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   4831篇
  免费   212篇
  国内免费   23篇
耳鼻咽喉   48篇
儿科学   289篇
妇产科学   92篇
基础医学   493篇
口腔科学   184篇
临床医学   339篇
内科学   976篇
皮肤病学   107篇
神经病学   220篇
特种医学   142篇
外科学   753篇
综合类   156篇
一般理论   4篇
预防医学   294篇
眼科学   250篇
药学   386篇
中国医学   24篇
肿瘤学   309篇
  2023年   36篇
  2022年   94篇
  2021年   218篇
  2020年   96篇
  2019年   121篇
  2018年   188篇
  2017年   122篇
  2016年   142篇
  2015年   151篇
  2014年   212篇
  2013年   255篇
  2012年   418篇
  2011年   403篇
  2010年   201篇
  2009年   196篇
  2008年   309篇
  2007年   252篇
  2006年   231篇
  2005年   250篇
  2004年   201篇
  2003年   133篇
  2002年   138篇
  2001年   73篇
  2000年   64篇
  1999年   52篇
  1998年   26篇
  1997年   15篇
  1996年   21篇
  1995年   20篇
  1994年   19篇
  1993年   14篇
  1992年   26篇
  1991年   21篇
  1990年   31篇
  1989年   23篇
  1988年   29篇
  1987年   21篇
  1986年   17篇
  1985年   15篇
  1984年   18篇
  1983年   13篇
  1982年   8篇
  1981年   10篇
  1979年   11篇
  1978年   7篇
  1976年   9篇
  1973年   9篇
  1972年   7篇
  1971年   7篇
  1941年   6篇
排序方式: 共有5066条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Fracture of the metatarsal head is uncommon, and reports of isolated osteochondral fracture of the metatarsal head are rare. Because of the distal location of the fracture, it is difficult to achieve and maintain reduction, and potential complications include avascular necrosis and subchondral fatigue fracture. The authors present a case of an osteochondral fracture in a 40-year-old man, which was treated by open reduction and internal fixation with a single twist-off screw, with good results 12 months postoperatively.  相似文献   
6.
7.
Memory performance of elderly patients in the early stages of Alzheimer's disease (DAT) was compared with that of elderly control subjects. In explicit tests of recognition memory, which involve conscious recollection, the DAT patients were grossly impaired. In implicit tests of anagram solution and wordstem completion, which do not require conscious recollection, the DAT patients were not impaired. These findings further support the idea that a separate memory system, episodic memory, underlies conscious recollection, that it is this system which is most commonly damaged in amnesia, and that memory systems not involving conscious recollection may be spared in the early stages of Alzheimer's disease.  相似文献   
8.
Restriction maps of the rDNA cistron of twelve species of mosquitoes in six genera of the subfamily Culicinae were constructed using eight 6 bp recognition restriction enzymes. Anopheles albimanus was used as an outgroup. The size of the rDNA cistron ranged from 8.5 kb in Aedes katherinensis to 12.9 kb in Ae. polynesiensis. A total of twenty-six sites were scored; eighteen were polymorphic among ingroup taxa. The proportion of polymorphic nucleotide sites (Pnuc) was 0.059 and the heterozygosity per nucleotide site (Hnuc) was 0.028. Wagner and Fitch Parsimony, Dollo Parsimony and Nei-Li distance/neighbour-joining methods were used to construct phylogenetic trees. The rDNA RFLP dataset did not provide a well-supported phylogeny among culicine taxa. The RFLP phylogenies are incongruent with the morphology character based and molecular phylogenies and derived relationships did not correspond with current taxonomic classifications. The lack of resolution was due to homoplasy arising from frequent independent loss or gain of restriction sites among unrelated taxa.  相似文献   
9.
We present two children discovered to have a total cataract in one eye with a posterior subcapsular cataract in the other eye. Sequential photography documented rapid progression of the posterior subcapsular cataract to a preexisting posterior capsule defect and subsequently to a white, mature cataract. We propose that early intervention be considered in cases with any posterior subcapsular changes (no matter how subtle) and history of total cataract in the fellow eye, especially in any situation where loss of follow-up is likely to occur. In the event surgery is not advised, parents should be warned about possible cataract progression and the importance of regular follow-up examinations.  相似文献   
10.
Background: Ingestion of coins is a common clinical problem in children. Many of the coins are ferromagnetic and can be retrieved with the help of a magnet. We describe the use of a novel endoscopic accessory for removing ferromagnetic coins. Material and methods: Two magnet discs of 1.5 cm diameter were joined to a 200 cm steel wire of 0.75 mm thickness with a terminal 5 cm spring. A Teflon tube (160 cm, 7 F) was used along with this instrument as a sleeve. The use of this accessory was analyzed prospectively in subjects presenting with a history of coin ingestion. The time taken for removal of coins, complications during the procedure and failure rate was noted. Effect of the magnet on cardiac rhythm was also noted during the procedure. Results: A total of 55 children (mean age 5.1 ± 2.3 years) with coin ingestion presented over a period of 1 year. Forty‐four coins were ferromagnetic. All ferromagnetic coins were removed successfully. Mean time for removal was 68 ± 22 s. No complications were encountered. Conclusion: The novel magnetic instrument is precise, safe and quick for the removal of ferromagnetic coins under direct vision.  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