90 ̊C), high ionic strenght (100 mM NaCl) and low pH (1,5). The solution should also contain a high protein concentration (80 mg/ml) and a high weight% seeds (10%). When all of the variables are placed on the optimal level the gelling times are further reduced. Vassleprotein gelbildning fibriller PNF Chemical Engineering Kemiteknik
2	Flexible and recyclable electronics made from nanoreinforced silk / Flexibla och återvinningsbara elektronikkomponenter baserade på nanoförstärkt spindelsilke Bukovský, Marek January 2020 (has links) Forskningsområdet för bärbar elektronik är fortfarande relativt ungt och det finns ett stort behov av utveckling av nya material inom området. Olika typer av kompositer är mycket intressanta och de ska uppvisa såväl hög hållfasthet som goda ledande egenskaper. I detta avseende är silkes fibroin och MXene mycket intressanta utgångsmaterial eftersom silkestrådarna kan ge en struktur med god jonledningsförmåga och god flexibilitet och MXene kan bidra med hög styvhet och god elektrisk ledningsförmåga. Med detta som bakgrund beslöts att undersöka om kompositer av silkestrådar och MXene kan användas i kompositer som kan användas i bärbar elektronik. 3 olika typer av hydrogeler studerades och de innehöll silkes fibroin med 0, 1 och 5% MXene. De egenskaper som utvärderades var struktur, mekaniska egenskaper, stabilitet i vatten, bionedbrytbarhet och både statisk och dynamisk ledningsförmåga. Resultaten visar att de tillverkade nanokompositerna har lovande förutsättningar inom området eftersom en kombination av silkes fibroin med 5 % MXene har god stabilitet, konduktivitet och en hög och stabil Gauge-faktor. / As the research area of wearable electronics is still relatively new, material science with this focus opens plenty of unexplored fields. That is why a study characterizing the unexplored composite system of silk fibroin and MXene (Silk/MXene) was conducted. These two biocompatible materials are complementary with regard to the requirements for wearable electronics materials. Silk fibroin dispose an ionic conductivity and solid flexibility, while MXene brings mechanical strength and significant increase of electrical conductivity. The reinforced hydrogel materials were studied at two concentrations of fillers, 1% and 5% and compared to pristine silk fibroin. All three materials were studied from the point of view of their structure, mechanical properties, behaviour in aqueous environment, biodegradability and electrical conductivity, both static and dynamic. Nanocomposite systems of silk fibroin and MXene have shown a potential for being used in the intended application area, as Silk/MXene 5% film displays good stability, conductivity with high andstable Gauge factor. Wearable electronics flexible electronics silk fibroin MXene nanocomposites Bärbar elektronik flexibel elektronik silkes fibriller MXene nanokompositer Materials Chemistry Materialkemi
3	Bovint serum albumin påverkar överlevnad och Aβ-nivåer i Alzheimers sjuka Drosophila flugor. : Bovine serum albumin affects survival and Aβ-levels in Alzheimer's diseased Drosophila flies. Tani, Milena January 2024 (has links) Alzheimer's disease (AD) was first described more than 100 years ago and is today the most common cause of dementia. It is one of the progressive neurodegenerative diseases that affect 47 million people around the world between the ages of 60 and 90. One of the contributing factors to AD is extracellular amyloid – β (Aβ) plaques that form as a result of protein aggregation. These Aβ proteins are neurotoxic, leading to degeneration of brain neurons and loss of cognitive abilities. Because AD largely affects society, researchers are constantly working to find a cure, which currently does not exist. The purpose of this study was to use Drosophila melanogaster as a living organism model for the expression of two types of Aβ proteins related to AD, Arctic (Glu22Gly) and TandemAβ, and to study the survival of these AD flies when Bovine serum albumin (BSA) was added to the fly food. The hypothesis was that BSA would be effective in slowing down and/or preventing formation of toxic Aβ-aggregates. The focus was therefore to investigate whether the AD flies would live longer if they were allowed to eat Bovine serum albumin and whether the soluble/insoluble Aβ levels in these flies would decrease in comparison to the control AD flies that were not allowed to eat BSA. The effect of BSA on toxicity was evaluated using survival assay on male flies and the levels of soluble/insoluble Aβ were evaluated using Meso Scale Discovery (MSD) on female flies. In both experiments, the following six groups of flies were examined: myow1118 ± BSA; myoArctic ± BSA; myoTandemAβ ± BSA. Conclusions from the studies are that the survival of AD flies could not be extended by adding 0.61 mM BSA to the food, rather the data showed a weak but significant toxic effect in the presence of BSA in the AD flies. However, MSD data showed a reduction of insoluble Aβ aggregates and an equilibrium shift from insoluble Aβ aggregates to soluble Aβ aggregates in the presence of BSA in the AD flies. Equilibrium shifts were particularly detectable in Myo-TandemAβ flies fed with BSA. In Myo-Arctic flies fed with BSA only reduction of insoluble Aβ could be detected. This shows that it is not the amount of Aβ aggregates that is decisive for toxicity, but rather the presence of specific aggregates that have toxic properties. If BSA shows good results in further studies, it could be used in the future to improve AD symptoms in patients. Drosophila melanogaster Alzheimer AD BSA Bovine serum albumin Human serum albumin HSA Toxicity Aβ survival assay MSD Meso Scale Discovery Arctic (Glu22Gly) TandemAβ oligomers fibrills GAL4-UAS TM6B CyO enterocytes Drosophila melanogaster bananfluga Alzheimers BSA Bovint serum albumin Aβ Amyloida plack Överlevnad MSD Meso Scale Discovery AD Toxicitet Arctic (Glu22Gly) TandemAβ HSA Humant serum albumin GAL4-UAS TM6B CyO fibriller oligomerer enterocyter Natural Sciences Naturvetenskap Other Chemistry Topics Annan kemi Biochemistry and Molecular Biology Biokemi och molekylärbiologi Other Biological Topics Annan biologi Genetics Genetik

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