Sophia University

About: Sophia University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Nonlinear system & Catalysis. The organization has 4986 authors who have published 7657 publications receiving 106567 citations. The organization is also known as: Jōchi Daigaku.

Crystal structure of metallo DNA duplex containing consecutive Watson-Crick-like T-Hg(II)-T base pairs.

Abstract: The metallo DNA duplex containing mercury-mediated T–T base pairs is an attractive biomacromolecular nanomaterial which can be applied to nanodevices such as ion sensors. Reported herein is the first crystal structure of a B-form DNA duplex containing two consecutive T–HgII–T base pairs. The HgII ion occupies the center between two T residues. The N3-HgII bond distance is 2.0 A. The relatively short HgII-HgII distance (3.3 A) observed in consecutive T–HgII–T base pairs suggests that the metallophilic attraction could exist between them and may stabilize the B-form double helix. To support this, the DNA duplex is largely distorted and adopts an unusual nonhelical conformation in the absence of HgII. The structure of the metallo DNA duplex itself and the HgII-induced structural switching from the nonhelical form to the B-form provide the basis for structure-based design of metal-conjugated nucleic acid nanomaterials.

Tyrosine phosphorylation in plant bending.

Abstract: Puckering in a ticklish plant is controlled by dephosphorylation of its actin The phosphorylation of the amino acid tyrosine in animal proteins acts as an on–off switch in numerous pathways that regulate growth, differentiation and oncogenesis1,2 In the unicellular slime mould Dictyostelium , tyrosine-phosphorylation of actin controls cell-shape changes and spore activity3,4, but the significance of protein-tyrosine phosphorylation in plants is unknown5 Here we show that actin in the contact-sensitive plant Mimosa pudica L is heavily tyrosine-phosphorylated and that changes in the extent of phosphorylation correlate with the degree of bending of the plant's petioles We propose that tyrosine-phosphorylation of actin controls movements in plants

Flood inundation assessment for the Hanoi Central Area, Vietnam under historical and extreme rainfall conditions

Abstract: Flash floods have long been common in Asian cities, with recent increases in urbanization and extreme rainfall driving increasingly severe and frequent events. Floods in urban areas cause significant damage to infrastructure, communities and the environment. Numerical modelling of flood inundation offers detailed information necessary for managing flood risk in such contexts. This study presents a calibrated flood inundation model using referenced photos, an assessment of the influence of four extreme rainfall events on water depth and inundation area in the Hanoi central area. Four types of historical and extreme rainfall were input into the inundation model. The modeled results for a 2008 flood event with 9 referenced stations resulted in an R2 of 0.6 compared to observations. The water depth at the different locations was simulated under the four extreme rainfall types. The flood inundation under the Probable Maximum Precipitation presents the highest risk in terms of water depth and inundation area. These results provide insights into managing flood risk, designing flood prevention measures, and appropriately locating pump stations.

MgSiN2 Addition as a Means of Increasing the Thermal Conductivity of β‐Silicon Nitride

Abstract: Si3N4 powders with the concurrent addition of Yb2O3 and MgSiN2 were sintered at 1900°C for 2–48 h under 0.9 MPa nitrogen pressure. Microstructure, lattice oxygen content, and thermal conductivity of the sintered specimens were evaluated and compared with Si3N4, Yb2O3, and MgO addition. MgSiN2 addition was effective for improving the thermal conductivity of Si3N4 ceramics, and a material with high thermal conductivity over 140 W·(m·K)−1 could be obtained. For both specimens, lattice oxygen content was decreased with sintering time. However, the thermal conductivity of the MgSiN2-doped specimen was slightly higher than the MgO-doped specimen with the same oxygen content.