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1.
Food Chem ; 335: 127649, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32738538

RESUMO

Rosa rugosa Thunb. seed oil (RR) extracted by supercritical CO2 was investigated. RR chemical composition, radical scavenging effect and oxidative stability were evaluated. RR aqueous emulsions were examined for cell cytotoxicity, proliferation, redox state and migration using mouse embryonic fibroblast Balb/3T3, human dermal fibroblast NHDF cell lines, and on neoplastic cell lines: acute monocytic leukemia THP-1 and lung adenocarcinoma A549. RR total contents of phytosterols, tocopherols, carotenoids and phenolics were 10115.23, 784.16, 40.32 and 10.30 mg/kg, respectively. Rich antioxidant composition of RR was reflected in its high antioxidant activity (2.1 mM/kg Trolox equivalent) as well as oxidative stability (activation energy 105.6 kJ/mol). The RR emulsions led to marked augmentation of the total cell protein content in BALB/3T3 and NHDF cultures, inhibited cancer cell migration and reduced ROS formation. The studied RR oil proved to have a remarkable combination of bioactive compounds and to exert an antioxidative and chemopreventive effects.


Assuntos
Óleos Vegetais/química , Óleos Vegetais/farmacologia , Rosa/química , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Dióxido de Carbono/química , Carotenoides/química , Carotenoides/isolamento & purificação , Carotenoides/farmacologia , Linhagem Celular , Cromatografia com Fluido Supercrítico , Humanos , Camundongos , Oxirredução , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Fitosteróis/química , Fitosteróis/isolamento & purificação , Fitosteróis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Óleos Vegetais/isolamento & purificação , Sementes/química , Tocoferóis/química , Tocoferóis/isolamento & purificação , Tocoferóis/farmacologia
2.
Food Chem ; 334: 127487, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32688178

RESUMO

Biodegradable films poly(butylene adipate-co-butylene terephthalate) (PBAT)/poly(lactic acid) (PLA) incorporated with nano-polyhedral oligomeric silsesquioxane (POSS(epoxy)8) as a reactive compatibilizer were developed by melt processing. Structural, morphological, mechanical, and gas permeability properties of the films were determined. 1H NMR and GPC demonstrated that the POSS(epoxy)8 was chemically bound at the PBAT/PLA boundary phase via an epoxide ring opening reaction. SEM micrographs of impact fracture surfaces demonstrated the POSS(epoxy)8 improved interfacial adhesion between PBAT and PLA matrix. The mechanical properties of the PBAT/PLA films containing POSS(epoxy)8 were enhanced relative to pristine PBAT/PLA films. The water vapor, CO2 and O2 permeability of the PBAT/PLA films were improved by POSS(epoxy)8 addition. PBAT/PLA films containing POSS(epoxy)8 were shown to be superior to pristine PBAT/PLA films and polyethylene films in food storage tests. Results suggest that POSS(epoxy)8 addition during PBAT/PLA film production offers a simple strategy for the production of high performance biodegradable plastic packaging films.


Assuntos
Plásticos Biodegradáveis/química , Embalagem de Alimentos/métodos , Nanocompostos/química , Poliésteres/química , Dióxido de Carbono/química , Armazenamento de Alimentos/métodos , Oxigênio/química , Permeabilidade , Resistência à Tração
3.
Food Chem ; 336: 127625, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32771897

RESUMO

The solubility of carbon dioxide (CO2) in the moisture and protein components of cheese matrices and the influence of changing pH, salt and temperature levels remains unclear. In this study, model casein matrices were prepared, by renneting of micellar casein concentrate (MCC), with modulation of salt and pH levels by adding salt and glucono delta-lactone, respectively, to the MCC solutions prior to renneting. Different moisture-to-protein levels were achieved by freeze-drying, incubation of samples at different relative humidities, or by applying varying pressures during gel manufacture. The CO2 solubility of samples decreased linearly with both increasing temperature and salt-in-moisture content, whereas solubility of CO2 increased with increasing pH. A non-linear relationship was observed between CO2 solubility and the moisture-to-protein ratio of experimental samples. Overall, such knowledge may be applied to improve the quality and consistency of eye-type cheese, and in particular to avoid development of undesirable slits and cracks.


