Reduction of bacterial adhesion to biocompatible polymer surfaces via plasma processing

Plasma processing of the surfaces of biomaterials is interesting because it enables modification of the characteristics of a surface without affecting bulk properties. In addition, the results are strongly influenced by the conditions of the treatment. Therefore, by adjusting the plasma parameters it is possible to tailor the surface properties to best fulfill the requirements of a given application. In this work, polyurethane substrates have been subjected to sulfur hexafluoride glow discharge plasmas. The influences of different SF 6 plasma exposure times and pressures on the adhesion of Staphylococcus aureus and Pseudomonas aeruginosa to the polymer have been investigated. The wettability and surface free energy have been evaluated via contact angle measurements. At low pressure (6.7 Pa) the contact angle decreases with increasing exposure time in the 180 s to 540 s interval, but at higher pressure (13.3 Pa) it increases as a function of the same variable. Bacterial adhesion has been quantified from in vitro experiments by determining the growth of colonies on Petri dishes treated with agar nutrient. It has been observed that the surface properties play an important role in microbe adhesion. For instance, the density of adhered P. aeruginosa decreased as the surface contact angle increased. S. aureus preferred to adhere to hydrophobic surfaces. © 2011 by Begell House, Inc.

Optical characterization of one dental composite resin using bovine enamel as reinforcing filler

The use of composite resins for restorative procedure in anterior and posterior cavities is highly common in Dentistry due to its mechanical and aesthetic properties that are compatible with the remaining dental structure. Thus, the aim of this study was to evaluate the optical characterization of one dental composite resin using bovine enamel as reinforcing filler. The same organic matrix of the commercially available resins was used for this experimental resin. The reinforcing filler was obtained after the gridding of bovine enamel fragments and a superficial treatment was performed to allow the adhesion of the filler particles with the organic matrix. Different optical images as fluorescence and reflectance were performed to compare the experimental composite with the human teeth. The present experimental resin shows similar optical properties compared with human teeth. © 2012 SPIE.

Estádios de maturação de pêssegos 'Aurora-1' para o processamento mínimo

The experiment aimed to verify the effect of maturation stage on the quality of minimally processed peaches. Fruits were used in two stages of maturity, on time corresponding to the background color yellow-green, and mature, which corresponds completely to the background color yellow. The minimum process consisted of washing, sanitizing, enzyme peel, cut lengthwise and removed the stone fruits. Halves obtained were immersed in water chlorinated to 10 mg L-1 of water and left on standing to drain the excess liquid. Afterwards, it was proceeded the packaging of the halves in containers of polyethylene terephthalate (PET) and with transparent lid, and the storage at 3 ± 2 ° C and RH = 65% for 12 days, with assessments every three days. The variables evaluated were appearance, weight loss, firmness, soluble solids, titratable acidity, soluble and reduced sugars, ascorbic acid, total and soluble pectin, coloring and activity of polyphenoloxidase. The storage of minimally processed peaches 'Aurora-1' mature harvested was limited mainly by the loss of freshness and firmness, and because they have darker appearance, and lower levels of reduced sugars and ascorbic acid. Peaches 'Aurora-1', harvested at the maturity stage on time, had better quality and longer duration of their minimally processed products.

Influence of ethanol and glycerol concentration over functional and structural properties of zein-oleic acid films

This study was performed in order to determine the effect of the addition of different concentrations of glycerol and ethanol over functional and structural properties of zein-oleic acid films. Films were prepared from zein and oleic acid formulations, containing: 0, 10, 20 and 30% (w/w) of glycerol as plasticizer and 75, 80, 85, 90 and 95% (v/v) of ethanol as zein solvent. Water vapor permeability (WVP) at 4 and 24 C, opacity, water solubility and structural behavior of the film were assessed. The film water barrier properties, WVP and water solubility, were increased when higher ethanol concentration and lower glycerol concentration were used. Furthermore, WVP at 4 C was lower than WVP at 24 C due to the crystalline solid state of oleic acid at lower temperatures. Likewise, opacity, homogeneity and structure of the composite film were improved as ethanol increased and glycerol lowered. © 2013 Elsevier B.V. All rights reserved.

A ressonância magnética no estudo da desintegração de comprimidos marcados com açaí (Euterpe oleracea)

Pós-graduação em Biologia Geral e Aplicada - IBB

Desenvolvimento de métodos de cultivo de Gluconacetobacter xylinus para obtenção de compósitos à base de celulose bacteriana e colágeno tipo I adicionado in situ

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência da paralisação escalonada da aeração na eficiência do tratamento aeróbio na manipueira em batelada

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo das propriedades elétricas e ópticas de nanocompósitos transparentes e condutores

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Preparação e caracterização de blendas de poliuretano derivado do óleo de mamona e poli (o-metoxianilina) e sua avaliação como sensor

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hibridos siloxano-polímero no comportamento hidrofilico de diferentes materiais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação dos parâmetros de processo de reticulação do polietileno de baixa densidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Imobilização e caracterização parcial de lipase produzida por Fusarium oxysporum em fermentação submersa

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Processamento mínimo de melão tipo Orange Flesh e de melancia 'Crimson Sweet'

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Caracterização estrutural e propriedades óticas e mecânicas do diglime polimerizado a plasma

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo dos sistemas integrados de filmes finos óxidos em substratos poliméricos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)