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101.
102.
Tomoko Ichibangase Kyoji Moriya Kazuhiko Koike Kazuhiro Imai 《Biomedical chromatography : BMC》2009,23(5):480-487
In plasma proteomics, before a proteome analysis, it is essential to prepare protein samples without high‐abundance proteins, including albumin, via specific preparation techniques, such as immunoaffinity capture. However, our preliminary experiments suggested that functional changes with use alter the ability of the immunoaffinity column. Thus, in this study, to evaluate the changes of the removal ability of abundant proteins from plasma by the immunoaffinity column, plasma proteome analysis was performed for the long‐term test for the reproducibility of the affinity column using the fluorogenic derivatization–liquid chromatography–tandem mass spectrometry method combined with an IgY column. The specific adsorption for albumin decreased with an increase in the number of the column usage before its expiration date. Moreover, it was demonstrated that hydrophobic high molecular weight compounds in plasma adsorbed onto the column materials surface contributed to the functional changes from specific immunoaffinity adsorption into hydrophobic interaction. These results suggested that, in quantitative plasma proteomics studies, it is important to keep in mind the risk of not only the nonselective loss but also the changes in the adsorption ability of the immunoafinity column. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
103.
Kazuhiro Nagata Daisuke Sano Yu Shimizu Michiko Miyazaki Takuya Kanemitsu Takashi Itoh 《Tetrahedron: Asymmetry》2009,20(21):2530-2536
The catalytic asymmetric alkylation of α-cyanocarboxylates and acetoacetates with an alkyl halide was performed under phase-transfer conditions to afford compounds which have a chiral quaternary carbon with up to 97% and 94% ee, respectively. As applications of this method, chiral 2-oxindole derivatives and a β-lactam derivative were synthesized. 相似文献
104.
Akira Kasahara Taeko Izumi Satoshi Murakami Kazuhiro Miyamoto Toshimi Hino 《Journal of heterocyclic chemistry》1989,26(5):1405-1413
The palladium-catalyzed cross-coupling reaction of 2-bromonitrobenzenes or 2-bromoacetanilides with ethylene has been used to produce a variety of substituted indoles. The mild reaction conditions and selectivity inherent in the coupling reaction have been utilized to produce regiochemically pure 4-, 5-, 6-, and 7-substituted indoles. 相似文献
105.
Progress in theory and experiment on the early stage of decomposition of alloys is reviewed. In the first half of this paper, theoretical treatments on decomposition of alloys by spinodal and nucleation mechanism and also continuum theories and the discrete lattice theories are comparatively reviewed. In the latter half of this paper, experimental results on Al-Zn, Ni-Al, Cu-Co and Al-Ag alloys are discussed. 相似文献
106.
Dr. Randa K. Gabr Prof. Dr. Takuji Hatakeyama Prof. Dr. Kazuhiro Takenaka Prof. Dr. Shinobu Takizawa Yoshihiro Okada Prof. Dr. Masaharu Nakamura Prof. Dr. Hiroaki Sasai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(29):9518-9525
The reaction pathway of an enantioselective 5‐endo‐trig‐type cyclization of 3‐alkenoic acids catalyzed by a chiral palladium–spiro‐bis(isoxazoline) complex, Pd–SPRIX, has been studied by density functional theory calculations. The most plausible pathway involves intramolecular nucleophilic attack of the carboxylate moiety on the C?C double bond activated by Pd–SPRIX and β‐H elimination from the resulting organopalladium intermediate. The enantioselectivity was determined in the cyclization step through the formation of a π‐olefin complex, in which one of the two enantiofaces of the olefin moiety was selected. The β‐H elimination occurs via a seven‐membered cyclic structure in which the acetate ligand plays a key role in lowering the activation barrier of the transition state. In the elimination step, the SPRIX ligand was found to behave as a monodentate ligand due to the hemilability of one of the isoxazoline units thereby facilitating the elimination. Natural population analysis of this pathway showed that the more weakly electron‐donating SPRIX ligand, compared with the bis(oxazoline) ligand, BOX, facilitated the formation of the π‐olefin complex intermediate, leading to a smaller overall activation energy and a higher reactivity of the Pd–SPRIX catalyst. 相似文献
107.
108.
Gang Wei Nozomu Sasage Yusuke Kusanagi Kazuhiro Fujiki Takeshi Yamauchi Norio Tsubokawa 《Journal of polymer science. Part A, Polymer chemistry》2008,46(12):4218-4226
The surface grafting of hyperbranched cyclotriphosphazene polymer onto silica nanoparticles and carbon black was investigated. The grafting of hyperbranched cyclotriphosphazene polymer onto these surfaces was achieved by the repeated reactions of hexachlorocyclotriphosphazene with hexamethylenediamine from surface amino groups and sodium carboxylate groups, respectively. The percentage of grafting onto silica and carbon black surfaces exceeded 760 and 390%, respectively. However, it proved difficult to achieve the theoretical growth of cyclotriphosphazene polymer from these surfaces because of steric hindrance. The introduction of sulfonic acid groups was successfully achieved by the reaction of terminal chlorophosphazene groups of the hyperbranched polymer‐grafted silica and carbon black with sulfanilic acid. The content of sulfonic acid groups introduced onto silica and carbon black surfaces was 4.98 mmol/g and 5.70 mmol/g, respectively. The sulfonated cyclotriphosphazene polymer‐grafted carbon black was extremely hydrophilic, yielding stable colloidal dispersions in polar solvents. The sulfonated cyclotriphosphazene polymer‐grafted silica and carbon black showed ionic conductivity, with the conductance increasing exponentially with increasing relative humidity and temperature. This study may offer important leads in the application of silica nanoparticles and carbon black in polymeric membranes for fuel cells. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4218–4226, 2008 相似文献
109.
Takaaki Horaguchi Kazuhiro Miyazawa Eietsu Hasegawa Takahachi Shimizu Tsuneo Suzuki Kiyoshi Tanemura 《Journal of heterocyclic chemistry》1990,27(4):941-948
A variety of 2,5-dioxacyclohepta[jkl]-as-indacenes 5, 7–14 were synthesized as a new heterocycle by the treatment of diethyl (5,9-dioxobenzocyclohepten-1,4-diyloxy)diacetates 4a-e with potassium hydroxide or sodium hydride in dioxane. The mechanism of furan-ring formation from 4a-e was discussed. 相似文献