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Co-localization of molecules involved in antigen processing and presentation in an early endocytic compartment 总被引:21,自引:0,他引:21
L E Guagliardi B Koppelman J S Blum M S Marks P Cresswell F M Brodsky 《Nature》1990,343(6254):133-139
The pathways of intracellular traffic involved in antigen processing and presentation have been defined by immunoelectron microscopy. The export pathway for class II histocompatibility molecules and the antigen import pathway meet in a peripheral endocytic compartment having all the molecular machinery believed to be required for antigen processing and presentation, including internalized surface immunoglobulins, proteolytic enzymes and invariant chains. This compartment defines a site where peptides from endocytosed antigen can bind class II molecules en route to the cell surface for presentation to T cells. 相似文献
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<正>世上有两种企业家,你需要知道你属于哪一种。根据我26年的从商经历,我意识到开办公司的有两种人:喜欢冒险的人和不喜欢冒险的人。无论你属于哪一种,如果你想创立自己的商业王国,必然要面对很大的挑战。第一种企业家最好控制自己,不要屡屡涉险,否则很有可能因决策失误而使公司陷入困境。第二种企业家必须明白,如果毫不冒险也很难有所建树。问题的关键在于:你能承担多少风险和你为了达到目的应该承担多少风险? 相似文献
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浅部开采条件下地表残余变形分析是岩层移动领域的一个棘手问题.通过老采空区影响下地表残余变形和地基承载能力变化对地面新建建筑物的影响分析,提出了老采区上方新建建筑物地基稳定性计算公式、岩层移动参数、评价方法.应用鹤岗市和谐花园小区建筑物实例进行了验证. 相似文献
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研究循环码周期分布的反问题,即对于给定的正整数n和非负整数序列,是否存在Fq上的某个〔n,k〕-循环码,使得其周期分布恰好为(A1,A2,...An)。 相似文献
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The effect of Ru on microstructure stability and stress rupture properties of a Ni3Al single-crystal alloy was investigated. The experimental results showed that the addition of 2% Ru (mass fraction) improved the microstructure stability due to the res traint of harmful Y-NiMo phase formation during the thermal exposure at the high temperature above 1 000 °C. And the reason may be that the addition of Ru increased the degree of Mo supersaturation in both γ and γ′ phases, and hence suppressed the precipitation of Y-NiMo phase. The results of stress rupture tests under the testing condition of 1 100 °C, 120 MPa showed that the addition of 2% Ru in the alloy improved the stress rupture lives significantly for ther mal exposed samples. The improvement of the stress rupture properties may be attributed to the restraint of Y-NiMo phase precipitation and growth by the addition of the proper amount Ru. 相似文献
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West AP Brodsky IE Rahner C Woo DK Erdjument-Bromage H Tempst P Walsh MC Choi Y Shadel GS Ghosh S 《Nature》2011,472(7344):476-480
Reactive oxygen species (ROS) are essential components of the innate immune response against intracellular bacteria and it is thought that professional phagocytes generate ROS primarily via the phagosomal NADPH oxidase machinery. However, recent studies have suggested that mitochondrial ROS (mROS) also contribute to mouse macrophage bactericidal activity, although the mechanisms linking innate immune signalling to mitochondria for mROS generation remain unclear. Here we demonstrate that engagement of a subset of Toll-like receptors (TLR1, TLR2 and TLR4) results in the recruitment of mitochondria to macrophage phagosomes and augments mROS production. This response involves translocation of a TLR signalling adaptor, tumour necrosis factor receptor-associated factor 6 (TRAF6), to mitochondria, where it engages the protein ECSIT (evolutionarily conserved signalling intermediate in Toll pathways), which is implicated in mitochondrial respiratory chain assembly. Interaction with TRAF6 leads to ECSIT ubiquitination and enrichment at the mitochondrial periphery, resulting in increased mitochondrial and cellular ROS generation. ECSIT- and TRAF6-depleted macrophages have decreased levels of TLR-induced ROS and are significantly impaired in their ability to kill intracellular bacteria. Additionally, reducing macrophage mROS levels by expressing catalase in mitochondria results in defective bacterial killing, confirming the role of mROS in bactericidal activity. These results reveal a novel pathway linking innate immune signalling to mitochondria, implicate mROS as an important component of antibacterial responses and further establish mitochondria as hubs for innate immune signalling. 相似文献
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In this paper we present results of a simulation study to assess and compare the accuracy of forecasting techniques for long‐memory processes in small sample sizes. We analyse differences between adaptive ARMA(1,1) L‐step forecasts, where the parameters are estimated by minimizing the sum of squares of L‐step forecast errors, and forecasts obtained by using long‐memory models. We compare widths of the forecast intervals for both methods, and discuss some computational issues associated with the ARMA(1,1) method. Our results illustrate the importance and usefulness of long‐memory models for multi‐step forecasting. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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