Decoding the Reactivity Enhancement of Ln2Ce2O7 Compounds (Ln = Yb, Y, Tb, and Gd) for Soot Combustion: The Remarkable Contribution of Variable Valence A-Sites.

The impact of variable valence A-sites on the redox property and reactivity of Ln2Ce2O7 compounds in soot particulate combustion has been investigated. It was observed that Yb2Ce2O7, Y2Ce2O7, and Gd2Ce2O7 formed a rare earth C-type phase, while Tb2Ce2O7 formed a solid solution phase. Both Tb2Ce2O7 and Yb2Ce2O7 possess dual valence state A-sites, resulting in significantly more surface vacancies. Additionally, the advantageous solid solution phase structure of Tb2Ce2O7 leads to even more surface vacancies than Yb2Ce2O7, which is crucial to generate active oxygen sites. Moreover, the introduction of NO into the reaction feed enhances combustion activity by producing active surface monodentate nitrates. A catalyst with higher numbers of surface vacancies exhibits improved NO oxidation ability and better NO2 utilization efficiency. Consequently, the Tb2Ce2O7 compound demonstrates not only the best soot combustion activity, but also an optimal NOx-assistance effect. Therefore, it is concluded that variable valence A-site is the intrinsic factor to improve the reactivity of Ln2Ce2O7 catalysts.

Roles of SP/KLF transcription factors in odontoblast differentiation: From development to diseases.

OBJECTIVES: A zinc-finger transcription factor family comprising specificity proteins (SPs) and Krüppel-like factor proteins (KLFs) plays an important role in dentin development and regeneration. However, a systematic regulatory network involving SPs/KLFs in odontoblast differentiation has not yet been described. This review examined the expression patterns of SP/KLF gene family members and their current known functions and mechanisms in odontoblast differentiation, and discussed prospective research directions for further exploration of mechanisms involving the SP/KLF gene family in dentin development. MATERIALS AND METHODS: Relevant literature on SP/KLF gene family members and dentin development was acquired from PubMed and Web of Science. RESULTS: We discuss the expression patterns, functions, and related mechanisms of eight members of the SP/KLF gene family in dentin development and genetic disorders with dental problems. We also summarize current knowledge about their complementary or synergistic actions. Finally, we propose future research directions for investigating the mechanisms of dentin development. CONCLUSIONS: The SP/KLF gene family plays a vital role in tooth development. Studying the complex complementary or synergistic interactions between SPs/KLFs is helpful for understanding the process of odontoblast differentiation. Applications of single-cell and spatial multi-omics may provide a more complete investigation of the mechanism involved in dentin development.