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   1991篇
  免费   204篇
  国内免费   8篇
耳鼻咽喉   15篇
儿科学   106篇
妇产科学   22篇
基础医学   271篇
口腔科学   45篇
临床医学   232篇
内科学   308篇
皮肤病学   50篇
神经病学   172篇
特种医学   233篇
外科学   239篇
综合类   73篇
一般理论   2篇
预防医学   187篇
眼科学   57篇
药学   97篇
中国医学   1篇
肿瘤学   93篇
  2022年   9篇
  2021年   19篇
  2020年   20篇
  2019年   23篇
  2018年   34篇
  2017年   18篇
  2016年   39篇
  2015年   43篇
  2014年   48篇
  2013年   77篇
  2012年   80篇
  2011年   49篇
  2010年   76篇
  2009年   70篇
  2008年   69篇
  2007年   90篇
  2006年   85篇
  2005年   74篇
  2004年   76篇
  2003年   68篇
  2002年   60篇
  2001年   52篇
  2000年   37篇
  1999年   50篇
  1998年   59篇
  1997年   59篇
  1996年   63篇
  1995年   60篇
  1994年   40篇
  1993年   41篇
  1992年   43篇
  1991年   39篇
  1990年   28篇
  1989年   42篇
  1988年   46篇
  1987年   35篇
  1986年   50篇
  1985年   39篇
  1984年   33篇
  1983年   37篇
  1982年   18篇
  1981年   30篇
  1980年   16篇
  1979年   12篇
  1978年   18篇
  1977年   18篇
  1976年   19篇
  1974年   15篇
  1973年   11篇
  1972年   9篇
排序方式: 共有2203条查询结果,搜索用时 15 毫秒
101.
102.
103.
We evaluated the association of body mass index (BMI) with migraine and migraine specifics in a cross-sectional study of 63 467 women aged ≥ 45 years, of whom 12 613 (19.9%) reported any history of migraine and 9195 had active migraine. Compared with women without migraine and a BMI < 23 kg/m2, women with a BMI ≥ 35 kg/m2 had adjusted odds ratios (ORs) (95% confidence intervals) of 1.03 (0.95, 1.12) for any history of migraine. Findings were similar for active migraineurs. Women with a BMI of ≥ 35 kg/m2 had increased risk for low and high migraine frequency, with the highest estimate for women who reported daily migraine. Compared with women with the lowest associated risk (migraine frequency < 6 times/year; BMI between 27.0 and 29.9 kg/m2), women with a BMI ≥ 35 kg/m2 had an OR of daily migraine of 3.11 (1.12, 8.67). Among the women with active migraine, a BMI ≥ 35 kg/m2 was associated with increased risk of phonophobia and photophobia and decreased risk of a unilateral pain characteristic and migraine aura. Our data confirm previous findings that the association between BMI with migraine is limited to migraine frequency and specific migraine features.  相似文献   
104.
105.
Clinical long‐term outcomes have shown that partial leaflet resection followed by ring annuloplasty is a reliable and reproducible surgical repair technique for treatment of mitral valve (MV) leaflet prolapse. We report a 61‐year‐old male for three‐dimensional transesophageal echocardiography (3DTEE)‐based virtual posterior leaflet resection and ring annuloplasty. Severe mitral regurgitation was found and computational evaluation demonstrated substantial leaflet malcoaptation and high stress concentration. Following virtual resection and ring annuloplasty, posterior leaflet prolapse markedly decreased, sufficient leaflet coaptation was restored, and high stress concentration disappeared. Virtual MV repair strategies using 3DTEE have the potential to help optimize MV repair.  相似文献   
106.
107.
Accurate pregnancy dating is vital to obstetric management. However, first trimester fetal charts commonly used in Australia rely on data reported more than three decades ago. This study reports first trimester dating and growth charts for crown‐rump length between 5 and 14 weeks of gestation and biparietal diameter between 9 and 14 weeks of gestation on an Australia population using modern real‐time ultrasound equipment. All consenting eligible women attending a large Sydney clinic for first trimester ultrasound between March 2005 and December 2006 were recruited. Measurements were carried out to Australasian Society for Ultrasound in Medicine standard protocols. Statistical analyses were undertaken using polynomial regression models and thorough diagnostic checks made. Overall 396 eligible women consented to the study, with 268 between 9 and 14 weeks of gestation. The average participant age was 34 years (range 22–45 years), 371 and all yielded valid biometry measurements. Equations, means and 90% reference intervals for crown‐rump length measurements and biparietal diameter measurements were derived using polynomial regression models. Thorough residual and diagnostic checks were made. Once validated by others, we believe they will warrant consideration for use by Australasian Society for Ultrasound in Medicine.  相似文献   
108.
109.
A cross sectional study assessed the bone mineral density (BMD) of 20 young adult patients who received a renal transplantation in childhood. The BMD of the lumbar spine, mainly trabecular bone, and of the total body, mainly cortical bone, were measured and expressed as an SD score. Fourteen patients (70%) had a BMD SD score of the lumbar spine below -1, of whom six patients were below -2. Fifteen patients (75%) had a BMD SD score of the total body below -1, of whom seven patients were below -2, Both trabecular and cortical bone appeared to be involved in the osteopenic process. The cumulative dose of prednisone was inversely correlated to both lumbar spine and total body BMD SD score. In a multiple regression analysis the cumulative dose of prednisone appeared to be the only factor with a significant effect on BMD SD score. Most young adult patients who had received a renal transplantation in childhood had moderate to severe osteopenia. Corticosteroid treatment played a major part in the development of osteopenia in these patients.  相似文献   
110.
Prevention of subglottic stenosis in neonatal ventilation   总被引:1,自引:0,他引:1  
Mechanical ventilation of the newborn is now widely used in neonatal intensive care. The oro-tracheal route of intubation is simpler, but for long-term ventilation has been considered unstable. A method of fixation of oro-tracheal tubes is described which overcomes this instability. Five hundred consecutive ventilated infants were intubated by the oro-tracheal route and the tube was fixed by the method described. Of the 500 ventilated infants, 213 died without being extubated. Of the 287 survivors, 44 developed a degree of post-extubation stridor. No surviving infant developed clinical evidence of subglottic stenosis and in almost 200 postmortem examinations laryngeal narrowing was not identified. The method of oro-tracheal fixation described is stable and may reduce the incidence of subglottic stenosis.  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