全文获取类型
收费全文 | 137篇 |
免费 | 0篇 |
专业分类
系统科学 | 5篇 |
教育与普及 | 1篇 |
理论与方法论 | 2篇 |
现状及发展 | 42篇 |
研究方法 | 26篇 |
综合类 | 58篇 |
自然研究 | 3篇 |
出版年
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2014年 | 5篇 |
2013年 | 3篇 |
2012年 | 14篇 |
2011年 | 13篇 |
2010年 | 9篇 |
2009年 | 1篇 |
2008年 | 11篇 |
2007年 | 6篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2000年 | 1篇 |
1996年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 4篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1966年 | 1篇 |
1960年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有137条查询结果,搜索用时 46 毫秒
31.
Sarin KY Cheung P Gilison D Lee E Tennen RI Wang E Artandi MK Oro AE Artandi SE 《Nature》2005,436(7053):1048-1052
TERT, the protein component of telomerase, serves to maintain telomere function through the de novo addition of telomere repeats to chromosome ends, and is reactivated in 90% of human cancers. In normal tissues, TERT is expressed in stem cells and in progenitor cells, but its role in these compartments is not fully understood. Here we show that conditional transgenic induction of TERT in mouse skin epithelium causes a rapid transition from telogen (the resting phase of the hair follicle cycle) to anagen (the active phase), thereby facilitating robust hair growth. TERT overexpression promotes this developmental transition by causing proliferation of quiescent, multipotent stem cells in the hair follicle bulge region. This new function for TERT does not require the telomerase RNA component, which encodes the template for telomere addition, and therefore operates through a mechanism independent of its activity in synthesizing telomere repeats. These data indicate that, in addition to its established role in extending telomeres, TERT can promote proliferation of resting stem cells through a non-canonical pathway. 相似文献
32.
MYCN haploinsufficiency is associated with reduced brain size and intestinal atresias in Feingold syndrome 总被引:3,自引:0,他引:3
van Bokhoven H Celli J van Reeuwijk J Rinne T Glaudemans B van Beusekom E Rieu P Newbury-Ecob RA Chiang C Brunner HG 《Nature genetics》2005,37(5):465-467
Feingold syndrome is characterized by variable combinations of esophageal and duodenal atresias, microcephaly, learning disability, syndactyly and cardiac defect. We show here that heterozygous mutations in the gene MYCN are present in Feingold syndrome. All mutations are predicted to disrupt both the full-length protein and a new shortened MYCN isoform, suggesting that multiple aspects of early embryogenesis and postnatal brain growth in humans are tightly regulated by MYCN dosage. 相似文献
33.
Regulation of intracellular calcium by a signalling complex of IRAG, IP3 receptor and cGMP kinase Ibeta 总被引:8,自引:0,他引:8
Schlossmann J Ammendola A Ashman K Zong X Huber A Neubauer G Wang GX Allescher HD Korth M Wilm M Hofmann F Ruth P 《Nature》2000,404(6774):197-201
Calcium release from the endoplasmic reticulum controls a number of cellular processes, including proliferation and contraction of smooth muscle and other cells. Calcium release from inositol 1,4,5-trisphosphate (IP3)-sensitive stores is negatively regulated by binding of calmodulin to the IP3 receptor (IP3R) and the NO/cGMP/cGMP kinase I (cGKI) signalling pathway. Activation of cGKI decreases IP3-stimulated elevations in intracellular calcium, induces smooth muscle relaxation and contributes to the antiproliferative and pro-apoptotic effects of NO/cGMP. Here we show that, in microsomal smooth muscle membranes, cGKIbeta phosphorylated the IP3R and cGKIbeta, and a protein of relative molecular mass 125,000 which we now identify as the IP3R-associated cGMP kinase substrate (IRAG). These proteins were co-immunoprecipitated by antibodies directed against cGKI, IP3R or IRAG. IRAG was found in many tissues including aorta, trachea and uterus, and was localized perinuclearly after heterologous expression in COS-7 cells. Bradykinin-stimulated calcium release was not affected by the expression of either IRAG or cGKIbeta, which we tested in the absence and presence of cGMP. However, calcium release was inhibited after co-expression of IRAG and cGKIbeta in the presence of cGMP. These results identify IRAG as an essential NO/cGKI-dependent regulator of IP3-induced calcium release. 相似文献
34.
35.
Drori Ben-Ishay Ruth Saliternik A. Welner 《Cellular and molecular life sciences : CMLS》1972,28(11):1321-1322
Résumé La réponse au régime Doca-sel (D. S.) a été utilisée comme critère de sélection pour séparer, par croisement consanguin, deux colonies de rats manifestant une susceptibilité bien différente à l'hypertension artérielle. Les résultats obtenus dans la 6ème génération de nos colonies normotensive et hypertensive font l'objet de ce raport. Le rôle des facteurs héréditaires dans la susceptibilité ou la résistance à l'hypertension du type D. S. est démontrée. 相似文献
36.
Chi-Hua Wang Sheri M. Linnell Ruth Rosenblum Nancy Wang 《Cellular and molecular life sciences : CMLS》1971,27(3):243-244
Résumé Le N-Benzyl-1,4-dihydronicotinamide réduit, par un mécanisme redox de transfert d'un électron, laliaison disulfide de plusieurs disulfides organiques tels que le diphényl disulfide, l'-lipoamide et le tétraméthylthiuram disulfide. Les réactions chimiques sont comparées à l'oxydation enzymique de la nicotinamide-adénine nucléotide. 相似文献
37.
38.
39.
Ruth A. Bernstein 《Cellular and molecular life sciences : CMLS》1978,34(10):1281-1282
Summary Evidence of slave-making habits in 2 species of the subfamily Dolichoderinae has been found in arid habitats of western North America. The enslaved species are of the subfamilies Myrmicinae and Formicinae. In previously reported cases of slavery in ants, both the slave-making and enslaved species are of the subfamily Formicinae., In the 2 new cases of slavery reported here, presence of slaves of another species in a colony significantly increases the breadth of diet and/or the range of temperatures at which the colony forages. 相似文献
40.
Wernig M Meissner A Foreman R Brambrink T Ku M Hochedlinger K Bernstein BE Jaenisch R 《Nature》2007,448(7151):318-324