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61.
62.
Masahiro Igarashi 《Journal of Number Theory》2012,132(4):565-578
In this paper, we prove that certain parametrized multiple series satisfy the same relation as Ohno?s relation for multiple zeta values. This result gives us a generalization of Ohno?s relation for multiple zeta values. By virtue of this generalization, we obtain a certain equivalence between the above relation among the parametrized multiple series and a subfamily of the relation. As applications of the above results, we obtain some results on multiple zeta values. 相似文献
63.
64.
Yasuhiro Igarashi Daisuke Asano Kazuo Furihata Naoya Oku Satoshi Miyanaga Hiroaki Sakurai Ikuo Saiki 《Tetrahedron letters》2012,53(6):654-656
During the course of screening natural products for the inhibitors of tumor cell invasion, pterocidin, a linear polyketide with a δ-lactone terminus, was rediscovered from a Streptomyces strain of a marine sediment-origin. A series of J-based configuration analyses and NOESY analysis, coupled with chemical derivatization and chiral anisotropy analysis, established the absolute stereochemistry of five asymmetric centers in this compound. 相似文献
65.
M. Igarashi K. KakimotoT. Hayashida Y. HanadaS. Fujita K. MoritaN. Nakamura S. HanyuY. Sutoh H. KutamiY. Iijima T. Saitoh 《Physica C: Superconductivity and its Applications》2010,470(20):1230-1233
We have studied a hot-wall heating system to produce GdBa2Cu3Oy (GdBCO) films with large critical currents (Ic) at a high production rate by a pulsed-laser-deposition (PLD) method. GdBCO films fabricated at a production rate of 30 m/h under the optimized conditions, especially a distance of 95 mm between the target and the substrate (T–S), exhibited high critical current densities (Jc) of about 3 MA/cm2 and Ic over 300 A at a thickness of 1–2 μm. Furthermore, long GdBCO tapes prepared by repeated depositions at each tape-passing speed of 80 m/h showed uniform Ic distribution along the longitudinal direction, because the hot-wall system enabled to stabilize temperature within a few degrees at 800 °C. A 170 m long tape with Ic over 600 A was successfully fabricated at a production rate of 16 m/h using a laser power of 360 W. 相似文献
66.
Masanobu Yamamoto Ryoko Maruyama Yoko Murakami Yuki Sakamoto Rei Yamakawa Tetsu Ando 《Analytical and bioanalytical chemistry》2013,405(23):7405-7414
trans-11,12-Epoxy-(6Z,9Z)-6,9-henicosadiene (posticlure) has been identified from a pheromone gland of the lymantriid species, Orgyia postica. Since the diversity of Lepidoptera suggests that some species utilize the structure-related epoxy compound as a sex pheromone component, epoxydienes and epoxytrienes derived from (6Z,9Z,11E)-6,9,11-trienes and (3Z,6Z,9Z,11E)-3,6,9,11-tetraenes with a C19–C21 chain were systematically synthesized and the chemical data were accumulated in order to contribute to a new pheromone research. Peracid oxidation of each triene and each tetraene produced, respectively, a mixture of three epoxydienes (cis-6,7-epoxy-9,11-diene; cis-9,10-epoxy-6,11-diene; and trans-11,12-epoxy-6,9-diene) and four epoxytrienes (cis-3,4-epoxy-6,9,11-triene; cis-6,7-epoxy-3,9,11-triene; cis-9,10-epoxy-3,6,11-triene; and trans-11,12-epoxy-3,6,9-triene). While the 9,10-epoxy compounds were unstable and, interestingly, converted into 9-ketone derivatives after chromatography over SiO2, each positional isomer was isolated by HPLC equipped with an ODS column, and the chemical structure was determined by NMR analysis. On the GC-MS analysis with a DB-23 column, the positional isomers were also eluted separately and characteristic mass spectra were proposed. By comparing the spectral data of the epoxy compounds with a different carbon chain, diagnostic fragment ions reflecting the chemical structure were determined as follows: m/z 79, 109, 113, and M-114 for the 6,7-epoxydienes; m/z 69, 97, 111, 139, and M-111 for the 9,10-epoxydienes; m/z 57, 79, 109, 136, M-151, and M-111 for the 11,12-epoxydienes; m/z 79, 91, 105, and 119 for the 3,4-epoxytrienes; m/z 79, 124, M-124, M-96, and M-69 for the 6,7-epoxytrienes; m/z 79, 95, 109, 137, and M-108 for the 9,10-epoxytrienes; and m/z 79, 134, M-149, M-109, and M-95 for the 11,12-epoxytrienes. 相似文献
67.
