全文获取类型
收费全文 | 230篇 |
免费 | 13篇 |
专业分类
243篇 |
出版年
2023年 | 2篇 |
2020年 | 2篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 13篇 |
2014年 | 9篇 |
2013年 | 16篇 |
2012年 | 17篇 |
2011年 | 12篇 |
2010年 | 12篇 |
2009年 | 12篇 |
2008年 | 14篇 |
2007年 | 4篇 |
2006年 | 11篇 |
2005年 | 9篇 |
2004年 | 15篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 3篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1964年 | 2篇 |
1963年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1959年 | 1篇 |
1939年 | 1篇 |
1938年 | 2篇 |
1932年 | 1篇 |
1929年 | 1篇 |
1928年 | 2篇 |
1927年 | 1篇 |
排序方式: 共有243条查询结果,搜索用时 17 毫秒
91.
92.
Proteus vulgaris (Штамм P2) весьма устойчив к облучению. Средней летальной дозой оказалось облучение 10 000 r. Крупнье круглые тельца, образующиеся под действием, пенициллина, так зе чувствительны к рентгеновскому облучению, как палочки. После облучения, уже начиная с дозы в 5–10 тысяч r, набльдалось слияние нуклеоидов (ядерных эквивалентов) подобно тому, как под действием охлаждения до 6° C. В среде без солей это явление не наблюдалось. 相似文献
93.
94.
95.
Replication stress from stalled or collapsed replication forks is a major challenge to genomic integrity. The anticancer agent camptothecin (CPT) is a DNA topoisomerase I inhibitor that causes fork collapse and double-strand breaks amid DNA replication. Here we report that hMSH5 promotes cell survival in response to CPT-induced DNA damage. Cells deficient in hMSH5 show elevated CPT-induced γ-H2AX and RPA2 foci with concomitant reduction of Rad51 foci, indicative of impaired homologous recombination. In addition, CPT-treated hMSH5-deficient cells exhibit aberrant activation of Chk1 and Chk2 kinases and therefore abnormal cell cycle progression. Furthermore, the hMSH5-FANCJ chromatin recruitment underlies the effects of hMSH5 on homologous recombination and Chk1 activation. Intriguingly, FANCJ depletion desensitizes hMSH5-deficient cells to CPT-elicited cell killing. Collectively, our data point to the existence of a functional interplay between hMSH5 and FANCJ in double-strand break repair induced by replication stress. 相似文献
96.
97.
98.
99.
TIMP-2 protein has been intensively studied as a promising anticancer candidate agent, but the in vivo mechanism underlying its anticancer effect has not been clearly elucidated by previous works. In this study, we investigated the mechanism underlying the anti-tumor effects of a TIMP-2 fusion protein conjugated with human serum albumin (HSA/TIMP-2). Systemic administration of HSA/TIMP-2 effectively inhibited tumor growth at a minimum effective dose of 60 mg/kg. The suppressive effect of HSA/TIMP-2 was accompanied by a marked reduction of in vivo vascularization. The anti-angiogenic activity of HSA/TIMP-2 was directly confirmed by CAM assays. In HSA/TIMP-2-treated tumor tissues, MMP-2 expression was profoundly decreased without a change in MT1-MMP expression of PECAM-1-positive cells. MMP-2 mRNA was also decreased by HSA/TIMP-2 treatment of human umbilical vein endothelial cells. Zymographic analysis showed that HSA/TIMP-2 substantially decreased extracellular pro-MMP-2 activity (94-99% reduction) and moderately decreased active MMP-2 activity (10-24% reduction), suggesting MT1-MMP-independent MMP-2 modulation. Furthermore, HSA/TIMP-2 had no effect on in vitro active MMP-2 activity and in vivo MMP-2 activity. These studies show that HSA/TIMP-2 potentiates anti-angiogenic activity by modulating MMP-2 expression, but not MMP-2 activity, to subsequently suppress tumor growth, suggesting an important role for MMP-2 expression rather than MMP-2 activity in anti-angiogenesis. 相似文献
100.
Jae-Hyuk Her Bretni S. Kennon William W. Shum Peter W. Stephens Joel S. Miller 《Inorganica chimica acta》2008,361(12-13):3462-3464
LnIII[Ru2(CO3)4] · 8H2O (Ln = Gd, Nd, Ho, Yb) is formed from the reaction of LnIII and [Ru2(CO3)4]3? in water. These LnIII materials have a 3D network structure composed of linked chains and μn-CO3 linkages to both Ru and LnIII sites, and are best described as LnIII(OH2)4[Ru2(CO3)4]1/2[Ru2(CO3)4(OH2)2]1/2 · 3H2O. Complete characterization of the GdIII species is presented, as the other LnIII are isostructural and exhibit large spin–orbit coupling leading to complex magnetic behavior. Magnetic ordering is not observed above 2 K. 相似文献