A Single E627K Mutation in the PB2 Protein of H9N2 Avian Influenza Virus Increases Virulence by Inducing Higher Glucocorticoids (GCs) Level

While repeated infection of humans and enhanced replication and transmission in mice has attracted more attention to it, the pathogenesis of H9N2 virus was less known in mice. PB2 residue 627 as the virulent determinant of H5N1 virus is associated with systemic infection and impaired TCR activation, but the impact of this position in H9N2 virus on the host immune response has not been evaluated. In this study, we quantified the cellular immune response to infection in the mouse lung and demonstrate that VK627 and rTsE627K infection caused a significant reduction in the numbers of T cells and inflammatory cells (Macrophage, Neutrophils, Dendritic cells) compared to mice infected with rVK627E and TsE627. Further, we discovered (i) a high level of thymocyte apoptosis resulted in impaired T cell development, which led to the reduced amount of mature T cells into lung, and (ii) the reduced inflammatory cells entering into lung was attributed to the diminished levels in pro-inflammatory cytokines and chemokines. Thereafter, we recognized that higher GCs level in plasma induced by VK627 and rTsE627K infection was associated with the increased apoptosis in thymus and the reduced pro-inflammatory cytokines and chemokines levels in lung. These data demonstrated that VK627 and rTsE627K infection contributing to higher GCs level would decrease the magnitude of antiviral response in lung, which may be offered as a novel mechanism of enhanced pathogenicity for H9N2 AIV

Sources of Mg Enrichments in Vent Fluids From the Kermadec Arc Recorded by Li, B, and Mg Isotopes

Abstract Magnesium concentrations in acid‐sulfate fluids from Brothers and Macauley volcano, Kermadec arc, Western Pacific, exceed those of seawater and differ from previously known acid‐sulfate fluids with seawater‐like Mg concentrations. Earlier studies explained these Mg enrichments as due to phase separation, caminite (Mg1.25SO4(OH)0.5 × 0.5H2O) dissolution, water‐rock interaction and/or “mining” of deep seated magmatic brines. Since these different and partly contradictory explanations could neither be confirmed nor refuted, we investigated B, Li, and Mg isotope compositions in acid‐sulfate and black smoker fluids from both Brothers and Macauley to understand the origin of the high Mg concentrations and investigate a possible connection with the alteration of basement rocks. In addition, we performed seawater heating experiments to investigate Mg isotope fractionation during caminite precipitation. Lithium and B isotope signatures in all studied acid‐sulfate fluids indicate water‐rock interaction. Magnesium isotopes in fluids from Macauley correspond to seawater, implying Mg enrichment through phase separation in the fluids. In contrast, Mg‐enriched acid‐sulfate fluids from Brothers volcano have higher δ26Mg values (up to −0.62‰) than seawater. Considering that our seawater heating experiment shows a preferential incorporation of 24Mg into caminite, caminite dissolution would lead to lower δ26Mg values and thus cannot solely account for the enriched Mg concentrations seen at Brothers. Additionally, we thus suppose leaching of Mg from the basement during the interaction of acidic fluids with a relatively unaltered basement

Application of B, mg, li, and sr isotopes in acid-sulfate vent fluids and volcanic rocks as tracers for fluid-rock interaction in back-arc hydrothermal systems

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Wilckens, F. K., Reeves, E. P., Bach, W., Seewald, J. S., & Kasemann, S. A. Application of B, mg, li, and sr isotopes in acid-sulfate vent fluids and volcanic rocks as tracers for fluid-rock interaction in back-arc hydrothermal systems. Geochemistry Geophysics Geosystems, 20, (2019): 5849-5866, doi: 10.1029/2019GC008694.The Manus Basin hosts a broad range of vent fluid compositions typical for arc and back‐arc settings, ranging from black smoker to acid‐sulfate styles of fluid venting, as well as novel intermediate temperature and composition “hybrid” smokers. We investigated B, Li, Mg, and Sr concentrations and isotopic compositions of these different fluid types as well as of fresh and altered rocks from the same study area to understand what controls their compositional variability. In particular, the formation of acid‐sulfate and hybrid smoker fluids is still poorly understood, and their high Mg concentrations are explained either by dissolution of Mg‐bearing minerals in the basement or by mixing between unmodified seawater and magmatic fluids. Mg isotope ratios of the acid‐sulfate fluids from the Manus Basin are seawater‐like, which supports the idea that acid‐sulfate fluids in this study area predominantly form by mixing between unmodified seawater and a Mg‐free magmatic fluid. Changes in the B, Li, and Sr isotope ratios relative to seawater indicate water‐rock interaction in all acid‐sulfate fluids. Further, the combination of δ7Li with B concentrations of the same fluids links changes in δ7Li to changes in (1) basement alteration, (2) water‐to‐rock ratios during water‐rock interaction, and/or (3) the reaction temperature. These isotope systems, thus, allow tracing of basement composition and acid‐sulfate‐driven alteration of the back‐arc crust and help increase our understanding of hydrothermal fluid‐rock interactions and the behavior of fluid‐mobile elements.The authors would like to thank the crew of the R/V Melville and R/V Sonne as well as the technical groups of ROV Jason II and ROV MARUM‐QUEST. This study was part of MARUM project GB4 and was funded by the DFG‐Research Centre/Cluster of Excellence “The Ocean in the Earth System” at MARUM—Centre for Environmental Sciences, University of Bremen (EXC309/FZT15) and was supported from the German Research Foundation (DFG) Major Research Instrumentation Program (INST 144/308‐1). We would also like to thank Dionysis Foustoukos and an anonymous reviewer for the thorough reviews, which improved the manuscript a lot. The data reported in this paper are archived in Pangaea (https://doi.pangaea.de/10.1594/PANGAEA.908303)

Optimisation of Water-Based Cathode Inks for Solid Oxide Fuel Cells

A new cathode ink for a solid oxide fuel cell has recently been developed (UK Patent Publication Number GB2490869). It was found to give a power density of 0.33 W/cm 2 at 0.7 V at 750°C running on hydrogen. Further optimisation work has been undertaken, focusing on the dispersant: Poly(N-VinylPyrrolidone) -PVP. The effects of chain length and weight percentage of PVP have been investigated, and Poly (ethylene glycol) -PEG -was tested for comparison. PEG was found to give good performance at lower weight percentages, but had a negative impact on ink rheology at higher concentrations. Optimisation of the ink formulation increased the power at 0.7 V to 0.46 W/cm 2 under identical test conditions

Optimization of Water-Based Cathode Inks for Solid Oxide Fuel Cells

A new cathode ink for a solid oxide fuel cell has recently been developed (UK Patent Publication Number GB2490869). It was found to give a power density of 0.33 W/cm2 at 0.7 V at 750°C running on hydrogen. Further optimisation work has been undertaken, focusing on the dispersant: Poly(N-VinylPyrrolidone) - PVP. The effects of chain length and weight percentage of PVP have been investigated, and Poly (ethylene glycol) – PEG - was tested for comparison. PEG was found to give good performance at lower weight percentages, but had a negative impact on ink rheology at higher concentrations. Optimisation of the ink formulation increased the power at 0.7 V to 0.46 W/cm2 under identical test conditions