Identification of Al(III) species in a solution containing equimolar concentrations of Al(III) and citric acid using varying-temperature 27Al NMR spectrometry.

27Al NMR spectra of an equimolar (10 mM) Al(III)-citrate system were obtained at different temperatures. The linewidths of the signals decreased in the spectra recorded at elevated temperatures, which enabled us to unequivocally identify the resonance lines. From the spectrum recorded at 65 approximately C, a mononuclear Al(III)-citrate complex was identified at a solution pH of 3.0 in addition to trinuclear Al(III)-citrate complex, which dominated at pH 4.0.     

Photo-Absorption and photochemical decomposition of copper and alkaline-earth ß-diketonates as source gases of high-Tc superconducting films

For low-temperature deposition of oxide films relating to Bi-Sr-Ca-Cu-O superconductors, photo-absorption and -decomposition properties were examined with respect to copper and alkaline-earth ß-diketonates. It was confirmed that all ß-diketonates examined were promising as source materials for photochemical vapour deposition (photo-CVD) using a low-pressure mercury lamp, in view of their large light absorption coefficients at wavelength 254 nm. The light irradiation was effective for the formation of highly crystalline oxide films at temperatures below 600 °C. By combining two sources, Ca₂CuO₃ and SrCuO₂ films were prepared. Photo-CVD of c-axis oriented Bi₂Sr₂CuO_x film was achieved by the irradiation of ternary sources of Bi(C₆H₅)₃ and strontium and copper ß-diketonates at 500 °C.     

HPLC determination of (+)-pseudoephedrine and (-)-ephedrine in Japanese herbal medicines containing Ephedra herb using solid-phase extraction

We developed a rapid and simple HPLC method combined with solid-phase extraction (SPE) for quantitative analysis of (+)-pseudoephedrine (PEP) and (-)-ephedrine (EP) in Japanese herbal (Kampo) medicines such as Kakkon-to, Sho-seiryu-to, Goshaku-san and Bofu-tsusho-san. SPE was performed on TOYOPAK IC-SP M containing propylsulfonic groups. Determination of PEP and EP was carried out using ion-pair reversed-phase HPLC with sodium dodecyl sulfate. N-Benzyldiethylamine was used as an internal standard. The analytical procedure was validated with regard to specificity, linearity, accuracy, and precision. These data suggest that the analytical method developed in this study is useful for quantitative analysis of PEP and EP in various formulations of Kampo medicine containing Ephedra herb.     

Determination of237Np in environmental samples using inductively coupled plasma mass spectrometry

Ammonium uranates (AU) obtained by the addition of aqueous NH₄ OH to a solution of UO₂ (NO₃)₂ or the equilibrium reaction of UO₃ · 2H₂ O with the vapour over concentrated NH₄ OH have been studied by X-ray diffraction (XRD) analysis, diffuse reflectance Fourier transform infrared spectrometry (DR-FTIR) and chemical analysis. Ammonia can be present as either NH₃ or NH ₄ ⁺ . For precipitates obtained at a pH of 3.7, ammonia in the form of NH₃ is predominant. For ammonium uranate obtained by reaction over concentrated NH₄OH, most of the ammonia is bonded as NH ₄ ⁺ . The reaction mechanism and structures of the products are also discussed.     

Measurement of attachment force of microbial cells

A parallel-plate flow chamber consisting of two transparent electro-conductive glass plates was constructed. The two glass plates were set parallel to each other and connected to a potentiostat apparatus to regulate the strength of the electric field between the plates. A microbial cell suspension was flowed through the chamber. This system enabled the application of an electrostatic force to suspend charged particles, e.g. microbial cells, existing between the two plates. The time course of the cell attachment of Pseudomonas syringae pv. atropurpurea NIAES 1309 suspended in 10 mM phosphate buffer solution (pH 7.0) to the glass plate was investigated at various electric field strengths ranging from −4.2 to +4.1 V cm⁻¹. The attachment rate and the maximum number of attached cells increased linearly with the increase in the strength of the positive electric field. In contrast, the rate and the number of cells decreased linearly with the decrease in the strength of the negative electric field. These linear relations gave a specific value for the strength of the electric field (−5.9 ± 0.7 V cm⁻¹) where the electrostatic repulsion and the microbial attachment force were thought to be equal, resulting in no cell attachment. From this value, the electrostatic repulsion, i.e. the microbial attachment force, was calculated to be 5.0 × 10⁻¹¹ N cell⁻¹ for cells of average size.     

Sensitive measurement of methylene blue active substances by attenuated total reflection spectrometry with a trimethylsilane-modified glass slab optical waveguide

Attenuated total reflection spectrometry with a slab optical waveguide (SOWG) was explored for the simple, rapid and sensitive measurement of total anionic surfactants by the methylene blue active substance (MBAS) method. A fused-silica sheet used as a guiding layer was modified with trimethylsilane (TMS) to extract and concentrate the MBASs on the SOWG surface. Based on preliminary studies of the adsorption behavior and visible ATR spectrum of MB on the modified silica surface, a detection wavelength of 600 nm was chosen for the sensitive measurement of anionic surfactants. When the concentration of MB was set at 10 microM in the final measurement solution, the calibration curve for a typical anionic surfactant (sodium dodecylbenzenesulfonate) was linear up to 0.6 microM and the detection limit was 0.07 microM. The proposed method was applied to the determination of total anionic surfactants in river water.     

