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   33361篇
  免费   4986篇
  国内免费   146篇
耳鼻咽喉   595篇
儿科学   880篇
妇产科学   837篇
基础医学   3516篇
口腔科学   751篇
临床医学   5763篇
内科学   6716篇
皮肤病学   654篇
神经病学   3052篇
特种医学   1092篇
外科学   4481篇
综合类   940篇
现状与发展   2篇
一般理论   15篇
预防医学   4242篇
眼科学   555篇
药学   2306篇
  2篇
中国医学   129篇
肿瘤学   1965篇
  2023年   507篇
  2022年   237篇
  2021年   611篇
  2020年   687篇
  2019年   514篇
  2018年   957篇
  2017年   922篇
  2016年   922篇
  2015年   1074篇
  2014年   1215篇
  2013年   1797篇
  2012年   1493篇
  2011年   1482篇
  2010年   1173篇
  2009年   1177篇
  2008年   1293篇
  2007年   1396篇
  2006年   1355篇
  2005年   1309篇
  2004年   1140篇
  2003年   1173篇
  2002年   1043篇
  2001年   863篇
  2000年   799篇
  1999年   742篇
  1998年   547篇
  1997年   506篇
  1996年   512篇
  1995年   494篇
  1994年   399篇
  1993年   316篇
  1992年   603篇
  1991年   562篇
  1990年   533篇
  1989年   545篇
  1988年   483篇
  1987年   473篇
  1986年   418篇
  1985年   487篇
  1984年   420篇
  1983年   337篇
  1982年   314篇
  1981年   278篇
  1980年   257篇
  1979年   355篇
  1978年   306篇
  1976年   255篇
  1974年   276篇
  1973年   287篇
  1972年   239篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
31.
A G Lewis 《Postgraduate medicine》1989,86(3):141-4, 147-51
Initial assessment of common forefoot deformities by the primary care physician is quite feasible. A thorough history, examination of the foot with the patient standing and seated, assessment of the patient's footwear, and radiographic evaluation can often lead to gratifying relief with use of simple office measures. Even in cases that require referral to an orthopedic surgeon, interim relief of symptoms and the patient's increased awareness of the problem and its cause enhance the patient's understanding and the final outcome as well.  相似文献   
32.
33.
Research on physical activity (PA) by level of acculturation in Hispanic children is limited and findings have been mixed. We examined PA participation by primary language used with parents in a representative sample of 4th, 8th, and 11th grade Texas public school students. Mixed-effects regression models were conducted using cross-sectional data from the 2004–2005 School Physical Activity and Nutrition Study (n = 22,049). Self-reported PA was compared among three language-ethnic groups: Spanish-Hispanic (SH) (referent); English-Hispanic (EH); and English-Other (EO). EH and/or EO girls were generally between 1.25 and 2.58 [OR] times more likely to participate in PA across grade levels, with the largest differences found for school sports in 8th grade girls. EH and EO 8th grade boys were 1.71 (CI: 1.40, 2.10) and 2.06 (CI: 1.68, 2.51) times, respectively, more likely to participate in school sports. Findings indicate important disparities in Spanish-speaking Hispanic children’s PA participation.  相似文献   
34.
35.
36.
Popliteal artery aneurysms representing 80% of peripheral artery aneurysms rarely rupture (a reported incidence of 0.1–2.8 %) and second commonest in frequency after aorto-iliac aneurysms. They usually present with pain, swelling, occlusion or distal embolisation and can cause diagnostic difficulties. We report a 78 year old man who was previously admitted to hospital with a pulmonary embolus secondary to deep venous thrombosis. He was heparinized then warfarinised and was readmitted with a ruptured popliteal aneurysm leading to a large pseudo aneurysm formation. The pulmonary embolus had been due to popliteal vein thrombosis and propagation of the clot. A thorough review of literature identified only one previously reported case of ruptured popliteal artery aneurysm and subsequent large pseudo aneurysm formation. We feel it is important to exclude a popliteal aneurysm in a patient with DVT. This may be more common than the published literature suggests.  相似文献   
37.
38.
OBJECTIVE: To identify the possible contribution of electromyogram (EMG) to scalp electroencephalogram (EEG) rhythms at rest and induced or evoked by cognitive tasks. METHODS: Scalp EEG recordings were made on two subjects in presence and absence of complete neuromuscular blockade, sparing the dominant arm. The subjects undertook cognitive tasks in both states to allow direct comparison of electrical recordings. RESULTS: EEG rhythms in the paralysed state differed significantly compared with the unparalysed state, with 10- to 200-fold differences in the power of frequencies above 20 Hz during paralysis. CONCLUSIONS: Most of the scalp EEG recording above 20 Hz is of EMG origin. Previous studies measuring gamma EEG need to be re-evaluated. SIGNIFICANCE: This has a significant impact on measurements of gamma rhythms from the scalp EEG in unparalysed humans. It is to be hoped that signal separation methods will be able to rectify this situation.  相似文献   
39.
40.
Insulin-like growth factor-1 (Igf-1), a critical mediator of tissue repair, is significantly decreased in diabetic wounds. Furthermore, decreased levels of hypoxia-inducible factor 1-alpha (Hif-1alpha) and its target genes are also associated with impaired wound healing in diabetic mice. The aim of our study was to examine whether the reduced levels of Igf-1 are responsible for the reduction in Hif-1alpha protein synthesis and activity in diabetic wounds. We provide evidence that Igf-1 regulates Hif-1alpha protein synthesis and activity during wound repair. In addition, Igf-1 stimulated phosphytidylinositol 3-kinase activity in diabetic fibroblasts, which, in turn, increased activation of the translational regulatory protein, p70 S6 kinase. Moreover, improved healing of diabetic wounds by addition of recombinant IGF-1 protein was associated with an increase in Hif-1alpha protein synthesis and function in vivo.  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