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In this study, the accumulation rate of plastic litter was investigated by sampling quadrats placed on the North Island of Qilianyu, and the composition was analyzed and identified to determine its source. The results showed that the annual average accumulation rate of plastic litter on North Island was 0.64 ± 0.32 pieces·m−2·month−1, with a mass accumulation rate of 11.30 ± 7.73 g·m−2·month−1. The accumulation rate of plastic litter was mainly influenced by wind speed and direction, with higher accumulation rates occurring during the southwest monsoon season and tropical cyclones. ATR-FTIR analysis indicated that polyethylene (44 %) and polypropylene (41 %) were the most abundant types of polymers. This study reveals the current status of plastic litter pollution in green turtle nesting grounds on North Island in Qilianyu, which can be used as a reference for management strategies that mitigate plastic litter pollution. • The accumulation rate of plastic litter is influenced by the monsoon winds. • Polyethylene and polypropylene were the most abundant types of polymers. • Plastic litter on North Island mainly originated from human coastal activities. [ABSTRACT FROM AUTHOR]

The type III secretion system encoded in the Salmonella pathogenicity island-2 (SPI-2) gene cluster facilitates intracellular growth of nontyphoidal Salmonella by interfering with the maturation of Salmonella-containing vacuoles along the degradative pathway. SPI-2 gene products also protect Salmonella against the antimicrobial activity of reactive oxygen species (ROS) synthesized by the phagocyte NADPH oxidase 2 (NOX2). However, a potential relationship between inflammatory ROS and the activation of transcription of SPI-2 genes by intracellular Salmonella is unclear. Here, we show that ROS engendered in the innate host response stimulate SPI-2 gene transcription. We found that the expression of SPI-2 genes in Salmonella-sustaining oxidative stress conditions involves DksA, a protein otherwise known to regulate the stringent response of bacteria to nutritional stress. We also demonstrate that the J and zinc-2-oxidoreductase domains of DnaJ as well as the ATPase activity of the DnaK chaperone facilitate loading of DksA onto RNA polymerase complexed with SPI-2 promoters. Furthermore, the DksA-driven transcription of SPI-2 genes in Salmonella experiencing oxidative stress is contingent on upstream OmpR, PhoP, and SsrB signaling events that participate in the removal of nucleoid proteins while simultaneously recruiting RNA polymerase to SPI-2 promoter regions. Taken together, our results suggest the activation of SPI-2 gene transcription in Salmonella subjected to ROS produced by the respiratory burst of macrophages protects this intracellular pathogen against NOX2-mediated killing. We propose that Salmonella have co-opted inflammatory ROS to induce SPI-2-mediated protective responses against NOX2 host defenses. [ABSTRACT FROM AUTHOR]

• Definition of new type 18 operator to enhance the model ability of GO methodology for MC(k,n) system. • Optimization of BN structure corresponding to large-scale MC(k,n) system. • Mapping procedure transforming GO model of MC(k,n) system to corresponding BN. • Fault diagnosis and improvement guidance of MC(k,n) system based on extended GO model and BN. As a success-oriented system reliability and safety analysis technique, GO methodology is widely used in the modeling and analysis scenarios of critical safety engineering systems with signal flow, such as nuclear, chemical industry, electric power transportation, wireless network and microwave communication network. Consecutive- k -out-of- n systems are also widely applied in these fields, but due to their relatively complex logic, there are no corresponding graphical modeling and calculation methods. In this paper, the basic GO methodology is extended to support the modeling and analysis of multi-state linear and circular consecutive- k -out-of- n : F system (MLC(k,n) &MCC(k,n)) models. Two new operators are defined in graphical modeling to represent the two types of complex system logic. The multi-state logic semantics of the new operators and mapping rules to Bayesian networks (BN) are given. And the programmable process is presented to transform the extended GO model into BN, and the reliability of the MLC(k,n)/MCC(k,n) is calculated. Finally, three cases are used to verify i) the correctness of the method supporting multi-state model, ii) the efficiency and ability of the algorithm, and iii) the forward calculation and reverse diagnosis of the MLC(k,n) and MCC(k,n) systems with external shared components. [ABSTRACT FROM AUTHOR]

