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   16293篇
  免费   1382篇
  国内免费   41篇
耳鼻咽喉   93篇
儿科学   600篇
妇产科学   391篇
基础医学   1935篇
口腔科学   240篇
临床医学   1820篇
内科学   2778篇
皮肤病学   284篇
神经病学   1355篇
特种医学   436篇
外科学   1796篇
综合类   215篇
一般理论   26篇
预防医学   3410篇
眼科学   174篇
药学   950篇
中国医学   32篇
肿瘤学   1181篇
  2023年   87篇
  2022年   149篇
  2021年   264篇
  2020年   276篇
  2019年   306篇
  2018年   438篇
  2017年   302篇
  2016年   354篇
  2015年   354篇
  2014年   502篇
  2013年   794篇
  2012年   993篇
  2011年   911篇
  2010年   625篇
  2009年   646篇
  2008年   919篇
  2007年   1008篇
  2006年   900篇
  2005年   958篇
  2004年   863篇
  2003年   838篇
  2002年   808篇
  2001年   233篇
  2000年   182篇
  1999年   281篇
  1998年   297篇
  1997年   341篇
  1996年   337篇
  1995年   248篇
  1994年   141篇
  1993年   217篇
  1992年   129篇
  1991年   109篇
  1990年   96篇
  1989年   124篇
  1988年   109篇
  1987年   99篇
  1986年   97篇
  1985年   120篇
  1984年   79篇
  1983年   89篇
  1982年   101篇
  1981年   93篇
  1980年   77篇
  1979年   57篇
  1978年   84篇
  1977年   71篇
  1976年   54篇
  1975年   48篇
  1974年   39篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
We conducted an observational cohort study in three nurse-midwifery services to identify patient characteristics and clinical care measures related to perineal trauma at birth. Data were collected on all women who began care with a nurse-midwife in labor, using an adaptation of the Nurse-Midwifery Clinical Data Set (n = 3,049). Study variables included demographics, perineal management techniques and position for birth, and other intrapartum care and events. Univariate and multivariate analyses showed that episiotomy was strongly related to fetal bradycardia, prolonged second stage, ethnic status, and maternal education level. Warm compresses and flexion/counterpressure to slow delivery were protective. Spontaneous lacerations were influenced by these factors as well. The lateral position for birth was protective, and use of oils or lubricants and the lithotomy position increased lacerations. Multisite studies in nurse-midwifery practices may provide an ideal means of determining effective care measures in healthy populations.  相似文献   
42.
43.
44.
45.
46.
47.
48.
49.
Advancing age is associated with a remarkable number of changes in body composition, including reduction in lean body mass and increase in body fat, which have been well documented. Decreased lean body mass occurs primarily as a result of losses in skeletal muscle mass. This age-related loss in muscle mass has been termed “sarcopenia”. Loss in muscle mass accounts for the age-associated decreases in basal metabolic rate, muscle strength, and activity levels, which, in turn are the cause of the decreased energy requirements of the elderly. In sedentary persons, the main determinant of energy expenditure is fat-free mass, which declines by about 15% between the third and eighth decade of life. It also appears that declining energy needs are not matched by an appropriate decline in energy intake, with the ultimate result being increased body fat content. Increased body fatness and increased abdominal obesity are thought to be directly linked to the greatly increased incidence of non-insulin-dependent diabetes mellitus among the elderly. In this review we will discuss the extent to which regularly performed exercise can affect nutrition needs and functional capacity in the elderly. We will also discuss a variety of concerns when prescribing exercise in the elderly, such as planning for a wide variability in functional status, medical status, and training intensity and duration. Finally, we will attempt to provide some basic guidelines for beginning an exercise program for older men and women and establishing community-based programs.  相似文献   
50.
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