High performance liquid chromatographic separation of diacylglycerol acetates to quantitate disaturated species of lung phosphatidylcholine

A high-performance liquid chromatographic (HPLC) separation of diacylglycerol acetates to quantitatite disaturated species of lung phosphatidylcholine (PC) was studied. The diacylglycerol acetates were applied on a reversed phase column, eluted by an isocratic solvent, acetonitrile/isopropanol/water (35:15:1, v/v/v) at a flow rate of 1 ml/min, and detected by differential refractometry (RI). This isocratic HPLC method was useful to separate disaturated species from the others of lung PC. The quantitative analysis of the molecular species separated by HPLC was studied by RI detection. Chroamtograms obtained by RI detection and radioactivity determination of diacylglycerol [³H]acetates prepared by [³H]acetic anhydride were almost identical. The RI detector responsed in the same degree for different, authentic standards of diacylglycerol acetates. The detection limit with RI detection was about 30 nmoles. Molecular species of PCs from human lung and carcinoma tissues were analyzed by this HPLC method. The contents of disaturated species were very similar to those reported previously. These results indicate that RI detection is very useful in the nmole range for the quantitative analysis among the molecular species containing disaturated species.     

Multiple quasi-phase-matched device using continuous phase modulation of /spl chi//sup (2)/ grating and its application to variable wavelength conversion

We propose a new multiple quasi-phase-matched wavelength converter based on the continuous phase modulation of a /spl chi//sup (2)/ grating for use in variable wavelength conversion. A numerical study shows that the proposed device exhibits a high conversion efficiency, flexible design, and robust fabrication tolerance. A waveguide device fabricated by annealed proton exchange agrees well with the numerical design. Fine-tuning the device enabled us to demonstrate variable wavelength conversion between signals on the standard optical frequency grid. Using the device, we also demonstrated fast (<100 ps) wavelength switching of 4-channel 40-Gb/s signals. The obtained results clearly show that the proposed multiple quasi-phase-matched devices will be useful when constructing future flexible photonic networks.     

Hot-water treatment of sol–gel derived SiO2–TiO2 microparticles and application to electrophoretic deposition for thick films

SiO₂–TiO₂ spherical microparticles of about 0.7 μm in diameter were prepared by the sol–gel method. Anatase nanocrystals were formed in the microparticles and their specific surface area was increased after a hot-water treatment at 90 °C. From the changes in the concentration of I₂ photocatalytically generated from KI aqueous solution, the activity of the SiO₂–TiO₂ microparticles was found to increase with increasing the hot-water treatment time. Particulate, thick films were electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates using the anatase nanocrystal-precipitated SiO₂–TiO₂ microparticles. The thickness of the electrophoretically deposited particulate film increased to be approximately 10 μm with an increase in applied voltage. The resultant thick film showed a high photocatalytic activity.     

Determination of emotional content of video clips by low-level audiovisual features

Affective analysis of video content has greatly increased the possibilities of the way we perceive and deal with media. Different kinds of strategies have been tried, but results are still opened to improvements. Most of the problems come from the lack of standardized test set and real affective models. In order to cope with these issues, in this paper we describe the results of our work on the determination of affective models for evaluation of video clips using audiovisual low-level features. The affective models were developed following two classes of psychological theories of affect: categorial and dimensional. The affective models were created from real data, acquired through a series of user experiments. They reflect the affective state of a viewer after watching a certain scene from a movie. We evaluate the detection of Pleasure, Arousal and Dominance coefficients as well as the detection rate of six affective categories. For this end, two Bayesian network topologies are used, a Hidden Markov Model and an Autoregressive Hidden Markov Model. The measurements were done using audio-only models, video-only models and fused models. Fusion is done using two different methods, a Decision Level Fusion and Feature Level Fusion. All tests were conducted using localized affective models, both categorial and dimensional. Results are presented in terms of detection rate and accuracy for affective families, affective dimensions and probabilistic networks. Arousal was the best detected dimension, followed by dominance and pleasure.     

