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   704913篇
  免费   49931篇
  国内免费   1299篇
耳鼻咽喉   9168篇
儿科学   23268篇
妇产科学   17606篇
基础医学   110413篇
口腔科学   19961篇
临床医学   63759篇
内科学   134341篇
皮肤病学   16165篇
神经病学   49455篇
特种医学   25745篇
外国民族医学   76篇
外科学   104513篇
综合类   14817篇
现状与发展   2篇
一般理论   160篇
预防医学   51405篇
眼科学   16321篇
药学   53941篇
  3篇
中国医学   2359篇
肿瘤学   42665篇
  2019年   5435篇
  2018年   7861篇
  2017年   6107篇
  2016年   6822篇
  2015年   7551篇
  2014年   10265篇
  2013年   15381篇
  2012年   20493篇
  2011年   21488篇
  2010年   12721篇
  2009年   11937篇
  2008年   19996篇
  2007年   21514篇
  2006年   21911篇
  2005年   20447篇
  2004年   19991篇
  2003年   18944篇
  2002年   18463篇
  2001年   36336篇
  2000年   36910篇
  1999年   30382篇
  1998年   7885篇
  1997年   6667篇
  1996年   6970篇
  1995年   6630篇
  1994年   6096篇
  1993年   5589篇
  1992年   22975篇
  1991年   22926篇
  1990年   22311篇
  1989年   22078篇
  1988年   20035篇
  1987年   19420篇
  1986年   18468篇
  1985年   17308篇
  1984年   12698篇
  1983年   10741篇
  1982年   5921篇
  1979年   11518篇
  1978年   8128篇
  1977年   6832篇
  1976年   6595篇
  1975年   7268篇
  1974年   8500篇
  1973年   8143篇
  1972年   7658篇
  1971年   7128篇
  1970年   6877篇
  1969年   6306篇
  1968年   5780篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
The distribution of methionine-enkephalin-Arg6-Gly7-Leu8, a unique peptide derived from proenkephalin A in the rat brainstem, was studied immunocytochemically by using a highly specific antiserum to this octapeptide sequence. Immunoreactive perikarya with various shapes and sizes were detected in many regions of the rat brainstem. Dense accumulation of immunoreactive perikarya and fibers was seen in the nuclei associated with special sensory and visceral functions, such as the interpeduncular nucleus, the parabrachial nucleus, the nucleus of the solitary tract, and the nucleus of the spinal tract of the trigeminal nerve. Clusters of methionine-enkephalin-Arg6-Gly7-Leu8-like immunoreactive perikarya and fibers were observed in certain areas considered to play a role in nociception and analgesia, such as the central gray of the midbrain central gray and the raphe magnus nucleus. Some methionine-enkephalin-Arg6-Gly7-Leu8-like immunoreactive perikarya were distributed in the lateral reticular nucleus, the nucleus of the solitary tract, and the raphe magnus nucleus, where monoaminergic neurons were also detected. In addition to the previously reported enkephalinergic cells, we found many methionine-enkephalin-Arg6-Gly7-Leu8 containing neurons; the rostral and caudal linear nucleus of raphe, the median raphe nucleus, entire length of the raphe magnus nucleus, the medial longitudinal fasciculus, the cuneate nucleus, the external cuneate nucleus, the gracile nucleus, and the area postrema. The wide distribution of this octapeptide-like immunoreactivity reflected neurons expressing the preproenkephalin A gene distributed more widely than previously reported and that innervated many regions.  相似文献   
982.
Cerebral blood flow measured by xenon-133   总被引:1,自引:0,他引:1  
  相似文献   
983.
984.
985.
Arousal from propofol   总被引:1,自引:0,他引:1  
  相似文献   
986.
To determine the relationship between severity of illness and mortality, therapeutic intervention score (TISS) and acute physiology score (APS) were determined on admission to the Surgical Intensive Care Unit (SICU). Patients were divided into survivors and nonsurvivors and differences were compared by chi-square analysis. The 1524 patients admitted to the SICU during a 12-month period had a mean TISS of 3.03 and a mean APS of 13. The average length of stay (LOS) was 3.75 days. Of the 1524 patients, 97 (6.4%) died. The number of nonsurvivors increased with higher TISS and APS scores (P less than 0.001). There were no deaths in the TISS Category 1 patients or in the APS 0-5 group. Mortality rates dramatically increased with APS greater than 20 (P less than 0.001). There were 1286 patients with APS less than 20, and 24 (2%) of these patients died, whereas 73 (31%) of 238 patients with APS greater than 20 died. Nonsurvivors had a mean TISS of 3.6, mean APS of 27, and LOS of 4.88 days, all of which totals were higher than the survivors' totals. In this study population, risk of death was one in three if the APS was greater than 20. These data indicate that TISS and APS scores are effective means of assessing mortality risk in SICU patients.  相似文献   
987.
Successful treatment of an infected vascular graft with gentamicin beads   总被引:1,自引:0,他引:1  
This short report describes the successful healing of an infected axillo-bifemoral graft by the insertion of Gentamicin beads, this technique cannot be recommended for all infected grafts the majority of which will have to be removed and replaced.  相似文献   
988.
989.
Spontaneously elevated nociceptive threshold levels were markedly diminished after Naloxone injections in 4 patients with congenital insensitivity to pain. This finding suggested the hypothesis of a relation between congenital insensitivity to pain and permanent hyperfunction of an endomorphinic system. Radio-immunoassay of CSF beta-endorphin was performed in all 4 cases. The normal or only slightly elevated levels cannot explain electrophysiologic findings, but as a function of the multiplicity of endogenous opioid systems, hyperactivity of another endomorphinic system cannot be excluded. Other hypotheses may also be proposed.  相似文献   
990.
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