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   1364900篇
  免费   97265篇
  国内免费   2929篇
耳鼻咽喉   19874篇
儿科学   41167篇
妇产科学   39428篇
基础医学   191277篇
口腔科学   40413篇
临床医学   116236篇
内科学   267349篇
皮肤病学   30658篇
神经病学   109028篇
特种医学   54901篇
外国民族医学   438篇
外科学   211912篇
综合类   31657篇
现状与发展   6篇
一般理论   477篇
预防医学   95782篇
眼科学   32031篇
药学   102262篇
  4篇
中国医学   3013篇
肿瘤学   77181篇
  2018年   12264篇
  2016年   11031篇
  2015年   12349篇
  2014年   17346篇
  2013年   26214篇
  2012年   34430篇
  2011年   36260篇
  2010年   21554篇
  2009年   20961篇
  2008年   34853篇
  2007年   38033篇
  2006年   38556篇
  2005年   37279篇
  2004年   36333篇
  2003年   35262篇
  2002年   34698篇
  2001年   64540篇
  2000年   66285篇
  1999年   56216篇
  1998年   15016篇
  1997年   13771篇
  1996年   13233篇
  1995年   12462篇
  1994年   11745篇
  1992年   43428篇
  1991年   41888篇
  1990年   41157篇
  1989年   40087篇
  1988年   37481篇
  1987年   36916篇
  1986年   35374篇
  1985年   33619篇
  1984年   25242篇
  1983年   21364篇
  1982年   12883篇
  1981年   11799篇
  1979年   24293篇
  1978年   17340篇
  1977年   15040篇
  1976年   13600篇
  1975年   15469篇
  1974年   18306篇
  1973年   17766篇
  1972年   17016篇
  1971年   15919篇
  1970年   15101篇
  1969年   14531篇
  1968年   13591篇
  1967年   12145篇
  1966年   11344篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
996.
997.
998.
We report a successful endovascular stent-graft treatment of a patient with type A dissection with primary entry tear at the ascending aorta. Simultaneous coronary stenting was performed. A literature review was performed and the possible use of endovascular treatment for ascending aortic dissections is discussed.  相似文献   
999.
BACKGROUND: Functional neuroimaging studies have detected abnormal limbic and paralimbic activation to emotional probes in posttraumatic stress disorder (PTSD), but few studies have examined neurochemical mechanisms that underlie functional alterations in regional cerebral blood flow. The mu-opioid neurotransmitter system, implicated in responses to stress and suppression of pain, is distributed in and is thought to regulate the function of brain regions that are implicated in affective processing. METHODS: Here we examined the micro-opioid system with positron emission tomography and the micro-opioid receptor-selective radiotracer [11C] carfentanil in 16 male patients with PTSD and two non-PTSD male control groups, with (n = 14) and without combat exposure (n = 15). Differences in micro-opioid receptor binding potential (BP2) were detected within discrete limbic and paralimbic regions. RESULTS: Relative to healthy controls, both trauma-exposed groups had lower micro-opioid receptor BP2 in extended amygdala, nucleus accumbens, and dorsal frontal and insular cortex but had higher BP2 in the orbitofrontal cortex. PTSD patients exhibited reduced BP2 in anterior cingulate cortex compared with both control groups. Micro-opioid receptor BP2 in combat-exposed subjects without PTSD was lower in the amygdala but higher in the orbitofrontal cortex compared with both PTSD patients and healthy controls. CONCLUSIONS: These findings differentiate the general response of the micro-opioid system to trauma from more specific changes associated with PTSD.  相似文献   
1000.
Spinal cord stimulation (SCS) involves the use of an epidurally placed, multiple electrode lead. Electrical stimulation between electrodes produces stimulation of the posterior spinal cord and can provide excellent pain relief and increased blood flow in a number of chronic limb pain conditions. Its efficacy has more recently been demonstrated in angina. Chronic stable angina pectoris is a major cause of disability and suffering. The aims of treatment are to prevent MI and death (increase the quantity of life) and reduce the symptoms (improve the quality of life). In the non‐acute condition, practitioners often struggle to manage angina because of a lack of understanding of modern concepts of pain. There is a widely held misconception that only revascularisation improves prognosis in chronic refractory angina‐ the term used to describe patients with stable angina that is treatment refractory. Over the last decade two pain services in New Zealand have been approached by cardiologists to provide spinal cord stimulation for such patients. This has been an intriguing experience! We have demonstrated that the placement of such leads in the lower cervical cord region provides excellent relief of angina. The technology is expensive (akin to the overall cost of CAVG surgery). We have demonstrated cost recoupment, by decreased hospitalisation, at approximately16 months post procedure. Sadly, this therapy has not been embraced. Possible reasons for this will be discussed. The concept of electrically modifying the neuronal signals versus re‐plumbing the blockage appears to be an anathema to cardiologists.  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