全文获取类型
收费全文 | 1154篇 |
免费 | 72篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 73篇 |
妇产科学 | 11篇 |
基础医学 | 96篇 |
口腔科学 | 34篇 |
临床医学 | 128篇 |
内科学 | 281篇 |
皮肤病学 | 22篇 |
神经病学 | 26篇 |
特种医学 | 243篇 |
外科学 | 70篇 |
综合类 | 59篇 |
预防医学 | 67篇 |
眼科学 | 21篇 |
药学 | 47篇 |
中国医学 | 10篇 |
肿瘤学 | 36篇 |
出版年
2023年 | 2篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 14篇 |
2018年 | 14篇 |
2017年 | 10篇 |
2016年 | 10篇 |
2015年 | 21篇 |
2014年 | 40篇 |
2013年 | 67篇 |
2012年 | 33篇 |
2011年 | 36篇 |
2010年 | 41篇 |
2009年 | 62篇 |
2008年 | 36篇 |
2007年 | 54篇 |
2006年 | 31篇 |
2005年 | 30篇 |
2004年 | 22篇 |
2003年 | 15篇 |
2002年 | 21篇 |
2001年 | 14篇 |
2000年 | 15篇 |
1999年 | 16篇 |
1998年 | 78篇 |
1997年 | 53篇 |
1996年 | 63篇 |
1995年 | 44篇 |
1994年 | 49篇 |
1993年 | 44篇 |
1992年 | 11篇 |
1991年 | 7篇 |
1990年 | 11篇 |
1989年 | 40篇 |
1988年 | 27篇 |
1987年 | 25篇 |
1986年 | 19篇 |
1985年 | 12篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 14篇 |
1981年 | 20篇 |
1980年 | 13篇 |
1979年 | 8篇 |
1978年 | 9篇 |
1977年 | 16篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1973年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1235条查询结果,搜索用时 15 毫秒
71.
Essential fatty acids are claimed to have positive effects in atopic diseases. In a double blind, placebo controlled, parallel group study 58 out of 60 children, with atopic dermatitis and the need for regular treatment with topical skin steroids, completed a 16 weeks' treatment period with either Epogam evening primrose oil or placebo capsules. Twenty two of these subjects also had asthma. The parents used diaries to record symptom scores and concomitant medication. Peak expiratory flow was measured and disease activity was monitored by the clinician every four weeks. The plasma concentrations of essential fatty acids increased significantly in the group treated with Epogam capsules. The study demonstrated significant improvements of the eczema symptoms but no significant difference was found between the placebo and the Epogam groups. No therapeutic effect was shown on asthma symptoms or fidget. 相似文献
72.
A premature infant developed pericardial effusion four days after the insertion of a 25-gauge silastic percutaneous central venous catheter. The effusion contained parenteral nutrition fluid and resolved rapidly after withdrawal of the catheter. Pericardial effusion is a potential complication of percutaneous, as well as surgically placed, central venous catheters. 相似文献
73.
The STR system in the human phenylalanine hydroxylase gene: true fragment length obtained with fluorescent labelled PCR primers 总被引:5,自引:0,他引:5
J Zschocke CA Graham JJ McKnight NC Nevin 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(S407):41-42
We present a simple, fast, non-radioactive method for the analysis of the polymorphic short tandem repeat (STR) system in the human phenylalanine hydroxylase gene. Previously, sizing of the STR marker involved radiolabelling of PCR amplified fragments and resolution on denaturing polyacrylamide gels using M13 sequencing ladder as a standard. However, this method consistently gave sizes 2 bp longer than the known sequence. The fluorescent method presented here employs internal lane standards and enables accurate sizing of the fragments. To avoid confusion, we suggest that the true fragment lengths are used as reference values in the future. The analysis of STR alleles is valuable for population genetic studies and for targeted mutation screening in phenylketonuria (PKU). It can replace RFLP-based haplotype analysis for carrier detection, and we report its use for prenatal diagnosis in a Northern Irish family with PKU. The analysis of 250 Northern Irish chromosomes, including 128 PKU alleles, showed no significant difference between normal and PKU alleles, with fragment lengths of 238 and 242 bp most common in both groups. 相似文献
74.
Molecular analysis of PKU in Ireland 总被引:1,自引:0,他引:1
CA O'Neill RC Eisensmith DT Croke ER Naughten SF Cahalane SLC Woo 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(S407):43-44
Classical phenylketonuria (PKU: McKusick No. 261600) is caused by mutations occurring at the phenylalanine hydroxylase (PAH) locus on chromosome 12 and has a prevalence in Ireland of 1 in 4500. We examined 304 independent alleles from 350 patients for the presence of six mutations and have characterized VNTR alleles within the minisatellite region 3' to the PAH gene in patients carrying the most prevalent mutation. R408W was the most common mutation found, with a relative frequency of 42%. All other mutations had relative frequencies of <10%. VNTR analysis showed that the R408W mutation is associated with the VNTR-8 allele in the Irish population, indicating that R408W is associated with RFLP haplotype 1. This differs from that reported from eastern Europe where R408W is associated with RFLP haplotype 2/VNTR-3; an observation which has led several groups to propose a Balto-Slavic origin for this mutation. These results support the hypothesis of a second, independent founding event for the R408W mutation on an RFLP haplotype 1 VNTR-8 chromsome background in the Irish/Celtic population. 相似文献
75.
Fructosamine and glycated haemoglobin were measured simultaneously in 147 children with diabetes. If glycated haemoglobin is considered as the 'gold standard' for long term glycaemic control, then fructosamine is a poor indicator of actual glycated haemoglobin values, with wide 95% confidence (fiducial) limits. This shows that it is impossible to accurately predict glycated haemoglobin concentrations and therefore, by implication, longer term glycaemic control, from measurements of fructosamine. As the major studies on the prevention of microvascular complications in diabetes have used glycated haemoglobin levels to assess glycaemic control, it is suggested that this measurement should be used in all children with diabetes in preference to the measurement of fructosamine. 相似文献
76.
77.
78.
79.
80.
由于治疗方法的进步,近80%的儿童和青少年癌症患者能够长期生存。在美国,约有270000例儿童癌症的幸存者,即每640名20至39岁成年人中就有一名幸存者。大量的幸存者有利于儿童癌症治疗后长期健康结果的研究。现在可以明确的是,化疗和放疗所致的儿童各器官系统损害在临床上可能潜伏多年。为了全面了解治疗儿童癌症而继发的健康问题,重要的是衡量三项长期结果:健康状况、死亡率和患病率。这三项中,关于前两项已有相当好的研究报道。在一项对20227例癌症5年生存者的回顾性分析中,Mertens等发现以下原因导致的超额死亡率具有统计学意义:继发癌症(… 相似文献