In this study, we determined the influences of different drying techniques such as natural air (ND), hot-air (HD), vacuum (VD), infrared (ID), microwave (MD), and freeze drying (FD) methods on the ...color, shrinkage ratio (SR), rehydration ratio (RR), firmness, crispness, microstructures, nutritional components, and free amino acids of Pleurotus eryngii. The results showed that these parameters were markedly influenced by different drying techniques. Among them, FD was the most effective drying method which retained the main characteristics of the fresh P. eryngii in above mentioned indexes, followed by ND and HD at 40 °C. Finally, despite the least drying time, MD treatment was not suitable to the drying process of P. eryngii slices since it damaged physicochemical properties and caused massive losses of the main nutrients and free amino acids. The results will provide a theoretical basis for industrial processing of P. eryngii.
Chlorogenic acid is a well-known antioxidant and has more isomers according to the difference in binding location and number of caffeic on quinic acid. In this study, we investigated and compared the ...profiles of antioxidant and DNA-protective activities of chlorogenic acid isomers including three caffeoylquinic acid isomers (3-O-caffeoylquinic acid, 3-CQA; 4-O-caffeoylquinic acid, 4-CQA; and 5-O- caffeoylquinic acid, 5-CQA) and three dicaffeoylquinic acid isomers (3,5-dicaffeoyl-quinic acid, ICAA; 3,4-dicaffeoylquinic acid, ICAB; and 4,5-dicaffeoyl-quinic acid, ICAC). The results showed that each of chlorogenic acid isomers studied exhibited antioxidant activities and DNA damage protective effects to various extents. On the whole, dicaffeoylquinic acids possessed better antioxidant activities, mostly because they have more hydroxyl groups than caffeoylquinic acids. Three caffeoylquinic acid isomers showed quite similar antioxidant activities, indicating that the position of esterification on the quinic moiety of caffeoylquinic acid had no effect on its antioxidant activities. Quite the contrary, a difference among dicaffeoylquinic acid isomers was observed, namely, ICAA and ICAB exhibited the same antioxidant activities, whereas ICAC had higher antioxidant activities than ICAA and ICAB in some assays, which implied that their antioxidant activities were probably influenced by the position of esterification on the quinic moiety. We speculated that this difference might be due to the fact that there may exist a steric hindrance effect in the ICAC. However, this assumption needs to be further confirmed.
Fennel (Foeniculum vulgare Mill.) is widely cultivated and used as a culinary spice. In this work, the chemical composition of the essential oil obtained by hydrodistillation of fennel seeds was ...analyzed by gas chromatography-mass spectrometry (GC–MS), and 28 components were identified. Trans-anethole (68.53%) and estragole (10.42%) were found to be the major components. The antibacterial activity, minimum inhibitory concentration (MIC), and minimum bactericide concentration (MBC) of essential oil against several food-borne pathogens were evaluated. The results showed that the gram positive and gram negative strains of bacteria had different sensitivities to essential oil of fennel seeds, the essential oil exhibited antibacterial activity against Staphylococcus albus, Bacillus subtilis, Salmonella typhimurium, Shigella dysenteriae and Escherichia coli according to the results of MIC and MBC. Among these bacteria, S. dysenteriae was the most sensitive to essential oil, showing the lowest MIC and MBC values of 0.125 and 0.25 mg/mL respectively. In addition, kill-time assay also showed that the essential oil had a significant effect on the growth rate of surviving S. dysenteriae. We concluded that the mechanism of action of the essential oil against S. dysenteriae might be described as essential oil acting on membrane integrity according to the results of the leakage of electrolytes, the losses of contents (proteins, reducing sugars and 260 nm absorbing materials) assays and electron microscopy observation.
•Analyzed the chemical compositions of essential oil from fennel seeds.•Investigated the antibacterial activity of essential oil from fennel seeds.•Evaluated the action mechanism of essential oil against Shigella dysenteriae.
