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   2358726篇
  免费   172634篇
  国内免费   3645篇
耳鼻咽喉   32142篇
儿科学   76057篇
妇产科学   62764篇
基础医学   349161篇
口腔科学   63837篇
临床医学   212542篇
内科学   458680篇
皮肤病学   51902篇
神经病学   185760篇
特种医学   88359篇
外国民族医学   491篇
外科学   354828篇
综合类   48586篇
现状与发展   14篇
一般理论   852篇
预防医学   183428篇
眼科学   54547篇
药学   176171篇
  20篇
中国医学   5043篇
肿瘤学   129821篇
  2021年   19496篇
  2019年   19909篇
  2018年   27423篇
  2017年   20691篇
  2016年   23050篇
  2015年   26032篇
  2014年   36607篇
  2013年   54543篇
  2012年   75462篇
  2011年   80112篇
  2010年   47562篇
  2009年   44952篇
  2008年   75084篇
  2007年   79957篇
  2006年   80716篇
  2005年   78170篇
  2004年   74703篇
  2003年   72012篇
  2002年   69617篇
  2001年   108882篇
  2000年   111568篇
  1999年   93577篇
  1998年   27048篇
  1997年   23709篇
  1996年   24091篇
  1995年   22757篇
  1994年   20927篇
  1993年   19730篇
  1992年   72030篇
  1991年   70113篇
  1990年   68420篇
  1989年   65686篇
  1988年   60325篇
  1987年   59146篇
  1986年   55231篇
  1985年   53012篇
  1984年   39327篇
  1983年   33403篇
  1982年   19865篇
  1979年   35879篇
  1978年   25660篇
  1977年   21233篇
  1976年   20336篇
  1975年   21823篇
  1974年   26159篇
  1973年   24816篇
  1972年   23206篇
  1971年   22043篇
  1970年   20251篇
  1969年   19321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