1,679 research outputs found

    Co-exposure of the organic nanomaterial fullerene C60 with benzo[a]pyrene in Danio rerio (zebrafish) hepatocytes: Evidence of toxicological interactions

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    Compounds from the nanotechnology industry, such as carbon-based nanomaterials, are strong candidates to contaminate aquatic environments because their production and disposal have exponentially grown in a few years. Previous evidence shows that fullerene C60, a carbon nanomaterial, can facilitate the intake of metals or PAHs both in vivo and in vitro, potentially amplifying the deleterious effects of these toxicants in organisms. The present work aimed to investigate the effects of fullerene C60 in a Danio rerio (zebrafish) hepatocyte cell lineage exposed to benzo[a]pyrene (BaP) in terms of cell viability, oxidative stress parameters and BaP intracellular accumulation. Additionally, a computational docking was performed to investigate the interaction of the fullerene C60 molecule with the detoxificatory and antioxidant enzyme πGST. Fullerene C60 provoked a significant (p 0.05) alter the enzyme activity when added to GST purified extracts from the zebrafish hepatocyte cells. These results show that fullerene C60 can increase the intake of BaP into the cells, decreasing cell viability and impairing the detoxificatory response by phase II enzymes, such as GST, and this latter effect should be occurring at the transcriptional level.Fil: Ribas Ferreira, Josencler L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lonné, María Noelia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: França, Thiago A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Maximilla, Naiana R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lugokenski, Thiago H.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: Costa, Patrícia G.. Universidade Federal do Rio Grande do Sul; BrasilFil: Fillmann, Gilberto. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, Félix A.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: de la Torre, Fernando Roman. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Monserrat, José María. Universidade Federal do Rio Grande do Sul; Brasil. Instituto Nacional de Ciência e Tecnologia de Nanomateriais de Carbono; Brasi

    Molecular recognition of an acyl–enzyme intermediate on the lipase B from <i>Candida antarctica</i>

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    This investigation provides evidence of the acyl enzyme species involved in the interaction of R/Sketoprofen with the lipase B from Candida antarctica. The interaction between the profen and the enzyme was studied by in situ time-resolved ATR-FTIR under both static and transient conditions. Particularly, modulation excitation spectroscopy (MES) with phase sensitive detection (PSD) allowed us to univocally distinguish the signals belonging to the interaction between ketoprofen and the enzyme from the strong background signals. These experimental tools coupled with theoretical DFT analysis allowed us to propose various species derived from the interaction of ketoprofen with serine through H bonding (without reaction) and the acyl enzyme species (ester bond formation) which are the intermediates in the biocatalytic assisted esterification and hydrolysis using lipases.Centro de Investigación y Desarrollo en Ciencias AplicadasFacultad de Ciencias Exacta

    Biting midges (Diptera: Ceratopogonidae) from an urban forest fragment in Central Amazon (Brazil): Effects of opening areas on abundance, richness, and composition

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    We assessed the immature stages of Ceratopogonidae (Diptera) in artificial containers in an urban forest fragment in Manaus (Brazil), including their behavioral, biological and ecological information. In addition, we evaluated the effects of deforestation in an open and forested area on Ceratopogonidae communities. Immatures were sampled between August 2012 and July 2014 in artificial containers installed in both habitat types. We collected 685 immatures of seven morpho-species of Bezzia Kieffer, Culicoides Latreille, Dasyhelea Kieffer, Forcipomyia Meigen, and Palpomyia Meigen. In the open area, we recorded higher temperature and electrical conductivity values than in the forested area; however, these variables did not differ between seasons. Water volume was higher in open area and in rainy season, while pH was similar in both areas and seasons. Species richness was higher in forested area, but did not differ between seasons. We did not record differences in abundance between areas or seasons. Community composition differed between areas, but not between seasons. We provide the first records of Culicoides (Hoffmania) insignis Lutz and C. (Haematomyidium) quasiparaensis Clastrier in artificial containers from the state of Amazonas. Our results suggest that the preservation of forested areas in Amazonas is fundamental for the maintenance of the life cycle of some species of Ceratopogonidae.Centro de Estudios Parasitológicos y de VectoresFacultad de Ciencias Naturales y Muse

    Multigene germline testing usefulness instead of BRCA1/2 single screening in triple negative breast cancer cases

