全文获取类型
收费全文 | 291篇 |
免费 | 0篇 |
专业分类
系统科学 | 10篇 |
理论与方法论 | 1篇 |
现状及发展 | 77篇 |
研究方法 | 23篇 |
综合类 | 166篇 |
自然研究 | 14篇 |
出版年
2022年 | 1篇 |
2018年 | 4篇 |
2016年 | 1篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 6篇 |
2011年 | 29篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 11篇 |
2007年 | 12篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 7篇 |
2003年 | 13篇 |
2002年 | 13篇 |
2001年 | 13篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 7篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 10篇 |
1975年 | 7篇 |
1974年 | 5篇 |
1973年 | 6篇 |
1972年 | 3篇 |
1971年 | 9篇 |
1970年 | 9篇 |
1969年 | 2篇 |
1968年 | 5篇 |
1967年 | 6篇 |
1966年 | 6篇 |
1965年 | 3篇 |
1963年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有291条查询结果,搜索用时 15 毫秒
121.
New inhibitor of reagin-mediated anaphylaxis 总被引:4,自引:0,他引:4
B J Broughton P Chaplen P Knowles E Lunt D L Pain K R Wooldridge R Ford S Marshall J L Walker D R Maxwell 《Nature》1974,251(5476):650-652
122.
123.
F. D. Walker 《Cellular and molecular life sciences : CMLS》1975,31(3):308-309
Résumé Les enregistrements électriques non-perturbants des neurones maintenus en culture, ont montré des décharges spontanées prototypes des aires du système nerveux central desquelles les groupes de cellules cultivées avaient été obtenues. Les groupes de neurones dont les enregistrements figurent ci-dessus, ont été extraits du télencéphale, mésencéphale, cervelet, et des tubercules quadrijumeaux de souris nouveau-nées. Seuls les neurones provenant du télencéphale n'ont pas produit de décharge électrique rhythmique.
This work was supported in part by a Grant-in-Aid from Eli Lilly & Co. 相似文献
This work was supported in part by a Grant-in-Aid from Eli Lilly & Co. 相似文献
124.
125.
Hageman factor activation and tight junction disruption in mice challenged with attenuated endotoxin
R. I. Walker M. Porvaznik June E. Egan A. M. Miller 《Cellular and molecular life sciences : CMLS》1979,35(6):759-762
Summary Endotoxin treated with chromium chloride is less toxic to mice than the parent molecule, but can disrupt intestinal permeability barriers and has an enhanced ability to activate Hageman factor.We wish to thank Drs M.W. Brightman and T.S. Reese from the Department of Neurocytology, National Institutes of Health for the use of their Balzers freeze-fracture instrument. 相似文献
126.
N S Levine R E Salisbury E Seifter H L Walker A D Mason B A Pruitt 《Experientia》1975,31(11):1309-1312
High doses of vitamin A decreased the severity of tumor development in mice inoculated with a murine sarcoma virus; the same doses of vitamin A had no effect on the increased tumorigenesis seen in animals severely stressed with thermal injury or the increased tumorigenesis induced by exogenous glucocorticoid administration. 相似文献
127.
Triads in foetal skeletal muscle 总被引:2,自引:0,他引:2
128.
Collins PJ Haire LF Lin YP Liu J Russell RJ Walker PA Skehel JJ Martin SR Hay AJ Gamblin SJ 《Nature》2008,453(7199):1258-1261
The potential impact of pandemic influenza makes effective measures to limit the spread and morbidity of virus infection a public health priority. Antiviral drugs are seen as essential requirements for control of initial influenza outbreaks caused by a new virus, and in pre-pandemic plans there is a heavy reliance on drug stockpiles. The principal target for these drugs is a virus surface glycoprotein, neuraminidase, which facilitates the release of nascent virus and thus the spread of infection. Oseltamivir (Tamiflu) and zanamivir (Relenza) are two currently used neuraminidase inhibitors that were developed using knowledge of the enzyme structure. It has been proposed that the closer such inhibitors resemble the natural substrate, the less likely they are to select drug-resistant mutant viruses that retain viability. However, there have been reports of drug-resistant mutant selection in vitro and from infected humans. We report here the enzymatic properties and crystal structures of neuraminidase mutants from H5N1-infected patients that explain the molecular basis of resistance. Our results show that these mutants are resistant to oseltamivir but still strongly inhibited by zanamivir owing to an altered hydrophobic pocket in the active site of the enzyme required for oseltamivir binding. Together with recent reports of the viability and pathogenesis of H5N1 (ref. 7) and H1N1 (ref. 8) viruses with neuraminidases carrying these mutations, our results indicate that it would be prudent for pandemic stockpiles of oseltamivir to be augmented by additional antiviral drugs, including zanamivir. 相似文献
129.
Beng T. Ho P. M. Gardner S. F. Pong K. E. Walker 《Cellular and molecular life sciences : CMLS》1973,29(5):527-529
Resumen Yoduro de 2, 9-dimetilo-carbolinio (DMCI) y no sus metabolitos inhibió la enzyma monoamino oxidasa y elevó14C-serotonia en el corazón e higado, pero no en el cerebro de ratas.
This work is taken in part from the M. S. thesis presented byP. M. Gardner to the University of Texas Graduate School of Biomedical Sciences at Houston, 1971. 相似文献
This work is taken in part from the M. S. thesis presented byP. M. Gardner to the University of Texas Graduate School of Biomedical Sciences at Houston, 1971. 相似文献
130.
Walker LM Huber M Doores KJ Falkowska E Pejchal R Julien JP Wang SK Ramos A Chan-Hui PY Moyle M Mitcham JL Hammond PW Olsen OA Phung P Fling S Wong CH Phogat S Wrin T Simek MD;Protocol G Principal Investigators Koff WC Wilson IA Burton DR Poignard P 《Nature》2011,477(7365):466-470
Broadly neutralizing antibodies against highly variable viral pathogens are much sought after to treat or protect against global circulating viruses. Here we probed the neutralizing antibody repertoires of four human immunodeficiency virus (HIV)-infected donors with remarkably broad and potent neutralizing responses and rescued 17 new monoclonal antibodies that neutralize broadly across clades. Many of the new monoclonal antibodies are almost tenfold more potent than the recently described PG9, PG16 and VRC01 broadly neutralizing monoclonal antibodies and 100-fold more potent than the original prototype HIV broadly neutralizing monoclonal antibodies. The monoclonal antibodies largely recapitulate the neutralization breadth found in the corresponding donor serum and many recognize novel epitopes on envelope (Env) glycoprotein gp120, illuminating new targets for vaccine design. Analysis of neutralization by the full complement of anti-HIV broadly neutralizing monoclonal antibodies now available reveals that certain combinations of antibodies should offer markedly more favourable coverage of the enormous diversity of global circulating viruses than others and these combinations might be sought in active or passive immunization regimes. Overall, the isolation of multiple HIV broadly neutralizing monoclonal antibodies from several donors that, in aggregate, provide broad coverage at low concentrations is a highly positive indicator for the eventual design of an effective antibody-based HIV vaccine. 相似文献