Metabolic Profiling as Well as Stable Isotope Assisted Metabolic and Proteomic Analysis of RAW 264.7 Macrophages Exposed to Ship Engine Aerosol Emissions: Different Effects of Heavy Fuel Oil and Refined Diesel Fuel

Exposure to air pollution resulting from fossil fuel combustion has been linked to multiple short-term and long term health effects. In a previous study, exposure of lung epithelial cells to engine exhaust from heavy fuel oil (HFO) and diesel fuel (DF), two of the main fuels used in marine engines, led to an increased regulation of several pathways associated with adverse cellular effects, including pro-inflammatory pathways. In addition, DF exhaust exposure was shown to have a wider response on multiple cellular regulatory levels compared to HFO emissions, suggesting a potentially higher toxicity of DF emissions over HFO. In order to further understand these effects, as well as to validate these findings in another cell line, we investigated macrophages under the same conditions as a more inflammationrelevant model. An air-liquid interface aerosol exposure system was used to provide a more biologically relevant exposure system compared to submerged experiments, with cells exposed to either the complete aerosol (particle and gas phase), or the gas phase only (with particles filtered out). Data from cytotoxicity assays were integrated with metabolomics and proteomics analyses, including stable isotope-assisted metabolomics, in order to uncover pathways affected by combustion aerosol exposure in macrophages. Through this approach, we determined differing phenotypic effects associated with the different components of aerosol. The particle phase of diluted combustion aerosols was found to induce increased cell death in macrophages, while the gas phase was found more to affect the metabolic profile. In particular, a higher cytotoxicity of DF aerosol emission was observed in relation to the HFO aerosol. Furthermore, macrophage exposure to the gas phase of HFO leads to an induction of a pro-inflammatory metabolic and proteomic phenotype. These results validate the effects found in lung epithelial cells, confirming the role of inflammation and cellular stress in the response to combustion aerosols

Der Rat der niederschwäbischen Reichsstädte : Rechtsgeschichtliche Untersuchungen über die Ratsverfassung der Reichsstädte Niederschwabens bis zum Ausgang der Zunftbewegungen im Rahmen der oberdeutschen Reichs- und Bischofsstädte /

Issued also as thesis, Tübingen.Bibliography: p. [xv]-xxix

Porosity determination of carbon fiber reinforced plastics (CFRP) in aviation applications using ultrasound without a back wall echo

The use of CFRP increased not only in the field of aviation structures. Also regarding lightweight construction in the automotive industry CFRP is moving forward. Porosity is one of the main quality parameters of CRFP. X-ray computer tomography (CT) is nowadays one of the standard reference techniques for quantitative imaging of porosity. However, CT sample size is limited if µm local resolution is required. For process control ultrasonic attenuation measurements are therefore prevalent, either in pulse-echo mode by evaluating the back wall echo amplitude, or in transmission mode. However other approaches are required, when only single sided access is given or when no back wall echo is detectable due to thickness of the component or due to damping effects in case of increased porosity. Every individual time-of-flight signal carries phase and frequency information in addition to the amplitude information. The phase and the frequency variation of the transmitted and backscattered ultrasonic signals can be correlated to the inner fibre and matrix structure of the material to be assessed and to additional material inhomogeneity like pores, cracks and delaminations. Within this presentation results based on phase and frequency analysis of ultrasonic A-scans when no back wall information is present will be discussed. X-ray computer tomography data were used for calibration of the ultrasound results. These results are based on the analysis and processing of ultrasonic A-scans acquired with commercial single element transducers and using conventional state-of-the-art ultrasonic hardware

A detailed view on 1,8-cineol biosynthesis by Streptomyces clavuligerus

The stereochemical course of the cyclisation reaction catalysed by the bacterial 1,8-cineol synthase from Streptomyces clavuligerus was investigated using stereospecifically deuterated substrates. In contrast to the well investigated plant enzyme from Salvia officinalis, the reaction proceeds via (S)-linalyl diphosphate and the (S)-terpinyl cation, while the final cyclisation reaction is in both cases a syn addition, as could be shown by incubation of (2-13C)geranyl diphosphate in deuterium oxide

First preparation of nanocrystalline zinc silicate by chemical vapor synthesis using an organometallic single-source precursor

A method is presented to prepare nanocrystalline α-Zn2SiO4 with the smallest crystal size reported so far for this system. Our approach combines the advantages of organometallic single-source precursor routes with aerosol processing techniques. The chemical design of the precursor enables the preferential formation of pure zinc silicates. Since gas-phase synthesis reduces intermolecular processes, and keeps the particles small, zinc silicate was synthesized from the volatile organometallic precursor [{MeZnOSiMe3}4], possessing a Zn-methyl- and O-silyl-substituted Zn4O4-heterocubane framework (cubane), under oxidizing conditions, using the chemical vapor synthesis (CVS) method. The products obtained under different process conditions and their structural evolution after sintering were investigated by using various analytical techniques (powder X-ray diffraction, transmission electron microscopy, EDX analysis, solid-state NMR, IR, Raman, and UV/Vis spectroscopy). The deposited aerosol obtained first (processing temperature 750 °C) was amorphous, and contained agglomerates with primary particles of 12 nm in size. These primary particles can be described by a [Zn-O-Si] phase without long-range order. The deposit obtained at 900 °C contained particles with embedded nanocrystallites (3-5 nm) of β-Zn2SiO4, Zn1.7SiO4, and ZnO in an amorphous matrix. On further ageing, the as-deposited particles obtained at 900 °C form α-Zn2SiO4 imbedded in amorphous SiO2. The crystallite sizes and primary particle sizes in the formed α-Zn2SiO4 were found to be below 50 nm and mainly spherical in morphology. A gas-phase mechanism for the particle formation is proposed. In addition, the solid-state reactions of the same precursor were studied in detail to investigate the fundamental differences between a gas-phase and a solid-state synthesis route