Profile of micronucleus frequencies and DNA damage in different species of fish in a eutrophic tropical lake

Lake Paranoá is a tropical reservoir for the City of Brasilia, which became eutrophic due to inadequate sewage treatment associated with intensive population growth. At present, two wastewater treatment plants are capable of processing up to 95% of the domestic sewage, thereby successfully reducing eutrophization. We evaluated both genotoxic and cytotoxic parameters in several fish species (Geophagus brasiliensis, Cichla temensis, Hoplias malabaricus, Astyanax bimaculatus lacustres, Oreochromis niloticus, Cyprinus carpio and Steindachnerina insculpita) by using the micronucleus (MN) test, the comet assay and nuclear abnormality assessment in peripheral erythrocytes. The highest frequencies of MN were found in Cichla temensis and Hoplias malabaricus, which were statistically significant when compared to the other species. However, Steindachnerina insculpita (a detritivorous and lake-floor feeder species) showed the highest index of DNA damage in the comet assay, followed by C. temensis (piscivorous). Nuclear abnormalities, such as binucleated, blebbed, lobed and notched cells, were used as evidence of cytotoxicity. Oreochromis niloticus followed by Hoplias malaricus, ominivorous/detritivotous and piscivorous species, respectively, presented the highest frequency of nuclear abnormalities, especially notched cells, while the herbivorous Astyanax bimaculatus lacustres showed the lowest frequency compared to the other species studied. Thus, for biomonitoring aquatic genotoxins under field conditions, the food web should also be considered

O poder da nanofabricação: substratos de alta performance para células solares ultrafinas de CIGS

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: O grupo de Nanofabrication for Optoelectronic Applications -NOA- inserido no International Iberian Nanotechnology Laboratory (INL) tem focado grande parte da sua investigação e operações no desenvolvimento de substratos de alta performance, baseados em diferentes esquemas de manipulação da luz para aplicação em células solares de Cu(In,Ga)Se2 (CIGS). Estes substratos baseiam-se na inserção de uma camada dielétrica de passivação entre o contacto posterior (Mo) e a camada de CIGS. Esta abordagem permite mitigar defeitos ativos na interface posterior, bem como a absorção ótica parasítica no Mo. Neste manuscrito compara-se o desempenho de duas células solares de CIGS ultrafino: uma célula solar com arquitetura convencional e uma segunda célula solar com um substrato contendo uma camada passivadora de 18 nm de SiOx, com um esquema de contactos por nano-pontos. Todos os valores das figuras de mérito da célula solar são melhorados quando é adicionado o substrato de alta performance à arquitetura da célula solar de CIGS ultrafino.ABSTRACT: The Nanofabrication for Optoelectronic Applications -NOA- group belongs to the International Iberian Nanotechnology Laboratory (INL), and has been focusing its investigation efforts on the development of high-performance substrates for Cu(In,Ga)Se2 (CIGS) solar cells. Through the incorporation of a dielectric passivation layer between the rear contact (Mo) and the CIGS layer, we are able to mitigate active recombination centers at the rear interface and the Mo parasitic optical absorption. In this manuscript the performance of two ultrathin CIGS solar cells are evaluated: one solar cell with a conventional architecture and a second solar cell with a substrate based on 18 nm SiOX point contact scheme. All figures of merit values are improved when the high-performance substrate is added to the solar cell architecture in comparison with the conventional ultrathin CIGS solar cell.info:eu-repo/semantics/publishedVersio