945 resultados para Bioengineering chambers
Resumo:
Cardiac or ventricular remodeling is characterized by molecular, cellular, and interstitial alterations that lead to changes in heart size, mass, geometry and function in response to a given insult. Currently, tobacco smoke exposure is recognized as one of these insults. Indeed, tobacco smoke exposure induces the enlargement of the left-sided cardiac chambers, myocardial hypertrophy, and ventricular dysfunction. Potential mechanisms for these alterations include hemodynamic and neurohormonal changes, oxidative stress, inflammation, nitric oxide bioavailability, matrix metalloproteinases and mitogen-activated protein kinase activation. This review will focus on the concepts, relevance, and potential mechanisms of cardiac remodeling induced by tobacco smoke.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
This study investigated the transdentinal cytotoxicity of glutahaldehyde-containing solutions/materials on odontoblast-like cells. Dentin discs were adapted to artificial pulp chambers. MDPC-23 cells were seeded on the pulpal side of the discs and the occlusal surface was treated with the following solutions: water, 2% glutaraldehyde (GA), 5% GA, 10% GA, Gluma Comfort Bond+Desensitizer (GCB+De) or Gluma Desensitizer (GDe). Cell viability and morphology were assessed by the Alamar Blue assay and SEM. The eluates were collected and applied on cells seeded in 24-well plates. After 7 or 14 days the total protein (TP) production, alkaline phosphatase activity (ALP) and deposition of mineralized nodules (MN) were evaluated. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (p<0.05). GA solutions were not cytotoxic against MDPC-23. GCB+De (85.1%) and GDe (77.2%) reduced cell viability as well as TP production and ALP activity at both periods. After 14 days, GCB+De and GDe groups produced less MN. Affected MDPC-23 presented deformation of the cytoskeleton and reduction of cellular projections. The treatment with 2.5%, 5% and 10% GA was not harmful to odontoblast-like cells. Conversely, when GA was combined with other components like HEMA, the final material became cytotoxic. Glutaraldehyde has been used to decrease dentin hypersensitivity. This substance is also capable of preventing resin-dentin bond degradation by cross-linking collagen and MMPs. This study showed that GA might be safe when applied on acid etched dentin. However, when combined with HEMA the product becomes cytotoxic.
Resumo:
To evaluate the transdentinal cytotoxicity of resin-based luting cements (RBLCs), with no HEMA in their composition, to odontoblast-like cells. Human dentine discs 0.3 mm thick were adapted to artificial pulp chambers (APCs) and placed in wells of 24-well plates containing 1 mL of culture medium (DMEM). Two categories of HEMA-free RBLCs were evaluated: group 1, self-adhesive Rely X Unicem (RU; 3M ESPE), applied directly to the dentine substrate; and group 2, Rely X ARC (RARC; 3M ESPE), applied to dentine previously acid-etched and treated with a bonding agent. In group 3 (control), considered as representing 100% cell metabolic activity, no treatment was performed on dentine. The APC/disc sets were incubated for 24 h or 7 days at 37 °C and 5% CO2 . Then, the extracts (DMEM + dental materials components that diffused through dentine) were applied to cultured odontoblast-like MDPC-23 cells for 24 h. After that, the cell viability (MTT assay), cell morphology (SEM), total protein production (TP) and alkaline phosphatase (ALP) activity were assessed. Data from MTT assay and TP production were analysed by Kruskal-Wallis and Mann-Whitney tests (α = 5%). Data from ALP activity were analysed by one-way anova and Tukey's test (α = 5%). In group 1, a slight reduction in cell viability (11.6% and 16.8% for 24-h and 7-day periods, respectively) and ALP activity (13.5% and 17.9% for 24-h and 7-day periods, respectively) was observed, with no significant difference from group 3 (control) (P > 0.05). In group 2, a significant reduction in cell viability, TP production and ALP activity compared with group 3 (control) occurred (P < 0.05), regardless of incubation time. Alteration in MDPC-23 cell morphology was observed only in group 2. HEMA-free Rely X ARC cement caused greater toxicity to odontoblast-like MDPC-23 cells than did Rely X Unicem cement when both resin-based luting materials were applied to dentine as recommended by the manufacturer.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Bacterial cellulose (BC) and silk fibroin (SF) are natural biopolymers successfully applied in tissue engineering and biomedical fields. In this work nanocomposites based on BC and SF were prepared and characterized by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). In addition, the investigation of cytocompatibility was done by MTT, XTT and Trypan Blue dye technique. Cellular adhesion and proliferation were detected additionally. The evaluation of genotoxicity was realized by micronucleus assay. In vitro tests showed that the material is non-cytotoxic or genotoxic. SEM images revealed a greater number of cells attached at the BC/SF:50% scaffold surface than the pure BC one, suggesting that the presence of fibroin improved cell attachment. This could be related to the SF amino acid sequence that acts as cell receptors facilitating cell adhesion and growth. Consequently, BC/SF:50% scaffolds configured an excellent option in bioengineering depicting its potential for tissue regeneration and cultivation of cells on nanocomposites.
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Interventions in nature made by man are very common since the beginnings of human history, especially in the case regarding the storage of water. The construction of dams have been and still are fundamental in maintaining human life due to the vital importance that water plays. The size of these structures vary according to need, such as water catchment, fish-farming or electricity generation. Embankment dams are the most common type of these structures. Can be defined as dams natural material obtained from loan chambers located near the dam site. This type of barrier may be divided into earth dams and rockfill dams. The study area covers an earth dam located in Cordeirópolis (SP) and is essentially composed of diabases altered soil of the Serra Geral Formation of the Paraná Basin. With the aid of geophysics, more specifically of the Electrical Resistivity method, the aim is to check any water infiltration zones in the dam's body. Given the risks associated with water seepage in earth dams, that may generate breakdown structures, erosion, and consequently accidents and / or harmful factors in the nearby areas. One of the main structural problems married by water infiltration is the possible generation of pipes that could jeopardize the dam structure. This work aims to contribute towards the evaluation of the effectiveness of using an indirect technique of research and monitoring in aid to direct research techniques such as piezometers and drive stakes. The results are presented in the form of 2D and 3D geophysical models, the analysis shows a low resistivity zone with typical values of the presence of humidity originating upstream of the dam and downstream bottleneck trend, that are the basis for interpretation by percolation or not water in the dam
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
The Frances Lander Spain Papers consists of correspondence, clippings, photographs, memorabilia, and copies of her publications relating to her involvement with professional library organizations such as the American Library Association; her library work in Thailand as a Fulbright and Rockefeller Foundation grantee (1951-1952 and 1964-1965); and her work as coordinator of children’s services at the N.Y. Public Library (1953-1961). Correspondents include librarian Louis Round Wilson. There is also a family history which includes the family names Chambers, Collier, Cook, Crossland, Dantzler, Gran, Hardeman, Lander, McDaniel, McPherson, Miller, Pearce, Pierce, Schenk, Snead, Spain, Sparks, Warlick and Zimmerman.