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.

Structural Analysis of Sucrose-Derived Hard Carbon and Correlation with the Electrochemical Properties for Lithium, Sodium, and Potassium Insertion

Abstract: Hard carbon possesses the ability to store Li, Na, and K ions between stacked sp2 carbon layers and voids (micropores). We have explored hard carbon as a candidate for negative electrode materials ...

DNA polymerase θ contributes to the generation of C/G mutations during somatic hypermutation of Ig genes

Abstract: Somatic hypermutation of Ig variable region genes is initiated by activation-induced cytidine deaminase; however, the activity of multiple DNA polymerases is required to ultimately introduce mutations. DNA polymerase η (Polη) has been implicated in mutations at A/T, but polymerases involved in C/G mutations have not been identified. We have generated mutant mice expressing DNA polymerase (Polθ) specifically devoid of polymerase activity. Compared with WT mice, Polq-inactive (Polq, the gene encoding Polθ) mice exhibited a reduced level of serum IgM and IgG1. The mutant mice mounted relatively normal primary and secondary immune responses to a T-dependent antigen, but the production of high-affinity specific antibodies was partially impaired. Analysis of the JH4 intronic sequences revealed a slight reduction in the overall mutation frequency in Polq-inactive mice. Remarkably, although mutations at A/T were unaffected, mutations at C/G were significantly decreased, indicating an important, albeit not exclusive, role for Polθ activity. The reduction of C/G mutations was particularly focused on the intrinsic somatic hypermutation hotspots and both transitions and transversions were similarly reduced. These findings, together with the recent observation that Polθ efficiently catalyzes the bypass of abasic sites, lead us to propose that Polθ introduces mutations at C/G by replicating over abasic sites generated via uracil-DNA glycosylase.

Hole-doping-induced changes in the electronic structure of La 1 − x Sr x FeO 3 : Soft x-ray photoemission and absorption study of epitaxial thin films

Abstract: We have studied the electronic structure of epitaxially grown thin films of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{FeO}}_{3}$ by in situ photoemission spectroscopy (PES) and x-ray-absorption spectroscopy (XAS) measurements. The $\mathrm{Fe}$ $2p$ and valence-band PES spectra and the $\mathrm{O}$ $1s$ XAS spectra of ${\mathrm{LaFeO}}_{3}$ have been successfully reproduced by configuration-interaction cluster-model calculation and, except for the satellite structure, by band-structure calculation. From the shift of the binding energies of core levels, the chemical potential was found to be shifted downward as $x$ was increased. Among the three peaks in the valence-band spectra of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{FeO}}_{3}$, the peak nearest to the Fermi level $({E}_{F})$, due to the ``${e}_{g}$ band,'' was found to move toward ${E}_{F}$ and became weaker as $x$ was increased, whereas the intensity of the peak just above ${E}_{F}$ in the $\mathrm{O}$ $1s$ XAS spectra increased with $x$. The gap at ${E}_{F}$ was seen for all values of $x$. These results indicate that changes in the spectral line shape around ${E}_{F}$ are dominated by spectral weight transfer from below to above ${E}_{F}$ across the gap and are therefore highly nonrigid-bandlike changes.