1,007 research outputs found
Purification of plant complex protein extracts in non-denaturing conditions by in-solution isoelectric focusing
An alternative approach for plant complex protein extracts pre-purification by in-solution isoelectric focusing in non-denaturing conditions is presented. The separation of biologically active proteins, in narrow ranges of isoelectric point (pI) was obtained by a modified OFFGEL electrophoresis. Two different water-soluble protein extracts from Phragmites leaves were fractionated into 24 fractions within a 3-10 pI range at 10 °C in the absence of denaturing/reducing agents. One-dimensional electrophoretic analysis revealed different protein distribution patterns and the effective fractionation of both protein extracts. Peroxidase activity of each fraction confirmed that proteins remained active and pre-purification occurred. Biological triplicates assured the needed reproducibility
O Comportamento Cíclico do Capital dos Bancos Brasileiros
No contexto de transição regulamentar para os padrões do acordo de Basiléia II, este artigo analisa o comportamento cíclico do capital bancário brasileiro sob a regulação atual. Utilizamos um painel não-balanceado de dados dos bancos operando no Brasil entre 2003 e 2008 para estimar, através de técnicas de painel dinâmico, uma equação do capital econômico dos bancos. Nossos resultados mostram que esta variável move-se com o ciclo de negócios.Bancos, Basiléia II, Ciclos Econômicos, Capital dos Bancos
Extração de taninos de Acacia sp. com potencial uso na coagulação: um contributo para a bioeconomia
Coagulation-flocculation is one of the most important steps in water treatment. In Water Treatment Plants, pre-polymerized inorganic coagulants are traditionally used; however, recent studies have shown the potential of condensed tannins for the production of natural coagulants as an alternative to chemical coagulants. In this context, the present work intends to highlight the importance of the development of nature-based solutions that can be alternative to conventional processes, due to the environmental, social and economic benefits they can provide. The study focused on optimizing condensed tannin extraction process from Acacia dealbata barks, as a strategy for valuing forest residues, promoting the territory bioeconomy and sustainability. In the tested extraction conditions, the best yield was obtained at a temperature of 40 oC, using 50% ethanol (v/v) as the solvent, without stirring and an extraction time of 30 min. The highest concentrations of condensed tannins and phenolic compounds were observed in samples of Acacia sp. with higher vegetative development (trunk perimeter of 20 cm), corresponding to 246,2 ± 9,4 miligrams per gram of dry extract (mg ges-1) and 706,2 ± 27,2 mg ges-1, respectively.Este trabalho foi desenvolvido no âmbito do projeto TECH - Tecnologia, Ambiente, Criatividade e Saúde, Norte-01-0145-FEDER-000043, cofinanciado pelo Programa Operacional Regional do Norte (NORTE 2020), através do Portugal 2020 e do Fundo Europeu de Desenvolvimento Regional (FEDER). Leonel Nunes foi apoiado pela
proMetheus - Unidade de Investigação & Desenvolvimento em Materiais, Energia e Ambiente para a Sustentabilidade- UIDP/05975/2020, financiado por fundos nacionais através de FCT — Fundação para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio
Identification and characterisation of xylanolytic yeasts isolated from decaying wood and sugarcane bagasse in Brazil
In this study, yeasts associated with lignocellulosic materials in Brazil, including decaying wood and sugarcane bagasse, were isolated, and their ability to produce xylanolytic enzymes was investigated. A total of 358 yeast isolates were obtained, with 198 strains isolated from decaying wood and 160 strains isolated from decaying sugarcane bagasse samples. Seventy-five isolates possessed xylanase activity in solid
medium and were identified as belonging to nine species: Candida intermedia, C. tropicalis, Meyerozyma guilliermondii, Scheffersomyces shehatae, Sugiyamaella smithiae, Cryptococcus diffluens, Cr. heveanensis, Cr. laurentii and Trichosporon mycotoxinivorans. Twenty-one isolates were further screened for total xylanase activity in liquid medium with xylan, and five xylanolytic yeasts were selected for further
characterization, which included quantitative analysis of growth in xylan and xylose and xylanase and ß-d-xylosidase activities. The yeasts showing the highest growth rate and cell density in xylan, Cr. laurentii
UFMG-HB-48, Su. smithiae UFMG-HM-80.1 and Sc. shehatae UFMG-HM-9.1a, were, simultaneously, those exhibiting higher xylanase activity. Xylan induced the highest level of (extracellular) xylanase activity in Cr.
