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   1346903篇
  免费   98071篇
  国内免费   1790篇
耳鼻咽喉   17608篇
儿科学   43372篇
妇产科学   37172篇
基础医学   200510篇
口腔科学   37074篇
临床医学   123022篇
内科学   266838篇
皮肤病学   29582篇
神经病学   108425篇
特种医学   48510篇
外国民族医学   267篇
外科学   188781篇
综合类   26157篇
现状与发展   3篇
一般理论   591篇
预防医学   114148篇
眼科学   29918篇
药学   98866篇
  7篇
中国医学   2301篇
肿瘤学   73612篇
  2021年   10945篇
  2019年   11788篇
  2018年   16392篇
  2017年   12121篇
  2016年   12949篇
  2015年   14976篇
  2014年   20089篇
  2013年   30814篇
  2012年   43233篇
  2011年   45637篇
  2010年   25993篇
  2009年   24396篇
  2008年   42387篇
  2007年   45276篇
  2006年   44734篇
  2005年   43866篇
  2004年   41880篇
  2003年   39960篇
  2002年   38646篇
  2001年   58236篇
  2000年   59400篇
  1999年   49973篇
  1998年   13751篇
  1997年   12465篇
  1996年   12899篇
  1995年   12120篇
  1994年   11270篇
  1992年   39122篇
  1991年   38528篇
  1990年   37274篇
  1989年   35967篇
  1988年   33349篇
  1987年   32722篇
  1986年   31156篇
  1985年   29367篇
  1984年   22395篇
  1983年   19530篇
  1982年   11526篇
  1979年   21406篇
  1978年   15664篇
  1977年   13025篇
  1976年   12106篇
  1975年   13081篇
  1974年   16014篇
  1973年   15750篇
  1972年   14851篇
  1971年   13852篇
  1970年   13167篇
  1969年   12408篇
  1968年   11565篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
The absence of the temporary incisors could be to a genetic illness or to some multiple premature extractions. These extractions are the aftermaths of the carious lesions or some traumatisms underwent by the temporary incisors. Beyond measure the loss of the space, the premature loss some temporary incisors very often assign the relational development of the child and disturb its psychological development and the aesthetic function. Across some cases clinics, the authors show that the replacement of the temporary incisors is the therapeutic ideal solution. Indeed, the child prosthesis, replacing the temporary absent incisors, solves the psychological, aesthetic and relational problems of the child.  相似文献   
64.
Contour defects resulting in deformity caused by lack of tissue can be improved by conventional surgery using autologous tissue, but there is always a donor site morbidity. Integra has been available since the early 1980's for use in acute burns and more recently in reconstruction. It has been shown histologically to act as a tissue regeneration template. The regenerated dermis is buried under an autologous thin split-skin graft. In this study, the principle of burying Integra (without the silicone layer) has been applied to deep tissue defects in 12 reconstructive cases. Such regenerated tissues survive at least 3 years after burying. Modification to the technique to avoid visible edges are being developed.  相似文献   
65.
Summary The third-stage larvae of Daniconema anguillae Moravec et K?ie, 1987 are found in the eels fins caught from Dringis Lake (Lithuanian National park). The morphology of these larvae is briefly described.  相似文献   
66.
67.
OBJECTIVE: To evaluate the effect of statins on aneurysm growth in a group of consecutive patients under surveillance for infrarenal aortic aneurysms (AAA). MATERIALS AND METHODS: All patients (59 statin users, 91 non-users) under surveillance between January 2002 and August 2005 with a follow-up for aneurysm growth of at least 12 months and a minimum of three diameter evaluations were retrospectively included in the analysis. Multiple regression analysis, weighted with the number of observations, was performed to test the influence of statins on AAA growth rate. RESULTS: During a median period of 3.1 (1.1-13.1) years the overall mean aneurysm growth rate was 2.95+/-2.8 mm/year. Statin users had a 1.16 mm/year lower AAA growth rate compared to non-users (95% CI 0.33-1.99 mm/year). Increased age was associated with a slower growth (-0.09 mm/year per year, p = 0.003). Female gender (+1.82 mm/year, p = 0.008) and aneurysm diameter (+0.06 mm/year per mm, p = 0.049) were associated with increased AAA growth. The use of non-steroidal anti-inflammatory drugs, chronic lung disease, or other cardiovascular risk factors were not independently associated with AAA growth. CONCLUSIONS: Statins appear to be associated with attenuation of AAA growth, irrespective of other known factors influencing aneurysm growth.  相似文献   
68.
69.
目的:通过16例经内窥镜及病理证实为Barrett食管的钡餐检查表现,初步探讨Barrett食管及其并发症放射学检查的意义。方法:回顾性分析16例Barrett食管的内窥镜和气钡检查的记录及表现,着重探讨气钡检查的X线表现。结果:食管内窥镜和组织学检查全部病例均有炎症改变,其他可见胃食管反流、食管溃疡和食管腺癌。放射学钡餐检查结果:Barrett食管炎4例,Barrett食管溃疡7例,Barrett食管癌5例。结论:Barrett食管及其并发症至今无明确放射学征象,改进对“Z”线的检查技术和方法,有可能提高其发现率。钡餐发现胃食管反流、食管裂孔疝同时并发食管炎、食管溃疡及食管癌者均应考虑到本症的可能。  相似文献   
70.
There is increasing evidence that the assessment of eosinophilic airway inflammation using induced sputum and measurement of airway hyperresponsiveness provides additional, clinically important information concerning asthma control. The aim of this study was to directly compare the effects of different treatments on these markers in patients with asthma and persistent symptoms, despite the use of low-dose inhaled corticosteroids. A double-blind four-way crossover study was performed, which compared a 1-month treatment with budesonide 400 mug b.i.d., additional formoterol, additional montelukast and placebo in 49 patients with uncontrolled asthma despite budesonide 100 mug b.i.d., with each treatment separated by a 4-week washout period. The change in sputum eosinophil count with formoterol (2.4 to 3.8% change, 0.6-fold reduction, 95% confidence interval (CI) 0.5-0.9) differed significantly from placebo (2.8 to 2.5% change, 1.1-fold reduction, 95% CI 0.7-1.6) and high-dose budesonide (2.7 to 1.6% change, 1.6-fold reduction, 95% CI 1.2-2.2). The effects of montelukast did not differ from placebo. The changes in methacholine airway responsiveness were small and did not differ between treatments. High-dose budesonide had the broadest range of beneficial effects on other outcomes, including symptom scores, morning peak expiratory flow and forced expiratory volume in one second. In conclusion, treatment given in addition to low-dose inhaled corticosteroids results in modest benefits. Formoterol and high-dose budesonide have contrasting effects on eosinophilic airway inflammation.  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