3 research outputs found

    Ventilated modular tile design in resin and unfired clay

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    En muchas ocasiones se han buscado alternativas a los materiales con que se cubren las viviendas, y uno de los materiales más usados es la teja criolla, un material hecho con barro dándole forma y horneado después, es por ello que el objetivo de este trabajo fue proponer una teja en resina y arcilla sin cocimiento alguno, con esto se pretende mejorar el cómo se cubren las viviendas y ahorrando energía en su cocción, este trabajo fue de corte documental y descriptivo, ya que se analizaron materiales los cuales se propusieron para la realización de la teja, con esto se espera mejorar el desempeño de la teja antes utilizada con base a conseguir un material con un menor peso y menor costo.On many occasions, alternatives to the materials used to cover the houses have been sought, and one of the most used materials is the creole tile, a material made with clay giving it shape and baked afterwards, that is why the objective of this work was to propose a tile in resin and clay without any baking, This work was documentary and descriptive, since the materials proposed for the production of the tile were analyzed. It is hoped that this will improve the performance of the tile previously used, based on obtaining a material with a lower weight and lower cost

    Risk of COVID-19 after natural infection or vaccinationResearch in context

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    Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health
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