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Using ion pair chromatography, separation and analysis of shorter mRNA fragments was possible. The aim of the study was to develop a separation method for quantitation of 5’capped versus uncapped mRNA. Cleavage of mRNA was performed by complementary probes and the enzyme RNase H which created shorter mRNA fragments containing the 5’ end. During this study, several separation methods have been tested where the amount organic solvent proved to be a crucial factor for elution of the fragments. To identify the peaks during the method development, LC-MS had to be used which resulted in an adjustment of the methods parameters. With the mass spectrometric analyses could a capped fragment as well as a capped fragment containing an extra guanine nucleotide be identified, however, there was no presence of the uncapped fragment. Enzymatic protocols have been investigated where the purpose was to create uncapped RNA fragments to be used as a reference. A minor validation of the final separation method has been carried out where the generated data can be used to establish acceptable system suitability test criteria for separation methods when analyzing mRNA drug products. / Genom användandet av jonparskromatografi var separation och analys av kortare mRNA fragment möjlig. Syftet med studien var att sätta upp en kvantifieringsmetod för analys av förhållandet 5’cappat kontra icke-cappat mRNA. Klyvning skedde med hjälp av en komplementär probe och enzymet RNase H som skapade korta mRNA fragment innehållande cap strukturen. Under studiens gång har flertalet separationsmetoder testats, där halt organiskt lösningsmedel var en viktig faktor för eluering. För att identifiera topparna behövdes masspektrometri användas vilket resulterade i en justering av metodens parametrar. Med hjälp av LC-MS kunde det cappade fragmentet detekteras, dock fanns ingen närvaro av ett icke-cappat mRNA. Enzymatiska undersökningar har utförts där målet var att skapa icke-cappat RNA för att använda som referens. En mindre validering av den finala separationsmetoden har genomfört där de genererade datavärdena sedan kan användas för att fastställa accepterbara kriterier för separationsmetoder vid analys av läkemedelsprodukter baserade på mRNA.

This project investigates how different types of perovskite solar cells, differentiated by choice of materials and processing techniques, compares to each other regarding performance and characterization. The purpose of the project is to further develop perovskite solar cells and to improve the method of manufacturing for better performance. A total of 160 perovskite solar cells are constructed, divided into eight distinct types. Two different perovskites, MAPbI3 and MAFAPbI3, are used and prepared using two different solvents: isopropanol (IPA) and pentanol (PenOH). Furthermore half of the solar cells contain phenethylammonium iodide (PEAI). When completed, the solar cells' performances are measured and compared. Lastly, the solar cells and the perovskites are compared through characterization measurements. An incident-photon-to-current-efficiency (IPCE) spectroscopy is performed on the solar cells to get a better understanding of the efficiency depending on the wavelength of the incident light. An UV-vis-NIR spectroscopy is performed on the thin film to analyze the absorbance and determine the band gap of the material. The pre-crystallized perovskite powders are compared through characterization measurements, such as X-ray Photoelectron Spectroscopy (XPS) characterization and scanning electron microscopy (SEM) measurements. This results in comparing material compositions and optical properties of the solar cells. The results indicate that MAPbI3 (PenOH) is the highest performing type independent of the presence of PEAI. The measured mean power conversion efficiency (PCE) are 15.47% and 13.84% for MAPbI3 (PenOH) with and without PEAI respectively. The best performing individual solar cell contains MAPbI3 (PenOH) with PEAI and has a PCE of 20.21%. On the contrary, MAFAPbI3 (PenOH) with and without PEAI perform the worst. The best improvement of the PCE after two weeks is +22.13%, given by MAPbI3 (PenOH) with PEAI. Generally, solar cells with MAPbI3 have a larger band gap, 1.61 eV, compared to MAFAPbI3's 1.55 eV, regardless of the presence of PEAI. MAPbI3 (PenOH) can convert a larger portion of incident photons to electrical energy, up to almost 80%. MAFAPbI3 (IPA) converts almost as much, over 70%, while MAPbI3 (IPA) and MAFAPbI3 (PenOH) in some measurements barely has a 50% conversion rate.

Total oxidizable precursor assay (TOPA) has been used to understand the contribution of unknown precursors to the extractable organofluorine (EOF) compounds. The investigation of compounds containing a CF3 moiety especially connected to an aromatic ring is important because any compounds with such a moiety (pharmaceuticals) may oxidize to form trifluoroacetic acid (TFA). This information may help to increase the understanding of the sources of TFA in the environment. TOPA has been used for this purpose, however, this method has a weakness as the conditions during oxidation results in samples containing high concentrations of sulfates. The sulfates might compete with C2-C3 perfluoroalkyl acids (PFAAs) for binding sites in the solid-phase extraction (SPE), which in turn decreases the recovery of these compounds substantially. This study aimed to optimize the extraction following the TOP assay to increase the recovery of C2-C3 PFAAs, and to apply the improved method to determine whether selected pharmaceuticals (fluoxetine, seproxetine and celecoxib) may oxidize to form TFA. The main parameters affecting the recoveries of C2-C3 PFAAs were found to be pH as well as sorbent volume of the SPE cartridge. The optimized method included adjusting samples to pH 2.0 using formic acid prior to solid phase extraction (SPE), as well as using 500 mg sorbent cartridges for SPE. By optimizing the extraction, it was possible to increase the recovery of TFA from 2% to 54%. All three pharmaceuticals were oxidized into TFA to various extent (molar ratio of TFA from fluoxetine: 35%, seproxetine: 63% and celecoxib: 35%). This knowledge could be used as an indication of potential precursors in a sample and can help understand the contribution of CF3-containing pharmaceuticals to the EOF.

