Actividad antimicrobiana de la solución de nanopartícula de plata en cultivo de Enterococcus faecalis

Objective. The objective of this study was to evaluate the antimicrobial activity of the silver nanoparticles solution in enterococcus faecallis cultures (ATCC 29212), compared with various solutions of sodium hypoclorithe (NaOCl). Material and methods. Five Agar Petri plates were inoculated with E. faecallis and each of them was placed a cellulose dish embedded with silver nanoparticles solution, or a solution of sodium hypochlorite evaluated (Viarzon, Cloralex, Clorox). Chlorhexidine digluconate 2% was used as positive control and sterile saline solution was used as negative control. After 24 hours of incubation at 37ºc, under aerobic conditions, the zones of inhibition of bacterial growth were measured and the results subjected to the statistical t test among the experimental groups (= 5%). Results. The Cloralex showed to be the most effective reflected in the extent of inhibition in relation to other substances (p< 0.05), except that the chlorhexidine digluconate 2% (p> 0.05). The solution of silver nanoparticles provided a greater zone of inhibition than the sodium hypochlorite solution (Clorox) and Viarzon (p< 0.05). Clorox and Viarzon didn't provide zones of inhibition and were similar to each other (p> 0.05). Conclusions. The solution of silver nanoparticles presents antimicrobial activity in cultured E. faecallis, even higher than other commercial forms of sodium hypochlorite. Further studies should be carried out to determine its viability as irrigating solution in endodontics (AU)

Fractal descriptors for discrimination of microscopy images of plant leaves

This study proposes the application of fractal descriptors method to the discrimination of microscopy images of plant leaves. Fractal descriptors have demonstrated to be a powerful discriminative method in image analysis, mainly for the discrimination of natural objects. In fact, these descriptors express the spatial arrangement of pixels inside the texture under different scales and such arrangements are directly related to physical properties inherent to the material depicted in the image. Here, we employ the Bouligand-Minkowski descriptors. These are obtained by the dilation of a surface mapping the gray-level texture. The classification of the microscopy images is performed by the well-known Support Vector Machine (SVM) method and we compare the success rate with other literature texture analysis methods. The proposed method achieved a correctness rate of 89%, while the second best solution, the Co-occurrence descriptors, yielded only 78%. This clear advantage of fractal descriptors demonstrates the potential of such approach in the analysis of the plant microscopy images.

Validação de aplicativo comercial visando a incorporação da realidade aumentada a um modelo de avaliação pós-ocupação

Post-Occupancy Evaluation of buildings considers user satisfaction, building pathologies and performance, as well as users interventions in the built environment. The possibility of identifying interventions regardless of the user could provide a significant gain in the efficiency of Post-Occupancy Evaluations. We foresee the application of Augmented Reality (AR) to improve the identification of renovations by overlapping the construction information model with an image of the actual building. This article validates the use of AR on existing smartphone and tablet applications. This study proposes the incorporation of AR into the planning, execution and application of Post-Occupancy Evaluation. For the planning, this study proposes the development of a new research tool. With regards to the execution, this study examined the data collection conditions on site through the visualization of overlapping models. For the application, this study proposes displaying the results through the use of RA information layers. The transparency oft he RA model was used to allow comparison between the virtual model and the real model. The development and adaptation of the virtual model and the solution developed for the experiment of the RA proposal are presented and discussed. The experiment points to shortcomings that still make the proposed technological solution unfeasible.

Aplicação da equação de Fokker-Planck no estudo de canais iônicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sintomas de deficiências de macronutrientes em pepineiro

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Fabricação de membranas fibrosas de compósito PVDF/TIO2 pelo método de fiação por sopro em solução

Pós-graduação em Ciência dos Materiais - FEIS