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   1426056篇
  免费   117513篇
  国内免费   4758篇
耳鼻咽喉   18473篇
儿科学   46746篇
妇产科学   41223篇
基础医学   202940篇
口腔科学   38027篇
临床医学   128592篇
内科学   286279篇
皮肤病学   33549篇
神经病学   117747篇
特种医学   54497篇
外国民族医学   477篇
外科学   212189篇
综合类   36591篇
现状与发展   8篇
一般理论   487篇
预防医学   110713篇
眼科学   31981篇
药学   100628篇
  22篇
中国医学   4513篇
肿瘤学   82645篇
  2021年   11972篇
  2019年   12339篇
  2018年   17340篇
  2017年   13327篇
  2016年   14922篇
  2015年   17029篇
  2014年   23787篇
  2013年   34416篇
  2012年   46902篇
  2011年   49610篇
  2010年   29137篇
  2009年   27799篇
  2008年   45311篇
  2007年   47778篇
  2006年   48410篇
  2005年   46847篇
  2004年   44402篇
  2003年   42269篇
  2002年   40691篇
  2001年   73398篇
  2000年   74953篇
  1999年   62006篇
  1998年   17282篇
  1997年   15715篇
  1996年   15779篇
  1995年   14990篇
  1994年   13609篇
  1993年   12697篇
  1992年   45945篇
  1991年   43588篇
  1990年   41599篇
  1989年   39624篇
  1988年   36254篇
  1987年   35410篇
  1986年   32910篇
  1985年   31328篇
  1984年   23842篇
  1983年   20034篇
  1982年   12219篇
  1981年   10738篇
  1979年   20669篇
  1978年   14547篇
  1977年   12035篇
  1976年   11316篇
  1975年   11583篇
  1974年   13966篇
  1973年   13512篇
  1972年   12622篇
  1971年   11459篇
  1970年   10894篇
排序方式: 共有10000条查询结果,搜索用时 937 毫秒
131.
ABSTRACT

Communication between health professionals and patients is an intergroup phenomenon where the health professional has the most power and status. Over the past few decades, there has been a steady increase in the availability to patients of information about healthcare and specific diseases on the Internet. In this paper, we ask whether the use of Internet health information assists patients to manage their consultations with health professionals better and whether it alters the intergroup dynamic by providing a more equal status for patients. In this study 370 participants from Australia and Canada completed a survey that included a ‘willingness to communicate with health professionals’ scale. They also commented on their use and trust of Internet health information. Thematic analysis suggests that patients’ use of Internet health information serves as a broker between patients and their health provider in health consultations. We discuss the implications of these findings for health practitioners as they address how easier Internet access influences patient interactions with health professionals. We consider future research directions these finding provide in explaining communication behaviour in this context.  相似文献   
132.
Background: Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease. Methods: Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function. Results: All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation. Conclusions: Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications.  相似文献   
133.
134.
135.
136.
137.
138.

Background

Early dumping is a poorly defined and incompletely understood complication after Roux-en-Y gastric (RYGB).

Objective

We performed a mixed-meal tolerance test in patients after RYGB to address the prevalence of early dumping and to gain further insight into its pathophysiology.

Setting

The study was conducted in a regional hospital in the northern part of the Netherlands.

Methods

From a random sample of patients who underwent primary RYGB between 2008 and 2011, 46 patients completed the mixed-meal tolerance test. The dumping severity score for early dumping was assessed every 30 minutes. A sum score at 30 or 60 minutes of ≥5 and an incremental score of ≥3 points were defined as indicating a high suspicion of early dumping. Blood samples were collected at baseline, every 10 minutes during the first half hour, and at 60 minutes after the start.

Results

The prevalence of a high suspicion of early dumping was 26%. No differences were seen for absolute hematocrit value, inactive glucagon-like peptide-1, and vasoactive intestinal peptide between patients with or without early dumping. Patients at high suspicion of early dumping had higher levels of active glucagon-like peptide-1 and peptide YY.

Conclusion

The prevalence of complaints at high suspicion of early dumping in a random population of patients after RYGB is 26% in response to a mixed-meal tolerance test. Postprandial increases in both glucagon-like peptide-1 and peptide YY are associated with symptoms of early dumping, suggesting gut L-cell overactivity in this syndrome.  相似文献   
139.
140.
At this study a multi-criteria model was developed to examine the available procedures, techniques and methods of handling infectious waste in the large healthcare unit of University Regional General Hospital of Patras, Western Greece. Particularly, this study examined the: a) current legislation and Directives issued for medical waste management at Greece and among the other EU-members, b) contribution of healthcare wastes (HCW) generation rate on social and economic parameters in selected European countries, c) available procedures, techniques, and methods upon the disposal of infectious wastes at the healthcare studied, and, d) propositions for integrated management of such hazardous wastes. Specifically, the Analytic Hierarchy Process (AHP) methodology was applied under pair wise comparison matrices in two stages: 1) the scale factors and the indicators, and 2) the criteria and their sub–criteria. The assessment of these pair wise matrices included the indicators and the sub–criteria. Subsequently, two pair wise comparison matrices, upon a) the “Fulfillment of environmental objectives” indicator and b) the “Energy consumption” sub criterion, were denoted. The AHP methodology yielded good results; however there is still space of improving the environmental performance. The normalized relative weights obtained for the criteria and sub criteria motivated specific actions that have to be handled. Particularly, the results indicated a very good value in environmental management criteria due the values obtained for the commitment towards the environmental policy standards and the waste management procedures. However, further improvements on staff awareness (such as development programs to enhance sensitivity) and more green purchasing suppliers, should be further addressed.  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