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   862163篇
  免费   70600篇
  国内免费   1848篇
耳鼻咽喉   12807篇
儿科学   24628篇
妇产科学   25097篇
基础医学   124232篇
口腔科学   25484篇
临床医学   75331篇
内科学   164544篇
皮肤病学   16975篇
神经病学   70073篇
特种医学   35201篇
外国民族医学   171篇
外科学   136160篇
综合类   24654篇
现状与发展   2篇
一般理论   263篇
预防医学   66869篇
眼科学   20524篇
药学   64707篇
中国医学   1610篇
肿瘤学   45279篇
  2018年   7340篇
  2015年   7738篇
  2014年   11119篇
  2013年   16784篇
  2012年   22718篇
  2011年   23830篇
  2010年   13867篇
  2009年   13067篇
  2008年   22566篇
  2007年   24623篇
  2006年   24499篇
  2005年   24140篇
  2004年   23704篇
  2003年   22827篇
  2002年   21924篇
  2001年   35825篇
  2000年   36465篇
  1999年   30899篇
  1998年   9220篇
  1997年   8549篇
  1996年   8479篇
  1995年   8010篇
  1994年   7723篇
  1992年   26660篇
  1991年   26099篇
  1990年   25619篇
  1989年   24679篇
  1988年   23219篇
  1987年   22884篇
  1986年   21740篇
  1985年   21097篇
  1984年   16385篇
  1983年   13996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   10147篇
  1974年   12641篇
  1973年   12136篇
  1972年   11538篇
  1971年   10685篇
  1970年   10218篇
  1969年   9909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.
Abstract Perioscan requires a plaque sample to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA) from relatively few anaerobic periodontal pathogens. Periocheck assays the presence of neutral proteases in crevicular fluid. The aim of this study was to compare these test kits with traditional clinical methods of detecting periodontal disease and to monitor the ability of the kits to reflect the response to initial therapy. 19 patients with moderately severe chronic periodontitis were seen before and after a course of oral hygiene and root instrumentation consisting of 4 appointments. Clinical measurements and test assays were collected at 5 diseased sites and 2 healthy sites in each subject. Complete data from 125 sites were available for statistical analysis. At baseline Periocheck had a sensitivity of 88% and a specificity of 61% whereas Perioscan had a sensitivity of 99% and a specificity of 55%, when related to the clinical diagnosis. A composite clinical assessment, based on improvement or deterioration of one whole unit change of the subjective clinical indices and 2mm changes or greater in probing depth or probing attachment level, revealed 75 sites which improved following treatment, whereas 45 sites did not change and 5 sites deteriorated. The probability that the tests agreed with the clinical outcome after treatment, was calculated as 50.4% for Periocheck and 52% for Perioscan. The diagnostic kits did not reliably reflect the clinical assessment of periodontal disease in the cross sectional study, or the outcome following treatment.  相似文献   
53.
54.
55.
Bladder mucosa in urethral reconstructions   总被引:6,自引:0,他引:6  
  相似文献   
56.
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   
57.
58.
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   
59.
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   
60.
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