The use of Amazon fungus (Trametes sp.) in the production of cellulase and xylanase

In order to use the residue from the beneficiation of Brazil nuts (Bertholletia excelsa HBK) as substrate in solid-sate fermentation (SSF), in this work, the production of cellulase and xylanase by the fungus Trametes sp. was investigated, using the residue as a carbon source. Employing a 24-1 fractional experimental design, the influence of substrate moisture, nutrient addition and inoculum quantity on enzymatic activities was verified. Moisture was detected to be statistically significant for the production of both enzymes, and increasing the moisture leads to the improvement of cellulase and xylanase activities. Nitrogen and phosphate were also important for enzymes production by the Amazon Trametes sp. The use of this Amazon strain to obtain cellulase and xylanase via SSF of Brazil nut residue appears to be feasible when maintaining substrate moisture at 80%, nitrogen source at 0.9% and low inoculum concentrations.Key words: Cellulolytic activity, xylanolytic activity, Trametes sp., experimental design

Produção de celulases por actinobactérias cultivadas em diferentes substratos / Production of cellulases by actinobacteria cultivated on different substrates

As celulases são enzimas responsáveis pela degradação da celulose, principal composto presente no tecido vegetal. O pré-tratamento da celulose é um elemento chave para sua conversão biológica, tornando o processo mais ecológico e econômico, pois diminui os custos com máquinas e aterros. Dessa forma, a busca por microrganismos produtores de celulases, bem como o estudo de sua produção utilizando resíduos agroindustriais torna-se relevante. Neste trabalho foi investigada a produção de celulases por actinobactérias em cultivo submerso utilizando diferentes substratos como fonte de carbono. Foram utilizadas três linhagens de actinobactérias e os substratos carboximetilcelulose, sabugo de milho, casca de maracujá, resíduo solido urbano e resíduo da hidrodestilação de pau-rosa. Os cultivos foram realizados durante 7 dias a 37oC e 180 rpm em shaker. A atividade endoglucanásica foi avaliada diariamente. As três actinobactérias avaliadas demonstraram potencial para produção de celulases a partir dos diferentes resíduos. A linhagem isolada do solo de Pernambuco foi a mais promissora, em especial quando cultivada no resíduo da hidrodestilação do pau-rosa. 

Comparison between calcium hydroxide mixtures and mineral trioxide aggregate in primary teeth pulpotomy: a randomized controlled trial

Objectives: To evaluate the effect of calcium hydroxide (CH) associated with two different vehicles as a capping material for pulp tissue in primary molars, compared with mineral trioxide aggregate (MTA). Methodology: Forty-five primary mandibular molars with dental caries were treated by conventional pulpotomy using one of the following materials: MTA only (MTA group), CH with saline (CH+saline group) and CH with polyethylene glycol (CH+PEG group) (15 teeth/group). Clinical and periapical radiographic examinations of the pulpotomized teeth were performed 3, 6, and 12 months after treatment. Data were tested by chi-squared analysis and a multiple comparison post-test. Results: The MTA group showed both clinical and radiographic treatment success in 14/14 teeth (100%), at all followup appointments. By clinical evaluation, no teeth in the CH+saline and CH+PEG groups had signs of mobility, fistula, swelling or inflammation of the surrounding gingival tissue. However, in the CH+saline group, radiographic analysis detected internal resorption in up to 9/15 teeth (67%), and interradicular bone resorption and furcation radiolucency in up to 5/15 teeth (36%), from 3 to 12 months of follow-up. In the CH+PEG group, 2/11 teeth (18%) had internal resorption and 1/11 teeth (9%) presented bone resorption and furcation radiolucency at all follow-up appointments. Conclusion: CH with PEG performed better than CH with saline as capping material for pulpotomy of primary teeth. However, both combinations yielded clinical and radiographic results inferior to those of MTA alone

The European Union and United Kingdom's deforestation-free supply chains regulations : implications for Brazil

This paper analyses the potential implications of the proposed European Union Deforestation Regulation (EUDR) and the recently adopted United Kingdom (UK) legislation on deforestation-free supply chains (henceforth ‘the legislation’) for different stakeholders in Brazil. These regulations intend to address global commodity-driven deforestation and forest degradation by ensuring that targeted commodities and products placed on (or exported from) markets are of minimal risk of being associated with - in the EU - deforestation and forest degradation or - in the UK - illegal deforestation. The paper examines potential compliance readiness in cattle, cocoa, coffee, palm oil, soybean and tropical timber supply chains in Brazil, indicating specific challenges that may arise. Through the construction of a “Compliance Likelihood Index”, our research provides comparable indications to policymakers on sectors and stakeholders that may need stronger support to meet the requirements, in order to maintain Brazil's access to EU and UK markets. The paper indicates that coffee is the sector with the highest level of incentivization and smallest hurdles for compliance, while the cattle sector may face stronger challenges to rapidly adjust its production system towards a deforestation-free value chain and prove compliance. Results of our analysis also highlight the need for collaboration between the EU/UK and Brazil in order to promote alignment between domestic and demand-side legislations so that they are mutually reinforcing. Results of this exercise, which has a focus on the producer-country view of demand-side legislation, will contribute to discussions on the merits of different approaches to strengthen the governance of deforestation-risk commodity trade