laurentii UFMG-HB-48 and the highest level of (intracellular, extracellular and membrane-associated) ß-d-xylosidase activity in Su. smithiae UFMG-HM-80.1. Also, significant ß-d-xylosidase levels were detected in
xylan-induced cultures of Cr. laurentii UFMG-HB-48 and Sc. shehatae UFMG-HM-9.1a, mainly in extracellular and intracellular spaces, respectively. Under xylose induction, Cr. laurentii UFMG-HB-48 showed the highest intracellular ß-d-xylosidase activity among all the yeast tested. C. tropicalis UFMG-HB 93a showed its higher (intracellular) ß-d-xylosidase activity under xylose induction and higher at 30 °C than at 50 °C. This study revealed different xylanolytic abilities and strategies in yeasts to metabolise xylan and/or its hydrolysis products (xylo-oligosaccharides and xylose). Xylanolytic yeasts are able to secrete xylanolytic
enzymes mainly when induced by xylan and present different strategies (intra- and/or extracellular hydrolysis) for the metabolism of xylo-oligosaccharides. Some of the unique xylanolytic traits identified here should
be further explored for their applicability in specific biotechnological processes
Cerium uptake, translocation and toxicity in the salt marsh halophyte Halimione portulacoides (L.), Aellen
Halimione portulacoides plants were exposed to dissolved cerium (Ce) in a hydroponic medium for five days. Ce accumulation in plants followed the metal's increase in the medium although with a very low translocation factor (TF < 0.01) between roots and shoots. Ce median concentrations in roots were 586, 988 and 1103 μg/g (dry wt.), while in shoots the median values reached 1.9, 3.5 and 10.0 μg/g (dry wt.), for plants exposed to 300, 600 and 1200 μg/L of Ce, respectively. No significant differences occurred in the length of roots and shoots among treatment groups, albeit plants exposed to the highest Ce concentration showed a clear loss of turgor pressure on the fifth day. An increase of hydrogen peroxide and malondialdehyde levels were observed in the plant shoots at 1200 μg/L of Ce. The highest concentration also triggered an answer by the shoots' antioxidant enzymes with a decrease in the activity of superoxide dismutase and an increase in peroxidase. However, no significant change in catalase activity was observed, compared to the control group, which may indicate that peroxidase played a more crucial role against the oxidative stress than catalase. Combined results indicate that H. portulacoides was actively responding to a toxic effect imposed by this higher Ce concentration. Nevertheless, changes in normal environmental conditions, may increase the bioavailability of Ce, while in areas where acid mine drainage may occur, the highest Ce concentration tested in this study may be largely exceeded, placing the sustainability of halophytes and estuarine marshes at risk
A quantitative proteomic approach to highlight Phragmites sp. adaptation mechanisms to chemical stress induced by a textile dyeing pollutant
Phragmites sp. is present worldwide in treatment wetlands though the mechanisms involved in the phytoremediation remain unclear. In this study a quantitative proteomic approach was used to study the prompt response and adaptation of Phragmites to the textile dyeing pollutant, Acid Orange 7 (AO7). Previously, it was demonstrated that AO7 could be successfully removed from wastewater and mineralized in a constructed wetland planted with Phragmites sp. This azo dye is readily taken up by roots and transported to the plant aerial part by the xylem. Phragmites leaf samples were collected from a pilot scale vertical flow constructed wetland after 0.25, 3.25 and 24.25h exposure to AO7 (400mgL-1) immediately after a watering cycle used as control. Leaf soluble protein extraction yielded an average of 1560 proteins in a broad pI range (pH3-10) by two-dimensional gel electrophoresis. A time course comparative analysis of leaf proteome revealed that 40 proteins had a differential abundance compared to control (p<0.05) within a 3.25h period. After 24.25h in contact with AO7, leaf proteome was similar to control. Adaptation to AO7 involved proteins related with cellular signalling (calreticulin, Ras-related protein Rab11D and 20S proteasome), energy production and conversion (adenosine triphosphate synthase beta subunit) carbohydrate transport and metabolism (phosphoglucose isomerase, fructose-bisphosphate aldolase, monodehydroascorbate reductase, frutockinase-1 and Hypothetical protein POPTR_0003s12000g and the Uncharacterized protein LOC100272772) and photosynthesis (sedoheptulose-1,7-bisphosphatase and ferredoxin-NADP+ reductase). Therefore, the quantitative proteomic approach used in this work indicates that mechanisms associated with stress cell signalling, energy production, carbohydrate transport and metabolism as well as proteins related with photosynthesis are key players in the initial chemical stress response in the phytoremediation process of AO7
