全文获取类型
收费全文 | 1263796篇 |
免费 | 94815篇 |
国内免费 | 1578篇 |
专业分类
耳鼻咽喉 | 16313篇 |
儿科学 | 40999篇 |
妇产科学 | 34947篇 |
基础医学 | 189387篇 |
口腔科学 | 34731篇 |
临床医学 | 117750篇 |
内科学 | 247789篇 |
皮肤病学 | 27278篇 |
神经病学 | 101847篇 |
特种医学 | 46758篇 |
外国民族医学 | 265篇 |
外科学 | 178576篇 |
综合类 | 25749篇 |
现状与发展 | 3篇 |
一般理论 | 568篇 |
预防医学 | 104649篇 |
眼科学 | 28044篇 |
药学 | 92556篇 |
7篇 | |
中国医学 | 2022篇 |
肿瘤学 | 69951篇 |
出版年
2018年 | 13530篇 |
2017年 | 10390篇 |
2016年 | 11323篇 |
2015年 | 13078篇 |
2014年 | 17999篇 |
2013年 | 27477篇 |
2012年 | 37572篇 |
2011年 | 39966篇 |
2010年 | 23053篇 |
2009年 | 22250篇 |
2008年 | 37752篇 |
2007年 | 40381篇 |
2006年 | 39962篇 |
2005年 | 39095篇 |
2004年 | 37542篇 |
2003年 | 35953篇 |
2002年 | 34864篇 |
2001年 | 56029篇 |
2000年 | 57042篇 |
1999年 | 48095篇 |
1998年 | 13396篇 |
1997年 | 12222篇 |
1996年 | 12643篇 |
1995年 | 11914篇 |
1994年 | 11107篇 |
1993年 | 10399篇 |
1992年 | 38198篇 |
1991年 | 37671篇 |
1990年 | 36445篇 |
1989年 | 35258篇 |
1988年 | 32690篇 |
1987年 | 32027篇 |
1986年 | 30524篇 |
1985年 | 28786篇 |
1984年 | 21941篇 |
1983年 | 19192篇 |
1982年 | 11364篇 |
1981年 | 10321篇 |
1979年 | 20944篇 |
1978年 | 15393篇 |
1977年 | 12790篇 |
1976年 | 11845篇 |
1975年 | 12810篇 |
1974年 | 15588篇 |
1973年 | 15362篇 |
1972年 | 14512篇 |
1971年 | 13552篇 |
1970年 | 12786篇 |
1969年 | 12065篇 |
1968年 | 11229篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Taurine in pediatric nutrition: review and update 总被引:2,自引:0,他引:2
G E Gaull 《Pediatrics》1989,83(3):433-442
Taurine was long considered an end product of the metabolism of the sulfur-containing amino acids, methionine and cyst(e)ine. Its only clearly recognized biochemical role had been as a substrate in the conjugation of bile acids. Taurine is found free in millimolar concentrations in animal tissues, particularly those that are excitable, rich in membranes, and generate oxidants. Various lines of evidence suggest one major nutritional role as protecting cell membranes by attenuating toxic substances and/or by acting as an osmoregulator. The totality of evidence suggests that taurine is nonessential in the rodent, it is an essential amino acid in the cat, and it is conditionally essential in man and monkey. Absence from the diet of a conditionally essential nutrient does not produce immediate deficiency disease but, in the long term, can cause problems. Taurine is now added to many infant formulas as a measure of prudence to provide improved nourishment with the same margin of safety for its newly identified physiologic functions as that found in human milk. Such supplementation can be justified by the finding of improved fat absorption in preterm infants and in children with cystic fibrosis, as well as by salutary effects on auditory brainstem-evoked responses in preterm infants. Experimental findings in animal models and in human cell models provide further justification for taurine supplementation of infant formulas. 相似文献
992.
L R Baker W J Mallinson M C Gregory E A Menzies W R Cattell H N Whitfield W F Hendry J E Wickham A M Joekes 《British journal of urology》1987,60(6):497-503
Sixty patients with idiopathic retroperitoneal fibrosis presenting between 1965 and 1984 are reviewed. Their mean age at presentation was 56 years and the male:female ratio was 3:1. The commonest presenting symptoms were flank and abdominal pain, weight loss, nausea and polyuria. Physical examination was usually normal, expect for the presence of hypertension. Anaemia and elevation of erythrocyte sedimentation rate were usually present. Proteinuria was found in less than a third of patients at presentation and significant bacteriuria was uncommon. The correct diagnosis was made or suspected in very few patients before referral. The cumulative actuarial survival rate was 86% at 1 year and 78% at 2 years. Seventeen patients died; they were significantly older and more uraemic at the time of referral than those who survived. A few patients did well with either corticosteroid therapy or ureterolysis alone. In the majority, both operation and steroid treatment were necessary. In bilateral obstruction with residual function in both kidneys, bilateral ureterolysis proved superior to unilateral operation (each followed by steroid therapy) in conserving renal function. Operation alone or steroid therapy alone should be considered in cases where steroids or surgery respectively present particular hazards. The less traumatic unilateral operation should be considered in poor risk patients and in those whose renal function is absent on one side. In many survivors, disease activity has persisted for many years. Life-long follow-up is recommended. 相似文献
993.
994.
995.
996.
997.
Serum ferritin in haemodialysis patients: is there a relationship to 'haemochromatosis alleles' HLA A3, B7, B14? 总被引:1,自引:0,他引:1
Serum ferritin levels were measured in 57 patients on maintenance haemodialysis to determine if patients who possessed 1 or more of the histocompatibility antigens associated with idiopathic haemochromatosis (HLA A3, B7 or B14) were at increased risk of iron overload. There was no significant difference in the mean serum ferritin levels between those patients with HLA A3, B7 or B14 (357.9 +/- 522.6 ng/1; n = 19) and those without these antigens (393.7 + 556.2 ng/1; n = 38). Iron overload in haemodialysis patients is not a histocompatibility-linked disorder. 相似文献
998.
999.
Genetic aspects of immotile cilia syndrome 总被引:3,自引:0,他引:3
J M Sturgess M W Thompson E Czegledy-Nagy J A Turner 《American journal of medical genetics》1986,25(1):149-160
The genetics of the immotile cilia syndrome has been analyzed in a series of 46 affected individuals from 38 families. Both sexes were equally affected: there were 20 males and 26 females in this series. All patients had upper and lower respiratory disease with chronic sinusitis, otitis, and chronic cough from early childhood. Bronchiectasis was common in older children and adults. Situs inversus occurred randomly, affecting 11 males and 15 females. Biopsies of nasal and bronchial mucosa from these subjects have been investigated by electron microscopy and identified as having specific ultrastructural defects of respiratory tract cilia including deficiencies in outer dynein arms (19), inner dynein arms (3), both inner and outer dynein arms (15), radial spoke defect (5); and microtubular transposition anomaly (4). Segregation analysis of proband sibships was consistent with autosomal recessive inheritance. However, the different ultrastructural defects that underly the immotile cilia syndrome involve presumably different genetic determinants, and the different types have not been analyzed separately. Examination of paternal age and birth order gave no evidence of new autosomal dominant mutation in the series. 相似文献
1000.