RESUMO
BACKGROUND: Okara cellulose is a highly abundant, green, sustainable, and biodegradable polymer with many potential industrial applications. In this study, we fabricated composite hydrogels with okara cellulose nanofibers (CNFs) and chitosan (CH) by hydrating, sonicating, and heating them at 100 °C for 30 min, and then induced their assembly by cooling. The effects of okara CNF (with and without 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) oxidation) and CH concentration on the structure and properties of the hydrogels was examined, including their microstructure, surface properties, rheological properties, and thermal stability. RESULTS: Our results indicate that there was an electrostatic attraction between the anionic okara CNF and cationic CH, which facilitated hydrogel formation. The surface, textural, rheological, and thermal stability properties were better for the composite hydrogels than for the single CH ones, as well as for the CNF that had undergone TEMPO oxidation. For the TC-CH hydrogels, the contact angle was 39.5°, the interfacial tension was 69.1 mN m-1 , and the surface tension was 1.44 mN m-1 . CONCLUSION: In this study, the novel hydrogels developed may be useful as a soft material in a range of applications in foods, supplements, health care products, cosmetics, and drugs. © 2023 Society of Chemical Industry.
Assuntos
Quitosana , Nanofibras , Celulose/química , Quitosana/química , Hidrogéis/química , Nanofibras/química , SonicaçãoRESUMO
The electrochemical N2 reduction reaction (NRR) demonstrates a process of NH3 synthesis from N2 molecules under ambient conditions, which is environmentally friendly and recyclable. However, it requires an efficient electrocatalyst to activate inert N2 molecules, which is still difficult to satisfy. Recently, as an active NRR electrocatalyst and a typical metal oxide, CeO2 has featured ultrahigh thermal stability and the ability to apply heteroatom doping, which is an imperative approach importing oxygen vacancy by replacing metal ions with selective elements to greatly influence the activity of catalysts. Here, we analyze the unique properties of manganese dopants in modulating the activity of CeO2 nanospheres for NRR. It attains a larger NH3 yield of 27.79 µg h-1 mgcat-1 and a higher Faradaic efficiency of 9.1% than pure CeO2 at -0.30 V in 0.1 M HCl, with high electrochemical and structure stability. With calculations by density functional theory, the performance enhancement of Mn-doped CeO2 is also proved mathematically.
RESUMO
Due to the assets such as adequate discharge capacity and rational cost, LiNi0.8Co0.15Al0.05O2(NCA), a high-nickel ternary layered oxide, is regarded to be a favorable cathode contender for lithium-ion batteries. However, the superior commercial application is restricted by the surface residual alkaline lithium salt (LiOH or/and Li2CO3) of nickel-rich cathode materials, which will expedite the disintegration of the structure and the engendering of gas (CO2). Therefore, in this paper, we devise and fabricate a Y(PO3)3modified LiNi0.8Co0.15Al0.05O2(NCA), intending to optimize the surface residual alkaline lithium salt (antecedent deportation of H2O and CO2) while forming anin situtriple composite Li-ion conductor coating (Y(PO3)3-Li3PO4-YPO4) to enhance the electrochemical behavior. Under this method, the 2 mol% Y(PO3)3modified NCA electrode reveals exceptional rate capability (5 C/156.3 mAh g-1) and extraordinary cycle stability after 200 cycles (2 C/88.3%), whereas the original sample is only 5 C/123.1 mAh g-1and 2 C/71.2% after 200 cycles. Conspicuously, even under the draconian circumstances of the high temperature and the high rate at 55 °C/1 C, the 2 mol% Y(PO3)3modified NCA electrode sustains a high reversible capacity, with an admirable capacity retention rate of 89.4% after 100 cycles. These contented results signify that the surface remodeling tactic presents a viable scheme for ameliorating high-nickel materials' performance and appropriateness.
