A dynamical gluon mass solution in a coupled system of the Schwinger-Dyson equations

We study numerically the Schwinger-Dyson equations for the coupled system of gluon and ghost propagators in the Landau gauge and in the case of pure gauge QCD. We show that a dynamical mass for the gluon propagator arises as a solution while the ghost propagator develops an enhanced behavior in the infrared regime of QCD. Simple analytical expressions are proposed for the propagators, and the mass dependency on the ΛQCD scale and its perturbative scaling are studied. We discuss the implications of our results for the infrared behavior of the coupling constant, which, according to fits for the propagators infrared behavior, seems to indicate that α s(q2) → 0 as q2 → 0. © SISSA/ISAS 2004.

Tocopherol in the lipid stability of tilapia (Oreochromis niloticus) hamburgers

Presence of tocopherol is effective for fish preservation during frozen storage, inhibiting lipid degradation by oxidation. This work evaluated the antioxidant effects of α-tocopherol in diet and postmortem addition on the final quality of hamburgers produced from tilapia fillets kept frozen for zero, 30, 60, and 90 days. Chemical composition varied within the values found for tilapia fish. The increase in α-tocopherol levels reduced the values of thiobarbituric acid reactive substances (TBARS) in the samples at all time intervals. Tocopherol supplementation in diets protected the hamburgers from lipid oxidation more effectively than postmortem addition. © 2007 Elsevier Ltd. All rights reserved.

Sodium dodecyl sulfate (SDS) effect on the thermal stability of oxy-HbGp: Dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) studies

Glossoscolex paulistus (HbGp) hemoglobin is an oligomeric protein, presenting a quaternary structure constituted by 144 globin and 36 non-globin chains (named linkers) with a total molecular mass of 3.6MDa. SDS effects on the oxy-HbGp thermal stability were studied, by DLS and SAXS, at pH 5.0, 7.0 and 9.0. DLS and SAXS data show that the SDS-oxy-HbGp interactions induce a significant decrease of the protein thermal stability, with the formation of larger aggregates, at pH 5.0. At pH 7.0, oxy-HbGp undergoes complete oligomeric dissociation, with increase of temperature, in the presence of SDS. Besides, oxy-HbGp 3.0mg/mL, pH 7.0, in the presence of SDS, has the oligomeric dissociation process reduced as compared to 0.5mg/mL of protein. At pH 9.0, oxy-HbGp starts to dissociate at 20°C, and the protein is totally dissociated at 50°C. The thermal dissociation kinetic data show that oxy-HbGp oligomeric dissociation at pH 7.0, in the presence of SDS, is strongly dependent on the protein concentration. At 0.5mg/mL of protein, the oligomeric dissociation is complete and fast at 40 and 42°C, with kinetic constants of (2.1±0.2)×10-4 and (5.5±0.4)×10-4s-1, respectively, at 0.6mmol/L SDS. However, at 3.0mg/mL, the oligomeric dissociation process starts at 46°C, and only partial dissociation, accompanied by aggregates formation is observed. Moreover, our data show, for the first time, that, for 3.0mg/mL of protein, the oligomeric dissociation, denaturation and aggregation phenomena occur simultaneously, in the presence of SDS. Our present results on the surfactant-HbGp interactions and the protein thermal unfolding process correspond to a step forward in the understanding of SDS effects. © 2013 Elsevier B.V.

About the thermal stability and pore elimination in the ordered hexagonal mesoporous silica SBA-15

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

Effect of intrinsic nanoparticle pigmentation on the color stability of denture base acrylic resins

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

The conservation of number and location of 18S sites indicates the relative stability of rDNA in species of Pentatomomorpha (Heteroptera)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cetyltrimethylammonium chloride (CTAC) effect on the thermal stability of oxy-HbGp: Dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) studies

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

SAXS Studies of the Endoglucanase Cel12A from Gloeophyllum trabeum Show Its Monomeric Structure and Reveal the Influence of Temperature on the Structural Stability of the Enzyme

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

Hopf bifurcation in the full repressilator equations

In this paper, we prove that the full repressilator equations in dimension six undergo a supercritical Hopf bifurcation.

Effect of rosemary (Rosmarinus officinalis) extracts on the oxidative stability and sensory acceptability of soybean oil

Background: Plant extracts have b een used as an alternative to the use of synthetic antioxidants in order to preserve oils fromoxidative degradation. Additionally, these extracts add special flavors and aromas to the food. Thus, the objective of this studywas to evaluate the effect of hydroethanolic extracts of fresh and freeze-dried rosemar y in the oxidative stability of soybean oilunder accelerated storage in an oven. Results: The application of the extracts in the oil showed that that freeze-dried extract was better in reducing the formation ofoxidation products, showing 8.6 meq kg−1of peroxides after 20 days of storage. On the other hand, the mixture of the naturalextract with t-butylhydroquinone conferred better oxidative stability index until the 20th day, 9.7 h. Both extracts prevented theloss of tocopherol, not d iffering between each other (P > 0.05), and present approximately 505 mg kg−1of residual tocopherols.The sensory evaluation revealed that consumers accepted equally the oils added and not added of the rosemary extracts. Conclusion: The extracts are therefore potential sources of natural antioxidants and they would be well accepted by consumersif applied by the food industry to replace synthetic antioxidants.

Chitosan nanoparticles loaded the herbicide paraquat: The influence of the aquatic humic substances on the colloidal stability and toxicity

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

Long-term clinical evaluation of the color stability and stainability of acrylic resin denture teeth

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

Massive spin-2 particles via embedment of the Fierz-Pauli equations of motion

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of postpolymerization method on the color stability of composite resins submitted to ultraviolet aging

The aim of this research was to evaluate the effect of postpolymerization method on the color stability of resin-based composites. Samples of direct and indirect restorative materials were polymerized with two photo-curing units (Visio photo-curing oven system and LED Elipar Freelight 2). All samples were submitted to an initial chromatic analysis using a spectrometer and submitted to ultraviolet-accelerated artificial aging. The direct material showed less color change than the indirect material, independent of the photo-activation method used. Samples photo cured with the LED system showed less change than those photo cured with the Visio system. The postpolymerization oven did not improve the color stability of direct and indirect resin-based composites.