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: Catalysis & Thin film. 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.

Application of high pressure induced by water-freezing to the direct catalytic asymmetric three-component List-Barbas-Mannich reaction

Abstract: High pressure induced by water-freezing has been successfully applied to the direct catalytic asymmetric-three component List-Barbas-Mannich reaction, in which higher yield and better enantioselectivity can be realized than those from the reaction at room temperature under 0.1 MPa.

Superconductivity above 50 K in LnFeAsO1-y (Ln = Nd, Sm, Gd, Tb, and Dy) Synthesized by High-Pressure Technique

Abstract: We have succeeded in synthesizing single-phase polycrystalline samples of oxygen-deficient oxypnictide superconductors, Ln FeAsO 1- y ( Ln : lanthanide elements) with Ln = La, Ce, Pr, Nd, Sm, Gd, Tb, and Dy using high-pressure technique. It is found out that the synthesis pressure is a key parameter for synthesizing samples, in particular for the heavier Ln 's, such as Tb and Dy. The lattice parameters systematically decrease with the atomic number of Ln , reflecting the shrinkage of Ln ionic radius. For the lighter Ln 's (La, Ce, Pr, Nd), T c increases monotonously with decreasing the lattice parameters from 26 K for Ln = La to 54 K for Ln = Nd, then stays at the constant value around 53 K for the heavier counterpart (Nd, Sm, Gd, Tb, and Dy). The results suggest the intimate relationship between the crystal structural parameters and the superconductivity, as well as the possible existence of the inherent maximum T c , which is located around 50 K in the Ln FeAsO based materials.

Neutrino Signals from the Formation of a Black Hole: A Probe of the Equation of State of Dense Matter

Abstract: The gravitational collapse of a nonrotating, black-hole-forming massive star is studied by {nu}-radiation-hydrodynamical simulations for two different sets of realistic equation of state of dense matter. We show that the event will produce as many neutrinos as the ordinary supernova, but with distinctive characteristics in luminosities and spectra that will be an unmistakable indication of black hole formation. More importantly, the neutrino signals are quite sensitive to the difference of equation of state and can be used as a useful probe into the properties of dense matter. The event will be unique in that they will be shining only by neutrinos (and, possibly, gravitational waves) but not by photons, and hence they should be an important target of neutrino astronomy.

Low Dose γ-Rays Activate Immune Functions via Induction of Glutathione and Delay Tumor Growth

Abstract: We examined whether the increase of glutathione level induced by low dose gamma-ray irradiation is involved in the appearance of enhanced natural killer (NK) activity and antibody-dependent cellular cytotoxicity (ADCC), leading to delayed tumor growth in Ehrlich solid tumor-bearing mice. NK activity in ICR mouse splenocytes significantly increased from 4 h to 6 h after whole-body gamma-ray irradiation at 0.5 Gy, and thereafter decreased almost to the zero-time level by 24 h post-irradiation. ADCC also increased significantly in a similar way. Reduced glutathione exogenously added to splenocytes obtained from normal mice enhanced both NK activity and ADCC in a dose-dependent manner. Since immune functions were enhanced through the induction of cellular glutathione after low-dose irradiation, the inhibitory effect of the radiation on tumor growth was then examined in Ehrlich solid tumor-bearing mice. Tumor growth after inoculation was significantly delayed by the radiation. These results suggest that low-dose gamma-rays activate immune functions via an induction of glutathione, leading to a delay of tumor growth.