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   179025篇
  免费   11835篇
  国内免费   706篇
耳鼻咽喉   2527篇
儿科学   4904篇
妇产科学   3439篇
基础医学   23259篇
口腔科学   3567篇
临床医学   17556篇
内科学   38381篇
皮肤病学   2801篇
神经病学   18008篇
特种医学   6227篇
外国民族医学   13篇
外科学   26532篇
综合类   2314篇
现状与发展   3篇
一般理论   203篇
预防医学   13363篇
眼科学   4784篇
药学   11576篇
中国医学   204篇
肿瘤学   11905篇
  2023年   699篇
  2022年   1221篇
  2021年   2871篇
  2020年   1764篇
  2019年   2889篇
  2018年   3405篇
  2017年   2457篇
  2016年   2863篇
  2015年   3464篇
  2014年   5121篇
  2013年   7893篇
  2012年   11418篇
  2011年   12274篇
  2010年   6856篇
  2009年   6319篇
  2008年   11554篇
  2007年   12326篇
  2006年   11819篇
  2005年   12174篇
  2004年   11561篇
  2003年   11042篇
  2002年   10654篇
  2001年   1499篇
  2000年   1131篇
  1999年   1601篇
  1998年   2337篇
  1997年   2029篇
  1996年   1710篇
  1995年   1584篇
  1994年   1429篇
  1993年   1358篇
  1992年   1057篇
  1991年   965篇
  1990年   843篇
  1989年   831篇
  1988年   851篇
  1987年   727篇
  1986年   850篇
  1985年   922篇
  1984年   1230篇
  1983年   1180篇
  1982年   1642篇
  1981年   1520篇
  1980年   1419篇
  1979年   792篇
  1978年   915篇
  1977年   802篇
  1976年   714篇
  1975年   571篇
  1974年   602篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Congenital heart disease is a rare but important finding in adults who experience sudden death. Examination of the congenitally malformed heart has historically been considered esoteric and best left to those with expertise. The Cardiac Risk in the Young cardiovascular pathology laboratory based at St George's University of London has now received over 6,000 cases. Of these, 21 congenitally malformed hearts were retained for research and educational purposes. Hearts were assessed using sequential segmental analysis, and causes of death were adjudicated based on thorough macroscopic examination and histology. Congenital malformations that were encountered included atrial septal defects, ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries in both its regular and congenitally corrected variants. Findings also included hearts with mirror-imaged and isomeric atrial appendages. Direct causes of death included myocardial fibrosis, pulmonary hypertension, and hemorrhage. A small but notable proportion did not reveal a substrate for arrhythmia, raising the question of whether the terminal event was due to the congenital heart disease itself, or an underlying channelopathy. Here, we demonstrate the value of simple sequential segmental analysis in describing and categorizing the cases, with the concept of the “morphological method” serving to identify the distinguishing features of the cardiac components. Clin. Anat. 33:394–404, 2020. © 2019 Wiley Periodicals, Inc.  相似文献   
52.
53.
54.
55.
Background: Little is known of stroke outcomes in low- and middle-income countries with limited formal stroke rehabilitation services and of homebased-stroke services delivered within the primary health care (PHC) context by community health workers (CHWs).

Objectives: To describe and analyze the outcomes of patients with stroke from a rural PHC setting in the Western Cape, South Africa.

Methods: In a longitudinal survey, 93 stroke patients, referred to home and community-based care services (HCBC) between June 2015 and December 2017, were assessed at baseline, one month and three months. Changes in function (Barthel Index (BI)), caregiver strain (Caregiver Strain Index (CSI)), impact of environmental factors and satisfaction with stroke care were measured.

Results: HCBC was delayed, fragmented and brief (median session duration 20 minutes (IQR 15.0–30.0)). Although function improved significantly, dependence remained high: median BI score changed from 40.0 (IQR 15.0–70.0) to 62.5 (IQR 30.0–81.25) (p = .019). A third (33.0% (30/91)) of caregivers initially experienced strain and the median CSI score remained 3.0 (IQR 0.0–7.0) (p = .672). Overall, patient and caregiver satisfaction with HCBC was low with only 46.9% (31/66) of caregivers and 17.4% (12/69) of patients satisfied with all aspects of care. Only 47.6% of assistive product needs were met. Environmental factors negatively impacted on patient function and caregiving.

Conclusions: Clinical practice pathways and referral guidelines should be developed for the HCBC platform. Specific training of CHWs, focusing on how to educate, support and train family caregivers, provide assistive devices and refer to health services is needed.  相似文献   

56.
Anatomical understanding of the peritrochanteric space and abductor insertions has been well documented in the literature. Extrapolating this knowledge to perform a “successful” abductor tendon repair has led to controversy over the best method to achieve a durable, stable repair and improve patient outcomes. I feel that the debate in the hip over single- versus double-row fixation is only beginning and we are in for a ride to uncover the best method, as we have with the shoulder over the last 15 years. What is best? Single or double row?  相似文献   
57.
58.
59.
60.

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   
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