Development of a chromatographic method for simultaneous analysis of glutathione forms

Reduced glutathione (GSH)is the most abundant low molecular weight thiol-containing tripeptide (glycine, cysteine, and glutamate) which is synthesized in the cells. GSHplays critical roles in protecting cells from oxidative damage and the toxicity of xenobiotics. Besides, it is also involved in the regulation of intracellular redox homeostasis, which leads to its oxidation into oxidized glutathione (GSSG). Determining the ratio of GSH/GSSG in different biological samples is a major procedure for the evaluation of an individual’s oxidative status and can be a potential biomarker of oxidative stress.info:eu-repo/semantics/publishedVersio

Influence of lime on strength of structural unreinforced masonry: toward improved sustainability in masonry mortars

The choice of a sustainable construction material needs to take into account not just the environmental impact of the material, but according to the 2030 Agenda for Sustainable Development by the UN, one also needs to consider ease of access, the utilization of locally available materials, and the durability and reliability of the construction itself. Mortared masonry has been used around the world for several hundred years as an accessible type of construction. In masonry mortars, lime and cement are often integrated together for combined advantages: enhanced workability, breathability, and better environmental performance due to the former, and higher strength and shorter setting duration due to the latter. However, despite being extensively studied for their effects on the mechanical properties of mortar, not much is known about the impact of varying lime and cement ratios in the binder on the mechanical performance of masonry as a whole. Variations in the properties of mortars do not always have a significant impact on the mechanical behavior of masonry structures. Therefore, this article details an experimental campaign to measure the compressive strength, E-modulus, flexural strength, and shear bond strength of masonry samples containing two distinct lime–cement mortars (1:2:9 and 1:1:6 cement:lime:sand) and one cement mortar (1:0:5). The results show that more than the presence of lime in the mortar, the strength of the mortar influenced the flexural strength of the masonry ranging from 0.1 to 1.2 MPa. No discernable correlation was observed between the presence of lime in the mortar and the cohesion in the masonry (0.29 to 0.41 MPa). The values of the compressive strength (6.0 to 7.2 MPa) and E-modulus (3.8 to 4.5 GPa) of the masonry decreased and pre-peak ductility increased with an increase in the quantity of lime in the mortar. The recommendations of Eurocode 6 for the flexural strength of the initial shear bond strength were found to be conservative for different mortar strength classes, and significantly unconservative for compressive strength (by 50% to 70%).This work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under reference LA/P/0112/2020. The authors gratefully acknowledge the European Lime Association for funding this project. The funding provided by the Portuguese Foundation for Science and Technology (FCT) to the research project PTDC/ECM-EST/1056/2014 (POCI-01-0145-FEDER-016841), as well to the research unit ISISE (POCI-01-0145-FEDER-007633) and the scholarship SFRH/BD/137358/2018, is also gratefully acknowledged

The Regional North Indian Popular Music Industry in 2014: From Cassette Culture to Cyberculture

This article explores the current state of the regional vernacular popular music industry in North India, assessing the changes that have occurred since around 2000 with the advent of digital technologies, including DVD format, and especially the Internet, cellphones and ‘pen-drives’. It provides a cursory overview of the regional music scene as a whole, and then focuses, as a case study, on a particular genre, namely the languriya songs of the Braj region, south of Delhi. It discusses how commercial music production is adapting, or failing to adapt, to recent technological developments, and it notes the vigorous and persistent flowering of regional music scenes such as that in the Braj region

Speciation and bioavailability of Pb and Cu in wines : Influence of Cu on the kinetics of fermentation by Saccharomyces cerevisiae

