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   388726篇
  免费   35206篇
  国内免费   27811篇
耳鼻咽喉   3456篇
儿科学   4005篇
妇产科学   5660篇
基础医学   47373篇
口腔科学   6713篇
临床医学   54706篇
内科学   58462篇
皮肤病学   3602篇
神经病学   22005篇
特种医学   14252篇
外国民族医学   247篇
外科学   39083篇
综合类   61513篇
现状与发展   90篇
一般理论   32篇
预防医学   23948篇
眼科学   11729篇
药学   39685篇
  398篇
中国医学   21823篇
肿瘤学   32961篇
  2024年   1199篇
  2023年   5888篇
  2022年   15648篇
  2021年   19461篇
  2020年   14516篇
  2019年   12807篇
  2018年   13550篇
  2017年   11870篇
  2016年   11267篇
  2015年   17165篇
  2014年   21286篇
  2013年   18486篇
  2012年   27329篇
  2011年   31089篇
  2010年   19220篇
  2009年   14912篇
  2008年   20387篇
  2007年   20411篇
  2006年   20566篇
  2005年   20420篇
  2004年   12865篇
  2003年   11942篇
  2002年   10284篇
  2001年   9122篇
  2000年   9967篇
  1999年   10798篇
  1998年   6653篇
  1997年   6588篇
  1996年   5211篇
  1995年   4755篇
  1994年   3902篇
  1993年   2539篇
  1992年   3346篇
  1991年   2847篇
  1990年   2525篇
  1989年   2212篇
  1988年   1850篇
  1987年   1591篇
  1986年   1308篇
  1985年   1072篇
  1984年   596篇
  1983年   418篇
  1982年   275篇
  1981年   269篇
  1980年   203篇
  1979年   239篇
  1978年   82篇
  1977年   89篇
  1974年   102篇
  1973年   83篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
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   
63.
64.
Two new 11-methoxyl substituted triterpenoids, named as mimengosides J (1) and K (2), along with seven known compounds, were isolated from the fruits of Buddleja lindleyana. Their structures were elucidated on the basis of spectroscopic analysis. In addition, the new ones were evaluated for protective effects against damage of SH-SY5Y cells induced by 1-methyl-4-phenylpyridinium ion (MPP+) and the results indicated that those may be one of the candidate compositions of Buddleja lindleyana for the treatment of neurodegenerative disease.

  相似文献   

65.
66.
Donor site morbidity following radial forearm flap (RFF) harvest remains a controversial issue. The aim of this meta-analysis was to answer the question “Are the range of wrist movements (range of motion, ROM) and hand strength affected after RFF harvesting?” The PubMed, Embase, Scopus, and Cochrane Library electronic databases were systematically searched (to December 2019). Self-controlled studies evaluating hand biomechanics after RFF harvest were included. Weighted mean differences with 95% confidence intervals were calculated using the random-effects model. The outcome variables were ROM, forearm movements, grip, and pinch strengths. Thirteen studies involving a total of 335 patients were included. With the exception of grip strength and supination, which showed statistically significant reductions of about 2.40 kg and 2.86° (P < 0.05), all other ROM, forearm movements, and pinch strengths showed an insignificant difference when the operated hand was compared to the non-operated hand (P > 0.05). Regression analysis showed that the method of donor site closure and size of the donor site defect had an insignificant impact on hand biomechanics. This study confirms the lack of discernible biomechanical morbidity after RFF transfer. The minimal reduction in hand biomechanics after RFF is considered to be clinically negligible.  相似文献   
67.
68.
69.
70.
A pulmonary artery (PA) sling is a very rare congenital cardiovascular anomaly, and only a few studies have reported PA slings in fetuses. The relationship of the PA, aorta, ductus arteriosus, and trachea can be evaluated in the 3‐vessel and 3‐vessel and trachea views during fetal echocardiography. A PA sling can be detected by abnormal positioning of the left PA in relation to the trachea when sweeping from the 3‐vessel view cranially to the 3‐vessel and trachea view. Here we report 3 cases of fetal PA slings and their follow‐ups. Two cases were confirmed by postnatal echocardiography, and the other case was confirmed by a cardiovascular cast after pregnancy termination. We emphasize that the 3‐vessel and 3‐vessel and trachea views are of crucial importance in the prenatal diagnosis of a PA sling.  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