MoS 2 have been regarded as promising catalysts for the hydrogen evolution reaction (HER). However, its poor catalytic performance in neutral and alkaline solution would be problematic for the practical application. Combining semiconductors with metals as Mott-Schottky heterojunctions (MSH) has been regarded as an effective way to improve catalytic activity. Herein, a pH-universal adaptability Mo-MoS 2 MSH has been constructed via an in-situ lithiation method. The constructed MSH structure can effectively optimize the sulfur sites' electronic structure with interfacial electron redistribution and enhance the proton adsorption property under all pH conditions. To achieve the current density of 10 mA cm−2, it only needs overpotentials of 91, 138 and 128 mV in 0.5 M H 2 SO 4 , 1.0 M KOH and 1.0 M PBS, respectively, which has been one of the best values of current noble-metal-free electrocatalyst. This work can pave a valuable approach for the design high activity HER electrocatalysts for pH-universal with Pt-like activity. [Display omitted] • Mo-MoS 2 Mott-Schottky heterojunctions have been successfully constructed by means of in-situ lithiation tailoring methods. • The performance of Mo-MoS 2 Mott-Schottky heterojunctions is superior to Pt/C at high current density in a wide pH range. • The Mo-MoS 2 Mott–Schottky heterostructure can induce the interfacial electron redistribution. • Mo-MoS 2 Mott-Schottky heterojunctions is demonstrated to own excellent proton adsorption and ultralow overpotential for HER. [ABSTRACT FROM AUTHOR]

This study evaluated microplastic pollution in beaches that have served as historical nesting grounds for green turtles in Hainan Island, China and explored the sources of microplastic pollutants to conduct habitat restoration for sea turtles. The average abundance of the microplastics in the beach surface sediments was 2567.38 ± 2937.37 pieces·m−2 or 641.85 ± 734.34 thousand pieces·m−3, foam and plastic block were the main microplastics identified. Microplastic size was predominantly within the 0.05–1 mm category (small microplastic particles), and most microplastic particles were white. Polystyrene and polyethylene were the dominant plastic compositions. The type and compositions of microplastics indicate that most microplastics in this study were broken from large plastic blocks and foam. To reduce the threat of microplastic pollution to marine life, including sea turtles, we suggested removing plastic litter, especially small plastic on beaches, and replacing and recovering the foam used in aquaculture before it ages and fragments. • Microplastic were found in all beaches that served as historical nesting grounds for green turtles in Hainan Island, China. • Polystyrene and polyethylene were the dominant compositions of microplastic in this study. • Microplastic size was mostly in 0.05–1 mm (small microplastic particles), and the color of microplastic was mostly white. • Removing small plastic litter and replacing and recovering the foam maybe can reduce microplastic pollution. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) process involves the magnetic reversal of oxygen-containing intermediates, and the influence of defect structures on the magnetic behavior of catalysts might play a crucial role in this process. There is scarce research on the intrinsic relationship among defects, magnetism and catalysis. Herein, cation vacancy β -Ni(OH) 2 nanosheets were successfully prepared through alkaline selective etching. To further analyze their spin-magnetic behavior, we found that the presence of defects caused the transformation of Ni(OH) 2 from antiferromagnetic to ferromagnetic. Furthermore, to further elucidate their intrinsic spin-magnetic effects, it was observed that the initially antiferromagnetic β -Ni(OH) 2 exhibited almost no spin-magnetic response upon the introduction of a magnetic field, with the overpotential almost unchanged. Conversely, introducing defect structures showed a noticeable spin-magnetic effect, reducing the overpotential by 20 mV at 20 mA cm−2. The combination of defects and magnetic fields provides new principles for developing high-performance catalysts and understanding catalytic mechanisms at the spin-electronic level. • Ni 1-x Vac x (OH) 2 was prepared to investigate the spin-magnetic behavior of defect. • The defects of Ni(OH) 2 led to transformation from antiferromagnetic to ferromagnetic. • The spin-magnetic effect can reduce the overpotential by 20 mV at 20 mA cm−2. [ABSTRACT FROM AUTHOR]

