1,475 research outputs found

    Technical note : Estimating aqueous solubilities and activity coefficients of mono- and alpha,omega-dicarboxylic acids using COSMOtherm

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    We have used the COSMOtherm program to estimate activity coefficients and solubilities of mono- and alpha, omega-dicarboxylic acids and water in binary acid-water systems. The deviation from ideality was found to be larger in the systems containing larger acids than in the systems containing smaller acids. COnductor-like Screening MOdel for Real Solvents (COSMO-RS) underestimates experimental monocarboxylic acid activity coefficients by less than a factor of 2, but experimental water activity coefficients are underestimated more especially at high acid mole fractions. We found a better agreement between COSMOtherm-estimated and experimental activity coefficients of monocarboxylic acids when the water clustering with a carboxylic acid and itself was taken into account using the dimerization, aggregation, and reaction extension (COSMO-RS-DARE) of COSMOtherm. COSMO-RS-DARE is not fully predictive, but fit parameters found here for water-water and acid-water clustering interactions can be used to estimate thermodynamic properties of monocarboxylic acids in other aqueous solvents, such as salt solutions. For the dicarboxylic acids, COSMO-RS is sufficient for predicting aqueous solubility and activity coefficients, and no fitting to experimental values is needed. This is highly beneficial for applications to atmospheric systems, as these data are typically not available for a wide range of mixing states realized in the atmosphere, due to a lack of either feasibility of the experiments or sample availability. Based on effective equilibrium constants of different clustering reactions in the binary solutions, acid dimer formation is more dominant in systems containing larger dicarboxylic acids (C-5-C-8), while for monocarboxylic acids (C-1-C-6) and smaller dicarboxylic acids (C-2-C-4), hydrate formation is more favorable, especially in dilute solutions.Peer reviewe

    Impact of STROBE Statement Publication on Quality of Observational Study Reporting: Interrupted Time Series versus Before-After Analysis

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    Background:In uncontrolled before-after studies, CONSORT was shown to improve the reporting of randomised trials. Before-after studies ignore underlying secular trends and may overestimate the impact of interventions. Our aim was to assess the impact of the 2007 STROBE statement publication on the quality of observational study reporting, using both uncontrolled before-after analyses and interrupted time series.Methods:For this quasi-experimental study, original articles reporting cohort, case-control, and cross-sectional studies published between 2004 and 2010 in the four dermatological journals having the highest 5-year impact factors (≥4) were selected. We compared the proportions of STROBE items (STROBE score) adequately reported in each article during three periods, two pre STROBE period (2004-2005 and 2006-2007) and one post STROBE period (2008-2010). Segmented regression analysis of interrupted time series was also performed.Results:Of the 456 included articles, 187 (41%) reported cohort studies, 166 (36.4%) cross-sectional studies, and 103 (22.6%) case-control studies. The median STROBE score was 57% (range, 18%-98%). Before-after analysis evidenced significant STROBE score increases between the two pre-STROBE periods and between the earliest pre-STROBE period and the post-STROBE period (median score2004-0548% versus median score2008-1058%, p<0.001) but not between the immediate pre-STROBE period and the post-STROBE period (median score2006-0758% versus median score2008-1058%, p = 0.42). In the pre STROBE period, the six-monthly mean STROBE score increased significantly, by 1.19% per six-month period (absolute increase 95%CI, 0.26% to 2.11%, p = 0.016). By segmented analysis, no significant changes in STROBE score trends occurred (-0.40%; 95%CI, -2.20 to 1.41; p = 0.64) in the post STROBE statement publication.Interpretation:The quality of reports increased over time but was not affected by STROBE. Our findings raise concerns about the relevance of uncontrolled before-after analysis for estimating the impact of guidelines

    Hepatitis C, diagnosis and management: a survey of practicing physicians in Hawaii.

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    We surveyed 652 Hawaii physicians who diagnosed hepatitis C (HCV) since 1997. Less than 20% of licensed physicians have diagnosed HCV and initial estimates suggest there are 12,000 to 18,000 undiagnosed HCV cases in Hawaii. Treatment is concentrated among twelve physicians and aggressive case finding may overwhelm present resources. More primary care physicians need to participate in the detection and management of HCV

    Attitudes of editors of core clinical journals about whether systematic reviews are original research: a mixed-methods study.

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    In 2009, not all journal editors considered systematic reviews (SRs) to be original research studies, and not all PubMed Core Clinical Journals published SRs. The aim of this study was to conduct a new analysis about editors' opinion regarding SRs as original research. We conducted a survey and qualitative interview study of journal editors. All editors listed as editor-in chief of 118 PubMed Core Clinical Journals. We contacted editors via email and asked them whether they considered SRs original research, whether they published SRs in the journal and, if yes, in which section. We searched PubMed for any SRs (or meta-analyses) published in the included journals in 2017; if we did not find any, we hand-searched these journals. Editors were invited to participate in a follow-up qualitative interview study. We received responses from 73 editors representing 72 (62%) journals. Fifty-two (80%) editors considered SRs original research, either for any type of SR (65%) or only for SRs with a meta-analysis (15%) and almost all (91%) of editors published SRs. Compared with the results of the 2009 study of Core Clinical Journals, a similar proportion of editors considered SRs to be original studies (71%), accepted SRs as original on certain condition such as presence of meta-analysis (14%) or published SRs (94%). Interviews with editors showed that they used various criteria to decide whether a SR is original research, including methodology, reproducibility, originality of idea and level of novelty. The majority of editors of core clinical journals consider that SRs are original research. Among editors, there was no uniform approach to defining what makes a SR, or any study, original. This indicates that the concepts of originality of SRs and research are evolving and that this would be a relevant topic for further discussion

