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   3296771篇
  免费   246115篇
  国内免费   8368篇
耳鼻咽喉   44861篇
儿科学   106534篇
妇产科学   88632篇
基础医学   472186篇
口腔科学   91127篇
临床医学   301251篇
内科学   645194篇
皮肤病学   74580篇
神经病学   265516篇
特种医学   126667篇
外国民族医学   745篇
外科学   499102篇
综合类   72112篇
现状与发展   14篇
一般理论   1309篇
预防医学   264827篇
眼科学   75417篇
药学   241063篇
  16篇
中国医学   6117篇
肿瘤学   173984篇
  2019年   26269篇
  2018年   36528篇
  2017年   27850篇
  2016年   31930篇
  2015年   36037篇
  2014年   50782篇
  2013年   76962篇
  2012年   101917篇
  2011年   109062篇
  2010年   65882篇
  2009年   62863篇
  2008年   102279篇
  2007年   109262篇
  2006年   110513篇
  2005年   107495篇
  2004年   102566篇
  2003年   99354篇
  2002年   95723篇
  2001年   147163篇
  2000年   150857篇
  1999年   127500篇
  1998年   39097篇
  1997年   34388篇
  1996年   34948篇
  1995年   33939篇
  1994年   31317篇
  1993年   29487篇
  1992年   101419篇
  1991年   98969篇
  1990年   96242篇
  1989年   92395篇
  1988年   85279篇
  1987年   83693篇
  1986年   78821篇
  1985年   75924篇
  1984年   57450篇
  1983年   48878篇
  1982年   30114篇
  1981年   27100篇
  1979年   52519篇
  1978年   37978篇
  1977年   31711篇
  1976年   29996篇
  1975年   31908篇
  1974年   38008篇
  1973年   36127篇
  1972年   33920篇
  1971年   31746篇
  1970年   29124篇
  1969年   27711篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
144.
Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.  相似文献   
145.
146.
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   
147.
Both vascular surgery and endovascular interventions traumatise the arterial wall, especially the endothelium. The vessel responds with neointimal hyperplasia and/or constrictive remodelling, and this is still the limiting factor in curative interventions. Stent placement prevents constrictive remodelling but is the main trigger for in-stent restenosis. Hyperproliferation of neointimal tissue is the main response to arterial thrombosis, local inflammation or medio-intimal injury such as occurs, for example, after balloon dilatation in the region of arterial anastomoses or of a thrombectomy (Fogarty-manoeuvre). At present, research on prevention of restenosis is focused on inhibiting neointimal hyperproliferation by using drug-eluting stents, and especially sirolimus- or paclitaxel-eluting stents. In addition, further experimental research work is in progress, with the aim of esablishing new treatment regimens and solving the problem of neointimal formation, thrombosis and constrictive remodelling. These include both local and systemic pharmacological therapy, brachy- and laser therapy, and many genetic treatment options, some of which are currently the subjects of experimental studies and early-stage clinical trials. Gene therapy seems like a promising way of preventing restenosis, but has not yet been tested in clinical trials. In the near future, selective, simultaneous, and perhaps even polyphasic regulation for gene silencing of two or more genes involved in the development of restenosis could improve the long-term patency rate.  相似文献   
148.
This article describes the proceedings of the 2006 Annual Meeting of the Fetal Alcohol Spectrum Disorders Study Group (FASDSG), which was held in Baltimore, Maryland on June 24, 2006. The meeting was held in conjunction with the annual meeting of the Research Society on Alcoholism and was supported by a grant from the National Institute on Alcohol Abuse and Alcoholism. The 2005-2006 FASDSG officers, Daniel J. Bonthius (President), Heather Carmichael Olson (Vice-President), and Jennifer Thomas (Secretary-Treasurer), organized the meeting. Nationally prominent speakers delivered plenary lectures on topics of newborn screening, ethics, and neuroscience. Selected members of the FASDSG provided brief scientific data (FASt) reports, describing new research findings. Representatives from national agencies involved in fetal alcohol syndrome (FAS) research, treatment, and prevention provided updates regarding priorities, funding, and agency activities. Presentations were also made by the 2006 Student Merit Award recipient and by the 2006 Rosett Award recipient. The meeting served as a forum for clinicians, neuroscientists, psychologists, social scientists, and other professionals to discuss recent advances in FAS research and to identify the most important gaps in the understanding of alcohol-induced teratology.  相似文献   
149.
150.
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