An improved apparatus for the determination of krypton-85 and xenon-133 in an emergency situation

A simple and portable apparatus was developed for measurements of⁸⁵Kr and¹³³Xe that would be released into the atmosphere in an emergency situation of nuclear facilities. The method is based on cryogenic adsorption of these gases on charcoal followed by chromatographic separation from other gases. The⁸⁵Kr and¹³³Xe recovered from atmospheric air are determined separately by liquid scintillation counting. It takes about 1 hour for the stepwise determination of⁸⁵Kr and¹³³Xe. The atmospheric concentration of 3·10^–3 Ci per m³ air (1.1·10² Bq/m³ air) is measurable for both nuclides with 20% counting error.     

Free boson realization of

We construct a realization of the quantum affine algebra of an arbitrary level k in terms of free boson fields. In the q1 limit this realization becomes the Wakimoto realization of. The screening currents and the vertex operators (primary fields) are also constructed; the former commutes with modulo total difference, and the latter creates the highest weight state from the vacuum state of the boson Fock space.fellow of Soryushi ShogakukaiAddress after June 1: Department of Physics, Faculty of Liberal Arts, Shinshu University, Matsumoto 390, Japan     

Speciation of mercury in salmon egg cell cytoplasm in relation with metallomics research

Speciation of mercury in salmon egg cell cytoplasm was investigated by surfactant-mediated high-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICP-MS), where an ODS (octadecylsilica) column coated with a bile acid derivative, CHAPS (3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate), was used for species separation. Prior to the speciation analysis, total Hg in the cell cytoplasm was determined by ICP-MS at m/z 202 in a flow injection mode. For the precise measurement, salmon egg cell cytoplasm was diluted five-fold with 0.1 M Tris (Tris(hydroxymethyl)aminomethane)-HNO₃ buffer solution, and the standard addition method was employed. Thus, the total concentration of Hg in cell cytoplasm was estimated to be 12.4 ng g⁻¹ on the wet weight basis. Next, the cell cytoplasm diluted five-fold with 0.1 M Tris-HNO₃ buffer solution was analyzed by surfactant-mediated HPLC with the dual detection system of a UV absorption detector and an ICP-MS instrument. Two peaks corresponding to some proteins and small molecules were mainly observed in those chromatograms. When salmon egg cell cytoplasm was diluted five-fold with 0.01 M Tris buffer solution or pure water, some precipitates appeared probably because of precipitation of hydrophobic proteins in cytoplasm. After the precipitates were eliminated with a membrane filter, the filtrate was subjected to the analysis by surfactant-mediated HPLC/UV/ICP-MS. As a result, the peaks for small molecular species of Hg were clearly observed at the retention time near 4.0 min (corresponding to low-molecular weight zone) in the chromatograms with UV absorption detection as well as with Hg- and S-specific ICP-MS detections. The small molecule bound with Hg was identified as cysteine through the cysteine-spiked experiment. In addition, the protein fraction on the chromatogram obtained by using the CHAPS-coated ODS column was further analyzed by SEC (size exclusion chromatography). Consequently, several protein peaks with molecular weight of 300, 50 and 12 kDa were observed in all the detections of UV absorption, Hg and Se, although two peaks among them were coincident in the case of S. These results indicate that Hg in salmon egg cell cytoplasm binds with proteins containing selenocysteine and/or cysteine residues in proteins.     

Preparation of rapidly disintegrating tablet using new types of microcrystalline cellulose (PH-M series) and low substituted-hydroxypropylcellulose or spherical sugar granules by direct compression method

To decrease the sensation of roughness when a tablet, which is rapidly disintegrated by saliva (rapidly disintegrating tablet), is orally taken, we prepared rapidly disintegrating tablets using microcrystalline cellulose (Avicel PH-M series), a new type of pharmaceutical excipient that is spherical and has a very small particle size (particle size, 7-32 microm), instead of conventional microcrystalline cellulose (PH-102) used in the formulation of tablets containing acetaminophen or ascorbic acid as model drugs for tableting study. Tablets (200 mg) prepared using spherical microcrystalline cellulose, PH-M-06, with the smallest particle size (mean value, 7 microm) had sufficient crushing tolerance (approximately, 8 kg) and were very rapidly, disintegrated (within 15 s) when the mixing ratio of PH-M-06 to low-substituted hydroxypropylcellulose (L-HPC) was 9:1. Sensory evaluation by volunteers showed that PH-M-06 was superior to PH-102 in terms of the feeling of roughness in the mouth. Consequently, it was found that particle size is an important factor for tablet preparation using microcrystalline cellulose. It is possible to prepare drugs such as acetaminophen and ascorbic acid (concentration of approximately 50%) in the tablet form using PH-NM-06 in combination with L-HPC as a good disintegrant at a low compression force (1-6 kN). To solve the problem of poor fluidity in the preparation of these tablets, we investigated the use of spherical sugar granules (Nonpareil, NP-101 (sucrose and starch, composition ratio of 7:3), NP-103 (purified sucrose), NP-107 (purified lactose) and NP-108 (purified D-mannitol)). Rapidly disintegrating tablets can be prepared by the direct compression method when suitable excipients such as fine microcrystalline cellulose (PH-M-06) and spherical sugar granules (NP) are used.