The essential oil of clove has a wide range of pharmacological and biological activities and is widely used in the medicine, fragrance and flavoring industries. In this work, 22 components of the ...essential oil obtained from clove buds were identified. Eugenol was the major component (76.23%). The essential oil exhibited strong antibacterial activity against Staphylococcus aureus ATCC 25923 with a minimum inhibitory concentration (MIC) of 0.625 mg/mL, and the antibacterial effects depended on its concentration and action time. Kill-time assays also confirmed the essential oil had a significant effect on the growth rate of surviving S. aureus. We hypothesized that the essential oil may interact with the cell wall and membrane first. On the one hand it destroys cell wall and membranes, next causing the losses of vital intracellular materials, which finally result in the bacterial death. Besides, essential oil penetrates to the cytoplasmic membrane or enters inside the cell after destruction of cell structure, and then inhibits the normal synthesis of DNA and proteins that are required for bacterial growth. These results suggested that the effects of the clove essential oil on the growth inhibition of S. aureus may be at the molecular level rather than only physical damage.
It is well accepted that the microwave absorption performance (MAP) of carbon nanotubes (CNTs) can be enhanced via coating magnetic nanoparticles on their surfaces. However, it is still unclear if ...the magnetic coating structure has a significant influence on the microwave absorption behavior. In this work, nano-Fe3O4 compact-coated CNTs (FCCs) and Fe3O4 loose-coated CNTs (FLCs) are prepared using a simple solvothermal method. The MAP of the Fe3O4-coated CNTs is shown to be adjustable via controlling the Fe3O4 nanocoating structure. The results reveal that the overall MAP of coated CNTs strongly depends on the magnetic coating structure. In addition, the FCCs show a much better MAP than the FLCs. It is shown that the microwave absorption difference between the FLCs and FCCs is due to the disparate complementarities between the dielectric loss and the magnetic loss, which are related to the coverage density of Fe3O4 nanoparticles on the surfaces of CNTs. For FCCs, the mass ratio of CNTs to Fe3+ is then optimized to maximize the effective complementarities between the dielectric loss and the magnetic loss. Finally, a comparison is made with the literature on Fe3O4-carbon-based composites. The FCCs at the optimized CNT to Fe3+ ratio in the present work show the most effective specific RLmin (28.7 dB·mm–1) and the widest effective bandwidth (RL < −10 dB) (8.3 GHz). The excellent MAP of the as-prepared FCC sample is demonstrated to result from the consequent dielectric relaxation process and the improved magnetic loss. Consequently, the structure–property relationship revealed is significant for the design and preparation of CNT-based materials with effective microwave absorption.
The β‐relaxation is one of the major dynamic behaviors in metallic glasses (MGs) and exhibits diverse features. Despite decades of efforts, the understanding of its structural origin and contribution ...to the overall dynamics of MG systems is still unclear. Here two palladium‐based Pd─Cu─P and Pd─Ni─P MGs are reported with distinct different β‐relaxation behaviors and reveal the structural origins for the difference using the advanced X‐ray photon correlation spectroscopy and absorption fine structure techniques together with the first‐principles calculations. The pronounced β‐relaxation and fast atomic dynamics in the Pd─Cu─P MG mainly come from the strong mobility of Cu atoms and their locally favored structures. In contrast, the motion of Ni atoms is constrained by P atoms in the Pd─Ni─P MG, leading to the weakened β‐relaxation peak and sluggish dynamics. The correlation of atomic dynamics with microscopic structures provides a way to understand the structural origins of different dynamic behaviors as well as the nature of aging in disordered materials.
The atomic origins of diverse beta‐relaxations in Pd‐based metallic glasses (MGs) are systematically investigated, which are due to the dynamic heterogeneity, i.e., local packing difference which favors the fast diffusion of certain atoms. This work reveals that the bonding between the metalloid‐ and metallic‐atoms can significantly alter the atomic dynamics, providing a hint to obtain MGs with good glass‐forming ability.
