Authors:Markus M. Heimesaat, Thomas Alter, Stefan Bereswill, and Greta Gölz
We have previously shown that Arcobacter butzleri induces intestinal, extra-intestinal, and systemic immune responses in perorally infected gnotobiotic IL-10−/− mice in a strain-dependent fashion. Here, we present a comprehensive survey of small and large intestinal expression profiles of inflammatory and regulatory mediators as well as of the matrix-degrading gelatinases MMP-2 and MMP-9 following murine A. butzleri infection. Gnotobiotic IL-10−/− mice were infected with A. butzleri strains CCUG 30485 or C1 of human and chicken origin, respectively. At day 6 following A. butzleri infection, mucin-2 mRNA, an integral part of the intestinal mucus layer, was downregulated in the colon, whereas TNF and IL-23p19 mRNA were upregulated in the ileum. Furthermore, IFN-γ, IL-17A, IL-1β, and IL-22 mRNA were upregulated in both colonic and ileal ex vivo biopsies at day 6 post strain CCUG 30485 infection. These changes were accompanied by downregulated colonic MMP-9 levels, whereas both MMP-2 and MMP-9 mRNA were upregulated in the ileum. In conclusion, these data indicate that A. butzleri infection induces changes in the expression of genes involved in pro-inflammatory and regulatory immune responses as well as in tissue degradation.
Authors:Mohammad R. Saraji-Bozorgzad, Thorsten Streibel, Markus Eschner, Thomas M. Groeger, Robert Geissler, Erwin Kaisersberger, Thomas Denner, and Ralf Zimmermann
A newly developed measurement technique for evolved gas analysis in thermogravimetry, viz. a thermo balance coupled to comprehensive gas chromatography/single photon ionization mass spectrometry (TG–GC × SPIMS), has been applied to investigate the thermal degradation of two polymers (polycarbonate (PC) blended with ABS and PVC). This detection method provides a two-dimensional analysis of the evolved gaseous products. TG relevant data is obtained as well as an improved resolution power to separate isobaric molecular structures without losing any fraction of the samples. In addition, this solution is not associated with any extension of the measurement time. The assignment of the substance pattern to distinct species is improved compared to solely using MS without a preceding separation step. Furthermore, hitherto undetected compounds when compared to applying TG–SPIMS without GC such as benzonitrile and its methylated derivatives have been found in the evolved gases from the thermal degradation of PC/ABS blend. Finally, a first estimation of the limit of detection has been carried out, yielding 400 ppt for styrene and 500 ppt for toluene from the thermal decomposition of PC/ABS blend.
Authors:Thomas B. Swanton, Alex Blaszczynski, Cynthia Forlini, Vladan Starcevic, and Sally M. Gainsbury
Background and aims: Despite the many benefits of technological advancements, problematic use of emerging technologies may lead to consumers experiencing harms. Substantial problems and behavioral addictions, such as gambling and gaming disorders, are recognized to be related to Internet-based technologies, including the myriad of new devices and platforms available. This review paper seeks to explore problematic risk-taking behaviors involving emerging technologies (e.g., online gambling and gaming, online sexual behaviors, and oversharing of personal information via social networking sites) that have the potential to lead to problematic outcomes for individuals.
Results and discussion: Previous research has focused on policy frameworks for responding to specific issues (e.g., online gambling), but a broader framework is needed to address issues as they emerge, given lags in governments and regulators responding to dynamically evolving technological environments. In this paper, key terms and issues involved are identified and discussed. We propose an initial framework for the relative roles and responsibilities of key stakeholder groups involved in addressing these issues (e.g., industry operators, governments and regulators, community groups, researchers, treatment providers, and individual consumers/end users).
Conclusion: Multidisciplinary collaboration can facilitate a comprehensive, unified response from all stakeholders that balances individual civil liberties with societal responsibilities and institutional duty of care.
Authors:M. Douglas, J. Friese, L. Greenwood, O. Farmer, M. Thomas, T. Maiti, E. Finn, S. Garofoli, P. Gassman, M. Huff, S. Schulte, S. Smith, K. Thomas, and P. Bachelor
Quantitative measurement of fission and activation products resulting from neutron irradiation of fissile materials is of
interest for applications in environmental monitoring, nuclear waste management, and national security. Based on established
separation processes involving co-precipitation, solvent extraction, and ion-exchange and extraction chromatography, we have
optimized a proposed sequence of separation steps to allow for the timely quantification of analytes of interest. We have
recently evaluated this scheme using an irradiated sample to examine the adequacy of separations for measurement of desired
analytes by gamma spectrometry. Here we present the radiochemical separations utilized and the yields and purity obtained.
Authors:J. Thomas, M. Fallavier, J. Mackowski, C. Pijolat, J. Tousset, and M. Wehr
A review is presented summarizing the specific nuclear microanalysis methods applied in our laboratory to study amorphous
semiconductor thin films. For backscattering, ∼3 MeV Li ions are applicable when depth resolution and sensitivity are required
while up to 8 MeV α-particles allow larger depths to be probed and elemental interferences to be solved. These features are
predominant for diffusion studies between metal electrodes and chalcogenide films. On the other hand hydrogen profiling using
the1H(1 5N, αψ) resonant nuclear reactions is described and analytical problems associated with its use are discussed. Applications
to the elaboration conditions of hydrogenated (a)Si is developed.
