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The postharvest quality of winter jujubes is prone to deterioration, including inevitable pericarp reddening and rapid nutrient loss from the flesh, significantly impacting its edible quality and commercial value. As a crucial metabolic pathway in plants, phenylpropane metabolism not only regulates plant stress resistance but also closely relates to various coloration effects. In this study, we investigated the effects of luteolin solutions on postharvest color changes and phenylpropanoid metabolism in winter jujube. The results indicated that compared to the control group, winter jujube fruit treated with 200 mg L-1 luteolin exhibited improved quality indexes, increased antioxidant capacity (capability of eliminating ABTS and DPPH radicals), and higher activities of antioxidant enzymes(superoxide dismutase (SOD), and catalase (CAT)). This led to a reduction in the oxidation of phenolic substances in winter jujube. Furthermore, luteolin treatment inhibited phenylpropanoid metabolism by suppressing the activities of 4-Coumarate: coenzyme A ligase (4CL), phenylalanine ammonilyase (PAL), and cinnamate 4 hydroxylase (C4H), as well as the expression of ZjUFGT, ZjDFT, and ZjPAL genes. Consequently, anthocyanin and quercetin synthesis were limited while the degradation rate of chlorophyll and carotenoid synthesis were slowed down after luteolin treatment. This resulted in delayed reddening of winter jujube following luteolin treatment. In conclusion, luteolin exhibits potential application prospects as a preservative for inhibiting reddening and browning in winter jujubes.
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BACKGROUND: Patients using web-based health care communities for e-consultation services have the option to choose their service providers from an extensive digital market. To stand out in this crowded field, doctors in web-based health care communities often engage in prosocial behaviors, such as proactive and reactive actions, to attract more users. However, the effect of these behaviors on the volume of e-consultations remains unclear and warrants further exploration. OBJECTIVE: This study investigates the impact of various prosocial behaviors on doctors' e-consultation volume in web-based health care communities and the moderating effects of doctors' digital and offline reputations. METHODS: A panel data set containing information on 2880 doctors over a 22-month period was obtained from one of the largest web-based health care communities in China. Data analysis was conducted using a 2-way fixed effects model with robust clustered SEs. A series of robustness checks were also performed, including alternative measurements of independent variables and estimation methods. RESULTS: Results indicated that both types of doctors' prosocial behaviors, namely, proactive and reactive actions, positively impacted their e-consultation volume. In terms of the moderating effects of external reputation, doctors' offline professional titles were found to negatively moderate the relationship between their proactive behaviors and their e-consultation volume. However, these titles did not significantly affect the relationship between doctors' reactive behaviors and their e-consultation volume (P=.45). Additionally, doctors' digital recommendations from patients negatively moderated both the relationship between doctors' proactive behaviors and e-consultation volume and the relationship between doctors' reactive behaviors and e-consultation volume. CONCLUSIONS: Drawing upon functional motives theory and social exchange theory, this study categorizes doctors' prosocial behaviors into proactive and reactive actions. It provides empirical evidence that prosocial behaviors can lead to an increase in e-consultation volume. This study also illuminates the moderating roles doctors' digital and offline reputations play in the relationships between prosocial behaviors and e-consultation volume.
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Internet , Humanos , China , Femenino , Masculino , Médicos/psicología , Médicos/estadística & datos numéricos , Conducta Social , Adulto , Consulta Remota/estadística & datos numéricos , Consulta Remota/métodosRESUMEN
Cuticle wax chemicals are cultivar-dependent and contribute to storage quality. Few research reported on wax analysis between melting flesh-type (MF; 'Jinhuami 25') and nonmelting flesh-type (NMF; 'Xizhoumi 17' and 'Chougua') Hami melons. Chemicals and crystal structures of Hami melon cuticular wax, cell wall metabolism related to fruit melting, and fruit physiology were analyzed to observe wax functions. Results showed that Hami melon cuticle wax predominantly consists of esters, alkanes, alcohols, aldehydes, and terpenoids. MF-type has a lower alkane/terpenoid ratio, concomitant to its higher weight loss and cuticle permeability. Micromorphology of wax crystals appears as numerous platelets with irregular crystals, and the transformation of wax structure in NMF Hami melon is delayed. Waxy components affect cell wall metabolism and physiological quality, which results in the pulp texture difference between MF-type and NMF-type during storage. Results provide a reference for the regulation of wax synthesis in both types of melons.