Assuntos
Dióxido de Carbono/química , Caseínas/química , Cloreto de Sódio/química , Água/química , Queijo/análise , Concentração de Íons de Hidrogênio , Pressão Parcial , Solubilidade , Temperatura
4.
J Breath Res ; 14(4): 046012, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33021213

RESUMO

Breath analysis holds promise for non-invasive in vivo monitoring of disease related processes. However, physiological parameters may considerably affect profiles of exhaled volatile organic substances (VOCs). Volatile substances can be released via alveoli, bronchial mucosa or from the upper airways. The aim of this study was the systematic investigation of the influence of different sampling sites in the respiratory tract on VOC concentration profiles by means of a novel experimental setup. After ethical approval, breath samples were collected from 25 patients undergoing bronchoscopy for endobronchial ultrasound or bronchoscopic lung volume reduction from different sites in the airways. All patients had total intravenous anaesthesia under pressure-controlled ventilation. If necessary, respiratory parameters were adjusted to keep PETCO2 = 35-45 mm Hg. 30 ml gas were withdrawn at six sampling sites by means of gastight glass syringes: S1 = Room air, S2 = Inspiration, S3 = Endotracheal tube, S4 = Trachea, S5 = Right B6 segment, S6 = Left B6 segment (S4-S6 through the bronchoscope channel). 10 ml were used for VOC analysis, 20 ml for PCO2 determination. Samples were preconcentrated by solid-phase micro-extraction (SPME) and analysed by gas chromatography-mass spectrometry (GC-MS). PCO2 was determined in a conventional blood gas analyser. Statistically significant differences in substance concentrations for acetone, isoprene, 2-methyl-pentane and n-hexane could be observed between different sampling sites. Increasing substance concentrations were determined for acetone (15.3%), 2-methyl-pentane (11.4%) and n-hexane (19.3%) when passing from distal to proximal sampling sites. In contrast, isoprene concentrations decreased by 9.9% from proximal to more distal sampling sites. Blank bronchoscope measurements did not show any contaminations. Increased substance concentrations in the proximal respiratory tract may be explained through substance excretion from bronchial mucosa while decreased concentrations could result from absorption or reaction processes. Spatial mapping of VOC profiles can provide novel insights into substance specific exhalation kinetics and mechanisms.


Assuntos
Testes Respiratórios/métodos , Broncoscopia , Expiração , Manejo de Espécimes , Compostos Orgânicos Voláteis/análise , Dióxido de Carbono/química , Feminino , Humanos , Limite de Detecção , Pulmão/química , Masculino , Pessoa de Meia-Idade , Pressão Parcial
5.
PLoS One ; 15(9): e0239340, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941542

RESUMO

In this study, an enzymatic pathway has been developed to replicate the Calvin Cycle by creating the individual steps of the carbon cycle in a bioreactor. The technology known as "artificial photosynthesis" converts CO2 emissions into a variety of intermediates that serve as precursors to high-value products. CO2, light, water, and electricity were used as feedstock. An electrochemical reactor was also studied for the regeneration of active NADH operating at constant electrode potential. Initially, a batch electrochemical reactor containing 80 mL of 0.2 mM NAD+ in Tris-buffer (pH 7.40) was used to evaluate the electrode material operating at normal temperature and pressure. The results showed that the cathode is highly electrocatalytically efficient and selective to regenerate 97.45±0.8% of NADH from NAD+ at electrode potential of -2.3 V vs. mercury standard electrode (MSE). The NADH regeneration system was then integrated with ATP regeneration system and bioreactor containing Ribulose bisphosphate carboxylase/oxygenase (RuBisCO). NADH was regenerated successfully during the process electrochemically and then was used by the enzymatic reaction to produce triose phosphate and 3-Phosphoglycerate (3GPA).


