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   638篇
  免费   35篇
  673篇
  2022年   3篇
  2021年   6篇
  2018年   7篇
  2017年   8篇
  2016年   5篇
  2015年   16篇
  2014年   12篇
  2013年   18篇
  2012年   22篇
  2011年   30篇
  2010年   12篇
  2009年   19篇
  2008年   38篇
  2007年   24篇
  2006年   19篇
  2005年   26篇
  2004年   19篇
  2003年   22篇
  2002年   21篇
  2001年   26篇
  2000年   23篇
  1999年   29篇
  1998年   16篇
  1997年   6篇
  1996年   7篇
  1995年   8篇
  1994年   3篇
  1993年   5篇
  1992年   17篇
  1991年   14篇
  1990年   14篇
  1989年   14篇
  1988年   14篇
  1987年   15篇
  1986年   16篇
  1985年   14篇
  1984年   9篇
  1983年   7篇
  1982年   7篇
  1981年   5篇
  1979年   4篇
  1978年   6篇
  1976年   6篇
  1975年   8篇
  1974年   6篇
  1973年   11篇
  1972年   7篇
  1971年   7篇
  1970年   4篇
  1967年   3篇
排序方式: 共有673条查询结果,搜索用时 0 毫秒
271.
Histidine-rich glycoprotein (HRG) is a monomeric plasma glycoprotein involved in the modulation of coagulation and fibrinolysis. Using Southern analysis of human-rodent somatic cell hybrid DNA with a human HRG-specific cDNA probe, the HRG gene was assigned to chromosome 3. One hybrid that was known to contain only a segment of chromosome 3 also reacted positively with the HRG probe. Hybridization analysis with a set of chromosome 3-specific probes showed that the segment of chromosome 3 present in this hybrid is missing the region pter-p14, which indicates that HRG is not located in this region. No restriction fragment length polymorphisms were detected for HRG with 10 commonly used restriction enzymes.  相似文献   
272.
273.
274.
275.
Maturation was induced in Asterias oocytes with 1-methyladenine (1-MA) at a final concentration of 2 microM. At 5, 10, and 30 min of treatment, oocytes were homogenized and the cytosolic fraction was prepared. The cytosol was incubated with [gamma-32P]ATP and [gamma-32P]GTP. The phosphorylated proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the radioactivity in the gels was determined by autoradiography. The cytosol prepared from 1-MA-treated oocytes incubated with [gamma-32P]ATP showed a marked increase in the radiolabeling of proteins with estimated molecular weights of 70,000 and 62,000 Da. With [gamma-32P]GTP a 56,000-Da protein showed increased radiolabeling. The present finding suggests that an early biochemical event of 1-MA-induced oocyte maturation in Asterias is the stimulation of phosphorylation of specific proteins.  相似文献   
276.
The effect of lipopolysaccharide on doxorubicin-induced cell death was studied by using mouse RAW 264.7 macrophage cells. Pretreatment with lipopolysaccharide at 10 ng/mL prevented doxorubicin-induced cell death and the inhibition was roughly dependent on the concentration of lipopolysaccharide. Posttreatment with lipopolysaccharide for 1 hour also prevented doxorubicin-induced cell death. Lipopolysaccharide inhibited DNA fragmentation and caspase-3 activation in doxorubicin-treated RAW 264.7 cells, suggesting the prevention of doxorubicin-induced apoptosis. Lipopolysaccharide did not significantly inhibit doxorubicin-induced DNA damage detected by single-cell gel electrophoresis (comet) assay. Lipopolysaccharide definitely inhibited the stabilization and nuclear translocation of p53 in doxorubicin-treated RAW 264.7 cells. Lipopolysaccharide, as well as being an inhibitor of p53, abolished doxorubicin-induced apoptosis. Therefore, p53 was suggested to play a pivotal role in the prevention of doxorubicin-induced apoptosis in RAW 264.7 cells by lipopolysaccharide.  相似文献   
277.
The amino acid sequence of the N-terminus of the immunoglobulin binding factor of human seminal plasma was determined. The initial 30 amino acids showed complete identity with that of prostatic secretory protein, beta-microseminoprotein and beta-inhibin. In conclusion, these proteins are probably a single entity.  相似文献   
278.

Background  

The endometrium prepares for implantation under the control of steroid hormones. It has been suggested that there are complicated interactions between the epithelium and stroma in the endometrium during menstrual cycle. In this study, we demonstrate a difference in gene expression between the epithelial and stromal areas of the secretory human endometrium using microdissection and macroarray technique.  相似文献   
279.
Tumor-initiating cells (TICs) play a central role in tumor development, metastasis, and recurrence. In the present study, we investigated the effect of disulfiram (DSF), an inhibitor of aldehyde dehydrogenase, toward tumor-initiating hepatocellular carcinoma (HCC) cells. DSF treatment suppressed the anchorage-independent sphere formation of both HCC cells. Flow cytometric analyses showed that DSF but not 5-fluorouracil (5-FU) drastically reduces the number of tumor-initiating HCC cells. The sphere formation assays of epithelial cell adhesion molecule (EpCAM)+ HCC cells co-treated with p38-specific inhibitor revealed that DSF suppresses self-renewal capability mainly through the activation of reactive oxygen species (ROS)-p38 MAPK pathway. Microarray experiments also revealed the enrichment of the gene set involved in p38 MAPK signaling in EpCAM+ cells treated with DSF but not 5-FU. In addition, DSF appeared to downregulate Glypican 3 (GPC3) in a manner independent of ROS-p38 MAPK pathway. GPC3 was co-expressed with EpCAM in HCC cell lines and primary HCC cells and GPC3-knockdown reduced the number of EpCAM+ cells by compromising their self-renewal capability and inducing the apoptosis. These results indicate that DSF impaired the tumorigenicity of tumor-initiating HCC cells through activation of ROS-p38 pathway and in part through the downregulation of GPC3. DSF might be a promising therapeutic agent for the eradication of tumor-initiating HCC cells.  相似文献   
280.
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