15 research outputs found

    Liquid marbles: principles and applications

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    The ability of particles to adhere to a fluid–fluid interface can stabilize the formation of an emulsion. When the encapsulated fluid is a liquid and the fluid in which it is immersed is air, the object formed is called a “Liquid Marble”. Here we discuss how liquid marbles can be created, their fundamental properties and their transport and potential uses. We show how they arise naturally as an insect waste disposal system, from impact of droplets on powders and on hydrophobic soil, and in the mixing of particulate containing liquids. Our principal aim is to review research on macroscopic single marbles and their potential uses in sensors and droplet microfluidics. However, we also illustrate the similarity between liquid marbles, Pickering emulsions and “Dry Water”, and the potential application of assemblies of liquid marbles within cosmetics and pharmaceutical formulations. Finally, we discuss how modifying the surface structure of particles and providing heterogeneous surface chemistry on particles (e.g. Janus particles) might provide new types of liquid marbles and applications

    Framboidal ABC triblock copolymer vesicles: a new class of efficient Pickering emulsifier

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    Pickering emulsions offer important advantages over conventional surfactant-stabilized emulsions, including enhanced long-term stability, more reproducible formulations and reduced foaming problems. The recent development of polymerization-induced self-assembly (PISA) offers considerable scope for the design of a wide range of block copolymer nanoparticles with tunable surface wettability that may serve as bespoke Pickering emulsifiers. In the present study, we exploit PISA to design a series of model framboidal ABC triblock copolymer vesicles with exquisite control over surface roughness. Transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) were utilized to characterize these nanoparticles, which were subsequently used to stabilize n-dodecane emulsion droplets in water. The adsorption efficiency, Aeff, of the nanoparticles at the n-dodecane/water interface was determined as a function of increasing vesicle surface roughness using a turbidimetry assay. A strong correlation between surface roughness and Aeff was observed, with Aeff increasing from 36% up to 94%. This is a significant improvement in Pickering emulsifier efficiency compared to that reported previously for similar vesicles with smooth surfaces. In summary, nanoparticles with appreciable surface roughness are much more effective Pickering emulsifiers and this parameter can be readily fine-tuned using a highly efficient PISA formulation

    The heart healthy lenoir project-an intervention to reduce disparities in hypertension control: study protocol

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    Background Racial disparities in blood pressure control are well established; however the impact of low health literacy (LHL) on blood pressure has garnered less attention. Office based interventions that are created with iterative patient, practice and community stakeholder input and are rolled out incrementally, may help address these disparities in hypertension control. This paper describes our study protocol. Methods/design Using a community based participatory research (CBPR) approach, we designed and implemented a cohort study that includes both a practice level and patient level intervention to enhance the care and support of patients with hypertension in primary care practices in a rural region of eastern North Carolina. The study is divided into a formative phase and an ongoing 2.5 year implementation phase. Our main care enhancement activities include the integration of a community health coach, using home blood pressure monitoring in clinical decision making, standardizing care delivery processes, and working to improve medication adherence. Main outcomes include overall blood pressure change, the differential change in blood pressure by race (African American vs. White) and health literacy level (low vs. higher health literacy). Discussion Using a community based participatory approach in primary care practice settings has helped to engage patients and practice staff and providers in the research effort and in making practice changes to support hypertension care. Practices have engaged at varying levels, but progress has been made in implementing and iteratively improving upon the interventions to date

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges
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