Aspectos deposicionais, diagenéticos e estratigráficos de microfácies da Formação Riachuelo, Albiano, Bacia de Sergipe, Brasil

As rochas da Formação Riachuelo, Bacia de Sergipe, Brasil, representam um exemplo de sedimentação carbonática relacionada à fase drift, durante a abertura do oceano Atlântico Sul. As pedreiras Carapeba e Brejo exibem os melhores afloramentos onshore da seção carbonática drift em toda margem continental brasileira. Estudos de campo e análises microfaciológicas da seção sedimentar aflorante evidenciaram seis tipos de depósitos sedimentares relacionados à fisiografia de uma plataforma carbonática. Depósitos proximais mistos são representados por dolomitos ricos em terrígenos. Níveis alternados de arenitos e siltitos são aqui relacionados às fácies distais de leques subaquosos. Mudstones com miliolídeos e textularídeos representam ambiente lagunar em plataforma média, semirrestrita. Packstones, grainstones e eventualmente wackestones com oncólitos, intraclastos e peloides representam depósitos sedimentares relacionados à retaguarda de bancos arenosos rasos e ambientes na interface com a laguna. Grainstones com oólitos, oncólitos, intraclastos e bioclastos, com estratificação cruzada acanalada, representam ambiente de shoreface sobre o banco carbonático raso na plataforma externa. Os cimentos e outras feições pós-deposicionais observadas sugeriram diagênese progressiva em quatro ambientes diagenéticos: a) marinho freático com circulação de águas; b) marinho freático com água estagnada; c) meteórico freático; d) ambiente de soterramento. Os pacotes sedimentares formam ciclos de rasamento ascendente, sobrepostos no topo por uma provável superfície transgressiva, o que pode indicar a passagem de um trato de sistema de mar baixo para um trato de sistema transgressivo. _________________________________________________________________________________________ ABSTRACT: The rocks of the Riachuelo Formation, Sergipe Basin, Brazil, represent an example of carbonate sedimentation related to the drift phase during the opening of the South Atlantic Ocean. The Carapeba and Brejo quarries exhibit the best onshore outcrops of the drift carbonate section along the Brazilian continental edge. Field studies and microfacies analysis of the outcropped sedimentary section showed six sedimentary deposits related to the physiography of a carbonate shelf. Proximal mixed deposits are represented by the rich-terrigenous dolostone. Levels with alternate layers of fine grained sandstones and siltstones are here related to distal facies of submarine fans deposits. Mudstones with miliolids and textularids represent a lagoonal environment in a semi-restricted middle shelf. Packstones, grainstones and occasionally wackestones with oncoids, intraclasts and peloids represent sedimentary deposits related to the back of shallow sandy bars and environments at the interface with the lagoon. Grainstones whit ooliths, oncoids, intraclasts and bioclasts, with trough cross-bedding, represent a shallower shoreface environment over the shallow carbonate back on outer shelf. Cements and other post-depositional features suggest four different diagenetic environments: a) marine phreatic diagenetic environment with active water circulation; b) marine phreatic diagenetic environment with stagnant water; c) freshwater phreatic diagenetic environment; d) burial diagenetic environment. The sedimentary succession is formed by shallowing upward cycles overlain by a possible transgressive surface, which may indicate the passage of a lowstand to a transgressive system tract

Inhibitors of the 5-lipoxygenase arachidonic acid pathway induce ATP release and ATP-dependent organic cation transport in macrophages

