Publications by authors named "Renato Cordeiro"

Coastal sedimentary systems are affected by continental and marine metal pollutant inputs associated with different hydrodynamic characteristics and geochemical processes. These include the formation of acid-volatile sulfides (AVS) within sediments, which affects metal bioavailability and associated aquatic biota toxicity risks. Physicochemical changes in these environments in the face of extreme natural or man-made environmental influences can dramatically alter metal bioavailability and toxicity through metal binding and immobilization as insoluble sulfides.

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Forest fragments from Amazon are important long-term carbon (C) reservoirs with an essential role in the global C balance. They are often impacted by understory fires, deforestation, selective logging and livestock. Forest fires convert soil organic matter into pyrogenic carbon (PyC), but little is known about its distribution and accumulation along the soil profile.

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Dredging activities cause sediment resuspension, which can change the bioavailability of nutrients such as phosphorus (P) in aquatic ecosystems due to remobilization. This study evaluated the remobilization of P in the solid and dissolved phase before and after sediment resuspension in the Meriti and Iguaçu River estuaries and the Rio de Janeiro and Niterói harbor in Guanabara Bay (Rio de Janeiro, Brazil). Three water and sediment samples were collected at each point.

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Article Synopsis
  • - The study examines the microbial diversity in sediments from Airo Lake, a floodplain lake in the Amazon, using metagenomics and biogeochemical analysis to understand the impact of the Negro River on the lake's environment.
  • - Three sediment layers were analyzed, revealing distinct microbiomes: older, deeper sediments had a higher abundance of specific bacteria like Burkholderia, while more recent layers contained different microbes like Thermococcus, indicating changes over time.
  • - A significant number of metagenome-assembled genomes (MAGs) identified in the older strata are linked to unknown taxa, suggesting potential new species, and show enrichment in sulfur cycle genes, highlighting the complexity of microbial interactions in this ecosystem.
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Background: Gold nanoparticles (AuNPs) can inhibit pivotal pathological changes in experimental asthma, but their effect on steroid-insensitive asthma is unclear. The current study assessed the effectiveness of nebulized AuNPs in a murine model of glucocorticoid (GC)-resistant asthma.

Methods: A/J mice were sensitized and subjected to intranasal instillations of ovalbumin (OVA) once a week for nine weeks.

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  • A large amount of carbon captured by terrestrial plants is stored in lake sediments, but there's limited data on this process in tropical rainforest lakes affected by human activities.
  • Researchers collected new data from 13 lakes in remote Amazon regions and added existing literature to analyze organic carbon burial in these lakes over the last 50-100 years.
  • The study reveals that humid tropical forest lakes are significant carbon sinks, storing about 80 Tg of carbon per year and highlights the importance of temperature and forest conservation in preserving these carbon reserves.
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The sediment contamination by trace metals in coastal aquatic ecosystems is a worldwide environmental problem, since metals can be toxic, persistent, and bioaccumulated. In case of natural events, such as storms, or anthropogenic activities, like dredging, the sediment resuspension to the water column occurs and can solubilize metals, probably increasing their bioavailability and consequently the risk to aquatic life. This study evaluated the bioavailability on reactive trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in estuarine sediments from Iguaçu and Meriti Rivers, both in the drainage basin of Guanabara Bay (Rio de Janeiro, Brazil).

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The Abrolhos bank is home of the richest coral reef system of the Southwestern Atlantic, where endemic coral species are found. It has been reported that Abrolhos' corals are under intense stress due to increasing of Marine Heat Waves during the last decades. Additionally, anthropic interventions along the adjacent coastal regions are a factor of concern since they contribute to the increase in the sediment load and to organic debris input in the reef domain.

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A growing number of smart wearable biosensors are operating in the medical IoT environment and those that capture physiological signals have received special attention. Electrocardiogram (ECG) is one of the physiological signals used in the cardiovascular and medical fields that has encouraged researchers to discover new non-invasive methods to diagnose hyperglycemia as a personal variable. Over the years, researchers have proposed different techniques to detect hyperglycemia using ECG.

