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排序方式: 共有496条查询结果,搜索用时 31 毫秒
101.
Yoshimi Uchida Tadanori Shimomura Jun Hirayama Hiroshi Nishina 《Applied magnetic resonance》2012,42(1):69-77
To guarantee that organism’s biological rhythms remain tied to the rhythms of its environment, the circadian clock must be
able to reset itself in response to environmental cues. The main environmental stimulus for organisms is light, which is provided
by day–night cycles. Cultured lines of zebrafish cells have been established as an attractive vertebrate cell-based model
suitable for the examination of the light signaling pathway for entraining the circadian clock. Studies using these cell lines
have revealed critical roles for the mitogen-activated protein kinase (MAPK) signaling pathways in light-dependent circadian
entrainment. Here, we show in cultured zebrafish cells that artificial magnetic fields induce extracellular signal-regulated
kinase (ERK)/MAPK activation with kinetics analogous to those elicited by light, suggesting that magnetic fields may influence
circadian regulation in zebrafish. Our findings indicate that cultured zebrafish cells represent a valuable system for investigating
the links between magnetic fields and the signaling pathways responsible for the synchronization of vertebrate circadian clocks
under laboratory conditions. 相似文献
102.
Two macrocyclic compounds with a rhomboid molecular shape, composed of a π-conjugated framework and an imine or amine functionality, were synthesized. The amine-containing macrocycle crystallizes with step-like interaction of each molecule, forming a columnar arrangement, although dispersion of the imine gelates upon ultrasonification. 相似文献
103.
Ide Y Torii M Tsunoji N Sadakane M Sano T 《Chemical communications (Cambridge, England)》2012,48(56):7073-7075
Hiroshima University Silicate-1 (HUS-1), composed of silicate sheets with a halved sodalite cage and the interlayer tetramethylammonium (TMA) cation in the cage, was modified with dimethyldichlorosilane to form the organic derivative in which a dimethyl group was grafted onto the interlayer surface and a part of the TMA was removed, and the silylated HUS-1 effectively and selectively adsorbed TMA from water even in the presence of aqueous phenol. 相似文献
104.
Yoshimi Sueishi Masashi Hori Naoya Inazumi 《Journal of inclusion phenomena and macrocyclic chemistry》2012,72(3-4):467-472
The structure of the inclusion complex of α-tocopherol (vitamin E compound) with 2,6-di-O-methylated β-cyclodextrin (DM-β-CD) was characterized by 2D ROESY NMR measurements, suggesting that DM-β-CD includes the side-chain moiety of α-tocopherol. The inclusion complexation of DM-β-CD showed the usefulness of water solubilizer for the radical scavenging assay of vitamin E compounds in aqueous solution. Using the electron paramagnetic resonance (EPR) competitive spin trapping method, we determined the oxygen radical (RO?) scavenging abilities of seven vitamin E compounds (tocopherols and tocotrienols), which were solubilized by DM-β-CD in water. The order of the RO? radical scavenging abilities for vitamin E compounds solubilized by DM-β-CD are α- > β- ≈ γ- > δ-, which is in agreement with the oxidation potential values of antioxidants. It is noted that the RO? radical scavenging abilities of tocotrienols are comparable to those of tocopherols. Based on the results, the mechanism of the antioxidant reaction of vitamin E compounds with the RO? radical is discussed. 相似文献
105.
Haruka Egawa OoyamaAkiko Hayashi Toshiki MamuraTakashi Ide Toshihiko HinoTakuya Tanigami Katsuhira Yoshida 《Journal of photochemistry and photobiology. A, Chemistry》2012,230(1):38-46
Structural isomers of unsymmetric polycyclicphenazine-type D-π-A fluorescent dyes have been newly synthesized and characterized in both solution and polymer films. The dyes exhibited two strong absorption bands at around 328-401 nm and 516-532 nm, and an intense fluorescence band at around 595-629 nm (Φ = 0.32-0.84) in 1,4-dioxane. The dye-doped polymer films showed good ability of wavelength conversion; the films can efficiently convert ultraviolet and green-yellow lights into red light (Φ = 0.43-0.86). Moreover, the photostability of the dyes-doped PS, PMMA, and PLA films has been investigated. 相似文献
106.
Yoshimi Ohmae Natsuko I. Kobayashi Keitaro Tanoi Atsushi Hirose Takayuki Saito Akihiko Noda Naoko Iwata Akimasa Nakano Satoru Nakamura Tomoko M. Nakanishi 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(1):241-244
The mineral composition of frozen food of taro [Colocasia esculenta (L.) Schott] was analyzed to categorize the geographical production place of taro. The concentrations of Co and H2PO4
− were found to be useful to separate the producing place between Japan and China. The analysis was performed by instrumental
neutron activation analysis (INAA) and ion chromatography (IC). In the case of INAA, the samples were dried and sealed in
a vinyl bag and irradiated with thermal neutrons from JRR3M, installed at Japan Atomic Energy Agency (JAEA). The activated
samples were cooled down for a few weeks and the elements (Co, Cr, Fe, Rb, Zn) were determined. Cobalt concentration of frozen
taro from China was higher than that from Japan. The tendency was the same in the fresh sample of taro. When concentration
of H2PO4
− of frozen sample was measured, taro from Japanese product was higher than that of Chinese one, contrary to fresh sample.
