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   20386篇
  免费   2009篇
  国内免费   26篇
耳鼻咽喉   274篇
儿科学   766篇
妇产科学   567篇
基础医学   2903篇
口腔科学   635篇
临床医学   2436篇
内科学   3795篇
皮肤病学   356篇
神经病学   1710篇
特种医学   1148篇
外科学   2373篇
综合类   535篇
一般理论   9篇
预防医学   2020篇
眼科学   285篇
药学   1544篇
  1篇
中国医学   23篇
肿瘤学   1041篇
  2021年   290篇
  2020年   179篇
  2019年   293篇
  2018年   351篇
  2017年   279篇
  2016年   295篇
  2015年   322篇
  2014年   464篇
  2013年   657篇
  2012年   804篇
  2011年   836篇
  2010年   562篇
  2009年   496篇
  2008年   854篇
  2007年   856篇
  2006年   880篇
  2005年   748篇
  2004年   725篇
  2003年   667篇
  2002年   672篇
  2001年   641篇
  2000年   663篇
  1999年   546篇
  1998年   332篇
  1997年   273篇
  1996年   295篇
  1995年   271篇
  1994年   221篇
  1993年   271篇
  1992年   457篇
  1991年   437篇
  1990年   447篇
  1989年   492篇
  1988年   470篇
  1987年   384篇
  1986年   409篇
  1985年   458篇
  1984年   302篇
  1983年   245篇
  1982年   189篇
  1981年   195篇
  1980年   170篇
  1979年   216篇
  1978年   206篇
  1977年   225篇
  1976年   193篇
  1975年   185篇
  1974年   172篇
  1973年   181篇
  1972年   169篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.

Background  

There are few effective strategies reported for the primary prevention of low back pain (LBP). Core stabilization exercises targeting the deep abdominal and trunk musculature and psychosocial education programs addressing patient beliefs and coping styles represent the current best evidence for secondary prevention of low back pain. However, these programs have not been widely tested to determine if they are effective at preventing the primary onset and/or severity of LBP. The purpose of this cluster randomized clinical trial is to determine if a combined core stabilization exercise and education program is effective in preventing the onset and/or severity of LBP. The effect of the combined program will be compared to three other standard programs.  相似文献   
12.
13.
14.
15.
16.
17.
The investigation of AUSTROLIABUM CANDIDUM afforded, in addition to several known sesquiterpene lactones, four new ones, including three germacranolides with an ether bridge, as well as an unusual glucoside. The structures were elucidated by spectroscopic methods.  相似文献   
18.
19.
The benefit of internal mammary artery (IMA) grafting as a long-lasting intervention for coronary artery disease is well recognized. However, largely because they are less invasive, catheter based alternatives are frequently chosen, particularly to treat single or double vessel disease. To retain the advantages of the IMA graft, and to offset the invasiveness of conventional coronary artery bypass grafting, we developed a new minimally invasive method using an anterior mediastinotomy for treating left anterior descending (LAD) or right coronary artery disease, or both. Feasibility studies using 16 pigs and a human cadaver led to approval by the Institutional Review Board for use of this procedure to treat six patients (four men, two women; mean age, 63.8 ± 13.6 [SD] yrs) who granted informed consent. Pedicle dissection of the IMA, using video assisted thoracoscopy if necessary, was made through a 2-to 3-inch horizontal anterior mediastinotomy. The underlying LAD artery was grafted during femoral vessel cardiopulmonary bypass, with cooling to 30°C, induced ventricular fibrillation, and left ventricular venting if required. Transesophageal echocardiography performed after bypass showed that two patients maintained normal wall motion and four had improvement from the original impairment. One patient suffered a recurrence of angina 4 weeks after the procedure; recatheterization showed an acutely angled IMA, subsequently corrected by balloon angioplasty. The results of follow-up dobutamine echocardiographic stress tests were negative in all patients. With this minimally invasive approach, the procedure should provide the benefits of IMA grafting with shorter hospital stay, more rapid recovery, and less overall cost.  相似文献   
20.
Both cyproterone acetate (CPA) and the gonadotrophin-releasing hormone agonist (GnRHa) have been shown to be effective for the treatment of hirsutism. We wished to compare the effectiveness of CPA in two standard doses with GnRHa and add-back therapy and to compare the length of remission after these treatments. A total of 60 hirsute hyperandrogenic women was assigned to the following treatment groups: CPA 2 mg with 35 microg of ethinylestradiol for 21 days each month (Diane group), CPA 50 mg, days 5-15, and ethinylestradiol 50 microg, days 5-25, each month (CPA group) or Decapeptyl 3.75 mg i.m. every 28 days with the addition of conjugated oestrogen 0.625 mg, days 1-21, and medroxyprogesterone acetate 10 mg, days 12-21 (GnRHa group). Hirsutism was graded by the Ferriman-Gallwey-Lorenzo (FGL) index and anagen hair shaft diameters and serum luteinizing hormone (LH) and testosterone were assessed before and every 3 months during and after treatment. All women were treated for 1 year with 1 year follow-up. At baseline hirsutism and endocrine patterns were similar in all groups. After one year of treatment, hirsutism decreased in all groups but the changes were greater (P <0.05) in the CPA and GnRHa groups than in the Diane group. Serum LH and testosterone were lowest in the GnRHa group. After withdrawal, hirsutism increased rapidly in the Diane and CPA groups and after 6 months, FGL scores and hair shaft diameters were similar to pretreatment values. In the GnRHa group, hirsutism increased more gradually and after 1 year of withdrawal, FGL scores and hair diameters were significantly (P <0.05) less than pretreatment values. Serum LH and testosterone increased rapidly in all three groups reaching pretreatment values by 6 months. These data suggest equal efficacy of the GnRHa and the high dose CPA regimen for the treatment of hirsutism in hyperandrogenic women. GnRHa with add-back treatment appears to result in a longer remission of hirsutism in comparison with CPA.   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