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The escalating issue of multidrug-resistant (MDR) bacteria indicates the urgent need for new and effective strategies to combat this global health challenge. Here, we describe a new combinatorial approach that can be put forward for experimental therapy application against MDR bacteria. Specifically, we have developed a tri-system that includes the coadministration of two different membrane-disrupting-type antimicrobial agents─a synthetic antimicrobial polymer

An efficient and green approach to selective synthesis of alkyl amines and N-vinylazoles from vinyl sulfonium salts with N-nucleophiles is described.

Metal-free allylic C(sp3)−H alkylation of branched α-styryl sulfonium salts based on [2,3]-sigmatropic rearrangement strategies has been developed. This operationally simple protocol enables allylic C(sp3)−H alkylation of a wide range of...

Microbial resistance to antibiotics is one of the greatest global healthcare challenges. There is an urgent need to develop effective strategies to overcome antimicrobial resistance. We, herein, report photoinduced in situ growth of a cationic polymer from theiN/i-terminus of lysozyme. The attachment of the cationic polymer improves the proteolytic and thermal stability of lysozyme. Notably, the conjugate can efficiently overcome lysozyme resistance in Gram-positive bacteria and antibiotics-resistance in Gram-negative bacteria, which may be ascribed to the synergistic interactions of lysozyme and the cationic polymer with the bacteria to disrupt their cell membranes. In a rat periodontitis model, the lysozyme-polymer conjugate not only greatly outperforms lysozyme in therapeutic efficacy but also is superior to minocycline hydrochloride, which is the gold standard for periodontitis therapy. These findings may provide an efficient strategy to dramatically enhance the antimicrobial activities of lysozyme and pave a way to overcome antimicrobial resistance.

A procedure for the synthesis of 1,2-diamines from vinyl sulfonium salts and arylamines under mild conditions was developed. This present synthetic protocol not only obviates the need for a transition-metal catalyst and an oxidizing reagent but also features a broad substrates scope. The practicability of this protocol is demonstrated by the one-pot synthesis, a scale-up reaction, and transformations of the products to diverse

Biogas resources in the Sanhu area of the Qaidam Basin have great potential, but there are few studies on biogas from shale, especially on the accumulation conditions of shale biogas. The study of biogas accumulation conditions of quaternary shale in the Sanhu area is of great significance to the theory of biogas accumulation and the guidance of exploration and development. This paper takes Quaternary shale in the Sanhu area as the research object. It is analyzed from multiple perspectives of shale hydrocarbon generation conditions, reservoir conditions, as well as hydrodynamic and structural conditions. Through the experiments of soluble organic carbon analysis and porosity and permeability analysis, the accumulation conditions of shale biogas reservoirs are clarified. The results show that the quaternary shale has a high soluble organic carbon content and high salinity formation water, which is conducive to late methane biochemical generation. Quaternary shale has the characteristics of high porosity and low permeability, mainly developing intergranular pores and intragranular pores. The large pore volume and specific surface area provide a lot of storage space for free gas and adsorbed gas, and the reservoir conditions are good. Under the structural characteristics of high in the south and low in the north and the action of formation hydrodynamics, biogas migrated from the south and deep to the north of the basin. The north slope is the main biogas-rich zone. On the whole, the quaternary shale in the Sanhu area has the characteristics of continuous hydrocarbon generation and dynamic accumulation, which has huge resource potential and exploration and development value.

The Sanhu Depression in Qaidam Basin is the largest Quaternary biogenic gas exploration area with the shallowest burial depth in the world. The shallow high abundance of gas reservoirs and high-quality pure methane have become the main production areas. The development characteristics of loose mudstone reservoirs are restricted by extreme heterogeneity. Therefore, the Quaternary Qigequan Formation mudstone in Qaidam Basin is selected as the research object. Based on the study of the sedimentary background, petrological characteristics, and pore structure characteristics, by comparing the characteristics of different mudstone reservoirs, the controlling factors of the development of different mudstone reservoirs and the control of gas migration are clarified. Research shows the following: (1) The mudstone reservoirs of the Qigequan Formation mainly develop intergranular pores, clay mineral pores, and intragranular pores. The pore size distribution varies from nanometers to micrometers, and mesopores mainly contribute to the specific surface area. (2) Rigid minerals and clay minerals are the main controlling factors for the pore structure of mudstone reservoirs. The increase in the content of rigid minerals is conducive to the development of macropores or larger micropores, while the increase in the content of clay minerals is conducive to the development of mesopores and provides an important specific surface area for gas adsorption. (3) The gas migration form of pure mudstone is mainly dominated by Fick diffusion and slippage flow, which has the characteristics of self-sealing accumulation. The gas migration form of silty mudstone is the coexistence of Fick diffusion, slippage flow, and Darcy flow, which has the features of self-sealing and Darcy flow accumulation. The gas migration form of sandy mudstone is mainly Darcy flow, only with Darcy flow accumulation characteristics. The flow form of gas creates different accumulation modes of mudstone biogas. The Quaternary mudstone reservoir shows different particularity under different material components, and the exploration targets should be treated differently according to specific mudstone types.

Graphene quantum dots (GQDs) as a new type of fluorescent carbon nanomaterials, showing excellent photoluminescence properties, biocompatibility, photoelectric properties, have become the current research focus. Iron element as an essential element in the human body and an important part of hemoglobin, is very important for human health, so the detection of ferric ions has great significance. In this paper, GQDs with strong blue light emission were prepared through pyrolysis treatment using citric acid as a carbon source. Through characterization by transmission electron microscopy (TEM) and fluorescence spectrometer, it was observed that the GQDs have a uniform particle size distribution and highly fluorescent intensity with a quantum yield of 27.4%. Due to the strong quenching effect of Fe3+ on GQDs fluorescence, GQDs was used as a green and facile fluorescence sensor to detect Fe3+ selectively and sensitively. The GQDs fluorescence sensor shows a sensitive response to Fe3+ in a wide linear range (3.5 × 10−6-6.7 × 10−4 M), a low detection limit of 1.6 μM (S/N = 3) and good selectivity. Importantly, the new sensor realizes the detection of Fe3+ ions in tap water because of its low detection limit, wide linear range, and high sensitivity.

