Browsing by Author "Silva, Renata"
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- Advantages of structural inspection and diagnosis for traditional buildings’ refurbishment: A Life Cycle Assessment perspectivePublication . Silva, Renata; Surra, Elena; Quelhas, Bruno; Costa, Alexandre A.; Lapa, Nuno; Delerue-Matos, CristinaThis work demonstrated, through Life Cycle Assessment (LCA), the environmental advantages brought by the application of the Structural Inspection and Diagnosis (SID) methodology to the structural refurbishment of 7 traditional buildings located in the city of Porto (Portugal), when compared to the common total demolition and reconstruction approach. The early diagnosis of the conservation state of the existing structural elements, and their characterization provides fundamental information for optimizing the design of the refurbishment towards environmental sustainability. SID approach can reduce by 75.3%, on average, the demolished material and provide the lowest environmental burdens in the environmental categories of Global Warming, Acidification, Eutrophication, Ozone, and Abiotic Depletion, Photochemical Ozone Creation potential, Human Toxicity as well as Energy Demand when compared with the total demolition and reconstruction scenarios. In terms of relative environmental impact for the reconstruction scenarios, it was concluded that reinforced concrete, in the form of lightweight and solid slabs, presents the worst performance due to the concrete production process. Furthermore, timber structures show better environmental performance when compared to the use of glued laminated timber. The establishment of the SID tool as a consolidated methodology can be a unique opportunity to systematically include, in the refurbishment of traditional buildings, the principles of the environmental sustainability required by EU policies in the construction sector, providing a significant reduction of demolition wastes and the maximization of the preservation of existing structural materials.
- Disclosing the antifungal mechanisms of the Cyclam Salt H4[H2(4-CF3PhCH2)2Cyclam]Cl4 against Candida albicans and Candida kruseiPublication . Costa, Inês; Lopes, Inês; Morais, Mariana; Silva, Renata; Remião, Fernando; Medeiros, Rui; Alves, Luís G.; Pinto, Eugénia; Cerqueira, FátimaMycoses are one of the major causes of morbidity/mortality among immunocompromised individuals. Considering the importance of these infections, the World Health Organization (WHO) defined a priority list of fungi for health in 2022 that include Candida albicans as belonging to the critical priority group and Pichia kudriavzevii (Candida krusei) to the medium priority group. The existence of few available antifungal drugs, their high toxicity, the acquired fungal resistance, and the appearance of new species with a broader spectrum of resistance, points out the need for searching for new antifungals, preferably with new and multiple mechanisms of action. The cyclam salt H4[H2(4-CF3PhCH2)2Cyclam]Cl4 was previously tested against several fungi and revealed an interesting activity, with minimal inhibitory concentration (MIC) values of 8 µg/mL for C. krusei and of 128 µg/mL for C. albicans. The main objective of the present work was to deeply understand the mechanisms involved in its antifungal activity. The effects of the cyclam salt on yeast metabolic viability (resazurin reduction assay), yeast mitochondrial function (JC-1 probe), production of reactive oxygen species (DCFH-DA probe) and on intracellular ATP levels (luciferin/luciferase assay) were evaluated. H4[H2(4-CF3PhCH2)2Cyclam]Cl4 induced a significant decrease in the metabolic activity of both C. albicans and C. krusei, an increase in Reactive Oxygen Species (ROS) production, and an impaired mitochondrial function. The latter was observed by the depolarization of the mitochondrial membrane and decrease in ATP intracellular levels, mechanisms that seems to be involved in the antifungal activity of H4[H2(4-CF3PhCH2)2Cyclam]Cl4. The interference of the cyclam salt with human cells revealed a CC50 value against HEK-293 embryonic kidney cells of 1.1 μg/mL and a HC10 value against human red blood cells of 0.8 μg/mL.