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   886篇
  免费   65篇
  国内免费   21篇
耳鼻咽喉   4篇
儿科学   39篇
妇产科学   10篇
基础医学   137篇
口腔科学   24篇
临床医学   87篇
内科学   197篇
皮肤病学   8篇
神经病学   104篇
特种医学   60篇
外科学   84篇
综合类   21篇
预防医学   60篇
眼科学   14篇
药学   54篇
中国医学   9篇
肿瘤学   60篇
  2023年   11篇
  2022年   11篇
  2021年   18篇
  2020年   11篇
  2019年   18篇
  2018年   18篇
  2017年   15篇
  2016年   15篇
  2015年   28篇
  2014年   19篇
  2013年   27篇
  2012年   34篇
  2011年   50篇
  2010年   46篇
  2009年   40篇
  2008年   37篇
  2007年   48篇
  2006年   40篇
  2005年   41篇
  2004年   30篇
  2003年   29篇
  2002年   33篇
  2001年   16篇
  2000年   10篇
  1999年   11篇
  1998年   31篇
  1997年   28篇
  1996年   20篇
  1995年   20篇
  1994年   21篇
  1993年   13篇
  1992年   14篇
  1991年   10篇
  1990年   8篇
  1989年   11篇
  1988年   17篇
  1987年   7篇
  1986年   13篇
  1985年   10篇
  1984年   8篇
  1982年   14篇
  1981年   5篇
  1980年   4篇
  1979年   6篇
  1977年   4篇
  1976年   5篇
  1975年   5篇
  1974年   4篇
  1970年   5篇
  1968年   5篇
排序方式: 共有972条查询结果,搜索用时 15 毫秒
831.
Severe acute malnutrition (SAM) among children in Nigeria is tackled through the outpatient therapeutic programme (OTP) of the Community‐based Management of Acute Malnutrition (CMAM) programme. CMAM is evidently effective in resolving SAM, but little evidence exists on the remaining risk of SAM relapse for children discharged as cured from the OTP. We aimed to measure and compare the 6‐month incidence of SAM among OTP‐cured and community control children and identify factors associated with SAM relapse. We conducted a prospective matched cohort study that tracked 553 OTP‐cured and 526 control children in Sokoto State, Northern Nigeria. Outcomes and covariates were measured fortnightly in up to 12 home visits. We used multivariate Cox and accelerated failure time models to identify significant risk correlates, where the covariates to be tested for correlation with relapse were selected using domain knowledge and automatic feature selection methods. SAM incidence rates were 52 times higher in the OTP‐cured cohort (0.204/100 child‐days) than in the community control cohort (0.004/100 child‐days). Children with lower mid‐upper arm circumference at OTP admission, with lower height/length‐for‐age z‐scores, whose household head did not work over the full year, who lived in an area previously affected by environmental shocks, who were female and who had diarrhoea before the visit had a significantly higher relapse risk. Our study shows that OTP‐cured children remain at a significantly excess risk of SAM. To improve long‐term health outcomes of these children, programmes adopting a CMAM approach should strengthen follow‐up care and be integrated with other preventive services.  相似文献   
832.

Background  

Asthma is the most common chronic disease in childhood, characterized by chronic airway inflammation. There are problems with the diagnosis of asthma in young children since the majority of the children with recurrent asthma-like symptoms is symptom free at 6 years, and does not have asthma. With the conventional diagnostic tools it is not possible to differentiate between preschool children with transient symptoms and children with asthma. The analysis of biomarkers of airway inflammation in exhaled breath is a non-invasive and promising technique to diagnose asthma and monitor inflammation in young children. Moreover, relatively new lung function tests (airway resistance using the interrupter technique) have become available for young children. The primary objective of the ADEM study (Asthma DEtection and Monitoring study), is to develop a non-invasive instrument for an early asthma diagnosis in young children, using exhaled inflammatory markers and early lung function measurements. In addition, aetiological factors, including gene polymorphisms and gene expression profiles, in relation to the development of asthma are studied.  相似文献   
833.
Three new prenylated anthranoids, harunmadagascarins C (1) and D (2) and kenganthranol D (3), together with three known compounds (4-6) were isolated from the leaves of Harungana madagascariensis. Their structures were assigned by spectroscopic methods and by comparison with literature data. In the three new natural products 1-3, one or two prenyl groups are incorporated in furan, pyran, or cyclohexane rings in four different modes of annulation. Compounds 2, 4, and 6 were strongly active against the Gram-positive Bacillus megaterium.  相似文献   
834.
835.
836.
PURPOSE: To evaluate salivary gland function after inversely planned stereotactic intensity-modulated radiotherapy (IMRT) for tumors of the head-and-neck region using quantitative pertechnetate scintigraphy. METHODS AND MATERIALS: Since January 2000, 18 patients undergoing IMRT for cancer of the head and neck underwent pre- and posttherapeutic scintigraphy to examine salivary gland function. The mean dose to the primary planning target volume was 61.5 Gy (range 50.4-73.2), and the median follow-up was 23 months. In all cases, the parotid glands were directly adjacent to the planning target volume. The treatment planning goal was for at least one parotid gland to receive a mean dose of <26 Gy. Two quantitative parameters (change in maximal uptake and change in the relative excretion rate before and after IMRT) characterizing the change in salivary gland function after radiotherapy were determined. These parameters were compared with respect to the dose thresholds of 26 and 30 Gy for the mean dose. In addition, dose-response curves were calculated. RESULTS: Using IMRT, it was possible in 16 patients to reduce the dose for at least one parotid gland to < or =26 Gy. In 7 patients, protection of both parotid glands was possible. No recurrent disease adjacent to the protected parotid glands was observed. Using the Radiation Therapy Oncology Group/European Organization for the Research and Treatment of Cancer scoring system, only 3 patients had Grade 2 xerostomia. No greater toxicity was seen for the salivary glands. The change in the relative excretion rate was significantly greater, if the parotid glands received a mean dose of > or =26 Gy or > or =30 Gy. For the change in maximal uptake, a statistically significant difference was seen only for the parotid glands and a dose threshold of 30 Gy. For the end point of a reduction in the parotid excretion rate of >50% and 75%, the dose-response curves yielded a dose at 50% complication probability of 34.8 +/- 3.6 and 40.8 +/- 5.3 Gy, respectively. CONCLUSION: Using IMRT, it is possible to protect the parotid glands and reduce the incidence and severity of xerostomia in patients. Doses <26-30 Gy significantly preserve salivary gland function. The results support the hypothesis that application of IMRT does not lead to increased local failure rates.  相似文献   
837.
