全文获取类型
收费全文 | 133246篇 |
免费 | 6260篇 |
国内免费 | 255篇 |
专业分类
139761篇 |
出版年
2018年 | 1766篇 |
2017年 | 1891篇 |
2016年 | 3836篇 |
2015年 | 7325篇 |
2014年 | 7121篇 |
2013年 | 7227篇 |
2012年 | 6761篇 |
2011年 | 4006篇 |
2010年 | 3393篇 |
2009年 | 3174篇 |
2008年 | 2324篇 |
2007年 | 2193篇 |
2006年 | 2194篇 |
2005年 | 7999篇 |
2004年 | 6610篇 |
2003年 | 4745篇 |
2002年 | 2269篇 |
2001年 | 3952篇 |
2000年 | 2895篇 |
1999年 | 3305篇 |
1998年 | 992篇 |
1997年 | 727篇 |
1992年 | 3182篇 |
1991年 | 3130篇 |
1990年 | 3119篇 |
1989年 | 2999篇 |
1988年 | 2848篇 |
1987年 | 2680篇 |
1986年 | 2366篇 |
1985年 | 2420篇 |
1984年 | 1640篇 |
1983年 | 1325篇 |
1982年 | 827篇 |
1981年 | 749篇 |
1980年 | 647篇 |
1979年 | 1662篇 |
1978年 | 1191篇 |
1977年 | 1014篇 |
1976年 | 981篇 |
1975年 | 1349篇 |
1974年 | 1550篇 |
1973年 | 1528篇 |
1972年 | 1486篇 |
1971年 | 1443篇 |
1970年 | 1313篇 |
1969年 | 1328篇 |
1968年 | 1144篇 |
1967年 | 1095篇 |
1966年 | 985篇 |
1965年 | 695篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
L V Gankovskaia A Z Tskhovrebova N A Gvozdeva L V Koval'chuk A N Cheredeev 《Biulleten' eksperimental'no? biologii i meditsiny》1986,102(8):210-213
Fractions containing macrophage migration inhibition factor (MIF) and leucocyte migration inhibition factor (LIF) were obtained using Sephadex G-200 filtration from supernatant fluids of human lymphocyte cultures stimulated by PHA. The fractions were tested for the ability to affect migration and phagocytic activity of target cells. Peripheral blood leucocyte migration capacity was inhibited by the fraction with the molecular mass of 60,000-70,000 D (LIF), while migration activity of mouse peritoneal exudate cells was suppressed by the fraction with the molecular mass of 20,000-30,000 D (MIF). MIF- and LIF-containing fractions increased almost three-fold Fc-receptor-mediated phagocytic activity of neutrophils. 相似文献
122.
123.
124.
125.
The cytotoxic and radiosensitizing effects of hyperthermia was shown on Ehrlich ascites tumor cells heated in vitro. The effect of hyperthermia resulted in the formation of local lesions in membranes of dying cells. 相似文献
126.
H Zitzer H H H?nck D B?chner D Richter H J Kreienkamp 《The Journal of biological chemistry》1999,274(46):32997-33001
By using the yeast two-hybrid system we identified a novel protein from the human brain interacting with the C terminus of somatostatin receptor subtype 2. This protein termed somatostatin receptor interacting protein is characterized by a novel domain structure, consisting of six N-terminal ankyrin repeats followed by SH3 and PDZ domains, several proline-rich regions, and a C-terminal sterile alpha motif. It consists of 2185 amino acid residues encoded by a 9-kilobase pair mRNA; several splice variants have been detected in human and rat cDNA libraries. Sequence comparison suggests that the novel multidomain protein, together with cortactin-binding protein, forms a family of cytoskeletal anchoring proteins. Fractionation of rat brain membranes indicated that somatostatin receptor interacting protein is enriched in the postsynaptic density fraction. The interaction of somatostatin receptor subtype 2 with its interacting protein was verified by overlay assays and coimmunoprecipitation experiments from transfected human embryonic kidney cells. Somatostatin receptor subtype 2 and the interacting protein display a striking overlap of their expression patterns in the rat brain. Interestingly, in the hippocampus the mRNA for somatostatin receptor interacting protein was not confined to the cell bodies but was also observed in the molecular layer, suggesting a dendritic localization of this mRNA. 相似文献
127.
V T Kondakov A B Okulov M A Filippkin R Z Tandilava I U Artamonov O A Voronenko A N Sazonov 《Vestnik rentgenologii i radiologii》1991,(4):31-35
The paper is concerned with analysis of the results of intraoperative phlebotesticulography, performed in 50 patients with varicocele of degree I-II during Ivanissevich's operation. The effect of surgical intervention was shown to depend upon the quality of ligation of the testicular vein, some parts of which are anastomosed between themselves. The localization of this anastomosis is revealed by means of intraoperative phlebotesticulography, which permits increasing the results of surgical treatment and predicting a course of a postoperative period. 相似文献
128.
129.
C K?nig Y L Yan J Postlethwait S Wendler J A Campos-Ortega 《Mechanisms of development》1999,86(1-2):17-28
We describe the characterization of the zebrafish homologue of the human gene DLG3. The zebrafish dlg3 gene encodes a membrane-associated guanylate kinase containing a single PDZ domain. This gene was cloned using a gene-trap construct inserted in the gene's first intron. The insertion co-segregates with a viable mutation called humpback (hmp), which leads to formation of ankylotic vertebrae in adult fishes. Insertion and mutation have both been mapped to chromosome 12, in a segment which is syntenic with region p12 to q12 of human chromosome 17. The hmp mutant phenotype, however, appears to be due to two point mutations in the guanylate kinase domain rather than to the transgene insertion itself. The results of this study are discussed in the light of the possible function of the guanylate kinase domain. 相似文献
130.