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   7156篇
  免费   501篇
  国内免费   25篇
耳鼻咽喉   125篇
儿科学   197篇
妇产科学   183篇
基础医学   956篇
口腔科学   157篇
临床医学   497篇
内科学   1827篇
皮肤病学   226篇
神经病学   580篇
特种医学   229篇
外科学   1110篇
综合类   38篇
一般理论   1篇
预防医学   616篇
眼科学   108篇
药学   370篇
中国医学   33篇
肿瘤学   429篇
  2023年   41篇
  2022年   105篇
  2021年   188篇
  2020年   101篇
  2019年   199篇
  2018年   239篇
  2017年   167篇
  2016年   186篇
  2015年   192篇
  2014年   279篇
  2013年   367篇
  2012年   456篇
  2011年   493篇
  2010年   311篇
  2009年   306篇
  2008年   424篇
  2007年   432篇
  2006年   430篇
  2005年   426篇
  2004年   348篇
  2003年   365篇
  2002年   304篇
  2001年   144篇
  2000年   183篇
  1999年   171篇
  1998年   52篇
  1997年   54篇
  1996年   42篇
  1995年   29篇
  1994年   24篇
  1993年   31篇
  1992年   74篇
  1991年   59篇
  1990年   73篇
  1989年   54篇
  1988年   39篇
  1987年   43篇
  1986年   41篇
  1985年   38篇
  1984年   27篇
  1983年   19篇
  1982年   12篇
  1981年   9篇
  1980年   9篇
  1979年   8篇
  1978年   10篇
  1977年   8篇
  1976年   8篇
  1975年   10篇
  1971年   13篇
排序方式: 共有7682条查询结果,搜索用时 15 毫秒
991.
Eight hundred twenty-four patients who had cardiac valve replacement with a porcine bioprosthesis were given either Coumadin (sodium warfarin) or aspirin. No patient in sinus rhythm no matter what valve or valves were replaced had thromboembolism whether treated with Coumadin (124 patients) or aspirin (260 patients). One hundred fifty-one patients who had mitral valve replacement, were in atrial fibrillation, and were treated with Coumadin had seven embolic events (4.6%), while 135 similar patients treated with aspirin had five embolic events (3.7%). Fifty-one patients who had double-valve replacement, were in atrial fibrillation, and were treated with Coumadin had three embolic episodes (5.9%), while 86 similar patients treated with aspirin had three embolic events (3.5%).No statistical difference was found in the incidence of thromboembolism between similar groups of patients whether treated with Coumadin or aspirin (p > 0.05). Hemorrhagic complications were higher and reached statistical significance (p < 0.001) for the group treated with Coumadin. This study shows that aspirin prevents thromboembolic complications as well as Coumadin in patients having cardiac valve replacement with a bioprosthesis, and results in a lower rate of complications.  相似文献   
992.
993.
Eight malnourished patients (5 men and 3 women, mean age 26.5 +/- 0.4 years) suffering from Inflammatory Bowel Disease were prospectively included at admission to study the effect on protein-energy and vitamin status of a specially designed enterally tube fed formula diet. Eighty nine healthy individuals (36 men and 53 women, mean age 34 +/- 2 years) were used as controls. All but one patient were on steroids. The mean caloric supply was 58.2 +/- 2.4 kcal/kg/day with a mean nitrogen content of 0.37 +/- 0.02 gN/kg/day. The mean Total Enteral Nutrition period lasted 20.8 +/- 2.3 days (range 12 to 28 days). Fat- and water-soluble vitamins were studied at admission and after the nutritional period. Likewise both the protein-energy nutritional status and the activity of the disease were evaluated. At admission, plasma levels of folate, biotin, beta-carotene and vitamins A, C and E were significantly lower in patients than in controls. Tocopherol/cholesterol ratio, and vitamin B1, B2, B6, and B12 status were normal. At the end, plasma values of folate, biotin and vitamin C remained unchanged. However, the protein-energy nutritional status and the activity of the disease significantly improved. At admission, 4 out of 8 patients were at risk of developing hypovitaminosis for vitamins A, C, biotin, beta-carotene, and folate. At the end, a similar percentage remained at risk for these vitamins except for vitamin A. The content of some vitamins in the best designed formula diets does not meet the needs for patients with Inflammatory Bowel Disease.  相似文献   
994.
995.
996.
Orthopaedic examinations were carried out in 242 children studying string instruments. Various indispositions and deformations of the motor organs were found in 31 children. It has been demonstrated that they were mainly the result of technical errors in holding of the instrument, which caused overloading of the upper extremities and the spine.  相似文献   
997.
998.
999.
1000.
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