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   14953篇
  免费   1095篇
  国内免费   65篇
耳鼻咽喉   206篇
儿科学   249篇
妇产科学   201篇
基础医学   2233篇
口腔科学   159篇
临床医学   1532篇
内科学   3627篇
皮肤病学   478篇
神经病学   1421篇
特种医学   646篇
外国民族医学   10篇
外科学   2313篇
综合类   40篇
一般理论   5篇
预防医学   685篇
眼科学   200篇
药学   954篇
中国医学   14篇
肿瘤学   1140篇
  2024年   18篇
  2023年   161篇
  2022年   279篇
  2021年   647篇
  2020年   350篇
  2019年   544篇
  2018年   655篇
  2017年   419篇
  2016年   485篇
  2015年   547篇
  2014年   729篇
  2013年   867篇
  2012年   1303篇
  2011年   1282篇
  2010年   698篇
  2009年   632篇
  2008年   967篇
  2007年   937篇
  2006年   822篇
  2005年   747篇
  2004年   643篇
  2003年   547篇
  2002年   478篇
  2001年   115篇
  2000年   117篇
  1999年   95篇
  1998年   90篇
  1997年   62篇
  1996年   62篇
  1995年   57篇
  1994年   47篇
  1993年   41篇
  1992年   60篇
  1991年   69篇
  1990年   60篇
  1989年   53篇
  1988年   38篇
  1987年   38篇
  1986年   36篇
  1985年   23篇
  1984年   29篇
  1983年   31篇
  1982年   34篇
  1981年   14篇
  1980年   15篇
  1979年   21篇
  1978年   17篇
  1977年   14篇
  1974年   14篇
  1972年   13篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
H5ts107 and H5ts125 are two adenoviruses type 5 (Ad5) mutants with a temperature-sensitive DNA replication. Both mutants contain an altered gene encoding the DNA binding protein (DBP). We have established by nucleotide sequence analysis that both mutants carry exactly the same mutation in the DBP gene resulting in the substitution of a proline residue at position 413 in the wild-type DBP amino acid sequence (529 amino acid residues long) by a serine residue. Revertants of H5ts107 and H5ts125, which are temperature independent in plaque efficiency and growth in HeLa cells at 32 degrees and 39 degrees, were characterized by nucleotide sequence analysis of their DBP genes. Four types of revertants could be distinguished: revertants with the wild-type DBP amino acid sequence (type I) and, revertants carrying, in addition to the original H5ts107/H5ts125 mutation at position 413, intragenic second site mutations at position 508 histidine leads to tyrosine (type II), at position 352 glycine leads to aspartic acid (type III), and at position 347 alanine leads to proline (type IV), respectively. All intragenic second site mutations are located, together with the H5ts107/H5ts125 mutation, in the C-terminal 45-kD fragment of the adenovirus DBP molecule. This provides further evidence that this part of the DBP molecule plays an important role in viral DNA replication. Phenotypic characterization of the revertants (J.C. Nicolas, F. Suarez, A.J. Levine, and M. Girard (1981), Virology 108, 521-524; (J.C. Nicolas, D. Ingrand, P. Sarnow, and A.J. Levine (1982), Virology 122, 481-485) has shown that the second site mutations reveal additional functional domains in the DBP molecule.  相似文献   
62.
Summary Purified DNA from 45 isolates of suis herpes virus 1 (SHV1) collected between 1980 and 1987 from clinical outbreaks of Aujeszky's disease on French farms was compared by restriction fragment pattern (RFP) analysis. The BamHI generated RFPs were found to be distinguishable, confirming RFP analysis as a potential epidemiological tool. The RFP could be assigned to two established major electrophoretic types and different subtypes. The RFP analysis indicated that the majority of outbreaks were caused by ADV with a central European genome type. The heterogeneity of RFPs among PRV isolates recovered from the central nervous system, lung, and foetus was not restricted specifically to one clinical entity. Variations in the virulence of the 45 isolates studied in mice, chicks, or piglets were unrelated to the RFP subtypes. One unusual RFP has been described for one strain of low virulence.  相似文献   
63.
Despite magnesium (Mg2+) representing the second most abundant cation in the cell, its role in cellular physiology and pathology is far from being elucidated. Mg2+ homeostasis is regulated by Mg2+ transporters including Mitochondrial RNA Splicing Protein 2 (MRS2), Transient Receptor Potential Cation Channel Subfamily M, Member 6/7 (TRPM6/7), Magnesium Transporter 1 (MAGT1), Solute Carrier Family 41 Member 1 (SCL41A1), and Cyclin and CBS Domain Divalent Metal Cation Transport Mediator (CNNM) proteins. Recent data show that Mg2+ transporters may regulate several cancer cell hallmarks. In this review, we describe the expression of Mg2+ transporters in digestive cancers, the most common and deadliest malignancies worldwide. Moreover, Mg2+ transporters’ expression, correlation and impact on patient overall and disease-free survival is analyzed using Genotype Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) datasets. Finally, we discuss the role of these Mg2+ transporters in the regulation of cancer cell fates and oncogenic signaling pathways.  相似文献   
64.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Nach der Collectivity-of-Drinking-Cultures-Theorie von Skog finden Veränderungen des Alkoholkonsums in allen...  相似文献   
65.
We detected 3 genotypes of highly pathogenic avian influenza A(H5N8) virus in France during winter 2016–17. Genotype A viruses caused dramatic economic losses in the domestic duck farm industry in southwestern France. Our phylogenetic analysis suggests that genotype A viruses formed 5 distinct geographic clusters in southwestern France. In some clusters, local secondary transmission might have been started by a single introduction. The intensity of the viral spread seems to correspond to the density of duck holdings in each production area. To avoid the introduction of disease into an unaffected area, it is crucial that authorities limit the movements of potentially infected birds.  相似文献   
66.
Neurosurgical Review - Trigeminal nerve schwannomas (TS) are uncommon intracranial tumors, frequently presenting with debilitating trigeminal and/or oculomotor nerve dysfunction. While surgical...  相似文献   
67.
68.
69.
70.
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