Metal reduction in wine using PVI-PVP copolymer and its effects on chemical and sensory characters

We studied the influence of an adsorbent PVI-PVP resin (a copolymer of vinylimidazole and vinylpyrrolidone), on the removal of heavy metals in wines, mainly copper (Cu), iron (Fe), lead (Pb), cadmium (Cd) and aluminium (Al). The study also investigated the influence of PVI-PVP on the physical-chemical and sensory characteristics of white and red wines, comparing its effect when applied in the must and in the wine. The removal of metals was more effective when PVI-PVP was applied to the wine than to the must. The removal of Fe and Pb was more effective in white wines than in red wines, while the removal of Cu and Al was higher in red wines. In general, the higher the PVI-PVP dose, the greater the quantity of metallic elements (copper, iron, lead and aluminium) that are removed. PVI-PVP had a minor effect on phenolic composition. The wines showed some decrease in total acidity and an increase in pH with PVI-PVP. The application of PVI-PVP at the dose rates employed here did not affect the wine’s sensory characteristics significantly

Organosolv delignification of steam exploded wheat straw

Atualmente tem-se aumentado o interesse no estudo de processos alternativos depolpação que conciliam um alto desempenho e causando pouco impacto ambiental. Da mesmamaneira, o uso de resíduos agrícolas é cada vez mais citado como matéria-prima promissorapara produção de produtos químicos. A palha de trigo é um resíduo agrícola muito abundantee foi usado em muitos países para a produção de polpas de celulose. Este trabalho descreveo efeito do pré-tratamento através de uma explosão a vapor seguido de uma polpação comacetona/água na palha de trigo. As amostras de palha de trigo foram tratadas através de explosão a vapor com temperaturas variando entre 190 e 210 oC durante 4 min e em seguidasubmetidas ao tratamento com acetona/água (1:1/v:v) a diferentes temperaturas (140, 160e 200oC) durante um tempo de 60 min de polpação. O pré-tratamento por explosão a vaporlevou a um aumento da quantidade de lignina extraída pela polpação organossolve. Esteefeito foi mais pronunciado para as polpações realizadas a menores temperaturas. O uso detemperaturas mais elevadas no tratamento por explosão a vapor foi mais signi…cativo, poisresultou em menores valores de rendimento de polpa e maiores taxas de deslignificação

Exposure to Leishmania braziliensis triggers neutrophil activation and apoptosis.

BACKGROUND: Neutrophils are the first line of defense against invading pathogens and are rapidly recruited to the sites of Leishmania inoculation. During Leishmania braziliensis infection, depletion of inflammatory cells significantly increases the parasite load whereas co-inoculation of neutrophils plus L. braziliensis had an opposite effect. Moreover, the co-culture of infected macrophages and neutrophils also induced parasite killing leading us to ask how neutrophils alone respond to an L. braziliensis exposure. Herein we focused on understanding the interaction between neutrophils and L. braziliensis, exploring cell activation and apoptotic fate. METHODS AND FINDINGS: Inoculation of serum-opsonized L. braziliensis promastigotes in mice induced neutrophil accumulation in vivo, peaking at 24 h. In vitro, exposure of thyoglycollate-elicited inflammatory or bone marrow neutrophils to L. braziliensis modulated the expression of surface molecules such as CD18 and CD62L, and induced the oxidative burst. Using mCherry-expressing L. braziliensis, we determined that such effects were mainly observed in infected and not in bystander cells. Neutrophil activation following contact with L. braziliensis was also confirmed by the release of TNF-α and neutrophil elastase. Lastly, neutrophils infected with L. braziliensis but not with L. major displayed markers of early apoptosis. CONCLUSIONS: We show that L. braziliensis induces neutrophil recruitment in vivo and that neutrophils exposed to the parasite in vitro respond through activation and release of inflammatory mediators. This outcome may impact on parasite elimination, particularly at the early stages of infection

Automatic flow systems based on sequential injection analysis for routine determinations in wines

Sequential injection systems for wine analysis have been developed in recent years for determination of more than 20 species. Several aspects of these systems are reviewed in the present paper. Special focus is given to implementation of in-line sample treatment and adaptation of system operation through software control to enable determination in different types of wine. The strategies used to enhance selectivity and the capacity for multi-parameter determination are also addressed

Influence of halloysite nanotubes on physical and mechanical properties of cellulose fibres reinforced vinyl ester composites

Natural fibres are generally added to polymer matrix composites to produce materials with the desirable mechanical properties of higher specific strength and higher specific modulus while at the same time to maintain a low density and low cost. The physical and mechanical properties of polymer composites can be enhanced through the addition of nanofillers such as halloysite nanotubes. This article describes the fabrication of vinyl ester eco-composites and eco-nanocomposites and characterizes these samples in terms of water absorption, mechanical and thermal properties. Weight gain test and Fourier transform infrared analysis indicated that 5% halloysite nanotube addition gave favourable reduction in the water absorption and increased the fibre–matrix adhesion leading to improved strength properties in the eco-nanocomposites. However, halloysite nanotube addition resulted in reduced toughness but improved thermal stability