Mechanistic Study of Enhanced CO Oxidation Activity on Rare-Earth and Transition Metal Doped CeO2

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Boosting Support Reducibility and Metal Dispersion by Exposed Surface Atom Control for Highly Active Supported Metal Catalysts

For oxide-supported metal catalysts, support reducibility and metal dispersion are the key factors to determine the activity and selectivity in many essential reactions involving redox process. Herein, we tuned the exposed surface atoms of the catalyst by facet control and doping methods, which were simultaneously applied to boost the reducibility and metal dispersion of an oxide support. Pd supported on Cu-doped CeO2 (Pd/CDC) for water???gas shift reaction (WGSR) was considered a model system; Cu was doped into the cubic and octahedral CeO2 enclosed with (100) and (111) facets, respectively. By a systematic combination of density functional theory calculations and experimental analyses, the WGSR activity of the Pd/CDC cube was verified to synergistically increase by more than just the sum of the morphology and Cu doping effects. The effect of each tuning method on the activity was further investigated from a mechanistic perspective. This work presents a rational design knowledge to enhance the catalytic activity that can be extended to a wide range of supported metal systems

The Brain-Enriched MicroRNA miR-9-3p Regulates Synaptic Plasticity and Memory

MicroRNAs (miRNAs) are small, noncoding RNAs that posttranscriptionally regulate gene expression in many tissues. Although a number of brain-enriched miRNAs have been identified, only a few specific miRNAs have been revealed as critical regulators of synaptic plasticity, learning, and memory. miR-9-5p/3p are brain-enriched miRNAs known to regulate development and their changes have been implicated in several neurological disorders, yet their role in mature neurons in mice is largely unknown. Here, we report that inhibition of miR-9-3p, but not miR-9-5p, impaired hippocampal long-term potentiation (LTP) without affecting basal synaptic transmission. Moreover, inhibition of miR-9-3p in the hippocampus resulted in learning and memory deficits. Furthermore, miR-9-3p inhibition increased the expression of the LTP-related genes Dmd and SAP97, the expression levels of which are negatively correlated with LTP. These results suggest that miR-9-3p-mediated gene regulation plays important roles in synaptic plasticity and hippocampus-dependent memory,close0