Antifungal Abietane-Type Diterpenes from the Cones of <Emphasis Type="Italic">Taxodium distichum</Emphasis> Rich

The chemical composition of Taxodium distichum cones and the antifungal activities of twelve diterpenoids against two wood decay fungi, Trametes versicolor (white-rot) and Fomitopsis palustris (brown-rot) were examined. The chemical composition of the major extractive fraction, the n-C₆H₁₄ extract, was evaluated and its antifungal properties were identified. Twelve diterpenoids including ten abietane-type components were isolated from the n-C₆H₁₄ extract: 6,7-dehydroferruginol (1), ferruginol (2), 6,7-dehydroroyleanone (3), sandaracopimaric acid (4), taxodione (5), taxodal (6), taxodone (7), sugiol (8), xanthoperol (9), salvinolone (10), 5,6-dehydrosugiol (11), and 14-deoxycoleon U (12). Compounds 5 and 12 were highly active against both wood-decay fungi. In particular, the activities of these compounds against F. palustris were potent. The results suggest that the position and the number of hydroxyl groups on abietane-type structures may be related to antifungal activities against T. versicolor and F. palustris.     

The effect of La oxide additive on the solubility of NiO in molten carbonates

A comprehensive analysis on a novel energy recovery system for reformate-based proton exchange membrane (PEM) fuel cell systems is presented. The energy recovery system includes a throttling valve, a heat exchanger, a compressor, and is coupled with a coolant loop for the fuel cell stack. The feed stock of the fuel reformer, which is primarily a mixture of water and fuel, is vaporized in the heat exchanger and is then compressed to a sufficiently high pressure before it is ducted into the fuel reformer. The analysis includes the throttling of two-phase fuel/water mixture and vaporization in the heat exchanger to obtain the temperature and pressure of the mixture at the inlet of the compressor. The results indicate that the power plant efficiency with the energy recovery system can be increased by more than 20% compared to that of a fuel cell power plant without the energy recovery system. Additionally, more than 25% of the waste heat generated by the fuel cell stack can be removed due to the energy recovery system, and the fuel burned for the fuel reforming purpose is reduced by more than 70%.     

Identification of the main constituents in sandarac resin, a natural gum base

Sandarac resin, a natural gum base, is described as "a substance composed mainly of sandaracopimaric acid obtained from the secretion of sandarac trees" in the List of Existing Food Additives in Japan. To evaluate its quality as a food additive, the main constituents in a sandarac resin product were investigated. Three constituents were isolated and identified as sandaracopimaric acid, sandaracopimarinol and 4-epidehydroabietic acid by MS and 2D-NMR. Quantification of the main constituent, sandaracopimaric acid, was performed by HPLC and its content in the product was determined to be 11.6%.     

Rapid Quantitative Profiling of N-Glycan by the Glycan-Labeling Method Using 3-Aminoquinoline/α-Cyano-4-hydroxycinnamic Acid

Protein glycosylation is a crucial phenomenon for understanding protein functions, since its patterns and degree are associated with many biological processes, such as intercellular signaling and immune response. We previously reported a novel glycan-labeling method using a 3-ainoquinoline/α-cyano-4-hydroxycinnamic acid (3-AQ/CHCA) liquid matrix for highly sensitive detection by matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry (MS). In the present study, we examined the practicality of this method for qualitative and quantitative glycan profile analysis. We first investigated the reproducibility of the data for 16 N-glycans prepared from human epidermal growth factor receptor type 2 (HER2). All of the data obtained in intra-assays and interassays were highly correlated with statistical significance (R(2) > 0.9, p < 0.05). In addition, the HER2 glycosylation pattern differed significantly between different breast cancer cell lines SK-BR-3 and BT474 in a comparative analysis of profile data. Finally, the quantitative capability of this method was examined by using PA-labeled monosialylated N-glycan as an internal standard (IS). Using IS for AQ-labeled neutral and sialylated standard glycans, the ion peak intensity was highly linear (R(2) > 0.9) from 0.5 to 5000 fmol. Furthermore, using IS for HER2 N-glycans, all of the N-glycans were highly linear with their dilution factors (R(2) > 0.9). These results suggest that our developed AQ labeling method enabled rapid qualitative and quantitative analyses of glycans. This glycan analysis method should contribute to the field of biomarker discovery and biomedicine in applications such as quality control of biotechnology-based drugs.     

Nonmechanical axial scanning laser Doppler velocimeter with directional discrimination

An axial scanning laser Doppler velocimeter (LDV) with directional discrimination not requiring any moving mechanism in its probe is proposed. The proposed LDV utilizes frequency shift induced by acousto-optic modulators (AOMs) for discriminating the direction of velocity. The measurement position is axially scanned by changing the wavelength of the light input to the probe. The experimental result reveals that both the axial scan and the directional discrimination can be realized by using the proposed method without any moving element in the probe.     

