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   2590255篇
  免费   185716篇
  国内免费   7565篇
耳鼻咽喉   34323篇
儿科学   85313篇
妇产科学   71686篇
基础医学   364123篇
口腔科学   69729篇
临床医学   234879篇
内科学   516204篇
皮肤病学   62521篇
神经病学   213704篇
特种医学   99981篇
外国民族医学   737篇
外科学   386908篇
综合类   50405篇
现状与发展   5篇
一般理论   969篇
预防医学   196387篇
眼科学   56709篇
药学   188201篇
  8篇
中国医学   5344篇
肿瘤学   145400篇
  2021年   20023篇
  2019年   20670篇
  2018年   29329篇
  2017年   22637篇
  2016年   26288篇
  2015年   29572篇
  2014年   40540篇
  2013年   60544篇
  2012年   80391篇
  2011年   84658篇
  2010年   51104篇
  2009年   49234篇
  2008年   79175篇
  2007年   83996篇
  2006年   85732篇
  2005年   81896篇
  2004年   78840篇
  2003年   76178篇
  2002年   73466篇
  2001年   128477篇
  2000年   131390篇
  1999年   110575篇
  1998年   31302篇
  1997年   27963篇
  1996年   28260篇
  1995年   27407篇
  1994年   25098篇
  1993年   23449篇
  1992年   85212篇
  1991年   81601篇
  1990年   78826篇
  1989年   76102篇
  1988年   69516篇
  1987年   68034篇
  1986年   63578篇
  1985年   60548篇
  1984年   44964篇
  1983年   37969篇
  1982年   22477篇
  1981年   20000篇
  1979年   38995篇
  1978年   27477篇
  1977年   23280篇
  1976年   21515篇
  1975年   22842篇
  1974年   26813篇
  1973年   25391篇
  1972年   23783篇
  1971年   22003篇
  1970年   20206篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Continuity of relationship between physician and patient is a fundamental aspect of the health care provided by family physicians. Measurement of continuity has proved difficult, however. Commonly applied measures, usual provider of care (UPC), continuity of care (COC), and the modified continuity index (MCI), either ignore key aspects of continuity or provide misleading results. Consequently, a new measure of continuity, the modified, modified continuity index (MMCI), with a possible range of 0 to 1, was developed to overcome these problems. It was applied to a residency model practice, in which mean MMCI was found to be 0.59 (range 0.3 to 1.0). Mean COC was .41 and a mean MCI was .44. Thus, unlike COC and MCI, MMCI suggests fairly good continuity of care in this practice while still implying possible improvement. The MMCI should be useful for enhancing training and practice of family medicine.  相似文献   
992.
993.
994.
In order to prevent essential fatty acid (EFA) deficiency induced by fat-free total parenteral nutrition (TPN), 10 infants on TPN were rubbed three times daily for 20 days using oenethera oil (80% EFA). Total EFA amount provided cutaneously was 1900 mg/kg/d. Plasma and red blood cells phospholipids were determined on days 1 and 20 in these 10 treated and six untreated infants on TPN and compared with those of normal control infants. On day 1, plasma nonessential FA including 20:3 n-9(p less than 0.01) were increased in both TPN groups while 18:2 n-6 and 18:3 n-3 (p less than 0.001 and p less than 0.01) were decreased. On the 20th day, EFA deficiency had worsened with a decrease in plasma level of 20:4 n-6 (p less than 0.02) and a higher than normal triene/tetraene ratio : 3.4 +/- 1.1 and 2.3 +/- 0.6 vs 0.1 +/- 0.1 (p less than 0.02). As for red blood cells phospholipids, 16:0 was increased and 18:2 n-6 and 20:3 n-6 were decreased (p less than 0.05) on day 1. On day 20, these FA were more abnormal while 20:3 n-9 became significantly increased (p less than 0.05). No difference was observed between the TPN groups at any time. These results show that cutaneous application of large amounts of EFA-rich oil is unable to prevent or cure TPN induced EFA deficiency.  相似文献   
995.
996.
997.
998.
999.
Forty-one multiplex families, from published sources and new data from the National Cancer Institute, segregating for Hodgkin's disease and HLA, have been studied. A reanalysis of these data strongly suggests a recessive mode of inheritance for susceptibility to Hodgkin's disease. The HLA haplotype sharing data between affected relatives demonstrate that approximately 60% of cases in multiplex families are due to an HLA-linked susceptibility gene, the remaining 40% being due to other familial factors. The data clearly support the hypothesis of etiological heterogeneity for Hodgkin's disease, with both HLA-linked and HLA-unlinked factors being responsible. Finally, there is an increased concordance of histological types between affected relatives, but this concordance seems independent of HLA sharing.  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