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Mikio Hori Tadashi Kataoka Hiroshi Shimizu Eiji Imai Yukiharu Matsumoto Iwao Miura 《Tetrahedron letters》1981,22(13):1259-1262
The novel ring transformation reactions were found in the reactions of 1,3,7,9-tetra-alkyl-8,9-dihydroxanthines and acetylenic compounds. The reaction of the dihydroxanthine with DMAD gave a propellane type compound and with methyl propiolate afforded the similar type compound and a pyrimido[4,5-b]diazepine derivative. The mechanism of these reactions was also discussed. 相似文献
13.
Self-assembling structures of long-chain phenyl glucoside influenced by the introduction of double bonds 总被引:1,自引:0,他引:1
Jung JH John G Yoshida K Shimizu T 《Journal of the American Chemical Society》2002,124(36):10674-10675
Four long-chain phenyl glucoside amphiphiles possessing a saturated or unsaturated long alkyl chain group as the self-assembling unit of a highly organized molecular architecture were synthesized. Their self-assembling properties were investigated by EF-TEM, SEM, CD, FT-IR, and XRD. Compound 2 possessing one double bond in the lipophilic portion showed twisted helical fibers, which formed a bilayered structure with a 3.59 nm period, while compound 3 showed the helical ribbons and left-handed nanotubular structures with 150-200 nm inner diameters and ca. 20 nm of wall. Very interestingly, compound 4 possessing three double bonds showed a nanotubular structure with ca. 70 nm of inner diameter through a helical ribbon, which formed a loose bilayered structure with 4.62 nm. These results indicate that self-assembling properties strongly depend on the number of cis double bonds. 相似文献
14.
K. Noguchi M. Shimizu E. Sairenji 《Journal of Radioanalytical and Nuclear Chemistry》1985,90(1):217-223
Mercury contents in head hair of 58 dentists employed at the NUSD hospital and 50 dentists employed at the private hospitals or clinics were determined using neutron activation analysis. The arithmetic means were 5.8 ppm and 5.2 ppm, and geometric means were 5.4 ppm and 4.8 ppm, respectively. They were much lower than the values reported in the past year, and agreed well with those of normal Japanese men of the same age. Therefore, it was concluded that the mercury pollution in the working environment of dentists might be practically non-existent in Japan today. 相似文献
15.
The clinical significance of osteocalcin in sera of bone tumors were measured in sera of various kinds of bone tumors. The levels of osteocalcin were higher in bone tumors than those in normal subjects. Serum osteocalcin levels in hypercalcemic groups of bone metastasis and myeloma showed a remarkable increase in a parallelism with serum ALP and LDH levels. These results suggested to be directly or indirectly activated on osteoblast by bone tumors and to be synthesized osteocalcin in osteoblast. 相似文献
16.
N Saito H Kawaguchi Y Ohtsuka N Shimizu S Inayama 《Chemical & pharmaceutical bulletin》1991,39(11):3085-3087
Hansenula anomala, which catalyzes an asymmetric reduction, was immobilized in bulk or spherical crosslinked polymers. The catalytic activity of the yeast for enantio-selective reduction of 3,8-dioxo-4-methoxycarbonyl-9-methyl-delta 4(10)-octalin (lab) was severely affected by the immobilization conditions, such as the crosslink density, and by hydrophobicity of polymers and other components used for immobilization, oxygen concentration in the medium, etc. In some immobilized systems, the ratio of resulting enantiomers was inverted from that in a free yeast system. 相似文献
17.
Mituko Ozima Jun-Ichi Susaki Syun-Iti Akimoto Yoshio Shimizu 《Journal of solid state chemistry》1982,44(3):307-317
Phase relations in the system BaOGeO2 were investigated in the pressure range 20–70 kbar in the temperature range 750–1200°C. Several new phases were identified in this system: an atmospheric phase of BaGe2O5 (monoclinic BaGe2O5 I), two high-pressure phases of BaGe2O5 (monoclinic BaGe2O5 II and tetragonal BaGe2O5 III), and a high-pressure phase of Ba2Ge5O12. The phase boundary curve between BaGe2O5 II and BaGe2O5 III was preliminarily determined as P(kbar) = 7.7 + 0.047T (°C). The high-pressure phases of BaGeO3, which were previously reported by Y. Shimizu, Y. Syono, and S. Akimoto (High Temp.-High Pressures2, 113 (1970)) in the pressure range 15–95 kbar, were interpreted to be not single-phase materials but complicated mixtures of more than two phases in the system BaOGeO2. X-Ray powder diffraction data for the new compounds synthesized in this study are given. 相似文献
18.
Shimizu T Kameoka N Iki H Tabata T Hamaguchi N Igari Y 《Chemical & pharmaceutical bulletin》2003,51(9):1029-1035
The purpose of this study was to develop enteric-coated microgranules for the lansoprazole fast-disintegrating tablet (LFDT), which is a rapidly disintegrating tablet containing enteric-coated microgranules. In our previous study, it was clarified that sufficient flexibility of the enteric layer was achieved by the optimized combined ratio of methacrylic acid copolymer dispersion to ethyl acrylate-methyl methacrylate copolymer dispersion and adding the optimized concentration of triethyl citrate to reduce the damage during the compression process. However, since triethyl citrate has an unpleasant bitter taste and is especially incompatible with lansoprazole, it adversely affects the taste and stability of lansoprazole in the enteric-coated microgranules. The enteric layer containing macrogol 6000 was proven useful to improve the unpleasant bitter taste and stability of lansoprazole, because macrogol 6000 does not have an unpleasant bitter taste and is more compatible than triethyl citerate. By covering the inner (first enteric layer) and outer side (third enteric layer) of the enteric layer containing triethyl citrate (second enteric layer) with the enteric layer containing macrogol 6000, we resolved the stability problem of lansoprazole and the unpleasant bitter taste. Finally, we developed enteric-coated microgranules comprising seven layers: 1) core, 2) active compound layer, 3) intermediate layer, 4) first enteric layer, 5) second enteric layer, 6) third enteric layer, and 7) over coating layer. The enteric-coated microgranules have the multiple functions of reducing the damage to the enteric layer during the compression process, improving the stability of lansoprazole, and masking the unpleasant bitter taste. 相似文献
19.
Ditzler WR Hill D Hoftiezer J Johnson KF Lopiano D Shima T Shimizu H Spinka H Stanek R Underwood D Wagner RG Yokosawa A Burleson GR Faucett JA Fontenla CA Garnett RW Luchini C Rawool-Sullivan MW Bhatia TS Glass G Hiebert JC Kenefick RA Nath S Northcliffe LC Damjanovich R Jarmer JJ Vaninetti J Jeppesen RH Tripard GE 《Physical review D: Particles and fields》1992,46(7):2792-2830
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