103 research outputs found

    Hongos liquenizados y liquenícolas de la Sierra de Albarracín (Teruel, España)

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    Se presenta un catálogo de 462 hongos liquenizados y liquenícolas de la Sierra de Albarracín (Teruel, Aragón, España), como resultado de la IV Campaña de Recolección organizada por la Sociedad Española de Liquenología (SEL). Diplotomma hedinii es novedad para la Península Ibé- rica y Lepraria leuckertiana constituye una segunda cita peninsular, 69 taxones son novedad para Aragón y 86 lo son para la provincia de Teruel

    Sympherobius barberi (Banks, 1903) (Neuroptera: Hemerobiidae): morfología, presas y rango de distribución en México y América

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    Los hemeróbidos tienen una distribución cosmopolita y destacan por sus hábitos entomófagos sobre insectos pequeños de cuerpo blando. En México, la especie Sympherobius barberi (Banks, 1903) se registra en Baja California, Estado de México Guanajuato, y Morelos. El interés sobre su potencial uso comercial como agente de control biológico en el país motivó la revisión de esta especie. Tanto en publicaciones científicas como en bases de datos y colecciones biológicas, se documentan los caracteres taxonómicos requeridos para determinar esta especie y se propone sustituir la taxonomía básica basada en patrones de manchas alares. Además, se reporta nueva información sobre presas y plantas hospederas: Brevicoryne brassicae (Linnaeus, 1758) en Brassica spp.; Dactylopius confusus (Cockerell, 1893) en varias especies del género Opuntia y Nopalea cochenillifera; Dactylopius opuntiae (Cockerell, 1896) sobre Opuntia ficus-indica; Phenacoccus solenopsis Tinsley, 1898 en algodón; Planococcus ficus Signoret, 1875 en vid; y larvas de Plutella xylostella (Linnaeus, 1758) en brócoli.Brown lacewings have a cosmopolitan distribution and stand out for their entomophagous habits on small, soft-bodied prey. In Mexico, the species Sympherobius barberi (Banks, 1903) is recorded from Baja California, Estado de Mexico, Guanajuato, and Morelos. Interest in its potential commercial use as a biological control agent in the country motivated the review of this species. Both in scientific publications and in databases and biological collections, the taxonomic characters required to determine this species are documented, proposing to replace the basic taxonomy based on wing spot patterns. In addition, new information on prey and host plants is recorded: Brevicoryne brassicae (Linnaeus, 1758) in Brassica spp.; Dactylopius confusus (Cockerell, 1893) in various species of Opuntia y Nopalea cochenillifera; Dactylopius opuntiae in Opuntia ficus-indica; Phenacoccus solenopsis Tinsley, 1898 in cotton; Planococcus ficus Signoret, 1875 in grapevine; and larvae of Plutella xylostella (Linnaeus, 1758) in broccoli

    In situ monitoring of the phenomenon of electrochemical promotion of catalysis

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    In this work we investigate by in-situ near-ambient pressure photoemission (NAPP) spectroscopy the phenomenon of Electrochemical Promotion of Catalysis (EPOC). We studied the reduction and diffusion kinetics of alkaline ions in a solid electrolyte cell formed by a nickel electrode supported on K+-β-alumina electrolyte. Experiments in ultra-high vacuum and in the presence of steam showed that the amount of potassium atoms supplied to the surface is probably affected by nickel electronic modifications induced by adsorbed OH− groups. It was also deduced that part of the segregated potassium would be adsorbed at inner interfaces where it would be inaccessible to the photoelectron analyzer. A migration mechanism of the promoter is proposed consisting in: (i) the electrochemical reduction of the alkali ions (potassium) at the Ni/solid electrolyte/gas interface; (ii) the spillover of potassium atoms onto the Ni gas-exposed surface; and (iii) the diffusion of potassium atoms to Ni inner grain boundary interfaces.En este trabajo investigamos mediante espectroscopía de fotoemisión a presión cercana al ambiente in situ (NAPP) el fenómeno de la Promoción Electroquímica de la Catálisis (EPOC). Estudiamos la cinética de reducción y difusión de iones alcalinos en una celda de electrolito sólido formada por un electrodo de níquel soportado sobre electrolito K + -β-alúmina. Los experimentos en vacío ultraalto y en presencia de vapor mostraron que la cantidad de átomos de potasio suministrados a la superficie probablemente se ve afectada por modificaciones electrónicas de níquel inducidas por OH adsorbido .grupos También se dedujo que parte del potasio segregado sería adsorbido en las interfaces internas donde sería inaccesible para el analizador de fotoelectrones. Se propone un mecanismo de migración del promotor que consiste en: (i) la reducción electroquímica de los iones alcalinos (potasio) en la interfase Ni/electrolito sólido/gas; (ii) el derrame de átomos de potasio sobre la superficie expuesta al gas Ni; y (iii) la difusión de átomos de potasio a las interfaces de límite de grano interno de Ni

