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  • 1
    ISSN: 0992-7689
    Keywords: Meterology and atmospheric dynamics (atmospheric electricity; convective processes; lightning)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Since the summer of 1996, scientists from China and Japan have conducted a joint observation of natural cloud-to-ground lightning discharges in the Zhongchuan area that is located close to Qinghai-Xizang (Tibet) Plateau, China. It has been found that the long-duration of intracloud discharge processes, just before the first return stroke, lasted more than 120 ms for 85% of cloud-to-ground flashes in this area, with a mean duration of 189.7 ms and a maximum of 300 ms. We present the results of charge sources neutralized by four ground flashes and two intracloud discharge processes, just before the first return stroke, by using the data from a 5-site slow antenna network synchronized by GPS with 1 μs time resolution. The result shows that the altitudes of the neutralized negative charge for three negative ground flashes were between 2.7 to 5.4 km above the ground, while that of neutralized positive charges for one positive ground flash and one continuing current process were at about 2.0 km above the ground. The comparison with radar echo showed that the negative discharges initiated in the region greater than 20 dBZ or near the edge of the region with intense echoes greater than 40 dBZ, while positive discharge initiated in the weak echo region.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 46 (1990), S. 481-484 
    ISSN: 1420-9071
    Keywords: Hypothalamus ; interleukin-1 ; prostaglandin ; corticotropin releasing factor ; ACTH ; acute phase response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We investigated whether hypothalamic prostaglandin E2 (PGE2) and corticotropin releasing factor (CRF) are responsible for the development of the adrenocorticotropic hormone (ACTH) response induced by interleukin-1α (IL-1α). The present results show that ACTH responses induced by intravenous injection of IL-1α were suppressed by systemic pretreatment with indomethacin and that intrahypothalamic injection of PGE2 stimulates the secretion of ACTH. Furthermore, systemic pretreatment with anti-CRF antibody significantly suppressed the ACTH response induced by intrahypothalamic injection of PGE2. These data suggest that the ACTH response induced by IL-1 is mediated by CRF secretion stimulated by hypothalamic PGE2.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Applied microbiology and biotechnology 54 (2000), S. 104-111 
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Lignin-degrading manganese (II) peroxidase (MnP) purified from the culture of a wood-rotting basidiomycete, Bjerkandera adusta, was used in the polymerization of guaiacol. MnP was found to catalyze polymerization of guaiacol in 50% aqueous acetone, dimethyl formamide, methanol, ethanol, dioxane, acetonitrile, ethylene glycol and methylcellosolve. Maximum yield of polyguaiacol was achieved in 50% aqueous acetone. The weight average molecular weight (M w) of the polymer was estimated to be 30 300 by gel permeation chromatography. However, matrix-assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF-MS) analysis gave a more reliable M w of 1690. IR, 13C-NMR, MALDI-TOF-MS and pyrolysis GC-MS analyses showed the presence of C–C and C–O linkages and quinone structure in polyguaiacol. It was also indicated that polyguaiacol has a methoxy-phenyl group as the terminal moiety. This suggests that polyguaiacol is a branched polymer in which guaiacol units are cross-linked at the phenolic group. Thermal gravimetric and differential scanning calorimetric analyses were also carried out. MnP also catalyzed the polymerization of o-cresol, 2,6-dimethoxyphenol and other phenolic compounds and aromatic amines. M w of these polymers ranged from around 1000 to 1500.
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  • 4
    ISSN: 1432-1041
    Keywords: Key words  ACAT inhibitor ; YM17E ; Pharmaco- kinetics ; Hypocholesterolaemic activity ; Tolerability ; Volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract   We conducted a single and repeat oral dose study of YM17E, a novel inhibitor of acyl coenzyme A (CoA): cholesterol acyltransferase, in healthy male volunteers to evaluate the pharmacokinetic profile, tolerability and effect of the drug on serum cholesterol. In the single administration study, YM17E was administered after a meal to two groups of subjects (each containing six subjects taking the drug and three taking placebo) receiving 3, 60 and 300 mg or 15, 60 and 450 mg YM17E, respectively. Plasma concentrations of unchanged drug following single oral administration at 3–300 mg after a meal increased with increasing dose. In contrast, plasma concentrations after administration of 450 mg were almost the same as after 300 mg. Unchanged YM17E was not detected in urine after single administration, suggesting that it was excreted via the bile or urine after metabolism. Five active metabolites (M1, M2-a, M2-b, M3 and M4) were observed in plasma at concentrations comparable to those of unchanged YM17E. Their plasma concentrations increased in a slightly greater than dose-dependent manner from 3 to 300 mg. The effect of food was studied in an open crossover design with a 1-week washout period. Twelve subjects received 150 mg YM17E in both the fasted and postprandial states. The AUC and Cmax after fasting were closely similar to those after a meal, showing that bioavailability was not affected by food intake. In the repeated oral dose study, the subjects received test drug at 150 mg or 300 mg (n = 6 each) or placebo (n = 3) twice a day (after breakfast and after dinner) for 7 days. On days 1 and 7, the subjects received YM17E once a day (after breakfast) for evaluation of pharmacokinetic properties. After repeated oral administration of 150 mg b.d., plasma concentrations reached steady state by day 5 (mean Cmin 48.6 ng · ml−1). After repeated administration of 300 mg b.d., plasma concentrations prior to each daily morning dose increased up to the 5th day (mean Cmin 166.6 ng · ml−1) and then tended to decrease until the 7th day. No significant signs, symptoms or changes in serum cholesterol levels were observed during the single and repeated oral dose studies at 150 mg b.d. Although statistical analysis was not conducted because of the small number of subjects, all subjects receiving repeated oral administration of 300 mg twice daily showed a 25% decrease in serum cholesterol level on day 7, but also the simultaneous occurrence of diarrhoea.
