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关键词： Charge distribution   Excited state hydrogen bonding interaction   Excited state intramolecular proton transfer   Potential energy surface   Solvent polarity  

摘要： In this work, a systematic investigation was carried out into the excited-state intramolecular double proton transfer (ESDPT) mechanism linked to the 2,7-bis-(5-ethyl-benzooxazol-2-yl)-phenanthrene-1,6-diol (BEPD) molecule dispersed in acetonitrile, dichloromethane and heptane, together with how it responds to solvent polarities. Analysis of structural parameters relevant to hydrogen bonds revealed the reinforcement of intramolecular hydrogen bonding in the excited state among all solvents under investigation, with the O4H5···N6 hydrogen bond exhibiting a more pronounced strengthening effect in the excited state than the O1H2···N3 hydrogen bond. To shed light on the impacts of solvent polarity, we performed a thorough analysis of the core-valence bifurcation (CVB) index, infrared (IR) vibrational spectra and potential energy surfaces (PESs). The results demonstrate that the strength of excited-state hydrogen bonding increases with the reduction of solvent polarity. Furthermore, frontier molecular orbitals (FMOs) analysis was performed to examine charge redistribution during the ESDPT process. Reaction PESs were scanned and transition states (TS) were identified, confirming that BEPD undergoes a stepwise ESDPT mechanism along the O4H5···N6 and then O1H2···N3 hydrogen bond chain in acetonitrile and dichloromethane, while only the excited-state intramolecular singl

关键词： Alzheimer's disease   Mitophagy   Schisandra chinensis(Turcz.)Baill   PINK1/Parkin   MCL-1   Triterpenoids  

摘要： Schisandra chinensis(Turcz.)*** the Schisandraceae has been scientifically validated for its medicinal and dietary properties,with its leaves being ***,the leaves of *** are abundant in tri-terpenoids that exhibit neuroprotective effects and may possess potential therapeutic value for Alzheimer's disease(AD).HPLC combined with UPLC-Q-TOF-MS was used to characterize the components eluted with 95%EtOH,and a total of 28 triterpenoid compounds were ***,the intricate mechanisms underlying the action of SC in treating AD remain incompletely *** investigate this,an AD model was established using 3×Tg-AD mice,and the protective effects of SC were assessed through various techniques,including the Morris water maze test,Nissl staining,immunohistochemistry,transmission electron microscopy,and Western ***,in SH-SY5Y cells induced by CCCP treatment,the protective effect of SC was further verified using JC-1 staining and WB ***1/Parkin-dependent mitophagy induced by SC is mediated by SIRT3/FOXO3a and STAT3/TRPML1 signaling,along with MCL-1 *** enhancing effect improves cognitive dysfunction and simultaneously alleviates the pathological changes associated with *** addition,SC reduced CCCP-induced SH-SY5Y cell death and increased mitophagy-related *** results suggest that SC holds significant promise as a therapeutic agent for AD through its ability to promote mitophagy.

摘要： Liquid-liquid equilibrium (LLE) data were obtained for water + sulfuric acid + {1-butanol, isopentanol, 1-pentanol, or 1-heptanol} ternary systems at temperatures of 298.2 K and 323.2 K under atmospheric pressure (P ≈ 101.9 kPa). The immiscibility regions were experimentally identified through binodal curves using the cloud point method. Tie-line data were determined through direct sulfuric acid composition measurements and mass fraction calibration curves. Based on these data, distribution coefficients, alcohol selectivity and extraction percentage were calculated to evaluate the influence of different alcohols and temperature on sulfuric acid separation potential. Experimental LLE data were correlated using the Non-Random Two-Liquid model, presenting a root-mean-square deviation equal to 1.1768 % for all studied systems. The model also allowed the estimation of binodal curves and plait points. These results contribute to the understanding and optimization of solvent extraction processes involving sulfuric acid recovery in industrial water streams.

