Radiation-induced hardening (RIH) severely degrades the mechanical performance and service stability of metallic nuclear structural materials. High-entropy alloys (HEAs) have emerged as promising radiation-tolerant candidates owing to their unique lattice distortion effect and excellent mechanical properties, yet they are still susceptible to RIH under irradiation environments. In this work, molecular dynamics simulations were performed to reveal the atomic-scale RIH mechanism of the equiatomic FeNiCrCoCu HEA. The threshold displacement energy was calculated, and weaker anisotropy was observed compared with medium-entropy alloys and pure Ni, due to severe lattice distortion of the HEA. Overlapping radiation cascade simulations further demonstrated continuous defect generation and aggregation with increasing irradiation dose up to 0.09 dpa. Comparative nanoindentation simulations were conducted on pristine and irradiated HEAs to clarify the coupled evolution of defects and dislocations during plastic deformation. Different from the conventional hardening mechanism, irradiation-induced defects serve as stress concentrators to facilitate initial dislocation nucleation, leading to earlier pop-in behavior at lower indentation loads in irradiated samples. During loading, radiation-induced defects interact with geometrically necessary dislocations and form dense, stable entangled dislocation networks. Upon unloading, residual defects exert strong pinning forces that prevent dislocation network contraction and preserve permanent dislocation substructures. The synergistic effects of defect-induced dislocation pinning and constrained dislocation propagation dominate the RIH behavior of FeNiCrCoCu HEA. This work clarifies the intrinsic atomic-scale mechanism of irradiation hardening in HEAs, providing theoretical guidance for the design and optimization of advanced radiation-resistant nuclear structural materials.
Breast cancer (BC) is a serious global health problem with increasing incidence and mortality, while current treatments are often associated with severe side effects and drug resistance. Therefore, new therapeutic agents with enhanced efficacy and minimal adverse effects are needed. Our previous study reported the anti-angiogenic effect of Monacolin X, a secondary metabolite of a marine-sponge-associated fungus, using combined in vitro, ex vivo, in vivo (including a DMBA-induced mammary carcinoma rat model) and in silico approaches, identifying VEGFR2 as its principal target. In this study, molecular docking and molecular dynamics (MD) simulations were performed to investigate the interactions between Monacolin X and key anti-angiogenic targets, including IGFR, EGFR, neuropilin 1 (NRP1), Tie-2, VEGFR1/2, and PDGFRα, using Schrödinger Glide XP. Selective inhibitors were used for comparison. Docking analysis showed significant binding affinities of Monacolin X toward IGFR (G-score = −9.05), PDGFRα (−7.57), VEGFR1 (−7.42), Tie-2 (−7.40), VEGFR2 (−7.515), EGFR (−6.80), and NRP1 (−5.15), with hydrogen bonding, hydrophobic contacts, and electrostatic interactions contributing to stable complexes. Notably, IGFR and Tie-2 exhibited strong interactions, suggesting potential inhibition of angiogenic signaling. MD simulations were performed for 50 ns at 300 K and 1 bar; complex stability was assessed using RMSD and RMSF analyses, and the persistence of key active site hydrogen bonds was quantified as a percentage of simulation frames. MM-PBSA binding free-energy calculations further supported the thermodynamic feasibility of these interactions. Overall, these findings highlight Monacolin X’s potential as an anti-angiogenic agent for BC. However, further in vitro and in vivo studies are required to validate its efficacy and clinical relevance.
Cobalt ferrite (CoFe2O4) photocatalysts were synthesized through a citric acid–ethylene glycol-assisted sol–gel route by systematically varying the Co2+ precursor concentration from 0.1 to 0.5 M. Precursor concentration significantly influenced the structural, optical, surface, and photocatalytic properties of the resulting CoFe2O4. Among the synthesized samples, Sp3, prepared using 0.3 M Co2+ precursor, exhibited the smallest crystallite size (17 nm), the largest (311) d-spacing (0.268 nm), and an indirect optical band gap of approximately 1.3 eV. XPS analysis of the optimized catalyst revealed mixed Co2+/Co3+ and Fe2+/Fe3+ oxidation states together with lattice and defect-associated oxygen species, indicating a redox-active surface environment. Under UV–Vis irradiation using a 350 W xenon (Xe) lamp, Sp3 achieved complete phenol removal within approximately 40 min and exhibited the highest apparent pseudo-first-order rate constant (0.162 min−1) among the synthesized samples. H2O2 addition further accelerated phenol degradation. Reactive-species scavenging experiments identified •OH as the predominant reactive species, with additional contributions from •O2− and h+. TOC removal reached approximately 88% after 15 min under the optimized conditions, demonstrating substantial mineralization. Furthermore, recycling experiments, post-reaction XRD, and ICP-OES analysis demonstrated good structural and chemical stability of the optimized catalyst. These results demonstrate that controlled precursor concentration provides an effective approach for optimizing CoFe2O4 for photocatalytic degradation of phenolic pollutants under UV–Vis irradiation.
The unsaturated organic salt sodium 4-vinylbenzenesulfonate was investigated by differential pulse voltammetry as an additive in non-aqueous solutions containing various organic analytes. This work focuses on alcohols, which exhibit a high background current compared with other organic solvents. This high interference prevents the voltammetric determination of the dissolved analytes, as their signals are obscured by the background current. The addition of sodium 4-vinylbenzenesulfonate significantly increased the detectability of analytes, resulting in remarkably sharper peaks. Mixtures of many organic solvents with methanol and 1-propanol showed significant differences, with acetonitrile providing the most promising results mainly due to its low viscosity and low background current. The applicability of the method was further demonstrated using a broader range of analytes.
Poly-β-hydroxybutyrate (PHB), a microbially biodegradable polyester, suffers from high crystallinity, intrinsic surface hydrophobicity and a narrow thermal processing window, which greatly restrict its practical application. In this work, high-molecular-weight commercial poly-β-hydroxybutyrate (PHB) was degraded through ethylene-glycol alcoholysis to obtain a hydroxyl-terminated PHB-diol prepolymer. A block copolymer was further synthesized by coupling the prepolymer with hydrophilic poly(ethylene glycol) (PEG-1500) using hexamethylene diisocyanate as the chain extender. Molecular-weight measurements confirm that alcoholysis reduces the peak molecular weight of PHB-diol to 9.12 × 103, and the subsequent coupling reaction raises the peak molecular weight of the resulting block copolymer up to 2.40 × 105. After chemical modification, the water contact angle decreases from 75.5° to 43.6°, while the surface free energy increases notably from 28.4 mN/m to 54.1 mN/m. Morphological observations show that the introduction of poly(ethylene glycol) (PEG) segments inhibits the regular spherulite growth of PHB. Due to flexible PEG segments and thermally sensitive carbamate linkages formed in the reaction, the thermal stability of this block copolymer declines. This chemical coupling strategy effectively improves the surface hydrophilicity of PHB. It should be noted that biodegradation performance is only inferred from structural features, without direct biodegradation experimental verification. This work provides fundamental experimental support for the hydrophilic modification of PHB-based degradable polymer materials.
