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Nickel cobalt selenide presents a typical Faraday charge storage mechanism, but its electrochemical performance is limited due to its poor reaction kinetics. As a common defect type, vacancy defects can eliminate the limitations of intrinsic chemical and structural characteristics, thereby improving the reaction kinetics of the electrode. Herein, we report a Va-NiCo2Sex nanomaterial with adjustable Se vacancy concentrations achieved by NaBH4 induction, realizing an enhancement of the performance of the supercapacitor. This adjustment of vacancy concentrations can not only essentially regulate the adsorption site and ion valence state and enhance the adsorption capacity and redox activity of ions, but also reveal the significant improvement of vacancy modification on the surface reaction kinetics of electrode materials through density functional theory (DFT) calculation. The electrochemical results show that the V2-NiCo2Sex electrode material with optimal vacancy concentrations has the highest specific capacity of 310.8 mA h g−1 at 1 A g−1. The assembled hybrid supercapacitor V2-NiCo2Sex//AC-HSC can provide a high energy density of 76.5 W h kg−1 at a power density of 800.1 W kg−1. This work provides an effective strategy for exploring the structure–function relationship between vacancy concentrations and electrochemical performance. [ABSTRACT FROM AUTHOR]

Transition metal selenide is a typical pseudocapacitive material used in supercapacitor electrodes, but its practical application is restricted due to its insufficient utilization rate of active sites and slow kinetics of redox reaction. Defect engineering can effectively adjust the electronic structure, provide additional intercalation sites, and realize the regulation of energy storage mechanism within the lattice. At present, heteroatom doping is an effective strategy that can provide abundant vacancy defects by introducing heterogeneous atoms, thereby achieving significantly improved electrochemical performance. Based on this, NiCo2Se4 electrode materials with Se vacancies were prepared by P doping for supercapacitors. The double-effect synergy of P doping and vacancy engineering can effectively change the electronic structure and improve the adsorption capacity of ions, which are more prone to redox reactions. The assembled hybrid supercapacitor (NiCo2Sex-P1//AC) has 90.2% capacity retention and 100% coulombic efficiency after 10 000 consecutive charge–discharge cycles, and it exhibits a high energy density of 94.6 W h kg−1 at a power density of 799.9 W kg−1. This provides an effective strategy for constructing high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Hyaluronic acid is a high-molecular-weight polysaccharide that is widely distributed in animal tissues. Bacterial hyaluronidases degrade hyaluronic acid as secreted enzymes and have been shown to contribute to infection. Staphylococcus aureus UAMS-1 is a clinical isolate that codes for two hyaluronidases (hysA1 and hysA2). Previous research has shown the presence of a full-length HysA1 protein from the S. aureus UAMS-1 strain with no evidence of enzymatic activity. In this study, the coding and upstream promoter regions of hysA1 from the S. aureus UAMS-1 strain were cloned, sequenced, and compared to the hysA1 gene from the S. aureus Sanger 252 strain. A single base change resulting in an E480G amino acid change was identified in the hysA1 gene from the S. aureus UAMS-1 strain when compared to the hysA1 gene from S. aureus Sanger 252. A plasmid copy of hysA1 from S. aureus Sanger 252 transduced into an S. aureus UAMS-1 hysA2 deletion mutant strain restored near wild-type levels of enzymatic activity. Homology modeling of the HysA1 hyaluronidase was performed with SWISS-MODEL using hyaluronidase from Streptococcus pneumoniae as the template, followed by a series of structural analyses using PyMOL, PLIP, PDBsum, and HOPE servers. This glutamic acid is highly conserved among hyaluronidases from Staphylococcus and other gram-positive bacteria. A series of structural analyses suggested that Glu-480 in HysA1 is critically responsible for maintaining the structural and functional ensemble of the catalytic and tunnel-forming residues, which are essential for enzyme activity. The missense mutation of Glu-480 to Gly introduces a loss of side chain hydrogen bond interactions with key residues Arg-360 and Arg-364, which are responsible for the tunnel topology, resulting in displacement of the substrate from an ideal position for catalysis through a localized conformational change of the active site. There is a high degree of relatedness among several gram-positive bacterial hyaluronidases; the loss of enzymatic activity of HysA1 in the S. aureus UAMS-1 strain is most likely caused by the mutation identified in our study. The role of hyaluronidase in staphylococcal infection and the redundancy of this gene are yet to be determined. [ABSTRACT FROM AUTHOR]

Research has been conducted on the Ralstonia solanacearum twitching motility, a form of bacterial translocation over the firm surfaces requiring retractile type IV pili. Results indicate that R. solanacearum exhibits twitching motility via the type IV pilus system which contributes to the tomato plant pathogenesis.

With the rapid development of China's economic construction and the rapid advancement of urban-rural integration construction, meteorological detection environment has been damaged repeatedly, which seriously affects the representativeness, accuracy, and comparability of meteorological data, so it is urgent to protect meteorological detection environment. Based on the investigation and evaluation method of detection environment of national ground meteorological observation stations and high-altitude meteorological observation stations, satellite remote sensing data, and climate analysis method, the evaluation method of detection environment and meteorological data was improved to comprehensively assess the detection environment and meteorological data of stations. After the evaluation results were compared with the results of the survey and evaluation in 2013, it is found that the new assessment method maintains the continuity of detection environment assessment and can objectively reflect the changes of the station detection environment. The research on the method and standard for the evaluation of detection environment and data analysis of meteorological stations provides a scientific basis for the establishment of detection environmental protection plans by stations at all levels, and provides technical support for the scientific and rational adjustment of station network by administrative departments at all levels. [ABSTRACT FROM AUTHOR]