This work was made to discover if greenhouse crops, particularly broccoli and Chinese cabbage, can change their metabolism and therefore their nutritional profile depending on what ultraviolet radiation (UV) they were exposed during growth. This is important since the world’s population increases and therefore, we need to be able to produce foods with increased nutritional quality. To explore whether we can use UV for that, we first analyzed the plant extracts searching for changes in plant metabolism after exposure to UV light and then subjected the plants exposed or not to UV to an in vitro fermentation system that mimics the digestion by the human gut microbiota. The latter was done to understand how our gut microbiota can metabolize plants with distinct metabolite profile and whether this will impact in the levels of metabolites with beneficial health effects. We started by applying different UV treatments during growth of broccoli and Chinese cabbage (i.e., plants were grown using standard growth conditions or they were exposed to supplementary UVA or to supplementary UVB) and for the analysis of plants, we applied a non-targeted approach to explore overall changes in metabolism induced by UV light. The plants were further subjected to an in vitro fermentation approach to simulate human digestion. The obtained fermentation extracts were further analyzed for levels of short-chain fatty acids (SCFA) at different time points during the in vitro fermentation. Major insights from this experiment were that the different light contributes to significant changes in the plant’s metabolic profile depending on what light they were cultured in. However, such changes in plant metabolism does not change how our gut microbiota produce SCFA during fermentation. Another conclusion when exploring broccoli and Chinese cabbage is that UV effects cannot be generalized to different plants. This depends on their different genotypes, even in the same species, which gives different response of light on the plant’s receptors. No differences in the SCFA profile were found after fermentation of control and UV-exposed plants; however, results from plant extracts indicate that a more comprehensive analysis of fermentation extracts might reveal changes in how our gut microbiota metabolizes plant components. Although further analysis is needed to confirm such hypothesis, the pipeline showed that UV light influences metabolism of broccoli and cabbage and therefore modulate plant metabolism and their potential impact on human health by increasing the levels of compounds with antioxidant properties.

