Spatial transcription of CYP1A in fish liver

<p>Abstract</p> <p>Background</p> <p>The aim of this work was to study how evenly detoxifying genes are transcribed spatially in liver tissue of fish. Ten Atlantic salmon <it>Salmo salar </it>were intraperitoneally injected with 50 mg/kg of the strong CYP1A inducer β-naphthoflavone and liver tissue harvested seven days later. The liver from 10 control and 10 exposed fish were split into eight sections, RNA extracted and three reference (β-actin, elongation factor 1A_B(EF1A_B)) and two detoxifying genes (CYP1A and GST) quantified with real-time RT-PCR. The cellular localization of the EF1A_Band CYP1A mRNA in the liver of control and β-naphthoflavone treated fish was then determined by <it>in situ </it>hybridization (ISH) using EF1A_Band CYP1A biotinylated oligonucleotide probes.</p> <p>Results</p> <p>The study shows that genes encoding phase I and phase II conjugating enzymes are unevenly transcribed in different parts of the liver of Atlantic salmon seven days after a single-dose of β-naphthoflavone exposure. Transcription of CYP1A and GST was higher in the middle section of the liver compared to the distal and proximal parts of the organ. The ISH data suggest that CYP1A transcription happens mainly in hepatocyte cells in the liver, and that hepatocytes in the vicinity of blood vessels respond stronger to β-naphthoflavone than cells further away from the blood supply.</p> <p>Conclusion</p> <p>Overall, the qRT-PCR and ISH results reported here suggest that gene expression analysis should be performed on as pure cell populations as possible. If bulk tissue samples are to be used, one should always check how evenly the target genes are expressed in tissue sections and organs in every study.</p

Improved conductivity of aluminum-doped ZnO : the effect of hydrogen diffusion from a hydrogenated amorphous silicon capping layer

Plasma-deposited aluminum-doped ZnO (ZnO:Al) demonstrated a resistivity gradient as function of the film thickness, extending up to about 600¿nm. This gradient decreased sharply when the ZnO:Al was capped by a hydrogenated amorphous silicon layer (a-Si:H) and subsequently treated according to the solid phase crystallization (SPC) procedure at 600¿°C. The resistivity reduced from 1.2¿·¿10-1 to 2.6¿·¿10-3 O¿·¿cm for a film thickness of 130¿nm, while for thicker films the decrease in resistivity was less pronounced, i.e., a factor of 2 for a film thickness of 810¿nm. While the carrier concentration was not affected, the mobility significantly increased from 7 to 30 cm2/V¿·¿s for the thick ZnO:Al layers. This increase was ascribed to the passivation of grain boundary defects by hydrogen, which diffused from the a-Si:H toward the ZnO:Al during the SPC procedure. The passivation effect was more pronounced in thinner ZnO:Al layers, characterized by a smaller grain size, due to the presence of large grain boundaries. For thicker films with grain sizes up to 200–300¿nm the mobility became progressively less affected by the presence of grain boundaries. Therefore, the hydrogen-induced improvement in conductivity was less significant for the thick ZnO:Al film

Symmetrical Exsolution of Rh Nanoparticles in Solid Oxide Cells for Efficient Syngas Production from Greenhouse Gases

Carbon dioxide and steam solid oxide co-electrolysis is a key technology for exploiting renewable electricity to generate syngas feedstock for the Fischer–Tropsch synthesis. The integration of this process with methane partial oxidation in a single cell can eliminate or even reverse the electrical power demands of co-electrolysis, while simultaneously producing syngas at industrially attractive H2/CO ratios. Nevertheless, this system is rather complex and requires catalytically active and coke tolerant electrodes. Here, we report on a low-substitution rhodium-titanate perovskite (La0.43Ca0.37Rh0.06Ti0.94O3) electrode for the process, capable of exsolving high Rh nanoparticle populations, and assembled in a symmetrical solid oxide cell configuration. By introducing dry methane to the anode compartment, the electricity demands are impressively decreased, even allowing syngas and electricity cogeneration. To provide further insight on the Rh nanoparticles role on methane-to-syngas conversion, we adjusted their size and population by altering the reduction temperature of the perovskite. Our results exemplify how the exsolution concept can be employed to efficiently exploit noble metals for activating low-reactivity greenhouse gases in challenging energy-related applications.</p