RESUMO
In this paper, via a facile wet coating method, the LaPO4coating layer has been introduced onto the LiNi0.87Co0.09Al0.04O2(NCA) surface while a small part of La3+has also been doped on the surface to realize the dual functions modification of coating and doping. The morphology and structure of the samples were investigated by XRD, SEM and TEM measurements. The chemical compositions of the samples were analyzed via EDS and XPS data. The results showed that the coating of LaPO4and the doping of La3+were successfully achieved on the surface of NCA. Electrochemical tests indicate that the sample modified with 2 wt% LaPO4(L2-NCA) possesses the best electrochemical performance. After 100 cycles, compared with the capacity retention rate of pristine NCA of 87.1%/74.2% at 0.5 C at 25 °C/60 °C, L2-NCA showed better cycling stability, and the capacity retention rate increased to 96.0%/85.1%, respectively. Besides, the rate performance of the modified samples at 1 C, 2 C and 5 C were also significantly improved. These satisfactory results reveal that the surface modification of LaPO4provides a feasible scheme to uprate the performance of Ni-rich cathode materials.
RESUMO
Pecan (Carya cathayensis) is an important economic crop, and its hydrolyzed peptides have been evidenced to reduce the effect of oxidative stress due to their antioxidant capacity. Hence, the protocols of ultrafiltration and gel filtration chromatography were established to obtain bioactive peptides from by-products of C. cathayensis (pecan cake). As measured by DPPH/ABTS radical scavenging, the peptides with less molecular weight (MW) possess higher antioxidant capacity. PCPH-III (MW < 3 kDa) presented higher radical scavenging capacity than PCPH-II (3 kDa < MW < 10 kDa) and PCPH-I (MW > 10 kDa) measured by DPPH (IC50: 111.0 µg/ mL) and measured by ABTs (IC50: 402.9 µg/mL). The secondary structure and amino acid composition varied by their MW, in which PCPH-II contained more α-helices (26.71%) and ß-sheets (36.96%), PCPH-III contained higher ratios of ß-turns (36.87%), while the composition of different secondary of PCPH-I was even 25 ± 5.76%. The variation trend of α-helix and random experienced slightly varied from PCPH-I to PCPH-II, while significantly decreased from PCPH-II to PCPH-III. The increasing antioxidant capacity is followed by the content of proline, and PCPH-III had the highest composition (8.03%). With regard to the six peptides identified by LC-MS/MS, two of them (VYGYADK and VLFSNY) showed stronger antioxidant capacity than others. In silico molecular docking demonstrated their combining abilities with a transcription factor Kelch-like ECH-associated protein 1 (Keap1) and speculated that they inhibit oxidative stress through activating the Keap1-Nrf2-ARE pathway. Meanwhile, increased activity of SOD and CATantioxidant markerswere found in H2O2-induced cells. The residue of tyrosine was demonstrated to contribute the most antioxidant capacity of VYGYADK and its position affected less. This study provided a novel peptide screening and by-product utilization process that can be applied in natural product developments.
Assuntos
Produtos Biológicos , Carya , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Hidrolisados de Proteína/metabolismo , Antioxidantes/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Peróxido de Hidrogênio/metabolismo , Cromatografia Líquida , Simulação de Acoplamento Molecular , Espectrometria de Massas em Tandem , Peptídeos/química , Estresse Oxidativo , Aminoácidos/metabolismo , Superóxido Dismutase/metabolismo , Prolina/metabolismo , Tirosina/metabolismo , Produtos Biológicos/farmacologia , ChinaRESUMO
LiNi0.8Co0.15Al0.05O2(NCA), a promising ternary cathode material of lithium-ion batteries, has widely attracted attention due to its high energy density and excellent cycling performance. However, the presence of residual alkali (LiOH and Li2CO3) on the surface will accelerate its reaction with HF from LiPF6, resulting in structural degradation and reduced safety. In this work, we develop a new coating material, LiH2PO4, which can effectively optimize the residual alkali on the surface of NCA to remove H2O and CO2and form a coating layer with excellent ion conductivity. Under this strategy, the coated sample NCA@0.02Li3PO4(P2-NCA) provides a capacity of 147.8 mAh g-1at a high rate of 5 C, which is higher than the original sample (126.5 mAh g-1). Impressively, the cycling stabilities of P2-NCA under 0.5 C significantly improved from 85.2% and 81.9% of pristine-NCA cathode to 96.1% and 90.5% at 25 °C and 55 °C, respectively. These satisfied findings indicate that this surface modification method provides a feasible strategy toward improving the performance and applicability of nickel-rich cathode materials.
