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   905篇
  免费   62篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   88篇
妇产科学   12篇
基础医学   141篇
口腔科学   60篇
临床医学   95篇
内科学   136篇
皮肤病学   8篇
神经病学   43篇
特种医学   33篇
外科学   95篇
综合类   10篇
预防医学   141篇
眼科学   25篇
药学   50篇
中国医学   4篇
肿瘤学   26篇
  2023年   7篇
  2021年   20篇
  2020年   7篇
  2019年   19篇
  2018年   14篇
  2017年   15篇
  2016年   30篇
  2015年   28篇
  2014年   27篇
  2013年   41篇
  2012年   51篇
  2011年   63篇
  2010年   33篇
  2009年   18篇
  2008年   33篇
  2007年   46篇
  2006年   38篇
  2005年   57篇
  2004年   40篇
  2003年   37篇
  2002年   23篇
  2001年   14篇
  2000年   12篇
  1999年   18篇
  1998年   6篇
  1996年   8篇
  1994年   8篇
  1993年   7篇
  1992年   8篇
  1991年   6篇
  1989年   7篇
  1988年   8篇
  1987年   9篇
  1986年   7篇
  1985年   8篇
  1984年   11篇
  1983年   5篇
  1982年   9篇
  1981年   15篇
  1980年   9篇
  1979年   13篇
  1978年   8篇
  1976年   9篇
  1975年   9篇
  1974年   10篇
  1973年   8篇
  1972年   6篇
  1971年   10篇
  1970年   6篇
  1966年   6篇
排序方式: 共有970条查询结果,搜索用时 31 毫秒
101.
102.
A severe impairment of nutrition frequently occurs with morphological alterations in the oral cavity and the pharynx as well as with neurogenic disorders of the swallowing articulation. Complications like frequent aspirations are life-threatening. If the natural protection reflex for the respiratory tract, the cough reflex, does not work because of a reduced tracheal sensitivity, swallowing disorders often remain unrecognized. The ability of swallowing must be examined particularly with stroke-patients and weakened old patients. With radiological and endoscopic evaluations, oropharyngeal dysphagias can be assessed in detail. A wide spectrum of surgical measures and exercise treatment can clearly improve the life quality of the patients even if the aim, to make a complete and safe oral nutrition possible again, is not reached in every case.  相似文献   
103.
104.
Background: The aim of this study is to investigate the impact of alcohol consumption on clinical attachment loss (AL) progression over a period of 5 years. Methods: A multistage probability sampling strategy was used to draw a representative sample of the metropolitan area of Porto Alegre, Brazil. Five hundred thirty‐two individuals (209 males and 293 females) aged 18 to 65 years at baseline with no medical history of diabetes and at least six teeth were included in this analysis. Full‐mouth periodontal examinations with six sites per tooth were conducted at baseline and after 5 years. Alcohol consumption was assessed at baseline by asking participants about the usual number of drinks consumed in a week. Four categories of alcohol consumption were defined: 1) non‐drinker; 2) ≤1 glass/week; 3) >1 glass/week and ≤1 glass/day; and 4) >1 glass/day. Individuals showing at least two teeth with proximal (clinical AL) progression ≥3 mm over 5 years were classified as having disease progression. Multiple Poisson regression models adjusted for age, sex, smoking, socioeconomic status, and body mass index were used to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: Overall, individuals who consumed >1 glass/day had 30% higher risk for clinical AL progression (RR = 1.30; 95% CI: 1.07 to 1.58) than non‐drinkers. Among males, risk of clinical AL progression for individuals drinking >1 glass/day was 34% higher than non‐drinkers (RR = 1.34; 95% CI: 1.09 to 1.64). Never‐smoker males drinking ≤1 glass/week had significantly lower risk for clinical AL progression than non‐drinkers (RR = 0.52; 95% CI: 0.30 to 0.89), whereas those drinking >1 glass/day had significantly higher risk (RR = 1.50; 95% CI: 1.08 to 1.99). Among females, no association between alcohol consumption and clinical AL progression was observed. Conclusions: Alcohol consumption increased the risk of clinical AL progression, and this effect was more pronounced in males. Low dosages (≤1.37 g of alcohol/day) of alcohol consumption may be beneficial to prevent periodontal disease progression in males. The impact of alcohol cessation initiatives on periodontal health should be evaluated.  相似文献   
105.
106.
Strongly decreased leucocyte counts and a reduced CD4/CD8 T cell ratio in the cerebrospinal fluid (CSF) of natalizumab (NZB)‐treated multiple sclerosis (MS) patients may have implications on central nervous (CNS) immune surveillance. With regard to NZB‐associated progressive multi‐focal leucoencephalopathy, we aimed at delineating a relationship between free NZB, cell‐bound NZB, adhesion molecule (AM) expression and the treatment‐associated shift in the CSF T cell ratio. Peripheral blood (PB) and CSF T cells from 15 NZB‐treated MS patients, and CSF T cells from 10 patients with non‐inflammatory neurological diseases and five newly diagnosed MS patients were studied. Intercellular adhesion molecule‐1 (ICAM‐1), leucocyte function antigen‐1 (LFA‐1), very late activation antigen‐4 (VLA‐4), NZB saturation levels, and T cell ratios were analysed by flow cytometry. NZB concentrations were measured by enzyme‐linked immunosorbent assay (ELISA). Lower NZB saturation levels (P < 0·02) and a higher surface expression of ICAM‐1 and LFA‐1 (P < 0·001) were observed on CSF CD8 T cells. CSF T cell ratios (0·3–2·1) and NZB concentrations (0·01–0·42 µg/ml) showed a pronounced interindividual variance. A correlation between free NZB, cell‐bound NZB or AM expression levels and the CSF T cell ratio was not found. Extremely low NZB concentrations and a normalized CSF T cell ratio were observed in one case. The differential NZB saturation and AM expression of CSF CD8 T cells may contribute to their relative enrichment in the CSF. The reduced CSF T cell ratio appeared sensitive to steady‐state NZB levels, as normalization occurred quickly. The latter may be important concerning a fast reconstitution of CNS immune surveillance.  相似文献   
107.

Background

The risk factors that characterize metabolic syndrome (MetS) may be present in childhood and adolescence, increasing the risk of cardiovascular disease in adulthood.

Objective

Evaluate the prevalence of MetS and the importance of its associated variables, including insulin resistance (IR), in children and adolescents in the city of Guabiruba-SC, Brazil.

Methods

Cross-sectional study with 1011 students (6-14 years, 52.4% girls, 58.5% children). Blood samples were collected for measurement of biochemical parameters by routine laboratory methods. IR was estimated by the HOMA-IR index, and weight, height, waist circumference and blood pressure were determined. Multivariate logistic regression models were used to examine the associations between risk variables and MetS.

Results

The prevalence of MetS, IR, overweight and obesity in the cohort were 14%, 8.5%, 21% and 13%, respectively. Among students with MetS, 27% had IR, 33% were overweight, 45.5% were obese and 22% were eutrophic. IR was more common in overweight (48%) and obese (41%) students when compared with eutrophic individuals (11%; p = 0.034). The variables with greatest influence on the development of MetS were obesity (OR = 32.7), overweight (OR = 6.1), IR (OR = 4.4; p ≤ 0.0001 for all) and age (OR = 1.15; p = 0.014).

Conclusion

There was a high prevalence of MetS in children and adolescents evaluated in this study. Students who were obese, overweight or insulin resistant had higher chances of developing the syndrome.  相似文献   
108.
109.
110.
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