The purpose of this study was to characterize neural crest-derived cells within the adult murine iris. The iris was isolated from P0-Cre ⁄ Floxed-EGFP transgenic (TG) mice. The isolated iris cells formed EGFP-positive spheres on non-adhesive culture plates. Immunostaining showed that these EGFP-positive spheres expressed neural crest markers including Sox10 and p75NTR, and these cells showing in vitro sphere-forming ability were originally resided in the iris stroma (IS), in vivo. Real-time RT-PCR showed that the EGFP-positive spheres expressed significantly higher levels of the neural crest markers than EGFP-negative spheres and bone marrow-derived mesenchymal stem cells. Furthermore, the iris stromal sphere had capability to differentiate into various cell lineages including smooth muscle and cartilage. These data indicate that neural crest-derived multipotent cells can be isolated from the murine IS and expanded in sphere culture.

We examined chemical etching of the Ge surface assisted by single sheets of chemically modified graphene in O2-containing water. Three types of graphene sheets were used: graphene oxide (GO), hydrazine-reduced GO (hyd-rGO), and hydrothermally treated GO in an ammonia solution (amm-rGO). amm-rGO possessing pyridinic-N atoms produced the highest etching rates of the graphene used for all water temperatures tested. We propose that graphene sheets catalyze Ge oxidation underneath the sheets and that this phenomenon probably originates from the enhanced adsorption of O2 molecules in water at local defects, such as graphene edges and carbon atoms next to pyridinic-N, in the sheets. Because O2 adsorption is the initial step of either the oxygen reduction reaction or direct oxidation, it results in the formation of soluble GeO2 at the graphene/Ge interface, leaving etched hollows under the sheets. In addition, we combined graphene-assisted chemical etching with lithography by using photoresist to fabricate a trench pattern on Ge.

Optically active 2-azanorbornane-based organocatalysts were designed and synthesized, and the catalytic activity of these catalysts in enantioselective aldol reactions of isatins with ketones was investigated. Among these catalysts, 2-azanorbornylmethanol showed the best catalytic activity to afford the corresponding aldol product in excellent chemical yield (up to 95%) and with moderate stereoselectivity (up to 64% ee, up to syn:anti = 36: 64).

In the field of fuel cells, the microscopic understanding of the catalytic activity of nanocarbons or graphene-based materials for oxygen reduction reaction (ORR) is required. In the current study, a novel concept is presented to achieve this, which is a different approach from familiar electrochemical measurements. To prove this concept, we prepared two nanocarbon materials whose ORR activities were tested and compared via macroscale cyclic and linear sweep voltammetry. Next, considering the electrochemical potential of ORR and the band-edge position semiconductors, we chose single-crystalline Ge as the substrate on which the single-sheet nanocarbons were dispersed. We found that etched hollows formed under the loaded nanocarbons after immersing the nanocarbon/Ge sample into O2-containing water. The histogram analysis of the hollows represented the difference in catalytic activities to promote Ge etching between the used nanocarbons, and the corresponding trends agreed qualitatively with the electrochemical measurements.

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