Three-dimensional butterfly-like BiVO was successfully synthesized by a simple solvothermal method at a proper volume ratio (1:4) of EG/HO mixed solution. It was found that ethylene glycol (EG) had an obvious influence on the morphologies of the final products. BiVO with different morphologies could be obtained by simply adjusting the volume ratio of the EG/HO. The crystal structures, morphologies, and photophysical properties of the products were well characterized. The photocatalytic activities of the samples were evaluated by decolorization of methylene blue (MB) under simulated sunlight irradiation. The results demonstrated that BiVO with butterfly-like morphology was better than that of BiVO-1, BiVO-3 and BiVO-4 for photodegradation of MB. The monoclinic butterfly-like BiVO-2 possessed bigger specific surface area, lower band gap energy, and interesting morphology, resulting in the highest photocatalytic activity under simulated sunlight irradiation. [ABSTRACT FROM AUTHOR]

Three-dimensional butterfly-like BiVO was successfully synthesized by a simple solvothermal method at a proper volume ratio (1:4) of EG/HO mixed solution. It was found that ethylene glycol (EG) had an obvious influence on the morphologies of the final products. BiVO with different morphologies could be obtained by simply adjusting the volume ratio of the EG/HO. The crystal structures, morphologies, and photophysical properties of the products were well characterized. The photocatalytic activities of the samples were evaluated by decolorization of methylene blue (MB) under simulated sunlight irradiation. The results demonstrated that BiVO with butterfly-like morphology was better than that of BiVO-1, BiVO-3 and BiVO-4 for photodegradation of MB. The monoclinic butterfly-like BiVO-2 possessed bigger specific surface area, lower band gap energy, and interesting morphology, resulting in the highest photocatalytic activity under simulated sunlight irradiation. [ABSTRACT FROM AUTHOR]

Transition metal selenide is a typical pseudocapacitive material used in supercapacitor electrodes, but its practical application is restricted due to its insufficient utilization rate of active sites and slow kinetics of redox reaction. Defect engineering can effectively adjust the electronic structure, provide additional intercalation sites, and realize the regulation of energy storage mechanism within the lattice. At present, heteroatom doping is an effective strategy that can provide abundant vacancy defects by introducing heterogeneous atoms, thereby achieving significantly improved electrochemical performance. Based on this, NiCo2Se4 electrode materials with Se vacancies were prepared by P doping for supercapacitors. The double-effect synergy of P doping and vacancy engineering can effectively change the electronic structure and improve the adsorption capacity of ions, which are more prone to redox reactions. The assembled hybrid supercapacitor (NiCo2Sex-P1//AC) has 90.2% capacity retention and 100% coulombic efficiency after 10 000 consecutive charge–discharge cycles, and it exhibits a high energy density of 94.6 W h kg−1 at a power density of 799.9 W kg−1. This provides an effective strategy for constructing high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Abstract: Bi2WO6 microdiscs were synthesized via acetic acid-assisted hydrothermal process. The results revealed that the microdiscs were composed of numerous square nanoplates, and the nanoplates were stacked together through a side-by-side manner. The possible formation mechanism for the growth of microdiscs was discussed. The photocatalytic activity of the Bi2WO6 samples under solar-light irradiation was evaluated for degradation Rhodamine B (RhB). The as-prepared Bi2WO6 microdiscs exhibited excellent photocatalytic activity, and nearly 98% of RhB was degraded within 120min, which was nearly 9 times than that of the products prepared by traditional solid-state reaction. The excellent photocatalytic performance can be attributed to porous structure and the higher surface area. [Copyright &y& Elsevier]

Hyaluronic acid is a high-molecular-weight polysaccharide that is widely distributed in animal tissues. Bacterial hyaluronidases degrade hyaluronic acid as secreted enzymes and have been shown to contribute to infection. Staphylococcus aureus UAMS-1 is a clinical isolate that codes for two hyaluronidases ( hysA1 and hysA2 ). Previous research has shown the presence of a full-length HysA1 protein from the S. aureus UAMS-1 strain with no evidence of enzymatic activity. In this study, the coding and upstream promoter regions of hysA1 from the S. aureus UAMS-1 strain were cloned, sequenced, and compared to the hysA1 gene from the S. aureus Sanger 252 strain. A single base change resulting in an E480G amino acid change was identified in the hysA1 gene from the S. aureus UAMS-1 strain when compared to the hysA1 gene from S. aureus Sanger 252. A plasmid copy of hysA1 from S. aureus Sanger 252 transduced into an S. aureus UAMS-1 hysA2 deletion mutant strain restored near wild-type levels of enzymatic activity. Homology modeling of the HysA1 hyaluronidase was performed with SWISS-MODEL using hyaluronidase from Streptococcus pneumoniae as the template, followed by a series of structural analyses using PyMOL, PLIP, PDBsum, and HOPE servers. This glutamic acid is highly conserved among hyaluronidases from Staphylococcus and other gram-positive bacteria. A series of structural analyses suggested that Glu-480 in HysA1 is critically responsible for maintaining the structural and functional ensemble of the catalytic and tunnel-forming residues, which are essential for enzyme activity. The missense mutation of Glu-480 to Gly introduces a loss of side chain hydrogen bond interactions with key residues Arg-360 and Arg-364, which are responsible for the tunnel topology, resulting in displacement of the substrate from an ideal position for catalysis through a localized conformational change of the active site. There is a high degree of relatedness among several gram-positive bacterial hyaluronidases; the loss of enzymatic activity of HysA1 in the S. aureus UAMS-1 strain is most likely caused by the mutation identified in our study. The role of hyaluronidase in staphylococcal infection and the redundancy of this gene are yet to be determined.