831 resultados para HOMOGENEOUS SAMPLE


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This work proposes a new method to determine the chemical composition of magnetic ferrite nanoparticles by the slurry injection technique using the inductively coupled plasma optical emission spectroscopy. In this way, experimental conditions such as aerosol gas flow rate and colloidal stability were optimized in order to use aqueous calibration curves in the slurry nebulization and to determine the chemical composition of a series of sols containing chemically synthesized size-tailored NiFe 2O 4 nanograms. Then, the results of direct sampling and those of conventional aqueous introduction analysis are compared, showing the efficiency of the proposed method.

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Introduction. Dementia is a chronic and neurodegenerative disease responsible for a progressive decline of cognition and physical capacity. Objective: To verify the effectiviness of three months of physiotherapy intervention on cognitive functions and balance of institutionilized elderly people with dementia. Patients and methods. This study has comprised thirty subjects, divided in two groups: EG (experimental group) and CG (control group). EG was composed by 15 participants with mean age of 71,6 ± 8,5 years and scholarity of 4,7 ± 4,2 years. CG was formed by 15 subjects with mean age of 78,5 ± 7,6 years and scholarity of 2,2 ± 1,8 years. The sample was evaluated by means of the following instruments: Mini-Mental State Examination, Semantic Verbal Fluency test, Clock Drawing test, Berg Balance Scale and Timed Get Up and Go test. The statistical procedures were done by means of Multivariate Analisis of Variance (MANOVA), with significance of 5 % (p < 0,05). Results. The results has shown a heterogeneity of both groups related to age (F = 0,2, p < 0,05) and scholarity (F = 2,6, p < 0,05). MANOVA pointed beneficts of physiotherapy on balance (F = 7,3, p < 0,01) but not on cognitive functions (F = 0,3, p > 0,05). Conclusions. Three months of physiotherapy were effective to improuve physical capacity of institucionilized elderly people with dementia. Neverthless, it was not able to minimize cognitive decline commonly seen on dementia. The question if a prolonged intervention could propitiate cognitive beneficts remains, specially in a more homogeneous groups.

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Purpose: This study investigates the influence of age at onset of OCS on psychiatric comorbidities, and tries to establish a cut-off point for age at onset. Methods: Three hundred and thirty OCD patients were consecutively recruited and interviewed using the following structured interviews: Yale-Brown Obsessive Compulsive Scale; Yale Global Tic Severity Scale and the Structured Clinical Interview for DSM-IV. Data were analyzed with regression and cluster analysis. Results: Lower age at onset was associated with a higher probability of having comorbidity with tic, anxiety, somatoform, eating and impulse-control disorders. Longer illness duration was associated with lower chance of having tics. Female gender was associated with anxiety, eating and impulse-control disorders. Tic disorders were associated with anxiety disorders and attention-deficit/hyperactivity disorder. No cut-off age at onset was found to clearly divide the sample in homogeneous subgroups. However, cluster analyses revealed that differences started to emerge at the age of 10 and were more pronounced at the age of 17, suggesting that these were the best cut-off points on this sample. Conclusions: Age at onset is associated with specific comorbidity patterns in OCD patients. More prominent differences are obtained when analyzing age at onset as an absolute value. © 2008 Elsevier Masson SAS. All rights reserved.

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To simplify computer management, several system administrators are adopting advanced techniques to manage software configuration on grids, but the tight coupling between hardware and software makes every PC an individual managed entity, lowering the scalability and increasing the costs to manage hundreds or thousands of PCs. This paper discusses the feasibility of a distributed virtual machine environment, named Flexlab: a new approach for computer management that combines virtualization and distributed system architectures as the basis of a management system. Flexlab is able to extend the coverage of a computer management solution beyond client operating system limitations and also offers a convenient hardware abstraction, decoupling software and hardware, simplifying computer management. The results obtained in this work indicate that FlexLab is able to overcome the limitations imposed by the coupling between software and hardware, simplifying the management of homogeneous and heterogeneous grids. © 2009 IEEE.

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Objective: In this study, we compared the frequency and intensity of childhood traumas in alcohol- or other drug-dependent patients, in patients with depression, and in a control group without psychiatric diagnoses. Methods: The study had a retrospective design of a clinical sample of men and women from the groups listed above. They were evaluated by the same standardized instrument: the Childhood Trauma Questionnaire.. Results: A higher frequency and intensity of emotional, physical, and sexual abuse were found in alcohol- and other drug-dependent patients than in patients with depression, who, in turn, presented significantly higher proportions than the control group. In all of the cases, the frequency was higher among women than men. Conclusion: Because of the high frequency and intensity of childhood traumas among alcohol- or other drug-dependent patients and depressed patients, the assessment of problems due to childhood traumas among these patients is essential to a better understanding of the etiology of those disorders and to their treatment. © 2010 Elsevier Ltd. All rights reserved.

