Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Bioresour Technol ; 394: 130234, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38142906

RESUMO

A new alternative for hydrodynamic cavitation-assisted pretreatment of sugarcane bagasse was proposed, along with a simultaneous saccharification and co-fermentation (SSCF) process performed in interconnected columns. Influential variables in the pretreatment were evaluated using a statistical design, indicating that an ozone flow rate of 10 mg min-1 and a pH of 5.10 resulted in 86 % and 72 % glucan and xylan hydrolysis yields, respectively, in the subsequent enzymatic hydrolysis process. Under these optimized conditions, iron sulfate (15 mg L-1) was added to assess Fenton pretreatment, resulting in glucan and xylan hydrolysis yields of 92 % and 71 %, respectively, in a material pretreated for 10 min. In SSCF, ethanol volumetric productivities of 0.33 g L-1 h-1 and of 0.54 g L-1 h-1 were obtained in batch and fed-batch operation modes, achieving 26 g L-1 of ethanol in 48 h in the latter mode.


Assuntos
Celulose , Saccharomycetales , Saccharum , Celulose/metabolismo , Fermentação , Saccharum/metabolismo , Etanol , Hidrodinâmica , Células Imobilizadas/metabolismo , Xilanos , Hidrólise
3.
Bioresour Technol ; 345: 126458, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34863850

RESUMO

Environmental problems due to utilization of fossil-derived materials for energy and chemical generation has prompted the use of renewable alternative sources, such as lignocellulose biomass (LB). Indeed, the production of biomolecules and biofuels from LB is among the most important current research topics aiming to development a sustainable bioeconomy. Yet, the industrial use of LB is limited by the recalcitrance of biomass, which impairs the hydrolysis of the carbohydrate fractions. Hydrodynamic cavitation (HC) and Advanced Oxidative Processes (AOPs) has been proposed as innovative pretreatment strategies aiming to reduce process time and chemical inputs. Therefore, the underlying mechanisms, procedural strategies, influence on biomass structure, and research gaps were critically discussed in this review. The performed discussion can contribute to future developments, giving a wide overview of the main involved aspects.


Assuntos
Hidrodinâmica , Lignina , Biocombustíveis , Biomassa , Lignina/metabolismo , Estresse Oxidativo
4.
Lymphology ; 53(1): 29-37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32521128

RESUMO

One of the main obstacles to studying the pathophysiology of lymphedema development is the lack of appropriate experimental models. Fol-lowing up on a mouse-tail method that has been described, we performed changes to the method which made it easier to perform in our hands and demonstrated similar results. Twenty C57Black mice were operated on using the previous tech-nique and euthanized after 3 or 6 weeks. Another twenty mice were submitted to the new technique developed in our laboratory and euthanized at the same time points. Tissue samples were collected from the proximal part of the tail (control) and from the distal part (lymphedema) for both mod-els. Animals in both operative groups developed marked edema in the distal part of the tail. This was characterized by lymph vessels dilation, edema, inflammatory cell infiltration, and adipose tissue deposition. Lymphedema was detected after 3 weeks in both models, reaching its maximum after 6 weeks. Adipocytes detected by histology (Oil red O staining) and molecular markers for adipogenesis, lymphangiogenesis and inflam-mation (lipin 1 and 2, SLP76, and F4-80) were demonstrated to be increased equally in both models. In conclusion, both models provide a reliable method to study lymphedema pathophys-iology. However, our modified technique is easier and faster to perform while still providing reliable and consistent results.


Assuntos
Adipogenia , Modelos Animais de Doenças , Inflamação/patologia , Linfangiogênese , Vasos Linfáticos/patologia , Cauda/patologia , Animais , Inflamação/cirurgia , Camundongos , Camundongos Endogâmicos C57BL , Cauda/cirurgia
5.
Tissue Cell ; 53: 104-110, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30060820

RESUMO

Head and neck cancers are common in several regions of the world and the treatment usually includes radiotherapy. This treatment can generate adverse effects to the salivary flow, with a relationship between the dose and the damage caused. Salivary gland cells are highly permeable to water and therefore, they express aquaporins (AQPs). This study analyzed changes in the expression and location of these proteins and identified morphological changes induced by low radiation in rat submandibular gland. Female rats were divided into control and irradiated groups. Immunohistochemistry analysis allowed confirming the presence of AQP1 in the blood vessel endothelium. Intense and steady labelling granules were also observed in the cytoplasm of submandibular gland ductal cells. In addition, there was AQP5 positive labelling in ductal cells delimiting the lumen of intercalated duct, in the cytoplasm and membrane of acinar cells. Finally, the decrease of AQP labelling in irradiated animal glands validated their radiosensitivity. Thus, the decrease in AQP1 protein levels in the endothelium and AQP5 in gland ductal cells of irradiated animals may have hindered the removal of water from the lumen of ductal cells, inducing a delay in water absorption and triggering a slight lumen increase.


