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   577篇
  免费   25篇
  国内免费   20篇
耳鼻咽喉   4篇
儿科学   24篇
妇产科学   5篇
基础医学   38篇
口腔科学   12篇
临床医学   50篇
内科学   148篇
皮肤病学   4篇
神经病学   44篇
特种医学   179篇
外科学   32篇
综合类   15篇
预防医学   19篇
眼科学   3篇
药学   31篇
  2篇
肿瘤学   12篇
  2023年   2篇
  2021年   2篇
  2018年   5篇
  2017年   2篇
  2015年   4篇
  2014年   5篇
  2013年   5篇
  2012年   10篇
  2011年   13篇
  2010年   12篇
  2009年   12篇
  2008年   9篇
  2007年   24篇
  2006年   14篇
  2005年   9篇
  2004年   10篇
  2003年   11篇
  2002年   19篇
  2001年   6篇
  2000年   11篇
  1999年   17篇
  1998年   32篇
  1997年   31篇
  1996年   28篇
  1995年   22篇
  1994年   22篇
  1993年   25篇
  1992年   7篇
  1991年   12篇
  1990年   14篇
  1989年   33篇
  1988年   19篇
  1987年   30篇
  1986年   17篇
  1985年   30篇
  1984年   20篇
  1983年   12篇
  1982年   8篇
  1981年   8篇
  1980年   11篇
  1979年   5篇
  1978年   3篇
  1977年   13篇
  1976年   9篇
  1971年   2篇
  1970年   1篇
  1969年   1篇
  1966年   1篇
  1965年   1篇
  1936年   1篇
排序方式: 共有622条查询结果,搜索用时 15 毫秒
71.
Urine-compatible polymer for long-term ureteral stenting   总被引:1,自引:0,他引:1  
Internal double-J ureteral stents were designed from a urine-compatible polymer (C-Flex), and 35 stents were placed in patients. The overall patency rate for the stents was 80%, with most stent failures occurring before 2 months; the follow-up period ranged from 2 to 16 months, with a mean follow-up for all stents of 5.0 months. Stents were considered patent at last follow-up only if they had been in place for at least 2 months. No migration or fracture of the stents occurred. Physical properties of urine-exposed stents were compared with those of virgin tubing and tubing exposed for 1 year to shelf conditions. Stent patency was optimized by increasing urine flow by increasing the patient's voluntary oral intake, administering prophylactic oral antibiotics, and avoiding placement of stents into grossly bloody or infected collecting systems.  相似文献   
72.
Meniscal tears of the knee: accuracy of MR imaging   总被引:39,自引:0,他引:39  
Crues  JV  d; Mink  J; Levy  TL; Lotysch  M; Stoller  DW 《Radiology》1987,164(2):445-448
Before surgery, 277 menisci in 144 knees were examined with magnetic resonance (MR) imaging. They were then examined directly with arthroscopy or arthrotomy. Menisci were graded on a scale of 1-3 according to the character of the intrameniscal MR imaging signal. At surgery, 137 of 154 (89%) menisci exhibiting only grade 1 or grade 2 signal were found to be normal. One hundred sixteen of 123 (94%) menisci exhibiting intrameniscal signal communicating with a meniscal articular surface (grade 3 signal) had tears. If only a grade 3 signal is considered consistent with meniscal tears, then MR findings and surgical findings agreed in 91.3% of menisci. MR imaging can separate surgically significant from nonsignificant meniscal lesions and is useful in the noninvasive preoperative screening of suspected meniscal tears.  相似文献   
73.
74.
75.
The relative contribution of socioeconomic, behavioural and biological factors operating in fetal and infant life, childhood and adulthood to risk for cardiovascular disease, respiratory diseases and non-insulin-dependent diabetes in middle age has become an important research issue. All 1142 babies born in Newcastle upon Tyne in May and June 1947 were recruited into a prospective cohort study of child health (the ‘Thousand Families’ study) and followed in great detail to the age of 15 y, with a brief further follow up at age 22 y. Children from poorer families were at greatest risk of severe respiratory tract infection in infancy. Children from professional and managerial families were on average taller and heavier throughout childhood than those from semi- and unskilled manual social classes. Repeated infections in early childhood greatly increased the risk of developing chronic respiratory disease by age 15 y. This paper outlines a new investigation designed to trace surviving members of this cohort and to chart the relationships between their socioeconomic circumstances, lifestyles, experiences and health from birth through to the present day. Existing data on socioeconomic circumstances and infections in infancy and childhood, infant nutrition, birthweight and physical development to age 22 y will be linked to information gained from a new study. This comprises a postal questionnaire survey of study members' adult health, socioeconomic circumstances and lifestyle, and a hospital based clinical examination including heart and lung function, glucose tolerance, blood lipids and anthropometric measurements at age 49–51 y. Out of a target sample of 979 people for whom sufficient data are available on the first year of life, 866 (88%) have been traced and 649 are still resident in the North of England. Those study members who have been traced are highly representative of the original cohort. The Thousand Families cohort provides a unique opportunity for detailed epidemiological study because of the wealth of data available on infant and childhood socioeconomic and family circumstances, all of which was collected prospectively. In addition, there has been comparatively little loss to follow-up since 1948.  相似文献   
76.
Gelfand  DW; Chen  YM; Ott  DJ 《Radiology》1987,162(3):829-834
Multiphasic examinations of 153 gastric abnormalities observed radiologically and endoscopically were reviewed to determine the efficacy of four radiologic techniques and of several common combinations of these techniques for examining the stomach. There were 68 gastric ulcers, 12 ulcer scars, 44 cases of gastritis including 27 with erosions, 24 benign neoplasms, and five malignancies. Double-contrast, compression, mucosal relief, and full-column techniques detected 82%, 65%, 62%, and 51%, respectively, of all lesions diagnosed with the complete multiphasic examinations. Results indicate that the greater the number of techniques employed, the more accurate the examination, with biphasic and multiphasic examinations detecting 9%-18% more lesions overall than simple single- or double-contrast studies.  相似文献   
77.
78.
79.
80.
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