329 research outputs found
Crystallographic and superconducting properties of the fully-gapped noncentrosymmetric 5d-electron superconductors CaMSi3 (M=Ir, Pt)
We report crystallographic, specific heat, transport, and magnetic properties
of the recently discovered noncentrosymmetric 5d-electron superconductors
CaIrSi3 (Tc = 3.6 K) and CaPtSi3 (Tc = 2.3 K). The specific heat suggests that
these superconductors are fully gapped. The upper critical fields are less than
1 T, consistent with limitation by conventional orbital depairing. High,
non-Pauli-limited {\mu}0 Hc2 values, often taken as a key signature of novel
noncentrosymmetric physics, are not observed in these materials because the
high carrier masses required to suppress orbital depairing and reveal the
violated Pauli limit are not present.Comment: 8 pages, 8 figure
High mobility group box 1 complexed with heparin induced angiogenesis in a matrigel plug assay
Angiogenesis involves complex processes mediated by several factors and is associated with inflammation and wound healing. High mobility group box 1 (HMGB1) is released from necrotic cells as well as macrophages and plays proinflammatory roles. In the present study, we examined whether HMGB1 would exhibit angiogenic activity in a matrigel plug assay in mice. HMGB1 in combination with heparin strongly induced angiogenesis, whereas neither HMGB1 nor heparin alone showed such angiogenic activity. The heparin-dependent induction of angiogenesis by HMGB1 was accompanied by increases in the expression of tumor necrosis factor-alpha (TNF-alpha) and vascular endothelial growth factor-A120 (VEGF-A120). It is likely that the dependence of the angiogenic activity of HMGB1 on heparin was due to the efficiency of the diffusion of the HMGB1-heparin complex from matrigel to the surrounding areas. VEGF-A165 possessing a heparin-binding domain showed a pattern of heparin-dependent angiogenic activity similar to that of HMGB1. The presence of heparin also inhibited the degradation of HMGB1 by plasmin in vitro. Taken together, these results suggested that HMGB1 in complex with heparin possesses remarkable angiogenic activity, probably through the induction of TNF-alpha and VEGF-A120.</p
Synthesis and photoemission study of as-grown superconducting MgB2 thin films
As-grown superconducting thin films of MgB2 were prepared by molecular beam
epitaxy (MBE), and studied by X-ray and ultraviolet photoelectron spectroscopy
(XPS and UPS). Only films prepared at temperatures between 150 and 320 deg.
showed superconductivity. A best TC onset of 36 K with a sharp transition width
of -1 K was obtained although the film crystallinity was poor. The in-situ
photoelectron spectra obtained on the surfaces of the MBE grown MgB2 films were
free from dirt peaks. XPS revealed that the binding energy of the Mg 2p levels
in MgB2 is close to that of metallic Mg, and the binding energy of B 1s is
close to that of transition-metal diborides. The valence UP spectra showed a
clear Fermi edge although the density of states (DOS) at EF is low and the
major components of the valence band are located between 5 and 11 eV.Comment: ISS 2001 proceedin
Superconductivity at 38 K in Iron-Based Compound with Platinum-Arsenide Layers Ca10(Pt4As8)(Fe2-xPtxAs2)5
We report superconductivity in novel iron-based compounds
Ca10(PtnAs8)(Fe2-xPtxAs2)5 with n = 3 and 4. Both compounds crystallize in
triclinic structures (space group P-1), in which Fe2As2 layers alternate with
PtnAs8 spacer layers. Superconductivity with a transition temperature of 38 K
is observed in the n = 4 compound with a Pt content of x ~ 0.36 in the Fe2As2
layers. The compound with n = 3 exhibits superconductivity at 13 K.Comment: OPEN SELECT article, 11 pages, 5 figures, 2 table
High-throughput powder diffraction measurement system consisting of multiple MYTHEN detectors at beamline BL02B2 of SPring-8
