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   2453748篇
  免费   172085篇
  国内免费   4818篇
耳鼻咽喉   33036篇
儿科学   80188篇
妇产科学   67126篇
基础医学   349625篇
口腔科学   71026篇
临床医学   221645篇
内科学   470645篇
皮肤病学   55798篇
神经病学   190054篇
特种医学   93552篇
外国民族医学   437篇
外科学   370396篇
综合类   53911篇
现状与发展   5篇
一般理论   759篇
预防医学   180201篇
眼科学   58011篇
药学   185298篇
  13篇
中国医学   6181篇
肿瘤学   142744篇
  2021年   18372篇
  2019年   19055篇
  2018年   27630篇
  2017年   21232篇
  2016年   23614篇
  2015年   26702篇
  2014年   36824篇
  2013年   53966篇
  2012年   74339篇
  2011年   78380篇
  2010年   46480篇
  2009年   43446篇
  2008年   72646篇
  2007年   77561篇
  2006年   78169篇
  2005年   74717篇
  2004年   71860篇
  2003年   68605篇
  2002年   66069篇
  2001年   128013篇
  2000年   130995篇
  1999年   108666篇
  1998年   28467篇
  1997年   24917篇
  1996年   24989篇
  1995年   23862篇
  1994年   21789篇
  1993年   20375篇
  1992年   82073篇
  1991年   79155篇
  1990年   76962篇
  1989年   73863篇
  1988年   67147篇
  1987年   65424篇
  1986年   61833篇
  1985年   58621篇
  1984年   42933篇
  1983年   36536篇
  1982年   20541篇
  1979年   38228篇
  1978年   26294篇
  1977年   22888篇
  1976年   20739篇
  1975年   22560篇
  1974年   26955篇
  1973年   25969篇
  1972年   24270篇
  1971年   22648篇
  1970年   20952篇
  1969年   19803篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
There is increasing evidence from human and experimental studies that the most important factor governing the outcome in head injury is the severity of diffuse axonal injuries. The authors have experienced 18 cases of severe diffuse axonal injury which showed post-traumatic coma for more than 24 hours and CT findings resembling those of shearing injuries of the cerebral white matter such as have been presented by Zimmerman et al. (1978). The consciousness levels on admission were 6 or less on the Glasgow Coma Scale and all cases were shown clinically to have primary brain stem injury. The main type of head trauma resulted from road traffic accidents (83%). Skull fractures were found in only 5 cases (28%). These findings suggested that acceleration/deceleration injury produce in the patients severe diffuse axonal injury. Initial ICP was below 20 mmHg in 11 cases out of 13 (85%). Parenchymal small hemorrhagic lesions of initial CT were basal ganglia (7 cases), corpus callosum (4 cases), pons (4 cases), midbrain (3 cases) and thalamus (2 cases). Extraparenchymal hemorrhagic lesions included intraventricular hemorrhage (6 cases) and subarachnoid hemorrhage (6 cases). Two autopsied cases of severe diffuse axonal injury (acute case and chronic case) showed remarkable congestion and edema in the deep part of the frontal white matter. Microscopic examination revealed marked axonal degeneration including axonal retraction ball in the corpus callosum, in the internal capsule and in the white matter of the brain stem. Glasgow Outcome Scale of the 18 patients at 3 months after the trauma made us concerned that no patients indicated good recovery or even only moderate disability.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
992.
The hepatotropic effect of nonsteroidal anti-inflammatory drugs (NSAID) such as indomethacin, voltaren, piroxicam, phenylbutazon, mefenamic acid was studied. It was found that according to their level of the pharmacological protection of the liver against tetrachlormethan these agents may be arranged in the following sequence: mefenamic acid, phenylbutazon, voltaren, piroxicam. The hepatoprotective effect of NSAID correlates with the antioxidant properties and fails to correlate with the antioxidant ones. The hepatotoxic effect of NSAID was determined by their ability to suppress synthesis of prostaglandins.  相似文献   
993.
994.
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   
995.
996.
997.
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   
998.
The dissociation of visuospatial neglect and neglect dyslexia.   总被引:5,自引:3,他引:2       下载免费PDF全文
A right-handed man with a left hemisphere lesion extending into the right hemisphere, with evidence of both a left-sided neglect dyslexia and right-sided visuospatial neglect is reported. When copying simple geometric designs he omitted to copy figures on the right-hand side of the page, when bisecting lines he tended to bisect the line to the left of the line's actual centre. He had a neglect dyslexia which was characterised by paralexic errors affecting the beginning (that is, left) of words. The occurrence of these two phenomena provides evidence of a dissociation of these forms of neglect. The findings are discussed in relation to the possible mechanisms of unilateral neglect.  相似文献   
999.
H Sasaki  K Sudoh  K Hamada  T Hamada  K Tashiro 《Neurology》1987,37(7):1258-1262
We studied two patients with nonfamilial olivopontocerebellar atrophy with skeletal myoclonus. Palatal or skeletal myoclonus is probably not a coincidental finding but another manifestation of the underlying disease. In both cases, the myoclonus was suppressed by administration of trihexyphenidyl, indicating a cholinergic disorder.  相似文献   
1000.
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   
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