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141.
142.
Naomi Tanikawa Hidetoshi Akimoto Katsunori Ogoh Wu Chun Yoshihiro Ohmiya 《Photochemistry and photobiology》2004,80(1):31-35
To collect information on gene expression during the dark period in the luminous dinoflagellate Lingulodinium polyedrum, normalized complementary DNA (cDNA) libraries were constructed from cells collected during the first hour of night phase in a 12:12 h light‐dark cycle. A total of 4324 5′‐end sequence tags were isolated. The sequences were grouped into 2111 independent expressed sequence tags (EST) from which 433 groups were established by similarity searches of the public nonredundant protein database. Homology analysis of the total sequences indicated that the luminous dinoflagellate is more similar to land plants and animals (vertebrates and invertebrates) than to prokaryotes or algae. We also isolated three bioluminescence‐related (luciferase and two luciferinbinding proteins [LBP]) and 37 photosynthesis‐related genes. Interestingly, two kinds of LBP genes occur in multiple copies in the genome, in contrast to the single luciferase gene. These cDNA clones and EST sequence data should provide a powerful resource for future genome‐wide functional analyses for uncharacterized genes. 相似文献
143.
144.
Naomi Nishioka Koji Takagi Takatoshi Kinoshita Hideo Kunisada Yasuo Yuki 《Journal of polymer science. Part A, Polymer chemistry》2004,42(5):1208-1215
Tropone‐fused, various π‐conjugated polymers ( P2 – P5 ) were synthesized by the palladium‐catalyzed coupling reaction of 1,4‐dibromo‐6,8‐dimethyl‐7H‐benzocyclohepten‐7‐one with aromatic divinyl, diboronic acid, and diethynyl compounds. The molecular orbital calculation of the model compounds was performed to discuss effective conjugation length of the repeating unit of the polymers. The absorption spectra of phenylenevinylene‐type polymers shifted to longer wavelengths than the model compounds by about 60 nm. They exhibited green fluorescence [λmax(em) = 544 and 561 nm]. The absorption spectrum of a phenylene‐type polymer blueshifted by 10 nm; however, that of a phenyleneethynylene‐type polymer redshifted by 83 nm as compared with their model compounds. They showed fluorescence with peak maxima at 457 and 489 nm, respectively. As a result, the absorption spectra of phenylene‐ and phenylenevinylene‐type polymers blueshifted, but that of a phenyleneethynylene‐type polymer redshifted by the annulation of tropone onto a benzene ring in the conjugated polymer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1208–1215, 2004 相似文献
145.
Hisashi Hayashi Masaki Kawata Atsushi Sato Naomi Kawamura 《Journal of Physics and Chemistry of Solids》2005,66(12):2168-2172
Kβ resonant inelastic X-ray scattering (RIXS) spectra of Mn and Ga compounds are studied to examine different types of selective XANES. RIXS spectra of MnO in Mn Kβ1,3 region and of GaCl2 in Ga Kβ2 region are plotted as contour maps over wide energy ranges in both excitation and emission. Through analyses of RIXS contour maps by the use of the Kramers-Heisenberg equation, spin-selective XANES spectra are deduced for MnO. In the case of a mixed valence compound GaCl2 selective XANES of Ga3+ ion can be obtained by making use of a large difference in transition probabilities. 相似文献
146.
Simulation study on microstructure formations in magnetic fluids 总被引:3,自引:0,他引:3
We propose the Langevin-type microscopic equations of motion for magnetic fluids. Magnetic fluids are modeled as an ensemble of interacting ferromagnetic nanoparticles suspended in a viscous fluid. The present model is described in terms of position vectors of nanoparticles and orientation vectors of their magnetic dipole moments. In this model, forces and torques arising from the magnetic origin and the surrounding fluid flow are included. Effects of non-spherical particle shape are also taken into account. From the Brownian dynamics simulations of the model, it is found that the present model exhibits various microstructure formation processes in magnetic fluids. 相似文献
147.
We investigate the dynamics of phase separations in quenched binary mixtures, such as binary alloys and polymer blends with low mobilities, at higher volume fractions. Computer simulations are performed using simple model equations in the presence of encounters of droplets. Four characteristics stages with three crossovers, including dynamical scaling behavior and temporal power laws, are found beyond a volume fraction of approximately 0.14, where each crossover is attributed to a transition from one growth mechanism to the other. The encounter effect is thus shown to strongly influence a transition from the diffusion-controlled (t1/2) stage to the coarsening (t1/3) stage. A simple analytical argument for the simulation results is also presented. 相似文献
148.
149.
Susumu Ohira Hiroyuki Fujiwara Kiyomi Maeda Masaharu Habara Naomi Sakaedani Megumi Akiyama Atsuhito Kuboki 《Tetrahedron letters》2004,45(8):1639-1641
All diastereomers of pentenocin B, an inhibitor of interleukin-1β converting enzyme produced by Trichoderma hamatum FO-6903, were synthesized in chiral forms starting from l-threonine. Absolute configurations of natural pentenocin B were clarified to be 4S, 5R, and 6R. 相似文献
150.
Yukiko Enomoto Hiroshi Kamitakahara Toshiyuki Takano Fumiaki Nakatsubo 《Cellulose (London, England)》2006,13(4):437-448
Novel cellobiose and cellulose (DP
n
=ca. 30) derivatives, N-(1-pyrenebutyloyl)-4-O-(β-d-glucopyranosyl)-β-d-glucopyranosylamine (6), N-(15-(1-pyrenebutyloylamino)-pentadecanoyl)-4-O-(β-d-glucopyranosyl)-β-d-glucopyranosylamine (7), N-(1-pyrenebutyloyl)-β-cellulosylamine (13), N-(15-(1-pyrenebutyloylamino)-pentadecanoyl)-β-cellulosylamine (14) carrying a pyrene group as a single fluorescent probe at the reducing end, were prepared in order to investigate their self-assembly systems in solutions. The relative intensity of the excimer emission at ca. 480 nm due to dimerized pyrenes (intensity I
E) to the monomer emission at ca. 380 nm due to isolated pyrene (intensity I
M), i.e., I
E/I
M, was monitored in various solutions. In water/dimethyl sulfoxide (DMSO) mixed solvent (0–98%, v/v), the ratio I
E/I
M remained low (0.04) for compound 6 over the range of water concentrations, indicating that pyrenes at C-1 position of compound 6 were diffused. On the other hand, the ratio I
E/I
M increased (0.04–4.96) for compound 7 with the increase in water concentration, indicating that pyrenes at C-1 position were associated. In aqueous NaOH solutions (4.4–17.5%, w/w), compound 14 showed a large increase in the ratio I
E/I
M (0.84–8.14) with the increase in NaOH concentration, compared to compound 13 (0.06–0.41). It was found that the association of hydrophobic groups at the reducing-end of cellulose could be controlled by the hydrophilic–hydrophobic balance of compounds and the solvent polarity. 相似文献