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   1337549篇
  免费   94358篇
  国内免费   2928篇
耳鼻咽喉   19746篇
儿科学   40234篇
妇产科学   38680篇
基础医学   187355篇
口腔科学   39834篇
临床医学   112679篇
内科学   262869篇
皮肤病学   30266篇
神经病学   106415篇
特种医学   53756篇
外国民族医学   435篇
外科学   208641篇
综合类   31050篇
现状与发展   6篇
一般理论   436篇
预防医学   92092篇
眼科学   31375篇
药学   100163篇
  4篇
中国医学   2994篇
肿瘤学   75805篇
  2018年   11773篇
  2015年   11895篇
  2014年   16726篇
  2013年   25314篇
  2012年   33097篇
  2011年   34947篇
  2010年   20790篇
  2009年   20277篇
  2008年   33664篇
  2007年   36804篇
  2006年   37325篇
  2005年   36077篇
  2004年   35159篇
  2003年   34114篇
  2002年   33664篇
  2001年   63658篇
  2000年   65370篇
  1999年   55437篇
  1998年   14674篇
  1997年   13474篇
  1996年   12966篇
  1995年   12241篇
  1994年   11484篇
  1992年   42781篇
  1991年   41297篇
  1990年   40578篇
  1989年   39584篇
  1988年   36986篇
  1987年   36430篇
  1986年   34928篇
  1985年   33127篇
  1984年   24835篇
  1983年   21060篇
  1982年   12667篇
  1981年   11570篇
  1980年   10777篇
  1979年   23941篇
  1978年   17073篇
  1977年   14843篇
  1976年   13390篇
  1975年   15268篇
  1974年   18084篇
  1973年   17569篇
  1972年   16818篇
  1971年   15721篇
  1970年   14920篇
  1969年   14352篇
  1968年   13467篇
  1967年   12020篇
  1966年   11262篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Injury prevention and control comes of age   总被引:1,自引:0,他引:1  
  相似文献   
992.
993.
994.
995.
The immunohistochemical localization of manganese (Mn)-superoxide dismutase (Mn-SOD) was studied in the rat basal forebrain using polyclonal antibodies to Mn-SOD. Neurons of the basal forebrain exhibit a high density of Mn-SOD immunoreactivity. Double immunostaining with a monoclonal antibody to choline acetyltransferase demonstrated that both cholinergic and non-cholinergic neurons in the basal forebrain are intensely immunoreactive for Mn-SOD.  相似文献   
996.
Semen retrieval in spinal cord injured men.   总被引:1,自引:0,他引:1  
H B Rawicki  S Hill 《Paraplegia》1991,29(7):443-446
A fertility programme for spinal cord injured men has been in progress for nearly 5 years. Thirty eight men have been treated in this programme. Electroejaculation, vibration ejaculation and subcutaneous physostigmine have all been used successfully to obtain semen. Semen has been obtained from 21 of 24 men with a lesion at T8 or above, and from 4 of 11 men with lesions below T10. There have been 8 pregnancies from 6 couples.  相似文献   
997.
Stuttering and tetanic syndrome   总被引:1,自引:0,他引:1  
  相似文献   
998.
Rats were given subcutaneous or intraperitoneal injections of scopolamine, intraperitoneal injections of atropine, or control injections, and trained on a simple swim-to-platform task. Errors were proportional to dose for both drugs over a wide range. No difference was found in the effects of intraperitoneal or subcutaneous scopolamine but scopolamine was 25 times more potent than atropine. The potency of both drugs in impairing swim-to-platform behavior was similar to their potency in abolishing the cholinergic component of neocortical low voltage fast activity. The electrocortical effect of anticholinergic drugs may be a major factor in the behavioral impairment they produce.  相似文献   
999.
In the first part of this series on issues in ward management facing charge nurses, Helen Evers addresses the problem of communication between hospital and community on patient discharges. Recent years have seen the development of liaison and co-ordinator posts whose incumbents aim to facilitate planned and organised discharge procedures, but the appointment of such personnel may not provide a complete answer to the problem. The ultimate arbiter of effective transition from hospital to home is more likely to be the quality of communication between charge and district nurse.  相似文献   
1000.
Transvaginal ultrasonography with color flow mapping has been used to study changes in intrafollicular blood flow and morphology during follicular rupture and presumed ovulation in one human volunteer. Detailed monitoring started on day 11 of the menstrual cycle and the follicle began to rupture at 14.30 on day 13. This event was preceded by a defined rise and peak in the level of immunoreactive serum luteinizing hormone (LH) by 42 h and 17 h 20 min, respectively. Blood vessels were clearly visible in the inner ring of the follicle (the granulosa layer) at the time of the LH peak and part of the granulosa (probably containing the oocyte) started to detach before the follicle ruptured. The maximum value for the peak blood velocity in the inner vessels was observed 10 s after the start of follicular rupture and there was a concurrent increase in the impedance to blood flow, as reflected by the resistance index and the pulsatility index. The follicle took 14 min 29 s to empty and the corpus haemorrhagicum started to form about 1 min later. These preliminary data suggest that intrafollicular angiogenesis and changes in blood flow can be monitored by a relatively non-invasive technique. Changes in vascularity might be used to predict imminent ovulation and could possibly be identified or modified biochemically to help achieve or avoid a pregnancy.  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