Collagenofibrotic Glomerulopathy: Three Case Reports in Brazil
<p>Abstract</p> <p>Background</p> <p>We are reporting the first Collagenofibrotic Glomerulopathy (CG) in South America. So, this collagen type III glomerulopathy is not limited to Japan but may be found throughout the world.</p> <p>Case Reports</p> <p>We describe three patients that presented some factors in common, such as sex, age and the presence of non-nephrotic proteinuria associated with microscopic hematuria. The findings with the immunofluorescence microscopy, of immunoglobulins, and components of the complement were usually negative. The picrosyrius staining showed the presence of reddish material in the mesangium, when it was seen under standard microscopy; however, when it was seen with birefringence, it became greenish under polarized light, showed the collagen found in this area of the glomerulus. The identification of CG was made through electronic microscopic scanning, and curved and disorganized fibers were found.</p> <p>Conclusion</p> <p>These cases are the first from South America to be reported, and they are about an idiopathic renal disease that is not related to any specific races or locations. The reports contribute to a better understanding of this disease, which although not so prevalent, should be considered as an importantly differential diagnostic of cases of proteinuria.</p
The Glance of an Observer on the War of Brands of Food Products
The present work proposes a model to compare means of many constructs that evaluate competitiveness of brands of the Brazilian chilled and frozen food industry. Such a model is based on a nomological network, which was built over the concepts pointed by [4] [13] [8], and [7] by the NUME – Marketing and Strategy Research Center of the Federal University of Minas Gerais - research group. Besides the validation of the new research instrument for gauging and generalization, it will be made an evaluation of brands - the ones well-positioned at the market - using the comparison of the indexes and averages of the nomological chain built for the companies, in relation to the following concepts: Tangibility (perception of packings, flavors and smells); Reliability in the Brand; Satisfaction; Loyalty; Image of the Brand; Perceived Value and Functional Conflict
Assessing local acid mine drainage impacts on natural regeneration-revegetation of São Domingos mine (Portugal) using a mineralogical, biochemical and textural approach
São Domingos sulfide mine was shut down more than 50 years ago leaving behind eroded and depositional surfaces due to acid mine drainage (AMD). The aim of this study was to assess six selected sites subjected to AMD, considered phytotoxic regions characterized by vegetation scarcity. Two main criteria, nature and composition of soluble fractions and total chemistry of surficial products related to jarosites presence, enabled to set up an overall dichotomy between superficial proximal/discharge and distal/sedimentation areas. Wet and dry sieving results comparison revealed that samples have a predominant sandy texture and lithic (phyllite, quartzite and volcanic country rocks) composition. Quartz, and subordinate feldspar enrichment is also detected in the coarse silt fraction. The results also suggest that the materials under study, when subjected to the local torrential hydrologic regime, have a high mechanical vulnerability, facilitating erosion and mud transport, both critical for vegetation support, and triggering contamination transfer and dispersion. The vicinity and ground-level surfaces of discharging areas are enriched in the jarosite group minerals whereas the sedimentation ones present hypersaline aluminous tendency. The formation of jarosite is considered as an efficient positive environmental contribution to metals and metalloids sequestration/immobilization. The remediation/revegetation solutions to be adopted in each location must have into consideration these differentiating aspects
- …