全文获取类型
收费全文 | 1615941篇 |
免费 | 132340篇 |
国内免费 | 2606篇 |
专业分类
耳鼻咽喉 | 21816篇 |
儿科学 | 53339篇 |
妇产科学 | 46487篇 |
基础医学 | 229764篇 |
口腔科学 | 47621篇 |
临床医学 | 142270篇 |
内科学 | 317320篇 |
皮肤病学 | 34335篇 |
神经病学 | 131334篇 |
特种医学 | 65491篇 |
外国民族医学 | 499篇 |
外科学 | 245498篇 |
综合类 | 39834篇 |
现状与发展 | 3篇 |
一般理论 | 548篇 |
预防医学 | 124639篇 |
眼科学 | 36621篇 |
药学 | 122484篇 |
3篇 | |
中国医学 | 3024篇 |
肿瘤学 | 87957篇 |
出版年
2018年 | 14997篇 |
2016年 | 13119篇 |
2015年 | 15280篇 |
2014年 | 20968篇 |
2013年 | 31816篇 |
2012年 | 43206篇 |
2011年 | 45447篇 |
2010年 | 26725篇 |
2009年 | 25706篇 |
2008年 | 43652篇 |
2007年 | 45860篇 |
2006年 | 46703篇 |
2005年 | 45293篇 |
2004年 | 44676篇 |
2003年 | 42752篇 |
2002年 | 41805篇 |
2001年 | 76050篇 |
2000年 | 78691篇 |
1999年 | 66704篇 |
1998年 | 17896篇 |
1997年 | 16454篇 |
1996年 | 16405篇 |
1995年 | 16135篇 |
1994年 | 15235篇 |
1993年 | 14446篇 |
1992年 | 55886篇 |
1991年 | 54221篇 |
1990年 | 52897篇 |
1989年 | 51046篇 |
1988年 | 47411篇 |
1987年 | 46755篇 |
1986年 | 44441篇 |
1985年 | 43020篇 |
1984年 | 32167篇 |
1983年 | 27654篇 |
1982年 | 16237篇 |
1981年 | 14523篇 |
1980年 | 13645篇 |
1979年 | 30584篇 |
1978年 | 21158篇 |
1977年 | 17856篇 |
1976年 | 16781篇 |
1975年 | 17679篇 |
1974年 | 21627篇 |
1973年 | 20792篇 |
1972年 | 18947篇 |
1971年 | 17866篇 |
1970年 | 16387篇 |
1969年 | 15358篇 |
1968年 | 14026篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
R G Jones J W Bass M E Weisse J M Vincent 《The Pediatric infectious disease journal》1991,10(8):557-559
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
122.
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
123.
Lipid metabolism and hyperandrogenism. 总被引:1,自引:0,他引:1
R A Wild 《Clinical obstetrics and gynecology》1991,34(4):864-871
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
124.
125.
126.
127.
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
128.
129.
130.
Eight-eight female weanling Sprague-Dawley rats were fed diets containing either 650 or 150 mg magnesium/kg diet and 7.0 or 3.5 mg pyridoxine-HCl/kg diet, in a 2 x 2 factorial arrangement, during growth, gestation, and lactation. The objective of the study was to determine whether concurrent dietary deficiencies of magnesium and pyridoxine were synergistic, additive, or antagonistic with regards to effects on reproductive performance, growth, and development of offspring, and tissue content of magnesium and calcium. Body weight of dams and pups was not different between groups until day 9 of lactation, at which point those animals in either low magnesium group weighed less than the other. Litter size and birth weight were not different. Development, as measured by timing of unfolding of the external ear, opening of both eyes, and clinical emergence of incisors, was delayed in pups from litters in the low magnesium groups. A synergistic effect on delay of onset of ear unfolding by deficiency of both magnesium and pyridoxine was observed. Calcium content of heart and kidney from dams was increased in the low magnesium groups. Renal calcium was not further increased by the level of pyridoxine deficiency in this study. The calcium to magnesium ratio in heart from pups was higher in those from litters in the low magnesium and pyridoxine group than in the others. Results indicate that simultaneous deficiencies of magnesium and pyridoxine may impair function synergistically. Because these two nutrients are often reported to be presented in inadequate amounts in diets of women in their reproductive years, the potential exists for impaired reproductive success. 相似文献