Objetivou-se observar a influência da fluorose dental nas características do padrão de condicionamento ácido e na penetração de sistemas adesivos no esmalte, por microscopia eletrônica de varredura (MEV) e na resistência de união de sistemas adesivos ao esmalte, por teste de microtração. Para tal, 196 dentes permanentes posteriores foram classificados seguindo o Índice Thylstrup e Fejerskov (TF= 0, 1 e 4), sendo selecionados 69 deles. Adesivos de 2 passos, um autocondicionante, Clearfil SE Bond®, e um de condicionamento ácido total, Adper Single Bond 2® foram usados. Para análise em MEV do padrão de condicionamento e das réplicas de resina, 27 pré-molares foram seccionados no sentido mesiodistal e divididos em 9 grupos (n=3). As superfícies vestibulares foram selecionadas e seccionadas no sentido longitudinal, sendo metade para cada análise. Os espécimes pertencentes ao grupo do ácido fosfórico foram condicionados com tempos de 15 ou 60 segundos, lavados com ar/água por 20 segundos e secos. Os espécimes do grupo Clearfil SE Bond® receberam aplicação do primer do material, e em seguida, tratamento para removê-lo. Para obter as réplicas de resina, as superfícies foram delimitadas (2x2mm) com fita isolante, tratadas com cada adesivo, e submetidas à construção de bloco de resina (Filtek Z250TM ? 3M do Brasil) com 2 mm de altura. Esses espécimes foram imersos em HCl a 18% por 48h e lavados com água destilada em ultra-som por 15 minutos. O teste de microtração foi realizado na superfície vestibular intacta de 42 terceiros molares divididos em 7 grupos e subdivididos de acordo com grau de fluorose e com sistemas adesivos sendo que no grupo TF4 foram usados dois tempos condicionamento (15 e 60 segundos). Após profilaxia com pedra-pomes, lavagem e secagem, procedeu-se à aplicação dos sistemas adesivos. e construção de bloco de resina composta Filtek Z250TM (3M ESPE) de 5x5x5mm sobre a superfície tratada. Após 24h, os blocos foram seccionados no sentido X e Y perpendiculares à interface de união, obtendo-se palitos com área aproximada de 1mm2. Os palitos foram submetidos às forças de tração à velocidade de 1mm/min e os valores obtidos à Análise de Variância (p<0,05). As superfícies condicionadas, as réplicas e palitos fraturados foram processados para análise em MEV. Houve diferença estatística significativa entre os adesivos (p = 0,008), sendo que o Single Bond 2® apresentou os maiores valores de resistência de união. A severidade da fluorose não influenciou nos valores de resistência de união, no padrão de condicionamento ou na formação de tags de resina. O aumento do tempo de condicionamento, testado em TF4 influenciou na resistência de união, mostrando menores valores em 60 segundos. Concluiu-se que o adesivo de condicionamento ácido total mostrou-se melhor que o autocondicionante em termos de resistência de união, padrão de condicionamento e penetração de sistemas adesivos, independentemente do grau de fluorose. O aumento do tempo de condicionamento na fluorose mais severa (TF4) prejudicou a resistência de união. / The purpose of this study was to observe the influence of dental fluorosis on the characteristics of the acid etch pattern and penetration of adhesive systems into enamel, by means of scanning electron microscopy (SEM), and on the bond strength of adhesive systems to enamel, through microtensile testing. In order to do so, 196 permanent posterior teeth were classified according to the Thylstrup and Fejerskov Index (TF= 0.1 and 4) and 69 of them were selected. Two-steps adhesive systems, one self-etching, Clearfil SE Bond®, and one total-etching, Adper Single Bond 2®, were used. For SEM analysis of the etch pattern and of the resin replicas, 27 premolars were sectioned mesiodistally and divided into 9 groups (n=3). The buccal surfaces were selected and longitudinally sectioned, using the half for each analysis. Specimens of the phosphoric acid gel at 37% (Magic acid®) group were etched using the two etching times (15 and 60 seconds), washed with air/water for 20 seconds and dried. Specimens of the Clearfil SE Bond® group received application of the material?s primer followed by a treatment to remove it. In order to obtain the resin replicas, the surfaces were outlined (2x2mm) using insulating tape, they were treated with each adhesive and underwent the building of a resin block (Filtek Z250TM ? 