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Article Synopsis
  • The study investigates microbial diversity in marine sediments of Guanabara Bay, Brazil, using metagenomics and biogeochemical tools across various sediment depths.
  • Findings reveal that methanogens dominate at shallower depths (1 mbsf), while sulfate-reducing microbes are more prevalent in deeper layers (4 mbsf).
  • A novel microbial order called Guanabacteria was discovered, showcasing distinct genetic traits relevant to sulfur and carbon cycles, highlighting the complex interactions and adaptations of microbial communities in impacted ecosystems.
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Glucagon has been shown to be beneficial as a treatment for bronchospasm in asthmatics. Here, we investigate if glucagon would prevent airway hyperreactivity (AHR), lung inflammation, and remodeling in a murine model of asthma. Glucagon (10 and 100 µg/Kg, i.

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The importance of developing new animal models to assess the pathogenesis of glucocorticoid (GC)-insensitive asthma has been stressed. Because of the asthma-prone background of A/J mice, we hypothesized that asthma changes in these animals would be or become resistant to GCs under repeated exposures to an allergen. A/J mice were challenged with OVA for 2 or 4 consecutive d, starting on day 19 postsensitization.

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The study of the uptake and distribution of elements in marine environments is of great interest for understanding their pathways and accumulation. Here, we investigated in laboratory experiments the accumulation behavior of Cd in the sea anemone Bunodosoma caissarum and the mussel Perna perna. Specimens were incubated with isotopically enriched Cd in aquariums.

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Surface sediments were collected from Guanabara Bay, at 14 stations distributed in five sectors, over three sampling campaigns. Analyses of metals, grain size fractions and total organic carbon analyses were performed. The geo-accumulation index and the enrichment factor were estimated to assess contamination status based on background values.

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Background: TNF-α is a key cytokine involved in prostate carcinogenesis and is mediated by the TNF-α receptor type 1 (TNFR-1). This receptor triggers two opposite pathways: cell death or cell survival and presents a protective or stimulator role in cancer. Thus, the purpose of this study was to evaluate the role of TNF signaling in chemically induced prostate carcinogenesis in mice.

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Background: Inhaled lidocaine antagonized bronchospasm in animal models and patients, but adverse effects limited its efficacy. This study evaluated the antibronchospasm potential of the analog JM25-1, exploring in vitro mechanisms and translation to an animal model.

Methods: The effectiveness of JM25-1 was assessed in GH3 cells, rat tracheal rings, mouse lymphocytes, and human eosinophil systems in vitro, assessing changes in Na current, contraction, proliferation, and survival, respectively.

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Article Synopsis
  • Gold nanoparticles show potential in preventing allergic asthma by reducing inflammation and oxidative stress in murine models, highlighting their beneficial biological properties.
  • In experiments, both Swiss-Webster and A/J mice treated with gold nanoparticles before allergen exposure exhibited significant inhibition of inflammatory cell accumulation and cytokine production.
  • The study concludes that gold nanoparticles effectively prevented major asthma symptoms, such as airway hyper-reactivity and lung remodeling, possibly by lowering oxidative stress and inflammation in lung tissue.
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Mercury (Hg) has a complex biogeochemical cycle in aquatic environments. Its most toxic form, methylmercury (MeHg), is produced by microorganisms. This study investigated how the sea anemone Bunodosoma caissarum affects Hg distribution, methylation and volatilization in laboratory model systems.

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Background: Evidence suggests that nebulized lidocaine is beneficial in asthma therapy, but to what extent and the mechanisms underlying this effect remain poorly understood. The aim of this study was to assess the impact of lidocaine treatment using a murine model of allergic asthma characterized by expression of pivotal features of the disease: inflammation, mucus production, and lung remodeling.

Methods: A/J mice sensitized with ovalbumin were treated with inhaled lidocaine or vehicle immediately after ovalbumin intranasal challenges.

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Mast cell function and survival have been shown to be down-regulated under diabetic conditions. This study investigates the role of the peroxisome proliferator-activated receptor (PPAR)-γ in reducing mast cell number and reactivity in diabetic rats. The effect of rosiglitazone on mast cell apoptosis was also evaluated.

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Inhalation of JMF2-1, an analog of lidocaine with reduced anesthetic activity, prevents airway contraction and lung inflammation in experimental asthma models. We sought to test if the JMF2-1 effects are a consequence of increased intracellular cAMP levels in asthma cell targets, such as smooth muscle cells and T cells. Functional effect of JMF2-1 on carbachol-induced contraction of intact or epithelial-denuded rat trachea was assessed in conventional organ baths.

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