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91.
Takashi Uneyama Yuichi Masubuchi Kazushi Horio Yumi Matsumiya Hiroshi Watanabe Jai A. Pathak C. Michael Roland 《Journal of Polymer Science.Polymer Physics》2009,47(11):1039-1057
For type‐A polymer chains having type‐A dipoles parallel along the chain backbone (such as cis‐polyisoprene), a theoretical analysis was conducted for the rheodielectric response to relate this response to the chain dynamics. The rheodielectric response in the shear gradient direction (y direction) under steady shear was analyzed on the basis of a Langevin equation. It turned out that the relaxation time is exactly the same for the rheodielectric relaxation function and the end‐to‐end vector autocorrelation function defined in the shear gradient direction and that the relaxation mode distribution also coincides for these functions at least up to second order of the shear rate (corresponding to the lowest order of nonlinearities of these functions). Consequently, the Green‐Kubo theorem holds satisfactorily, and the rheodielectric intensity is proportional to the squared chain size in y direction, 〈R〉, averaged over the time‐independent conformational distribution function under steady shear. The situation is more complicated under large amplitude oscillatory strain (LAOS) because the conformational distribution function fLAOS is synchronized with LAOS to oscillate at the LAOS frequency, Ω. The rheodielectric response under LAOS was found to detect this oscillation of fLAOS being coupled with the oscillation of the electric field, E(t) = E0sin ωt, and thus, split into a series of components oscillating at frequencies ω and ω ± βΩ (β = 1, 2, …). Consequently, the rheodielectric intensity under LAOS, evaluated from the component oscillating at ω, is no longer proportional to 〈R〉. However, the relative mode distribution and relaxation time of this component can be directly related to those of the end‐to‐end vector correlation averaged over a nonoscillatory part of fLAOS. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1039–1057, 2009 相似文献
92.
Yoko Shiraishi-Yamaguchi Yumi Sato Rieko Sakai Akihiro Mizutani Thomas Kn?pfel Nozomu Mori Katsuhiko Mikoshiba Teiichi Furuichi 《BMC neuroscience》2009,10(1):25
Background
Homer is a postsynaptic scaffold protein that links various synaptic signaling proteins, including the type I metabotropic glutamate receptor subunits 1α and 5, the inositol 1,4,5-trisphosphate receptor, Shank and Cdc42 small GTPase. Overexpression of Homer induces changes in dendritic spine morphology in cultured hippocampal neurons. However, the molecular basis underpinning Homer-mediated spine morphogenesis remains unclear. In this study, we aimed to elucidate the structural and functional properties of the interaction between Cupidin/Homer2 and two actin-cytoskeletal regulators, Cdc42 small GTPase and Drebrin. 相似文献93.
Akira Hirao Mayumi Hayashi Yumi Negishi Naoki Haraguchi Surapich Loykulnant 《Macromolecular Symposia》2002,181(1):73-94
Novel well-defined chain-end- and in-chain-functionalized polystyrenes with six, eight, twelve, and sixteen benzyl chloride moieties and with four and eight D-glucose residues have been successfully synthesized by developing the methodology based on living anionic polymerization of using new functionalized agents derived from functionalized 1,1-diphenylethylene (DPE) derivatives. They are 1,10-dichloro-4,4-7,7-tetra(3-methoxymethylphenyl)decane, its iodide derivative, the dianion prepared from 1,1-bis(3-methoxymethylphenyl)ethylene and potassium naphthalenide, and 1,1-bis[3′,5′-bis(1,2:5,6-di-O-isopropylidene-α-D-glucofuranose-3-oxymethyl)phenyl]ethylene. The developed methodology involves diverse modes of reactions of polystyryllithium with new functionalized agents and either the subsequent transformation reaction with BCl3 into benzyl chloride moieties or acid-hydrolysis to regenerate D-glucose residues. The resulting chain-multi-functionalized polystyrenes were precisely controlled with respect to chain length and quantitatively functionalized within experimental errors. 相似文献
94.
K. Ichinose K. Fujiwara M. Nakamura M. Oyasato A. Tsujimura 《Journal of magnetism and magnetic materials》1987,70(1-3):154-156
Nuclear magnetic resonances of 59Co nuclei in (Mg1−xRx)Co2 (R = Y, Gd) compounds at 4.2 K have been observed for 0x1. By replacing Mg with R, the 59Co hyperfine field decreases or is nearly constant in the C14 range and increases in the C15 range. These results are explained by the difference of the contribution from R atoms. 相似文献
95.
