Máscaras de tecido na prevenção da COVID-19: expectativa ou realidade?

Com a pandemia da COVID-19, causada pelo vírus SARS-Cov-2, o uso de máscaras para evitar transmissão tornou-se imprescindível em todo mundo,  preconizado como medida essencial para proteção, em conjunto as condutas de higienização das mãos e distanciamento social. As máscaras ideais, que fornecem maior proteção, são denominadas N95 e PFF2; já as máscaras cirúrgicas, mais utilizadas e conhecidas, têm faixas variáveis de proteção dependendo dos fornecedores. Em função da alta demanda mundial e necessidade de priorizar as máscaras de proteção e cirúrgicas aos profissionais que atuam na linha de frente no combate a pandemia, as autoridades de saúde mundialmente estimulam o uso de máscaras de tecido, também denominadas máscaras caseiras, que são produzidas artesanalmente, surgindo questionamentos da validade ou não do uso na prevenção da COVID-19. Assim, este trabalho objetivou revisar os estudos na temática, constatando que há opiniões divergentes de pesquisadores quando a eficiência desse utensílio, mas há metodologias capazes de avaliar o potencial desses utensílios, demonstrando que a eficácia está condicionada a qualidade dos materiais e técnica de confecção empregada, passível de obtenção de máscaras de tecidos com benefício na contenção dessa infecção. Assim, o trabalho disponibiliza orientações para confecção e manejo dessas máscaras; concluindo que uso de máscaras adequadas de tecidos pode representar ferramenta de grande utilidade na prevenção da COVID-19. ABSTRACTWith the pandemic of COVID-19, caused by the SARS-Cov-2 virus, the use of masks to prevent transmission has become essential worldwide, recommended as an essential measure for protection, together with hand hygiene and social distance. The ideal masks, which provide greater protection, are called N95 and PFF2; the surgical masks, more used and known, have variable protection bands depending on the suppliers. Due to the high global demand and the need to prioritize protective and surgical masks for professionals working on the front lines in the fight against the pandemic, health authorities worldwide encourage the use of fabric masks, also called homemade masks, which are produced handcrafted, raising questions about the validity or not of use in the prevention of COVID-19. Thus, this study aimed to review the studies on the theme, noting that there are divergent opinions from researchers when the efficiency of this tool, but there are methodologies capable of evaluating the potential of these tools, demonstrating that the effectiveness is conditioned to the quality of the materials and the cooking technique employed, capable of obtaining tissue masks with benefit in containing this infection. Thus, the work provides guidelines for making and handling these masks; concluding that the use of appropriate fabric masks can represent a very useful tool in the prevention of COVID-19.Keywords: SARS-CoV-2; homemade masks; efficiency; confection. RESUMENCon la pandemia de COVID-19, provocada por el virus SARSCov-2, el uso de mascarillas para prevenir la transmisión se ha vuelto imprescindible a nivel mundial, recomendado como medida imprescindible de protección, junto con la higiene de manos y el distanciamiento social. Las máscaras ideales, que brindan mayor protección, se denominan N95 y PFF2; las mascarillas quirúrgicas, más utilizadas y conocidas, tienen bandas de protección variables según los proveedores. Debido a la alta demanda mundial y la necesidad de priorizar las mascarillas protectoras y quirúrgicas para los profesionales que trabajan en primera línea en la lucha contra la pandemia, las autoridades sanitarias de todo el mundo fomentan el uso de mascarillas de tela, también llamadas mascarillas caseras, que se producen de forma artesanal. planteando dudas sobre la validez o no del uso en la prevención de COVID-19. Así, este trabajo tuvo como objetivo revisar los estudios sobre el tema, notando que existen opiniones divergentes de los investigadores a la hora de la eficiencia de este utensilio, pero existen metodologías capaces de evaluar el potencial de estos utensilios, demostrando que la efectividad está condicionada a la calidad. de los materiales y la técnica de cocción empleada., capaz de obtener mascarillas de tejido con beneficio para contener esta infección. Por lo tanto, el trabajo proporciona pautas para la fabricación y manipulación de estas máscaras; concluyendo que el uso de máscaras de tela adecuadas puede representar una herramienta muy útil en la prevención de COVID-19.Palabras Clave: SARS-CoV-2; Máscaras caseras; Eficiencia; Confección

Perspectivas atuais sobre o uso de psilocibina no manejo da depressão resistente: revisão sistemática

