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   8290篇
  免费   12篇
  国内免费   19篇
耳鼻咽喉   259篇
儿科学   12篇
妇产科学   134篇
基础医学   996篇
口腔科学   261篇
临床医学   1557篇
内科学   815篇
皮肤病学   7篇
神经病学   103篇
特种医学   424篇
外科学   1973篇
综合类   20篇
预防医学   601篇
眼科学   151篇
药学   324篇
中国医学   1篇
肿瘤学   683篇
  2019年   1篇
  2018年   3篇
  2017年   3篇
  2016年   3篇
  2015年   9篇
  2014年   10篇
  2013年   12篇
  2012年   319篇
  2011年   667篇
  2010年   323篇
  2009年   12篇
  2008年   476篇
  2007年   683篇
  2006年   701篇
  2005年   687篇
  2004年   803篇
  2003年   802篇
  2002年   867篇
  2001年   546篇
  2000年   737篇
  1999年   377篇
  1998年   125篇
  1997年   15篇
  1996年   10篇
  1995年   6篇
  1994年   11篇
  1993年   33篇
  1992年   2篇
  1991年   7篇
  1990年   4篇
  1989年   7篇
  1988年   4篇
  1987年   2篇
  1986年   4篇
  1985年   6篇
  1984年   7篇
  1983年   7篇
  1982年   3篇
  1981年   1篇
  1980年   1篇
  1979年   2篇
  1978年   3篇
  1977年   3篇
  1975年   2篇
  1974年   2篇
  1972年   5篇
  1971年   1篇
  1970年   1篇
  1966年   2篇
  1964年   1篇
排序方式: 共有8321条查询结果,搜索用时 15 毫秒
1.
2.
3.
The article gives an analysis of causes of recurrences of ulcer disease of the stomach and duodenum in 913 patients. The use of various methods of examination enabled the authors to make a conclusion that in spite of diversity of causes of recurrent ulcer disease it is necessary to clearly establish the prevailing action of one of the causes which will allow to determine correct volume of reoperations aimed at making the conditions of digestion in the upper parts of the gastro-intestinal tract close to physiological ones.  相似文献   
4.
59 angiomyolipomas were studied: immunohistochemistry (IHC) was used in 24 cases, electron microscopy (EM) in 6 cases. 57 tumors had a typical structure, 2 did not contain fat component. Premelanosomes were found by EM in one tumor. Smooth muscle actin was found in all tumor cells. Involvement of lymph nodes was observed in 2 patients. Histogenesis of this tumor is discussed.  相似文献   
5.
The aim of this work, that was carried out using Wistar rats, was to characterize the response of neurons of different morphofunctional types to amphetamine administration and to study the possibility of correction of these changes by delta-sleep inducing peptide (DSIP). Single intraperitoneal injection of 60 microg/kg of DSIP following a long term amphetamine administration (2.5 mg/kg for 3 weeks) was shown to result in normalization of brain metabolism, that was disturbed by the drug. The correcting DSIP effect was found in rat brain structures judging by the parameters of the state of proteins in neurons of sensomotor cortex and caudate nucleus and by the activity of enzymes of neurotransmitter metabolism, such as type A and B monoamine oxidases and acetylcholine esterase, that was determined in subfractions of the same brain structures. DSIP modulating effect in phenamine stereotypy supports its role as an adaptogen of intercenter relations in CNS pathology.  相似文献   
6.
Morphology of microparticles of the microencapsulated measles vaccine was studied by cryofractography, transmission electronic microscopy and by atomic force microscopy; co-polymers of polyacrylic acid and of sodium-alginate (spermidine) complexes were used as the matrix. The different-composition microcapsules had clear-cut borders and a certain range of sizes; but they were different in morphology, and their structures and densities varied identically with regard for a medium acidity, which is apparently preconditioned by some conformation-type alterations of matrix molecules. The studied preparations can, probably, protect the viral material in the stomach aggressive medium and release the material to ensure its contact with the intestine lymph tissue; thereof, they can be referred to as promising for further study of mucosal vaccines.  相似文献   
7.
The laboratory verified cases of Crimean-Congo hemorrhagic fever (CCHF) in the piedmont steppes of the North Caucasus (Malgobeksky District, Republic of Ingushetia) are first described. The source of the first infection was Ixodidae ticks; three subsequent sources were contacts with the bloody discharges from patients. CCHF virus genome was detected in the blood of the cattle from an epidemic focus and in the pools of the Ixodes ticks Haemaphysalis parva Neum., 1897 and Boophilus annulatus Say, 1821, taken from cattle. The problem of including the piedmont steppes of the North Caucasus into the CCHF nosological area is discussed.  相似文献   
8.
9.
10.
The aim of this chronic experimental study performed in 16 dogs was to determine the effect of epidural infusion of 0.01% clopheline solution on the morphological and histoenzymological characteristics of spinal ganglion neurons. Daily infusions of clopheline at the dose of 15 mg/kg for 14 days caused a decrease in capillary permeability in the spinal ganglia at the injection site and its increase in the intact areas. This finding suggests the changes in the activity of the microcirculatory bed with a disturbed interaction in capillary-neuron system. Analysis of morphometric parameters has demonstrated the presence of some functional and reversible dystrophic changes in spinal ganglion neurons, which were associated with epidural infusion of both clopheline and isotonic solution of sodium chloride. Determination of the activity of oxidation-reduction enzymes, which reflect the course of aerobic and anaerobic processes in spinal ganglion neurons, has shown no significant differences between the groups of animals infused with or isotonic solution of sodium chloride. In conditions of chronic experiment no significant variations were found in RNA content in ganglionic cells at and outside the sites of infusion of clopheline and of isotonic solution of sodium chloride.  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