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关键词： HipHop pharmacophore   Molecular docking   Molecular dynamics   Natural products   S1PR1 agonist   Virtual screening  

摘要： Sphingosine-1-phosphate receptor 1 (S1PR1), a member of the G protein-coupled receptor (GPCR) family, is a crucial therapeutic target for various diseases. Activation of S1PR1 has been recognized as an effective therapeutic strategy for multiple sclerosis (MS), inflammatory bowel disease (IBD), and psoriasis. Natural products (NPs) serve as a rich source of bioactive compounds for drug discovery. Here, we aimed to discover novel S1PR1 agonists from NPs via multi-level virtual screening (VS). Using a validated HipHop pharmacophore model, we screened a database containing 54,642 NPs, followed by molecular docking. Based on binding mode analysis, four candidate S1PR1 agonists (NPC323626, NPC264112, NPC469907, and NPC22192) were selected. Subsequent molecular dynamics (MD) simulations and binding free energy calculations confirmed the stability of the receptor-ligand complexes and their binding affinities. Among the four candidates, NPC469907 exhibited the strongest binding affinity for S1PR1, with a value of −58.08 ± 0.13 kJ/mol. Furthermore, hydrogen bonds formed between NPC469907 and Glu121 of S1PR1 were found to be essential for receptor activation. Quantum mechanical calculations further revealed that the phenyl-ring-attached hydrogen site in NPC469907 could be modified without compromising its ability to activate S1PR1. The analysis of Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) indicated that NPC469907 possessed favorable pharmacokinetic properties and low toxicity. In conclusion, our study identified NPC469907 as a promising natural S1PR1 agonist and established an effective VS strategy for the discovery of novel S1PR1 agonists.

关键词： Nonrecurrent orbit   Hausdorff Dimension   Hausdorff Dimension   (-beta)-Transformation  

摘要： We investigate the size of the set of beta > 1 for which the orbits of 1 are nonrecurrent under the (-beta)-transformation T-beta. We prove that the set of beta > 1 with sup(n >= 1)T(-beta)(2n-1)(1) < 1 has Lebesgue measure 0. By constructing fractal sets in a neighborhood of an algebraic number beta > 1, we show that the set {beta is an element of (1,root 5 + 1/ 2) :sup(n >= 1)T(-beta)(n)(1) < 1} is of full Hausdorff dimension. The result of this paper significantly extends the related known result of beta-transformation and that of T-beta for beta >= root 5+1/ 2.

关键词： poverty reduction   decent work and economic growth   sustainable development   dynamic RDM-DDF DEA model  

摘要： Addressing regional disparities while pursuing sustainable development has become a critical policy challenge. This study develops a meta parallel two-stage dynamic range directional measure (RDM) directional distance function (DDF) data envelopment analysis (DEA) model to evaluate the efficiency of poverty reduction (SDG 1) and decent work and economic growth (SDG 8) across 30 provinces in China. Given uneven regional development, the provinces are grouped into eastern, central, and western regions, and kernel density estimation is employed to examine the spatial and temporal evolution of efficiency. The results indicate that: (1) The overall efficiency is moderate, with an average score of 0.67, highest in the eastern region, followed by the western, and lowest in the central region. (2) The efficiency of SDG 8 (0.93) significantly exceeds that of SDG 1 (0.87), while the regional ranking remains consistent with the overall efficiency. (3) The technology gap among the three regions shows dynamic changes: the western region has overtaken the eastern region to become the most advanced. In contrast, the central region continues to lag, and its gap with the other regions is steadily widening.

摘要： Ferroelectricity in Hf_1-xZr_xO₂ (HZO) films is strongly governed by phase stability, which becomes increasingly sensitive to both film thickness and composition as scaling proceeds into the few-nanometer regime. While near-equimolar Hf:Zr compositions are widely reported to yield robust ferroelectricity in ∼10 nm-thick HZO films, the validity of this conventional composition strategy at ultrathin thicknesses remains unclear. Here, we investigate the coupled effects of thickness and composition on ferroelectric phase stability and switching behavior in atomic-layer-deposited HZO films with thicknesses of 3–5 nm. By independently controlling the film thickness and the Hf:Zr ratio, we reveal a clear thickness-dependent shift of the ferroelectric composition window toward the Hf-rich side. At a thickness of 5 nm, an intermediate composition exhibits the strongest diffraction contribution associated with the orthorhombic phase and remanent polarization, whereas at 3 nm, Hf-rich compositions exhibit the most robust ferroelectric switching, with representative endurance confirmed for the optimized composition. This composition shift is qualitatively consistent with a surface-energy-based Helmholtz free energy framework, in which surface contributions increasingly dominate phase stability at reduced thicknesses. These results establish a thickness–composition design guideline for stabilizing ferroelectricity in ultrathin HZO films and provide insights into phase stability and materials design for nanoscale ferroelectric applications.

