To evaluate the risks of hair dye exposure, we investigated cellular and molecular effects of Arianor Ebony dye, which is a mixture of azo and anthraquinone dyes, used in the composition of the black color. Cytotoxicity, genotoxicity, and gene expression of relevant molecules of apoptotic and oxidative stress mechanisms were investigated in HepG2 cells exposed to Arianor Ebony. Results showed that the dye did not induce cytotoxicity to exposed cells at a concentration up to 50 µg/mL compared to the negative control. However, genotoxic assays indicated that the dye was able to damage the genetic material at a concentration of 25 µg/mL, with induction factor values of exposed cells two- to five-fold higher than those recorded for the negative control. Moreover, the lowest observed effect concentration was 12.5 µg/mL. For gene expression, relevant changes were observed in cytochrome c and caspase 9, which decreased in cells incubated with the dye in a dose-dependent manner when compared with the negative control. In parallel, the expression of genes for antioxidant enzymes was increased in exposed cells, suggesting the presence of metabolic routes that protect cells against the toxic effect of the dye, avoiding exacerbated cellular death. Results suggested that the dye disrupted cellular homeostasis through mitochondrial dysfunction, which may be hazardous to human health. Thus, further investigations are necessary to deeply understand the mechanisms of action of the dye, considering its toxic potential found in our ex vivo assays.

Abstract A characterization technique, including a mathematical model involving extensive computational resources, is introduced to study the behavior of an electro-optical space switch based on semiconductor optical amplifier (SOA). The model encompasses the precise emulation of device nonlinearities and its transient performance, allowing the characterization of its transient response. The calibration process includes the evaluation of parasites from the SOA connection, mounting and encapsulation, and parameter extraction of the active cavity. The numerical results are compared to experimental data for various operational conditions, with close similarities. The characterization technique can be adapted for other electro-optical devices, such as directed-modulated lasers, amplitude modulators and electro-optical switches.

Abstract The systemic behavior of a Semiconductor Optical Amplifier model was optimized through extensive simulations, reaching reasonable approximation to experimental obtained from commercial devices for the optical gain versus bias current, for different optical inputs powers (-25 up to 0 dBm), and for the gain saturation profile for different I-bias (0 up to 180 mA). For that, parameters such as active region thickness, confinement factor, linear gain coefficient, and the transparency current were adjusted by the presented method. The method can be applied for different SOAs, enabling more accurate numerical predictions for black-box devices.

Abstract The present work aims to study the nonlinear behavior of reinforced concrete structures via Refined Plastic Hinge Method (RPHM). Pseudo-springs are used at the finite element ends, where the gradual loss of stiffness is determined by the combination of the normal force and bending moment (NM) in the cross section. The limiting of the uncracked, elastic and plastic regimes is done in the NM diagram. The concrete cracking is explicitly simulated with two approaches to calculate the effective moment of inertia of the cross section. The displacement-based formulation is referenced to the co-rotational system and coupled with continuation strategies to allow to overcome the possible critical points in the equilibrium paths. For validation of the numerical simulations, the results found with the proposed formulation are confronted with experimental and numerical data present in literature.

RESUMOOs reguladores vegetais podem ser utilizados para promover, retardar ou inibir o crescimento vegetativo. Neste sentido, o objetivo deste trabalho foi determinar os efeitos de épocas e número de aplicações do trinexapac-ethyl sobre o crescimento e a produtividade da cana-de-açúcar. O experimento foi delineado em blocos casualizados com quatro repetições. Os tratamentos foram arranjados em esquema fatorial (3 x 2 + 2); o fator A correspondeu às épocas de aplicação do regulador vegetal (120, 200 e 240 dias após a brotação das gemas (DAB) da cana-de-açúcar), e o fator B, ao número de aplicações (uma ou duas). Além disso, foram adicionadas duas testemunhas (uma com três aplicações e outra sem aplicação do regulador). A aplicação do trinexapac-ethyl reduziu o número e a distância entre gemas, a altura, o volume radicular e a produtividade da cana-de-açúcar. A aplicação sequencial (duas ou três vezes) promoveu incremento no diâmetro do caule, e três aplicações do produto aumentaram o número de perfilhos das plantas. O uso do regulador vegetal aplicado aos 240 DAB reduziu a altura das plantas, porém sem alterar o número de gemas. Conclui-se que o trinexapac-ethyl altera o crescimento e a produção da cana-de-açúcar, independentemente da época e do número de aplicações.

ABSTRACT Growth regulators can be used to further retard or inhibit vegetative growth. In this sense, the objective of this study was to determine the effects of age and number of trinexapac-ethyl applications on the growth and yield of sugarcane. The experiment was in a randomized complete block design with four replications. The treatments were in a 3 x 2 + 2 factorial arrangement, where factor A corresponded to the application times of the plant growth regulator (120, 200 and 240 days after bud burst (DAB) of sugarcane) and factor B to the number of applications (one or two applications). In addition, two controls (one with three applications and another application without the regulator) were added. The application of trinexapac-ethyl decreased the number and the distance between buds, height, root volume and sugarcane yield. The sequential application (2 or 3 times) induced an increase in stem diameter and three applications of the product increased the number of plant tillers. The use of growth regulators applied at 240 DAB has reduced plant height, however without changing the number of buds. It can be concluded that trinexapac-ethyl changes sugarcane growth and yield, regardless of season and number of applications.

ResumoNeste trabalho se propõe uma metodologia para a obtenção da curva de interação para seções mistas de aço e concreto, sujeitas à flexão composta normal, com base nos domínios de deformação de estruturas de concreto armado definidos pela ABNT NBR 6118[1]. Para isso, foram desenvolvidas expressões para o esforço normal, o momento fletor e para as deformações do concreto, das armaduras e dos elementos que compõem o perfil metálico em cada domínio de deformação. Com base nessas expressões criou-se um programa computacional denominado MDCOMP (2014). Neste trabalho utilizaram-se como valores limites das deformações do perfil metálico nos trechos comprimidos e tracionados, os mesmos estabelecidos pela ABNT NBR 6118[1]para as deformações das armaduras de aço. Para verificar as implementações numéricas realizadas, as curvas de interação e os esforços máximos de plastificação da seção obtidos com o programa MDCOMP (2014) foram comparados com os determinados a partir das recomendações do EUROCODE 4[2], da ABNT NBR 8800[3]ou com respostas da literatura.

AbstractThis paper proposes a methodology for obtaining the interaction curve for composite steel-concrete sections subject to combined compression and bending based on the deformation domains of reinforced concrete structures defined by ABNT NBR 6118 [1]. For this, were developed expressions for the axial force, the moment and the strains of concrete, longitudinal reinforcement and the elements comprising the metal profile in each deformation domain.Based on these expressions a computer program called MDCOMP (2014) was created. In this study the same limit values of longitudinal reinforcement strain defined by ABNT NBR 6118 [1] were used for the steel profile strains. To verify the numerical implementations performed, the interaction curves and the plastic resistance of the section obtained by MDCOMP program were compared with those determined from the recommendations of Eurocode 4 [2], of ABNT NBR 8800 [3] or literature responses.