Characterisation of TiN films prepared by electron shower,arc ion-plating and sputtering methods

It has been found that TiN films with high wear resistance and high adhesion can be prepared by electron shower deposition and arc ion plating on glass and austenitic stainless steel (SUS 316) substrates. The high wear resistance is principally explained by the grain size and surface morphology. Fine {100}-faceted crystals (10–150 nm) grew on the surface. The typical morphology of the crystals was triangular pyramidal. The crystallite size was changed by the bias voltage. Faceted crystals produced by arc ion plating were rounded and smoothed by a change in bias, but were unaltered in samples prepared by the electron shower process. The fine faceted surfaces had higher wear resistance than the granularly rounded ones. When TiO₂ was formed at the interface of the glass substrate, the adhesion was lowered. The high-adhesion film prepared by electron shower deposition contained a small amount of TiO₂ at the interface.     

Charge integrating type position-sensitive proportional chamber for time-resolved measurements using intense X-ray sources

A position-sensitive detecting system for time-resolved diffraction measurements with very intensive X-ray sources has been developed. It consists of a charge integrating type gas-filled detector, multichannel analog multiplexers, a signal processor and a memory (120 ch.×128 phases×24 bits). The detector is 120 mm long in effective length by 10 mm×10 mm in cross section with a single anode of 20 μm diameter. One of the cathode planes consists of 120 cathode strips with a pitch of 1 mm. The spatial resolution is equal to the pitch under a certain detector current limit. The gas gain is adjustable to an appropriate value according to the X-ray intensity range of interest. For experiments with 8 keV X-ray sources, maximum absorption rates of 9×10⁷ photons/s·mm with low applied voltage and minimum absorption rates of about 3 photons/s·mm with high applied voltage can be achieved. This system was applied to a time-resolved X-ray diffraction study on frog muscle using a synchrotron radiation source at the Photon Factory and we could collect diffraction patterns with a time resolution of 10 ms and only 10 stimulations.     

Recent developments of rotary forming in Japan

Rotary forming is a method of forming various axisymmetric profiles by a rotary compressive process. This process has developed into an advanced technology capable of producing an ever growing range of products due to the recent developments of rotary forming machines. The recent trends of research and development of rotary forming in Japan are described.     

The early component of the visual evoked magnetic field

Several EEG studies have reported an early component of the visual evoked potential. However, it is controversial whether this component is cortical or subcortical. Our study has aimed to clarify this problem using MEG and EEG in nine normal volunteers. A total of 4000 stimuli were presented to the monocular visual hemifield through a light-proof stimulating goggle and the visual evoked magnetic field and visual evoked potential was measured above the occipital lobe. The early component was observed in three of the nine subjects. The latency ranged from 40 to 45 ms in MEG and from 39 to 47 ms in EEG. The result of dipole localization analysis showed that its origin was cortical, and specifically, the striate cortex.     

Oxygen induced direct hydrogenation of CO on Ni(100) surface

A trace amount of oxygen in H₂ promotes a new type of direct hydrogenation reaction of adsorbed CO on Ni(100) surface. The formation of H_xCO_y was suggested by high resolution electron energy loss spectroscopy (HREELS) and thermal desorption spectroscopy (TDS). HREEL spectra showed the formation of surface hydroxyl (OH) and the C-H bonds of H_iCO_y species but no carbonyl (C=O) loss peak was detected although thermal desorption yielded large amount of CO. The H _x CO _y undergoes the decomposition at 400–450 K on the hex-OH Ni(100) surface, which yielded CO, CO₂, H₂ and H₂CO. It was confirmed that no C-H bond formation occurs on c(2 × 2)-O, p(2 × 2)-O Ni(100) and hex-OH Ni(100) as well as on clean Ni(100) surfaces. This fact indicates that the gas phase oxygen may induce the direct hydrogenation of CO to form H _x CO _y , which is analogous to the hydrogenation of O to form hex-OH onNi(100).     

(4<Emphasis Type="Italic">Z</Emphasis>,15<Emphasis Type="Italic">Z</Emphasis>)-Octadecadienoic Acid Inhibits Glycogen Synthase Kinase-3β and Glucose Production in H4IIE Cells

Many uncommon non-methylene-interrupted fatty acids (NMI FA) are present in limpet gonads, but their biological properties remain unknown. To investigate new biological effects of naturally occurring NMI FA in eukaryotic cells, the biological activities of structurally analogous (4Z,15Z)-octadecadienoic acid (1), (9Z,20Z)-tricosadienoic acid (2), and (12Z,23Z)-hexacosadienoic acid (3) were examined by using a yeast-based drug-screening system using the Ca²⁺-sensitive mutant strain, Saccharomyces cerevisiae (zds1Δ erg3Δ pdr1Δ pdr3Δ). Among 1–3, 1 showed restored growth activity at a dose of 80 µg/disc in the mutant yeast strain. This phenotype suggests that 1 suppresses Ca²⁺-signaling of the mutant yeast through inhibition of glycogen synthase kinase-3β (GSK-3β) or calcineurin pathways or both. From this result, the inhibitory activity of 1–3 against GSK-3β was further determined. 1–3 showed potent inhibitory activity against GSK-3β with IC₅₀ values ranging from 8.7 to 21.9 µM. Inhibition of GSK-3β reduces gene expression of the gluconeogenic key enzymes in liver, so we analyzed glucose production in rat hepatoma H4IIE cells to assess GSK-3β inhibitory activity of 1–3. Acid 1 inhibited glucose production at 25 µM in H4IIE cells. Our results would open up new possibilities for an anti-diabetic effect of 1 and might provide important insights into understanding the biological properties of naturally occurring NMI FA.     

