999 resultados para Membrana amniótica homógena
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Worldwide environmental degradation is an undesirable byproduct resulting from the increasing demand for natural resources. Water sources are suffering intense contamination since they usually receive a huge amount of domestic and industrial effluents - which are mostly wasted without proper treatment - inserting a large number of pollutants in the environment, heavy metals included. Mercury holds great toxicological importance because, under some physicochemical conditions in a water environment, Hg (II) ion turns into methylated compounds stemming from this element, such as methylmercury CH3Hg, which is highly toxic for the aquatic community in which bioaccumulation occurs. Nowadays passive sampling techniques are being developed to enable the analytical procedures which are applied in environmental monitoring. Diffusive gradients in thin-films technique (DGT) has been proven an interesting tool for the determination of labile metal species due to its in situ application. The DGT technique consists of a piston-like device on which the following series of agents is disposed: a binding agent (conventionally Chelex 100 resin), a diffusive agent, usually a polyacrylamide gel, and a membrane filter. Nevertheless, the agents conventinally used for this technique don't usually show satisfactory results in mercury sampling. The main goal of this study was to evaluate the phosphate-treated cellulose membrane (Whatman P 81), an alternative material, as binding agent in the DGT to determine labile mercury fractions in aquatic systems. In this context, we conducted a study of the behavior of this material in relation with system variables, pH and ionic strength. Afterwards we performed immersions of the DGT devices in real and enriched samples and in situ aiming the determination of mercury
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Abstract : The objective of this study was to evaluate quantitatively and to describe qualitatively the process of bone repair in the interface of receptor bed and graft autogenous bone block with or without a e-PTFE membrane, in osteopenia induced rats. To this end, we used forty-eight Wistar rats weighing about 300g, in which, with the aid of 4.1 mm trephine a graft was removed from the parietal bone and fixed to the surface of the left mandibular ramus. The animals were randomly divided into four experimental groups: Group 1 (n=12): SHAM operated and autogenous bone graft only; Group 2 (n=12): SHAM and autogenous bone graft covered by e-PTFE membrane; Group 3 (n=12): ovariectomized rats (OVX) and autogenous bone graft only; Group 4 (n=12): OVX and autogenous bone graft covered by e-PTFE membrane. The animals in each group were sacrificed at three time periods: 21, 45 and 60 days, each time with 4 animals per group. The specimens were decalcified and included, the sections were stained with HE and subjected to histological and histomorphometric analysis in light microscopy. The results of the ANOVA showed that the variables on the condition (OVZ and SHAM), and the time (21, 45 and 60 days) were statistically significant, and can be established with the Tukey test (5%) that the period 21-day differs significantly from the periods of 45 and 60 days, which did not differ among themselves. The descriptive histological analysis showed integration of the graft in all animals. It was concluded that the initial integration of the graft bed was negatively affected in the presence of induced osteopenia, and that the use or not of a e-PTFE membrane did not interfere in the process of integration
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Imunomarcação da OPG e RANKL no reparo ósseo após a cirurgia de elevação do seio maxilar com Bio-Oss
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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From the last decade of the twentieth century, the rapid growth of nanotechnology has resulted in the discovery of a number of forms of nanoparticles and nanoclusters. We can cite as an example: nanotubes, nanowires, nanobelts, and nanoconesnanoclusters which have a wide range of applications, particularly as catalysts magnetic material nanodevices, chemical sensors, degradation of toxic chemicals, or even as possible carriers for the isotope medical applications.. The first step is the production and characterization of nanowires multithreaded using different types of metals (nickel, silver, gold) and polymers (pyrrole), which are prepared by electrochemical deposition process. Will be held by the characterization of the same images of scanning electron microscopy (SEM) and transmission electron microscopy (TEM)
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Pós-graduação em Biotecnologia - IQ
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The aim of this study was to evaluate the clinical, tomographic, and histological similarity within the use of HA+β-TCP (Boneceramic) alone or associated with enamel matrix derived (EMD) proteins in sinus lifting procedures with subsequent dental implant placement. We selected two patients with residual bony ridges between 3 mm and 5 mm in height in need of bone grafts. Six months later, eight implants were installed (two implants at each site). Biopsies were made, and the tissue was processed and stained with HE solution. Tomographic evaluation showed bone height gain up to 10.0 mm on average. Histology showed new bone formation for both groups, with similar bone density and trabecular interconnectivity. It can be concluded that the HA+β-TCP graft isolated or associated to EMD provided bone height gain in sinus lifting procedures, with similar clinical, tomographic and histological characteristics.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Odontologia - FOA
Avaliação clínica e radiográfica de pacientes submetidos ao levantamento da membrana do seio maxilar
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Implant dentistry is a dental specialty which presents great predictability in the rehabilitation at posterior, partially edentulous maxillary areas. Early tooth loss results in significant jaw remodeling. The maxillary sinus lifting followed by implant placement is a predictable technique initially described in 1980. Since then, several different techniques have been investigated varying filling materials and the management of complications in order to provide effective guidance in the rehabilitation of these patients. The current study evaluated ten patients who underwent sinus lifting before implant placement and crown installation. First, a retrospective analysis of the medical records was conducted to obtain information about possible postoperative complications. Clinical and radiographic analyses were performed at baseline and 180 days after surgeries. The sinus lifting with immediate implant placement provided satisfactory outcomes and can be considered a safe procedure. Treatment predictability was demonstrated in 90% of patients and for 86.96% of implants placed. It is important to highlight knowledge of anatomical structures at this area, the use of delicate surgical techniques, and strict patient follow-up.
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The constant petrol fuel leak in gas stations has caused concern in many countries around the world. Those fuels have toxic organic compounds in their composition, like Polycyclic Aromatic Hydrocarbons (PAH), which are harmful to the human health. In this work the efficiency of the protection layer with a High Density Polyethylene (HDPE) membrane of 2.5 mm thickness was evaluated. The study was based in the diffusive process in the intact membrane by a permeameter developed to evaluate the diffusive process. The membrane was putted in the middle of the system to separate two sides: a local soil impregnated with diesel oil (in one side) and pure water (in the other side). The chromatography technique was conducted to evaluate the contamination in the pure water. The analyses were made monthly in a total period of 6 months of research. The results tests show that the membrane was less effective to antracene and naphthalene compounds. Despite that, the results showed that the HDPE membrane is a good alternative to prevent contamination of water and soil by the compounds under study up to one year, based on the performance in the time of study.