In this study, we developed a user-friendly automatic powder diffraction measurement system for Debye–Scherrer geometry using a capillary sample at beamline BL02B2 of SPring-8. The measurement system consists of six one-dimensional solid-state (MYTHEN) detectors, a compact auto-sampler, wide-range temperature control systems, and a gas handling system. This system enables to do the automatic measurement of temperature dependence of the diffraction patterns for multiple samples. We introduced two measurement modes in the MYTHEN system and developed new attachments for the sample environment such as a gas handling system. The measurement modes and the attachments can offer in situ and/or time-resolved measurements in an extended temperature range between 25 K and 1473 K and various gas atmospheres and pressures. The results of the commissioning and performance measurements using reference materials (NIST CeO2 674b and Si 640c), V2O3 and Ti2O3, and a nanoporous coordination polymer are presented
Establishment of in Vitro Binding Assay of High Mobility Group Box-1 and S100A12 to Receptor for Advanced Glycation Endproducts: Heparin's Effect on Binding
Interaction between the receptor for advanced glycation end products (RAGE) and its ligands has been implicated in the pathogenesis of various inflammatory disorders. In this study, we establish an in vitro binding assay in which recombinant human high-mobility group box 1 (rhHMGB1) or recombinant human S100A12 (rhS100A12) immobilized on the microplate binds to recombinant soluble RAGE (rsRAGE). The rsRAGE binding to both rhHMGB1 and rhS100A12 was saturable and dependent on the immobilized ligands. The binding of rsRAGE to rhS100A12 depended on Ca2 and Zn2, whereas that to rhHMGB1 was not. Scatchard plot analysis showed that rsRAGE had higher affinity for rhHMGB1 than for rhS100A12. rsRAGE was demonstrated to bind to heparin, and rhS100A12, in the presence of Ca2, was also found to bind to heparin. We examined the effects of heparin preparations with different molecular sizesunfractionated native heparin (UFH), low molecular weight heparin (LMWH) 5000Da, and LMWH 3000Da on the binding of rsRAGE to rhHMGB1 and rhS100A12. All 3 preparations concentration-dependently inhibited the binding of rsRAGE to rhHMGB1 to a greater extent than did rhS100A12. These results suggested that heparin's anti-inflammatory effects can be partly explained by its blocking of the interaction between HMGB1 or S100A12 and RAGE. On the other hand, heparin would be a promising effective remedy against RAGE-related inflammatory disorders.</p
Specific Removal of Monocytes from Peripheral Blood of Septic Patients by Polymyxin B-immobilized Filter Column
Lipopolysaccharide (LPS) is one of the major causes of septic shock. The polymyxin B-immobilized filter column (PMX) was developed for the adsorption of endotoxin by direct hemoperfusion and has been used for the treatment of LPS-induced septic shock. In this study, we demonstrated that PMX also specifically bound monocytes from the peripheral blood leukocytes of septic patients by mean of an analysis of bound cells using immunocytochemical and electron microscopic techniques. The specific removal of monocytes from septic patients may produce beneficial effects by reducing the interaction between monocytes and functionally associated cells including vascular endothelial cells
Gene Expression and Localization of High-mobility Group Box Chromosomal Protein-1 (HMGB-1) in Human Osteoarthritic Cartilage
We investigated the expression and localization of high-mobility group box chromosomal protein-1 (HMGB-1) in human osteoarthritic (OA) cartilage in relation to the histopathological grade of cartilage destruction, and examined the role of HMGB-1 in the regulation of proinflammatory cytokine expression in chondrocytes. An immunohistochemical study demonstrated that total HMGB-1-positive cell ratios increase as the Osteoarthritis Research Society International (OARSI) histological grade increased. The population of cytoplasmic HMGB-1-positive chondrocytes was especially increased in the deep layers of higher-grade cartilage. The ratios and localization of receptors for advanced glycation end products (RAGE) expression by chondrocytes in Grade 2, 3, and 4 were significantly higher than those in Grade 1. In vitro stimulation with IL-1β, but not TNFα, significantly upregulated the expression of HMGB-1 mRNA by human OA chondrocytes. Both IL-1β and TNFα promoted the translocation of HMGB-1 from nuclei to cytoplasm. IL-1β and TNFα secretions were stimulated at higher levels of HMGB-1. The results of our study suggest the involvement of HMGB-1 in the pathogenesis of cartilage destruction in OA
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