Identification of <Emphasis Type="Italic">Cellulosimicrobium</Emphasis> sp., a poly(3-hydroxybutyrate)-degrading bacterium isolated from washed rind cheese,Pont-l’évêque lait cru

Environmental pollution caused by commodity plastics has become a global issue. As a result, biodegradable plastics have found multiple applications in recent years, particularly in the manufacture of food packaging containers. However, microbes present in fermented foods have been found to degrade biodegradable plastics. In this study, we report, for the first time, a poly(3-hydroxybutyrate) (P(3HB))-degrading bacterium isolated from a type of washed rind cheese, Pont-l'évêque lait cru. The P(3HB)-degrading isolate, designated as PONα, was characterized in detail. The strain was found to be gram-positive and filamentous-shaped; the DNA G+C content was 71.6 mol%, and anteiso-C15:0 was found to be the major fatty acid. The strain grew well in the range of 37–40 °C and formed a large clear zone on P(3HB) medium at 37 °C. The phenotypic properties and phylogenetic inference indicated that strain PONα is closely related to Cellulosimicrobium cellulans. Strain PONα formed a clear zone on P(3HB), LB with P(3HB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and chitin media plates, whereas no clear zone was found on poly(ethylene succinate) (PESu), poly(butylene succinate) (PBSu), poly(ε-caprolactone) (PCL), poly(lactic acid) (PLA), poly(butylene adipate-co-butylene terephthalate) (PBAT), poly(butylene succinate-co-butylene adipate) (PBSA), and olive oil media plates. Relatively higher P(3HB) hydrolytic activity was observed in the culture supernatant under the co-existence of P(3HB) and the cheese, suggesting that a component of the cheese plays an important role in the hydrolytic activity. These results indicate that microbiota in fermented foods such as cheese can degrade biodegradable plastics, thereby reducing their quality. Therefore, because P(3HB) may be degraded by the microbiota present in cheese, these findings may affect the application of P(3HB) in cheese packaging.     

Static and dynamic deformation mechanisms of a high-density polyethylene having rownucleated crystalline texture of a-axis orientation as observed by orientation distribution function of crystallites

The rheo-optical properties of a high-density polyethylene having a row-nucleated crystalline texture of a-axis orientation were investigated in the machine direction (MD) and transverse direction (TD) of fabricating the specimen. The tensile complex dynamic compliance function $\text{J1}$ displays two dispersions designated as the α₂ and α₂ mechanical retardation processes with activation energies of about 21 and 35 kcal mol^?1, respectively, for both MD and TD specimens, and the complex dynamic stress-optical coefficient function $\text{M1}$ exhibits a single discrete dispersion designated as the α optical retardation process with an activation energy of about 24 kcal mol^?1 for both specimens over the same frequency and temperature ranges as those covered for the dynamic mechanical measurements. The real and imaginary components of $\text{M1}$ converge from positive values to almost zero at the highest frequencies and lowest temperatures covered for both specimens, with the exception of the real component of the MD specimen which converges to a small but definitely negative value. The analysis of this anomalous behaviour of the MD specimen in terms of the optical retardation time spectrum has ascribed the negative convergence to a negative form birefringence that arises from a dynamic lamellar splaying or bending process responding in phase with the dynamic bulk stress. The dynamic X-ray diffraction studies have revealed the α optical dispersion and possibly the α mechanical dispersion to be mostly attributed to the crystal orientation dispersions involving intralamellar shearing processes, i.e. detwisting and tilting processes of the lamellar segments for the MD and TD specimens, respectively. The optical dispersion, if any, associated with the lamellar splaying or bending process may be expected at higher frequencies or lower temperatures than those covered here to assign the β mechanical dispersion to the interlamellar shearing process.     

Synthesis of active sites for alkene metathesis reaction on molybdenum oxide films by the reaction with alkylidene radicals

A super active catalyst (T.F. = 0.2 0.3) for alkene metathesis reaction was prepared by coordinating CH₂ radicals onto sublimed molybdenum oxide films, where the radicals were prepared by the reaction of CH₂I₂ with Al or Mg metals deposited near the oxide film.The authors are indebted to the Iwatani Naoji Foundation and the Murata Science Foundation for the support of this work.     

Activation mechanism of methane-derived coke (CHx) by CO2 during dry reforming of methane – comparison for Pt/Al2O3 and Pt/ZrO2

The reaction of methane-derived coke (CH_x: intermediate of the reforming reaction and also a source of coke deposition) with CO₂ was studied on supported Pt catalysts in relation with CO₂ reforming of methane. Temperature-programmed hydrogenation (TPH) was performed to investigate the reactivity of coke deposition after the catalyst was exposed to CH₄/He at 1070 K. Coke on Pt/Al₂O₃ could be hydrogenated around 873 K, while for Pt/ZrO₂ this was above 1073 K. The results indicate that the reactivity of coke with hydrogen was higher on Pt/Al₂O₃ than on Pt/ZrO₂, which was different from the reactivity of coke towards CO₂. Thus, the reactivity of CO₂ was studied and compared on these catalysts by several technics. The amount of CO evolution was measured during CO₂ flow at 1070 and 875 K. Rate and amount of converted CO₂ were higher on Pt/ZrO₂ than on Pt/Al₂O₃. Pt/ZrO₂ was proven to react with CO₂ to produce CO and active oxygen (CO₂CO+O) (probably on its oxygen defect site) more easily than Pt/Al₂O₃.