Dissertação de Doutoramento em Química apresentada à Faculdade de Ciências da Universidade do PortoEstudou-se a influência da concentração de Cu no processo de fermentação alcoólica, nomeadamente no que respeita a fermentação de mostos. A fermentação alcoólica foi estudada num amplo intervalo de concentrações de Cu (desde níveis naturais até 1.0 mM), em dois meios de fermentação diferentes: mostos brancos (que constituem matrizes altamente complexas, contendo diversos ligandos de Cu) e "yeast nitrogen base" (YNB) com glucose. No meio YNB, a produção de etanol e a taxa de fermentação foram altamente influenciadas pela concentração de Cu, sendo que na presença de 0.50 e 1.0 mM Cu a produção de etanol foi dupla da verificada na ausência de Cu adicionado. No entanto, a cinética de fermentação foi mais lenta. Na produção de etanol a partir dos mostos apenas se verificaram efeitos ligeiros com a variação da concentração de Cu, o que significa que o teor de Cu não é responsável por alterações à fermentação, e por isso, encontra-se abaixo de níveis tóxicos relativamente ao desempenho das leveduras. Dum ponto de vista práctico-biotecnológico, os resultados sugerem o interesse em efectuar trabalho futuro sobre a influência do Cu nos meios usados na indústria de produção de etanol, usando a S. cerevisiae ou outras células. A explicação bioquímica para o fenómeno observado é um tópico de investigação que fica em aberto, sendo possível que exista uma ligação entre o efeito do Cu e a disponibilidade de Fe, uma vez que o Cu é necessário para o transporte de Fe para o interior das leveduras.Estudaram-se por potenciometria as propriedades complexométricas para Pb e Cu de quatro vinhos tintos diferentes, produzidos a partir de apenas uma das seguintes castas cultivadas na Região Demarcada do Douro: Tinta Barroca (TB), Tinta Roriz (TR), Touriga Nacional (TN) e Touriga Francesa (TF). Paralelamente estudou-se as propriedades complexométricas dos polifenóis isolados das graínhas (taninos condensados) e das películas (maioritariamente antocianas) duma mistura de uvas das quatro casta ..

A PROGRAM OF WORKING PLACE GYMNASTICS CONSIDERATIONS ON ERGONOMICS AND MUSCULOSKELETAL DISORDERS

info:eu-repo/semantics/publishedVersio

Impact of combined heat and salt stresses on tomato plants-insights into nutrient uptake and redox homeostasis

Currently, salinity and heat are two critical threats to crop production and food security which are being aggravated by the global climatic instability. In this scenario, it is imperative to understand plant responses to simultaneous exposure to different stressors and the cross-talk between underlying functional mechanisms. Thus, in this study, the physiological and biochemical responses of tomato plants (Solanum lycopersicum L.) to the combination of salinity (100 mM NaCl) and heat (42 degrees C; 4 h/day) stress were evaluated. After 21 days of co-exposure, the accumulation of Na+ in plant tissues was superior when salt-treated plants were also exposed to high temperatures compared to the individual saline treatment, leading to the depletion of other nutrients and a harsher negative effect on plant growth. Despite that, neither oxidative damage nor a major accumulation of reactive oxygen species took place under stress conditions, mostly due to the accumulation of antioxidant (AOX) metabolites alongside the activation of several AOX enzymes. Nonetheless, the plausible allocation of resources towards the defense pathways related to oxidative and osmotic stress, along with severe Na toxicity, heavily compromised the ability of plants to grow properly when the combination of salinity and heat was imposed.This research was partially supported through national funds by the Foundation for Science and Technology (FCT), within the scope of UIDB/05748/2020 and UIDP/05748/2020 (GreenUPorto), UIDB/04050/2020 (CBMA), UIDB/50006/2020 (LAQV-REQUIMTE), as well as the PEST(bio)CIDE project (PCIF/GVB/0150/2018) and the Val-Wrack project (POCI-01-0145-FEDER-029818). The work was also supported by the FCT and European funds (FEDER/POCI/COMPETE2020) through the research project "BerryPlastid" with ref. POCI-01-0145-FEDER-028165 and ref. PTDC/BIA-FBT/28165/2017. The authors also acknowledge the support by the I&D project "AgriFood XXI", ref. NORTE-01-0145-FEDER-000041, co-financed by the European Regional Development Fund (FEDER), as well as the support given through NORTE 2020 (Northern Regional Operational Program 2014/2020)

Abordagem multi-física ao comportamento em serviço das estruturas de betão: monitorização dos campos intermos de humidade

