468 research outputs found
Adsorbate-induced lifting of substrate relaxation is a general mechanism governing titania surface chemistry
Under ambient conditions, almost all metals are coated by an oxide. These coatings, the result of a chemical reaction, are not passive. Many of them bind, activate and modify adsorbed molecules, processes that are exploited, for example, in heterogeneous catalysis and photochemistry. Here we report an effect of general importance that governs the bonding, structure formation and dissociation of molecules on oxidic substrates. For a specific example, methanol adsorbed on the rutile TiO2(110) single crystal surface, we demonstrate by using a combination of experimental and theoretical techniques that strongly bonding adsorbates can lift surface relaxations beyond their adsorption site, which leads to a significant substrate-mediated interaction between adsorbates. The result is a complex superstructure consisting of pairs of methanol molecules and unoccupied adsorption sites. Infrared spectroscopy reveals that the paired methanol molecules remain intact and do not deprotonate on the defect-free terraces of the rutile TiO2(110) surface
Observation of Large Differences in the Diffraction of Normal- and Para-H2 from LiF(001)
Theoretical Chemistr
Viral hepatitis testing and treatment in community pharmacies:a systematic review and meta-analysis
Background: The World Health Organization seeks to eliminate viral hepatitis as a public health threat by 2030. This review and meta-analysis aims to evaluate the effectiveness of programs for hepatitis B and C testing and treatment in community pharmacies. Methods: Medline, Embase, Cochrane CENTRAL, and Global Health were searched from database inception until 12 November 2023. Comparative and single arm intervention studies were eligible for inclusion if they assessed delivery of any of the following interventions for hepatitis B or C in pharmacies: (1) pre-testing risk assessment, (2) testing, (3) pre-treatment assessment or (4) treatment. Primary outcomes were proportions testing positive and reaching each stage in the cascade. Random effects meta-analysis was used to estimate pooled proportions stratified by recruitment strategy and setting where possible; other results were synthesised narratively. This study was pre-registered (PROSPERO: CRD42022324218). Findings: Twenty-seven studies (4 comparative, 23 single arm) were included, of which 26 reported hepatitis C outcomes and four reported hepatitis B outcomes. History of injecting drug use was the most identified risk factor from pre-testing risk assessments. The pooled proportion hepatitis C antibody positive from of 19 studies testing 5096 participants was 16.6% (95% CI 11.0%–23.0%; heterogeneity I 2 = 96.6%). The pooled proportion antibody positive was significantly higher when testing targeted people with specified risk factors (32.5%, 95% CI 24.8%–40.6%; heterogeneity I 2 = 82.4%) compared with non-targeted or other recruitment methods 4.0% (95% CI 2.1%–6.5%; heterogeneity I 2 = 83.5%). Meta-analysis of 14 studies with 813 participants eligible for pre-treatment assessment showed pooled attendance rates were significantly higher in pharmacies (92.7%, 95% CI 79.1%–99.9%; heterogeneity I 2 = 72.4%) compared with referral to non-pharmacy settings (53.5%, 95% CI 36.5%–70.1%; heterogeneity I 2 = 92.3%). The pooled proportion initiating treatment was 85.6% (95% CI 74.8%–94.3%; heterogeneity I 2 = 75.1%). This did not differ significantly between pharmacy and non-pharmacy settings. Interpretation: These findings add pharmacies to the growing evidence supporting community-based testing and treatment for hepatitis C. Few comparative studies and high degrees of statistical heterogeneity were important limitations. Hepatitis B care in pharmacies presents an opportunity for future research. Funding: None.</p
Accounting for the increasing benefits from scarce ecosystems
Governments are catching up with economic theory and practice by increasingly integrating ecosystem service values into national planning processes, including benefitcost analyses of public policies. Such analyses require information not only about today’s benefits from ecosystem services but also on how benefits change over time. We address a key limitation of existing policy guidance, which assumes that benefits from ecosystem services remain unchanged. We provide a practical rule that is grounded in economic theory and evidence-based as a guideline for how benefits change over time: They rise as societies get richer and even more so when ecosystem services are declining. Our proposal will correct a substantial downward bias in currently used estimates of future ecosystem service values. This will help governments to reflect the importance of ecosystems more accurately in benefit-cost analyses and policy decisions they inform
MoleculARweb: A Web Site for Chemistry and Structural Biology Education through Interactive Augmented Reality out of the Box in Commodity Devices
Augmented/virtual realities (ARs/VRs) promise to revolutionize STEM education. However, most easy-to-use tools are limited to static visualizations, which limits the approachable content, whereas more interactive and dynamic alternatives require costly hardware, preventing large-scale use and evaluation of pedagogical effects. Here, we introduce https://MoleculARweb.epfl.ch, a free, open-source web site with interactive AR webpage-based apps that work out-of-the-box in laptops, tablets, and smartphones, where students and teachers can naturally handle virtual objects to explore molecular structure, reactivity, dynamics, and interactions, covering topics from inorganic, organic, and biological chemistry. With these web apps, teachers and science communicators can develop interactive material for their lessons and hands-on activities for their students and target public, in person or online, as we exemplify. Thousands of accesses to moleculARweb attest to the ease of use; teacher feedback attests to the utility in online teaching and homework during a pandemic; and in-class plus online surveys show that users find AR engaging and useful for teaching and learning chemistry. These observations support the potential of AR in future education and show the large impact that modern web technologies have in democratizing access to digital learning tools, providing the possibility to mass-test the pedagogical effect of these technologies in STEM education.Fil: RodrĂguez, Fabio CortĂ©s. École Polytechnique FĂ©dĂ©rale de Lausanne; Suiza. Swiss Institute of Bioinformatics; SuizaFil: Frattini, Gianfranco. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas; ArgentinaFil: Krapp, Lucien F.. Ecole Polytechnique Federale de Lausanne; Francia. Swiss Institute of Bioinformatics; SuizaFil: Martinez Hung, Hassan. Universidad de Oriente; VenezuelaFil: Moreno, Diego Martin. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de QuĂmica Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de QuĂmica Rosario; ArgentinaFil: Roldán, Mariana. Provincia de CĂłrdoba. Instituto Colbert; ArgentinaFil: SalomĂłn, Jorge Eduardo. Provincia de Buenos Aires. Escuela de EducaciĂłn TĂ©cnica Nro. 4; ArgentinaFil: Stemkoski, Lee. Adelphi University; Estados UnidosFil: Traeger, Sylvain. École Polytechnique FĂ©dĂ©rale de Lausanne; Suiza. Swiss Institute of Bioinformatics; SuizaFil: Dal Peraro, Matteo. École Polytechnique FĂ©dĂ©rale de Lausanne; Suiza. Swiss Institute of Bioinformatics; SuizaFil: Abriata, Luciano Andres. École Polytechnique FĂ©dĂ©rale de Lausanne; Suiza. Swiss Institute of Bioinformatics; Suiz
Clinical practice guidelines for the management of non-specific low back pain in primary care: an updated overview
Objective: The aim of this study was to provide an overview of the recommendations regarding the diagnosis and treatment contained in current clinical practice guidelines for patients with non-specific low back pai
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