全文获取类型
收费全文 | 55242篇 |
免费 | 4871篇 |
国内免费 | 5984篇 |
专业分类
66097篇 |
出版年
2024年 | 190篇 |
2023年 | 798篇 |
2022年 | 1761篇 |
2021年 | 2805篇 |
2020年 | 2010篇 |
2019年 | 2502篇 |
2018年 | 2363篇 |
2017年 | 1824篇 |
2016年 | 2418篇 |
2015年 | 3613篇 |
2014年 | 4336篇 |
2013年 | 4448篇 |
2012年 | 5394篇 |
2011年 | 4853篇 |
2010年 | 3062篇 |
2009年 | 2853篇 |
2008年 | 3121篇 |
2007年 | 2865篇 |
2006年 | 2458篇 |
2005年 | 2143篇 |
2004年 | 1851篇 |
2003年 | 1584篇 |
2002年 | 1303篇 |
2001年 | 898篇 |
2000年 | 704篇 |
1999年 | 685篇 |
1998年 | 498篇 |
1997年 | 387篇 |
1996年 | 371篇 |
1995年 | 299篇 |
1994年 | 282篇 |
1993年 | 177篇 |
1992年 | 203篇 |
1991年 | 177篇 |
1990年 | 168篇 |
1989年 | 146篇 |
1988年 | 114篇 |
1987年 | 100篇 |
1986年 | 76篇 |
1985年 | 80篇 |
1984年 | 52篇 |
1983年 | 33篇 |
1982年 | 25篇 |
1981年 | 19篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1976年 | 3篇 |
1969年 | 3篇 |
1968年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
R W Butcher R J Ho H C Meng E W Sutherland 《The Journal of biological chemistry》1965,240(11):4515-4523
13.
In the search for candidate genes for the tuberous sclerosis (TSC1) disease locus on chromosome 9q34, we have isolated an overlapping series of 22 plasmid and phage cDNA clones covering nearly 7 kb and with an open reading frame of 5070 bp encoding a protein of 1690 amino acids. The putative protein product is a member of the kinesin superfamily and is homologous to the mouse KIF1A and theCaenorhabditas elegansunc-104 genes. Both KIF1A and unc-104 function in the anterograde axonal transport of synaptic vesicles. The human homolog is therefore termed H-ATSV (axonal transporter of synaptic vesicles, HGMW-approved nomenclature ATSV) Screening of DNA from 107 tuberous sclerosis patients and 80 unaffected individuals with H-ATSV cDNA probes by pulsed-field gel electrophoresis/Southern blotting following digestion by rare-cutting methylation-sensitive restriction enzymes showed variant banding patterns in three patients with tuberous sclerosis. However, further analysis indicated that these variant fragments represent a rare polymorphism probably associated with methylation of clustered restriction sites. There is no evidence to support H-ATSV as a candidate gene for TSC1. 相似文献
14.
15.
本文引用等效模型,对激光消融过程进行了推导与计算,和实验结果比较表明,所得公式与实验结果能较好相符,可用于描述紫外激光消融过程。 相似文献
16.
17.
本文报道在我国广西隆林壮族中发现一个罕見的HbQ复合α,β地中海贫血家系。先证者女,18岁,贫血面容,肝脾肿大。化学结构分析确证本Hb变异体为HbQ Thailand[α74(EF3)Asp→His]。血红蛋白组成以及α和β珠蛋白基因分析结果表明,先证者的珠蛋白基因型为-α~Q/-α~T复合β°/β°(IVSI-1G→T/Codon17A→T);先证者父的基因型为-‘α~Q/-复合β~O/β~A(IVSI-1G→T/β~A);先证母的基因型为-α~T/αα复合β~O/β~A(Codon17A→T/β~A)。 相似文献
18.
19.
20.
Hongkui Jin Renhui Yang Gilbert A. Keller Anne Ryan Annie Ko David Finkle Todd A. Swanson WeiLi Diane Pennica William I. Wood Nicholas F. Paoni 《Cytokine》1996,8(12):920-926
Cardiotrophin-1 (CT-1) is a recently discovered cytokine that was isolated based on its ability to induce cardiac myocyte hypertrophy in vitro. In this study, the effects of chronic administration of CT-1 to mice (0.5 or 2 μg by intraperitoneal injection, twice a day for 14 days) were determined. A dose-dependent increase in both the heart weight and ventricular weight to body ratios was observed in the treated groups. The body weights of the animals were unaffected. These results indicate that CT-1 can induce cardiac hypertrophy in vivo. CT-1 was not specific for the heart, however. It stimulated the growth of the liver, kidney, and spleen, and caused atrophy of the thymus. CT-1 administration also increased the platelet counts by 70%, with no change in mean platelet volume. Red blood cell counts were increased in the treated animals, and there was a concomitant increase in haemoglobin concentration. Thus, CT-1 has a broad spectrum of biological activities in vivo. This observation is consistent with previous in-vitro findings showing that the mRNA for CT-1 is expressed in several tissues, and that CT-1 can function through binding to the leukaemia inhibitory factor (LIF) receptor and signalling through the gp130 pathway. 相似文献