421 research outputs found
Efeito da termociclagem e da técnica de inserção na infiltração de restaurações em resina composta
The objective of this study was to evaluate in vitro the effect on leakage of two incremental filling techniques and two composite resins with different elastic modulus and similar polymerization shrinkage. Eighty Class V cavities (4x4x2mm) were prepared in bovine incisors and were randomly restored with Z-250 (Z) or Durafill VS (D) + Single Bond in axial (a) or oblique (o) increments. The restorations were divided into two groups: Not Aged - N (4-hour-storage in water at 37ºC) and Aged - A (1-week storage in water at 37ºC + 1000 x - 5º-55ºC / 1-min dwell time). The specimens were covered with 2 coats of nail varnish so that only the restoration margins were exposed to silver nitrate 50% (2h) and developed under fluorescent light (8h). After they were sectioned twice in buccal-lingual direction, the four exposed surfaces were digitized (Vidcap) and the silver nitrate penetration was measured (ImageLab) at the incisal and gingival walls. Data were analyzed by a 3-way ANOVA (Resin, Filling Technique and Aging) separately for incisal and gingival walls (alpha=0.05). Resin and Aging were statistically significant either for the incisal and the gingival walls. The microfill composite resin infiltrated more than the hybrid composite. The thermal cycling caused an overall increase in silver nitrate penetration. The filling technique affected leakage depending on the composite resin and aging regimen.O objetivo deste estudo foi avaliar o efeito de duas técnicas incrementais de inserção na infiltração de restaurações de resinas compostas com módulos de elasticidade distintos e contração de polimerização semelhante. Para isto, foram preparadas 80 cavidades Classe V (4x4x2 mm) em incisivos bovinos que foram restauradas de modo aleatório com Z-250 (Z) ou Durafill VS (D) + Single Bond em incrementos axiais (a) ou oblíquos (o). As restaurações foram divididas em dois grupos: Não Envelhecidas - N (4 h em água destilada a 37º C) e Envelhecidas - E (1 semana de armazenagem em água a 37º C + 1000 x - 5º-55ºC / 1 min de imersão). Os espécimes foram recobertos com duas camadas de esmalte cosmético de modo que apenas as margens das restaurações ficassem expostas ao nitrato de prata (2h) seguido de imersão em revelador (8h) sob luz fluorescente. Posteriormente, eles foram secionados duas vezes no sentido vestíbulo-lingual, as superfïcies expostas (4) foram digitalizadas (Vidcap) e a penetração do nitrato de prata medido (ImageLab) nas paredes incisal e gengival. Os dados foram analisados por análise de variância de três fatores (Resina, Técnica de Inserção e Envelhecimento) separadamente para as paredes incisal e gengival. Resina e Envelhecimento foram significativos. A resina composta de micropartículas mostrou maior infiltração que a híbrida. A técnica de inserção influenciou a infiltração marginal dependendo da resina e do emprego ou não de ciclos térmicos
Photoelastic Stress Analysis Surrounding Implant-Supported Prosthesis and Alveolar Ridge on Mandibular Overdentures
The purpose of this research was to evaluate the maximum stress around osseointegrated implants and alveolar ridge, in a mandible with left partial resection through a photoelastic mandibular model. The first group consisted of two implants: traditional model (T), implants placed in the position of both canines; fulcrum model (F), implants placed in the position of left canine CL and right lateral incisor LiR. Both models linked through a bar and clips. The second group was consisted of three implants, with implants placed in the position of both canines (CR and CL) and the right lateral incisor (LiR), which composed four groups: (1) model with 3 “O” rings, (2) model 2 ERAs, bar with clips, (3) model 2 ERAs bar without clips; (4) model “O” ring bar and ERA. An axial and an oblique load of 6.8 kgf was applied on a overdenture at the 1st Pm, 2nd Pm, and 1st M. Results showed that the area around the left canine (CL) was practically free of stress; the left lateral incisor (LiL) developed only small tensions, and low stress in all the other cases; the right canine tooth suffered the largest concentrations of stress, mainly with the ERA retention mechanism
Predicting Brain Age at Slice Level : Convolutional Neural Networks and Consequences for Interpretability
Funding Information: NE was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior— Brasil (CAPES)—Finance Code 001. MM was financed in part by the Conselho Nacional de Pesquisa—Brasil (CNPq). Funding Information: Conflict of Interest: BF had a research grant from Pfizer outside of this study.Peer reviewe
