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   1292篇
  免费   60篇
  国内免费   6篇
耳鼻咽喉   12篇
儿科学   6篇
妇产科学   36篇
基础医学   163篇
口腔科学   91篇
临床医学   95篇
内科学   173篇
皮肤病学   6篇
神经病学   189篇
特种医学   187篇
外科学   156篇
综合类   5篇
预防医学   67篇
眼科学   19篇
药学   77篇
中国医学   1篇
肿瘤学   75篇
  2023年   2篇
  2022年   15篇
  2021年   32篇
  2020年   23篇
  2019年   20篇
  2018年   34篇
  2017年   20篇
  2016年   30篇
  2015年   37篇
  2014年   46篇
  2013年   50篇
  2012年   91篇
  2011年   105篇
  2010年   53篇
  2009年   64篇
  2008年   88篇
  2007年   91篇
  2006年   85篇
  2005年   109篇
  2004年   75篇
  2003年   69篇
  2002年   80篇
  2001年   17篇
  2000年   12篇
  1999年   7篇
  1998年   12篇
  1997年   10篇
  1996年   4篇
  1995年   6篇
  1994年   7篇
  1993年   4篇
  1992年   3篇
  1991年   7篇
  1990年   3篇
  1985年   4篇
  1984年   2篇
  1983年   4篇
  1981年   2篇
  1980年   3篇
  1975年   3篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
  1970年   2篇
  1958年   2篇
  1955年   3篇
  1938年   2篇
  1936年   2篇
  1933年   1篇
  1929年   1篇
排序方式: 共有1358条查询结果,搜索用时 31 毫秒
41.
PURPOSE: To evaluate remineralization and fluoride uptake of demineralized enamel specimens in artificial interproximal spaces using a 250 ppm fluoride mouthrinse (100 ppm amine fluoride and 150 ppm sodium fluoride) compared to a placebo-mouthrinse. METHODS: This was a two-way, double-blind, in situ study. 24 volunteers wore intraoral appliances in the lower jaw with mounted demineralized enamel specimens forming an artificial interproximal space. The volunteers rinsed their mouths for 28 days, twice a day with the respective mouthrinse and brushed their teeth at least twice a day with a fluoride-free dentifrice. The specimens were cleaned once a day to simulate the use of dental floss. For analysis methods transversal microradiography, fluoride content measurement and quantitative light-induced fluorescence were used. RESULTS: Mineral gain was significantly higher after the use of the fluoride mouthrinse: 571.88 Vol.% x microm (+/- 79.33 Vol.% x microm SEM) compared to the placebo treatment 51.14 Vol.% x microm (+/- 72.14 Vol.% x microm SEM). Significantly more fluoride uptake was observed after using the fluoride mouthrinse: 3666.39 microg/cm3 (+/- 513.50 microg/cm3 SEM) than after the placebo mouthrinse: 516.95 microg/cm3 (+/- 75.83 microg/cm3 SEM). The quantitative light-induced fluorescence showed a significant remineralizing effect after the fluoride treatment: -388.47 % x mm2 (+/- 18.76% x mm2 SEM) compared to the placebo treatment -27.88% x mm2 (+/- 20.19% x mm2 SEM).  相似文献   
42.
BACKGROUND: The authors conducted an in vitro study to evaluate the effect of an at-home bleaching product on the microhardness of six restorative materials under different surface treatments. METHODS: Four resin-based composite materials (a hybrid, flowable, microhybrid and nanohybrid), an ormocer (organic modified ceramic) material and a ceramic material were bleached with 15 percent carbamide peroxide. The authors prepared two groups of samples (polished and unpolished) (n = 7) from each resin-based composite material and the ormocer. The authors polished all of the samples in the ceramic group. Two samples from each group served as negative controls. The authors measured the microhardness of the samples before bleaching, after eight hours and 56 hours of bleaching, and 24 hours and one month after the end of bleaching. RESULTS: The statistical analysis showed that the at-home bleaching technique did not have a statistically significant effect on the microhardness of any of the restorative materials tested (hybrid, P = .0679; flowable, P = .5088; microhybrid, P = .0601; nanohybrid, P = .6166; ormocer, P = .2154; ceramic, P = .9943). CONCLUSION: At-home bleaching with 15 percent carbamide peroxide did not cause any harmful changes to the microhardness of tooth-colored restorative materials. CLINICAL IMPLICATIONS: Clinicians do not need to replace resin-based composite, ormocer or ceramic restorations after at-home bleaching treatment when the restorations are in posterior teeth.  相似文献   
43.
Peripartum cardiomyopathy (PPCM) occurs toward the end of pregnancy or in the months after delivery without previously known structural heart disease. Development of therapy-refractory cardiogenic shock is described in the literature with a limited number of overall presented cases in this young patient cohort. To provide differences and key points in the therapy of end-stage PPCM patients, we present a case series of four young women with PPCM referred to our department for potential VA ECMO support.  相似文献   
44.
45.
Aim: Compliance with infection control practices is the key to quality care and excellence in dentistry. Infection control remains one of the most cost-beneficial interventions available. However, implementing control procedures requires full compliance of the whole dental team. The aim of our study was to measure the compliance in daily clinical practice.Methods: The compliance with infection control practices in dentistry by dental health care personnel (DHCP) in a German university dental clinic was observed during clinical work. In addition, a survey was conducted to assess the individual knowledge about infection control procedures. Contamination of the workplace during invasive dental procedures was tested, as well.Results: A total of 58 invasive dental treatments implying close contacts between HCWs and patients were scrutinized. All HCWs (100%) wore gloves during dental work, but in some cases (female dentists: 14.3%; dental assistants: 28.6%) gloves were neither changed nor hands were disinfected between different activities or patient contacts (female dentists: 68.6%; male dentists: 60.9%; dental assistants: 93%). Only 31.4% of female and 39.1% of male dentists carried out adequate hygienic hand disinfection after removing gloves. Male dentists wore significantly more often (100%) protective eyewear compared to 77.1% of female dentists (p<0.05). In addition, most of female dentists (62.9%) and dental assistants (80.7%) wore jewelry during dental procedures. Conclusion: Despite the knowledge of distinct hygiene procedures only a small percentage of dental staff performs hygiene practices according to recommended guidelines. Strict audit is clearly needed in the dental setting to ensure compliance with infection control guidelines to prevent transmission of pathogens. Our results provide insights for the development of a targeted education and training strategy to enhance compliance of dental staff especially of dental assistants with infection control procedures.  相似文献   
46.

