首页 | 官方网站   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   584篇
  免费   52篇
医药卫生   636篇
  2023年   4篇
  2022年   8篇
  2021年   21篇
  2020年   11篇
  2019年   17篇
  2018年   20篇
  2017年   29篇
  2016年   24篇
  2015年   11篇
  2014年   30篇
  2013年   35篇
  2012年   54篇
  2011年   53篇
  2010年   38篇
  2009年   22篇
  2008年   40篇
  2007年   28篇
  2006年   31篇
  2005年   22篇
  2004年   25篇
  2003年   25篇
  2002年   15篇
  2001年   5篇
  2000年   3篇
  1999年   2篇
  1997年   2篇
  1995年   3篇
  1994年   3篇
  1992年   5篇
  1991年   3篇
  1986年   3篇
  1984年   2篇
  1983年   1篇
  1982年   3篇
  1980年   2篇
  1979年   1篇
  1976年   4篇
  1975年   2篇
  1974年   4篇
  1973年   1篇
  1972年   2篇
  1971年   1篇
  1970年   5篇
  1969年   2篇
  1968年   2篇
  1967年   2篇
  1966年   1篇
  1962年   1篇
  1943年   2篇
  1942年   1篇
排序方式: 共有636条查询结果,搜索用时 46 毫秒
1.
Nowadays, advanced extraction techniques and highly sensitive metabolic profiling methods are effectively employed to get new information on plant chemical constituents. Among them wild medicinal plants or their parts, with large and ancient use in folk medicine, are investigated for their potential functional use and cultivation. In this context, Inula viscosa leaves engaged our attention. A simple experimental design, based on Soxhlet extraction and chromatographic fractionation, allowed us to obtain the investigated polyphenol fraction (IvE). UHPLC-HRMS analyses revealed shikimoyl depsides of caffeic acid and unusual dihydrobenzofuran lignans as main secondary metabolites. These compounds, together with cinchonain-type phenols, and hydroxycinnamoyl flavonol glycosides, are reported for the first time in inula. Overall, forty-three secondary metabolites were identified. The extract exerted a remarkable antiradical activity towards DPPH? and ABTS+?. Furthermore, it was able to inhibit cell viability and mitochondrial redox activity of neuroblastoma, hepatoblastoma and colon carcinoma cells, whereas it did not affect cell density of HaCaT cells immortalized human keratinocytes. As detected by the oxidant-sensing probe 2′,7′-dichlorodihydrofluorescein diacetate, the inhibitory responses seemed to be related to IvE-induced increase of intracellular reactive oxygen species (ROS). The obtained results highlighted that inula leaves, nowadays even undervalued and unexplored, could be considered a renewable source of nutraceutical compounds.  相似文献   
2.
This article describes early stages in the acquisition of a first vocabulary by infants and young children. It distinguishes two major stages, the first of which operates by a stand‐alone word‐to‐world pairing procedure and the second of which, using the evidence so acquired, builds a domain‐specific syntax‐sensitive structure‐to‐world pairing procedure. As we show, the first stage of learning is slow, restricted in character, and to some extent errorful, whereas the second procedure is determinative, rapid, and essentially errorless. Our central claim here is that the early, referentially based learning procedure succeeds at all because it is reined in by attention‐focusing properties of word‐to‐world timing and related indicants of referential intent.  相似文献   
3.
Although the rising incidence of breast cancer has prompted a surge of intervention strategies aimed at increasing women's use of mammography screening, the majority of patient-directed interventions have not been driven by relevant theoretical work on persuasive health communication. The authors evaluated an intervention derived from prospect theory that was designed to increase women's adherence to recommendations for annual mammography screening. They sent 1 of 3 reminder letters (positive frame, negative frame, or standard hospital prompt) to 929 randomly selected women who were due for mammography screening and had been identified as having either a positive or negative family history of breast cancer. The primary hypothesis that women with a positive history would be more responsive to negatively framed messages, whereas women with a negative history would be more responsive to positively framed letters, was not confirmed. The lack of support for predictions derived from prospect theory raises important questions about the generalizability of laboratory research to natural settings.  相似文献   
4.
5.
6.
7.
The success of vaccination programs is contingent upon irrefutable scientific safety data combined with high rates of public acceptance and population coverage. Vaccine hesitancy, characterized by lack of confidence in vaccination and/or complacency about vaccination that may lead to delay or refusal of vaccination despite the availability of services, threatens to undermine the success of coronavirus disease 2019 (COVID-19) vaccination programs. The rapid pace of vaccine development, misinformation in popular and social media, the polarized sociopolitical environment, and the inherent complexities of large-scale vaccination efforts may undermine vaccination confidence and increase complacency about COVID-19 vaccination. Although the experience of recent lethal surges of COVID-19 infections has underscored the value of COVID-19 vaccines, ensuring population uptake of COVID-19 vaccination will require application of multilevel, evidence-based strategies to influence behavior change and address vaccine hesitancy. Recent survey research evaluating public attitudes in the United States toward the COVID-19 vaccine reveals substantial vaccine hesitancy. Building upon efforts at the policy and community level to ensure population access to COVID-19 vaccination, a strong health care system response is critical to address vaccine hesitancy. Drawing on the evidence base in social, behavioral, communication, and implementation science, we review, summarize, and encourage use of interpersonal, individual-level, and organizational interventions within clinical organizations to address this critical gap and improve population adoption of COVID-19 vaccination.  相似文献   
8.
9.
10.

Therapist-report measures of evidence-based interventions have enormous potential utility as quality indicators in routine care; yet, few such tools have shown strong psychometric properties. This study describes reliability and validity characteristics of a therapist-report measure of family therapy techniques for treating adolescent conduct and substance use problems: Inventory of Therapy Techniques for Core Elements of Family Therapy (ITT-CEFT). Study participants included 31 staff therapists treating 68 adolescent clients in eight community-based mental health and substance use clinics. Therapists submitted ITT-CEFT checklists and companion audio recordings for 189 sessions. The ITT-CEFT contains 13 techniques identified as core elements of three manualized family therapy models that are empirically supported for the target group. Therapists also reported on their use of three motivational interventions, and independent observers coded the submitted recordings. ITT-CEFT factor validity was shown via confirmatory factor analyses of the tool’s theoretical structure. Derived modules were: Family Engagement (four items; Cronbach’s α?=?.72); Relational Orientation (five items; α?=?.74); and Interactional Change (four items; α?=?.66). Concurrent validity analyses showed fair-to-excellent therapist reliability compared to observer ratings (ICCs range .64–.75); they showed moderate therapist accuracy compared to observer mean scores, reflecting a tendency to overestimate delivery of the techniques. Discriminant validity analyses showed tool differentiation from motivational interventions. Results offer provisional evidence for the feasibility of using the therapist-report ITT-CEFT to anchor quality procedures for family therapy interventions in real-world settings.

Trial Registration: The parent clinical trial is registered at www.ClinicalTrials.gov, ID: NCT03342872 (registration date: 11.10.17).

  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-23

京公网安备 11010802026262号