Santa Maria do Suaçuí, Brazil
Santa Maria do Suaçuí, Brazil

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An adapted Portuguese translation of a text by Bethe and Bacher published in 1873 is offered, which are discussed a disproof of the existence of electrons in the atomic nucleus. © 2017, Sociedade Brasileira de Física. Printed in Brazil.

Bizzi C.A.,Federal University of Santa Maria | Flores E.L.M.,Federal Technological University of Paraná | Nobrega J.A.,Federal University of São Carlos | Oliveira J.S.S.,Federal University of Santa Maria | And 2 more authors.
Journal of Analytical Atomic Spectrometry | Year: 2014

Many efforts have been made in order to reduce the amount of reagents and waste produced in analytical laboratories. However, suitable digestion efficiency must be considered, and depending on the sample preparation procedure, incomplete digestion can result in severe matrix effects during analysis by spectrometric techniques such as ICP OES and ICP-MS. In the present work a procedure based on the use of H2O2 was developed in order to minimize the consumption of HNO3 without decreasing the efficiency of digestion. Although H2O2 has been used combined with HNO3 for sample digestion, its role is still not completely elucidated even as its action combined with O2 in pressurized systems. The performance obtained using H2O2 was similar to that observed when adding O2 to the reaction vessel, driving the better understanding of the role of H2O2 in closed digestion procedures. Digestion using H2O2 allowed the use of HNO3 solutions as diluted as 1 mol L-1 to digest sample masses of biological materials as high as 500 mg. The proposed procedure allowed a reduction of up to 14 and 9.3-fold in the HNO3 amount normally used in whole milk powder and bovine liver digestions, respectively, without decreasing the digestion efficiency. Calcium, Cu, Fe, K, Mg, Mn, Mo, Na, and Zn were determined by ICP OES, while Cd, Co, and Pb were determined by ICP-MS. Using diluted HNO3 solution low blank values were obtained resulting in relatively lower limits of detection and relative standard deviations. The accuracy was evaluated by using certified reference materials of milk powder and bovine liver (agreement was better than 95% to certified values for all evaluated analytes). © 2014 The Royal Society of Chemistry.

Ardenghi T.M.,Federal University of Santa Maria | Piovesan C.,Centro Universitario Franciscano | Antunes J.L.F.,University of Sao Paulo
Revista de Saude Publica | Year: 2014

OBJECTIVE: To evaluate the influence of social inequalities of individual and contextual nature on untreated dental caries in Brazilian children. METHODS: The data on the prevalence of dental caries were obtained from the Brazilian Oral Health Survey (SBBrasil 2010) Project, an epidemiological survey of oral health with a representative sample for the country and each of the geographical micro-regions. Children aged five (n = 7,217) in 177 municipalities were examined and their parents/guardians completed a questionnaire. Contextual characteristics referring to the municipalities in 2010 (mean income, fluorodized water and proportion of residences with water supply) were supplied by the Fundação Instituto Brasileiro de Geografia e Estatística (Brazilian Institute of Geography and Statistics). Multilevel Poisson regression analysis models were used to assess associations. RESULTS: The prevalence of non-treated dental caries was 48.2%; more than half of the sample had at least one deciduous tooth affected by dental caries. The index of dental caries in deciduous teeth was 2.41, with higher figures in the North and Northeast. Black and brown children and those from lower income families had a higher prevalence of untreated dental caries. With regards context, the mean income in the municipality and the addition of fluoride to the water supply were inversely associated with the prevalence of the outcome. CONCLUSIONS: Inequalities in the prevalence of untreated dental caries remain, affecting deciduous teeth of children in Brazil. Planning public policies to promote oral health should consider the effect of contextual factors as a determinant of individual risk.

Orengo G.,Centro Universitario Franciscano | De Oliveira Graca C.,Laboratorio Do Gerador Of Neutrons
Annals of Nuclear Energy | Year: 2012

The use of neutron generators has been growing with the development of Neutron Capture Therapies (NCTs), mainly in Boron Neutron Capture Therapy (BNCT). In the absence of nuclear reactors in Brazil the neutron generators plays an important role for medical application. So the neutron transport calculation and neutron generators experiment analysis is very important to implement BNCT in Brazil. The aim of this work was to develop a method of calculating the 14 MeV neutron angular and energetic distribution for the D-T reaction in realistic conditions to compare with experimental data produced in our Neutron Generator Laboratory. The angular and energetic spectrum is obtained in a format as input for the discrete ordinates method used to solve the neutron transport equations, ANISN, DORT and TORT are the codes that will be used for this purpose. © 2011 Elsevier Ltd. All rights reserved.

Lara I.V.,Federal University of Santa Maria | Zanella I.,Centro Universitario Franciscano | Fagan S.B.,Centro Universitario Franciscano
Chemical Physics | Year: 2014

The dependence of the structural and the electronic properties of functionalized (5, 5) single-walled carbon nanotubes (SWNT) were investigated through ab initio density functional simulations when the carboxyl group is bonded on the flatter or curved regions. Radial deformations result in diameter decrease of up to 20 per cent of the original size, which was the limit reduction that maintains the SWNT functionalized structure. Changes on the electronic structure were observed due to the symmetry break of the SWNT caused by both the carboxyl group and the C-C bond distortions resulted by the radial deformation. It is observed that the functionalization process is specially favored by the sp3 hybridization induced on the more curved region of the deformed SWNT. © 2013 Elsevier B.V. All rights reserved.

