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.

Helios Enhances Treg Cell Function in Cooperation With FoxP3

Abstract: Objective Helios+FoxP3+CD4+ (Helios+) Treg cells are believed to be involved in the regulation of various autoimmune diseases; however, the regulatory mechanisms underlying the development of Helios+ Treg cells remain uncertain. This study was undertaken to elucidate the regulatory mechanisms of Helios expression in CD4+ T cells and its roles in transforming growth factor β (TGFβ)–induced Treg cell function. Methods We examined the expression of Helios in CD4+ T cells in patients with rheumatoid arthritis by DNA microarray analysis before and after treatment with biologic agents. We also examined the effect of interleukin-6 (IL-6) and TGFβ on Helios expression in CD4+ T cells in humans and mice. The effect of forced expression of Helios on murine induced Treg cell function was also examined. The role of FoxP3 in the induction and function of Helios was assessed by using CD4+ T cells from FoxP3-deficient scurfy mice. Results Tocilizumab, but not tumor necrosis factor (TNF) inhibitors or abatacept, increased Helios expression in CD4+ T cells in patients with a good response. IL-6 inhibited the TGFβ-induced development of Helios+ induced Treg cells in both humans and mice. Both cell-intrinsic FoxP3 expression and TGFβ signaling were required for Helios induction in murine induced Treg cells. The forced expression of Helios enhanced the expression of various Treg cell–related molecules and the suppressive function in murine induced Treg cells. Helios-mediated enhancement of the suppressive function of induced Treg cells was obvious in FoxP3-sufficient CD4+ T cells but not in FoxP3-deficient CD4+ T cells. Conclusion Our findings indicate that Helios enhances induced Treg cell function in cooperation with FoxP3.

Preferential Location of Coinage Metal Dopants (M = Ag or Cu) in [Au25–xMx(SC2H4Ph)18]− (x ∼ 1) As Determined by Extended X-ray Absorption Fine Structure and Density Functional Theory Calculations

Abstract: The preferential locations of Ag and Cu atoms in the initial stage of doping into [Au25(SC2H4Ph)18]− were studied by X-ray absorption spectroscopy and density functional theory computations. The extended X-ray absorption fine structure (EXAFS) spectra of [Au23.8Ag1.2(SC2H4Ph)18]− at the Ag K-edge were reproduced using a model structure in which the Ag dopant occupied a surface site in the icosahedral Au13 core that was computationally the most stable site. In contrast, the Cu K-edge EXAFS spectra of [Au23.6Cu1.4(SC2H4Ph)18]− indicated that the Cu dopant was preferentially located at the oligomer site that was computationally less stable than the surface site. This discrepancy between the Cu location experimentally determined and that theoretically predicted was explained in terms of variations in the stability of the Cu dopant at the two sites against aerobic oxidation. These results demonstrate that the mixing patterns of bimetallic clusters are determined not only by the thermodynamic stability but also...

High-energy spin and charge excitations in electron-doped copper oxide superconductors

Abstract: Understanding spin dynamics in the cuprates is vital to understanding the origin high-temperature superconductivity. X-ray and neutron spectra obtained by Ishii et al. suggest that the spins in electron-doped cuprates are itinerant, in contrast to recent evidence that in hole-doped cuprates they are localized.

Redox potentials of primary electron acceptor quinone molecule (QA)− and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d

Abstract: In a previous study, we measured the redox potential of the primary electron acceptor pheophytin (Phe) a of photosystem (PS) II in the chlorophyll d–dominated cyanobacterium Acaryochloris marina and a chlorophyll a–containing cyanobacterium, Synechocystis We obtained the midpoint redox potential (Em) values of −478 mV for A marina and −536 mV for Synechocystis In this study, we measured the redox potentials of the primary electron acceptor quinone molecule (QA), ie, Em(QA/QA−), of PS II and the energy difference between [P680·Phe a−·QA] and [P680·Phe a·QA−], ie, ΔGPhQ The Em(QA/QA−) of A marina was determined to be +64 mV without the Mn cluster and was estimated to be −66 to −86 mV with a Mn-depletion shift (130–150 mV), as observed with other organisms The Em(Phe a/Phe a−) in Synechocystis was measured to be −525 mV with the Mn cluster, which is consistent with our previous report The Mn-depleted downshift of the potential was measured to be approximately −77 mV in Synechocystis, and this value was applied to A marina (−478 mV); the Em(Phe a/Phe a−) was estimated to be approximately −401 mV These values gave rise to a ΔGPhQ of −325 mV for A marina and −383 mV for Synechocystis In the two cyanobacteria, the energetics in PS II were conserved, even though the potentials of QA− and Phe a− were relatively shifted depending on the special pair, indicating a common strategy for electron transfer in oxygenic photosynthetic organisms