Universidade de Pernambuco

About: Universidade de Pernambuco is a education organization based out in Recife, Brazil. It is known for research contribution in the topics: Population & Artificial neural network. The organization has 6147 authors who have published 6948 publications receiving 73648 citations.

[Characteristics of leprosy reactions in paucibacillary and multibacillary individuals attended at two reference centers in Recife, Pernambuco].

Abstract: INTRODUCAO: As reacoes sao frequentes e importantes no contexto da hanseniase, representando uma significativa parcela de pacientes com incapacidades e submetidos ao retratamento da hanseniase. A caracterizacao clinico-epidemiologica dos padroes reacionais e primordial para o manejo dos pacientes. O objetivo desse trabalho e descrever as caracteristicas epidemiologicas e clinicas das reacoes hansenicas em individuos paucibacilares e multibacilares. METODOS: Estudo transversal onde foram avaliados 201 pacientes com historia de quadro reacional, atendidos em dois centros de referencia para tratamento da hanseniase. Variaveis como baciloscopia inicial, sexo, idade, fototipo, procedencia, forma clinica, tipo de tratamento e de reacao, indice baciloscopico final e periodo de surgimento da reacao em relacao ao tratamento foram avaliados. A analise estatistica foi realizada usando-se frequencias simples. Para calculo dos fatores de risco para as formas multibacilares, foram realizadas analises univariada e multivariada. RESULTADOS: Sexo masculino, idade entre 30-44 anos, fototipo V, a forma clinica borderline, tratamento regular, reacao tipo I, neurite, presenca de 10 a 20 nodulos e surgimento da reacao hansenica durante o tratamento foram os achados mais frequentes. CONCLUSOES: Predominaram os individuos do sexo masculino que se associaram a um maior risco de desenvolvimento da forma multibacilar. As reacoes hansenicas foram mais frequentes durante o tratamento, os pacientes multibacilares foram mais propensos ao retratamento da hanseniase e aqueles com reacoes tipo I e II, apresentaram maior frequencia de neurite, linfadenopatia, artrite e irite do que aqueles com reacao isolada.

Hybrid Training Method for MLP: Optimization of Architecture and Training

Abstract: The performance of an artificial neural network (ANN) depends upon the selection of proper connection weights, network architecture, and cost function during network training. This paper presents a hybrid approach (GaTSa) to optimize the performance of the ANN in terms of architecture and weights. GaTSa is an extension of a previous method (TSa) proposed by the authors. GaTSa is based on the integration of the heuristic simulated annealing (SA), tabu search (TS), genetic algorithms (GA), and backpropagation, whereas TSa does not use GA. The main advantages of GaTSa are the following: a constructive process to add new nodes in the architecture based on GA, the ability to escape from local minima with uphill moves (SA feature), and faster convergence by the evaluation of a set of solutions (TS feature). The performance of GaTSa is investigated through an empirical evaluation of 11 public-domain data sets using different cost functions in the simultaneous optimization of the multilayer perceptron ANN architecture and weights. Experiments demonstrated that GaTSa can also be used for relevant feature selection. GaTSa presented statistically relevant results in comparison with other global and local optimization techniques.

The in vitro morphological effects of some current pre-treatments on dentin surface: a SEM evaluation.

