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   592篇
  免费   46篇
  国内免费   2篇
耳鼻咽喉   17篇
儿科学   50篇
妇产科学   7篇
基础医学   99篇
口腔科学   10篇
临床医学   50篇
内科学   106篇
皮肤病学   18篇
神经病学   29篇
特种医学   16篇
外科学   73篇
综合类   51篇
一般理论   1篇
预防医学   33篇
眼科学   16篇
药学   27篇
肿瘤学   37篇
  2024年   4篇
  2023年   5篇
  2022年   10篇
  2021年   24篇
  2020年   6篇
  2019年   5篇
  2018年   22篇
  2017年   10篇
  2016年   21篇
  2015年   27篇
  2014年   25篇
  2013年   24篇
  2012年   48篇
  2011年   41篇
  2010年   26篇
  2009年   16篇
  2008年   30篇
  2007年   40篇
  2006年   23篇
  2005年   39篇
  2004年   25篇
  2003年   16篇
  2002年   18篇
  2001年   10篇
  2000年   9篇
  1999年   12篇
  1998年   8篇
  1997年   5篇
  1996年   3篇
  1995年   2篇
  1994年   2篇
  1993年   2篇
  1992年   7篇
  1991年   16篇
  1990年   10篇
  1989年   9篇
  1988年   7篇
  1987年   5篇
  1986年   3篇
  1985年   4篇
  1984年   5篇
  1982年   2篇
  1981年   3篇
  1980年   2篇
  1976年   2篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
  1969年   1篇
  1942年   1篇
排序方式: 共有640条查询结果,搜索用时 15 毫秒
41.

Background  

Detachment of the Tricuspid Valve Leaflet (TVD) has been described for better access to repair Perimembranous Ventricular Septal Defects (pVSD). The present report is our early experience with which has been found to be safe and easy with reproducible results.  相似文献   
42.
Sahni SK 《Thrombosis research》2007,119(5):531-549
As an important component of the vasculature, endothelial cell lining covers the inner surface of blood vessels and provides an active barrier interface between the vascular and perivascular compartments. In addition to maintaining vasomotor equilibrium and organ homeostasis and communicating with circulating blood cells, the vascular endothelium also serves as the preferred target for a number of infectious agents. This review article focuses on the roles of interactions between vascular endothelial cells and invading pathogens and resultant endothelial activation in the pathogenesis of important human diseases with viral and bacterial etiologies. In this perspective, the signal transduction events that regulate vascular inflammation and basis for endothelial cell tropism exhibited by certain specific viruses and pathogenic bacteria are also discussed.  相似文献   
43.
The NHS Bowel Cancer Screening Programme is the first nationally coordinated screening programme to be introduced in the UK for 18 years. Currently, the screening algorithm is based upon faecal occult blood testing and colonoscopy for those screenees testing positive. This commentary provides radiologists with an update on the rationale for colorectal cancer screening, explains the organizational structure of the new UK NHS programme, and explores the possible role for radiology in the current and future screening algorithms.  相似文献   
44.
45.
46.
47.
48.
49.
Analysis of receptor status has become standard procedure for assessing breast cancer patients. Estrogen causes epithelial proliferation in breast tissue via the estrogen receptor (ER). The progesterone receptor (PR) is also regulated by the estrogen gene. Analyzing ER and PR together gives information regarding the likely response of carcinoma patients to hormonal therapy. The aim of the present study was to record the expression patterns of ER and PR in normal mammary tissue in different age groups to provide reference data to facilitate histological diagnosis. Breast tissues from the upper outer quadrant of each side of 27 adult female cadavers were examined after H & E staining. ER and PR were identified and examined by immunohistochemistry. The percentage area occupied by parenchyma relative to stromal tissue was calculated in different age groups and was about 4:6, 3.5:6.5, 3:7, 2:8, and 1.5:8.5 in the 3rd, 4th and 5th, 6th, 7th, 8th and 9th, and 10th decades of life, respectively. Both ER and PR were present in all age groups and the numbers of both receptors were maximal during the 4th decade. The distribution and staining patterns for both ER and PR were recorded in different age groups. The contiguous pattern of ER, which is considered pathognomonic of breast carcinoma, was not seen except in one case in the 6th decade. Moderately stained ER and PR receptor sites predominated throughout. The study of normal breast tissue of similar age might provide comparisons that will help histopathologists to make clinical diagnoses from breast biopsies. Clin. Anat. 29:729–737, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   
50.
The effects of variations in carbohydrate and fat intake and body position on behavioral activity states were evaluated in 64 healthy, growing low birth weight infants (birth weight, 750-1600 g). The infants, enrolled in a prospective, randomized, double-blind, controlled study of effects of quality of dietary energy, were fed one of the five formulas. These formulas contained fixed intakes of protein (4 g/kg per day) but different intakes of carbohydrate (9.1 to 20.4 g/kg per day) and fat (4.3 to 9.5 g/kg per day). Six-hour daytime sleep studies were performed at 2-wk intervals from time of full enteral intake until discharge (mean postconceptional age at first study, 33.2 +/- 1.8 wk). Infants were randomly assigned to the prone or supine position for the first 3-h postprandial period; the position was reversed during the second 3 h. Behavioral activity state, i.e. quiet sleep (QS), active sleep, indeterminate sleep, awake, or crying was coded each minute throughout the postprandial period. The overall incidence of QS was almost double in the prone position versus the supine (p < 0.0001). In contrast, the probability of being in either of the two wakeful states (awake and crying) was increased when infants were placed in supine position (p < 0.0001). Increased likelihood of being in QS while prone was found only during the 30 min after and before feeding in a 150-min prandial cycle. In contrast, increased amounts of awake and crying in supine position were observed throughout the feeding interval. As carbohydrate intake increased, time spent in QS in supine position increased (from 8.6% to 12.5%, p < 0.02), and a trend in the same direction was noted for the prone position (p = 0.06). However, during postprandial minutes 10-100, when QS is likely to be entrained by the nutrient intake, enhancement of QS was found in the prone position only (p < 0.02). Carbohydrate intake influences the total time spent and the distribution of behavioral activity states within the postprandial period in low birth weight infants. The effect of nutrient intake on sleep profile is dependent on body position and time after feed. Mechanistic hypotheses relating sudden infant death syndrome to sleeping position may need to take these observations into account.  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