RESUMO
Laser streaming is a phenomenon in which liquid streaming is driven directly from the laser through an in situ fabricated nanostructure. In this study, liquid streaming of a gold nanoparticle suspension driven by a pulsed laser was studied using a high-speed camera. The laser streaming formation time, streaming velocity, and relative energy conversion efficiency of laser streaming was measured for different nanoparticle concentrations, focal lens position, laser powers, and laser repetition rates. In addition to the laser intensity, which played a significant role in the formation process of laser streaming, the optical gradient force was found to be an important approach involved in the transport and provision of nanoparticles during the formation of laser streaming. This finding facilitated a better understanding of the formation mechanism of laser streaming and demonstrated the possibilities of a new potential laser etching technique based on nanosecond lasers and nanoparticle suspensions. This result can also expand the application of laser streaming in microfluids and other fields that require lasers to move macroscopic objects at relatively high speeds.
RESUMO
BACKGROUND: The content of protein components of glutinous rice significantly affects the quality of Chinese rice wine. Therefore, the effects of protein components on the quality of Chinese rice wine were investigated by adding the exogenous proteins glutelin and albumin individually or in combination RESULTS: Compared with the control, the samples with increased glutelin components exhibited improved formation of numerous alcohol esters with alcoholic and fruity representatives. The promotion rates of glutelin to total alcohols and total esters were 18% and 99%, respectively. The amount of 4-vinylguaiacol characterized by a spicy, smoky odor was reduced to 40%. Correlation analysis between chemical composition and sensory characteristics showed a significant positive correlation between umami and amino nitrogen (r = 0.935) and total amino acid content (r = 0.729). The bitterness of Chinese rice wine was related to the change of alcohol content (r = 0.689) and total soluble solid (r = 0.904). Sensory analysis revealed that the increase of the glutelin component of Chinese rice wine increased its alcoholic, fruity, and honey-like features, as well as its umami, acidity and bitterness. The increase also reduced the caramel-like, herb-like, and smoky sensory characteristics of Chinese rice wine and its Qu aroma and sweetness CONCLUSION: The protein content of glutinous rice significantly affects the quality of rice wine. The Glutelin has a significant relationship with fruity, honey, and umami flavors; the albumin has a significant relationship with medicinal, bitter, and astringent flavors. Therefore, reasonable adjustment of the glutelin content of glutinous rice can effectively improve the sensory quality of rice wine. © 2020 Society of Chemical Industry.
Assuntos
Aromatizantes/química , Glutens/química , Oryza/química , Compostos Orgânicos Voláteis/química , Vinho/análise , Aminoácidos/análise , Aminoácidos/metabolismo , China , Fermentação , Aromatizantes/metabolismo , Glutens/metabolismo , Humanos , Odorantes/análise , Oryza/metabolismo , Paladar , Compostos Orgânicos Voláteis/metabolismoRESUMO
Consumption of phytosterols (PSs), the plant-based analogs of cholesterol, can reduce serum cholesterol levels. This review discusses the current state of the art into the research of the structural features and dietary sources of PSs and their derivatives. The effect of PSs on individual lipid metabolites is summarized in the present review. PS-related nonalcoholic fatty liver disease (NAFLD), obesity, and the alleviation of inflammatory bowel diseases are discussed. PSs reduce the risk of having NAFLD by improving the blood biochemical parameters related to lipid transport and metabolism. However, current research on the circulating PSs indicates its safety concern regarding fatty liver disease induction. In addition, PS oxidation products exhibit pro-atherogenic properties, cytotoxicity oxidative stress, apoptosis, and pro-inflammatory properties. Further research is needed to investigate the bioavailability and safety issues of PSs and their derivatives in animal models and clinical trials.
