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   698篇
  免费   43篇
  国内免费   5篇
耳鼻咽喉   22篇
儿科学   34篇
妇产科学   8篇
基础医学   84篇
口腔科学   18篇
临床医学   88篇
内科学   141篇
皮肤病学   32篇
神经病学   34篇
特种医学   124篇
外科学   27篇
综合类   24篇
预防医学   60篇
眼科学   4篇
药学   20篇
  1篇
肿瘤学   25篇
  2022年   3篇
  2021年   4篇
  2020年   2篇
  2019年   5篇
  2018年   12篇
  2017年   6篇
  2016年   9篇
  2015年   12篇
  2014年   11篇
  2013年   28篇
  2012年   10篇
  2011年   14篇
  2010年   31篇
  2009年   33篇
  2008年   11篇
  2007年   24篇
  2006年   17篇
  2005年   17篇
  2004年   14篇
  2003年   9篇
  2002年   16篇
  2001年   9篇
  2000年   12篇
  1999年   11篇
  1998年   39篇
  1997年   45篇
  1996年   38篇
  1995年   26篇
  1994年   33篇
  1993年   25篇
  1992年   11篇
  1991年   10篇
  1990年   14篇
  1989年   23篇
  1988年   26篇
  1987年   11篇
  1986年   9篇
  1985年   10篇
  1984年   14篇
  1983年   16篇
  1982年   14篇
  1981年   16篇
  1980年   12篇
  1979年   2篇
  1978年   7篇
  1977年   2篇
  1976年   5篇
  1970年   5篇
  1969年   6篇
  1968年   3篇
排序方式: 共有746条查询结果,搜索用时 875 毫秒
11.
Abdominal trauma: use of oral contrast material for CT is safe   总被引:2,自引:0,他引:2  
  相似文献   
12.
The aim of this study was to determine the variability of measurements of ankle and brachial systolic pressures and ankle brachial ratios in order to assess their suitability for use in epidemiological studies of arterial disease in the lower limbs. Thirty-six subjects had repeat measurements taken by four observers on two separate days using a Doppler probe and random zero sphygmomanometer. The variability in the measurement of ankle systolic pressure was comparable to that for brachial systolic pressure. The 95% confidence limits of one measurement of the ankle brachial ratio was estimated to be +/- 16%, reducing to +/- 10% for the mean of four measurements taken by two observers on two days. Analysis of variance indicated that the variability in the measurement of ankle brachial ratios attributable to observers, days, timing of measurements on the same day, and repeat measurements was considerably less than the "biological" variability between subjects and between legs. These results suggest that repeatability of the ankle brachial ratio is such that a single measurement is suitable for most epidemiological studies of atherosclerotic peripheral arterial disease.  相似文献   
13.
14.
Serum follicle stimulating hormone (FSH) is routinely measured when evaluating the infertile male for intracytoplasmic sperm injection (ICSI). However, among the sperm parameters, only its relationship with sperm concentration is well documented. Few investigations concern the relationship between FSH and sperm motility and morphology, and the results of ICSI. A retrospective study of 316 couples who underwent ICSI was carried out to determine the relationships between serum FSH concentrations in the male and (i) standard sperm parameters_(concentration, motility and morphology) and (ii) fertilization, cleavage, pregnancy and implantation rates after ICSI. There was an inverse correlation with sperm concentration and total motility but no relationship was found with progressive motility and sperm morphology. Neither was any relationship found between serum FSH and fertilization, cleavage, pregnancy and implantation rates, and the results of ICSI. These findings suggest the need to review the routine measurement of serum FSH in the infertile male when ICSI is the planned treatment procedure.   相似文献   
15.
16.
17.
18.
19.
研究资料表明,人巨细胞病毒(HCMv)单一蛋白的单一抗原决定簇只能被部分患者阳性血清识别。组建在血清学诊断中能够替代全病毒抗原的基因工程抗原,需要含有病毒多种主要抗原蛋白的抗原决定簇。为搞清在表达载体中重复插入某一抗原决定簇基因是否能表达出更高抗原效价的融会蛋白,我们用点突变的方法,在表达载体中分别插入了人HCMv的ppUL32蛋白羧基端一个抗原决定簇基因的1个、2个和3个拷贝。在免疫转印检测中,这些克隆表达的融合蛋白与特异性阳性血清的反应性差别不明显。这表明,插入表达载体中目的基因的多寡对表达蛋白的抗原效价没有显著影响。  相似文献   
20.
Although the conventional method of pain relief during outpatient oocyte recovery involves physician-administered drugs, patient- controlled analgesia (PCA) offers an alternative technique with the potential to give women more control over peroperative analgesia. We conducted a prospective randomized study to compare the effect of fentanyl administered either through a PCA delivery system or by a physician. Thirty-nine women were randomized to PCA during egg collection while 42 were allocated to receive intermittent doses administered by a physician. Pain was evaluated by means of a 100 mm linear analogue scale. The mean (SD) pain score in the PCA group was 38.5 (19.8) while in the other group it was 46.1 (21.3) (P = 0.1). In the PCA group, 64% of women felt very satisfied with their analgesia as compared with 57% in the non-PCA group (P = 0.6). Among the PCA users, 39% of demands were successful. Significantly more fentanyl (97.5 microg) was used in the PCA group than in the other group (84.6 microg) (P = 0.03). Though intraoperative PCA with fentanyl is an effective alternative to physician-administered techniques, many women still feel the need for more analgesia during the procedure.   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