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   3229642篇
  免费   250581篇
  国内免费   7563篇
耳鼻咽喉   45505篇
儿科学   101603篇
妇产科学   86746篇
基础医学   461062篇
口腔科学   92514篇
临床医学   303487篇
内科学   621652篇
皮肤病学   64975篇
神经病学   271269篇
特种医学   125219篇
外国民族医学   1128篇
外科学   472195篇
综合类   76418篇
现状与发展   2篇
一般理论   1363篇
预防医学   269809篇
眼科学   75038篇
药学   241018篇
  10篇
中国医学   6507篇
肿瘤学   170266篇
  2018年   34815篇
  2017年   26604篇
  2016年   29112篇
  2015年   33152篇
  2014年   47098篇
  2013年   72474篇
  2012年   98354篇
  2011年   104083篇
  2010年   61054篇
  2009年   57693篇
  2008年   97572篇
  2007年   103733篇
  2006年   104567篇
  2005年   101561篇
  2004年   97259篇
  2003年   93518篇
  2002年   91718篇
  2001年   144647篇
  2000年   149514篇
  1999年   126481篇
  1998年   37269篇
  1997年   33816篇
  1996年   33239篇
  1995年   32125篇
  1994年   30165篇
  1993年   28238篇
  1992年   102266篇
  1991年   99353篇
  1990年   96232篇
  1989年   92318篇
  1988年   85770篇
  1987年   84342篇
  1986年   80234篇
  1985年   76660篇
  1984年   58287篇
  1983年   49737篇
  1982年   30287篇
  1981年   26969篇
  1979年   54356篇
  1978年   38456篇
  1977年   32158篇
  1976年   30628篇
  1975年   32106篇
  1974年   39445篇
  1973年   37965篇
  1972年   35372篇
  1971年   32823篇
  1970年   30688篇
  1969年   28405篇
  1968年   26279篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
In 1983, 1623 primary and secondary schoolchildren took part in a health survey which was organized by the Busselton Population Studies Group. Age, sex, weight, height and country of birth were recorded for each child. Where possible, the country of birth of parents and the occupation of the father were extracted from previous Busselton surveys of adults. Compared with Perth schoolchildren, the difference in the attained weight and height of Busselton children at any age was small. This was so even though the two communities differ in location (rural compared with metropolitan), in ethnic origin (mainly British compared with diverse origins) and, probably, in social-rank distribution. Data from the two communities showed that a similar small secular increase in height had occurred since 1970/1971. This increase averaged at 1.2 cm for children at each year of age in Busselton and 1.5 cm to 1.6 cm for children in Perth.  相似文献   
992.
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   
993.
994.
Electrical stimulation of rat habenular complex induces analgesia, evaluated by the tail-flick test, dependent on intensity of stimulation with a long post-effect, that is reversible by naloxone and without behavior effects at less that 400 mA. Bilateral destruction of habenula fails to provoke hyperesthesia but causes more marked long-term tolerance effects than in controls. Anatomy suggests that the habenula activates an inhibitory descending system in the spinal cord with a probable relay in the dorsal raphe and involving an endogenous opioid-dependent stage.  相似文献   
995.
Obese, overweight, desirable, ideal: where to draw the line in 1986?   总被引:1,自引:0,他引:1  
In February 1985, the National Institutes of Health sponsored the Consensus Development Conference on the Health Implications of Obesity. The panel of experts concluded that height and weight tables based on mortality data and the body mass index (BMI) are helpful measures to determine the presence of obesity and the need for treatment. For the dietitian, however, practical concerns arise regarding which index to select. The usefulness of the BMI in patient education and contradictions between the 1959 and 1983 Metropolitan Life Insurance height-weight tables are discussed. A temporary solution is offered in light of the need for further investigation into morbidity experience at weights recommended in the 1983 table.  相似文献   
996.
997.
998.
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   
999.
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