EM - Escola de Minas

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6

Notícias

A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.

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20222

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Autor: search.filters.author.Freitas, Erico Tadeu Fraga

Resultados da Pesquisa

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    Equisetum hyemale‑derived unprecedented bioactive composite for hard and soft tissues engineering.
    (2022) Silva, Rosangela Maria Ferreira da Costa e; Diniz, Ivana Márcia Alves; Gomes, Natália Aparecida; Silva, Guilherme Jorge Brigolini; Ferreira, José Maria da Fonte; Freitas Filho, Rubens Lucas de; Freitas, Erico Tadeu Fraga; Martins, Darliane Aparecida; Domingues, Rosana Zacarias; Andrade, Ângela Leão
    Although Bioactive Glasses (BGs) have been progressively optimized, their preparation often still involves the use of toxic reagents and high calcination temperatures to remove organic solvents. In the present work, these synthesis related drawbacks were overcome by treating the ashes from the Equisetum hyemale plant in an ethanol/water solution to develop a bioactive composite [glass/ carbon (BG-Carb)]. The BG-Carb was characterized by scanning electron microscopy, and transmission electron microscopy; and its chemical composition was assessed by inductively coupled plasmaoptical emission spectroscopy. Brunauer–Emmett–Teller gas adsorption analysis showed a specifc surface area of 121 m2 ­g−1. The formation of hydroxyapatite (HA) surface layer in vitro was confrmed by Fourier-transform infrared spectroscopy analysis before and after immersion in simulated body fuid (SBF) solution. The Rietveld refnement of the XRD patterns and selected area electron difraction analyses confrmed HA in the sample even before immersing it in SBF solution. However, stronger evidences of the presence of HA were observed after immersion in SBF solution due to the surface mineralization. The BG-Carb samples showed no cytotoxicity on MC3T3-E1 cells and osteodiferentiation capacity similar to the positive control. Altogether, the BG-Carb material data reveals a promising plant waste-based candidate for hard and soft tissue engineering.
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    Ultrastructure of the gill ciliary epithelium of Limnoperna fortunei (Dunker 1857), the invasive golden mussel.
    (2022) Freitas, Erico Tadeu Fraga; Moreira, Amanda Maria Siqueira; Paula, Rayan Silva de; Andrade, Gabriela Rabelo; Carvalho, Marcela David de; Assis, Paulo Santos; Jorge, Erika Cristina; Cardoso, Antônio Valadão
    Background: Limnoperna fortunei is a freshwater bivalve mollusc originally from southern Asia that invaded South America in the 1990’s. Due to its highly efcient water pumping and fltering, and its capacity to form strong adhe- sions to a variety of substrates by byssus thread, this invasive species has been able to adapt to several environments across South America, causing signifcant ecological and economic damages. By gaining a deeper understanding of the biological and ecological aspects of L. fortunei we will be able to establish more efective strategies to manage its invasion. The gills of the mollusc are key structures responsible for several biological functions, including respiration and feeding. In this work, we characterized the ultrastructure of L. fortunei gills and its ciliary epithelium using light microscopy, transmission and scanning electron microscopies. This is the frst report of the morphology of the epithe- lial cells and cilia of the gill of L. fortunei visualized in high resolution. Results: The analysis showed highly organized and abundant ciliary structures (lateral cilia, laterofrontal cirri and fron- tal cilia) on the entire length of the branchial epithelium. Mitochondria, smooth endoplasmic reticulum and glycogen granules were abundantly found in the epithelial cells of the gills, demonstrating the energy-demanding function of these structures. Neutral mucopolysaccharides (low viscosity mucus) were observed on the frontal surface of the gill flaments and acid mucopolysaccharides (high viscosity mucus) were observed to be spread out, mainly on the lateral tract. Spherical vesicles, possibly containing mucus, could also be observed in these cells. These fndings demonstrate the importance of the mucociliary processes in particle capture and selection. Conclusions: Our data suggest that the mechanism used by this mollusc for particle capture and selection could contribute to a better understanding of key aspects of invasion and also in the establishment of more efcient and economically viable strategies of population control.