Métodos de campo para a avaliação da obesidade em crianças e adolescentes

In large samples, the methods for obtaining information on obesity need to be simple, inexpensive and reasonably accurate. This review deals with articles focusing on various field methods for the evaluation of body composition. The Bioimpedance and Near Infrared methods are simple to execute but their advantage in relation to Body Mass Index is obscure. Although the Bioimpedance and near infrared methods provide estimates of fat content, they may be no better than waist circumference measurements. The latter does not distinguish body fat but points to a more direct relationship concerning health risk. Regardless of the advantages, waist circumference continues to be under discussion: there is a lack of standardization and no reference populations or cutoff points have been established. No perfect method exists, but the number of errors could be reduced, if care were taken in drawing up protocols, standardization, and the analysis of sample properties.Em amostras grandes, os métodos para se obter informações sobre a obesidade precisam ser simples, baratos e razoavelmente acurados. Essa revisão narrativa foi desenvolvida a partir de artigos e focará alguns métodos de campo para avaliação da composição corporal. Os métodos de Bioimpedância e do Infravermelho são de simples execução, baratos mas sua vantagem em relação ao Índice de Massa Corpórea é obscura. Apesar dos métodos de Bioimpedância e Infra-vermelho apresentarem estimativas da porcentagem de gordura, talvez não sejam superiores às medidas de circunferência da cintura. Essa não distingue a gordura corporal mas aponta para uma relação mais direta com o risco à saúde. Apesar das vantagens, a ciurcunferência da cintura continua em discussão: faltam as padronizações, o estabelecimento de populações de referência e pontos de corte. Não há método perfeito, mas os erros serão diminuídos se houver precaução na elaboração dos protocolos, na padronização e na análise das características da amostra.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Programa de Pós-Graduação em NutriçãoUNIFESP, EPM, Programa de Pós-Graduação em NutriçãoSciEL

Flexural cyclic fatigue resistance of NiTi rotatory instruments due to number of users and torque.

O objetivo do presente estudo foi avaliar a resistência à fadiga cíclica flexural de instrumentos rotatórios de níquel-titânio de número 25, conicidade 0,04 e 25 mm de comprimento (K3, SybronEndo), submetidos a variados torques de acionamento e repetidos ciclos de usos em canais simulados, valendo-se de dispositivo apropriado para ensaios dinâmicos. Procurou-se determinar se, além do fator de variação número de uso, há influência relacionada com o torque e, ainda, a possibilidade de interação entre número de uso e torque. Valendo-se motor elétrico acionado à velocidade de 300 rpm foram instrumentados 320 canais simulados, utilizado-se 80 instrumentos divididos em 4 grupos com 20 espécimes cada, de acordo com os torques (0,5 Ncm, 1,0 Ncm, 2,0 Ncm e 6,0 Ncm) a que seriam submetidos. Cada grupo foi subdividido em 4 subgrupos com 5 espécimes, de acordo com o número de usos (1, 3, 5 e 7 ciclos de usos). Todos os instrumentos foram submetidos a ensaio de fadiga cíclica flexural que foi realizado num dispositivo que permitia ao instrumento girar livremente, reproduzindo a instrumentação rotatória num canal curvo (40º e raio de curvatura de 5 mm), simulando o movimento de pecking, onde o instrumento deslizava pelo sulco criado no anel de aço temperado. Foi utilizada peça de mão com contra-ângulo redutor de 16:1, acionado por motor elétrico na velocidade de 300 rpm e torque idêntico ao empregado durante a fase de preparo dos canais simulados. A fratura do instrumento era facilmente detectada pelo sensor, e neste momento o contador e o temporizador paravam imediatamente. Os dados registrados no contador e no temporizador foram tranformados em segundos. Para a avaliação estatística empregou-se ANOVA e o teste t de Student (p<0,01). No que diz respeito ao fator de variação número de uso, não houve diferença estatística significante, enquanto as comparações feitas com o torque de 6,0 Ncm apresentaram valores de t calculado altamente significativo, com p < 0,01. Também não ocorreu interação significante entre os fatores de variação número de usos e torque. Baseado nos resultados deste estudo pode-se concluir que o torque afetou a resistência à fadiga cíclica flexural dos instrumentos rotatórios de NiTi, sendo menor naqueles submetidos à torque elevado, enquanto o número de usos em até 7 vezes não afetou .The aim of the present study was to evaluate the flexural cyclic fatigue resistance of nickel-titanium rotary instruments, number 25, taper 0,04, and length of 25mm (K3, SybronEndo), when submitted to several torque values and number of uses in simulated canal blocks, by using devices appropriated for dynamic tests. It was tried to detect whether, in addition to the factor number of uses, there would be an influence related to torque, or even the possibility of an interaction between number of uses and torque. The data was collected from 320 simulated canals that were prepared, driven by an electrical motor at 300 rpm, using 80 instruments divided in 4 groups of 20 sample each, based on torque values (0,5 Ncm, 1,0 Ncm, 2,0 Ncm e 6,0 Ncm). Each group was randomly divided in 4 subgroups of 5 samples each, according to the number of uses (1, 3, 5 and 7 cycles). All files were submitted to flexural cyclic fatigue test realized in a device that allows the instrument to freely rotate, reproducing the movement of an instrument rotating in a curved canal (40º angle and 5 mm of radius), simulating the pecking movement, where the instrument slide over the groove created in the hardened steel. An electric motor hand-piece was used with a contra-angle 16:1 reduction set at 300 rpm and torque value identical to that used during preparation of simulated canals. The fracture of the instrument was easily detected at moment which the counter and the timer were immediately stopped. Data collected by the counter and the timer were converted in seconds and analysed by ANOVA and t Student test (p<0.01). In regards to the number of uses factor, there was not a statistically significant difference, while comparisons made with torque value set at 6,0 Ncm showed t values significantly high, with p<0.01. It was not seen any interaction between both variables, number of uses and torque. Based on the results of this investigation, it can be concluded that torque affected the resistance to flexural cyclic fatigue of nickel-titanium rotary instruments, being low on those tested at high torque value; while the factor number of uses up to 7 times did not affect the results

