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Nevin Çelebi Osamu Shirakura Yoshiharu Machida Tsuneji Nagai 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(4):407-413
Inclusion complex formation of piromidic acid (PA) with dimethyl--cyclodextrin (DM--CD) in aqueous solution and in the solid state was confirmed by the solubility method, differential scanning calorimetry (DSC) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The apparent stability constant,K
c
, of the complex was estimated to be 244 M–1. The stoichiometry of the complex was given as the ratio 1:2 of PA to DM--CD. The dissolution rate of the PA/DM--CD complex was much greater than that of intact PA.Presented at the Fourth International Symposium on Inclusion Phenomena and the Third International Symposium on Cyclodextrins, Lancaster, U.K., 20–25 July 1986. 相似文献
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Teruhiro Shirakura 《Annals of the Institute of Statistical Mathematics》1986,38(1):145-159
Summary For a given fractional 2
m
factorial (2
m
-FF) designT, the constitution of a block plan to divideT intok (2
r−1<k≦2
r
) blocks withr block factors each at two levels is proposed and investigated. The well-known three norms of the confounding matrix are used
as measures for determining a “good” block plan. Some theorems concerning the constitution of a block plan are derived for
a 2
m
-FF design of odd or even resolution. Two norms which may be preferred over the other norm are slightly modified. For each
value ofN assemblies with 11≦N≦26, optimum block plans fork=2 blocks with block sizes [N/2] andN−[N/2] minimizing the two norms are presented forA-optimal balanced 24-FF designs of resolutionV given by Srivastava and Chopra (Technometrics,13, 257–269). 相似文献
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O. Shirakura N. Nambu T. Nagai 《Journal of inclusion phenomena and macrocyclic chemistry》1984,2(3-4):613-621
The effect of -cyclodextrin (-CD) on the disposition of hexobarbital (HBA) and phenobarbital (PhBA) after intravenous administration, with the simultaneous administration with -CD, was investigated in mice.In the case of HBA, the whole blood concentration was slightly heightened, the brain and liver concentrations were significantly lowered, and the kidney concentration was significantly heightened. Moreover, -CD also influenced the disposition and formation of 3-hydroxy- and 3-keto-HBA. On the other hand, in the case of PhBA, the whole blood concentration was slightly lowered, the time at maximum brain concentration (t-max) was prolonged about 30 to 60 min, the kidney concentration was significantly heightened at the initial stage, while the liver concentration did not show a clear difference by the simultaneous administration with -CD. These results suggest that the disposition of drugs might be modified by the use of CD. 相似文献
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The C-H bond of a terminal alkyne adds to a carbon-carbon double bond of 1,3-dienes, styrenes, and norbornene at room temperature in the presence of a nickel catalyst in regio- and stereoselective manners. Reaction of triisopropylsilylacetylene with 1-substituted 1,3-butadiene derivatives afforded hydroalkynylation products via introduction of a hydrogen atom and a triisopropylsilylethynyl group to 4- and 3-positions of the dienes, respectively. Likewise, 1-triisopropylsiloxy-1,3-butadiene, 1,3-pentadiene, 1-cyclohexen-1-yl-1,3-butadiene, and 1,3-cyclohexadiene underwent the hydroalkynylation reaction, giving the corresponding 1,4-enyne derivatives in good yields at room temperature. Reaction of p-substituted styrene with triisopropylsilylacetylene also proceeded in the presence of the nickel catalyst, giving the branched hydroalkynylation products in good yields. Norbornene gave a exo-addition product in good yield under the same reaction conditions. 相似文献
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Takahashi N. Shimoda T. Miyatake H. Mitsuoka S. Mizoi Y. Kobayashi H. Sasaki M. Shirakura T. Ueno H. Asahi K. Morinobu S. 《Hyperfine Interactions》1996,97(1):469-477
A novel method was tried successfully to trap ions and to freeze out their nuclear polarization inside aggregates of helium atoms, snowballs, in superfluid helium. Spin polarized12B (T
1/2=20.4 ms) ions were introduced into superfluid helium and snowballs were created around the impinged impurity ions. Beta-ray asymmetry was measured to obtain the nuclear polarization of decaying12B. The comparison with the initial value of12B polarization produces that no relaxation in polarization was observed throughout lifetime of12B. 相似文献
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Suginome M Shirakura M Yamamoto A 《Journal of the American Chemical Society》2006,128(45):14438-14439
Alkynylboration has been achieved in the reaction of alkynyl(pinacol)boranes with alkynes in the presence of nickel catalysts, giving cis-1-borylbut-1-en-3-yne derivatives. 1-Aryl-1-alkynes underwent the alkynylboration regioselectively with the selective introduction of the alkynyl groups at their 1-positions, where the aryl groups were attached. The boryl-substituted enynes were reacted with sp2 halides under the Suzuki-Miyaura coupling conditions, giving highly conjugated enynes in high yields. 相似文献