FERNANDA CAROLINE SILVA MAMEDE

FERNANDA CAROLINE SILVA MAMEDE

Página do item completo

Resultados de Busca

Agora exibindo 1 - 5 de 5

In vitro and in vivo toxicity of coal fly Ash Lechatee
2018 - DAMASCENO, K.C.; CAVALCANTE, A.K.; MAZIERO, J.S.; MARTINI, G.A.; ORMENIO, M.B.; MAMEDE, F.C.; MIRANDA, C.S.; CAMPELLO, F.A.; IZIDORO, J.C.; ROGERO, S.O.; FUNGARO, D.A.; LOPES-FERREIRA, M.; ROGERO, J.R.
Coal Fly ash is a major solid waste from coal-fired power stations. In Brazil, more than 4 million tons per year of fly ash are generated and only 30% is applied as raw material for cement and concrete production. The remaining is disposed in on-site ponds, nearby abandoned or active mine sites and landfills. The inadequate disposal of fly ash may pose a significant risk to the environment due to the possible leaching of hazardous pollutants into the surrounding soil and groundwater. A combination of leaching tests, cytotoxicity and ecotoxicological assays were used in this studyin order toevaluate the possible adverse effects of coal fl y ash in non-target organisms. The sample was collected from coal-fi red power plant located in Southern Brazil and the coal fly ash was submitted to a leaching procedure using USEPA SW 864 Method 1311. The leachate was prepared in six dilutions: 1.56%, 3.12%, 6.25%, 12.5%, 25% and 50%. Acute toxicity tests were performed on NCTC clone 929 (CCIAL-020) culture cells by neutral red uptake cytotoxicity method; acute ecotoxicity usingDaphnia similisand Danio rerio embryos according to ABNT NBR 12713 and OECD 236, respectively were employed. The cytotoxicity index (CI50) obtained was 33%; the EC50of D. similis after 48 h of exposure to the leachate was 7.25% and the LC50of D. rerio after 96 h of exposure was 4.39%. The results of these bioassays indicated toxicity of the coal fly ash leachate toward exposed organisms.
Ecotoxicology as a tool in nanotechnology
2017 - CAVALCANTE, A.K.; LUGAO, A.B.; ROGERO, J.R.; ROGERO, S.; MAMEDE, F.C.S.; MAZIERO, J.S.
The commercial applications of nanoparticles are diverse, such as use in the food industry, textile industry, electronics, water treatment and products used in medicine and health. The increase in the production and use of nanoparticles has caused great concern about the potential impacts and risks that these can cause to the environment and to human health. Nanoparticles can be released to the environment in a variety of ways and can reach the aquatic ecosystem and pose biota risks. Ecotoxicology is the study of the behavior and transformations of chemical agents and abiotic factors in the environment, as well as their effects on biota. The evaluation of the toxicity of chemical agents in the aquatic environment occurs by means of ecotoxicological tests. The purpose of this review was to summarize some ecotoxicological assays by addressing some concepts and data from nanoparticle ecotoxicity assays in order to demonstrate that ecotoxicological evaluation is an important tool for nanotechnology and that it has efficient methodologies for analyzing the Environmental health of aquatic ecosystems.
In vitro and in vivo toxicity evaluation of resveratrol assisted gold nanoparticles
2017 - BARROS, JANAINA A.G.; MAZIERO, JOANA S.; MAMEDE, FERNANDA C.S.; CAVALCANTE, ADRIANA K.; ROGERO, SIZUE O.; BATISTA, JORGE G.S.; VARCA, GUSTAVO H.C.; ROGERO, JOSE R.; LUGAO, ADEMAR B.
Gold nanoparticles (AuNP) are being investigated for diagnostic and therapeutic nanomedicines considering their low toxicity and stability against oxidation, among other features. The increasing production and use of AuNP can result in release of them into aquatic environment and the impacts on the aquatic organisms are not clear and the safety of AuNPs are still under investigation. This work aimed analyze the toxicity of resveratrol assisted AuNP synthesized in buffer phosphate pH 7.0 with approximately 47 nm in DLS and 15 nm in TEM analysis and gold ionic solution (Au+3). Cytotoxicity by neutral red uptake method and acute ecotoxicological assay on Daphnia similis were used. AuNP presented no cytotoxicity up to 246 mg L-1 while Au+3 showed IC50=7.95 mg L-1. AuNP CE50 was 113.15 mg L-1 and for Au+3 0.05 mg L-1. More studies can be conducted for the determination of safety ionic Au+3 and AuNP concentrations in aquatic environment.
Resveratrol radiomodifier effect on Danio rerio embriolarval assay
2017 - DAMASCENO, KELME C.; MAMEDE, FERNANDA C.S.; CAVALCANTE, ADRIANA K.; ROGERO, SIZUE O.; FERREIRA, MONICA L.; ROGERO, JOSE R.
The ionizing radiation can cause fatal damages to cells by the direct interaction with DNA and RNA or a series of toxic reactions occasioning chemical and biological changes. There are compounds with radioprotective potential, like resveratrol. For use the organism. Resveratrol is a substance found in peanuts, grapes and wine and its production occurs in plants as a response to physical, chemical and biological stress. Some studies benefits. Danio rerio (zebrafish) is a vertebrate animal and has become the model of several studies related to human diseases, due to its genomes similarity of 70 %, rapid embryonic development and the transparency o the eggs, which make it possible to observe the effects during the test period. The aim of the present study to verify the resveratrol radiomodifier effect on zebrafish during the embryolarval development by modified Fish Embryo Acute Toxicity (FET) (LC50) was 66.9 mg.L-1. Before, to understand the effects of radiation, was carried out the gamma radiation lethal dose (LD50) assay and the LD50 was 25 Gy. With these results the projec study of the radiomodifier effect of resveratrol in the presence of gamma radiation
Ecotoxicity evaluation of Coal Fly ash to Daphnia similis and Danio rerio
2017 - CAVALCANTE, A.K.; DAMASCENO, K.C.; MAZIERO, J.S.; MARTINI, G.A.; ORMENIO, M.B.; MAMEDE, F.C.S.; MIRANDA, C.S.; IZIDORO, J.C.; CAMPELLO, F.A.; FUNGARO, D.A.; ROGERO, S.O.; ROGERO, J.R.
Coal Fly ash is a major solid waste from coal-fired power stations. In Brazil, more than 4 million tons per year of fly ash are generated with a tendency to increase every year. Only 30% of fly ash is applied as raw material for cement and concrete production. The remaining is disposed in onsite ponds, nearby abandoned or active mine sites, or landfills. The inadequate disposal of fly ash may pose a significant risk to the environment due to the possible leaching of hazardous pollutants into the surrounding soil and groundwater. A combination of leaching tests and ecotoxicological analyses were used in this work for the evaluation of the adverse effects of coal fly in non-target organisms. Ashes were collected from coal-fired power plant located in South of Brazil. Acute toxicity tests were performed with Danio rerio embryos and Daphnia similis, according to OECD 236 and ABNT NBR 12713, respectively. Coal fly ash sample was subjected to a leaching procedure using USEPA SW 864 Method 1311. The leachate was prepared in seven dilutions: 1.56%, 3.12%, 6.25%, 12.5%, 25%, 50%, and 100%. The assays were performed in triplicates and the results showed lethality of Danio rerio after 96 hours of exposure to the leachate, and the calculated LC50 was 4.39%. The ecotoxicity tests with Daphnia similis, observed immobility after 48 hours of exposure to the leachate, and EC50 calculated was 7.25%. The results of these tests indicate toxicity of the coal fly ash leachate toward exposed organisms.