Compliance of commercial bleaches and stability of 1 g/L-dilutions using different sources of drinking water / Conformidad de lavandinas comerciales y estabilidad de diluciones 1g/L utilizando diferentes fuentes de agua potable

Introducción y Objetivos: En el contexto de COVID-19, la Organización Mundial de la Salud recomienda el uso de soluciones de hipoclorito de sodio 1 g/L, como una concentración capaz de inactivar el SARS-CoV-2 y la gran mayoría de patógenos presentes en el entorno sanitario. En consecuencia, hay un renovado interés en realizar estudios de estabilidad de estas disoluciones. El objetivo de este trabajo es verificar la concentración de cloro activo en varias marcas comerciales de hipoclorito de sodio y proponer una fecha límite de uso para soluciones de 1 g/L, obtenidas por dilución con agua potable proveniente de diferentes fuentes.Métodos: La concentración de cloro activo de preparaciones comerciales con concentración nominal entre 25-60 g/L fue valorada por titulación iodométrica. A partir de una de las marcas comerciales se prepararon diluciones de 1 g/L usando agua proveniente de diferentes plantas potabilizadoras en Córdoba, Argentina. Las disoluciones se almacenaron a temperatura ambiente, tanto expuestas como protegidas de la luz y fueron posteriormente tituladas a intervalos de tiempo preestablecidos. La fecha límite de uso se alcanzó cuando la concentración de cloro activo cayó por debajo del 90 % de la inicial.Resultados: La concentración de cloro activo en las soluciones comerciales estuvo dentro de los valores establecidos por la normativa vigente. Las diluciones protegidas de la luz mostraron una disminución menor al 10 % en la concentración de cloro activo durante los primeros 10 días de ensayo. (AU)

Introduction and objectives: In the context of COVID-19, the World Health Organization has recommended the use of extemporaneously prepared bleach solutions of 1 g/L, as a conservative concentration able to inactivate SARS-CoV-2 and the vast majority of other pathogens that may be present in the healthcare setting. Consequently, there is a renewed interest in conducting stability studies of these solutions. The goal of this work was to verify the available chlorine concentration in several bleach solutions trademarks and to propose a beyond use date for 1 g/L bleach solutions, obtained after dilution with drinking water from different sources.Methods: Bleach trademarks, with nominal concentrations between 25-60 g/L, were subjected to iodometric titration to determine the available chlorine concentration. One trademark was used to prepare 1 g/L dilutions using water from different purification plants in Córdoba, Argentina. The samples were stored at room-temperature, both exposed or protected from light. The available chlorine concentration was determined by titration at preestablished time intervals. The beyond use date was reached when the available chlorine concentration dropped below 90 % of its initial.Results: The concentration of active chlorine in the different trademark bleaches was within the values established by current regulations. Diluted solutions protected from light showed a decrease of less than 10 % in active chlorine concentration during the first 10 days of assay. However, one sample exceeded the acceptance limit after 14 days. In contrast, in the samples exposed to light, the concentration of active chlorine dropped to 96.4 % at 24 hours and 79.3 % after 48 hours. (AU)

A contribuição dos estudos críticos da branquitude para compreensão do preconceito racial na psicologia social / La contribución de los estudios críticos del blanqueo a la comprensión del prejuicio racial en la psicología social / The contribution of critical whiteness studies to the understanding of racial prejudice in social psychology

Este artigo tem como objetivo apresentar as principais abordagens em que a psicologia social clássica norte-americana teorizou sobre o preconceito racial, o racismo e o antirracismo e, a partir delas, trazer os estudos críticos da branquitude como possibilidades para superar os limi-tes identificados nessa corrente, que ora apresenta um indivíduo fora da estrutura, ora a estru-tura sem indivíduos. Para isto, neste artigo definimos três abordagens propostas pela psicologia social norte-americana: teste de associação implícita; teoria do contato intergrupal e racismo aversivo; e emoções específicas. A partir daí mostramos como os estudos críticos da branquitu-de se apresentam como uma síntese entre essas duas posições opostas, que oscilam entre o in-divíduo e a estrutura. Nesta perspectiva, a estrutura se manifesta na própria experiência sub-jetiva do indivíduo, que se torna capaz de identificá-la em seu próprio campo experiencial. (AU)

The goal of this article is to present the main approaches through which classical North Amer-ican social psychology has theorized about racial prejudice, racism and antiracism, and on that basis present critical whiteness studies as possibilities to overcome the limits identified within these approaches, which presents us either with individuals outside the structure, or with a structure with no individuals. For that purpose, in this article we identify three main ap-proaches in North American social psychology: implicit association test; intergroup contact theory and aversive racism; and specific emotions. On that basis we show how critical white-ness studies may be presented as a synthesis between these two extremes, which oscillates between the individual and the structure. In this perspective, the structure is manifested in the individual’s subjective experience in the world, and thus identifiable in one’s own experi-ential field. (AU)

La contribución de Francis Home (1720-1813) y William Lewis (1708-1781), autores farmacéuticos, a los álcalis y el blanqueo / The contribution of Francis Home (1720-1813) and William Lewis (1708-1781), pharmaceutical authors, to the alkalis and bleaching

Se efectúa una aproximación al blanqueo de tejidos y al uso de los álcalis con carácter previo a considerar las contribuciones de Francis Home y William Lewis, autores de perfiles farmacéuticos. Se muestra la relevancia de sus trabajos y el valor de sus publicaciones. La química y la práctica van de la mano en el desarrollo de estos temas (AU)

A brief on bleaching and alkalis is given previous to the life and contributions of Francis Home and William Lewis, pharmaceutical profile authors. The relevance of their work and the worth of their publications are revealed. Chemistry and practice go hand in hand in the development of these issues (AU)

Hiperpigmentación facial simétrica adquirida / Acquired Symmetric Facial Hyperpigmentation

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Blanqueamiento ocular quirúrgico. Cosmética versus seguridad / Surgical eye whitening. Cosmesis versus safety

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