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121.
Effects of -tocopherol (Toc) and -tocopherol acetate (TocA) on the hydrolysis activity of phospholipase D (fromStreptomyces chromofuscus) were studied in small unilamellar vesicles (SUV) of egg yolk phosphatidylcholine (PC). Choline produced in the reaction was monitored by use of a choline oxidase — oxygen electrode. Addition of 18 mol% Toc into SUV (2 mM PC) brought about a twofold rate of choline production. On the other hand, the effect of 18 mol% TocA in SUV was very small. The apparent maximum velocity,V
max(app), increased by addition of Toc in SUV. The apparent Michaelis constant,K
m(app), was unchanged by addition of Toc and TocA in SUV. The Toc and TocA molecules did not have significant effects when PC was solubilized in the micelles of heptaethylene glycol dodecyl ether. The effects of Toc and TocA are, therefore, not due to specific ones on the enzyme itself, but rather upon the bilayer-organization of the substrate. Measurements of spreading pressure showed complete miscibility of PC and Toc, and limited mutual solubility of PC and TocA, suggesting stronger attractive interactions between Toc and PC than those between TocA and PC in the bilayers. 相似文献
122.
Methyl (E)-4,4-dimethyl-5-oxo-2-pentenoate ( 1 , X = O) reacted with 1,2- or 1,3-aminoalcohols 3 to yield oxazolidines 4a-c or tetrahydro-1,3-oxazines 4d,e. The corresponding imino ester 1 (X = NBu-t) also gave 4 on reaction with 3 . Compounds 4 on heating at 230° yielded 4,5-dihydrooxazoles 5a-c or 5,6-dihydro-4H-1,3-oxazines 5d,e along with methyl 4-methyl-3-pentenoate ( 6 ). 相似文献
123.
Thermogravimetry of 22 metal chelates of 1,1,1-trifluoropentane-2,4-dione, H(tfa) in a flow of helium and helium containing H(tfa) vapor is described. Samples were placed in an inserted tube in the inlet port of a gas chromatograph and heated stepwise. The presence of H(tfa) vapor in the helium flow was very effective in suppressing thermal dissociation of hydrated tfa chelates, which decomposed in a helium flow but could be completely vaporized, after dehydration, in a flow of helium containing H(tfa) vapor. The relationship between the volatility and the structure of the tfa chelates is discussed. Results obtained by the proposed method and with a conventional thermobalance are compared. 相似文献
124.
The system H(+)Na(+) has been studied on Sephadex C-25 and C-50 at two ionic strengths by potentiometry. The data have been fitted by the H?gfeldt three-parameter model. For ionic strength 0.100 M (Na)ClO(4) an excellent fit is obtained with a standard deviation of +/-0.013 for both gels. For ionic strength 0.010 M (Na)ClO(4) a satisfactory fit could only be obtained by excluding the lowest and highest pH-value for each gel. 相似文献
125.
Takeshi Doi You Osada Atsushi MorishigeOkihito Tokunaga Teijiro Miyata Kouichi HirotaMichihiro Nakajima Mikihisa Komiya Kiyonori Miyajima Shigekazu Baba 《Radiation Physics and Chemistry》1993,42(4-6)
According to the basic research performed using a small size reactor at TRCRE of JAERI, the electron beam irradiation process was proved to be very effective for NOx, SO2 and HC removals from flue-gas of municipal waste incinerators. Based on this result, a pilot-plant was constructed for the demonstration of NOx, SO2 and HC removal performance using electron accelerator of maximum energy 0.95 MeV and maximum power 15kW.The pilot-plant was constructed at Matsudo City waste Disposal Center. The flue-gas of 1,000 Nm3/hr is guided from the waste incinerator flue-gas line of 30,000Nm3/hr to the pilot-plant to be processed by spraying Ca(OH)2 slurry or powder and irradiation with high-energy electron beam of the accelerator. NOx, SO2 and HC are removed simultaneously from the flue-gas by the enhanced reaction with Ca (OH)2 under irradiation.A brief explanation of the pilot-plant and preliminary results of the experiments are introduced in this paper. 相似文献
126.
Tooru Kitagawa Yukihiro Abe Hideki Sugihara Takeshi Ohazama 《高分子科学杂志,A辑:纯化学与应用化学》2016,53(11):699-708
As was shown in the previous study using X-ray analyses, poly-p-phenylene benzobisoxazole fibers can accommodate copper phthalocyanine molecules with a molecularly-dispersed state in the fiber structure. It is necessary for us to investigate the presence/absence of chemical interactions between the two molecules mentioned above for the purpose to make clear the mechanism why such characteristic structures with the well dispersion of copper phthalocyanine molecules in the hybrid fiber were realized. Spectroscopic analyses based on electron spin resonance and Raman scattering were adopted. Because the copper phthalocyanine molecule take a plane form having D4h symmetry in an ideal state, the spectra from the molecule would express the consequences based on its symmetry as the shape of the spectrum; the presence of characteristic bands in the spectra would be a proof of the existing state of copper phthalocyanine and poly-p-phenylene benzobisoxazole molecules in the hybrid fiber. It is found that both the spectroscopic methods suggested that there were no chemical bond observed between the two molecules of copper-phthalocyanine and poly-p-phenylene benzobisoxazole in the hybrid fiber. 相似文献
127.
128.
129.
Schiff's bases 1 derived from ketones and t-butylamine reacted with diphenyl malonate, diphenyl methyl-malonate and diphenyl phenylmalonate to give 4-hydroxy-2-pyridones 4–6 . Schiff's bases b on reaction with trimethyl methanetricarboxylate afforded 4-hydroxy-3-methoxycarbonyl-2-pyridones 12 . 相似文献
130.
Revisiting thiol-yne chemistry: Selective and efficient monoaddition for block and graft copolymer formation
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Johannes K. Sprafke Jason M. Spruell Kaila M. Mattson Damien Montarnal Alaina J. McGrath Robert Pötzsch Daigo Miyajima Jerry Hu Allegra A. Latimer Brigitte I. Voit Takuzo Aida Craig J. Hawker 《Journal of polymer science. Part A, Polymer chemistry》2015,53(2):319-326
The untapped potential of radical thiol-yne mono-addition chemistry is exploited to overcome the known limitations of thiol-ene chemistry in polymer coupling and block copolymer formation. By careful choice of alkyne, the reaction can selectively lead to the mono-addition product with efficiencies surpassing those achieved by traditional thiol-ene chemistry. This improvement is illustrated by the nearly quantitative synthesis of a variety of diblock and graft copolymers. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 319–326 相似文献