1,307 research outputs found

    Coordination cages as permanently porous ionic liquids

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    Porous materials are widely used in industry for applications that include chemical separations and gas scrubbing. These materials are typically porous solids, although the liquid state can be easier to manipulate in industrial settings. The idea of combining the size and shape selectivity of porous domains with the fluidity of liquids is a promising one and porous liquids composed of functionalized organic cages have recently attracted attention. Here we describe an ionic-liquid, porous, tetrahedral coordination cage. Complementing the gas binding observed in other porous liquids, this material also encapsulates non-gaseous guests—shape and size selectivity was observed for a series of isomeric alcohols. Three gaseous chlorofluorocarbon guests, trichlorofluoromethane, dichlorodifluoromethane and chlorotrifluoromethane, were also shown to be taken up by the liquid coordination cage with an affinity that increased with their size. We hope that these findings will lead to the synthesis of other porous liquids whose guest-uptake properties may be tailored to fulfil specific functions

    Use of Twitter in Neurology: Boon or Bane?

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    Twitter is a free, open access social media platform that is widely used in medicine by physicians, scientists, and patients. It provides an opportunity for advocacy, education, and collaboration. However, it is likely not utilized to its full advantage by many disciplines in medicine, and pitfalls exist in its use. In particular, there has not been a review of Twitter use and its applications in the field of neurology. This review seeks to provide an understanding of the current use of Twitter in the field of neurology to assist neurologists in engaging with this potentially powerful application to support their work

    Are antenatal interventions effective in improving multiple health behaviours among pregnant women? A systematic review protocol.

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    BACKGROUND: Maternal behaviours in pregnancy associated with adverse pregnancy, birth and health outcomes include tobacco smoking, poor nutrition, alcohol consumption and low physical activity, collectively referred to as the SNAP risk factors. Due to the high prevalence, co-occurrence and possible interactive health effects of such health behaviours in pregnancy, antenatal interventions that support pregnant women to improve multiple SNAP behaviours have a greater potential impact on the health outcomes of women and their children than interventions addressing single behaviours. The objective of this review is to determine the effectiveness of interventions delivered as part of antenatal care that aim to improve multiple SNAP behaviours among pregnant women. METHODS: Seven electronic databases will be searched for potentially eligible studies. Eligible studies will include those where pregnant women are attending antenatal care. Studies that examine the effect of an intervention that addresses multiple SNAP behaviours (≥ 2 behaviours) during pregnancy and are delivered or instigated through antenatal care in a healthcare service will be included. Systematic reviews of randomised controlled trials (RCTs), RCTs, cluster RCTs, stepped-wedge RCTs and non-randomised control trials will be eligible. Studies that include a no-intervention control, wait-list control group, standard/usual care, or another active single behavioural intervention (e.g. addressing one behaviour only) will be considered. Two independent reviewers will conduct study screening, data extraction and risk of bias assessment. Discrepancies will be resolved by consensus or a third reviewer if required. A random effects model will be used to synthesise the results. Alternative synthesis methods will be investigated in instances where a meta-analysis is not appropriate, such as summarising effect estimates, combining P values, vote counting based on direction of effect, or synthesis in narrative form. DISCUSSION: The review will synthesise the evidence on the effect of interventions that address multiple SNAP behaviours in antenatal care and will help researchers, policy-makers and health services to develop and deliver best practice integrated models of antenatal care that have the potential to impact on both the short- and long-term health outcomes for women and their children. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018095315

    Pyrite-type ruthenium disulfide with tunable disorder and defects enables ultra-efficient overall water splitting

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    The exploration of efficient electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is significant for water splitting associated with the storage of clean and renewable energy. Here, we report a simple and scalable low-temperature sulfuration method to achieve simultaneous modulation of disorder and defects in pyrite-type RuS2 nanoparticles to dramatically enhance the HER and OER catalytic activity. The disordered structure can increase the electrochemically active surface area, while defect engineering can effectively regulate the electronic structure and thus improve the intrinsic activity, as revealed by combined experimental and theoretical density functional theory (DFT) investigations. Through controllable disorder and defect engineering, the optimized RuS2-500 catalyst (with a sulfuration temperature of 500 °C) supported on a glassy carbon electrode exhibits ultra-efficient bifunctional electrocatalytic activity with η-10 = 78 mV for the HER and η10 = 282 mV for the OER, superior to various Ru-based and pyrite-type catalysts. Remarkably, when used as both the anode and the cathode in an alkaline water electrolyzer, RuS2-500 delivers 10 mA cm-2 at an ultralow cell voltage of 1.527 V with long-term stability, outperforming the benchmark Pt/C//RuO2 couple and most state-of-the-art overall-water-splitting electrocatalysts ever reported. This work thus provides a new and facile way for improving the catalytic activity through a synergistic modulation strategy