Effect of different torques in cyclic fatigue resistance of K3 rotary instruments

Abstract Aim: To assess the effect of different torque values on cyclic fatigue resistance of K3 rotary nickeltitanium (NiTi) files. Methods: Eighty K3 files, size 25 mm, taper 0.04 were divided in 4 groups according to different torques (0.5, 1, 2 and 6 Ncm) and were submitted to a cyclic fatigue test. This test was performed with a device that allowed the file to rotate inside a stainless steel artificial curved canal, simulating the pecking motion. Files rotated until fracture occurred and time to failure was recorded in seconds with a stopwatch. Data were analyzed by ANOVA and Tukey tests (p&lt;0.05). Results: All groups were compared and only the group of 6 N.cm showed statistically significant difference (p=0.0002). Conclusions: For #25.04 K3 files, the evaluated torques up to 2 N.cm had no influence on cyclic fatigue resistance. Using 6 N.cm torque value resulted in lower resistance to cyclic fatigue

Effect of different torques in cyclic fatigue resistance of K3 rotary instruments

assess the effect of different torque values on cyclic fatigue resistance of K3 rotary nickeltitanium (NiTi) files. Methods: Eighty K3 files, size 25 mm, taper 0.04 were divided in 4 groups according to different torques (0.5, 1, 2 and 6 Ncm) and were submitted to a cyclic fatigue test. This test was performed with a device that allowed the file to rotate inside a stainless steel artificial curved canal, simulating the pecking motion. Files rotated until fracture occurred and time to failure was recorded in seconds with a stopwatch. Data were analyzed by ANOVA and Tukey tests (p<0.05). Results: All groups were compared and only the group of 6 N.cm showed statistically significant difference (p=0.0002). Conclusions: For #25.04 K3 files, the evaluated torques up to 2 N.cm had no influence on cyclic fatigue resistance. Using 6 N.cm torque value resulted in lower resistance to cyclic fatigue

Resistance to Flexural Fatigue of Reciproc R25 Files under Continuous Rotation and Reciprocating Movement

Introduction: The aim of the present work was to evaluate the resistance to flexural fatigue of Reciproc R25 nickel-titanium files, 25 mm, used in continuous rotation motion or reciprocation motion, in dynamic assays device. Methods: Thirty-six Reciproc R25 files were divided into 2 groups (n = 18) according to kinematics applied, continuous rotary (group CR) and reciprocation motion (group RM). The files were submitted to dynamic assays device moved by an electric engine with 300 rpm of speed that permitted the reproduction of pecking motion. The files run on a ring's groove of temperate steel, simulating instrumentation of a curved root canal with 400 and 5 mm of curvature radius. The fracture of file was detected by sensor of device, and the time was marked. The data were analyzed statistically by Student's t test, with level of significance of 95%. Results: The instruments moved by reciprocating movement reached significantly higher numbers of cycles before fracture (mean, 1787.78 cycles) when compared with instruments moved by continuous rotary (mean, 816.39 cycles). Conclusions: The results showed that the reciprocation motion improves flexural fatigue resistance in nickel-titanium instrument Reciproc R25 when compared with continuous rotation movement. (J Endod 2012;38:684-687

Effects of biomass burning on nasal mucociliary clearance and mucus properties after sugarcane harvesting

Objective: Biofuel from sugarcane is widely produced in developing countries and is a clean and renewable alternative source of energy. However, sugarcane harvesting is mostly performed after biomass burning. The aim of this study was to evaluate the effects of harvesting after biomass burning on nasal mucociliary clearance and the nasal mucus properties of farm workers. Methods: Twenty seven sugarcane workers (21-45 years old) were evaluated at the end of two successive time-periods: first at the end of a 6-month harvesting period (harvesting), and then at the end of a 3-month period without harvesting (non-harvesting). Nasal mucociliary clearance was evaluated by the saccharine transit test, and mucus properties were analyzed using in vitro mucus contact angle and mucus transportability by sneeze. Arterial blood pressure, heart rate, respiratory rate, pulse oximetry, body temperature, associated illness, and exhaled carbon monoxide were registered. Results: Data are presented as mean values (95% confidence interval). The multivariate model analysis adjusted for age, body-mass index, smoking status and years of working with this agricultural practice showed that harvesting yielded prolonged saccharine transit test in 7.83 min (1.88-13.78), increased mucus contact angle in 8.68 degrees (3.18-14.17) and decreased transportability by sneeze in 32.12 mm (-44.83 to -19.42) compared with the non-harvesting period. No significant differences were detected in any of the clinical parameter at either time-period. Conclusion: Sugarcane harvesting after biomass burning negatively affects the first barrier of the respiratory system in farm workers by impairing nasal mucociliary clearance and inducing abnormal mucus properties. (C) 2011 Elsevier Inc. All rights reserved.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico[CNPq 470393/2008-4]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[FAPESP 2007/51605-9