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   12260篇
  免费   948篇
  国内免费   4篇
  13212篇
  2022年   84篇
  2021年   196篇
  2020年   136篇
  2019年   182篇
  2018年   193篇
  2017年   186篇
  2016年   315篇
  2015年   450篇
  2014年   589篇
  2013年   711篇
  2012年   863篇
  2011年   905篇
  2010年   554篇
  2009年   547篇
  2008年   702篇
  2007年   724篇
  2006年   700篇
  2005年   635篇
  2004年   615篇
  2003年   600篇
  2002年   582篇
  2001年   147篇
  2000年   98篇
  1999年   127篇
  1998年   132篇
  1997年   114篇
  1996年   105篇
  1995年   118篇
  1994年   85篇
  1993年   116篇
  1992年   88篇
  1991年   62篇
  1990年   79篇
  1989年   64篇
  1988年   53篇
  1987年   62篇
  1986年   47篇
  1985年   67篇
  1984年   91篇
  1983年   66篇
  1982年   94篇
  1981年   82篇
  1980年   66篇
  1979年   48篇
  1978年   49篇
  1977年   41篇
  1976年   35篇
  1975年   37篇
  1974年   63篇
  1973年   36篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
The allelopathic potential of the dry fruits of Washingtonia filifera (L. Linden) H. Wendl. was investigated. Leachates from fruits inhibited the germination of lettuce, wheat, red cabbage and cucumber seeds. The inhibitory effect was partly neutralized by kinetin (20 mg 1−1) and gibberellic acid (50 mg 1−1). The effect of kinetin was more pronounced at 25°C than at 20°C. Substances inhibiting germination were localized in the pericarp of the fruit and were resistant to high temperature.  相似文献   
5.
Induction of inflammation by turpentine injection caused 1.5–2-fold increase of both sialy- and galactosyltransferase activity in liver homogenates. The effect was apparent after 12 h turpentine treatment. Serum sialytransferase activity started to increase in the inflamed rats after 18 h, reaching a maximum of 4-fold at 48 h. In contrast, galactosyltransferase activity in serum showed no significant increase. The coordinated and temporal increase of sialytransferase activity in liver and serum suggest involvement of a specific mechanism for the preferential release of this enzyme into serum.  相似文献   
6.
7.
8.
9.
The Multiskan spectrophotometric system and Coomassie brilliant blue G-250 protein-dye binding method have been used together to measure NaOH-solubilized protein in subcellular membrane fractions prepared from isolated rat adipose cells. Forty-eight samples can be read in duplicate within 1 min. Sucrose in concentrations up to 0.7 m interfere only moderately with the assay. A rapid and convenient method is, therefore, now available for multiple protein determinations following sucellular fractionation on sucrose gradients.  相似文献   
10.
Human noroviruses (HuNoV) are a major cause of nonbacterial gastroenteritis worldwide, yet details of the life cycle and replication of HuNoV are relatively unknown due to the lack of an efficient cell culture system. Studies with murine norovirus (MNV), which can be propagated in permissive cells, have begun to probe different aspects of the norovirus life cycle; however, our understanding of the specific functions of the viral proteins lags far behind that of other RNA viruses. Genome-wide functional profiling by insertional mutagenesis can reveal protein domains essential for replication and can lead to generation of tagged viruses, which has not yet been achieved for noroviruses. Here, transposon-mediated insertional mutagenesis was used to create 5 libraries of mutagenized MNV infectious clones, each containing a 15-nucleotide sequence randomly inserted within a defined region of the genome. Infectious virus was recovered from each library and was subsequently passaged in cell culture to determine the effect of each insertion by insertion-specific fluorescent PCR profiling. Genome-wide profiling of over 2,000 insertions revealed essential protein domains and confirmed known functional motifs. As validation, several insertion sites were introduced into a wild-type clone, successfully allowing the recovery of infectious virus. Screening of a number of reporter proteins and epitope tags led to the generation of the first infectious epitope-tagged noroviruses carrying the FLAG epitope tag in either NS4 or VP2. Subsequent work confirmed that epitope-tagged fully infectious noroviruses may be of use in the dissection of the molecular interactions that occur within the viral replication complex.  相似文献   
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