Evaluation of characteristic deuterium distributions of ephedrines and methamphetamines by NMR spectroscopy for drug profiling

We have established a method for quantitative analysis of the deuterium contents (D/H) at the phenyl, methine, benzyl, N-methyl and methyl groups of l-ephedrine/HCl, d-pseudoephedrine/HCl and methamphetamine/HCl by 2H NMR spectroscopy. Comparison of the 5 position-specific D/H values of l-ephedrine/HCl and d-pseudoephedrine/HCl prepared by three methods (chemical synthesis, semichemical synthesis, and biosynthesis) showed that chemically synthesized ephedrines and semisynthetic ephedrines have highly specific distributions of deuterium at the methine position and at the benzyl position, compared with the other positions. The classification of several methamphetamine samples seized in Japan in terms of the D/H values at these two positions clearly showed that the methamphetamine samples had been synthesized from ephedrines extracted from Ephedra plants or semisynthetic ephedrines but not from synthetic ephedrine. This isotope ratio analysis method should be useful to trace the origins of seized methamphetamine in Southeast Asia.     

Two‐Stage Oxidation of Glucose by an Enzymatic Bioanode

The present study reports the design of a novel bioanode to deeply oxidize glucose in an enzymatic biofuel cell (EFC). This enzymatic glucose cell utilizes three co‐immobilized enzymes: NAD‐dependent glucose dehydrogenase (GDH), NAD(P)⁺‐dependent gluconate‐5‐dehydrogenase (Ga5DH), and diaphorase (DI). Glucose is oxidized to gluconate by NAD‐dependent GDH, gaining two electrons per glucose; the gluconate obtained as a by‐product is oxidized at the C5 carbon to 5‐keto‐gluconate by Ga5DH. Operation of our bioanode enabled the oxidation of glucose in two stages, resulting in the gain of four electrons. The three‐enzyme EFC provides a maximum power density of 10.51 ± 1.72 μW cm^–2, which is about 1.6 times higher than the maximum power density of an EFC using a bioanode based on the co‐immobilization of two enzymes (GDH and DI). Our results hold promise for increasing the current density of EFCs, and for application in glucose biosensor.     

Phosphorus release-storage reaction and organic substrate behavior in biological phosphorus removal

This paper represents the results of an experimental investigation conducted on the mechanism of biological phosphorus removal. The relationship between phosphorus release-storage reaction, and behavior of extracellular and intracellular organic substrates under anaerobic-aerobic conditions is studied in detail.The results obtained are as follows: (1) the amount of intracellular carbohydrate increases under the presence of extracellular glucose, but decreases when extracellular glucose is depleted in the anaerobic condition. (2) The amount of intracellular poly-β-hydroxybutylate (PHB) gradually increases under the anaerobic condition. The increase in intracellular PHB content appears to be related to the decrease in intracellular carbohydrate content when extracellular glucose is depleted. (3) Rate of phosphorus release under the anaerobic condition is related to the amount of releasable phosphorus in the cells. The observed ratios of postulated “maximum phosphorus storage capacity” to total amount of intracellular phosphorus are similar to those of the low molecular weight polyphosphate fraction in the cells. (4) Release of phosphorus under the anaerobic condition appears to be related to both ingestion of extracellular organic substrates and formation of intracellular PHB. (5) Release of phosphorus under the anaerobic condition appears to be limited once a fixed portion of intracellular phosphorus is released, even if substantial amount of extracellular organic substrate still remains available. (6) The amount of intracellular PHB increases in the subsequent aerobic condition under presence of a sufficient amount of extracellular organic substrate, but the amount decreases when the extracellular organic substrate is depleted. Similarly, the amount of intracellular carbohydrate initially increases, then gradually decreases following the decrease in PHB content. (7) Ingestion rate for phosphorus in the aerobic condition appears to be dependent on unsaturated storage capacity of intracellular phosphorus as well as on the concentration of extracellular phosphorus.     

Spanwise pressure coherence on prisms using wavelet transform and spectral proper orthogonal decomposition based tools

This paper presents new approaches to clarifying spanwise pressure coherence on typical prisms using some advanced tools based on continuous wavelet transform and spectral-branched proper orthogonal decomposition. Wavelet coherence and coherence modes have been developed for mapping characteristics of spanwise coherence of pressure and turbulence. Temporal-spectral spanwise coherence maps have been represented in the time-frequency plane and spatial-spectral spanwise coherence maps have been expressed in the space-frequency plane. Some new findings are that spanwise pressure coherence not only depends on spanwise separation, frequency and turbulent conditions, but is also influenced by bluff body flow and time. Intermittent and time-dependent pressure coherence in the time domain has been investigated as the nature of pressure coherence. Furthermore, distribution and intermittency of pressure coherence are significantly influenced by analyzed time-frequency resolutions and parameters of the analyzed wavelet function. The coherence mode has been proposed for better understanding of the effect of bluff body flow on pressure coherence. Physical measurements of surface fluctuating pressure and turbulence have been carried out on typical prisms with slenderness ratios of B/D=1 and 5 in turbulent flow.     

