Vernhes M.,CEADEN |
Gonzalez-Pumariega M.,University of Habana |
Passaglia A.,University of Sao Paulo |
Martins F.C.,University of Sao Paulo |
Sanchez-Lamar A.,University of Habana
Ars Pharmaceutica | Year: 2013
Aim: The aim of this work was to evaluate the protective effect of aqueous extract of Phyllanthus Orbicularis, K from the damage induced by UV radiation. Material and methods: The plasmid-based non cellular system was used. The extract capacity to induce DNA strand breaks was evaluated at 0.0001-2.0 mg/ml concentrations. The protective effect of extract against UVB and UVC radiation was evaluated at 0.1-2.0 mg/ml concentrations. The transmittance of extract was measured for both UV radiations. Results: The P. orbicularis aqueous extract was not genotoxic even after 30 min of exposure. Concentrations ≥ 1 mg/ml of extract induced strand breaks at major times of exposition. P. Orbicularis extract protected DNA against UVB and UVC radiation at concentrations ≥ 0.1 mg/ml and 0.5 mg/ml respectively. Conclusions: In our experimental conditions, P. Orbicularis aqueous extract protects DNA from damage induced by UV radiation.
Arce P.,CIEMAT |
Ignacio Lagares J.,CIEMAT |
Harkness L.,University of Liverpool |
Perez-Astudillo D.,CIEMAT |
And 7 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2014
Gamos is a software system for Geant4-based simulation. It comprises a framework, a set of components providing functionality to simulation applications on top of the Geant4 toolkit, and a collection of ready-made applications. It allows to perform Geant4-based simulations using a scripting language, without requiring the writing of C++ code. Moreover, Gamos design allows the extension of the existing functionality through user-supplied C++ classes. The main characteristics of Gamos and its embedded functionality are described. © 2013 Elsevier B.V.
Rivas F.R.,Clinica Central Cira Garcia |
IFMBE Proceedings | Year: 2013
This work attempts to develop a functional prototype for stimulating biological systems with visible light. This system consists of different technologies (Power PSoC, EZ-Color, PrISM, CapSense) which help in controlling radiation parameters. Each of them have been implemented taking advantage of the on-chip programmable device CY8CLED04 of Cypress Semiconductor and are controlled through PSoC Express 3 software. This software offers an easily adaptable visual interface that permits the development of applications dynamically. PSoC Express 3 makes use of the chromatic diagram CIE 1931 to select the different wavelength to stimulate which are generated by three high brightness light emission diodes (HB-LEDs): red, green and blue (RGB). This light passes through a diffuser that favors the homogeneity of the resulting radiation. © 2013 Springer.
Evseev I.G.,Federal University of Technology of Parana |
Schelin H.R.,Federal University of Technology of Parana |
Paschuk S.A.,Federal University of Technology of Parana |
Milhoretto E.,Federal University of Technology of Parana |
And 6 more authors.
Applied Radiation and Isotopes | Year: 2010
Proton computerized tomography deals with relatively thick targets like the human head or trunk. In this case precise analytical calculation of the proton final energy is a rather complicated task, thus the Monte Carlo simulation stands out as a solution. We used the GEANT4.8.2 code to calculate the proton final energy spectra after passing a thick Al absorber and compared it with the same conditions of the experimental data. The ICRU49, Ziegler85 and Ziegler2000 models from the low energy extension pack were used. The results were also compared with the SRIM2008 and MCNPX2.4 simulations, and with solutions of the Boltzmann transport equation in the Fokker-Planck approximation. © 2009 Elsevier Ltd. All rights reserved.
Cerello P.,National Institute of Nuclear Physics, Italy |
Christian Cheran S.,National Institute of Nuclear Physics, Italy |
Bagnasco S.,National Institute of Nuclear Physics, Italy |
Bellotti R.,University of Bari |
And 11 more authors.
Pattern Recognition | Year: 2010
3-D object segmentation is an important and challenging topic in computer vision that could be tackled with artificial life models. A Channeler Ant Model (CAM), based on the natural ant capabilities of dealing with 3-D environments through self-organization and emergent behaviours, is proposed. Ant colonies, defined in terms of moving, pheromone laying, reproduction, death and deviating behaviours rules, is able to segment artificially generated objects of different shape, intensity, background. The model depends on few parameters and provides an elegant solution for the segmentation of 3-D structures in noisy environments with unknown range of image intensities: even when there is a partial overlap between the intensity and noise range, it provides a complete segmentation with negligible contamination (i.e., fraction of segmented voxels that do not belong to the object). The CAM is already in use for the automated detection of nodules in lung Computed Tomographies. © 2009 Elsevier Ltd. All rights reserved.
Bresson C.,CEADEN |
Spezia R.,CNRS Laboratory for Analysis and Modelling for Biology and Environment |
Solari P.L.,Synchrotron SOLEILMARS Beamline |
Jankowski C.K.,CEADEN |
And 2 more authors.
