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   230篇
  免费   1篇
  国内免费   30篇
丛书文集   6篇
教育与普及   5篇
现状及发展   9篇
综合类   241篇
  2020年   2篇
  2018年   1篇
  2016年   2篇
  2015年   1篇
  2014年   5篇
  2013年   1篇
  2012年   1篇
  2011年   3篇
  2010年   13篇
  2009年   6篇
  2008年   10篇
  2007年   16篇
  2006年   16篇
  2005年   12篇
  2004年   25篇
  2003年   22篇
  2002年   22篇
  2001年   18篇
  2000年   32篇
  1999年   22篇
  1998年   4篇
  1997年   5篇
  1996年   4篇
  1995年   2篇
  1994年   5篇
  1993年   4篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
排序方式: 共有261条查询结果,搜索用时 15 毫秒
211.
The plant hormone auxin influences a variety of developmental and physiological processes. But the mechanism of its action is quite unclear. In order to identify and analyze the expression of auxin responsive genes, a cDNA array approach was used to screen for genes with altered expression from Arabidopsis suspension culture after IAA treatment and was identified 50 differentially expressed genes from 13824 cDNA clones. These genes were related to signal transduction, stress responses, senescence, photosynthesis, protein biosynthesis and transportation. The results provide the molecular evidence that auxin influences a variety of physiological processes and pave a way for further investigation of the mechanism of auxin action. Furthermore,we found that the expression of a ClpC (regulation subunit of Clp protease) was repressed by exogenous auxin, but increased in dark-induced senescing leaves. This suggests that ClpC may be a senescence-associated gene and can be regulated by auxin.  相似文献   
212.
A photoperiod-sensitive genic male-sterile (PSGMS) line was found in 1973 as a spontaneous mutant of the rice variety Nongken 58 (Oryza sativa ssp. japonica) in Hubei Province, China[1]. The fertility of this line was determined by day length and temperat…  相似文献   
213.
细胞周期蛋白依赖性激酶抑制剂(ICK)是一种能够影响细胞生长和发育的重要调控蛋白.以水稻(9311)为材料,利用RT-PCR技术,扩增获得了1个新的可能为水稻细胞周期蛋白依赖性激酶抑制剂的基因,命名为OsICK1.核苷酸序列分析表明,该基因的开放阅读框为585bp,编码194个氨基酸.与Genbank中预测的水稻ICK基因序列(NM_196964)比对,两者同源性为79.84%;氨基酸序列分析表明,该基因氨基酸序列3'端附近存在植物ICK所固有的保守序列,与玉米ICK1保守序列的同源性高达95.5%.  相似文献   
214.
从豇豆成熟叶片中提取总RNA,反转录合成cDNA第一链,根据钙调蛋白结构基因两端保守序列设计引物,PCR扩增豇豆钙调蛋白基因,克隆到T-easy载体上并测定了其全序列.序列分析结果表明,豇豆钙调蛋白基因由450个核苷酸组成,编码150个氨基酸.与已知的多种植物钙调蛋白基因相比有很高的相似性,核苷酸序列相似性在80%以上,编码的氨基酸序列相似性在90%以上.  相似文献   
215.
通过神经胚cDNA文库的大规模测序,从青岛文昌鱼(Brachiostoma belcheri tsingtauense)成功分离到一个泛素cDNA(AmphiUh52)克隆,演绎出的128位氨基酸序列揭示该基因产物为一个融合蛋白(76个氨基酸的泛素和52个氨基酸的60S核糖体蛋白).序列同源性分析表明该基因在所有的真核生物中都高度保守.在52个氨基酸的核糖体蛋白中可能含有一个“锌指”模式参于核酸的结合.  相似文献   
216.
火菇素cDNA的初步免疫学筛选   总被引:1,自引:0,他引:1  
火菇素是一种具有抗癌活性的简单蛋白,从金针菇中分离纯化火菇素的方法如下:金针菇子实体经乙酸液浸提、硫酸铵和乙醇分级沉淀后,通过DEAE-Sephadex A-50除去色素和部分杂蛋白,最后经CM.Sephadex C-50离子交换柱层析分离,得到了电泳均一的纯化蛋白.以火菇素为抗原制备的抗血清为探针对构建的金针菇cDNA表达文库进行免疫印记筛选,对获得的阳性克隆进行PCR、酶切以及在大肠杆菌中诱导表达等初步鉴定,为进一步确证、克隆火菇素基因打下了基础.  相似文献   
217.
218.
Earthworm fibrinolytic enzyme component A(EFEa),a protein with dual fibrinolytic activity ,is one of the major therapeutically important earthworm fibrinoltic enzyme components .The cDNA fragment encoded the mature protein was cloned from earthworm (Eisenia fetida )by the RT-PCR technique,The deduced amino acid sequence of the EFE component A show high homology with some members of serine proteases trypsin family,and the amino acid residues constituting the active sites are conserved in the EFEa as compared with the other proteins of the trypsin family ,The cDNA fragment was subcloned into the expression vector pQE31 and pMAL-c2X of E.coli.The resulting expression plasmids,pQE-efea and pMAL-efea ,were used to transform the E.coli strain M15.Recombinant protein bands corresponding with calcuated molecular witht were induced .The induced His6-EFEa fusion protein with pQE-efea was accumulated into inclusion body ,while the induced MBP-EFEa fusion protein with pMAL-efea was soluble and showed fibrinoloytic activities.  相似文献   
219.
Using Arabidopsis thaliana as experimental materials, the variations induced by low-energy N+ have been investigated. Germination rate of the treated seeds is lower than that of the control, and it decreases with the intensification of the radiation. The phenotypic variations have been observed in M2 plants irradiated with higher doses, such as chlorisis, semilethality, plant morphology, and changes of blooming habit and fertility. In random amplified polymorphic DNA (RAPD) analysis on M2 seedlings, some differences including band deletions or additions are found in treated plants compared to the control and the differences are associated with the radiation doses. One of the M1 plants from the seeds irradiated with the dose of 80×1015 N+/cm2 is a dwarf variant. Its stable M6 generation, mutant T80II, is used to construct subtractive cDNA library and to clone differentially expressed cDNA. A 721 bp cDNA fragment is partly homologous with GRF7 gene.  相似文献   
220.
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