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The ability of Shigella flexineri to spread within and between epithelial cells is essential for Shigella infection causing bacillary dysentery. This is a particular problem in the developing world. The movement of Shigella within the host cell requires the accumulation of actin at one pole of the bacterium and the protein VirG is responsible for this function. While the C-terminal domain (β-domain) of VirG is integrated into the outer membrane of Shigella, the N-Terminal domain (α-domain) is exposed on the surface of the bacterium. The β-domain acts as autotransporter of the α-domain. The exposed α-domain has multiple binding partners including N-WASP, Vinculin and IcsB that are required for infection in man and cell to cell spread. To understand the molecular basis of VirG’s activity, it is first necessary to produce the protein in quantity; this study investigates the expression of VirG α-domain in E.coli. The optimum construct corresponded to residues 58-506 of VirG expressed in Rossetta-gami cells.

The local structure evolution as a function of composition and temperature, and the resulting electrical conductivities were studied in samples with general composition (Yb1-xNdx)2Zr2O7, using Reverse Monte Carlo (RMC) modelling of total neutron scattering data and Impedance Spectroscopy. At low neodymium content (0.00 ≤ x ≤ 0.50), this system crystallizes in the fluorite structure with space group Fm3̄m, where-as at high neodymium content (0.75 ≤ x ≤ 1.00), a pyrochlore structure with space group Fd3̄m is observed. For compositions with high neodymium content prepared at lower temperatures, a fluorite structure is seen, which shows gradual evolution of pyrochlore ordering with increasing calcination temperature. Cation anti-site disorder was present throughout the compositional range. Total conductivity increases with increasing Nd content, up to a maximum at x = 0.75 and then decreases. The conductivity of these oxides is of the order of 10-4 S cm−1 at 700 °C. Variable temperature neutron powder diffraction experiments were carried out on the (Nd1-xCax)2Zr2O7-x (0.10 ≤ x ≤ 0.50) system, to investigate the local structural evolution as a function of composition and temperature. The entire compositional range studied exhibits a single phase with a pyrochlore-type structure. The variable temperature study showed that the pyrochlore structure is maintained throughout the temperature range studied. No cation anti-site disorder was present in any of the compositions, over the temperature range studied. Total conductivity increases with increasing Ca content, up to a maximum at x = 0.30 and then decreases. The conductivity of these oxides is of the order of 10-3 S cm−1 at 700 °C. Structural evolution in oxidising and reducing atmospheres was investigated in cerium zirconate, Ce2Zr2O7+δ. A number of transformations were revealed, depending on the atmosphere (O2 vs CO) and temperature. Upon heating the pyrochlore phase in flowing O2, three distinct phases were observed, with transitions at ca. 140 C and 410 C. At around 140 C, a previously un-identified phase formed, which was fitted with a triclinic model that contained 10 Ce and 10 Zr sites, each with a distorted cubic coordination. Above 410 C, the triclinic phase transformed to a cubic phase, corresponding to the κ-phase (space group P213). RMC modelling of the local structure of the -phase, revealed an ordered, pyrochlore-like cation sub-lattice, with a disordered anion sub-lattice. Upon re-heating the κ-phase in CO, the pyrochlore phase re-appeared at around 260 °C. At 290 °C, the pyrochlore phase was phase pure.

Wine characterization of taste and odor of a wine is important to keep up with consumersinterest and ensure quality of wine. In Sweden, wine is sent for destruction every year and oneof the reasons is that some wines have a deviant taste and odor profiles than described on thelabel. The aim for this project was to perform a chemical analysis of wine to identify differenttaste-active compounds to connect to different taste sensations such as sweetness, acidity,bitterness and the mouthfeel of astringency. Wine profile patterns were also created todistinguish between the composition of these compounds in sixteen different wines of differentcolors. The targeted compounds were fifteen compounds which included phenolic compounds,amino acids and organic acids. The analysis were performed by liquid chromatography massspectrometry. A literature survey was performed for selection of an appropriate method for theanalysis of the targeted compounds. Fourteen out of fifteen compounds were detected in thewine samples. Fifteen out of sixteen wines contained tartaric acid, while proline was found inall wines and vanillin only in one sparkling wine. The red wines showed higher concentrationsin compounds connected to bitterness and astringency and sparkling wine contained higheramounts of the compounds connected to sweet and sour taste. The wine profile patterns werecompared to see both similarities and differences within the same color wines.

Wine is a drink that can enhance the flavour experience of food, which is why it is important that the wine’s sensory profile is explained correctly to the consumers. In this study, headspace solid-phase microextraction gas chromatography mass spectrometry was used to characterise odourant compounds in wine to find chemical markers to explain wine sensory profiles instead of sensory analysis. The study included 16 different wines, red, white, orange and sparkling, where the nine most abundant peaks in each wine sample were evaluated. Homologue patterns based on areas were used to compare profiles between different wines. When studying homologue patterns for each wine and comparing within wine groups, differences and similarities can be seen. All wine samples contained isoamyl alcohol and the majority of them also contained ethyl decanoate, octanoic acid and decanoic acid. Six out of eight red wines contained ethyl succinate and five of them also contained ethyl hexanoate. All white wine samples showed presence of ethyl octanoate and ethyl hexanoate. The orange wines also contained ethyl octanoate and ethyl hexanoate, along with pentanoic acid. Both sparkling wines contained ethyl octanoate and ethyl hexanoate in addition with phenylethyl alcohol. However, a more thorough study covering more compounds to identify the less obvious differences of wine would have to be performed for a more precise explanation of the wine’s characterisation and sensory profile. It should be noted that the method of this study does leave room for improvements to improve the quality of the results. For example, since the most abundant compounds are not necessarily the ones with the most powerful odours, quantification based on response of an internal standard would strengthen the study. Additional compounds in the samples could also be further investigated. Statistically the method would also need improvement for satisfactory results regarding reproducibility of the samples.

The number of environmental pollutants has increased due to the increased production and the use of various chemicals in different applications. An estimation of today’s synthetic chemicals is approximately 50,000 to 100,000 and many of them may be harmful to humans and the environment. Persistent Organic Pollutants (POPs) are a specific type of environmental pollutants that are very stable and do not decompose easily. Example of those are pesticides, phthalates, phenols and per-/polyfluorinated alkyl substances (PFASs). Several studies have reported that environmental pollutants may particularly affect pregnant women and the fetus. The aim of the present study was to characterize the environmental pollutant profile in serum extracts of pregnant women, by analyzing the blood and characterizing the chemicals using a suspect screening approach with chromatography combined with high-resolution mass spectrometry. The samples in this study were extracted with solid-phase extraction (SPE) prior to the instrumental analysis, to precipitate the proteins as well as to remove some phospholipids and other contaminants that could interfere with the instrumental analysis. Quality control samples was used to validate the instrumental performance. Twelve compounds out of the 38 suspects were identified with this method, including both fatty acids and a few environmental pollutants. The detection rate of the fatty acids was higher than the environmental pollutants, which are; perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), monooctyl phthalate and 3,5-ditertbutyl salicylic acid. The low detection rate of the environmental pollutants, particularly of PFASs could be due to the low sensitivity of the method for the PFASs but also due to the decreased exposure to those compounds, since the samples were collected between 2013 to 2016, after the restrictions in the use of the two most common PFASs; PFOA and PFOS.

No description available.