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Cucumis melo , Frutas , Ceras , Ceras/química , Frutas/química , Cucumis melo/química , Pared Celular/químicaRESUMEN
Wearable flexible sensors with high sensitivity and wide detection range are applied in motion detection, medical diagnostic result and other fields, but poor resilience and hysteresis remain a challenge. In this study, a high-resilience foam sensor was prepared through a combination of additive manufacturing and green physical foaming method. The conductive filaments were prepared by using MWCNTs-modified TPU by the physical method of melt blending. Samples were prefabricated using the FFF printer and then saturated with CO2 in an autoclave before being removed and heated to foam. The composite foam effectively reduced residual strain, demonstrating the high resilience of the 3D-printed composite materials with a foam porous structure. The residual strain of the sample before foaming was >6% after a single cycle, and then gradually increased. The residual strain of the foamed samples is less than 5%. In addition, composite foam has high sensitivity and can monitor subtle pressure changes (0~40 kPa). The sensing performance of the composite foam was evaluated, and the current signal remained stable under different loading rates and small compression strains (2~5%). By using this highly resilient conductive composite material, a hierarchical shoe insole was designed that successfully detected human walking and running movements.
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Winter jujube fruit is susceptible to aging, peel reddening, dehydration, shrinkage, and tissue softening during shelf life after it is removed from the cold storage conditions. In this study, the effects of 1-methylcyclopropene (1-MCP) and salicylic acid (SA) on the quality of winter jujube fruit during shelf life were investigated by measuring physiological indexes and the activities of antioxidant enzymes and enzymes related to reactive oxygen species (ROS) metabolism of winter jujube fruit. The results showed that 1-MCP treatment and SA treatment suppressed weight loss, respiratory rate, malondialdehyde (MDA) content, H2O2 content, and O 2 - · production rate, but improved firmness, color difference (ΔE), soluble solid content (SSC), titratable acidity (TA), superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), phenylalanine ammonia-lyase (PAL) activities, ascorbic acid content, glutathione content, total phenolic content, and total flavonoid content in comparison with the control. Particularly, the combined treatment of 1-MCP and SA (1-MCP+SA treatment) showed the maximum efficacy compared to the 1-MCP treatment and SA treatment alone. 1-MCP+SA treatment exhibited the best preservation effect, followed by SA treatment and 1-MCP treatment. Thus, the combined treatment of 1-MCP and SA is an effective approach to maintain the postharvest quality of winter jujube fruit and extend the shelf life.
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The fast-paced lifestyle resulting from China's rapid economic development has caused more than 500 million sudden cardiac deaths in 2020. Online first-aid education for the public is considered a key potential solution to avoid such incidents and would have great practical value. This study focuses on understanding the impact of past first-aid experience on the intention for online learning of first-aid knowledge and skills from the perspective of individual psychological factors based on the construction level and prosociality theories. More specifically, it tests the mediating roles of psychological distances and prosociality, which reflect psychological status, in the relationship between experience and learning intention along with a series of associated demographic variables. Primary data collected via a survey are analyzed through regression analysis. The results show that first-aid experience has a significant positive impact on online first-aid learning intention. In addition, psychological distances from first-aid events, and prosociality, play mediating roles in the relationship between first-aid experience and learning intention. Thus, this study contributes to understanding first-aid learning intention by revealing the impact of the individual factors of psychological distances and prosociality.
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The edible and medicinal perennial herb dandelion is known to have antitumor, antioxidant, and anticomplement properties. However, the structural characterization and biological effects of its polysaccharides are not well understood. Here, we aimed to extract and investigate a novel polysaccharide from dandelion. A water-soluble polysaccharide, PD1-1, was successfully obtained from dandelion through ultrasonic-assisted extraction and purification using diethylaminoethyl (DEAE)-Sepharose fast flow and Sephadex G-75 columns. The results showed that PD1-1 is an inulin-type polysaccharide with a molecular weight of 2.6 kDa and is composed of glucose (52.39%), and mannose (45.41%). Glycosidic linkage analysis demonstrated that PD1-1 contains terminal α-d-Man/Glcp-(1â and â1)-ß-d-Man/Glcf-(2â glycosidic linkage conformations. A physicochemical analysis indicated that PD1-1 has a triple helix structure and exhibits important properties, including good swelling, water-holding, and oil-holding capacities. Furthermore, PD1-1 showed good antioxidant activities in DPPH and hydroxyl free radical scavenging abilities, with IC50 values of 0.23 mg/mL and 0.25 mg/mL, respectively, and good hypoglycemic activities in α-amylase and α-glucosidase inhibition, with IC50 values of 0.53 mg/mL and 0.40 mg/mL, respectively, in a concentration-dependent manner. Results suggest that PD1-1 possesses efficacious antioxidant and hypoglycemic properties and has potential applications as a functional food ingredient.