关键词： Atom probe tomography   Bubbles   CLF-1 steel   Cold work   Irradiation hardening   Nano-sized oxide particles   ODS steel  

摘要： Both uniformly dispersed nano-oxide particles and dislocations introduced by cold work are key approaches to enhancing the irradiation tolerance of materials. This study systematically investigates the irradiation responses of China Low-Activation Ferrite steel (CLF-1) steels (with 0 % and 10 % cold-work reductions, denoted as CW 0 % and CW 10 %) and oxide dispersion-strengthened (ODS) steel under sequential H⁺-(Fe²⁺+He⁺) irradiation at 350 °C and 450 °C. Microstructural evolution, including bubbles and dislocation loops, was characterized via transmission electron microscopy (TEM). And atom probe tomography (APT) elucidated the configuration of nano-sized oxide particles in ODS steel. At both irradiation temperatures, CW 10 % exhibited an increase in the number density of dislocation loops and bubbles but a decrease in average size compared to CW 0 %, attributed to the enhanced defect sinks induced by cold work. The analysis results of ODS steel based on APT indicate that the average size and number density of oxide particles are significantly dependent on the irradiation temperature, and the aggregation of Cr element was found in the oxide particles at both irradiation conditions, with slightly elevated levels observed at 450 °C compared to 350 °C. Notably, CW 10 % and ODS steel demonstrated comparable irradiation hardening resistance, rationalized by the similar strength of the primary sinks they introduced individually. The contributions of dislocation loops, bubbles, oxide particles, and dislocation lines to irradiation hardening are quantified using the Dispersed Barrier Hardening (DBH) model and Friedel-Kroupa-Hirsch (FKH) model. These results demonstrate that dislocations introduced by controlled cold working and dispersed nanoscale oxide particles of tailored size and density exert a comparable effect in mitigating irradiation hardening, which offers different promising pathways to improve the irradiation tolerance of advanc

摘要： The low concentration of methane emitted by lean-burn compressed natural gas vehicles is 20 times more potent than CO₂ as a greenhouse gas and must be catalytically removed urgently. Herein, the well-defined Pd_1-xCu_xO_δ@SiO₂ (x = 0, 0.1, 0.2, 0.5, 0.8) core–shell structures were constructed through the reverse microemulsion method, and subsequently deposited onto the Al₂O₃ support to yield the Pd_1-xCu_xO_δ@SiO₂/Al₂O₃ catalyst. Catalytic evaluation revealed that the introduction of non-noble Cu not only cut the Pd loading by almost half but also delivered a slightly higher reaction rate than the pristine Pd counterpart (Pd_0.5Cu_0.5O_δ@SiO₂/Al₂O₃: 0.0038 mol_CH4∙g_Pd^-1∙s⁻¹ vs. PdO@SiO₂/Al₂O₃: 0.0033 mol_CH4∙g_Pd^-1∙s⁻¹). Systematic characterizations revealed that the metals existed as PdO–CuO solid solution within the SiO₂ shell, wherein PdO was entirely encapsulated while a fraction of CuO resided in the shallow subsurface or on the surface, yielding a detectable signal. Moreover, the oxygen-vacancy concentration increased with the Cu content, leading to a consequent enhancement in methane oxidation activity and stability. In situ diffuse reflectance infrared Fourier transform spectroscopy exhibited that the lean methane combustion reaction followed the Langmuir-Hinshelwood mechanism. By reducing noble-metal usage without sacrificing performance, this work provides vital theoretical guidance for developing catalysts for the high-efficiency purification of CH₄ in CNG vehicle exhaust.

