187 research outputs found

    Aplicação e avaliação do uso de concentrador centrifugo a5-b para obtenção de concentrado de minério primário de au – Peixoto de Azevedo (mt)

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    Atualmente, num mundo cada vez mais competitivo, o rendimento das atividades humanas deve ser o maior possível, seja através da melhoria de técnicas ou tecnologias. Com o preço do ouro em alta e baixos teores de ouro nas reservas torna-se imperativo o aproveitamento máximo do minério, onde recuperação de metais nobres através de processos gravimétricos tem contemplado um grande avanço através do surgimento dos concentradores centrífugos. Este trabalho apresenta o processo de melhoria nas atividades de beneficiamento do minério de ouro (gravimetria) com a utilização de um sistema de concentração centrífuga através de um cesto cônico perfurado, onde, por diferença de densidade, o metal (ouro) é concentrado na parte externa do cesto. São descritos os equipamentos utilizados, bem como a metodologia adotada para britagem e peneiramento do material. Os fundamentos teóricos são mostrados de forma simplificada, de forma a permitir o pleno entendimento da proposta. Os resultados obtidos neste piloto, quando comparados à média obtida para região, se mostram extremamente satisfatórios, comprovando que a proposta apresentada é de grande valia para o ramo de beneficiamento de metais auríferos, pois garante grande recuperação de ouro frente a um pequeno investimento em equipamentos.Peer ReviewedPostprint (published version

    Caracterização de rejeito aluvionar de minério de ouro da região de Peixoto de Azevedo (mt)

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    A extração de ouro nos garimpos, que na maioria das vezes é feita de forma rudimentar (apenas por gravimetria), não garante a obtenção de um bom rendimento, o que gera rejeitos (curimã) com alto teor de minério (ouro). Visando a melhoria no estado da arte do processamento de minérios aluvionares, este estudo de caso visa caracterizar o rejeito do Garimpo Jatobá no vale do rio Peixoto de Azevedo, através de ensaios de concentração gravimétrica, análises granulométrica e química. O método adotado foi a coleta do material direto no garimpo através de um trado, elaboração de curva granulométrica (método Rosin-Rammler), peneiramento, separação de amostras e a análise físico/química de onde foram obtidos os diversos teores de ouro presentes em cada amostra e plotado um quadro comparativo.Peer ReviewedObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version

    Polymeric micelles containing resveratrol: development, characterization, cytotoxicity on tumor cells and antimicrobial activity

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    Antimicrobial and antitumor activities of resveratrol, a compound found mainly in grapes, have already been demonstrated. However, its low bioavailability is a limiting factor for therapeutic application. Polymeric micelles can be an approach to solve this problem since they can encapsulate hydrophobic substances. We developed and characterized micellar formulations containing resveratrol and evaluated their cytotoxic and antimicrobial effects. The formulations were prepared by the cold dispersion method with different concentrations of F127 (5 or 10% w/w) and resveratrol (500 or 5000 µM). The formulations were characterized according to size, polydispersity index, pH, encapsulation rate and in vitro release. Cytotoxic effect was evaluated on a bladder cancer cell line and antimicrobial effect was evaluated on E. coli, S. aureus and C. albicans. One of the formulations (10% w/w of F127 and 5000 µM of resveratrol) was a monodispersed solution with high encapsulation rate, thus it was chosen for the cytotoxicity and antimicrobial assays. MS10+RES-3 was able to preserve the antimicrobial and cytotoxic activity of resveratrol. This is the first study that evaluated antimicrobial potential and cytotoxicity of micelles containing resveratrol on bladder cancer cells and the results showed that micellar nanostructures could ensure the maintenance of the biological activity of resveratrol

    Methods for in vitro evaluating antimicrobial activity of medicinal plants : the need for standardization.

