425 research outputs found

    Biosurfactants : microbiology and biotechnology

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    Effect of synthesis temperature on crystallinity, morphology and cell viability of nanostructured hydroxyapatite via wet chemical precipitation method: Effect of temperature on hydroxyapatite properties

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    Hydroxyapatite (HA) is the main natural mineral constituent of bones and is a good alternative for biomedical applications because it is osteoconductive, non-allergenic, and non-carcinogenic, which ensures high biocompatibility. A commonly used method for obtaining hydroxyapatite is the wet route, which is simple and low-cost, produces only water as a final residue, and provides HA with a crystallinity comparable to that of bone tissue, which favors its biocompatibility. Therefore, the objective of this work is to synthesize hydroxyapatite via the wet chemical precipitation method at different temperatures (4°C, 30°C, 50°C, or 70°C) to observe the influence of temperature on crystallinity, morphology, and cytotoxicity. The results of X-ray diffraction show that all syntheses resulted in pure hydroxyapatite, while increasing the temperature led to higher crystallinity (10.6% to 56.2%) and the crystal size was slightly affected. The increase in temperature changed the particle shape from irregular to needle-like. Cell viability was tested by PicoGreen® in VERO cells for samples at concentrations of 30 and 300µg/mL, and the samples synthesized at 4°C, with lower crystallinity, caused less DNA damage to cells compared to the negative control. &nbsp

    Capturing a soil carbon economy

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    Current carbon pricing and trading mechanisms, despite their efficacy in reducing GHG emissions from industry, will not be sufficient to achieve Net Zero targets. Current mechanisms that redress emissions are largely economic disincentives, in effect financial penalties for emitters. In order to attain Net Zero futures, financial incentives for activities that sequester carbon from the atmosphere are needed. Herein, we present the environmental and economic co-benefits of soil re-carbonization and justify support for soil carbon remuneration. With increasing momentum to develop green economies, and projected increases in carbon price, growth in the global carbon market is inevitable. The establishment of a soil-based carbon economy, within this emerging financial space, has the potential to deliver a paradigm shift that will accelerate climate change mitigation, and concurrently realize net gains for soil health and the delivery of soil ecosystem services. Pivotal to the emergence of a global soil carbon economy will be a consensus on certification instruments used for long-term soil carbon storage, and the development of robust institutional agreements and processes to facilitate soil carbon trading

    Cerebral malaria model applying human brain organoids

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    Neural injuries in cerebral malaria patients are a significant cause of morbidity and mortality. Nevertheless, a comprehensive research approach to study this issue is lacking, so herein we propose an in vitro system to study human cerebral malaria using cellular approaches. Our first goal was to establish a cellular system to identify the molecular alterations in human brain vasculature cells that resemble the blood–brain barrier (BBB) in cerebral malaria (CM). Through transcriptomic analysis, we characterized specific gene expression profiles in human brain microvascular endothelial cells (HBMEC) activated by the Plasmodium falciparum parasites. We also suggest potential new genes related to parasitic activation. Then, we studied its impact at brain level after Plasmodium falciparum endothelial activation to gain a deeper understanding of the physiological mechanisms underlying CM. For that, the impact of HBMEC-P. falciparum-activated secretomes was evaluated in human brain organoids. Our results support the reliability of in vitro cellular models developed to mimic CM in several aspects. These systems can be of extreme importance to investigate the factors (parasitological and host) influencing CM, contributing to a molecular understanding of pathogenesis, brain injury, and dysfunction.This research was funded by National funds through the Foundation for Science and Technology (FCT) SFRH/BD/131540/2017, SFRH/BD/5813/2020, COVID/BD/152416/2022 and UMINHO/BIM-CNCG/2022/143. This work has been funded by ICVS Scientific Microscopy Platform, member of the national infrastructure PPBI - Portuguese Platform of Bioimaging (PPBIPOCI-01-0145-FEDER-022122; by National funds, through the FCT—project UIDB/50026/2020 and UIDP/50026/2020. Moreover, this work was funded by IF/00143/2015/CP1294/CT0001, PTDC/SAU-PAR/2766/2021 and UIDB/04469/2020. O.M. is funded by the project NORTE-01- 0247-FEDER-045914, supported by POFC–COMPETE and FCT, under the programs PT2020 and NORTE2020. M.I.V. thanks FCT for her contract funding provided through 2020.03113.CEECIND.info:eu-repo/semantics/publishedVersio

    A Secreted NlpC/P60 Endopeptidase from Photobacterium damselae subsp. piscicida Cleaves the Peptidoglycan of Potentially Competing Bacteria