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    Producción CientíficaTriple negative breast cancer is considered as the worst aggressive subtype with poor prognosis. Recent studies suggest a hereditary component is involve in TNBC development, especially in young patients. However, genetic spectrum remains unclear. Our purpose was to evaluate the usefulness of multigene panel testing in triple negative patients respect overall breast cancer cases as well as contributing to elucidate which genes are most implicated in TNBC development with respect to the remaining breast cancer subtypes. A breast cancer patients sample comprised of 100 triple negative breast cancer patients and 100 other breast cancer subtypes patients were analyzed by Next-Generation Sequencing using an On-Demand panel which included 35 predisposition cancer genes associated with inherited cancer susceptibility. Triple negative breast cancer patients obtained a higher percentage of germline variant carriers. ATM, PALB2, BRIP1 and TP53 were the most non-BRCA mutated genes. Moreover, triple negative breast cancer patients without family history related which proved to be carriers were diagnosed at significant earlier age. As conclusion, our study reinforces the usefulness of multigene panel testing in breast cancer cases but specifically in those with triple negative subtype regardless family history.Junta de Castilla y León. Dirección Regional de Salud de Castilla y León (GRS/2180/A/2020 y GRS/2351/A/2021

    Description of Culicoides (Mataemyia) felippebauerae sp. n., Forcipomyia musae immatures, and occurrence of F. genualis, breeding in banana stems in Brazilian Amazonia (Diptera: Ceratopogonidae)

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    The following three species of Ceratopogonidae were collected breeding in the rhizomatous herb Phenakospermum guyannense Endl., 1833 in the vicinity of Manaus, Brazil, a new species, Culicoides (Mataemyia) felippebauerae Spinelli, Forcipomyia (Forcipomyia) genualis (Loew), and F. (Phytohelea) musae Clastrier & Dellécole. C. (M.) felippebauerae is described and illustrated as adult, pupa, and fourth instar larva, the adult compared with the adult of C. barthi Taveres and Souza and larva and pupa with those of C. dicrourus Wirth & Blanton and C. macieli Tavares & Ruiz, the only species with known immatures in the subgenus. The pupa and fourth instar larva of F. (P.) musae are described and illustrated and compared with immatures of F. (P.) edwardsi Saunders.Facultad de Ciencias Naturales y Museo (FCNM

    Description of Culicoides (Mataemyia) felippebauerae sp. n., Forcipomyia musae immatures, and occurrence of F. genualis, breeding in banana stems in Brazilian Amazonia (Diptera: Ceratopogonidae)

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    The following three species of Ceratopogonidae were collected breeding in the rhizomatous herb Phenakospermum guyannense Endl., 1833 in the vicinity of Manaus, Brazil, a new species, Culicoides (Mataemyia) felippebauerae Spinelli, Forcipomyia (Forcipomyia) genualis (Loew), and F. (Phytohelea) musae Clastrier & Dellécole. C. (M.) felippebauerae is described and illustrated as adult, pupa, and fourth instar larva, the adult compared with the adult of C. barthi Taveres and Souza and larva and pupa with those of C. dicrourus Wirth & Blanton and C. macieli Tavares & Ruiz, the only species with known immatures in the subgenus. The pupa and fourth instar larva of F. (P.) musae are described and illustrated and compared with immatures of F. (P.) edwardsi Saunders

    Wave Attenuation by Spartina Saltmarshes in the Chesapeake Bay Under Storm Surge Conditions

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    This material is based upon work supported by the National Fish and Wildlife Foundation and the U.S. Department of the Interior under grant 43932.This material is also based upon work supported by the National Science Foundation under grant SES‐1331399.This research was also supported in part by the Thomas F. and Kate Miller Jeffress Memorial Trust, Bank of America, Trustee. M. Maza, J.L. Lara, and I.J. Losada are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided in the RETOS INVESTIGACION 2014 (grant BIA2014‐59718‐R) grant program

    Preliminary Study of Recycled Aggregate Mortar for Electric Arc Furnace Dust Encapsulation

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    This article shows the preliminary results of a study carried out to determine the technical feasibility of encapsulating a high percentage of EAFD in cement-based mortars manufactured with the fine fraction of recycled concrete aggregates (RCA). Two families of mortars, with natural aggregate as a reference and with RCA, were studied. An incorporation rate by weight of two parts mortar to one part EAFD was tested. The mechanical strengths (compressive strength and tensile strength) before and after immersion in water, the rate of delitescence and the leaching behavior were studied. Mortars made with RCA showed similar mechanical strengths to the reference mortars made with natural aggregates; however, the incorporation of EAFD decreased the mechanical strengths. Encapsulation considerably reduced the leaching of heavy metals, although the Pb concentration remained above the hazardous waste limit. With this preliminary study, two wastes are managed together, and the results have shown that the use of RCA instead of natural aggregate is a viable alternative since it does not significantly impair the mechanical or leaching properties of the cement-based matrices used to encapsulate EAFD
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