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.

Identification of Tim4 as a phosphatidylserine receptor.

Abstract: During programmed cell death in multicellular organisms, a large number of cells are engulfed by macrophages, thus avoiding the release of noxious materials from the dying cells. These 'apoptotic' cells expose phosphatidylserine (PS) on their surface as an 'eat-me' signal. Miyanishi et al. show that the receptors Tim4 and Tim1 are implicated in phagocyte recognition of PS, while Park et al. show that the BAI1 protein is a receptor for PS in mammalian macrophages. Apoptotic cells expose phosphatidylserine as an 'eat-me' signal for macrophages. This paper shows that the receptors Tim4 and Tim1 are implicated in phagocyte recognition of phosphatidylserine. In programmed cell death, a large number of cells undergo apoptosis, and are engulfed by macrophages to avoid the release of noxious materials from the dying cells1,2. In definitive erythropoiesis, nuclei are expelled from erythroid precursor cells and are engulfed by macrophages. Phosphatidylserine is exposed on the surface of apoptotic cells3 and on the nuclei expelled from erythroid precursor cells4; it works as an ‘eat me’ signal for phagocytes5,6. Phosphatidylserine is also expressed on the surface of exosomes involved in intercellular signalling7. Here we established a library of hamster monoclonal antibodies against mouse peritoneal macrophages, and found an antibody that strongly inhibited the phosphatidylserine-dependent engulfment of apoptotic cells. The antigen recognized by the antibody was identified by expression cloning as a type I transmembrane protein called Tim4 (T-cell immunoglobulin- and mucin-domain-containing molecule; also known as Timd4)8. Tim4 was expressed in Mac1+ cells in various mouse tissues, including spleen, lymph nodes and fetal liver. Tim4 bound apoptotic cells by recognizing phosphatidylserine via its immunoglobulin domain. The expression of Tim4 in fibroblasts enhanced their ability to engulf apoptotic cells. When the anti-Tim4 monoclonal antibody was administered into mice, the engulfment of apoptotic cells by thymic macrophages was significantly blocked, and the mice developed autoantibodies. Among the other Tim family members, Tim1, but neither Tim2 nor Tim3, specifically bound phosphatidylserine. Tim1- or Tim4-expressing Ba/F3 B cells were bound by exosomes via phosphatidylserine, and exosomes stimulated the interaction between Tim1 and Tim4. These results indicate that Tim4 and Tim1 are phosphatidylserine receptors for the engulfment of apoptotic cells, and may also be involved in intercellular signalling in which exosomes are involved.

Mechanism of electrical conductivity of transparent InGaZnO 4

Abstract: The electronic structure of ${\mathrm{InGaZnO}}_{4},$ which has a layered structure with alternating laminated layers of ${\mathrm{InO}}_{2}$ and ${\mathrm{GaZnO}}_{2},$ was calculated in order to investigate the mechanism of electrical conductivity. In the crystal structure obtained through relaxation calculations using classical two-center potentials, the Ga ion in the ${\mathrm{GaZnO}}_{2}$ layer has pentagonal coordination forming a bipyramid with five oxygen ions, while the Zn ion in the same layer has tetrahedral coordination, losing a bond with the oxygen at the top of one pyramid. The molecular orbitals of model clusters for the relaxed structure, which were calculated by the discrete variational $X\ensuremath{\alpha}$ method using a model cluster, show strong two-dimensional structures. The electronic states at the edge of the conduction band are the result of overlapping between In $5s$ orbitals, and delocalize in the ${\mathrm{InO}}_{2}$ layer. The energy in the Ga $4s$ and Zn $4s$ states in the ${\mathrm{GaZnO}}_{2}$ layer was too large to be doped with electrons. The In $5s$ states are considered to be conduction paths for carrier electrons. A very high conductivity can be expected in the case where dopant ions are introduced into the ${\mathrm{GaZnO}}_{2}$ layers.

Salient Object Detection: A Discriminative Regional Feature Integration Approach

Abstract: Salient object detection has been attracting a lot of interest, and recently various heuristic computational models have been designed. In this paper, we regard saliency map computation as a regression problem. Our method, which is based on multi-level image segmentation, uses the supervised learning approach to map the regional feature vector to a saliency score, and finally fuses the saliency scores across multiple levels, yielding the saliency map. The contributions lie in two-fold. One is that we show our approach, which integrates the regional contrast, regional property and regional background ness descriptors together to form the master saliency map, is able to produce superior saliency maps to existing algorithms most of which combine saliency maps heuristically computed from different types of features. The other is that we introduce a new regional feature vector, background ness, to characterize the background, which can be regarded as a counterpart of the objectness descriptor [2]. The performance evaluation on several popular benchmark data sets validates that our approach outperforms existing state-of-the-arts.

Primary structure and expression from complementary DNA of skeletal muscle ryanodine receptor.

Abstract: The sequence of 5,037 amino acids composing the ryanodine receptor from rabbit skeletal muscle sarcoplasmic reticulum has been deduced by cloning and sequencing the complementary DNA The predicted structure suggests that the calcium release channel activity resides in the C-terminal region of the receptor molecule, whereas the remaining portion constitutes the 'foot' structure spanning the junctional gap between the sarcoplasmic reticulum and the transverse tubule

Funktionale poröse Koordinationspolymere

Abstract: Die Chemie der Koordinationspolymere hat sich in den vergangenen Jahren rasant entwickelt. Strukturen aus einer Vielzahl molekularer Bausteine mit unterschiedlichen Wechselwirkungen sind mittlerweile zuganglich. Die nachste Stufe ist die chemische und physikalische Funktionalisierung dieser Architekturen durch Einstellung ihrer Porositaten. Dieser Aufsatz konzentriert sich auf drei Aspekte von Koordinationspolymeren: 1) Anwendung von Kristall-Engineering zum Aufbau poroser Geruste aus Konnektoren und Linkern (“Nanospace-Engineering”), 2) Charakterisierung und Katalogisierung poros-struktureller Funktionalitat fur Anwendungen in Speicherungs-, Austausch-, Trennprozessen etc. und 3) poros-strukturelle Funktionalitat auf der Basis dynamischer Kristallumwandlungen durch Gastmolekule oder physikalische Reize. Ziel ist es, den aktuellen Stand der Forschung zur Chemie und Physik von und in den Mikroporen poroser Koordinationspolymere vorzustellen.