No âmbito do projeto de investigação denominado SeLCo – “Comportamento em serviço de estruturas de betão: uma abordagem multi-física das tensões autoinduzidas” – está a ser realizado um conjunto de trabalhos conducentes ao estabelecimento de abordagens de simulação higro-mecânica para estudo do carácter não uniforme das tensões associadas à retração de secagem em estruturas de betão armado. De facto, a secagem do betão ocorre de forma progressiva da superfície para o interior, originando deformações impostas. Para que possam ser simuladas as tensões decorrentes destes processos é primeiramente necessário dispor de modelos capazes de simular os campos de humidade, devidamente fundamentados em resultados obtidos através de medições experimentais. O presente artigo dedica atenção ao último aspeto, apresentando um conjunto de trabalhos realizados com o intuito de melhor compreender os desafios envolvidos na monitorização da humidade interna no betão. Apesar de haver vários trabalhos na bibliografia relativamente a este assunto, são escassos os que comparam o desempenho de metodologias e sensores para medição da humidade interna no betão. Neste trabalho são apresentados vários conjuntos de experiências que comparam o desempenho de sensores e de procedimentos de monitorização, explanando-se as principais ilações e estratégias a adotar no contexto do programa experimental a conduzir no âmbito da investigação sobre tensões autoinduzidas no betão

Multivariate analysis applied to X-ray fluorescence to assess soil contamination pathways: case studies of mass magnetic susceptibility in soils near abandoned coal and W/Sn mines

Determining the origin and pathways of contaminants in the natural environment is key to informing any mitigation process. The mass magnetic susceptibility of soils allows a rapid method to measure the concentration of magnetic minerals, derived from anthropogenic activities such as mining or industrial processes, i.e., smelting metals (technogenic origin), or from the local bedrock (of geogenic origin). This is especially effective when combined with rapid geochemical analyses of soils. The use of multivariate analysis (MVA) elucidates complex multiple-component relationships between soil geochemistry and magnetic susceptibility. In the case of soil mining sites, X-ray fluorescence (XRF) spectroscopic data of soils contaminated by mine waste shows statistically significant relationships between magnetic susceptibility and some base metal species (e.g., Fe, Pb, Zn, etc.). Here, we show how qualitative and quantitative MVA methodologies can be used to assess soil contamination pathways using mass magnetic susceptibility and XRF spectra of soils near abandoned coal and W/Sn mines (NW Portugal). Principal component analysis (PCA) showed how the first two primary components (PC-1 + PC-2) explained 94% of the sample variability, grouped them according to their geochemistry and magnetic susceptibility in to geogenic and technogenic groups. Regression analyses showed a strong positive correlation (R2 > 0.95) between soil geochemistry and magnetic properties at the local scale. These parameters provided an insight into the multi-element variables that control magnetic susceptibility and indicated the possibility of efficient assessment of potentially contaminated sites through mass-specific soil magnetism

