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   2375088篇
  免费   173314篇
  国内免费   3424篇
耳鼻咽喉   32260篇
儿科学   76922篇
妇产科学   63445篇
基础医学   351586篇
口腔科学   63966篇
临床医学   214656篇
内科学   462102篇
皮肤病学   52219篇
神经病学   187955篇
特种医学   88588篇
外国民族医学   489篇
外科学   356294篇
综合类   47769篇
现状与发展   12篇
一般理论   877篇
预防医学   185769篇
眼科学   54702篇
药学   176599篇
  11篇
中国医学   4621篇
肿瘤学   130984篇
  2021年   19645篇
  2019年   20263篇
  2018年   27869篇
  2017年   20914篇
  2016年   23370篇
  2015年   26291篇
  2014年   37038篇
  2013年   55362篇
  2012年   76673篇
  2011年   81461篇
  2010年   48254篇
  2009年   45537篇
  2008年   76294篇
  2007年   81330篇
  2006年   82049篇
  2005年   79433篇
  2004年   75850篇
  2003年   73089篇
  2002年   70662篇
  2001年   108903篇
  2000年   111587篇
  1999年   93678篇
  1998年   27245篇
  1997年   23889篇
  1996年   24220篇
  1995年   22860篇
  1994年   21009篇
  1993年   19856篇
  1992年   72086篇
  1991年   70138篇
  1990年   68444篇
  1989年   65712篇
  1988年   60359篇
  1987年   59151篇
  1986年   55249篇
  1985年   53035篇
  1984年   39353篇
  1983年   33434篇
  1982年   19903篇
  1979年   35893篇
  1978年   25678篇
  1977年   21253篇
  1976年   20344篇
  1975年   21828篇
  1974年   26160篇
  1973年   24814篇
  1972年   23213篇
  1971年   22045篇
  1970年   20257篇
  1969年   19320篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Two hundred and thirty pregnancies were studied in 196 diabetic women. Seven women with babies found to have major malformations had a higher median first trimester haemoglobin A1 (12.9%) than the median HbA1 (10.8%) in those with normal babies (p = 0.06). No relationship was found between the occurrence of minor malformations and first trimester maternal haemoglobin A1. Two of the seven congenital malformations were diagnosed antenatally at a time when therapeutic abortion could be offered. Expert antenatal ultrasound scanning should be offered to all pregnant diabetic women as poor glycaemic control at the time of conception and organogenesis, as evidenced by raised first trimester HbA1, predisposes to congenital malformation.  相似文献   
992.
This paper gives the historical sketch necessary for an understanding of the current state of American psychiatry. It reviews some of the reasons why the rendering of good hospital care must be reconsidered, and describes some of the main features of the future public institution.  相似文献   
993.
During almost 12 years of development and clinical trials, diclofenac sodium has been shown to be both effective and safe as a new nonsteroidal antiinflammatory drug (NSAID) for the treatment of rheumatic diseases including ankylosing spondylitis (AS). We compared the safety and efficacy of 75, 100, or 125 mg/day of diclofenac with the same doses of indomethacin in a multicenter, randomized, parallel group trial in patients with AS. A single blind placebo washout period of 2 days to 2 weeks preceded the 13-week double blind treatment period. Both diclofenac and indomethacin produced significant (p less than 0.001) improvement from baseline for all 14 efficacy variables analyzed. There were no significant between treatment differences. Differences favored diclofenac in the frequency and the severity of adverse experiences reported and in the frequency of complaints affecting the central nervous system.  相似文献   
994.
Various cases are presented demonstrating the role of computed tomography (CT) in the assessment of serosal and bowel wall pathology. Reference is made to the morphology of the lesions. Illustrative examples of tumors, secondary malignant dissemination, irradiation injury to the gut, and intramural gas associated with ulcerative colitis, are all illustrated.  相似文献   
995.
996.
997.
998.
The spontaneous quantal and nonquantal acetylcholine release was investigated at the temperature range from 10 to 35 degrees C in white mouse semidiaphragm. The quantal release was evaluated by calculation of miniature end-plate potentials frequency, while the nonquantal one--from the H-effect value. The spontaneous quantal release increased exponentially with the temperature growth. The temperature dependence of the nonquantal release showed two relative maxima: at 20 degrees and 35 degrees C. At 10 degrees C the nonquantal release was absent. The value of calculated effective energy of activation of the quantal release was 57.0 kJ/mol in the investigated temperature range. The effective energy of activation for the nonquantal release process in intervals 15-20 degrees C and 25-35 degrees C was 45.5 and 38.2 kJ/mol, relatively. It is suggested that the nonquantal release is rather due to active transport processes than to simple diffusion of acetylcholine molecules.  相似文献   
999.
Application of thiamine (1 X 10(-11)-1 X 10(-3) mol/l) on the membrane of cochlear round window increased the amplitude and decreased the latency of the auditory nerve action potential, waves I and II of brainstem auditory-evoked electrical potentials in response to acoustic clicks of different intensity. The mechanism of thiamine action on auditory-evoked electric potentials is discussed.  相似文献   
1000.
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