Reaction of α,β‐unsaturated ketones with cerium(IV) salts in alcohol

Reaction of α,β‐unsaturated ketones with cerium(IV) salts or lanthanide triflates in alcohols gave good yields of the corresponding β‐alkoxy compounds. In the case of 2‐cyclopentenone and 2‐cyclohexenone, the 1,1,3‐trialkoxy acetal derivatives were obtained preferentially accompanied by β‐alkoxyketone, except 2‐cycloheptenone. However, in the reaction of 2‐cycloheptenone with alcohol using cerium(IV) sulfate (CS)‐molecular sieve, 1,1,3‐trialkoxy derivatives were obtained. Also, in the cases of 1‐penten‐3‐one, 4‐hexen‐3‐one and 3‐hepten‐2‐one, 1,1,3‐trialkoxy derivatives were obtained preferentially. Copyright © 2006 John Wiley & Sons, Ltd.     

Adsorption ability comparison of plasma proteins on amorphous carbon surface

To understand why amorphous carbon (a-C:H) film shows antithrombogenicity, an adsorption ability of plasma proteins on a-C:H surface was investigated. Protein adsorption is the initial process of clot formation. The protein adsorption ability on a-C:H film surface was compared by the detection using the surface plasmon resonance (SPR) phenomenon to estimate the protein adsorption. The protein adsorption abilities of a fibrinogen (Fib) and a human γ-globulin (HGG) were estimated by the SPR method using a multilayer structure of a-C:H/Au/Cr/glass. Although the adsorption of HGG for a-C:H was saturated at 32 μM in HGG concentration, the adsorption of Fib was not saturated under the detection limit of this method. These results indicated that the adsorption ability to the a-C:H film surface of Fib was higher than HGG.     

Long-length IBAD-MgO buffer layers for high performance RE-123 coated conductors by a large ion beam source

In Fujikura, a large-scale ion-beam-assisted deposition (IBAD) system with a large ion source has been employed to fabricate biaxially textured MgO films. The large-scale IBAD system has multiple deposition lanes where substrate tapes move, and therefore we have to optimize experimental conditions at each lane. We selected an appropriate deposition area and, finally, we successfully fabricated a 1 km-length IBAD-MgO film at a production rate of 1 km/h. We also studied pulsed-laser-deposited (PLD) CeO₂ films directly on the IBAD-MgO films in spite of a large lattice mismatch between CeO₂ and MgO. From transmission electron microscope (TEM) observations at an interface between MgO and CeO₂ films, it is revealed that there is domain-matching-epitaxy relationship between MgO and CeO₂ films. We also fabricated thin (1.0 μm) and thick (3.7 μm) PLD – GdBa₂Cu₃O_7−x (GdBCO) film on the long-length CeO₂/MgO substrate (over 150 m). Critical currents (I_c) and current density (J_c) were over 300 A and 3 MA/cm² respectively for the thin GdBCO film and were about 645 A and 1.7 MA/cm² for the thick GdBCO film at 77 K in self-field.     

Polymer-mediated extraction of the fluorescent compounds derived by Hantzsch reaction with dimedone for the sensitive determination of aliphatic aldehydes in air

An extraction method based on the thermo-responsive precipitation of a water-soluble polymer, poly(N-isopropylacrylamide) [PNIPAAm], was applied to the concentration of dimedone (5,5-dimethylcycrohexane-1,3-dion) derivatives for the highly sensitive determination of aldehydes in air. Aliphatic aldehydes including formaldehyde, acetaldehyde, propanal, 1-butanal, 1-heptanal, and 1-hexanal in air were well solubilized into the aqueous solution of dimedone and ammonium acetate by mixing the solution and air sample in a polyvinyl fluoride bag. Fluorescent derivatives of aldehydes that had formed by the Hantzsch reaction with dimedone were concentrated by polymer-mediated extraction. The recoveries of the fluorescent compounds increased with increasing the carbon number of aldehyde and were more than 80% for the derivatives from aldehydes having more than three carbon atoms under the optimal conditions. Microgram per m3 (sub-ppb) levels of the aliphatic aldehydes, propanal, 1-butanal, 1-heptanal, and 1-hexanal, in ambient air were successfully determined by HPLC separation with fluorometric detection. The sampling volume and time required were only 1l and 20 s, respectively.     

