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   861993篇
  免费   70577篇
  国内免费   1840篇
耳鼻咽喉   12799篇
儿科学   24623篇
妇产科学   25096篇
基础医学   124226篇
口腔科学   25484篇
临床医学   75305篇
内科学   164529篇
皮肤病学   16973篇
神经病学   70069篇
特种医学   35190篇
外国民族医学   171篇
外科学   136152篇
综合类   24605篇
现状与发展   2篇
一般理论   263篇
预防医学   66868篇
眼科学   20517篇
药学   64685篇
中国医学   1594篇
肿瘤学   45259篇
  2018年   7331篇
  2015年   7724篇
  2014年   11106篇
  2013年   16775篇
  2012年   22708篇
  2011年   23826篇
  2010年   13859篇
  2009年   13060篇
  2008年   22561篇
  2007年   24616篇
  2006年   24487篇
  2005年   24133篇
  2004年   23696篇
  2003年   22829篇
  2002年   21923篇
  2001年   35824篇
  2000年   36464篇
  1999年   30896篇
  1998年   9221篇
  1997年   8550篇
  1996年   8476篇
  1995年   8006篇
  1994年   7724篇
  1992年   26659篇
  1991年   26098篇
  1990年   25620篇
  1989年   24677篇
  1988年   23220篇
  1987年   22883篇
  1986年   21740篇
  1985年   21097篇
  1984年   16385篇
  1983年   13997篇
  1982年   8854篇
  1981年   8201篇
  1980年   7671篇
  1979年   16736篇
  1978年   12114篇
  1977年   10181篇
  1976年   9328篇
  1975年   10148篇
  1974年   12642篇
  1973年   12136篇
  1972年   11538篇
  1971年   10685篇
  1970年   10219篇
  1969年   9910篇
  1968年   8900篇
  1967年   8230篇
  1966年   7653篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Bladder mucosa in urethral reconstructions   总被引:6,自引:0,他引:6  
  相似文献   
53.
Patient history and clinical examination are important for the diagnosis of degenerative joint disease. Here the typical statements of a patient suffering from early osteoarthritis are described and, as far as possible, explained. The joint in question must be systematically examined. Furthermore, the neighboring joints and soft-tissue structures, i.e., muscles, tendons etc., should be examined and evaluated with respect to their importance in hindering the functional chain. The neuroreflectory mechanisms involved herein are described.  相似文献   
54.
55.
Effects of the MAO-A-inhibitor brofaromine (BRO), 10 mg/kg po after repeated (twice daily for 14 days) administration on the spontaneous behavior (exploratory and basal locomotor activities) and the exploratory activity modified by methoxamine, clonidine and d-amphetamine in male Wistar rats were studied in both light and dark phases of a diurnal cycle (L: 0700-1900 h). After single administration BRO in the light phase had no effects. In the dark phase BRO decreased the exploration (62% of control, p less than 0.01), increased the clonidine-evoked hypoactivity and amphetamine-evoked hyperactivity. The L-D differences occurred also after repeated administration. BRO in the light phase did not influence the exploration, decreased basal locomotor activity, did not change methoxamine and clonidine action and potentiated the action of amphetamine. In the dark phase, however, it did not influence the exploration and basal locomotor activity, intensified the methoxamine effect, and did not change the clonidine and amphetamine actions. The results demonstrate that the effects of BRO on behavior in rats: 1) differ from the effects caused by other antidepressants which are not MAO inhibitors; 2) are phase-dependent after both single and repeated administration.  相似文献   
56.
A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'v) rather than equivalent dioptric power (Fm) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use.  相似文献   
57.
58.
An ultrasound contrast agent which survives transit through the pulmonary circulation after injection into a peripheral vein can also be used for the demonstration of flow characteristics in the peripheral organs. Such a substance (SH U 508 A, Schering AG, Berlin) was tested in the Gynecological Department of the University of Marburg for its suitability for enhancing color-coded Doppler signals in mammary diagnosis in a group of ten women with breast tumors. The observations made are compared with the histologically confirmed diagnoses. The very distinct enhancement of the color-coded Doppler signals allows reliable demonstration of the vascularization characteristics, not only of the malignant, but also of all benign solid tumors examined. Color signals were even recorded from normal mammary tissue, which means that the demonstration of perfusion can no longer be used on its own as a diagnostic criterion. Observation of the characteristics of the blood supply to a tumor might, on the other hand, be an advantage, not only in respect of tumor typing, but also as regards the prognosis of a tumor. In this connection, the registration of the arrival, retention and wash-out phases specific to a contrast agent appears to furnish particularly interesting information about the growth dynamics of a tumor.  相似文献   
59.
60.
SUMMARY. Samples from 1828 donations were screened for anti-HBc at seven sites in the UK using kits supplied by 10 manufacturers. Only 10 (0.55%) donations were considered to have true anti-HBc reactivity and these were detected by all 10 kits. Additional markers of HBV infection were found in nine of these 10 donations. Additional reactives were found by all kits, the number ranging from 1 to 43.
In the four more specific kits, the 10 true reactives were clearly distinguished from the 'false reactives' by the strength of the reaction. It is concluded that the reliance on a single ELISA test for anti-HBc diagnosis is unwise. The use of a second test known to be more specific than the screening ELISA is recommended.  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