78 research outputs found
Flux front penetration in disordered superconductors
We investigate flux front penetration in a disordered type II superconductor
by molecular dynamics (MD) simulations of interacting vortices and find scaling
laws for the front position and the density profile. The scaling can be
understood performing a coarse graining of the system and writing a disordered
non-linear diffusion equation. Integrating numerically the equation, we observe
a crossover from flat to fractal front penetration as the system parameters are
varied. The value of the fractal dimension indicates that the invasion process
is described by gradient percolation.Comment: 5 pages, 4 figures, to appear in Phys. Rev. Let
Zener transitions between dissipative Bloch bands. II: Current Response at Finite Temperature
We extend, to include the effects of finite temperature, our earlier study of
the interband dynamics of electrons with Markoffian dephasing under the
influence of uniform static electric fields. We use a simple two-band
tight-binding model and study the electric current response as a function of
field strength and the model parameters. In addition to the Esaki-Tsu peak,
near where the Bloch frequency equals the damping rate, we find current peaks
near the Zener resonances, at equally spaced values of the inverse electric
field. These become more prominenent and numerous with increasing bandwidth (in
units of the temperature, with other parameters fixed). As expected, they
broaden with increasing damping (dephasing).Comment: 5 pages, LateX, plus 5 postscript figure
Inverse Fusion PCR Cloning
Inverse fusion PCR cloning (IFPC) is an easy, PCR based three-step cloning method that allows the seamless and directional insertion of PCR products into virtually all plasmids, this with a free choice of the insertion site. The PCR-derived inserts contain a vector-complementary 5′-end that allows a fusion with the vector by an overlap extension PCR, and the resulting amplified insert-vector fusions are then circularized by ligation prior transformation. A minimal amount of starting material is needed and experimental steps are reduced. Untreated circular plasmid, or alternatively bacteria containing the plasmid, can be used as templates for the insertion, and clean-up of the insert fragment is not urgently required. The whole cloning procedure can be performed within a minimal hands-on time and results in the generation of hundreds to ten-thousands of positive colonies, with a minimal background
Association between high-dose erythropoiesis-stimulating agents, inflammatory biomarkers, and soluble erythropoietin receptors
<p>Abstract</p> <p>Background</p> <p>High-dose erythropoiesis-stimulating agents (ESA) for anemia of chronic kidney disease (CKD) have been associated with adverse clinical outcomes and do not always improve erythropoiesis. We hypothesized that high-dose ESA requirement would be associated with elevated inflammatory biomarkers, decreased adipokines, and increased circulating, endogenous soluble erythropoietin receptors (sEpoR).</p> <p>Methods</p> <p>A cross-sectional cohort of anemic 32 CKD participants receiving ESA were enrolled at a single center and cytokine profiles, adipokines, and sEpoR were compared between participants stratified by ESA dose requirement (usual-dose darbepoetin-α (< 1 μg/kg/week) and high-dose (≥1 μg/kg/week)).</p> <p>Results</p> <p>Baseline characteristics were similar between groups; however, hemoglobin was lower among participants on high-dose (1.4 μg/kg/week) vs usual-dose (0.5 μg/kg/week) ESA.</p> <p>In adjusted analyses, high-dose ESA was associated with an increased odds for elevations in c-reactive protein and interleukin-6 (p < 0.05 for both). There was no correlation between high-dose ESA and adipokines. Higher ESA dose correlated with higher levels of sEpoR (r<sub>s </sub>= 0.39, p = 0.03). In adjusted analyses, higher ESA dose (per μcg/kg/week) was associated with a 53% greater odds of sEpoR being above the median (p < 0.05).</p> <p>Conclusion</p> <p>High-dose ESA requirement among anemic CKD participants was associated with elevated inflammatory biomarkers and higher levels of circulating sEpoR, an inhibitor of erythropoiesis. Further research confirming these findings is warranted.</p> <p>Trial registration</p> <p>Clinicaltrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT00526747">NCT00526747</a></p
Chemical vapour deposition of Ir-based coatings : chemistry, processes and applications
Chemical and materials science aspects of iridium-containing thin film formation by Chemical Vapor Deposition (CVD) methods for modern high-precision technology applications are considered. Chemical approaches to the synthesis of the main precursors used in CVD techniques, thin film growth processes and mechanisms as well as the main structure, composition and properties of iridium-containing thin films are analyzed, and modern thin film application examples are outlined. Numerical characterization of iridium-based thin film growth in 3D objects is presented