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    A crescente incid?ncia de pat?genos resistentes aos medicamentos atuais incentiva a busca de novos agentes antimicrobianos. Neste contexto, as plantas medicinais se destacam, sendo uma importante fonte de novos f?rmacos. Existem diversos m?todos para avaliar a atividade antibacteriana e antif?ngica de extratos, fra??es, ?leos essenciais e subst?ncias isoladas de vegetais. Os mais conhecidos incluem m?todos de difus?o, dilui??o e bioautografia. A proposta desse trabalho ? apresentar os m?todos mais utilizados atualmente, juntamente com suas vantagens, desvantagens e fatores interferentes. Entre os artigos indexados na biblioteca SciELO, abrangendo os ?ltimos dez anos, somente 4,4% das pesquisas com plantas medicinais est?o relacionadas com atividade antimicrobiana. O m?todo mais utilizado foi a microdilui??o (57,9%), o mais recomendado devido ? alta sensibilidade, ? quantidade m?nima de reagentes e amostra e ? possibilidade de um maior n?mero de r?plicas. Nos trabalhos que utilizaram esse m?todo, foram verificadas diverg?ncias de fatores que podem interferir nos resultados. A fim de facilitar a obten??o de resultados compar?veis e reprodut?veis, destaca-se a necessidade da padroniza??o dos m?todos utilizadas pelos pesquisadores. Recomenda-se utilizar como refer?ncia as normas estabelecidas pelo CLSI para meio de cultura e concentra??o de in?culo nos testes. Al?m disso, tamb?m recomenda-se a inclus?o de um controle negativo da forma de solubiliza??o das amostras, com quantifica??o do crescimento microbiano, para evitar a interfer?ncia nos resultados.The increasing incidence of resistant pathogens to current drugs encourages the search for new antimicrobial agents. In this context, medicinal plants are an important source of new drugs. There are several methods for evaluating the antibacterial and antifungal activity of extracts, fractions, essential oils and isolated substances from the plant. The most known include diffusion, dilution and bioautography methods. The purpose of this paper is to present the most used methods currently, along with their advantages, disadvantages and interfering factors. Among the works available in the SciELO database, covering the last ten years, only 4,4% of research on medicinal plants are related to the antimicrobial activity. The most used method is microdilution (57,9%), the best recommended due to high sensitivity, the minimum quantity of reagents and sample and the possibility of a more significant number of replicates. In articles that used this method, differences were observed in factors that may affect the results. Thereby, there is the need for standardization of methods used by researchers to facilitate obtaining comparable and reproducible results. To achieve comparable and reproducible results, there is the need to standardize the methods used by the researchers. It is recommended to use as reference the standards established by CLSI for culture medium and inoculum concentration in the tests. It also recommended the inclusion of negative control of the solubilization of the samples with quantification of microbial growth to avoid interference with the results

    Níveis de acidez do solo para recomendação de calagem e aumento de produção da amora-preta

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    The objective of this work was to determine the acidity levels to obtain adequate soil chemical attributes for the maximum fruit yield of blackberry trees grown in acidic soils subjected to increasing limestone rates. The BRS Tupy, Brazos, Guarani, and BRS Xavante blackberry cultivars were evaluated on the Typic Hapludox (LVdf) and Rhodic Hapludox (LVd) soils, to which four rates of dolomitic limestone were applied (0, 1.5, 3.0, and 6.0 Mg ha-1). The effect of liming on soil chemical attributes, in a 2×4 factorial arrangement (soils and limestone rates), as well as leaf nutrient content and fruit yield, in a 2×4×4 factorial arrangement (soils, limestone rates, and cultivars), were evaluated. The maximum fruit yield was obtained with 3.3 Mg ha-1 dolomitic limestone. The blackberry cultivars showed a high demand for Ca, Mg, and base saturation and a low tolerance to aluminum in the soils. From 3.3 Mg ha-1 dolomitic limestone, the maximum fruit yield of blackberry trees grown in acidic soils is obtained with pH 5.6, maximum tolerated aluminum saturation of 6%, Ca and Mg concentration of 45.3 mmolc kg-1, and base saturation of 48.3%.O objetivo deste trabalho foi determinar os níveis de acidez para obter os atributos químicos do solo adequados à máxima produção de frutos de amoreiras-pretas cultivadas em solos ácidos submetidos a doses crescentes de calcário. Foram avaliadas as cultivares de amoreira-preta BRS Tupy, Brazos, Guarani e BRS Xavante nos solos Latossolo Vermelho Distroférico (LVdf) e Latossolo Vermelho distrófico (LVd), aos quais foram aplicadas quatro doses de calcário dolomítico (0, 1,5, 3,0 e 6,0 Mg ha-1). Foram avaliados o efeito da calagem sobre os atributos químicos do solo, em arranjo fatorial 2×4 (solos e doses de calcário), bem como o teor de nutrientes foliares e a produção de frutos, em arranjo fatorial 2×4×4 (solos, doses de calcário e cultivares). A produção máxima de frutos foi obtida com 3,3 Mg ha-1 de calcário dolomítico. As cultivares de amoreira-preta apresentaram alta demanda por Ca, Mg e saturação por bases e baixa tolerância ao alumínio nos solos. A partir de 3,3 Mg ha-1 de calcário dolomítico, a produção máxima de frutos de amoras-pretas cultivadas em solos ácidos é obtida com pH 5,6, saturação máxima tolerada de alumínio de 6%, concentração de Ca e Mg de 45,3 mmolc kg-1 e saturação por bases de 48,3%