AbstractWe have previously described that arachidonic acid (AA)-5-lipoxygenase (5-LO) metabolism inhibitors such as NDGA and MK886, inhibit cell death by apoptosis, but not by necrosis, induced by extracellular ATP (ATPe) binding to P2X7 receptors in macrophages. ATPe binding to P2X7 also induces large cationic and anionic organic molecules uptake in these cells, a process that involves at least two distinct transport mechanisms: one for cations and another for anions. Here we show that inhibitors of the AA-5-LO pathway do not inhibit P2X7 receptors, as judged by the maintenance of the ATPe-induced uptake of fluorescent anionic dyes. In addition, we describe two new transport phenomena induced by these inhibitors in macrophages: a cation-selective uptake of fluorescent dyes and the release of ATP. The cation uptake requires secreted ATPe, but, differently from the P2X7/ATPe-induced phenomena, it is also present in macrophages derived from mice deficient in the P2X7 gene. Inhibitors of phospholipase A2 and of the AA-cyclooxygenase pathway did not induce the cation uptake. The uptake of non-organic cations was investigated by measuring the free intracellular Ca2+ concentration ([Ca2+]i) by Fura-2 fluorescence. NDGA, but not MK886, induced an increase in [Ca2+]i. Chelating Ca2+ ions in the extracellular medium suppressed the intracellular Ca2+ signal without interfering in the uptake of cationic dyes. We conclude that inhibitors of the AA-5-LO pathway do not block P2X7 receptors, trigger the release of ATP, and induce an ATP-dependent uptake of organic cations by a Ca2+- and P2X7-independent transport mechanism in macrophages

High anti-SARS-CoV-2 antibody seroconversion rates before the second wave in Manaus, Brazil, and the protective effect of social behaviour measures: results from the prospective DETECTCoV-19 cohort

Background: The city of Manaus, Brazil, has seen two collapses of the health system due to the COVID-19 pandemic. We report anti-SARS-CoV-2 nucleocapsid IgG antibody seroconversion rates and associated risk factors in Manaus residents before the second wave of the epidemic in Brazil. Methods: A convenience sample of adult (aged ≥18 years) residents of Manaus was recruited through online and university website advertising into the DETECTCoV-19 study cohort. The current analysis of seroconversion included a subgroup of DETECTCoV-19 participants who had at least two serum sample collections separated by at least 4 weeks between Aug 19 and Oct 2, 2020 (visit 1), and Oct 19 and Nov 27, 2020 (visit 2). Those who reported (or had no data on) having a COVID-19 diagnosis before visit 1, and who were positive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at visit 1 were excluded. Using an in-house ELISA, the reactivity index (RI; calculated as the optical density ratio of the sample to the negative control) for serum anti-SARS-CoV-2 nucleocapsid IgG antibodies was measured at both visits. We calculated the incidence of seroconversion (defined as RI values ≤1·5 at visit 1 and ≥1·5 at visit 2, and a ratio >2 between the visit 2 and visit 1 RI values) during the study period, as well as incidence rate ratios (IRRs) through cluster-corrected and adjusted Poisson regression models to analyse associations between seroconversion and variables related to sociodemographic characteristics, health access, comorbidities, COVID-19 exposure, protective behaviours, and symptoms. Findings: 2496 DETECTCoV-19 cohort participants returned for a follow-up visit between Oct 19 and Nov 27, 2020, of whom 204 reported having COVID-19 before the first visit and 24 had no data regarding previous disease status. 559 participants were seropositive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at baseline. Of the remaining 1709 participants who were seronegative at baseline, 71 did not meet the criteria for seroconversion and were excluded from the analyses. Among the remaining 1638 participants who were seronegative at baseline, 214 showed seroconversion at visit 2. The seroconversion incidence was 13·06% (95% CI 11·52–14·79) overall and 6·78% (5·61–8·10) for symptomatic seroconversion, over a median follow-up period of 57 days (IQR 54–61). 48·1% of seroconversion events were estimated to be asymptomatic. The sample had higher proportions of affluent and higher-educated people than those reported for the Manaus city population. In the fully adjusted and corrected model, risk factors for seroconversion before visit 2 were having a COVID-19 case in the household (IRR 1·49 [95% CI 1·21–1·83]), not wearing a mask during contact with a person with COVID-19 (1·25 [1·09–1·45]), relaxation of physical distancing (1·31 [1·05–1·64]), and having flu-like symptoms (1·79 [1·23–2·59]) or a COVID-19 diagnosis (3·57 [2·27–5·63]) between the first and second visits, whereas working remotely was associated with lower incidence (0·74 [0·56–0·97]). Interpretation: An intense infection transmission period preceded the second wave of COVID-19 in Manaus. Several modifiable behaviours increased the risk of seroconversion, including non-compliance with non-pharmaceutical interventions measures such as not wearing a mask during contact, relaxation of protective measures, and non-remote working. Increased testing in high-transmission areas is needed to provide timely information about ongoing transmission and aid appropriate implementation of transmission mitigation measures. Funding: Ministry of Education, Brazil; Fundação de Amparo à Pesquisa do Estado do Amazonas; Pan American Health Organization (PAHO)/WHO.World Health OrganizationRevisión por pare