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  • 5
    ISSN: 1432-0983
    Keywords: Key words Basidiomycete ; Transformation ; White-rot fungi ; Carboxin ; Succinate:ubiquinone oxidoreductase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A novel selection marker gene for transformation of the white-rot basidiomycete Pleurotus ostreatus was developed by introducing a point mutation in a gene which encodes the iron-sulfur protein (Ip) subunit of succinate dehydrogenase. The mutant gene, Cbx R, encodes a modified Ip subunit with an amino-acid substitution (His239 to Leu) and confers resistance to the systemic fungicide, carboxin. The DNA sequence was integrated ectopically in the chromosome of the transformants. This is the first report of a homologous marker gene which is available for the molecular breeding of an edible mushroom.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Bulletin of environmental contamination and toxicology 60 (1998), S. 669-676 
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Annales geophysicae 14 (1996), S. 342-350 
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The seasonal change in CO2 flux over an artificial grassland was analyzed from the ecological and meteorological point of view. This grassland contains C3 and C4 plants; the three dominant species belonging to the Gramineae; Festuca elatior (C3) dominated in early spring, and Imperata cylindrica (C4) and Andropogon virginicus (C4) grew during early summer and became dominant in mid-summer. CO2 flux was measured by the gradient method, and the routinely observed data for the surface-heat budget were used to analyze the CO2 and H2O exchange between the grassland and atmosphere. From August to October in 1993, CO2 flux was reduced to around half under the same solar-radiation conditions, while H2O flux decreased 20% during the same period. The monthly values of water use efficiency, i.e., ratio of CO2 flux to H2O flux decreased from 5.8 to 3.3 mg CO2/g H2O from August to October, the Bowen ratio increased from 0.20 to 0.30, and the ratio of the bulk latent heat transfer coefficient CE to the sensible heat transfer coefficient CH was maintained around 0.40-0.50. The increase in the Bowen ratio was explained by the decrease in air temperature from 22.3 °C in August to 16.6 °C in October without considering biological effects such as stomatal closure on the individual leaves. The nearly constant CE/CH ratios suggested that the contribution ratio of canopy resistance to aerodynamic resistance did not change markedly, although the meteorological conditions changed seasonally. The decrease in the water use efficiency, however, suggested that the photosynthetic rate decreased for individual leaves from August to October under the same radiation conditions. Diurnal variations of CO2 exchange were simulated by the multi-layer canopy model taking into account the differences in the stomatal conductance and photosynthetic pathway between C3 and C4 plants. The results suggested that C4 plants played a major role in the CO2 exchange in August, the contribution of C4 plants decreased in September, and daily variations of CO2 exchange were mainly due to C3 plants in October. The results also suggested that the decrease in the net canopy CO2 exchange from August to October was induced partly by the decrease of net photosynthesis on the individual leaves in both C4 and C3 plants, which could be due to aging of the leaves.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of sol gel science and technology 19 (2000), S. 803-806 
    ISSN: 1573-4846
    Keywords: modified sol-gel ; J-aggregates ; nonlinear optical susceptibility ; z-scan method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We tried to embed stable J-aggregates of 1,1′-diethyl-2,2′-cyanine bromide into a thin silica film by simple sol-gel processing. Its third order susceptibility |χ(3)| was about 5 × 10−7 esu at resonance wavelength of the J band by Z-scan method using a 180-femtosecond pulse laser beam at 77 K in vacuum environment (〈10−5 Torr). The net |χ(3)| value of pure J-aggregates should be 4 × 10−6 esu from the doping ration of J-aggregates in silica film.
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  • 9
    ISSN: 1573-482X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Non-exponentialities of the decay curve of a.c. thin-film electroluminescence devices are explained by applying the Yokota Tanimoto (Y-T) equation. In applying the equation it is assumed that the distributions of donors and acceptors are non-uniform; the concentrations increase from the bottom to the top of an active layer. Electron-spin resonance (ESR) measurements of the active layers indicate that the concentrations of isolated Mn2+ ions, Mn2+ pairs and Mn2+ triples in the layer agree approximately with those of donors and acceptors used in the Y-T equation to obtain a good fit to the measured decay curves, where the Mn2+ triples are assumed to work as the acceptors (i.e. quenchers), and the isolated Mn2+ ions and the Mn2+ pairs as the donors (i.e. luminescent centres).
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of sol gel science and technology 19 (2000), S. 257-261 
    ISSN: 1573-4846
    Keywords: J-aggregates ; nonlinear optical property ; organic-inorganic composite material
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We synthesized thin silica films doped with condensed J aggregates of pseudisocyanine dyes (PIC) as a material for nonlinear optical devices by simple sol-gel processing and spincasting. The sol and the silica films were characterized with UV-visible absorption spectroscopy, fluorescence spectroscopy and fluorescence microscopy. The films contain plenty J aggregates, and are optically transparent and stable at room temperature. J aggregation dependence on dye concentration in the sol and spin speed during spincasting were investigated. It was found that dye condensation in the sol solution and fast spinning promote the formation of J aggregates in the films. Because of the high third order nonlinear susceptibility around 10−7 esu, the films are expected to be useful for non-linear optical devices.
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