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Proton radiation therapy is a precise form of radiation therapy, but the avoidance of damage to critical normal tissues and the prevention of geographical tumor misses require accurate knowledge of the dose delivered to the patient and the verification of his position demand a precise imaging technique. In proton therapy facilities, the X-ray Computed Tomography (xCT) is the preferred technique for the planning treatment of patients. This situation has been changing nowadays with the development of proton accelerators for health care and the increase in the number of treated patients. In fact, protons could be more efficient than xCT for this task. One essential difficulty in pCT image reconstruction systems came from the scattering of the protons inside the target due to the numerous small-angle deflections by nuclear Coulomb fields. The purpose of this study is the comparison of an analytical formulation for the determination of beam lateral deflection, based on Molière's theory and Rutherford scattering with Monte Carlo calculations by SRIM 2008 and MCNPX codes. © 2010 American Institute of Physics.

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Includes bibliography

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A poly glutamic acid film modified electrode exhibited a catalytic response toguanosine oxidation potential and higher peak current value. Linear concentration curve was obtained in the concentration interval of 1.0 a 10.0 μmol L-1 in 0.04 mol L-1 B-R buffer pH 2.0 with a detection limit of 0.198 μmol L-1. The electrode was used for the determination of guanosine in the potential of +1.1 V (vs. Ag/AgCl) using differential pulse voltammetry (DPV) at urine sample with good recovery. © 2010 by CEE.

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Includes bibliography

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Includes bibliography

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Purpose. To evaluate the prevalence and reasons for teeth extractions in a sample from a dental clinic in Brazil. Methods. The prevalence of teeth mortality was analyzed by gender, age, tooth type and reasons for extraction on 800 teeth of 439 subjects, whose data was collected in clinical records in a convenience sample. Results. The groups with range from 35 to 44 years, 45 to 54 years and 55 to 64 years revealed significantly greater number of teeth extractions than other age groups (P < 0.0001). The anterior teeth loss increased significantly with aging, while the tooth mortality of premolar and molar were higher in younger people. The caries was the more prevalent reason for tooth mortality among young and adults up to 44 years old, while the periodontal disease was the main reason for extractions from 45 years old until range of 81 years (P < 0.0001). Conclusions. It can be suggested that some reasons for tooth loss were age-dependent, but the caries and the periodontal diseases were the main reasons for tooth mortality in this Brazilian sample. Copyright © 2012 Andréia Montandon et al.

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Anadenanthera macrocarpa (Benth.) Brenan is a tree species belonging to the family Leguminosae-Mimosoideae which is popularly known as mimosa-black. It features characteristics of early successional, natural occurrence in Brazil and can form clusters almost homogeneous, with great potential in the recovery of degraded areas. This study was conducted at the Center for Agricultural Sciences, University Federal of Alagoas state, aiming at the physical and morphological characterization of seeds, describing the various stages of post-seminal development, and to evaluate various conditions of temperature and substrate to perform the test germination. The seeds were manually extracted, then homogenized, where two samples of 50 seeds were used to determine the initial moisture. Another sample, consisting of eight repetitions of 100 seeds was used to measure the biometry and the number of seeds per fruit. The morphological characterization and the seeds were immersed in distilled water to allow the cuts to the observed structure in microscopes. In the post-seminal study, it was observed the daily processes of seedling growth in rolled paper filter and constant temperature of 30 °C. To assess the germination behavior, the constant temperatures of 15 °C, 25 °C, 30 °C, 40 °C and 20-30 °C as well as the paper and the sand substrates were tested and it was evaluated the percentage, the rate of germination, the relative frequency distribution, and the tests conducted in a randomized design in factorial 5 x 2 (x substrate temperature) with four replicates of 25 seeds, and the averages compared by Duncan 5 % probability. The fruits of black angico show great variation in the seed number per fruit. The embryonic axis occupies part of the central region of the seed with axial and linear positions. The germination is epigeal and the seedlings are fanerocotylar. The temperature determines the 30 °C and the filter paper substrate provided higher average percentage and germination rate.

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Traditional methods of submerged aquatic vegetation (SAV) survey last long and then, they are high cost. Optical remote sensing is an alternative, but it has some limitations in the aquatic environment. The use of echosounder techniques is efficient to detect submerged targets. Therefore, the aim of this study is to evaluate different kinds of interpolation approach applied on SAV sample data collected by echosounder. This study case was performed in a region of Uberaba River - Brazil. The interpolation methods evaluated in this work follow: Nearest Neighbor, Weighted Average, Triangular Irregular Network (TIN) and ordinary kriging. Better results were carried out with kriging interpolation. Thus, it is recommend the use of geostatistics for spatial inference of SAV from sample data surveyed with echosounder techniques. © 2012 IEEE.