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   8364篇
  免费   697篇
  国内免费   43篇
耳鼻咽喉   36篇
儿科学   230篇
妇产科学   135篇
基础医学   910篇
口腔科学   234篇
临床医学   843篇
内科学   2175篇
皮肤病学   188篇
神经病学   800篇
特种医学   511篇
外科学   1087篇
综合类   150篇
一般理论   28篇
预防医学   677篇
眼科学   280篇
药学   469篇
中国医学   20篇
肿瘤学   331篇
  2023年   52篇
  2021年   133篇
  2020年   92篇
  2019年   159篇
  2018年   188篇
  2017年   147篇
  2016年   124篇
  2015年   142篇
  2014年   181篇
  2013年   279篇
  2012年   362篇
  2011年   424篇
  2010年   272篇
  2009年   212篇
  2008年   370篇
  2007年   392篇
  2006年   412篇
  2005年   362篇
  2004年   300篇
  2003年   345篇
  2002年   257篇
  2001年   189篇
  2000年   191篇
  1999年   188篇
  1998年   130篇
  1997年   129篇
  1996年   133篇
  1995年   115篇
  1994年   101篇
  1993年   91篇
  1992年   177篇
  1991年   147篇
  1990年   144篇
  1989年   169篇
  1988年   169篇
  1987年   168篇
  1986年   158篇
  1985年   146篇
  1984年   111篇
  1983年   73篇
  1982年   58篇
  1979年   93篇
  1978年   81篇
  1977年   70篇
  1976年   59篇
  1975年   55篇
  1974年   68篇
  1973年   61篇
  1972年   62篇
  1971年   59篇
排序方式: 共有9104条查询结果,搜索用时 31 毫秒
1.
Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome.  相似文献   
2.
Despite a population of nearly 60 million, there is currently not a single interventional radiologist in Tanzania. Based on an Interventional Radiology (IR) Readiness Assessment, the key obstacles to establishing IR in Tanzania are the lack of training opportunities and limited availability of disposable equipment. An IR training program was designed and initiated, which relies on US-based volunteer teams of IR physicians, nurses, and technologists to locally train radiology residents, nurses, and technologists. Preliminary results support this strategy for addressing the lack of training opportunities and provide a model for introducing IR to other resource-limited settings.  相似文献   
3.

Background

The purpose of this analysis is to describe the differences in cardiac magnetic resonance characteristics between benign and malignant tumors, which would be helpful for surgical planning.

Methods

This was a prospective cohort study of 130 patients who underwent cardiac magnetic resonance imaging for evaluation of a suspected cardiac mass. After excluding thrombi and tumors without definitive diagnosis, 66 tumors were evaluated for morphologic features and tissue composition.

Results

Of the 66 patients, 39 (59.0%) had malignant tumors and 27 (41.0%) had benign tumors. Patients with malignant tumors were younger when compared with those with benign tumors (age 51 years [42.8-60.0] vs 65 years [60.0-71.0] median). Malignant tumors more often demonstrated tumor invasion (69% vs 0% P < .001) and were more often associated with pericardial effusion (41% vs 7.4% P = .004). Presence of first-pass perfusion (100% vs 33% P < .001) and late gadolinium enhancement (100% vs 59.2%, P < .001) were significantly higher in malignant tumors. In logistic regression modeling, tumor invasion (P < .001) and first-pass perfusion (P < .001) were independently associated with malignancy. Furthermore, using classification and regression tree analysis, we developed a decision tree algorithm to help differentiate benign from malignant tumors (diagnostic accuracy ~90%). The algorithm-weighted cost of misclassifying a malignant tumor as benign was twice that of classifying a benign tumor as malignant.

Conclusions

Our study demonstrates that cardiac magnetic resonance imaging is a useful noninvasive method for differentiating malignant from benign cardiac tumors. Tumor size, invasion, and first-pass perfusion were useful imaging characteristics in differentiating benign from malignant tumors.  相似文献   
4.
5.
Sonoelasticity imaging of prostate cancer: in vitro results   总被引:2,自引:0,他引:2  
  相似文献   
6.
7.
Various cases are presented demonstrating the role of computed tomography (CT) in the assessment of serosal and bowel wall pathology. Reference is made to the morphology of the lesions. Illustrative examples of tumors, secondary malignant dissemination, irradiation injury to the gut, and intramural gas associated with ulcerative colitis, are all illustrated.  相似文献   
8.
9.
It was hypothesized that members of an older cohort of seriously mentally ill community mental health clients would develop stronger alliances with intensive case managers. Eighty-six clients participating in a study of case management services completed a measure of working alliance and structured interviews. It was found that older cohort clients, those age 45 or older, showed much stronger alliances with their case managers than younger clients.This research is funded by NIMH/SAMHSA grant R18MH46082.  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