Plasma activated electrolysis for cogeneration of nitric oxide and hydrogen from water and nitrogen

With increasing global interest in renewable energy technology given the backdrop of climate change, storage of electrical energy has become particularly relevant. Most sustainable technologies (e.g., wind and solar) produce electricity intermittently. Thus, converting electrical energy and base molecules (i.e., H2O, N2) into energy-rich ones (e.g., H2, NH3) or chemical feedstock (e.g., NO) is of paramount importance. While H2O splitting is compatible with renewable electricity, N2 fixation is currently dominated by thermally activated processes. In this work, we demonstrate an all-electric route for simultaneous NO and H2 production. In our approach, H2O is reduced to H2 in the cathode of a solid oxide electrolyzer while NO is produced in the anode by the reaction of O2– species (transported via the electrolyte) and plasma-activated N2 species. High faradaic efficiencies up to 93% are achieved for NO production at 650 °C, and NO concentration is &gt;1000 times greater than the equilibrium concentration at the same temperature and pressure.</p

Heterogeneous and homogeneous hydrogen kinetics in plasma chemistry

Abstract. A review of gas phase and surface kinetics of hydrogen radicals in excited hydrogen molecules strongly influences the mechanisms of the chemical reactions. Both homo-and heterogeneous collisional processes are analysed in that respect. As will be shown, ionizing plasmas are dominated by gas phase rovibrationai excitation phenomena. By contrast the kinetics of recombining plasmas are strongly influenced by heterogeneous elementaly processes, where they can be distinguished in a natural way. Examples of heterogeneous catalysis in plasmas, i.e. particle excitation phenomena at surfaces, are discussed

Hydrogenation reactions of carbon on Earth: Linking methane, margarine, and life

Hydrogenation reactions are a major route of electron and proton flow on Earth. Interfacing geology and organic chemistry, hydrogenations occupy pivotal points in the Earth’s global geochemical cycles. Some examples of hydrogenation reactions on Earth today include the production and consumption of methane in both abiotic and biotic reactions, the reduction of protons in hydrothermal settings, and the biological synthesis and degradation of fatty acids. Hydrogenation reactions were likely important for prebiotic chemistry on the early Earth, and today serve as one of the fundamental reaction classes that enable cellular life to construct biomolecules. An understanding and awareness of hydrogenation reactions is helpful for comprehending the larger web of molecular and material inter-conversions on our planet. In this brief review we detail some important hydrogenation and dehydrogenation reactions as they relate to geology, biology, industry, and atmospheric chemistry. Such reactions have implica- tions ranging from the suite of reactions on early Earth to industrial applications like the production of hydrocarbon fuel

A major population of mucosal memory CD4⁺ T cells, coexpressing IL-18Rα and DR3, display innate lymphocyte functionality

Mucosal tissues contain large numbers of memory CD4(+) T cells that, through T-cell receptor-dependent interactions with antigen-presenting cells, are believed to have a key role in barrier defense and maintenance of tissue integrity. Here we identify a major subset of memory CD4(+) T cells at barrier surfaces that coexpress interleukin-18 receptor alpha (IL-18Rα) and death receptor-3 (DR3), and display innate lymphocyte functionality. The cytokines IL-15 or the DR3 ligand tumor necrosis factor (TNF)-like cytokine 1A (TL1a) induced memory IL-18Rα(+)DR3(+)CD4(+) T cells to produce interferon-γ, TNF-α, IL-6, IL-5, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-22 in the presence of IL-12/IL-18. TL1a synergized with IL-15 to enhance this response, while suppressing IL-15-induced IL-10 production. TL1a- and IL-15-mediated cytokine induction required the presence of IL-18, whereas induction of IL-5, IL-13, GM-CSF, and IL-22 was IL-12 independent. IL-18Rα(+)DR3(+)CD4(+) T cells with similar functionality were present in human skin, nasal polyps, and, in particular, the intestine, where in chronic inflammation they localized with IL-18-producing cells in lymphoid aggregates. Collectively, these results suggest that human memory IL-18Rα(+)DR3(+) CD4(+) T cells may contribute to antigen-independent innate responses at barrier surfaces.Mucosal Immunology advance online publication, 1 October 2014; doi:10.1038/mi.2014.87