This result might be caused by the leakage of H2PO4
− during freezing process, indicating that we should be careful to apply the discrimination indicators. In addition to Co,
there was a significant difference of Rb and Fe concentrations between frozen taro from Japan and China. 相似文献
107.
Asahi K. Ogawa H. Ueno H. Kobayashi Y. Sato W. Yoshimi A. Watanabe H. Kameda D. Miyoshi H. Sakai K. Imai N. Yoneda K. Watanabe Y. X. Fukuda N. Aoi N. Yoshida A. Kubo T. Ishihara M. 《Hyperfine Interactions》2001,136(3-8):183-187
Magnetic dipole and electric quadrupole moments of nuclei in the light-mass neutron-rich region have been studied by taking
advantage of spin-polarized radioactive nuclear beams that have been obtained from the projectile fragmentation reaction.
Analyses of the results reveal a few interesting phenomena characteristic of nuclear structures in this region. In particular,
we report in some detail the latest result on the magnetic moment of the 17C ground state. The distinctly small value of the g-factor obtained, |g(17C)|=0.5054±0.0025, clearly excludes a I
π=1/2+ candidate for the spin-parity assignment of this marginally bound nucleus, providing a reasonable account of the non-halo
nature reported in recent breakup reaction experiments. Finally, future plans at the upcoming radioactive beam facility presently
under construction at RIKEN are briefly mentioned.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
108.
T. Watanabe T. Sameshima M. Ide 《Applied Physics A: Materials Science & Processing》2001,73(4):429-432
The fabrication of three-dimensional layered structures with 180-nm-thick TaOx top layers supported by 1.5-μm-thick Mo pillars formed on a glass substrate is presented. The photoresist used for planarization
was successfully removed through the TaOx layers using heat treatment at 270 °C with mixed vapors of ethyl alcohol and pure water at high pressure for 3 h. Vacancies
underlying the TaOx layers were consequently formed. The possibility of rapid and lateral crystallization of amorphous silicon films was demonstrated
when the silicon films formed on the TaOx overlaying the vacancy regions were irradiated using a frequency-doubled YAG laser at 250 mJ/cm2. Energy sensors using Cr/Al metal wires, with a high sensitivity of 0.07 mW/cm2, were also demonstrated using the present structure with vacancy regions for reduction of heat diffusion.
Received: 22 January 2001 / Accepted: 24 January 2001 / Published online: 27 June 2001 相似文献
109.
Gigantic colloidal single crystals (2–6 mm) are formed for fluorine-containing polymer spheres (120–210 nm in diameter) in
exhaustively deionized aqueous suspensions. The spheres used are poly(tetrafluoroethylene) (PTFEA and PTFEB), copolymer of
tetrafluoroethylene and perfluorovinylether (PFA) and copolymer of tetrafluoroethylene and perfluoropropylene (PTP). The phase
diagrams of these spheres are obtained in the deionized suspensions and also in the presence of sodium chloride for PFA. The
critical sphere concentrations of crystal melting (φ
c) for these spheres are around 0.0006 in volume fraction, which are close to, but slightly larger than, those of monodispersed
polystyrene spheres (φ
c ≈ 0.00015) and colloidal silica spheres(φ
c = 0.0002–0.0004) reported previously. The crystals are largest when the sphere concentrations are a bit higher than the φ
c value and their size decreases as the sphere concentration increases. Reflection spectra are taken in sedimentation equilibrium
as a function of the height from the bottom of the suspension. The static elastic modulus is estimated to be 10.8 and 28.7 Pa
for PTFEA and PTP spheres at the sphere concentrations 0.00325 and 0.00322 in volume fraction, respectively.
Received: 27 October 1999 Accepted in revised form: 16 November 1999 相似文献
110.
A. Tsuchida K. Taguchi E. Takyo H. Yoshimi S. Kiriyama T. Okubo M. Ishikawa 《Colloid and polymer science》2000,278(9):872-877
Rate coefficients (k) in the colloidal crystallization of monodispersed silica spheres in the presence of sodium chloride are studied in microgravity
achieved by parabolic flights of an aircraft. Time-resolved reflection spectroscopy is made with a continuous circulating-type
stopped-flow cell system. The k values decrease as the salt concentration increases both at 0 and 1 G and those in microgravity are smaller than those in
normal gravity by 16% (maximum), especially in water and in the presence of a small amount of the salt lower than 2 × 10−6 mol/l. The rates in flight at 1 G are larger by 15% (maximum) compared with those at 1 G on the ground. The k values obtained at 0 G, 1 G in flight and 1 G on the ground agree excellently with each other for the suspensions with 3 × 10−6 and 4 × 10−6 mol/l sodium chloride. Disappearance of the downward diffusion of spheres and no convection of the suspensions are important
for retardation in microgravity.
Received: 20 January 2000 Accepted: 9 March 2000 相似文献