Electrochemical characterization of samples of commercial steel treated with acetylene plasma
104-111Cutting tools have been employed in wood processing must be corrosion and wear resistant due to the acidic composition of wood and the wear generated during cutting, which lead to the deterioration of steel saws. Hydrogenated amorphous carbon films possess mechanical, tribological and barrier properties that can increase the hardness, wear and corrosion resistance of this type of tool. This work has involved an investigation of the effectiveness of plasma-deposited amorphous carbon thin films in protecting commercial carbon steel saws. Before deposition, the substrates were sputter-cleaned in argon plasma (19.27 Pa; 50 W) for 180 s. The films have been deposited using acetylene and argon mixtures excited by a radio frequency power supply (13.56 MHz, 70 W). The concentration of acetylene in the mixture has been varied in the inverse proportion to that of argon so as to maintain a constant total gas pressure of 1.8 Pa. The deposition time was 3600 s. The chemical behavior of the coated saws have been evaluated by electrochemical impedance spectroscopy (EIS) and polarization curves.Surface images of the plasma-coated samples have been recorded by scanning electron microscopy (SEM). The results have indicated that the plasma treatment has increased the corrosion resistance of carbon steel samples in acidic solutions
Sensory profile of portuguese white wines using long-term memory: a novel nationwide approach
White wine sensory profiling of all 12 Protected Geographical Indications (PGIs)
of mainland Portugal was achieved through completion of extended sensory
questionnaires by 20 professional wine experts. No samples were assessed; the
experiment was based on memory alone. Three macro-zonings were found and
typicality differences were statistically validated and sensory described. PGI
MINHO was found the most typical of all PGIs, with several extreme rates on
Color, Aroma and Taste. SOUTHERN cluster of the four meridional PGIs
presented several extreme, therefore typical, sensory assessments, mostly opposite
to the profile of PGI Minho. Color tonality, alcohol and acidity were mutually
related and respective variations were correlated with published findings and
expressed as key factors for regional macro-zoning differentiation. Moreover, with
the proposed methodology it was possible to achieve a novel nationwide sensory
characterization of PGIs, overcoming ongoing macroscaling and sample
representativeness limitations and envisaging new nation-sized sensory studiesinfo:eu-repo/semantics/publishedVersio
Porto com a referència europea de l’envelliment actiu i saludable
[cat] Al llarg dels darrers anys s’ha anat concretant, al conjunt d’Europa, també a Portugal, l’augment de l’envelliment i del sobreenvelliment. Aquest procés es dona en un context de fortes limitacions de les polítiques públiques. En paral·lel, han canviat les concepcions sobre l’envelliment, cosa que ha generat un nou enfocament centrat en el desenvolupament actiu i saludable de les persones grans. El repte que suposa compaginar aquestes dimensions de l’envelliment implica una responsabilitat compartida: administració, societat civil organitzada, ciutadans. En aquest sentit, s’han desenvolupat accions molt diverses, però les que ofereixen millors resultats són les iniciatives locals i regionals de treball en xarxa per aprofitar totes les capacitats. L’experiència de Porto, liderada per la Universitat i per l’Ajuntament, és un dels exemples de referència en el conjunt d’Europa. Centrada en l’aprofitament de la generalització actual de les tecnologies de la informació i la comunicació, ha focalitzat accions innovadores per promoure l’apoderament dels ciutadans de més edat. Aquesta iniciativa exemplar va rebre el reconeixement europeu, en forma de suport financer, però també científic, de connexió internacional, etc. A l’article es presenten els primers resultats, un any després del reconeixement europeu de la iniciativa.[spa] Durante los últimos años se ha ido concretando, en el conjunto de Europa, también en Portugal, el aumento del envejecimiento y del sobreenvejecimiento. Este proceso se da en un contexto de fuertes limitaciones de las políticas públicas. En paralelo, han cambiado las concepciones sobre el envejecimiento, lo que ha generado un nuevo enfoque centrado en el desarrollo activo y saludable de las personas mayores. El reto que supone compaginar estas dimensiones del envejecimiento implica una responsabilidad compartida: administración, sociedad civil organizada, ciudadanos. En este sentido, se han desarrollado acciones muy diversas, pero las que ofrecen mejores resultados son las iniciativas locales y regionales del trabajo en red, para aprovechar todas las capacidades. La experiencia de Oporto, liderada por la Universidad y por el Ayuntamiento, es uno de los ejemplos de referencia en el conjunto de Europa. Centrada en el aprovechamiento de la generalización actual de las tecnologías de la información y la comunicación, ha focalizado acciones innovadoras para promover el empoderamiento de los ciudadanos de más edad