The rise of Industry 4.0 is pushing more machine devices into the connection of the communication network. Internet of Things (IoT) emerges as an enabling technique to support automatic information transmission and the universal interconnection among massive machine devices. Unlike the human type communication (HTC) in the conventional Internet, IoT features machine type communication (HTC) with small data granularity and massive connections, which impose new challenges on the network resource allocation earlier designed for HTC communication. One of the challenging issues is how we can manage the network resource for the IoT service provisioning. As a promising network architecture for the “last-mile” access in 5G communication, Fiber-Wireless (FiWi) access network compromises the high bandwidth capacity of the optical access network and the flexibility of wireless access network. Especially, network virtualization as an emerging technique provides FiWi with the feasibility for the coordinated bandwidth allocation of wireless access network and optical access network. The evolution of FiWi access network should be not only oriented to the technological breakthrough in regular traffic, but also be supportive of the emerging IoT traffic. In this paper, we focus on the resource allocation problem in FiWi access network supporting IoT service. We first analyze the dynamics of regular traffic and propose the traffic prediction method based on Q-Learning. Then, we propose a virtual network embedding algorithm to map exactly the virtual networks of IoT traffic to the idle resource of the virtual networks of regular traffic without degrading the performance of regular traffic. Thus, the proposed algorithm can improve the resource utilization more effectively. The simulation results demonstrate that the proposed algorithm can achieve a higher acceptance ratio and lower migration ratio of IoT traffic.

Because of the problem of bacterial resistance, inorganic antibacterial materials represented by metallic nanomaterials have attracted attention for their antimicrobial properties. However, their antibacterial efficiency and safety need to be improved, and the cost of preparation needs to be reduced. Here a novel and highly stable cysteine-directed silver-copper composite nanoclusters hydrogel (AgCu NCs hydrogel) was prepared by employing a simple and green UV photoreduction one-pot method. The optical properties, structure and synthesis principle of AgCu NCs hydrogel were characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), and X-Ray photoelectron spectroscopy (XPS), respectively. The antibacterial activities of AgCu NCs hydrogel against Esherichia coli (E.coli) and Staphylococcus aureus (S.aureus) were evaluated using zones of inhibition, minimum inhibitory concentrations (MIC), minimum bactericidal concentration (MBC), and growth curves. The AgCu NCs hydrogel shows highly synergistic antibacterial performance toward both E.coli and S.aureus with the MIC of 0.781 μg/mL, 3.125 μg/mL and MBC of 12.5 μg/mL, 100 μg/mL, respectively. In addition, due to the good biocompatibilities, the AgCu NCs hydrogel has a good therapeutic effect on burn wounds. It will eventually become a new, low-cost, and highly effective antibacterial medical dressing.

A high-performance electrochemical H2O2 sensor was prepared by constructing multiple interfaces using platinum nanoparticles (Pt NPs), ferumoxytol (Fer) and reduced graphene oxide (rGO) on a glassy carbon electrode (GCE). The morphology of Fer/rGO and Fer/rGO-Pt was characterized by field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. Cyclic voltammetry and chronoamperometry were adopted to characterize the electrochemical properties of the sensor. Because of the synergistic catalytic effect of the compositions (rGO, Fer and Pt NPs) on the multiple interfaces, the sensor exhibits particularly high electrocatalytic activity toward the reduction of H2O2 with a low detection limit (~0.38 μM), a linear range (0.0004–0.01, 0.0075–4.3 and 4.9–10.8 mM), and a high sensitivity (340 μA mM−1 cm−2, n = 4) operated at a typical working voltage of +0.1 V (vs. Ag/AgCl). The electrode is selective and long-term stable. It was successfully applied to the determination of H2O2 in (spiked) milk samples.

Graphene quantum dots (GQDs) as a new type of fluorescent carbon nanomaterials, showing excellent photoluminescence properties, biocompatibility, photoelectric properties, have become the current research focus. Iron element as an essential element in the human body and an important part of hemoglobin, is very important for human health, so the detection of ferric ions has great significance. In this paper, GQDs with strong blue light emission were prepared through pyrolysis treatment using citric acid as a carbon source. Through characterization by transmission electron microscopy (TEM) and fluorescence spectrometer, it was observed that the GQDs have a uniform particle size distribution and highly fluorescent intensity with a quantum yield of 27.4%. Due to the strong quenching effect of Fe

A method is described for fluorometric determination of cysteine (Cys) and glutathione (GSH), either in solution by using a fluorescence spectrometer, or by using a paper-based test with visual observation. The method is based on the finding that the yellow fluorescence of the gold/silver nanoclusters (AuAg NCs), with excitation/emission maxima of 358/574 nm, is quenched by Cys and GSH via NCs aggregation. The method is selective for Cys and GSH. The limits of detection for both Cys and GSH are 0.74 nM in solution state and 5.0 μM on paper-based test. Response is linear in the range from 2.3 nM to 110 μM and from 2.3 nM to 63 μM in solution for Cys and GSH, respectively. The method is not interfered by other amino acids even if their concentrations are 10 times higher. It was successfully applied to the determination of Cys in spiked serum samples.