Journal of Inorganic Biochemistry | Year: 2015
In the present work, we have investigated the coordination modes of cobalt with glutathione (γ-L-glutamyl-L-cysteinyl-glycine, GSH). A systematic study of cobalt-GSH complexes at basic and neutral pH has been undertaken with a multi-spectroscopic approach combined with quantum chemistry calculations. XAS (x-ray absorption spectroscopy) has been performed at the cobalt K edge in order to shed light into the cation coordination sphere and formal oxidation states. XANES (x-ray absorption near edge structure) enabled to showthat in basic and neutral media, cobalt oxidation state is equal to +III and +II respectively. EXAFS (extended x-ray absorption fine structure) provided indications on the donor atoms involved in the coordination with cobalt as well as the bond lengths. DFT (density functional theory)-based calculations and NMR experiments have been performed to assess the most stable structure of the cobalt-GSH complex in basic conditions. © 2014 Elsevier Inc. All rights reserved.
Garcia-Basabe Y.,University of Habana |
Garcia-Basabe Y.,University of Matanzas |
Gomez A.,University of Guelph |
Rodriguez-Iznaga I.,University of Habana |
And 4 more authors.
Journal of Physical Chemistry C | Year: 2010
The location of extra-framework cations in low-silica zeolites is determined from in-house X-ray powder diffraction pattern by a successful implementation of a newly developed methodology. The method combines reciprocal and direct space methods plus a cost function that accounts for simultaneous fit of the chemical composition and the X-ray diffractogram. We demonstrated that the iterative combination of relaxation methods (Monte Carlo exploration and lattice energy minimization) helps to improve the structural refinement. The methodology is successfully applied to the study of natural clinoptilolite samples enriched with Ni and Co; in both cases, two different cation sites were found octahedrally coordinated to water molecules. The most populated site is located in the center of the A channel, while the second one is found in the window of the B channel. This result was validated using XANES and EXAFS spectroscopies. © 2010 American Chemical Society.
Arce P.,CIEMAT |
Lagares J.I.,CIEMAT |
Harkness L.,University of Liverpool |
Desorgher L.,SpaceIT GmbH |
And 3 more authors.
IEEE Nuclear Science Symposium Conference Record | Year: 2012
The wide range of physics models available in GEANT4, as well as its outstanding geometry and visualization tools, has made it gain widespread use in several fields of physics, like high energy, medical, space, etc. Nevertheless the use of GEANT4 often requires a long learning-curve, which implies a good knowledge of C++ and the GEANT4 code itself. GAMOS facilitates the use of GEANT4 by avoiding the need to use C++, providing instead a set of user commands. One of the novelties of GAMOS with respect to similar simulation codes lies in its flexibility, which makes it appropriate for simulation in many physics fields. This flexibility is sustained by the wide range of geometrical configurations, primary generators and physics lists supported and by the comprehensive set of tools that help the user in extracting detailed information from the simulation through user commands. The use of the plug-in technology contributes to this flexibility, as it facilitates the extension of the framework to include extra functionality not foreseen by the framework authors. GAMOS counts already with several hundreds registered users in the five continents; while it is more frequently used in the medical physics field, its use has also been extended to other fields, like high energy physics, space physics, neutron shielding, etc. © 2011 IEEE.
Cabal Rodriguez A.E.,CEADEN |
Cabal Rodriguez A.E.,University of Antwerp |
Leyva Pernia D.,CEADEN |
Schalm O.,Artesis University College of Antwerp |
Van Espen P.J.M.,University of Antwerp
Analytical and Bioanalytical Chemistry | Year: 2012
X-ray radiographic images of paintings often show little or no contrast. In order to increase the contrast in radiographic images we measured the X-ray spectrum of a low power X-ray tube, after passing through the painting, with a high energy-resolution SDD detector. To obtain images, the detector is collimated with a 400 μm diameter pinhole and the painting was moved through the beam in the x and y-direction using a dwell time of a few seconds per pixel. The data obtained consists of a data cube of, typically, 200∈×∈ 200 pixels and a 512-channel X-ray spectrum for each pixel, spanning the energy range from 0 to 40 keV. Having the absorbance spectrum available for each pixel, we are able, a posteriori, to produce images by edge subtraction for any given element. In this way high contrast, element-specific, images can be obtained. Because of the high energy-resolution a much simpler edge subtraction algorithm can be applied. We also used principal-component imaging to obtain, in a more automated way, images with high contrast. Some of these images can easily be attributed to specific elements. It turns out that preprocessing of the spectral data is crucial for the success of the multivariate image processing. © 2011 Springer-Verlag.
PubMed | CEADEN
Type: Journal Article | Journal: Analytical and bioanalytical chemistry | Year: 2012
X-ray radiographic images of paintings often show little or no contrast. In order to increase the contrast in radiographic images we measured the X-ray spectrum of a low power X-ray tube, after passing through the painting, with a high energy-resolution SDD detector. To obtain images, the detector is collimated with a 400 m diameter pinhole and the painting was moved through the beam in the x and y-direction using a dwell time of a few seconds per pixel. The data obtained consists of a data cube of, typically, 200 200 pixels and a 512-channel X-ray spectrum for each pixel, spanning the energy range from 0 to 40 keV. Having the absorbance spectrum available for each pixel, we are able, a posteriori, to produce images by edge subtraction for any given element. In this way high contrast, element-specific, images can be obtained. Because of the high energy-resolution a much simpler edge subtraction algorithm can be applied. We also used principal-component imaging to obtain, in a more automated way, images with high contrast. Some of these images can easily be attributed to specific elements. It turns out that preprocessing of the spectral data is crucial for the success of the multivariate image processing.