Yuri Goto Yumi Shima Satoshi Morimoto Yukihiro Shoyama Hiroki Murakami Akihiko Kusai Kazutetsu Nojima 《Journal of mass spectrometry : JMS》1994,29(11):668-671
In order to form the monoclonal antibody against tetrahydrocannabinolic acid (THCA), THCA was coupled with bovine serum albumin (BSA) or human serum albumin (HSA) using β-alanine as a linker or without β-alanine to produce individual antigen conjugates. The number of haptens contained in the antigen conjugates was determined by matrix-assisted laser desorption ionization mass spectrometry using BSA or HSA as an internal standard. The formation of monoclonal antibody is also discussed. 相似文献
96.
The construction of a new post-column photochemical reactor with quartz flow cells in series for high-performance liquid chromatography (HPLC) is described. The performance of the new reactor was compared with a conventional open tubular PTFE coil reactor. The sensitivity, accuracy and precision obtained with both reactors are comparable. The new reactor has the obvious advantages of smaller cell volume as well as inertness and resistance to not only light and heat produced by the UV lamp, but also to organic solvents in the mobile phases, which results in greatly improved durability, reduced peak broadening and shorter chromatographic run times. Application of the new reactor to the fluorescence detection of DU-6859a, a new fluoroquinolone antimicrobial agent, in human serum is reported. 相似文献
97.
Kaneko T Hamada K Kuboshima Y Akashi M 《Langmuir : the ACS journal of surfaces and colloids》2005,21(21):9698-9703
Crystalline polymeric nanospheres composed of poly{stearyl methacrylate (SMA)-co-poly(ethylene glycol) monomethacrylate (PEGm)}s were prepared by the dispersion radical polymerization of SMA and PEGm in an ethanol/water solution. Scanning electron microscopy showed that the nanospheres were highly spherical, and had a narrow size distribution. Electron spectroscopy for chemical analysis and X-ray diffraction studies of the nanospheres suggested a core-corona-type structure; the hydrophilic PEGm corona accumulated on the nanosphere surface, while the hydrophobic SMA core formed a layered structure. Heat treatment caused a melting of the SMA layers, but successive cooling allowed it to re-form. Accompanying this reversible order-disorder transition, the nanospheres also showed a reversible aggregation/deaggregation behavior in their water-dispersion state. 相似文献
98.
H. Shinohara M. Iwasaki S. Tsujimura K. Watanabe S. Okazaki 《Journal of polymer science. Part A, Polymer chemistry》1972,10(7):2129-2137
It has been demonstrated that the poly(vinyl fluoride) film can be fluorinated by exposing the polymer to an environment of fluorine under atmospheric pressure and at ambient temperature. Fluorine content, infrared spectra, thermal properties, and solubilities in the polar solvents were investigated for the fluorinated products and the following results were obtained. In the case of films less than 10 μ in thickness, the fluorination appeared to proceed homogeneously. Under any fluorinating conditions applied, i.e., fluorine pressure of up to 800 mm Hg and temperatures of up to 90°C, the fluorine content never exceeded 65% which corresponds to a composition of C2F2.5H1.5. The activation energy of the reaction was calculated to be 6.8 kcal/mole. The polymer reacted with a small amount of oxygen contained in the fluorine to form acyl fluoride groups. The fluorinated films became insoluble in boiling N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide, but colored gradually to a dark brown. The occurrence of some crosslinking in the products was revealed. 相似文献
99.
The triethylborane-induced solid-phase radical reaction was studied. The solid-phase radical reaction of oxime ether anchored to Wang resin proceeded smoothly to give the α-amino acid derivatives. The carbon-carbon bond-forming radical reaction of TentaGel OH resin-bound glyoxylic oxime ether proceeded even in aqueous media. 相似文献
100.
Treatment of magnesium alkylidene carbenoids, which were generated from 1-chlorovinyl p-tolyl sulfoxides with isopropylmagnesium chloride at −78 °C in toluene, with N-lithio arylamines gave ortho-alkenylated arylamines in moderate to good yields. The reaction was found to proceed in a highly stereospecific manner at the carbenoid carbon. This reaction offers a quite novel and direct alkenylation of arylamines at the ortho-position of the aromatic ring. 相似文献