3M ESPE Brazil) of 2mm height. These specimens were immersed in 18% HCl for 48 hours and washed with distilled water under ultrasonication for 15 minutes. Microtensile testing was conducted on the intact buccal surface of 42 third molars that were divided into 7 groups and subdivided according to the degree of fluorosis and to the type of adhesive system, being that two etch times (15 and 60 seconds) were used in the TF4 group. After prophylaxis with pumice, washing and drying, the adhesive systems were applied and the composite resin blocks (Filtek Z250TM ? 3M ESPE Brazil) of 5x5mm were built upon a treated surface. After 24 hours, the blocks were sectioned in the X and Y directions perpendicular to the bond interface in order to obtain stick-shaped specimens with an area of approximately 1mm2. The sticks were submitted to tensile forces at a speed of 1mm/min and the values obtained underwent variance analysis (p<0.05). The etched surfaces, the replicas and fractured sticks were processed for analysis by SEM. There was a statistically significant difference between the adhesives (p = 0.008), being that Single Bond 2® presented the highest bond strength values. The severity of fluorosis did not influence the bond strength values, the etch pattern or the formation of resin tags. The increase in etch time, tested in TF4, influenced the bond strength, showing lower values for the 60 seconds time. In conclusion, the total-etch adhesive presented better results than the self-etch one in terms of bond strength, etch pattern and penetration of adhesive systems, regardless of the degree of fluorosis. The increase in etch time for the most severe fluorosis (TF4) cases impaired bond strength.

Introdução: A qualidade de vida de crianças órfãs por aids pode sofrer um impacto negativo no desenvolvimento e crescimento físico. Objetivo: Estimar a força muscular de membros inferiores de crianças órfãs por aids, segundo características sociodemográficas, condições clínicas, atividade física e crescimento corporal. Material e métodos: Estudo transversal realizado com 171 crianças órfãs por aids no município de São Paulo. A variável dependente foi a força muscular, avaliada por meio do teste salto horizontal. As variáveis independentes foram os aspectos sociodemográficos, condições clínicas, atividade física habitual, brincadeiras no lazer, estágio maturacional, estado nutricional e composições corporais. Na análise estatística, foi utilizado o teste “t"de Student e análise de variância ANOVA. Resultados: Crianças órfãs por aids apresentaram menor força muscular em relação a outras crianças brasileiras. Meninos tiveram melhores resultados no teste de força. Crianças cuidadas por um dos pais saltaram mais. Resultados semelhantes foram obtidos para crianças mais velhas e de maior grau de escolaridade. Maior gordura corporal influenciou negativamente o salto horizontal. Crianças com maior circunferência de panturrilha saltaram mais. Conclusão: Os resultados apontam para a necessidade de atenção à saúde das crianças órfãs por aids. / Background: The quality of life of children orphaned by AIDS may suffer a negative impact on their development and growth. Objective: To estimate the muscular strength of low limb in children orphaned by AIDS according to sociodemographic characteristics, clinical conditions, physical activity, and body growth. Methods: A cross-sectional study was conducted with 171 children orphaned by AIDS in the city of São Paulo. The dependent variable was muscular strength, measured by long jump. The independent variables were sociodemographic characteristics, clinical conditions, habitual physical activity, playing during free time, maturation stage, nutrition state, and body composition. The analyses included Student’s t-Test and ANOVA. Results: Children orphaned by AIDS showed less muscular strength when compared to Brazilian children. Boys had better results in the test of strength. Higher jump was observed among children taken care of by a parent, older children and children with a higher educational level. Higher body fat affected negatively the long jump. Children with higher calf circumference performed long jump better. Conclusion: The results highlight the need of addressing attention to the healthcare of children orphaned by AIDS.

