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   23203篇
  免费   1500篇
  国内免费   447篇
耳鼻咽喉   125篇
儿科学   399篇
妇产科学   308篇
基础医学   2948篇
口腔科学   280篇
临床医学   2978篇
内科学   5324篇
皮肤病学   350篇
神经病学   1038篇
特种医学   482篇
外国民族医学   1篇
外科学   1825篇
综合类   1502篇
现状与发展   2篇
一般理论   47篇
预防医学   3921篇
眼科学   373篇
药学   1442篇
  25篇
中国医学   558篇
肿瘤学   1222篇
  2024年   91篇
  2023年   2339篇
  2022年   5165篇
  2021年   6852篇
  2020年   4547篇
  2019年   258篇
  2018年   239篇
  2017年   193篇
  2016年   223篇
  2015年   242篇
  2014年   396篇
  2013年   407篇
  2012年   314篇
  2011年   397篇
  2010年   342篇
  2009年   321篇
  2008年   315篇
  2007年   326篇
  2006年   309篇
  2005年   243篇
  2004年   259篇
  2003年   225篇
  2002年   149篇
  2001年   129篇
  2000年   108篇
  1999年   87篇
  1998年   83篇
  1997年   61篇
  1996年   74篇
  1995年   44篇
  1994年   29篇
  1993年   39篇
  1992年   27篇
  1991年   29篇
  1990年   22篇
  1989年   13篇
  1988年   12篇
  1987年   8篇
  1985年   36篇
  1984年   38篇
  1983年   24篇
  1982年   23篇
  1981年   23篇
  1980年   16篇
  1979年   13篇
  1977年   10篇
  1976年   5篇
  1975年   10篇
  1974年   6篇
  1973年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
. This is a report of unexplained anemia that persisted for 4 months in an adolescent renal transplant patient receiving immunosuppression that included prednisone, tacrolimus, and mycophenolate mofetil. This patient required monthly blood transfusions for fatigue, palpitations, and hematocrit levels between 15% and 17%. In addition, his posttransplant course was notable for the development of insulin-dependent diabetes mellitus. While receiving low-dose prednisone, he was switched from tacrolimus to cyclosporin and tapered off insulin injections over the next 2 months. At 4.5 months post-transplantation, further diagnostic evaluation was suggestive of parvovirus B19 infection as the cause for our patient’s chronic anemia. After testing negative for serum-specific parvovirus B19 IgM and IgG antibodies, parvovirus B19 infection was detected in blood by the polymerase chain reaction. Treatment with intravenous immunoglobulin (1 g/kg per day × 2 days) resulted in normalization of both his reticulocyte count and hematocrit within 6 weeks. At 4 months after receiving the immunoglobulin infusion, he has maintained a normal hematocrit level and stable renal function without requiring further blood transfusions. Received August 23, 1996; received in revised form and accepted November 20, 1996  相似文献   
12.
《Movement disorders》2003,18(11):1240-1249
The identification of disease genes using family‐based approaches has provided important insights into the pathogenesis of Parkinson's disease (PD) demonstrating the importance of genetic studies on monogenic forms of the disease. We studied a large Cuban family with typical, late‐onset PD and probable autosomal dominant inheritance. Mean age at onset was 61.2 years (±12.53, 45–76). Other phenotypes such as essential tremor and atypical parkinsonism were observed in this family. We carried out a genome‐wide scan and linkage analyses. The genetic data were analyzed using a conservative model in which only patients with clinically definite or likely PD were considered affected, other phenotypes were regarded as “unknown.” Multipoint analyses yielded a maximum LOD of 2.26 between markers D19S221 and D19S840. Haplotype analysis showed a region on chromosome 19 shared by six of seven PD patients. The essential tremor phenotype and the atypical parkinsonism do not segregate with this haplotype, suggesting a different etiology. Our findings suggest the presence of a novel locus for PD on chromosome 19p13.3–q12. We propose that an oligogenic model with moderate contribution of two or three genes rather than a “pure” monogenic model might explain better the wide range in age at onset, the reduced penetrance and the phenotypical variability observed in PD families. © 2003 Movement Disorder Society  相似文献   
13.
14.
