993 resultados para 21-209


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Special thanks to Christopher Blair and Mumtaz Baig for their suggestions. This work was supported by National Basic Research Program of China (973 Program, 2007CB411600), National Natural Science Foundation of China (30621092), and Bureau of Science and Technology of Yunnan Province.

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The workshop agenda included: presentations from collaborative institutions, national governments and resource persons; a draft scoping study on nutrient loading; and an ecosystem approach to pollution management was tested.

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《胞内共生与细胞研究》( 《Endocytobiosis and Cell Research》)是由国际胞内共生学会(International Society of Endocytobiology, ISE)主办的期刊, 它主要发表有关内共生物(endosy mbioses)和真核细胞的起源、发展、分化、进化和系统发育的研究论文. 在胞内共生和真核细胞的起源进化研究领域享有声誉. 去年该杂志发表了我国学者李靖炎先生的长篇论著“The primitive nucleus model and the origin of the cell nucleus(原始细胞核的模型与细胞核的起源)”(见1999, 13(1-3):1-86). 国外一家 SCI 收录的专业性刊物为中国学者发表一篇长达86页的 Review, 实不多见, 是我国学者在此领域的殊荣。

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An immersed finite element method is presented to compute flows with complex moving boundaries on a fixed Cartesian grid. The viscous, incompressible fluid flow equations are discretized with b-spline basis functions. The two-scale relation for b-splines is used to implement an elegant and efficient technique to satisfy the LBB condition. On non-grid-aligned fluid domains and at moving boundaries, the boundary conditions are enforced with a consistent penalty method as originally proposed by Nitsche. In addition, a special extrapolation technique is employed to prevent the loss of numerical stability in presence of arbitrarily small cut-cells. The versatility and accuracy of the proposed approach is demonstrated by means of convergence studies and comparisons with previous experimental and computational investigations.

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报道了采自云南片马的鼠兔属1新种,以其体色在鼠兔属中最为深黑为其主要特征而命名为片马黑鼠兔Ochotona nigritia sp. nov.。正模标本保存在中国科学院昆明动物研究所,副模标本保存在云南省流行病防治研究所。

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<正> 世界鲸类动物的人工饲养已经有100多年的历史,鲸类动物的人工饲养不但为人们提供了一种非常有趣的娱乐项目,而且为深入研究、繁殖和保护鲸类动物提供了很好的条件。我国鲸类动物的人工饲养于1965年由青岛海产博物馆从饲养江豚开始

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The behavior of trapped electrons, in a dielectric close to the channel of a silicon SOI-FET, is studied by cryogenic microwave spectroscopy. On-resonance microwave excitation causes one of these trapped electrons to undergo spatial Rabi oscillations between widely separated trap sites. This charge displacement causes a change in the drain current of the transistor, resulting in high quality factor resonances in continuous wave spectroscopy. The potential of this effect for non-classical information processing is investigated through polychromatic single-shot spectroscopy, using on-resonance and difference frequencies. Interaction between different trapped electrons is seen in the post excitation behavior and the possibilities of quantum gate operations are discussed. © The Electrochemical Society.

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Polybrominated diphenyl ethers (PBDEs) are an important class of halogenated organic brominated flame retardants. Because of their presence in abiotic and biotic environments widely and their structural similarity to polychlorinated biphenyls (PCBs), concern has been raised on their possible adverse health effects to humans. This study was designed to determine the anti-proliferative, apoptotic properties of decabrominated diphenyl ether (PBDE-209), using a human hepatoma Hep G2 line as a model system. Hep G2 cells were cultured in the presence of PBDE-209 at various concentrations (1.0-100.0 mu mol/L) for 72 h and the percentage of cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The results showed that PBDE-209 inhibited the cells viability in time and concentration-dependent characteristics at concentrations (10.0-100.0 mu mol/L). We found that anti-proliferative effect of PBDE-209 was associated with apoptosis on Hep G2 cells by determinations of morphological changes, cell cycle and apoptosis. Mechanism study showed that PBDE-209 could increase the generation of intracellular reactive oxygen species (ROS) concentration-dependently. Antioxidant N-acetylcyteine partially inhibited the increase of ROS. The mechanism for its hepatoma-inhibitory effects was the induction of cellular apoptosis through ROS generation. In addition, activity of lactate dehydrogenase (LDH) release increased when the cells incubated with PBDE-209 at various concentrations and times. These results suggested that PBDE-209 had the toxicity activity of anti-proliferation and induction of apoptosis in tumor cells in vitro. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

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简要介绍了欧洲 NESSIE( new European schemes for signatures,integrity,and encryption)大计划最近公布的 17个分组密码算法的基本设计思想、最新分析结果及其有效性 .