7 research outputs found

    Photo-Induced Self-Cleaning and Wettability in TiO2 Nanocolumn Arrays Obtained by Glancing-Angle Deposition with Sputtering

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    In this work, the preparation of regular nanosized columnar structures of titanium dioxide by means of glancing angle deposition with magnetron sputtering (MS-GLAD) followed by thermal annealing is reported. MS-GLAD gives rise to metallic titanium columnar structures with regular width and length that after thermal treatment are fully oxidized to form TiO2 nanocolumns that maintain the morphological features of the original metallic ones. Further functionalization with gold by means of multiple ion cluster source results in well-dispersed Au nanoparticles across the nanocolumns’ surface with a narrow size distribution centered at ca. 8.5 nm. The obtained nanostructures show photocatalytic self-cleaning activity as shown by the elimination of an organic layer deposited on their surface and the detection of hydroxyl radicals. Photoelectrochemical measurements show a better charge separation at the Au/TiO2 interface. In addition, wettability studies show that the degree of hydrophobicity of the surface is increased by the presence of nanocolumns, both in the dark and under UV illumination. This behavior is not modified by the presence of Au nanoparticles on the surface. The obtained results open up interesting implications in the tunability of the properties of nanostructured thin films for this kind of photo-activated application.Financial support from the Spanish Ministry of Science, Innovation, and Universities (MICINN) through the projects SOLPAC (ENE2017-89170-R, MCIU/AEI/FEDER, EU), MAT2014-59772-C2-1-P, and MAT2014-59772-C2-2-P is gratefully acknowledged. The authors also acknowledge the service from the MiNa Laboratory at IMN funded by Comunidad de Madrid (S2018/NMT-4291 TEC2SPACE), MICINN (CSIC13-4E-1794), and the EU (FEDER, FSE). Also, this work has been funded by the regional government of Madrid and European Structural Funds through their financial support to FotoArt-CM program (S2018/NMT-4367), and from Fundación Ramon Areces though the ArtLeaf project. M.B. thanks MICINN for a Juan de la Cierva Incorporación (IJC2019-042430-I) grant.Peer reviewe

    Antimicrobial Consumption in Latin American Countries: First Steps of a Long Road Ahead

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    Background: Irrational antimicrobial consumption (AMC) became one of the main global health problems in recent decades. Objective: In order to understand AMC in Latin-American Region, we performed the present research in 6 countries. Methods: Antimicrobial consumption (J01, A07A, P01AB groups) was registered in Argentina, Chile, Colombia, Costa Rica, Paraguay, and Peru. Source of information, AMC type, DDD (Defined Daily Doses), DID (DDD/1000 inhabitants/day), population were variables explored. Data was analyzed using the Global Antimicrobial Resistance and Use Surveillance System (GLASS) tool. Results: Source of information included data from global, public, and private sectors. Total AMC was highly variable (range 1.91-36.26 DID). Penicillin was the most consumed group in all countries except in Paraguay, while macrolides and lincosamides were ranked second. In terms of type of AMC according to the WHO-AWaRe classification, it was found that for certain groups like “Reserve,” there are similarities among all countries. Conclusion and Relevance: This paper shows the progress that 6 Latin-American countries made toward AMC surveillance. The study provides a standardized approach for building a national surveillance system for AMC data analysis. These steps will contribute to the inclusion of Latin-America among the regions of the world that have periodic, regular, and quality data of AMC.Facultad de Ciencias Médica

    Prospective individual patient data meta-analysis of two randomized trials on convalescent plasma for COVID-19 outpatients

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    Data on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk of hospitalization of outpatients. Two multicenter, double-blind randomized trials (NCT04621123, NCT04589949) were merged with data pooling starting when = 50 years and symptomatic for <= 7days were included. The intervention consisted of 200-300mL of CP with a predefined minimum level of antibodies. Primary endpoints were a 5-point disease severity scale and a composite of hospitalization or death by 28 days. Amongst the 797 patients included, 390 received CP and 392 placebo; they had a median age of 58 years, 1 comorbidity, 5 days symptoms and 93% had negative IgG antibody-test. Seventy-four patients were hospitalized, 6 required mechanical ventilation and 3 died. The odds ratio (OR) of CP for improved disease severity scale was 0.936 (credible interval (CI) 0.667-1.311); OR for hospitalization or death was 0.919 (CI 0.592-1.416). CP effect on hospital admission or death was largest in patients with <= 5 days of symptoms (OR 0.658, 95%CI 0.394-1.085). CP did not decrease the time to full symptom resolution

    Additions of host associations and new records of bat ectoparasites of the families Spinturnicidae, Nycteribiidae and Streblidae from Honduras

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    We captured mormoopids, phyllostomids, and vespertilionids in Honduras to collect bat ectoparasites. Two species of Spinturnicidae (Acari) are the first reports of this family in Honduras. One species of Basilia Miranda Ribeiro, 1903, and four of Streblidae are recorded for the first time in Honduras. With these results, the current species number of each family for Honduras are two species of Spinturnicidae, three of Nycteribiidae, and 48 of Streblidae. We compared the number of species of Streblidae and bats in Honduras to highly sampled countries in Central and South America. Clearly, more effort is still needed in Honduras, although this is the third attempt to study the bat ectoparasites in Honduras

    Photo-induced self-cleaning and hydrophilic properties of columnar TiO2 nanostructures obtained by glancing-angle magnetron sputtering

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    Trabajo presentado en la 6th European Conference on Environmental Applications of Advanced Oxidation Processes (EAAOP6), celebrada en Portorož (Eslovenia), del 26 al 30 de junio de 2019Self-cleaning and anti-fogging technology is already used in a variety of the products today, among which glazing products prevail. Their function is based on two principles, either hydrophobicity (Lotus effect) or photocatalytic hydrophilicity. In the latter case, the self-cleaning action is based on the combination of photocatalysis and photoinduced superhydrophilicity, where dirt removal by uniform spreading of water over the whole surface is improved with photocatalytic decomposition of organic contaminants (Zhang et al., 2012). In spite of the high readiness level of this technology, with competitive products already in the market, there is room to improve the properties of existing self-cleaning and anti-fogging surfaces by designing and tailoring new nanoarchitectures for light-activated thin films (Lavrenčič Štangar et al., 2014). Among photoactive materials, TiO2 gathers nearly all the desired characteristics of a photocatalyst, with the main exception that it is only active under UV light and thus can only use around 5% of the solar spectrum. The synthesis and applications of titania 1D and 2D structures such as nanorods, nanowires and nanotubes has increased in the last decades due to their singular properties in terms of surface area, charge separation and transport, and tuneability (Fresno et al., 2014). In this work, we have obtained highly regular TiO2 nanostructures by oxidation of metallic Ti nanocolumns (NCs) obtained on silicon wafers by the so-called glancing angle deposition technique by magnetron sputtering (MS-GLAD). MS-GLAD is a powerful technique for producing nanostructured coatings in large areas and with a large variety of morphologies (Izquierdo-Barba et al., 2015). In addition, the TiO2 NCs have been decorated with gold nanoparticles (NPs) by means of high-power impulse magnetron sputtering (Mayoral et al., 2019)
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