403 research outputs found

    Técnica de colheita de autoenxerto ósseo no decurso de uma artroplastia primária da anca

    Get PDF
    Durante a implantação de uma prótese primária da anca para o tratamento de uma coxartrose, pode haver necessidade de se recorrer à aplicação de enxertos ósseos, na condição de medida terapêutica complementar. Para isso, os autoenxertos ósseos provenientes da cabeça femoral excisada sob diversas formas, dimensões e tipos encontram a melhor indicação. Descreve-se uma técnica simples e eficaz para a colheita de autoenxerto ósseo sob a forma de grânulos a partir da cabeça femoral artrósica, no decurso de uma artroplastia primária da anca

    Uso de drogas entre crianças e adolescentes em situação de rua: o que ajuda?

    Get PDF
    The aim of this study was to investigate factors associated to frequent and heavy drug use among street children and adolescents aged 10 to 18 years. A sample of 2,807 street children and adolescents from the 27 Brazilian state capital cities was analyzed. A World Health Organization questionnaire for non-students was adapted for use in Brazil. Data analysis was performed using logistic regression and decision tree models. Factors inversely associated with frequent and heavy drug use were: being age nine to 11 years (OR = 0.1); school attendance (OR = 0.3); daily time (one to five hours) spent on the streets (OR = 0.3 and 0.4); not sleeping on the streets (OR = 0.4); being on the streets for less than one year (OR = 0.4); maintenance of some family bonds (OR = 0.5); presence on the streets of a family member (OR = 0.6); not suffering domestic violence (OR = 0.6); being female (OR = 0.8). All of these variables were significant at the p < 0.05 level. The findings suggest that being younger, having family bonds and engagement in school are important protective factors that affect drug use among this population and should be considered in the formulation of public policies.O objetivo do estudo foi verificar fatores associados ao uso frequente e pesado de drogas entre adolescentes em situação de rua no Brasil. Estudo transversal com amostra representativa nacional de 2.807 crianças e adolescentes (10-18 anos). Foi usado um questionário da Organização Mundial da Saúde adaptado para o Brasil e análise dos dados, modelo de regressão logística. Fatores inversamente associados ao uso frequente e pesado de drogas: faixa etária entre 9-11 anos (OR = 0,1); frequentar escola (OR = 0,3); permanecer entre 1 e 5 horas na rua (OR = 0,3 e 0,4); não dormir na rua (OR = 0,4); estar na rua há menos de um ano (OR = 0,4); manter algum vínculo familiar (OR = 0,5); permanecer na rua com algum membro da família (OR = 0,6); não ter sofrido violência doméstica (OR = 0,6); gênero feminino (OR = 0,8). Todas essas variáveis apresentaram p < 0,05. Os achados sugerem que ser mais jovem, ficar menos tempo na rua e manter vínculos com escola e família são importantes fatores de proteção para essa população quanto ao uso frequente e pesado de drogas. Esses são fatores importantes na formulação de políticas públicas para essa população.Universidade Federal de São Paulo (UNIFESP) Departamento de PsicobiologiaUniversidade Federal de São Paulo (UNIFESP) Departamento de Medicina PreventivaUniversidade Federal do Rio Grande Instituto de Ciências Humanas e da InformaçãoUniversidade Federal do Rio Grande do Sul Instituto de PsicologiaUNIFESP, Depto. de PsicobiologiaUNIFESP, Depto. de Medicina PreventivaSciEL

    Development of dark Ti(C,O,N) coatings prepared by reactive sputtering

    Get PDF
    Accepted manuscriptDirect current reactive magnetron sputtering was implemented to successfully deposit dark Ti(C,O,N) thin films on silicon substrates. A titanium target was sputtered while a mixture of oxygen and nitrogen was injected into the deposition chamber, independently from an acetylene source. The deposition parameters were chosen as a function of pre-existing knowledge about sputtered Ti–O–N and Ti–C–O films. Tuning the oxygen/(nitrogen+carbon) ratio allowed obtaining a large spectrum of properties. In particular, the colour of the films was characterized by spectral reflectance spectroscopy, and expressed in the CIE 1976 L*a*b* colour space. An accurate control of the reactive gas mixture flow rate allowed obtaining intrinsic, stable and attractive dark colour for decorative applications. Surprisingly, the coatings with the lowest content of carbon and the highest content of oxygen presented the darkest tones. Composition analysis by electron probe microanalysis was done to quantify the titanium and metalloid concentrations in the films. X-ray diffraction experiments revealed the evolution of the film structure from a fcc structure for the lowest (O2+N2) flow rates to an amorphous one for the highest flow rates.Fundação para a Ciência e Tecnologia (FCT) - SFRH/BPD/27114/2006 and PTDC/CTM/69362/2006. CRUP (Acção Integrada Luso-francesa No. F-2307). GRICES/CNRS collaboration (Proc. 4.1.1 França

    Taper angle optimization of scarf repairs in carbon-epoxy laminates

    Get PDF
    The increasing use of Carbon-Fibre Reinforced Plastic (CFRP) laminates in high responsibility applications introduces an issue regarding their handling after damage. The availability of efficient repair methods is essential to restore the strength of the structure. The availability of accurate predictive tools for the repairs behaviour is also essential for the reduction of costs and time associated to extensive tests. This work reports on a numerical study of the tensile behaviour of three-dimensional (3D) adhesively-bonded scarf repairs in CFRP structures, using a ductile adhesive. The Finite Element (FE) analysis was performed in ABAQUS® and Cohesive Zone Models (CZM’s) was used for the simulation of damage in the adhesive layer. A parametric study was performed on two geometric parameters. The use of overlaminating plies covering the repaired region at the outer or both repair surfaces was also tested as an attempt to increase the repairs efficiency. The results allowed the proposal of design principles for repairing CFRP structures

