Atividade anti-Helicobacter pylori de extratos hidroetanólicos de caule e folhas de Astronium fraxinifolium e Astronium graveolens

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

Ensaios laboratoriais para a determinação da resistência de conexão entre geogrelhas de PVA e blocos segmentais

During the retaining wall project in soil reinforced with geogrids and face milling system for segmental blocks is essential to determine the maximum connection resistance between the block and the geogrid. Thus, the aim of this study was to analyze the connection resistance based on ASTM D- 6638-01 between the segmental block model MW of Muros Terrae® company with the geogrids model Fortrac® M 35 / 20x20, Fortrac® M 55 / 30x20, Fortrac® M 80 / 30x20 and Fortrac® M 110 / 30x20 of HUESKER Synthetic GmbH using gravel 1 as a filling material. As a result, the resistance curves were obtained for the four models of geogrids and was described how it fracture. An additional investigation was the average gain connection resistance percentage when it is applied to geogrid a second layer instead of a single layer. The average percentage gains in the connection resistance to the geogrids model Fortrac® M 35 / 20x20, Fortrac® M 55 / 30x20, Fortrac® M 80 / 30x20 and Fortrac® M 110 / 30x20 were, respectively, 63.20 %, 63, 47%, 62.23 % and 51.34 %. Finally, we made a comparative analysis of the results of this study with those obtained by Guimarães (2006), Urashima et. al (2008) and Almeida and Toma (2011) to evaluate which combinations offered higher connection resistance

Usinabilidade do aço DIN C45 trefilado de alta resistência

Pós-graduação em Engenharia Mecânica - FEG

Resistência a fungicidas estrobilurinas em populações de Pyricularia oryzae de áreas de trigo no Brasil

Pós-graduação em Agronomia - FEIS

Desenvolvimento de sistema eletrônico para instrumentar um DPL em ensaio dinâmico de resistência do solo

Pós-graduação em Engenharia Elétrica - FEIS

Adsorção de antibióticos em meio aquoso utilizando diferentes adsorventes

Pós-graduação em Ciência dos Materiais - FEIS

Conflito, resistência e philía no Héracles furioso de Eurípides

In Heracles Mainomenos, by Euripides, the hero is submited to the ultimate test: win himself, accepting stay alive after committing an irremediable error. The dramatic action has dual motivation, human and divine. The human conflict requires resilience of families and friends of Heracles and the opposition of Lico is a key element to the action. In the subsequent clash between Heracles and the goddess Hera, victory lies with the deity, motivating the disaster, but confirms the heroics of Heracles, that resists the urge to annihilation after the murder of children. His friend, King Theseus, provides him the support needed to dissuade him from his purpose of annihilation and strengthens him for endurance. The valuation of philia is an important element in shaping the sense of this euripidean text.

Resistência de união e microinfiltração em restaurações de resina

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

Resistência ao cisalhamento de bráquetes fotopolimerizados com arco de plasma, LED e luz halógena utilizando diferentes tempos

This study evaluated in vitro the shear bond strength of brackets bonded with xenon plasma arc light, light-emitting diode (LED) and conventional halogen light using different curing times. Brackets were bonded to the buccal surface of 60 human maxillary premolars allocated to five groups. In groups 1 and 2, the resin was cured with the plasma arc for three and six seconds (s), respectively; in groups 3 and 4, the LED was used for five and ten s, respectively; and in group 5, the halogen light was used for 40 s. The specimens were stored in water for 24 hours and subjected to a shear force until bracket failure. The debonding pattern was classified according to the adhesive remnant index (ARI). The results were assessed by Anova and the SNK post-hoc test. No differences were detected among groups 2, 4 and 5, which showed higher averages than groups 1 and 3, which were not different between themselves. The ARI scores showed no differences among the three types of light sources in all times tested. Plasma arc and LED lights can be used with shorter curing times, within certain limits, than conventional halogen light for bonding orthodontic brackets, without decreasing bond strength.

