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In recent years, hepatitis B virus (HBV) core protein allosteric modulators (CpAMs) have become a hot spot to develop new anti‐HBV drugs. Sulfonamide analogues are a new class of CpAMs targeting HBV core protein (Cp), while their biological activity is still needed to be improved and the binding mechanism is unclear still. In this study, we utilized molecular docking and molecular dynamics simulation to explore the binding mode between the novel compounds and HBV Cp. Combining with binding free energy calculation and decomposition, we inferred that TyrE132, ValE124, ThrE128, ThrD109, and IleD105 were key residues during the binding process, and especially, the conformational change of TryE132 was responsible for the stable binding. Besides, reasonable CoMFA (q2 = 0.515, r2ncv = 0.994, and r2pred = 0.628) and CoMSIA (q2 = 0.602, r2ncv = 0.988, and r2pred = 0.681) models were constructed to explore the 3D structure‐activity relationship of the novel compounds. The results suggested that it was favorable to increase the biological activity of sulfonamide analogues when introducing hydrophobic groups to R1 and electronegative groups to R2. In conclusion, we explored the binding mode and structure‐activity relationship between sulfonamides and HBV Cp and provided a theoretical basis for the optimization of this series of compounds. [ABSTRACT FROM AUTHOR]

This study investigates the impacts of the joint assimilation of ground-based microwave radiometer (MWR) and FY-3D microwave sounder (MWTS-2/MWHS-2) observations on the analyses and forecasts for precipitation forecast. Based on the weather research and forecasting data assimilation (WRFDA) system, four experiments are conducted in this study, concerning a heavy precipitation event in Beijing on 2 July 2021, and 10-day batch experiments were also conducted. The key study findings include the following: (1) Both ground-based microwave radiometer and MWTS-2/MWHS-2 data contribute to improvements in the initial fields of the model, leading to appropriate adjustments in the thermal structure of the model. (2) The forecast fields of the experiments assimilating ground-based microwave radiometer and MWTS-2/MWHS-2 data show temperature and humidity performances closer to the true fields compared with the control experiment. (3) Separate assimilation of two types of microwave radiometer data can improve precipitation forecasts, while joint assimilation provides the most accurate forecasts among all the experiments. In the single-case, compared with the control experiment, the individual and combined assimilation of MWR and MWTS-2/MWHS-2 improves the six-hour cumulative precipitation threat score (TS) at the 25 mm level by 57.1%, 28.9%, and 38.2%, respectively. The combined assimilation also improves the scores at the 50 mm level by 54.4%, whereas individual assimilations show a decrease in performance. In the batch experiments, the MWR_FY experiment's TS of 24 h precipitation forecast improves 28.5% at 10 mm and 330% at 25 mm based on the CTRL. [ABSTRACT FROM AUTHOR]

Pin1 (protein interacting with never-in-mitosis akinase-1) is a member of the family of peptidylprolyl cis–trans isomerases (PPIases) that specifically recognize and isomerize substrates containing phosphorylated Ser/Thr-Pro sequences. Pin1 is involved in many cellular processes and plays a key role in the cell cycle, transcriptional regulation, cell metabolism, proliferation and differentiation, and its abnormalities lead to degenerative and neoplastic diseases. Pin1 is highly expressed in human cancers and promotes the development of tumors by activating multiple oncogenes and inactivating multiple tumor suppressor genes, making it an attractive target for cancer therapy. In this study, we investigated the binding mechanism and conformational relationship between benzimidazole Pin1 inhibitors and Pin1 proteins by molecular docking, three-dimensional quantitative structure–activity relationship (3D-QSAR) modeling, binding free energy calculations and decomposition, and molecular dynamics simulations. Molecular docking and molecular dynamics simulations disclosed the most likely binding pose of benzimidazoles with the Pin1 protein. The results of 3D-QSAR modeling indicated that electrostatic fields, hydrophobic fields and hydrogen bonding play important roles in the binding process of inhibitors to proteins. The binding free energy calculations and energy decomposition indicated that Lys63, Arg69, Cys113, Leu122, Met130, and Ser154 may be key residues in the binding of benzimidazole-based inhibitors to the Pin1 protein. This study provides an important theoretical basis for the design and optimization of benzimidazole compounds. [ABSTRACT FROM AUTHOR]