Denna licentiatavhandling behandlar effekten av två inneboende egenskaper (fissions produkter och egenbestrålning) hos utbränt kärnbränsle på hastigheten för strålningsinducerad upplösning av bränslematris (UO2). I ett framtida djupförvar kommer det utbrända kärnbränslet att deponeras 500 meter ner i berggrunden i en reducerande miljö. Under dessa förhållanden är UO2-matrisen själv en av de skyddande barriärerna mot frigörande av radionuklider, på grund av dess låga löslighet. När bränslet kommer i kontakt med vatten kommer U(IV) att oxideras till U(VI) av radiolysprodukter från vattnet och lösligheten för bränslematrisen kommer därmed att öka betydligt. De flesta tidigare studier har utförts på obestrålad UO2 som skiljer sig signifikant från utbränt kärnbränsle. I utbränt kärnbränsle är de flesta fissionsprodukterna och neutronaktivieringsprodukterna radioaktiva och bränslet kommer därför bli bestrålat av sig självt. Effekten av joniserande strålning på reaktiviteten för UO2(s) har undersökts här. UO2 (pulver och fragment av en kuts) bestrålades i en 60Co γ-källa eller framför en elektronaccelerator varpå reaktiviteten för UO2 studerades genom oxidation av UO2 med MnO4 -. Det visade sig att reaktiviteten för UO2 ökar när det blir bestrålat för första gången (<20 kGy). Effekten ökar med ökande dos tills den når ett maxvärde ~1.3 gånger reaktiviteten för obestrålad UO2 vid torrbestrålning. Vid våtbestrålning ökar en dos på 140 kGy reaktiviteten 2.5 gånger. Effekten verkar vara permanent. Tidigare studier har visat att H2O2 är den viktigaste oxidanten för upplösning av utbränt kärnbränsle under djupförvarsförhållanden. I vätgasatmosfär, som förväntas i ett djupförvar, har det visat sig att upplösningshastigheten är långsammare. Det har delvis förklarats med reaktionen mellan H2O2 och H2, som är väldigt långsam utan katalysator. Den katalytiska effekten av UO2 på den reaktionen har undersökts och det visades att den inte katalyseras av UO2. En annan möjlig katalysator för reaktionen är ε-partiklar (ädelmetallpartiklar bestående av Mo, Ru, Tc, Pd och Rh) som bildats av fissionsprodukterna. Pd är en välkänd katalysator för reduktion med H2. Den eventuella katalytiska effekten av Pd har undersökts här. Även en eventuell katalytisk effekt av Pd på reduktionen av U(VI) med H2 undersöktes, både i vattenfas och i UO2-kutsar innehållande olika mängder Pd (som en modell för ε-partiklar). Vi fann att Pd har en katalytisk effekt på reaktionen mellan H2O2 och H2 och andra ordningens hastighetskonstant är bestämd till (2.1±0.1)x10-5 m s-1. Pd har också en katalytisk effekt på reduktionen av U(VI) med H2 både i vattenlösning, hastighetskonstant (1.5±0.1)x10-5 m s-1, och i den fasta fasen. Hastighetskonstanten för processen i fast fas är 4x10-7 m s-1 och 7x10-6 m s-1 för kutsar med 1 respektive 3 % Pd. Dessa värden är väldigt nära diffusionsgränsen för den här typen av system. Den katalytiska effekten i den fasta fasen visar att upplösningen för 100 år gammalt bränsle kan stoppas helt. Vid 40 bar H2 krävs 10-20 ppm ädelmetallpartiklar och med 1 % ädelmetallpartiklar räcker det med 0.1 bar H2 för att stoppa upplösningen. / This licentiate thesis deals with the influence of two inherent properties (fission products and self irradiation) of spent nuclear fuel on the rate of radiation induced fuel matrix (UO2) dissolution. In a future deep repository the spent nuclear fuel will be deposited 500 meters down in the bedrock in a reducing environment. Under these conditions the UO2-matrix itself is one of the protective barriers against release of radionuclides due to its very low solubility. When the fuel comes in contact with water, U(IV) will be oxidized to U(VI) by products from radiolysis of water and the solubility of the fuel matrix will increase significantly. Most previous studies have been performed on unirradiated UO2 which differ significantly from spent nuclear fuel. In spent nuclear fuel most of the fission products and neutron activation products are radioactive and therefore the fuel will be irradiated by itself. The effect of ionizing radiation on the reactivity of UO2 has been investigated here. UO2 (powder and fragment of a pellet) has been exposed to irradiation in a 60Co γ-source or in an electron accelerator and then the redox reactivity was studied. The kinetics for oxidation of UO2 by MnO4 - was used as a monitoring reaction. It was shown that the reactivity of UO2 increases when being irradiated for the first time (<20kGy). The effect increases with increasing dose until reaching a maximum value ~1.3 times the reactivity of unirradiated UO2 for dry irradiation. For wet irradiation a dose of 140 kGy increases the reactivity ~2.5 times. This effect appears to be permanent. Previous studies have shown that H2O2 is the most important oxidant for spent nuclear fuel dissolution under deep repository conditions. Under H2 atmosphere, as expected in a deep repository, it has been shown that the dissolution rate is slower. This has partly been attributed to the reaction between H2O2 and H2 which is very slow without a catalyst. The catalytic effect of UO2 on this reaction was examined showing that UO2 does not catalyze this reaction. Another possible catalyst for this reaction is the ε-particles (noble metal particles containing Mo, Ru, Tc, Pd and Rh) formed by the fission products. Pd is a well known catalyst for reduction by H2. The possible catalytic effect of Pd on the reaction between H2O2 and H2 is examined here. The possible catalytic effect of Pd on the reduction of U(VI) by H2 is also examined, both in aqueous phase and in UO2 pellets containing different amounts of Pd (as a model for spent fuel containing ε-particles). It was found that Pd has a catalytic effect on the reaction between H2O2 and H2, the second order rate constant is determined to (2.1±0.1)x10-5 m s-1. Pd also has a catalytic effect on the reduction of U(VI) by H2 both in aqueous solution, rate constant (1.5±0.1)x10-5 m s-1, and in the solid phase, rate constants 4x10-7 m s-1 and 7x10-6 m s-1 for pellets with 1 and 3 % Pd respectively. These values are very close to the diffusion limit for these systems. The catalytic effect in the solid phase shows that the dissolution for 100 year old fuel can be completely inhibited, at 40 bar H2 a noble metal particle content of 10-20 ppm is needed and with 1 % noble metal particle content 0.1 bar H2 is enough to stop the dissolution. / QC 20101119

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The in-biology novel high-valent manganese cofactor {MnIII MnIV} has been elucidated and characterized in a ribonucleotide reductase from Facklamia ignava, establishing the new radical-free ribonucleotide reductase class; class Id. The cofactor was found to be directly connected to catalytic activity and a mixed-metal cofactor was disproven using a newly formulated in vitro assembly protocol and activity assays. The cofactor was assembled in vitro using hydrogen peroxide, and it was shown that the F. ignava ribonucleotide reductase can perform catalase activity, with the cofactor formation as a side-reaction. Using electron paramagnetic resonance spectroscopy to study the in vitro assembled cofactor, a hydrogen peroxide-driven assembly mechanism was proposed, where the mechanism is like that of manganese catalases. An over-oxidized {MnIV MnIV} intermediate is suggested to be the direct precursor to the {MnIII MnIV} cofactor. The cofactor was also shown to be able to be assembled with superoxide, with in situ generation of superoxide using hydroquinone. An in vivo assembly mechanism was proposed to involve superoxide generated by some unknown accessory enzyme, similar to the NrdI assembly system of class Ib ribonucleotide reductases.