BACKGROUND: Coronary atherosclerotic-plaque thrombosis is a key event in the pathogenesis of unstable angina and myocardial infarction. Although plaque rupture or fissuring frequently occurs in atherosclerosis, only a small proportion of ruptured plaques develop thromboses. METHODS: Tissue-factor antigen and activity were measured in atherectomy samples from 50 consecutive patients with coronary artery disease (stable angina n = 19, unstable angina n = 24, and myocardial infarction n = 7). FINDINGS: Median tissue-factor antigen and activity concentrations were significantly higher in plaques from patients with unstable angina and myocardial infarction than in those from patients with stable angina (antigen: 66.1 pg/mg [interquartile range 43.8-82.5] vs 32.4 pg/mg [9.8-43.4], p = 0.0001; activity: 0.22 mU/mg [0.17-0.41] vs 0.13 mU/mg [0.05-0.16], p = 0.0004). INTERPRETATION: Tissue-factor, an initiator of the coagulation cascade, may account for the different thrombotic responses to the rupture of human coronary atherosclerotic plaques. 相似文献
Digital fonts are easily available today and their use has become widespread. Nevertheless, the visual quality of printed and displayed text and the technical quality of digital typefaces are often unsatisfactory. The foremost reason for this situation is that font manufacturing systems manipulate font representations through low-level operations. In this paper we examine several aspects of font quality, and present a method for enhancing the quality of a typeface given in today's standard representation, the outline (boundary) representation. The method is based on the usage of high-level typographic features, and includes enhancements to both individual glyphs and complete fonts. Glyph enhancements include elimination of redundant points, insertion of essential points, corrections to contour orientations and inter-penetrations, and vertical and horizontal coherence. Font enhancements include regularization of font weights and sizes, serif unification, and feature extraction and discrimination. Our method is comprised of several algorithms that have been implemented in a commercial font manufacturing system, achieving enhanced quality of the fonts produced. 相似文献
Virtual Reality - Virtual reality (VR) sickness is a condition that may occur during or after exposure to a virtual environment and can induce symptoms such as headache and eye strain. VR sickness... 相似文献
In the state-of-the-art parallel programming approaches OpenCL and CUDA, so-called host code is required for program’s execution. Efficiently implementing host code is often a cumbersome task, especially when executing OpenCL and CUDA programs on systems with multiple nodes, each comprising different devices, e.g., multi-core CPU and graphics processing units; the programmer is responsible for explicitly managing node’s and device’s memory, synchronizing computations with data transfers between devices of potentially different nodes and for optimizing data transfers between devices’ memories and nodes’ main memories, e.g., by using pinned main memory for accelerating data transfers and overlapping the transfers with computations. We develop distributed OpenCL/CUDA abstraction layer (dOCAL)—a novel high-level C++ library that simplifies the development of host code. dOCAL combines major advantages over the state-of-the-art high-level approaches: (1) it simplifies implementing both OpenCL and CUDA host code by providing a simple-to-use, high-level abstraction API; (2) it supports executing arbitrary OpenCL and CUDA programs; (3) it allows conveniently targeting the devices of different nodes by automatically managing node-to-node communications; (4) it simplifies implementing data transfer optimizations by providing different, specially allocated memory regions, e.g., pinned main memory for overlapping data transfers with computations; (5) it optimizes memory management by automatically avoiding unnecessary data transfers; (6) it enables interoperability between OpenCL and CUDA host code for systems with devices from different vendors. Our experiments show that dOCAL significantly simplifies the development of host code for heterogeneous and distributed systems, with a low runtime overhead.
Water-soluble silicon nanoparticles (SiNPs) have been synthesized with photoluminescence quantum yield more than 32% via a hydrothermal treatment of 3-aminopropyltriethoxysilane as silicon sources and maleic acid (MA) as surface-stabilizing ligands. Prepared SiNPs showed the presence of carboxylic acid groups through the incorporation of MA. The presence of 48.8 and 51.2% of Si–Si and Si–O binding was observed in the resulting carboxylic acid-functionalized SiNPs (COOH-SiNPs). As revealed by the fluorescence lifetime images, COOH-SiNPs possesses several fluorophores mainly composed of above Si–Si binding inside of single particle, which explains the excitation-dependent fluorescence emission behavior of COOH-SiNPs. Also, the presence of oxides mainly composed of Si–O binding and MA on the surface of COOH-SiNPs provides long-term stability for both fluorescence and dispersion. The potential use of COOH-SiNPs as fluorescence bioimaging agents for cellular media has been demonstrated. COOH-SiNPs showed excellent cell viability more than 91% for both MDAMB and MDCK cells even in 1,000 ppm concentration, and multicolor fluorescence imaging (blue, green, and red) of MDAMB cells was successfully accomplished with different excitation wavelengths. 相似文献
Machine Learning - The COVID-19 global pandemic is a threat not only to the health of millions of individuals, but also to the stability of infrastructure and economies around the world. The... 相似文献
Equations suitable for computing specific interfacial energies of precipitates dissolving by a first order transformation were developed on the basis of the singularities taking place at the critical temperature,Tc, under equilibrium conditions. These equations employ data which can be determined by differential scanning calorimetry. Also the conditions for reaching dynamic equilibrium of particle volume fraction belowTc are analysed in terms of a maximum permissible experimental heating rate. The results obtained for disperse order inCu-Al alloys are in good agreement with those expected from the observed particle features. 相似文献