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   1224526篇
  免费   91363篇
  国内免费   3524篇
耳鼻咽喉   15463篇
儿科学   40362篇
妇产科学   32546篇
基础医学   175076篇
口腔科学   31998篇
临床医学   113432篇
内科学   241255篇
皮肤病学   26002篇
神经病学   101191篇
特种医学   45970篇
外国民族医学   315篇
外科学   183289篇
综合类   26942篇
一般理论   683篇
预防医学   97349篇
眼科学   28641篇
药学   87485篇
  9篇
中国医学   2369篇
肿瘤学   69036篇
  2021年   11677篇
  2019年   12054篇
  2018年   15905篇
  2017年   12266篇
  2016年   13826篇
  2015年   15783篇
  2014年   22106篇
  2013年   32624篇
  2012年   45211篇
  2011年   47720篇
  2010年   27977篇
  2009年   25946篇
  2008年   43737篇
  2007年   46209篇
  2006年   46635篇
  2005年   45209篇
  2004年   43414篇
  2003年   41399篇
  2002年   39445篇
  2001年   48865篇
  2000年   49494篇
  1999年   42381篇
  1998年   13936篇
  1997年   12412篇
  1996年   12148篇
  1995年   11697篇
  1994年   10660篇
  1993年   9918篇
  1992年   33383篇
  1991年   32513篇
  1990年   31889篇
  1989年   30728篇
  1988年   28045篇
  1987年   28165篇
  1986年   26283篇
  1985年   25466篇
  1984年   19495篇
  1983年   16531篇
  1982年   10527篇
  1981年   9588篇
  1979年   17491篇
  1978年   12907篇
  1977年   10894篇
  1976年   10288篇
  1975年   10612篇
  1974年   12755篇
  1973年   12201篇
  1972年   11190篇
  1971年   10370篇
  1970年   9598篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
This study surveyed male and female athletes from 22 midwesterncolleges and universities regarding behaviors and attitudesassociated with anorexia nervosa and bulimia nervosa. The responserate was 66% (N= 695) and the findings indicated that the bodyimage of some athletes may be distorted; one-seventh perceivedthemselves as fat even though they were not. Many athletes seemedpreoccupied with food and weight; almost one-third reportedroutinely thinking about food and weight and more than one-thirdreported dramatic annual weight fluctuations (9 lb or greater)related to bingeing and fasting. Athletes also did not feelin control when they ate and their habits related to food consumptionappeared to be extreme; one-tenth reported a lack of controlwhen they ate, more than one-third binged, one-twentieth ateuntil they were physically ill, and a similar proportion preferrednot to eat in the presence of others. In addition, it was foundthat as many men as women athletes reported these perceptionsbut significant sex differences were noted for specific items.It was suggested that behaviors and attitudes be viewed on acontinuum with normals at one end, eating disordered individuals at the other end,and college athletes in between. Health education that focuseson behaviors and attitudes as symptoms of eating disorders wasrecommended for athletes and those working closely with athletes.Future research was suggested to determine reasons for the undesirablebehaviors and attitudes and to study the onset, development,long-term effects and whether these behaviors and attitudeslead to an eating disorder.  相似文献   
103.
The epidemiologic correlation of chronic dietary salt intake among populations with the prevalence of hypertension has resulted in the concept that sodium plays an etiologic role in the development of essential hypertension (EH). However, the association of sodium intake with blood pressure in individuals within populations has been difficult to demonstrate. The differing human responses to sodium intake are dependent upon the individual level of sodium sensitivity or sodium resistance. Factors associated with sodium sensitivity are race, age, and other dietary factors. More recent investigations have pursued the interaction of sodium intake with other physiologic parameters including neurogenic activity, vascular structure, renal function, and other cations such as potassium and calcium. The observations that some humans demonstrate very little increase in blood pressure despite high levels of sodium intake supports the concept that a high sodium intake alone is not a single causal factor in hypertension. Sodium intake appears to interact with renal excretory capacity and vascular compliance. These varying physiologic functions must be delineated to characterize sodium sensitivity.  相似文献   
104.
In transmitting the body's weight, the ankle is subject to frequent static and dynamic injury due to concentrated stresses during standing and movement. The frequency of athletic ankle injuries ranges from 10 to 90 percent, with the highest rate occurring in basketball players. There is prolonged disability and recurrent instability for months to years for 25 to 40 per cent of these patients. Because most of this trauma is handled by primary care physicians, this review presents the mechanism of injury, relevant anatomy, physical examination, and appropriate therapeutic intervention in the acute and rehabilitative phases.  相似文献   
105.
Recurrent erosion   总被引:1,自引:0,他引:1  
  相似文献   
106.
Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery.  相似文献   
107.
Abstract This paper examines the impact of medical technology on the careers of people with post-polio respiratory disability. The data have been taken from multiple in-depth interviews with ten people who contracted polio during the epidemics of the early 1950s, all of whom used or had used a variety of methods of mechanical respiratory support. It focuses on ideologies of disability and the adoption of technology, the management of respiratory insufficiency and strategies of'trading off whereby the benefits of technology are maximized and the costs minimized. While technology made an enormous contribution to the quality of life of these people, the problems it created transformed both their experience of the illness and the character of their everyday existence.  相似文献   
108.
109.
Eighty-nine cases of chronic bronchitis were matched against167 asymptomatic controls from the glass bangle industry ofFirozabad. Factors of age, social status, smoking habit andduration of exposure were studied. Duration of exposure wasfound to be a factor contributing significantly to the causationof disease. Requests for reprints should be addressed to: Dr B. N. Gupta, Division of Epidemilogy, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow P.O. Box 80, 226001, India  相似文献   
110.
The composition of the clientele from an ophthalmological practitioner's office is described with special reference to the occurrence of glaucoma and disc haemorrhages (h in singular; hh in plural). This study could not be planned as an epidemiological survey and gives no clue to sensitivity or specificity of hh in glaucoma. During a period of about 10 years ending with 1986 there were 731 patients with h and/or glaucoma. When detected, 185 patients had h but no glaucoma, 33 had both h and glaucoma and 513 had glaucoma but no h. During the follow-up period hh were detected in 83 cases of glaucoma, and glaucoma developed in 27 cases with hh. The detection rate of hh among glaucoma was low but steady, indicating that hh may occur at any stage of the glaucoma process. This study shows no predilection for hh in cases with general hypertension or diabetes, nor is the frequency of hh among pseudoexfoliation cases significantly lower than among cases without this stigma.  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