Objectives

To determine whether depression and anxiety in adulthood are associated with abuse exposure in childhood.

Methods

A search of PUBMED, EMBASE and PSYCHINFO databases (2002–2012) was supplemented by hand searches of bibliographies of articles and reviews. We included studies contrasting abuse exposure vs. no-abuse exposure before age 16 years to depression and anxiety after age 16 years. Data on sample and exposure and outcome instruments, covariates and odds ratios (ORs) with the respective 95 % confidence intervals (CI) were extracted. Combined ORs and 95 % CI were calculated using random effects models. Heterogeneity was quantified using the I 2 test.

Results

Inclusion criteria were met by 19 studies with 115,579 study participants, for assessing depression (n = 14) and anxiety (n = 13). The combined ORs for depression were 2.04 (95 % CI: 1.65–2.53) for sexual abuse and 1.49 (95 % CI: 1.29–1.72) for physical abuse. The combined ORs for anxiety were 2.52 (95 % CI: 2.12–2.98) for sexual abuse and 1.70 (95 % CI: 1.33–2.18) for physical abuse.

Conclusions

High levels of depression, anxiety and distress are reported in adults exposed to childhood sexual and physical abuse. These findings require increased awareness for the potential needs of adults exposed to child abuse and public health interventions to prevent child abuse.  相似文献   
47.
48.

