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   1046542篇
  免费   83853篇
  国内免费   2517篇
耳鼻咽喉   14778篇
儿科学   29549篇
妇产科学   28968篇
基础医学   147770篇
口腔科学   29527篇
临床医学   92933篇
内科学   203640篇
皮肤病学   19427篇
神经病学   87871篇
特种医学   41321篇
外国民族医学   184篇
外科学   164967篇
综合类   27626篇
现状与发展   4篇
一般理论   543篇
预防医学   83984篇
眼科学   24367篇
药学   77350篇
  1篇
中国医学   1906篇
肿瘤学   56196篇
  2018年   10850篇
  2016年   9560篇
  2015年   11270篇
  2014年   16467篇
  2013年   24603篇
  2012年   34081篇
  2011年   36300篇
  2010年   20979篇
  2009年   19522篇
  2008年   34461篇
  2007年   37252篇
  2006年   36685篇
  2005年   36840篇
  2004年   35781篇
  2003年   34261篇
  2002年   32821篇
  2001年   37517篇
  2000年   37787篇
  1999年   32734篇
  1998年   11700篇
  1997年   10664篇
  1996年   10416篇
  1995年   9709篇
  1994年   9259篇
  1993年   8665篇
  1992年   27715篇
  1991年   27113篇
  1990年   26528篇
  1989年   25494篇
  1988年   24108篇
  1987年   23773篇
  1986年   22607篇
  1985年   22027篇
  1984年   17662篇
  1983年   15255篇
  1982年   10418篇
  1981年   9602篇
  1980年   9010篇
  1979年   17435篇
  1978年   12947篇
  1977年   11002篇
  1976年   10040篇
  1975年   10758篇
  1974年   13223篇
  1973年   12658篇
  1972年   11911篇
  1971年   11002篇
  1970年   10511篇
  1969年   10123篇
  1968年   9077篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
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   
63.
64.
65.
Bladder mucosa in urethral reconstructions   总被引:6,自引:0,他引:6  
  相似文献   
66.
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   
67.
68.
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   
69.
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   
70.
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