摘要： Fiber combiners (FCs), which fuse multiple input fibers into a common output port, offer a strategic approach to scaling laser power and expanding spectral coverage, especially in the mid- and long-wave infrared (MWIR/LWIR) bands where individual laser performance is often limited. Chalcogenide glasses serve as ideal materials for such combiners due to their broad infrared transparency and superior thermal stability. However, fabricating FCs capable of withstanding high laser power while maintaining high beam quality remains challenging, particularly when targeting wavelengths beyond 8 μm. Here, we present the first demonstration of a high-beam-quality 4 × 1 fiber combiner based on Ge-As-Se glass, designed for MWIR/LWIR laser combination. The device integrates four few-mode input fibers (50 μm core) into a multimode output fiber (150 μm core) via an optimized taper geometry (transition region length L_t= ∼10 mm, taper ratio R = ∼4.6). The fabricated FC had a total length of ∼ 60 cm. At 8.3 μm, the combiner achieved a port transmission efficiency of 81.6% and maintained an output beam quality of M² = 3.62 under four-port excitation. Power combining at 2.1 μm yielded 6.5 W from four 3.0-W inputs, corresponding to a power-combining efficiency of 82.7%. Furthermore, the combiner successfully synthesized a broadband spectrum by integrating discrete laser lines at 3.2, 4.6, 4.9, and 8.3 μm. These results establish the few-mode Ge-As-Se fiber combiner as a promising platform that delivers both high-power combination and high beam quality across the MWIR and LWIR bands for advanced infrared photonic systems.

关键词： 4,4′,6,6′-tetra(azido)hydrazo-1,3,5-triazine   Adiabatic time-to-explosion   Combustion   High-nitrogen compounds   Thermal safety  

摘要： High-nitrogen compounds are promising energetic materials due to their high enthalpy of formation (${\Delta }_{\mathrm{f}}{H}_{\mathrm{m}}^{\theta }$) and environmentally friendly combustion products. However, the thermal decomposition kinetics, thermal safety and combustion behavior of 4,4′,6,6′-tetra(azido)hydrazo-1,3,5-triazine (TAHT) have not yet been systematically clarified.

关键词： Hirota-Maccari system   Lyapunov exponent   Melnikov theory   Modulational instability   Stochastic nonlinear dynamics  

摘要： This paper investigates a stochastic (2+1)-dimensional Hirota-Maccari system under multiplicative noise modeled via Stratonovich calculus, emphasizing novel analytical and numerical methodologies. A noise-adaptive traveling-wave ansatz reduces the stochastic PDEs to deterministic second-order nonlinear oscillators using stochastic averaging techniques. Employing Hamiltonian formalism and phase-plane analysis, we systematically classify nonlinear wave solutions including periodic, bright solitons, and kink-type structures. We rigorously derive a new modulational instability dispersion relation, capturing intricate interactions between nonlocal coupling, higher-order dispersion, and noise-induced stabilization effects. Using Melnikov theory complemented by numerical Lyapunov exponent calculations, we demonstrate both homoclinic and heteroclinic chaos, providing compelling analytical and numerical evidence of chaotic dynamics. Numerical simulations confirm theoretical predictions, illustrating noise-induced broadening, amplitude fluctuations, and altered wave stability. The presented integrative approach significantly advances understanding of stochastic nonlinear wave phenomena, offering robust methodologies for analyzing complex wave dynamics under realistic noisy conditions.