Assuntos
Dióxido de Carbono/química , Carbono/química , Eletroquímica/instrumentação , NAD/química , Tampões (Química) , Catálise , Eletrodos , Oxirredução , Fosfatos/química
6.
PLoS One ; 15(9): e0238193, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881875

RESUMO

INTRODUCTION: Detection of Mycobacterium tuberculosis (Mtb) in patient-derived bioaerosol is a potential tool to measure source case infectiousness. However, current bioaerosol sampling approaches have reported low detection yields in sputum-positive TB cases. To increase the utility of bioaerosol sampling, we present advances in bioaerosol collection and Mtb identification that improve detection yields. METHODS: A previously described Respiratory Aerosol Sampling Chamber (RASC) protocol, or "RASC-1", was modified to incorporate liquid collection of bioaerosol using a high-flow wet-walled cyclone (RASC-2). Individuals with GeneXpert-positive pulmonary TB were sampled pre-treatment over 60-minutes. Putative Mtb bacilli were detected in collected fluid by fluorescence microscopy utilising DMN-Trehalose. Exhaled air and bioaerosol volumes were estimated using continuous CO2 monitoring and airborne particle counting, respectively. Mtb capture was calculated per exhaled air volume sampled and bioaerosol volume for RASC-1 (n = 35) and for RASC-2 (n = 21). Empty chamber samples were collected between patients as controls. RESULTS: The optimised RASC-2 protocol sampled a median of 258.4L (IQR: 226.9-273.6) of exhaled air per patient compared with 27.5L (IQR: 23.6-30.3) for RASC-1 (p<0.0001). Bioaerosol volume collection was estimated at 2.3nL (IQR: 1.1-3.6) for RASC-2 compared with 0.08nL (IQR: 0.05-0.10) for RASC-1 (p<0.0001). The detection yield of viable Mtb improved from 43% (median 2 CFU, range: 1-14) to 95% (median 20.5 DMN-Trehalose positive bacilli, range: 2-155). These improvements represent a lowering of the limit of detection in the RASC-2 platform to 0.9 Mtb bacilli per 100L of exhaled air from 3.3 Mtb bacilli per 100L (RASC-1). CONCLUSION: This study demonstrates that technical improvements in particle collection together with sensitive detection enable rapid quantitation of viable Mtb in bioaerosols of sputum positive TB cases. Increased sampling sensitivity may allow future TB transmission studies to be extended to sputum-negative and subclinical individuals, and suggests the potential utility of bioaerosol measurement for rapid intervention in other airborne infectious diseases.


Assuntos
Aerossóis/análise , Manejo de Espécimes/métodos , Tuberculose/diagnóstico , Adulto , Dióxido de Carbono/química , Expiração , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/microbiologia
7.
Proc Natl Acad Sci U S A ; 117(37): 22873-22879, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32900930

RESUMO

All life on Earth is built of organic molecules, so the primordial sources of reduced carbon remain a major open question in studies of the origin of life. A variant of the alkaline-hydrothermal-vent theory for life's emergence suggests that organics could have been produced by the reduction of CO2 via H2 oxidation, facilitated by geologically sustained pH gradients. The process would be an abiotic analog-and proposed evolutionary predecessor-of the Wood-Ljungdahl acetyl-CoA pathway of modern archaea and bacteria. The first energetic bottleneck of the pathway involves the endergonic reduction of CO2 with H2 to formate (HCOO-), which has proven elusive in mild abiotic settings. Here we show the reduction of CO2 with H2 at room temperature under moderate pressures (1.5 bar), driven by microfluidic pH gradients across inorganic Fe(Ni)S precipitates. Isotopic labeling with 13C confirmed formate production. Separately, deuterium (2H) labeling indicated that electron transfer to CO2 does not occur via direct hydrogenation with H2 but instead, freshly deposited Fe(Ni)S precipitates appear to facilitate electron transfer in an electrochemical-cell mechanism with two distinct half-reactions. Decreasing the pH gradient significantly, removing H2, or eliminating the precipitate yielded no detectable product. Our work demonstrates the feasibility of spatially separated yet electrically coupled geochemical reactions as drivers of otherwise endergonic processes. Beyond corroborating the ability of early-Earth alkaline hydrothermal systems to couple carbon reduction to hydrogen oxidation through biologically relevant mechanisms, these results may also be of significance for industrial and environmental applications, where other redox reactions could be facilitated using similarly mild approaches.


