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   1160篇
  免费   60篇
  国内免费   16篇
耳鼻咽喉   1篇
儿科学   113篇
妇产科学   34篇
基础医学   212篇
口腔科学   37篇
临床医学   90篇
内科学   187篇
皮肤病学   67篇
神经病学   59篇
特种医学   112篇
外科学   115篇
综合类   16篇
预防医学   59篇
眼科学   20篇
药学   30篇
中国医学   1篇
肿瘤学   83篇
  2023年   8篇
  2022年   8篇
  2021年   22篇
  2020年   20篇
  2019年   21篇
  2018年   22篇
  2017年   13篇
  2016年   19篇
  2015年   25篇
  2014年   51篇
  2013年   46篇
  2012年   55篇
  2011年   51篇
  2010年   70篇
  2009年   58篇
  2008年   62篇
  2007年   58篇
  2006年   51篇
  2005年   39篇
  2004年   38篇
  2003年   26篇
  2002年   32篇
  2001年   23篇
  2000年   28篇
  1999年   19篇
  1998年   45篇
  1997年   26篇
  1996年   17篇
  1995年   16篇
  1994年   16篇
  1993年   13篇
  1992年   12篇
  1991年   8篇
  1990年   16篇
  1989年   19篇
  1988年   23篇
  1987年   20篇
  1986年   14篇
  1985年   14篇
  1984年   8篇
  1983年   6篇
  1982年   13篇
  1981年   10篇
  1980年   13篇
  1979年   5篇
  1978年   8篇
  1977年   6篇
  1976年   8篇
  1975年   7篇
  1970年   4篇
排序方式: 共有1236条查询结果,搜索用时 250 毫秒
81.
AIM—To measure drug adherence in children with mild asthma receiving long term prophylactic treatment.
METHODS—Double blind randomised placebo controlled trial. Patients received inhaled budesonide 100 µg or 200 µg daily, or placebo for 27 months. All participants were asked to inhale medication or placebo from two different Turbuhalers (morning and evening) during the study. A total of 122 children (80 boys, 42 girls) aged 7-16 years with mild asthma (mean FEV1 103.7% of predicted) were included in the trial. Drug adherence was assessed by counting the number of remaining doses in the inhaler when study medication was returned at six month intervals.
RESULTS—A statistically significant and continuing decrease in measured drug adherence was found from three to nine months and then to 27 months, reaching mean values of 40.6% and 46.9% for inhaled morning and evening medication respectively. Drug adherence declined more rapidly in the placebo group (compared to active treatment); this difference became significant after two years of treatment. Children aged 9 years or less had better drug adherence during the entire study period, but the difference was only significant for the first three months of the study. Measured drug adherence was significantly higher for evening medication compared to morning medication for all study intervals after nine months.
CONCLUSION—Measured drug adherence diminishes significantly when treating children with mild asthma in a long term trial. This emphasises the importance of monitoring compliance in clinical trials.

  相似文献   
82.
83.
84.
Background: Optomap uses the ultra‐wide field scanning laser ophthalmoscopy to provide retinal examination. It permits fundus examination without the use of a mydriatic, which is more comfortable for the patients. This paper determines the sensitivity and specificity of the Optomap for detecting retinal signs under non‐mydriatic conditions. Methods: Fifty‐four eyes identified with retinal/choroidal signs and eight normal eyes were recruited from 31 Hong Kong Chinese subjects. Photo‐documentation of fundal changes was obtained with the Optomap under non‐mydriatic conditions before a dilated fundus examination by a clinician using standard procedures. The eyelid was retracted using a cotton bud when necessary. Dilated fundus examinations were performed by another clinician using binocular indirect ophthalmoscopy and slitlamp biomicroscopy with a fundus lens. The Optomap images were evaluated by four other investigators under masked condition. The International Classification of Disease, Ninth Revision (ICD‐9‐CM) was adopted for recording retinal features. Screening results were compared with those obtained using the dilated fundus examination as the gold standard. Results: The cotton bud method for eyelid retraction showed an improvement in the area of retina that could be visualised. The sensitivity and specificity of the Optomap averaged 76.4 and 71.9 per cent, respectively. Some fundal signs were missed by all observers in the Optomap but not with the biomicroscope. These included white‐without‐pressure, lattice degeneration, paramacular drusen and pigmentary changes at central fundus. Conclusion: Optomap serves as a reliable screening tool for fundus examination especially because it covers a much wider area of the peripheral retina than other digital instruments for fundus photography.  相似文献   
85.

Background  

Epidemiologic studies are often confounded by the human and environmental interactions that are complex and dynamic spatio-temporal processes. Hence, it is difficult to discover nuances in the data and generate pertinent hypotheses. Dynamic mapping, a method to simultaneously visualize temporal and spatial information, was introduced to elucidate such complexities. A conceptual framework for dynamic mapping regarding principles and implementation methods was proposed.  相似文献   
86.