Assuntos
Células Acinares/metabolismo , Aquaporina 1/biossíntese , Aquaporina 5/biossíntese , Raios gama/efeitos adversos , Regulação da Expressão Gênica/efeitos da radiação , Glândula Submandibular/metabolismo , Células Acinares/patologia , Animais , Relação Dose-Resposta à Radiação , Feminino , Ratos , Ratos Wistar , Glândula Submandibular/patologia
6.
Rev. bras. plantas med ; 18(1,supl.1): 297-306, 2016. tab
Artigo em Português | LILACS | ID: lil-782969

RESUMO

RESUMO O presente trabalho teve como objetivo determinar a composição centesimal (cinzas, umidade, proteínas, lipídeos e carboidratos totais) e mineral (Na, K, Ca, Cu, Fe, Mg, Mn e Zn) das plantas medicinais Barbatimão (Stryphnodendron adstringens (Mart.) Coville), Carqueja (Baccharis trimera (Less) D.C.), Mangava-Brava (Lafoensia pacari A. St.-Hil.), e Quebra Pedra (Phyllanthus niruri L.) comercializadas no mercado do Porto de Cuiabá, MT. As amostras foram identificadas botanicamente por meio da exsicata feita no Instituto de Botânica da Universidade Federal de Mato Grosso, Campus Cuiabá. A composição centesimal foi determinada de acordo com as recomendações da Association of Official Analytical Chemists e a concentração dos minerais foi quantificada por Espectrometria de Absorção Atômica em Chama. Os resultados obtidos foram: umidade (7,72% a 12,10%); cinzas (1,64% a 8,44%); proteínas (2,36% a 9,35%); lipídeos (0,41% a 2,05%); carboidratos totais (72,09% a 82,37%) e, foram encontradas diferenças significativas entre as amostras (p < 0,05). As concentrações dos minerais nas amostras variaram de 0,01 a 21,57 mg/g nas plantas secas e 0,01 a 32,17 mg/200mL das infusões. Os resultados médios obtidos indicam que, exceto para o K, Ca e Mn todas as amostras não apresentaram diferenças significativas (p ≥ 0,05) nas concentrações de minerais. A capacidade de extração dos minerais da matéria seca para a infusão obedeceu à seguinte ordem: Na>K>Zn>Cu>Mg>Mn>Ca>Fe. Os valores obtidos em 200 mL das infusões quando comparados aos índices diários recomendados para minerais sugerem que os chás avaliados podem ser fonte de minerais, principalmente de K e Mn.


ABSTRACT The purpose of this study was to determine the proximal (ash, moisture, protein, lipids, and total carbohydrates) and mineral (Na, K, Ca, Cu, Fe, Mg, Mn, and Zn) composition of the medicinal plants barbatimão (Stryphnodendron adstringens (Mart.) Coville), carqueja (Baccharis trimera (Less) D.C.), mangava-brava (Lafoensia pacari A. St.-Hil.), pau-tenente (Quassia amara L.), and quebra pedra (Phyllanthus niruri L.), commercialized in the Cuiabá Port Market in Mato Grosso. The samples were botanically identified by the voucher specimen grown in the Botanical Institute of the Federal University of Mato Grosso, at the Cuiabá campus. Proximal composition was determined according to the recommendations of the Association of Official Analytical Chemists and the concentration of minerals was quantified by flame atomic absorption spectrometry. The results obtained were: moisture content (7.72% to 12.10%); ashes (1.64% to 8.44%); protein (2.36% to 9.35%); lipids (0.41% to 2.05%), and total carbohydrates (72.09% to 82.37%), and significant differences were found between the samples (p≥0.05). The mineral concentrations varied from 0.01 to 21.57 mg/g in the plants and 0.01 to 32.17 mg/200mL in the infusions. No significant differences (p≥0.05) were found between the samples for mineral composition, except for K, Ca, and Mg. The mineral extraction capacity of the dry matter for infusions was as follows: Na>K>Zn>Cu>Mg>Mn>Ca>Fe. The daily index values of the metal species quantified in 200 mL infusions suggest that teas can be a source of minerals, especially K and Mn.


Assuntos
Plantas Medicinais/classificação , Escala Centesimal , Metais/análise , Minerais/análise
8.
Talanta ; 83(5): 1763-8, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21238781

RESUMO

A carbon paste electrode was used for the electrochemical determination of linuron concentrations in water and vegetable extracts. Optimal conditions were established with respect to electrode activation (electrochemical pretreatment), time accumulation, potential accumulation, scan rate, and pH. The limit of detection achieved with a pre-concentration step was 23.0 µg L(-1). Recovery measurements in vegetable extract and natural water samples were in the range of 98-103%, indicating that the proposed electrochemical method can be employed to analyze linuron in these matrices. The determination results were in good agreement with HPLC results.


Assuntos
Carbono/química , Linurona/química , Verduras/química , Água/química , Cromatografia Líquida de Alta Pressão , Eletroquímica/métodos , Eletrodos , Herbicidas/química , Linurona/análise , Estrutura Molecular , Potenciometria
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA