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The Himatanthus genus presents anti-inflammatory, antioxidant activities, suggesting potential wound-healing properties. This study aimed to develop and analyze the wound-healing properties of a photopolymerizable gelatin-based hydrogel (GelMA) containing an ethanolic extract of Himatanthus bracteatus in a murine model. The extract was obtained under high pressure conditions, incorporated (2%) into the GelMA (GelMA-HB), and physically characterized. The anti-inflammatory activity of the extract was assessed using a carrageenan-induced pleurisy model and the GelMA-HB scarring properties in a wound-healing assay. The extract reduced IL-1β and TNF-α levels (48.5 ± 6.7 and 64.1 ± 4.9 pg/mL) compared to the vehicle (94.4 ± 2.3 pg/mL and 106.3 ± 5.7 pg/mL; p < 0.001). GelMA-HB depicted significantly lower swelling and increased resistance to mechanical compression compared to GelMA (p < 0.05). GelMA-HB accelerated wound closure over the time course of the experiment (p < 0.05) and promoted a significantly greater peak of myofibroblast differentiation (36.1 ± 6.6 cells) and microvascular density (23.1 ± 0.7 microvessels) on day 7 in comparison to GelMA (31.9 ± 5.3 cells and 20.2 ± 0.6 microvessels) and the control (25.8 ± 4.6 cells and 17.5 ± 0.5 microvessels) (p < 0.05). In conclusion, GelMA-HB improved wound healing in rodents, probably by modulating the inflammatory response and myofibroblastic and microvascular differentiation.

Biomass gasification is one of the primary thermal conversion processes where fluidized bed reactors are often used to produce syngas with low heating values. However, there has not yet been an effective model to predict gasification yield with broad applicability. In this study, machine learning was adopted to realize the prediction of syngas compositions and lower heating values (LHV) using various lignocellulosic biomass feedstocks at a wide range of operating conditions. Three machine learning techniques, i.e., Random Forest (RF), Support Vector Machine (SVM) and Artificial Neural Network (ANN) were adopted after determining hyperparameters optimization. Pearson correlation and permutation importance were used for the sensitivity analysis. RF and ANN were found to have high prediction accuracy with R2 and RMSE results (RF: R2=0.809-0.946, RMSE=1.39-11.54%; ANN: R2=0.565-0.924, RMSE=1.46-10.56%). Monte Carlo filtering (MCF) was integrated into the three machine learning algorithms to forecast the desired products by predicting the important features of the operating conditions and biomass characteristics. Considering the desired H2/CO > 1.1 and LHV > 5.86 MJ/m3, the RF-MCF was a more suitable approach with R2=0.791-0.902 for H2, CO and LHV features. The machine learning approach can be widely adapted in various scenarios predicting output features as well as MCF for finding the significant variables for optimization.

The increased demand for biotechnological processes in industrial applications requires the development of highly active and stable heterogeneous biocatalysts. For this reason, the present work aimed to study the immobilization process by physical adsorption of lipase from Burkholderia cepacia (BCL) on aerogel modified with protic ionic liquid (2-hydroxy-N-methylethanaminium pentanoate – C5). The adsorption study of BCL on aerogel modified with protic ionic liquid (Aerogel-IL) has been performed and compared with unmodified support (Aerogel-Control). It was observed that the modification of aerogel allowed a greater retention of BCL (337 mg.gsupport –1 or 977.7 U.gsupport –1) than the unmodified support (297 mg.gsupport –1 or 863.5 U.gsupport –1). Experimental data obtained in physical adsorption of BCL on Aerogel-IL and Aerogel-Control were well-fitted to Sips and Redlich-Peterson isotherm models, respectively. BCL adsorption on both supports was found to be a spontaneous process. Immobilized BCL on Aerogel-IL has shown a better thermal stability than free and immobilized BCL on unmodified support being active for more than 14 days. These results reveal that the modified aerogel prepared in this work can be a promising support to prepare stable and active biocatalysts.

