Avaliação fermentativa da levedura floculante e termotolerante Saccharomyces cerevisiae CA11 utilizando materiais lignocelulósicos pré-tratados

A oportunidade de utilizar materiais lignocelulósicos (MLCs) residuais ou cultivados em áreas inóspitas como matérias-primas para a produção de etanol é de extrema importância para a produção economicamente viável e sustentável do etanol. Neste sentido, o cacto, casca de coco verde, fibra de coco maduro e a casca de coco maduro foram pré-tratados com peróxido de hidrogênio seguido de hidróxido de sódio, autohidrólise, hidrotérmico catalisado com hidróxido de sódio e organosolv, os MLCs que melhor responderam a cada pré-tratamento foram selecionados, hidrolisados e posteriormente testados por sacarificação e fermentação simultânea (SSF) pela Saccharomyces cerevisiae CA11. Os rendimentos de conversão em etanol foram de 0.42 a 0.47 g/g. Os resultados obtidos pela SSF demonstram a promissora utilização desses MLCs pré-tratados juntamente com a levedura floculante e termotolerante na produção de etanol celulósico

Hidrólise enzimática, sacarificação e fermentação simultânea de materiais lignocelulósicos usando Saccharomyces cerevisiae CA11

A necessidade de aumentar a oferta de energia líquida e limpa na matriz energética mundial possibilita a produção de etanol como uma solução emergente e eficaz. Neste contexto, o objetivo desse trabalho consiste em analisar a hidrólise enzimática dos materiais lignocelulósicos pré-tratados (10 % p/v) e a fermentação e sacarificação simultânea (SSF) pela levedura floculante e termotolerante Saccharomyces cerevisiae CA11. As hidrólises enzimas apresentaram conversões dos materiais lignocelulósicos em glicose entre 75 a 85 %. A SSF realizada pela S. cerevisiae CA11 sob a fibra de coco maduro pré-tratada hidrotermicamente catalisada com hidróxido de sódio resultou em produção e rendimento de etanol de 25.83 g/L e 0.46 g/g, respectivamente. Dessa forma, os resultados obtidos sinalizam a possibilidade benéfica de utilizar esses materiais lignocelulósicos pré-tratados e a S. cerevisiae CA11 na produção de etanol celulósico

Bioethanol production from hydrothermally pretreated coconut fibre mature catalyzed with sodium hydroxide

In search to increase the offer of liquid energy, clean, renewable and sustainable in the world energy matrix, arises the alternative in the use lignocellulosic materials in bioethanol production. The objective of this work was evaluated the bioethanol production using different strategies as simultaneous (SSF) and semi-simultaneous (SSSF) saccharification on hydrothermally pretreated coconut fibre mature as raw material catalyzed with sodium hydroxide. The bioethanol production was performed by S. cerevisiae PE-2, P. stipitis Y7124 and Z. mobilis B14023. The coconut fibre mature after of the hydrothermal pretreatment was characterized by SEM, X-ray and crystallinity index. The semi-simultaneous saccharification at 48 ºC for 8 h had a positive effect on the overall ethanol yield, increasing from 84.64, 79.27, 81.71 % to 89.15, 85.04, 85.65 % for S. cerevisiae PE-2, P. stipitis Y7124 and Z. mobilis, respectively. For all the cases S. cerevisiae PE-2, P. stipitis Y7124 and Z. mobilis, SSSF strategy allowed obtained higher ethanol production than SSF

Structural and electrical properties of Zr-doped K0.48 Na 0.52 NbO 3 ceramics: “Hard” lead-free piezoelectric

The structural and electrical properties of K0.48Na0.52Nb1−xZrxO3−δ (x = 0–0.04) ceramics prepared by the conventional solid-state reaction method were studied. Pellets with composition x ≤ 0.03 sintered at 1125 °C for 2 h showed single-phase of potassium sodium niobate (KNN) perovskite structure. Based on X-ray diffraction and Raman results, a mixture of orthorhombic and monoclinic phases was observed in intermediate compositions. The addition of Zr improved the sinterability and the “hard” piezoelectric properties of KNN, increasing the Ec and Qm values. The composition with x = 0.03 presented the highest permittivity at room temperature, ɛr′ = 363 and the lowest dielectric losses, tan δ = 0.027. Moreover, it was the sample with the highest Qm and d33 values, with Qm = 1781 and d33 = 82 pC/N. It was therefore the best compositions to obtain a “hard” piezoelectric material based on Zr-doped KNN, which makes it promising candidate for use as “hard” lead-free piezoelectric material for high power applications

Comparison of delignified coconuts waste and cactus for fuel-ethanol production by the simultaneous and semi-simultaneous saccharification and fermentation strategies

