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101.
We report on a patient whose sputum contained both Mycobacterium tuberculosis and Mycobacterium avium complex (MAC). The MAC failed to be detected by the PCR-based AMPLICOR test. The unrecognized coexistence of MAC in the sample modified the results of drug susceptibility tests. Experiments revealed that the presence of both M. tuberculosis and MAC was not detected by the AMPLICOR test under certain conditions.  相似文献   
102.
Aluminum and boron ion implantations into n-type 6H-SiC epilayers have been systematically investigated. Redistribution of implanted atoms during high-temperature annealing at 1500°C is negligibly small. The critical implant dose for amorphization is estimated to be 1 × 1015 cm−2 for Al+ implantation and 5 × 1015 cm-2 for B+ implantation. By Al+ implantation followed with 1500°C-annealing, p-type layers with a sheet resistance of 22 kΩ/ can be obtained. B+ implantation results in the formation of highly resistive layers, which may be attributed to the deep B acceptor level.  相似文献   
103.
RP105 was originally discovered as a mouse B-cell surface molecule that transmits an activation signal. The signal leads to resistance against irradiation-induced apoptosis and massive B-cell proliferation. Recently, we found that mouse RP105 is associated with another molecule, MD-1. We have isolated here the human MD-1 cDNA. We show that human MD-1 is also associated with human RP105 and has an important role in cell surface expression of RP105. We also describe a monoclonal antibody (MoAb) that recognizes human RP105. Expression of RP105 is restricted to CD19(+) B cells. Histological studies showed that RP105 is expressed mainly on mature B cells in mantle zones. Germinal center cells are either dull or negative. RP105 is thus a novel human B-cell marker that is preferentially expressed on mature B cells. Moreover, the anti-RP105 MoAb activates B cells, leading to increases in cell size, expression of a costimulatory molecule CD80, and DNA synthesis. The B-cell activation pathway using RP105 is conserved in humans.  相似文献   
104.
Porous anodic aluminum oxide (AAO) membranes template the growth of photochromic crystalline nanowires. The resulting organic–inorganic composite can function as a photomechanical bending actuator. In order to investigate how the nanostructural properties of both the organic and inorganic components affect the photomechanical response, the composite mechanical properties are characterized using a variety of methods. There is a significant variation in both morphology and elastic modulus for two commercially available AAO templates with nominally identical pore diameters of 200 nm. After these templates are filled with diarylethene molecules that undergo a ring‐open to ring‐closed photoisomerization, the light‐generated curvature and mechanical work are evaluated using two different methods. The templates with a lower average elastic modulus (16 GPa vs 68 GPa) generate almost an order of magnitude more photomechanical work. The dependence of the photomechanical response on the chemical structure of the photochrome is assessed by comparing the performance of a diarylethene that undergoes a crystal expansion to that of one that undergoes a contraction, which leads to a decrease in curvature. Both the inorganic template and the organic active component play important roles in the overall photomechanical response, with substantial room to improve the performance.  相似文献   
105.
Veal calves reared by the Animal Physiology and Genetics Institute, USDA, on milk supplemented with tocopherol then on a diet containing encapsulated safflower oil demonstrated increases in the concentrations of linoleic acid (18:2) and tocopherols in their depot fats. The expected decrease in the induction period of oxidation for these fats with 18:2 levels of 7–12.9% was not observed in the fats with increased tocopherol content. The fat of the treated calves was more stable to oxidation than the fat of commercial veal or pork. ARS, USDA.  相似文献   
106.
We investigated limiting factors of carrier lifetimes and their enhancement by post-growth processes in lightly-doped p-type 4H-SiC epitaxial layers (N A ~ 2 × 1014 cm?3). We focused on bulk recombination, surface recombination, and interface recombination at the epilayer/substrate, respectively. The carrier lifetime of 2.8 μs in an as-grown epilayer was improved to 10 μs by the combination of VC-elimination processes and hydrogen annealing. By employing surface passivation with deposited SiO2 followed by POCl3 annealing, a long carrier lifetime of 16 μs was obtained in an oxidized epilayer. By investigating carrier lifetimes in a self-standing p-type epilayer, it was revealed that the interface recombination at the epilayer/substrate was smaller than the surface recombination on a bare surface. We found that the VC-elimination process, hydrogen annealing, and surface passivation are all important for improving carrier lifetimes in lightly-doped p-type epilayers.  相似文献   
107.
108.
Intelligent systems need to understand and respond to human words to enable them to interact with humans in a natural way. Several studies attempted to realize these abilities by investigating the symbol grounding problem. For example, we proposed multilayered multimodal latent Dirichlet allocation (mMLDA) to enable the formation of various concepts and inference using grounded concepts. We previously reported on the issue of connecting words to various hierarchical concepts and also proposed a simple preliminary algorithm for generating sentences. This paper proposes a novel method that enables a sensing system to verbalize an everyday scene it observes. The method uses mMLDA and Bayesian hidden Markov models (BHMM) and the proposed algorithm improves the word inference of our previous work. The advantage of our approach is that grammar learning based on BHMM not only boosts concept selection results but enables our method to process functional words. The proposed verbalization algorithm produces results that are far superior to those of previous methods. Finally, we developed a system to obtain multimodal data from human everyday activities. We evaluate language learning and sentence generation as a complete process under this realistic setting. The results demonstrate the effectiveness of our method.  相似文献   
109.
Preference query processing is important for a wide range of applications involving distributed databases, such as network monitoring, web-based systems, and market analysis. In such applications, data objects are generated frequently and massively, which presents an important and challenging problem of continuous query processing over distributed data stream environments. A top-k dominating query, which has been receiving much research attention recently, returns the k data objects that dominate the highest number of data objects in a given dataset, and due to its dominance-based ranking function, we can easily obtain superior data objects. An emerging requirement in distributed stream environments is an efficient technique for continuously monitoring top-k dominating data objects. Despite of this fact, no study has addressed this problem. In this paper, therefore, we address the problem of continuous top-k dominating query processing over distributed data stream environments. We present two algorithms that monitor the exact top-k dominating data and efficiently eliminate unqualified data objects for the result, which reduces both communication and computation costs. In addition to these algorithms, we present an approximate algorithm that further reduces both communication and computation costs. Extensive experiments on both synthetic and real data have demonstrated the efficiency and scalability of our algorithms.  相似文献   
110.
Al2O3/Y2O3-doped ZrO2 composite powders with 50 mol% Al2O3 are prepared by the hydrazine method. As-prepared powders are mixtures of AlO(OH) gel and amorphous ZrO2 solid solutions containing Y2O3 and Al2O3. The formation process leading to α-Al2O3- t -ZrO2 composite powders is examined. Hot isostatic pressing is performed for 2 h at 1400°C under 196 MPa using θ-Al2O3- t -ZrO2 composite powders. The resulting dense, sintered α-Al2O3- t -ZrO2 composites show excellent mechanical strength.  相似文献   
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