Síntese e caracterização da hidroxiapatita por meio de tratamento alcalino utilizando escamas do Aruanã (Osteoglossum bicirrhosum): Synthesis and characterization of hydroxyapatite by alkaline treatment using Arowana scales (Osteoglossum bicirrhosum)

Neste trabalho foi realizada a obtenção da hidroxiapatita por meio de tratamento alcalino com aquecimento de escamas do Aruanã (Osteoglossum bucirrhosum). As escamas foram adquiridas e passaram por processos de lavagem e secagem.  Posteriormente foram calcinadas e a caracterização do material obtido foi realizada através de Difração de Raios-X, Microscopia Eletrônica de Varredura e Espectroscopia no Infravermelho com Transformada de Fourier. Através da análise de indexação confirmou-se a presença de hidroxiapatita (HAp) como a única fase cristalina em todas as amostras de acordo com difratograma de hidroxiapatita comercial. A amostra não calcinada apresentou morfologia não concreta, assemelhando-se a grandes aglomerados. A hidroxiapatita calcinada a 600ºC não mostrou picos definidos, apresentou estrutura ainda desordenada e partículas de tamanhos distintos. A hidroxiapatita calcinada a 800ºC por duas horas apresenta partículas homogêneas com morfologia esférica e superfície lisa, com o tamanho das partículas variando de 200nm a 400nm. Os resultados obtidos na caracterização da hidroxiapatita pelos métodos DRX, MEV e FTIR foram condizentes com os apresentados em literatura revisada para o desenvolvimento desse trabalho

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Lying in Wait: The Resurgence of Dengue Virus After the Zika Epidemic in Brazil

After the Zika virus (ZIKV) epidemic in the Americas in 2016, both Zika and dengue incidence declined to record lows in many countries in 2017-2018, but in 2019 dengue resurged in Brazil, causing ~2.1 million cases. In this study we use epidemiological, climatological and genomic data to investigate dengue dynamics in recent years in Brazil. First, we estimate dengue virus force of infection (FOI) and model mosquito-borne transmission suitability since the early 2000s. Our estimates reveal that DENV transmission was low in 2017-2018, despite conditions being suitable for viral spread. Our study also shows a marked decline in dengue susceptibility between 2002 and 2019, which could explain the synchronous decline of dengue in the country, partially as a result of protective immunity from prior ZIKV and/or DENV infections. Furthermore, we performed phylogeographic analyses using 69 newly sequenced genomes of dengue virus serotype 1 and 2 from Brazil, and found that the outbreaks in 2018-2019 were caused by local DENV lineages that persisted for 5-10 years, circulating cryptically before and after the Zika epidemic. We hypothesize that DENV lineages may circulate at low transmission levels for many years, until local conditions are suitable for higher transmission, when they cause major outbreaks

A relação entre a apneia do sono e doenças cardiovasculares / The relation between sleep apnea and cardiovascular diseases

INTRODUÇÃO: A apneia do sono ocorre devido ao colabamento das vias aéreas superiores e possui importante associação a doenças cardiovasculares. METODOLOGIA: Trata-se de uma revisão literária realizada por meio de pesquisa na base de dados PubMed, tendo como descritores "sleep apnea syndromes" e "cardiovascular diseases" e publicações nos idiomas inglês e português com disponibilização do texto completo. RESULTADOS: Os estudos ocorreram entre os anos de 2016 e 2020, sendo 2019 o ano de maior índice. Todos os trabalhos são estudos de revisão e dentre os 24 artigos selecionados, 7 foram fundamentais para execução desta pesquisa e destacaram-se como principais referenciais teóricos. DISCUSSÃO: A apneia do sono é uma condição que provoca alterações na fisiologia respiratória, e isso pode acarretar em consequências cardiovasculares. Indivíduos com apneia do sono estão predispostos a diversas afecções cardiovasculares como: hipertensão arterial sistêmica, fibrilação atrial, morte súbita, doença coronariana e consequentemente insuficiência cardíaca, e isso pode ser explicado por diversos mecanismos. CONCLUSÃO: Os estudos mostraram que existe uma intensa correlação entre a apneia do sono e patologias cardiovasculares, que é explicada por alguns eventos que ocorrem no nosso corpo e geram um processo de remodelação da atividade elétrica do coração e também uma remodelação estrutural