Purpose

Over the last years, adolescents and young adults with cancer (AYA) have moved strongly into scientific focus. However, there have only been a few studies about the quality of life of the AYA group, and gender differences have very rarely been examined.

Methods

A cross-sectional study was conducted with young adult cancer patients who were aged 18–39 years at the time of survey and had completed their acute treatment. We used the quality of life questionnaire European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30). The EORTC QLQ-C30 contains five function scales (physical, role, emotional, cognitive and social), nine symptom scales and a global quality of life scale. The patient sample was compared to a gender- and age-matched representative sample (REP).

Results

Compared to the general population (N = 585), significantly poorer quality of life (p = .001) was observed for the 117 young cancer patients (40 male, 77 female) on all scales and items of the EORTC QLQ-C30. Analyses of variance with the factors group (AYA vs. REP) and gender showed interaction effects for the physical (p < .012), emotional (p < .029) and cognitive function scales (p < .008) and fatigue (p < .026) as well as for the items insomnia (p < .011), constipation (p < .037) and financial difficulties (p < .026). The pattern of the interaction was that female cancer patients reported the lowest quality of life outcomes. The same effects were found for the three calculated sum scales function, symptom and total.

Conclusions

Results clearly indicate that young adult cancer patients have a reduced quality of life in comparison with the general population even long after the treatment of their disease is complete. Women had a lower quality of life than men. Age-specific interventions should be offered that lead to improvements in quality of life for this age group. And future studies should clarify what factors lead to women’s quality of life being worse than men’s.  相似文献   
49.

Purpose

The health state classifier EQ-5D of the EuroQoL group has been expanded to a 5-level instrument (EQ-5D-5L), but studies on psychometric properties of this new instrument, applied to the general population, are rare.

Methods

A sample of 2,469 subjects, representatively selected from the German general population, was asked to fill in the EQ-5D-5L and several other questionnaires. Crude sum scores of the EQ-5D-5L were calculated and compared with scores derived from two sets of utilities, one from a German and one from a UK sample.

Results

The mean sum score (0–100 scale) was 91.5. Males reported better health states than females, and there was a nearly linear age trend. The list of the 45 most frequent health patterns (those with at least 0.2 % of the respondents) showed that almost half of the participants (47.5 %) responded being in the optimal health state, indicating a ceiling effect. Correlations between EQ-5D-5L scores and other questionnaires were very similar for all three scoring systems of the EQ-5D-5L. Finally, normative scores are given on the basis of sum scores.

Conclusions

The applicability of the EQ-5D-5L in the general population is limited because of the skewness. Sum scores are useful because of their simplicity, international generalizability, and construct validity.  相似文献   
50.

Objectives

Interdental cleaning is an essential component of home plaque control to prevent periodontitis and caries. There is limited data on the efficacy of commonly used metal-core interdental brushes in comparison to metal-free interdental brushes. The aim of this study was to compare a new rubber interdental bristle (Fuchs®) with a standard metal-core interdental brush (TePe®) for their impact upon gingival bleeding, plaque removal, and patient experience.

Materials and methods

A single-blind, prospective, randomized, and controlled clinical trial with a crossover design was used to measure plaque index (Turesky-Modified Quigley & Hein Index), bleeding index (Eastman Interdental Bleeding Index by Caton & Polson), and patient satisfaction by means of questionnaires in 39 patients. Each patient was randomly assigned with regard to the sequence of interdental product used and recalled.

Results

Both groups showed statistically significant decreases of plaque after a single usage, respectively. Bleeding was statistically significantly reduced after 4 weeks, with no statistically significant differences concerning between the two tested interdental brushes. Rubber interdental bristles reached significantly higher scores with regard to patient acceptance in overall assessment and in sub-items for less pain during usage, comfort of brushing, and willingness to buy the product.

Conclusion

Rubber interdental bristles were similarly effective compared to the interdental brushes. In addition, rubber interdental bristles were significantly more comfortable for participants than metal-core brushes.

Clinical relevance

Rubber interdental bristles can be used as an alternative interdental cleaning product which may be more accepted by patients.  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