Composite resin susceptibility to red wine staining after water sorption

Color stability of restorative materials is essential for longevity of esthetic composite restoration over time. The aim of this investigation was assess the effect of prior water immersion on the color stability of a composite resin to red wine staining. Seventy disccshaped specimens (6mm x 1.5mm) were carried out and randomized in 7 groups (n = 10), according to distilled water immersion time at 0 (control), 24, 48, 72,120,192, and 240 h. Baseline color was measured according to the ciel*a*b* system using a reflection spectrophotometer(uvc2450, shimadzu).After that, the specimens were storage in red wine for 7 days. Color difference (∆e) after aging was calculated based on the color coordinates before(baseline) and after storage period.Data were subjected to onecway anova(alpha=0.05).The different times of immersion in.Water before to the red wine storage showed similar behavior on the color stability, without statistical difference compared to control group, immersed directly in the wine(p=0.7057).The previous water uptake of composite resin evaluated did not decrease the susceptibility to red wine staining.

Development and in vitro skin delivery of dexamethasone acetate-loaded surfactant-based systems

Topical corticosteroids, e.g., dexamethasone acetate (DMA), are extensively used to treat cutaneous inflammatory disorders even though their use is correlated with potential local and systemic side effects. The objective of this study was to develop and test the topical delivery of DMA-loaded surfactant based systems in vitro; these studies could guarantee a suitable delivery and therapeutic efficacy, as well as minimize DMA's side effects. A phase diagram was constructed using polyoxypropylene (5) polyoxyethylene (20) cetyl alcohol as the surfactant (S), isopropyl myristate as the oil phase (O) and water (W). The systems were characterized using polarization light microscopy (PLM), as well as rheological and small angle X-ray scattering (SAXS) measurements. Depending on the concentration of the constituents, it was possible to obtain microemulsions (MEs) and liquid crystalline mesophases (lamellar and hexagonal). These types of arrangement were verified using PLM measurements. The SAXS results revealed that increasing the W/S ratio led to ME, as well as lamellar (LAM) and hexagonal (HEX) arrangements. The MEs displayed typical Newtonian behavior while the LAM and HEX phases exhibited pseudoplasticity and plasticity, respectively. The MEs displayed excellent drug solubilization that was approximately 10-fold higher than was observed with the individual components. The in vitro cutaneous permeation studies using pig ear skin and analysis of the mechanical parameters (hardness, compressibility, cohesiveness and adhesiveness) were carried out with a HEX phase and O/W emulsion. The HEX phase achieved better drug permeation and retention in the skin while its mechanical properties were suitable for skin administration. PPG-5-CETETH-20-based systems may be a promising platform delivering DMA and other topical corticosteroids through the skin.

Surfactant-based transdermal system for fluconazole skin delivery

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

Evaluation of bamboo particleboards produced with urea-formaldheyde resin

The bamboo waste can be an alternative material to sustain the crescent demand for particleboards, also bringing ecological benefits as reduction of the pressure for raw materials and landfill space demands. In this context, this research aimed to manufacture and determine some physical and mechanical properties of particleboards with bamboo waste particles (Dendrocalamus giganteus), obtained from different sources, bonded with four different percentages of urea–formaldehyde (UF) based resin (6%, 8%, 10% and 12% related to dry material of particles). Response variables investigated were: density; moisture content; thickness swelling in 2 and 24 hours; water absorption in 2 and 24 hours; internal adhesion (STpe); strength in tension parallel to faces (STpa); modulus of elasticity (MOE) and modulus of rupture (MOR). Results permitted to conclude that particleboards as mentioned showed good performance only in the physical properties requirements imposed by Brazilian Standard NBR 14810, but this was not observed to mechanical properties considered. New researches are needed in order to optimize the producing process parameters.

