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   180909篇
  免费   1345篇
  国内免费   12篇
耳鼻咽喉   1178篇
儿科学   6748篇
妇产科学   3103篇
基础医学   17401篇
口腔科学   1589篇
临床医学   12905篇
内科学   32124篇
皮肤病学   702篇
神经病学   16968篇
特种医学   9141篇
外科学   29412篇
综合类   2339篇
一般理论   1篇
预防医学   18578篇
眼科学   2857篇
药学   9877篇
中国医学   625篇
肿瘤学   16718篇
  2023年   35篇
  2022年   75篇
  2021年   138篇
  2020年   89篇
  2019年   116篇
  2018年   22006篇
  2017年   17443篇
  2016年   19604篇
  2015年   1028篇
  2014年   960篇
  2013年   984篇
  2012年   7260篇
  2011年   21354篇
  2010年   18977篇
  2009年   11718篇
  2008年   19814篇
  2007年   22067篇
  2006年   938篇
  2005年   2531篇
  2004年   3679篇
  2003年   4616篇
  2002年   2729篇
  2001年   396篇
  2000年   531篇
  1999年   282篇
  1998年   276篇
  1997年   258篇
  1996年   164篇
  1995年   153篇
  1994年   137篇
  1993年   115篇
  1992年   120篇
  1991年   155篇
  1990年   190篇
  1989年   137篇
  1988年   109篇
  1987年   83篇
  1986年   57篇
  1985年   51篇
  1984年   51篇
  1983年   45篇
  1982年   52篇
  1980年   53篇
  1974年   36篇
  1970年   28篇
  1969年   33篇
  1938年   61篇
  1934年   32篇
  1932年   64篇
  1930年   48篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
The leaf essential oil of Eugenia zuchowskiae from Monteverde, Costa Rica, has been obtained by hydrodistillation and analyzed by GC–MS. The principal constituents of E. zuchowskiae leaf oil were α-pinene (28.3%), β-caryophyllene (13.2%), α-humulene (13.1%), and α-copaene (8.1%). The leaf essential oil of E. zuchowskiae showed pronounced in-vitro cytotoxic activity against MCF-7, MDA-MB-468, and UACC-257 human tumor cell lines. The major components showed cytotoxic activities comparable to doxorubicin (LC50 14–70 μg/ml).  相似文献   
62.
63.
64.
65.
The prevalence of primary headache (PH) in a multiple sclerosis (MS) sample vs. control healthy subjects was investigated at a neurological clinic in 2004–2005: 122 of 238 (51%) MS patients and 57 of 238 (23%) controls proved to be affected by headache. The groups did not differ for the rates of PH types. Headache types of MS patients were comparable to those of PH patients that were observed at the same institute in a case-control comparison. First symptoms of headache preceded those of MS in two thirds of cases. Headache features did not significantly change after MS onset. Comorbidity of MS and PH could be explained by some common clinical and biological traits.  相似文献   
66.
Single-agent chemotherapy of metastatic breast cancer is the treatment of choice in patients with slow tumor progression and asymptomatic disease. In this patient group, the choice of drugs is based more on good tolerability than on efficacy. By contrast, symptomatic or rapidly progressing disease requires the use of highly active regimens where more weight is put on reliable antitumor activity. While anthraycline-based combination regimens have set the standard of effective treatment, the addition of docetaxel (and to a lesser extent paclitaxel) has improved tumor response, but failed to induce a consistent prolongation of survival. Based on retrospective analyses, it is hypothesised that the combined use of anthracyclines and taxanes in first-line therapy may be most beneficial in defined subgroups: after adjuvant chemotherapy, in patients with HER-2 gene amplification, possibly also in patients with rapidly progressing visceral disease.  相似文献   
67.
68.
69.
70.
Antegrade interlocking nailing of humeral shaft fractures   总被引:5,自引:0,他引:5  
The results of 39 humeral shaft fractures (37 patients) treated with antegrade locked nailing using a Russell–Taylor nail were reviewed. There were 30 acute fractures, 6 fractures malaligned in a hanging cast or brace, and 3 pathological fractures. Patient age ranged from 26 to 80 years (average, 59.7 years) and average follow-up was 25.7 months (range, 6–48 months). Fracture union was achieved in 92.3% of our cases, while shoulder function was excellent or good in 87.2% of cases. Antegrade locked nailing offers a dependable solution for the treatment of humeral shaft fractures, especially in polytrauma patients and cases of segmental or pathological fractures. Far less satisfactory results were obtained in comminuted fractures of the proximal third in the humerus, especially in osteoporotic patients, and we therefore advocate caution with the use of intramedullary nailing in this type of fracture. Certain technical aspects such as avoiding nailing the fracture in distraction, properly countersinking the tip of the nail, and achieving adequate fixation stability have been found to be of paramount importance to reduce the incidence of delayed union/non-union rate and to obtain better functional results from the shoulder joint.  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