Finite element method as an alternative to study the electronic structure of confined atoms.

The finite element method (FEM) based on a nonregular mesh is used to solve Hartree-Fock and Kohn-Sham equations for three atoms (hydrogen, helium, and beryllium) confined by finite and infinite potentials, defined in terms of piecewise functions or functions with a well-defined first derivative. This approach's reliability is shown when contrasted with Roothaan's approach, which depends on a basis set. Therefore, its exponents must be optimized for each confinement imposed over each atom, which is a monumental task.

Subspace-constrained deconvolution of auditory evoked potentials.

Auditory evoked potentials can be estimated by synchronous averaging when the responses to the individual stimuli are not overlapped. However, when the response duration exceeds the inter-stimulus interval, a deconvolution procedure is necessary to obtain the transient response. The iterative randomized stimulation and averaging and the equivalent randomized stimulation with least squares deconvolution have been proven to be flexible and efficient methods for deconvolving the evoked potentials, with minimum restrictions in the design of stimulation sequences.

On the Tribological and Oxidation Study of Xanthophylls as Natural Additives in Castor Oil for Green Lubrication.

The present study focuses on an introductory analysis of the use of three xanthophylls as additives for green lubricant applications. For this purpose, the additives were characterized by FTIR and H-NMR techniques, and the bio-lubricants were described by their physical properties. The effect of the natural compounds on the friction and wear properties of bio-lubricants were evaluated by sliding friction tests under boundary conditions, as confirmed by an analysis of the lubricating film thickness.

[Chromosome abnormalities in hyperparathyroidism: utility of comparative genomic hybridization in the study of parathyroid hyperplasias].

Genetic abnormalities responsible for primary (pHPT) and secondary hyperparathyroidism (sHPT) are not well described, especially those underlying the autonomous and refractory behaviour of glands from uremic patients with glandular hyperplasia and nodular growth. Comparative Genomic Hybridization (CGH) is a molecular cytogenetic technique based on a double-color in situ fluorescent analysis, allowing a global description of gains and losses of genomic material. It is a useful tool that localizes unstable genetic areas whose alteration could modify the expression of one or several genes related to the pathology in study.