    Evolving Convolutional Neural Networks for Glaucoma Diagnosis / Redes neurais convolucionais em evolução para diagnóstico de glaucoma

    Get PDF
    O glaucoma é uma doença ocular que causa danos ao nervo óptico do olho e sucessivo estreitamento do campo visual nos pacientes afetados, o que pode levar o paciente, em estágio avançado, à cegueira. Este trabalho apresenta um estudo sobre o uso de Redes Neurais Convolucionais (CNNs) para o diagnóstico automático através de imagens de fundo de olho. No entanto, a construção de uma CNN capaz de alcançar resultados satisfatórios para o diagnóstico do glaucoma, envolve muito esforço que, em muitas situações, nem sempre é capaz de tais resultados. O objetivo deste trabalho é utilizar um algoritmo genético (AG) para otimizar arquiteturas de CNNs através da técnica de evolução de algoritmos que possa aprimorar o diagnóstico do glaucoma em imagens de fundo do olho do conjunto de dados RIM-ONE-r2. Nosso artigo demonstra resultados satisfatórios após o treinamento do melhor indivíduo escolhido pelo AG, com a obtenção de uma acurácia de 91%

    Kinetic studies of trans-[Co(en)2Cl2]Cl aquation

    Get PDF
    The trans-dichlorobis(ethylenediamine)cobalt(III) chloride was synthesized in an undergraduate laboratory and its aquation reaction was carried out at different temperatures. This reaction follows pseudo-first-order kinetics and the rate constants, determined at 25, 35, 45, 55 and 70 º C, are 1.44 x 10-3; 5.14 x 10-3; 1.48 x 10-2; 4.21 x 10-2 and 2.21 x 10-1 s-1, respectively. The activation energy is 93.99 &plusmn; 2.88 kJ mol-1

    Damage indices evaluation for one-dimensional guided wave-based structural health monitoring

    Get PDF
    Damage detection in structures and systems is essential for monitoring parameters that can affect their integrity. This paper evaluates the efficiency of four damage indices (DIs) commonly used with temporal wave signals. The root mean square deviation, mean absolute percentage deviation, covariance, and correlation coefficient deviation DIs are presented, and a normalization is then proposed. An Euler-Bernoulli beam is used as a guided wave modelled with the spectral element method and excited by a toneburst signal. It includes the theoretical background of the throw-off beam, undamaged and cracked beam spectral elements. The DIs for a single crack position and a map varying crack depth and positions are calculated with deterministic and random temporal signal responses derived from noise addition. Results showed that DIs could identify and quantify the damage conditioned to the pulse location point and the influence of noise in the estimation, which leads in an analysis comparable to practical applications

    Microtiming patterns and interactions with musical properties in Samba music

    Get PDF
    In this study, we focus on the interaction between microtiming patterns and several musical properties: intensity, meter and spectral characteristics. The data-set of 106 musical audio excerpts is processed by means of an auditory model and then divided into several spectral regions and metric levels. The resulting segments are described in terms of their musical properties, over which patterns of peak positions and their intensities are sought. A clustering algorithm is used to systematize the process of pattern detection. The results confirm previously reported anticipations of the third and fourth semiquavers in a beat. We also argue that these patterns of microtiming deviations interact with different profiles of intensities that change according to the metrical structure and spectral characteristics. In particular, we suggest two new findings: (i) a small delay of microtiming positions at the lower end of the spectrum on the first semiquaver of each beat and (ii) systematic forms of accelerando and ritardando at a microtiming level covering two-beat and four-beat phrases. The results demonstrate the importance of multidimensional interactions with timing aspects of music. However, more research is needed in order to find proper representations for rhythm and microtiming aspects in such contexts

    Fracture toughness determination of adhesive and co-cured joints in natural fibre composites

    Get PDF
    Adhesive bonding has become more efficient in the last few decades due to the adhesives developments, granting higher strength and ductility. On the other hand, natural fibre composites have recently gained interest due to the low cost and density. It is therefore essential to predict the fracture behavior of joints between these materials, to assess the feasibility of joining or repairing with adhesives. In this work, the tensile fracture toughness (Gc n) of adhesive joints between natural fibre composites is studied, by bonding with a ductile adhesive and co-curing. Conventional methods to obtain Gc n are used for the co-cured specimens, while for the adhesive within the bonded joint, the J-integral is considered. For the J-integral calculation, an optical measurement method is developed for the evaluation of the crack tip opening and adherends rotation at the crack tip during the test, supported by a Matlab sub-routine for the automated extraction of these quantities. As output of this work, an optical method that allows an easier and quicker extraction of the parameters to obtain Gc n than the available methods is proposed (by the J-integral technique), and the fracture behaviour in tension of bonded and co-cured joints in jute-reinforced natural fibre composites is also provided for the subsequent strength prediction. Additionally, for the adhesively- bonded joints, the tensile cohesive law of the adhesive is derived by the direct method
    • …
    corecore