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121.
Radiation-induced polymerization of acrylonitrile-urea canal complexes formed in frozen ethylene glycol or tert-butyl alcohol media was investigated. Formation of canal complexes in the frozen state was prolonged. The initial rate of polymerization was enhanced in the frozen state. The degree of polymerization of polymers obtained is found to show no depression at high conversions and is higher in the frozen state, suggesting stabilization of canal complexes by the frozen medium. 相似文献
122.
Atsuhiro Nabei Takayoshi Kuroda-Sowa Toshiyuki Shimizu Takashi Okubo Masahiko Maekawa Megumu Munakata 《Polyhedron》2009,28(9-10):1734-1739
The preparation and magnetic properties of three Fe(II)–bis-Schiff base complexes, [Fe2(L1)2(4,4′-bpy)] · MeOH (1), [Fe(L2)(EtOH)] (2) and [Fe(L3)(MeOH)] (3) (L1 = N,N′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine; L2 = N,N′-bis(salicylidene)-1,2-phenylenediamine; L3 = N,N′-bis(5-Cl-salicylidene)-1,2-phenylenediamine; 4,4′-bpy = 4,4′-bipyridine) are reported. X-ray single crystal structure analyses for 1–3 reveal that 1 shows a dinuclear Fe(II)–bis-Schiff base complex bridged by 4,4′-bpy, while 2 and 3 show mononuclear structures. Molecular packing of 2 shows a uniform one-dimensional chain structure through hydrogen bonds and Fe?π interaction and that of 3 indicates significant π–π interaction to form a dimmer structure. The χT–T plots of 1–3 show all ferromagnetic interaction at low temperature. The origin of the ferromagnetic interaction observed in 2 is tentatively ascribed to the dimer formation through Fe?π interaction at low temperature. 相似文献
123.
M. Yoshida K. Ishii K. Ikeuchi I. Jarrige Y. Murakami J. Mizuki K. Tsutsui T. Tohyama S. Maekawa K. Kudo Y. Koike Y. Endoh 《Physica C: Superconductivity and its Applications》2010
We report a resonant inelastic X-ray scattering (RIXS) study of charge excitations in the two-leg ladder Sr14Cu24O41. RIXS spectra at 1–5 eV are found to be dependent on temperature. An intraband excitation of the ladder, which appears as a continuum intensity below the Mott gap, decreases in intensity with temperature. Because the intraband excitation is related to the dynamics of doped holes in the ladder, its decrease of the intraband excitation is attributed to the reduction of the mobile holes in the ladder at low temperature. 相似文献
124.
Synthetic study for two 2H‐chromenic acids, 8‐chlorocannabiorcichromenic acid and mycochromenic acid
Seiji Yamaguchi Masahiro Nedachi Mikiko Maekawa Yohei Murayama Masahiro Miyazawa Yoshiro Hirai 《Journal of heterocyclic chemistry》2006,43(1):29-41
Two 2H‐chromenes having a fully substituted benzene ring, 8‐chlorocannabiorcichromene ( 1 ) and mycochromenic acid ( 2 ), were synthesized by a condensation of salicylaldehydes with isopropylidenemalonate or the thermal cyclization of corresponding propargyl ethers. 相似文献
125.
Spontaneous current jump resulting in the formation of closed field equilibrium has been observed in electron-cyclotron-heated toroidal plasmas under steady external fields composed of a toroidal field and a relatively weak vertical field in the low aspect ratio torus experiment device. This bridges the gap between the open field equilibrium maintained by a pressure-driven current in the external field and the closed field equilibrium at a larger current. Experimental results and theoretical analyses suggest a current jump model that is based on the asymmetric electron confinement along the field line appearing upon simultaneous transitions of field topology and equilibrium. 相似文献
126.
Gerrit E.W. Bauer Allan H. MacDonald Sadamichi Maekawa 《Solid State Communications》2010,150(11-12):459-460
127.
Masamitsu Tanaka Manabu Kinoshita Yasuo Yoshihara Nariyoshi Shinomiya Shuhji Seki Koichi Nemoto Yuji Morimoto 《Photochemistry and photobiology》2010,86(2):403-409
Although there have been some reports about the cytotoxic effects of photodynamic therapy (PDT) on multidrug-resistant bacteria, there have been few reports in which favorable results of PDT on a local infection site are described. This study aimed to verify the hypothesis that the low efficacy of PDT on a local infection site is due to the cytotoxic effect of PDT on leukocytes. PDT using Photofrin® exerted significant cytotoxicity for cultured methicillin-resistant Staphylococcus aureus (MRSA). Nevertheless, this therapeutic modality was not effective for a murine MRSA arthritis model. Approximately 30% of intra-articular leukocytes, mainly neutrophils, died immediately after PDT, and a further decrease in the number of intra-articular leukocytes and atrophy of the synovial tissue were seen 24 h after PDT. Isolated peripheral neutrophils showed significant affinity for Photofrin® and showed significant morphological damage, resulting in cell death, when they were subject to PDT using Photofrin®. These results indicate that intra-articular neutrophils have an influence on the effects of PDT for MRSA arthritis. 相似文献
128.
John Hendri Akihiro Hiroki Yasunari Maekawa Masaru Yoshida Ryoichi Katakai 《Radiation Physics and Chemistry》2001,60(6)
Temperature- and pH-sensitive copolymer gels were synthesized by the simultaneously occurring radiation-induced polymerization and self-bridging of acryloyl-
-proline methyl ester (A-ProOMe) with acrylic acid (AAc) in aqueous solutions. The gel swelling behavior and the metal permeation characteristic of its gel membrane were investigated with regard to very slight changes of temperature and pH. The pH threshold of the swelling of a copoly(A-ProOMe/AAc, 70/30 mol%) gel in the range of 5–30°C lay in the region between pH 4.0 and 5.0. The permeability results of metal ions showed that at 40°C the gel membrane blocks the permeation of lithium (Li) and cesium (Cs) ions at pH values lower than 4.75 and 4.60, respectively. The permselectivity (PLi/Cs value) of the two metal ions at 30°C was also studied and, as a result, its value was obtained to be 1.33 at pH 4.65 and 30°C. This permeation study indicates that the selective metal separation of copoly(A-ProOMe/AAc) gel membranes can be controlled by changing temperature and pH values. 相似文献
129.
130.
Doi M Nishi Y Uchiyama S Nishiuchi Y Nakazawa T Ohkubo T Kobayashi Y 《Journal of the American Chemical Society》2003,125(33):9922-9923
Collagen model peptide (Pro-Pro-Gly)10 has a triple helical structure and undergoes a thermal transition to a single random coil structure. The transition temperature of the analogous model peptides depends largely on amino acid substitution. Substitution of Pro by 4-hydroxyproline (Hyp) or 4-fluoroproline (fPro) has especially attracted attention because the position of substitution and chirality of the hydroxyl group or fluorine atom affect the transition temperatures. Here, we demonstrated that (4(S)-fPro-Pro-Gly)10 takes a triple helical structure, but (4(R)-fPro-Pro-Gly)10 exists in a single chain structure. This is not consistent with the case of Hyp substitution in our previous report where both (4(S)-Hyp-Pro-Gly)10 and (4(R)-Hyp-Pro-Gly)10 are in a single random coil state. 相似文献