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   1321篇
  免费   131篇
  国内免费   7篇
耳鼻咽喉   6篇
儿科学   18篇
妇产科学   13篇
基础医学   203篇
口腔科学   20篇
临床医学   132篇
内科学   265篇
皮肤病学   36篇
神经病学   68篇
特种医学   97篇
外科学   237篇
综合类   80篇
一般理论   1篇
预防医学   87篇
眼科学   23篇
药学   51篇
中国医学   4篇
肿瘤学   118篇
  2023年   15篇
  2022年   30篇
  2021年   67篇
  2020年   44篇
  2019年   28篇
  2018年   59篇
  2017年   45篇
  2016年   43篇
  2015年   36篇
  2014年   49篇
  2013年   59篇
  2012年   91篇
  2011年   89篇
  2010年   51篇
  2009年   48篇
  2008年   75篇
  2007年   80篇
  2006年   52篇
  2005年   72篇
  2004年   40篇
  2003年   37篇
  2002年   41篇
  2001年   23篇
  2000年   31篇
  1999年   17篇
  1998年   10篇
  1997年   9篇
  1996年   8篇
  1995年   7篇
  1994年   9篇
  1993年   20篇
  1992年   22篇
  1991年   28篇
  1990年   16篇
  1989年   9篇
  1988年   14篇
  1987年   10篇
  1986年   7篇
  1985年   9篇
  1984年   10篇
  1983年   8篇
  1982年   8篇
  1981年   3篇
  1980年   9篇
  1979年   5篇
  1977年   3篇
  1975年   3篇
  1972年   4篇
  1968年   1篇
  1924年   1篇
排序方式: 共有1459条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
This is a retrospective analysis of 5037 patients with squamous cell carcinoma of the nasopharynx treated during the years 1976-1985. The stage distribution according to Ho's classification was 9% Stage I, 13% II, 50% III, 22% IV, and 6% Stage V. Only 4488 (89%) patients had a full course of megavoltage radiation therapy. The median equivalent dose to the nasopharyngeal region was 65 Gy and cervical region in node-positive patients 53 Gy. Seventy percent (906/1290) of the node-negative patients had no prophylactic neck irradiation. The overall actuarial 10-year survival rate was 43%, and the corresponding failure-free survival 34%. Altogether, 4157 (83%) patients achieved complete remission lasting more than 6 months, but 53% (2205/4157) of them relapsed after a median interval of 1.4 years. The 10-year actuarial local, regional, and distant failure-free rates were 61%, 64%, and 59%, respectively. Thirty-eight percent (338/891) of all patients with local recurrence achieved second local remission. The local complete remission rate with aggressive re-irradiation alone was 47% (333/706). But 37% (124/338) of the responders recurred the second time. The incidence of distant failure correlated significantly with both the N-stage and the T-stage, with the highest (57%) occurring in patients with N3 disease. The incidence of nodal relapse in node-negative patients was 11% (44/384) among those given prophylactic neck irradiation, but 40% (362/906) among those without. Therapeutic irradiation achieved a complete regional remission rate of 90% (306/339). However, despite successful salvage, these patients had a significantly higher distant failure rate than those without nodal relapse, even if they remained local-failure-free (21% vs 6%). Patients treated during 1981-1985 achieved significantly better treatment results than those treated during 1976-1980, especially in terms of the overall survival (57% vs 47% at 5-year), the overall failure-free survival (42% vs 35% at 5-year), and the local failure-free rate (70% vs 63% at 5-year). The possible contributing factors are discussed.  相似文献   
5.
Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.  相似文献   
6.
7.
Deprenyl, a selective inhibitor of monoamine oxidase, type B, which is free of the "tyramine effect," may ameliorate symptom fluctuations in advanced Parkinson's disease (PD). We randomized 96 patients with marked symptom fluctuations at three centers to receive either deprenyl 5 mg b.i.d. or placebo in parallel fashion in addition to a previously optimized levodopa/carbidopa (Sinemet) regimen. Disability was recorded hourly at home by patients 3 days weekly during the 2-week baseline and the 6-week treatment period. Disability during the "on" state was assessed each week by examination. Mean hourly self-assessment of gait improved in 28 of 50 patients (56%) receiving deprenyl (mean degree of improvement 0.25 points on a 0-2 scale) and in 14 of 46 (30.4%) taking placebo (mean 0.15). Mean hourly overall symptom control improved in 29 (58%) taking deprenyl (mean 0.34) and in 12 (26.1%) taking placebo (mean 0.15) (p less than 0.01 for each parameter). No significant improvement occurred in the objective quality of the "on" state with deprenyl. Mean daily Sinemet dosage decreases were 17% in the deprenyl group and 7% in the placebo group. Adverse effects included nausea, light-headedness, dyskinesias, and hallucinations, all of which abated after the Sinemet dose was reduced. We conclude that deprenyl is of moderate benefit in a majority of patients with symptom fluctuations complicating PD and is generally well tolerated.  相似文献   
8.
The status of training in clinical genetics and genetic counseling in Asia is at diverse stages of development and maturity. Most of the training programs are in academic training centers where exposure to patients in the clinics or in the hospital is a major component. This setting provides trainees with knowledge and skills to be competent geneticists and genetic counselors in a variety of patient care interactions. Majority of the training programs combine clinical and research training which provide trainees a broad and integrated approach in the diagnosis and management of patients while providing opportunities for research discoveries that can be translated to better patient care. The background on how the training programs in clinical genetics and genetic counseling in Asia evolved to their current status are described. Each of these countries can learn from each other through sharing of best practices and resources.  相似文献   
9.
10.
An assessment was made of the value of: (i) the demonstration of intestinal alkaline phosphatase in plasma for the differentiation of intrahepatic from post-hepatic jaundice in 122 jaundiced patients; and (ii) the demonstration of an intermediate molecular mass gamma glutamyltransferase in plasma for the identification of post-hepatic cholestasis in 74 jaundiced patients. The first test had a diagnostic sensitivity of only 32% with a specificity of 86%; the second test had a sensitivity of 50% and specificity of 75%. It is concluded that neither procedure is worth while.  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