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   208776篇
  免费   2842篇
  国内免费   188篇
耳鼻咽喉   1502篇
儿科学   7393篇
妇产科学   3644篇
基础医学   22797篇
口腔科学   2320篇
临床医学   14983篇
内科学   37147篇
皮肤病学   1545篇
神经病学   19870篇
特种医学   10358篇
外科学   33448篇
综合类   2468篇
一般理论   15篇
预防医学   19656篇
眼科学   3460篇
药学   11815篇
中国医学   645篇
肿瘤学   18740篇
  2021年   381篇
  2020年   321篇
  2019年   531篇
  2018年   22440篇
  2017年   17764篇
  2016年   20012篇
  2015年   1578篇
  2014年   1616篇
  2013年   1981篇
  2012年   8641篇
  2011年   22717篇
  2010年   19974篇
  2009年   12623篇
  2008年   21351篇
  2007年   23573篇
  2006年   2483篇
  2005年   4170篇
  2004年   5240篇
  2003年   6141篇
  2002年   4378篇
  2001年   613篇
  2000年   692篇
  1999年   567篇
  1998年   711篇
  1997年   626篇
  1996年   457篇
  1995年   440篇
  1994年   385篇
  1993年   319篇
  1992年   254篇
  1991年   293篇
  1990年   304篇
  1989年   250篇
  1988年   232篇
  1987年   180篇
  1986年   157篇
  1985年   200篇
  1984年   211篇
  1983年   196篇
  1982年   228篇
  1981年   178篇
  1980年   172篇
  1977年   154篇
  1938年   179篇
  1933年   183篇
  1932年   230篇
  1931年   167篇
  1930年   210篇
  1928年   163篇
  1926年   164篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
41.
Coronary flow reserve (CFR) has been used toassess coronary microcirculation and epicardial coro-nary stenoses[1— 3 ] . CFR is defined as the ratio ofcoronary flow under maximal coronary vasodilatationto coronary flow under resting conditions[4 ] .Whenthe cross- sectional area of epicardial coronary arteriesis constant,coronary flow velocity (CFV) ratios areequal to volume flow ratios.The most common method used clinically formeasuring CFVR is intracoronary Doppler flow(ICD) analysis re…  相似文献   
42.
43.
44.
While the benefits of training manuals can hardly be questioned, they are exceedingly limited in reducing variability attributed to the "therapist factor." We propose that manuals provide a useful outline of the general principles of a therapeutic approach, but can only reduce therapist variability at the expense of other essential therapeutic phenomena. Manuals cannot adequately convey, for example, how the effective therapist functions as a model of adult living and as a person who provides guidance. We suggest that such an experience cannot readily be packaged in manualized form, though manuals may serve as a useful beginning. Recommendations for therapist manualized training include greater attention to the subtleties of human relationships and adequately conveying that any technique is effective only when catalysed by a living, relational process.  相似文献   
45.
46.
47.
48.
49.
BACKGROUND: The problems associated with rectal surgery are frequently discussed with no reference being made to the distance of the tumor from the anal verge. This study examined the effect of the location of the tumor on early postoperative results. PATIENTS AND METHODS: This was a multicenter study involving 75 German hospitals and 3756 patients, of whom 1463 had rectal carcinoma. On the basis of the location of the tumor (distance from the anal verge), four groups were distinguished: <4, 4-7.9, 8-11.9, and 12-16 cm. RESULTS: Resection and abdominoperineal resection rates and the incidence of postoperative complications depended on the location of the tumor. Significantly higher resection rates and fewer specific complications, and a significant reduction in overall postoperative morbidity were found with tumor locations more than 8 cm from the anal verge. The highest anastomotic leak rate was observed with anastomoses less than 7 cm from the anal verge. The logistic regression showed that the distance of the tumor from the anal verge is an independent variable for the development of an anastomotic leak. CONCLUSIONS: Early results are greatly affected by the location of the rectal carcinoma. This applies to both abdominoperineal resection rates and specific postoperative complications, such as anastomotic leak rate and operation morbidity in general.  相似文献   
50.
Summary Monospecific antibodies to actin and to tubulin were used as immunofluorescent probes to evaluate the distribution of microtubules and actin filaments in the organ of Corti in mouse and guinea pig. The results indicate that in cochlear receptor cells actin and actin filaments as well as tubulin and microtubules are integral cytoskeletal elements. The presence of actin suggests a possible contractile mechanism within the sensory cilia whereas tubulin is thought to play an important role in the stability of sensory cells. Both proteins are discussed to form structural elements required for the mechano-chemical coupling in hearing.
Abbreviations ATP adenosin-tri-phosphate - SDS sodium-dodecyl-sulphate - PBS phosphate-buffered saline Dedicated to Professor Dr. A. Herrmann on the occasion of his 80th birthday  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