首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   371篇
  免费   23篇
  2023年   4篇
  2022年   4篇
  2021年   19篇
  2020年   13篇
  2019年   24篇
  2018年   11篇
  2017年   11篇
  2016年   18篇
  2015年   15篇
  2014年   26篇
  2013年   29篇
  2012年   35篇
  2011年   31篇
  2010年   13篇
  2009年   10篇
  2008年   21篇
  2007年   19篇
  2006年   11篇
  2005年   16篇
  2004年   10篇
  2003年   11篇
  2002年   14篇
  2001年   2篇
  2000年   3篇
  1999年   1篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   4篇
  1988年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1980年   2篇
  1979年   2篇
  1977年   1篇
  1974年   1篇
排序方式: 共有394条查询结果,搜索用时 920 毫秒
361.
Probiotics and Antimicrobial Proteins - The aim of this study was to investigate the effect of synbiotic and probiotic supplementation on serum vascular dysfunction and necrosis markers in...  相似文献   
362.
363.
A novel natural compound, 11-hydroxy-16-hentriacontanone, has been isolated from the leaf cuticular wax of Annona squamosa along with its known isomer 10-hydroxy-16-hentriacontanone in a ratio of 67:33. This isomeric mixture of hydroxy ketones constituted together 16.5% of the total cuticular waxes. The new compound was characterised using spectral and chromatographic techniques. The major component was found to be 16-hentriacontanone (palmitone), which constituted up to 48% of the total cuticular wax, together with a homologous series of hydrocarbons, fatty aldehydes, fatty alcohols, fatty acids and sterols as minor components. The antimicrobial activity of the isomeric hydroxy ketones was tested against selected Gram-positive and Gram-negative bacterial strains, and also some selected fungal strains, and compared with palmitone. The antibacterial activity of palmitone was significantly higher than that of the isomeric hydroxy ketones, but their antifungal activities were comparable.  相似文献   
364.
International Journal of Peptide Research and Therapeutics - Viruses of the picornavirus-like supercluster mainly achieve cleavage of polyproteins into mature proteins through viral 3-chymotrypsin...  相似文献   
365.
366.
367.
Differentiation is an inseparable process of development in multicellular organisms. Mouse embryonic stem cells (mESCs) represent a valuable research tool to conduct in vitro studies of cell differentiation. Apoptosis as a well known cell death mechanism shows some common features with cell differentiation, which has caused a number of ambiguities in the field. The research question here is how cells could differentiate these two processes from each other. We have investigated the role of the mitochondrial apoptotic pathway and cell energy level during differentiation of mESCs into the cardiomyocytes and their apoptosis. p53 expression, cytochrome c release, apoptosome formation, and caspase-3/7 activation are observed upon induction of both apoptosis and differentiation. However, remarkable differences are detected in time of cytochrome c appearance, apoptosome formation, and caspase activity upon induction of both processes. In apoptosis, apoptosome formation and caspase activity were observed rapidly following the cytochrome c release. Unlike apoptosis, the release of cytochrome c upon differentiation took more time, and the maximum caspase activity was also postponed for 24 h. This delay suggests that there is a regulatory mechanism during differentiation of mESCs into cardiomyocytes. The highest ATP content of cells was observed immediately after cytochrome c release 6 h after apoptosis induction and then decreased, but it was gradually increased up to 48 h after differentiation. These observations suggest that a delay in the release of cytochrome c or delay in ATP increase attenuate apoptosome formation, and caspase activation thereby discriminates apoptosis from differentiation in mESCs.  相似文献   
368.
We have identified a chitinase with antifungal activity in the bulbs of the plant Urginea indica(Indian squill) and purified it about 26-fold. The purified preparation contained a Mr 29 kDa protein that was an active growth inhibitor of the fungal pathogens Fusarium oxysporum and Rhizoctonia solani in an in vitro assay. Amino acid sequence analysis of the Mr 29 kDa protein revealed it to be highly homologous to the family 19 glycoside hydrolases, which are known to possess chitinase activity. The U. indica chitinase lacked a cysteine-rich N-terminal domain (characteristic of class I chitinases) and contained a conserved motif indicative of the signature 1 of family 19 glycoside hydrolases. It shared a approximately 70% sequence identity with the 26 kDa endochitinase of Hordeum vulgare, a typical class II chitinase of family 19. The five cysteines in the partial sequence of the Mr 29 kDa chitinase were found to be identical in location to five of the seven cysteines present in the catalytic domain of the H. vulgare enzyme. The molecular weight, the lack of an N-terminal cysteine-rich sequence, and the striking identity to the H. vulgare endochitinase suggest that the Mr 29 kDa U. indica protein is a putative class II chitinase. The antifungal activity is presumably mediated through the chitinolytic activity of the Mr 29 kDa protein.  相似文献   
369.
USP32, on chromosomal band 17q23.1-17q23.2, is a highly conserved but uncharacterized gene that gave rise during evolution to a well-known hominoid-specific proto-oncogene, USP6. We investigated the expression profile of USP32 in human tissues and examined its functions to gain insight into this novel member of the well-conserved ubiquitination system. We detected ubiquitous USP32 expression across tissues and confirmed the predicted deubiquitination function owing to the presence of conserved peptidase signature aspargine, cysteine, histidine, and aspartic acid domains of ubiquitin-specific proteases. A Golgi localization of GFP-fused USP32 was detected by fluorescent protection assay and BODIPY-TR staining. In addition, stable silencing of USP32 caused a significant decrease in the proliferation and migration rate of cells. Based on these and the fact that USP32 maps to 17q23, which is commonly amplified in breast cancers, we analyzed USP32 expression in breast cancer cells. We detected high expression of USP32 in 50% (9 of 18) of breast cancer cell lines and 22% (9 of 41) of primary breast tumors compared to mammary epithelial cells. In summary, we report the preliminary characterization of this novel deubiquitinating enzyme on 17q23 and demonstrate its functional role in the ubiquitin system and its potential involvement in tumorigenesis.  相似文献   
370.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号