Atividade alelopática de extratos brutos de três espécies de copaifera (leguminosae-caesalpinioideae)

For the past few years, special attention has been given to chemical composites involved in interaction between plants, especially when the potential of their use in weed management is known. The Amazon region with its enormous biodiversity and abundance of plant species may offer excellent opportunities for the discovery of innovative chemical molecules capable of being used in agriculture. Thus, in this paper, a comparative analysis was made between the potential allelopathic activity of three species of Copaifera, characterizing the variations of the intensity of the allelopathic effects of the donating species, plant fraction and chemical component polarity. Hexanic and ethanolic extracts, prepared at 1.0% from the leaves, branches and barks of Copaifera duckei, C. marti and C. reticulata, were tested on seed germination and development of Mimosa pudica and Senna obtusifolia weed roots. The results showed that the intensity of the effects varied according to the variables studied. The ethanolic extract of C. martii and C. reticulate leaves and barks showed high potential to inhibit seed germination, especially of M. pudica species. The species C. duckei showed low allelopathic inhibitory potential in the germination of two receptor species. Barks, branches and especially leaves of C. duckei presented more expressive inhibitory potential for root development. Polar, and especially non-polar chemical composites, are involved in the allelopathic activity of C. duckei. Differently for C. martii and C. reticulata, the polar composites are preferentially involved in the inhibitory activity evidenced by these species, especially those located on the leaves and barks. Comparatively, it was observed that the weed species receptor tended to show more sensitivity to the allelopathic effects of the extracts, especially in the germination bioassay

Volatile Compounds, Chemical Composition and Biological Activities of <em>Apis mellifera</em> Bee Propolis

Propolis is a wax-like resin collected by bees from tree shoots and/or other botanical sources that is used as glue to seal cracks or open spaces in the hive. Its color varies from green to brown and reddish, depending on its botanical origin. Among the substances that can be found in propolis, low molecular weight compounds, such as monoterpenes and sesquiterpenes are the most common. Several biological activities are attributed to these classes of substances, such as antifungal, antibacterial, and others. The objective of this work was to evaluate the chemical composition of volatile compounds present in propolis samples and to analyze their correlation with biological activities

O PERFIL DO DIRIGENTE PRINCIPAL DAS UNIVERSIDADES BRASILEIRAS: um estudo preliminar

O presente estudo, de abordagem predominantemente quantitativa, descritiva quanto aos objetivos, documental e bibliográfica quanto aos procedimentos técnicos, teve como objetivo apresentar o perfil predominante do atual dirigente máximo das universidades brasileiras públicas e privadas. Para isso foram realizadas buscas no cadastro e-MEC de Instituições e Cursos de Educação Superior e na plataforma Lattes de integração de bases de dados de Currículos, de Grupos de pesquisa e de Instituições. Nesse sentido, identificou-se que o perfil predominante do atual dirigente máximo das universidades brasileiras é composto por indivíduos do sexo masculino (cerca de 75%); com formação nos cursos de Administração, Ciências Econômicas, Pedagogia, Medicina, Filosofia, Direito e/ou Engenharias (aproximadamente 52%do total de registros); com formação máxima em nível de Mestrado e/ou Doutorado (cerca de 95%); que já ocuparam cargo de gestão educacional ou acadêmica de alto escalão anteriormente (aproximadamente 83%); e que cumprem seu primeiro mandato enquanto dirigente máximo (cerca de 63%). Como sugestão para pesquisas futuras, recomenda-se ampliar os critérios analisados, para que se possa definir de forma ainda mais rica o perfil dos dirigentes máximos das instituições de ensino superior brasileiras

Invasive Species in the Amazon

One of the main reasons for environmental disturbances such as declination in pasture productivity and biodiversity losses is the high infestation of herbaceous weeds, generally referred to as “Juquira” in the Amazon region. If they are not adequately controlled, such infestation might lead to degradation of pasture, resulting in complete loss of productivity and subsequent abandonment of the area. In this sense, this chapter aims to describe the main invasive species present in the Amazon region, as well as to characterize both the old and innovative techniques of use in agriculture, in large and small scale, for the control of agricultural pests

Modelos moleculares confeccionados em papel para estudo do conteúdo de estereoquímica / Molecular models made on paper to study of the stereochemistry

O estudo de estereoquímica tem grande dificuldade entre os alunos, principalmente pelo fato de ser abstrato, decorativo e fora de contexto, quando o aluno participa da aula confeccionando o seu próprio material didático com certeza haverá um melhor entendimento, com base nessa premissa, desenvolveu-se um modelo molecular confeccionado em papel e recortado com tesoura, para o entendimento do conteúdo de estereoquímica, tais como quiralidade, plano de simetria, enantiômero, diastereoisômero, meso-isômero, entre outros

Aproveitamento das folhas de Annona mucosa / Utilization of leaves Annona mucosa

O biribazeiro (Annona mucosa) é uma planta frutífera da região amazônica, apreciada pelo seu fruto, o biribá, sendo bastante estudada devido aos seus componentes químicos. Neste trabalho, as folhas foram submetidas a extração hexanica, para a obtenção do extrato hexanico alcaloídico, visando a sua caracterização via CLAE e Espectrometria de massas, dando como resultado a presença do alcaloide do tipo aporfínico, anonaina

Análise por HPLC e Espectrometria de Massas do Extrato Alcaloídico Hexânico das Folhas de Annona muricata/ HPLC and Mass Spectrometry analysis of Hexane Extract Alkaloidal from the Leaves of Annona muricata

Annona muricata, uma planta frutífera da região amazônica, muito apreciada pelo seu fruto, a graviola, comum na região Amazônica e bastante estudada devido aos seus componentes químicos, alcalóides e acetogeninas. Com base nessas informações, neste trabalho relata-se a análise via HPLC e Espectrometria de massas do extrato alcaloídico obtido a partir do extrato hexânico das folhas, via partição ácido/ base

[Covid-19 in the Northeast of Brazil: from lockdown to the relaxation of social distancing measures].

Even in the period when the Covid-19 pandemic was on the rise in the Northeast of Brazil, the relaxation of social distancing measures was introduced. The scope of the study is to assess, in the light of the epidemiological-sanitary situation in the region, the suitability of relaxation of social distancing measures. Based on the WHO guidelines for relaxation of social distancing, operational indicators were created and analyzed for each guideline in the context of the Northeast. To analyze the behavior of the epidemic, according to selected indicators, Joinpoint trend analysis techniques, heat maps, rate ratios and time trends between capitals and the state interior were compared. The weekly growth peak of the epidemic occurred in May-July 2020 (epidemiological weeks 19 to 31). In most capitals, there was no simultaneous downward trend in the number of cases and deaths in the 14 days prior to flexibilization. In all states the number of tests performed was insufficient. In epidemiological week 24, the state percentages of ICU/Covid-19 bed occupancy were close to or above 70%. The epidemiological situation of the nine Northeastern state capitals analyzed here did not meet criteria and parameters recommended by the World Health Organization for the relaxation of social distancing measures

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