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   175536篇
  免费   53060篇
  国内免费   6072篇
耳鼻咽喉   2242篇
儿科学   5980篇
妇产科学   2190篇
基础医学   25098篇
口腔科学   6936篇
临床医学   24388篇
内科学   36742篇
皮肤病学   8577篇
神经病学   17963篇
特种医学   6349篇
外国民族医学   32篇
外科学   24195篇
综合类   19433篇
现状与发展   18篇
一般理论   35篇
预防医学   12674篇
眼科学   3881篇
药学   16289篇
  63篇
中国医学   7806篇
肿瘤学   13777篇
  2024年   356篇
  2023年   1399篇
  2022年   3454篇
  2021年   5776篇
  2020年   8350篇
  2019年   13241篇
  2018年   12890篇
  2017年   14178篇
  2016年   14646篇
  2015年   15860篇
  2014年   16899篇
  2013年   18016篇
  2012年   12640篇
  2011年   12991篇
  2010年   15373篇
  2009年   10946篇
  2008年   8578篇
  2007年   7336篇
  2006年   7012篇
  2005年   5898篇
  2004年   5198篇
  2003年   4941篇
  2002年   4338篇
  2001年   3656篇
  2000年   2884篇
  1999年   1836篇
  1998年   780篇
  1997年   836篇
  1996年   604篇
  1995年   484篇
  1994年   458篇
  1993年   281篇
  1992年   379篇
  1991年   340篇
  1990年   276篇
  1989年   246篇
  1988年   213篇
  1987年   184篇
  1986年   150篇
  1985年   102篇
  1984年   81篇
  1983年   65篇
  1982年   44篇
  1981年   37篇
  1980年   28篇
  1979年   58篇
  1978年   34篇
  1977年   32篇
  1975年   33篇
  1973年   31篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
First described in 1955 in New Jersey, epizootic haemorrhagic disease (EHD) causes a severe clinical disease in wild and domestic ruminants worldwide. Epizootic haemorrhagic disease outbreaks occur in deer populations each year from summer to late autumn. The etiological agent is EHD virus (EHDV) which is a double‐stranded segmented icosahedral RNA virus. EHD virus utilizes point mutations and reassortment strategies to maintain viral fitness during infection. In 2018, EHDV serotype 2 was predominantly detected in deer in Illinois. Whole genome sequencing was conducted for two 2018 EHDV2 isolates (IL41747 and IL42218) and the sequence analyses indicated that IL42218 was a reassortant between different serotypes whereas IL41747 was a genetically stable strain. Our data suggest that multiple strains contribute to outbreaks each year.  相似文献   
84.
85.
86.
87.
88.
89.
In the search for a therapeutic schedule for spinal cord injury, it is necessary to understand key genes and their corresponding regulatory networks involved in the spinal cord injury process. However, ad hoc selection and analysis of one or two genes cannot fully reveal the complex molecular biological mechanisms of spinal cord injury. The emergence of second-generation sequencing technology(RNA sequencing) has provided a better method. In this study, RNA sequencing technology was used to analyze differentially expressed genes at different time points after spinal cord injury in rat models established by contusion of the eighth thoracic segment. The numbers of genes that changed significantly were 944, 1362 and 1421 at 1, 4 and 7 days after spinal cord injury respectively. After gene ontology analysis and temporal expression analysis of the differentially expressed genes, C5ar1, Socs3 and CCL6 genes were then selected and identified by real-time polymerase chain reaction and western blot assay. The mRNA expression trends of C5ar1, Socs3 and CCL6 genes were consistent with the RNA sequencing results. Further verification and analysis of C5ar1 indicate that the level of protein expression of C5ar1 was consistent with its nucleic acid level after spinal cord injury. C5ar1 was mainly expressed in neurons and astrocytes. Finally, the gene Itgb2,which may be related to C5ar1, was found by Chilibot database and literature search. Immunofluorescence histochemical results showed that the expression of Itgb2 was highly consistent with that of C5ar1. Itgb2 was expressed in astrocytes. RNA sequencing technology can screen differentially expressed genes at different time points after spinal cord injury. Through analysis and verification, genes strongly associated with spinal cord injury can be screened. This can provide experimental data for further determining the molecular mechanism of spinal cord injury, and also provide possible targets for the treatment of spinal cord injury. This study was approved ethically by the Laboratory Animal Ethics Committee of Jiangsu Province, China(approval No. 2018-0306-001) on March 6, 2018.  相似文献   
90.
Tuberculosis (TB) remains one of a major health problem worldwide. Tuberculosis vaccine research has made an extraordinary progress over the past few years. However, there is still no replacement for the Bacillus Calmette‐Guérin vaccine, the only TB vaccine licensed for human use. Therefore, the discovery and development of new TB vaccines remains a priority. This article discusses current strategies used to diversify TB vaccines and includes discussion of the status of efforts to improve protection against Mycobacterium tuberculosis (M tb) infection or TB disease by developing new and safe TB vaccines. This article also highlights the current research efforts in immune‐enhancing approaches to improve vaccination efficacy. The development of more effective TB vaccines might have significant impact on global TB control.  相似文献   
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