Prediction of ductile fracture using uncoupled damage models

Dissertação de Mestrado Integrado em Engenharia Mecânica apresentada à Faculdade de Ciências e TecnologiaNo panorama tecnológico atual os materiais de elevada resistência têm ganho um lugar de destaque, sendo cada vez mais empregues a nível industrial. Contudo, esta vantagem em relação a outros materiais é conseguida à custa da redução de ductilidade. Neste contexto, surgem desafios acrescidos em termos da conceção dos produtos, na medida em que existem limitações no processo de conformação plástica do material. Desta forma torna-se imprescindível que, em processos como a estampagem de chapas metálicas, se consiga prever a fratura dúctil do material, para que seja possível desenvolver processos de fabrico que minimizem a ocorrência deste tipo de defeitos. Consequentemente, é essencial ter noção do dano acumulado pelo material durante o processo de conformação, uma vez que este determina as propriedades mecânicas em fases de conformação subsequentes e mesmo em serviço. Assim, na simulação numérica de processos de conformação de materiais metálicos com o Método dos Elementos Finitos recorre-se a modelos de dano para efetuar a previsão da fratura dúctil. Esta ocorre quando a variável utilizada para quantificar a acumulação do dano atinge um valor crítico. O objetivo desta dissertação é melhorar o conhecimento acerca dos modelos de dano desacoplados, através de uma análise numérica com o Método dos Elementos Finitos, recorrendo ao solver DD3IMP. Para tal, foram estudados dois modelos de dano distintos: o modelo proposto por Bao (2003) e o modelo proposto por Xue (2007). Numa primeira fase, a implementação destes modelos no DD3IMP foi validada com base em resultados conhecidos, ou seja, reproduziram-se resultados apresentados na literatura. Para o modelo proposto por Bao (2003) foi analisada uma liga Al-Si, obtida por fundição. Globalmente, os resultados obtidos com o DD3IMP mostraram uma excelente correlação com os resultados numéricos apresentados na literatura, exceto para o deslocamento à fratura, que foi sempre sobrestimado quando a força é subestimada. Para o modelo proposto por Xue (2007) foi analisada uma liga de alumínio 2024-T351. Também neste caso observou-se uma boa correlação com os valores experimentais disponíveis na literatura. Numa segunda fase, efetuou-se a calibração dos parâmetros dos dois modelos de dano para um aço DP780, com base em resultados numérico-experimentais de Roth e Mohr (2016). O procedimento de calibração proposto recorre necessariamente a uma abordagem numérico-experimental para caracterizar o estado de tensão que conduz à fratura dúctil, em cada ensaio. Constatou-se que a discretização espacial adotada nos modelos numéricos dos ensaios mecânicos selecionados para a calibração pode condicionar este processo, uma vez que influência os valores previstos para as grandezas que caracterizam o estado de tensão (triaxialidade, pressão hidrostática e ângulo de Lode). Por outro lado, estas grandezas não apresentam valores constantes, mesmo para ensaios que foram construídos com esse objetivo. Nestas circunstâncias será necessário recorrer a metodologias de análise inversa para calibração dos parâmetros, caso contrário os valores de deformação plástica equivalente na fratura previstos numericamente apresentam discrepâncias consideráveis em relação às curvas ou superfícies de fratura calibradas para os modelos de dano.In the current technological panorama, high strength materials have gained a prominent place, being increasingly used at the industrial level. However, their advantages over other materials are achieved at the expense of a reduction in ductility. As a consequence, greater challenges arise in terms of product design, as there are limitations in the material’s forming process. It is thus imperative to be able to predict the material’s ductile fracture in the design of processes such as the deep-drawing of metal sheets, so that an efficient manufacturing process can be developed in order to avoid this type of defects. To achieve this, it is essential to be aware of the damage accumulated by the material during the forming process, since it determines its mechanical properties in subsequent forming phases and even the in-service behavior. In this context, in the numerical simulation of sheet metal forming processes using the Finite Element Method, damage models are used to predict the material’s ductile fracture. This occurs when the variable used to quantify the damage accumulation reaches a critical value. The objective of this work is to improve the knowledge concerning uncoupled damage models, when performing the numerical analysis with the Finite Element Method, using the DD3IMP solver. Two different damage models were studied: one suggested by Bao (2003) and the other by Xue (2007). In a first phase, the implementation of these models in the DD3IMP solver was validated based on results presented in the literature. For the model suggested by Bao (2003), a casted Al-Si alloy was analyzed. Overall, the results obtained using DD3IMP showed an excellent correlation with the numerical results presented in the literature, except for the fracture displacement, which was always overestimated when the force is underestimated. For the model suggested by Xue (2007), the 2024-T351 aluminum alloy was analyzed. The results showed a good correlation with the experimental ones available in the literature. In a second phase, the parameters of the two damage models were calibrated for a DP780 steel, based on the results of a hybrid experimental-numerical approach conducted by Roth and Mohr (2016). This calibration procedure requires a numerical-experimental approach to characterize the stress state that leads to the material’s ductile fracture in each test. It was observed that the spatial discretization adopted in the numerical models of the mechanical tests selected for the calibration can strongly affect this process, since it influences the predicted values of the quantities that characterize the stress state (triaxiality, hydrostatic pressure and Lode angle). Moreover, these quantities sometimes present non-constant evolutions, even for tests that are designed with this objective in mind. Under these circumstances, it is necessary to use methodologies based on inverse analysis to calibrate the parameters, otherwise the numerically predicted values of equivalent plastic strain at fracture can present significant discrepancies when compared with the curves or fracture surfaces calibrated for the damage models