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71.
An enzyme reactor consisting of a 2.6-m-long silicon capillary with glucose oxidase immobilized on the inner surface was fabricated using micromachining techniques. A V-shaped groove of 100 μm width, formed by anisotropic etching, was anodically bonded to a glass plate to create the capillary. Glucose oxidase was covalently immobilized with 3-aminopropyltriethoxysilane and glutaraldehyde. The reactor was evaluated by connecting it to a Flow injection analysis system for glucose detection. Glucose concentrations were in the range of 10−3 to 5 × 10−2M with a volume of 0.2 μl of glucose solution. 相似文献
72.
Kazuhiro Kobayashi Hiroyasu Takeuchi Shinzo Seko Yoshikazu Kanno Sachiko Kujime Hiroshi Suginome 《Helvetica chimica acta》1993,76(8):2942-2950
The 2,3-dihydro-1H-benz[f]indole-4,9-diones 3a–d , h were formed in a one-step reaction in 13–82% yield by an unprecedented [3 + 2] regioselective photoaddition of 2-amino-1,4-naphthoquinone ( 1 ) with various electronrich alkenes 2 (Scheme 1, Table). The [3 + 2] photoadducts derived from 1 with vinyl ethers and vinyl acetate gave 1H-benz[f]indole-4,9-diones 4e , f , i , in 33–72% yield, by spontaneous loss of the corresponding alcohol or AcOH from the resulting adducts; 4i has a kinamycin skeleton. The [3 + 2] photoaddition also took place on irradiation of the differently substituted amino-1,4-benzoquinones 6 , 7 , and 12 and excess alkenes 2 in benzene, giving 1H-indole-4,7-dione derivatives 13 and 14 (Scheme 3), 15a and 16 (Scheme 4), and 18 (Scheme 4), respectively. The initial products in these photoadditions were proved to be hydroquinones, the air oxidation of which yielded the heterocyclic quinones; 2,3-dihydro-2-methoxy-2-methyl-5-phenyl-1H-indole-1,4,7-triyl triacetate ( 19 ) was isolated after treatment of the crude photoaddition mixture obtained from 2-amino-5-phenyl-1,4-benzoquinone ( 7 ) and 2-methoxyprop-1-ene ( 2f ) with Ac2O and pyridine under N2. A pathway leading to the annelated hydroquinones involving ionic intermediates arising from an electron transfer in these photoadditions is proposed (Scheme 5). 相似文献
73.
Takeuchi Y Nishikawa M Hachiya H Yamamoto H 《Magnetic resonance in chemistry : MRC》2005,43(8):662-664
High-resolution solid-state magic angle spinning (73)Ge NMR spectra of some organogermanium compounds were measured. Most tetrasubstituted germanes with identical substituents exhibited signals except for one case. Tetrasubstituted germanes with two kinds of different but somewhat similar substituents exhibited broad peaks. Trisubstituted germanes failed to show signals, indicating the importance of symmetry around germanium. 相似文献
74.
Harayama T Akiyama T Nakano Y Nishioka H Abe H Takeuchi Y 《Chemical & pharmaceutical bulletin》2002,50(4):519-522
A palladium-assisted coupling reaction of aryl triflate with arene was investigated, and a novel Pd reagent prepared from equimolar Pd(OAc)2, 1,3-Bis[diphenylphosphino]propane (DPPP), and Bu3P was developed. This method is useful for intramolecular biaryl coupling reactions, not only between aryl triflate and arene (triflate-amide), but also between aryl halide and arene (halo-amide). 相似文献
75.
pi-Allyl-nickel complexes initiated addition polymerisation of 2-phenyl-1-methylenecyclopropane to give a polymer with three-membered rings; the formed polymer showed a high Tg and negligible thermal decomposition up to 300 degrees C. 相似文献
76.
77.
78.
Y Kawashima T Niwa T Handa H Takeuchi T Iwamoto Y Itoh 《Chemical & pharmaceutical bulletin》1989,37(2):425-429
Prolonged-release spherical micro-matrices of ibuprofen with acrylic polymer (Eudragit RS) were prepared using a novel emulsion-solvent diffusion method. It was found by examining cross sections of the spherical matrix before and after dissolution tests with a scanning electron microscope and a porosimeter that the resultant micro-matrix had a sponge-like internal structure. The spherical matrices were successfully recovered with a relatively high concentration of the drug in ethanol (0.4-0.6 g/ml) and over a wide range of temperatures (5-35 degrees C). The size of the spherical matrix could be easily controlled by varying the agitation speed of the system and the concentration of emulsifier added to the aqueous medium. The drug release rate from the spherical matrix decreased with increasing concentration of polymer formulated due to the reduced diffusion path and increased tortuosity in the matrix. Spherical matrices with ibuprofen:Eudragit RS = 3:1 improved the bioavailability of the drug and prolonged the drug action in beagle dogs. 相似文献
79.
Itsuo Mori Yoshikazu Fujita Minako Toyoda Yoko Takeuchi 《Fresenius' Journal of Analytical Chemistry》1992,344(6):292-294
Summary A highly sensitive determination of osmium(VIII) is based on the decolouring reaction with pyrogallolphthalein (gallein) and hydrogen peroxide in the presence of Brij 35. Beer's law was obeyed in the range of 0–0.5 ng of osmium(VIII) per 10 ml and the apparent decomposed absorption coefficient was 2.5×109 l mol–1 cm–1 at 535 nm.Application of xanthene derivatives in analytical chemistry. Part XCIII. Part XCII see ref. [1] 相似文献
80.
Using a technique of laser flash photolysis coupled with vacuum ultraviolet laser-induced fluorescence spectroscopy, the rate coefficients of O(1D) reactions with N2, O2, N2O, and H2O at 295 ± 2 K have been determined to be , kO2=(4.06±0.24)×10-11, kN2O=(1.35±0.08)×10-10 and . The quoted uncertainties include estimated errors and are the 95% confidence level. The kN2 and kN2O values obtained are larger than the current NASA/JPL recommendations by 26% and 16%, respectively, although they are still within the error limits associated with the recommendations. 相似文献