    Graphene Formation Mechanism by the Electrochemical Promotion of a Ni Catalyst

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    In this work, we show that multilayer graphene forms by methanol decomposition at 280 °C on an electrochemically promoted nickel catalyst film supported on a K-βAl2O3 solid electrolyte. In operando near ambient pressure photoemission spectroscopy and electrochemical measurements have shown that polarizing negatively the Ni electrode induces the electrochemical reduction and migration of potassium to the nickel surface. This elemental potassium promotes the catalytic decomposition of methanol into graphene and also stabilizes the graphene formed via diffusion and direct K–C interaction. Experiments reveal that adsorbed methoxy radicals are intermediate species in this process and that, once formed, multilayer graphene remains stable after electrochemical oxidation and back migration of potassium to the solid electrolyte upon positive polarization. The reversible diffusion of ca. 100 equivalent monolayers of potassium through the carbon layers and the unprecedented low-temperature formation of graphene and other carbon forms are mechanistic pathways of high potential impact for applications where mild synthesis and operation conditions are required.En este trabajo mostramos que el grafeno multicapa se forma por descomposición del metanol a 280 °C sobre una película de catalizador de níquel promovida electroquímicamente soportada sobre un K-βAl 2 O 3electrolito sólido. Operando cerca de la espectroscopia de fotoemisión a presión ambiental y las mediciones electroquímicas han demostrado que la polarización negativa del electrodo de Ni induce la reducción electroquímica y la migración del potasio a la superficie del níquel. Este potasio elemental promueve la descomposición catalítica del metanol en grafeno y también estabiliza el grafeno formado a través de la difusión y la interacción directa K-C. Los experimentos revelan que los radicales metoxi adsorbidos son especies intermedias en este proceso y que, una vez formado, el grafeno multicapa permanece estable después de la oxidación electroquímica y la migración de regreso del potasio al electrolito sólido tras la polarización positiva. La difusión reversible de ca

    Laser treatment of Ag@ZnO nanorods as long-life-span SERS surfaces.

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    This is the accepted manuscript. The final version is available from ACS at http://pubs.acs.org/doi/abs/10.1021/am506622x.UV nanosecond laser pulses have been used to produce a unique surface nanostructuration of Ag@ZnO supported nanorods (NRs). The NRs were fabricated by plasma enhanced chemical vapor deposition (PECVD) at low temperature applying a silver layer as promoter. The irradiation of these structures with single nanosecond pulses of an ArF laser produces the melting and reshaping of the end of the NRs that aggregate in the form of bundles terminated by melted ZnO spherical particles. Well-defined silver nanoparticles (NPs), formed by phase separation at the surface of these melted ZnO particles, give rise to a broad plasmonic response consistent with their anisotropic shape. Surface enhanced Raman scattering (SERS) in the as-prepared Ag@ZnO NRs arrays was proved by using a Rhodamine 6G (Rh6G) chromophore as standard analyte. The surface modifications induced by laser treatment improve the stability of this system as SERS substrate while preserving its activity.We thank the Junta de Andalucía (TEP8067, FQM-6900 and P12-FQM-2265) and the Spanish Ministry of Economy and Competitiveness (Projects CONSOLIDER-CSD 2008-00023, MAT2011-28345-C02-02, MAT2013-40852-R, MAT2013-42900-P and RECUPERA 2020) for financial support. The authors also thank the European Union Seventh Framework Programme under Grant Agreements 312483-ESTEEM2 (Integrated Infrastructure Initiative-I3) and REGPOT-CT-2011-285895-Al-NANOFUNC, and the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC grant agreement 291522 - 3DIMAGE. R. J. Peláez acknowledges the grant JCI-2012_13034 from the Juan de la Cierva program

    Antibacterial Nanostructured Ti Coatings by Magnetron Sputtering: from Laboratory Scales to Industrial Reactors

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    Based on an already tested laboratory procedure, a new magnetron sputtering methodology to simultaneously coat two-sides of large area implants (up to ~15 cm2) with Ti nanocolumns in industrial reactors has been developed. By analyzing the required growth conditions in a laboratory setup, a new geometry and methodology have been proposed and tested in a semi-industrial scale reactor. A bone plate (Depuy Synthes) and a pseudo-rectangular bone plate extracted from a patient have been coated following the new methodology, obtaining that their osteoblast proliferation efficiency and antibacterial functionality were equivalent to the coatings grown in the laboratory reactor on small areas. In particular, two kinds of experiments have been performed: analysis of bacterial adhesion and biofilm formation, and osteoblasts-bacteria competitive in vitro growth scenarios. In all these cases, the coatings show an opposite behavior towards osteoblast and bacterial proliferation, demonstrating that the proposed methodology represents a valid approach for industrial production and practical application of nanostructured titanium coatings

    A Membrane Fusion Protein αSNAP Is a Novel Regulator of Epithelial Apical Junctions

