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The influence of short term (7-day) exposure of male rats to the brominated flame retardant hexabromocyclododecane (HBCD) was studied by investigation of the liver proteome, both in euthyroid and hypothyroid rats and by comparing results with general data on animal physiology and thyroid hormone, leptin, insulin and gonadotropin concentrations determined in parallel. Proteome analysis of liver tissue by two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) revealed that only small protein pattern changes were induced by exposure in males, on just a few proteins with different functions and not involved in pathways in common. This is in contrast to previous findings in similarly exposed eu- and hypothyroid female rats, where general metabolic pathways had been shown to be affected. The largest gender-dependent effects concerned basal concentrations of liver proteins already in control and hypothyroid animals, involving mainly the pathways which were also differently affected by HBCD exposure. Among them were differences in lipid metabolism, which – upon exposure to HBCD – may also be the reason for the considerably higher ratio of γ-HBCD accumulated in white adipose tissue of exposed female rats compared to males. The results further elucidate the already suggested different sensitivity of genders towards HBCD exposure on the protein level, and confirm the need for undertaking toxicological animal experiments in both genders. [ABSTRACT FROM AUTHOR]

The atmospheric corrosion of coated steel samples with artificial defects was characterized to determine the environmental variables that are important in the corrosion process. Coated steel samples were exposed to different climates in Hawaii, Florida, and Ohio. The iron oxides formed under the coating were identified with Raman spectroscopy, which allowed the corrosion mechanisms to be deduced. Those mechanisms were influenced by the time of wetness (TOW) and the deposition rate of chloride and sulfur that were measured at the different sites. Two corrosion morphologies were observed: bead-like corrosion was formed in the defect vicinity and filiform corrosion (FFC) was initiated from the bead-like corrosion. Bead-like corrosion was influenced by the TOW and the salt deposition, whereas FFC grew in the humid environment, but its mechanism was independent of the salt deposition. At almost all of the sites tested, chloride was the only salt that participated in the corrosion process. [ABSTRACT FROM AUTHOR]

Filiform corrosion (FFC) has been shown to occur during field exposure of scribed organic-coated steel. In this paper, the FFC filament morphologies formed under polyvinyl butyral (PVB) and bisphenol A based epoxy coatings after initiation with hydrochloric acid (HCl) solution were compared. Under the epoxy coating, secondary filaments were observed at right angles from the main filament. These secondary filaments suggested that chloride had migrated perpendicular to the filament direction. This perpendicular chloride migration may be driven by the straight (more open) head/tail boundaries, which were noticeable on the filaments growing under the epoxy coating. Under PVB, the filament depth increased with the number of moles of chloride and the filament head radius. These tendencies were not measured under the epoxy coating because the filament head changed shape during propagation, which may have been associated with anisotropic coating properties. The effects of prior exposure to ASTM G85 and ASTM G154 environments on FFC initiation and propagation were investigated. Pre-exposutes affected the initial stage ofFCC, but, once initiated, the filament propagation only depended on the filament head size. Degradation of the coating/ steel interface during ASTM G85 exposure reduced FCC incubation time and increased the number of initial sites. Improvement in interface stability during exposure to ASTM G154 for PVB-coated steel increased FCC incubation time and reduced the size and the number of initial sites. [ABSTRACT FROM AUTHOR]

In a previous paper, it was demonstrated that the measurement of cathodic delamination by the Scanning Kelvin Probe can assess the interface stability of poly(vinyl butyral) (PVB) coated steel after field exposure. This technique was utilized to characterize the degradation of the polymer/metal interface in several outdoor climates. In this paper, the effects of environmental factors on the interface degradation were investigated in the laboratory. The mechanisms measured in the field were reproduced to provide input in the development of an appropriate accelerated test for PVB coated steel. The ASTM B117 and G154 standardized tests were investigated individually and sequentially. The interface stability improved after 24h of ASTM G154 exposure. After 144h of exposure to ASTM G154 exposure, polymer oxidation took place simultaneously with interface degradation. The condensation phase of the ASTM G154 test was responsible for the interface improvement while the ultraviolet radiation triggered the interface degradation. Pre-exposure to ASTM G154 delayed wet de-adhesion during ASTM B117 exposure. After wet de-adhesion caused by 6h of ASTM B117, exposure to ASTM G154 for 24h increased the interface stability. The effects of ultraviolet radiation, relative humidity, temperature and environment on interface degradation were investigated in a special chamber. Humidity was the primary factor found to influence the interface improvement during G154 exposure. A wet/dry salt fog cycle with irradiation by an ultraviolet or filtered xenon arc lamp around room temperature was suggested to reproduce the competition between the interface improvement and the interface degradation that takes place in the field. [ABSTRACT FROM AUTHOR]