Authors:Greta Gölz, Gül Karadas, André Fischer, Ulf B. Göbel, Thomas Alter, Stefan Bereswill, and Markus M. Heimesaat
Arcobacter butzleri causes sporadic cases of gastroenteritis, but the underlying immunopathological mechanisms of infection are unknown. We have recently demonstrated that A. butzleri-infected gnotobiotic IL-10−/− mice were clinically unaffected but exhibited intestinal and systemic inflammatory immune responses. For the first time, we here investigated the role of Toll-like receptor (TLR)-4, the main receptor for lipopolysaccharide and lipooligosaccharide of Gram-negative bacteria, in murine arcobacteriosis. Gnotobiotic TLR-4/IL-10-double deficient (TLR-4−/− IL-10−/−) and IL-10−/− control mice generated by broad-spectrum antibiotics were perorally infected with A. butzleri. Until day 16 postinfection, mice of either genotype were stably colonized with the pathogen, but fecal bacterial loads were approximately 0.5–2.0 log lower in TLR-4−/− IL-10−/− as compared to IL-10−/− mice. A. butzleri-infected TLR-4−/− IL-10−/− mice displayed less pronounced colonic apoptosis accompanied by lower numbers of macrophages and monocytes, T lymphocytes, regulatory T-cells, and B lymphocytes within the colonic mucosa and lamina propria as compared to IL-10−/− mice. Furthermore, colonic concentrations of nitric oxide, TNF, IL-6, MCP-1, and, remarkably, IFN-γ and IL-12p70 serum levels were lower in A. butzleri-infected TLR-4−/− IL-10−/− versus IL-10−/− mice. In conclusion, TLR-4 is involved in mediating murine A. butzleri infection. Further studies are needed to investigate the molecular mechanisms underlying Arcobacter—host interactions in more detail.
Authors:R. E. White, P. S. Thomas, M. R. Phillips, and R. Wuhrer
Summary Cold pressed linseed oil and paints prepared using the inorganic pigments; lead white and red lead, were characterized using non-isothermal differential scanning calorimetry (DSC) in an air atmosphere to determine the effect of the pigment on the oxidative polymerisation of the drying oil medium. For each paint sample, the onset temperature for oxidation was reduced from 166°C to the range 50 to 60°C when a heating rate of 5 K min-1 was used. In order to determine the rate of drying, the non-isothermal experiments were carried out using a range of heating rates. A change in the mechanism oxidative polymerization was observed as the heating rate was increased.
Authors:S. Bowyer, D. Gerlach, H. Miley, S. Pratt, C. Thomas, J. Wacker, and M. Kniedler
The Comprehensive Test Ban Treaty calls for the monitoring of aerosol radionuclides throughout the globe. Pacific Northwest
National Laboratory has developed the Radionuclide Aerosol Sampler/Analyzer (RASA) for the Department of Energy to automatically
collect and measure radioactive aerosols from the atmosphere. The RASA passes high volumes of air through a 3MTM Substrate Blown Microfiber Media (SBMF) specifically designated as SBMF-40VF. It then automatically moves the filter media
in front of a high-purity germanium detector and collects a gamma spectrum. If further analysis on the filter is desired,
the filter is sent to a laboratory and radiochemical analysis is performed. This paper discusses the method of dissolution
of the SBMF-40VF filter media and the separation of the radioisotopes of interest.
Authors:P. S. Thomas, B. H. Stuart, N. McGowan, J. P. Guerbois, M. Berkahn, and V. Daniel
The potential of thermogravimetric analysis (TG) as a tool for the characterisation of ochre paint used in indigenous Australian bark paintings has been investigated. TG has been combined with differential scanning calorimetry (DSC) and mass spectrometry (MS) to identify and quantify the main inorganic and organic components present in the paints. The results obtained were supported by comparison with infrared spectra and XRD data obtained for the same specimens. The potential of thermal methods for the characterisation ochres has been demonstrated, with subtle differences between small samples being able to be identified.
Authors:Markus M. Heimesaat, Gül Karadas, André Fischer, Ulf B. Göbel, Thomas Alter, Stefan Bereswill, and Greta Gölz
Sporadic cases of gastroenteritis have been attributed to Arcobacter butzleri infection, but information about the underlying immunopathological mechanisms is scarce. We have recently shown that experimental A. butzleri infection induces intestinal, extraintestinal and systemic immune responses in gnotobiotic IL-10−/− mice. The aim of the present study was to investigate the immunopathological role of Toll-like Receptor-4, the receptor for lipopolysaccharide and lipooligosaccharide of Gram-negative bacteria, during murine A. butzleri infection. To address this, gnotobiotic IL-10−/− mice lacking TLR-4 were generated by broadspectrum antibiotic treatment and perorally infected with two different A. butzleri strains isolated from a patient (CCUG 30485) or fresh chicken meat (C1), respectively. Bacteria of either strain stably colonized the ilea of mice irrespective of their genotype at days 6 and 16 postinfection. As compared to IL-10−/− control animals, TLR-4−/− IL-10−/− mice were protected from A. butzleri-induced ileal apoptosis, from ileal influx of adaptive immune cells including T lymphocytes, regulatory T-cells and B lymphocytes, and from increased ileal IFN-γ secretion. Given that TLR-4-signaling is essential for A. butzleri-induced intestinal inflammation, we conclude that bacterial lipooligosaccharide or lipopolysaccharide compounds aggravate intestinal inflammation and may thus represent major virulence factors of Arcobacter. Future studies need to further unravel the molecular mechanisms of TLR-4-mediated A. butzleri-host interactions.