2,390 research outputs found

    Bringing Earth-Abundant Plasmonic Catalysis to Light : Gram-Scale Mechanochemical Synthesis and Tuning of Activity by Dual Excitation of Antenna and Reactor Sites

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    The localized surface plasmon resonance (LSPR) excitation in plasmonic nanoparticles (NPs) in the visible and near-infrared ranges is currently at the forefront of improving photocatalytic performances via plasmonic photocatalysis. One bottleneck of this field is that the NPs that often display the best optical properties in the visible and near-infrared ranges are based on expensive noble metals such as silver (Ag) and gold (Au). While earth-abundant plasmonic materials have been proposed together with catalytic metals in antenna-reactor systems, their performances remain limited by their optical properties. Importantly, the synthesis of plasmonic photocatalysts remains challenging in terms of scalability while often requiring several steps, high temperatures, and special conditions. Herein, we address these challenges by developing a one-pot, gram-scale, room-temperature synthesis of earth-abundant plasmonic photocatalysts while improving their activities beyond what has been dictated by the LSPR excitation of the plasmonic component. We describe the mechanochemical synthesis of earth-abundant plasmonic photocatalysts by using MoO3 (antenna) and Au (reactor) NPs as a proof-of-concept example and demonstrate that the dual plasmonic excitation of antenna and reactor sites enables the tuning of plasmonic photocatalytic performances toward the reductive coupling of nitrobenzene to azobenzene as a model reaction. In addition to providing a pathway to the facile and gramscale synthesis of plasmonic photocatalysts, the results reported herein may open pathways to improved activities in plasmonic catalysis.Peer reviewe

    Currents issues in cardiorespiratory care of patients with post-polio syndrome

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    Post-polio syndrome (PPS) is a condition that affects polio survivors years after recovery from an initial acute attack of the poliomyelitis virus. Most often, polio survivors experience a gradual new weakening in muscles that were previously affected by the polio infection. The actual incidence of cardiovascular diseases (CVDs) in individuals suffering from PPS is not known. However, there is a reason to suspect that individuals with PPS might be at increased risk. Method: A search for papers was made in the databases Bireme, Scielo and Pubmed with the following keywords: post polio syndrome, cardiorespiratory and rehabilitation in English, French and Spanish languages. Although we targeted only seek current studies on the topic in question, only the relevant (double-blind, randomized-controlled and consensus articles) were considered. Results and Discussion: Certain features of PPS such as generalized fatigue, generalized and specific muscle weakness, joint and/or muscle pain may result in physical inactivity deconditioning obesity and dyslipidemia. Respiratory difficulties are common and may result in hypoxemia. Conclusion: Only when evaluated and treated promptly, somE patients can obtain the full benefits of the use of respiratory muscles aids as far as quality of life is concerned.Ctr Univ Augusto Motta, Programa Posgrad Ciencias Reabilitacao, Rio De Janeiro, RJ, BrazilUniv Severino Sombra, Fac Med, Vassouras, RJ, BrazilUniv Fed Rio de Janeiro, Inst Psiquiatria, Lab Mapeamento Cerebral & EEG, BR-22290140 Rio De Janeiro, RJ, BrazilUniv Fed Fluminense, Hosp Univ Antonio Pedro, Niteroi, RJ, BrazilInst Fed Educ Ciencia & Tecnol Rio de Janeiro, Curso Fisioterapia, Rio De Janeiro, RJ, BrazilUniv Fed Piaui, Parnaiba, PI, BrazilUniv Fed Sao Paulo, Dept Neurol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Neurol, Sao Paulo, SP, BrazilWeb of Scienc

    Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna

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    Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes—the most species-rich continental vertebrate fauna on Earth—to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades. Five abrupt shifts in net diversification rates occurred during the Paleogene and Miocene (between 30 and 7 Ma) in association with major landscape evolution events. Net diversification accelerated from the Miocene to the Recent (c. 20 to 0 Ma), with Western Amazonia having the highest rates of in situ diversification, which led to it being an important source of species dispersing to other regions. All regional biotic interchanges were associated with documented hydrogeographic events and the formation of biogeographic corridors, including the Early Miocene (c. 23 to 16 Ma) uplift of the Serra do Mar and Serra da Mantiqueira and the Late Miocene (c. 10 Ma) uplift of the Northern Andes and associated formation of the modern transcontinental Amazon River. The combination of high diversification rates and extensive biotic interchange associated with Western Amazonia yielded its extraordinary contemporary richness and phylogenetic endemism. Our results support the hypothesis that landscape dynamics, which shaped the history of drainage basin connections, strongly affected the assembly and diversification of basin-wide fish fauna

    Relative rates of B meson decays into psi(2S) and J/psi mesons

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    We report on a study of the relative rates of B meson decays into psi(2S) and J/psi mesons using 1.3 fb^-1 of pbar p collisions at sqrt(s) = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe the channels B^0_s -> psi(2S)phi, B^0_s -> J/psi phi, B^+/- -> psi(2S) K^+/-, and B^+/- -> J/psi K^+/- and we measure the relative branching fractions for these channels to be B(B^0_s -> psi(2S)phi)/B(B^0_s -> J/psi phi) = 0.55 +/- 0.11 (stat) +/- 0.07 (syst) +/- 0.06 (B), B(B^+/- -> psi(2S) K^+/-)/B(B^+/- -> J/psi K^+/-) = 0.65 +/- 0.04 (stat) +/- 0.03 (syst) +/- 0.07 (B) where the final error corresponds to the uncertainty in the J/psi and psi(2S) branching ratio into two muons.Comment: Published in Phys. Rev. D - Rapid Communicatio

    Challenges and priorities for river cetacean conservation

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    River cetaceans are particularly vulnerable to anthropogenic impacts due to their constrained ranges in freshwater systems of China, South Asia, and South America. We undertook an exhaustive review of 280 peer-reviewed papers and grey literature reports (1998-2020) to examine the current status of knowledge regarding these cetaceans and their conservation. We aimed to better understand the scale of threats they face, and to identify and propose priority future efforts to better conserve these species. We found that the species have been studied with varying frequency and that most of the research on threats has focused on habitat degradation and fragmentation (43%, mainly driven by dams and extractive activities such as sand mining and deforestation), and fishery interactions (39%, in the form of bycatch and direct take). These threats occur across all species, but more information is needed, primarily on quantifying the population impacts as a basis for designing mitigation measures. Other threats identified include pollution, vessel collisions, traditional use, and poorly managed tourism. Emerging methods such as environmental DNA and unmanned aerial vehicles are described for studying these species. Promising conservation interventions include cetacean-specific protected areas, natural ex situ protection, community-led conservation, and education programmes. However, transnational political will is required for a step change towards broad-scale protection in freshwater environments. In addition, we propose increasing capacity building, developing management plans, working closely with fishing communities, enhancing public awareness, expanding regional collaborations, and diversifying funding
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