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Rio de Janeiro, Brazil

Farias M.S.,Cidade Universitaria Ilha do Fundao | Nedjah N.,Rua Sao Francisco Xavier | De MacEdo Mourelle L.,Rua Sao Francisco Xavier
International Journal of High Performance Systems Architecture | Year: 2011

Clustering algorithms are used extensively to organise and categorise abundant data. This paper describes the implementation of subtractive clustering algorithm in hardware. The solution developed in this paper seeks a hardware implementation to automatic and fast identification of cluster centres. This hardware proposed is generic so it can be used in any data classification problems, omnipresent in identification systems. Copyright © 2011 Inderscience Enterprises Ltd.

Campos P.B.,Cidade Universitaria Ilha do Fundao | Campos P.B.,Hospital Universitario Clementino Fraga Filho Laboratorio Nacional Of Celulas Tronco Embrionarias | Sartore R.C.,Cidade Universitaria Ilha do Fundao | Sartore R.C.,Hospital Universitario Clementino Fraga Filho Laboratorio Nacional Of Celulas Tronco Embrionarias | And 5 more authors.
Mutagenesis | Year: 2012

Zidovudine (3′-azido-3′-deoxythymidine; AZT) is a nucleoside analogue widely used for the treatment of acquired immune deficiency syndrome (AIDS). Medical guidelines recommend the use of AZT by pregnant women in order to reduce risk of HIV vertical transmission. Although it is efficacious, little is known about the side effects of AZT on embryonic development. In this sense, we used murine embryonic stem (mES) cells as a model to investigate the consequences of AZT exposure for embryogenesis. Firstly, mES colonies were incubated with AZT (50 or 100 mM) and cell cycle profile was evaluated. While 27.7 ± 5.43% of untreated mES cells were in G2/M phase, this percentage raised to 45.96 ± 4.18% after AZT exposure (100 μM). To identify whether accumulation of cells in G2/M phase could be related to chromosome missegregation with consequent cell cycle arrest, aneuploidy rate was evaluated after AZT treatment. Untreated colonies presented 39.6 ± 8.4% of cells aneuploid, while after AZT 100 μM treatment, the proportion of aneuploid cells raised to 67.8 ± 3.4% with prevalence of chromosome loss. This event was accompanied by micronuclei formation as AZT 100 μM treated mES cells presented a 2-fold increase compared to untreated ones. These data suggest that AZT exerts genotoxic effects and increases chromosome instability at early stages of embryonic development. © The Author 2012. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved.

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