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   6030篇
  免费   402篇
  国内免费   46篇
耳鼻咽喉   67篇
儿科学   274篇
妇产科学   179篇
基础医学   652篇
口腔科学   234篇
临床医学   470篇
内科学   1365篇
皮肤病学   124篇
神经病学   397篇
特种医学   187篇
外科学   873篇
综合类   303篇
一般理论   19篇
预防医学   328篇
眼科学   155篇
药学   464篇
中国医学   110篇
肿瘤学   277篇
  2024年   4篇
  2023年   44篇
  2022年   187篇
  2021年   307篇
  2020年   142篇
  2019年   198篇
  2018年   257篇
  2017年   126篇
  2016年   160篇
  2015年   236篇
  2014年   241篇
  2013年   312篇
  2012年   452篇
  2011年   511篇
  2010年   267篇
  2009年   234篇
  2008年   371篇
  2007年   307篇
  2006年   318篇
  2005年   299篇
  2004年   281篇
  2003年   219篇
  2002年   246篇
  2001年   78篇
  2000年   62篇
  1999年   67篇
  1998年   38篇
  1997年   36篇
  1996年   40篇
  1995年   26篇
  1994年   36篇
  1993年   27篇
  1992年   45篇
  1991年   40篇
  1990年   36篇
  1989年   30篇
  1988年   22篇
  1987年   20篇
  1986年   19篇
  1985年   10篇
  1984年   12篇
  1983年   14篇
  1982年   19篇
  1981年   18篇
  1980年   13篇
  1978年   11篇
  1977年   9篇
  1976年   10篇
  1974年   3篇
  1966年   3篇
排序方式: 共有6478条查询结果,搜索用时 15 毫秒
1.
2.

Objectives

Iatrogenic injury of the Profunda Femoris Artery (PFA) at time of hip fixation surgery can increase morbidity and mortality and prolong the hospital stay. This is an injury that tends to pass unnoticed as a cause of postoperative deterioration despite being frequently reported in the literature. Our study aims to describe the anatomy of the PFA in relation to the medial femoral cortex with specific emphasis on its orientation relative to the position of a sliding hip screw side plate construct. By doing so we are able to present clear guidance to orthopaedic surgeons on how to avoid iatrogenic PFA injury at the time of hip fracture fixation.

Methods

Using Computed Tomography Angiographic (CTA) studies, the course of the PFA in relation to the medial femoral cortex was traced in 44 patients (28 males and 16 females) with mean age of 65.6 years. Coronal and axial CT sections were cross-linked to specify the position of the PFA at 1?cm intervals.

Results

The course of the artery could be divided into three parts relative to a fixed reference point. Proximal and distal parts of the artery were in a safer position in comparison to the middle part of the artery that was found very close to the femoral cortex and along the coronal axis of the femur (mean angle 2.9° from the femoral coronal axis and 13.8?mm from the medial femoral cortex). Using the commercially available side plate constructs, this part of the artery corresponded to the distal part of the plate (third and fourth holes).

Conclusion

Special attention needs to be practiced by the operating surgeon while drilling into the third and fourth holes of the side plate.  相似文献   
3.
4.
INTRODUCTIONThemicrotubule-associatedprotein蚲ishyperphos-phorylatedandglycosylatedinAlzheimerdisease(AD),andtheseabnormalmodificationsformedthebasisofprogressivelyretrogradeneurofibrillarydegenerationseeninADbrainandtherebythedementia(1,2).ADab-normallyphosphorylated蚲notonlyismicrotubuleas-semblyincompetent,butalsoinhibitsassemblyanddis-assemblesthepreassembledmicrotubulesinvitro(3).Inthetangle-bearingneuronsinADbrain,thenormalcytoskeletonisdisruptedandreplacedwi…  相似文献   
5.
Cloning and transgenesis in mammals: Implications for xenotransplantation   总被引:2,自引:0,他引:2  
Availability of suitable organs for transplantation remains of major concern and projections indicate that the problem will continue to increase. Therefore, alternatives to the use of human organs for transplantation, continue to be explored including use of stem cells, artificial organs, and organs from other species (xenotransplantation). In xenotransplantation, the species of choice remains the pig due to its physiological similarities to humans, reduced costs, ease of manipulation, and reduced ethical concerns to its use. However, in order to develop pig organs that are suitable for xenotransplantation, complex genetic modification need to be undertaken. These modifications require the introduction of precise genetic changes into the pig that can only be accomplished at this time using somatic cell nuclear transfer. We cover in this review advances in transgenic manipulation and cloning in swine and how the development of these two technologies is critical to the eventual utilization of the pig as a human organ donor.  相似文献   
6.
7.
Pharmacokinetic parameters of two antifolates, trimethoprim and aditoprim, were studied in buffalo calves. The elimination half-life of aditoprim (6.14 h) was nearly twice as long as that of trimethoprim (3.08 h) and compares well with values observed in heifers. This longer half-life of aditoprim is a result of its much larger distribution volume (four to five times larger) because the clearance of aditoprim was about twice as high as that of trimethoprim. The longer half-life of aditoprim is expected to give a longer duration of in vivo bacteriostatic activity than that of trimethoprim.  相似文献   
8.
9.
PURPOSE: To report early clinical experience with virtual histology intravascular ultrasound (VH IVUS) in carotid endoluminal repair. TECHNIQUE: A 2.9-F, 20-MHz catheter that utilizes computer software to demonstrate the histological components of arteriosclerotic plaque was evaluated during carotid angioplasty and stenting. VH IVUS images were created following a pullback through the carotid stenosis and produced a color-coded map of the different histological constituents of the disease (dark green: fibrous, yellow/green: fibrofatty, white: calcified, and red: necrotic lipid core plaque). CONCLUSION: VH IVUS produces a color-coded map of the different histological components of artery plaque. It has the potential to predict how the plaque is likely to behave at the moment of endoluminal treatment.  相似文献   
10.
A case of mucous metaplasia of mesothelium in an 80 year old woman is described. Its cause is unknown, but it is important not to confuse it with secondary tumour.  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