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   4091篇
  免费   511篇
  国内免费   16篇
耳鼻咽喉   212篇
儿科学   56篇
妇产科学   128篇
基础医学   54篇
口腔科学   72篇
临床医学   709篇
内科学   416篇
皮肤病学   38篇
神经病学   177篇
特种医学   83篇
外科学   1948篇
综合类   3篇
预防医学   90篇
眼科学   416篇
药学   24篇
肿瘤学   192篇
  2024年   18篇
  2023年   72篇
  2021年   26篇
  2020年   92篇
  2019年   43篇
  2018年   127篇
  2017年   141篇
  2016年   157篇
  2015年   155篇
  2014年   284篇
  2013年   302篇
  2012年   139篇
  2011年   163篇
  2010年   228篇
  2009年   317篇
  2008年   128篇
  2007年   99篇
  2006年   166篇
  2005年   85篇
  2004年   65篇
  2003年   55篇
  2002年   56篇
  2001年   92篇
  2000年   43篇
  1999年   54篇
  1998年   92篇
  1997年   121篇
  1996年   111篇
  1995年   108篇
  1994年   103篇
  1993年   85篇
  1992年   96篇
  1991年   70篇
  1990年   47篇
  1989年   64篇
  1988年   71篇
  1987年   36篇
  1986年   45篇
  1985年   28篇
  1984年   36篇
  1983年   23篇
  1982年   34篇
  1981年   23篇
  1980年   20篇
  1979年   18篇
  1978年   15篇
  1962年   16篇
  1956年   28篇
  1955年   22篇
  1954年   15篇
排序方式: 共有4618条查询结果,搜索用时 0 毫秒
1.
2.
Wound healing involves a number of cellular and molecular events, many of which are controlled by soluble growth factors. In the process of healing, hepatocyte growth factor, a cytokine known to act as mitogen, motogen, and morphogen, has been postulated to play multiple roles during several stages of this complex biological process. Produced primarily by stromal fibroblasts, hepatocyte growth factor regulates angiogenesis, vascular permeability, cell migration, matrix deposition and degradation, and other biological processes. The current article discusses recent progress in understanding the multiple roles played by this growth factor in tissue repair.  相似文献   
3.
To produce a stable epidermis, keratinocytes need to be firmly attached to the basement membrane. However, following wounding, keratinocytes are required to develop a migratory phenotype in order to reepithelialize the wound. To investigate some of the issues underlying reepithelialization, we have developed a three-dimensional in vitro model of tissue-engineered skin, comprising sterilized human dermis seeded with human keratinocytes and dermal fibroblasts. Using this model, we have shown that the inclusion of fibroblasts within the model increases the stability of keratinocyte attachment. We have also demonstrated that keratinocyte migration occurs most effectively in the absence of a basement membrane and following the inclusion of fibroblasts in the model. In addition, subjecting the keratinocyte layer to mechanical trauma induces a migratory phenotype. We conclude that this three-dimensional in vitro wound model can be used to increase our understanding of the factors that enhance keratinocyte migration and hence wound healing in vivo.  相似文献   
4.
Background Despite improving surgical techniques, treatment of heart valve disease in children remains controversial. Somatic growth and adequate anticoagulation are of concern when children undergo valve replacement. We conducted this study to evaluate the performance of valves in this age group. Methods 42 children under the age of 13 years who underwent valve replacement were included in this study. Totally, 50 valves were implanted in 42 patients: 48 were mechanical prostheses, two were bioprosthetic both in pulmonary position. 37 (74%) valves were implanted in mitral position, 10 (20%) in aortic position, 1 (2%) in tricuspid position and 2 (4%) in pulmonary position. Preoperatively, 14 (33,3%) patients were in New York Heart Association (NYHA) class IV, while 27 (64.2%) were in NYHA class III. Results There were 2 (4.7%) hospital deaths and 2 (4.7%) late deaths while 2 (4.7%) patients were lost to follow up. The mean follow up period was 9.4 yrs. 35 (83.3%) patients are in NYHA Class I and free of all medications except warfarin. 3 (7.1%) patients have undergone 5 successful pregnancies. The median INR was 2.23. Major thrombo-embolic episode occurred in 1 (2.3%) patient. Conclusions In view of the problems of sizing, anticoagulation and need for re-operation at an early age, there is a reluctance to replace valves in children. This study shows that despite these problems, valve replacement can be undertaken safely and successfully in children, when repair has failed or not technically feasible.  相似文献   
5.
Over the last 15 years photodynamic therapy (PDT) has become a viable treatment for pre-malignant and malignant disease of the oesophagus. Its initial use was in the palliation of oesophageal malignant obstruction bringing improved swallowing hence increasing nutritional intake and improving general quality of life. As the therapeutic boundaries of PDT have stretched, current studies look at the role of PDT in the treatment of pre-malignant dysplastic Barrett's epithelium and early malignancy as a curative mucosal ablative technique. As a curative treatment in early oesophageal cancer, PDT provides an alternative treatment to oesophagectomy for those more elderly or less medically fit patients.This paper reviews the uses of photodynamic therapy in oesophageal cancer with reference to the available publications on its use in the palliation of oesophageal cancer and treatment of early cancer and high grade dysplasia in Barrett's mucosa.  相似文献   
6.
7.
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   
8.
9.
Abstract: Stellate ganglion block is commonly used to treat the sympathetically maintained pain which may occur in one‐third of patients with complex regional pain syndrome type 1. A complication that followed a single block and presented a diagnostic dilemma for the ophthalmologist is reported.  相似文献   
10.
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