59 resultados para Two stages

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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A mordida aberta é uma anomalia com características distintas que, além da complexidade dos múltiplos fatores etiológicos, traz consequências estéticas e funcionais. Muitas alternativas têm sido utilizadas em seu tratamento, entre elas a grade palatina, forças ortopédicas, ajuste oclusal, camuflagem com ou sem exodontias, mini-implantes ou miniplacas e cirurgia ortognática. O diagnóstico preciso e a determinação da etiologia permitem estabelecer os objetivos e o plano de tratamento ideal para essa má oclusão. O presente relato descreve o tratamento de uma má oclusão Classe I de Angle, com padrão esquelético de Classe II e mordida aberta anterior, realizado em duas fases e que foi apresentado à diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO), representando a categoria 2, como parte dos requisitos para a obtenção do título de Diplomado pelo BBO.

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Objetivou-se neste trabalho estudar modelos com efeitos não-aditivos diretos e maternos em uma população composta em clima tropical, tentando minimizar esses efeitos para obtenção dos valores genéticos dos animais avaliados. Foram utilizados dados de animais de uma população composta, por meio da comparação de três modelos que incluíram os efeitos fixos de grupo contemporâneo, ordem de parto e heterose direta e materna e os efeitos aleatórios de efeito genético aditivo direto e materno. As análises foram realizadas em duas etapas; na primeira foram estudadas as estimativas dos efeitos raciais e de heterose individual e materna e na segunda etapa, calculadas as variâncias, herdabilidades e os valores genéticos dos animais. O efeito materno, quando não foi considerado no modelo, pareceu superestimar o efeito aditivo racial. Os efeitos aditivos raciais, racial materno e de heterose individual e materna influenciaram significativamente o ganho médio diário no pré-desmame, obtendo-se diferentes estimativas entre os tipos biológicos. Considerando o arquivo de dados corrigidos para os efeitos não-aditivos diretos e maternos, as herdabilidades direta e materna foram de 0,22 e 0,20, respectivamente. Os efeitos racial materno e de heterose individual e materna foram importantes fontes de variação para o ganho médio diário no pré-desmame e devem ser considerados durante a avaliação genética de uma população multirracial.

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OBJETIVO: Estimar a proporção de automedicação em adultos de baixa renda e identificar fatores associados. MÉTODOS: Foram utilizados dados de inquérito populacional realizado no município de São Paulo em 2005, cujo plano amostral incluiu dois domínios, favela e não favela, com amostragem por conglomerados em dois estágios, totalizando 3.226 indivíduos elegíveis. Além de características sociodemográficas e econômicas, foram analisados: uso de medicamentos nos 15 dias anteriores à entrevista, tipo de acesso (gratuito, comprado ou outra) aos medicamentos e os tipos de morbidades (crônicas ou agudas) tratadas, em análise de regressão logística múltipla. RESULTADOS: A proporção de automedicação foi de 27% a 32%. Automedicação esteve fortemente associada à morbidade aguda, ao acesso ao medicamento por compra, à idade menor que 47 anos e medicamentos do grupo terapêutico que atuam no sistema nervoso central. O grupo que atua no sistema nervoso central foi o mais utilizado na automedicação. CONCLUSÕES: O acesso gratuito aos medicamentos mostrou-se fator de proteção para a automedicação. A distribuição de medicamentos e o atendimento adequado devem ser considerados para orientação e redução dos riscos que o uso irracional de medicamentos pode gerar à saúde.

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Noise is an intrinsic feature of population dynamics and plays a crucial role in oscillations called phase-forgetting quasicycles by converting damped into sustained oscillations. This function of noise becomes evident when considering Langevin equations whose deterministic part yields only damped oscillations. We formulate here a consistent and systematic approach to population dynamics, leading to a Fokker-Planck equation and the associate Langevin equations in accordance with this conceptual framework, founded on stochastic lattice-gas models that describe spatially structured predator-prey systems. Langevin equations in the population densities and predator-prey pair density are derived in two stages. First, a birth-and-death stochastic process in the space of prey and predator numbers and predator-prey pair number is obtained by a contraction method that reduces the degrees of freedom. Second, a van Kampen expansion in the inverse of system size is then performed to get the Fokker-Planck equation. We also study the time correlation function, the asymptotic behavior of which is used to characterize the transition from the cyclic coexistence of species to the ordinary coexistence.

