147 research outputs found

    Effect of zeolite nanomaterials in methanogenic communities

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    Recently, the application of zeolite structures in methanogenic communities has attracted significant attention, since they may enhance the anaerobic digestion process, by affecting specifically the methanogenic activity of the sludges1. Zeolites are solid inorganic crystalline materials comprised of silicon, aluminum and oxygen in the three-dimensional structure. The building blocks become arranged in a periodic way to form channels and cages on a nano- and subnanometer scale of strictly regular dimensions, named micropores. The presence of the aluminum in the zeolite framework create a negative charge in the lattice, which can be balanced by the exchangeable cations, as sodium or metal ions.2 In this study, commercial zeolite structures (ZSM5, USY, NaX and NaY) with different particle sizes and different exchangeable cations (Co, Cu, Zn, Fe) were used in order to investigate their effect towards the specific methanogenic activity, both acetoclastic and hydrogenotrophic, of anaerobic sludge. In the acetoclastic methanogenic activity, NaY modified with Cobalt (CoY) decreased the activity in comparison with the control (without zeolite). The remaining zeolites (ZSM5, USY, NaX and NaY), even when modified with metal ions (Zn, Fe, Cu), seems to have no effect on this methanogenic pathway. On the other hand, the hydrogenotrophic methanogenesis was improved by the presence of NaY (109 %), which did not happen in the presence of ZSM5 and USY zeolites. Additionally, the effect of different zeolite concentration was accessed. Overall, the increase of zeolite concentration from 1 g/L to 5 g/L resulted in a higher inhibition towards the methanogenic activity. In addition, the application of these nanomaterials can be evaluated in pure cultures of methanogens, in order to understand and fine-tune the best zeolite nanomaterial concentration that may improve the specific methanogenic activity.We thank the Fundação para a Ciência e Tecnologia (FCT) for financial support through Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016) and BioTecNorte (operation NORTE-01-0145-FEDER-000004), and through Centre of Biological -engineering (UIDB/04469/2020 unit). Cátia S. N. Braga holds a grant SFRH/BD/132003/2017 funded by FCT and European Union (EU), through the Portuguese State Budget and the European Social Fund under the scope of Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    Health-related quality of life and associated factors: regional differences among oldest-old in Brazil

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    © 2022 The Authors. Published by SAGE. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1177/00469580221086922Purpose: The aim of this research was to investigate the extent to which socioeconomic and regional differences in Brazil may influence the quality of life. To this end, we examined factors associated with health-related quality of life in two populations of oldest-old people, aged 80 and over: one from the Northeast of Brazil and the other from the Southeast. Methods: 417 participants aged 80 and over were interviewed face-to-face, 179 from Brejo dos Santos, one of the poorest regions in the Northeast; and 238 from São Paulo, one of the largest urban metropolises in Southeast Brazil. Data, which included socioeconomic and demographic factors, health status, and health-related quality of life, were collected using a structured questionnaire. The dependent variable was determined by the completion rate of the 12-item Short Form Survey and analyzed using Pearson correlation and multiple logistic regression. Results: Although the population of São Paulo had four times as many long-lived women than men, had better literacy levels, used more medications, and presented a greater prevalence of symptoms suggestive of depression in comparison to the Northeast’s population, no difference was observed in the proportion of good physical components among the two populations, 54.3% in Brejo dos Santos’ oldest-old and 50.4% in São Paulo’s (p=0.6272). Quality and quantity of sleep were factors that most affected the quality of life among the oldest-old of Northeast. Conclusion: Factors associated with health-related quality of life were different among the oldest-old people of the two locations, thereby corroborating the heterogeneous nature of the oldest-old population

    Pervasive gaps in Amazonian ecological research

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