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   532069篇
  免费   27802篇
  国内免费   502篇
耳鼻咽喉   6708篇
儿科学   16973篇
妇产科学   12605篇
基础医学   92867篇
口腔科学   12380篇
临床医学   48645篇
内科学   95961篇
皮肤病学   11915篇
神经病学   34196篇
特种医学   19901篇
外国民族医学   53篇
外科学   78322篇
综合类   7619篇
现状与发展   2篇
一般理论   108篇
预防医学   38741篇
眼科学   11954篇
药学   41543篇
  1篇
中国医学   1128篇
肿瘤学   28751篇
  2021年   3939篇
  2018年   5798篇
  2017年   4170篇
  2016年   4905篇
  2015年   5443篇
  2014年   7184篇
  2013年   10595篇
  2012年   15692篇
  2011年   17513篇
  2010年   10028篇
  2009年   8885篇
  2008年   15823篇
  2007年   17562篇
  2006年   17083篇
  2005年   16385篇
  2004年   15992篇
  2003年   15340篇
  2002年   14848篇
  2001年   22490篇
  2000年   23040篇
  1999年   18976篇
  1998年   5252篇
  1997年   4380篇
  1996年   4413篇
  1995年   4135篇
  1992年   14431篇
  1991年   15841篇
  1990年   15972篇
  1989年   15645篇
  1988年   14320篇
  1987年   14210篇
  1986年   13184篇
  1985年   12700篇
  1984年   9407篇
  1983年   8018篇
  1982年   4182篇
  1979年   8957篇
  1978年   6387篇
  1977年   5157篇
  1976年   5507篇
  1975年   6616篇
  1974年   7427篇
  1973年   7168篇
  1972年   6602篇
  1971年   6311篇
  1970年   5892篇
  1969年   5473篇
  1968年   5164篇
  1967年   4627篇
  1966年   3966篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis.  相似文献   
24.
25.
In rare cases the usage of the internal thoracic vessels as recipient vessels in reconstructive surgery of the head and neck region with free tissue transfer is a challenging but valid alternative if local recipient vessels are unusable.  相似文献   
26.
Endoscopic clips have been used mainly for control of gastrointestinal (GI) bleeding and occasionally for closure of GI perforations. However, closure of spontaneous esophageal perforation (Boerhaave's syndrome) by clipping has not been reported. We described successful non-surgical closure of spontaneous esophageal perforation by endoscopic clipping in a patient with bilateral pyopneumothorax and septicemia.  相似文献   
27.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  相似文献   
28.
29.
Published data devoted to making and characterization of the properties of polymeric wound dressings with proteolytic action are reviewed. These data are indicative of individual dependence of the physicochemical properties, activity, and stability of each particular enzyme on the type of polymer matrix and the method of immobilization. In order to obtain wound dressings, which are active in physiological medium and retain their activity upon sterilization, it is necessary to optimize the composition and characteristics of a polymer matrix and the enzyme included into its structure. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 8, pp. 24–28, August, 2006.  相似文献   
30.
A Survey of Plants Used as Wild Vegetables in Four Districts of Botswana   总被引:1,自引:0,他引:1  
A survey of plants used as wild vegetables was conducted in four districts of Botswana in August and September 2005. The objective was to determine which wild plants were used as vegetables in the study area, and to document their cooking and preservation methods. Fourteen species representing seven families were mentioned as wild vegetables. In addition, six species from four families had other uses in traditional medicine. The implications of the documented processing methods on the retention of nutrients in the vegetables are discussed.  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