Browsing by Author "Jiang, X"

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    A3A′3Zn6Te4O24 (A = Na, A′ = rare earth) garnets: A-site ordered noncentrosymmetric structure, photoluminescence, and Na-ion conductivity
    (American Chemical Society, 2021-11-16) Fang, Z; Jiang, P; Avdeev, M; Wei, H; Wang, R; Jiang, X; Yang, T
    A large number of oxides that adopt the centrosymmetric (CS) garnet-type structure (space group Ia3̅d) have been widely studied as promising magnetic and host materials. Hitherto, no noncentrosymmetric (NCS) garnet has been reported yet, and a strategy to NCS garnet design is therefore significant for expanding the application scope. Herein, for the series A3A′3Zn6Te4O24 (A = Na, A′ = La, Eu, Nd, Y, and Lu), we demonstrated that the structural symmetry evolution from CS Ia3̅d (A′ = La) to NCS I4122 (A′ = Eu, Nd, Y, and Lu) could be achieved due to the A-site cationic ordering-driven inversion symmetry breaking. Na3A′3Zn6Te4O24 (A′ = rare earth) are the first garnets that possess NCS structures with A-site cationic ordering. Diffuse reflectance spectra and theoretic calculations demonstrated that all these NCS garnets are indirect semiconductors. Moreover, their potential applications as host materials for red phosphors and Na-ion conductors were also investigated in detail, which firmly confirmed the NCS structure and A-site cationic ordering. Our findings have paved the way to design NCS or even polar garnets that show intriguing functional properties, such as ferroelectricity, multiferroicity, and second harmonic generation. © 2021 American Chemical Society
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    Arginine catabolism is essential to polymyxin dependence in Acinetobacter baumannii
    (Elsevier, 2024-07) Han, ML; Alsaadi, Y; Zhao, JX; Zhu, Y; Lu, J; Jiang, X; Ma, W; Patil, NA; Dunstan, RA; Le Brun, AP; Wickremasinghe, H; Hu, X; Wu, Y; Yu, HH; Wang, J; Barlow, CK; Bergen, PJ; Shen, HH; Lithgow, T; Creek, DJ; Velkov, T; Li, J
    Polymyxins are often the only effective antibiotics against the "Critical" pathogen Acinetobacter baumannii. Worryingly, highly polymyxin-resistant A. baumannii displaying dependence on polymyxins has emerged in the clinic, leading to diagnosis and treatment failures. Here, we report that arginine metabolism is essential for polymyxin-dependent A. baumannii. Specifically, the arginine degradation pathway was significantly altered in polymyxin-dependent strains compared to wild-type strains, with critical metabolites (e.g., L-arginine and L-glutamate) severely depleted and expression of the astABCDE operon significantly increased. Supplementation of arginine increased bacterial metabolic activity and suppressed polymyxin dependence. Deletion of astA, the first gene in the arginine degradation pathway, decreased phosphatidylglycerol and increased phosphatidylethanolamine levels in the outer membrane, thereby reducing the interaction with polymyxins. This study elucidates the molecular mechanism by which arginine metabolism impacts polymyxin dependence in A. baumannii, underscoring its critical role in improving diagnosis and treatment of life-threatening infections caused by "undetectable" polymyxin-dependent A. baumannii. ª 2024 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC licence