摘要： Currently, in sparse representation of signals, the synthesis model has been extensively studied, while the analysis model receives comparatively less attention. Regarding the sparsity metric, ℓ₁/ℓ₂ norm ratio not only has a sharp approximation to ℓ₀-norm, but also satisfies the scale invariance property inherent to ℓ₀-norm. Motivated by these, this work introduces an analysis model based ℓ₁/ℓ₂-regularized minimization for signal recovery, and conducts theoretical analysis on it under reasonable assumptions that the measurement matrix is full row rank and the observed vector is nonzero. First, under a sufficient condition related to the regularization parameter, we prove that its global minimizer cannot be zero and its solution set is nonempty. Then, we derive an upper bound for any local minimizer of it in terms of ℓ₂-norm. Given that it is nontrivial to directly solve this problem, we relax it by the penalty technique, and provide theoretical analysis for the relaxed version under the aforesaid assumptions, including the nonzero-ness of the global minimizer and the solution existence with the same sufficient condition. Similarly, an upper bound for any local minimizer in terms of ℓ₂-norm is derived. An algorithm for solving the relaxed version is proposed by leveraging alternating minimization and difference-of-convex algorithm, its complexity analysis is also given. Our algorithm is tested via extensive experiments involving numerical examples of one dimensional signal recovery and applications in several image restoration tasks, showing its superiority and competitiveness over some rivals.

关键词： Apoptosis   CAR   Chondrocytes   CIA   Inflammation   Interleukin-1β   JAK/STAT/SOCS signalling   Rheumatoid arthritis  

摘要： Rheumatoid arthritis (RA) is a highly prevalent autoimmune syndrome characterised by consecutive inflammation, synovial hyperplasia, and chondrocyte apoptosis. Carvocal (CAR) is a monoterpenes phenol that commonly occurs in Thymus vulgaris and Origanum vulgare, which exhibits antioxidative, anti-inflammatory, and antitumor activity. Hence, this work has to assess the anti-arthritic and anti-apoptotic activities of CAR in both in vivo and in vitro models. IL-1β-induced chondrocytes reduced (p < 0.05) cell viability, antioxidants, and PTEN, while enhancing (p < 0.05) the levels of ROS, MDA, nitrite, cytokines, inflammatory enzymes, MMPs, and PI3K/Akt versus control. These levels were reversed by the administration of CAR (25, 50, and 100 µM/ml) in a quantity-related manner. An in vivo RA rat model was induced using collagen (CIA), and the anti-arthritic and anti-apoptotic effects of CAR were compared with Diclofenac (DCF, 2.5 mg/kg bw). Treatment with CAR (20 and 40 mg/kg bw) reduced (p < 0.05) loss of body weight, organ weight, inflammatory enzymes, cytokines, chemokines, and histopathological alterations in a dosage-related way when compared to RA rats. Molecular docking analyses were performed to confirm the compound’s multi-targeting potency that CAR could prevent proliferation and inflammation by triggering apoptosis in arthritis. By validating the CAR multi-targeting effectiveness against arthritis, as suggested by the results of docking analysis and MD simulation of COX-2 and iNOS. Furthermore, CAR could attenuate (p < 0.05) the levels of caspase-3, -9, PGE2, Ang-1, MMP-9, and JAK/STAT while elevating SOCS signalling. Thus, CAR has potential as an anti-arthritic and anti-apoptotic component in both types of models. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.

关键词： Gastric cancer   Migration and infiltration   SPIN1   Slug   Claudin-1  

摘要： Metastases are responsible for over 90% of the deaths in patients with gastric cancer (GC). Our previous study revealed that SPIN1 promotes the invasion and metastasis of GC; however, the underlying mechanism remains unclear.

摘要： We report a continuous-wave thulium (Tm)-doped fiber laser oscillator with >1 kW output power operating at 1940 nm under the optimized cooling condition. Using a water calorimetry method, the temperature increases and its impact on output power were experimentally investigated, confirming good agreement with theoretical predictions. To mitigate thermal effects on laser performance, a bi-directional pumping configuration was implemented, theoretically reducing the maximum Tm fiber temperature by ∼40% compared to forward pumping. Under the optimized cooling condition, the Tm fiber laser yielded a maximum output power of 1032 W for an incident pump power of 1785 W, corresponding to a slope efficiency of 58.5%. A near-diffraction-limited beam quality was maintained at all power levels, along with excellent output stability.