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Abstract Micro-/nano-hydroxyapatite (MHA/NHA) has been used to reduce the concentration of available heavy metals and increase soil pH in the remediation of heavy metal-contaminated soils. However, little is known about the effects of MHA and NHA on soil fungal communities and function. In this study, fungal community composition was characterized from copper-contaminated soils amended with MHA, NHA and three other classic amendments combined with Elsholtzia splendens during a 3-year immobilization experiment. High-throughput sequencing results showed that applications of MHA increased the richness and diversity of the fungal community, which was opposite the results of NHA. SIMPER analysis indicated that both the relative abundance of fungi associated with biosorption and plant growth promotion increased, whereas the relative abundance of fungi related to bioleaching and potential pathogens decreased after applying MHA. Redundancy (RDA) analysis revealed that the soil pH was a crucial environmental factor in the succession of fungal communities. In addition, the results of functional prediction via FUNGuild suggested that the application of MHA had the potential to reduce the risk of pathogens infecting animals and plants in the soil but that NHA had some environmental risks. Overall, fungal community showed a synergistic effect of immobilization with the test amendments, and MHA was better for the remediation of heavy metal-contaminated soils than the other test amendments. Highlights • Fungal community structure significantly varied with the application of MHA/NHA combined with phytoremediation. • The applications of MHA increased the richness and diversity of the fungal community, which was opposite the results of NHA. • The relative abundance of fungi associated with heavy metal-leaching decreased by application of MHA. • The application of MHA had the potential to reduce the risk of pathogens in the soil but that NHA had some environmental risks. [ABSTRACT FROM AUTHOR]

In this study, five Fucus vesiculosus polysaccharides (FVPs; FVP-2, FVP-4, FVP-7, FVP-10, and FVP-13) were extracted by different pH, and their physicochemical characteristics and α -glucosidase inhibitory activity were investigated. Results showed that extraction pH significantly affected the chemical composition, molecular weight, zeta potential, structure characterization, and rheological property of FVPs. The viscosity consistency index of Fucus vesiculosus polysaccharides at high concentration (40 mg/mL) were ranked in decreasing order as FVP-10 > FVP-4 > FVP-7 > FVP-2 > FVP-13, which was strictly in accordance with the order of Mw. Among the five polysaccharides, FVP-13 showed the strongest α -glucosidase inhibitory activity, which might be related to its the lowest Mw and relatively higher xylose content. Fluorescence quenching analysis indicated that the interaction of FVPs and α -glucosidase was predominated by a dynamic mechanism. Thermodynamic analysis showed that the main driving forces for the interaction was hydrophobic interaction. Circular dichroism spectrum analysis found that FVPs could induce the secondary structure of α -glucosidase changes like the decrease of β -sheet content and the increase of β -turn and random coil content to inhibit α -glucosidase activity. These results suggested that extraction with high pH was an efficient method to obtain FVPs with strong α -glucosidase inhibition activity. • Five Fucus vesiculosus polysaccharides were obtained at different extraction pH. • FVP-13 showed the stronger α -glucosidase inhibitory activity. • The α -glucosidase inhibitory mechanism of polysaccharide was studied. • Hydrophobic interaction played a key role in the bonding of FVPs to α -glucosidase. [ABSTRACT FROM AUTHOR]

Abstract: Porcine β defensin 1 (pBD1) is a cationic antimicrobial peptide with three pairs of disulfide bonds. When expressed in insect cells, two polypeptides of different length (pBD138 and pBD142) accumulated, which differed by N-terminal truncation. However, only pBD142 was found in pigs. pBD142 had stronger antimicrobial activity than pBD138, and thus could be a good candidate as a bactericidal agent for pigs. In this study, pBD142 gene, obtained by RT-PCR using the tongue total RNA as a template, was cloned into pET30a expression vector and transformed into Escherichia coli BL21 (DE3) plysS. The recombinant pBD142 was expressed after induction by IPTG and purified by His tag affinity column with 90% purity. The recombinant pBD142 exhibited antimicrobial activity against both Gram-positive Staphylococcus aureus and Gram-negative E. coli including the multi-resistant E. coli. The minimum inhibitory concentrations (MICs) of recombinant pBD142 against tested bacteria were 100μg/mL for E. coli and 80μg/mL for S. aureus. In addition, pBD142 showed low hemolytic activity and high thermal stability. These properties are relevant for the biotechnological applications of the peptide. [Copyright &y& Elsevier]

Spacecraft devices have strict restrictions on weight and volume for high fuel efficiency and endurance requirements. In this paper, a method for designing an ultrathin passive vibration isolator based on multi-layer plain-woven wire mesh is proposed. The isolator is structurally inspired by O-type wire rope isolators, and the wire mesh is pre-compressed to buckling for lower stiffness and higher stability. The isolator stiffness in the post-buckling process is analyzed by simplifying the single wire as a strut. The motion equation of the strut is constructed and calculated by the fourth-order Runge–Kutta method and the shooting method. The morphology and stiffness variation of the wire mesh during pre-compression process and repeated compression process are analyzed, and the structural compaction ratio is calculated. This computational method has been experimentally validated and proven to be effective. To prevent collisions between the protected objects and the base during the shock process, the system is simplified and described using a single-degree-of-freedom (SDOF) system with displacement restrictors. The system's motion equation is formulated and solved using the central difference method. Subsequently, the maximum compression displacement of the isolator is determined through the calculation. A wire mesh isolator with a thickness of less than 10 mm is fabricated for a specific application. Experimental results confirm that the isolation efficiency surpasses 65%, and the isolator is capable of withstanding a peak acceleration of 60 g while maintaining a shock acceleration magnification below 1.2. • A method for designing vibration isolators composed of the wire mesh is proposed. • The isolator stability performance is enforced by pre-compressing the wire mesh. • The morphology and stiffness variation of the wire mesh are calculated. • The shock displacement amplitude is calculated using the central difference method. [ABSTRACT FROM AUTHOR]