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101.
A predual of B_σ-spaces is investigated. A predual of a predual of B_σ-spaces is also investigated,which can be used to investigate the boundedness property of the commutators. The relation between Herz spaces and local Morrey spaces is discussed. As an application of the duality results, one obtains the boundedness of the singular integral operators, the Hardy-Littlewood maximal operators and the fractional integral operators, as well as the commutators generated by the bounded mean oscillation(BMO) and the singular integral operators.What is new in this paper is that we do not have to depend on the specific structure of the operators. The results on the boundedness of operators are formulated in terms of B_σ-spaces and B_σ-spaces together with the detailed comparison of the ones in Herz spaces and local Morrey spaces. Another application is the nonsmooth atomic decomposition adapted to B_σ-spaces. 相似文献
102.
Fumihiko Maekawa Okiru Komine Katsushige Sato Tomoyuki Kanamatsu Motoaki Uchimura Kohichi Tanaka Hiroko Ohki-Hamazaki 《BMC neuroscience》2006,7(1):1-13
Background
Results of the Women's Health Initiative Memory Study (WHIMS) raised concerns regarding the timing and formulation of hormone interventions. Conjugated equine estrogens (CEE), used as the estrogen therapy in the WHIMS trial, is a complex formulation containing multiple estrogens, including several not secreted by human ovaries, as well as other biologically active steroids. Although the full spectrum of estrogenic components present in CEE has not yet been resolved, 10 estrogens have been identified. In the present study, we sought to determine which estrogenic components, at concentrations commensurate with their plasma levels achieved following a single oral dose of 0.625 mg CEE (the dose used in the WHIMS trial) in women, are neuroprotective and whether combinations of those neuroprotective estrogens provide added benefit. Further, we sought, through computer-aided modeling analyses, to investigate the potential correlation of the molecular mechanisms that conferred estrogen neuroprotection with estrogen interactions with the estrogen receptor (ER).Results
Cultured basal forebrain neurons were exposed to either β-amyloid25–35 or excitotoxic glutamate with or without pretreatment with estrogens followed by neuroprotection analyses. Three indicators of neuroprotection that rely on different aspects of neuronal damage and viability, LDH release, intracellular ATP level and MTT formazan formation, were used to assess neuroprotective efficacy. Results of these analyses indicate that the estrogens, 17α-estradiol, 17β-estradiol, equilin, 17α-dihydroequilin, equilinen, 17α-dihydroequilenin, 17β-dihydroequilenin, and Δ8,9-dehydroestrone were each significantly neuroprotective in reducing neuronal plasma membrane damage induced by glutamate excitotoxicity. Of these estrogens, 17β-estradiol and Δ8,9-dehydroestrone were effective in protecting neurons against β-amyloid25–35-induced intracellular ATP decline. Coadministration of two out of three neuroprotective estrogens, 17β-estradiol, equilin and Δ8,9-dehydroestrone, exerted greater neuroprotective efficacy than individual estrogens. Computer-aided analyses to determine structure/function relationships between the estrogenic structures and their neuroprotective activity revealed that the predicted intermolecular interactions of estrogen analogues with ER correlate to their overall neuroprotective efficacy.Conclusion
The present study provides the first documentation of the neuroprotective profile of individual estrogens contained within the complex formulation of CEE at concentrations commensurate with their plasma levels achieved after an oral administration of 0.625 mg CEE in women. Our analyses demonstrate that select estrogens within the complex formulation of CEE contribute to its neuroprotective efficacy. Moreover, our data predict that the magnitude of neuroprotection induced by individual estrogens at relatively low concentrations may be clinically undetectable and ineffective, whereas, a combination of select neuroprotective estrogens could provide an increased and clinically meaningful efficacy. More importantly, these data suggest a strategy for determining neurological efficacy and rational design and development of a composition of estrogen therapy to alleviate climacteric symptoms, promote neurological health, and prevent age-related neurodegeneration, such as AD, in postmenopausal women. 相似文献103.
Fumihiko Maekawa Okiru Komine Katsushige Sato Tomoyuki Kanamatsu Motoaki Uchimura Kohichi Tanaka Hiroko Ohki-Hamazaki 《BMC neuroscience》2006,7(1):75
Background
Imprinting behavior is one form of learning and memory in precocial birds. With the aim of elucidating of the neural basis for visual imprinting, we focused on visual information processing. 相似文献104.
Abstract The HCl and DCl salts of pheny1-4-pyridyldiazomethane were prepared and irradiated at 6 K to generate the carbenes. Their ESR spectra indicated presence of plural triplet carbenes with slightly-different zero-field splitting constants. Besides the triplet species, we found a quintet species whose signal intensity decreases with increasing temperature. The quintet spin state was concluded to be a ground state which was produced by an intermolecular ferromagnetic interaction of the triplet carbenes. The ferromagnetic interaction would be explained by the McConnell mechanism, judging from the crystal structure of the HCl salt of phenyl-4-pyridylketone. 相似文献
105.
