全文获取类型
收费全文 | 24846篇 |
免费 | 52篇 |
国内免费 | 88篇 |
专业分类
系统科学 | 97篇 |
丛书文集 | 259篇 |
教育与普及 | 60篇 |
理论与方法论 | 112篇 |
现状及发展 | 10654篇 |
研究方法 | 1121篇 |
综合类 | 12263篇 |
自然研究 | 420篇 |
出版年
2013年 | 179篇 |
2012年 | 395篇 |
2011年 | 798篇 |
2010年 | 176篇 |
2008年 | 455篇 |
2007年 | 469篇 |
2006年 | 471篇 |
2005年 | 483篇 |
2004年 | 485篇 |
2003年 | 433篇 |
2002年 | 416篇 |
2001年 | 738篇 |
2000年 | 702篇 |
1999年 | 507篇 |
1992年 | 445篇 |
1991年 | 338篇 |
1990年 | 389篇 |
1989年 | 379篇 |
1988年 | 382篇 |
1987年 | 385篇 |
1986年 | 337篇 |
1985年 | 489篇 |
1984年 | 364篇 |
1983年 | 280篇 |
1982年 | 309篇 |
1981年 | 266篇 |
1980年 | 323篇 |
1979年 | 746篇 |
1978年 | 559篇 |
1977年 | 559篇 |
1976年 | 502篇 |
1975年 | 572篇 |
1974年 | 644篇 |
1973年 | 626篇 |
1972年 | 680篇 |
1971年 | 718篇 |
1970年 | 910篇 |
1969年 | 772篇 |
1968年 | 784篇 |
1967年 | 740篇 |
1966年 | 660篇 |
1965年 | 460篇 |
1964年 | 128篇 |
1959年 | 264篇 |
1958年 | 481篇 |
1957年 | 318篇 |
1956年 | 293篇 |
1955年 | 245篇 |
1954年 | 258篇 |
1948年 | 214篇 |
排序方式: 共有10000条查询结果,搜索用时 812 毫秒
101.
Mutations in the gene encoding the basal body protein RPGRIP1L, a nephrocystin-4 interactor, cause Joubert syndrome 总被引:7,自引:0,他引:7
Arts HH Doherty D van Beersum SE Parisi MA Letteboer SJ Gorden NT Peters TA Märker T Voesenek K Kartono A Ozyurek H Farin FM Kroes HY Wolfrum U Brunner HG Cremers FP Glass IA Knoers NV Roepman R 《Nature genetics》2007,39(7):882-888
Protein-protein interaction analyses have uncovered a ciliary and basal body protein network that, when disrupted, can result in nephronophthisis (NPHP), Leber congenital amaurosis, Senior-L?ken syndrome (SLSN) or Joubert syndrome (JBTS). However, details of the molecular mechanisms underlying these disorders remain poorly understood. RPGRIP1-like protein (RPGRIP1L) is a homolog of RPGRIP1 (RPGR-interacting protein 1), a ciliary protein defective in Leber congenital amaurosis. We show that RPGRIP1L interacts with nephrocystin-4 and that mutations in the gene encoding nephrocystin-4 (NPHP4) that are known to cause SLSN disrupt this interaction. RPGRIP1L is ubiquitously expressed, and its protein product localizes to basal bodies. Therefore, we analyzed RPGRIP1L as a candidate gene for JBTS and identified loss-of-function mutations in three families with typical JBTS, including the characteristic mid-hindbrain malformation. This work identifies RPGRIP1L as a gene responsible for JBTS and establishes a central role for cilia and basal bodies in the pathophysiology of this disorder. 相似文献
102.
Loss of GLIS2 causes nephronophthisis in humans and mice by increased apoptosis and fibrosis 总被引:4,自引:0,他引:4
103.
E. Schraufstätter 《Cellular and molecular life sciences : CMLS》1948,4(12):484-486
Summary Chalcone, flavanone, flavone, and its derivatives had a certain bacteriostatic effect onSt. aureus. Flavonol has no activity and morin, a derivative of flavonol, showed only a weak inhibition of the bacterial growth.Cystein did not have any antagonistic effect.Extracts of drugs, which contain natural flavanones, flavones, isoflavones and flavonols, are more or less bacteriostatic. 相似文献
104.
105.
106.
107.
108.
The venoms of predatory cone snails harbor a rich repertoire of peptide toxins that are valuable research tools, but recently
have also proven to be useful drugs. Among the conotoxins with several disulfide bridges, the O-superfamily toxins are characterized
by a conserved cysteine knot pattern: C-C-CC-C-C. While ω-conotoxins and κ-conotoxins block Ca2+ and K+ channels, respectively, the closely related δ- and μO-conotoxins affect voltage-gated Na+ channels (Nav channels). δ-conotoxins mainly remove the fast inactivation of Nav channels and, thus, functionally resemble long-chain scorpion α-toxins. μO-conotoxins are functionally similar to μ-conotoxins,
since they inhibit the ion flow through Nav channels. Recent results from functional and structural assays have gained insight into the underlying molecular mechanisms.
Both types of toxins are voltage-sensor toxins interfering with the voltage-sensor elements of Nav channels.
Received 27 December 2006; received after revision 30 January 2007; accepted 19 February 2007 相似文献
109.
110.