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Biochars prepared from agricultural and forestry biomass resources have been widely used to remove wastewater pollutants. However, the theoretical analysis of the role of biochar functional groups in pollutant removal and the visualization of the adsorption mechanism is still in its initial stage. In this study, a kind of biochar with satisfied adsorption potential was prepared from Fructus Aurantii Immaturus residues (FAIR). A Fructus Aurantii Immaturus residue biochar (FRB) structural model was constructed based on its physicochemical characterization, and the adsorption mechanism of FRB for methylene blue (MB) was clarified at the molecular level through the adsorption experiments, adsorption models and DFT calculations. The results indicated that the FRB prepared by NaOH activation has abundant functional groups, higher porosity and specific surface area, and its saturated adsorption capacity for MB reached 298.90 mg/g. The adsorption process of the FRB for MB can be suitably described by the pseudo-second-order kinetic model and the Freundlich isothermal adsorption model, and it is an endothermic entropy-driven non-spontaneous process. The adsorption mechanism depended on the electrostatic attraction, hydrogen bond, π–π interaction and van der Waals force formed by the interaction between the -COOH, -OH and -NH-CO- in the FRB structure and the amino groups in the MB structure. Notably, the results of the DFT calculations were highly consistent with the theoretical analysis of the adsorption experiments and adsorption models. [Display omitted] • A biochar from phytoextraction residues of Citrus aurantium L. was prepared. • Saturated adsorption capacity of biochar for MB reached 298.90 mg/g. • Adsorption mechanism of biochar for MB was analyzed via experiments and models. • Role of biochar functional groups for dye adsorption was explained. • Interaction between the MB and biochar surface was verified by DFT calculations. [ABSTRACT FROM AUTHOR]

Abstract: This Letter presents an adaptive neural network control method for the chaos control problem. Based on a single layer neural network, the dynamic about the unstable fixed period point of the chaotic system can be adaptively identified without detailed information about the chaotic system. And the controlled chaotic system can be stabilized on the unstable fixed period orbit. Simulation results of Henon map and Lorenz system verify the effectiveness of the proposed control method. [Copyright &y& Elsevier]

Constructing carrier materials with polysaccharides to enhance the solubility of insoluble active ingredients is a crucial strategy for improving bioavailability. This research constructed pectin-based hesperidin microcapsules (PHM) through self-assembly processes in the deep eutectic solvent, improving the solubility, storage stability, and bioavailability of hesperidin (HES). PHM exhibited high encapsulation efficiency (91.7%) and loading capacity (11.5%), with a small particle size (1.73 μm). The interaction mechanism was clarified through physical characterization and density functional theory (DFT) calculations. The vitro release demonstrated that the release ratio of PHM was only 6.4% in simulated gastric fluid (SGF), but reached 80.9% in simulated intestinal fluid (SIF). The release mechanism of PHM in SGF followed Fickian diffusion, while in SIF followed skeleton dissolution diffusion with a stable rate. Furthermore, the cell cytotoxicity experiments confirmed the remarkable biocompatibility of PHM toward human colon cells, which suggested its potential application in food and pharmaceutical fields. [Display omitted] • PHM was successfully prepared by self-assembly method in deep eutectic solvent. • Solubility, stability, and bioavailability of hesperidin were obviously improved. • Interaction mechanism was elucidated by experiments and DFT calculations. • Release behavior in vitro was clearly revealed by mathematical models. • PHM exhibited potential application in food and pharmaceutical fields. [ABSTRACT FROM AUTHOR]

Survivin is the smallest member of IAP (inhibitor of apoptosis protein) family, which plays important roles in both mitosis and apoptosis. It has become an attractive drug target due to its overexpression in many human cancers. Survivin has been proven to bind to Smac/DIABLO protein that indirectly inhibits apoptosis. Meanwhile, it is the key subunit of chromosome passenger complex (CPC) which bind to the N-terminal tail of phosphorylated histone H3T3ph during mitosis. Up to now, Survivin directly targeting inhibitor has yet to merge since the difficulty of disrupting the protein-protein interactions (PPIs) between Survivin and its substrate proteins. Nevertheless, currently known binding partners of Survivin provide crucial information about conserved recognition mechanism, which can assist in the detection of some uncharted substrates and also the Survivin inhibitors. Herein, we adopted a method that using four substrates to analyze the common binding mode of Survivin. To accomplish this, conventional molecular dynamics (MD) simulations, molecular mechanics/generalized born surface area (MM-GBSA) binding free energy calculations and energy decomposition were carried out to assess the binding affinity and per-residue contributions. We found that there are two anchor sites of Survivin responsible for maintaining the binding conformation and one sub-pocket for intermolecular recognition. The results of this study synthetically describe the binding mechanism and provide valuable guidance for rational drug design of PPI inhibitor. [ABSTRACT FROM AUTHOR]

A mild and efficient oxidation of 3β-hydroxysteroids to the corresponding 3-keto steroids can be carried out at room temperature, using DDQ in the presence of catalytic TEMPO. Oxidation of saturated 3β-hydroxysteroids gave the corresponding ketones in excellent yield. The 5-unsaturated 3β-hydroxysteroids are oxidized selectively to 4-en-3-one or 4,6-diene-3-one derivatives according to the amount of DDQ in reaction. This is a good method for the synthesis of 4,6-diene-3-one from the corresponding 3β-hydroxy-5-ene steroids. Meanwhile, configurations of the oxidation compounds 2a , 2b , 3b , 2c , 2f and 2g were identified by X-ray diffraction. A possible mechanism is presented and discussed. [ABSTRACT FROM AUTHOR]