全文获取类型
收费全文 | 99篇 |
免费 | 0篇 |
专业分类
现状及发展 | 60篇 |
研究方法 | 11篇 |
综合类 | 26篇 |
自然研究 | 2篇 |
出版年
2020年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 3篇 |
1966年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有99条查询结果,搜索用时 15 毫秒
81.
"The starting hypothesis of this paper was the actual occurrence of important interactions between demographic and socio-economic factors when trying to reach population forecasts that may be more efficient than those obtained by mere extrapolative methods. In order to be able to implement this approach to the Spanish case it has been necessary to reconstruct first the Spanish population series by age and sex groups from 1910 to 1980. Later, we proceed to obtain population forecasts using alternative modeling strategies and comment on the potential problems that the new demographic situation may have for future public policy." 相似文献
82.
Existence of a reactive zone in the interrenal gland of reptiles 总被引:1,自引:0,他引:1
E Del Conte 《Experientia》1972,28(4):451-453
83.
Di Cesare A Del Piccolo P Zacchetti D Grohovaz F 《Cellular and molecular life sciences : CMLS》2006,63(21):2546-2553
Astrocytes are a heterogeneous population of cells that are endowed with a great variety of receptors for neurotransmitters
and neuromodulators. Recently prostaglandin E2 has attracted great interest since it is not only released by astrocytes but also activates receptors coupled to either phospholipase
C or adenylyl cyclase. We report that EP2 receptor stimulation triggers cAMP production but also causes release of Ca2+ from intracellular stores. This effect is shared by other receptors similarly coupled to adenylyl cyclase and elicited by
direct stimulation of the enzyme or application of cAMP analogues. However, the stimulation of the Ca2+ response by cAMP is not mediated by protein kinase A, since a specific antagonist of this kinase had no effect. Such a cross-talk
between cAMP and Ca2+ was not observed in all astrocytes. It might therefore reflect a specific resource of either a subpopulation or astrocytes
in a specific functional state.
Received 6 June 2006; received after revision 25 July 2006; accepted 31 August 2006 相似文献
84.
D. Parolini M. Meregalli M. Belicchi P. Razini R. Lopa B. Del Carlo A. Farini S. Maciotta N. Bresolin L. Porretti M. Pellegrino Y. Torrente 《Cellular and molecular life sciences : CMLS》2009,66(4):697-710
Among the heterogeneous population of circulating hematopoietic and endothelial progenitors, we identified a subpopulation
of CD133+ cells displaying myogenic properties. Unexpectedly, we observed the expression of the B-cell marker CD20 in blood-derived
CD133+ stem cells. The CD20 antigen plays a role in the modulation of intracellular calcium homeostasis through signaling pathways
activation. Several observations suggest that an increase in intracellular calcium concentration ([Ca2+]i) could be involved in the etiology of the Duchenne muscular dystrophy (DMD). Here, we show that a CD20-related signaling
pathway able to induce an increase in [Ca2+]i is differently activated after brain derived neurotrophic factor (BDNF) stimulation of normal and dystrophic blood-derived
CD133+ stem cells, supporting the assumption of a “CD20-related calcium impairment-affecting dystrophic cells. Presented findings
represent the starting point toward the expansion of knowledge on pathways involved in the pathology of DMD and in the behavior
of dystrophic blood-derived CD133+ stem cells.
Received 15 October 2008; received after revision 27 November 2008; accepted 05 December 2008 相似文献
85.
Kras is the most frequently mutated ras family member in lung carcinomas, whereas Hras mutations are common in tumors from stratified epithelia such as the skin. Using a Hras knock-in mouse model, we demonstrate that specificity for Kras mutations in lung and Hras mutations in skin tumors is determined by local regulatory elements in the target ras genes. Although the Kras 4A isoform is dispensable for mouse development, it is the most important isoform for lung carcinogenesis in vivo and for the inhibitory effect of wild-type (WT) Kras on the mutant allele. Kras 4A expression is detected in a subpopulation of normal lung epithelial cells, but at very low levels in lung tumors, suggesting that it may not be required for tumor progression. The two Kras isoforms undergo different post-translational modifications; therefore, these findings can have implications for the design of therapeutic strategies for inhibiting oncogenic Kras activity in human cancers. 相似文献
86.
iASPP preferentially binds p53 proline-rich region and modulates apoptotic function of codon 72-polymorphic p53 总被引:6,自引:0,他引:6
Bergamaschi D Samuels Y Sullivan A Zvelebil M Breyssens H Bisso A Del Sal G Syed N Smith P Gasco M Crook T Lu X 《Nature genetics》2006,38(10):1133-1141
iASPP is one of the most evolutionarily conserved inhibitors of p53, whereas ASPP1 and ASPP2 are activators of p53. We show here that, in addition to the DNA-binding domain, the ASPP family members also bind to the proline-rich region of p53, which contains the most common p53 polymorphism at codon 72. Furthermore, the ASPP family members, particularly iASPP, bind to and regulate the activity of p53Pro72 more efficiently than that of p53Arg72. Hence, escape from negative regulation by iASPP is a newly identified mechanism by which p53Arg72 activates apoptosis more efficiently than p53Pro72. 相似文献
87.
88.
89.
This paper publishes the correspondence between S. Germain and C.F. Gauss. The mathematical notes enclosed in her letters are published for the first time. These notes, in which she submitted some of her results, proofs and conjectures to Gauss for his evaluation, were inspired by her study of the Disquisitiones Arithmeticae. The interpretation of these mathematical notes not only shows how deeply she went into Gauss’s treatise and mastered it long before any other mathematician, but also, more importantly, shows that she obtained interesting results in the theory of power residues that have never previously been attributed to her. 相似文献
90.
M. Rguez-Mariscal A. S. Del Barrio J. Larralde J. A. Martínez 《Cellular and molecular life sciences : CMLS》1993,49(4):308-312
The administration of metaproterenol induced an increase in gastrocnemius muscle weight without change in body growth rate or tissue protein concentrations, while epididymal fat was reduced. This effect was accompanied by an enhancement in the levels of intracellular amino acids in muscle. By contrast, liver amino acids were unaffected by treatment with the mixed -adrenergic agonist. 相似文献