Thermal and structural properties of tantalum alkali-phosphate glasses

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

EPR, optical absorption and luminescence studies of Cr3+-doped antimony phosphate glasses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

PREDICTABLE INTERPROXIMAL TISSUE REMOVAL WITH A SURGICAL STENT

The correction of diastemas in the anterior region with composite resin is considered to be practical and conservative. Harmony between the restorative material and the periodontium is necessary to achieve satisfactory functional and esthetic results. Whenever excessive gingiva occurs in the interproximal region, removal is necessary to avoid excessively contoured restorations. A predictable technique is described to conservatively remove interproximal tissue in situations in which crown lengthening is required to treat bilateral diastemas. A surgical template based on the diagnostically waxed cast was produced to serve as a reference during periodontal surgery.

Carbon Film Coating of Abutment Surfaces: Effect on the Abutment Screw Removal Torque

Purpose: To evaluate the effect of diamond-like carbon (DLC) coating of prefabricated implant abutment on screw removal torque (RT) before and after mechanical cycling (MC).Materials and Methods: Fifty-four abutments for external-hex implants were divided among 6 groups (n = 9): S, straight abutment (control); SC, straight coated abutment; SCy, straight abutment and MC; SCCy, straight coated abutment and MC; ACy, angled abutment and MC; and ACCy, angled coated abutment and MC. The abutments were attached to the implants by a titanium screw. RT values were measured and registered. Data (in Newton centimeter) were analyzed with analysis of variance and Dunnet test (alpha = 0.05).Results: RT values were significantly affected by MC (P = 0.001) and the interaction between DLC coating and MC (P = 0.038). SCy and ACy showed the lowest RT values, statistically different from the control. The abutment coated groups had no statistical difference compared with the control. Scanning electron microscopy analysis showed DLC film with a thickness of 3 mm uniformly coating the hexagonal abutment.Conclusion: DLC film deposited on the abutment can be used as an alternative procedure to reduce abutment screw loosening.

Rapid Assessment of Seed Removal and Frugivore Activity as a Tool for Monitoring the Health Status of Tropical Forests

Ecological processes in tropical forests are being affected at unprecedented rates by human activities. Yet, the continuity of ecological functions like seed dispersal is crucial for forest regeneration. It thus becomes increasingly urgent to be able to rapidly assess the health status of these processes in order to take appropriate management measures. We tested a method to rapidly evaluate seed removal rates on two animal-dispersed tree species, Virola kwatae and V.michelii (Myristicaceae), at three sites in French Guiana with increasing levels of anthropogenic disturbance. We counted fallen fruits, fruit valves, and seeds of each focal fruiting tree in a single 1m2 quadrat, and calculated two indices: the proportion of seeds removed and the proportion of fruits opened by mammals. They both provide an indirect and rapid assessment of frugivore activity. Our results showed a significant decrease in the proportion of removed seeds (16%) and fruits opened (19%) at the most impacted site in comparison with the other two sites (79% for seeds, 60% and 35% for fruits). This testifies to an increased impoverishment of the primate and toucan communities at the disturbed sites. This standardized protocol provides fast information about the health status of the community of seed dispersers and predators and of their seed removal services. It is time- and cost-effective and is not species-specific, allowing comparisons among sites or over time. We suggest using it with the pantropical Myristicaceae and any other capsule-producing family to rapidly assess the health status of seed removal processes across the tropics.

The Influence of the Heat Treatment Temperatures in Calcium Phosphate Synthesis

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

Novel bioassay for the discovery of inhibitors of the 2-C-Methyl-D-erythritol 4-Phosphate (MEP) and terpenoid pathways leading to carotenoid biosynthesis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of Parstatin on Experimental Periodontal Disease and Repair in Rats

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

Study of the removal of chemical oxygen demand of the cheese whey and wastewater from dairy industry using Spirulina platensis

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

Polymeric alginate microspheres containing biochar to immobilize phosphate ions

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

Removal of dyes by lignocellulose adsorbents originating from biodiesel production

