18 research outputs found

    Global Emergency Medicine: A Review of the Literature From 2012

    Full text link
    Objectives The Global Emergency Medicine Literature Review ( GEMLR ) conducts an annual search of peer‐reviewed and grey literature relevant to global emergency medicine ( EM ) to identify, review, and disseminate the most important new research in this field to a worldwide audience of academics and clinical practitioners. Methods This year, our search identified 4,818 articles written in six languages. These articles were distributed among 20 reviewers for initial screening based on their relevance to the field of global EM . Two additional reviewers searched and screened the grey literature. A total of 224 articles were deemed appropriate by at least one reviewer and were approved by their editor for formal scoring of overall quality and importance. Results Of the 224 articles that met our predetermined inclusion criteria, 56% were categorized as Emergency Care in Resource‐limited Settings, 18% as EM development, and 26% as Disaster and Humanitarian Response. A total of 28 articles received scores of 16 or higher and were selected for formal summary and critique. Inter‐rater reliability for two reviewers using our scoring system was good, with an intraclass correlation coefficient of 0.625 (95% confidence interval = 0.512 to 0.711). Conclusions In 2012 there were more disaster and humanitarian response articles than in previous years. As in prior years, the majority of articles addressed the acute management of infectious diseases or the care of vulnerable populations such as children and pregnant women. Resumen Medicina de Urgencias y Emergencias Global: Una Revisión de la Literatura de 2012 Objetivos La revisión de la literatura publicada en Medicina de Urgencias y Emergencias ( MUE ) global comporta una búsqueda anual de los trabajos relevantes para la MUE global, tanto publicados tras revisión por pares como corresponedientes a literatura gris. La finalidad es identificar, revisar y diseminar las investigaciones novedosas más importantes en este campoa médicos clínicos y universitarios de todo el mundo. Metodología Este año, nuestra búsqueda identificó 4.818 artículos escritos en seis lenguas. Estos artículos se distribuyeron entre 20 revisores para el despistaje inicial basándose en su relevancia para el campo de la MUE global. Dos revisores adicionales buscaron y filtraron la literatura gris. Un total de 224 artículos se consideraron apropiados por al menos un revisor, y se aprobaron por su editor para la puntuación formal de la calidad e importancia totales. Resultados De los 224 artículos que cumplieron nuestros criterios de inclusión predeterminados, un 56% se clasificaron como atención de urgencias y emergencias en ámbitos de recursos limitados, un 18% como desarrollo de la MUE y un 26% como catástrofes y respuesta humanitaria. Un total de 28 artículos recibieron una puntuación de 16 o más y se seleccionaron para el resumen y la crítica formal. La fiabilidad interobservador para los 2 revisores usando nuestro sistema de puntuación fue buena, con un coeficiente de correlación intraclase de 0,625 ( IC 95% = 0,512 a 0,711). Conclusiones En 2012 hubo más artículos sobre catástrofes y respuesta humanitaria que en años anteriores. Como en los años previos, la mayoría de los artículos valoraron el manejo agudo de enfermedades infecciosas o la atención de poblaciones vulnerables como los niños y las mujeres embarazadas.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99685/1/acem12173.pd

    Thermal and Electrochemical Properties of Solid Polymer Electrolytes Prepared via Lithium Salt-Catalyzed Epoxide Ring Opening Polymerization

    No full text
    Solid polymer electrolytes have been widely proposed for use in all solid-state lithium batteries. Advantages of polymer electrolytes over liquid and ceramic electrolytes include their flexibility, tunability and easy processability. An additional benefit of using some types of polymers for electrolytes is that they can be processed without the use of solvents. An example of polymers that are compatible with solvent-free processing is epoxide-containing precursors that can form films via the lithium salt-catalyzed epoxide ring opening polymerization reaction. Many polymers with epoxide functional groups are liquid under ambient conditions and can be used to directly dissolve lithium salts, allowing the reaction to be performed in a single reaction vessel under mild conditions. The existence of a variety of epoxide-containing polymers opens the possibility for significant customization of the resultant films. This review discusses several varieties of epoxide-based polymer electrolytes (polyethylene, silicone-based, amine and plasticizer-containing) and to compare them based on their thermal and electrochemical properties

    Use of Solid-State NMR Spectroscopy for the Characterization of Molecular Structure and Dynamics in Solid Polymer and Hybrid Electrolytes

