全文获取类型
收费全文 | 102083篇 |
免费 | 8467篇 |
国内免费 | 6582篇 |
出版年
2023年 | 1055篇 |
2022年 | 1262篇 |
2021年 | 4708篇 |
2020年 | 3206篇 |
2019年 | 4055篇 |
2018年 | 3911篇 |
2017年 | 2787篇 |
2016年 | 4008篇 |
2015年 | 6111篇 |
2014年 | 7136篇 |
2013年 | 7976篇 |
2012年 | 9151篇 |
2011年 | 8433篇 |
2010年 | 5027篇 |
2009年 | 4519篇 |
2008年 | 5445篇 |
2007年 | 4867篇 |
2006年 | 4170篇 |
2005年 | 3480篇 |
2004年 | 2937篇 |
2003年 | 2603篇 |
2002年 | 2212篇 |
2001年 | 2006篇 |
2000年 | 1988篇 |
1999年 | 1827篇 |
1998年 | 1077篇 |
1997年 | 1026篇 |
1996年 | 1007篇 |
1995年 | 946篇 |
1994年 | 887篇 |
1993年 | 673篇 |
1992年 | 1005篇 |
1991年 | 820篇 |
1990年 | 711篇 |
1989年 | 621篇 |
1988年 | 498篇 |
1987年 | 427篇 |
1986年 | 372篇 |
1985年 | 338篇 |
1984年 | 241篇 |
1983年 | 226篇 |
1982年 | 125篇 |
1981年 | 134篇 |
1980年 | 91篇 |
1979年 | 152篇 |
1978年 | 84篇 |
1977年 | 95篇 |
1976年 | 79篇 |
1975年 | 111篇 |
1974年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
105.
106.
M T Hsieh H C Chen P H Hsu T Shibuya 《Proceedings of the National Science Council, Republic of China. Part B, Life sciences》1986,10(1):43-48
Previously, it was found that the ancient Chinese remedy of Suanzaorentang could be a promising anxiolytic drug (Chen and Hsieh, 1985a, Chen and Hsieh, 1985b). To understand the mechanism of the action of Suanzaorentang, the effects of Suanzaorentang on behavior changes and central monoamines and their metabolites were studied in rats. It was found that Suanzaorentang significantly (1) prolonged the period from the onset of clonic to tonic convulsions induced by pentylenetetrazol or picrotoxin, (2) prolonged the sleep duration induced by hexobarbital, (3) reduced locomotor activity, (4) enhanced the hypomotility induced by alpha-MT, (5) reduced the locomotor stimulation produced by levodopa plus benserazide, and (6) reduced central HVA, VMA, and 5-HIAA, but had no significant effects on central DA, NA, and 5-HT. These facts implied that Suanzaorentang decreased the turnover rate of central monoamines and central catecholaminergic activity. 相似文献
107.
E Gluckman J Lotsberg A Devergie X M Zhao R Melo M Gomez-Morales M C Mazeron Y Pérol 《Revue fran?aise de transfusion et immuno-hématologie》1984,27(3):391-396
In a double-bind controlled study, oral Acyclovir has been compared to a placebo in a series of 39 consecutive patients undergoing bone marrow transplantation. A dose of 200 mg was given every 6 h from day 8 to day 35 after transplantation. Pharmacokinetic studies have shown the good absorption of the drug despite intestinal damage related to chemoradiotherapy or gut graft-versus-host disease (GVHD), there was no sign of toxicity. The protection against herpes simplex virus (HSV) infection was complete in the treated group when compared to the control group even in patients with high anti-HSV antibody titres. The same protection was observed against cytomegalovirus (CMV) infection. The incidence of HSV and CMV was the same in both groups after treatment ended. This study confirms the efficacy of Acyclovir against HSV infection and possibly against CMV infection when it is given prophylactically after bone marrow transplantation. 相似文献
108.
109.
Nucleotide sequence of the mouse ornithine decarboxylase gene. 总被引:6,自引:3,他引:3
110.
Bcl-2 phosphorylation is required for inhibition of oxidative stress-induced lysosomal leak and ensuing apoptosis. 总被引:2,自引:0,他引:2
B-cell leukemia/lymphoma 2 (Bcl-2) blocks oxidant-induced apoptosis at least partly by stabilizing lysosomes. Here we report that phosphorylation of Bcl-2 may be required for these protective effects. J774 cells overexpressing wild-type Bcl-2 resist oxidant-induced lysosomal leak as well as apoptosis, and this protection is amplified by pretreatment with phorbol 12-myristate 13-acetate (which promotes protein kinase C (PKC)-dependent phosphorylation of Bcl-2). In contrast, cells overexpressing the Bcl-2 mutant S70A (which cannot be phosphorylated) are not protected in either circumstance. Transfection with Bcl-2(S70E), a constitutively active Bcl-2 mutant which does not require phosphorylation, is protective independent of PKC activation. In contrast, C(2)-ceramide, a putative protein phosphatase 2A activator, abolishes the protective effects of wild-type Bcl-2 overexpression but does not diminish protection afforded by Bcl-2(S70E). Additional results suggest that, perhaps as a consequence of lysosomal stabilization, Bcl-2 may prevent activation of phospholipase A2, an event potentially important in the ultimate initiation of apoptosis. 相似文献