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   1698308篇
  免费   127169篇
  国内免费   4151篇
耳鼻咽喉   21800篇
儿科学   55693篇
妇产科学   46232篇
基础医学   242045篇
口腔科学   48820篇
临床医学   152049篇
内科学   334164篇
皮肤病学   38698篇
神经病学   131489篇
特种医学   64103篇
外国民族医学   243篇
外科学   257813篇
综合类   39821篇
现状与发展   8篇
一般理论   532篇
预防医学   124536篇
眼科学   40491篇
药学   124422篇
  13篇
中国医学   4849篇
肿瘤学   101807篇
  2021年   13146篇
  2019年   13764篇
  2018年   20180篇
  2017年   15434篇
  2016年   16811篇
  2015年   19321篇
  2014年   26582篇
  2013年   38312篇
  2012年   53244篇
  2011年   55966篇
  2010年   33130篇
  2009年   30902篇
  2008年   51879篇
  2007年   55107篇
  2006年   55597篇
  2005年   52880篇
  2004年   50992篇
  2003年   48375篇
  2002年   46571篇
  2001年   91937篇
  2000年   93748篇
  1999年   77138篇
  1998年   19790篇
  1997年   17361篇
  1996年   17479篇
  1995年   16840篇
  1994年   15343篇
  1993年   14121篇
  1992年   57466篇
  1991年   55348篇
  1990年   53037篇
  1989年   50813篇
  1988年   46179篇
  1987年   44977篇
  1986年   42252篇
  1985年   40006篇
  1984年   29368篇
  1983年   24924篇
  1982年   13913篇
  1979年   25541篇
  1978年   17585篇
  1977年   14916篇
  1976年   13877篇
  1975年   14572篇
  1974年   17643篇
  1973年   16952篇
  1972年   15673篇
  1971年   14455篇
  1970年   13435篇
  1969年   12518篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
981.
The effect of oxitropium bromide (Ba253), a quaternary scopolamine derivative, on the resting tonus and agonist-induced contraction of isolated guinea pig airway smooth muscle and on the anaphylactic release of histamine and immunoreactive leukotrienes (i-LTs) from lung fragments were investigated and compared with those of Sch1000, atropine and isoproterenol. Ba253 dose-dependently inhibited the acetylcholine (ACh)-induced contraction of the isolated trachea and lung parenchyma. The degree of inhibitory potency was similar to that of Sch1000 and 10 times higher than that of atropine. Ba253 minimally influenced the resting tonus or contractions induced by other agonists including histamine, serotonin and LTD4. Sch1000 and atropine had similar or slightly stronger inhibitory effects on the tonus and contractions than Ba253. On the other hand, low concentrations of isoproterenol solely relaxed the resting tonus and inhibited the the agonist-induced contractions of both preparations. Neither Ba253 nor Sch1000 inhibited the anaphylactic release of histamine and LTs from both guinea pig and human lung fragments, but both mediator releases from either species were slightly inhibited with dose-dependency by atropine and potently inhibited by isoproterenol. From these results, it is suggested that Ba253 is a relatively specific antagonist to cholinergic receptors and might be possibly effective as an inhalant for asthma.  相似文献   
982.
983.
Three cases of voluntary posterior instability of the shoulder are presented. They have all responded well to a program of electromyographic monitored biofeedback. This method offers a means of enhancing the results of nonoperative treatment.  相似文献   
984.
985.
986.
Spinal antinociceptive effects of adenosine compounds in mice   总被引:1,自引:0,他引:1  
The effects of injecting ATP, ADP, AMP, adenosine and adenine intrathecally on the pain response induced by the injection of substance P (10 ng/mouse) intrathecally were studied. All the compounds except adenine inhibited the pain response in a dose-related manner. The ED50 values of ATP, ADP, AMP and adenosine were 2.10, 0.93, 0.88 and 0.48 micrograms/mouse, respectively. Pretreatment with theophylline at a dose of 100 mg/kg p.o. markedly diminished all the antinociceptive effects. The effect of adenosine was not affected by s.c. injection of naloxone. These results suggest the existence of adenosine receptors which modulate spinal nociceptive sensory processing, independently of the endogenous opiate system.  相似文献   
987.
Reported in this paper are postoperative results recorded from 120 patients, 3 years after selective proximal vagotomy for uncomplicated duodenal ulcer. There was no intraoperative lethality and no recurrence in 96.7 per cent of all cases, while Visick grades I on II were recorded from 98.2 per cent. Radiologically and gastroscopically detected pathological processes receded soon. Average postoperative reduction in acid secretion was 66.2 per cent in BAO and 46.8 per cent in MAO. Acid values re-increased thereafter, and three years later reduction rates still amounted to 43.7 per cent in BAO and 28.6 per cent in MAO. Indications for proximal gastric vagotomy are discussed in some detail.  相似文献   
988.
989.
Experience with the 'skew flap' below-knee amputation   总被引:3,自引:0,他引:3  
A review of 353 lower limb amputations over the last 7 years has been performed to assess the results of the skew flap myoplastic below-knee amputation which was introduced in April 1983 because of reported advantages in terms of wound healing and earlier ambulation. Comparing the first 3 1/2 year period with the second, the total number of amputations decreased by 31 per cent. The number of above-knee amputations remained similar in the two periods (82,62), whilst the number of Gritti-Stokes amputations fell from 79 to 21 (0.001 greater than P greater than 0.01). The proportion of below-knee (BK) amputations increased from 50 (23.7 per cent) to 59 (41.5 per cent) (0.01 greater than P greater than 0.025). The groups were comparable in terms of previous vascular surgery and co-existing medical conditions. The time to full stump healing was significantly shorter in the skew flap group compared with the earlier Burgess type BK amputation (P = 0.001), and there was a trend to fewer stump failures in the skew flap group. We therefore feel that the skew flap amputation gives superior results to the Burgess BK amputation in terms of healing and a lower complication rate, allowing a higher proportion of BK amputations to be performed. A prospective randomized trial of the two techniques is in hand to determine the accuracy of this hypothesis.  相似文献   
990.
Topical analgesia for relief of post-circumcision pain   总被引:1,自引:0,他引:1  
  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