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   1858篇
  免费   214篇
  国内免费   11篇
耳鼻咽喉   12篇
儿科学   57篇
妇产科学   67篇
基础医学   200篇
口腔科学   46篇
临床医学   209篇
内科学   370篇
皮肤病学   26篇
神经病学   213篇
特种医学   202篇
外科学   250篇
综合类   47篇
预防医学   191篇
眼科学   26篇
药学   97篇
  2篇
中国医学   2篇
肿瘤学   66篇
  2021年   23篇
  2020年   14篇
  2019年   25篇
  2018年   26篇
  2017年   26篇
  2016年   19篇
  2015年   27篇
  2014年   44篇
  2013年   53篇
  2012年   68篇
  2011年   62篇
  2010年   47篇
  2009年   53篇
  2008年   60篇
  2007年   74篇
  2006年   75篇
  2005年   63篇
  2004年   60篇
  2003年   65篇
  2002年   65篇
  2001年   62篇
  2000年   64篇
  1999年   43篇
  1998年   43篇
  1997年   40篇
  1996年   33篇
  1995年   26篇
  1994年   30篇
  1993年   24篇
  1992年   50篇
  1991年   39篇
  1990年   40篇
  1989年   56篇
  1988年   46篇
  1987年   55篇
  1986年   46篇
  1985年   58篇
  1984年   37篇
  1983年   30篇
  1982年   21篇
  1981年   21篇
  1980年   19篇
  1979年   31篇
  1978年   20篇
  1977年   14篇
  1976年   25篇
  1975年   27篇
  1974年   21篇
  1973年   18篇
  1971年   16篇
排序方式: 共有2083条查询结果,搜索用时 500 毫秒
51.
We report on a case of a deforming arthropathy in a young man with a lysosomal storage disorder. A 31-year-old man with a known diagnosis of mannosidosis presented with a painful swollen right elbow. Radiographs of his right elbow showed a disorganised joint with multiple fragments resembling the appearances of a neuropathic joint. This case provides further evidence that a deforming arthropathy may occur as part of the spectrum of skeletal abnormalities seen in mannosidosis. Received: 17 November 1999 Revision requested: 13 December 1999 Revision received: 6 March 2000 Accepted: 9 March 2000  相似文献   
52.
53.
54.
IntroductionAdaptive techniques to deliver radiotherapy to the bladder may ensure treatment accuracy whilst sparing organs at risk. This study assesses the frequency of when an alternative plan to the current standard may be beneficial and establish the treatment resource implications of adaptive techniques. Assess the variation in accuracy of skeletal surrogate compared to the target. Additionally describes a training package for therapeutic radiographers evaluating CBCT datasets for adaptive techniques.MethodsA library of three plans was created for each patient, small, standard and large. Weekly CBCT and planar imaging data were acquired from 10 bladder cancer patients receiving radical radiotherapy. Bladder volumes from weekly CBCT were compared to the planning scan. Image registration was performed using bone and soft tissue structures on the CBCT images. A database of images was created to develop competency assessment and a training package.ResultsMatching to a skeletal surrogate may under estimate movement of the target. Bladder volume can vary significantly during the course of treatment, even in the presence of bladder preparation protocols. The additional time required to implement this technique is 4 min per fraction compared to standard treatment with planar imaging.ConclusionsThis feasibility study is a useful process to facilitate the implementation of adaptive techniques. However a limitation of this study is the low number of CBCT datasets evaluated. The advent of IGRT and adaptive techniques gives increased confidence to reduce margins, consequently facilitating hypo-fractionation, and may provide a gain in linear accelerator efficiency and reduce the number of hospital visits for the patient. CBCT paired with a development programme for therapeutic radiographers is an effective and efficient means of implementing adaptive radiotherapy.  相似文献   
55.
56.
'If anticoagulants had been administered sooner, my client would not have died' was a central claim put to us, as statistician expert witnesses, by a Claimant's and Defendant's lawyers. To assist other litigants, and without identifying the specific case, we set out the study types that contribute to the evidence base, and their limitations. We then explain why it is difficult to adduce evidence about the relative risk of dying from pulmonary embolism within 12 hours of admission to accident and emergency even when it is well accepted that anticoagulation reduces the risk of dying within the next seven days of patients at objectively confirmed risk of pulmonary embolism. No matter how much we may want an answer, or how tragic an individual outcome, we can only work from the available evidence or work to improve the evidence base, which needs to be resourced.  相似文献   
57.
58.
59.
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