O crucifixo é um elemento chave na prova das argolas na Ginástica Artística Masculina. A posição anatômica durante a sua execução requer a abdução do ombro em 90° no plano frontal, o que provoca grande solicitação mecânica nas articulações do ombro. Em condição de treino, um aparelho modificado é mundialmente utilizado para diminuir as cargas no ombro e permitir maior numero de repetições do crucifixo. Estudos sugerem que há diferenças na ativação muscular no ombro entre a situação de treino e competição. Entretanto, ainda não há conhecimento sobre a especificidade dos aparelhos de treino no âmbito da biomecânica, considerando a cinemática, cinética e eletromiografia em bases individuais. O objetivo geral desta tese projeto é investigar a biomecânica do crucifixo com o uso das argolas de competição e de treinamento. Doze ginastas brasileiros de alto nível foram testados em dinamômetro isocinético para verificação de assimetria na força de ombros e eletromiografia. Após intervalo de uma semana, os participantes realizaram, em seus ginásios de treinamento, três crucifixos nas argolas de competição e no aparelho de treino em ordem aleatória. Foi utilizada uma câmera de vídeo digital, uma célula de carga acoplada em cada cabo das argolas e eletromiografia de superfície em nove músculos do membro superior. Os resultados foram comparados por testes paramétricos, não paramétricos e estatística descritiva. A assimetria nas forças de ombro foi de 9,9±6,4%. Os ângulos do ombro no aparelho de treino tiveram menor desvio da posição alvo com 90° de abdução do que nas argolas para o ombro direito e esquerdo, e menores valores de simetria. As forças nos cabos foram semelhantes em ambos os aparelhos, como também a simetria. Não houve diferença na eletromiografia de nove músculos e valores de co-contração entre os dois aparelhos. As argolas de treino permitiram aos ginastas um melhor desempenho do crucifixo sem alterar o padrão de ativação muscular do ombro das argolas de competição. A orientação individualizada é necessária para que os ginastas realizem o crucifixo no aparelho de treino da mesma maneira que realizam nas argolas de competição, para que as equivalentes características biomecânicas sejam mantidas / The cross is a key element in Male Artistic Gymnastics rings routines. The anatomical position during its execution requires 90° of shoulder abduction in frontal plane, which implies a large mechanical demand of shoulder joints. For training condition, a modified rings apparatus is worldwide used to decrease shoulder load and allow more repetitions of cross. Studies suggest that there is different shoulder muscle activation between training and competition conditions. However, is not clear the training apparatuses specificity regarding biomechanics, considering kinematics, kinetics and electromyography in an individual basis. The aim of this thesis is to investigate the biomechanics of the cross using training and competition rings devices. Twelve Brazilian elite gymnasts were tested on isokinetic dynamometer for shoulder strength asymmetry and electromyography assessment. Within one week interval, participants performed in their training place, three crosses in rings and in training apparatus randomly. One digital video camera, one strain gauge in each cable and surface electromyography of nine shoulder muscles were used. Statistical analyses were performed by parametric and non-parametric tests and descriptive statistics. Shoulder strength asymmetry RMS values were 9.9±6.4%. The asymmetry of shoulder strength and cross performance on rings had an individual basis relation. Shoulder angles on training device had less deviation from target 90° of abduction on training apparatus than on rings and smaller asymmetry value. Cable forces had similar values in both apparatuses, as the asymmetry values. Electromyography of nine muscles and co contraction values differences were not different between the types of rings. The training rings allowed the gymnasts to better perform the cross without changing shoulder muscle activation patterns. An individual orientation for gymnasts to perform the cross on training apparatus within the same way they perform in competition rings, it is necessary for the maintenance of equivalent biomechanical characteristics

Orientador: Antonio Jorge Abdalla / Banca: Marcelo dos Santos Pereira / Banca: José Vitor Candido dos Santos / Banca: Leonardo Fanton / Banca: Rafael Humberto Mota de Siqueira / Resumo: O objetivo deste trabalho é avaliar e comparar a resistência mecânica da união de aços dissimilares, o aço Maraging 300 com o aço 300M-ESR pelos processos de soldagens autógenas a Plasma (Plasma Arc Welding - PAW) e a Laser (Laser Beam Welding - LBW). As juntas foram submetidas à avaliação da resistência mecânica através de ensaios de tração e de dureza Vickers (HV) no cordão de solda e zona termicamente afetada. Foram também realizadas análises químicas e metalográficas das juntas soldadas, correlacionando a microestrutura com as propriedades observadas. Em ambos os processos foram aplicados tratamentos térmicos antes e após as soldagens, com o objetivo de endurecer os materiais e procurando aproximar a dureza de ambos os aços e da zona fundida (ZF) e zona termicamente afetada pelo calor (ZTA). Foram realizados vários testes com tempos e temperaturas para se definir quais eram os melhores tratamentos térmicos adotados para a equalização das propriedades mecânicas. Os tratamentos térmicos aplicados após a solda mostraram-se convenientes para o nivelamento dos valores das durezas, somente exibindo poucas perdas nas ZTAs dos aços Maraging. Com a aplicação destes tratamentos também foi possível notar uma equalização nas resistências à tração, em torno de 1300 MPa e aumentos consideráveis das mesmas, comparado com a mesma condição sem tratamento. As soldas mostraram-se eficientes para a união das chapas, porém, em algumas situações da soldagem a Laser, apresentou pequenas falhas,... