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   894篇
  免费   34篇
  2022年   5篇
  2021年   6篇
  2019年   14篇
  2018年   8篇
  2017年   2篇
  2016年   17篇
  2015年   29篇
  2014年   29篇
  2013年   95篇
  2012年   37篇
  2011年   49篇
  2010年   26篇
  2009年   44篇
  2008年   38篇
  2007年   40篇
  2006年   33篇
  2005年   54篇
  2004年   64篇
  2003年   57篇
  2002年   56篇
  2001年   11篇
  2000年   8篇
  1999年   11篇
  1998年   21篇
  1997年   16篇
  1996年   7篇
  1995年   8篇
  1994年   12篇
  1993年   14篇
  1992年   10篇
  1991年   4篇
  1990年   10篇
  1989年   6篇
  1988年   6篇
  1987年   6篇
  1986年   6篇
  1985年   3篇
  1984年   7篇
  1983年   9篇
  1982年   9篇
  1981年   11篇
  1980年   8篇
  1979年   3篇
  1978年   3篇
  1977年   2篇
  1974年   3篇
  1972年   2篇
  1965年   1篇
  1963年   1篇
  1954年   1篇
排序方式: 共有928条查询结果,搜索用时 15 毫秒
921.
922.
923.
Phototrophic bacterial cells in the effluent from a lighted upflow anaerobic sludge blanket reactor supplied with a medium containing 142 mg S (as SO4 2–) l–1 accumulated a 6.8% w/w oleic acid content in cells and 19 mg cell-bound oleic acid l–1 in the effluent. Pure cultures of Rhodopseudomonas palustris and Blastochloris sulfoviridis isolated from the effluent also accumulated 5.1 and 6.4% w/w oleic acid contents in cells, respectively. The oleic acid content in the cells recovered from the LUASB reactor effluent was related to the phototrophic bacterial population in the LUASB reactor. The inverse relationship was observed in the LUASB reactor between phototrophic bacterial growth and sulfate concentration in the influent.  相似文献   
924.
925.
 The study was designed to clarify the difference in pharmacokinetics of monoclonal antibodies (mAb) in animal models and humans, and to elucidate the applicability of animal models. 99mTc-labeled murine mAb – against carcinoembryonic antigen (designated BW431/26), and neural cell adhesion molecule (NE150) – and one chimeric mouse/human mAb against nonspecific cross-reacting antigen (chNCA) were administered i.v. to normal mice and athymic mice (370 kBq, 400 ng) xenografted with human cancer cells expressing antigens, and into patients with tumor (925 MBq, 1 mg). The biodistribution of two of the three mAb (not 99mTc-BW431/26) differed clearly in mice and patients. 99mTc-NE150 showed specific uptake in xenografted tumor and otherwise a normal biodistribution; however, clinical examination showed increased uptake in the liver with rapid blood clearance (mean α half-life = 31.1 min) compared with 99mTc-BW431/26 (28.4 h). 99mTc-chNCA demonstrated increased blood clearance and renal excretion in both normal and athymic mice, with accumulation in tumors. Clinical examination showed rapid blood clearance (mean α half-life = 6.4 min) and increased uptake in the liver. High-performance liquid chromatographic analysis of 99mTc-chNCA revealed the immune complex in blood, suggesting uptake of the complex by the reticuloendothelial cells. The biodistribution of radiolabeled mAb in animal and human models was variable and specific for each of the three mAb. The results of animal studies with mAb should be evaluated carefully before being extrapolated to humans, on the basis of the nature of the mAb and interacting substances. Received: 9 April 1997 / Accepted 3 March 1998  相似文献   
926.
927.
Yamazaki  Yuji  Kitamura  ·Jyun-ichi  Ikeya  Koki  Mori  ·Seiichi 《Genetica》2021,149(3):179-190
Genetica - Recently, anthropogenic alterations have had severe and negative impacts on the terrestrial and aquatic species and environments. To conserve species that have a small and limited...  相似文献   
928.
Using Agrobacterium tumefaciens harboring a vector that carriedthe rolC gene under the control of the 35S RNA promoter of cauliflowermosaic virus, we produced several transgenic plants. Two ofthem were periclinal chimeras with altered leaves that had wrinkleddark green margins and inner pale green regions. One chimericplant had shortened internodes, reduced apical dominance, smallflowers and exhibited male sterility, but the other had a normalphenotype. Analysis of proteins, RNA and DNA indicated thatthe inner pale green tissues consisted of transformed cellswhile the outer dark green tissues were composed of non-transformedcells. Histological analysis indicated that mesophyll cellswere distorted and larger intercellular spaces were presentin the transformed pale green regions. Furthermore, in youngleaves, transformed mesophyll cells were larger than non-transformedcells. However, the normal parts had larger numbers of cellsper unit area than the transformed parts. These observationssuggest that ths expression of 35S-rolC in leaves caused inhibitionof cell division in developing leaves and that the undulatingmargins, composed of non-transformed cells, were a consequenceof the requirement for accommodating more cells in less spacewithin the region of rolC-transformed cells. (Received January 29, 1993; Accepted May 17, 1993)  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