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51.
Pain is an essential modality of sensation in the body. Purinergic signaling plays an important role in nociceptive pain transmission, under both physiological and pathophysiological conditions, and is important for communication between both neuronal and non-neuronal cells. Microglia and astrocytes express a variety of purinergic effectors, and a variety of receptors play critical roles in the pathogenesis of neuropathic pain. In this review, we discuss our current knowledge of purinergic signaling and of the compounds that modulate purinergic transmission, with the aim of highlighting the importance of purinergic pathways as targets for the treatment of persistent pain. 相似文献
52.
Kazuhide Tani Aika Iseki Tsuneaki Yamagata 《Angewandte Chemie (International ed. in English)》1998,37(24):3381-3383
A new piece in the puzzle. Hydrido(alkoxo) complexes of late transition metals have often been postulated as intermediates or transition states in the catalytic hydrogenation of carbonyl compounds and catalytic hydrogen transfer reactions. Here the facile oxidative addition of the O−H bonds of alcohol and water to iridium(I ) complexes of peraryldiphosphanes [Eq. (a)] is reported and the resulting complexes are described. R=H, Me. 相似文献
53.
54.
H. Haba T. Akiyama D. Kaji H. Kikunaga T. Kuribayashi K. Morimoto K. Morita K. Ooe N. Sato A. Shinohara T. Takabe Y. Tashiro A. Toyoshima A. Yoneda T. Yoshimura 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):81-86
A review is given on the startup of the superheavy element (SHE) chemistry
at RIKEN. A gas-jet transport system for the SHE chemistry has been coupled
to the gas-filled recoil ion separator GARIS at the RIKEN Linear
Accelerator. The performance of the system was appraised using 206Fr
and 245Fm produced in the 169Tm (40Ar, 3n) 206Fr and
208Pb (40Ar, 3n) 245Fm reactions, respectively. The α
particles of 206Fr and 245Fm separated with GARIS and transported
by the gas-jet were identified with a rotating wheel system for α
spectrometry under desired low background condition. The high gas-jet
efficiencies over 80% were independent of the beam intensities up to 2
particle μA. A gas-jet coupled target system for the production of SHEs
was also installed on the beam line of the RIKEN K70 AVF cyclotron. The
gas-jet transport of 255No and 261Rf produced in the
238U (22Ne, 5n) 255No and 248Cm (18O, 5n) 261Rf
reactions, respectively, was conducted for the future chemical studies of
265Sg via the 248Cm (22Ne, 5n) 265Sg reaction. 相似文献
55.
We describe the dopant dependence of Raman gain in germanium- and fluorine-doped optical fibers. We clarify, both theoretically and experimentally, the effective Raman gain characteristic in an optical fiber, which is closely related to the fiber's refractive-index profile and electromagnetic field profile. We also show that this experimentally determined relationship can be used to evaluate the effective Raman gain characteristic in a germaninum- or a fluorine-doped optical fiber with an arbitrary index profile. 相似文献
56.
Kazuhide Ichikawa Yuji Ikeda Ayumu Wagatsuma Kouhei Watanabe Paweł Szarek Akitomo Tachibana 《International journal of quantum chemistry》2011,111(14):3548-3555
We report on the structures of aluminum hydrides derived from a tetrahedral aluminum (Al4) cluster using ab initio quantum chemical calculation. Our calculation of binding energies of the aluminum hydrides reveals that stability of these hydrides increases as more hydrogen atoms are adsorbed, while stability of Al – H bonds decreases. We also analyze and discuss the chemical bonds of those clusters by using recently developed method based on the electronic stress tensor. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
57.
Tatsuki Morimoto Junji Tanabe Kazuhiko Sakamoto Kazuhide Koike Osamu Ishitani 《Research on Chemical Intermediates》2013,39(1):437-447
Rhenium(I) biscarbonyl complexes with two phosphine ligands photocatalyzed not only CO2 reduction under CO2 atmosphere but also H2 evolution under Ar. The reductant 1-benzyl-1,4-dihydronicotinamide (BNAH) worked only as a one-electron donor, and it was quantitatively converted to its corresponding oxidized dimer (BNA2). The photocatalytic reactions required addition of a base such as triethanolamine, because deprotonation from the oxidized BNAH (BNAH?+) is essential for the suppression of the back electron transfer from the reduced rhenium(I) complex to BNAH?+. 1H, 13C, and 31P NMR studies under vacuum or 13CO2 atmosphere indicated that the rhenium(I) complex is relatively stable under the CO2 reduction conditions, but it is converted to some other complexes under the H2 evolution conditions. 相似文献
58.
