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   5441篇
  免费   368篇
  国内免费   39篇
耳鼻咽喉   48篇
儿科学   105篇
妇产科学   74篇
基础医学   640篇
口腔科学   66篇
临床医学   512篇
内科学   1440篇
皮肤病学   99篇
神经病学   723篇
特种医学   174篇
外科学   926篇
综合类   6篇
一般理论   1篇
预防医学   238篇
眼科学   59篇
药学   418篇
中国医学   19篇
肿瘤学   300篇
  2024年   5篇
  2023年   55篇
  2022年   137篇
  2021年   209篇
  2020年   105篇
  2019年   165篇
  2018年   199篇
  2017年   138篇
  2016年   166篇
  2015年   164篇
  2014年   233篇
  2013年   285篇
  2012年   410篇
  2011年   399篇
  2010年   239篇
  2009年   232篇
  2008年   360篇
  2007年   343篇
  2006年   333篇
  2005年   349篇
  2004年   333篇
  2003年   282篇
  2002年   233篇
  2001年   34篇
  2000年   32篇
  1999年   41篇
  1998年   60篇
  1997年   37篇
  1996年   41篇
  1995年   28篇
  1994年   39篇
  1993年   21篇
  1992年   12篇
  1991年   12篇
  1990年   9篇
  1989年   20篇
  1988年   12篇
  1987年   11篇
  1986年   8篇
  1985年   5篇
  1984年   8篇
  1983年   11篇
  1982年   6篇
  1980年   4篇
  1979年   4篇
  1976年   3篇
  1975年   2篇
  1974年   2篇
  1970年   2篇
  1968年   3篇
排序方式: 共有5848条查询结果,搜索用时 15 毫秒
61.
BackgroundElevation of the joint line frequently occurs in revision total knee arthroplasty (RTKA) because of a wider flexion space than extension space. One solution to balance this flexion-extension space involves the introduction of couplers between the stem and femoral components, and the use of posteriorly offset femoral stems that we hypothesized would improve gap balancing and facilitate joint line restoration.MethodsWe retrospectively reviewed a selected series of 43 RTKA. Postoperative joint line height was subtracted from intended height using postoperative lateral radiographs. The value was negative if the joint line position was lowered, and positive if raised.ResultsForty knees were followed for a mean of 3.5 years. Mean postoperative joint line position change from intended position was 1.5 mm (range ? 2.5–7.5 mm). In 28 knees (70%), the joint line position was restored to within ± 2 mm of the intended position; in eight knees (20%), from 2–4 mm; and in four knees (10%), > 4 mm. Joint line position was raised in 32 knees (80%) and lowered in eight (20%). In the offset stem knees, the intended joint line position was 0.9 mm (range ? 1.2–3.4 mm) as compared with 3.2 mm (range ? 2.5–7.5 mm) for the straight stem knees.ConclusionsA coupler system between the femoral stem and femoral component restored the joint line in 70% of cases. The posterior offset stem provided increased posterior condylar offset, addressed the wider flexion space, provided better positioning of the stem, and restored the joint line.Level of evidenceTherapeutic Study Level IV  相似文献   
62.
63.
64.
65.
The aim of the review is to describe the different techniques and materials available to reconstruct the tarsoconjunctival layer of the eyelid; to analyze their indications, advantages, and disadvantages.

We searched the Cochrane, PubMed, and Ovid MEDLINE databases for English articles published between January 1990 and January 2017 using variations of the following key words: “posterior lamella,” “eyelid reconstruction,” “tarsoconjunctival,” “flap,” and “graft.” Two reviewers checked the abstracts of the articles found to eliminate redundant or not relevant articles. The references of the identified articles were screened manually to include relevant works not found through the initial search.

The search identified 174 articles. Only a few articles with a therapeutic level of evidence were found. Techniques for the posterior lamellar reconstruction can be categorized as local, regional, and distant flaps; tarsoconjunctival, heterotopic, homologous, and heterologous grafts. Several techniques and variations on the techniques exist to reconstruct the posterior lamella, and, for similar indications, there’s no evidence of the primacy of one over the other. Defect size and location as well as patient features must guide the oculoplastic surgeon’s choice. The use of biomaterials can avoid possible complications of the donor site.  相似文献   

66.
Aims: The aim of this study was to examine 24 cases of obstetric brachial plexus palsy (OBPP) in 41,002 deliveries occurred at San Camillo–Forlanini Hospital in Rome, during the period 2000–2012.

Materials and methods: A population-based retrospective case-control study was designed and the database of the hospital was searched; for each case, maternal and fetal records were examined and some risk factors were evaluated.

Results: A statistically significant association between the 24 cases OBPP and the following risk factors: primiparity (p?p?p?p?p?Conclusions: The absence of OBPP cases in cesarean deliveries highlighted in this study supports the option of proposing an elective cesarean in the presence of known risk factors after a full disclosure with the mother of risks and benefits in order to obtain a valid consent. Furthermore, when cases of OBPP occur, communication between the physician and the parents of newborns is crucial and it may represent a valid risk-management tool to reduce malpractice lawsuits.  相似文献   
67.
68.
69.

Adolescent smoking is a major public health problem. While the socioeconomic status (SES) of the neighbourhood and that of the family are known to play a role in smoking onset and progression, it is not clear whether it modifies the association between parental influences and adolescent behaviour. The purpose of this study is to investigate family correlates of adolescent smoking experimentation and to explore the modifying role of socioeconomic context and European geographical area in a sample of European adolescents. This is a secondary analysis of the baseline survey of the European Drug Addiction Prevention (EU-Dap) trial which took place in seven European countries and involved 7079 students. School SES was used as indicator of socioeconomic context. European countries were aggregated in two geographical areas: North-Central and South. The associations between parental, family factors, and adolescents smoking experimentation were analysed through multilevel mixed-effect logistic regression models, stratified by school SES and European geographical area. Parental smoking, permissiveness towards tobacco, family conflicts, problematic relationships, low connectedness, and low parental control were significantly associated with adolescent smoking experimentation. Paternal smoking was a stronger correlate of adolescent smoking in low SES schools, while maternal smoking in high SES schools. Parental permissiveness was a stronger correlate in low SES schools. Family conflicts and low parental control were correlates only in low SES schools. The associations did not substantially differ between European geographical areas, with the exception of parental smoking that was a stronger correlate in the North, and parental control that was a correlate only in the South of Europe. To reduce inequalities in tobacco-related outcomes, prevention efforts in low socioeconomic contexts appear to be a public health priority. Parental smoking, permissiveness, family relationships, and connectedness should be addressed in preventive programs.

  相似文献   
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