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Yu-Fang Hsiao Huei-Jyuan Pan Yi-Chung Tung Chien-Chang Chen Chau-Hwang Lee 《Biomicrofluidics》2015,9(2)
We employed a microfluidic device to study the effects of hydraulic pressure on cardiomyoblast H9c2. The 170 mm Hg pressure increased the cellular area and the expression of atrial natriuretic peptide. With the same device, we demonstrated that the effects of hydraulic pressure on the cardiomyoblast could be reduced by the inhibitor of focal adhesion kinase. This mechanical–chemical antagonism could lead to a potential therapeutic strategy of hypertension-induced cardiac hypertrophy. 相似文献
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This paper reports a two-layered polydimethylsiloxane microfluidic device—Flip channel, capable of forming uniform-sized embryoid bodies (EBs) and performing stem cell differentiation within the same device after flipping the microfluidic channel. The size of EBs can be well controlled by designing the device geometries, and EBs with multiple sizes can be formed within a single device to study EB size-dependent stem cell differentiation. During operation of the device, cells are positioned in the designed positions. As a result, observation and monitoring specific population of cells can be achieved for further analysis. In addition, after flipping the microfluidic channel, stem cell differentiation from the EBs can be performed on an unconfined flat surface that is desired for various differentiation processes. In the experiments, murine embryonic stem cells (ES-D3) are cultured and formed EBs inside the developed device. The size of EBs is well controlled inside the device, and the neural differentiation is performed on the formed EBs after flipping the channel. The EB size-dependent stem cell differentiation is studied using the device to demonstrate its functions. The device provides a useful tool to study stem cell differentiation without complicated device fabrication and tedious cell handling under better-controlled microenvironments. 相似文献
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Formative assessment (FA) has been a popular discourse in education, but its potential benefit is fundamentally dependent on teachers’ willingness to make changes to their classroom practices. These changes bring about much assessment tension (AT). This paper argues that how well teachers experience and manage AT determines the efficacy of their FA practices. Past studies have warned that AT experienced by teachers is complex and problematic. Therefore, it would be useful to investigate the variation of AT experienced by teachers, and how well they are dealing with these tensions. This phenomenographic research examines the use of FA in the context of different ways that AT is experienced. Findings on teachers’ conceptions of AT are presented, and each is then discussed for insights into teachers’ meanings and practices of assessment. In particular, instances of how AT hindered or helped FA are identified to highlight more productive ways of understanding and using assessment to support students’ learning. Implications of the research findings for the Singapore Teaching Practice (STP) will be discussed.
相似文献4.
Cheng-Chun Chang Tien-Ying Kuo Yi-Chung Lo Heung-No Lee David Askey Zhi-Hong Mao 《Journal of The Franklin Institute》2012,349(3):879-890
In recent years, more and more point-to-point communication systems involve simultaneous transmission of multiple sources of human perceptual data over a single communication medium. For example, in a teleoperation system or a telerobotic system, streams of video, audio, and haptic data need to be sent from a field place to a remote human operator. Each type of data demands a certain range of transmission rate. This creates conflicts among these data when the available bandwidth is limited.In this paper we study the bandwidth allocation for multiple sources of human perceptual data transmitted over a rate-limited communication channel. We aim to maximize the overall user satisfaction in the data transmission, and formulate an optimization problem for the bandwidth allocation. Using either the logarithmic or exponential form of human perceptual satisfaction function, we are able to derive closed-form solutions for the optimization problem. We show that the optimal bandwidth allocation for each type of data is piecewise linear with respect to the total available bandwidth. 相似文献
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ABSTRACT This paper examines the social construction of ‘fashionability’ – namely, what is ‘desirable’ and ‘fashionable’ – with reference to the concept ‘cultural mediators’ that foregrounds agency, negotiation and the contested practices of market actors in cultural production. It zeroes in on the cultural mediators’ attitudes and positions in the two markets by drawing on 25 in-depth interviews with industry veterans. It shows that the mediators in South Korea and China increasingly occupy hybrid occupational roles and social positions across industries and sectors yet achieve limited success in countering the status quo of Western fashion through mediation. The analysis contributes to the literature with a categorisation of seven mediation practices that shape the valuation of fashion products (i.e. ‘fashionability’) in two ways. Empirically, this categorisation illuminates how cultural mediators make reference habitually to the broader social and cultural contexts to co-construct cultural-aesthetic objects. Theoretically, it advances a cultural-economic approach to the understanding of cultural mediation and challenges the reductionist viewpoint of actor–network theory through the notion of a matrix of cultural-economic agency. 相似文献
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An empirical investigation of students' behavioural intentions to use the online learning course websites 总被引：2，自引：0，他引：2
Su-Chao Chang Feng-Cheng Tung 《British journal of educational technology : journal of the Council for Educational Technology》2008,39(1):71-83
With the development of the Internet in the era of knowledge‐driven economy, e‐learning is experiencing rapid growth. The online learning course websites are drawing more attention as well. This research combines the innovation diffusion theory and the technology acceptance model, and adds two research variables, perceived system quality and computer self‐efficacy to propose a new hybrid technology acceptance model to study students' behavioural intentions to use the online learning course websites. This research finds that compatibility, perceived usefulness, perceived ease of use, perceived system quality and computer self‐efficacy were critical factors for students' behavioural intentions to use the online learning course websites. By explaining students' behavioural intentions from a user's perspective, the findings of this research help to develop more user‐friendly websites and also provide insight into the best way to promote new e‐learning tools for students. 相似文献
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In this paper, we develop a microfluidic device capable of generating nitric oxide (NO) gradients for cell culture using spatially controlled chemical reactions. NO plays an essential role in various biological activities, including nervous, immune, and cardiovascular systems. The device developed in this paper can control NO gradients without utilizing expensive and hazardous high purity NO gas sources or direct addition of NO donors. Consequently, the device provides an efficient, cost-effective, robust, and stable platform to generate NO gradients for cell culture studies. In the experiments, NO gradients are first characterized using a NO-sensitive fluorescence dye, and cell experiments using aortic smooth muscle cells are conducted. The results demonstrate that the device can alter the intracellular NO concentrations and further affect the Ca2+ concentration oscillation for the cells. The device developed in this paper provides a powerful platform for researchers better study the biological roles of NO and its spatial distribution using in vitro cell models with minimal instrumentation. 相似文献
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Creative literacy activities promote positive reading attitude in children learning English as a foreign language 
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下载免费PDF全文 Bonnie Wing‐Yin Chow Anna Na Na Hui Barbie Hiu‐Tung Chui 《Journal of Research in Reading》2018,41(2):278-289
This study investigated the effects of creative literacy classroom activities on the acquisition of English as a foreign language. Ninety Chinese second graders were tested on reading attitude and English receptive vocabulary knowledge. They were randomly assigned to either a control group or an experimental group, which engaged in English creative classroom activities for 10 weeks. Repeated measures analyses showed a significant interaction effect for reading attitude, providing empirical evidence that English creative classroom activities can enhance reading attitude. This study extends past research by demonstrating the links between creative activities and reading attitude, as well as highlights the feasibility of incorporating creative literacy activities within foreign language education. This provides a new direction for researchers and educators to develop instructional practices that incorporate a stimulating environment for English‐as‐a‐foreign‐language students. Future longitudinal research could examine whether these benefits can be maintained over a longer period. 相似文献