Fluorescence visualization of the molecular assembly processes during solvent evaporation via aggregation-induced emission in a cyanostilbene derivative

The initial stage of organic crystal formation during solvent evaporation was observed using aggregation-induced enhanced emission, indicating that the fluorescence from the J-aggregates was established prior to the increase in total intensity at the assembly process. This suggests that the kinetics of the transformation of J-aggregates into embryonic nuclei, and subsequently into crystals, can be visualized using fluorescence.ArticleCRYSTENGCOMM. 16(42):9779-9782 (2014)journal articl

Fluorescence Enhancement of a Dicyanostilbene Derivative Film Casted from an Alcoholic Solution Triggered by UV-light Irradiation

The films of a dicyanostilbene derivative (DBDCS) cast from an alcoholic solution show aggregation-induced emission enhancement by UV light irradiation and a fluorescence color change from green to blue upon heating. The former can be attributed to the planarization by rotational motion around the olefin moieties due to elevation in the local temperature via the excited state by UV irradiation. The latter originates from the phase transformation of DBDCS with cooperative alcoholic desorption and molecular reorganization.ArticleChemistry Letters.45(4):421-423(2016)journal articl

Universal partitioning of the hierarchical fold network of 50-residue segments in proteins

<p>Abstract</p> <p>Background</p> <p>Several studies have demonstrated that protein fold space is structured hierarchically and that power-law statistics are satisfied in relation between the numbers of protein families and protein folds (or superfamilies). We examined the internal structure and statistics in the fold space of 50 amino-acid residue segments taken from various protein folds. We used inter-residue contact patterns to measure the tertiary structural similarity among segments. Using this similarity measure, the segments were classified into a number (<it>K</it>_c) of clusters. We examined various <it>K</it>_cvalues for the clustering. The special resolution to differentiate the segment tertiary structures increases with increasing <it>K</it>_c. Furthermore, we constructed networks by linking structurally similar clusters.</p> <p>Results</p> <p>The network was partitioned persistently into four regions for <it>K</it>_c≥ 1000. This main partitioning is consistent with results of earlier studies, where similar partitioning was reported in classifying protein domain structures. Furthermore, the network was partitioned naturally into several dozens of sub-networks (i.e., communities). Therefore, intra-sub-network clusters were mutually connected with numerous links, although inter-sub-network ones were rarely done with few links. For <it>K</it>_c≥ 1000, the major sub-networks were about 40; the contents of the major sub-networks were conserved. This sub-partitioning is a novel finding, suggesting that the network is structured hierarchically: Segments construct a cluster, clusters form a sub-network, and sub-networks constitute a region. Additionally, the network was characterized by non-power-law statistics, which is also a novel finding.</p> <p>Conclusion</p> <p>Main findings are: (1) The universe of 50 residue segments found here was characterized by non-power-law statistics. Therefore, the universe differs from those ever reported for the protein domains. (2) The 50-residue segments were partitioned persistently and universally into some dozens (ca. 40) of major sub-networks, irrespective of the number of clusters. (3) These major sub-networks encompassed 90% of all segments. Consequently, the protein tertiary structure is constructed using the dozens of elements (sub-networks).</p

Catalytic activity of graphene-covered non-noble metals governed by proton penetration in electrochemical hydrogen evolution reaction

Hu, K., Ohto, T., Nagata, Y. et al. Catalytic activity of graphene-covered non-noble metals governed by proton penetration in electrochemical hydrogen evolution reaction. Nat Commun 12, 203 (2021). https://doi.org/10.1038/s41467-020-20503-

Dynamic lighting sign system for way-finding by people with low vision

金沢大学大学院自然科学研究科情報システムWe developed and proposed a dynamic lighting sign (DLS for short) system for people with poor vision to use to find their way. The DLS system uses a chain of lighting units with LED to indicate the way and is controlled by means of a PC. We implemented the DLS system for helping people to find their way and evaluated it in terms of light-flashing time, spatial interval and colour. We also carried out an experiment to evaluate its effectiveness in helping people find their way. © Springer-Verlag 2004

Near room temperature chemical vapor deposition of graphene with diluted methane and molten gallium catalyst

Direct growth of graphene integrated into electronic devices is highly desirable but difficult due to the nominal ~1000 °C chemical vapor deposition (CVD) temperature, which can seriously deteriorate the substrates. Here we report a great reduction of graphene CVD temperature, down to 50 °C on sapphire and 100 °C on polycarbonate, by using dilute methane as the source and molten gallium (Ga) as catalysts. The very low temperature graphene synthesis is made possible by carbon attachment to the island edges of pre-existing graphene nuclei islands, and causes no damages to the substrates. A key benefit of using molten Ga catalyst is the enhanced methane absorption in Ga at lower temperatures; this leads to a surprisingly low apparent reaction barrier of ~0.16 eV below 300 °C. The faster growth kinetics due to a low reaction barrier and a demonstrated low-temperature graphene nuclei transfer protocol can facilitate practical direct graphene synthesis on many kinds of substrates down to 50–100 °C. Our results represent a significant progress in reducing graphene synthesis temperature and understanding its mechanism