As probabilistic analyses spread in industrial practice, inverse probabilistic modelling of the sources of uncertainty enjoys a growing interest as it is often the only way to estimate the input probabilistic model of unobservable quantities. This article addresses the identification of intrinsic physical variability of the systems. After showing its theoretical differences with the more classical data assimilation or parameter identification algorithms, this article introduces a new non-parametric algorithm that does not require linear nor Gaussian assumptions. This technique is based on the simulation of the likelihood of the observed samples, coupled with a kernel method to limit the number of physical model runs and facilitate the subsequent maximization. It is implemented inside an industrial application in order to identify the key parameter that controls the vibration amplification of steam turbines. Hence, experimental resonance frequencies observations are used to adjust the probabilistic model of the unobservable manufacturing imperfections between theoretically identical units. [ABSTRACT FROM AUTHOR]

Abstract: The neurotoxic compound methylmercury (MeHg) is a commonly encountered pollutant in the environment, and constitutes a hazard for human health through fish eating. To study the impact of MeHg on mitochondrial structure and function, we contaminated the model fish species Danio rerio with food containing 13μg of MeHg per gram, an environmentally relevant dose. Mitochondria from contaminated zebrafish muscles presented structural abnormalities under electron microscopy observation. In permeabilized muscle fibers, we observed, a strong inhibition of both state 3 mitochondrial respiration and functionally isolated maximal cytochrome c oxidase (COX) activity after 49 days of MeHg exposure. However, the state 4 respiratory rate remained essentially unchanged. This suggested a defect at the level of ATP synthesis. Accordingly, we measured a dramatic decrease in the rate of ATP release by skinned muscle fibers using either pyruvate and malate or succinate as respiratory substrates. However, the amount and the assembly of the ATP synthase were identical in both control and contaminated muscle mitochondrial fractions. This suggests that MeHg induced a decoupling of mitochondrial oxidative phosphorylation in the skeletal muscle of zebrafish. Western blot analysis showed a 30% decrease of COX subunit IV levels, a 50% increase of ATP synthase subunit α, and a 40% increase of the succinate dehydrogenase Fe/S protein subunit in the contaminated muscles. This was confirmed by the analysis of gene expression levels, using RT-PCR. Our study provides a basis for further analysis of the deleterious effect of MeHg on fish health via mitochondrial impairment. [Copyright &y& Elsevier]

