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   2504766篇
  免费   199695篇
  国内免费   4547篇
耳鼻咽喉   36704篇
儿科学   77972篇
妇产科学   66589篇
基础医学   353563篇
口腔科学   71694篇
临床医学   225242篇
内科学   491163篇
皮肤病学   51883篇
神经病学   212572篇
特种医学   102156篇
外国民族医学   900篇
外科学   381578篇
综合类   57125篇
现状与发展   1篇
一般理论   1003篇
预防医学   196807篇
眼科学   59161篇
药学   186624篇
  4篇
中国医学   4664篇
肿瘤学   131603篇
  2018年   26444篇
  2017年   20602篇
  2016年   23087篇
  2015年   26062篇
  2014年   36513篇
  2013年   55019篇
  2012年   74980篇
  2011年   78206篇
  2010年   46036篇
  2009年   43768篇
  2008年   74521篇
  2007年   79457篇
  2006年   80371篇
  2005年   78862篇
  2004年   75824篇
  2003年   73383篇
  2002年   72433篇
  2001年   116693篇
  2000年   120816篇
  1999年   102130篇
  1998年   29127篇
  1997年   26558篇
  1996年   26266篇
  1995年   25253篇
  1994年   23766篇
  1993年   22083篇
  1992年   81063篇
  1991年   77983篇
  1990年   75180篇
  1989年   72334篇
  1988年   67192篇
  1987年   66087篇
  1986年   62559篇
  1985年   59595篇
  1984年   45117篇
  1983年   38403篇
  1982年   23382篇
  1981年   20812篇
  1979年   42339篇
  1978年   29751篇
  1977年   24995篇
  1976年   23404篇
  1975年   24752篇
  1974年   30476篇
  1973年   28812篇
  1972年   27016篇
  1971年   24899篇
  1970年   23439篇
  1969年   21725篇
  1968年   19803篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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   
62.
63.
64.
65.
66.
67.
68.
We evaluated the acquisition and performance of a high-precision locomotor task in patients with Parkinson's disease (PD) and healthy subjects. All subjects walked on a treadmill and had to step repetitively as low as possible over an obstacle without touching it. During blocks 1 and 2, the subjects had full vision and received additional acoustic warning and feedback signals. During block 3, vision became restricted. Changes in foot clearance and the number of obstacle hits were evaluated. Initially, PD patients performed poorer and improved foot clearance slower. After task repetition, the groups performed similarly. Restricting vision deteriorated performance in both groups. The similar performance of PD patients after task repetition might indicate that adequate training could improve adaptive locomotor behavior in PD patients.  相似文献   
69.
An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders.  相似文献   
70.
The aim of the current study was to investigate whether alterations in N-terminal pro brain natriuretic peptide (NT-proBNP) reflect changes in right ventricular structure and function in pulmonary hypertension patients during treatment. The study consisted of 30 pulmonary hypertension patients; 15 newly diagnosed and 15 on long-term treatment. NT-proBNP, right heart catheterisation and cardiac magnetic resonance imaging measurements were performed, at baseline and follow-up. There were no significant differences between newly diagnosed patients and those on treatment at baseline or follow-up with respect to NT-proBNP, haemodynamics and right ventricular parameters. Relative changes in NT-proBNP during treatment were correlated to the relative changes in right ventricular end-diastolic volume index (r = 0.59), right ventricular mass index (r = 0.62) and right ventricular ejection fraction (r = -0.81). N-terminal pro brain natriuretic peptide measurements reflect changes in magnetic resonance imaging-measured right ventricular structure and function in pulmonary hypertension patients. An increase in N-terminal pro brain natriuretic peptide over time reflects right ventricular dilatation concomitant to hypertrophy and deterioration of systolic function.  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