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1.
Molecules ; 26(23)2021 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-34885736

RESUMEN

Biomass thermochemical liquefaction is a chemical process with multifunctional bio-oil as its main product. Under this process, the complex structure of lignocellulosic components can be hydrolysed into smaller molecules at atmospheric pressure. This work demonstrates that the liquefaction of burned pinewood from forest fires delivers similar conversion rates into bio-oil as non-burned wood does. The bio-oils from four burned biomass fractions (heartwood, sapwood, branches, and bark) showed lower moisture content and higher HHV (ranging between 32.96 and 35.85 MJ/kg) than the initial biomasses. The increased HHV resulted from the loss of oxygen, whereas the carbon and hydrogen mass fractions increased. The highest conversion of bark and heartwood was achieved after 60 min of liquefaction. Sapwood, pinewood, and branches reached a slightly higher conversion, with yields about 8% greater, but with longer liquefaction time resulting in higher energy consumption. Additionally, the van Krevelen diagram indicated that the produced bio-oils were closer and chemically more compatible (in terms of hydrogen and oxygen content) to the hydrocarbon fuels than the initial biomass counterparts. In addition, bio-oil from burned pinewood was shown to be a viable alternative biofuel for heavy industrial applications. Overall, biomass from forest fires can be used for the liquefaction process without compromising its efficiency and performance. By doing so, it recovers part of the lost value caused by wildfires, mitigating their negative effects.


Asunto(s)
Biomasa , Lignina/química , Aceites de Plantas/química , Polifenoles/química , Incendios Forestales , Hidrógeno/química , Hidrólisis , Oxígeno/química , Péptido Hidrolasas/química , Pinus/química , Temperatura , Agua , Madera/química
2.
Molecules ; 26(13)2021 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-34206169

RESUMEN

In addition to the vast diversity of fauna and flora, the Brazilian Amazon has different climatic periods characterized by periods with greater and lesser rainfall. The main objective of this research was to verify the influence of climatic seasons in the Brazilian Amazon (northeast of Pará state) concerning the aromatic and bioactive profiles of fermented and dried cocoa seeds. About 200 kg of seeds was fermented using specific protocols of local producers. Physicochemical analyzes (total titratable acidity, pH, total phenolic compounds, quantification of monomeric phenolics and methylxanthines) and volatile compounds by GC-MS were carried out. We observed that: in the summer, the highest levels of aldehydes were identified, such as benzaldehyde (6.34%) and phenylacetaldehyde (36.73%), related to the fermented cocoa and honey aromas, respectively; and a total of 27.89% of this same class was identified during winter. There were significant differences (p ≤ 0.05, Tukey test) in the profile of bioactive compounds (catechin, epicatechin, caffeine, and theobromine), being higher in fermented almonds in winter. This study indicates that the climatic seasons in the Amazon affect the aromatic and bioactive profiles and could produce a new identity standard (summer and winter Amazon) for the cocoa almonds and their products.


Asunto(s)
Cacao , Ecosistema , Flavonoides , Fenoles , Estaciones del Año , Semillas , Cacao/química , Cacao/metabolismo , Flavonoides/química , Flavonoides/metabolismo , Odorantes , Fenoles/química , Fenoles/metabolismo , Semillas/química , Semillas/metabolismo
3.
J Surg Case Rep ; 2022(1): rjab596, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35087654

RESUMEN

Mechanical intestinal obstruction is a common cause of acute abdominal pain that brings patients to the emergency department. One of the main causes is adhesion in the abdomen after abdominal surgery, but rarer causes exist and are a diagnostic challenge due to the similarity of the presenting symptoms. Here, we present a case of intestinal obstruction caused by diaphragmatic hernia.

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