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   2052654篇
  免费   158865篇
  国内免费   7659篇
耳鼻咽喉   27329篇
儿科学   66298篇
妇产科学   57030篇
基础医学   284920篇
口腔科学   56533篇
临床医学   180731篇
内科学   416904篇
皮肤病学   46912篇
神经病学   167066篇
特种医学   83834篇
外国民族医学   596篇
外科学   321712篇
综合类   47012篇
现状与发展   2篇
一般理论   636篇
预防医学   159783篇
眼科学   44909篇
药学   145431篇
  5篇
中国医学   3726篇
肿瘤学   107809篇
  2018年   20489篇
  2016年   18562篇
  2015年   20993篇
  2014年   29646篇
  2013年   44940篇
  2012年   56923篇
  2011年   60885篇
  2010年   37724篇
  2009年   36460篇
  2008年   57438篇
  2007年   61374篇
  2006年   62374篇
  2005年   60802篇
  2004年   58032篇
  2003年   56467篇
  2002年   54329篇
  2001年   96591篇
  2000年   99523篇
  1999年   83692篇
  1998年   24530篇
  1997年   22118篇
  1996年   22827篇
  1995年   22458篇
  1994年   21114篇
  1993年   19756篇
  1992年   68246篇
  1991年   65972篇
  1990年   63933篇
  1989年   61074篇
  1988年   56709篇
  1987年   55666篇
  1986年   52916篇
  1985年   50844篇
  1984年   38591篇
  1983年   32628篇
  1982年   20164篇
  1981年   17936篇
  1980年   16986篇
  1979年   35044篇
  1978年   25132篇
  1977年   21198篇
  1976年   19675篇
  1975年   20971篇
  1974年   24838篇
  1973年   23713篇
  1972年   22249篇
  1971年   20500篇
  1970年   19019篇
  1969年   17907篇
  1968年   16856篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
For many parents stopping life-sustaining medical treatment on their dying infant is psychologically impossible. Dostoevsky's insights into human behavior, particularly the fact that individuals do not want the anxiety and guilt associated with responsibility for making difficult decisions, might change the way physicians approach parents for permission to withdraw life-prolonging medical interventions on dying infants.  相似文献   
93.
94.
Four clinical trials of porcine islet transplantation have been reported, and there are verbal reports that clinical trials on much larger scales are continuing in centers in China and Russia. The four reported trials are briefly reviewed and, in the light of the present status of experimental islet xenotransplantation, consideration is given to whether such trials are currently justified. The Ethics Committee of the International Xenotransplantation Association has (1) emphasized the need for encouraging studies in non-human primates before clinical trials should be undertaken, (2) mandatory monitoring for the transfer of porcine microorganisms, and (3) careful regulation and oversight by recognized bodies. Other aspects of the topic, such as the need for informed consent, are briefly discussed. We conclude that, at the present time, more data documenting convincing efficacy, focused on clinically applicable immunosuppressive regimens, are needed to justify the initiation of closely monitored clinical trials. A clinical trial may then be justified even though the potential risk to the patients, and possibly for society, will not be zero.  相似文献   
95.
Summary: The mosaic (Atp7a mo-ms ) is an X-linked, lethal mutation in mice. In mosaic mutant males, many clinical features characteristic of defective copper metabolism have been observed and they die at the age of 15 days, exhibiting strongsimilarities to the brindled and macular mutants. About 4% of the mutant males live to sexual maturity and some of them are fertile. In this paper, alterationsin the structure of the kidney from adult mutants are described. Owing to an inherited defect of efflux, copper is accumulated in the kidney of the mutants up to a toxic level and this leads to severe damage of the renal cortex. Pathological changes in the kidney mostly affected the structure of the renal corpuscle and renaltubules.  相似文献   
96.
97.
98.
99.
100.
OBJECTIVE: A safe entry zone to tegmental lesions was identified based on intraoperative electrophysiological findings, the compound muscle action potentials (CMAP) from the extraocular muscles, and anatomic considerations. This entry zone is bordered caudally by the intramesencephalic path of the trochlear, laterally by the spinothalamic tract, and rostrally by the caudal margin of the brachium of the superior colliculus. METHODS: Four intrinsic midbrain lesions were operated upon via the safe entry zone using the infratentorial paramedian supracerebellar approach. All lesions involved the tegmentum and included an anaplastic astrocytoma, a metastatic brain tumor, a radiation necrosis, and a cavernous angioma. CMAP were bilaterally monitored from the inferior recti (for oculomotor function) and superior oblique (for trochlear nerve function) muscles. RESULTS: In three of four cases, CMAP related to the oculomotor nerve were obtained upon stimulation at the cavity wall after removal of the tumor. Stimulation at the surface of the quadrigeminal plate, however, did not cause any CMAP response. Using this monitoring as an indicator, the lesions were totally removed. CONCLUSIONS: In the surgery of tegmental lesions, CMAP monitoring from extraocular muscles is particularly helpful to prevent damage to crucial neural structures during removal of intrinsic lesions, but less so to select the site of the medullary incision. The approach via the lateral part of the colliculi is considered to be a safe route to approach the tegmental lesions.  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