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11.
We synthesized the DNA oligonucleotide containing a new cross-linkable 4-amino-2-oxo-6-vinyltriazine (AOVT) nucleobase analogue (Et-AOVT) and evaluated these properties. Our results of the cross-link assay and thermal denaturing assay of duplexes containing AOVT demonstrated that the additional aza of AOVT has an impact on the duplex stability and crosslink properties. Our data suggests that the additional 5-aza of AOVT is involved in the hydrogen bonding with the complementary guanine, and this hydrogen bonding system successfully flipped the reactive vinyl group out to the major groove of the duplex demonstrating a new paradigm of a “cross-linkable duplex”. 相似文献
12.
Masaya Nakata Takashi Ishiyama Youichi Hirose Hiroshi Maruoka Kuniaki Tatsuta 《Tetrahedron letters》1993,34(52):8439-8442
The enantiospecific synthesis of the oligomycin B degradation product 2, corresponding to the C19–C34 spiroketal portion, has been achieved by sequential coupling of the C19–C21, C22–C27, and C28–C34 subunits, establishing the absolute stereochemistry of oligomycin B. 相似文献
13.
H. Kono X. Wang H. Ueda A. Ishiyama T. Saitoh Y. Aoki M. Yagi S. Mukoyama N. Fujiwara 《Physica C: Superconductivity and its Applications》2010,470(20):1334-1337
In high temperature superconductor applications used in electric power devices, YBCO coated conductors may be subjected to short-circuit fault-currents that are 10–30 times the normal operating current. These over-currents cause heat generation, resulting in Ic degradation of the YBCO coated conductor. Therefore, it is necessary to fully investigate the degradation characteristics of YBCO coated conductors. We previously conducted preliminary experiments on the degradation of YBCO sample tapes resulting from the over-current pulse drive. 相似文献
14.
This article summarizes the computational analysis of the vibrational sum frequency generation (SFG) spectroscopy with molecular dynamics simulation. The analysis allows direct comparison of experimental SFG spectra and microscopic interface structure obtained by molecular simulation, and thereby obviates empirical fitting procedures of the observed spectra. In the theoretical formulation, the frequency-dependent nonlinear susceptibility of an interface is calculated in two ways, based on the energy representation and time-dependent representation. The application to aqueous interfaces revealed a number of new insights into the local structure of electrolyte interfaces and the interpretation of SFG spectroscopy. 相似文献
15.
Assay of angiotensin I-converting enzyme (ACE) inhibitory activity always draws much attention because of diverse applications in the field of antihypertension and related pathogenesis. Recently, the use of a new synthetic substrate, 3-hydroxybutyrylglycyl-glycyl-glycine (3HB-GGG), for the assay of ACE inhibitory activity has been confirmed. To construct a rapid, economical, and automatic determination system of ACE inhibitory activity using 3HB-GGG, a flow injection analysis (FIA) system with enzymatic reactors was developed in this study. Enzyme reactors were composed of aminoacylase and 3-hydroxybutyrate dehydrogenase immobilized separately on CNBr-activated Sepharose 4B. The assay condition was optimized in terms of the conversion of 3HB-G into NADH by the enzymatic reactors when the reaction solution containing 3HB-G generated from 3HB-GGG (after the incubation with ACE) was repetitively injected into the FIA system. Under the optimized conditions, 3HB-G was converted to 3HB, and then 3HB was oxidized by NAD+ to form NADH. The developed system successfully detected practical ACE inhibitors with a great sensitivity, high sampling frequency (10 samples h−1) and a durable stability of the enzymatic reactors. 相似文献
16.
Prof. Takahisa Omata Aman Sharma Prof. Issei Suzuki Tomohiro Ishiyama Shinji Kohara Koji Ohara Prof. Madoka Ono Prof. Yang Ren Khurelbaatar Zagarzusem Prof. Masaya Fujioka Prof. Gaoyang Zhao Prof. Junji Nishii 《Chemphyschem》2022,23(3):e202100840
Anhydrous silicophosphoric acid glass with an approximate composition of H5Si2P9O29 was synthesized and its thermal and proton-conducting properties were characterized. Despite exhibiting a glass transition at 192 °C, the supercooled liquid could be handled as a solid up to 280 °C owing to its high viscosity. The glass and its melt exhibited proton conduction with a proton transport number of ∼1. Although covalent O−H bonds were weakened by relatively strong hydrogen bonding, the proton conductivity (4×10−4 S cm−1 at 276 °C) was considerably lower than that of phosphoric acid. The high viscosity of the melt was due to the tight cross-linking of phosphate ion chains by six-fold-coordinated Si atoms. The low proton conductivity was attributed to the trapping of positively charged proton carriers around anionic SiO6 units (expressed as (SiO6/2)2−) to compensate for the negative charges. 相似文献
17.
