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As advances in microfluidics continue to make contributions to diagnostics and life sciences, broader awareness of this expanding field becomes necessary. By leveraging low-cost microfabrication techniques that require no capital equipment or infrastructure, simple, accessible, and effective educational modules can be made available for a broad range of educational needs from middle school demonstrations to college laboratory classes. These modules demonstrate key microfluidic concepts such as diffusion and separation as well as "laboratory on-chip" applications including chemical reactions and biological assays. These modules are intended to provide an interdisciplinary hands-on experience, including chip design, fabrication of functional devices, and experiments at the microscale. Consequently, students will be able to conceptualize physics at small scales, gain experience in computer-aided design and microfabrication, and perform experiments-all in the context of addressing real-world challenges by making their own lab-on-chip devices.  相似文献   
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We present a microfluidic approach to characterizing temperature-dependent biomolecular interactions. Solvated L-arginine vasopressin (AVP) and its immobilized RNA aptamer (spiegelmer) were allowed to achieve equilibrium binding in a microchip at a series of selected temperatures. Unbound AVP were collected and analyzed with matrix-assisted laser desorption∕ionization mass spectrometry (MALDI-MS), yielding melting curves that reveal highly temperature-dependent zones in which affinity binding (36–45 °C) or dissociation (25–33 °C and 50–65 °C) occurs. Additionally, temperature-dependent binding isotherms were constructed; from these, thermodynamic quantities involved in binding were extracted. The results illustrated a strong change in heat capacity of interaction for this system, suggesting a considerable thermodynamic influence controlling vasopressin-spiegelmer interaction.  相似文献   
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Education and Information Technologies - Peer assessment has an important role in teaching and learning nowadays. However, the existing techniques tend to be limited due to a lack of a suitable...  相似文献   
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Education and Information Technologies - Analysing pre-service teachers’ learning design conversations in relation to Technological Pedagogical and Content Knowledge (TPACK) framework to...  相似文献   
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In this paper, we present an on-chip hand-powered membrane pump using a robust patient-to-chip syringe interface. This approach enables safe sample collection, sample containment, integrated sharps disposal, high sample volume capacity, and controlled downstream flow with no electrical power requirements. Sample is manually injected into the device via a syringe and needle. The membrane pump inflates upon injection and subsequently deflates, delivering fluid to downstream components in a controlled manner. The device is fabricated from poly(methyl methacrylate) (PMMA) and silicone, using CO2 laser micromachining, with a total material cost of ∼0.20 USD/device. We experimentally demonstrate pump performance for both deionized (DI) water and undiluted, anticoagulated mouse whole blood, and characterize the behavior with reference to a resistor-capacitor electrical circuit analogy. Downstream output of the membrane pump is regulated, and scaled, by connecting multiple pumps in parallel. In contrast to existing on-chip pumping mechanisms that typically have low volume capacity (∼5 μL) and sample volume throughput (∼1–10 μl/min), the membrane pump offers high volume capacity (up to 240 μl) and sample volume throughput (up to 125 μl/min).  相似文献   
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Around the world, 4.3 million students are engaged in international education each year. However, there is a paucity in theory and empirical research on teachers’ professionalism in international education. This paper aims to fill out this gap and contribute to our understanding of teachers’ changing roles and identity due to the impact of internationalisation and the growth of international students. Drawing on positioning theory as a conceptual framework to understand teachers’ roles and identity, this paper shows the emergence of teacher sub-identities as a reciprocal intercultural learner and an adaptive agent. It argues that these sub-identities are central to teachers’ development of cosmopolitan qualities in the contemporary context of international education.  相似文献   
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This paper examines data from a larger study that focused upon students’ experiences and motivations in a college algebra course. The study revealed that students failed this course because of various factors and continued to view this course as a “gatekeeper” class. Through a stepwise multiple regression, the analysis of the ARCS instrument showed that Attention, Relevance, and Confidence were strong predictors of Satisfaction in the course.  相似文献   
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In this paper, we consider the super-twisting observer-based sliding mode control algorithm with fuzzy variable gains (STOSMC) for the fully-actuated hexarotor. Our hexarotor has full actuation due to six titled propellers that allows to control position and orientation (attitude) simultaneously, and resolves the singularity problem of the rotational matrix by using the quaternion modeling framework. We show that the proposed STOSMC for the hexarotor guarantees finite-time convergence of the estimation error and asymptotic stability of the hexarotor. In simulations, we demonstrate the nonsingularity and fully-actuated control performance of the hexarotor by considering extreme position and attitude control scenarios. Moreover, the simulation results show that the hexarotor achieves the fast and precise tracking performance to the desired position and the desired attitude and the chattering phenomenon is reduced compared with the fixed-gains observer-based super-twisting sliding mode control due to the fuzzy mechanism.  相似文献   
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Vietnam is an important case for studying the impact of foreign firms’ backward linkages on local firms’ productivity. As an emerging economy Vietnam became the second most popular FDI destination after China in Pacific Asia since 2014. Our empirical analysis for Vietnam as a whole demonstrates a significant difference in the productivity growth between domestic suppliers who have a direct linkage with foreign firms and non-suppliers. This is also true for the Southeast Region (SE) with Ho-Chi-Minh City as economic center. However, in the Red River Delta (RRD), that difference is not statistically significant. Based on in-depth interviews with domestic suppliers, we reveal that in the RRD, effects of foreign firms on the productivity upgrading of domestic suppliers are indirect and limited while internal factors like absorptive capacity are more important for the productivity growth. These regional differences can be traced back to different regional specializations which still persist from the pre-reform era.  相似文献   
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