The neutrophil is the most abundant blood leukocyte in humans and the first cell involved in an immune response like infection, rejection or injury of the lung. Neutrophils were long considered as simple short-lived cells. However, several distinct neutrophil subsets, maturation and activation stages with functional heterogeneity are identified. This spiked our interest to perform an in-depth neutrophil characterization, focusing on their maturation and activation characteristics, in broncho-alveolar lavage fluid (BALF) and peripheral blood of lung transplantation (LTx) patients who received standard immunosuppression. BALF and blood neutrophils were microscopically evaluated and identified by multicolor flow cytometry (CD16+/CD66b+) to examine expression of maturation/activation markers and adhesion molecules (CD10, CD62L, CD11b, CD11c, CD15, HLA-DR) and chemoattractant receptors (CXCR1-4, CCR1-3, FPR1-2, C5aR and BLTR1) within healthy control subjects (n = 11), stable LTx patients (n = 8-14), and LTx patients with infection (n = 9) or chronic lung allograft dysfunction (n = 2-6). LTx patients had a significantly higher (p<0.05) percentage of banded, CD10 negative blood neutrophils as compared to healthy controls. In accordance with this immature phenotype, blood neutrophils from LTx patients showed decreased expression of the low-affinity FcγR CD16 (p<0.01) and chemoattractant receptor CXCR2 (p<0.001). However, no significant differences were found in the ratio of immature/mature neutrophils in LTx blood versus BALF. Neutrophils in BALF of LTx patients showed an activated phenotype featured by shedding of CD62L (p<0.001), down-regulation of CXCR1, CXCR2 and C5aR (all p<0.0001) and enhanced CD66b expression (p<0.05) compared to LTx blood neutrophils. Strikingly, a significant population (p<0.0001) of BALF neutrophils from stable LTx patients stained positive for chemokine receptor CXCR3. CXCR3 regulates migration of activated lymphocytes and natural killer cells but in general is absent on neutrophils. We demonstrated a compromised maturation of neutrophils in peripheral blood and BALF of LTx patients versus healthy controls. In addition, we observed a more activated status of BALF neutrophils with a surprisingly increased expression of CXCR3 on their membrane in stable LTx patients. [ABSTRACT FROM AUTHOR]

Hexabromocyclododecane (HBCD) is a brominated flame retardant known for its low acute toxicity as observed in animal experiments. However, HBCD exposure can affect liver functioning and thyroid hormone (TH) status. As exact mechanisms are unknown and only limited toxicological data exists, a gel-based proteomic approach was undertaken. In a eu- and hypothyroid female rat model, rats were exposed to 3 and 30 mg/kg bw/day HBCD for 7 days via their diet, and exposure was related to a range of canonical endpoints (hormone status, body weight) available for these animals. Alterations in the liver proteome under HBCD exposure were determined in comparison with patterns of control animals, for both thyroid states. This revealed significantly changed abundance of proteins involved in metabolic processes (gluconeogenesis/glycolysis, amino acid metabolism, lipid metabolism), but also in oxidative stress responses, in both euthyroid and hypothyroid rats. The results provide a more detailed picture on the mechanisms involved in these alterations, e.g. at the protein level changes of the proposed influence of HBCD on the lipid metabolism. Present results show that proteomic approaches can provide further mechanistic insights in toxicological studies. [ABSTRACT FROM AUTHOR]

Following lung transplantation, the surgical intervention with ischemic periods and the foreign allograft are the first to trigger a response from the innate immune system, which represents the primary nonspecific defense against "non-self". In this study, we investigated the diversity of the emerging innate immune cells and the timing of their appearance in a murine orthotopic left lung transplant model. Mouse orthotopic left lung transplantation was performed in isografts (C57BL/6 to C57BL/6) and allografts (Balbc to C57BL/6). All mice received daily immunosuppression of 10 mg/kg cyclosporin A and 1.6 mg/kg methylprednisolone. Serial sacrifice was performed at day 1, 7 and 35 post-transplantation (n=6 at each time point for each group). Left transplanted lungs were harvested, single cell suspension was made and absolute numbers of innate immune cells were quantified by flow cytometry. Following transplantation, isografts and allografts showed an increase in neutrophil (p=0.017) and tissue resident NK cell (p=0.002) numbers at day 1, and in eosinophil (p=0.002) numbers at day 7 post-lung transplant. Granulocytes demonstrated similar patterns in isografts and allografts. Allografts demonstrated an increase in antigen presenting cells i.e. patrolling monocytes (Ly6C-) (p=0.002), interstitial macrophages (p<0.0001) and dendritic cells (p=0.005) at day 7 compared to isografts. Classical NK cells were increased in allografts at day 7 versus isografts (p=0.03). All cell numbers returned to baseline isograft values at day 35 post-transplant, except for dendritic cells (p=0.0045). Diverse innate immune cell types show different patterns over time post-lung transplantation depending on transplant induced ischemia-reperfusion injury and/or alloimmune response against the foreign graft. These differences may be very important to dissect the various pathophysiological processes triggered by lung transplantation. [ABSTRACT FROM AUTHOR]