Dietary intake association with IFG and responses of a lifestyle changing protocol in a community-b based adult cohort

Objective: Investigate the association of diet on Impaired Fasting Glucose (IFG) and response of a lifestyle changing protocol (LISC) on a community sample of adults. Methods: A cross sectional study of LISC was conducted with 1004 subjects. From those, 264 adults individuals participated in a 20-week intervention based on physical exercises and dietary counseling and were divided in three groups, normoglycemic, IFG, and T2DM. Evaluations were done at baseline (M0) and after a 20-week intervention (M1). The analyses were performed by using SAS, version 9.2., and results were discussed based on the level of significance of p<0.05. Results: At baseline, the three groups differed for plasma triglycerides, and number of altered metabolic syndrome (MetS) components. T2DM differed from normoglicemic by presenting higher intake of meat, lower of sugar, and less dietary variety, along with higher plasma levels of uric acid. After 20-week intervention, normoglicemics, IFG and T2DM responded similarly to LISC. Both genders increased body fatness. Men increased fasting plasma insulin, saturated fatty acid intake, along with a decrease of vegetable oil intake while women showed a significant increase in HEI and dietary fiber intake and a trend to higher sugar and protein intake and lower vegetable oil intake. Overall T2DM decreased 68% from M0 (9.5%) to M1 (6.4%) of LISC. Conclusion: Our data showed a significant difference in food composition on altered plasma glucose, and its further normalization with lifestyle intervention was independent of significant body weight and body fat changes.

Influência do comprimento do pino de fibra de vidro na resistência à fratura de raízes fragilizadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do comprimento do pino de fibra de vidro na resistência à fratura de raízes fragilizadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determination of labile barium in petroleum-produced formation water using paper-based DGT samplers

A polyacrylamide hydrogel containing the Chelex-100 resin has traditionally been used as the binding agent for the diffusion gradients in thin films (DGT) technique. The Chelex-100 resin, although important for the determination of various transition metals, is unsatisfactory for the determination of alkaline earth metals, particularly Ba. In this paper, a cellulose membrane, treated with phosphate (P81 membrane), was evaluated as a binding agent for DGT devices for the determination of Ba in produced formation water (PEW) samples. In addition, diffusive layers of filter paper (cellulose) were tested to diffuse Ba through the DGT devices. Experiments to evaluate the key variables of the technique (pH, deployment time, and ionic strength/salinity) were performed. The Ba sampled by these DGT devices was measured using inductively coupled plasma optical emission spectrometry. Aiming to generate information (related to bioavailability of Ba) on the reuse of PEW for irrigation, the determination of Ba in onshore and offshore samples was performed. The new approach was effective for determination of Ba in onshore samples. To determine Ba in offshore samples, it was necessary to use an alternative calibration procedure due to the high NaCl concentration in these samples. (C) 2012 Elsevier B.V. All rights reserved.

Screening, immobilization and utilization of whole cell biocatalysts to mediate the ethanolysis of babassu oil

The screening. biomass growth of lipase-producing fungus isolated from different sources and available at URM (University Recife Mycologia). as well as, the immobilization and utilization of the whole cells for the transesterification of babassu oil were investigated. Rhizopus oryzae (URM 3231, 4692), Mucor circinelloides (URM 4140, 4182) and Penicillium citrinum URM 4216 were considered to be good intracellular lipase producers whereas those from Mucor hiemalis URM 4144 and Mucor piriformis URM 4145 were weaker. Fungi biomass containing high lipase activities was immobilized on different biomass support particles (BSPs) and with the exception of Penicillium citrinum URM 4216 all the other fungi strains exhibited high lipase activity (20-50 Ug(-1)) when immobilized in situ using polyurethane foam particles. Transesterification activities of the immobilized whole cells were evaluated in the ethanolysis reaction with babassu oil and the highest performance was attained by M. circinelloides URM 4182 giving 83.22 +/- 3.68% ester yield in less than 96 h reaction. The biocatalyst operational stability was also assessed and an inactivation profile was found to follow the Arrhenius model, revealing values of 26 days and 2.6 x 10(-2)day(-1), for half-life and a deactivation coefficient, respectively. The purified product (biodiesel) exhibited viscosity (6.63 cSt) close to the value to attend specifications by the ASTM 06751 to be used as biofuel. Results are favorable compared with data already reported in the literature and demonstrated that M. circinelloides URM 4182 whole cells is a cheaper biocatalyst that can be used in the biodiesel synthesis. (C) 2012 Elsevier B.V. All rights reserved.

