Organic acids and protein compounds causing the photoluminescence properties of natural rubber membranes and the quenching phenomena from Au nanoparticle incorporation

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

Comparison of the performance of natural latex membranes prepared with different procedures and PTFE membrane in guided bone regeneration (GBR) in rabbits

This work assessed the performance of membranes made of natural latex extracted from Hevea brasiliensis prepared with three different methods: polymerized immediately after collection without the use of ammonia (L1); polymerized after preservation in ammonia solution (L2); and polymerized after storage in ammonia, followed by Soxhlet technique for the extraction of substances (L3). Polytetrafluoroethylene (PTFE) membrane was used as control. Two 10-mm diameter bone defects were surgically made in the calvaria of thirty adult male New Zealand rabbits. Defects (total n = 60) were treated with guided bone regeneration (GBR) using L1, L2, L3 or PTFE membranes (n = 15 for each membrane). Ten animals were euthanized after 7, 20 and 60 days postoperatively so that five samples (n = 5) of each treatment were collected at each time, and bone regeneration was assessed microscopically. The microscopic analysis revealed defects filled with blood clot and new bone formation at the margins of the defect in all 7-day samples, while 20-day defects were mainly filled with fibrous connective tissue. After 60 days defects covered with L1 membranes showed a significantly larger bone formation area in comparison to the other groups (P < 0.05, ANOVA, Tukey). Additionally, bone tissue hypersensitization for L1 and PTFE membranes was also investigated in six additional rabbits. The animals were subjected to the same surgical procedure for the confection of one 10-mm diameter bone defect that was treated with L1 (n = 3) or PTFE (n = 3). Fifty-three days later, a second surgery was performed to make a second defect, which was treated with the same type of membrane used in the first surgery. Seven days later, the animals were euthanized and samples analyzed. No differences among L1 and PTFE samples collected from sensitized and non-sensitized animals were found (P > 0.05, Kruskal-Wallis). Therefore, the results demonstrated that latex membranes presented performance comparable to PTFE membranes, and that L1 membranes induced higher bone formation. L1 and PTFE membranes produced no hypersensitization in the bone tissue.

Estimating the concentration of gold nanoparticles incorporated on natural rubber membranes using multi-level starlet optimal segmentation

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

PEDOT:PSS self-assembled films to methanol crossover reduction in Nafion (R) membranes

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

Vaccination of grazing calves with antigens from the intestinal membranes of Haemonchus contortus: effects against natural challenge with Haemonchus placei and Haemonchus similis

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

Mechanisms of SnO2 Nanoparticles Formation and Growth in Acid Ethanol Solution Derived from SAXS and Combined Raman-XAS Time-Resolved Studies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Preparation of TiO2/SnO2 Thin Films by Sol-Gel Method and Periodic B3LYP Simulations

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

Mechanical properties and fracture dynamics of silicene membranes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cord blood cytokine levels in focal early-onset neonatal infection after preterm premature rupture of membranes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Electrical properties of highly conducting Sno2:Sb nanocrystals synthesized using a nonaqueous sol gel method

This work describes the synthesis of highly conducting antimony-doped tin oxide (ATO) nanocrystals prepared via a nonaqueous sol–gel route in the size range of 4–6 nm and provides insights into its electrical properties. The antimony composition was varied from 1 to 18 mol% and the lowest resistivity (4.0 × 10−4Ω·cm) was observed at room temperature in the SnO2:8.8 mol% Sb composition. The samples were evaluated by X-ray diffraction, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscope, and resistivity measurements were taken in the four-probe mode in the temperature range of 13–300 K. The results show highly crystalline nanoparticles in a monodisperse colloidal system, dependence on the shape of ATO nanoparticles as a function of Sb distribution, low resistivity, and semiconductor–metal transition.

Influence of the concentration of Sb2O3 on the electrical properties of SnO2 varistors

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

SnO2 dense ceramic microwave sintered with low resistivity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Infrared to visible up-conversion in biocellulose yttrium vanadate nanoparticle composite membranes. Demonstration of chloroaluminum phthalocyanine light emission under up-converted light excitation

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

Electrical Properties at Grain Boundaries Influenced by Cr3+ Diffusion in SnO2.ZnO.Nb2O5-Films Varistor Prepared by Electrophoresis Deposition

SnO2-based varistors are strong candidates to replace the ZnO-based varistors due to ordering fewer additives to improve its electrical behavior as well as by showing similar nonlinear characteristics of ZnO varistors. In this work, SnO2-nanoparticles based-varistors with addition of 1.0 %mol of ZnO and 0.05 %mol of Nb2O5 were synthesized by chemical route. SnO2.ZnO.Nb2O5-films with 5 μm of thickness were obtained by electrophoretic deposition (EPD) of the nanoparticles on Si/Pt substrate from alcoholic suspension of SnO2-based powder. The sintering step was carried out in a microwave oven at 1000 °C for 40 minutes. Then, Cr3+ ions were deposited on the films surface by EPD after the sintering step. Each sample was submitted to different thermal treatments to improve the varistor behavior by diffusion of ions in the samples. The films showed a nonlinear coefficient (α) greater than 9, breakdown voltage (VR) around 60 V, low leakage current (IF ≈ 10-6 A), height potential barrier above 0.5 eV and grain boundary resistivity upward of 107 Ω.cm.