Partial Oxidation of Methane to Synthesis Gas Over Ru-Loaded Y2O3 Catalyst

Ru-loaded Y₂O₃ catalyst was investigated for the partial oxidation of methane to synthesis gas. Ru(0.5 wt%)/Y₂O₃ catalyst afforded a high CH₄ conversion of 27% at a CH₄:O₂ ratio of 5 to give nearly a 1:2 ratio of CO and H₂ with a selectivity of 75% at 873 K. Ru(0.5 wt%)/Y₂O₃ catalyst maintained high catalytic activity over 10 h in the partial oxidation of methane. Carbon deposition of the catalyst surface in the reaction of CH₄ was examined by thermogravimetric analyses, and it was found that no carbon deposition occurred on the Ru(0.5 wt%)/Y₂O₃ catalyst. The synthesis-gas production proceeded basically via a two-step reaction consisting of methane combustion to give H₂O and CO₂, followed by the reforming of methane from CO₂ and steam.     

A novel spherical carbon

We developed a novel spherical carbon material. The spherical carbon is composed of a high density of carbon nanotubes or nanofilaments, and includes an oxidized diamond particle as a core. Syntheses of this carbon in high volume with high selectivity may be possible. It is expected that this carbon will be useful as a catalyst material for fuel cells, electric double-layer capacitors, etc.     

Acrolein formation in the oxidation of ethane over silica catalysts supporting iron and cesium

A significant yield of aldehydes was obtained by the partial oxidation of ethane over alkali‐modified Fe/SiO₂ catalysts at 475°C (<2% in the case of Cs–Fe/SiO₂). Not only acetaldehyde and formaldehyde but also acrolein were produced in the present system. There are no reports regarding the catalysts for the direct acrolein formation from partial oxidation of ethane. Such significant promoting effect of alkali‐modified Fe/SiO₂ catalysts in the partial oxidation of hydrocarbons has never been observed. Aldol‐type condensation for formation of acrolein could occur in the partial oxidation of ethane over alkali‐modified Fe/SiO₂ catalysts. This revised version was published online in July 2006 with corrections to the Cover Date.     

Template-assisted synthesis of PbTiO3 nanotubes

Nanotubes of ferroelectric lead titanate (PbTiO₃) have been made by a template-assisted method. An equimolar Pb–Ti sol was dropped onto porous alumina membranes and penetrated into the channels of the template. Single-phase PbTiO₃ perovskite nanotubes were obtained by annealing at 700 °C for 6 h. The nanotubes had diameters of 200–400 nm with a wall thickness of approximately 20 nm. Excess PbO or annealing in a Pb-containing atmosphere was not necessary in order to achieve single-phase PbTiO₃ nanotubes. The influence of the heating procedure and the sol concentration is discussed.     

Formation Process of Super-Water-Repellent Al2O3 Coating Films with High Transparency by the Sol–Gel Method

Alumina thin films with a roughness of 20 to 50 nm were formed by immersing porous alumina gel films prepared by the sol-gel method in boiling water. When hydrolyzed fluoroalkyltrimethoxysilane was coated on the alumina films, the contact angle for water was increased with an increase of immersion time, and immersion for 30 s was long enough to give super-water-repellency and high transparency; the contact angle for water of the film was 165° and the transmittance for the visible light was higher than 92%. It was found that the surface of the alumina gel films immersed in boiling water consisted of boehmite crystals. It was shown that the existence of air in the hydrophobic pores on the surface caused the super-water-repellency.     

Preparation of CdS-doped Glasses from Gels Containing Diethyldithiocarbamatocadmium

CdS-doped SiO₂ glasses were prepared via silica gels containing diethyldithiocarbamatocadmium Cd(S₂CN(C₂H₅)₂)₂. Heat treatment of the gels gave transparent yellow SiO₂glasses doped with hexagonal CdS crystals. In optical absorption and fluorescence spectra, the optical absorption edge and the emission peak clearly exhibited a blue shift, which was attributed to the quantum size effect of the carrier confinement, as the CdS content was decreased. In the fluorescence spectra of the CdS-doped silica glasses, the emission peak was observed only near 500 nm and not observed at longer wavelengths which were known to be present if there were sulfur vacancies.