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   1840篇
  免费   200篇
  国内免费   6篇
耳鼻咽喉   14篇
儿科学   54篇
妇产科学   17篇
基础医学   234篇
口腔科学   36篇
临床医学   205篇
内科学   379篇
皮肤病学   26篇
神经病学   262篇
特种医学   83篇
外科学   231篇
综合类   39篇
一般理论   2篇
预防医学   223篇
眼科学   37篇
药学   113篇
中国医学   1篇
肿瘤学   90篇
  2023年   21篇
  2022年   8篇
  2021年   38篇
  2020年   20篇
  2019年   30篇
  2018年   31篇
  2017年   35篇
  2016年   35篇
  2015年   35篇
  2014年   44篇
  2013年   78篇
  2012年   85篇
  2011年   95篇
  2010年   62篇
  2009年   59篇
  2008年   77篇
  2007年   70篇
  2006年   70篇
  2005年   83篇
  2004年   67篇
  2003年   89篇
  2002年   59篇
  2001年   75篇
  2000年   68篇
  1999年   55篇
  1998年   40篇
  1997年   31篇
  1996年   30篇
  1995年   25篇
  1994年   24篇
  1993年   27篇
  1992年   38篇
  1991年   40篇
  1990年   21篇
  1989年   49篇
  1988年   33篇
  1987年   23篇
  1986年   29篇
  1985年   27篇
  1984年   34篇
  1983年   22篇
  1982年   17篇
  1981年   6篇
  1980年   19篇
  1979年   17篇
  1978年   19篇
  1977年   10篇
  1976年   10篇
  1974年   6篇
  1973年   6篇
排序方式: 共有2046条查询结果,搜索用时 93 毫秒
1.
OBJECTIVE: To explore the impact of timing and type of ultrasound, particularly three-dimensional (3D), exposure on maternal-fetal attachment and maternal health behavior during pregnancy. METHODS: Subjects were 68 women aged 18 years or older expecting their first child who presented for a routine ultrasound scan at around either 12 or 18 weeks' gestation in Nepean Hospital, Western Sydney. Women completed questionnaires assessing maternal-fetal attachment and health behavior, and were then allocated arbitrarily to either two-dimensional (2D) or 3D ultrasound examination. Repeat questionnaires were completed 1 week later. RESULTS: Maternal-fetal attachment increased after both 2D and 3D ultrasound exposure, and the effect was moderated by the timing of exposure, with women receiving their first ultrasound examination at around 12 weeks showing the greatest change. Alcohol consumption was the only behavior to show significant change following ultrasound exposure, with a reduction in the reported average number of drinks per week. There was no significant difference in the pattern of change for 2D compared with 3D ultrasound exposure, and no effect of ultrasound exposure on maternal perception of the fetus. CONCLUSIONS: Ultrasound has a positive impact on maternal-fetal attachment, particularly in the first trimester. 3D ultrasound did not offer enhanced benefits. Associations between ultrasound exposure and alcohol consumption warrant further investigation. Larger samples are needed to clarify the moderating effects of gestational age and type of ultrasound exposure.  相似文献   
2.
OBJECTIVE: Cervical nerve root stimulation (CRS) is a technique of assessing the proximal segments of motor axons destined to upper extremity muscles. Few studies report normal values. The objective was to determine CMAP onset-latencies and CMAP amplitude, area, and duration changes in healthy controls for the abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps, and riceps muscles. In addition, to determine the tolerability of CRS, as measured by the visual analog scale (VAS). METHODS: We studied 21 healthy volunteers prospectively with CRS using four target muscles (APB, ADM, biceps, and triceps) bilaterally. Collision studies were used in all APB recordings. VAS was obtained in all subjects. RESULTS: Mean CMAP onset-latencies were: APB 14 +/- 1.5 ms; ADM 14.2 +/- 1.5 ms; biceps 5.4 +/- 0.6 ms; triceps 5.4 +/- 1.0 ms. Onset-latency significantly correlated with height for all nerves. The mean change in CMAP amplitude and area (%) between most distal stimulation and CRS was: APB reduction of 15.1 +/- 11.6 and 4.9 +/- 3.6%; ADM reduction of 21.1 +/- 10.7 and 17.2 +/- 8.8; biceps reduction of 10 +/- 11.5 and reduction of 8.7 +/- 6.8; triceps increase of 3.3 +/- 5.2 and 11.0 +/- 9.9% respectively. Mean CMAP duration change between most distal stimulation and CRS was: APB, increase of 20.4 +/- 7.4%; ADM, increase of 14.4 +/- 8.5%; biceps, increase of 13.9 +/- 10.8%; triceps, increase of 7.7 +/- 6.7%. The mean VAS score was 3.8 +/- 1.2, and all subjects completed the study. CONCLUSIONS: The present study establishes normative data and indicates that CRS is a well-tolerated technique. SIGNIFICANCE: The normal values may be used as reference data for the needle CRS technique in the assessment of proximal conduction abnormalities.  相似文献   
3.
4.
In order to investigate the possible relationship between physical health and political violence in Northern Ireland a random sample of residents of four electoral areas (two with relatively high violence and two with relatively low violence) was interviewed at home. Each person was asked to rate their health in terms of common physical symptoms, to indicate their use of family doctor and hospital services, and to rate the level of political violence in their neighbourhood. Analysis of covariance (with a measure of psychological well-being, a measure of trait neuroticism plus age and socioeconomic status as covariates) revealed that women reported more physical symptoms than did men, people in the ‘high’ violence areas reported more symptoms than did those in the ‘low’ violence areas, while those who rated their own neighbourhood most highly in terms of perceived violence also reported the greatest number of physical symptoms. However, a series of χ2 tests revealed no association between political violence or perceived political violence and uptake of services.  相似文献   
5.
6.
7.
8.
Irving  HD; Burbridge  BE 《Radiology》1989,173(1):91-92
In vitro and in vivo precipitation of iodinated contrast agents when ioxaglate and papaverine are given together has been reported. To verify these reports and to investigate other medications not previously tested, the authors analyzed mixtures of contrast agents and medications in vitro with a light spectrophotometer and observed them for visible precipitates for up to 120 minutes. Previously reported incompatibilities between ionic or low-osmolality contrast media and medications were verified, and several new incompatibilities were discovered. No incompatibilities were found when the drugs tested were mixed with the new nonionic contrast media.  相似文献   
9.
10.
Sequential contrast-enhanced MR imaging of the penis   总被引:1,自引:0,他引:1  
Kaneko  K; De Mouy  EH; Lee  BE 《Radiology》1994,191(1):75
  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