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101.
采用PFFIFFPS软件计算PF线圈的电动力.结果发现:PF中的最大电动力位于NO.5~6号线圈内;三对外部线圈中的最大电动力位于NO.7~8号线圈内.这将为使用有限元分析系统(COSMOS/M2.0)对PF线圈进行进一步分析和计算作好准备.  相似文献   
102.
The acrosome reaction has long been thought to be induced by the zona pellucida. Here we report the identification and function of a novel human sperm glycosylphosphatidylinositol (GPI)-anchored membrane protein, NYD-SP8. The release of the protein during sperm-egg interaction and its binding to the cumulus, the first layer of egg investment, elicits cross-talk between the gametes and produces calcium dependant release of progesterone, which lead to the acrosome reaction. An in vivo mouse model of NYD-SP8 immunization is also established showing a reduced fertility rate. Thus, contrary to accepted dogma, our study demonstrates for the first time that, prior to reaching the zona pellucida, sperm may release a surface protein that acts on the cumulus cells leading to the acrosome reaction, which may be important for determining the outcome of fertilization. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Received 11 August 2008; received after revision 18 December 2008; accepted 22 December 2008  相似文献   
103.
Tianhuafen is a kind of traditional Chinese medicine for abortion, which has long been used in China. The basic protein trichosanthin (TCS) is responsible for such activity. As a ribosome inactivating protein (RIP), trichosanthin removes A4304 in the 28s rRNA via the N-glycosidase activity and inactivates the ribosome. However, it remains unclear how TCS can enter the cytoplasm. In the experiment, monolayers at air/water interface have been used to study the interaction between TCS and phospholipid membrane. The results show that TCS can penetrate negatively charged phospholipid monolayer under acid condition, and its membrane penetrating ability is obviously pH-dependent. A hypothesis of TCS penetrating biological membrane under acid condition is proposed based on the obtained result.  相似文献   
104.
W Wu  K Wong  J Chen  Z Jiang  S Dupuis  J Y Wu  Y Rao 《Nature》1999,400(6742):331-336
Although cell migration is crucial for neural development, molecular mechanisms guiding neuronal migration have remained unclear. Here we report that the secreted protein Slit repels neuronal precursors migrating from the anterior subventricular zone in the telencephalon to the olfactory bulb. Our results provide a direct demonstration of a molecular cue whose concentration gradient guides the direction of migrating neurons. They also support a common guidance mechanism for axon projection and neuronal migration and suggest that Slit may provide a molecular tool with potential therapeutic applications in controlling and directing cell migration.  相似文献   
105.
极值调节器是DDZ-Ⅲ型或DDZ-Ⅱ型系列仪表的一个新单元,可用于生产过程的静态最佳控制,如燃烧效率控制、蒸发器最佳液位控制,由于本调节器是由模拟线路构成,所以在模拟信号的保持,传送以及梯度方向的判断遇到某些困难,本文介绍这些问题及其解决办法。这台仪表的精度为±0.5%。  相似文献   
106.
Chronic kidney disease (CKD), impairment of kidney function, is a serious public health problem, and the assessment of genetic factors influencing kidney function has substantial clinical relevance. Here, we report a meta-analysis of genome-wide association studies for kidney function-related traits, including 71,149 east Asian individuals from 18 studies in 11 population-, hospital- or family-based cohorts, conducted as part of the Asian Genetic Epidemiology Network (AGEN). Our meta-analysis identified 17 loci newly associated with kidney function-related traits, including the concentrations of blood urea nitrogen, uric acid and serum creatinine and estimated glomerular filtration rate based on serum creatinine levels (eGFRcrea) (P < 5.0 × 10(-8)). We further examined these loci with in silico replication in individuals of European ancestry from the KidneyGen, CKDGen and GUGC consortia, including a combined total of ~110,347 individuals. We identify pleiotropic associations among these loci with kidney function-related traits and risk of CKD. These findings provide new insights into the genetics of kidney function.  相似文献   
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109.
Tenascin-C is an extracellular matrix glycoprotein, whose expression is highly restricted in normal adult tissues, but markedly up-regulated in a range of tumors, and therefore serves as a potential receptor for targeted anticancer drug or gene delivery. We describe here a liposomal carrier system in which the targeting ligand is sulfatide. Experiments with tenascin-C-expressing glioma cells demonstrated that binding of liposomes to the extracellular matrix relied essentially on the sulfatide-tenascin-C interaction. Following binding to the extracellular matrix, the sulfatide-containing liposomes were internalized via both caveolae/lipid raft- and clathrin-dependent pathways, which would ensure direct cytoplasmic release of the cargoes carried in the liposomes. Such natural lipid-guided intracellular delivery targeting at the extracellular matrix glycoproteins of tumor cells thus opens a new direction for development of more effective anticancer chemotherapeutics in future. K. Shao & Q. Hou: These authors contributed equally to this work. Received 22 September 2006; received after revision 5 December 2006; accepted 9 January 2007  相似文献   
110.
TREX1 acts in concert with the SET complex in granzyme A-mediated apoptosis, and mutations in TREX1 cause Aicardi-Goutières syndrome and familial chilblain lupus. Here, we report monoallelic frameshift or missense mutations and one 3' UTR variant of TREX1 present in 9/417 individuals with systemic lupus erythematosus but absent in 1,712 controls (P = 4.1 x 10(-7)). We demonstrate that two mutant TREX1 alleles alter subcellular targeting. Our findings implicate TREX1 in the pathogenesis of SLE.  相似文献   
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