Aesthetic posts and cores for metal-free restoration of endodontically treated teeth.

Utilization of contemporary post and core systems has facilitated the aesthetic restoration of endodontically treated teeth. Light transmission and biocompatibility have been enhanced by the introduction of metal-free post systems. The periodontal and endodontic status, root length, and histological structure of the devitalized teeth must be considered in order to achieve successful restoration following endodontic treatment. This article presents various restorative criteria for the aesthetic placement and buildup of post and core materials, as well as the preservation of maximum coronal and root structure.

A study of the effect of overshooting deep convection on the water content of the TTL and lower stratosphere from Cloud Resolving Model simulations

Simulations of overshooting, tropical deep convection using a Cloud Resolving Model with bulk microphysics are presented in order to examine the effect on the water content of the TTL (Tropical Tropopause Layer) and lower stratosphere. This case study is a subproject of the HIBISCUS (Impact of tropical convection on the upper troposphere and lower stratosphere at global scale) campaign, which took place in Bauru, Brazil (22° S, 49° W), from the end of January to early March 2004. Comparisons between 2-D and 3-D simulations suggest that the use of 3-D dynamics is vital in order to capture the mixing between the overshoot and the stratospheric air, which caused evaporation of ice and resulted in an overall moistening of the lower stratosphere. In contrast, a dehydrating effect was predicted by the 2-D simulation due to the extra time, allowed by the lack of mixing, for the ice transported to the region to precipitate out of the overshoot air. Three different strengths of convection are simulated in 3-D by applying successively lower heating rates (used to initiate the convection) in the boundary layer. Moistening is produced in all cases, indicating that convective vigour is not a factor in whether moistening or dehydration is produced by clouds that penetrate the tropopause, since the weakest case only just did so. An estimate of the moistening effect of these clouds on an air parcel traversing a convective region is made based on the domain mean simulated moistening and the frequency of convective events observed by the IPMet (Instituto de Pesquisas Meteorológicas, Universidade Estadual Paulista) radar (S-band type at 2.8 Ghz) to have the same 10 dBZ echo top height as those simulated. These suggest a fairly significant mean moistening of 0.26, 0.13 and 0.05 ppmv in the strongest, medium and weakest cases, respectively, for heights between 16 and 17 km. Since the cold point and WMO (World Meteorological Organization) tropopause in this region lies at ∼ 15.9 km, this is likely to represent direct stratospheric moistening. Much more moistening is predicted for the 15-16 km height range with increases of 0.85-2.8 ppmv predicted. However, it would be required that this air is lofted through the tropopause via the Brewer Dobson circulation in order for it to have a stratospheric effect. Whether this is likely is uncertain and, in addition, the dehydration of air as it passes through the cold trap and the number of times that trajectories sample convective regions needs to be taken into account to gauge the overall stratospheric effect. Nevertheless, the results suggest a potentially significant role for convection in determining the stratospheric water content. Sensitivity tests exploring the impact of increased aerosol numbers in the boundary layer suggest that a corresponding rise in cloud droplet numbers at cloud base would increase the number concentrations of the ice crystals transported to the TTL, which had the effect of reducing the fall speeds of the ice and causing a ∼13% rise in the mean vapour increase in both the 15-16 and 16-17 km height ranges, respectively, when compared to the control case. Increases in the total water were much larger, being 34% and 132% higher for the same height ranges, but it is unclear whether the extra ice will be able to evaporate before precipitating from the region. These results suggest a possible impact of natural and anthropogenic aerosols on how convective clouds affect stratospheric moisture levels.

Fracture resistance of composite resin cores with or without prefabricated posts over different substrates

The fracture resistance of endodontically treated teeth has been an obstacle to the durability of the remaining teeth and restorations. The aim of this study was to evaluate the fracture resistance of endodontically treated bovine and human teeth that were restored with either prefabricated metal posts, glass fiber posts, or composite resin cores. Statistical analysis revealed significant difference between different substrates, but there was no statistically significant difference between different types of intraradicular posts or in the interaction between substrate and post types. The intraradicular posts do not increase the fracture resistance of endodontically treated teeth. The metal posts presented more unfavorable fracture modes when compared to glass fiber posts and composite resin cores.

Composição de cores através da calibração radiométrica e fotométrica de LEDs: Teoria e experimento

In the present work, the basic concepts of radiometric, photometric and colorimetric calibration are presented, which were applied to three light-emitting diodes (LEDs) used to compose the different color sensations that the human eye perceives in the visible region of the electromagnetic spectrum. In this sense, an experimental setup comprising a LED drive circuit and a home-made integrating sphere was assembled for the initial radiometric and photometric calibration as well as to obtain a set of intensity and spectral combinations associated to different colorimetric CIE (Commission Internationale de l'Eclairage) coordinates. The reader can, therefore, understand, in a simple manner, the process of color composition inside a color monitor or display picture element (pixel ). © Sociedade Brasileira de Física.

A influência dos sistemas de gerenciamento de cores em provas digitais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Olhar tecer des: (cor)pos forças fluxos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese dos isótopos do monóxido de carbono no meio interestelar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Trombose venosa profunda aguda: avaliação prospectiva do início do processo de revanalização das veias dos membros inferiores pelo mapeamento dúplex em cores

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

Cloud computing in Latin America: Current situation and policy proposals

Includes bibliography.

The advance of cloud computing

The “Implementation of the National Data Centre” project, Augusto Espín, Deputy Minister of Telecommunications and Information Society, Ecuador .-- Cloud computing and public policy in Brazil, Rafael Henrique Rodrigues Moreira, Ministry of Science, Technology and Innovation, Brazil .-- “The cloud is being taken up more quickly in Latin America than in the rest of the world”, interview to Lalo Steinmann, Microsoft .-- The impact of education and research networks on the development of cloud computing Eduardo Vera, University of Chile .-- “The cloud helps to narrow divides by providing access to technology resources that used to be unaffordable”, interview to Luis Urzúa, Movistar Chile .-- “Cloud computing will be a strategic sector of the economy in the coming years”, interview to Jean-Bernard Gramunt, France’s digital strategy .-- “If take-up in Latin America is as strong as predicted, it will be a good opportunity to create and export technology”, interview to Flavio Junqueira, Yahoo! Labs.