Browsing by Author "Freitas, S."
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- Elucidating the mechanisms Involved in the cytotoxicity induced by marine cyanobacteria strains against the RKO colon carcinoma cell linePublication . Freitas, S.; Urbatzka, R.; Osório, H.; Costa, M.; Barros, Piedade; Vasconcelos, V.; Martins, RosárioCyanobacteria are known to synthesize secondary metabolites that may have potential as drugs for the treatment of human diseases such as cancer. Previous studies on marine cyanobacteria isolated from the Portuguese coast revealed strains of the picoplanktonic genera Cyanobium and Synechocystis as potential sources of anticancer compounds. The ethyl acetate fraction of the strains Cyanobium sp. LEGE06113 and the Synechocystis salina LEGE06155 was found to reduce cell viability of cancer cell lines. This work aimed to elucidate the mechanisms involved in the cytotoxicity of this strains in the colon adenocarcinoma cell line RKO by employing real-time PCR (RT-PCR) for genes involved in cell cycle and apoptosis, by flow cytometry for cell cycle and by two-dimensional gel electrophoresis for protein expression. RT-PCR results revealed differences in mRNA expression of genes CCNB1 (cell cycle) and BCL-2 (apoptosis). Flow cytometry results revealed a decrease in the G0/G1 and S phase and increased its number in the G2/M phase, which is in accordance with the lower expression of CCNB1. The proteomic results demonstrated different protein patterns comparing treatment groups with control. Proteins differentially regulated in exposed RKO cells were involved in cell cycle regulation, apoptosis, cell structure, protein regulation and cell metabolism. Although several of these proteins were identified in cells exposed to both cyanobacterial extracts, the data provides an indication that the cytotoxicity is induced by different toxic mechanisms in LEGE06113 and LEGE06155 fractions.
- Embedded Electricity Quality AnalyzerPublication . Freitas, S.; Martins, R.; Martins, F.; Felgueiras, CarlosElectric installations are traditionally designed for supplying an electric service. The only one associated instrument is the energy meter that is introduced only for measure the total amount of energy that will be charged to the user. However, the exploration of parameters associated with electricity can provide several advantages such the household performance devices, legal issues and later one a more sustainable way to use the electricity energy. This work presents the principle of a low cost energy analyzer that will be part of an electric home installation. Electric parameters are measured and then transmitted via Wi-Fi to a domestic server where all data are stored. This data exploitation can be later one used for several purposes, since electric efficiency to electric charges prediction.