Assuntos
Dióxido de Carbono/química , Ciclo do Carbono , Transporte de Elétrons , Hidrogênio/química , Concentração de Íons de Hidrogênio , Fontes Hidrotermais/química , Oxirredução , Força Próton-Motriz
9.
Br J Anaesth ; 125(5): 773-778, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32859360

RESUMO

BACKGROUND: Increasing fresh gas flow (FGF) to a circle breathing system reduces carbon dioxide (CO2) absorbent consumption. We assessed the environmental and economic impacts of this trade-off between gas flow and absorbent consumption when no inhalational anaesthetic agent is used. METHODS: A test lung with fixed CO2 inflow was ventilated via a circle breathing system of an anaesthetic machine (Dräger Primus or GE Aisys CS2) using an FGF of 1, 2, 4, or 6 L min-1. We recorded the time to exhaustion of the CO2 absorbent canister, defined as when inspired partial pressure of CO2 exceeded 0.3 kPa. For each FGF, we calculated the economic costs and the environmental impact associated with the manufacture of the CO2 absorbent canister and the supply of medical air and oxygen. Environmental impact was measured in 100 yr global-warming potential, analysed using a life cycle assessment 'cradle to grave' approach. RESULTS: Increasing FGF from 1 to 6 L min-1 was associated with up to 93% reduction in the combined running cost with minimal net change to the 100 yr global-warming potential. Most of the reduction in cost occurred between 4 and 6 L min-1. Removing the CO2 absorbent from the circle system, and further increasing FGF to control CO2 rebreathing, afforded minimal further economic benefit, but more than doubled the global-warming potential. CONCLUSIONS: In the absence of inhalational anaesthetic agents, increasing FGF to 6 L min-1 reduces running cost compared with lower FGFs, with minimal impact to the environment.


Assuntos
Anestésicos Inalatórios/química , Dióxido de Carbono/química , Poluição Ambiental/análise , Gases/química , Anestesia com Circuito Fechado , Anestesia por Inalação , Anestésicos Inalatórios/economia , Poluição Ambiental/economia , Poluição Ambiental/prevenção & controle , Gases/economia , Aquecimento Global , Humanos , Pulmão/fisiologia , Modelos Anatômicos , Respiração Artificial , Hidróxido de Sódio
10.
Proc Natl Acad Sci U S A ; 117(35): 21079-21087, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817563

RESUMO

The amplitude of the atmospheric CO2 seasonal cycle has increased by 30 to 50% in the Northern Hemisphere (NH) since the 1960s, suggesting widespread ecological changes in the northern extratropics. However, substantial uncertainty remains in the continental and regional drivers of this prominent amplitude increase. Here we present a quantitative regional attribution of CO2 seasonal amplification over the past 4 decades, using a tagged atmospheric transport model prescribed with observationally constrained fluxes. We find that seasonal flux changes in Siberian and temperate ecosystems together shape the observed amplitude increases in the NH. At the surface of northern high latitudes, enhanced seasonal carbon exchange in Siberia is the dominant contributor (followed by temperate ecosystems). Arctic-boreal North America shows much smaller changes in flux seasonality and has only localized impacts. These continental contrasts, based on an atmospheric approach, corroborate heterogeneous vegetation greening and browning trends from field and remote-sensing observations, providing independent evidence for regionally divergent ecological responses and carbon dynamics to global change drivers. Over surface midlatitudes and throughout the midtroposphere, increased seasonal carbon exchange in temperate ecosystems is the dominant contributor to CO2 amplification, albeit with considerable contributions from Siberia. Representing the mechanisms that control the high-latitude asymmetry in flux amplification found in this study should be an important goal for mechanistic land surface models moving forward.


Assuntos
Atmosfera/química , Dióxido de Carbono/química , Carbono/química , Regiões Árticas , Ciclo do Carbono/fisiologia , Dióxido de Carbono/análise , Clima , Mudança Climática , Ecossistema , América do Norte , Fotossíntese , Estações do Ano , Sibéria
11.
J Chromatogr A ; 1626: 461352, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797832