Sintomas visuais de deficiência de macronutrientes e boro em maracujazeiro-doce

Conduziu-se experimento em casa de vegetação com objetivo de caracterizar sintomas visuais de deficiências de macronutrientes e de B em folhas e frutos de maracujazeiro-doce cultivados em caixas com areia lavada e irrigados com solução nutritiva. Utilizou-se delineamento experimental em blocos casualizados, com oito tratamentos (solução completa, -N, -P, -K, -Ca, -Mg, -S e -B), com quatro repetições. Os sintomas de deficiência observados, entre 85 e 240 dias após a aplicação dos tratamentos, foram: -N: clorose generalizada e queda prematura das folhas e frutos com cor verde- amarelada e aspecto translúcido; -P: folhas velhas com coloração verde-escura brilhante que, com progressão da deficiência, ficavam mais claras; -K: clorose e posterior necrose na porção basal da nervura central das folhas velhas que progrediam para as bordas e queda das folhas e frutos com enrugamento do epicarpo; -Ca: deformação e necrose nas bordas das folhas novas e frutos com rachaduras no epicarpo e no mesocarpo, além de podridão apical; -Mg: folhas velhas com clorose internerval; -S: clorose das folhas novas com pequenas manchas mais claras e -B: folhas novas com aspecto coriáceo e ondulação nos bordos e frutos com faixas marrons de cortiça na casca

Presentation and treatment of carotid cavernous aneurysms Apresentação e tratamento dos aneurismas intracavernosos

We analyzed a group of patients with the diagnosis of internal carotid aneurysms in its intracavernous segment, with emphasis in prevalence, clinical features, treatments, evolution and neurological prognosis. Neurological signs and symptoms at initial presentation were registered and compared with final outcome. Patients were divided into two stratified groups, one with 19 patients which underwent interventionist treatment, and another with 21 patients who were conservatively treated. The present study demonstrated that intervention is significantly correlated with a better prognosis considering evolution of pain symptoms secondary to neurovascular compression (p=0,002). Regarding neurological deficits, an interventionist approach was also significantly correlated with better outcome in comparison with initial presentation (p=0,008). These results indicate that interventionist treatment determines improvement or resolution of pain symptoms in comparison with patients conservatively treated, as well as stabilization or partial improvement of neuro-ophthalmological deficits.Analisamos um grupo de pacientes com diagnóstico de aneurismas da artéria carótida interna, em sua porção intracavernosa, estudando-se: prevalência, apresentação clínica, formas de tratamento, evolução e prognóstico neurológico. Os sintomas e sinais neurológicos da apresentação foram registrados e comparados ao término do acompanhamento, com um grupo de 21 aneurismas submetidos a tratamento conservador e outro com 19 a tratamento intervencionista. O estudo demonstrou que a intervenção está relacionada a um melhor prognóstico, quanto à evolução do quadro álgico secundário à compressão neurovascular (p=0,002). Em relação ao déficit neurológico, a abordagem intervencionista pôde ser associada com uma melhora do quadro inicial (p=0,008). Estes resultados indicam que o tratamento intervencionista proporcionou melhora ou resolução do sintoma dor em comparação ao grupo de pacientes com tratamento conservador, além de levar a uma estabilização ou melhora parcial dos déficits neuro-oftalmológicos