24 research outputs found
ESTUDOS DO PROCESSO DE QUEIMA DA CERÂMICA PRÉ-HISTORICA DO SÍTIO ARQUEOLÓGICO SERRA DO EVARISTO I – BATURITÉ-CE/BRASIL.
Essa pesquisa analisa o processo de queima da cerâmica pré-histórica do sítio arqueológico Serra do Evaristo I, localizado no município de Baturité, no estado do Ceará, na região Nordeste do Brasil. Na análise deste material verificou-se uma variação na coloração da cerâmica que pode indicar diferentes processos de queima. Entretanto, no contexto pré-histórico e etno-histórico dos grupos, no Nordeste do Brasil, as informações apontam para utilização apenas da queima em atmosfera oxidante. Desta forma questiona-se se essa variação estaria relacionada a diferentes processos de produção da cerâmica ou a diferentes tipos de argila. Para este objetivo foram realizadas análises petrográficas e aplicada a técnicas de difratrometria por Raios-X (RXD), que demonstraram através dos resultados que os ceramistas da Serra do Evaristo I utilizavam argilas de dois depósitos distintos e que poderiam misturar os dois tipos de argilominerais de acordo com o tipo de vasilha a ser produzida
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
Physiological implications of trehalose in the ectomycorrhizal fungus Pisolithus sp. under thermal stress
The trehalose cycle in filamentous fungi has been suggested to be an important mechanism of tolerance against adverse stress conditions, particularly in thermal stress. Here, we demonstrate that trehalose and trehalase activity can be involved as an additional mechanism in development of thermotolerance in Pisolithus sp. In response to heat shock at 42 °C, an accumulation of intracellular trehalose and an increase in trehalase activity in the mycelial mass of the fungus was observed, when compared to the control treatment (28 °C). In vitro, assays showed that trehalose had a protective effect on β-glucosidase activity under thermal stress. Therefore, trehalose production may be an important mechanism of protection in ectomycorrhizal fungi, and this capacity could be used in the selection of isolates with greater capacity for adaptation to environmental stress
Epulorhiza epiphytica sp. nov. isolated from mycorrhizal roots of epiphytic orchids in Brazil
Epulorhiza epiphytica sp. nov. isolated from the roots of two Brazilian native epiphytic orchid species is described. In culture, it differs from the known species of Epulorhiza in the minute size of monilioid cells with foveate surfaces. This is the first report of an orchid mycorrhizal fungus from Brazil