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    Peptidoglycan (PG) is a major component of the bacterial cell wall, forming a mesh-like structure enwrapping the bacteria that is essential for maintaining structural integrity and providing support for anchoring other components of the cell envelope. PG biogenesis is highly dynamic and requires multiple enzymes, including several hydrolases that cleave glycosidic or amide bonds in the PG. This work describes the structural and functional characterization of an NlpC/P60-contain-ing peptidase from Photobacterium damselae subsp. piscicida (Phdp), a Gram-negative bacterium that causes high mortality of warm-water marine fish with great impact for the aquaculture industry. PnpA (Photobacterium NlpC-like protein A) has a four-domain structure with a hydrophobic and narrow access to the catalytic center and specificity for the γ-D-glutamyl-meso-diaminopimelic acid bond. However, PnpA does not cleave the PG of Phdp or PG of several Gram-negative and Gram-positive bacterial species. Interestingly, it is secreted by the Phdp type II secretion system and degrades the PG of Vibrio anguillarum and Vibrio vulnificus. This suggests that PnpA is used by Phdp to gain an advantage over bacteria that compete for the same resources or to obtain nutrients in nutrient-scarce environments. Comparison of the muropeptide composition of PG susceptible and resistant to the catalytic activity of PnpA showed that the global content of muropeptides is similar, suggesting that susceptibility to PnpA is determined by the three-dimensional organization of the muropeptides in the PG. IMPORTANCE Peptidoglycan (PG) is a major component of the bacterial cell wall formed by long chains of two alternating sugars interconnected by short peptides, generating a mesh-like structure that enwraps the bacterial cell. Although PG provides structural integrity and support for anchoring other components of the cell envelope, it is constantly being remodeled through the action of specific enzymes that cleave or join its components. Here, it is shown that Photobacterium damselae subsp. piscicida, a bacterium that causes high mortality in warm-water marine fish, produces PnpA, an enzyme that is secreted into the environment and is able to cleave the PG of potentially competing bacteria, either to gain a competitive advantage and/or to obtain nutrients. The specificity of PnpA for the PG of some bacteria and its inability to cleave others may be explained by differences in the structure of the PG mesh and not by different muropeptide composition.Europeu de Desenvolvimento Regional (FEDER) funds through the COMPETE 2020 Operacional Program for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior and Fundação para a Ciência e a Tecnologia (FCT), I.P., within the scope of the Norma Transitória - DL57/2016/CP1355/CT0010. This work had also support from the State Agency for Research (AEI) of Spain cofunded by the FEDER Program from the European Union (grants AGL2016-79738-R and BIO2016-77639-P

    Trenzado y alfabetizaciones: informes de un proyecto de Investigación y Práctica Pedagógica en la Escuela Tupinikim de Aldeia Comboios - Aracruz/ES

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    O presente relato nasce de um projeto pedagógico desenvolvido na Aldeia Tupinikim de Comboios, município de Aracruz- ES, durante a disciplina Projetos de Pesquisa e Prática Pedagógica – PPPP III, no curso de Licenciatura Intercultural Indígena Tupinikim e Guarani, do Programa de Licenciaturas Indígenas – PROLIND, oferecido pela Universidade Federal do Espírito Santo – UFES. O projeto teve como objetivos: Pesquisar com os mais velhos os tipos de trançados, colaborando na reafirmação cultural do nosso povo Tupiniquim; Reconhecer os tipos de trançados Tupiniquim; Confeccionar alguns tipos de trançados; Produzir textos coletivos a partir dos trançados e analisar o processo de letramento a partir de atividades contextualizadas. O projeto se apoiou metodologicamente na pesquisa-ação com intuito de identificar as técnicas e manuseios dos trançados Tupinikim, construindo momentos de partilhas com os anciãos e intercâmbios entre outras aldeias Tupinikim. Palavras-chave: Trançados; Letramentos; Povo Tupinkim; PROLIND.The present report is born from a pedagogical project developed in the Tupinikim Village of Comboios, municipality of Aracruz-ES, during the discipline Projects of Research and Pedagogical Practice - PPPP III, in the course of Indigenous Licentiate Tupinikim and Guarani, PROLIND, offered by the Federal University of Espírito Santo - UFES. The project had as objectives: To research with the older the types of braids, collaborating in the cultural reaffirmation of our Tupiniquim people; Recognize the types of Tupiniquim braids; Make some types of braids; Produce collective texts from the braids and analyze the process of literacy from contextualized activities. The project was methodologically based on action research in order to identify the techniques and manipulations of the Tupinikim braids, building moments of sharing with the elders and exchanges among other Tupinikim villages. Keywords: Braided; Lettering; Tupinkim people; PROLIND.Este informe es el resultado de un proyecto pedagógico desarrollado en la aldea Tupinikim de Comboios, municipio de Aracruz-ES, durante la disciplina Proyectos de investigación y práctica pedagógica - PPPP III, en el curso de licenciatura intercultural indígena Tupinikim y Guaraní, del Programa de licenciatura indígena - PROLIND, ofrecido por la Universidad Federal de Espírito Santo - UFES. El proyecto tenía como objetivos: investigar con los ancianos los tipos de trenzas, colaborando en la reafirmación cultural de nuestra gente tupiniquim; Reconocer los tipos de Tupiniquim trenzado; Hacer algunos tipos de trenzas; Produzca textos colectivos basados ​​en los hilos y analice el proceso de alfabetización basado en actividades contextualizadas. El proyecto se basó metodológicamente en la investigación de acción para identificar las técnicas y el manejo de las trenzas Tupinikim, creando momentos de intercambio con los ancianos e intercambios entre otras aldeas Tupinikim.Palabras clave: trenzado; Alfabetizaciones; Pueblo tupinkim; PROLIND
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