57 research outputs found

    Cooling Stability Test of MgB₂ Wire Immersed in Liquid Hydrogen under External Magnetic Field

    Get PDF
    11th European Conference on Applied Superconductivity (EUCAS2013)Liquid hydrogen (LH₂), which has large latent heat, low viscosity coefficient, is expected to be a candidate for a cryogen for superconducting wires, not only MgB₂ but also other HTC superconductors. LH₂ cooled superconducting wires are expected to have excellent electro-magnetic characteristics, which is necessary to be clear for cooling stability design of LH₂ cooled superconducting device, however, due to handling difficulties of LH₂, there are only few papers on the properties of LH₂ cooled superconductors, especially under external magnetic field. We designed and made an experimental setup which can energize superconducting wires immersed in LH₂ with the current of up to 500A under the condition of external magnetic field up to 7 T and pressure up to 1.5 MPa. In order to confirm experimental method and safety operation of the setup, over current tests were carried out using MgB₂ superconducting wires under various external magnetic field conditions. Critical current of the test wire at the temperature 21, 24, 27, 29 K under external magnetic fields up to 1.2 T was successfully measured. The resistance of the wire also was measured, while the transport current exceeded the critical current of the wire

    Surgical Outcomes of Posterior Short Segment Fixation for Thoracolumbar Burst Fractures: A Study of Patients Treated without Vertebroplasty

    Get PDF
    There is no widespread agreement regarding the treatment of thoracolumbar burst fractures. While performing posterior short segment fixation of thoracolumbar burst fractures, we evaluated therapeutic outcomes in patients treated with screw insertion into fractured vertebral bodies without vertebroplasty. We also investigated the limitations associated with the treatment of burst fractures when vertebroplasty is not performed. Twenty-one of 51 patients with thoracolumbar burst fractures who were treated surgically in Ohta Nishinouchi Hospital were evaluated in the present study. These patients underwent posterior short segment fixation with screw insertion into the fractured vertebral bodies (only pedicle screws were inserted one level above and one level below the fractured vertebral bodies) without vertebroplasty. Vertebral angles were measured before surgery, immediately after surgery, and at the final follow-up examination. Changes in vertebral angles were compared and analyzed. The mean vertebral angles before and after surgery and at the final follow-up examination were 15.4°, 6.6°, and 9.1°, respectively. The mean postoperative correction loss was 2.5°. The therapeutic outcomes of posterior short segment fixation with screw insertion into fractured vertebral bodies without vertebroplasty were generally favorable

    Tumor growth inhibitory effect of ADAMTS1 is accompanied by the inhibition of tumor angiogenesis

    Get PDF
    Angiogenesis plays an important role in tumor progression. Several reports have demonstrated that a disintegrin and metalloproteinase with thrombospondin motifs1 (ADAMTS1) inhibited angiogenesis via multiple mechanisms. The aim of this study was to investigate the effect of ADAMTS1 on endothelial cells in vitro and on tumor growth with regard to angiogenesis in vivo. We examined the effects of the transfection of ADAMTS1 using two constructs, full-length ADAMTS1 (full ADAMTS1) and catalytic domain-deleted ADAMTS1 (delta ADAMTS1). Transfection of both the full ADAMTS1 and delta ADAMTS1 gene constructs demonstrated the secretion of tagged-ADAMTS1 protein into the conditioned medium, so we examined the effects of ADAMTS1-containing conditioned medium on endothelial cells. Both types of conditioned media inhibited endothelial tube formation, and this effect was completely abolished after immunoprecipitation of the secreted protein from the medium. Both types of conditioned media also inhibited endothelial cell migration and proliferation. We then examined the impact of ADAMTS1 on endothelial cell apoptosis. Both conditioned media increased the number of Annexin V-positive endothelial cells and caspase-3 activity and this effect was attenuated when z-vad was added. These results indicated that ADAMTS1 induced endothelial cell apoptosis. We next examined the effects of ADAMTS1 gene transfer into tumor-bearing mice. Both full ADAMTS1 and delta ADAMTS1 significantly inhibited the subcutaneous tumor growth. Collectively, our results demonstrated that ADAMTS1 gene transfer inhibited angiogenesis in vitro and in vivo, likely as a result of the induction of endothelial cell apoptosis by ADAMTS1 that occurs independent of the protease activity

    Facile formation of gold nanoparticles on periodic mesoporous bipyridine-silica

    Get PDF
    Outline Highlights Abstract Graphical abstract Keywords 1. Introduction 2. Experimental 3. Results and discussion 4. Conclusions References Show full outline Figures (9) Unlabelled figure Scheme 1. Formation of Au complex on BPy-PMO Fig. 1. (a) Au L3-edge XANES, (b) EXAFS oscillation, (c) Fourier transforms of EXAFS Fig. 2. (a) N2 adsorption isotherms and (b) NLDFT pore diameter distribution curves of Fig. 3. XRD patterns of BPy-PMO (black line) and AuNPs/BPy-PMO (blue line) in (a) low Fig. 4. (a) N2 adsorption isotherms and (b) XRD patterns of bare (black line) and Show all figures Elsevier Catalysis Today Volume 298, 1 December 2017, Pages 258-262 Catalysis Today Facile formation of gold nanoparticles on periodic mesoporous bipyridine-silica Silica-supported gold nanoparticles (AuNPs) can be synthesized on a bipyridine incorporated periodic mesoporous organosilica (BPy-PMO) as an inorganic support. Reaction of a bipyridine group in the periodic mesoporous organosilica with HAuCl4 forms an AuCl2-based complex, and its structure corresponds to a homogeneous complex, [AuCl2(bpy)]Cl. Thermal reduction of the complex in H-2 results in the formation of small gold nanoparticles with an average size of ca. 3.8 nm. Combined with nitrogen adsorption, XRD, UV/Vis, TEM, and XAFS measurements, it is demonstrated that uniform gold nanoparticles are homogeneously distributed inside mesopores. The size and distribution of gold nanoparticles are mainly controlled by strong interaction of surface metallic Au with pore walls of the periodic mesoporous organosilica. AuNPs/BPy-PMO shows higher catalytic activity than Au/MCM-41 in aerobic oxidation of benzaldehyde. (C) 2017 Elsevier B.V. All rights reserved

    Ruthenium-Immobilized Periodic Mesoporous Organosilica: Synthesis, Characterization, and Catalytic Application for Selective Oxidation of Alkanes

    Get PDF
    Periodic mesoporous organosilica (PMO) is a unique material that has a crystal-like wall structure with coordination sites for metal complexes. A Ru complex, [RuCl2(CO)(3)](2), is successfully immobilized onto 2,2'-bipyridine (BPy) units of PMO to form a single-site catalyst, which has been confirmed by various physicochemical analyses. Using NaClO as an oxidant, the Ru-immobilized PMO oxidizes the tertiary CH bonds of adamantane to the corresponding alcohols at 57 times faster than the secondary CH bonds, thereby exhibiting remarkably high regioselectivity. Moreover, the catalyst converts cis-decalin to cis-9-decalol in a 63% yield with complete retention of the substrate stereochemistry. The Ru catalyst can be separated by simple filtration and reused without loss of the original activity and selectivity for the oxidation reactions
    corecore