Assuntos
Metabolismo dos Lipídeos , Fitosteróis/química , Fitosteróis/farmacologia , Animais , Anticolesterolemiantes , Colesterol/sangue , Dieta , Humanos , Doenças Inflamatórias Intestinais/dietoterapia , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Obesidade/dietoterapia , Obesidade/prevenção & controle , Oxirredução , Fitosteróis/efeitos adversosRESUMO
This study aimed to further investigate the toxic mechanism of chiral polychlorinated biphenyl (PCB) 91 in adult zebrafish ( Danio rerio) exposed to racemic (rac-), (+)-, or (-)-PCB91 for 63 days. The enantioselective mortalities of adult zebrafish exposed to rac-/(+)-/(-)-PCB91 were 95.86, 50.08, and 81.50%, respectively. Tubular necrosis and cellular hypertrophy occurred in the kidneys of (-)-PCB91-treated groups, whereas demyelination and immune cell infiltration occurred in brains of the rac-, (+)-, and (-)-PCB91-treated groups. Additionally, exposure to chiral PCB91 enantioselectively induced neurotoxicity, apoptosis, and inflammation in brain tissues owing to perturbations of gene expression, protein content and sphingolipid levels. The high mortality after rac-/(+)-PCB91 exposure might be due to toxic effects on brain tissue, while the high mortality after (-)-PCB91 exposure might be due to toxic effects on kidney as well as brain tissues. Thus, our findings offer an important reference for elucidating the enantioselective toxicological mechanism of chiral PCBs in aquatic organisms.
Assuntos
Bifenilos Policlorados , Animais , Expressão Gênica , Estereoisomerismo , Peixe-ZebraRESUMO
Three-dimensional (3D) Pd-Pt alloy with coral-like nanostructures were synthesized via bubble dynamic templated electrodeposition method at room temperature. The morphology of the as-prepared nanostructures was characterized using scanning electron microscopy (SEM), EDS, high-resolution transmission electron microscopy (HRTEM), respectively. Cyclic voltammetry method was adopted to evaluate the electrocatalytic activities of the synthesized electrodes toward oxygen reduction in KCl solution. The electrochemical results indicated that the Pd-Pt alloy with coral-like nanostructures hold the high performance for oxygen reduction.
Assuntos
Antozoários , Nanoestruturas , Paládio/química , Platina/química , Animais , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Análise Espectral/métodos , Difração de Raios XRESUMO
With regard to deep mining in metal mines, an investigation into the failure mode of deep fractured rock masses and their corresponding acoustic emission signal characteristics is conducted via uniaxial compression tests. Subsequently, a fractal damage renormalization group mechanical model is developed to explain the behavior of those fractured rock masses. Employing the bonded block model (BBM) numerical simulation method, fracture process in synthetic rock samples is analyzed, thereby validating the efficacy of the mechanical model. The numerical simulations highlight the critical role of fractures expansion in underlying the deterioration of rock mass strength. As the peak load decreases, the fracture fractal dimension increases, leading to a significant 14.2% reduction in compressive strength accompanied by an approximate 8.7% rise in average fracture fractal dimension. A comparative analysis of tetrahedral and voronoi block synthetic rock samples reveals the tetrahedral block samples exhibit a superior ability to depict the fracture behavior of fractured rock masses. Specifically, they offer a more accurate simulation of acoustic emission characteristics and failure modes. Furthermore, variations in the fracture fractal dimension with respect to the hole defect's position are observed, with the maximum value occurring along the vertical axis of the hole defect. This observation underscores the potential utility of visually monitoring deep rock fracture dynamics as an effective mean for quantitatively evaluating fracture damage and strength degradation in deep rock formations.
RESUMO
Activated sludge (AS) plays a vital role in removing organic pollutants and nutrients from wastewater. However, the risks posed by horizontal gene transfer (HGT) between bacteria in AS are still unclear. Here, a total of 478 high-quality non-redundant metagenome-assembled genomes (MAGs) were obtained. >50 % and 5 % of MAGs were involved in at least one HGT and recent HGT, respectively. Most of the transfers (82.4 %) of antimicrobial resistance genes (ARGs) occurred among the classes of Alphaproteobacteria and Gammaproteobacteria. The bacteria involved in the transfers of virulence factor genes (VFGs) mainly include Alphaproteobacteria (42.3 %), Bacteroidia (19.2 %), and Gammaproteobacteria (11.5 %). Moreover, the number of ARGs and VFGs in the classes of Alphaproteobacteria and Gammaproteobacteria was higher than that in other bacteria (P < 0.001). Mobile genetic elements were important contributors to ARGs and VFGs in AS bacteria. These results have implications for the management of antimicrobial resistance and virulence in activated sludge microorganisms.