关键词： 4O2 catalyst   sub>4Zr31   DRM   Ni   Oxygen vacancy   Photothermal catalysis  

摘要： Dry reforming of methane (DRM) is a pivotal technology in the carbon cycle field. It can co-convert CH₄ and CO₂ into syngas, achieving the resource utilization of greenhouse gases and providing an innovative solution for mitigating the climate crisis. Based on prior research on Ce_1-xZr_xO₂ catalysts, the present study constructs a model featuring Ni clusters supported on the Ce_1/4Zr_3/4O₂(111) surface with the introduction of oxygen vacancies. By integrating density functional theory (DFT) calculations, we explore the enhancement effect of oxygen vacancies and their synergy with photothermal conditions on the DRM reaction mechanism. The results show that oxygen vacancies optimize the charge distribution and serve as key active sites for improving catalytic performance. In the reaction pathway, CH species react through an oxygen-assisted dehydrogenation route, effectively suppressing carbon deposition. By applying an external electric field to simulate the photo-generated carrier effect, it is found that the field can drive the directional migration of electrons from the support to the active metal Ni, generating a synergistic enhancement effect with the electron supply from oxygen vacancies. This synergy significantly optimizes the adsorption configurations and transition state energies of reaction intermediates. The current study reveals, at the atomic scale, the mechanism by which the synergy between oxygen vacancies and photothermal conditions enhances DRM efficiency, providing a basis for designing catalysts.

关键词： Carbon dioxide   Supercritical   Detector cooling   Heat transfer   Pressure drop   Experimental  

摘要： Supercritical CO${}_2$ (sCO${}_2$) is of high interest for compact cooling applications, yet local heat transfer data in millimetric scale horizontal tubes under electronics-relevant conditions remain scarce. This work reports local heat transfer coefficients, pressure drops and temperature-inlet-to-outlet values for CO${}_2$ at inlet pressures from 7.5 to 8.5 MPa flowing in a $1\mathrm{mm}$ horizontal stainless-steel tube with $G=2130$ kg m⁻² s⁻¹ ($\dot{m}\approx 1.8$ g s⁻¹) and uniform Joule heating over $L_h=0.903$ m at $q=$

关键词： Cascade activation   Immunogenic cell death   Precision immunotherapy   STING pathway   Tumor microenvironment  

摘要： Immunotherapy represents a pioneering approach in clinical cancer treatment, but its application is often limited by insufficient immune stimulation and off-target side effects. Therefore, developing novel nanomaterials capable of precisely reshaping the tumor microenvironment (TME) is crucial for enhancing the efficacy of tumor immunotherapy. Herein, we constructed a “precision immune bomb” DOX@MZIF-P3 embodying a “PD-L1-targeted, on-site unlocking, local detonation” strategy. It actively targets and blocks highly expressed programmed death ligand 1 (PD-L1) on tumor cells, achieving tumor accumulation while attenuating immune evasion. In response to the TME, it depletes glutathione (GSH) and releases effector substances including doxorubicin (DOX), Mn²⁺, and Zn²⁺. Specifically, DOX induces apoptosis via DNA damage and elevates intratumoral H₂O₂ levels. Mn²⁺ generates reactive oxygen species (ROS) through Fenton-like reactions to trigger ferroptosis, while simultaneously sensitizing and augmenting the stimulator of interferon genes (STING) pathway. Zn²⁺ overload induces tumor cell pyroptosis and further promotes immunogenic cell death (ICD). Additionally, synergy between activated STING pathway and ICD enhances immune cell infiltration in tumor tissue and increases the levels of related inflammatory factors in the TME, ultimately promoting immunotherapy. This strategy precisely activates tumor immunity while significantly reducing off-target toxicity, effectively inhibiting primary tumor growth and blocking metastasis, providing a new paradigm for precision tumor immunotherapy.

摘要： A combined experimental (FT-IR, FT-Raman, NMR and UV–Visible) and density functional theory (DFT) study was performed to investigate the structural, spectroscopic, electronic and nonlinear optical properties of 2-(2-bromophenyl)-1,3-dioxolane (2BPD), 2-(3-bromophenyl)-1,3-dioxolane (3BPD) and 2-(4-bromophenyl)-1,3-dioxolane (4BPD). Geometry optimization and torsional potential energy surface analysis at the B3LYP/6–311++G(d,p) level confirmed stable minimum-energy conformations. The computed vibrational frequencies and GIAO-based ¹H and ¹³C NMR chemical shifts showed good agreement with experimental results, validating the molecular structures. TD-DFT simulations successfully reproduced the UV–Visible absorption maxima, attributing the bands to n → π* and π → π* transitions. Frontier molecular orbital analysis revealed moderate HOMO–LUMO energy gaps (∼4.37–4.42 eV), indicating effective conjugation and charge transfer. Global reactivity descriptors suggest favorable kinetic stability with moderate reactivity. The enhanced first-order hyperpolarizability values, exceeding that of urea, indicate strong nonlinear optical (NLO) potential. NBO and MEP analyses further confirm significant π-electron delocalization, intramolecular charge transfer and well-defined reactive sites. Overall, these results highlight the suitability of the studied molecules for optoelectronic and NLO applications.