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this work is to evaluate and compare the mechanical strength of welded joints made of the dissimilar steels such as Maraging 300 steel with 300M-ESR steel by the autogenous Plasma Arc Welding (PAW) and Laser welding process (LBW). The joints were submitted to the mechanical strength evaluation by tensile test and hardness Vickers (HV) at the weld bead and thermally affected zone. Chemical analysis and metallographic analysis of the welded joints were also performed, correlating the microstructure observed with the properties. In both processes, heat treatments were applied before and after welding, with the objective of at harden the materials and seeking to approximate the hardness of both steels and the fusion zone and heat affected zone. Several tests were carried using different times and temperatures to determine which ones were the best heat treatments to be adopted aiming the equalization of mechanical properties. The heat treatments applied after welding proved to be convenient for the leveling of the hardness values, only showing few losses in the HAZs of the Maraging steels. Applying of these treatments, it was also possible to note the equalization of tensile strengths, around 1300 MPa and considerable increases of the same, compared to the same condition without treatment. The welds showed to be efficient for the joining of the plates, however, in some situations the Laser welding presented small flaws, such as presence of pores, in the weld beads... (Complete abstract click electronic access below) / Doutor

The purposes of this study were to compile demographic characteristics, educational backgrounds, coaching experiences, and duties of strength and conditioning (STC) coaches at NCAA Division II and III institutions, and compare the profile of Division II and III STC coaches to the Martinez (2004) study of Division I-A STC coaches. NCAA Division II and Division III athletic personnel (N=578) received an electronic survey for this study. The return rate from Division II and Division III STC coaches were as follows: Division II, 23 responses (n=175), Division III, 34 responses (n=403). Descriptive statistics were used to examine each item. STC coaches at NCAA Division II and III institutions are white, male, approximately 35 and 34 years of age respectively, earn an annual salary of $30,001-$40,000, hold the CSCS certification, and received a Master's degree. The results indicated differences between this study and Martinez's (2004) study of NCAA Division I-A STC coaches.

The purpose of this dissertation was to investigate the influence of lower body strength characteristics on change of direction (COD) performance in NCAA Division I soccer athletes. Specifically, this dissertation served to examine: 1) whether the lower body strength and power were related to COD performance, 2) whether stronger athletes had superior COD performance than weaker athletes, 3) whether the force production asymmetry and strength dominant (SD) associated with COD performance, and 4) weather sex differences existed in kinetic variables during the stand phase of cutting. The major findings of this dissertation include: 1) strength and power characteristics were moderately to strongly related to COD performance. Furthermore, soccer athletes’ straight-line sprinting times were significantly related to COD performance outcomes. 2) Stronger athletes demonstrated the tendency to perform superiorly in modified 505 COD test when compared to weaker athletes. 3) Athletes who had more lower body force production asymmetry were more likely to perform asymmetrically during a COD test. However, the SD and the magnitude of asymmetry were not limiting factors for athletes’ COD performance.4) Male athletes demonstrated statistically significantly less COD total time, longer ground contact time (GCT), and better ability to apply forces and impulses while performing cutting. Based on the results, vertical forces and impulses during both the braking and propulsive phases of cutting ranged from 2.51 to 3.14 times larger than horizontal direction. In summary, stronger and more powerful soccer athletes were able to perform in a superior manner for both the COD tasks and straight-line sprinting. This may be due to the ability to produce high force and power during the critical time periods. Although force production asymmetry during related to the asymmetrical performance during COD tasks, the SD and the magnitude of asymmetry did not limit the COD performance. Finally, statistical differences existed between sexes in kinetic variables during cutting may be due to the different approaches to apply force in this task. Moreover, the ability to generate higher force and impulse in the vertical direction could affect COD performance.