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Thermomechanical processing of tungsten-copper composites
A tungsten-40 wt% Cu composite was consolidated by liquid-phase sintering and further processed to full density by a number of deformation methods. Fully dense materials were obtained by hot extrusion or cold rolling of the W-Cu composite. Subsequent processing by cold rolling, cold swaging, or hot swaging did not produce large changes in the aspect ratio of the W particles. The materials develop high hardness with small grain sizes of 5 {mu}m or less. The work-hardening, recrystallization, and grain growth of the material are characterized, and the hardness and tensile properties are related to processing parameters. Wire with tensile strengths up to 1120 MPa were produced. Further improvements in properties are anticipated with optimized processing parameters
GMPLS: architecture and applications
The last two years have seen significant developments in the standardization of GMPLS and its implementation in optical and other networks. GMPLS: Architecture and Applications brings you completely up to date, providing the practical information you need to put the growing set of GMPLS-supported services to work and manage them effectively. This book begins by defining GMPLSs place in a transport network, leveraging your knowledge of MPLS to give you an understanding of this radically new control plane technology. An overview of GMPLS protocols follows, but the real focus is on what comes afterwards: in-depth examinations of the architectures underpinning GMPLS in real-world network environments and current and emerging GMPLS applications. This one-of-a-kind resource delivers immensely useful information for software architects, designers and programmers, hardware developers, system testers, and network operators--and also for managers and other decision-makers. + Written by two industry researchers at the forefront of the development of GMPLS. + Provides a practical look at GMPLS protocols for signaling, routing, link and resource management, and traffic engineering. + Delves deep into the world of GMPLS applications, including traffic engineering, path computation, layer one VPNs, point-to-multipoint connectivity, service management, and resource protection. + Explores three distinct GMPLS control plane architectures: peer, overlay, and hybrid, and explains the GMPLS UNI and NNIs. + Explains how provisioning challenges can be met in multi-region networks and details the provisioning systems and tools relied on by the GMPLS control plane, along with the standard MIB modules used to manage a GMPLS system.Title from title screen.Includes bibliographical references and index.Multiprotocol label switching -- An overview of transport networks -- From MPLS to GMPLS -- GMPLS signaling -- GMPLS routing -- Link management -- GMPLS and service recovery -- GMPLS and traffic engineering -- GMPLS path computation -- Constraint-based path computation -- Point-to-multipoint GMPLS -- Layer one virtual private networks -- Architectural models -- Provisioning systems -- GMPLS MIB modules.The last two years have seen significant developments in the standardization of GMPLS and its implementation in optical and other networks. GMPLS: Architecture and Applications brings you completely up to date, providing the practical information you need to put the growing set of GMPLS-supported services to work and manage them effectively. This book begins by defining GMPLSs place in a transport network, leveraging your knowledge of MPLS to give you an understanding of this radically new control plane technology. An overview of GMPLS protocols follows, but the real focus is on what comes afterwards: in-depth examinations of the architectures underpinning GMPLS in real-world network environments and current and emerging GMPLS applications. This one-of-a-kind resource delivers immensely useful information for software architects, designers and programmers, hardware developers, system testers, and network operators--and also for managers and other decision-makers. + Written by two industry researchers at the forefront of the development of GMPLS. + Provides a practical look at GMPLS protocols for signaling, routing, link and resource management, and traffic engineering. + Delves deep into the world of GMPLS applications, including traffic engineering, path computation, layer one VPNs, point-to-multipoint connectivity, service management, and resource protection. + Explores three distinct GMPLS control plane architectures: peer, overlay, and hybrid, and explains the GMPLS UNI and NNIs. + Explains how provisioning challenges can be met in multi-region networks and details the provisioning systems and tools relied on by the GMPLS control plane, along with the standard MIB modules used to manage a GMPLS system.Elsevie
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