Kyoto University

About: Kyoto University is a education organization based out in Kyoto, Japan. It is known for research contribution in the topics: Catalysis & Population. The organization has 85837 authors who have published 217215 publications receiving 6526826 citations. The organization is also known as: Kyōto University & Kyōto daigaku.

Aβ(1–42) fibril structure illuminates self-recognition and replication of amyloid in Alzheimer's disease

Abstract: Aβ(1–42) is the most pathogenic amyloid-β species in Alzheimer's disease (AD). The solid-state NMR–based atomic model of an Aβ(1–42) fibril elucidates the mechanism of fibril formation and propagation in AD and other amyloid diseases.

Foxp3+ natural regulatory T cells preferentially form aggregates on dendritic cells in vitro and actively inhibit their maturation.

Abstract: Naturally occurring CD4(+)CD25(+) regulatory T cells (Treg) suppress in vitro the proliferation of other T cells in a cell-contact-dependent manner. Dendritic cells (DCs) appear to be a target of Treg-mediated immune suppression. We show here that, in coculture of dye-labeled Treg cells and CD4(+)CD25(-) naive T cells in the presence of T cell receptor stimulation, Treg cells, which are more mobile than naive T cells in vitro, out-compete the latter in aggregating around DCs. Deficiency or blockade of leukocyte function-associated antigen-1 (LFA-1) (CD11a/CD18) abrogates Treg aggregation, whereas that of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) (CD152) does not. After forming aggregates, Treg cells specifically down-regulate the expression of CD80/86, but not CD40 or class II MHC, on DCs in both a CTLA-4- and LFA-1-dependent manner. Notably, Treg exerts this CD80/86-down-modulating effect even in the presence of strong DC-maturating stimuli, such as GM-CSF, TNF-alpha, IFN-gamma, type I IFN, and lipopolysaccharide. Taken together, as a possible mechanism of in vitro Treg-mediated cell contact-dependent suppression, we propose that antigen-activated Treg cells exert suppression by two distinct steps: initial LFA-1-dependent formation of Treg aggregates on immature DCs and subsequent LFA-1- and CTLA-4-dependent active down-modulation of CD80/86 expression on DCs. Both steps prevent antigen-reactive naive T cells from being activated by antigen-presenting DCs, resulting in specific immune suppression and tolerance.

The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lyα Emitters from z = 3.1 to 5.7 in the 1 deg2 Field: Luminosity Functions and AGN*

Abstract: We present luminosity functions (LFs) and various properties of Lyα emitters (LAEs) at z = 3.1, 3.7, and 5.7, in a 1 deg2 sky of the Subaru/XMM–Newton Deep Survey (SXDS) Field. We obtain a photometric sample of 858 LAE candidates based on deep Subaru Suprime-Cam imaging data and a spectroscopic sample of 84 confirmed LAEs from Subaru FOCAS and VLT VIMOS spectroscopy in a survey volume of ~106 Mpc3 with a limiting Lyα luminosity of ~3 × 1042 ergs s−1. We derive the LFs of the Lyα and UV continuum (1500 A) for each redshift, taking into account the statistical error and the field-to-field variation. We find that the apparent Lyα LF shows no significant evolution between z = 3.1 and 5.7 within factors of 1.8 and 2.7 in L* and *, respectively. On the other hand, the UV LF of LAEs increases from z = 3.1 to 5.7, indicating that galaxies with Lyα emission are more common at earlier epochs. We identify six LAEs with AGN activities from our spectra combined with VLA, Spitzer, and XMM-Newton data. Among the photometrically selected LAEs at z = 3.1 and 3.7, only 1% show AGN activities, while the brightest LAEs with log L(Ly α) 43.4–43.6 ergs s−1 appear to always host AGNs. Our LAEs are bluer in UV-continuum color than dropout galaxies, suggesting lower extinction and/or younger stellar populations. Our stacking analyses provide upper limits to the radio luminosity and the fHe II/fLyα line fraction and constrain the hidden star formation (+low-luminosity AGN) and the primordial population in LAEs.

One-dimensional imidazole aggregate in aluminium porous coordination polymers with high proton conductivity.

Abstract: The development of anhydrous proton-conductive materials operating at temperatures above 80 degrees C is a challenge that needs to be met for practical applications. Herein, we propose the new idea of encapsulation of a proton-carrier molecule--imidazole in this work--in aluminium porous coordination polymers for the creation of a hybridized proton conductor under anhydrous conditions. Tuning of the host-guest interaction can generate a good proton-conducting path at temperatures above 100 degrees C. The dynamics of the adsorbed imidazole strongly affect the conductivity determined by (2)H solid-state NMR. Isotope measurements of conductivity using imidazole-d4 showed that the proton-hopping mechanism was dominant for the conducting path. This work suggests that the combination of guest molecules and a variety of microporous frameworks would afford highly mobile proton carriers in solids and gives an idea for designing a new type of proton conductor, particularly for high-temperature and anhydrous conditions.