The isometric mid-thigh pull (IMTP) has been cited often in the scientific literature; however, there is still a lack of agreement as to the ideal body position used during this test, and how body position impacts the relationship between IMTP performance and dynamic performance. Thus, one aim of this dissertation was to compare two different IMTP positions and correlate the kinetic outputs from each position to vertical jump (VJ) performance. Another purpose of this dissertation was analyze which method of data normalization for IMTP force variables best correlates to squat jump (SJ) and countermovement jump (CMJ) performance. In the first study, subjects presented higher force outputs for an upright position (hip angles 145°, knee 125°) when compared to a bent position (hip angles 125°, knee 125°). However, there were no statistical differences among correlations from the two positions when correlating to VJ performance. Thus, we suggest that the upright position should be the one used for research and monitoring due to higher force values presented. The second part of this study was to compare correlations from non-normalized and normalized data from the IMTP to SJ and CMJ. Besides non-normalized data, five common methods of normalization were used – subtracting the body mass force, dividing the forces per body mass, allometric scale, scaling by height (Ford’s scale) and scaling by Sinclair coefficient value. In general, higher value correlations were presented with the non-normalized methods for both jumps – SJ and CMJ. Therefore, when using IMTP data to correlate with VJ performance, there is no need to normalize the data.

Objective: To determine the relationship between mineral density and microtensile bond strength of caries-affected dentin (CAD). Methods: Sixty-three extracted human molars with carious lesions and nine extracted sound human molars are collected and flattened to expose the dentin. Caries is removed using Caries Detector (Kuraray Medical, Tokyo, Japan) leaving a firm light pink stained dentin and then bonded with RBC (Z100, shade T, 3M ESPE, Germany) using an etch-and-rinse 3-step adhesive system (Optibond FL,Kerr, Orange, CA, USA). The bonded teeth are stored overnight at 37ºC before vertically sectioned with diamond saw blades (IsoMet 1000, Buehler Ltd., Lake Bluff, IL, USA). The sticks are then trimmed into dumbbell-shaped specimens with a cross-sectional area of 0.5 mm2 and a gauge length of 1 mm. Tensile testing is performed at a crosshead speed of 1 mm/min (Zwick Materials Testing Machine Z2.5/TN1S, Zwick, Ulm, Germany). X-ray microtomography was used to examine the fractured specimens (Micro-CAT II, Siemens Preclinical Solutions, Knoxville, TN) at maximum resolution of 27 microns. The mean mineral densities at the resin-dentin interface of the bonded specimens are calculated using a custom BMD (bone mineral density) analyzer software (Iowa City, IA, USA). Mineral density (image intensity) will be plotted against uTBS (MPa) to determine correlation between these two properties based on Spearman rank correlation test at 0.05 level of statistical significance. Results:There was a statistically significant relationship between µTBS and image intensity (p< 0.0001). However, the correlation coefficient was weak (0.31). Significant effect of the failure mode on the image intensity and the µTBS were observed (p < 0.0001). No significant difference in the mean image intensity was found between the 2 levels (p = 0.6519) and 3 levels of dye staining (p = 0.2531). Intra- and inter-examiner reliability was near perfect (0.99; 0.98) for mineral density measurements. Conclusion: Within the limits imposed in the experimental design, we concluded that the degree of mineralzation of CAD has an influence on its failure mode and µTBS. Positive increasing relationship was also found between CAD's failure mode and its µTBS. Additionally, no significant relationship was found between levels of dye staining and the degree of mineralization.

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