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   1720866篇
  免费   128482篇
  国内免费   3889篇
耳鼻咽喉   22115篇
儿科学   56397篇
妇产科学   46664篇
基础医学   244799篇
口腔科学   49271篇
临床医学   153975篇
内科学   339952篇
皮肤病学   39116篇
神经病学   133686篇
特种医学   64857篇
外国民族医学   243篇
外科学   261409篇
综合类   39330篇
现状与发展   4篇
一般理论   547篇
预防医学   126549篇
眼科学   40799篇
药学   125752篇
  8篇
中国医学   4529篇
肿瘤学   103235篇
  2021年   13258篇
  2019年   13994篇
  2018年   20529篇
  2017年   15666篇
  2016年   17089篇
  2015年   19461篇
  2014年   27013篇
  2013年   39206篇
  2012年   54554篇
  2011年   57331篇
  2010年   33856篇
  2009年   31693篇
  2008年   53366篇
  2007年   56901篇
  2006年   57374篇
  2005年   54556篇
  2004年   52767篇
  2003年   50054篇
  2002年   48287篇
  2001年   92017篇
  2000年   93771篇
  1999年   77239篇
  1998年   20142篇
  1997年   17597篇
  1996年   17707篇
  1995年   17027篇
  1994年   15553篇
  1993年   14312篇
  1992年   57563篇
  1991年   55417篇
  1990年   53110篇
  1989年   50872篇
  1988年   46265篇
  1987年   45080篇
  1986年   42349篇
  1985年   40130篇
  1984年   29577篇
  1983年   25118篇
  1982年   14191篇
  1981年   12645篇
  1979年   25630篇
  1978年   17710篇
  1977年   15042篇
  1976年   14003篇
  1975年   14656篇
  1974年   17716篇
  1973年   17014篇
  1972年   15729篇
  1971年   14485篇
  1970年   13459篇
排序方式: 共有10000条查询结果,搜索用时 546 毫秒
991.
Three evaluation instruments (global, check-list, and criterion referenced) were used by experienced and inexperienced examiners to evaluate dental sealant end products on 40 extracted teeth. Intra- and interexaminer reliabilities were measured. Experienced examiners achieved higher intrarater reliabilities with all three evaluation instruments than did inexperienced examiners. The highest intraexaminer agreement for all examiners occurred with use of the global evaluation. The highest interexaminer reliability was achieved with the second use of the criterion-referenced evaluation by the experienced examiner. Interexaminer reliability was improved for both types of examiners with the criterion-referenced evaluation.  相似文献   
992.
A 65-year-old man with spontaneous rupture of the esophagus survived with a direct suture of the esophagus 15 hours after the onset of symptoms. Endoscopic examination of the esophagus was especially of great help in determining the surgical procedure in this patient, and we want to stress the importance of prompt diagnosis and immediate surgery for this disease.  相似文献   
993.
994.
995.
Effects of dexamethasone on central and peripheral ACTH systems in the rat   总被引:1,自引:0,他引:1  
To investigate the simultaneous effects of dexamethasone on peripheral and central adrenocorticotropic hormone (ACTH) systems, rats were treated with dexamethasone or saline for 4 days. Pituitary, plasma, hypothalamus and cerebrospinal fluid (CSF) were then collected and analyzed for ACTH immunoreactivity. Additionally, hypothalamic tissue extracts were analyzed for corticotropin-releasing hormone (CRH) immunoreactivity. Dexamethasone significantly lowered peripheral levels of ACTH as measured in pituitary and plasma. Hypothalamic ACTH content significantly increased while CSF ACTH significantly decreased with dexamethasone treatment. Hypothalamic CRH concentrations showed a small but statistically insignificant decrease. These results suggest that prolonged exposure to dexamethasone affects central as well as peripheral ACTH activity, corroborate our previous findings in rhesus monkeys of decreased CSF ACTH in response to prolonged dexamethasone treatment, suggest that dexamethasone may inhibit the release of ACTH from hypothalamic neurons into the CSF, and provide evidence that the effect of dexamethasone on pituitary ACTH content is of greater magnitude than its effect on hypothalamic CRH.  相似文献   
996.
997.
Sub-trigonal phenol injection ensures a satisfactory response in about 50% of patients with detrusor instability. When oral anticholinergic treatment is poorly tolerated or ineffective, this minimally invasive technique has been found, in our series of 11 patients, to be a useful adjunct, at least temporarily.  相似文献   
998.
999.
1000.
K Nagai  T Suda  K Kawasaki  S Mathuura 《Surgery》1986,100(5):815-821
In rats treat-given hydrocortisone to suppress healing, tensile strength of the skin at the site of an incision wound was significantly higher in rats locally treated with carnosine than in untreated animals. Similar effects on the tensile strength of the skin were observed by the administration of beta-alanine and histidine, but not of beta-alanine alone. Exogenous carnosine was degraded in the body by carnosinase and histidine decarboxylase to yield histamine. Since beta-alanine, the other degradation product of carnosine, was found to stimulate the biosynthesis of nucleic acids and collagen, histamine derived from carnosine is considered to have enhanced the process of wound healing by stimulating effusion at the initial stage of inflammation. Thus, the enhancement by carnosine of wound healing may be ascribed to stimulation of early effusion by histamine and of collagen biosynthesis by beta-alanine. The wound-healing effects of carnosine were further demonstrated by the observation that carnosine significantly increased granulation suppressed by cortisone, mitomycin C, 5-fluorouracil, and bleomycin.  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