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A hybrid system to automatically detect, locate and classify disturbances affecting power quality in an electrical power system is presented in this paper. The disturbances characterized are events from an actual power distribution system simulated by the ATP (Alternative Transients Program) software. The hybrid approach introduced consists of two stages. In the first stage, the wavelet transform (WT) is used to detect disturbances in the system and to locate the time of their occurrence. When such an event is flagged, the second stage is triggered and various artificial neural networks (ANNs) are applied to classify the data measured during the disturbance(s). A computational logic using WTs and ANNs together with a graphical user interface (GU) between the algorithm and its end user is then implemented. The results obtained so far are promising and suggest that this approach could lead to a useful application in an actual distribution system. (C) 2009 Elsevier Ltd. All rights reserved.

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Activated slag cement (ASC) shows significantly higher shrinkage than ordinary Portland cement agglomerates. Cracking generated by shrinkage is one of the most critical drawbacks for broader applications of this promising alternative binder. This article investigates the relationship between ASC hydration, unrestrained drying and autogenous shrinkage of mortar specimens. The chemical and microstructure evolution due to hydration were determined on pastes by thermogravimetric analysis, conduction calorimetry and mercury porosimetry. Samples were prepared with ground blast furnace slag (BFS) activated with sodium silicate (silica modulus of 1.7) with 2.5, 3.5 and 4.5% of Na2O, by slag mass. The amount of activator is the primary influence on drying and autogenous shrinkage, and early hydration makes a considerable contribution to the total result, which increases with the amount of silica. Drying shrinkage occurred in two stages, the first caused by extensive water loss when the samples were exposed to the environment, and the second was associated with the hydration process and less water loss. Due to the refinement of ASC porous system, autogenous shrinkage is responsible for a significant amount of the total shrinkage. (C) 2007 Elsevier Ltd. All rights reserved.

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The water diffusion attributable to concentration gradients is among the main mechanisms of water transport into the asphalt mixture. The transport of small molecules through polymeric materials is a very complex process, and no single model provides a complete explanation because of the small molecule`s complex internal structure. The objective of this study was to experimentally determine the diffusion of water in different fine aggregate mixtures (FAM) using simple gravimetric sorption measurements. For the purposes of measuring the diffusivity of water, FAMs were regarded as a representative homogenous volume of the hot-mix asphalt (HMA). Fick`s second law is generally used to model diffusion driven by concentration gradients in different materials. The concept of the dual mode diffusion was investigated for FAM cylindrical samples. Although FAM samples have three components (asphalt binder, aggregates, and air voids), the dual mode was an attempt to represent the diffusion process by only two stages that occur simultaneously: (1) the water molecules are completely mobile, and (2) the water molecules are partially mobile. The combination of three asphalt binders and two aggregates selected from the Strategic Highway Research Program`s (SHRP) Materials Reference Library (MRL) were evaluated at room temperature [23.9 degrees C (75 degrees F)] and at 37.8 degrees C (100 degrees F). The results show that moisture uptake and diffusivity of water through FAM is dependent on the type of aggregate and asphalt binder. At room temperature, the rank order of diffusivity and moisture uptake for the three binders was the same regardless of the type of aggregate. However, this rank order changed at higher temperatures, suggesting that at elevated temperatures different binders may be undergoing a different level of change in the free volume. DOI: 10.1061/(ASCE)MT.1943-5533.0000190. (C) 2011 American Society of Civil Engineers.

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The rhizosphere constitutes a complex niche that may be exploited by a wide variety of bacteria. Bacterium-plant interactions in this niche can be influenced by factors such as the expression of heterologous genes in the plant. The objective of this work was to describe the bacterial communities associated with the rhizosphere and rhizoplane regions of tobacco plants, and to compare communities from transgenic tobacco lines (CAB1, CAB2 and TRP) with those found in wild-type (WT) plants. Samples were collected at two stages of plant development, the vegetative and flowering stages (1 and 3 months after germination). The diversity of the culturable microbial community was assessed by isolation and further characterization of isolates by amplified ribosomal RNA gene restriction analysis (ARDRA) and 16S rRNA sequencing. These analyses revealed the presence of fairly common rhizosphere organisms with the main groups Alphaproteobacteria, Betaproteobacteria, Actinobacteria and Bacilli. Analysis of the total bacterial communities using PCR-DGGE (denaturing gradient gel electrophoresis) revealed that shifts in bacterial communities occurred during early plant development, but the reestablishment of original community structure was observed over time. The effects were smaller in rhizosphere than in rhizoplane samples, where selection of specific bacterial groups by the different plant lines was demonstrated. Clustering patterns and principal components analysis (PCA) were used to distinguish the plant lines according to the fingerprint of their associated bacterial communities. Bands differentially detected in plant lines were found to be affiliated with the genera Pantoea, Bacillus and Burkholderia in WT, CAB and TRP plants, respectively. The data revealed that, although rhizosphere/rhizoplane microbial communities can be affected by the cultivation of transgenic plants, soil resilience may be able to restore the original bacterial diversity after one cycle of plant cultivation.

