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   1807篇
  免费   112篇
  2021年   21篇
  2019年   13篇
  2018年   19篇
  2017年   9篇
  2016年   28篇
  2015年   47篇
  2014年   53篇
  2013年   113篇
  2012年   82篇
  2011年   86篇
  2010年   51篇
  2009年   39篇
  2008年   91篇
  2007年   85篇
  2006年   96篇
  2005年   66篇
  2004年   75篇
  2003年   81篇
  2002年   72篇
  2001年   72篇
  2000年   74篇
  1999年   52篇
  1998年   14篇
  1997年   11篇
  1996年   17篇
  1995年   13篇
  1994年   9篇
  1992年   39篇
  1991年   52篇
  1990年   42篇
  1989年   36篇
  1988年   27篇
  1987年   27篇
  1986年   32篇
  1985年   28篇
  1984年   29篇
  1983年   18篇
  1982年   15篇
  1981年   20篇
  1980年   11篇
  1979年   19篇
  1978年   10篇
  1977年   8篇
  1976年   10篇
  1974年   9篇
  1973年   12篇
  1972年   10篇
  1970年   8篇
  1969年   9篇
  1968年   12篇
排序方式: 共有1919条查询结果,搜索用时 296 毫秒
41.
Infrared and electron paramagnetic resonance spectra of nitrosyl(protoporphyrin IX dimethyl ester)iron(II)(Fe(PPDME)(NO)) and its complexes with nitrogenous bases (N bases) such as imidazoles, pyridines, aliphatic amines, and anilines have been measured in various solvents. At room temperature, giso, Aiso, and nu NO values of five-coordinate Fe(PPDME)(NO) decreased with an increase in solvent polarity parameter ET, indicating the interaction between the solvent and the vacant axial coordination position. It has been found that the nu NO value of six-coordinate species is very sensitive to the solvent polarity, while the giso value is less sensitive. The solvent effect on the equilibrium constants, which are evaluated from the intensity change of the NO stretching band for five- and six-coordinate species, is discussed.  相似文献   
42.
43.
Summary Zymogramic analysis of esterase in the mouse, rat and guinea-pig salivary glands was undertaken and demonstrated species and organ specificities of esterase with electrophoretic method. Salivary glands esterase was classified into A, B and C types based on the electrophoretic mobility. Mouse submandibular gland had the most complicated pattern, while guinea-pig showed the simpliest patterns which was devoid of B type of esterase. Rat salivary glands exhibited rather regular patterns. Similar zymogram patterns were obtained with many kinds of ester compounds, that is simple and substituted naphthol esters and indoxyl derivatives. The tests of inhibition and activation for esterase activity was obtained. Histochemical properties applied to inhibitor test in the esterase zymogram patterns showed no marked differences between ducts and acini.  相似文献   
44.
Summary Analysis of lactate and malate dehydrogenase zymograms of rodent salivary glands showed species and organ specific patterns.Lactate dehydrogenase isoenzyme patterns occupied the middle positions in relation to those of skeletal and heart muscle. Activities of the major salivary glands were in the order submaxillary gland>parotid>sublingual gland. Zymogram of the mouse and rat showed LDH4 and LDH5 high activity patterns, while that of the rabbit was the fast moving active one. Hamster salivary gland exhibited a neutral type of the former and the latter.Malate dehydrogenase isoenzyme exhibited very similar patterns for the mouse, rat and hamster. Malate dehydrogenase zymogram of rabbit showed 3 active bands, which was different from the other rodents.  相似文献   
45.
46.
47.
48.
49.
50.
The binding of human monocyte chemoattractant protein-1 (MCP-1) to human monocytes was studied. MCP-1 was radioiodinated with Iodo-beads (Pierce Chemical Co., Rockford, IL) without significant loss of biologic activity. 125I-MCP-1 binding to PBMC occurred within 5 min at 0 degrees C and the binding was inhibited by unlabeled MCP-1 dose dependently but not by neutrophil attractant/activation protein-1 or FMLP. 125I-MCP-1 bound to monocytes; no significant binding to either neutrophils or lymphocytes was observed. Scatchard plot analysis indicated that monocytes had a minimum of 1700 +/- 600 binding sites per cell with a Kd of 1.9 +/- 0.2 x 10(-9) M. For analysis of binding by flow cytometry, MCP-1 was biotinylated. In contrast to radioiodination, biotinylation resulted in loss of activity; potency was 10-fold less, but the efficacy was retained. Detection by flow cytometry of bound biotinylated MCP-1 with avidin-FITC confirmed results obtained with 125I-MCP-1. Biotinylated MCP-1 bound to monocytes but not to lymphocytes; and the binding was inhibited by a 100-fold excess of unlabeled MCP-1.  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