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   64717篇
  免费   4578篇
  国内免费   155篇
耳鼻咽喉   829篇
儿科学   1756篇
妇产科学   1619篇
基础医学   10655篇
口腔科学   1693篇
临床医学   6094篇
内科学   12966篇
皮肤病学   986篇
神经病学   6069篇
特种医学   2665篇
外国民族医学   45篇
外科学   8309篇
综合类   536篇
一般理论   85篇
预防医学   5051篇
眼科学   1217篇
药学   4698篇
中国医学   164篇
肿瘤学   4013篇
  2022年   502篇
  2021年   1088篇
  2020年   667篇
  2019年   966篇
  2018年   1152篇
  2017年   801篇
  2016年   948篇
  2015年   1130篇
  2014年   1406篇
  2013年   2383篇
  2012年   3114篇
  2011年   3186篇
  2010年   2279篇
  2009年   1900篇
  2008年   2867篇
  2007年   2994篇
  2006年   2959篇
  2005年   2824篇
  2004年   2866篇
  2003年   2608篇
  2002年   2676篇
  2001年   2166篇
  2000年   2216篇
  1999年   1986篇
  1998年   882篇
  1997年   732篇
  1996年   645篇
  1995年   668篇
  1994年   554篇
  1993年   606篇
  1992年   1452篇
  1991年   1400篇
  1990年   1341篇
  1989年   1321篇
  1988年   1104篇
  1987年   1104篇
  1986年   1045篇
  1985年   959篇
  1984年   694篇
  1983年   650篇
  1982年   458篇
  1981年   442篇
  1980年   378篇
  1979年   624篇
  1978年   374篇
  1977年   357篇
  1975年   373篇
  1974年   414篇
  1973年   347篇
  1972年   340篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
A 53-year-old male with hepatitis C cirrhosis, who had been refused liver transplantation because of hypertrophic cardiomyopathy (HC), underwent nonsurgical septal ablation using alcohol with resolution of his ventricular outflow obstruction. This patient was able to subsequently undergo a successful deceased donor liver transplantation. This is the first reported case of alcohol induced septal ablation being performed in a cirrhotic patient with HC. Such nonsurgical procedures may be attractive in cirrhotic patients who are refused access to liver transplantation because of high surgical risk.  相似文献   
53.
Purpose. In the National Heart, Lung, and Blood Institute Guidelines for the Diagnosis and Management of Asthma, the expert panel recommends that a written asthma action plan be provided for all patients with asthma. Studies evaluating the usefulness of the asthma action plan in children are limited. We aim to determine exacerbation frequency and usefulness of the asthma action plan in managing exacerbations that occur in a pediatric primary care setting. Methods. Caretakers of asthmatic children attending the general pediatric clinic in an inner-city hospital completed a one-page questionnaire covering topics such as asthma severity, frequency of exacerbations, and possession/usefulness of an asthma action plan. Although controversy exists over the definition of yellow and red zone exacerbations, we defined the yellow zone as symptoms that require albuterol more than three times a day or more than two nights in succession. The red zone was defined as symptoms requiring systemic corticosteroids and/or an urgent physician visit. Results. Seventy of 75 subjects completed the survey. Almost 80% of respondents carried the diagnosis of persistent asthma, whereas the remainder had intermittent asthma. Exacerbation frequency over a 3-month period was determined. Approximately 80% of children experienced at least one yellow zone episode: 42% had one or two yellow zone episodes, and 39.6% had between three and five episodes. Sixty-three percent of patients did not experience a single red zone exacerbation. Almost 75% (44 of 59) of subjects possessed an asthma action plan. Ninety percent (37 of 41) of respondents with action plans found the plan to be useful in managing exacerbations. Conclusion. Approximately four of every five asthmatic children seen in this primary care setting experienced a yellow zone exacerbation at least once during a 3-month period. One third experienced at least one red zone episode. Nine of every 10 caretakers with an action plan reported the asthma action plan to be of value in managing exacerbations.  相似文献   
54.
Exhaled breath condensate (EBC) provides a noninvasive means of sampling the lower respiratory tract. Collection of EBC might be useful in the assessment of airway oxidative stress in smokers. The aim of this study was to determine 8-isoprostane and hydrogen peroxide levels in EBC, and, in addition, to investigate the reproducibility of these measurements. EBC samples were collected from 12 healthy male smokers at three time points within 1 week. 8-isoprostane and H2O2 were measured in nonconcentrated EBC using immunochemical and colorimetric assays, respectively. 8-isoprostane and H2O2 were detected in only 36 and 47% of all EBC samples, respectively. It was not possible to calculate the within-subject variation in a reliable manner since only three of the 12 smokers exhibited detectable 8-isoprostane concentrations on all three occasions (mean 4.6 pg x mL(-1); range 3.9-7.7 pg x mL(-1)), whereas H2O2 could not be detected on all three occasions in any of the smokers. Spiking experiments revealed a recovery of 83.5-109.5% for 8-isoprostane and 69.9-129.0%, for H2O2 in fresh EBC samples. It was concluded that levels of 8-isoprostane and hydrogen peroxide cannot be reproducibly assessed in exhaled breath condensate from healthy smokers because of their low concentration and/or the lack of sensitivity of the available assays.  相似文献   
55.
56.
The aim was to investigate to what extent low Apgar scores are linked to the partogram's result and, more specifically, if the action line should be set 3 rather than 4 h parallel and right to the alert line. Some 24.0% of all labours evolved left to the alert line and 26.3% of the labours right to the alert line crossed the 4-h action line. An Apgar score of 相似文献   
57.
58.
Objective: Referred obese adolescents often display psychological problems. The present study aimed at investigating whether Young's schema theory constitutes a comprehensive framework to understand psychopathology in youth in general and in referred obese adolescents in particular. Methods: 91 youngsters referred for obesity treatment and 91 normal weight controls (all between 12 and 18 years of age) filled out the Young Schema Questionnaire and the Youth Self‐Report. Parents were asked to complete the Child Behavior Checklist. Results: The obese youngsters displayed an overall greater severity of dysfunctional schemas than normal weight controls. The obese group scored significantly higher for the schemas Emotional Deprivation, Social Isolation/Alienation, Defectiveness/Shame, Failure to Achieve, Dependence/Incompetence and Subjugation. Social Isolation/Alienation and Vulnerability to Harm/Illness were highly predictive for internalizing symptoms in youth. The schemas Entitlement and Dependence/Incompetence were predictive for externalizing symptoms in youth. Conclusion: Referred obese individuals display high levels of maladaptive schemas and these are generally related to internalizing and externalizing symptoms. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
59.
60.
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