Discrete choice models typically incorporate product/service attributes, many of which are categorical. Researchers code these attributes in one of two ways: dummy coding and effects coding. Whereas ...previous studies favor effects coding citing that it resolves confounding between attributes, our analysis demonstrates that such confounding does not exist in either method, even when a choice model contains alternative specific constants. Furthermore, we show that because of the lack of understanding of the equivalence between the two coding methods, a sizeable number of previously published articles have misinterpreted effects coded results. The misinterpretation generates conflicting preference ordering and renders t‐statistics, marginal willingness to pay, as well as consumer surplus/compensating variation estimates invalid. We show that severe misinterpretation occurs for any categorical attribute that contains more than two discrete levels. The frequency of two‐level attributes used in discrete choice analyses may have led some past studies to overlook this error. Given its equivalence and lower likelihood of misinterpretation, we recommend dummy coding.
We analyze the dynamic changes in individuals' lifestyle during the COVID-19 outbreak and recovery period through a survey of 1061 Chinese households. Specifically, we are interested in individuals' ...bodyweight, time allocation and food choices. We find that COVID-19 is associated with weight gain, less time spent on exercise and more time on entertainment. The proportion of online food purchase and snack purchases also shows an upward trend. This study provides useful implications on the impact of COVID-19 and its associated lockdowns on individuals' lifestyle and offers foresights for countries in different stages of the pandemic. It explains how encouraging exercise, managing new food purchase venues, and reducing the intake of unhealthy food such as snacks may also need to be considered in dealing with the aftermath of COVID-19.
Endothelial cells (ECs) are located at the interface between flowing blood and the vessel wall, and abnormal EC proliferation induced by pathologic environments plays an important role in vascular ...remodeling in hypertensive conditions. Exchanges of information between blood components and ECs are important for EC function. Hence, the present study sought to determine how platelets induce EC dysfunction under hypertensive conditions. EC proliferation was increased in renal hypertensive rats established by abdominal aortic coarctation compared with control rats and that elevated thrombin in plasma promoted platelet activation, which may induce the release of platelet‐derived microparticles (PMPs). MicroRNA (MiR) array and qPCR revealed a higher level of miR‐142–3p in platelets and PMPs. In vitro, PMPs delivered miR‐142–3p into ECs and enhanced their proliferation via Bcl‐2‐associated transcription factor (BCLAF)1 and its downstream genes. These results indicate that PMPs deliver miR‐142–3p from activated platelets into ECs and that miR‐142–3p may play important roles in EC dysfunction in hypertensive conditions and may be a novel therapeutic target for maintaining EC homeostasis in hypertension.—Bao, H., Chen, Y.‐X., Huang, K., Zhuang, F., Bao, M., Han, Y., Chen, X.‐H., Shi, Q., Yao, Q.‐P., Qi, Y.‐X. Platelet‐derived microparticles promote endothelial cell proliferation in hypertension via miR‐142‐3p. FASEB J. 32, 3912–3923 (2018). www.fasebj.org
Green huajiao, which is the ripe pericarp of the fruit of Zanthoxylum schinifolium Sieb. et Zucc, is widely consumed in Asia as a spice. In this work, the chemical composition of the essential oil ...from green huajiao was analyzed by gas chromatography (GC) and GC/mass spectrometry (MS), and the majority of components were identified. Linalool (28.2%), limonene (13.2%), and sabinene (12.1%) were found to be the major components. The antibacterial activity, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of the essential oil were evaluated against selected bacteria, including food-borne pathogens. The results showed that the sensitivities to the essential oil were different for different bacteria tested, and the susceptibility of Gram-positive bacteria tested was observed to be greater than that of Gram-negative bacteria. The antibacterial activity of the essential oil was particularly strong against Staphylococcus epidermidis, with MIC and MBC values of 2.5 and 5.0 mg/mL, respectively. A postcontact effect assay also confirmed the essential oil had a significant effect on the growth rate of surviving S. epidermidis. The antibacterial activity of the essential oil from green huajiao may be due to the increase in permeability of cell membranes, and the leakage of intracellular constituents, on the basis of the cell constituents’ release assay and electron microscopy observations.
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