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991.
T. Kojima Y. Haruyama H. Tachibana R. Tanaka J. Okamoto K. Yagi N. Tamura H. Hara S. Kashiwazaki 《Radiation Physics and Chemistry》1993,42(4-6)
A new alanine-polystyrene (PS) dosimeter prepared with simplified molding procedure and an automatic desk-top dose-reader of alanine dosimeter were developed for the purpose of routine use. Combination of these two allows us to apply a reliable alanine/ESR dosimetry system to routine dosimetric process control in industrial gamma radiation processing. 相似文献
992.
Isao Aritome Hisashi Shimakoshi Yoshio Hisaeda 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):o563-o564
The title compound [systematic name: 3,10,13,20‐tetrabromo‐4,9,14,19‐tetrapropyl‐21,22,23,24‐tetraazapentacyclo[16.2.1.12,5.18,11.112,15]tetracosa‐2(22),3,5,7,9,11,13,15(24),16,18,20‐undecaene], C32H34Br4N4, crystallizes in two distinct crystalline forms, viz. monoclinic prisms and triclinic plates, and the first of these is described here. The molecule of the prismatic form has a centre of symmetry and a more warped structure than that of the triclinic plate‐like form. The shape of the central N4 cavity is rectanglar, enlarged in the direction of the methine‐bridge C atoms, and the N?N distances are 2.713 (3) and 2.818 (3) Å. 相似文献
993.
A bacterial sensor system based on Methylomonas flagellata AJ 3670 is described for methane determinations. The system consists of a bacterial, reactor, a reference reactor and two oxygen sensors. The current decreases with time until a steady state is reached within 30 s at 30°C; the maximum current difference is obtained at 30°C and pH 7.2. The response time for the determination of methane is less than 1 min. A linear relationship is obtained between the current difference and the methane concentration below 6.6 mM; the lower limit of determination is 5 μM, and the current decrease is reproducible within 5%. The current output of the sensor is almost stable for more than 10 days and 250 assays. 相似文献
994.
A new synthetic method for γ-acetoxy-α,β-unsaturated esters by the acetoxylation of β,γ-unsaturated esters catalyzed by PdCl2 in the presence of KOAc and pentyl nitrite in acetic acid is presented. The reaction takes place at γ-position of the esters regioselectively with double bond migration to α,β-position. The E configuration of the double bond was confirmed by NMR analysis. Preliminary investigation to synthesize pyrenophorin and pyrenophorol using this reaction is described. 相似文献
995.
Takakazu Kojima Fumihiko Nagasaki Yozo Ohtsuka 《Journal of heterocyclic chemistry》1980,17(3):455-459
A series of 5,6-disubstituted 3-alkoxypyrazine-2-carbonitriles ( 2a-i ) were prepared from 5,6-disubstituted pyrazine-2,3-dicarbonitriles ( 1a-d ) by direct substitution with alcohols. Treatment of 1 with amines gave either pyrrolopyrazines ( 3a,b ) or substitution products ( 4,5 ). In a low temperature range, 1 afforded imidates and related compounds ( 6–11 ). The preference among these reactions depended on the 5,6-substituents and on the reaction conditions. 相似文献
996.
Akira Matsumoto Isao Inoue Masayoshi Oiwa 《Journal of polymer science. Part A, Polymer chemistry》1976,14(10):2383-2389
The effect of temperature on the polymerization of diallyl phthalate was investigated in the temperature range of 80–150°C. The degree of polymerization increased slightly with temperature up to 100°C and then decreased; together with the results of primary chain length and the dependence of Rp on initiator concentration, these findings were interpreted in terms of the enhancement of the reinitiation ability of the allylic radical produced by the intramolecular chain-transfer reaction and of the reactivity of the cyclized radical at elevated temperature. The tendency for cyclization became more marked with increasing temperature. The gel point was almost unaffected. 相似文献
997.
Saito Y Miyauchi Y Okamoto A Saito I 《Chemical communications (Cambridge, England)》2004,(15):1704-1705
A novel fluorescence BDF probe containing pyrene-labeled 7-deaza-2[prime or minute]-deoxyadenosine has been developed for the detection of thymine base on a target DNA. 相似文献
998.
Shohgo Atarashi Hideaki Tsurumi Toshihiro Fujiwara Isao Hayakawa 《Journal of heterocyclic chemistry》1991,28(2):329-331
An efficient, highly enantioselective synthesis of (S)-(-)-7,8-difluoro-2,3-dihydro-3-methyl-4H-1,4-benzoxazine, a key intermediate of (S)-(-)-ofloxacin, using various chiral sodium triacyloxyborohydrides as reducing agents is reported. 相似文献
999.
T Aoyagi T Wada F Kojima M Nagai S Harada T Takeuchi K Hirokawa 《Chemical & pharmaceutical bulletin》1990,38(6):1750-1752
We previously reported an increase in aminobutyrate aminotransferase (GABA-T) activity in the cerebrum of Alzheimer patients. In the present study, we investigated whether such findings are common in the usual aging process as well. We examined the activity of various enzymes, which were examined in the previous study, in the cerebrum of Wistar-Kyoto rats and spontaneously hypertensive rats. In the two strains, we compared the enzyme activities between the two groups of animals, 5 weeks and 13 weeks of age. In both strains, the older animals had significantly higher activities of GABA-T and choline acetyltransferase (ChAc-T). In spite of other enzymatic changes coexisting, the above two enzymes were suggested by discriminant function analysis to be playing a major role in the multiple enzymatic changes in the cerebrum of the animals. 相似文献
1000.
Determination of cyanide using a microbial sensor 总被引:2,自引:0,他引:2
Keijiro Nakanishi Kazunori Ikebukuro Isao Karube 《Applied biochemistry and biotechnology》1996,60(2):97-106
A microbial cyanide sensor was prepared, consisting of immobilizedSaccharomyces cerevisiae and an oxygen electrode. When the electrode was inserted into a solution containing glucose, the respiration activity of
the microorganisms increased. The change in the respiration activity is monitored with the oxygen electrode. When cyanide
is added to the sample solution, the electron transport chain reaction of the respiration system in the mitochondria is inhibited,
resulting in a decrease in respiration. The inhibition is caused by cyanide binding with respiration enzymes such as the cytochrome
oxidase complex in the mitochondrial inner membrane. Therefore, the cyanide concentration can be measured from the change
in the respiration rate. When the sensor was applied to a batch system at pH 8.0 and 30°C, the cyanide calibration curve showed
linearity in the concentration range between 0.3 μM and 150 μM CN-. 相似文献