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Antioxidantes/química , Inhibidores de Glicósido Hidrolasas/química , Polisacáridos/química , Taraxacum/química , alfa-Amilasas , alfa-Glucosidasas/química , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/químicaRESUMEN
Objective: The aim of this study was to evaluate the remineralization efficacy of an amelogenin-based peptide on initial enamel carious lesions in vitro. Furthermore, we attempted to provide insights into the possible mechanism of the remineralization, including determining the calcium-binding properties of the peptide and its effects on calcium phosphate mineralization. Methods: The peptide comprising the N-terminus and the C-terminus of porcine amelogenin was synthesized by Synpeptide Co., Ltd. Fifty specimens were randomly assigned to five immersing treatment groups for 12 days: remineralizing medium only; 12.5 µg/mL peptide + remineralizing medium; 25 µg/mL peptide + remineralizing medium; 50 µg/mL peptide + remineralizing medium; fluoride + remineralizing medium. After immersion, mean mineral loss before and after remineralization of each specimen was determined using micro-CT. Mean mineral gain after remineralization was calculated. Calcium binding properties were measured by Isothermal titration calorimetry (ITC). TEM and Fourier transform-infrared were used to determine the effects of the peptide on calcium phosphate mineralization. Results: A significant decrease in mineral loss after remineralization process in all groups was observed (p < 0.05). Treatment in remineralizing medium resulted in the lowest mineral gain while the fluoridated treatment exhibited the highest mineral gain among all groups. Inclusion of synthetic peptide in the remineralizing medium exhibited a higher mineral gain and the gain of 50 µg/mL group was greater than that of the 25 µg/mL group. No significant difference in mineral gain was observed between the remineralizing medium only group and the 12.5 µg/mL peptide group (p > 0.05). ITC values showed that the Ca2+-binding affinity of the peptide is about 9.914 × 104M-1. Furthermore, the peptide was found to inhibit calcium phosphate precipitation and stabilize amorphous calcium phosphate formation for more than 2 h and finally transform into ordered hydroxyapatite crystals. Conclusion: Specific concentrations of the amelogenin-based synthetic peptide promoted in vitro remineralization, with higher concentrations exhibiting significantly greater remineralization. This study presented evidence suggesting that the peptide may act as a Ca2+carrier as well as a regulating factor. When the stabilizing calcium and phosphorus ions bind with the peptide they become biologically available for the remineralization of deeper carious lesions, while also regulated by the peptide to transform into ordered hydroxyapatite crystals.
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In this paper, reduced graphene oxide functionalized with cobalt ferrite nanocomposites (CoFe@rGO) as a novel type of electromagnetic wave (EW) absorbing materials was successfully prepared by a three-step chemical method including hydrothermal synthesis, annealing process and mixing with paraffin. The effect of the sample thickness and the amount of paraffin on the EW absorption properties of the composites was studied, revealing that the absorption peaks shifted toward the low frequency regions with the increasing thickness while other conditions had little or no effect. It is found that the CoFe@rGO enhanced both dielectric losses and magnetic losses and had the best EW absorption properties and the wide wavelength coverage of the hole Ku-Band when adding only 5wt% composites to paraffin. Therefore, CoFe@rGO could be used as an efficient and lightweight EW absorber. Compared with the research into traditional absorbing materials, this figures of merit are typically of the same order of magnitude, but given the lightweight nature of the material and the high level of compatibility with mass production standards, making use of CoFe@rGO as an electromagnetic absorber material shows great potential for real product applications.
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OBJECTIVES: To investigate the effect of Galla chinensis chemical compounds on enamel caries remineralization in rats. METHODS: A total of 40 rats were inoculated with Streptococcus sobrinus 6715 and fed a cariogenic diet (Keyes 2000). The rats were randomly divided into 4 groups and treated topically twice a day with each of the following extracts (or control) for 5 weeks: distilled and deionized water (DDW, negative control); 1,000 ppm NaF (positive control); 4,000 ppm G. chinensis crude aqueous extract (GCE), or 4,000 ppm gallic acid (GA). After the experimental period, Keyes' caries diagnosis and scoring technique was applied as a preliminary evaluation on the molar teeth. For more accurate remineralization data, the residual enamel volume of the first molar and the mineral density (MD) of the enamel were further analyzed by micro-CT. RESULTS: The severity of molar enamel caries decreased in the following order of treatment groups: DDW > GA > GCE > NaF (p < 0.05). In addition, the residual first molar enamel volume and MD values increased in the order of DDW, GA, GCE and NaF treatment groups (p < 0.05). In most molars, remineralization layers were observed on the surface of lesions. CONCLUSION: G. chinensis compounds remineralize enamel caries lesions in a rat model.