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   1618796篇
  免费   123665篇
  国内免费   2591篇
耳鼻咽喉   21813篇
儿科学   53149篇
妇产科学   46299篇
基础医学   228580篇
口腔科学   47439篇
临床医学   141450篇
内科学   316885篇
皮肤病学   34249篇
神经病学   130946篇
特种医学   65109篇
外国民族医学   474篇
外科学   245417篇
综合类   39732篇
现状与发展   3篇
一般理论   544篇
预防医学   123174篇
眼科学   36717篇
药学   121813篇
  38篇
中国医学   2983篇
肿瘤学   88238篇
  2018年   14909篇
  2016年   13037篇
  2015年   15143篇
  2014年   20785篇
  2013年   31507篇
  2012年   42821篇
  2011年   45033篇
  2010年   26518篇
  2009年   25469篇
  2008年   43291篇
  2007年   45573篇
  2006年   46339篇
  2005年   44968篇
  2004年   44392篇
  2003年   42466篇
  2002年   41537篇
  2001年   75963篇
  2000年   78613篇
  1999年   66594篇
  1998年   17829篇
  1997年   16405篇
  1996年   16389篇
  1995年   16073篇
  1994年   15133篇
  1993年   14292篇
  1992年   55601篇
  1991年   53931篇
  1990年   52727篇
  1989年   51013篇
  1988年   47353篇
  1987年   46684篇
  1986年   44411篇
  1985年   42971篇
  1984年   32109篇
  1983年   27639篇
  1982年   16170篇
  1981年   14452篇
  1980年   13584篇
  1979年   30509篇
  1978年   21092篇
  1977年   17802篇
  1976年   16715篇
  1975年   17599篇
  1974年   21515篇
  1973年   20703篇
  1972年   18892篇
  1971年   17792篇
  1970年   16326篇
  1969年   15297篇
  1968年   13983篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
113.
114.
This study examined electromyogram (EMG) and skin conductance level (SCL) as mediators of neuropsychological test performance of alcoholics. Alcoholics and controls with high EMG performed less well than low EMG subjects on 12 measures of neuropsychological performance. For SCL, the alcoholics and controls in the Low Group did not differ from those in the High Group on any measure. Analyses that used information intake (Low EMG and High SCL) and rejection (High EMG and Low SCL) information postures (IPs) demonstrated that the intake group outperformed the rejection group on 10 neuropsychological measures. Subjects with intake IPs reported more stimulation, concentration, and interest during the tasks than did subjects with rejection IPs. Results suggest that IPs can be used to identify alcoholics with neuropsychological deficits.  相似文献   
115.
We tested the urine of 30 infants 6 weeks to 7 months of age after they received standard 10-micrograms (0.5-ml) doses of HbOC (HibTITER) Haemophilus influenzae b (Hib) conjugate vaccine for the presence of Hib antigenuria using a commercially available latex particle agglutination assay (Directigen). Urines were collected within 1 hour, from 1 to 3 hours, at 24 hours and at 3, 6 and 9 days after vaccine administration and reactions were quantitated from 0 to 3+. In contrast to previous studies in older children which showed little or no antigenuria following HbOC vaccination, our study shows that in infants intense Hib antigenuria is evident within 2 to 3 hours and persists 3 days after vaccine administration and that less intense antigenuria may be detected in some infants for several days. With efficacious vaccines now being used in 2- to 6-month-old infants, invasive Hib disease may soon be limited to infants of this age just before their seroconversion. It should be recognized that antigenuria occurs for several days after vaccination with Hib conjugate vaccines and that it could be erroneously interpreted as evidence of invasive Hib infection.  相似文献   
116.
Analysis of accident logs in child day care centers indicates that biting is common, especially among toddlers 13 to 30 months of age. Children of this age often lack appropriate verbal skills and resort to aggressive means to achieve their goals. Still awkward in gross-motor skills, toddlers can also suffer self-bites following accidental falls. According to medical reports, human bites sometimes are more virulent than animal bites and can cause severe trauma. Although the AIDS virus has been cultured from saliva, transmission from saliva alone has not been documented. Bite injuries in day care, however, usually are minor and can be treated by washing, applying cold compresses, and comforting the child. Suggested methods to diminish the frequency of biting in day care include physical changes within the room, behavior modification, and other classroom management techniques.  相似文献   
117.
Lipid metabolism and hyperandrogenism.   总被引:1,自引:0,他引:1  
Hyperandrogenism and lipid metabolism were shown to be related intimately. Any discussion of the nature of their relationship must include other clinical and metabolic variables such as hyperinsulinemia and UBO. Despite the many correlations among each of these factors, the appropriate sequence in the pathogenesis of these conditions has not been defined. Do conditions that result in insulin resistance (e.g., genetic defects, insulin receptor antibodies, and obesity) also lead to the development of hyperandrogenemia by direct or indirect ovarian stimulation by insulin? Does hyperandrogenism of ovarian or adrenal origin cause abnormal upper body fat distribution, in turn leading to lipid abnormalities and insulin resistance? Regardless of the issue of mechanism of causality, women with hyperandrogenism are thought to be at greater risk for cardiovascular morbidity and mortality than their normoandrogenic counterparts. These women often are obese, hypertensive, and sedentary; ingest diets high in saturated fats; and have glucose intolerance and/or insulin resistance. All these abnormalities are well known independent risk factors for the development of lipid abnormalities and cardiovascular disease. Whether hyperandrogenism is a secondary consequence of any of these or whether it is an independent contributor to lipid aberrations requires future study. Treatment strategies for hyperandrogenic women, however, should not only be directed toward alleviation of the cosmetic problem of hirsutism but also toward the prevention and treatment of cardiovascular morbidity using modalities aimed at eradicating hyperinsulinemia, hypertension, and dyslipidemia. These modalities should include modifications in diet, exercise, and weight in addition to pharmacologic and/or surgical manipulation. Weight reduction will reduce many cardiovascular risk factors. Obesity is easier to target because of the many risk factors that result in it.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
118.
119.
120.
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   
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