RESUMO

In the present study, we characterize a famous Pirkle-type enantioselective stationary phase ((R,R)-Whelk-O1 from Regis Technologies) and an equivalent enantiomeric phase (ReproSil Chiral-NR from Dr. Maisch) in supercritical fluid chromatography (SFC) with carbon dioxide - methanol (90:10 v/v) mobile phase. First, the interactions contributing to retention are evaluated with a modified version of the solvation parameter model, comprising five Abraham descriptors (E, S, A, B, V), two additional descriptors to take account of molecular shape (flexibility F and globularity G), and two additional descriptors to take account of interactions with ionizable species (D- and D+). Linear solvation energy relationships (LSER) are established based on the retention of 212 achiral analytes. As expected, π-π interactions are the most significant to explain retention, while dipole-dipole, hydrogen bonding and ionic interactions with cationic species are of secondary importance. Secondly, the contributions of interactions to enantioseparations are discussed, based on the analysis of 79 racemates. Discriminant analyses (DA) were computed to gain some insight on retention mechanisms. The set of racemates is first divided between racemates eluted earlier than expected based on the LSER models, and those eluted later than expected. Small spherical molecules are more retained than expected, as they may better fit inside the cleft of the chiral selector. They are also most frequently resolved, probably for the same reason. Among the molecules that are less retained than expected, which are rather large and/or non-spherical, other features are favourable to enantiorecognition: π-electrons, dipoles and electron-donating properties. Contrary to the observations on other sorts of chiral selectors, flexibility was found to have no contribution on the enantiorecognition process.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Dióxido de Carbono/química , Análise Discriminante , Ligação de Hidrogênio , Íons , Metanol/química , Modelos Teóricos , Estereoisomerismo
12.
Chemosphere ; 260: 127639, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32758767

RESUMO

Lipids are biomolecules extracted from plant sources and plant residues and have a beneficial role in various food, nutrition and medical applications. Supercritical carbon-dioxide as an advanced high-pressure technology which increases the productivity and has negligible environmental impact is employed for the selective extraction of polar lipids from the lipid matrix in mango kernel for the first time. The process parameters affecting the extraction such as pressure, temperature and the flow rate of CO2 are ranged in the intervals of 30-50 MPa, 40-60 °C and 10-30 g min-1, respectively. Optimization using Box Behnken design obtained the highest yield of 3.38% at 40 °C, 50 MPa and 30 g min-1. The phosphorous content was evaluated to understand the behaviour of polar lipids extraction at higher pressures. The study showed the effect of process parameters having significant influence on polarity and solvating capacity of CO2 which enabled for the extraction of polar lipids adding value to the mango kernel converting waste into valuable industrial products. The economic evaluation estimates the return on investment of a plant processing 3000 tons of mango kernel per year to account net present value (NPV) almost five times higher than the investment expenses and the payback period is under 4 years.


Assuntos
Dióxido de Carbono/química , Fósforo/química , Cromatografia com Fluido Supercrítico , Análise Custo-Benefício , Lipídeos/química , Mangifera , Extratos Vegetais/química , Temperatura
13.
Food Chem ; 332: 127405, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32603919

RESUMO

The two-phase technology for olive oil extraction generates large amounts of patè olive cake (POC), a by-product that is rich in bioactive health-promoting compounds. Here, response surface methodology (RSM) was used to maximize supercritical-CO2 oil extraction from POC, while minimizing operative temperature, pressure and time. Under the optimal parameters (40.2 °C, 43.8 MPa and time 30 min), the oil yield was 14.5 g·100 g-1 dw (~65% of the total oil content of the freeze-dried POC matrix), as predicted by RSM. Compared with freeze-dried POC, the oil contained more phytosterols (13-fold), tocopherols (6-fold) and squalene (8-fold) and was a good source of pentacyclic triterpenes. When the biological effects of POC oil intake (20-40 µL·die-1) were evaluated in the livers of BALB/c mice, no significant influence on redox homeostasis was observed. Notably, a decline in liver triglycerides alongside increased activities of NAD(P)H:Quinone Oxidoreductase 1, Carnitine Palmitoyl-CoA Transferase and mitochondrial respiratory complexes suggested a potential beneficial effect on liver fatty acid oxidation.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Azeite de Oliva/química , Animais , Dióxido de Carbono/química , Peroxidação de Lipídeos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Olea/metabolismo , Azeite de Oliva/isolamento & purificação , Azeite de Oliva/farmacologia , Fitosteróis/química , Fitosteróis/isolamento & purificação , Propriedades de Superfície , Temperatura , Tocoferóis/química , Tocoferóis/isolamento & purificação , Triglicerídeos/metabolismo
14.
PLoS One ; 15(7): e0236367, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32701989

