Sound velocity and elastic properties of Fe–Ni–S–Si liquid: the effects of pressure and multiple light elements

Fe–Ni–S–Si alloy is considered to be one of the plausible candidates of Mercury core material. Elastic properties of Fe–Ni–S–Si liquid are important to reveal the density profile of the Mercury core. In this study, we measured the P-wave velocity (VP) of Fe–Ni–S–Si (Fe73Ni10S10Si7, Fe72Ni10S5Si13, and Fe67Ni10S10Si13) liquids up to 17 GPa and 2000 K to study the effects of pressure, temperature, and multiple light elements (S and Si) on the VP and elastic properties. The VP of Fe–Ni–S–Si liquids are less sensitive to temperature. The effect of pressure on the VP are close to that of liquid Fe and smaller than those of Fe–Ni–S and Fe–Ni–Si liquids. Obtained elastic properties are KS0 = 99.1(9.4) GPa, KS’ = 3.8(0.1) and ρ0 =6.48 g/cm3 for S-rich Fe73Ni10S10Si7 liquid and KS0 = 112.1(1.5) GPa, KS’ = 4.0(0.1) and ρ0=6.64 g/cm3 for Si-rich Fe72Ni10S5Si13 liquid. The VP of Fe–Ni–S–Si liquids locate in between those of Fe–Ni–S and Fe–Ni–Si liquids. This suggests that the effect of multiple light element (S and Si) on the VP is suppressed and cancel out the effects of single light elements (S and Si) on the VP. The effect of composition on the EOS in the Fe–Ni–S–Si system is indispensable to estimate the core composition combined with the geodesy data of upcoming Mercury mission

X-ray and Neutron Study on the Structure of Hydrous SiO2 Glass up to 10 GPa

The structure of hydrous amorphous SiO2 is fundamental in order to investigate the effects of water on the physicochemical properties of oxide glasses and magma. The hydrous SiO2 glass with 13 wt.% D2O was synthesized under high-pressure and high-temperature conditions and its structure was investigated by small angle X-ray scattering, X-ray diffraction, and neutron diffraction experiments at pressures of up to 10 GPa and room temperature. This hydrous glass is separated into two phases: a major phase rich in SiO2 and a minor phase rich in D2O molecules distributed as small domains with dimensions of less than 100 angstrom. Medium-range order of the hydrous glass shrinks compared to the anhydrous SiO2 glass by disruption of SiO4 linkage due to the formation of Si-OD deuterioxyl, while the response of its structure to pressure is almost the same as that of the anhydrous SiO2 glass. Most of D2O molecules are in the small domains and hardly penetrate into the void space in the ring consisting of SiO4 tetrahedra

Extracellular cyclophilin A possesses chemotaxic activity in cattle

International audienceCyclophilin A (CyPA) was originally discovered in bovine thymocytes as a cytosolic binding protein of the immunosuppressive drug cyclosporine A. Recent studies have revealed that in mice and humans, CyPA is secreted from cells in injured or infected tissues and plays a role in recruiting inflammatory cells in those tissues. Here we found that in cattle abundant level of extracellular CyPA was observed in tissues with inflammation. To aid in investigating the role of extracellular CyPA in cattle, we generated recombinant bovine CyPA (rbCyPA) and tested its biological activity as an inflammatory mediator. When bovine peripheral blood cells were treated with rbCyPA in vitro, we observed that rbCyPA reacts with the membranous surface of granulocytes, monocytes and lymphocytes. Chemotaxis analysis showed that the granulocytes migrate toward rbCyPA and the migration is inhibited by pre-treatment with an anti-bovine CyPA antibody. These results indicate that, as for mice and humans, extracellular CyPA possesses chemotactic activity to recruit inflammatory cells (e.g., granulocytes) in cattle, and could thus be a potential therapeutic target for the treatment of inflammation

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Wetting property of Fe‐S melt in solid core: Implication for the core crystallization process in planetesimals

In differentiated planetesimals, the liquid core starts to crystallize during secular cooling, followed by the separation of liquid–solid phases in the core. The wetting property between liquid and solid iron alloys determines whether the core melts are trapped in the solid core or they can separate from the solid core during core crystallization. In this study, we performed high-pressure experiments under the conditions of the interior of small bodies (0.5–3.0 GPa) to study the wetting property (dihedral angle) between solid Fe and liquid Fe-S as a function of pressure and duration. The measured dihedral angles are approximately constant after 2 h and decrease with increasing pressure. The dihedral angles range from 30° to 48°, which are below the percolation threshold of 60° at 0.5–3.0 GPa. The oxygen content in the melt decreases with increasing pressure and there are strong positive correlations between the S + O or O content and the dihedral angle. Therefore, the change in the dihedral angle is likely controlled by the O content of the Fe-S melt, and the dihedral angle tends to decrease with decreasing O content in the Fe-S melt. Consequently, the Fe-S melt can form interconnected networks in the solid core. In the obtained range of the dihedral angle, a certain amount of the Fe-S melt can stably coexist with solid Fe, which would correspond to the “trapped melt” in iron meteorites. Excess amounts of the melt would migrate from the solid core over a long period of core crystallization in planetesimals

Semi-in vitro detection of Mg2+-dependent DNase that specifically digest mitochondrial nucleoids in the zygote of Physarum polycephalum

The maternal/uniparental inheritance of mitochondria is controlled by the selective elimination of paternal/uniparental mitochondria and digestion of their mitochondrial DNA (mtDNA). In isogamy, the selective digestion of mtDNA in uniparental mitochondria is initiated after mating and is completed prior to the elimination of mitochondria, but the molecular mechanism of the digestion of uniparental mtDNA remains unknown. In this study, we developed a semi-in vitro assay for DNase, wherein the digestion of mitochondrial nucleoids (mt-nucleoids) was microscopically observed using isolated mitochondria from Physarum polycephalum and the DNase involved in uniparental inheritance was characterized. When myxamoebae of AI35 and DP246 are crossed, mtDNA and mt-nucleoid from only the DP246 parent are digested. The digestion of mt-nucleoids was observed in zygotes 3 h after plating for mating. During the digestion of mt-nucleoids, mitochondrial membrane integrity was maintained. In the semi-in vitro assay, the digestion of mt-nucleoids was only observed in the presence of Mg2+ at pH 7.5–9.0. Moreover, such Mg2+-dependent DNase activity was specifically detected in mitochondria isolated from zygotes 3 h after plating for mating. Therefore, Mg2+-dependent DNase is potentially involved in uniparental inheritance. Our findings provide insights into the DNase involved in uniparental inheritance and its regulatory mechanism

Thermoelastic properties of liquid Fe-C revealed by sound velocity and density measurements at high pressure

圧力とP波速度、密度は惑星の核の化学組成を知るうえで重要な要素である。我々は音速パルスエコー法とX線吸収法を用いてFe-3.5wt%Cにおいて3.4 GPa、1850Kまでの圧力、温度範囲でP波速度と密度の同時測定を行った。液体のFe-3.5wt%CのP波速度は圧力一定の条件で温度上昇に伴って直線的に減少した。また、炭素の添加は液体FeのP波速度を3 GPa、1700 Kの条件で約2％減少させ、Feの密度を2 GPa、1700 Kの条件で約2%減少させる