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   2258篇
  免费   135篇
  国内免费   25篇
耳鼻咽喉   11篇
儿科学   178篇
妇产科学   30篇
基础医学   220篇
口腔科学   58篇
临床医学   253篇
内科学   566篇
皮肤病学   41篇
神经病学   55篇
特种医学   500篇
外科学   213篇
综合类   29篇
预防医学   76篇
眼科学   25篇
药学   68篇
中国医学   4篇
肿瘤学   91篇
  2022年   10篇
  2021年   23篇
  2020年   20篇
  2019年   17篇
  2018年   42篇
  2017年   22篇
  2016年   33篇
  2015年   36篇
  2014年   62篇
  2013年   87篇
  2012年   67篇
  2011年   67篇
  2010年   87篇
  2009年   76篇
  2008年   62篇
  2007年   50篇
  2006年   63篇
  2005年   38篇
  2004年   43篇
  2003年   44篇
  2002年   40篇
  2001年   28篇
  2000年   45篇
  1999年   43篇
  1998年   136篇
  1997年   126篇
  1996年   132篇
  1995年   93篇
  1994年   75篇
  1993年   84篇
  1992年   30篇
  1991年   35篇
  1990年   26篇
  1989年   62篇
  1988年   53篇
  1987年   60篇
  1986年   48篇
  1985年   53篇
  1984年   26篇
  1983年   32篇
  1982年   36篇
  1981年   21篇
  1980年   37篇
  1979年   16篇
  1978年   17篇
  1977年   18篇
  1976年   25篇
  1975年   25篇
  1971年   8篇
  1965年   10篇
排序方式: 共有2418条查询结果,搜索用时 15 毫秒
1.
2.
The prevalence of latex allergy has been increasing not only in risk groups but also in the general population, where it is accepted to average 1%. In children, latex sensitization prevalence studies are scarce and involve different population sampling and allergy testing methods, which makes it difficult to compare across studies. Nevertheless, existing studies point towards a low prevalence of latex allergy in children, which still needs to be confirmed in the Portuguese population. Aiming at studying the prevalence of latex sensitization and allergy in a sample of Portuguese children, we studied 182 children from two different hospital outpatient clinics. A standardized questionnaire focusing on atopic background, previous history and allergic signs or symptoms on exposure to latex or fruits was given to all children and parents. Skin prick testing was performed with a battery of common aeroallergens as well as latex. Serum total IgE, Phadiatop, F x 5E and latex-specific IgE were determined in all children. Specific IgE to latex-crossreacting fruits was determined in latex-sensitized children. Based upon the questionnaire, the prevalence of latex allergy would be 0.5%. The prevalence of latex sensitization would be 3.8%, when based solely upon skin prick testing, and 12.1% (>/=0.35 IU/ml) or 6.6% (>/=0.70 IU/ml) when based singly upon determination of latex-specific IgE. When positive results for either test were considered, the prevalence of latex sensitization was 14.3%. All latex-sensitized children were atopic. Sensitivity to latex-crossreacting foodstuffs was demonstrated in 61.5% of latex-sensitized children (16/26). This study shows that the prevalence of latex allergy and sensitization in Portuguese atopic and non-atopic children, as analysed using various diagnostic methods, is similar to that observed in other countries. In addition, the assessment of latex allergy and sensitization should always include skin prick testing and determination of serum IgE.  相似文献   
3.
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   
4.
5.
6.
1. The modulation of L-type voltage-sensitive calcium channels in guinea-pig isolated ventricular myocytes by propafenone was examined by the whole cell voltage-clamp technique. 2. Propafenone, 10(-7) -5 x 10(-5) M, produced a concentration-dependent inhibition of Ca current (ICa) without any significant change in the current-voltage relation. Half-blocking concentration (IC50) of propafenone for the peak ICa at +10 mV was 5 x 10(-6) M. 3. The voltage-dependence of ICa inactivation was shifted in the hyperpolarizing direction in the presence of 5 x 10(-6) M propafenone. 4. A frequency-dependent relative block by propafenone was observed after repetitive depolarizing test pulses at a frequency of 0.5 and 1 Hz. The recovery of ICa from inactivation was prolonged by propafenone and the reactivation exhibited an additional exponential component attributed to the slow release from drug block of Ca channels. 5. These results suggest that propafenone, at therapeutic concentrations exhibits Ca channel blocking properties that may be involved in its antiarrhythmic mechanism.  相似文献   
7.
Evaluation of an on-line patient exposure meter in neuroradiology   总被引:1,自引:0,他引:1  
  相似文献   
8.
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   
9.
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