Tensile bond strength of adhesive systems: effects of primer and thermocycling
O objetivo desta pesquisa foi o de verificar o efeito do "primer" e dos ciclos térmicos na resistência da união entre adesivos multiuso e esmalte dental, sob ensaios de tração. Os seguintes sistemas adesivos foram aplicados, de acordo com as instruções dos fabricantes, na superfície vestibular (sem desgaste) de 96 pré-molares com ou sem a aplicação prévia do "primer": Scotchbond MP, OptiBond FL, Amalgambond Plus e OptiBond - "dual cure". Após a aplicação do sistema adesivo, foi confeccionado um cone de resina composta (Z100, 3M), e fotoativado dentro de um molde metálico. Metade do total de espécimes foi submetida a 3.000 ciclos térmicos (5-37ºC; 37-55ºC, 60 s de imersão); a outra metade permaneceu imersa em água a 37ºC pelo mesmo tempo dispensado no procedimento anterior. Os dados foram submetidos a uma análise de variância (p = 0,05) e nenhum efeito significante foi detectado, indicando que a resistência de união não foi afetada pelo sistema adesivo, pela aplicação do "primer" ou pelos ciclos térmicos.The objective of this study was to evaluate the effects of primer and thermocycling on the bond strength of multi-purpose adhesive systems applied to enamel, under tensile stress. The following bonding systems were applied, according to the manufacturers' instructions, on unground enamel buccal surfaces of 96 premolars, with or without the application of primer: Scotchbond MP, OptiBond FL, Amalgambond Plus and OptiBond (dual-cure). A composite resin (Z100, 3M) was applied and light-cured in a cast metal hollow cone, which was previously fixed to the enamel surfaces. Half of the sample was subjected to 3,000 thermocycles (5-37ºC; 37-55ºC, dwell time of 60 s), and the other half was stored in water at 37ºC for the same period. The data were treated by means of ANOVA and no significant effects were detected, which indicates that tensile bond strength was not affected by the adhesive systems, application of primer or thermocycling
A systematic review of participation in prevention family programs.
[ES] Una de las principales razones del fracaso de las intervenciones familiares está
relacionada con baja participación y retención de las familias. Las dificultades para promover
participación y retención adecuadas es uno de los obstáculos más importantes en la implementación y diseminación de las intervenciones familiares basadas en la evidencia. Aunque
en la literatura se describe una amplia gama de estrategias para involucrar a los padres, se
sabe poco sobre qué estrategias son más efectivas para mejorar la participación. Por ello, se
ha llevado a cabo una revisión sistemática de factores predictivos de la participación de los
padres y las estrategias de mejora en los programas parentales de prevención. Los criterios
de inclusión fueron: 1) estudios basados en evidencias con componente de intervención familiar, revisiones teóricas y empíricas de la literatura, y revisiones sistemáticas; 2) artículos
publicados en Portugués, Inglés y Español; 3) publicados entre 2000 y 2018. Se encontraron
39 artículos que informaron sobre una variedad de factores predictivos de la participación
familiar y métodos efectivos para involucrar a las familias en actividades preventivas. Surgieron cuatro dimensiones básicas: 1) predictores de participación; 2) características asociadas
al programa; 3) obstáculos para la participación; 4) estrategias para minimizar las barreras de
participación. Se identificaron cuatro grupos distintos de predictores de participación: patrones de interacción familiar; cogniciones y atribuciones de los padres sobre los problemas de
conducta del niño; variables psicológicas relacionadas con los padres; percepción parental
de la intervención. Varios atributos intrínsecos y extrínsecos de la intervención se asociaron
con la participación en programas familiares. Algunos obstáculos para la participación incluían
problemas o circunstancias logísticas del entorno social de la familia. Las estrategias para
minimizar las barreras incluyeron el uso de diferentes incentivos extrínsecos, el rol del capacitador y el ajuste de las expectativas y motivaciones de los padres durante la intervención.