Le Hoang Lam Tomoko Shimamura Sachiyo Manabe Munetaka Ishiyama Hiroyuki Ukeda 《Analytical sciences》2008,24(8):1057-1060
A newly synthesized substrate, 3-hydroxybutyrylglycyl-glycyl-glycine (3HB-GGG), was applied to the assay of ACE-inhibiting activity to overcome the smaller selectivity and sensitivity of the conventional method. In this study, an ACE-inhibiting assay was improved by the use of a water-soluble tetrazolium salt, 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate sodium salt (WST-1), for the detection of 3-hydroxybutyrate, derived from 3HB-GGG. The optimized conditions were as follows: 0.333 mM NAD(+), 0.333 mM WST-1, 0.1 mM EDTA, 0.633 U ml(-1) diaphorase, and 0.700 U ml(-1) 3-hydroxybutyrate dehydrogenase. The developed assay was efficiently applicable to evaluate the ACE-inhibiting activity of practical ACE inhibitors. 相似文献
18.
T. Nagaishi S. Ishiyama J. Yoshimura M. Matsumoto S. Yoshinaga 《Journal of Thermal Analysis and Calorimetry》1982,23(1-2):201-207
The reaction between ammonium sulphate with aluminium oxide was studied. It was confirmed by X-ray diffraction and chemical analysis that three intermediate reaction products, (NH4)3Al(SO4)3, NH4Al(SO4)2 and Al2(SO4)3, are formed. The thermal decompositions of these three compounds were carried out. It has been shown that the same rate law is valid for them. The activation energies for (NH4)3Al(SO4)3, NH4Al(SO4)2 and Al2(SO4)3 are 95.9, 177.9 and 291.0 kj/mol, respectively.
The authors are grateful to Dr. H. Osada and Mr. H. Nakamura, Department of Environmental Engineering, Kyushu Institute of Technology, for their helpful discussions. 相似文献
Zusammenfassung Die Reaktion von Ammoniumsulfat mit Aluminiumoxid wurde untersucht. Durch Röntgendiffraktion und chemische Analyse wurde bestätigt, daß drei Zwischenprodukte (NH4)3Al(SO4)3, NH4Al(SO4)2 und Al2(SO4)3 gebildet werden. Die thermische Zersetzung der drei Verbindungen wurde durchgeführt. Es wurde gezeigt, daß für alle drei dasselbe Geschwindigkeitsgesetz Gültigkeit hat. Die Aktivierungsenergien für (NH4)3Al(SO4)3, NH4Al(SO4)2 und Al2(SO4)3 sind 95.9, 177.9 und 291.0 kJ/Mol.
. - : (NH4)3Al(SO4)3, NH4Al(SO4)2 Al2(SO4)3. , , . (NH4)3Al(SO4)3, NH4Al(SO4)2 Al2(SO4)3, , 95.9; 177.9 291.0 . –1.
The authors are grateful to Dr. H. Osada and Mr. H. Nakamura, Department of Environmental Engineering, Kyushu Institute of Technology, for their helpful discussions. 相似文献
19.
A highly water soluble disulfonated tetrazolium salt, 4-[3-(2-methoxy-4-nitrophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate sodium salt, was synthesized. The compound is reduced by NADH in good yields at neutral pHs in the presence of 1-methoxy PMS to produce the corresponding formazan dye that absorbs at 460 nm. The formazan is soluble to water at concentrations higher than 0.1 M. The tetrazolium salt thus proved to be useful as a sensitive chromogenic indicator for NADH. It is also applicable to cell proliferation assays as a cell viability indicator. 相似文献
20.
Takeshi Shimizu Junichi KusakaHaruaki Ishiyama Tadashi Nakata 《Tetrahedron letters》2003,44(27):4965-4968
The 6,6-spiroacetal segment of spirofungin A, an antifungal antibiotic isolated from Streptomyces violaceusniger Tü 4113, was efficiently prepared via the coupling reaction of the Weinreb amide and the alkyne which are readily available from the common intermediate. The synthesis includes the unsymmetrization through a stereoinversion at the C11 position and the transacetalization as the key steps. 相似文献