Yucai Lü Ning Li Xufeng Yuan Binbin Hua Jungang Wang Masaharu Ishii Yasuo Igarashi Zongjun Cui 《Applied biochemistry and biotechnology》2013,171(7):1578-1588
The effect of a non-cellulolytic bacterium W2-10 (Geobacillus sp.) on the cellulose-degrading activity of a cellulolytic bacterium CTL-6 (Clostridium thermocellum) was determined using cellulose materials (paper and straw) in peptone cellulose solution (PCS) medium under aerobic conditions. The results indicated that in the co-culture, addition of W2-10 resulted in a balanced medium pH, and may provide the required anaerobic environment for CTL-6. Overall, addition of W2-10 was beneficial to CTL-6 growth in the adverse environment of the PCS medium. In co-culture with W2-10, the CTL-6 cellulose degradation efficiency of filter paper and alkaline-treated wheat straw significantly increased up to 72.45 and 37.79 %, respectively. The CMCase activity and biomass of CTL-6 also increased from 0.23 U ml?1 and 45.1 μg ml?1 (DNA content) up to 0.47 U ml?1 and 112.2 μg ml?1, respectively. In addition, co-culture resulted in accumulation of acetate and propionate up to 4.26 and 2.76 mg ml?1. This was a respective increase of 2.58 and 4.45 times, in comparison to the monoculture with CTL-6. 相似文献
68.
Shigekazu Usuda Kenichiro Yasuda Yoko Saito-Kokubu Fumitaka Esaka Chi-Gyu Lee Masaaki Magara 《International journal of environmental analytical chemistry》2013,93(9):663-675
From a viewpoint of physical and chemical form estimation, ultra-trace analytical techniques of nuclear materials in environmental samples for safeguards have been investigated at Japan Atomic Energy Research Institute. This article deals with (1) an outline of the developed techniques for bulk and particle analyses of uranium and plutonium in the safeguards environmental samples; (2) current R&D on techniques relating to estimation of the physical and chemical form, such as SEM images and EDX spectra for fine particles of nuclear materials and fission track observation applicable to fissile materials; and (3) possible analytical methodologies, as future works, applicable to ultra-trace amounts of nuclear materials in environmental samples. 相似文献
69.
Excited state intramolecular hydrogen atom transfer of phenylethynyl-substituted 2′-hydroxychalcones
Satomi Tasaki Atsuya Momotake Yoko Kanna Tatsuo Arai 《Research on Chemical Intermediates》2013,39(1):61-72
(E)-1-[2-Hydroxy-4-(phenylethynyl)phenyl]-3-[4-(phenylethynyl)phenyl]prop-2-en-1-one (1), (E)-1-[2-hydroxy-4-(phenylethynyl)phenyl]-3-phenylprop-2-en-1-one (2), and (E)-1-(2-hydroxyphenyl)-3-[4-(phenylethynyl)phenyl]prop-2-en-1-one (3), which belong to a new class of 2′-hydroxychalcones with phenylethynyl group(s) at the para position of the phenyl ring, were synthesized, and their photochemical properties were investigated. The lowest energy absorption band of 1 peaks at a longer wavelength (383 nm) with a much larger molar extinction coefficient (5.0 × 104 M ?1 cm?1) than that of the parent 2′-hydroxychalcone (2′HC) (2.0 × 104 M ?1 cm?1 at 318 nm). Upon photoexcitation, all three compounds underwent excited-state intramolecular hydrogen atom transfer (ESIHT) to produce an excited tautomer that emitted fluorescence with a large Stokes shift in the longer wavelength region at 600–700 nm. The quantum yield of the tautomer fluorescence of 1 was not high at 298 K (Φ f = 9.1 × 10?5), but was highest among 2′HC and its analogues. The Φ f values of 1–3 increased 10–30 fold upon reducing the temperature from 298 to 77 K. 相似文献
70.
Dr. Yu Nakagawa Takashi Doi Takara Taketani Prof. K. Takegoshi Prof. Yasuhiro Igarashi Dr. Yukishige Ito 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(32):10516-10525
Pradimicins (PRMs) and benanomicins are the only family of non‐peptidic natural products with lectin‐like properties, that is, they recognize D ‐mannopyranoside (Man) in the presence of Ca2+ ions. Coupled with their unique Man binding ability, they exhibit antifungal and anti‐HIV activities through binding to Man‐containing glycans of pathogens. Notwithstanding the great potential of PRMs as the lectin mimics and therapeutic leads, their molecular basis of Man recognition has yet to be established. Their aggregate‐forming propensity has impeded conventional interaction analysis in solution, and the analytical difficulty is exacerbated by the existence of two Man binding sites in PRMs. In this work, we investigated the geometry of the primary Man binding of PRM‐A, an original member of PRMs, by the recently developed analytical strategy using the solid aggregate composed of the 1:1 complex of PRM‐A and Man. Evaluation of intermolecular distances by solid‐state NMR spectroscopy revealed that the C2–C4 region of Man is in close contact with the primary binding site of PRM‐A, while the C1 and C6 positions of Man are relatively distant. The binding geometry was further validated by co‐precipitation experiments using deoxy‐Man derivatives, leading to the proposal that PRM‐A binds not only to terminal Man residues at the non‐reducing end of glycans, but also to internal 6‐substituted Man residues. The present study provides new insights into the molecular basis of Man recognition and glycan specificity of PRM‐A. 相似文献