Light-wave guidance through stratified photonic crystal metamaterials synthesized by superinductive layers of metallic nanostrips

The electrodynamic properties of a novel class of photonic-crystal metamaterial platform entirely synthesized by ultralow-refractive-index suspended nanostrips embedded in a dielectric matrix are described and investigated. The optical properties of the homogeneous metamaterial platform can be understood on the basis of equivalent distributed circuit extraction from an electromagnetic model that has negatively distributed superinductive properties. Low propagation loss, temperature-insensitive characteristics, and ultracompact size are the main advantages of the proposed technology, making this new type of metamaterial an excellent candidate for use in compact multilayer nanophotonic integrated systems.     

Does bulk metallic glass of elemental Zr and Ti exist?

To verify the high-pressure formation of the bulk metallic glass in elemental Zr and Ti, which Zhang and Zhao [Nature (London) 430, 332 (2004)] and Y. Wang et al. [Phys. Rev. Lett. 95, 155501 (2005)] recently reported, the high-pressure states were investigated by our newly developed in situ angle-dispersive x-ray diffraction using a two-dimensional detector and x-ray transparent anvils. Despite the disappearance of all the Bragg peaks in the one-dimensional energy-dispersive data, two-dimensional angle-dispersive data showed several intense Bragg spots even at the conditions where the amorphization was reported. This finding suggests that Zr and Ti do not transform into an amorphous state, but that their grain size becomes large, which causes the missing Bragg peaks in energy-dispersive data.     

In Vivo Photoacoustic Monitoring of Photosensitizer Distribution in Burned Skin for Antibacterial Photodynamic Therapy

For efficient antibacterial photodynamic therapy for wounds, information on the distribution of a photosensitizer in tissue is important, but conventional fluorescence measurement does not provide depth-resolved information. We previously proposed in vivo photoacoustic (PA) depth profiling of a photosensitizer, but the contrast of PA signals was not sufficiently high, mainly due to light absorption by blood in tissue. In this study, we performed dual-wavelength PA measurement; green light and red light were used to excite blood and photosensitzer, respectively, and the former signal was subtracted from the latter signal to compensate a blood-associated component. Methylene blue or porfimer sodium solution was injected into subcutaneous tissue in rats with deep dermal burn and two-dimensional PA measurement was performed. The signal subtraction diminished not only the signal originating from blood but also the signal originating from the stratum corneum and acoustic reflection noise, creating a high-contrast PA image. The distribution of PA signals was confirmed to coincide well with the distribution of photosensitizer-originating fluorescence measured for tissue biopsied after the PA measurement, demonstrating the validity of this method for in vivo photosensitizer dosimetry. On the basis of this method, temporal behaviors of two photosensitizers were compared.     

Elucidation of codoping effects on the solubility enhancement of Er3+ in SiO2 glass: striking difference between Al and P codoping

The codoping effect mechanism of Al and P on the solubility enhancement of Er(3+) ion in SiO(2) glass was clarified by electron spin-echo envelope modulation spectroscopy. It turned out that doped P ions preferentially coordinate to the Er(3+) ion to form a "solvation shell structure", and the environment is similar to that in phosphate glass, while doped Al ions do not form such a selective solvation structure, taking octahedral coordination. This striking difference indicates that the primary roles of the P-doping and the Al-doping are attributed to "enthalpy of mixing" and to "entropy of mixing", respectively.     

Effect of water extracts of aloe and some herbs in decreasing blood ethanol concentration in rats. II

Oral administration of ethanol to rats at a dose of 3 g/kg decreased alcohol dehydrogenase (ADH) activity and metabolism of lactate to pyruvate in the liver. The effects of water extracts of Aloe and some other herbs on blood ethanol concentration and on ADH activity in liver cytosol were examined. The water extracts of these herbs caused a faster elimination of ethanol from blood of normal rats when administered orally 30 min before oral administration of ethanol. The rapid elimination of ethanol seems to be due to a protection of ADH activity and the supply of nicotinamide dinucleotide, both of which are reduced by high ethanol concentration. The effects of ethanol in decreasing the enzyme activities relating to its own metabolism occur when high concentrations of ethanol pass through the liver, and thus may primarily appear during the absorption of alcohol from the gastrointestinal tract, when portal concentration of ethanol are very high.