    Knowledge of HIV status prior to a community HIV counseling and testing intervention in a rural district of south Africa: results of a community based survey

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    <p>Abstract</p> <p>Background</p> <p>The low uptake of facility-based HIV counseling and testing (HCT) in South Africa, particularly amongst men and youth has hindered attempts to increase access to effective treatment and prevention strategies. Many barriers to HIV testing have been described including long waiting times, transport to reach facilities, fear of lack of confidentiality and health systems factors such as stock outs of HIV test kits. The aim of this study was to undertake a community survey to determine rates of HCT in a rural area in order to plan a community intervention.</p> <p>Methods</p> <p>A community-based survey was undertaken in 16 communities in Sisonke district, KwaZulu-Natal between September and November 2008. A total of 5821 individuals participated in the survey of which 66% were females. Gender specific mixed effects logistic regression models were used to describe differences in socio-economic characteristics, and their association with HIV testing histories.</p> <p>Results</p> <p>Overall 1833 (32%) individuals in this rural area knew their HIV status. Prior testing was higher amongst women (39%) than amongst men (17%). Older men (> 24 years) were more likely to report having tested for HIV previously, with the highest likelihood (adjusted OR = 4.02; 95% CI: 2.71-5.99) among men in age group, 35-49 years. For women, age group 25-34 years had the highest likelihood of having been previously tested (adjusted OR = 1.30; 95% CI: 1.05-1.66). Being currently pregnant (adjusted OR 3.31; 95% CI: 2.29 - 4.78) or having a child under five (adjusted OR 7.00; 95% CI: 5.84 - 8.39) were also associated with prior HIV testing amongst women.</p> <p>Conclusions</p> <p>Overall, knowledge of HIV status in this rural sub-district is low. The relatively higher uptake of HIV testing among women is encouraging as it shows that PMTCT services are well functioning. However, these data suggest that there is an urgent need for scaling up HIV testing services in rural communities specifically targeting men and youth.</p

    Engaging Undergraduates in Science Research: Not Just About Faculty Willingness.

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    Despite the many benefits of involving undergraduates in research and the growing number of undergraduate research programs, few scholars have investigated the factors that affect faculty members' decisions to involve undergraduates in their research projects. We investigated the individual factors and institutional contexts that predict faculty members' likelihood of engaging undergraduates in their research project(s). Using data from the Higher Education Research Institute's 2007-2008 Faculty Survey, we employ hierarchical generalized linear modeling to analyze data from 4,832 science, technology, engineering, and mathematics (STEM) faculty across 194 institutions to examine how organizational citizenship behavior theory and social exchange theory relate to mentoring students in research. Key findings show that faculty who work in the life sciences and those who receive government funding for their research are more likely to involve undergraduates in their research project(s). In addition, faculty at liberal arts or historically Black colleges are significantly more likely to involve undergraduate students in research. Implications for advancing undergraduate research opportunities are discussed

    Multifrequency Strategies for the Identification of Gamma-Ray Sources

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    More than half the sources in the Third EGRET (3EG) catalog have no firmly established counterparts at other wavelengths and are unidentified. Some of these unidentified sources have remained a mystery since the first surveys of the gamma-ray sky with the COS-B satellite. The unidentified sources generally have large error circles, and finding counterparts has often been a challenging job. A multiwavelength approach, using X-ray, optical, and radio data, is often needed to understand the nature of these sources. This chapter reviews the technique of identification of EGRET sources using multiwavelength studies of the gamma-ray fields.Comment: 35 pages, 22 figures. Chapter prepared for the book "Cosmic Gamma-ray Sources", edited by K.S. Cheng and G.E. Romero, to be published by Kluwer Academic Press, 2004. For complete article and higher resolution figures, go to: http://www.astro.columbia.edu/~muk/mukherjee_multiwave.pd
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