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   32764篇
  免费   2487篇
  国内免费   1813篇
  2024年   42篇
  2023年   341篇
  2022年   832篇
  2021年   1567篇
  2020年   1067篇
  2019年   1330篇
  2018年   1324篇
  2017年   949篇
  2016年   1385篇
  2015年   2149篇
  2014年   2384篇
  2013年   2587篇
  2012年   2947篇
  2011年   2613篇
  2010年   1645篇
  2009年   1398篇
  2008年   1732篇
  2007年   1509篇
  2006年   1311篇
  2005年   1136篇
  2004年   900篇
  2003年   810篇
  2002年   619篇
  2001年   560篇
  2000年   446篇
  1999年   477篇
  1998年   285篇
  1997年   302篇
  1996年   289篇
  1995年   251篇
  1994年   242篇
  1993年   168篇
  1992年   239篇
  1991年   208篇
  1990年   147篇
  1989年   114篇
  1988年   90篇
  1987年   119篇
  1986年   89篇
  1985年   76篇
  1984年   57篇
  1983年   39篇
  1982年   37篇
  1981年   26篇
  1980年   22篇
  1979年   25篇
  1978年   18篇
  1975年   21篇
  1974年   18篇
  1972年   17篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
11.
Yang  Su-Rong  Sun  Huan-Xin  Hu  Zhen-Zhen  Wang  Si-Heng  Sun  Hui  Xue  Yin-Jia  Ye  Chen-Bo 《Sleep and biological rhythms》2017,15(1):57-65
Sleep and Biological Rhythms - Chronic sleep deprivation (SD) is an overwhelming problem in young students. Firstly, we investigated whether different levels of pre-training SD had effects on...  相似文献   
12.
Salmonella enterica serovar Enteritidis (SE) is a foodborne pathogen that can threaten human health through contaminated poultry products. Live poultry, chicken eggs and meat are primary sources of human salmonellosis. To understand the genetic resistance of egg‐type chickens in response to SE inoculation, global gene expression in the spleen of 20‐week‐old White Leghorn was measured using the Agilent 4 × 44 K chicken microarray at 7 and 14 days following SE inoculation (dpi). Results showed that there were 1363 genes significantly differentially expressed between inoculated and non‐inoculated groups at 7 dpi (I7/N7), of which 682 were up‐regulated and 681 were down‐regulated genes. By contrast, 688 differentially expressed genes were observed at 14 dpi (I14/N14), of which 371 were up‐regulated genes and 317 were down‐regulated genes. There were 33 and 28 immune‐related genes significantly differentially expressed in the comparisons of I7/N7 and I14/N14 respectively. Functional annotation revealed that several Gene Ontology (GO) terms related to immunity were significantly enriched between the inoculated and non‐inoculated groups at 14 dpi but not at 7 dpi, despite a similar number of immune‐related genes identified between I7/N7 and I14/N14. The immune response to SE inoculation changes with different time points following SE inoculation. The complicated interaction between the immune system and metabolism contributes to the immune responses to SE inoculation of egg‐type chickens at 14 dpi at the onset of lay. GC, TNFSF8, CD86, CD274, BLB1 and BLB2 play important roles in response to SE inoculation. The results from this study will deepen the current understanding of the genetic response of the egg‐type chicken to SE inoculation at the onset of egg laying.  相似文献   
13.
14.
15.
16.
17.
18.
19.
Intestinal mucosal injuries are directly or indirectly related to many common acute and chronic diseases. Long non-coding RNAs (lncRNAs) are expressed in many diseases, including intestinal mucosal injury. However, the relationship between lncRNAs and intestinal mucosal injury has not been determined. Here, we investigated the functions and mechanisms of action of lncRNA Bmp1 on damaged intestinal mucosa. We found that Bmp1 was increased in damaged intestinal mucosal tissue and Bmp1 overexpression was able to alleviate intestinal mucosal injury. Bmp1 overexpression was found to influence cell proliferation, colony formation, and migration in IEC-6 or HIEC-6 cells. Moreover, miR-128-3p was downregulated after Bmp1 overexpression, and upregulation of miR-128-3p reversed the effects of Bmp1 overexpression in IEC-6 cells. Phf6 was observed to be a target of miR-128-3p. Furthermore, PHF6 overexpression affected IEC-6 cells by activating PI3K/AKT signaling which was mediated by the miR-128-3p/PHF6 axis. In conclusion, Bmp1 was found to promote the expression of PHF6 through the sponge miR-128-3p, activating the PI3K/AKT signaling pathway to promote cell migration and proliferation.Subject terms: Cell growth, Cell migration  相似文献   
20.
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