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   1509922篇
  免费   108785篇
  国内免费   2529篇
耳鼻咽喉   20821篇
儿科学   44749篇
妇产科学   38186篇
基础医学   223928篇
口腔科学   44856篇
临床医学   134009篇
内科学   290910篇
皮肤病学   32750篇
神经病学   112862篇
特种医学   57543篇
外国民族医学   151篇
外科学   236426篇
综合类   31108篇
现状与发展   2篇
一般理论   382篇
预防医学   106144篇
眼科学   35277篇
药学   116667篇
  4篇
中国医学   4202篇
肿瘤学   90259篇
  2018年   15452篇
  2017年   12042篇
  2016年   13407篇
  2015年   15081篇
  2014年   20609篇
  2013年   30627篇
  2012年   41200篇
  2011年   43290篇
  2010年   25615篇
  2009年   24323篇
  2008年   41359篇
  2007年   43753篇
  2006年   44923篇
  2005年   42586篇
  2004年   41343篇
  2003年   39491篇
  2002年   38680篇
  2001年   81851篇
  2000年   83997篇
  1999年   69792篇
  1998年   17188篇
  1997年   14963篇
  1996年   15262篇
  1995年   14383篇
  1994年   13301篇
  1993年   12224篇
  1992年   53292篇
  1991年   51989篇
  1990年   50221篇
  1989年   49262篇
  1988年   44765篇
  1987年   43633篇
  1986年   41066篇
  1985年   39003篇
  1984年   28191篇
  1983年   23960篇
  1982年   12768篇
  1981年   11220篇
  1979年   25398篇
  1978年   17446篇
  1977年   14884篇
  1976年   13590篇
  1975年   14925篇
  1974年   17856篇
  1973年   17014篇
  1972年   16079篇
  1971年   15112篇
  1970年   14462篇
  1969年   13478篇
  1968年   12345篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The duodenal contents were examined in 81 patients with gastroduodenal ulcer. Bile acid concentrations, alkaline phosphatase activity, and sodium ion concentration were measured for the detection of duodenogastric reflux. Measurements of sodium ion concentration permitted estimation of the immediate volume of the duodenogastric reflux in the gastric contents. No methods for duodenogastric reflux detection should be given preference in examinations of peptic ulcer patients. Multiple-modality studies appear to be the most effective.  相似文献   
992.
Although general suggestions have been made regarding a radiology residency curriculum, no specific list of entities has been offered. Over the past ten years, we have developed a resident-run morning conference in musculoskeletal radiology that is supervised by faculty and covers a specific curriculum. We offer our curriculum as an example that may assist other departments in developing their own curricula.  相似文献   
993.
Computer competition analysis of 3H-DHA (3H-dihydroalprenolol, a nonselective beta-adrenergic radioligand) binding in the presence of unlabeled metoprolol (a beta 1-selective antagonist) indicates the existence of both beta 1- and beta 2-adrenergic receptor subtypes in the rat placenta and confirms previous reports that both beta-adrenoceptors are present in adult rat cortex. In the fetal brain (20th day of gestation), however, only beta 1-receptors were detected. Pregnant rats were chronically exposed to methadone from day 7 to day 20 of gestation via implanted osmotic minipumps (6.3-9.0 mg/kg/day). This treatment schedule did not induce a change in the affinity and density of either beta-receptor subtype in the placental, fetal and maternal brain homogenates. The results are discussed in terms of the reported monoaminergic and opiate receptor functional interactions.  相似文献   
994.
995.
996.
This report examines long-term and short-term benefits of achieving abstinence from opioids in a sample of opioid addicts who were reevaluated 2.5 years following seeking treatment. Extensive assessment of drug use history and drug-associated problems had been obtained when the subjects applied for treatment. At follow-up evaluations, detailed information was obtained on intervening course of drug use, treatment, legal problems, psychological problems, social functioning, occupational functioning, and medical status. The results were as follows: (1) Achieving abstinence from illicit opioids was associated with concurrent improvement in other aspects of functioning including reduction of criminal activity, improved medical status, improved social functioning, and reduced abuse of other psychoactive substances. However, many of these improvements were reversed immediately if relapse to opioid use occurred. (2) Achieving abstinence was associated with being in drug treatment, especially treatment in a methadone maintenance program. (3) Achievement of abstinence was not successfully predicted by client characteristics measured at entrance into treatment. (4) Long-range benefits of abstinence were detectable in social functioning even for those who had relapsed at the time of follow-up reevaluation.  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