This work aims to evaluate the activity and stability of solid acid catalysts (niobium oxide and sulfated zirconia) in the methyl esterification of oleic acid assisted by microwave heating, an alternative route to the base-catalyzed transesterification reaction using conventional heating. Both catalysts have yielded similar conversions (68% for Nb2O5 and 68.7% for sulfated zirconia at 200 °C, t = 20 min, methanol-to-fatty acid molar ratio = 10, 5% w/w catalyst), much higher than the one obtained without catalyst (39.3%), besides a small deactivation after the fourth use (3% for Nb2O5, 11% for sulfated zirconia, compared to the first use). The results have not indicated a pronounced increase on reaction conversions by using microwave heating when compared to conventional data found in the literature. However, microwave irradiation remains attractive for heating esterification systems, since it allows for achieving high temperatures at reduced times.

The global yield and composition of extracts obtained by supercritical carbon dioxide (SC-CO2) extraction from a dry ethanolic extract of propolis were measured in order to determine the possibility of using SC-CO2 to fractionate components of interest present in these extracts. The global yield extraction was measured, and also the concentrations of the following phenolic compounds in the resulting supercritical fluid extracts (SFEs): 3,5-diprenyl-4-hydroxycinnamic acid (known as artepillin C), 3-prenyl-4-hydroxycinnamic acid, 4-hydroxycinnamic acid (p-coumaric acid) and 4-methoxy-3,5,7-trihydroxyflavone (kaempferide), of which artepillin C was the target component of greatest interest. The results showed extraction yields between 3.82 (at 150 bar) and 13.07% (at 350 bar), which could be highly correlated with the density of the SC-CO2 at a constant temperature of 60C. The resulting concentrations in the SFE indicated that the selectivity of the carbon dioxide could be manipulated, and it was more selective at lower pressures, although with lower extraction yields. PRACTICAL APPLICATIONS Supercritical fluid extraction is an interesting process for the production of natural extracts because it is a clean process, and extractions using carbon dioxide (CO2) as the solvent have been gaining attention in recent years. This study presented important aspects with respect to the fractionation of a dry ethanolic extract of propolis using supercritical carbon dioxide, and it is important to explore the potential applications of propolis extracts and the biological properties of its fractions in the food, pharmaceutical and cosmetic industries, such as in dental hygiene products, wound healing creams and antibacterial soaps.

In this work, the stability of water-in-crude oil emulsions generated in laboratory was investigated using a phenomenological mathematical model based on the population balance equation, considerin...

In this work, the mutual solubilities of sets of ionic liquids ([CnMIM] [TF2N] (n = 4, 8, 12), [C4PY] [TF2N], [C8MIM] [OTF]) and organic compounds (heptane, o-xylene, toluene, or water) are investigated. The experimental data measured for these systems were used to adjust the binary interaction parameters between their components for the Non-Random Two Liquid (NRTL) model. The results showed that the solubility increased with temperature, with high hygroscopicity (10-1 in terms of mole fraction) of the ILs, low interactions with aliphatic hydrocarbons, high interactions with aromatic hydrocarbons and the presence of a lower critical solution temperature (LCST). In addition, this study is the first to show that [C12MIM] [TF2N] is completely soluble in toluene and ortho-xylene between 273.15 and 373.15 K at 1 bar. The average deviations related to the mole fraction between the experimental and calculated values by the NRTL were less than 2.4%.

Water-in-oil (W/O) emulsions are complex mixtures generally found in crude oil production in reservoirs and processing equipment. Sedimentation studies of water-oil emulsions enable the analysis of the fluid dynamic behavior concerning separation of this system composed of two immiscible liquids. Gravitational settling was evaluated in this article for a model emulsion system consisting of water and a Brazilian crude oil diluted in a clear mineral oil as organic phase. The effects of water content and temperature were considered in the study of sedimentation velocity of water-oil emulsions. Water contents between 10% and 50 % and temperatures of 25, 40 and 60 ºC were evaluated, and a Richardson-Zaki type correlation was obtained to calculate settling velocities as a function of the process variables investigated. Water contents and average droplet sizes were monitored at different levels in the settling equipment, thus enabling identification of the effect of these variables on the phenomena of sedimentation and coalescence of the emulsions studied. The results showed that the emulsion stability during sedimentation was governed by the emulsion water content, which yielded high settling velocities at low water contents, even when very small droplets were present. A quantitative analysis of the combined effects of drop size and droplet concentration supports the conclusion that a stronger effect is produced by the higher concentration of particles, compared with the relatively smaller effect of increasing the size of the droplets.

