Structural basis for self-association and receptor recognition of human TRAF2

Tumour necrosis factor (TNF)-receptor-associated factors (TRAFs) form a family of cytoplasmic adapter proteins that mediate signal transduction from many members of the TNF-receptor superfamily and the interleukin-1 receptor. They are important in the regulation of cell survival and cell death. The carboxy-terminal region of TRAFs (the TRAF domain) is required for self-association and interaction with receptors. The domain contains a predicted coiled-coil region that is followed by a highly conserved TRAF-C domain. Here we report the crystal structure of the TRAF domain of human TRAF2, both alone and in complex with a peptide from TNF receptor-2 (TNF-R2). The structures reveal a trimeric self-association of the TRAF domain, which we confirm by studies in solution. The TRAF-C domain forms a new, eight-stranded antiparallel beta-sandwich structure. The TNF-R2 peptide binds to a conserved shallow surface depression on one TRAF-C domain and does not contact the other protomers of the trimer. The nature of the interaction indicates that an SXXE motif may be a TRAF2-binding consensus sequence. The trimeric structure of the TRAF domain provides an avidity-based explanation for the dependence of TRAF recruitment on the oligomerization of the receptors by their trimeric extracellular ligands.     

模式识别与计算机视觉手册第三版

本书的第一、二、三版分别于1993、1999和2005年出版。书中全面提供了过去20年中在模式识别与计算机视觉领域中的进展和成就，作者都是这个领域的第一流专家，其中的两位Thomas　Huang和Jake　Aggarwal是权威的K．S．Fu奖金获得者，该项奖金是由国际模式识别协会（IAPR）授予。     

1-(substituted)benzyl-5-aminoimidazole-4-carboxamides are potent orally active inhibitors of Trypanosoma cruzi in mice

1-(Substituted)benzyl-5-aminoimidazole-4-carboxamides are potent orally active inhibitors of Trypanosoma cruzi infections in mice. The most active compounds are the 1-(4-chlorobenzyl)- and 1-(3,4-dichlorobenzyl)-analogs (L-153,094 [2] and L-153,153 [4], resp.) which are approximately 7-fold more potent upon oral administration than nifurtimox (Lampit) in suppressing parasite levels in the blood of mice with acute Trypanosoma cruzi infections.     

测井资料分析系统接口电路设计

从一种超声模拟测井记录的井下信号、深度信号送微机处理的实际要求出发，分析井下信号数据采集的工作原理，阐述了与１２位Ａ／Ｄ转换器实时配套工作的双存储体工作时序。通过对深度信号的解调，提出了一种解决４ＦＳＫ解调的有效方法。     

BP网络的抗干扰性研究及误差分析

从ＢＰ网络对信息存储的分布式特点出发，分析了连接权系数及输入变化对输出的影响，探讨了ＢＰ网络的容错性及抗干扰特性，得出了一些有益的结论。     

Effect of actinomycin D on Trypanosoma cruzi

Viable metacyclic forms of T. cruzi, Y strain, treated with an adequate dose of actinomycin D (50 micrograms Act-D/ml/10(7) parasites/ml for 72 h at 28 degrees C) showed the following properties: 1) they lost their ability to replicate in culture medium, in blood and in tissues of normal mice and were no longer able to incorporate tritiated thymidine; 2) they could not penetrate into Vero cells and could not replicate inside normal macrophages; 3) they retained their immunogenicity and the ability to protect mice against a virulent infection; 4) they did not induce histological lesions as described in chronic experimental Chagas' disease.     

任意波形合成系统硬件设计

提出并分析了任意波形合成系统（ＡＷＳ）──一种高度智能化的计算机仪器的几种典型结构及其特点，着重讨论了ＰＣ总线式任意波形合成系统的系统组成及各部分硬件电路设计的关键技术     

Alopecia induced in young mice by exposure to excess dietary zinc

Summary Second generation mice were exposed to normal (50 ppm, Group I) or excess (2000 ppm, Group II) zinc in the maternal diet during gestation and lactation, then weaned and continued on the mother's diet until sacrifice at 8 weeks. Tibia zinc reflected dietary intake. Group II had reduced plasma copper, body weight, and hematocrit; the second coat of hair appeared late and was lighter in color than Group I, possibly as an effect of copper and pigmentation development and hair growth.     

Caffeine induces a transient inward current in cultured cardiac cells

Electrical excitation of cardiac muscle may sometimes be due to initiation of inward current by the presence of Ca2+ ions at the inner surface of the cell membrane. During digitalis toxicity and other conditions that abnormally augment cellular Ca2+ stores, premature release of Ca2+ from the sarcoplasmic reticulum leads to a transient inward current, which is large enough to initiate premature beats and is accompanied by a transient contractile response. This inward current may be mediated either by electrogenic sodium-calcium exchange or by specific Ca2+-activated cation channels that have recently been characterized in tissue cultures of cardiac myocytes. An obvious question raised by these observations is whether release of the sequestered Ca2+ stores during each normal beat exerts a similar influence on membrane potential. To explore this, chick embryonic myocardial cell aggregates were voltage-clamped during abrupt exposure to caffeine, which is known to release Ca2+ from the sarcoplasmic reticulum. The speed of the perfusion system and the relative absence of diffusion barriers in the tissue-cultured cells allowed the effects of caffeine-induced Ca2+ release to be studied on a time scale comparable to that of a single normal beat. We report here that abrupt exposure of the cells to caffeine produced a transient inward current having similar features to that of digitalis toxicity, and which was both large enough and rapid enough to potentially contribute to the action potential.