RESUMO

Chemical absorption of carbon dioxide from flue or natural gas in hollow-fiber membrane contactors (HFMCs) has been one of the most beneficial techniques to alleviate its emission into the environment. A theoretical research study was done to investigate the change in membrane specifications and operating conditions on CO2 absorption using different alkanolamine solvents. The mathematical model was developed for a parallel counter-current fluid flow through a HFMC. The developed model's equations were solved based on finite element method. The simulations revealed that the increase in membrane porosity, length and the number of fibers has a positive impact on CO2 removal, while the gas flow rate and tortuosity enhancement resulted in the reduction of CO2 absorption. Furthermore, it was found that 4-diethylamino-2-butanol (DEAB) with approximately 100% CO2 absorption is suggested as the best solvent in this system, but ethyl-ethanolamine (EEA) with only 46% CO2 absorption had the lowest capacity for CO2 absorption (DEAB>MEA>EDA>MDEA>TEA>EEA). It is worth pointing out that the CO2 absorption can be improved using EEA solvent via change in membrane specifications such as increase in membrane porosity, length and the number of fibres.


Assuntos
Dióxido de Carbono/química , Etanolamina/química , Membranas/química , Modelos Teóricos , Adsorção/efeitos dos fármacos , Etanolaminas/química , Polipropilenos/química , Porosidade , Solventes/química
15.
Food Chem ; 332: 127385, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32623125

RESUMO

A promising way of processing Baltic herring, Clupea harengus membras, is turning the fish into boneless mince. However, Baltic herring is prone to lipid oxidation, which possesses a challenge for industrial applications. The aim of this work was to study the efficacy of press cakes from Finnish berries and a supercritical CO2 plant extract to limit lipid oxidation during frozen storage of Baltic herring mince and to determine the impact of these additions on consumer acceptance in a fish product. Peroxide value, formation of volatile oxidation products and loss of polyunsaturated fatty acids showed that the tested natural additives decreased oxidation to a greater or similar extent as conventional antioxidants during 10-month storage. While potential of berry press cakes and plant extracts as "green label antioxidants" was shown, consumer study indicated need for further research to reach both optimal antioxidative efficacy and sensory properties.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Produtos Pesqueiros/análise , Extratos Vegetais/química , Animais , Antioxidantes/química , Dióxido de Carbono/química , Ácidos Docosa-Hexaenoicos/análise , Ácido Eicosapentaenoico/análise , Peixes , Congelamento , Lipídeos/análise , Fenóis/análise , Compostos Orgânicos Voláteis/análise
16.
Food Chem ; 330: 127173, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569930

RESUMO

Pleurotus ostreatus is an edible mushroom with pharmacological potential, due to its metabolites, mainly polysaccharides. On here, the development of a new methodology for the recovery of extract rich in antioxidant polysaccharide was reported. The extracts were characterized, evaluated for antioxidant activity in vitro and in cell models and cytotoxicity. The best defined extraction condition was 25 MPa, 433.15 K, and 20% H2O, with 30.69% of the total yield and 0.921 mg of CHO3. The anomeric bonds, identified in the FTIR and NMR spectrum, indicate that the extracts are a mixture of heteropolysaccharides, ß-glucans, α-glucans, and oligosaccharides. The best extraction condition has 80.83% of antioxidant activity, without cytotoxic effect in vitro. In addition to antioxidant activity in cell model, increasing protection against oxidative damage induced by H2O2. Finally, H2O + CO2-SFE technology can be used to obtain extracts rich in antioxidant polysaccharides with pharmacological and food potential.


