1,239 research outputs found

    Coherent quantum transport in ferromagnet/superconductor/ferromagnet structures

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    The Blonder-Tinkham-Klapwijk (BTK) approach is extended to study coherent quantum transport in ferromagnet/superconductor/ferromagnet (FM/SC/SM) double tunnel junctions. In order to guarantee current conservation it is necessary to simultaneously consider spin-polarized electron currents along one direction and spin-polarized hole currents along the opposite direction, and to determine self-consistently the chemical potential in SC. It is found that all the reflection and transmission coefficients'in BTK theory as well as conductance spectra oscillate with energy, exhibiting different behavior in the metallic and tunnel limits.published_or_final_versio

    Effect of iron loading on isolated rat myocardium

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    2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Hydrogen peroxide augments the injury effect of iron on the isolated rat heart and cardiomyocytes

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    2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Meta-analysis of scalp acupuncture for acute hypertensive intracerebral hemorrhage

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    Objectives: Scalp acupuncture (SA) is a commonly used therapeutic approach for primary intracerebral hemorrhage (ICH) in Traditional Chinese Medicine (TCM), but the efficacy and safety of SA therapy are still undetermined. The aim of this study is to systematically evaluate the efficacy and safety of SA therapy for the treatment of acute hypertensive ICH. Methods: Literature reports with randomized controlled clinical trials and controlled clinical trials on SA therapy for acute hypertensive ICH were searched, and the efficacy and safety of SA therapy were evaluated by using the Cochrane systematic review methods. The primary outcome measures were death or dependency at the end of long-term follow-up (at least 3 months) and adverse events. The secondary outcome measure was neurological deficit improvement at the end of the treatment course. Results: Seven (7) independent trials (230 patients) were included in this study. All trials described the methods of randomization in which four trials had adequate concealment of randomization at the level of grade A, but no trial included sham acupuncture as a control group. None of the trials included "death or dependency" as a primary outcome measure. Four (4) trials contained safety assessments and stated that no adverse event was found, whereas the other three trials did not provide the information about adverse events. By using random effects statistical model, it was found that patients with acute hypertensive ICH who received SA therapy had significantly improved neurological deficit scores (Z=4.97, p<0.01). Conclusions: Although SA therapy is widely used to treat acute hypertensive ICH in TCM, the efficacy and safety of SA therapy remain to be further determined. No evidence is available on whether SA therapy can be used to treat acute ICH according to the primary outcome measure. However, SA therapy appears to be able to improve neurological deficit in patients with acute hypertensive ICH. © 2011, Mary Ann Liebert, Inc.published_or_final_versio

    Nodal quasiparticle meltdown in ultra-high resolution pump-probe angle-resolved photoemission

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    High-TcT_c cuprate superconductors are characterized by a strong momentum-dependent anisotropy between the low energy excitations along the Brillouin zone diagonal (nodal direction) and those along the Brillouin zone face (antinodal direction). Most obvious is the d-wave superconducting gap, with the largest magnitude found in the antinodal direction and no gap in the nodal direction. Additionally, while antinodal quasiparticle excitations appear only below TcT_c, superconductivity is thought to be indifferent to nodal excitations as they are regarded robust and insensitive to TcT_c. Here we reveal an unexpected tie between nodal quasiparticles and superconductivity using high resolution time- and angle-resolved photoemission on optimally doped Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta}. We observe a suppression of the nodal quasiparticle spectral weight following pump laser excitation and measure its recovery dynamics. This suppression is dramatically enhanced in the superconducting state. These results reduce the nodal-antinodal dichotomy and challenge the conventional view of nodal excitation neutrality in superconductivity.Comment: 7 pages, 3 figure. To be published in Nature Physic

    Potentiation of thrombus instability: a contributory mechanism to the effectiveness of antithrombotic medications

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    © The Author(s) 2018The stability of an arterial thrombus, determined by its structure and ability to resist endogenous fibrinolysis, is a major determinant of the extent of infarction that results from coronary or cerebrovascular thrombosis. There is ample evidence from both laboratory and clinical studies to suggest that in addition to inhibiting platelet aggregation, antithrombotic medications have shear-dependent effects, potentiating thrombus fragility and/or enhancing endogenous fibrinolysis. Such shear-dependent effects, potentiating the fragility of the growing thrombus and/or enhancing endogenous thrombolytic activity, likely contribute to the clinical effectiveness of such medications. It is not clear how much these effects relate to the measured inhibition of platelet aggregation in response to specific agonists. These effects are observable only with techniques that subject the growing thrombus to arterial flow and shear conditions. The effects of antithrombotic medications on thrombus stability and ways of assessing this are reviewed herein, and it is proposed that thrombus stability could become a new target for pharmacological intervention.Peer reviewedFinal Published versio

    A Conformation-Sensitive Monoclonal Antibody against the A2 Domain of von Willebrand Factor Reduces Its Proteolysis by ADAMTS13

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    The size of von Willebrand factor (VWF), controlled by ADAMTS13-dependent proteolysis, is associated with its hemostatic activity. Many factors regulate ADAMTS13-dependent VWF proteolysis through their interaction with VWF. These include coagulation factor VIII, platelet glycoprotein 1bα, and heparin sulfate, which accelerate the cleavage of VWF. Conversely, thrombospondin-1 decreases the rate of VWF proteolysis by ADAMTS13 by competing with ADAMTS13 for the A3 domain of VWF. To investigate whether murine monoclonal antibodies (mAbs) against human VWF affect the susceptibility of VWF to proteolysis by ADAMTS13 in vitro, eight mAbs to different domains of human VWF were used to evaluate the effects on VWF cleavage by ADAMTS13 under fluid shear stress and static/denaturing conditions. Additionally, the epitope of anti-VWF mAb (SZ34) was mapped using recombinant proteins in combination with enzyme-linked immunosorbent assay and Western blot analysis. The results indicate that mAb SZ34 inhibited proteolytic cleavage of VWF by ADAMTS13 in a concentration-dependent manner under fluid shear stress, but not under static/denaturing conditions. The binding epitope of SZ34 mAb is located between A1555 and G1595 in the central A2 domain of VWF. These data show that an anti-VWF mAb against the VWF-A2 domain (A1555-G1595) reduces the proteolytic cleavage of VWF by ADAMTS13 under shear stress, suggesting the role of this region in interaction with ADAMTS13

    Primary Phacoemulsification and Intraocular Lens Implantation for Acute Primary Angle-Closure

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    Background: To investigate the effect of primary phacoemulsification on intraocular pressure (IOP) in patients with acute primary angle-closure (PAC) and coexisting cataract. Methodology: Sixteen eyes of 14 patients with acute PAC received phacoemulsification and intraocular lens implantation as initial management for medically uncontrolled IOP in a retrospective chart review. The effects on IOP, vision, anterior chamber depth (ACD), and number of antiglaucoma medications were evaluated. Principal Findings: The postoperative IOP was reduced in 16 eyes (100%). The mean 6 standard deviation preoperative IOP was 48.81616.83 mm Hg, which decreased postoperatively to 16.46610.67 mm Hg at 1 day, 9.4363.03 mm Hg at 1 week
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