Design and development of second-generation titanium oxide photocatalyst materials operating under visible light irradiation by applying advanced ion-engineering techniques

Advanced ion-beam techniques such as metal ion-implantation, ionized cluster beam (ICB) deposition and RF-magnetron sputtering (RF-MS) deposition were found to enable the development of unique titanium oxide photocatalyst materials which are able to absorb and work not only under UV but also visible or solar light irradiation. Thus prepared visible light-responsive TiO₂ act as efficient photocatalysts for the NO decomposition reaction into N₂ and O₂ as well as the H₂ and O₂ evolution reaction from water.     

A rapid and sensitive analysis of diphenylarsinic acid in water by gas chromatography/mass spectrometry.

A rapid and sensitive analytical method using pentafluorothiophenol (PFTP) derivatization was applied to detect diphenylarsinic acid (DPAA) in water. In this study, the optimum derivatization conditions, such as acid concentration, reaction time and reaction temperature, were investigated to develop a suitable procedure for DPAA determination. After extracting the derivatives into benzene, the determination was carried out by gas chromatography/mass spectrometry (GC/MS) with selected ion monitoring (SIM). The detection limit of the method was 9.4 microg/l, and the overall recoveries obtained from real environmental samples were 88.9 - 104.7% and coefficient variations were 5.1 - 13.9%.     

Micrometer-sized graphitic balls produced together with single-wall carbon nanohorns

We present in this report a new type of particles with micrometer-order sizes, which we called giant graphitic balls (GG balls). The GG balls are produced by CO2 laser ablation of graphite together with single-wall carbon nanohorns. They have graphitic structures whose layers tend to align parallel with the GG-ball surfaces, resulting in polygonal-like arrangements. Comparing the GG-ball structure with that of the previously reported polygonal graphite-particles, the growth mechanism of the GG ball is discussed briefly.     

Penems. I. Novel synthesis of antibacterial penem compounds utilizing 1,3-dithiolane derivatives

A novel penem synthesis utilizing 1,3-dithiolane or 1,3-dithiane derivatives allowed us to synthesize a number of new antibacterial penem compounds.     

Evolved Colloidosomes Undergoing Cell‐like Autonomous Shape Oscillations with Buckling

In living systems, there are many autonomous and oscillatory phenomena to sustain life, such as heart contractions and breathing. At the microscopic level, oscillatory shape deformations of cells are often observed in dynamic behaviors during cell migration and morphogenesis. In many cases, oscillatory behaviors of cells are not simplistic but complex with diverse deformations. So far, we have succeeded in developing self‐oscillating polymers and gels, but complex oscillatory behaviors mimicking those of living cells have yet to be reproduced. Herein, we report a cell‐like hollow sphere composed of self‐oscillating microgels, that is, a colloidosome, that exhibits drastic shape oscillation in addition to swelling/deswelling oscillations driven by an oscillatory reaction. The resulting oscillatory profile waveform becomes markedly more complex than a conventional one. Especially for larger colloidosomes, multiple buckling and moving buckling points are observed to be analogous to cells.     

Analysis of water molecules around GTP in Hras-GTP complex and GDP in Hras-GDP complex by molecular dynamics simulations

We investigate the structures of the Hras-GTP and the Hras-GDP complexes in water solvents in order to understand the mechanism of GTP hydrolysis in the Hras-GTP complex. We performed MD simulations of these complexes in order to study the positions and the orientations of water molecules around the guanosine nucleotides. Using trajectories we calculated the angular distribution of water molecules around the most distant phosphorus from guanosine in our previous work. It was shown that water molecules are distributed evenly in GTP, although unevenly in GDP. This suggests that the trigger of GTP hydrolysis is possibly the attack of water molecule to γ?phosphate from the appropriate direction. In this paper, in order to investigate the role of water molecules in GTP hydrolysis in detail, we calculate the orientation of water molecules. The distribution of the orientation is different between GTP and GDP. In order to investigate the cause of this difference, we examine the hydrogen bonds between water molecules and oxygen atom of the most distant phosphate from guanosine. We find that these hydrogen bonds are formed. We also find that the oxygen atom of hydrogen bond is determined by the position of the water molecule of hydrogen bond.