Achieving improved energy efficiency, a green economy and degradation of environmental pollutants are important challenges to achieving sustainable development strategies. Herein, we have designed and synthesized a series of LaFe 1-x O 3 (LaFeO 3 , LaFe 0.95 O 3 , and LaFe 0.9 O 3) crystals with Fe vacancies for photo-assisted electrocatalysis (PAEC). These catalysts are used for both the anodic and cathodic reactions, where the anode efficiently removes persistent organic pollutants such as methylene blue (MB), and the cathode converts water into hydrogen gas. We observed that the presence of Fe vacancies leads to rearranging the electronic structure on the surface, enhancing the photo-assisted electrocatalytic activity. The rate constant for the photo-assisted electrocatalytic LaFe 0.90 O 3 was measured to be 0.996 min−1, which is 2.37 times and 2.74 times higher than that of the electrocatalytic (0.420 min−1) and photocatalytic (0.363 min−1) processes, respectively. The hydrogen production efficiency reached 1.42 μmol min−1. This study provides the first evidence of the photo-assisted electrocatalytic mechanism and potential applications of LaFeO 3 -based catalysts in enhancing the electro-oxidation of pollutants. It offers additional insights for the rational design and construction of more efficient PAEC catalysts for effective wastewater purification and energy recovery. [Display omitted] • The photo-assisted electrocatalysis for LaFe 1-x O 3 has been demonstrated. • The LaFe 0.90 O 3 owned outstanding electrocatalytic and photocatalytic performance. • The presence of Fe vacancies can enhance photo-assisted electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Members of glycosyltransferase family 75 (GT75) not only reversibly catalyze the autoglycosylation of a conserved arginine residue with specific NDP-sugars but also exhibit NDPpyranose mutase activity that reversibly converts specific NDP-pyranose to NDP-furanose. The latter activity provides valuable NDP-furanosyl donors for glycosyltransferases and requires a divalent cation as a cofactor instead of FAD used by UDP-D-galactopyranose mutase. However, details of the mechanism for NDP-pyranose mutase activity are not clear. Here we report the first crystal structures of GT75 family NDPpyranose mutases. The novel structures of GT75 member MtdL in complex with Mn2+ and GDP, GDP-D-glucopyranose, GDPL-fucopyranose, GDP-L-fucofuranose, respectively, combined with site-directed mutagenesis studies, reveal key residues involved in Mn2+ coordination, substrate binding, and catalytic reactions. We also provide a possible catalytic mechanism for this unique type of NDP-pyranose mutase. Taken together, our results highlight key elements of an enzyme family important for furanose biosynthesis. [ABSTRACT FROM AUTHOR]

Aflatoxins are a series of highly toxic and carcinogenic secondary metabolites that are synthesized by Aspergillus species. The degradation of aflatoxin enzymes is an important regulatory mechanism which modulates mycotoxin producing. The retromer complex is responsible for the retrograde transport of specific biomolecules and the vacuolar fusion in the intracellular transport. Late endosomal-associated GTPase (Rab7) has been shown to be a downstream effector protein of the retromer complex. A deficiency in the retromer complex or Rab7 results in several cellular trafficking problems in yeast and humans, like protein abnormal accumulation. However, whether retromer dysfunction is involved in aflatoxin synthesis remains unclear. Here, we report that the core retromer complex, which comprises three vacuolar protein sortingassociated proteins (AflVps26-AflVps29-AflVps35), is essential for the development of dormant and resistant fungal forms such as conidia (asexual reproductive spore) and sclerotia (hardened fungal mycelium), as well as aflatoxin production and pathogenicity, in Aspergillus flavus. In particular, we show the AflVps26-AflVps29-AflVps35 complex is negatively correlated with aflatoxin exportation. Structural simulation, sitespecific mutagenesis, and coimmunoprecipitation experiments showed that interactions among AflVps26, AflVps29, and AflVps35 played crucial roles in the retromer complex executing its core functions. We further found an intrinsic connection between AflRab7 and the retromer involved in vesicle-vacuole fusion, which in turn affected the accumulation of aflatoxin synthesis-associated enzymes, suggesting that they work together to regulate the production of toxins. Overall, these results provide mechanistic insights that contribute to our understanding of the regulatory role of the core retromer complex in aflatoxin metabolism. [ABSTRACT FROM AUTHOR]