    No full text
    Solid-state NMR spectroscopy is an established experimental technique which is used for the characterization of structural and dynamic properties of materials in their native state. Many types of solid-state NMR experiments have been used to characterize both lithium-based and sodium-based solid polymer and polymer–ceramic hybrid electrolyte materials. This review describes several solid-state NMR experiments that are commonly employed in the analysis of these systems: pulse field gradient NMR, electrophoretic NMR, variable temperature T1 relaxation, T2 relaxation and linewidth analysis, exchange spectroscopy, cross polarization, Rotational Echo Double Resonance, and isotope enrichment. In this review, each technique is introduced with a short description of the pulse sequence, and examples of experiments that have been performed in real solid-state polymer and/or hybrid electrolyte systems are provided. The results and conclusions of these experiments are discussed to inform readers of the strengths and weaknesses of each technique when applied to polymer and hybrid electrolyte systems. It is anticipated that this review may be used to aid in the selection of solid-state NMR experiments for the analysis of these systems

    Thermal and Electrochemical Properties of Solid Polymer Electrolytes Prepared via Lithium Salt-Catalyzed Epoxide Ring Opening Polymerization

    No full text
    Solid polymer electrolytes have been widely proposed for use in all solid-state lithium batteries. Advantages of polymer electrolytes over liquid and ceramic electrolytes include their flexibility, tunability and easy processability. An additional benefit of using some types of polymers for electrolytes is that they can be processed without the use of solvents. An example of polymers that are compatible with solvent-free processing is epoxide-containing precursors that can form films via the lithium salt-catalyzed epoxide ring opening polymerization reaction. Many polymers with epoxide functional groups are liquid under ambient conditions and can be used to directly dissolve lithium salts, allowing the reaction to be performed in a single reaction vessel under mild conditions. The existence of a variety of epoxide-containing polymers opens the possibility for significant customization of the resultant films. This review discusses several varieties of epoxide-based polymer electrolytes (polyethylene, silicone-based, amine and plasticizer-containing) and to compare them based on their thermal and electrochemical properties

    Quantifying Site-Specific Proton Dynamics in Phosphate Solid Acids by <sup>1</sup>H Double Quantum NMR Spectroscopy

    No full text
    Solid-state magic angle spinning (MAS) NMR was used to investigate changes in proton dynamics in phosphate solid acids that exhibited increased proton conductivity between room temperature and 110 °C. Double quantum dipolar recoupling methods were used to quantify site-specific changes in proton–proton dipolar coupling as a function of temperature. The static dipolar coupling and motionally induced changes to it were compared. This was accomplished by calculating (from crystal structures) and measuring (from the initial parts of the DQ recoupling curves) the root-sum-square of the dipolar coupling, a geometry-independent measure of dipolar coupling strength referred to as the “apparent dipolar coupling”, <i>D</i><sub>app</sub>. The analysis of KH<sub>2</sub>PO<sub>4</sub> and RbH<sub>2</sub>PO<sub>4</sub> showed that the experimentally determined apparent dipolar couplings were reduced from the calculated values at increased temperatures in dynamic systems. Higher proton conductivity was associated with greater reduction of the apparent dipolar coupling as measured by dipolar recoupling NMR methods. Most interestingly, in its monoclinic phase, RbH<sub>2</sub>PO<sub>4</sub> has two chemically distinct proton environments, one disordered and one ordered, which are resolved by <sup>1</sup>H MAS NMR. These sites exhibit different dipolar coupling responses as a function of temperature, revealing that proton conduction in this temperature range arises from motions involving only one of the sites. This site-specific dynamics is measured directly for the first time, using a combination of MAS to resolve the <sup>1</sup>H sites and dipolar recoupling experiments to probe the temperature dependence of the <sup>1</sup>H–<sup>1</sup>H dipolar interactions

    Apple Pectin-Based Hydrogel Electrolyte for Energy Storage Applications

    No full text
    Demand for flexible energy storage devices is rapidly increasing due to the development of new wearable and flexible electronics. These developments require improved integration of energy storage devices to meet the design specifications of these products. Polymer hydrogels are an alternative class of flexible electrolytes that can be used in power source systems. Herein, we present a new sustainable hydrogel electrolyte material made with apple pectin. Using an easy solution casting approach, a bio-based hydrogel was formed via pectin gelation. The resultant hydrogel was made with environmentally benign compounds including water, zinc and/or lithium sulfate salt, and a bio-based polymer. This hydrogel electrolyte exhibits ambient temperature ionic conductivities that are similar to those found in aqueous liquid electrolytes (∼5 × 10–2 S cm–1), depending on electrolyte hydration. Its wide thermal stability window enables the electrolyte to be used at both low temperatures (−20 °C) and intermediate temperatures (50 °C), without significant changes in ionic conductivity (>10–3 S cm–1). By proposing an energy-oriented solution using one of the food industry’s major waste materials, we report a novel approach to processing a bio-based polymer for energy storage purposes
    corecore