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   2107篇
  免费   166篇
  国内免费   23篇
耳鼻咽喉   3篇
儿科学   161篇
妇产科学   22篇
基础医学   280篇
口腔科学   55篇
临床医学   224篇
内科学   453篇
皮肤病学   29篇
神经病学   70篇
特种医学   480篇
外科学   156篇
综合类   39篇
预防医学   106篇
眼科学   18篇
药学   74篇
中国医学   3篇
肿瘤学   123篇
  2021年   11篇
  2020年   10篇
  2019年   10篇
  2018年   24篇
  2017年   12篇
  2016年   25篇
  2015年   33篇
  2014年   33篇
  2013年   73篇
  2012年   43篇
  2011年   35篇
  2010年   83篇
  2009年   71篇
  2008年   54篇
  2007年   52篇
  2006年   65篇
  2005年   48篇
  2004年   38篇
  2003年   42篇
  2002年   45篇
  2001年   18篇
  2000年   30篇
  1999年   36篇
  1998年   138篇
  1997年   129篇
  1996年   128篇
  1995年   96篇
  1994年   77篇
  1993年   82篇
  1992年   29篇
  1991年   31篇
  1990年   18篇
  1989年   67篇
  1988年   47篇
  1987年   55篇
  1986年   55篇
  1985年   57篇
  1984年   30篇
  1983年   36篇
  1982年   41篇
  1981年   26篇
  1980年   42篇
  1979年   18篇
  1978年   24篇
  1977年   20篇
  1976年   29篇
  1975年   27篇
  1965年   5篇
  1963年   5篇
  1956年   5篇
排序方式: 共有2296条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: Our aims in the present study were to estimate the influences of pain and urinary symptoms on quality of life, and to determine which of these two variables has the most predictive power with respect to quality of life in young men with chronic prostatitis-like symptoms. METHODS: Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index. Of the 28,841 men aged 20 years who lived in the study community, 18,495 men (a response rate 64.1%) agreed to participate in the study. A total of 1057 men who complained of symptoms indicative of chronic prostatitis were included in the study. The influences of pain and urinary symptoms on quality of life were determined using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to estimate the predictive ability of each of these variables with respect to quality of life. RESULTS: Results from multivariate analysis showed that both pain and urinary symptoms were associated with an increased likelihood of impaired quality of life, although pain contributed more to a reduced quality of life than urinary symptoms. Relative to men who experienced mild pain, men who experienced moderate pain had a 3.9-fold risk of poor quality of life (odds ratio [OR], 3.87; 95% confidence interval [CI], 2.86-5.23; P < 0.001) and those who experienced severe pain had a 15.7-fold risk of reduced quality of life (OR, 15.68; 95% CI, 6.59-37.35; P < 0.001). Moderate urinary symptoms were associated with a 1.4-fold risk of bother (OR, 1.41; 95% CI, 1.01-1.99; P < 0.001) and severe urinary symptoms were associated with 2.4-fold risk (OR, 2.39; 95% CI, 1.37-4.12; P < 0.001), relative to mild urinary symptoms. Comparison of the effects of pain and urinary symptoms showed that pain severity had the most predictive power for bother, quality of life, and quality-of-life impact. The areas under the ROC curves for bother, quality of life, and quality-of-life impact were 71.3%, 69.3% and 72.5%, respectively. CONCLUSION: Urinary symptoms and pain might be associated with an increased likelihood of impaired quality of life in young men with chronic prostatitis-like symptoms. In addition, our findings suggest that pain severity is the most influential variable for determining quality of life in this population.  相似文献   
2.
3.
4.
Evaluation of an on-line patient exposure meter in neuroradiology   总被引:1,自引:0,他引:1  
  相似文献   
5.
Pediatric knee MR imaging: pattern of injuries in the immature skeleton   总被引:3,自引:0,他引:3  
  相似文献   
6.
7.
Abstract: To investigate the distribution of blood lead levels in a sample of Victorian children, and to compare current levels with those from a similar survey in 1979, blood was tested for lead in 252 children (123 under five years) attending Royal Children's Hospital as outpatients and having venepuncture blood samples for medical reasons. Blood lead levels were determined by graphite furnace atomic absorption spectrophotometer. The mean blood lead level was 0.26 μmol/L (5.4 μg/dL). In the under-five age group, the mean was 0.28 μmol/L (5.7 μg/dL). Only 1.6 per cent of this group exceeded the National Health and Medical Research Council action level of 0.72 μmol/L (15 μg/dL). Levels in this age group have declined significantly since 1979, when the mean was 0.54 μmol/L (11.1 μg/dL) and 12.9 per cent exceeded 0.72 μmol/L (15 μg/dL). Average blood lead levels have halved since 1979, with likely contributing factors being reduced exposure from lead in diet, reduced access to lead in paint and reduced lead in ambient air. Children with elevated levels had identifiable risk factors such as pica or exposure to lead-based paint, suggesting the need for ongoing public health action to prevent exposure in these groups.  相似文献   
8.
9.
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.  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