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121.
122.
The Pd/fibroin (Fib) was easily prepared by the auto-reduction of the silk-fibroin conjugated Pd(OAc)2 using MeOH as a solvent and a reductant and exhibited good chemoselectivity in the hydrogenation of olefins and azides in the presence of aromatic carbonyls and/or halogens or an O-benzyl protective group. 相似文献
123.
Pyrimido[5,4-
]pteridine
-oxide (1) oxidizes efficiently benzene, toluene, and anisole under UV irradiation to give the corresponding phenol derivatives 4, though the easiness of the reaction significantly depends upon the nature of the substituents on the benzene ring. 相似文献
124.
Reactions of pyridine N-oxides, pyrazine di-N-oxides, and their benzologues with formamide are described. Carbamoylation mainly occurred at aromatic ring with loss of the N-oxide oxygen atom, however, 2,4,6-trimethylpyridine 1-oxide gave 2- and 4-pyrimidinyl derivatives. 相似文献
125.
Green tea: Health benefits as cancer preventive for humans 总被引:8,自引:0,他引:8
Fujiki H 《Chemical record (New York, N.Y.)》2005,5(3):119-132
Green tea is an acknowledged cancer preventive in Japan. The aim of this review article is to develop the concept of cancer prevention with green tea beverage for humans, which has largely been our exclusive research territory. This paper briefly reviews several topics, beginning with the introduction of our initial work on penta-O-galloyl-beta-D-glucose and (-)-epigallocatechin gallate (EGCG), the main constituent of green tea extract. The mechanisms of EGCG action, particularly the reduction of TNF-alpha are discussed, and we show how use of 3H-EGCG revealed a wide range of target organs for cancer prevention. The results of an epidemiological study in Saitama Prefecture allowed us to determine the cancer preventive amount of green tea-10 Japanese-size cups per day, about 2.5 g green tea extract-which made it possible for us to introduce the two-stage strategy of cancer prevention with green tea. The first stage is the delay of cancer onset for the general population. The second stage is the prevention of recurrence of cancer for patients following cancer treatment. Combination cancer prevention with green tea and cancer preventive drugs is proving especially beneficial for Japanese, who drink green tea every day. And finally, the stimulating comments of Prof. Jim Watson have encouraged green tea scientists. 相似文献
126.
PMR chemical shifts of various m- and p-substituted diphenylamines were correlated with σ-constants. However, the NH stretching frequencies of these amines were not linear with the σ- constants, and the irregularity in the νNHvs σ plot was interpreted by taking into accounts the following factors: the changes in hybridization of the imino N atoms, the normal electronic effect of the substituent and the steric effect on the planarity of the amine molecules. Results on the CN stretching absorptions were also presented. 相似文献
127.
128.
S. Shibata F. Hirota N. Kakuta T. Muramatsu 《International journal of quantum chemistry》1980,18(1):281-285
The differential cross-sections for high-energy electrons scattered from water have been measured over a wide range of momentum transfers. The effect of chemical binding was seen from the comparison between the experiment and the calculation for an independent-atom model. The ab initio calculation using SCF MO was carried out with respect to the elastic scattering. It was in a good agreement with the experiment and thus a reliable electron distribution in water was obtained. 相似文献
129.
The design and characterisation of a millimetre-wave uni-travelling-carrier photodiode with a monolithically integrated matching (impedance transform) circuit utilising a coplanar-waveguide short-stub are presented. The device with the matching circuit shows ~50% higher efficiency than one with a 50 Ω load design. The maximum saturation output power obtained is 13.6 mW at 100 GHz 相似文献
130.