Nitrosamines have become a focus of considerable research because of their carcinogenicity and environmental universality. In this study, to effectively remove nitrosamines, biological activated carbon (BAC) was acclimatized by a nitrosamine-reducing bacterial strain, and zero-valent iron (Fe0)-assisted BAC was used to degrade nitrosamines from aqueous solution. The influencing factors and degradation mechanism were investigated. Compared with activated carbon (AC), the removal efficiency of more strongly polar nitrosamines by BAC and BAC_Fe0 increased prominently (21.0%–32.3%), yet there was no change between BAC and BAC_Fe0. The highest ratios of nitrosamine degradation by BAC_Fe0 were 49.8%–99.0%, and degradation reaction kinetics conformed best to a pseudo-second-order model (R2>0.9269). The rate constants kobs for six nitrosamines ranged from 3.4×103 to 6.9 × 105 (M · s)−1. Additionally, the removal ratios and k2 of the linear nitrosamines partially scaled with their molecular weight, LogKH , and LogKow (R2=0.5661−0.952). All nitrosamines were degraded within 30 min under strong acidic conditions; the removal ratios increased by 11.2%−23.1% under anaerobic conditions, but were decreased by ∼10% in the presence of humic acid. The primary degradation products were secondary amines, methylamine, formic acid, nitrate, and nitrite resulting from the reduction of Fe0 and biodegradation by the nitrosamine-reducing bacteria. [ABSTRACT FROM AUTHOR]

Practical Application Edible mushrooms are rich in nutrients and bioactive compounds, but their browning affects their quality and commercial value. This article reviews various methods to inhibit polyphenol oxidase (PPO)‐induced browning in mushrooms. Physical methods such as heat treatment, low temperatures, irradiation, and ultrasound effectively reduce PPO activity but may affect mushroom texture and flavor. Chemical inhibitors, including synthetic chemicals and natural plant extracts, provide effective PPO inhibition but require careful monitoring of their content. Biological methods, including gene editing and microbial fermentation, show promise in targeting PPO genes and enhancing antioxidant production. Combining these methods offers a comprehensive strategy for preserving mushroom quality, extending shelf life, and maintaining nutritional value.These approaches can be applied in the food industry to improve post‐harvest mushroom preservation, enhance product quality, and reduce waste, benefiting both producers and consumers. Further research and innovation are needed to optimize the practical application of these methods in large‐scale processing and storage conditions. [ABSTRACT FROM AUTHOR]

Dual-level electronic structure calculation has been performed to investigate the mechanism and all possible channels of OH radical reaction with CH3CH2F. Geometries and frequencies are computed at the B3LYP/6-311G(d, p) level of theory for all stationary points and complexes and transition states are located. Potential energy surfaces are constructed at the PMP2/cc-pVTZ//B3LYP/6311G(d,p) level + ZPE correction. Four types of reaction channels are identified: hydrogen abstraction, fluorine abstraction and attack on carbon atom along or perpendicular to the C - C bond axis. Hydrogen abstraction channels have lower barriers and are more exothermic, while out-of-plane β - H abstraction with the lowest barrier is competitive with α - H abstraction. Due to the high energy barrier, contributions of non-H abstraction channels are excluded. The influence of hydrogen bonding interaction is clearly observed in the barrier heights. [ABSTRACT FROM AUTHOR]

In this paper, a method for the enzymatic modification of pectin, in which gallic acid (GA) and propyl gallate (PG) were grafted onto pectin molecules in an aqueous/organic two-phase system catalyzed by lipase, was proposed. The potential reaction mechanism was explored through UV–Vis, FTIR and 1H NMR spectroscopic methods and density functional theory. Results suggested that the lipase played a dual role during the modification by catalyzing the hydrolysis of methyl ester bonds of pectin in the aqueous phase and the esterification between the 4-OH of GA and PG and the –COOH of pectin in the organic phase. Moreover, the effects of GA and PG on the antioxidant and the antibacterial activities of pectin were evaluated, and results showed that the antioxidant and the antibacterial activities of modified pectin were better than those of native pectin. The effect of modified pectin on the quality of fresh bass (Lateolabrax maculatus) was further studied. Results suggested that, compared to control group, the total viable count, histamine level, malondialdehyde content and acid value of bass fillets treated with modified pectin were significantly reduced, whereas the sensory score was significantly increased. [Display omitted] • Gallic acid and propyl gallate were grafted onto pectin through enzymatic method in aqueous/organic two-phase system. • The modified pectins had a positive effect on the quality of bass during the storage. • The reaction mechanism was explored based on density functional theory. [ABSTRACT FROM AUTHOR]