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The synthesis and structures of two new isostructural mononuclear [Ln(L)(NO(3))(H(2)O)(3)](NO(3))(2) complexes, with Ln = Tb (complex 1) and Eu (complex 2), which display high activity in the hydrolysis of the substrate 2,4-bis(dinitrophenyl)phosphate, are reported. These complexes displayed catalytic behavior similar to the mononuclear gadolinium complex [Gd(L)(NO(3))(H(2)O)(3)](NO(3))(2) previously reported by us (lnorg. Chem. 2008, 47, 2919-2921); one hydrolysis reaction in two stages where the diesterase and monoesterase activities could be monitored separately, with the first stage dependent on and the second independent of the complex concentration. Through potentiometric studies, electrospray ionization mass spectrometry (ESI-MS) analysis, and determination of the kinetic behaviors of 1 and 2 in acetonitrile/water solution, the species present in solution could be identified and suggested a dinuclear species, with one hydroxo group, as the most prominent catalyst under mild conditions. The complexes show high activity (k(1)= 7 and 18 s(-1) for 1 and 2, respectively) and catalytic efficiency. Complexes 1 and 2 were found to be active toward the cleavage of plasmid DNA, and complete kinetic studies were carried out. Studies with a radical scavenger (dimethylsulfoxide) confirmed the hydrolytic action of 1 and 2 in the cleavage of DNA. Studies on the incubation of distamycin with plasmid DNA suggested that 1 and 2 are regio-specific, interacting with the minor groove of DNA. These complexes displayed luminescent properties. Complex 1 showed higher emission intensity than 2 due to a more efficient energy transfer between triplet and emission levels of terbium (T -> (5)D(4)), along with nonradiative deactivation mechanisms of the excited states of europium via multiphonon decays and the ligand-to-metal charge transfer state. Lifetime measurements of the (5)D(4) and (5)D(0) excited levels for 1 and 2, respectively, indicated the numbers of coordinated water molecules for the complexes.

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Background:The Nasal Obstruction Symptom Evaluation (NOSE) instrument is a disease-specific questionnaire for assessing the outcome of an intervention in nasal obstruction in trials. This instrument is only available in the English language and cross-culturally valid questionnaires are very important for all research, including nasal obstruction. The aim of the current study was to reproduce the cross-cultural adaptation process for the NOSE questionnaire in the Portuguese language (NOSE-p). Methodology: Cross-cultural adaptation and validation of the instrument were divided into two stages. Stage I involved four bilingual professionals, an expert committee and the author of the original instrument. In Stage 2, the NOSE-p was tested on 33 patients undergoing septoplasty for internal consistency, test-retest reliability, construct validity. discriminant validity, criterion validity, and response sensitivity. Results: The cross-cultural adaptation process was completed and the NOSE-p was demonstrated to be a valid instrument with satisfactory construct validity. It showed an adequate internal consistency reliability and adequate test-retest reliability. It could discriminate between patients with and without nasal obstruction and it has a high response sensitivity to change. Conclusions: The cross-cultural adaptation and validation process demonstrated to be valid and the NOSE-p proved to be applicable in Brazil.

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Background and objective: Dynamic indices represented by systolic pressure variation and pulse pressure variation have been demonstrated to be more accurate than filling pressures in predicting fluid responsiveness. However, the literature is scarce concerning the impact of different ventilatory modes on these indices. We hypothesized that systolic pressure variation or pulse pressure variation could be affected differently by volume-controlled ventilation and pressure-controlled ventilation in an experimental model, during normovolaemia and hypovolaemia. Method: Thirty-two anaesthetized rabbits were randomly allocated into four groups according to ventilatory modality and volaemic status where G1-ConPCV was the pressure-controlled ventilation control group, G2-HemPCV was associated with haemorrhage, G3-ConVCV was the volume-controlled ventilation control group and G4-HemVCV was associated with haemorrhage. In the haemorrhage groups, blood was removed in two stages: 15% of the estimated blood volume withdrawal at M1, and, 30 min later, an additional 15% at M2. Data were submitted to analysis of variance for repeated measures; a value of P < 0.05 was considered to be statistically significant. Results: At MO (baseline), no significant differences were observed among groups. At M1, dynamic parameters differed significantly among the control and hypovolaemic groups (P < 0.05) but not between ventilation modes. However, when 30% of the estimated blood volume was removed (M2), dynamic parameters became significantly higher in animals under volume-controlled ventilation when compared with those under pressure-controlled ventilation. Conclusions: Under normovolaemia and moderate haemorrhage, dynamic parameters were not influenced by either ventilatory modalities. However, in the second stage of haemorrhage (30%), animals in volume-controlled ventilation presented higher values of systolic pressure variation and pulse pressure variation when compared with those submitted to pressure-controlled ventilation.