Dos Santos C.L.,Centro Universitario Franciscano | Piquini P.,Federal University of Santa Maria
Journal of Applied Physics | Year: 2012

The one-dimensional character of the nanowires (NWs), with large surface to volume ratios, allows one to accommodate internal strains that would not be achieved in composite bulk materials with large mismatches. This opens a vast field to explore new materials with specific properties. One of the ways to efficiently exploit this characteristic feature of the NWs is through composition modulation. Using first principles calculations, we investigate the structural and electronic properties of core/shell modulated [111] zinc-blende InAs/InP NWs with different core/shell ratios and diameters (from 1.0 to 2.0 nm). Basic properties of these systems like the lattice parameter and the band gaps are seen to vary non-linearly with the core/shell ratio. The presence of an external InP shell is shown to improve the electronic mobility when compared with pure InAs NWs by eliminating the pinning of the Fermi level at InAs-derived surface states, while keeping the electron effective mass as low as in pure InAs NWs with similar diameters. We determine a type-I like band alignment, with a valence band offset depending on the core/shell ratio and a vanishing conduction band offset. We discuss the consequences of these results to the p-type conduction in the InAs core due to remote p-type doping at the InP shell region. © 2012 American Institute of Physics.

Power S.R.,Trinity College Dublin | De Menezes V.M.,Federal University of Santa Maria | Fagan S.B.,Centro Universitario Franciscano | Ferreira M.S.,Trinity College Dublin
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

The magnetic properties of graphene-related materials, and in particular, the spin-polarized edge states predicted for pristine graphene nanoribbons (GNRs) with certain edge geometries have received much attention recently due to a range of possible technological applications. However, the magnetic properties of pristine GNRs are not predicted to be particularly robust in the presence of edge disorder. In this work, we examine the magnetic properties of GNRs doped with transition-metal atoms using a combination of mean-field Hubbard and density functional theory techniques. The effect of impurity location on the magnetic moment of such dopants in GNRs is investigated for the two principal GNR edge geometries: armchair and zigzag. Moment profiles are calculated across the width of the ribbon for both substitutional and adsorbed impurities, and regular features are observed for zigzag-edged GNRs, in particular. Unlike the case of edge-state-induced magnetization, the moments of magnetic impurities embedded in GNRs are found to be particularly stable in the presence of edge disorder. Our results suggest that the magnetic properties of transition-metal-doped GNRs are far more robust than those with moments arising intrinsically due to edge geometry. © 2011 American Physical Society.

Ddine L.C.,Centro Universitario Franciscano
Arquivos brasileiros de cirurgia digestiva : ABCD = Brazilian archives of digestive surgery | Year: 2012

Chronic gastritis is an inflammation of the stomach mucosa, which is considered its main etiological factor the Helicobacter pylori. To observe the differences in patients with chronic gastritis as well as the presence and absence of H. pylori, to obtain a better understanding of the etiological factors, clinical, dietary and lifestyle habits and associated diseases. This was a descriptive study, retrospective medical records of patients with chronic gastritis treated as outpatients. Endoscopy and research of H. pylori was used in the diagnosis of chronic gastritis. The survey was conducted through a questionnaire to ascertain the risk factors for chronic gastritis and the clinical manifestations of disease, dietary and lifestyle habits, family history of the disease, weight changes and medications. For statistical analysis was used Spearman coefficient. Data were considered statistically significant p<0.05. Of the 94 patients evaluated were symptomatic with heartburn, belching, epigastric pain, fullness and nausea. In 56.6% (n = 54) of individuals was detected the presence of bacteria and in 43.6% (n = 40) was not found any specific etiologic factor. Was performed chi-square statistical test of clinical manifestations and factors such as stress and anxiety, leading to positive correlation. It became evident that the risk factors for disease are diverse, including the use of drugs, alcoholism, eating quickly, talking during meals, with significant relation to abdominal distension and reflux. The patients with the bacteria, had a higher risk of experiencing these symptoms. Various etiological factors in eating habits and lifestyle, as smoking, alcoholism, anxiety, stress, associated diseases and inadequate nutrition, interact to the onset of clinical manifestations, and the presence and absence of H. pylori did not show significant changes in patient clinical status.

Rhoden C.R.B.,Centro Universitario Franciscano | Zeni G.,Federal University of Santa Maria
Organic and Biomolecular Chemistry | Year: 2011

Due to the many new and remarkable findings and applications that have been published in recent years in seleno- and tellurophene chemistry, this review revisits the different aspects of this chemistry, including synthesis, reactivity and applications in the field of heterocycles. © The Royal Society of Chemistry 2011.

This phenomenological study aimed at understanding, in the light of Martin Buber's philosophy, what is to be a caregiver of children with AIDS. The phenomenological interview guided the meeting with seven caregivers of children with AIDS, selected in a teaching hospital of Porto Alegre-RS, southern of Brazil. The data were interpreted in the light of hermeneutics, emerging the unit of meaning Dialogues 'between' the familiar I and the Eternal THOU. The dialogues take place in the search for answers that allow the understanding of the significance of the impact and challenges they face while living with AIDS. As well, they reveal hope in changes, in the cure and in a vaccine development. We believe that knowing the importance of dialogue in the context of HIV/AIDS epidemic provide the development of a nursing care that brings together the technical-scientific and humanistic aspects.

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