Introduction: Although the mental health of Japanese‐Brazilian children in Japan has become a matter of concern, few studies have employed a psychological approach and no research of these children's mental health has previously been performed at Brazilian schools in Japan. Methods: The present study used a sample of 241 children aged 4 to 10 years at five Brazilian schools in Japan. The Strength and Difficulties Questionnaire was applied for their guardians and teachers to detect the probable cases of mental disorders. Demographic data of the children were also collected from their guardians and a further analysis was made to determine the risk factors of the probable cases of conduct disorders. Results: The proportion of probable cases was 0.8% for emotional disorders, 9.1% for conduct disorders, 2.1% for hyperactivity disorders, and 10.0% for any psychiatric disorder. The detected risk factors of conduct disorders were male sex, 8 to 10 years of age, living without a father, and not talking often with their teacher. Discussion: The proportions of probable cases of mental disorders were not as high compared to general prevalence ranges or earlier studies. Considering the school and home situation of the children, living without a father seemed to be the foremost risk factor of conduct disorders.  相似文献   
838.
背景和目的颅内动脉粥样硬化可造成众多患者发生缺血性卒中。过去10年间血管内治疗技术已经取得突破性进展,能够开展颅内动脉粥样硬化性狭窄的血管内治疗。采用血管成形术和支架辅助阻管成形术治疗颅内动脉粥样硬化性狭窄的患者例数不断增加。但是鉴于目前血管成形术和支架辅助血管成形术治疗狭窄性和闭塞性颅内动脉粥样硬化仍缺乏普遍认可的临床和放射学评估以及皿管内治疗技术及预后的规范,此文就是提供该方面报告标准、术语和书面定义的共识性建议。报告摘要报告标准是在技术评价委员会、神经介入外科学会、介入放射学会、美国神经外科医师协会和神经外科医师代表大会的脑血管外科分会、美国神经科学会的卒中和介入神经病学分会的联合写作组共同起草完成。对1997年1月-2007年12月间,美国国立图书馆医学文献数据库(PubMed)进行计算机检索,旨在确定已发表的狭窄性颅内动脉粥样硬化的神经介入治疗中,能用作质量评价基准的资料。我们尽可能地确定影响神经介入治疗成功及并发症可能性的危险调节变量。对狭窄性和闭塞性颅内动脉粥样硬化进行麻管内治疗的临床试验设计中,不同临床和技术问题可能影响血管内治疗的疗效,此文章为这些问题提供相关的理论基础。该指南中包括对血管内治疗试验报告标准的建议。虽然制定规范和标准主要是出于研究用途,但是这也将有助于临床实践,还适用于所有相关的出版物。结论总之,报告标准提出的建议将有助于构建有效的研究数据库,同时促进产生科学可靠的研究结果,使相似研究之间或内部能够进行可靠的比较。存某些情况下,为报告和出版的一致性,本文中的定义可能是写作组专家的共识性建议。这些建议将促使不同研究组的结果具有直接可比性。  相似文献   
839.
本刊经Philip M.Meyers博士代表写作组授权,将“ Reporting standards for angioplasty and stent-assisted angioplasty for intracranial atherosclerosis”译为中文在本刊刊登。标准中对患者的选择、颅内动脉狭窄程度的判断、最佳内科治疗、围手术期处理、血管内治疗、术后并发症等,进行了规范化总结,拟为今后的临床试验和研究的规范化确定标准,以保证结果的可比性,对神经介入医师具有重要的指导意义。  相似文献   
840.
Grazio S 《Reumatizam》2010,57(2):39-49
Assessment of the impact of the rheumatic disease on the individual patient is necessary to evaluate the outcome of an intervention targeted at the disease process as well as at the restoration of the patient's functioning. The International Classification of Functioning, Disability and Health (ICF) is a comprehensive tool designed to record and organise a wide range of information about health and health related states, based on bio-psycho-social perspective. The ICF components, namely, body functions, body structures, and activities and participation are complemented by the contextual components, environmental factors and personal factors. All of them are in mutual interactions. The ICF contains lists of so-called ICF categories that describe the components of the integrative World Health Organisation model. It uses an alphanumerical model where categories are 'nested' so that broader categories are defined to include more detailed subcategories of the parent categories. Organized in such a way and with more than 1400 categories ICF covers virtually all the spectrum of problems encountered in patients with musculoskeletal conditions. The main practical tools of the ICF include ICF check lists, ICF core sets, ICF categorical profile and ICF assessment sheet. The ICF is likely to become the generally accepted conceptual framework and will be increasingly used in clinical practice to structure patient problems, particularly in multidisciplinary care and for rehabilitation purposes.  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