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   2165580篇
  免费   154772篇
  国内免费   2839篇
耳鼻咽喉   29555篇
儿科学   70517篇
妇产科学   59272篇
基础医学   315572篇
口腔科学   60651篇
临床医学   197904篇
内科学   415325篇
皮肤病学   48198篇
神经病学   169670篇
特种医学   82673篇
外国民族医学   480篇
外科学   316680篇
综合类   44726篇
现状与发展   3篇
一般理论   785篇
预防医学   167508篇
眼科学   49708篇
药学   165728篇
  11篇
中国医学   4522篇
肿瘤学   123703篇
  2018年   22746篇
  2017年   17579篇
  2016年   19577篇
  2015年   22230篇
  2014年   30770篇
  2013年   46168篇
  2012年   62971篇
  2011年   66866篇
  2010年   39134篇
  2009年   37297篇
  2008年   62868篇
  2007年   67259篇
  2006年   67521篇
  2005年   65315篇
  2004年   62629篇
  2003年   60198篇
  2002年   58199篇
  2001年   104634篇
  2000年   107086篇
  1999年   89872篇
  1998年   24040篇
  1997年   21535篇
  1996年   21722篇
  1995年   20412篇
  1994年   18905篇
  1993年   17761篇
  1992年   69702篇
  1991年   67752篇
  1990年   66214篇
  1989年   64030篇
  1988年   58620篇
  1987年   57241篇
  1986年   54405篇
  1985年   51224篇
  1984年   38207篇
  1983年   32897篇
  1982年   18882篇
  1981年   16810篇
  1979年   35458篇
  1978年   25074篇
  1977年   21626篇
  1976年   19545篇
  1975年   21523篇
  1974年   25717篇
  1973年   25130篇
  1972年   23910篇
  1971年   22370篇
  1970年   20906篇
  1969年   19946篇
  1968年   18229篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
BackgroundSecond-hand smoking or environmental tobacco smoke is a critical health risk. Children are the most vulnerable to second-hand smoking because of their small bronchial ducts, less developed immunity, and low-physical activity.ObjectivesThe purpose of this study was to ascertain the effects of second-hand smoking on lung functions in athlete and non-athlete school-aged children.MethodsThis observational study included forty-six school-aged children, their age was 8–15 years, assigned to three groups; 2 study groups and 1 control group (n=15). The study groups comprised of 16 football players, and of 15 cyclists. Lung functions were evaluated recording forced vital capacity, forced expiratory volume in 1 sec and peak expiratory flow using digital spirometer.ResultsAll measures were recorded in definite values and the children were also classified into second-hand smoking (SH), or non-exposed to tobacco smoking (NE). The findings presented a significant increase (p<0.05) of the study groups in forced vital capacity, forced expiratory volume in 1 sec and peak expiratory flow solely for the non-exposed children. However, there were non-significant differences between the cyclists and football players or between the passive smoking children and non-exposed children in any of the two study groups (p>0.05).ConclusionThe outcomes of this study suggest beneficial influences of the sports activity on the lung functions, without different influences of the cyclists and football players on the lung functions.  相似文献   
83.
84.
As millions of people turn to social media for health information, better understanding the factors that guide health-related judgments and perceptions in this context is imperative. We report on two Web experiments (n > 400 total) examining the power of society’s widespread weight bias and related stereotypes to influence nutrition judgments in social media spaces. In Experiment 1, meals were judged as lower in nutritional quality when the person who recommended them (the source) was depicted as obese rather than of normal weight, an effect mediated by stereotypic beliefs about the source as a generally unhealthy person. Experiment 2 replicated this effect, which—notably—remained significant when controlling for objective nutritional information (calories and fat content). Results highlight spillover effects of weight bias that extend beyond person perception to color impressions of objects (here, food) that are associated with stigmatized attributes. Implications for everyday nutrition judgments and public health are considered.  相似文献   
85.
86.
87.
88.
89.
90.
A 48-year-old smoker with a history of hyperthyroidism treated 10 years prior to presentation with radioactive iodine ablation of the thyroid gland presented to his ophthalmologist with a 2-week history of transient loss of vision in the right eye occurring for 1 to 2 hours each morning. He denied ocular pain, diplopia or change in the prominence of one or both eyes. Examination revealed 2 mm of relative proptosis on the right, bilateral temporal flare and lower lid retraction. There was minimal upper lid retraction and no evidence of lid lag. Ocular motility was full. Dilated fundoscopic examination revealed bilateral optic nerve edema, right more than left. CT of the orbit demonstrated enlargement of the extraocular muscles bilaterally with marked enlargement of the right medial rectus and left inferior rectus muscles resulting in crowding at the orbital apex bilaterally. Laboratory testing revealed the patient to be hyperthyroid. The patient was treated with high dose oral steroids followed by orbital radiation. Hyperthyroidism was managed by the patient’s primary care physician. Visual symptoms rapidly improved with oral steroids and orbital radiation. Optic nerve edema completely resolved. Repeat CT imaging demonstrated a reduction in the enlargement of the extraocular muscles with relief of bilateral optic nerve compression.  相似文献   
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