Electron trapping at the lattice Ti atoms adjacent to the Nb dopant in Nb-doped rutile TiO2

The Nb-doped anatase TiO₂ is considered one of the most promising alternative transparent conducting oxides to substitute for indium tin oxide. However, studies have found that the conductivity emerges only in the anatase form, not in the rutile form. We applied the first-principle band structure method for the Nb-doped TiO₂ in both polymorphs. The calculation was carried out using the spin-restricted and spin-polarized GGA+U level of the theory. Special care was taken in the calibration of +U parameters to satisfy the generalized Koopman’s theorem. A significant difference was found between the spin-polarized and spin-restricted calculations. We noticed that spin polarization was necessary to reproduce the electron trapping in rutile. In addition, electrons are trapped at two lattice Ti atoms adjacent to the Nb_Ti dopant along the [001] direction, as described with the formal charge state of Ti^3.5+–Nb⁵⁺–Ti^3.5+. A careful convergence of the electron trapping character was conducted against the unit cell size based on the Bader population analysis.     

Eye-opening improved electroabsorption modulator/DFB laser diodewith optimized thickness of the separate-confinement heterostructurelayers

The separate-confinement heterostructure (SCH) of an electroabsorption modulator integrated with a distributed feedback laser diode (EAM-LD) was optimized to obtain a clear optical waveform (eye opening) without penalty of chirp characteristics. The electric field applied to the multiple-quantum-well (MQW) structure was controlled by employing the proper thickness of undoped SCH layers to attain gentle absorption characteristics of the EAM at the optical mark level. As a result, the eye opening of the modulated emission at 10 Gb/s was improved and the intersymbol interference was reduced. No severe drawback on chirp characteristics was found in an α-parameter measurement. EAM-LD's with the optimized SCH structure exhibited good transmission characteristics of power penalties under 1.5 dB at 10 Gb/s, and the reliability of 10 Gb/s transmission characteristics was also confirmed. We have also investigated how the optical waveform after transmission was affected by the dependence of the α-parameter on bias voltage. Measurement and numerical calculation of the optical waveform after transmission showed that the optical waveform was severely affected by the α-parameters at deep reverse voltages     

Structure and dynamics of polyrotaxane and slide-ring materials

Polyrotaxane (PR), in which cyclic molecules are threaded into a linear polymer chain, has generated great interest because the sliding and rotation of the cyclic molecules on the axial polymer chain lead to unique functional nanomaterials with novel dynamical properties. A typical example of the functional materials is a polyrotaxane network, called slide-ring (SR) material, prepared by cross-linking the cyclic molecules on different PRs. The cross-links composed of two cyclic molecules in a shape of figure-of-eight slide along the polymer chains and the sliding motion gives rise to remarkable physical properties of the SR materials. In order to understand the unique features of the functional materials including SR materials and develop novel applications of PR, it is necessary to reveal the physical properties of PR, especially the sliding motion of the cyclic molecules in PR. In this article, we review the static structure and molecular dynamics of PR based primarily on our recent studies. Furthermore, the difference between SR materials and usual chemical gels in deformation behavior is also described. The findings summarized in this review indicate the significance of the sliding motion of cyclic molecules characterizing PR and SR materials.     

Direct production of hydrogen peroxide from oxygen and hydrogen applying membrane-permeation mechanism

Direct synthesis of hydrogen peroxide is conducted using a palladium membrane reactor. The palladium membrane is prepared on the external surface of the porous α-alumina tubing, by electroless plating (ELP) or chemical vapor deposition (CVD). Thus prepared membrane is immersed into aqueous reaction solution. Hydrogen is supplied from inside of the palladium membrane, while oxygen was bubbled in the reaction solution. Both reacted at the surface of the membrane to produce hydrogen peroxide. Hydrogen peroxide is produced steadily for more than 80 h and the selectivity based on the amount of reacted hydrogen was estimated to be ca. 50%. The reactor performance is investigated in correlation with membrane properties and the hydrogen/oxygen supply pressures.     

NiZnCo ferrite films by spin spray technique: morphology and magnetic properties

In the present study, highly crystallized spinel NiZnCo ferrite films were prepared by spin-spray ferrite plating, employing a reaction solution (containing Fe²⁺, Ni²⁺, Zn²⁺ and Co²⁺) and an oxidizing solution (KNO₂ + CH₃COOK). The solutions were sprayed independently onto a glass substrate maintained at 90 °C. Series of films with various Zn and Co compositions were prepared and their structural and magnetic properties were studied. The films had a columnar structure perpendicular to the substrate surface as confirmed by scanning electron microscopy (SEM) studies and showed no preferential orientation confirmed by X-ray diffraction (XRD). The films had a saturization magnetization M _s of 325–520 emu/cc and H _c of 5–12 Oe. At the optimized compositions, we obtained an initial permeability of around 190 (Ni_0.18Zn_0.6Co_0.02Fe_2.2O_4−δ ) and resonance frequency f _r of 300 MHz (Ni_0.16Zn_0.2Co_0.02Fe_2.62O_4−δ ). Such films with high permeability can be employed as trimming layers of inductors to increase the inductance and films with high resonance frequency can be used as electromagnetic noise suppressors at high frequency.