A depressão resistente ao tratamento é um desafio global, impactando negativamente a qualidade de vida dos pacientes. Nesse contexto, a psilocibina, um composto psicodélico presente em certos cogumelos, desperta interesse como possível intervenção terapêutica. Seu potencial para influenciar positivamente o humor e a cognição, através da ativação dos receptores de serotonina no cérebro, sugere uma nova abordagem no tratamento da depressão resistente. Este estudo busca analisar as perspectivas atuais sobre o uso da psilocibina nesse contexto, destacando a necessidade de mais pesquisas sobre seus efeitos e segurança para sua integração clínica. Este estudo, baseado em uma revisão sistemática da literatura científica, abrange o período de 2016 a 2024, utilizando as bases de dados PubMed (Medline), Cochrane Library e Scientific Electronic Library Online (SciELO). No primeiro estudo, os efeitos agudos da psilocibina foram detectáveis de 30 a 60 minutos após a administração, atingindo o pico em 2 a 3 horas e diminuindo após pelo menos 6 horas. A substância foi bem tolerada, com eventos adversos leves e transitórios. Houve uma redução significativa nos sintomas depressivos, ansiedade e anedonia após o tratamento com doses altas. O segundo estudo envolveu 233 participantes distribuídos em grupos de doses diferentes. Houve uma redução significativa nos sintomas depressivos após o tratamento, com doses mais altas apresentando uma diferença estatisticamente maior em comparação com a dose mais baixa e o grupo de controle. Eventos adversos, como dor de cabeça e náusea, foram comuns entre os participantes. O terceiro estudo abordou as perspectivas futuras para o tratamento com psilocibina para depressão resistente. Recomendações incluíram equilibrar o tempo dos pacientes e terapeutas, aumentar gradualmente a intensidade das sessões e integrar a terapia sustentada ao tratamento. O envolvimento de pacientes experientes e estudos naturalísticos adicionais foi destacado como importante para abordagens mais personalizadas. Em resumo, a psilocibina mostra potencial como tratamento para a depressão resistente, com redução significativa dos sintomas depressivos e boa tolerabilidade. No entanto, são necessárias mais pesquisas para confirmar sua eficácia e segurança, destacando a importância de estudos adicionais e ensaios clínicos controlados

Molluscicidal effect of Euphorbia umbellata (Pax) Bruyns latex on Biomphalaria glabrata, Schistosoma mansoni host snail

Euphorbia umbellata (Pax) Bruyns is an easily cultivated shrub, with occurrence in the tropical regions of the American and African continents. Chemical studies have revealed that the latex of this plant is rich in terpene compounds, which are highly toxic to snails Biomphalaria glabrata (Basommatophora: Planorbidae). The aim of this study was to evaluate the chemical composition and molluscicidal activity of the latex produced by E. umbellata, as well as the safety of its application in aquatic environments. The concentration of latex that killed 90% of the exposed snails after 24 h exposure (LC90) was 3.69 mg/L. Toxicity bioassays using Danio rerio (zebrafish) revealed that these animals were less susceptible to latex than planorbids. However, it is important to perform other toxicity tests to ensure the feasibility of using latex to control populations of mollusks that contribute to schistosomiasis transmission. A phytochemical screening performed with the E. umbellata latex identified the triterpenoid and coumarin class. Further studies are warranted to isolate, identify, and test the active compounds of E. umbellata latex in B. glabrata

Molluscicidal effect of Euphorbia umbellata (Pax) Bruyns latex on Biomphalaria glabrata, Schistosoma mansoni host snail

ABSTRACT Euphorbia umbellata (Pax) Bruyns is an easily cultivated shrub, with occurrence in the tropical regions of the American and African continents. Chemical studies have revealed that the latex of this plant is rich in terpene compounds, which are highly toxic to snails Biomphalaria glabrata (Basommatophora: Planorbidae). The aim of this study was to evaluate the chemical composition and molluscicidal activity of the latex produced by E. umbellata, as well as the safety of its application in aquatic environments. The concentration of latex that killed 90% of the exposed snails after 24 h exposure (LC90) was 3.69 mg/L. Toxicity bioassays using Danio rerio (zebrafish) revealed that these animals were less susceptible to latex than planorbids. However, it is important to perform other toxicity tests to ensure the feasibility of using latex to control populations of mollusks that contribute to schistosomiasis transmission. A phytochemical screening performed with the E. umbellata latex identified the triterpenoid and coumarin class. Further studies are warranted to isolate, identify, and test the active compounds of E. umbellata latex in B. glabrata

Study of antimicrobial activity and atomic force microscopy imaging of the action mechanism of cashew tree gum