Assuntos
Antibacterianos , Esgotos , Esgotos/microbiologia , Virulência/genética , Antibacterianos/farmacologia , Genes Bacterianos , Transferência Genética Horizontal , Farmacorresistência Bacteriana/genética , Bactérias/genética , Fatores de Virulência/genéticaRESUMO
Staphylococcus aureus inhabits diverse habitats including food waste and wastewater treatment plants. Cases of S. aureus-induced infection are commonly reported worldwide. The emergence of antimicrobial resistance (AMR) of S. aureus is a growing public health threat worldwide. Here, we longitudinally monitored global trends in antibiotic resistance genes (ARGs) of 586 S. aureus strains, isolated between 1884 and 2022. The ARGs in S. aureus exhibited a significant increase over time (P < 0.0001). Mobile genetic elements play a crucial role in the transfer of ARGs in S. aureus strains. The structural equation model results revealed a significant correlation between the human development index and rising antibiotic consumption, which subsequently leads to an indirect escalation of AMR in S. aureus strains. Lastly, a machine learning algorithm successfully predicted the AMR risk of global terrestrial S. aureus with over 70% accuracy. Overall, these findings provided valuable insights for managing AMR in S. aureus.
Assuntos
Eliminação de Resíduos , Infecções Estafilocócicas , Humanos , Staphylococcus aureus , Antibacterianos/farmacologia , Alimentos , Farmacorresistência BacterianaRESUMO
Currently, there is great interest in converting edible agro-waste, such as okara from soybean production, into value-added products. For this study, we focus on fabricating composite hydrogels from okara cellulose nanofibers (CNFs) and carrageenan (CA). We also examined the effects of TEMPO oxidation of the okara CNFs, as well as CA concentration, on the microstructure and physicochemical properties of the composite hydrogels. The water holding capacity, oil holding capacity, surface tension, gel strength, and viscoelasticity of the composite microgels increased with increasing CA concentration, and it was found that the highest values were obtained for TC-CA2 hydrogel: contact angle = 43.6° and surface tension = 45.12 mN/m, which was attributed to the formation of a more regular and dense three-dimensional gel network. All the CNF-CA microgels had highly anionic ζ-potential values (-38.8 to -50.1 mV), with the magnitude of the negative charge increasing with TEMPO oxidation and carrageenan concentration. These results suggest there would be strong electrostatic repulsion between the composite hydrogels. The composite microgels produced in our work may be useful functional materials for utilization within the food industry, thereby converting a waste product into a valuable commodity.
Assuntos
Microgéis , Nanofibras , Celulose/química , Carragenina , Nanofibras/química , Hidrogéis/químicaRESUMO
This study aimed to utilize zinc coordination to promote the hypoglycemic and antioxidant properties of walnut-derived peptides, such as walnut protein hydrolysate (WPH) and Leu-Pro-Leu-Leu-Arg (LPLLR, LP5), of which LP5 was previously identified from WPH. The optimal conditions for the chelation were a peptide-to-zinc ratio of 6:1, pH of 9, duration of 50 min, and temperature of 50 °C. The WPH-Zn and LP5-Zn complexes increased the α-glucosidase inhibition, α-amylase inhibition, and antioxidant activity more than WPH and LP5 (p < 0.05). In particular, the antioxidant activity of WPH-Zn was superior to LP5-Zn. This is attributable to the WPH containing more aromatic amino acids, carboxylate groups and the imidazole groups, which implies its capacity to potentially coordinate with Zn2+ to form the WPH-Zn complex. Moreover, particle size, zeta potential, and scanning electron microscope indicated that the chelation of Zn2+ by peptides led to intramolecular and intermolecular folding and aggregation.