Abstract: This in vitro study morphologically evaluated the effect of some current surface pre-treatments on dentin, using scanning electron microscopy, and related these morphological alterations to clinical implications. The labial surfaces of 30 bovine lower incisors were ground to obtain a flat dentin surface and were finished with 600-grit SiC paper to produce standardized smear layers. The teeth were randomly divided into six groups of five each. Group 1 was the control group, smear layer covered dentin; Group 2 was etched with 37% phosphoric acid (PA) for 15 seconds; Group 3, 37% PA for 15 seconds, followed by 10% NaOCl for 60 seconds; Group 4, 10% NaOCl for 60 seconds; Group 5, a self-etching primer (Clearfil SE Bond, CSEB-primer) was applied for 20 seconds; Group 6, CSEB-primer for 20 seconds, followed by NaOCl for 60 seconds. The specimens were fixed, dehydrated, dried and analyzed by SEM. Treatment with 37% PA removed the smear layer, funneled the tubules and resulted in a collagen-rich surface which appeared to have collapsed in its outermost part, producing a dense surface layer covered with silica particles. When 37% PA treatment was followed by 10% NaOCl, the collagen network was removed to reveal an eroded, rough mineral surface with numerous lateral branches and larger than normal tubular orifices. The action of 10% NaOCl on the smear layer-covered dentin showed no significant alteration in surface morphology. The treatment with CSEB-primer dissolved the smear layer but only partially dissolved the smear plugs. The tubules did not present the typical funnel shape seen following PA treatment. These morphological aspects on dentin surface must influence bonding results. The dentin surface alterations produced by PA appeared to be a very severe demineralization pattern, quite irregular and less permeable to monomer infiltration, while the surface provided by the self-etching primer appeared to be a more uniform, less porous surface, and the association with simultaneous monomer infiltration may reduce the occurrence of mistakes in clinical bonding procedures.

Therapeutic effect of two fluoride varnishes on white spot lesions: a randomized clinical trial

Abstract: The aim of this randomized clinical trial study was to evaluate the therapeutic effect of two varnish formulations (G1 = 5% NaF, G2 = 6% NaF + 6% CaF(2)) on the remineralization of white spot lesions (WSL). The sample was composed of 15 (7- to 12-year-old) children with 45 active WSL in anterior permanent teeth. The children were randomly divided into two groups providing 22 lesions for G1 and 23 for G2. The children were submitted to weekly varnish applications 4 times. The WSL were evaluated twice: baseline and on week 4. Maximum lesion dimensions (mesiodistal and incisogingival) were measured in millimeters and classified in four grades of size. WSL were also assessed regarding lesion activity by one calibrated examiner. The Pearson chi-square and Fisher's exact tests were used (P 0.01). It was concluded that after 4 applications the two varnish formulations tested produced similar clinical effects, indicating the reduction and the control of carious activity in most WSL.

Prevalence of Staphylococcus aureus introduced into intensive care units of a University Hospital

Abstract: Staphylococcus aureus is one of the principal human pathogens that colonize healthy individuals in the community in general, and it is responsible for severe infections in hospitalized patients. Due to an increase in the prevalence of strains of methicillin-resistant S. aureus (MRSA), combating these microorganisms has become increasingly difficult. A descriptive study was carried out on 231 patients in intensive care at the Oswaldo Cruz University Hospital (HUOC) in Recife, Brazil between January and April 2003 to determine the prevalence of S. aureus and MRSA and to evaluate risk factors for colonization by these bacteria when introduced into Intensive Care Units (ICUs). Body secretions were collected from the nostrils, axillary and perineal regions, and from broken skin lesions, of all patients during the first 48 hours following admission to the ICU. Samples were inoculated into blood agar and mannitol-salt-agar culture medium and identified by Gram staining, and by coagulase, DNAse and agglutination (Slidex Staph Test) tests. Growth in Mueller-Hinton agar with 4% sodium chloride and 6 mg/L oxacillin was used to identify MRSA. In addition, the latex agglutination test was performed to identify penicillin-binding protein, PBP 2A. The prevalence of S. aureus and MRSA was 87/231 (37.7%) and 30/231 (12.98%), respectively. There was no association between any risk factor studied (age, sex, origin of the patient--whether hospital or community, previous hospitalization, use of current or previous antibiotic therapy, corticotherapy and/or immunotherapy, reason for hospitalization and place of hospitalization) and the presence of S. aureus. However, a significant association was established between previous hospitalization and the presence of MRSA (RR:1.85; CI:1.00-3.41; p=0.041). The nostrils were the principal site of colonization by both S. aureus (80.4%) and MRSA (26.4%), followed by the perineal area, with rates of 27.6% and 12.6%, respectively. If only the nostrils had been investigated, the study would have failed to diagnose 17 patients (19.5%) as carriers of the pathogen into the ICU, thus contributing towards cross-dissemination.