Efeito de um gel de peróxido de carbamida a 10% sobre a resistência de união de restaurações adesivas à dentina

The present study aimed to analyze the effects of tooth bleaching with 10% carbamide peroxide (CP) gel on the bond strength of resin composite restorations to dentin. Material and Methods: Twenty cavities were prepared on the buccal surface of bovine teeth. After acid etching and application of bonding agent on dentin and enamel, the cavities were restored with composite resin. The specimens were divided into groups according to treatment on the surface of enamel / restoration: G1 - control (no treatment) and G2 (10% PC gel application for 8h/day during 14 days). After this period, the teeth were cut to produce beams with 0.81 mm2 cross-sectional area, which were subjected to microtensile test. The fractures were examined with a stereomicroscope and classified as cohesive in resin or dentin, adhesive, or mixed. Results: The statistical analysis (ANOVA / χ2) revealed that the factor treatment interfered with the bond strength, which was significantly higher for specimens of G2 (p <0.05). Adhesive fractures occurred in most of specimens of both groups with values ranging from 48.3% to 75%. Mixed fractures were the second more frequent in G1 and cohesive resin failure in G2. Conclusion: It was concluded that tooth bleaching with 10% of PC increased the bond strength of adhesive restorations to dentin.

Resistência à flexão em porcelana feldspática: efeito da ciclagem mecânica e limite de fadiga pelo método escada

This study evaluated the fatigue limit (FL) by the staircase method and the effect of mechanical cycling on the flexural strength (FS) of Duceragold feldspathic porcelain. Specimens (25 x 5 x 2 mm) were made according to manufacturer’s directions and submitted to three-point flexural strength test (n = 10). To determine FL (n = 30; 10,000 cycles; 2 Hz), an initial loading of 60% of the FS and an incremental loading (step) of 3% of the FS were used. Data were analyzed by Anova and Tukey´s test (p < 0.05). Although the proposed cycles have not reduced FS significantly, fractography analysis showed striation, characteristic signs of mechanical fatigue.

Caracterização química e resistência à flexão de uma resina acrílica após a incorporação de um polímero com atividade antimicrobiana

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito das dimensões dos corpos de prova na resistência à flexão de compósitos restauradores

The aim of this study was to evaluate the influence of specimen size, in comparison with the ISO Standard, on the three point flexural strength of resin composite restorative materials Filtek Supreme and Filtek Z-250. Forty specimens were fabricated for each material with the following length, width and thickness measurements (n = 10): 1) 20 × 2 × 2 mm (ISO 4049); 2) 10 × 2 × 1 mm; 3) 10 × 1 × 1 mm; 4) 8 × 0.8 × 0.8 mm. The composites were inserted in a single increment into two-piece metal device and light-polymerized. The specimens were dry stored at 37 ± 1 °C and protected from light for 7 days. After this period, flexural strength was measured by three-point flexure test using MTS 810 equipment, with a load cell of 10 kN at a speed of 0.5 mm/min. For the evaluated sizes, the results showed significant variability (p = 0.00) with values when compared with the ISO Standard (116.700 MPa), being statistically higher for the test specimens measuring 10 × 1 × 1 mm (142.530 MPa), similar for those of 10  ×  2  ×  1  mm (115.815 MPa) and lower for those of 8 × 0.8 × 0.8 mm (86.650 MPa). There was statistical equality (p = 0.08) for the studied composites (Filtek Supreme, 125.270 MPa; Filtek Z-250, 108.130 MPa). Specimens measuring 10 × 2 × 1 mm provided flexural strength values equivalent to those obtained in the sizes recommended by the ISO 4049 standard, with lower consumption of material, energy and time.

Resistência à flexão de uma resina acrílica após a incorporação de um polímero antimicrobiano

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos da aplicação de resina hidrofóbica sobre a resistência de união de adesivos autocondicionantes de frasco único

Introduction: It is known that self-etching adhesive systems can act as semi-permeable membranes. Objective: Evaluate the effects of additional layer of hydrophobic resin on the microtensile bond strength of self-etching one-bottle adhesives. Material and method: Sixty bovine incisors were used in this study. The facial enamel surfaces of the crowns were abraded with silicon carbide paper to expose flat, mid-coronal dentin surfaces. The following adhesives were used: Clearfil Tri S Bond (CTSB), AdheSE One (ADH) and One Coat  7.0 (OC). Each material was tested with and without applying an additional layer of hydrophobic material from the same manufacturer. Z-350 composite resin was inserted in three 1 mm increments. All adhesive restorative procedure was performed under simulated pulpal pressure and the microtensile test was performed immediately after curing the composite resin. Data were submitted to ANOVA and Tukey test (p < 0.05). Result: For all adhesives tested, the worst results were observed in groups which the additional layer of hydrophobic resin was not applied. Conclusion: The application of additional layer of hydrophobic material can improve the adhesion of self-etching all-in-one adhesive systems.