Objectives

Recent studies have explored the potential for swimming pool disinfection by-products (DBPs), which are respiratory irritants, to cause asthma in young children. Here we describe the state of the science on methods for understanding children’s exposure to DBPs and biologics at swimming pools and associations with new-onset childhood asthma and recommend a research agenda to improve our understanding of this issue.

Data sources

A workshop was held in Leuven, Belgium, 21–23 August 2007, to evaluate the literature and to develop a research agenda to better understand children’s exposures in the swimming pool environment and their potential associations with new-onset asthma. Participants, including clinicians, epidemiologists, exposure scientists, pool operations experts, and chemists, reviewed the literature, prepared background summaries, and held extensive discussions on the relevant published studies, knowledge of asthma characterization and exposures at swimming pools, and epidemiologic study designs.

Synthesis

Childhood swimming and new-onset childhood asthma have clear implications for public health. If attendance at indoor pools increases risk of childhood asthma, then concerns are warranted and action is necessary. If there is no such relationship, these concerns could unnecessarily deter children from indoor swimming and/or compromise water disinfection.

Conclusions

Current evidence of an association between childhood swimming and new-onset asthma is suggestive but not conclusive. Important data gaps need to be filled, particularly in exposure assessment and characterization of asthma in the very young. Participants recommended that additional evaluations using a multidisciplinary approach are needed to determine whether a clear association exists.  相似文献   
87.
88.
We investigate whether socioeconomic status, measured by income and education, affects waiting time when controls for severity and hospital‐specific conditions are included. We also examine which aspects of the hospital supply (attachment to local hospital, traveling time, or choice of hospital) matter most for unequal treatment of different socioeconomic groups. The study uses administrative data from all elective inpatient and outpatient stays in somatic hospitals in Norway. The main results are that we find very little indication of discrimination with regard to income and education when both severity and aspects of hospital supply are controlled for. This result holds for both men and women. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
89.
Microbial risk assessment of local handling and use of human faeces   总被引:1,自引:0,他引:1  
Dry urine-diverting toilets may be used in order to collect excreta for the utilisation of nutrients. A quantitative microbial risk assessment was conducted in order to evaluate the risks of transmission of infectious disease related to the local use of faeces as a fertiliser. The human exposures evaluated included accidental ingestion of small amounts of faeces, or a mixture of faeces and soil, while emptying the storage container and applying the material in the garden, during recreational stays to the garden, and during gardening. A range of pathogens representing various groups of microorganisms was considered. Results showed that 12-months' storage before use was sufficient for the inactivation of most pathogens to acceptable levels. When working or spending time in the garden the annual risk of infection by Ascaris was still slightly above 10(-4) in these scenarios, although the incidence rate for Ascaris is very low in the population in question. Measures to further reduce the hygienic risks include longer storage, or treatment, of the faeces. The results can easily be extended to other regions with different incidence rates.  相似文献   
90.

Background

The aim of this study was to investigate the ‘acaricidal effect’ of Zataria multiflora and Artemisia annua essential oils on Rhipicephalus (Boophilus) annulatus.

Methods

This study was carried out in 2009 in the Laboratory of Parasitology of the Faculty of Veterinary Medicine of Shahrekord University, west central Iran. Six dilutions (5, 10, 20, 40, 60 and 80 µL/cm3) of both essential oils were used against engorged female R. (Boophilus) annulatus ticks using an in vitro immersion method. The mortality rates for each treatment were recorded 6, 15 and 24 hours post inoculation (hpi). Mortality rate was analyzed using Repeated Measures Analysis of Variance, and comparison of means was carried out using General Linear Models Procedure.

Results

The mortality rate caused by different dilutions of Z. multiflora essential oil ranged from 26.6% (using 10 µL/cm3) to 100% (using 40 µL/cm3) and for A. annua essential oil it was 33.2 to 100% (using 20 and 80 µL/cm3, respectively) by the end of the experiment (36 hpi). No mortality was recorded for the non-treated control group or for dilutions less than 5 and 10 µL/cm3 using Zataria and Artemisia essential oils, respectively. For Z. multiflora mortality peaked at 15 hpi for all concentrations other than 20 µL/cm3 and took 24 h to achieve its maximum effect while for A. annua the two highest concentrations needed 24 hpi to reach their full effect. In addition, essential oils applied at more than 20 and 60 µL/cm3 caused 100% egg-laying failure in engorged female ticks by Zataria and Artemisia, respectively while no failure was observed for the non-treated control group. The mortality rate in both botanical acaricides was dose-dependent.

Conclusion

Both these medicinal plants have high potential acaricidal effects on the engorged stage of R. (Boophilus) annulatus in vitro.  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