It is of the highest importance to study different alternatives/strategies as simultaneous (SSF) and semi-simultaneous (SSSF) saccharification and fermentation process, as well as the prospects of the utilization of lignocellulosic residues as raw materials for fuel-ethanol production. In the first part of this work, different raw materials (cactus (CAC), green coconut shell (GCS), mature coconut fibre (MCF) and mature coconut shell (MCS)) were pretreated by sequential alkaline hydrogen peroxide (Alk-H2O2)–sodium hydroxide (NaOH) process. The characterization of the obtained solids by FTIR, SEM, X-ray and crystallinity indexes confirmed the higher susceptibility of these pretreated materials to enzymatic action. These results were further confirmed by the corresponding glucose conversion yields – 68.44%, 70.20%, 76.21% and 74.50% for CAC, GCS, MCF and MCS, respectively. Subsequently, the comparison between SSF and SSSF using Saccharomyces cerevisiae, Pichia stipitis, Zymomonas mobilis and pretreated MCF (selected in the enzymatic hydrolysis step) was done, being shown that a short presaccharification step at 50 °C for 8 h in the SSSF had a positive effect on the overall ethanol yield, with an increase from 79.27–84.64% to 85.04–89.15%. In all the cases, the SSSF strategy allowed the obtention of higher ethanol concentrations than SSF.The authors gratefully acknowledge the Brazilian research funding agencies CNPq and CAPES for financial support

Proof-of-Concept Studies Directed toward the Formation of Metallic Ag Nanostructures from Ag3PO4 Induced by Electron Beam and Femtosecond Laser

In this work, for the first time, the instantaneous nucleation and growth processes of Ag nanoparticles on Ag3PO4 mediated by femtosecond laser pulses are reported and analyzed. The investigated samples are pure Ag3PO4sample, electron-irradiated Ag3PO4 sample, and laser-irradiated sample. Complete characterization of the samples is performed using X-ray diffraction (XRD), Rietveld refinements, field emission scanning electron microscopy, and energy dispersive spectroscopy (EDS). XRD confirms that the irradiated surface layer remains crystalline, and according to EDS analysis, the surface particles are composed primarily of Ag nanoparticles. This method not only offers a one-step route to synthesize Ag nanoparticles using laser-assisted irradiation with particle size control, but also reports a complex process involving the formation and subsequent growth of Ag nanoparticles through an unexpected additive-free in situ fabrication process

Increased density of endogenous adenosine A2A receptors in atrial fibrillation: from cellular and porcine models to human patients

Adenosine, an endogenous nucleoside, plays a critical role in maintaining homeostasis during stressful situations, such as energy deprivation or cellular damage. Therefore, extracellular adenosine is generated locally in tissues under conditions such as hypoxia, ischemia, or inflammation. In fact, plasma levels of adenosine in patients with atrial fibrillation (AF) are elevated, which also correlates with an increased density of adenosine A2A receptors (A2ARs) both in the right atrium and in peripheral blood mononuclear cells (PBMCs). The complexity of adenosine-mediated effects in health and disease requires simple and reproducible experimental models of AF. Here, we generate two AF models, namely the cardiomyocyte cell line HL-1 submitted to Anemonia toxin II (ATX-II) and a large animal model of AF, the right atrium tachypaced pig (A-TP). We evaluated the density of endogenous A2AR in those AF models. Treatment of HL-1 cells with ATX-II reduced cell viability, while the density of A2AR increased significantly, as previously observed in cardiomyocytes with AF. Next, we generated the animal model of AF based on tachypacing pigs. In particular, the density of the key calcium regulatory protein calsequestrin-2 was reduced in A-TP animals, which is consistent with the atrial remodelling shown in humans suffering from AF. Likewise, the density of A2AR in the atrium of the AF pig model increased significantly, as also shown in the biopsies of the right atrium of subjects with AF. Overall, our findings revealed that these two experimental models of AF mimicked the alterations in A2AR density observed in patients with AF, making them attractive models for studying the adenosinergic system in AF

Modelo de simulación dinámico de proyectos de desarrollo de software con scrum

En este trabajo se sintetizan los avances de una línea de investigación, la cual tiene definido por objetivo esencial: la construcción y mejora continua de un modelo de simulación dinámico que de soporte a la metodología de gestión de proyectos desarrollados con Scrum. Concretamente, se describen los subsistemas que componen actualmente el modelo propuesto y construido para simular los componentes esenciales de la gestión de un proyecto desarrollado con Scrum, así como también, se referencian los experimentos realizados con el modelo. El modelo construido resulta de utilidad para administradores de proyectos considerados novatos en la aplicación de la metodología referida, permitiéndoles conocer de antemano las consecuencias de sus decisiones. Adicionalmente, se presentan nuevos objetivos y trabajos futuros para la línea.Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI