1,044 research outputs found

    Depositional setting and stratigraphic patterns of Pre-Salt carbonates in a sector of the Santos Basin, Brazil

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    Tese de mestrado, Geologia (Estratigafia, Sedimentologia e Paleontologia) Universidade de Lisboa, Faculdade de Ciências, 2019This work aims to better understand the Pre-Salt Barra-Velha Formation lacustrine carbonates and their depositional setting and diagenetic evolution in a specific zone of Santos Basin, Brazil. A multi-scale workflow based on well core analysis and its relation with well log data and stratigraphic seismic interpretation was used to provide a better understanding of facies distribution and depositional cycles, with focus on the Upper Sag unit. The outcomes from the different tasks allowed to develop a conceptual depositional model with application on reservoir characterization, representing a generic regional propose applicable to the Pre-Salt carbonates in the studied area. The results from the six described wells demonstrate high depositional cyclicity, indicating mainly a shallow water environment, being possible to define a generic facies sequence based on base-level position and energy variations. Facies successions identification allowed the recognition of sequence boundaries, which demonstrated that changes in base-level and accommodation space were responsible for different facies deposition. The integration of multiscale data with seismic interpretation demonstrate a progressive basin fill, starting north and gradually reaching structural higher positions. Paleogeomorphology strongly controlled sediment deposition, as different depositional environment conditions were observed in different structural positions, with high base-level position and low energy facies being mainly recognized in structural lows and low base-level position and high energy facies being mostly identified in structural highs. It was also recognized an affinity of diagenetic processes with paleogeomorphology, with fluid circulation having a major impact in structural low positions resulting in porosity reduction processes, while in structural high positions, porosity generation or enhancing processes tend to be more frequent. The understanding of depositional environments retrieved from this study will enhance the geological understanding of Santos Basin depositional setting and may assist on hydrocarbon exploration by providing a more robust reservoir characterization, from a geological point of view

    Study of the potential toxicity of adrenaline to neurons, using the SH-SY5Y human cellular model

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    Prolonged overexposure to catecholamines causes toxicity, usually credited to continuous adrenoceptor stimulation, autoxidation, and the formation of reactive pro-oxidant species. Non-differentiated SH-SY5Y cells were used to study the possible contribution of oxidative stress in adrenaline (ADR)-induced neurotoxicity, as a model to predict the toxicity of this catecholamine to peripheral nerves. Cells were exposed to several concentrations of ADR (0.1, 0.25, 0.5 and 1mM) and two cytotoxicity assays [lactate dehydrogenase (LDH) release and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction] were performed at several time-points (24, 48, and 96h). The cytotoxicity of ADR was concentration- and time-dependent in both assays, since the lowest concentration tested (0.1mM) also caused significant cytotoxicity at 96h. N-acetyl-cysteine (1mM), a precursor of glutathione synthesis, prevented ADR-induced toxicity elicited by 0.5mM and 0.25mM ADR following a 96-h exposure, while the antioxidant Tiron (100µM) was non-protective. In conclusion, ADR led to mitochondrial distress and ultimately cell death in non-differentiated SH-SY5Y cells, possibly because of ADR oxidation products. The involvement of such processes in the catecholamine-induced peripheral neuropathy requires further analysis

    Non-Cooperative Facility Location Games: a Survey

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    The Facility Location problem is a well-know NP-Hard combinatorial optimization problem. It models a diverse set of situations where one aims to provide a set of goods or services via a set of facilities F to a set of clients T, also called terminals. There are opening costs for each facility in F and connection costs for each pair of facility and client, if such facility attends this client. A central authority wants to determine the solution with minimum cost, considering both opening and connection costs, in such a way that all clients are attended by one facility. In this survey we are interested in the non-cooperative game version of this problem, where instead of having a central authority, each client is a player and decides where to con- nect himself. In doing so, he aims to minimize his own costs, given by the connection costs and opening costs of the facility, which may be shared among clients using the same facility. This problem has several applications as well, specially in distributed scenarios where a central authority is too expensive or even infeasible to exist. In this paper we present a survey describing different variants of this problem and reviewing several results about it, as well as adapting results from existing literature concerning the existence of equilibria, Price of Anarchy and Price of Stability. We also point out open problems that remain to be addressed.

    Toxicometabolomics: small molecules to answer big toxicological questions

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    Given the high biological impact of classical and emerging toxicants, a sensitive and comprehensive assessment of the hazards and risks of these substances to organisms is urgently needed. In this sense, toxicometabolomics emerged as a new and growing field in life sciences, which use metabolomics to provide new sets of susceptibility, exposure, and/or effects biomarkers; and to characterize in detail the metabolic responses and altered biological pathways that various stressful stimuli cause in many organisms. The present review focuses on the analytical platforms and the typical workflow employed in toxicometabolomic studies, and gives an overview of recent exploratory research that applied metabolomics in various areas of toxicology.info:eu-repo/semantics/publishedVersio

    Oral fungal microflora associated with implant-supported VS. mucous-supported dentures

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    Poster presented at the 1st International Congress of CiiEM - From Basic Sciences to Clinical Research, 27-28 November 2015, Egas Moniz, Caparica, Portugal

    Changes in oral microflora in prosthetic patients on hygiene protocol

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    Poster presented at the 1st International Congress of CiiEM - From Basic Sciences to Clinical Research, 27-28 November 2015, Egas Moniz, Caparica, Portugal

    Sacramentalidade da fé e simbólica eucarística

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    O estudo da sacramentalidade da fé e simbólica eucarística exige que façamos o caminho desde a última ceia até aos nossos dias, a fim de conhecermos as interpretações que as sucessivas gerações de cristãos fizeram deste mistério. Neste vasto trabalho seguiremos pari passu a obra de Enrico Mazza, que é neste momento um dos melhores especialistas no sacramento da eucaristia. Concentraremos certos títulos e excluiremos os que não apresentam particular interesse para o presente trabalho. Relativamente, porém, à concepção que se desenvolveu na segunda metade do século XX, faremos uma síntese a partir da produção de outros teólogos
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