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   2855008篇
  免费   196393篇
  国内免费   7297篇
耳鼻咽喉   36326篇
儿科学   94450篇
妇产科学   76179篇
基础医学   402363篇
口腔科学   78534篇
临床医学   262603篇
内科学   548784篇
皮肤病学   58910篇
神经病学   230086篇
特种医学   108219篇
外国民族医学   592篇
外科学   420418篇
综合类   63771篇
现状与发展   5篇
一般理论   948篇
预防医学   229300篇
眼科学   65216篇
药学   206860篇
  12篇
中国医学   7362篇
肿瘤学   167760篇
  2021年   21170篇
  2019年   22169篇
  2018年   50415篇
  2017年   38719篇
  2016年   42983篇
  2015年   30833篇
  2014年   42353篇
  2013年   63081篇
  2012年   92168篇
  2011年   109276篇
  2010年   69684篇
  2009年   59864篇
  2008年   100864篇
  2007年   107956篇
  2006年   90309篇
  2005年   87953篇
  2004年   85676篇
  2003年   82418篇
  2002年   78347篇
  2001年   131560篇
  2000年   135074篇
  1999年   112414篇
  1998年   30907篇
  1997年   27310篇
  1996年   27106篇
  1995年   25953篇
  1994年   24046篇
  1993年   22308篇
  1992年   86912篇
  1991年   84380篇
  1990年   81356篇
  1989年   77849篇
  1988年   71448篇
  1987年   69788篇
  1986年   66149篇
  1985年   62962篇
  1984年   46784篇
  1983年   39851篇
  1982年   23093篇
  1979年   41864篇
  1978年   29352篇
  1977年   24569篇
  1976年   23360篇
  1975年   24342篇
  1974年   29624篇
  1973年   28729篇
  1972年   26641篇
  1971年   24719篇
  1970年   23003篇
  1969年   21314篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A 68 year-old woman presented with a two-week history of amaurosis fugax, ipsilateral fronto-temporal headache and jaw claudication suggesting carotid giant cell arteritis. However, this syndrome proved to be due to atherosclerosis causing complete occlusion of the external carotid artery at its origin and narrowing of the internal carotid artery. Combined external and internal carotid endarterectomy relieved the symptoms. The symptom complex of temporal arteritis may be rarely mimicked by carotid atherosclerotic occlusive disease.  相似文献   
992.
L H Phillips 《Neurology》1986,36(9):1251-1253
Long thoracic nerve palsy causes weakness of the serratus anterior muscle and winging of the scapula. It is usually traumatic in origin. Isolated long thoracic nerve palsy has not been recognized as the major manifestation of familial brachial plexus neuropathy, but I have studied the syndrome in four members of three generations of one family. One individual suffered an episode of facial paresis. The inheritance pattern was autosomal dominant.  相似文献   
993.
Numerous surveys at the national and regional level have demonstrated that large inequalities in infant health status exist in Southern Africa. Few studies have assessed infant mortality at the intra-urban scale of geographic analysis. Comparisons between infant mortality rates from different areas are made even more meaningful if the data are divided into two primary categories based on period-of-death; these being the neonatal and post-neonatal components. This study presents the results of a survey undertaken in Metropolitan Cape Town (population 1.6 million) during 1982. The aim was to determine the spatial variation of neonatal and post-neonatal mortality at the suburb (or community) level within the city. Overall, a total of 36,789 live births and 928 infant deaths were recorded; 53.4% in the neonatal period and 46.6% in the post-neonatal period. The mean infant mortality rate was 25.2 per 1000 live births; the neonatal mortality rate and post-neonatal mortality rate being 13.5/1000 and 11.7/1000, respectively. A marked range in death rates was evident for both components. For the neonatal category it was 0.0-49.9/1000 and 0.0-40.0/1000 for the post-neonatal period. The generally low post-neonatal mortality rate among the 69 suburbs studied has made the neonatal component the dominant contributor to the infant mortality rate. However, in the lowest socio-economic areas the post-neonatal mortality rate was responsible for over 60% of infant deaths.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
994.
Health risks among submarine personnel in the U.S. Navy, 1974-1979   总被引:1,自引:0,他引:1  
This study evaluated health risks associated with U.S. Navy submarine duty by comparing hospitalization rates of submariners with surface ship personnel. The groups were compared using age-adjusted hospitalization rates for 16 major diagnostic categories and several specific diagnoses postulated to be submarine associated. Submarine personnel did not have significantly higher hospitalization rates for any diagnostic categories nor for any of the submarine-associated illnesses. Submariner relative risk of hospital admissions was greater for a few selected diagnoses but statistical significance was not attained. Submarine personnel had lower hospitalization rates for nearly all of the diagnostic categories examined. Reasons for these lower rates may be stringent screening of submariners, higher levels of education among submariners, difficulty of evacuation from a submarine, and the healthy-worker effect. The health status of U.S. Navy personnel does not seem to be adversely affected by submarine duty.  相似文献   
995.
This paper describes a method for the detection of Entamoeba histolytica antigens in stool samples using a multi-layer ELISA. The method is sensitive and specific, showing no interference with other intestinal parasites, e.g. E. coli, E. hartmanni, Endolimax nana, Iodamoeba buetschlii, Hymenolepis nana, Giardia lamblia, Trichomonas and Ascaris. The method provides a rapid and simple screening assay for E. histolytica infections and should assist in diagnosis and epidemiological studies of the disease.  相似文献   
996.
997.
Results of an examination of 39 patients are described and critically assessed. An analysis of the resolving power of the method of ultrasonic angiography in pathological formations of major vessels of the neck is given.  相似文献   
998.
999.
Mean cell volume and mean cell water content were examined in Plasmodium yoelii-infected mouse erythrocytes by gas chromatography and 3H-sucrose. Mean cell volume increased by 16% in infected erythrocytes with late trophozoites and schizonts. Mean cell water content further increased by 23% in the infected erythrocytes. Measurement of the erythrocyte potassium and sodium concentrations by an atomic absorption spectrophotometer revealed that the infected erythrocytes contained highly elevated sodium and slightly reduced potassium levels when calculated per single erythrocyte. It is suggested that membrane transport processes of sodium and potassium are changed in P. yoelii-infected erythrocytes and that a passive inflow of sodium takes place, which results in an increase in intra-erythrocytic water content.  相似文献   
1000.
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