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Nematode parasites from the genus Strongyloides spp. are important pathogens of the intestinal mucosa of animals and humans. Their complex life cycles involve alternating developmental adaptations between larvae stages and the adult parthenogenetic female. Here, we report, primarily through homology-based searching, the existence of the major components of the ubiquitin-proteasome system in this genus, using the available EST data from S. ratti, S. stercoralis, and Parastrongyloides trichosuri. In this study, S. venezuelensis was used as our model organism for detection of proteasome activity and ubiquitinated substrates in cytosolic preparations from the L3 larvae and the adult female. Marked differences in proteasome capabilities were found when these two stages were compared. A preference for degradation of chymotryptic synthetic peptides was found in both stages with the adult exhibiting a higher rate of hydrolysis compared to the larvae. Due to the high evolutionary conservation of proteasome alpha subunits, an anti-human proteasome antibody was able to recognize proteasome subunits in these preparations by Western blotting, supporting the proposal that the activity of the ubiqutin-proteasome system is developmentally regulated in this nematode.

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Background: The aim of the present study is to evaluate the use of anorganic bovine bone (ABB) associated with a collagen membrane (CM) for a sinus graft by means of clinical, histologic, and radiographic parameters in cases with bone availability <= 7 mm. A preliminary evaluation consisted of a clinical examination, computed tomography (CT), and a panoramic x-ray. Methods: Ninety-two patients requiring bilateral sinus grafts and 222 requiring unilateral procedures (total: 406 sinuses) participated in this study. A total of 1,025 implants were placed in the grafted sinuses. A total of 118 implants were placed simultaneously with the sinus graft (one stage), and 907 implants were placed in a subsequent surgery (two stages), 6 to 12 months after the graft was performed. In seven cases, a biopsy was harvested for histomorphometric analysis. Recall appointments were scheduled every 6 months, and panoramic and periapical x-rays were required every year for 3 years. Results: Among 1,025 implants, 19 were lost (survival rate: 98.1%). The difference in survival rates for implants placed in native bone: <= 3 mm (98.1%), >3 to <= 5 mm (98.6%), and >5 to <= 7 mm (97.0%) was not statistically significant (P = 0.3408). The survival rates for implants with rough and machined surfaces (98.6% and 97.0%, respectively) were not statistically significant (P = 0.0840). The histomorphometric analysis showed new bone formation (39.0% +/- 12%), marrow space (52.9% +/- 9.3%), and residual ABB (8% +/- 2.7%). Conclusion: Our results indicated that 1,025 implants placed in sinuses grafted exclusively with ABB combined with CM led to an excellent and predictable survival rate of 98.1%. J Periodontol 2009;80:1920-1927.

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In this paper, we consider the problem of estimating the number of times an air quality standard is exceeded in a given period of time. A non-homogeneous Poisson model is proposed to analyse this issue. The rate at which the Poisson events occur is given by a rate function lambda(t), t >= 0. This rate function also depends on some parameters that need to be estimated. Two forms of lambda(t), t >= 0 are considered. One of them is of the Weibull form and the other is of the exponentiated-Weibull form. The parameters estimation is made using a Bayesian formulation based on the Gibbs sampling algorithm. The assignation of the prior distributions for the parameters is made in two stages. In the first stage, non-informative prior distributions are considered. Using the information provided by the first stage, more informative prior distributions are used in the second one. The theoretical development is applied to data provided by the monitoring network of Mexico City. The rate function that best fit the data varies according to the region of the city and/or threshold that is considered. In some cases the best fit is the Weibull form and in other cases the best option is the exponentiated-Weibull. Copyright (C) 2007 John Wiley & Sons, Ltd.

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In the last ten to fifteen years, there has been a predominant belief that the linear-supralinear-sublinear behaviour of the TL response of alkali halides to the radiation dose necessarily occurs in the heating stage for TL reading. It is based on the assumption that coloration in these crystals grows linear-sublinearly with the dose during irradiation. Since both colour centre and TL centre are based on the same point defects the TL response should also grow linear-sublinearly with dose. In 1950, half a dozen authors showed that the coloration of F-centres in KCl takes place in two stages, the second one being responsible for non-linear behaviour. In this paper, we show that indeed in NaCl both F-centre and TL grow linear-supralinear-sublinearly with the dose during irradiation.