Sonochemical degradation of dilute aqueous solutions of 2-, 3- and 4-chlorophenol and pentachlorophenol has been investigated under air or argon atmosphere. The degradation follows first-order kinetics in the initial state with rates in the range 4.5-6.6 microM min-1 under air and 6.0-7.2 microM min-1 under argon at a concentration of 100 microM of chlorophenols. The rate of OH radical formation from water is 19.8 microM min-1 under argon and 14.7 microM min-1 under air in the same sonolysis conditions. The sonolysis of chlorophenols is effectively inhibited, but not completely, by the addition of t-BuOH, which is known to be an efficient OH radical scavenger in aqueous sonolysis. This suggests that the main degradation of chlorophenols proceeds via reaction with OH radicals; a thermal reaction also occurs, although its contribution is small. The addition of appropriate amounts of Fe(II) ions accelerates the degradation. This is probably due to the regeneration of OH radicals from hydrogen peroxide, which would be formed from recombination of OH radicals and which may contribute a little to the degradation. The ability to inhibit bacterial multiplication of pentachlorophenol decreases with ultrasonic irradiation. 相似文献
106.
Hiroko X. Kondo Ayumi Kusaka Colin K. Kitakawa Jinta Onari Shusuke Yamanaka Haruki Nakamura Yu Takano 《Journal of computational chemistry》2019,40(23):2043-2052
Hydrogen-bond (H-bond) interaction energies in α-helices of short alanine peptides were systematically examined by precise density functional theory calculations, followed by a molecular tailoring approach. The contribution of each H-bond interaction in α-helices was estimated in detail from the entire conformation energies, and the results were compared with those in the minimal H-bond models, in which only H-bond donors and acceptors exist with the capping methyl groups. The former interaction energies were always significantly weaker than the latter energies, when the same geometries of the H-bond donors and acceptors were applied. The chemical origin of this phenomenon was investigated by analyzing the differences among the electronic structures of the local peptide backbones of the α-helices and those of the minimal H-bond models. Consequently, we found that the reduced H-bond energy originated from the depolarizations of both the H-bond donor and acceptor groups, due to the repulsive interactions with the neighboring polar peptide groups in the α-helix backbone. The classical force fields provide similar H-bond energies to those in the minimal H-bond models, which ignore the current depolarization effect, and thus they overestimate the actual H-bond energies in α-helices. © 2019 The Authors. Journal of Computational Chemistry published by Wiley Periodicals, Inc. 相似文献
107.
Takashi Fujikawa Hiroko Arai Rie Suzuki Hiroshi Shinotsuka Lszl Kvr Nobuo Ueno 《Journal of Electron Spectroscopy and Related Phenomena》2008,162(3):146-157
Recoil effects of photoelectrons excited by high-energy X-rays are studied beyond the simplest approximation where elastic scatterings of photoelectrons are completely neglected (single-site approximation). At first we have shown that the simple free atom energy shift is accurately obtained within the harmonic and the single-site approximations. Beyond the single-site approximation, this simple formula does not work, but still simple classically acceptable formula can be used to explain the recoil energy shift. Illustrative numerical calculations show that the energy shifts caused by the photoelectron diffraction amounts to 5–8 meV for graphite-like carbon and about 100 meV for LiI6 cluster at ?k=5–7 keV, and show oscillations as functions of the photoelectron energy. Furthermore we discuss the recoil effects in photoemission from extended levels by use of the tight-binding approach. Our approach naturally provides not only Debye–Waller factors but also the recoil factors. In addition to the phonon excitation, we also study the recoil effects associated with plasmon losses where intrinsic and extrinsic processes can interfere each other. Only the latter can contribute to the recoil energy shift. 相似文献
108.
P. Leproux V. Couderc A. de Angelis M. Okuno H. Kano H. Hamaguchi 《Journal of Raman spectroscopy : JRS》2011,42(10):1871-1874
We report, to the best of our knowledge, the first turn‐key and compact dual‐output sub‐nanosecond supercontinuum source applicable to ultrabroadband multiplex coherent anti‐Stokes Raman scattering microspectroscopy of biological samples. The light source design and the microspectroscopy setup are described in details. Easy multicolour imaging of Caenorhabditis elegans nematode is operated successfully and discussed. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
109.
Frontispiece: An Optically and Thermally Switchable Electronic Structure Based on an Anthracene–BODIPY Conjugate
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110.
Dr. Hironobu Hayashi Yuki Kato Dr. Akinobu Matsumoto So Shikita Dr. Naoya Aizawa Prof. Dr. Mitsuharu Suzuki Prof. Dr. Naoki Aratani Prof. Dr. Takuma Yasuda Prof. Dr. Hiroko Yamada 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(68):15565-15571
Substituted acene derivatives are regarded as promising materials for organic electronic devices such as organic light-emitting diodes (OLEDs). In particular, anthracene derivatives are known to exhibit good fluorescence property, with the air stability and solubility in common organic solvents expected to give advantages for solution-processed device fabrication. In this study, a series of bistriisopropylsilyl(TIPS)ethynyl anthracene derivatives with azaacene-containing iptycene wings have been synthesized by using condensation reactions. Effects of size of azaacenes on optical properties and packing structures were investigated. UV/Vis absorption and fluorescence spectra indicate that the π-elongation of iptycene units has small effects on the overall π-system, which is also supported by electrochemical measurements. Secondly, single-crystal X-ray analysis implies that the molecules likely have interactions with the iptycene units of adjacent molecules, while the iptycene wings and TIPSethynyl groups can prevent the central anthracene unit from undesirable non-radiative energy loss. Finally, the most emissive derivative was used as a dopant for solution-processed OLEDs, showing obvious electroluminescence with a luminance of over 920 cd m−2. 相似文献