    Elucidation of the Transport Properties of Calcium‐Doped High Entropy Rare Earth Aluminates for Solid Oxide Fuel Cell Applications

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    Solid oxide fuel cells (SOFCs) are paving the way to clean energy conversion,relying on efficient oxygen-ion conductors with high ionic conductivitycoupled with a negligible electronic contribution. Doped rare earth aluminatesare promising candidates for SOFC electrolytes due to their high ionicconductivity. However, they often suffer from p-type electronic conductivity atoperating temperatures above 500°C under oxidizing conditions caused bythe incorporation of oxygen into the lattice. High entropy materials are a newclass of materials conceptualized to be stable at higher temperatures due totheir high configurational entropy. Introducing this concept to rare earthaluminates can be a promising approach to stabilize the lattice by shifting thestoichiometric point of the oxides to higher oxygen activities, and thereby,reducing the p-type electronic conductivity in the relevant oxygen partialpressure range. In this study, the high entropy oxide (Gd,La,Nd,Pr,Sm)AlO3issynthesized and doped with Ca. The Ca-doped (Gd,La,Nd,Pr,Sm)AlO3compounds exhibit a higher ionic conductivity than most of thecorresponding Ca-doped rare earth aluminates accompanied by a reduction ofthe p-type electronic conductivity contribution typically observed underoxidizing conditions. In light of these findings, this study introduces highentropy aluminates as a promising candidate for SOFC electrolytes

    A systematic review investigating fatigue, psychological and cognitive impairment following TIA and minor stroke:protocol paper

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    Approximately 20,000 people have a transient ischemic attack (TIA) and 23,375 have a minor stroke in England each year. Fatigue, psychological and cognitive impairments are well documented post-stroke. Evidence suggests that TIA and minor stroke patients also experience these impairments; however, they are not routinely offered relevant treatment. This systematic review aims to: (1) establish the prevalence of fatigue, anxiety, depression, post-traumatic stress disorder (PTSD) and cognitive impairment following TIA and minor stroke and to investigate the temporal course of these impairments; (2) explore impact on quality of life (QoL), change in emotions and return to work; (3) identify where further research is required and to potentially inform an intervention study

    Das RECORD-Statement zum Berichten von Beobachtungsstudien, die routinemäßig gesammelte Gesundheitsdaten verwenden [The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) statement]

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    Routinely collected health data, obtained for administrative and clinical purposes without specific a priori research goals, are increasingly used for research. The rapid evolution and availability of these data have revealed issues not addressed by existing reporting guidelines, such as Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). The REporting of studies Conducted using Observational Routinely collected health Data (RECORD) statement was created to fill these gaps. RECORD was created as an extension to the STROBE statement to address reporting items specific to observational studies using routinely collected health data. RECORD consists of a checklist of 13 items related to the title, abstract, introduction, methods, results, and discussion section of articles, and other information required for inclusion in such research reports. This document contains the checklist as well as explanatory and elaboration information to enhance the use of the checklist. Examples of good reporting for each RECORD checklist item are also included. This document, as well as the accompanying website and message board (http://www.record-statement.org), will improve the implementation and understanding of RECORD. By implementing RECORD, authors, journals editors, and peer reviewers can enhance transparency of research reporting

    Речеповеденческие стратегии межкультурной коммуникации

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    Данное исследование посвящено изучению речеповеденческих стратегий в контексте межкультурной коммуникации в методике преподавания английского языка с помощью аутентичных видеороликов. Исследование затрагивает значимые источники образовательных ценностей старшеклассников. Целью исследования является разработка методики обучения студентов. Исследование позволяет сделать вывод: есть некоторые стратегии, которым следует обучать на уроках английского языка для успешной межкультурной коммуникации.This research deals with a study of speech-behavioral strategies in the context of intercultural communication in the methodology of teaching English through authentic videos. The study touches upon the significant sources of educational values of high school students. The purpose of the study is to develop a methodology for teaching students. The research arrives at a conclusion: there are some strategies should be taught at the lessons of English for successful intercultural communication

    Introducing EMMIE: An evidence rating scale to encourage mixed-method crime prevention synthesis reviews

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    Objectives This short report describes the need for, and the development of, a coding system to distil the quality and coverage of systematic reviews of the evidence relating to crime prevention interventions. The starting point for the coding system concerns the evidence needs of policymakers and practitioners. Methods The coding scheme (EMMIE) proposed builds on previous scales that have been developed to assess the probity, coverage and utility of evidence both in health and criminal justice. It also draws on the principles of realist synthesis and review. Results The proposed EMMIE scale identifies five dimensions to which systematic reviews intended to inform crime prevention should speak. These are the Effect of intervention, the identification of the causal Mechanism(s) through which interventions are intended to work, the factors that Moderate their impact, the articulation of practical Implementation issues, and the Economic costs of intervention
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