全文获取类型
收费全文 | 464篇 |
免费 | 48篇 |
国内免费 | 48篇 |
专业分类
儿科学 | 17篇 |
妇产科学 | 45篇 |
基础医学 | 49篇 |
口腔科学 | 3篇 |
临床医学 | 107篇 |
内科学 | 66篇 |
皮肤病学 | 2篇 |
神经病学 | 40篇 |
特种医学 | 56篇 |
外科学 | 25篇 |
综合类 | 21篇 |
预防医学 | 15篇 |
眼科学 | 5篇 |
药学 | 59篇 |
中国医学 | 1篇 |
肿瘤学 | 49篇 |
出版年
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 10篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 17篇 |
2014年 | 14篇 |
2013年 | 16篇 |
2012年 | 30篇 |
2011年 | 21篇 |
2010年 | 14篇 |
2009年 | 16篇 |
2008年 | 19篇 |
2007年 | 49篇 |
2006年 | 22篇 |
2005年 | 15篇 |
2004年 | 22篇 |
2003年 | 11篇 |
2002年 | 19篇 |
2001年 | 14篇 |
2000年 | 20篇 |
1999年 | 19篇 |
1998年 | 11篇 |
1997年 | 11篇 |
1996年 | 17篇 |
1995年 | 9篇 |
1994年 | 10篇 |
1993年 | 20篇 |
1992年 | 12篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 12篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1961年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有560条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
15.
Dimer formation drives the activation of the cell death protease
caspase 9 总被引:26,自引:0,他引:26 下载免费PDF全文
Martin Renatus Henning R. Stennicke Fiona L. Scott Robert C. Liddington Guy S. Salvesen 《Proceedings of the National Academy of Sciences of the United States of America》2001,98(25):14250-14255
A critical step in the induction of apoptosis is the activation of the apoptotic initiator caspase 9. We show that at its normal physiological concentration, caspase 9 is primarily an inactive monomer (zymogen), and that activity is associated with a dimeric species. At the high concentrations used for crystal formation, caspase 9 is dimeric, and the structure reveals two very different active-site conformations within each dimer. One site closely resembles the catalytically competent sites of other caspases, whereas in the second, expulsion of the "activation loop" disrupts the catalytic machinery. We propose that the inactive domain resembles monomeric caspase 9. Activation is induced by dimerization, with interactions at the dimer interface promoting reorientation of the activation loop. These observations support a model in which recruitment by Apaf-1 creates high local concentrations of caspase 9 to provide a pathway for dimer-induced activation. 相似文献
16.
包膜活性炭吸附血液灌流清除人血浆中毒鼠强的实验 总被引:1,自引:0,他引:1
目的:观察包膜活性炭对血浆中毒鼠强的清除率及吸附规律。方法:实验于2004-05/2006-04在军事医学科学院毒物药物研究所国家重点实验室完成。采用包膜活性炭灌流器对毒鼠强血浆样进行血液灌流吸附,在灌流的1,2,3h分别取样,经乙酸乙酯萃取后,用气相色谱氮磷检测器法(GC/NPD)测定其含量并计算清除率。结果:活性炭对毒鼠强的吸附作用在血液灌流1h最高,灌流2h后毒鼠强质量浓度无明显变化。400,200μg/L毒鼠强血液灌流1h清除率分别为(57.83±1.85)%,(48.18±1.81)%。结论:用包膜活性炭吸附剂进行血浆的灌流吸附,能清除大部分毒物,迅速降低血浆中毒鼠强的质量浓度。 相似文献
17.
