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   3420篇
  免费   248篇
  国内免费   19篇
耳鼻咽喉   32篇
儿科学   106篇
妇产科学   72篇
基础医学   522篇
口腔科学   35篇
临床医学   409篇
内科学   743篇
皮肤病学   48篇
神经病学   312篇
特种医学   111篇
外科学   436篇
综合类   28篇
一般理论   4篇
预防医学   242篇
眼科学   78篇
药学   210篇
中国医学   12篇
肿瘤学   287篇
  2024年   8篇
  2023年   36篇
  2022年   86篇
  2021年   146篇
  2020年   75篇
  2019年   101篇
  2018年   124篇
  2017年   88篇
  2016年   120篇
  2015年   137篇
  2014年   156篇
  2013年   194篇
  2012年   297篇
  2011年   275篇
  2010年   173篇
  2009年   149篇
  2008年   206篇
  2007年   179篇
  2006年   179篇
  2005年   205篇
  2004年   182篇
  2003年   163篇
  2002年   151篇
  2001年   41篇
  2000年   26篇
  1999年   34篇
  1998年   38篇
  1997年   21篇
  1996年   17篇
  1995年   14篇
  1994年   9篇
  1993年   9篇
  1992年   13篇
  1991年   7篇
  1990年   5篇
  1989年   1篇
  1987年   1篇
  1986年   3篇
  1985年   2篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   4篇
  1974年   1篇
  1969年   1篇
  1968年   3篇
排序方式: 共有3687条查询结果,搜索用时 31 毫秒
61.
Methods:This study was a retrospective chart review of 1377 patients (2–20 years) undergoing laparoscopic appendectomy for acute appendicitis in 2 tertiary care referral centers from January 2007 through December 2012. Twenty-two different operative technique/dressing variations were documented. The 6 technique/dressing groups with >50 patients were assessed, including a total of 1283 patients.Results:The surgical site infection rate of the 220 patients treated with TULAA and application of an umbilical vacuum dressing with dry gauze is 1.8% (95% CI, 0.0–10.3%). This compares to an infection rate of 4.1% (95% CI, 1.3–10.5%) in 97 patients with dry dressing without vacuum. In the 395 patients who received an umbilical vacuum dressing with gauze and bacitracin, the surgical site infection rate was found to be 4.3% (95% CI, 2.7–6.8%).Conclusions:Application of an umbilical negative-pressure dressing with dry gauze lowers the rate of umbilical site infections in patients undergoing transumbilical laparoscopic-assisted appendectomy for acute appendicitis.  相似文献   
62.
63.
64.
65.
66.
67.
The radical change of lifestyle during Ramadan fast has shown to affect cardiometabolic risk variables in adults. In youth, however, no studies are available. We aimed to evaluate the effect of Ramadan fast on Body Mass Index (BMI) and the cardiometabolic profile of obese adolescents. A prospective cohort study was conducted. We measured weight, height, body composition, blood pressure, heart rate, glucose, insulin, total cholesterol, low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol, triglycerides, and high sensitivity C-reactive protein (hs-CRP) levels before, during the last week of and at 6 weeks after Ramadan. Twenty-five obese adolescents were included. BMI and glucose metabolism did not change after Ramadan or at 6 week after cessation of Ramadan. At the end of Ramadan, a significant decrease in body fat percentage was observed, while significant increases in heart rate, total cholesterol, LDL cholesterol, HDL cholesterol, and hs-CRP were found (all P?<?0.05). Six weeks after Ramadan, all parameters returned to baseline levels. Conclusion: In this sample of 25 ethnic obese adolescents transient cardiometabolic changes were observed during Ramadan fasting. Since most of these changes were reversible within 6 weeks, there seems no harm or benefit for obese adolescents to participate in Ramadan.  相似文献   
68.
69.
70.
Ultrafine grained sheets were prepared from a twin-roll cast AA8006 aluminium alloy using accumulative roll-bonding process at room temperature. The evolution of microstructure of sheets after three accumulative roll-bonding passes during isochronal annealing with a constant step of 20 °C/20 min was studied by light and electron microscopy. The influence of the resulting microstructure on mechanical properties was monitored by microhardness measurements. The microhardness increases when the material is annealed up to 160 °C. Above this temperature a fast drop of microhardness occurs followed by a negligible variation at annealing temperatures exceeding 300 °C. In order to map continuously the microstructure changes during annealing, the in situ TEM experiments in the heating stage were performed as a supplement to post-mortem TEM observations.  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