Tokyo University of Science

About: Tokyo University of Science is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Thin film & Enantioselective synthesis. The organization has 15800 authors who have published 24147 publications receiving 438081 citations. The organization is also known as: Tōkyō Rika Daigaku & Science University of Tokyo.

Utilization of Metal Sulfide Material of (CuGa)(1-x)Zn(2x)S2 Solid Solution with Visible Light Response in Photocatalytic and Photoelectrochemical Solar Water Splitting Systems.

Abstract: Upon forming a solid solution between CuGaS2 and ZnS, we have successfully developed a highly active (CuGa)(1-x)Zn(2x)S2 photocatalyst for H2 evolution in the presence of sacrificial reagents under visible light irradiation. The Ru-loaded (CuGa)0.8Zn0.4S2 functioned as a H2-evolving photocatalyst in a Z-scheme system with BiVO4 of an O2-evolving photocatalyst and Co complexes of an electron mediator. The Z-scheme system split water into H2 and O2 under visible light and simulated sunlight irradiation. The (CuGa)(1-x)Zn(2x)S2 possessed a p-type semiconductor character. The photoelectrochemical cell with a Ru-loaded (CuGa)0.5ZnS2 photocathode and a CoO(x)-modified BiVO4 photoanode split water even without applying an external bias. Thus, we successfully demonstrated that the metal sulfide material group can be available for Z-scheme and electrochemical systems to achieve solar water splitting into H2 and O2.

Electrokinetics of soft particles

Abstract: Theories of electrokinetics of soft particles, which are particles covered with an ion-penetrable surface layer of polyelectrolytes, are reviewed. Approximate analytic expressions are given, which describe various electrokinetics of soft particles both in dilute and concentrated suspensions, that is, electrophoretic mobility, electrical conductivity, sedimentation velocity and potential, dynamic electrophoretic mobility, colloid vibration potential, and electrophoretic mobility under salt-free condition.

Suppression of differentiation and proliferation of early chondrogenic cells by Notch.

Abstract: Notch is a transmembrane protein involved in cell fate determination. In the present study, we observed temporally and spatially restricted expression of Notch1 in developing cartilage. Notch1 was localized starting from the mesenchymal condensation stage of embryonic mouse forelimbs. Interestingly, although localization could not be detected in the proliferating chondrocytes, obvious immunoreactivity indicating its expression was retained in the perichondrial region. Next, we investigated the expression of Notch1 and related molecules in a chondrogenic cell line, ATDC5 cells. Notch1, Delta-like (Dll)1, Deltex2, and Deltex3 were coexpressed after 6-day insulin treatment. Expression of Hairy and Enhancer of split homologue (HES)-1 followed thereafter. These results suggest that Notch may have a role in the early stage of chondrogenesis. To assess the effect of Notch activation, we cultured ATDC5 cells with a myeloma clone constitutively expressing Dll1, a ligand of Notch. We also used an adenovirus vector to express the constitutively active Notch1 intracellular domain (NIC). Activating either the endogenous or exogenous Notch receptor dramatically inhibited chondrogenic cell differentiation of ATDC5 cells, as assessed by Alcian blue staining of the cells and chondrocyte differentiation markers. Last, we investigated the effect of NIC on the proliferation of the ATDC5 cells. Expression of NIC by the adenovirus strongly suppressed thymidine incorporation. These results indicate that Notch is expressed in the initial stage of chondrogenic cell differentiation and has a strong inhibitory effect on both differentiation and proliferation of the cells when activated. The expression of Notch decreases as chondrogenic differentiation proceeds; however, a population of the cells with sustained expression of Notch1 become perichondrial cells. Considering that the perichondrium acts as a stem cell source of osteoblasts and chondrocytes, Notch1 may have a role in the formation of these cells by suppressing both differentiation and proliferation.

Nutrients, Clock Genes, and Chrononutrition

Abstract: Circadian clocks that comprise clock genes exist throughout the body and control daily physiological events. The central clock that dominates activity rhythms is entrained by light/dark cycles, whereas peripheral clocks regulating local metabolic rhythms are determined by feeding/fasting cycles. Nutrients reset peripheral circadian clocks and the local clock genes control downstream metabolic processes. Metabolic states also affect the clockworks in feedback manners. Because the circadian system organizes whole energy homeostasis, including food intake, fat accumulation, and caloric expenditure, the disruption of circadian clocks leads to metabolic disorders. Recent findings show that time-restricted feeding during the active phase amplifies circadian clocks and improves metabolic disorders induced by a high-fat diet without caloric reduction, whereas unusual/irregular food intake induces various metabolic dysfunctions. Such evidence from nutrition studies that consider circadian system (chrononutrition) has rapidly accumulated. We review molecular relationships between circadian clocks and nutrition as well as recent chrononutrition findings.