Assuntos
Antioxidantes/química , Pleurotus/química , Polissacarídeos/química , Dióxido de Carbono/química , Glucanos/química , Temperatura Alta , Peróxido de Hidrogênio/química , Oxirredução , Água/química
17.
Emerg Top Life Sci ; 4(2): 137-150, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32573736

RESUMO

Photosynthesis involves capturing light energy and, most often, converting it to chemical energy stored as reduced carbon. It is the source of food, fuel, and fiber and there is a resurgent interest in basic research on photosynthesis. Plants make excellent use of visible light energy; leaves are ideally suited to optimize light use by having a large area per amount of material invested and also having leaf angles to optimize light utilization. It is thought that plants do not use green light but in fact they use green light better than blue light under some conditions. Leaves also have mechanisms to protect against excess light and how these work in a stochastic light environment is currently a very active area of current research. The speed at which photosynthesis can begin when leaves are first exposed to light and the speed of induction of protective mechanisms, as well as the speed at which protective mechanisms dissipate when light levels decline, have recently been explored. Research is also focused on reducing wasteful processes such as photorespiration, when oxygen instead of carbon dioxide is used. Some success has been reported in altering the path of carbon in photorespiration but on closer inspection there appears to be unforeseen effects contributing to the good news. The stoichiometry of interaction of light reactions with carbon metabolism is rigid and the time constants vary tremendously presenting large challenges to regulatory mechanisms. Regulatory mechanisms will be the topic of photosynthesis research for some time to come.


Assuntos
Fotossíntese , Folhas de Planta/metabolismo , Plantas/metabolismo , Dióxido de Carbono/química , Clorofila/metabolismo , Produtos Agrícolas/metabolismo , Luz , Estrutura Molecular , Oxirredução , Oxigênio/química , Folhas de Planta/fisiologia , Fenômenos Fisiológicos Vegetais , Ribulose-Bifosfato Carboxilase/metabolismo , Transdução de Sinais , Amido/química , Termodinâmica
18.
PLoS One ; 15(4): e0232293, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353047

RESUMO

Equipment manufacturing industry is one of the major industries of the Chinese economy. Previous researches have revealed that the industry has dilemmas of unreasonable industrial structure and high pollution. Using the data of 30 provinces in 2006-2015 in China, this study calculated a comprehensive pollution indicator when estimating the possible pollution reduction brought by the optimization of industrial structure and then evaluated the reasonable level of capital allocation of provinces and industries by using the methods of nonlinear programming and stochastic frontier method. Under the target of collaborative emission reduction, the results show that the optimized output of China's equipment manufacturing industry could be increased by 5.42%, the energy intensity could be reduced by about 10.4%, and the comprehensive emission intensity could be reduced by about 7.47%. Due to the industry heterogeneity and regional heterogeneity, industrial capacity should be transferred between industries and regions. Since the capital investment in the equipment manufacturing industry is significantly mismatched between industries and regions, the capital allocation of provincial industries in China needs to be adjusted properly. This study provides theoretically and practically reference for collaborative pollution reduction, industry restructure, spatial layout and capital investment, which contributes to achieving the stereoscopic optimization of equipment manufacturing industry.


Assuntos
Poluição Ambiental/efeitos adversos , Poluição Ambiental/estatística & dados numéricos , Indústria Manufatureira/estatística & dados numéricos , Dióxido de Carbono/química , China , Desenvolvimento Econômico/estatística & dados numéricos , Investimentos em Saúde/estatística & dados numéricos
20.
J Chromatogr A ; 1624: 461172, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32376027

RESUMO

The enantiomers of a chiral building block to be used in pre-clinical manufacturing were separated using supercritical fluid chromatography (SFC). Despite an extensive evaluation of different columns and solvent combinations followed by a careful optimization of the chromatographic method, the preparative separation suffered from low throughput and high solvent consumption. Consequently, additional improvements were necessary. By utilizing stacked injections, the chromatographic run time was almost halved, and the high solvent consumption was reduced by recycling of the two mobile phase components, carbon dioxide and methanol. The carbon dioxide was reprocessed by the SFC instrument, whereas methanol was evaporated and recycled from the fractions collected. Hence, the originally inefficient separation method was turned into a more sustainable one, and the desired enantiopure intermediate was delivered to be used in the following synthesis of the selected candidate drug. Unfortunately, when the intermediate was used in the subsequent amide coupling, a surprisingly poor yield was obtained. This was caused by an unexpected formation of a stable carbonate salt of the intermediate under the chromatographic conditions used. By removal of the carbonate prior to the amide coupling reaction, the manufacturing campaign could be saved, and the candidate drug was successfully delivered in time.


Assuntos
Carbonatos/química , Cromatografia com Fluido Supercrítico/métodos , Dióxido de Carbono/química , Metanol/química , Sais , Solventes/química , Estereoisomerismo
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