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In this work, we reported a facile one-pot strategy to construct conjugated vinylene-extended viologen-based ionic radical polyacetylenes (denoted as VIRPs) for visible light-promoted photocatalytic carbon dioxide (CO2) cycloaddition under ambient conditions. As expected, the ionic polymer VIRP-1 was directly prepared in situ by the quaternization-induced spontaneous polymerization (QISP) reaction between 1,2-bis(4-pyridyl)ethylene (BPE) and propargyl bromide (PGB) in CH3CN at 100 °C for 24 h without any catalysts and initiators. To our delight, the radical character of the ionic radical polymer VIRP-2 could be significantly enhanced by using K2CO3 as an alkaline reductant in the QISP reaction process, similar to the synthesis of VIRP-1, which was confirmed by electron paramagnetic resonance (EPR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the use of K2CO3 not only achieved the in situ one-electron reduction of vinylene-extended viologen cations to stable viologen cationic radicals, but also could remove a large proportion of Br− anions and afford non-halogen anions CO32− within VIRP-2 by anion exchange during the synthetic process. Both ionic radical polyacetylenes VIRP-1 and VIRP-2 exhibit strong and broad visible light-harvesting ability; however, VIRP-2 with much stronger radical intensity possesses better photoinduced charge separation and migration ability. Therefore, the ionic radical polymer VIRP-2 was regarded as a highly efficient and green metal-free heterogeneous photocatalyst in the visible-light-promoted catalytic CO2 conversion with various epoxides into cyclic carbonates at room temperature and atmospheric pressure without using any cocatalysts and solvents. This work affords a new direction to construct task-specific ionic radical polymers towards photocatalytic CO2 cycloaddition under ambient conditions. [ABSTRACT FROM AUTHOR]

Background Allergic rhinitis (AR) a common and complicated upper airway disease mediated by specific IgE antibodies. Our study aims to explore the pharmacological effects of astragalus polysaccharide (APS) on AR and elucidate the mechanisms involved. Methods RT-qPCR and Western blotting were used to analyze mRNA and protein expression. Interleukin (IL)-13-treated human nasal epithelial cells (hNECs) was employed as the AR cell model. Cell apoptosis and viability were evaluated by TUNEL staining and MTT assay, respectively. ROS level was examined by the DCFH-DA probe. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels were measured by the corresponding kits. FBXW7 m6A modification level was assessed by MeRIP assay. Methods Our results showed that APS treatment reduced cell apoptosis, ROS, and MDA levels while increasing SOD, CAT, and GSH-Px levels in IL-13-treated hNECs by activating the Nrf2/HO-1 pathway. Moreover, APS alleviated IL-13-induced oxidative stress injury in hNECs by downregulating WTAP. In addition, WTAP knockdown increased FBXW7 mRNA stability by regulating FBXW7 mRNA m6A modification. It also turned out that APS alleviated IL-13-induced oxidative stress injury in hNECs through the WTAP/FBXW7 axis. Conclusions Taken together, APS inhibited WTAP-mediated FBXW7 m6A modification to alleviate IL-13-induced oxidative stress injury in hNECs. [ABSTRACT FROM AUTHOR]

In this work, we reported a facile one‐pot route to construct polyhedral oligomeric silsesquioxane (POSS) and phosphonium‐based ionic porous hypercrosslinked polymers (denoted as P‐iPHCPs) with multiple catalytic active sites, which could be regarded as efficient heterogeneous catalysts for the conversion of carbon dioxide (CO2) to highly value‐added cyclic carbonates. The targeted polymers P‐iPHCPs were prepared from a rigid building block octavinylsilsesquioxane (VPOSS) and a low‐cost commercially available organic ionic salt methyltriphenylphosphonium bromide ([Ph3PMe]Br) by the AlCl3‐catalyzed Friedel‐Crafts reaction. The series of polymers P‐iPHCPs that synthesized by different molar ratios of VPOSS to [Ph3PMe]Br possess hierarchical micro/mesoporous structures with high surface areas ranging from 376 to 429 m2 g−1 and behave the flower‐like nano‐morphology. Especially, the desired multiple active sites involved the mixed anions including free Cl−, Br− anions and the in‐situ formed metal‐halogen complex anion [AlCl3Br]− within phosphonium segments, and the enriched POSS‐derived SiOH hydrogen bond donor (HBD) groups that derived from the breakage of POSS cages during the synthetic process. The typical polymer P‐iPHCP‐14 has the aforementioned nucleophilic‐electrophilic multiple catalytic active sites, which was regarded as an efficient recyclable heterogeneous catalyst for synergistic catalytic conversion of CO2 with various epoxides into cyclic carbonates under mild conditions. [ABSTRACT FROM AUTHOR]

To settle the problem of phosphors with unsatisfactory luminescence efficiency and serious thermal quenching, Eu2+-activated Sr8Si4O12Cl8 cyan-emitting phosphors were designed. Excited at 387 nm, a dazzling cyan emission located at 492 nm is observed in the resultant phosphors and its maximum intensity is obtained when the Eu2+ content is 4 mol%. Moreover, the zero-thermal quenching luminescence, even when the temperature is 503 K, the integrated emission intensity still maintains 106% of its starting value at 303 K, is realized in resultant phosphors because of the efficient energy transfer from defect levels to Eu2+, which is confirmed by the thermoluminescence spectrum. The electroluminescence spectrum of the packaged white light-emitting diode (white-LED) is detected and it is found to possess a high color rendering index (91.0), low correlated color temperature (4875 K) and a superior luminous efficiency (68.7 lm W−1), implying that the developed phosphors can be adopted as cyan-emitting components to fulfill the cyan gap and realize a full spectrum white-LED. Furthermore, the cathodoluminescence (CL) performance of samples is also studied, in which its CL emission intensity is greatly impacted by the accelerating voltage and the filament current. Additionally, using the synthesized phosphors, various types of patterns are designed for use in information encryption. These achievements reveal that the Eu2+-activated Sr8Si4O12Cl8 phosphors are multifunctional cyan-emitting candidates for full spectrum white-LED, field-emission display and anti-counterfeiting applications. [ABSTRACT FROM AUTHOR]