[EN] One of the main reasons for the failure of family interventions is related to the
low participation and retention of families. Difficulty in promoting adequate engagement and
retention of participants is one of the most powerful obstacles and challenges to the implementation and dissemination of evidence-based family interventions. Although a wide range
of strategies to involve parents in interventions is described in the literature, little is known
as to what strategies are most effective in improving parental involvement. We conducted
a systematic review of the predictors of parent participation and enhancement strategies
in preventive parenting programs. Key inclusion criteria included: 1) evidence-based studies
with a family intervention component, theoretical and empirical reviews of the literature, and
systematic reviews; 2) articles published in Portuguese, English, and Spanish; 3) published
between 2000 to 2018. Thirty-nine articles reported a variety of predictors of family participation and effective methods to engage families in preventive activities. Four basic dimensions emerged: 1) predictors of participation; 2) characteristics associated with the program; 3)
obstacles to participation; and 4) strategies to minimize barriers to participation. Four distinct
groups of participation predictors were identified: 1) patterns of family interaction; 2) parents’
cognitions and attributions regarding their child’s behavioral problems; 3) psychological variables related to parents; and 4) parental perception of intervention. A variety of intrinsic and
extrinsic intervention attributes were associated with involvement in family programs. Some
obstacles to participation included several logistical issues and circumstances within the family’s social environment. Strategies to minimize barriers to participation included the use of
different extrinsic incentives, the role of the trainer, and adjusting parental expectations and
motivations throughout the intervention
Depression, anxiety, and lifestyle among essential workers : a web survey from Brazil and Spain during the covid-19 pandemic
Background: Essential workers have been shown to present a higher prevalence of positive screenings for anxiety and depression during the COVID-19 pandemic. Individuals from countries with socioeconomic inequalities may be at increased risk for mental health disorders. Objective: We aimed to assess the prevalence and predictors of depression, anxiety, and their comorbidity among essential workers in Brazil and Spain during the COVID-19 pandemic. Methods: A web survey was conducted between April and May 2020 in both countries. The main outcome was a positive screening for depression only, anxiety only, or both. Lifestyle was measured using a lifestyle multidimensional scale adapted for the COVID-19 pandemic (Short Multidimensional Inventory Lifestyle Evaluation–Confinement). A multinomial logistic regression model was performed to evaluate the factors associated with depression, anxiety, and the presence of both conditions. Results: From the 22,786 individuals included in the web survey, 3745 self-reported to be essential workers. Overall, 8.3% (n=311), 11.6% (n=434), and 27.4% (n=1027) presented positive screenings for depression, anxiety, and both, respectively. After adjusting for confounding factors, the multinomial model showed that an unhealthy lifestyle increased the likelihood of depression (adjusted odds ratio [AOR] 4.00, 95% CI 2.72-5.87), anxiety (AOR 2.39, 95% CI 1.80-3.20), and both anxiety and depression (AOR 8.30, 95% CI 5.90-11.7). Living in Brazil was associated with increased odds of depression (AOR 2.89, 95% CI 2.07-4.06), anxiety (AOR 2.81, 95%CI 2.11-3.74), and both conditions (AOR 5.99, 95% CI 4.53-7.91). Conclusions: Interventions addressing lifestyle may be useful in dealing with symptoms of common mental disorders during the strain imposed among essential workers by the COVID-19 pandemic. Essential workers who live in middle-income countries with higher rates of inequality may face additional challenges. Ensuring equitable treatment and support may be an important challenge ahead, considering the possible syndemic effect of the social determinants of health
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