HB Jatsa ET Ngo Sock LA Tchuem Tchuente P Kamtchouing 《African journal of traditional, complementary, and alternative medicines》2009,6(3):216-221
Clerodendrum umbellatum Poir (Verbenaceae) is traditionally used in Cameroon for the treatment of many diseases including intestinal helminthiasis. This study was undertaken to assess the in vivo antischistosomal activity of its leaves aqueous extract on a Schistosoma mansoni mice model and to determine the most effective dose of this extract. Mice showing a patent infection of S. mansoni were daily treated with C. umbellatum leaves aqueous extract at the doses of 40, 80 or 160 mg/kg body weight for 14 days. Seven days after administration of the extract, schistosomicidal activity was evaluated on the liver and spleen weights, faecal eggs releasing, liver egg count and worm burden. Treatment using C. umbellatum leaves aqueous extract resulted in an important reduction in faecal egg output by 75.49 % and 85.14 % for 80 mg/kg and 160 mg/kg of the extract respectively. These reduction rates did not differ significantly from the 100 % obtained in the group of infected mice treated with 100 mg/kg of praziquantel. C. umbellatum leaves aqueous extract was lethal to S. mansoni worm. A 100 % reduction rate was recorded in the group of infected mice treated with 160 mg/kg of the extract, as well as in praziquantel-treated mice. An amelioration of the hepatosplenomegaly was noticed in both the extract-treated mice and the praziquantel-treated mice. From these results, we can conclude that C. umbellatum leaves aqueous extract demonstrated schistosomicidal properties in S. mansoni model at doses of at least 80 mg/kg body weight. 相似文献
18.
Over the past decade, the unfortunate reality is that the income gap has widened between Canadian families. Educational outcomes are one of the key areas influenced by family incomes. Children from low-income families often start school already behind their peers who come from more affluent families, as shown in measures of school readiness. The incidence, depth, duration and timing of poverty all influence a child’s educational attainment, along with community characteristics and social networks. However, both Canadian and international interventions have shown that the effects of poverty can be reduced using sustainable interventions. Paediatricians and family doctors have many opportunities to influence readiness for school and educational success in primary care settings. 相似文献
19.
Comparative Analysis of Apoptosis and Inflammation Genes of Mice and Humans 总被引:4,自引:0,他引:4 下载免费PDF全文
John C. Reed Kutbuddin Doctor Ana Rojas Juan M. Zapata Christian Stehlik Loredana Fiorentino Jason Damiano Wilfried Roth Shu-ichi Matsuzawa Ruchi Newman Shinichi Takayama Hiroyuki Marusawa Famming Xu Guy Salvesen RIKEN GER Group GSL Members Adam Godzik 《Genome research》2003,13(6B):1376-1388
Apoptosis (programmed cell death) plays important roles in many facets of normal mammalian physiology. Host-pathogen interactions have provided evolutionary pressure for apoptosis as a defense mechanism against viruses and microbes, sometimes linking apoptosis mechanisms with inflammatory responses through NFκB induction. Proteins involved in apoptosis and NFκB induction commonly contain evolutionarily conserved domains that can serve as signatures for identification by bioinformatics methods. Using a combination of public (NCBI) and private (RIKEN) databases, we compared the repertoire of apoptosis and NFκB-inducing genes in humans and mice from cDNA/EST/genomic data, focusing on the following domain families: (1) Caspase proteases; (2) Caspase recruitment domains (CARD); (3) Death Domains (DD); (4) Death Effector Domains (DED); (5) BIR domains of Inhibitor of Apoptosis Proteins (IAPs); (6) Bcl-2 homology (BH) domains of Bcl-2 family proteins; (7) Tumor Necrosis Factor (TNF)-family ligands; (8) TNF receptors (TNFR); (9) TIR domains; (10) PAAD (PYRIN; PYD, DAPIN); (11) nucleotide-binding NACHT domains; (12) TRAFs; (13) Hsp70-binding BAG domains; (14) endonuclease-associated CIDE domains; and (15) miscellaneous additional proteins. After excluding redundancy due to alternative splice forms, sequencing errors, and other considerations, we identified cDNAs derived from a total of 227 human genes among these domain families. Orthologous murine genes were found for 219 (96%); in addition, several unique murine genes were found, which appear not to have human orthologs. This mismatch may be due to the still fragmentary information about the mouse genome or genuine differences between mouse and human repertoires of apoptotic genes. With this caveat, we discuss similarities and differences in human and murine genes from these domain families. 相似文献
20.
Cysteine proteases are widespread in nature. Their implication in numerous vital processes and pathologies make them highly attractive targets for drug design. The proper functioning and regulation of activity of cysteine proteases is a delicate balance of many factors, one of the most crucial being the protease inhibitors. In this review the basic principles of physiological protease inhibition by protein inhibitors are discussed with the focus on papain-like lysosomal cysteine proteases and the caspases, and their inhibitors. 相似文献