RESUMO – O uso de liquidos ionicos e irradiacao micro-ondas como desemulsificante de emulsoes de petroleo tipo agua/oleo representa um novo campo de estudo. O principal objetivo deste trabalho e investigar o efeito do par liquido ionico/etanol no processo de desemulsificacao de emulsoes de petroleo pesado via micro-ondas. Os resultados indicam a selecao de um solvente adequado pode facilitar a mistura do liquido ionico no petroleo bruto, produzindo melhores resultados de desemulsificacao em menores concentracoes.

This work reports experimental phase equilibrium data of binary and ternary systems involving carbon dioxide, propane, and glycidyl methacrylate (GMA). Phase equilibrium experimental data were obtained according to the static synthetic method using a variable volume view cell. The experiments covered the temperature range of (303 to 343) K, pressures up to 13 MPa, at several overall compositions. The experimental data were modeled with the Peng−Robinson equation of state (PR-EoS) with the conventional quadratic mixing rules. The EoS interaction parameters were fitted from binary systems and then used to predict the phase behavior of the ternary system. The results showed that, in the experimental range investigated, only vapor−liquid transitions were found and that the PR-EoS was capable of satisfactorily representing the experimental data.

The use of supercritical CO2 (SCCO2) as an alternative solvent in reactional systems has received increased attention nowadays because of its favorable transport properties that can accelerate mass-transfer limited reactions and also because of imposed environmental restrictions. The comprehension of the phase behavior of the reaction mixture is of relevance to determine selectivity and yield of such reactions at high pressures. In this context, the main objective of this work was to investigate the high-pressure phase equilibrium behavior of binary systems formed by CO2 with the reactant (limonene), the most common solvents (acetonitrile and dichloromethane), and catalysts and the main products (carvone and 1,2-limoneneoxide) of the limonene catalytic oxidation reactions. The experimental data were measured using the static synthetic method with a variable-volume view cell in the temperature range from (313 to 343) K. Experimental data obtained were corrected modeled with the Peng−Robinson equation of st...

Rapid expansion of supercritical solution (RESS) is a promising technique for microparticle production. The literature points out that the RESS technique can be applied to process a wide range of materials including ceramics, polymers, biopolymers, pharmaceutics, and organic compounds. In order to achieve an adequate understanding of the RESS process, it is necessary to conduct more comprehensive studies involving the hydrodynamic modeling of the fluid flow through the capillary, the phase behavior of a expanding mixture, and also with regard to the microparticle formation mechanism. In this context, this work is focused on the analysis of process hydrodynamic modeling and on phase equilibrium modeling (thermodynamic modeling of supersaturation), with a phase stability test coupled. The Gibbs tangent plane distance for the phase stability test was minimized using the simulated annealing algorithm. The results showed that the thermodynamic variables exert a remarkable effect simulated variables (temperature, velocity, density and degree of supersaturation) for the profile.

Hancornia speciosahas bioactive molecules such as phenolic compounds which exhibit antioxidant and anti-microbial properties. Nevertheless, the separation of these substances from a medicinal plant can be differentaccording to the extraction process and solvent used. Thus, the present study aimed was to separate phenoliccompounds fromHancornia speciosaleaves in three steps by using a sequential pressurized liquid extraction andevaluated their antioxidant and antibacterial activity. Results showed that the temperature increase from 25 to60° C provides a significative enhancement in the extraction yield. The raw ethanol extract (39.0 ± 0.2%)showed the highest overall extraction yield. However, fractionated ethanol extract (FEE) at 60 °C exhibited thehighest amount of total phenolic compounds (347.0 ± 4.12 mg/g extract). Fractionated ethyl acetate extract(FAE) at 60 °C presented improved quantity of totalflavonoids (230.4 ± 3.5 mg/g extract) and rutin content(16.6 ± 0.3 mg/mL extract). The antioxidant activity results for IC50of DPPH indicated that FEE(3.8 ± 0.1 ?g/mL) was the best free radical scavenger. FAE and FEE were able to inhibit the growth of mul-tidrug-resistantE. coli. Made available in DSpace on 2020-01-14T18:12:36Z (GMT). No. of bitstreams: 1 1s2.0S138358661930334Xmain.pdf: 429605 bytes, checksum: 20ef950a051821a5194a4f8d0e0b85df (MD5) Previous issue date: 2019