240 research outputs found
Translation of therapeutic strategies to modulate B cell reponses from non-human primate models to human kidney transplantation
Using novel drugs targeting lymphocyte costimulation, cytokines, antibody, complement, and plasma cells, we have developed strategies in a non-human primate model to modulate the B cell response to incompatible kidney transplants. After more than two decades of research supported by mechanistic studies, this has resulted in clinically relevant approaches that are currently enrolling in clinical trials or preparing for such. In this manner, we aim to address the problems of HLA sensitization for very highly sensitized patients awaiting transplantation and the unmet need of effective treatment for antibody-mediated rejection
Microstructural and Electron-Emission Characteristics of Nb-Si-N Films in Surface-Conduction Electron-Emitter Display
AbstractWe proposed ternary nitride Nb-Si-N film as a promising surface-conduction electron emitter (SCE) in surface-conduction electron-emitter display (SED). Nb-Si-N films consisted of continuous NbN polycrystalline phase with (Si3-xNb4x)N4 amorphous phase in NbN grain boundaries. After electroforming, serrated nanogaps were observed in Nb-Si-N SCE strips. The emission current of Nb-Si-N SCE array of 1×18 cells was 6.50μA with anode voltage of 1.5kV and device voltage of 22V, indicating satisfying potential for display applications comparing with NbN SCEs. © 2009 Published by Elsevier B.V
Ischemic postconditioning and pinacidil suppress calcium overload in anoxia- reoxygenation cardiomyocytes via down- regulation of the calcium-sensing receptor
ABSTRACT Ischemic postconditioning (IPC) and ATP sensitive potassium channel (KATP) agonists (e.g. pinacidil and diazoxide) postconditioning are effective methods to defeat myocardial ischemia-reperfusion (I/R) injury, but their specific mechanisms of reducing I/R injury are not fully understood. We observed an intracellular free calcium ([Ca 2
Approximate solutions to large nonsymmetric differential Riccati problems with applications to transport theory
In the present paper, we consider large scale nonsymmetric differential
matrix Riccati equations with low rank right hand sides. These matrix equations
appear in many applications such as control theory, transport theory, applied
probability and others. We show how to apply Krylov-type methods such as the
extended block Arnoldi algorithm to get low rank approximate solutions. The
initial problem is projected onto small subspaces to get low dimensional
nonsymmetric differential equations that are solved using the exponential
approximation or via other integration schemes such as Backward Differentiation
Formula (BDF) or Rosenbrok method. We also show how these technique could be
easily used to solve some problems from the well known transport equation. Some
numerical experiments are given to illustrate the application of the proposed
methods to large-scale problem
Recovery of an embedded obstacle and the surrounding medium for Maxwell's system
In this paper, we are concerned with the inverse electromagnetic scattering
problem of recovering a complex scatterer by the corresponding electric
far-field data. The complex scatterer consists of an inhomogeneous medium and a
possibly embedded perfectly electric conducting (PEC) obstacle. The far-field
data are collected corresponding to incident plane waves with a fixed incident
direction and a fixed polarisation, but frequencies from an open interval. It
is shown that the embedded obstacle can be uniquely recovered by the
aforementioned far-field data, independent of the surrounding medium.
Furthermore, if the surrounding medium is piecewise homogeneous, then the
medium can be recovered as well. Those unique recovery results are new to the
literature. Our argument is based on low-frequency expansions of the
electromagnetic fields and certain harmonic analysis techniques.Comment: 15 page
Disentangling superconducting and magnetic orders in NaFe_1-xNi_xAs using muon spin rotation
Muon spin rotation and relaxation studies have been performed on a "111"
family of iron-based superconductors NaFe_1-xNi_xAs. Static magnetic order was
characterized by obtaining the temperature and doping dependences of the local
ordered magnetic moment size and the volume fraction of the magnetically
ordered regions. For x = 0 and 0.4 %, a transition to a nearly-homogeneous long
range magnetically ordered state is observed, while for higher x than 0.4 %
magnetic order becomes more disordered and is completely suppressed for x = 1.5
%. The magnetic volume fraction continuously decreases with increasing x. The
combination of magnetic and superconducting volumes implies that a
spatially-overlapping coexistence of magnetism and superconductivity spans a
large region of the T-x phase diagram for NaFe_1-xNi_xAs . A strong reduction
of both the ordered moment size and the volume fraction is observed below the
superconducting T_C for x = 0.6, 1.0, and 1.3 %, in contrast to other iron
pnictides in which one of these two parameters exhibits a reduction below TC,
but not both. The suppression of magnetic order is further enhanced with
increased Ni doping, leading to a reentrant non-magnetic state below T_C for x
= 1.3 %. The reentrant behavior indicates an interplay between
antiferromagnetism and superconductivity involving competition for the same
electrons. These observations are consistent with the sign-changing s-wave
superconducting state, which is expected to appear on the verge of microscopic
coexistence and phase separation with magnetism. We also present a universal
linear relationship between the local ordered moment size and the
antiferromagnetic ordering temperature TN across a variety of iron-based
superconductors. We argue that this linear relationship is consistent with an
itinerant-electron approach, in which Fermi surface nesting drives
antiferromagnetic ordering.Comment: 20 pages, 14 figures, Correspondence should be addressed to Prof.
Yasutomo Uemura: [email protected]
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