Hubei University of Science & Technology

Nine previously undescribed phenylspirodrimane dimers, distachydrimanes G-O (1-6 and 8-10), along with one known analogue (7), were isolated from the fermentation culture of the coral-derived endophytic fungus Stachybotrys chartarum. Their structures were elucidated through comprehensive spectroscopic analyses, including NMR and HRESIMS, comparison of experimental and calculated ECD data, and single-crystal X-ray diffraction analysis. Compounds 1-6 comprise three isomeric pairs linked via a 6/7-membered oxygen heterocycle. Compounds 2, 4, and 6 possess the first-reported 22S,23R,23'R configuration, whereas compounds 1, 3, and 5 feature the rare 22R,23S,23'S configuration. Compound 10 represents the first C-18-C-23'-linked dimer with a furan-deficient monomer. Bioactivity assays demonstrated that compound 3 potently inhibited MSU-induced IL-1β secretion and pseudopodia formation in THP-1 cells. It attenuated oxidative stress by suppressing ROS generation, thereby blocking NF-κB p65 nuclear translocation and subsequent cascade of inflammatory responses, cellular senescence, and DNA damage. These findings highlight compound 3 as a promising lead for anti-gouty arthritis therapeutics.

Conventional X-ray shielding largely relies on lead (Pb) or lead-based materials; however, their high weight, limited flexibility, and toxicity raise concerns for modern medical and industrial applications. In addition, Pb-based shielding is not optimized for attenuation across the full diagnostic X-ray energy range, particularly below 100 keV. Consequently, recent research has focused on developing lead-free, non-toxic shielding materials with improved performance and reduced weight, including composites based on tungsten (W), bismuth (Bi), and lanthanum (La). This study investigates lead-free multi-element composites optimized for wide-spectrum (40-200 keV) medical X-ray shielding by integrating rare-earth elements such as samarium (Sm), erbium (Er), and europium (Eu), into non-toxic heavy-metal matrices. Monte Carlo simulations were employed to calculate linear and mass attenuation coefficients of candidate elements (W, Ta, Bi, La, Sm, Er, Eu) and their composites. Promising formulations were evaluated in terms of shielding effectiveness, equivalent dose reduction [H∗(10)], weight efficiency, and material cost. The results indicate that W and Ta exhibit superior attenuation at higher photon energies but reduced effectiveness below approximately 60 keV. The incorporation of rare-earth elements significantly enhances low-energy attenuation when blended with W-based matrices, while Bi contributes to improved mid-to-high energy performance. Among the evaluated formulations, W-rare-earth and W-Bi (70% W and 30% Bi) composites demonstrate balanced attenuation across the diagnostic energy range and reduce H∗(10) more effectively than Pb, while offering advantages in weight or cost depending on composition. These findings demonstrate that optimized tungsten-based, lead-free composites complemented by rare-earth elements can outperform conventional Pb shielding within targeted energy ranges, providing a theoretical framework for designing lightweight, non-toxic radiation shielding materials for medical and industrial applications.

The neural origin of bottom-up saliency for exogenous attention remains highly controversial. In this study, we investigated whether the earliest activity in the primary visual cortex (V1) encodes saliency signals defined by the eye-of-origin and feature-conjunction information. Electroencephalography (EEG) recordings from the human occipital cortex revealed early responses to eye-of-origin (E) and/or orientation (O) singletons, with larger response amplitudes to the double-feature (EO) singletons. The short onset latency (58-70 ms) and polarity reversal of the responses indicate an origin in the early visual areas, particularly V1. Importantly, the latency and amplitude of these responses predicted behavioral detection performance. Together, these findings suggest that the timing and amplitude of the earliest signals in V1 represent the saliency of combined feature contrasts for bottom-up attention. These signals unlikely originate from projections of other proposed source areas of saliency, due to the scarcity of necessary monocular neurons to process eye-of-origin information.