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   157篇
  免费   4篇
教育   51篇
科学研究   44篇
各国文化   1篇
体育   25篇
文化理论   19篇
信息传播   21篇
  2023年   1篇
  2022年   3篇
  2021年   6篇
  2020年   4篇
  2019年   15篇
  2018年   9篇
  2017年   12篇
  2016年   11篇
  2015年   7篇
  2014年   7篇
  2013年   21篇
  2012年   9篇
  2011年   12篇
  2010年   4篇
  2009年   6篇
  2008年   6篇
  2007年   2篇
  2006年   2篇
  2004年   1篇
  2003年   3篇
  2002年   2篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1996年   1篇
  1994年   2篇
  1991年   2篇
  1990年   1篇
  1988年   1篇
  1986年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1971年   1篇
排序方式: 共有161条查询结果,搜索用时 31 毫秒
151.
152.
At the obstetrical clinic of Modena University and a family center of the same municipality during the first six months of 1980 a questionnaire based on "Risks of Child Abuse" by Kempe, Gray and others was administered to 33 expectant mothers during the third trimester of pregnancy, a few days after delivery, and a month and one-half after childbirth, for the purpose of examining the mother-child relationship. Two principal groups of "risk factors" which may lead to child abuse and neglect appeared: mothers with preceding personal and social experiences, and cases of medical intervention (e.g., prematurity, caesarean). Use of a questionnaire that permitted early diagnosis made possible help in establishing a good mother-child relationship in the first months of life. Such help can be given by the hospital and public centers both before and after birth.  相似文献   
153.
This study adopts a public value perspective to examine the eHealth services deployed by national and regional governments to contain the coronavirus (Covid-19) pandemic, including symptoms checkers, information portals and contact-tracing applications. We analyse 50 cases of eHealth applications adopted in 25 European Economic Area (EEA) and outline how these systems and technologies map against four dimensions of public value: user orientation, participation, legality and equity. Our findings reveal that the public value of the eHealth applications adopted in the context of the current pandemic is affected by both endogenous and exogenous factors that undermine their ability to improve the quality of healthcare services and social wellbeing. We conclude by suggesting areas for further research to address such factors and the trade-offs emerging between different dimensions of public value.  相似文献   
154.
IntroductionThe measurement of serum free light chain (FLC) represents a fundamental aspect on the assessment of patients with monoclonal gammopathies (MG). Different analytical methods for FLC have become available with the possibility to obtain different value with a substantial impact on the assessment of patients with MG. This study aimed to evaluate FLC results obtained with two different assays and how the difference value obtained can impact in the patient’s assessment.Materials and methodsNinety-three patient serum samples that underwent analysis for FLC with two different methods, Serum Freelite (The Binding Site, Birmingham, UK) and N-Latex FLC (Siemens, Marburg, Germany), were included in this retrospective study. Statistical analysis was performed to evaluate correlation, difference, and the grade of concordance between the results obtained with the two methods.ResultsSignificant statistical differences between the results obtained from the two methods were found (P < 0.05). A good correlation was found (0.99 for κ FLC, 0.95 for λ FLC, and 0.94 for the κ/λ ratio, respectively). We found a weighted kappa value of 0.65 for κ/λ ratio, 0.65 for λ FLC and 0.90 for κ FLC. A positive bias found with the Bland-Altman plot mirrors overestimation of κ FLC and κ/λ ratio with Freelite compared to N-Latex, whilst a negative bias underscores underestimation of λ FLC by Freelite compared to N-Latex.ConclusionAlthough in general the concordance between Freelite and N-Latex appears satisfactory, several discrepancies could be evidenced and consequently the two assays are not interchangeable.  相似文献   
155.
