全文获取类型
收费全文 | 1263908篇 |
免费 | 94956篇 |
国内免费 | 1579篇 |
专业分类
耳鼻咽喉 | 16317篇 |
儿科学 | 41003篇 |
妇产科学 | 34947篇 |
基础医学 | 189401篇 |
口腔科学 | 34731篇 |
临床医学 | 117771篇 |
内科学 | 247920篇 |
皮肤病学 | 27278篇 |
神经病学 | 101855篇 |
特种医学 | 46759篇 |
外国民族医学 | 265篇 |
外科学 | 178606篇 |
综合类 | 25760篇 |
现状与发展 | 3篇 |
一般理论 | 568篇 |
预防医学 | 104659篇 |
眼科学 | 28045篇 |
药学 | 92563篇 |
7篇 | |
中国医学 | 2026篇 |
肿瘤学 | 69959篇 |
出版年
2018年 | 13540篇 |
2017年 | 10392篇 |
2016年 | 11325篇 |
2015年 | 13079篇 |
2014年 | 18004篇 |
2013年 | 27479篇 |
2012年 | 37576篇 |
2011年 | 39970篇 |
2010年 | 23054篇 |
2009年 | 22253篇 |
2008年 | 37760篇 |
2007年 | 40385篇 |
2006年 | 39967篇 |
2005年 | 39098篇 |
2004年 | 37547篇 |
2003年 | 35956篇 |
2002年 | 34868篇 |
2001年 | 56030篇 |
2000年 | 57048篇 |
1999年 | 48098篇 |
1998年 | 13397篇 |
1997年 | 12222篇 |
1996年 | 12644篇 |
1995年 | 11915篇 |
1994年 | 11107篇 |
1993年 | 10399篇 |
1992年 | 38200篇 |
1991年 | 37673篇 |
1990年 | 36448篇 |
1989年 | 35265篇 |
1988年 | 32691篇 |
1987年 | 32028篇 |
1986年 | 30525篇 |
1985年 | 28789篇 |
1984年 | 21945篇 |
1983年 | 19194篇 |
1982年 | 11366篇 |
1981年 | 10323篇 |
1979年 | 20948篇 |
1978年 | 15393篇 |
1977年 | 12794篇 |
1976年 | 11845篇 |
1975年 | 12812篇 |
1974年 | 15591篇 |
1973年 | 15364篇 |
1972年 | 14514篇 |
1971年 | 13553篇 |
1970年 | 12787篇 |
1969年 | 12066篇 |
1968年 | 11230篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
Three hundred and twenty samples of subgingival plaque were obtained from 80 caucasian girls, ranging from 10 to 13 years of age. The samples were analyzed to verify the influence of age upon colonization of the gingival sulcus by microorganisms potentially pathogenic to the periodontal tissues. The gingival and plaque status were evaluated through the gingival index (GI) and plaque index (PlI) and the microflora was assessed by the enzymatic method benzoyl-arginine-naphthylamide (BANA). The results of the BANA test were positive for 62.50% of the tested individuals and 40% of the examined sites. The influence of age was statistically significant on BANA reactivity, and the number of positive sites was greater at 11 (57.5%) than at 12 years (28.8%). 相似文献
74.
75.
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
76.
Nawf Sharief Judith E. Kingston Vanessa M. Wright Kate Costeloe 《Pediatric hematology and oncology》1991,8(4):323-327
We describe a familial case of Marfan's syndrome with associated intrathoracic stomach detected during the neonatal period. The patient developed a primitive leukemia at 3 months of age. Acute leukemia in a patient with Marfan's syndrome has not previously been reported. 相似文献
77.
A. Trovato S. Kirjavainen E. M. Galati A. M. Forestieri L. Iauk 《Phytotherapy research : PTR》1995,9(8):591-593
The decoction of Sclerocarya birroea Hochst. shows hypoglycaemic effects, an increase in plasma IRI in normal rats and an incremented oral-glucose tolerance. The decoction is also active against diet-induced hypercholesterolaemia. 相似文献
78.
Nearly 13 million people die each year from cardiovascular diseasesand half of these deaths occur in developing countries. Thisarticle reviews the appropriateness of cardiovascular diseaseintervention and focuses on decision-making and the perpetualquestion: When is it more appropriate to act on available evidencerather than to await further evidence? A fundamental and justifiedprinciple in science is trying to falsify all formulated hypotheses.This sceptical or conservative approach can, however, hampersocial development. It is therefore important for the scientistto distinguish between his role as a scientist and as a memberof society. Medical, epidemiological and economic aspects areconsidered together with an assessment of the feasibility ofdifferent intervention strategies. This review, like many others,indicates that population-based interventions combined withan improved high-risk strategy are appropriate from society'spoint of view in spite of the fact that there are several unsettledquestions which call for further research. 相似文献
79.
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
80.
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