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   184篇
  免费   25篇
  2023年   2篇
  2021年   2篇
  2016年   3篇
  2015年   7篇
  2014年   7篇
  2013年   16篇
  2012年   16篇
  2011年   22篇
  2010年   6篇
  2009年   4篇
  2008年   9篇
  2007年   14篇
  2006年   7篇
  2005年   5篇
  2004年   5篇
  2003年   6篇
  2002年   6篇
  2001年   6篇
  2000年   4篇
  1999年   3篇
  1994年   2篇
  1993年   3篇
  1992年   4篇
  1991年   4篇
  1990年   2篇
  1988年   3篇
  1987年   4篇
  1985年   1篇
  1984年   2篇
  1978年   1篇
  1975年   2篇
  1974年   1篇
  1973年   2篇
  1972年   2篇
  1970年   2篇
  1969年   1篇
  1940年   1篇
  1939年   1篇
  1937年   1篇
  1936年   1篇
  1927年   1篇
  1923年   1篇
  1921年   2篇
  1914年   2篇
  1909年   1篇
  1905年   1篇
  1904年   2篇
  1901年   1篇
  1890年   1篇
  1887年   1篇
排序方式: 共有209条查询结果,搜索用时 15 毫秒
1.
2.
3.
The change in polyphenol content in the primed leaves of burley, flue-cured, and Turkish tobaccos during air-curing was related to the activities and isozymes of polyphenol oxidase and peroxidase. The quantity of chlorogenic acid was rapidly reduced during the first week of curing. The decrease in rutin content during curing was less significant, especially when the concentration of chlorogenic acid was high in leaf tissues. This result was further confirmed by in vitro assays with partially purified tobacco polyphenol oxidase.  相似文献   
4.
Feedback control of gene expression   总被引:24,自引:0,他引:24  
  相似文献   
5.
Proceeding from the premise that a "youthful" eyelid has a pretarsal bulge while a "senile" eyelid has a pretarsal flatness, the tarsal fixation technique for lower blepharoplasty has been introduced--to reposition part of the orbicularis in front of the tarsus to produce a pretarsal bulge. The technique is presented as a suggested adjunct to the usual types of lower blepharoplasty.  相似文献   
6.
We have isolated a cDNA clone, Nah-2, encoding the cytochrome P-450Nah (naphthalene hydroxylase) from a mouse lung lambda ZAP cDNA library using anti-cytochrome P-450Nah IgG as a probe. This same antibody selectively blocked [Nagata, K., Martin, B.M., Gillette, J.R., & Sasame, H.A. (1990) Drug Metab. Dispos. 18, 557-564] the cytochrome P-450 in mouse lung microsomes that catalyzed the conversion of naphthalene to (1R,2S)-naphthalene 1,2-oxide, which has been postulated as a causative agent in the naphthalene-induced tissue-specific necrosis of Clara cells in mouse lung. The toxic effect is seen in mouse and not in rat. The cDNA encodes a polypeptide of 491 amino acids with a molecular mass of 50 kDa. Northern blot analysis with an Nah-2-specific probe revealed that the mRNA is expressed in a species- and tissue-specific manner, present only in mouse lung and liver and not in that of rat. The mRNA encoding Nah-2 is constitutively expressed and is not induced by either phenobarbital, pyrazole, pregnenolone 16 alpha-carbonitrile, or 3-methylcholanthrene. Comparative amino acid sequence analyses with other documented members of the P-450 gene superfamily revealed that this encoded protein is in the IIF subfamily. To analyze its substrate specificity, the cDNA was inserted into the vector, pAAH5, and expressed in the Saccharomyces cerevisiae strain, AH22. The presence of cytochrome P-450Nah in the microsomes isolated from transformed cells and analyzed by Western blot was confirmed by immunocomplexing product with anti-cytochrome P450Nah IgG. Furthermore, activity toward naphthalene in the microsomes from the transformed cells established that this clone encodes a naphthalene hydroxylase.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
7.
8.
9.
10.
Abelmoschus enbeepeegearense J. John et al. is a new species occurring at low elevations in the Western Ghats of India, comprising Kerala, Karnataka and Tamil Nadu. The taxon is morphologically allied to A. moschatus subsp. moschatus, A. moschatus subsp. tuberosus and A. crinitus, but easily distinguishable by virtue of its orthotropic branching, 3–5‐angled leaves, glandular hairy plant body with whitish waxy secretions, glandular non‐setose epiclayx segmens which is more than eight in number and ovate hirsute fruits with a short mucro at the apex. It can be crossed with all three taxa with varying degree of success, but the hybrids are sterile. The material belonging to it was earlier identified as and placed under A. moschatus Medik. The taxon is described and illustrated with notes on its phenology, ecology and distribution. In additions, a key to all Abelmoschus taxa occurring in India is provided.  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