    Quintal da saúde project : new care strategies

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    O projeto de extensão Quintal da Saúde busca unir e difundir amplamente os saberes científico e popular sobre as plantas medicinais. O projeto se desenvolve fisicamente nos jardins internos da FS, onde são cultivadas inúmeras espécies de plantas de maneira orgânica, permitindo além da interação do público com o projeto, a possibilidade de realizar ações voltadas para a educação em saúde por meio do uso de plantas medicinais e de outras práticas integrativas. No ano de 2020, o mundo foi surpreendido pela pandemia da Covid-19, o que levou a reformulação do projeto. As ações educativas migraram para as plataformas digitais, com postagens semanais, rodas de conversa com participação de pesquisadores de outros estados, além de vídeos, o que tornou possível a interação de um número maior de pessoas com os conteúdos produzidos.The Quintal da Saúde extension Project seeks to unite and widely disseminate scientific and popular knowledge about medicinal plants. The project is physically developed in the internal gardens of the FS, where numerous species of plants are grown organically, allowing, in addition to the public interaction with the project, the possibility of carrying out actions aimed at health education through the use of medicinal plants and other integrative practices. In 2020, the world was surprised by Covid-19 pandemic, which led to the reformulation of the project. Educational actions migrated to digital platforms, with weekly posts and conversation circles with the participation of researchers from other states, in addition to videos, which made it possible for a greater number of people to interact with the content produced

    Propiedades biológicas y caracterización fitoquímica del extracto acuoso de Miconia chamissois Naudin

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    The objective of this study was to evaluate biological and phytochemical properties of the aqueous extract from the leaves of Miconia chamissoisNaudin (AEMC). Phytochemical properties were assessed by analyzing the chromatographic profile and the polyphenol content of AEMC. Biological properties evaluation wasconducted based on cytotoxicity assay and by evaluating the antioxidant, antimicrobial, and enzymatic inhibition activities. Results indicated the presence of phytochemicals in AEMC such as flavonoids and polyphenols, including rutin, isoquercitrin and vitexin derivatives. AEMC showed antioxidant activity, which may be attributed to the high polyphenolic content. Moreover, AEMC demonstrated in vitro enzyme inhibition activity against tyrosinase and alpha-amylase, as well as showed low cytotoxicity. On the other hand, AEMC exhibited weak antimicrobial activity against S. aureusand C. albicans. Thus, AEMC is a promising alternative in search of potential drugs for the treatment of diseases induced by oxidative stress and inflammation, conditions due to hyperpigmentation processes, such as melisma, as well as for diabetes.El objetivo de este estudio fue detectar las propiedades biológicas y fitoquímicos del extracto acuoso de las hojas de Miconia chamissois Naudin (AEMC). Las propiedades fitoquímicas se evaluaron analizando el perfil cromatográfico y el contenido de polifenoles de AEMC. La evaluación de las propiedades biológicas se realizó en base al ensayo de citotoxicidad y evaluando las actividades de inhibición antioxidante, antimicrobiana y enzimática. Los resultados indicaron la presencia de fitoquímicos en AEMC, como flavonoides y polifenoles, que incluyen derivados de rutina, isoquercitrina y vitexina. AEMC mostró una actividad antioxidante considerable, que puede atribuirse al alto contenido polifenólico. Además, AEMC exhibió actividad de inhibición enzimática in vitro contra tirosinasa y alfa-amilasa, así como mostró baja citotoxicidad. Por otro lado, AEMC demostró actividad antimicrobiana débil contra S. aureus y C. albicans. Por lo tanto, AEMC es una alternativa prometedora en busca de posibles drogas para el tratamiento de enfermedades inducidas por el estrés oxidativo y la inflamación, afecciones debidas a procesos de hiperpigmentación, como el melasma, así como para la diabetes

    Antinociceptive and Anti-Inflammatory Activity from Algae of the Genus Caulerpa

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    Marine natural products have been the focus of discovery for new products of chemical and pharmacological interest. The aim of this study was to evaluate the antinociceptive activity of the methanolic (ME), acetate (AE), hexanic (HE) and chloroform (CE) extracts obtained from Caulerpa mexicana, and ME, CE and HE obtained from Caulerpa sertularioides. These marine algae are found all over the world, mainly in tropical regions. Models such as the writhing test, the hot plate test and formalin-induced nociception test were used to evaluate antinociceptive activity in laboratory mice. In the writhing test, all the extracts were administered orally at a concentration of 100 mg/kg, and induced high peripheral antinociceptive activity, with a reduction in the nociception induced by acetic acid above 65%. In the hot plate test, treatment with extracts from C. sertularioides (100 mg/kg, p.o.) did not significantly increase the latency of response, although the ME, AE and HE from C. mexicana showed activity in this model. This result suggests that these extracts exhibit antinociceptive activity. In the formalin test, it was observed that ME, AE and HE obtained from C. mexicana reduced the effects of formalin in both phases. On the other hand only CE from C. sertularioides induced significant inhibition of the nociceptive response in the first phase. To better assess the potential anti-inflammatory activity of the extracts, the carrageenan-induced peritonitis test was used to test Caulerpa spp. extracts on cell migration into the peritoneal cavity. In this assay, all extracts evaluated were able to significantly inhibit leukocyte migration into the peritoneal cavity in comparison with carrageenan. These data demonstrate that extracts from Caulerpa species elicit pronounced antinociceptive and anti-inflamatory activity against several nociception models. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for the antinociceptive action and also to identify the active principles present in the Caulerpa species
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