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   2362923篇
  免费   172550篇
  国内免费   3358篇
耳鼻咽喉   32159篇
儿科学   76367篇
妇产科学   63116篇
基础医学   349799篇
口腔科学   63803篇
临床医学   213214篇
内科学   459486篇
皮肤病学   51924篇
神经病学   186780篇
特种医学   88287篇
外国民族医学   490篇
外科学   355212篇
综合类   47653篇
现状与发展   13篇
一般理论   861篇
预防医学   184716篇
眼科学   54457篇
药学   175862篇
  12篇
中国医学   4587篇
肿瘤学   130033篇
  2021年   19482篇
  2019年   19978篇
  2018年   27590篇
  2017年   20763篇
  2016年   23199篇
  2015年   26091篇
  2014年   36613篇
  2013年   54773篇
  2012年   75762篇
  2011年   80542篇
  2010年   47633篇
  2009年   45065篇
  2008年   75419篇
  2007年   80366篇
  2006年   81060篇
  2005年   78489篇
  2004年   75024篇
  2003年   72247篇
  2002年   69903篇
  2001年   108817篇
  2000年   111515篇
  1999年   93585篇
  1998年   27084篇
  1997年   23738篇
  1996年   24105篇
  1995年   22771篇
  1994年   20929篇
  1993年   19750篇
  1992年   72027篇
  1991年   70090篇
  1990年   68408篇
  1989年   65680篇
  1988年   60320篇
  1987年   59146篇
  1986年   55248篇
  1985年   53019篇
  1984年   39347篇
  1983年   33406篇
  1982年   19885篇
  1979年   35878篇
  1978年   25662篇
  1977年   21239篇
  1976年   20351篇
  1975年   21836篇
  1974年   26159篇
  1973年   24808篇
  1972年   23205篇
  1971年   22044篇
  1970年   20250篇
  1969年   19316篇
排序方式: 共有10000条查询结果,搜索用时 14 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