全文获取类型
收费全文 | 139篇 |
免费 | 0篇 |
国内免费 | 2篇 |
专业分类
系统科学 | 1篇 |
理论与方法论 | 1篇 |
现状及发展 | 55篇 |
研究方法 | 15篇 |
综合类 | 63篇 |
自然研究 | 6篇 |
出版年
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2014年 | 1篇 |
2012年 | 8篇 |
2011年 | 12篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 2篇 |
2007年 | 9篇 |
2006年 | 5篇 |
2005年 | 14篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 8篇 |
1974年 | 2篇 |
1972年 | 8篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1961年 | 3篇 |
1959年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有141条查询结果,搜索用时 31 毫秒
101.
Vogt G Chapgier A Yang K Chuzhanova N Feinberg J Fieschi C Boisson-Dupuis S Alcais A Filipe-Santos O Bustamante J de Beaucoudrey L Al-Mohsen I Al-Hajjar S Al-Ghonaium A Adimi P Mirsaeidi M Khalilzadeh S Rosenzweig S de la Calle Martin O Bauer TR Puck JM Ochs HD Furthner D Engelhorn C Belohradsky B Mansouri D Holland SM Schreiber RD Abel L Cooper DN Soudais C Casanova JL 《Nature genetics》2005,37(7):692-700
Mutations involving gains of glycosylation have been considered rare, and the pathogenic role of the new carbohydrate chains has never been formally established. We identified three children with mendelian susceptibility to mycobacterial disease who were homozygous with respect to a missense mutation in IFNGR2 creating a new N-glycosylation site in the IFNgammaR2 chain. The resulting additional carbohydrate moiety was both necessary and sufficient to abolish the cellular response to IFNgamma. We then searched the Human Gene Mutation Database for potential gain-of-N-glycosylation missense mutations; of 10,047 mutations in 577 genes encoding proteins trafficked through the secretory pathway, we identified 142 candidate mutations ( approximately 1.4%) in 77 genes ( approximately 13.3%). Six mutant proteins bore new N-linked carbohydrate moieties. Thus, an unexpectedly high proportion of mutations that cause human genetic disease might lead to the creation of new N-glycosylation sites. Their pathogenic effects may be a direct consequence of the addition of N-linked carbohydrate. 相似文献
102.
103.
Dual regulation of voltage-gated calcium channels by PtdIns(4,5)P2 总被引:15,自引:0,他引:15
Voltage-gated calcium channels (VGCCs) conduct calcium into cells after membrane depolarization and are vital for diverse biological events. They are regulated by various signalling pathways, which has profound functional consequences. The activity of VGCCs decreases with time in whole-cell and inside-out patch-clamp recordings. This rundown reflects persistent intrinsic modulation of VGCCs in intact cells. Although several mechanisms have been reported to contribute to rundown of L-type channels, the mechanism of rundown of other types of VGCC is poorly understood. Here we show that phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2), an essential regulator of ion channels and transporters, is crucial for maintaining the activity of P/Q- and N-type channels. Activation of membrane receptors that stimulate hydrolysis of PtdIns(4,5)P2 causes channel inhibition in oocytes and neurons. PtdIns(4,5)P2 also inhibits P/Q-type channels by altering the voltage dependence of channel activation and making the channels more difficult to open. This inhibition is alleviated by phosphorylation by protein kinase A. The dual actions of PtdIns(4,5)P2 and the crosstalk between PtdIns(4,5)P2 and protein kinase A set up a dynamic mechanism through which the activity of VGCCs can be finely tuned by various neurotransmitters, hormones and trophic factors. 相似文献
104.
Adenohypophyseal degradation of thyrotropin releasing hormone regulated by thyroid hormones 总被引:1,自引:0,他引:1
Thyrotropin Releasing Hormone (TRH; pyroGlu-His-Pro-NH2) is important in the regulation of adenohypophyseal hormone secretion and also serves neurotropic functions in extra-hypothalamic brain areas, indicating that it is involved in neurotransmission and other forms of cellular communication. This hypothesis is strengthened by the observation that TRH is hydrolysed at the pyroGlu-His bond by a particulate enzyme located in the synaptosomal and adenohypophyseal plasma membrane. Furthermore, this enzyme has been identified as a heterogeneously distributed ectoenzyme which has a high degree of substrate specificity like the TRH-degrading serum enzyme studied previously. In the rat, the activity of the TRH-degrading serum enzyme has been shown to be influenced by the thyroid status of the animals; here I report that the activity of the membrane-bound TRH-degrading enzyme of the anterior pituitary is stringently controlled by thyroid hormones, but that the activity of the brain enzyme is not. 相似文献
105.
Zusammenfassung Mit Hilfe der Saccharosetrennwand-Methode wird nachgewiesen, dass Papaverin antinikotinisch an der glatten Muskulatur (Taenia coli) des Meerschweinchens wirkt. 相似文献
106.
107.
4',6-Dichloroflavan (BW683C), a new anti-rhinovirus compound 总被引:10,自引:0,他引:10
108.
Zusammenfassung Solcoseryl® ruft bei Mäusen 1 h vor Bestrahlung mit letalen Dosen von -Strahlen, i.p. oder p.o. appliziert, ein fast durchwegs 100%iges Überleben im Zeitraum von 30 Tagen hervor. 相似文献
109.
Cruikshank DP Dalton JB Dalle Ore CM Bauer J Stephan K Filacchione G Hendrix AR Hansen CJ Coradini A Cerroni P Tosi F Capaccioni F Jaumann R Buratti BJ Clark RN Brown RH Nelson RM McCord TB Baines KH Nicholson PD Sotin C Meyer AW Bellucci G Combes M Bibring JP Langevin Y Sicardy B Matson DL Formisano V Drossart P Mennella V 《Nature》2007,448(7149):54-56
Hyperion, Saturn's eighth largest icy satellite, is a body of irregular shape in a state of chaotic rotation. The surface is segregated into two distinct units. A spatially dominant high-albedo unit having the strong signature of H2O ice contrasts with a unit that is about a factor of four lower in albedo and is found mostly in the bottoms of cup-like craters. Here we report observations of Hyperion's surface in the ultraviolet and near-infrared spectral regions with two optical remote sensing instruments on the Cassini spacecraft at closest approach during a fly-by on 25-26 September 2005. The close fly-by afforded us the opportunity to obtain separate reflectance spectra of the high- and low-albedo surface components. The low-albedo material has spectral similarities and compositional signatures that link it with the surface of Phoebe and a hemisphere-wide superficial coating on Iapetus. 相似文献
110.