杨辉 《中国全科医学》2023,26(7):780-782
新型冠状病毒感染疫情防控期间,各国出现了不同程度的常规医疗服务减少情况,慢性病管理工作也相应受到影响。2022年12月,中国调整了新型冠状病毒感染疫情防控相关政策和方案,医疗卫生系统面临挑战,基层医疗压力增加。在此情况下,本文基于其他国家经验,建议中国基层医疗应注重开展慢性病患者的自我管理,并为复杂和高需求的慢性病患者提供主动服务,加强对远程医疗的应用与研究,强化基层服务的社区连接,重点完善医疗服务的补偿机制。  相似文献   
15.
Summary Genomic imprinting is a biological phenomenon determined by an evolutionally acquired, underlying system that may control harmonious development and growth in mammals. It is also relevant to some genetic disorders in man. In this article, lines of biological evidence of imprinting, characteristics of the mouse and human imprinted genes, and findings and mechanisms on the occurrence of several human imprinting disorders are reviewed.  相似文献   
16.
Serum C19 conjugates, specifically 3-androstanediol glucuronide(3G), reflect peripheral androgen action through the actionof 5-reductase activity. The origin of 5-reduced C19 conjugateshas been controversial and it has been suggested that they arederived primarily from adrenal androgens. We examined concentrationsof 3G, 3-androstanediol sulphate (3S), androsterone glucuronide(AoG) and androsterone sulphate (AoS) in 40 hirsute hyperandrogenicwomen. These patients were divided into four groups based uponindividual, combined or normal concentrations of the adrenalandrogens dehydroepiandrosterone (DHEAS) and 11-hydroxy-androstenedione.Testosterone, unbound testosterone and androstenedione weresimilar in these groups. Serum 3G was equally high in all groupsand was correlated significantly with hirsutism, while the otherconjugates were not. Androsterone glucuronide was raised inall groups but was higher in patients with raised DHEAS. Serum3S was raised in all groups and was higher where both adrenalandrogens were raised. Serum AoS was highly correlated withDHEAS. Serum 3G was correlated with unbound testosterone andandrostenedione but not with the adrenal androgens. The glucuronideconjugates were correlated with one another as were the sulphateconjugates but glucuronides and sulphates were not correlated.These data confirm ovarian and adrenal dependency of C19 conjugates.Serum 3G appears to reflect hirsutism most accurately and isleast dependent on adrenal androgens in patients with mixedhyperandrogenism.  相似文献   
17.
ABSTRACT

Coronaviruses (CoVs) mainly cause enteric and/or respiratory signs. Mammalian CoVs including COVID-19 (now officially named SARS-CoV-2) belong to either the Alphacoronavirus or Betacoronavirus genera. In birds, the majority of the known CoVs belong to the Gammacoronavirus genus, whilst a small number are classified as Deltacoronaviruses. Gammacoronaviruses continue to be reported in an increasing number of avian species, generally by detection of viral RNA. Apart from infectious bronchitis virus in chickens, the only avian species in which CoV has been definitively associated with disease are the turkey, pheasant and guinea fowl. Whilst there is strong evidence for recombination between gammacoronaviruses of different avian species, and between betacoronaviruses in different mammals, evidence of recombination between coronaviruses of different genera is lacking. Furthermore, the recombination of an alpha or betacoronavirus with a gammacoronavirus is extremely unlikely. For recombination to happen, the two viruses would need to be present in the same cell of the same animal at the same time, a highly unlikely scenario as they cannot replicate in the same host!  相似文献   
18.
19.
A total of 74 strains out of 33 strains of adenovirus type 19 (Ad19) plus 103 strains of type 37 (Ad37) isolated from patients with conjunctivitis at two ophthalmology clinics in Hiroshima City during the period March 1983 to December 1986 were analyzed by eight DNA restriction endonucleases in comparison with their prototype strains. All 27 Ad19 isolates examined displayed identical DNA cleavage patterns with all enzymes used (HindIII, KpnI, PstI, XhoI, BamHI, SacI, EcoRI, and SmaI), but their cleavage patterns were different from those of the prototype except with HindIII. The genome type of these isolates was tentatively named Ad19a. Forty-seven Ad37 isolates examined were divided into three genome types. They were tentatively named Ad37p, Ad37a, and Ad37b: 16 isolates (Ad37p) displayed DNA cleavage patterns identical with those of the prototype with all eight enzymes described above. Thirty isolates (Ad37a) showed the same patterns as the prototype except with EcoRI. One isolate (Ad37b) showed the same patterns as the prototype except with SmaI. The most frequently isolated genome type during the period studied was Ad37a, but the change of the predominant genome type in yearly incidences was observed.  相似文献   
20.
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