The aim of this work was to evaluate the antimicrobial potential of two grades of cashew tree gum (crude and purified) against eight microorganisms and to analyze the mechanism of cashew tree gum antimicrobial action via atomic force microscopy (AFM) imaging. The results indicated strong antimicrobial properties of pure cashew tree gum against all tested microorganisms, except for Candida albicans and Lactobacillus acidophilus. On the other hand crude cashew gum showed antimicrobial activity only against Gram-positive bacteria (MRSA, MSSA, Listeria innocua and Enterococcus faecium). Atomic force microscopy imaging showed that pure cashew tree gum lead to bacterial cell collapse. In conclusion cashew tree gum presented relevant antimicrobial activity against most of the studied bacteria, and the purification of the cashew gum affected its antimicrobial spectrum.info:eu-repo/semantics/publishedVersio

Green synthesis and characterization of silver nanoparticles reduced and stabilized by cashew tree gum

The advance in nanotechnology has enabled us to utilize particles in the size of the nanoscale. Among the most promising nanomaterials with antibacterial properties are metallic nanoparticles, which exhibit increased chemical activity due to their large surface to volume ratios. In the case of silver, the currently available data reveals the potential benefits and the wide range of applications. In this context, the application of green chemistry in the nano-science and technology is very important in the area of the preparation of various materials. The present study describes the development and the characterization of a rapid and low cost green synthesis of silver nanoparticles reduced and stabilized by exuded gum from Anacardium occidentale L. and evaluates in vitro their antibacterial activity. Characterization of cashew tree gumbased silver nanoparticles (AgNPs) was carried out based on UV-Vis spectroscopy, Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR). The main results revealed that the synthesized silver nanoparticles were spherical in shape, measuring about 4.5 to 6.5 nm in size with a uniform dispersal. AgNPs presented antibacterial activity, especially against Gram-negative bacteria

CHEMICAL CONSTITUENTS ISOLATED FROM Turnera subulata

Turnera subulata Sm., known as "Chanana" or "flor-do-Guarujá" in Brazilian folklore, is a plant species belonging to the subfamily Turneroideae of family Passifloraceae, which is used for various medicinal purposes in Brazil. The phytochemical study conducted here led to the isolation and identification of ten compounds present in T. subulata: two mixtures of steroids, sitosterol and stigmasterol (nonglycosylated and glycosylated); a mixture of flavonoids, 5,7,4′-trihidroxiflavona-8-C-α-glucopyranoside and 5,7,3′,4′-tetrahidroxiflavona-8-C-α-glucopyranosidel; and four phaeophytins, phaeophytin purpurin-18-phytyl ester, a rare natural product, phaeophytin a , 13²-hydroxy-(13²-S)-phaeophytin a , and phaeophytin b Phaeophytin b exhibited electrochemical activity similar to that of phthalocyanines

Antibacterial application of natural and carboxymethylated cashew gum-based silver nanoparticles produced by microwave-assisted synthesis

© 2019 Published by Elsevier Ltd.This study presents a green synthesis route to silver nanoparticles (AgNPs) stabilized with cashew gum (CG) or carboxymethylated cashew gum (CCG) using microwave-assisted synthesis and evaluates their antibacterial activity. The antimicrobial activity was measured by determining the minimum inhibitory concentration (MIC) with Staphylococcus aureus and Escherichia coli. In both cases of the presence of CG and CCG, it was found that higher pH lead to more efficient conversion of silver nitrate to AgNPs with well dispersed, spherical and stable particles as well as low crystallinity. CCG-capped AgNPs were slightly smaller (137.0 and 96.3 nm) than those coated with non-modified gum (144.7 and 100.9 nm). The samples presented promising antibacterial activity, especially on Gram-negative bacteria, resulting in significant membrane damage on treated bacteria in comparison to the untreated control, observed by atomic force microscopy. Thus, a quick and efficient synthesis route was applied to produce CGAgNPs and CCGAgNPs with antimicrobial potential.The authors gratefully acknowledge financial support from CAPES and FAPEPI; ACM are grateful to FAPESP (2014/02282-6 AND 2016/18023-5). YPM is grateful to CAPES (AUX-PERM-705/2009). The authors also acknowledge the CNPq and Capes for scholarship and financial aid. The authors are grateful to Fundação para a Ciência e a Tecnologia (MCTES funds) and European Union (European Social Fund and European Regional Development Fund), for financial support through project UID/QUI/50006/2013–POCI-01-0145-FEDER-007265 (LAQV-REQUIMTE), in the context of the COMPETE program from QREN, project NORTE-01-0145-FEDER-000011, in the context of the NORTE 2020 program, and fellowships SFRH/BD/97995/2013 (AP) and SFRH/BD/95983/2013 (MPdA), in the context of the POCH program, both from Portugal 2020 partnership agreement.info:eu-repo/semantics/publishedVersio