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    Tight junctions (TJs) and adherens junctions (AJs) are key determinants of the structure and permeability of epithelial barriers. Although exocytic delivery to the cell surface is crucial for junctional assembly, little is known about the mechanisms controlling TJ and AJ exocytosis. This study was aimed at investigating whether a key mediator of exocytosis, soluble N-ethylmaleimide sensitive factor (NSF) attachment protein alpha (αSNAP), regulates epithelial junctions. αSNAP was enriched at apical junctions in SK-CO15 and T84 colonic epithelial cells and in normal human intestinal mucosa. siRNA-mediated knockdown of αSNAP inhibited AJ/TJ assembly and establishment of the paracellular barrier in SK-CO15 cells, which was accompanied by a significant down-regulation of p120-catenin and E-cadherin expression. A selective depletion of p120 catenin effectively disrupted AJ and TJ structure and compromised the epithelial barrier. However, overexpression of p120 catenin did not rescue the defects of junctional structure and permeability caused by αSNAP knockdown thereby suggesting the involvement of additional mechanisms. Such mechanisms did not depend on NSF functions or induction of cell death, but were associated with disruption of the Golgi complex and down-regulation of a Golgi-associated guanidine nucleotide exchange factor, GBF1. These findings suggest novel roles for αSNAP in promoting the formation of epithelial AJs and TJs by controlling Golgi-dependent expression and trafficking of junctional proteins

    The first 80 days of the COVID-19 pandemic in the city of Belo Horizonte : from containment to reopening.

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    Este artigo examina o contexto e as implica??es da pandemia por Covid-19 na cidade de Belo Horizonte (BH) nos primeiros 80 dias da doen?a. Utilizamos um recorte anal?tico descritivo para mensurar a evolu??o dos casos, o excesso de ?bitos, a taxa de transmissibilidade do v?rus e a press?o da doen?a sobre o sistema de sa?de de BH e regi?o, atrav?s da taxa de ocupa??o hospitalar nos leitos p?blicos. Al?m disso, identificamos as principais pol?ticas de conten??o adotadas pelas autoridades locais, bem como as implica??es da redu??o do distanciamento social. Nossos resultados demonstram que o Sistema ?nico de Sa?de (SUS), bem gerido, ? fundamental para o enfrentamento da pandemia e a mitiga??o de suas consequ?ncias para a popula??o. O processo de flexibiliza??o que se inicia tem imposto novos desafios que requerer?o monitoramento atento das autoridades e da sociedade.The paper examines the implications of Co vid-19 pandemic for the city of Belo Horizonte (BH), during the fi rst 80 days of the disease. We use a descriptive-analytical approach to estimate the growth of Covid-19 cases over time, the excess of deaths, the virus? rate of transmissibility, and the consequent burden on the municipal the health system, measured by the rate of occupancy of public hospital beds. Also, we identify the main containment policies adopted by local authorities, and the implications of reopen ing measures and the following reduction of social distancing. Our fi ndings reveal that a well-managed Unifi ed Health System (SUS) is paramount to effectively tackle the pan demic and its consequences for the population. The reopening process has imposed new challenges that will require close monitoring by the authorities and by the Society

    Quality indicators for patients with traumatic brain injury in European intensive care units

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    Background: The aim of this study is to validate a previously published consensus-based quality indicator set for the management of patients with traumatic brain injury (TBI) at intensive care units (ICUs) in Europe and to study its potential for quality measur

    Variation in Structure and Process of Care in Traumatic Brain Injury: Provider Profiles of European Neurotrauma Centers Participating in the CENTER-TBI Study.

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    INTRODUCTION: The strength of evidence underpinning care and treatment recommendations in traumatic brain injury (TBI) is low. Comparative effectiveness research (CER) has been proposed as a framework to provide evidence for optimal care for TBI patients. The first step in CER is to map the existing variation. The aim of current study is to quantify variation in general structural and process characteristics among centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. METHODS: We designed a set of 11 provider profiling questionnaires with 321 questions about various aspects of TBI care, chosen based on literature and expert opinion. After pilot testing, questionnaires were disseminated to 71 centers from 20 countries participating in the CENTER-TBI study. Reliability of questionnaires was estimated by calculating a concordance rate among 5% duplicate questions. RESULTS: All 71 centers completed the questionnaires. Median concordance rate among duplicate questions was 0.85. The majority of centers were academic hospitals (n = 65, 92%), designated as a level I trauma center (n = 48, 68%) and situated in an urban location (n = 70, 99%). The availability of facilities for neuro-trauma care varied across centers; e.g. 40 (57%) had a dedicated neuro-intensive care unit (ICU), 36 (51%) had an in-hospital rehabilitation unit and the organization of the ICU was closed in 64% (n = 45) of the centers. In addition, we found wide variation in processes of care, such as the ICU admission policy and intracranial pressure monitoring policy among centers. CONCLUSION: Even among high-volume, specialized neurotrauma centers there is substantial variation in structures and processes of TBI care. This variation provides an opportunity to study effectiveness of specific aspects of TBI care and to identify best practices with CER approaches
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