This work examines the effect of nanocrystal diameter and surface coating on the reactivity of cerium oxide nanocrystals with H2O2 both in chemical solutions and in cells. Monodisperse nanocrystals were formed in organic solvents from the decomposition of cerium precursors, and subsequently phase transferred into water using amphiphiles as nanoparticle coatings. Quantitative analysis of the antioxidant capacity of CeO2-x using gas chromatography and a luminol test revealed that 2 mol of H2O2 reacted with every mole of cerium(III), suggesting that the reaction proceeds via a Fenton-type mechanism. Smaller diameter nanocrystals containing more cerium(III) were found to be more reactive toward H2O2. Additionally, the presence of a surface coating did not preclude the reaction between the nanocrystal surface cerium(III) and hydrogen peroxide. Taken together, the most reactive nanoparticles were the smallest (e.g., 3.8 nm diameter) with the thinnest surface coating (e.g., oleic acid). Moreover, a benchmark test of their antioxidant capacity revealed these materials were 9 times more reactive than commercial antioxidants such as Trolox. A unique feature of these antioxidant nanocrystals is that they can be applied multiple times: over weeks, cerium(IV) rich particles slowly return to their starting cerium(III) content. In nearly all cases, the particles remain colloidally stable (e.g., nonaggregated) and could be applied multiple times as antioxidants. These chemical properties were also observed in cell culture, where the materials were able to reduce oxidative stress in human dermal fibroblasts exposed to H2O2 with efficiency comparable to their solution phase reactivity. These data suggest that organic coatings on cerium oxide nanocrystals do not limit the antioxidant behavior of the nanocrystals, and that their redox cycling behavior can be preserved even when stabilized.

In 2020, the coronavirus disease (COVID-19) pandemic has resulted in a massive, unexpected, and sudden disruption to billions of employees around the world. Organizations and employees have been forced to transform their operational routines virtually overnight. This has resulted in unprecedented demands on managers to make decisions in very uncertain conditions. In times of crises such as those employees turn to organizational leaders for information, which heightens demands for effective communication of critical decisions (Van der Meer et al., 2017; Van Zoonen & Van der Meer, 2015). In general, in the "new normal" resulted from the COVID-19 pandemic many white-collar and professional employees are working from home. This presents a whole range of communication challenges. In response, organizations have adopted technology-driven solutions, where managers communicate time-critical information via multiple channels including but not limited to email, intranet, video conferencing, and other tools.

There is growing interest in the reforming of methanol and other bio-oxygenates as highdensity, CO 2 -neutral, renewable sources of H 2 . Photocatalysis is worthy of investigation as a potentially economic means to drive such endothermic processes. In this study, in-situ DRIFTS, adapted for optical pumping and coupled to on-line MS, was used to observe the surface of TiO 2 (Degussa P25) during photo-metallization from pre-sorbed hexachloroplatinate, at a nominal Pt loading of 1 wt%, and to evaluate photo-reforming of methanol over the resulting Pt/TiO 2 composite. The irreversible growth of a quasi-continuum absorption, characteristic of the surface plasmon resonance of zerovalent Pt nanoparticles, along with bands at 2050 and 1830 cm -1 typical of metal-adsorbed CO, indicated that photometallization was complete typically within 2 hours. Methanol reforming was photocatalyzed at room temperature but in low quantum efficiency, ø ≈ 0.01. However, this was raised substantially, to ø ≈ 0.07, simply by the application of mild heating (T ≤ 70 ºC). Photoreforming proceeded at a fixed rate but the H 2 /CO 2 ratio generally exceeded that of the reforming stoichiometry, suggesting some retention of CO 2 . The photo-thermal synergy was rationalized by model DRIFTS studies, starting from formalin (hydrated formaldehyde), which revealed key features of the mechanism. TiO 2 promoted the Cannizzaro disproportionation in the dark, yielding formate and methoxy species already at 40 ºC. While methoxy was effectively cycled back to the initial photo-dehydrogenation stage, the slow step was identified as formate decomposition to H 2 and CO 2 . The low value measured for the apparent activation energy (~40 kJ mol -1 ) was taken as supporting evidence for 'waterassisted destabilization' of formate, as originally reported by Shido and Iwasawa. No evidence was found for an alternative thermal or photo-reforming mechanism involving the Pt-CO ad species.

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