Assuntos
Juglans , Juglans/química , Antioxidantes/farmacologia , Zinco/química , Controle Glicêmico , Peptídeos/farmacologia , Quelantes , Hidrolisados de Proteína/químicaRESUMO
To improve the extraction process and quality of Camellia oleifera Abel. oil (COO). This study examined the influence of explosion-puffing (EP) pretreatment on the physicochemical properties, characteristic compounds and sensory quality of the COO. The results revealed that the seeds after EP pretreatment had cavities surface, which facilitated the extraction of the COO and the dissolution of bioactive compounds. Compared to the untreated group, the oil yield of the 6-7%/20 min was increased from 71.41 to 88.94%, as well as higher levels of squalene, phytosterol, α-tocopherol, and phenolic acids, leading to an increase in the antioxidant abilities. Moreover, the fatty acid composition in the COO was not significantly affected (P > 0.05). W1C, W5S, W3C, W5C, and W1W were the main sensors to distinguish the flavor profile of the COO. In summary, EP pretreatment may be a promising method for enhancing oil yield and quality of the COO.
RESUMO
The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which causes the coronavirus disease 2019 (COVID-19), is spreading worldwide. Although the COVID-19 epidemic has passed its peak of transmission, the harm it has caused deserves our attention. Scientists are striving to develop medications that can effectively treat COVID-19 symptoms without causing any adverse reactions. SARS-CoV-2 inhibitory peptides derived from animal proteins have a wide range of functional activities in addition to safety. Identifying animal protein sources is crucial to obtaining SARS-CoV-2 inhibitory peptides from animal sources. This review aims to reveal the mechanisms of action of these peptides on SARS-CoV-2 and the possibility of animal proteins as a material source of SARS-CoV-2 inhibitory peptides. Also, it introduces the utilization of computer-aided design methods, phage display, and drug delivery strategies in the research on SARS-CoV-2 inhibitor peptides from animal proteins. In order to identify new antiviral peptides and boost their efficiency, we recommend investigating the interaction between SARS-CoV-2 inhibitory peptides from animal protein sources and non-structural proteins (Nsps) using a variety of technologies, including computer-aided drug approaches, phage display techniques, and drug delivery techniques. This article provides useful information for the development of novel anti-COVID-19 drugs.
RESUMO
Different storage conditions can influence microbial community structure and metabolic functions, affecting rice grains' quality. However, the microbiological mechanisms by which different storage conditions affect the quality of rice grains are not yet well understood. This study monitored the quality (the content of starch, protein, etc.) and microbial community structure of rice grains stored under different storage conditions with nitrogen gas atmosphere (RA: normal temperature, horizontal ventilation, RB: normal temperature, vertical ventilation, RC: quasi-low temperature, horizontal ventilation). The results revealed that the rice grains stored under condition RB exhibited significantly lower quality compared to condition RA and RC. In addition, under this condition, the highest relative abundance of Aspergillus (16.0%) and Penicillium (0.4%) and the highest levels of aflatoxin A (3.77 ± 0.07 µg/kg) and ochratoxin B1 (3.19 ± 0.05 µg/kg) were detected, which suggested a higher risk of fungal toxin contamination. Finally, co-occurrence network analysis was performed, and the results revealed that butyl 1,2-benzenedicarboxylate was negatively correlated (p < 0.05) with Moesziomyces and Alternaria. These findings will contribute to the knowledge base of rice storage management and guide the development of effective control measures against undesirable microbial activities.
RESUMO
Hickory is an abundant source of phenolic compounds that exhibit a diverse range of bioactivities. In this study, phenolic compounds were extracted and purified from hickory green husk (HG), hickory nutshell (HN), and hickory seed coat (HS) using solid-phase extraction and ultrasonication (SPE-US). The effects of the SPE-US treatment on the structure and properties of the phenolic compounds were then investigated, including their composition, antioxidant activity, and antimicrobial activity. The dominant phenolic substances in the different extracts after SPE-US treatment were: ellagic acid and trans ferulic acid (HS); ellagic acid and sinapic acid (HN); and rutin (HG). The HS-SPE-US1 extract exhibited the highest total polyphenol content (416 ± 11 mg GAE/g DW), total flavonoid content (47.51 ± 0.68 mg RE/g DW), Fe3+ reduction ability (74.2 ± 1.0 mmol Fe2+/g DW), radical (DPPH and ABTS) scavenging ability, and antimicrobial activity against Staphylococcus aureus.