Water-in-Oil Micro-Emulsion Enhances the Secondary Structure of a Protein by Confinement

A scheme is presented in which an organic solvent environment in combination with surfactants is used to confine a natively unfolded protein inside an inverse microemulsion droplet. This type of confinement allows a study that provides unique insight into the dynamic structure of an unfolded, flexible protein which is still solvated and thus under near-physiological conditions. In a model system, the protein osteopontin (OPN) is used. It is a highly phosphorylated glycoprotein that is expressed in a wide range of cells and tissues for which limited structural analysis exists due to the high degree of flexibility and large number of post-translational modifications. OPN is implicated in tissue functions, such as inflammation and mineralisation. It also has a key function in tumour metastasis and progression. Circular dichroism measurements show that confinement enhances the secondary structural features of the protein. Small-angle X-ray scattering and dynamic light scattering show that OPN changes from being a flexible protein in aqueous solution to adopting a less flexible and more compact structure inside the microemulsion droplets. This novel approach for confining proteins while they are still hydrated may aid in studying the structure of a wide range of natively unfolded proteins.

Ceramic Primer Heat-Treatment Effect on Resin Cement/Y-TZP Bond Strength

The purpose of this study was to evaluate the effect of different heat-treatment strategies for a ceramic primer on the shear bond strength of a 10-methacryloyloxydecyl-dihydrogen-phosphate (MDP)-based resin cement to a yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic. Specimens measuring 4.5 x 3.5 x 4.5 mm(3) were produced from Y-TZP presintered cubes and embedded in polymethyl methacrylate (PMMA). Following finishing, the specimens were cleaned using an ultrasound device and distilled water and randomly divided into 10 experimental groups (n=14) according to the heat treatment of the ceramic primer and aging condition. The strategies used for the experimental groups were: GC (control), without primer; G20, primer application at ambient temperature (20 degrees C); G45, primer application + heat treatment at 45 degrees C; G79, primer application + heat treatment at 79 degrees C; and G100, primer application + heat treatment at 100 degrees C. The specimens from the aging groups were submitted to thermal cycling (6000 cycles, 5 degrees C/55 degrees C, 30 seconds per bath) after 24 hours. A cylinder of MDP-based resin cement (2.4 mm in diameter) was constructed on the ceramic surface of the specimens of each experimental group and stored for 24 hours at 37 degrees C. The specimens were submitted to a shear bond strength test (n=14). Thermal gravimetric analysis was performed on the ceramic primer. The data obtained were statistically analyzed by two-way analysis of variance and the Tukey test (alpha=0.05). The experimental group G79 without aging (7.23 +/- 2.87 MPa) presented a significantly higher mean than the other experimental groups without aging (GC: 2.81 +/- 1.5 MPa; G20: 3.38 +/- 2.21 MPa; G100: 3.96 +/- 1.57 MPa), showing no difference from G45 only (G45: 6 +/- 3.63 MPa). All specimens of the aging groups debonded during thermocycling and were considered to present zero bond strength for the statistical analyses. In conclusion, heat treatment of the metal/zirconia primer improved bond strength under the initial condition but did not promote stable bonding under the aging condition.

Effect of Temperature on the Degree of Conversion and Working Time of Dual-Cured Resin Cements Exposed to Different Curing Conditions

Objectives: This study evaluated the degree of conversion (DC) and working time (WT) of two commercial, dual-cured resin cements polymerized at varying temperatures and under different curing-light accessible conditions, using Fourier transformed infrared analysis (FTIR). Materials and Methods: Calibra (Cal; Dentsply Caulk) and Variolink II (Ivoclar Vivadent) were tested at 25 degrees C or preheated to 37 degrees C or 50 degrees C and applied to a similar-temperature surface of a horizontal attenuated-total-reflectance unit (ATR) attached to an infrared spectrometer. The products were polymerized using one of four conditions: direct light exposure only (600 mW/cm(2)) through a glass slide or through a 1.5- or 3.0-mm-thick ceramic disc (A2 shade, IPS e.max, Ivoclar Vivadent) or allowed to self-cure in the absence of light curing. FTIR spectra were recorded for 20 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm(-1)) immediately after application to the ATR. DC was calculated using standard techniques of observing changes in aliphatic-to-aromatic peak ratios precuring and 20-min postcuring as well as during each 1-second interval. Time-based monomer conversion analysis was used to determine WT at each temperature. DC and WT data (n=6) were analyzed by two-way analysis of variance and Tukey post hoc test (p=0.05). Results: Higher temperatures increased DC regardless of curing mode and product. For Calibra, only the 3-mm-thick ceramic group showed lower DC than the other groups at 25 degrees C (p=0.01830), while no significant difference was observed among groups at 37 degrees C and 50 degrees C. For Variolink, the 3-mm-thick ceramic group showed lower DC than the 1-mm-thick group only at 25 degrees C, while the self-cure group showed lower DC than the others at all temperatures (p=0.00001). WT decreased with increasing temperature: at 37 degrees C near 70% reduction and at 50 degrees C near 90% for both products, with WT reduction reaching clinically inappropriate times in some cases (p=0.00001). Conclusion: Elevated temperature during polymerization of dual-cured cements increased DC. WT was reduced with elevated temperature, but the extent of reduction might not be clinically acceptable.

