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   2364834篇
  免费   175025篇
  国内免费   3353篇
耳鼻咽喉   32182篇
儿科学   76588篇
妇产科学   63263篇
基础医学   350189篇
口腔科学   63829篇
临床医学   214719篇
内科学   459980篇
皮肤病学   51967篇
神经病学   186854篇
特种医学   88255篇
外国民族医学   490篇
外科学   355260篇
综合类   47769篇
现状与发展   12篇
一般理论   893篇
预防医学   185471篇
眼科学   54475篇
药学   176086篇
  11篇
中国医学   4588篇
肿瘤学   130331篇
  2021年   19305篇
  2019年   19887篇
  2018年   27427篇
  2017年   20626篇
  2016年   23030篇
  2015年   25966篇
  2014年   36557篇
  2013年   54767篇
  2012年   75788篇
  2011年   80509篇
  2010年   47681篇
  2009年   45158篇
  2008年   75731篇
  2007年   80689篇
  2006年   81423篇
  2005年   78873篇
  2004年   75478篇
  2003年   72691篇
  2002年   70340篇
  2001年   108880篇
  2000年   111572篇
  1999年   93636篇
  1998年   27256篇
  1997年   23847篇
  1996年   24242篇
  1995年   22880篇
  1994年   21048篇
  1993年   19853篇
  1992年   72108篇
  1991年   70152篇
  1990年   68495篇
  1989年   65734篇
  1988年   60409篇
  1987年   59188篇
  1986年   55299篇
  1985年   53097篇
  1984年   39405篇
  1983年   33483篇
  1982年   19998篇
  1979年   35934篇
  1978年   25727篇
  1977年   21279篇
  1976年   20399篇
  1975年   21884篇
  1974年   26214篇
  1973年   24888篇
  1972年   23238篇
  1971年   22070篇
  1970年   20280篇
  1969年   19339篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
C-reactive protein levels predict postoperative septic complications   总被引:5,自引:0,他引:5  
We studied 108 patients undergoing clean-contaminated and dirty surgical procedures to determine whether daily C-reactive protein (CRP) measurements for 14 days postoperatively could predict the occurrence of septic complications prior to clinical diagnosis. Diagnostic criteria for septic complications and positive CRP response were defined in advance of the study. The CRP assays were carried out using an automated laser nephelometer system after the patient's discharge from the hospital. Forty-six septic complications were diagnosed in 40 patients. These complications consisted of wound infection (23), urinary tract infection (11), pneumonia (six), upper respiratory tract infection (three), intra-abdominal abscess (one), and other (two). The CRP testing was found to have a positive predictive value of 69% and a negative predictive value of 78%. We conclude that serial CRP measurements may be a valuable adjunct to surgical care in patients at high risk of postoperative septic complications.  相似文献   
992.
Polymorphonuclear leukocyte (PMN) migration was assessed in vitro using the agarose plate method in patients with psoriasis vulgaris, and compared with an age- and sex-matched control group. No significant difference was found between the two groups in the PMN response to the chemotactic substances F-Met-Leu-Phe (FMLP) or zymosan activated serum (ZAS). Equally, the chemokinetic or chemotactic potential of psoriatic serum did not differ from control serum. Our results do not support a primary abnormality of PMN function in psoriasis.  相似文献   
993.
The results of a national survey of trauma centers concerning their assessment and response to the problem of alcohol and trauma are reported. Surveys were returned from 154 trauma centers located in 43 states and the District of Columbia. The profile of the 125,000 patients treated at the centers is a 30-year-old man sustaining blunt trauma, usually in a vehicular crash. Two-thirds of centers estimated that the majority of their patients had abused alcohol. While acknowledging alcohol as a significant cause of trauma, only 55.2% of centers routinely obtain admitting blood alcohol levels. Less than a third of the centers employ alcoholism counselors. Most trauma centers are not providing services that allow them to fulfill their responsibility to detect and initiate treatment of alcohol abuse, a major cause of traumatic injury.  相似文献   
994.
The vascular endothelium plays an important and complex role in vascular allograft rejection. Antigens expressed by the endothelium can act to promote and be the target of rejection reactions, which often lead to thrombosis and ischemic necrosis of the allograft. In this study, segments of femoral artery and femoral vein with or without endothelium were grafted between allogenic or autologous control rats. Immunocompetent Lewis (RT1(1] recipient rats were randomly selected for groups (N = 14 for each) receiving the following: ACI- (RT1a) allografts with intact endothelium, allografts with endothelium removed before operation, autografts with endothelium, and autografts with endothelium removed. Rejection was assessed by graft patency as well as morphologic and ultrastructural changes. At 5 days, the allografts with intact endothelium were totally occluded, whereas allografts without endothelium remained patent, as did autologous control grafts with or without endothelium. Two additional groups (N = 14 each) receiving the de-endothelialized allografts or autografts were examined at 120 days after operation, revealing that grafts in both groups were still patent and had been re-endothelialized. These findings indicate that physical removal of vascular endothelium may depress vessel allograft rejection without immunosuppressive therapy.  相似文献   
995.
996.
997.
998.
Since the role of cutaneous nerves in the pathogenesis of cutaneous diseases associated with diabetes mellitus is not well defined, cutaneous nerves in ten patients with severe diabetic neuropathy were electron microscopically investigated as a preliminary study. The specimens were taken from normal-appearing skin of their lower extremities. Cutaneous nerves were seen as axon-Schwann cell complexes in which variously degenerated axons and Schwann cells coexisted with normal ones. The degenerative changes were not, however, specific for diabetes mellitus.  相似文献   
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