Effect of nitrous oxide on spinal dorsal horn WDR neuronal activity in cats

The effects of nitrous oxide (75%) on the spinal dorsal born wide dynamic range (WDR) neuronal activity were studied in either spinal cord intact or spinal cord-transected cats. Extracellular activity was recorded in the dorsal horn from single WDR neurons responding to noxious and non-noxious stimuli applied to the cutaneous receptive fields on the left bind foot pads of intact or decerebrate, spinal cord-transected (L 1-2) cats. The experiment was divided into four sections as follows: (1) When 10 micrograms of bradykinin (BK) was injected into the femoral artery ipsilateral to the recording site as the noxious test stimulus in the spinal cord-transected cat, all of 6 WDR neurons gave excitatory responses which were not depressed by 75% nitrous oxide. (2) When the injection of 10 micrograms of BK into the femoral artery ipsilateral to the recording site was used in the spinal cord-intact cat, 6 of 15 WDR neurons (40%) gave excitatory responses, which were significantly depressed by 75% nitrous oxide, and 9 of 15 WDR neurons (60%) gave inhibitory responses, which were not affected by 75% nitrous oxide. (3) When 10 micrograms of bradykinin (BK) was injected into the femoral artery contralateral to the recording site as the noxious test stimulus in the spinal cord transected cat, 6 of 12 WDR neurons gave excitatory reasons, which were not depressed by 75% nitrous oxide. (4) When the injection of 10 micrograms of BK into the femoral artery contralateral to the recording site was used in the spinal cord-intact cat, 6 of 6 WDR neurons (100%) gave responses, which were affected by 75% nitrous oxide. We have observed that nitrous oxide reduces the excitation and inhibition of dorsal born WDR neuronal activities induced by BK injection in spinal cord-intact cats, but does not reduce the excitation of those in spinal cord-transected cats. This finding confirmed that the antinociceptive effect of nitrous oxide might be modulated by supraspinal descending inhibitory control systems. In addition our result showed that the supraspinal effect of nitrous oxide was mediated not only by an increase but also a decrease in a supraspinal descending inhibition.     

Application of system identification modelling to solar hybrid systems for predicting radiation, temperature and load

Uncertainties in local solar radiation, ambient temperature and thermal load data have been one of the major factors limiting the reliability and efficiency of solar thermal hybrid systems. In the present paper, moving average auto regressive exogenous (ARX) model based reasoning has been mooted and modified to include moving average method, as an effective tool for predictions of these data. The results show that the method is quite robust and is capable of predicting fairly accurate results, which would make these systems more viable in areas where meteorological data are not available or vague.     

Anodic characteristics of SrFe0.9M0.1O3(M: Ni,Co, Ti,Mn) electrodes

Anodic characteristics of the substituted oxides, SrFe_0.9M_0.1O₃(M: Ni, Co, Ti, Mn), were studied. It was found that the catalytic activities of the oxides substituted with Ni and Co ions for the oxygen evolution reaction are high in alkaline solution. The reaction mechanisms for the oxygen evolution reaction are proposed for all the substituted oxides under the assumption of Langmuirian adsorption condition. The current efficiencies of the anodic dissolution of the oxides were much higher in acidic solution than those in alkaline solution. The anodic dissolution is much suppressed by the substitution with Ni or Co ion in alkaline solution. Therefore, the oxides substituted with Ni and Co ions are most suitable as anode materials in alkaline solution. The anodic dissolution is based on the oxygen vacancy formed in the oxygen evolution process. The mechanism of the anodic dissolution of the oxides is proposed.     

Synthesis of hydrogels with a gradient crosslinking structure by electron beam radiation to an aqueous solution of poly(sodium acrylate)

Hydrogels were prepared by electron beam (EB) radiation to the aqueous solutions of poly(sodium acrylate) in the presence of potassium and ammonium peroxodisulfates. The effects of EB radiation dose, as well as polymer, and initiator concentrations on the formation of gels, were investigated. On the basis of the storage modulus, loss modulus, and complex viscosity of the isolated gels determined by rheological measurement, the relationship between the radiation conditions and the rheological properties of the gels was discussed. Furthermore, hydrogels with a gradient crosslinking structure in a depth direction were synthesized by controlling EB radiation dose.