Publications by authors named "Abraao T B Guimaraes"

The increasing use of cellulose-based materials (CBMs) has provided beneficial applications in different sectors. However, its release into environments may represent an ecological risk, therefore demanding that ecotoxicological studies be conducted to understand the risks (current and future) of CBM pollution. Thus, we evaluated the possible effects of microcrystalline cellulose (CMs) in Physalaemus cuvieri tadpoles.

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Although the ecotoxicity of carbon-based nanomaterials (CBNs) is known, the potential effect of carbon nanofibers (CNFs) on edaphic organisms has been insufficiently explored. Thus, we aimed at the ecotoxicity of CNFs (at 10 and 100 mg/kg) in Lumbricus terrestris earthworms naturally infected with Monocystis sp. After 28 days of exposure, treatments did not affect the survival rate.

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The growing use of synthetic chemical compounds/substances in vector control of mosquitoes, associated with their adverse effects on the environment and non-target organisms, has demanded the development of eco-friendly alternatives. In this context, this study aimed to evaluate the larvicidal action of different cellulose microcrystalline (CMs) concentrations and investigate their toxicity mechanisms in Culex quinquefasciatus fourth instar larvae as a model species. Probit analysis revealed that the median lethal concentrations (LC) for 24 h and 36 h exposure were 100 and 58.

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The COVID-19 pandemic has caused unprecedented negative impacts in the modern era, including economic, social, and public health losses. On the other hand, the potential effects that the input of SARS-CoV-2 in the aquatic environment from sewage may represent on non-target organisms are not well known. In addition, it is not yet known whether the association of SARS-CoV-2 with other pollutants, such as microplastics (MPs), may further impact the aquatic biota.

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While the multifaceted social, economic, and public health impacts associated with the COVID-19 pandemic are known, little is known about its effects on non-target aquatic ecosystems and organisms. Thus, we aimed to evaluate the potential ecotoxicity of SARS-CoV-2 lysate protein (SARS.CoV2/SP02.

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Although carbon-based nanomaterials (CNMs) toxicity has already been demonstrated in some animal models, little is known about the impact of carbon nanofibers (CNFs) on aquatic vertebrates. Thus, we aimed to evaluate the possible effects of long-term exposure of zebrafish (Danio rerio) juveniles (90 days) to CNFs in predicted environmentally relevant concentrations (10 ng/L and 10 μg/L). Our data revealed that exposure to CNFs did not affect the growth and development of the animals, in addition to not having induced locomotor alterations or anxiety-like behavior.

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We aimed to evaluate the possible effects of the application of zinc oxide nanoparticles [ZnO NPs; 68.96 ± 33.71 nm; at 100 and 500 mg/kg in a soil mixture of the Typic Dystrophic Red Latosol type and sand (2:1 ratio)] in the cultivation of Panicum maximum (until 125 days), using different biomarkers in addition to evaluating the uptake of Zn by the plants.

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More recently, the number of studies on the impacts of microplastics (MPs) on plants has drawn attention considerably. However, many of these studies focused on terrestrial plants, with vascular plants from freshwater ecosystems being little studied. Thus, we aimed to evaluate the possible effects of exposure of Salvinia auriculata, for 28 days, to different concentrations of polyethylene MPs (PE MPs - diameter: 35.

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Although the ecotoxicological effects of ZnO nanoparticles (ZnO NPs) have already been reported in different taxa, little is known about their impacts on amphibians. Thus, we aimed to evaluate the potential effects of exposure of Physalaemus cuvieri tadpoles to substrates enriched with ZnO NPs (and with its ionic counterpart, Zn, ZnCl - both at 100 mg/kg) previously used in the cultivation of Panicum maximum (Guinea grass). We showed that although exposure for 21 days did not impact the survival, growth, and development of tadpoles, we noted an increase in the frequency of erythrocyte nuclear abnormalities in the "ZnCl" and "ZnONP" groups, which was associated with suppression of antioxidant activity in the animals (inferred by SOD and CAT activity and DPPH free radical scavenging capacity).

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The dispersion of SARS-CoV-2 in aquatic environments via the discharge of domestic and hospital sewage has been confirmed in different locations. Thus, we aimed to evaluate the possible impacts of zebrafish (Danio rerio) exposure to SARS-CoV-2 peptide fragments (PSPD-2001, 2002, and 2003) alone and combined with a mix of emerging pollutants. Our data did not reveal the induction of behavioral, biometric, or mutagenic changes.

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Although the in vivo toxicity of nanoplastics (NPs) has already been reported in different model systems, their effects on mammalian behavior are poorly understood. Thus, we aimed to evaluate whether exposure to polystyrene (PS) NPs (diameter: 23.03 ± 0.

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The input of SARS-CoV-2 or its fragments into freshwater ecosystems (via domestic or hospital sewage) has raised concerns about its possible impacts on aquatic organisms. Thus, using mayfly larvae [Cloeon dipterum (L.), Ephemeroptera: Baetidae] as a model system, we aimed to evaluate the possible effects of the combined short exposure of SARS-CoV-2-derived peptides (named PSPD-2001, PSPD-2002, and PSPD-2003 - at 266.

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The identification of SARS-CoV-2 particles in wastewater and freshwater ecosystems has raised concerns about its possible impacts on non-target aquatic organisms. In this particular, our knowledge of such impacts is still limited, and little attention has been given to this issue. Hence, in our study, we aimed to evaluate the possible induction of mutagenic (via micronucleus test) and genotoxic (via single cell gel electrophoresis assay, comet assay) effects in Poecilia reticulata adults exposed to fragments of the Spike protein of the new coronavirus at the level of 40 μg/L, denominated PSPD-2002.

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Steel wool (SW) has a broad-spectrum of applicability, particularly as abrasives, cleaning household utensils and surfaces in general. However, when present in the natural environment, they can be ingested by animals, such as birds, and may represent a risk to the survival of individuals. Accordingly, in this study, we attempted the hypothesis that the ingestion of SW microfibers (SWMs) by Gallus gallus domesticus chicks (model system used) alters growth/development, induces redox imbalance and cholinesterasic effect, as well as promotes iron overload in different organs.

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For our knowledge, the roadside soils end up being the deposit of various residues discarded by drivers or passengers, plus, that coming from the runoff of rainwater. Basically, we do not know the impacts that this pollution causes on animals which inhabit these environments. Thus, in this study, our objective was to evaluate how the presence of plastic microfibers (MPFs), organic compounds and heavy metals affect the redox and cholinesterase homeostasis of mound-building termite [Cornitermes cumulans (workers) adults].

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Although the toxicity of conventional microplastic types (i.e., petroleum derivatives) in different organisms is already known, knowledge about the effects of alternative biopolymers on aquatic vertebrates remains incipient.

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