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  1. Abstract

    Tween 20 is frequently added to particle suspensions for reducing the particle–wall adhesion and particle–particle aggregation in microfluidic devices. However, the influences of Tween 20 on the fluid and particle behaviors have been largely ignored. We present in this work the first experimental study of the effects of Tween 20 addition on the electrokinetic transport of fluids and particles in a polydimethylsiloxane microchannel. We find that adding 0.1% v/v Tween 20 to a buffer solution can significantly reduce the electroosmotic mobility as well as the electrokinetic and electrophoretic mobilities of polystyrene particles and yeast cells. Further increasing the Tween 20 concentration within the range typically used in microfluidic applications continues reducing these mobility values, but at a smaller rate. Our finding suggests that Tween 20 should be used with care in electrokinetic microdevices when the flow rate or particle/cell throughput is an important parameter.

     
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    Free, publicly-accessible full text available March 21, 2025
  2. While uncertainty remains about what a smart city “is,” significant advances have been made in the technologies and applications that will underpin their roll out. In this paper, we argue that a smart city or region is not truly “smart” unless it places sustainability and quality of life at the center of the planning, governance, and innovation processes. The public sector lacks the resources to operate at this nexus alone, yet legitimacy challenges must be overcome to effectively draw on the capacities of non-state actors. By focusing on the Greater Phoenix Smart Region Consortium (The Connective), established in March 2019, we illustrate the role non-state actors play within the smart cities/regions space and highlight new types of partnerships to address climate change as part of their smart city vision. The regional and multi-stakeholder, participatory approach of The Connective offers lessons for advancing nexus governance in other jurisdictions. 
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  3. Abstract Over the past 5 years, advanced assisted reproductive technologies (ARTs), such as mitochondrial replacement therapies (MRTs) and heritable human genome editing (HHGE), have raised global policy concerns and fears of ‘unregulated’ proliferation. Yet, few innovations are ever truly unregulated and more often fall within the scope of one or more pre-existing regulatory regimes, a process referred to as ‘inherited regulation’. While the United Kingdom has enacted new legislation to specifically authorize and closely regulate MRTs, many jurisdictions will likely default to current oversight systems to manage advanced ARTs. This article evaluates and compares how several jurisdictions have already used four types of inherited regulatory regimes to manage MRTs and HHGE. Cases are drawn from jurisdictions where inherited regulatory interventions on advanced ARTs have taken place (USA, Greece, Ukraine, China, and Russia) and include jurisdictions closely connected with those cases (Mexico and Spain). When accounting for political, cultural, and religious contexts, many of these inherited regimes offer promise as starting points for governance of advanced ARTs, yet each will require further adjustments and tailoring to adequately manage the benefits and risks of these powerful innovations. 
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  5. Abstract

    Biology and biochemistry students must learn to visualize and comprehend the complex three‐dimensional (3D) structures of macromolecules such as proteins or DNA. However, most tools available for teaching biomolecular structures typically operate in two dimensions. Here, we present protocols and pedagogical approaches for using immersive augmented reality (AR) visors, specifically the Microsoft HoloLens, to reinforce learning with large scale 3D holographic structures. We developed a novel workflow to render vividly colored custom biomolecules in AR visors. In addition, we developed AR exercises to review concepts relevant to protein or DNA structure and then implemented the exercises in four different biology and biochemistry courses. Surveys showed that students reported greater interest in biomolecular structures after the exercise. We also highlight some of the advantages and disadvantages of the software and hardware of this upcoming technology.

     
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