Emergy analysis of oil production from microalgae

The use of microalgae and cyanobacteria for the production of biofuels and other raw materials is considered a very promising sustainable technology due to the high areal productivity, potential for CO2 fixation and use of non-arable land. The production of oil by microalgae in a large scale plant was studied using emergy analysis. The joint transformity calculated for the base scenario was 1.32E + 5 sej/J, the oil transformity was 3.51E + 5 sej/J, the emergy yield ratio (EYR) was 1.09 and environmental loading ratio was 11.10 and the emergy sustainability index (ESI) was 0.10, highlighting some of the key challenges for the technology such as high energy consumption during harvesting, raw material consumption and high capital and operation costs. Alternatives scenarios and the sensitivity to process improvements were also assessed, helping prioritize further research based on sustainability impact. (C) 2012 Elsevier Ltd. All rights reserved.

Oral health related quality of life of edentulous patients after denture relining with a silicone-based soft liner

Background: Knowledge of benefits caused by a treatment on quality of life is very relevant. Despite the wide use and acceptance of soft denture liners, it is necessary to evaluate the patient's response about the use of these materials with regard to improvement in oral health related quality of life (OHRQoL). Objectives: The aim of this study was to evaluate the influence of denture relining in the OHRQoL of edentulous patients. Materials and methods: Thirty-two complete denture wearers had their lower dentures relined with a silicone-based material (Mucopren soft, Kettenbach, Germany) according to chairside procedures. OHRQoL was assessed before and after 3 months of relining by means of OHIP-EDENT, and the median scores were compared by Wilcoxon test (p <= 0.05). Results: After 3 months of relining, participants reported significant improvement of their OHRQoL (p <= 0.01). Conclusion: Denture relining with a soft liner may have a positive impact on the perceived oral health of edentulous patients.

Life cycle assessment of sugarcane ethanol and palm oil biodiesel joint production

Sugarcane (Saccharum spp.) and palm tree (Elaeis guianeensis) are crops with high biofuel yields, 7.6 m(3) ha (1) y(-)1 of ethanol and 4 Mg ha(-1) y(-1) of oil, respectively. The joint production of these crops enhances the sustainability of ethanol. The objective of this work was comparing a traditional sugarcane ethanol production system (TSES) with a joint production system (JSEB), in which ethanol and biodiesel are produced at the same biorefinery but only ethanol is traded. The comparison is based on ISO 14.040:2006 and ISO 14044:2006, and appropriate indicators. Production systems in Cerrado (typical savannah), Cerradao (woody savannah) and pastureland ecosystems were considered. Energy and carbon balances, and land use change impacts were evaluated. The joint system includes 100% substitution of biodiesel for diesel, which is all consumed in different cropping stages. Data were collected by direct field observation methods, and questionnaires applied to Brazilian facilities. Three sugarcane mills situated in Sao Paulo State and one palm oil refinery located in Para State were surveyed. The information was supplemented by secondary sources. Results demonstrated that fossil fuel use and greenhouse gas emissions decreased, whereas energy efficiency increased when JSEB was compared to TSES. In comparison with TSES, the energy balance of JSEB was 1.7 greater. In addition, JSEB released 23% fewer GHG emissions than TSES. The ecosystem carbon payback time for Cerrado, Cerradao, and Degraded Grassland of JSEB was respectively 4, 7.7 and -7.6 years. These are typical land use types of the Brazilian Cerrado region for which JSEB was conceived. (C) 2012 Elsevier Ltd. All rights reserved.