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   7633篇
  免费   528篇
  国内免费   89篇
耳鼻咽喉   64篇
儿科学   191篇
妇产科学   105篇
基础医学   1113篇
口腔科学   137篇
临床医学   584篇
内科学   1660篇
皮肤病学   404篇
神经病学   530篇
特种医学   461篇
外科学   1184篇
综合类   167篇
一般理论   4篇
预防医学   374篇
眼科学   263篇
药学   367篇
中国医学   28篇
肿瘤学   614篇
  2023年   52篇
  2022年   87篇
  2021年   204篇
  2020年   138篇
  2019年   177篇
  2018年   196篇
  2017年   167篇
  2016年   222篇
  2015年   246篇
  2014年   335篇
  2013年   313篇
  2012年   557篇
  2011年   519篇
  2010年   289篇
  2009年   269篇
  2008年   396篇
  2007年   403篇
  2006年   338篇
  2005年   396篇
  2004年   331篇
  2003年   273篇
  2002年   306篇
  2001年   239篇
  2000年   232篇
  1999年   195篇
  1998年   95篇
  1997年   80篇
  1996年   75篇
  1995年   72篇
  1994年   58篇
  1993年   47篇
  1992年   95篇
  1991年   86篇
  1990年   83篇
  1989年   98篇
  1988年   110篇
  1987年   73篇
  1986年   64篇
  1985年   58篇
  1984年   39篇
  1983年   47篇
  1982年   14篇
  1981年   18篇
  1980年   13篇
  1979年   27篇
  1978年   17篇
  1977年   30篇
  1976年   13篇
  1975年   8篇
  1974年   9篇
排序方式: 共有8250条查询结果,搜索用时 421 毫秒
21.
22.
A 4 month-old boy who had double-inlet left ventricle, severe subaortic stenosis, hypoplastic ascending aorta and coarctation of the aorta revealed severe respiratory failure. An urgent Norwood operation was done. The procedure consisted of enlargement of the ascending aorta and main pulmonary artery and a systemic-pulmonary shunt using 5 mm PTFE tube. Postoperative course was uneventful.  相似文献   
23.
This study describes the effects of Norplant on haemostatic function after 5 years of use in 97 women. There was a decrease in vitamin-K dependent Factors II, V, VII and reduction in fibrinolytic activity at 2 and 4 years of use. Increased platelet numbers and accelerated platelet aggregation were found throughout the 5 years of Norplant use, whilst raised alpha 2-Macroglobulin (a2-M) and antithrombin III (ATIII) antigen level were observed for up to 4 years of use. Prolonged Norplant use does not appear to activate the coagulation system and does not enhance a state of hypercoagulation.  相似文献   
24.
Recently, metastasis to N3 lymph nodes group was regarded as distant metastasis by the new TNM staging system due to poor overall survival. However, the 5-year overall survival rate of patients with metastasis to N3 groups was 34.5% after curative surgery. Moreover, in patients with metastasis to lymph node subgroups of #12, #13, #14, the overall 5-year survival rate increased upto 47.2% after curative resection and adjuvant chemotherapy. This was similar to that of the patients with metastasis to N1 and N2 lymph nodes groups. But in these highly tumor burden states, no survival benefit was found with the addition of immunotherapy to chemotherapy as we achieved in stage II and III. Therefore, we suggest that, at least, metastasis to #12, #13, #14 lymph nodes subgroups should not be categorized as a distant metastasis. And in these situations, active curative radical surgery with extended lymphadenectomy and adjuvant chemotherapy are recommended.  相似文献   
25.
26.
Signals generated from muscles other than the muscle(s) of interest (cross talk) can confound the interpretation of surface electromyograms (EMGs). In this study, the amount of cross talk in surface EMGs of human hamstring muscles was estimated using a protocol in which the quadriceps femoris was electrically stimulated via the femoral nerve. EMGs were recorded from the vastus lateralis and the medial and lateral hamstring muscle groups. The amplitude of the EMG response of the vastus lateralis to electrical stimulation was adjusted to match that of its maximum voluntary effort (MVE) under isometric conditions. Subsequent power density spectrum analysis showed that the median frequencies of the signals generated by electrical stimulation and MVE were not significantly different. In conventional bipolar recordings, cross talk in lateral hamstring EMGs averaged 17.1% MVE and in medial hamstring EMGs 11.3% MVE (average-rectified values). The double differential technique significantly reduced cross talk to 7.6% MVE for the lateral hamstrings, and to 4.2% MVE for the medial hamstrings. The double differential technique appears to be more selective than the bipolar technique when recording EMGs from muscles with highly active neighbors and thus should be used in such situations. Software simulations of the double differential technique also appear to be more selective than the bipolar technique and may be used when the number of amplifiers available is limited.  相似文献   
27.
28.
Surgical results of total anomalous pulmonary venous connection (TAPVC) has been improved in recent years, however, late development of pulmonary venous obstruction was our concern in its total correction in early infancy. In the cardiac type of TAPVC, in which the pulmonary veins were connected to the right lateral wall, prosthetic patch is conventionally used in diversion of pulmonary venous flow into left atrium. It seemed favorable to repair this subset without using prosthesis. A 3-month-old female with TAPVCIIb according to Darling's classification underwent total correction on September 22th, 1988. Two pedicled flaps were developed using the right atrial wall and the atrial septum to create a pulmonary venous channel to divert arterial blood into left atrium and absorbable sutures were used throughout. Right atrium was entered through a vertical incision in its body and all the pulmonary veins were found in a recess in the lateral wall of the right atrium. Atrial septal defect in the cranial aspect of the fossa ovalis was enlarged by cutting the primum tissue along the right limbus and its caudal margin so as to form a pedicled flap attached to the left limbic tissue. Then the flap was sutured along the limbus to create a roof of the fossa ovalis. The second flap was made in the middle of the lateral atrial wall and was used to create a tunnel from the recess to the atrial septal defect. The defect in the right atrial wall was closed directly and no prosthetic patch was used. Postoperative course was uneventful and echocardiogram showed wide pulmonary venous channel draining into the left atrium.  相似文献   
29.
Nutrition resources in Chinese have been developed for the patients in St. Paul's Hospital's Renal Program. The goal was to support this patient subgroup to understand and practice the complicated diet guidelines within their own language and cultural contexts.  相似文献   
30.
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