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   3238篇
  免费   63篇
  3301篇
  2022年   21篇
  2021年   42篇
  2020年   22篇
  2019年   34篇
  2018年   37篇
  2017年   56篇
  2016年   48篇
  2015年   66篇
  2014年   82篇
  2013年   93篇
  2012年   101篇
  2011年   164篇
  2010年   80篇
  2009年   62篇
  2008年   113篇
  2007年   127篇
  2006年   104篇
  2005年   105篇
  2004年   116篇
  2003年   100篇
  2002年   104篇
  2001年   66篇
  2000年   60篇
  1999年   46篇
  1992年   72篇
  1991年   83篇
  1990年   104篇
  1989年   111篇
  1988年   69篇
  1987年   80篇
  1986年   55篇
  1985年   71篇
  1984年   53篇
  1983年   45篇
  1981年   24篇
  1979年   43篇
  1978年   34篇
  1977年   27篇
  1976年   33篇
  1975年   43篇
  1974年   51篇
  1973年   49篇
  1972年   45篇
  1971年   35篇
  1970年   39篇
  1969年   35篇
  1968年   37篇
  1967年   31篇
  1966年   24篇
  1965年   22篇
排序方式: 共有3301条查询结果,搜索用时 0 毫秒
31.
Four cyclic derivatives of des-Arg9[Leu8]bradykinin have been obtained by classical methods of peptide chemistry. They are cyclo-(-X-Arg-Pro-Pro-Gly-Phe-Gly-Pro-Leu-), where X=Lys or none, and cyclo-(Y-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Leu-), where Y= Lys or Orn. Peptide bonds have been formed by the pentafluorophenylester method, and cyclization has been carried out in a diluted dioxane solution with 40% yield. Subsequent cleavage of protecting groups was made by treatment with hydrogen fluoride. The products obtained were purified by droplet counter-current chromatography. These substances liberate histamine from the rat mast cells comparably to bradykinin and fail to produce myotripic and vascular effects.  相似文献   
32.
Consideration of an inflammation focus as an "open system" provided analogy between microbiological processes in inflamed wounds and in systems of continuous cultivation of microorganisms. Mathematical modeling of such systems is widely used. Some of the methods for the mathematical modeling were applied to chemoprophylaxis and chemotherapy of postoperative wounds. In modeling continuous cultivation of microorganisms it is usually necessary to determine optimal conditions for the maximum yield of their biomass. In modeling of wound treatment the aim was to determine the process parameters providing the minimum biomass. The described simple models showed that there could be certain optimal flow rate of the washing fluid in the aspiration-washing procedure for wound treatment at which the drug was not completely washed out while the growth rate of the microbial population was minimal. Such mathematical models were shown valuable in optimizing the use of bactericidal and bacteriostatic antibiotics.  相似文献   
33.
On the awake rabbits and cats under nembutal anesthesia it has been shown that the reticular nucleus of the thalamus takes considerable part in the formation of reticulogeniculate response of the lateral geniculate body (LGB) to electrostimulation of the mesencephalic reticular formation. It is assumed that the reticular nucleus of the thalamus takes basic part in a realization of "rapid" physical influences of the reticular formation on the LGB.  相似文献   
34.
The administration of a spleen extract of Testudo horsfieldi to mice exposed to lethal radiation of 8 Gy was shown to increase the survival rate and to stimulate haemopoiesis and formation of endocolonies in the spleen. The gel filtration method was used to obtain an active fraction which was subjected to chromatography on cation exchanger to give two more fractions. Active was the fraction with basic components.  相似文献   
35.
36.
37.
The N-acyl, 5'-O-trityl (MeOTr, (MeO)2Tr, Me3Tr), 2'-O-benzoyl (and anisole) nucleosides were prepared by selective aroylation of N,5'-protected nucleosides. By means of the reverse-phase microcolumn liquid chromatography it was shown that the rate of the aryl 2'----3'-isomerisation is lower in case of 2'-anisoylnucleosides and depends on structure of the 5'-O-protecting group. The prepared synthons were used for the manual H-phosphonate solid-phase synthesis of oligoribonucleotides (6-10-mers).  相似文献   
38.
It was shown that purified and concentrated by the "Diaferm" method antibotulin sera from horse and cattle blood failed to differ by anaphylactogenic properties; at the same time in sensitization of the organism to protein of one animal species the use of the sera of another species provided a lesser reactogenicity of the preparation. The antigenic activity of the purified and concentrated sera from the blood or horses and cows in testing on rabbits was identical, but in response to cow alpha-globulin the animals responsed by a more intensive production of precipitins. The activity of cow and horse antibotulin serum (determined by the rate and stability of their association with the corresponding toxin) proved to be identical.  相似文献   
39.
40.
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