Background: Academic, medical and research libraries frequently implement Web 2.0 services for users. Several reports notwithstanding, characteristics and effectiveness of services are unclear. Objectives: To find out: the Web 2.0 services implemented by medical, academic and research libraries; study designs, measures and types of data used in included articles to evaluate effectiveness; whether the identified body of literature is amenable to a systematic review of results. Methods: Scoping review mapping the literature on the topic. Searches were performed in 19 databases. Inclusion criteria: research articles in English, Italian, German, French and Spanish (publication date ≥2006) about Web 2.0 services for final users implemented by academic, medical and research libraries. Reviewers’ agreement was measured by Cohen’s kappa. From a data set of 6461 articles, 255 (4%) were coded and analysed. Results: Conferencing/chat/instant messaging, blogging, podcasts, social networking, wikis and aggregators were frequently examined. Services were mainly targeted at general academic users of English‐speaking countries. Conclusions: Data prohibit a reliable estimate of the relative frequency of implemented Web 2.0 services. Case studies were the prevalent design. Most articles evaluated different outcomes using diverse assessment methodologies. A systematic review is recommended to assess the effectiveness of such services.  相似文献   
156.
This work presents the development of an array of bioreactors where finely controlled stirring is provided at the microliter scale (100–300 μl). The microliter-bioreactor array is useful for performing protocol optimization in up to 96 parallel experiments of hematopoietic stem cell (HSC) cultures. Exploring a wide range of experimental conditions at the microliter scale minimizes cost and labor. Once the cell culture protocol is optimized, it can be applied to large-scale bioreactors for stem cell production at the clinical level. The controlled stirring inside the wells of a standard 96-well plate is provided by buoyancy-driven thermoconvection. The temperature and velocity fields within the culture volume are determined with numerical simulations. The numerical results are verified with experimental velocity measurements using microparticle image velocimetry (μPIV) and are used to define feasible experimental conditions for stem cell cultures. To test the bioreactor array’s functionality, human umbilical cord blood-derived CD34+ cells were cultured for 7 days at five different stirring conditions (0.24–0.58 μm∕s) in six repeated experiments. Cells were characterized in terms of proliferation, and flow cytometry measurements of viability and CD34 expression. The microliter-bioreactor array demonstrates its ability to support HSC cultures under stirred conditions without adversely affecting the cell behavior. Because of the highly controlled operative conditions, it can be used to explore culture conditions where the mass transport of endogenous and exogenous growth factors is selectively enhanced, and cell suspension provided. While the bioreactor array was developed for culturing HSCs, its application can be extended to other cell types.  相似文献   
157.
More than 20 years ago, electrical impedance spectroscopy (EIS) was proposed as a potential characterization method for flow cytometry. As the setup is comparably simple and the method is label-free, EIS has attracted considerable interest from the research community as a potential alternative to standard optical methods, such as fluorescence-activated cell sorting (FACS). However, until today, FACS remains by and large the laboratory standard with highly developed capabilities and broad use in research and clinical settings. Nevertheless, can EIS still provide a complement or alternative to FACS in specific applications? In this Perspective, we will give an overview of the current state of the art of EIS in terms of technologies and capabilities. We will then describe recent advances in EIS-based flow cytometry, compare the performance to that of FACS methods, and discuss potential prospects of EIS in flow cytometry.  相似文献   
158.
The growing interest in the conservation of historic buildings encourages the development of water-repellent materials and methodologies to consolidate and/or protect stones. Recently, particular attention was devoted to composites of inorganic oxides nanoparticles and hybrid siloxane or silicone polymers. Here we present a study on the water repellence of a thin protective coating obtained through sol-gel process starting from Glymo and Dynasylan 40®, and loading the silicate matrix with nano-sized silica particles (Aeroxide LE1® -Degussa-Evonik). The coatings were applied to limestone, sandstone and granite samples. The silica nanoparticles have been characterized by XRD, the siloxane matrix through micro-Raman spectroscopy, while the surface morphology was examined by SEM. The efficacy of the treatments has been evaluated through static contact angle measurements and capillary water absorption. The optical appearance of the coatings was evaluated by colorimetric measurements. Nanoparticles at suitable concentration gave high values for the static contact angle (up to ∼ 150°), for all stone species even for four months exposure to atmospheric conditions. The coatings, in the water capillary absorption tests, however, behave as expected only for granite even if the long-term water direct contact reduces the hydrophobicity.  相似文献   
159.
Education and Information Technologies - We aimed to model the direct effects of the theorized relationships of academic self-efficacy, computer use self-efficacy, learning management system...  相似文献   
160.
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