Ueno K Inaba A Ueki T Kondoh M Watanabe M 《Langmuir : the ACS journal of surfaces and colloids》2010,26(23):18031-18038
A novel soft material comprising thermosensitive poly(benzyl methacrylate)-grafted silica nanoparticles (PBnMA-g-NPs) and the ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl)amide ([C(2)mim][NTf(2)]), was fabricated. The thermosensitive properties were studied over a wide range of particle concentrations and temperatures. PBnMA-g-NPs in the IL underwent the lower critical solution temperature (LCST) phase transition at lower temperatures with a broader transition temperature range as compared to the free PBnMA solution. Highly concentrated suspensions formed soft glassy colloidal arrays (SGCAs) exhibiting a soft-solid behavior and angle-independent structural color. For the first time, we report a discrete change in the angle-independent structural color of SGCAs with temperature because of a temperature-induced colloidal glass-to-gel transition. The interparticle interaction changed from repulsive to attractive at the LCST temperature, and it was characterized by a V-shaped rheological response and a direct electron microscope observation of the colloidal suspension in the IL. With unique rheological and optical properties as well as properties derived from the IL itself, the thermosensitive SGCAs may be of interest as a new material for a wide range of applications such as electrochemical devices and color displays. 相似文献
59.
Tsuge M Hamatani S Kawai A Tsuji K Shibuya K 《Physical chemistry chemical physics : PCCP》2006,8(2):256-263
The D(1)-D(0) transitions of diphenylmethyl (DPM) and chlorodiphenylmethyl (CDPM) radicals were studied by laser induced fluorescence (LIF) spectroscopy in a supersonic jet. Laser induced fluorescence excitation and dispersed fluorescence (DF) spectra were obtained for DPM and CDPM radicals produced by ArF excimer laser (193 nm) photolyses of their chlorides. With the aid of the density functional theory (DFT) calculation, vibronic bands are assigned by comparing the observed LIF excitation spectra of the jet-cooled radicals with the single vibronic level DF spectra. Low-frequency vibrations of 55 and 53 cm(-1) in the ground and excited states, respectively, are assigned to the symmetric phenyl torsional mode of the DPM radical. The geometries of DPM in the ground and excited states are discussed with regards to observed spectra and DFT calculations. Similarly for the CDPM radical, symmetric phenyl torsional and Ph-C-Ph bending modes are assigned and the halogen-substitution effect in equilibrium geometry is discussed. 相似文献
60.
Yoshiki Katayama Ryuji Fukuda Toshiharu Iwasaki Kazuhide Nita Makoto Takagi 《Analytica chimica acta》1988
New crown ether dyes carrying two pendent anionic side-arms were synthesized for the extraction-spectrophotometry of alkaline earth metal ions. In the extraction of alkaline earth metal ions by these dianionic reagents, size recognition by the crown ether ring was more remarkable than in the case of alkali metal ion extraction by a similar type of monoanionic reagents. Dramatic changes in metal selectivity were observed when the nature of the anionic side-arm was changed while the crown ether skeleton was kept the same. The structure/selectivity relationship is discussed in terms of “chelate” and “intramolecular ion-pair” formation. Typically, when the basicity of the pendent anions was relatively high and a six-membered chelate was structurally possible for the pendent anions and the crown-bound metal, the extraction of calcium was favored by up to a factor of 3000 in the ratio of the Ca/Ba extraction constants for reagents of the diaza-18-crown-6 type. In contrast, the reagents which had pendent anions with only poor coordination ability for metal ions seemed to form complexes of the ion-pair type, and calcium ion was 105 times less extractable than barium ion for the same diaza-18-crown-6-skeleton. Strontium ion seemed to be extracted most effectively when the extracted complex assumed properties intermediate between the chelate and intramolecular ion-pair. 相似文献