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   8808篇
  免费   793篇
  国内免费   60篇
耳鼻咽喉   70篇
儿科学   311篇
妇产科学   276篇
基础医学   1074篇
口腔科学   380篇
临床医学   783篇
内科学   1706篇
皮肤病学   123篇
神经病学   1015篇
特种医学   618篇
外科学   1150篇
综合类   141篇
一般理论   9篇
预防医学   898篇
眼科学   162篇
药学   560篇
中国医学   6篇
肿瘤学   379篇
  2022年   75篇
  2021年   150篇
  2020年   114篇
  2019年   134篇
  2018年   135篇
  2017年   120篇
  2016年   133篇
  2015年   137篇
  2014年   207篇
  2013年   305篇
  2012年   369篇
  2011年   396篇
  2010年   219篇
  2009年   272篇
  2008年   371篇
  2007年   446篇
  2006年   381篇
  2005年   399篇
  2004年   364篇
  2003年   350篇
  2002年   332篇
  2001年   270篇
  2000年   281篇
  1999年   273篇
  1998年   119篇
  1997年   110篇
  1996年   119篇
  1995年   115篇
  1994年   91篇
  1993年   95篇
  1992年   200篇
  1991年   177篇
  1990年   164篇
  1989年   145篇
  1988年   149篇
  1987年   152篇
  1986年   172篇
  1985年   156篇
  1984年   136篇
  1983年   101篇
  1982年   74篇
  1980年   61篇
  1979年   97篇
  1978年   71篇
  1975年   70篇
  1974年   70篇
  1973年   58篇
  1972年   60篇
  1969年   59篇
  1968年   56篇
排序方式: 共有9661条查询结果,搜索用时 15 毫秒
51.
52.
53.
Familial Parkinson's disease: possible role of environmental factors   总被引:3,自引:0,他引:3  
We report here six families with Parkinson's disease in whom the onset of symptoms tended to occur at approximately the same time irrespective of the age of the patient. The mean difference in the time of onset in different generations was 4.6 years while the mean difference in age of onset in children and parents was 25.2 years. We construe this pattern of age separation within families as suggestive of an environmental rather than genetic cause. Support for this view derives from the lack of correlation between occurrence of the disease and the degree of consanguinity. We conclude that our findings are in accord with the hypothesis which attributes the cause of some cases of Parkinson's disease to early, subclinical environmental damage followed by age-related attrition of neurons within the central nervous system.  相似文献   
54.
55.
Value of scintigraphic localization of obscure gastrointestinal bleeding.   总被引:1,自引:0,他引:1  
A total of 51 technetium-99m (99mTc)-labelled autologous red cell (LRC) scans performed on 49 patients for the localization of obscure gastrointestinal bleeding over a 5-year period was reviewed. The sensitivity for LRC scanning was 72.7% with a positive predictive value of 84.2%. Forty patients underwent both LRC scanning and visceral angiography during the same admission; angiography had a sensitivity of 38.9% compared with 66.7% for LRC scanning and the positive predictive values were 77.8% and 85.7%, respectively. Overall, the site of bleeding was located in 22 (45%) of 49 patients, but LRC scanning alone was successful in identifying the lesion in 16 (33%) cases. In patients who continue to bleed to the point of requiring operation, a combination of scintigraphy and angiography will localize a source in 70% of patients.  相似文献   
56.
The frequencies of nine discrete cranial traits are contrasted among 10 skeletal series of central Italy to assess the patterning of biological affinity or divergence. In this study various statistical applications were used: Mean Measure of Divergence (MMD), which was elaborated using the WPGMA cluster analysis, neighbor-joining method and principal coordinate analysis. The results show two main groups divided by the Apennines, which probably were a geographic barrier to biological exchange during the Italian Iron Age. This fact induced endogamous phenomena in the populations on the two sides of Italy (Adriatic and Tyrrenian) and probably increased the familial segregation of traits. The group on the western side has a further division between samples of the central coast and those of the southern coast. The latter samples seem to be more closely connected to Sardinian peoples, and this indicates gene flow and cultural contacts, which were not hindered by the sea. This segregation appears to have receded by Roman times.  相似文献   
57.
58.
The surgical treatment of aneurysms that arise at the origin of the pericallosal artery is technically difficult. This report describes a technique that improves the exposure of the proximal vasculature during a craniotomy for pericallosal aneurysms. A portion of the corpus callosum was resected in two patients before the manipulation of their aneurysms. The resection provided excellent exposure of the A2 segment of the anterior cerebral artery, and both aneurysms were clipped safely. Neither patient exhibited signs of hemispheric disconnection. The authors conclude that partial callosal resection improves access to the proximal vessels during procedures for pericallosal aneurysms.  相似文献   
59.
60.
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