Influence of dental materials used for sealing caries lesions on laser fluorescence measurements

The aim of this study was to determine the influence of thickness and aging on the intrinsic fluorescence of sealing materials and their ability to block fluorescence from the underlying surface as assessed using a laser fluorescence device. Cavities of 0.5 mm and 1 mm depth were drilled into acrylic boards which were placed over two surfaces with different fluorescence properties: a low-fluorescence surface, to assess the intrinsic fluorescence of the sealing materials, and a high-fluorescence surface, to assess the fluorescence-blocking ability of the sealing materials. Ten cavities of each depth were filled with different sealing materials: Adper Scotchbond Multi-Purpose, Adper Single Bond 2, FluroShield, Conseal f and UltraSeal XT Plus. Fluorescence was measured with a DIAGNOdent pen at five different time points: empty cavity, after polymerization, and 1 day, 1 week and 1 month after filling. The individual values after polymerization, as well as the area under the curve for the different periods were submitted to ANOVA and the Tukey test (p < 0.05). At 0.5 mm, Scotchbond, FluroShield and UltraSeal showed insignificant changes in intrinsic fluorescence with aging and lower fluorescence after polymerization than Single Bond and Conseal. At 1 mm, Scotchbond and FluroShield showed the lowest intrinsic fluorescence, but only Scotchbond showed no chagnes in fluorescence with aging. At both depths, Scotchbond blocked significantly less fluorescence. All sealing materials blocked more fluorescence when applied to a depth of 1 mm. At 0.5 mm, fissure sealants blocked more fluorescence than adhesives, and did not show significant changes with aging. Scotchbond had the least affect on the fluorescence from the underlying surface and would probably have the least affect on the monitoring of sealed dental caries by laser fluorescence.

Efeito de agentes de controle sobre a qualidade reprodutiva de rainhas de Apis mellifera L. (Hymenoptera: Apidae) africanizadas

The agriculture with the use of products with less environmental impact is expanding. In it, the producers offer their products without the use of synthetic chemical inputs, solving the phytosanitary problems with the use of biological or alternative control agents such as parasites, predators, entomopathogenic, alternative products, plant extracts and essential oils. These products can be considered safe to non-target organisms, but studies are needed to find these features on natural enemies and on the beneficial insects such as bees, common frequenter of cultures. In this sense, this study aims to evaluate the effects of control over reproductive quality queens of Apis mellifera L. (Hymenoptera: Apidae) Africanized. For this, it tested the action of control products on the production of A. mellifera queens, using the commercial entomopathogenic fungus Boveril® 1,0x108 (Beauveria bassiana) and aqueous extract of pomegranate (Punica granatum) at a concentration of 5% sterile distilled water with Tween (0.01%) and sterile distilled water (controls). The treatments were incorporated into a tissue type gauze, wrapped in an acrylic plate and packed inside minirrecrias type colonies for the production of queens on the day before the transfer of larvae. The next day were introduced battens with 30 domes with larvae to produce queens, so the workers have contacted the agent tested. From the emergence of all the queens, they were monitored to determine the measures of body weight (mg), length and width of wing and abdomen, length, width and height of the chest (mm) as well as the time of emergence of queens. The next step was evaluated the influence of the control agents in production creates, performing measurements of creating areas in cm2 for six straight weeks. It was found that the area creates Queens did not differ among the treatments. Histological analysis of hipofaringeanas of workers glands that came into contact with the control agents and the midgut of virgin queens were also held. Histological analysis differences were observed in the tissues when the treatments were compared with the respective controls.

Los óleos alquídicos Griffin : Composición, propiedades y aplicación

Uno de los principales inconvenientes que tiene la pintura al óleo es su lento secado. Dicho esto, cabe preguntarse si existe algún tipo de pintura que tenga las cualidades de los óleos pero que sequen más rápido que estos. La respuesta, afirmativa, la encontramos en los óleos alquídicos, que en nuestro país únicamente se comercializan bajo la marca Griffin de Winsor & Newton. Se trata de unas pinturas relativamente recientes, poco conocidas por los pintores y muy poco estudiadas. Con el objetivo de paliar estas carencias, el presente artículo contiene las principales conclusiones de un trabajo en el que se ha estudiado la composición de las pinturas Griffin, sus principales características (viscosidad, brillo, flexibilidad, textura, opacidad, secado que es lo que más nos interesa, estabilidad etc.), su aplicación práctica mediante el arte pictórico (soportes, disolventes, reglas para pintar, correcciones, veladuras, barnizado, etc.) y su mezcla con otro tipo de procedimientos pictóricos como el óleo, el acrílico, la cera encáustica y diversos temples (huevo, cola y caseína).

Correlação entre as propriedades mecânicas de materiais impermeabilizantes a base de elastômeros de poliuréia e poliuretano com o desempenho do sistema aplicado em lajes estruturais

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, Programa de Pós-graduação em Estruturas e Construção Civil, 2015.

CONTROL OF SIZE AND MAGNETIC PROPERTIES OF CARBOXYL-FUNCTIONALIZED MAGNETITE PARTICLES: SYNTHESIS PROCEDURES, CHARACTERIZATIONS, AND APPLICATIONS

Magnetic nanoparticles (MNPs) are known for the unique properties conferred by their small size and have found wide application in food safety analyses. However, their high surface energy and strong magnetization often lead to aggregation, compromising their functions. In this study, iron oxide magnetic particles (MPs) over the range of nano to micro size were synthesized, from which particles with less aggregation and excellent magnetic properties were obtained. MPs were synthesized via three different hydrothermal procedures, using poly (acrylic acid) (PAA) of different molecular weight (Mw) as the stabilizer. The particle size, morphology, and magnetic properties of the MPs from these synthesis procedures were characterized and compared. Among the three syntheses, one-step hydrothermal synthesis demonstrated the highest yield and most efficient magnetic collection of the resulting PAA-coated magnetic microparticles (PAA-MMPs, >100 nm). Iron oxide content of these PAA-MMPs was around 90%, and the saturation magnetization ranged from 70.3 emu/g to 57.0 emu/g, depending on the Mw of PAA used. In this approach, the particles prepared using PAA with Mw of 100K g/mol exhibited super-paramagnetic behavior with ~65% lower coercivity and remanence compared to others. They were therefore less susceptible to aggregation and remained remarkably water-dispersible even after one-month storage. Three applications involving PAA-MMPs from one-step hydrothermal synthesis were explored: food proteins and enzymes immobilization, antibody conjugation for pathogen capture, and magnetic hydrogel film fabrication. These studies demonstrated their versatile functions as well as their potential applications in the food science area.

Antimicrobial effect of polymeric biomaterials for bone infection treatment

Dissertação de mestrado em Bioquímica, apresentada à Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2016.