In this study, use was made of tucumã cake, in natura (TCN) and thermally treated (TCT), as potential alternative adsorbents for the adsorption of cationic and anionic dyes. The effects of the parameters: contact time, adsorbent: adsorbate mass ratio, and initial concentration of dye were analyzed. The adsorption isotherms were established from optimized adsorption parameters. The best conditions for adsorption were: equilibrium time of 7 h, concentration of 25 mg L 1 and ratio of 1:200 for the methylene blue dye; and pH 6.5, concentration of 25 mg L 1 and ratio of 1:200 for the congo red dye. The adsorption process was best represented by the Dubinin–Radushkevich and Sips isotherms. The kinetics of adsorption of the dyes were best described by the pseudo-second-order kinetic and Elovich models. TCT showed the best maximum adsorption capacity (Qm) for the methylene blue dye (63.92 mg g 1 ).

White Light and Multicolor Emission Tuning in Triply Doped Yb3+/Tm3+/Er3+ Novel Fluoro-phosphate Transparent Glass-ceramics

New Yb3+, Er3+ and Tm3+ doped fluoro-phosphate glasses belonging to the system NaPO3–YF3–BaF2–CaF2 and containing up to 10 wt% of rare-earth ion fluorides were prepared and characterized by differential scanning calorimetry, absorption spectroscopy and up-conversion emission spectroscopy under excitation with a 975 nm laser diode. Transparent and homogeneous glass-ceramics have been reproducibly obtained with a view to manage the red, green and blue emission bands and generate white light. X-ray diffraction as well as electron microscopy techniques have confirmed the formation of fluorite-type cubic nanocrystals at the beginning of the crystallization process while complex nanocrystalline phases are formed after a longer heat-treatment. The prepared glass-ceramics exhibit high optical transparency even after 170 h of thermal treatment. An improvement of up-conversion emission intensity – from 10 to 160 times larger – was measured in the glass-ceramics when compared to the parent glass, suggesting an important incorporation of the rare-earth ions into the crystalline phase(s). The involved mechanisms and lifetime were described in detail as a function of heat-treatment time. Finally, a large range of designable color rendering (from orange to turquoise through white) can be observed in these materials by controlling the laser excitation power and the crystallization rate.

Fontes e doses de fósforo na presença e ausência de composto orgânico no estado nutricional e na produtividade da cana-de-açúcar

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

O uso do beta-tricálcio fosfato como substituto ósseo em odontologia

The correction of bone defects is the restoration of lost structures which can be replaced by alloplastic implants or bone grafts. Due to the known disadvantages of removal of autogenous grafts, most researches in dentistry aim to develop alloplastic or non-alloplastic materials able to replace bone without these limitations. Beta-Tricalcium Phosphate (β-TCP) is a synthetic granular bone substitute, biocompatible, osteoconductive, which can be used in the alveolar reconstruction. In this work, we perform a literature review on the β-TCP characteristics and discuss its application in dentistry.

Microstructural, physical, and fluid dynamic assessment of spinel-based and phosphate-bonded investments for dental applications

This work reports the experimental evaluation of physical and gas permeation parameters of four spinel-based investments developed with or without inclusion of sacrificial fillers. Data were compared with those of three commercial formulations. Airflow tests were conducted from 27 to 546°C, and permeability coefficients were fitted from Forchheimer's equation. Skeletal densities found for spinel- (ρs = 3635 ± 165 kg/m3) and phosphate-bonded (ρs = 2686 ± 11 kg/m3) samples were in agreement with the literature. The developed investments were more porous and less permeable than commercial brands, and the differences were ascribed to the different pore morphologies and hydraulic pore sizes of ceramic matrices. The inclusion of both fibers and microbeads resulted in increases of total porosity (42.6–56.6%) and of Darcian permeability coefficient k1 (0.76 × 10−14–7.03 × 10−14 m2). Air permeation was hindered by increasing flow temperatures, and the effect was related to the influence of gas viscosity on ΔP, in accordance with Darcy's law. Casting quality with molten titanium (CP Ti) was directly proportional to the permeability level of the spinel-based investments. However, the high reactivity of the silica-based investment RP and the formation of α-case during casting hindered the benefits of the highest permeability level of this commercial brand.