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61.
1-Alkyl-5,6-diphenylpyra2in-2(1H)-ones (1a-b) reacted with singlet oxygen in dichloromethane to afford the stable endoperoxide (1a-b), while in methanol to afford the 1:1-adduct (3a-b) of the endoperoxide (2a-b) and methanol. 相似文献
62.
Yoshitaka Ishii Koichi Hirao Takehiko Terao Tsutomu Terauchi Makoto Oba Kozaburo Nishiyama Masatsune Kainosho 《Solid state nuclear magnetic resonance》1998,11(3-4):169-175
A solid state NMR method is presented for determination of a backbone dihedral angle φ in peptides, being based on the previously reported method, relayed anisotropy correlation (RACO) NMR [Y. Ishii et al., Chem. Phys. Lett. 256 (1996) 133]. In the present method, the
and the
dipolar tensors in the
system are two-dimensionally (2D) correlated via polarization transfer from
to
under magic angle spinning (MAS). This method was applied to N-acetyl
,
-valine, and the H–C–N–H dihedral angle was determined to be 154.0±1.4° or 206.0±1.4°, the former agreeing with the X-ray value of 154±5°. 相似文献
63.
Reizo Kato Hayao Kobayashi Takehiko Mori Akiko Kobayashi Yukiyoshi Sasaki 《Solid State Communications》1985,55(5):387-392
In the crystals of the cation radical salts based on the organic donor BMDT-TTF, the charge separation is observed. This comes from (1) nonequivalency of the site potential and (2) the long range electron-electron interaction, which are related to the two-dimensional nature of the molecular arrangement. The effects of the charge separation on the elctronic structure are discussed. 相似文献
64.
Takehiko Yagi 《Journal of Physics and Chemistry of Solids》1978,39(5):563-571
Unit-cell volumes of four alkali halides, LiF, NaF, KF and CSCl, were measured to 90 kbar and 800°C using X-ray powder diffraction techniques. NaCl was used as an internal pressure standard. Experimental results were analyzed based on Decker's equation of state for NaCl and thermal expansívities of these four materials were determined as a function of pressure. Volume dependence of thermal expansivity is different for the NaCl and CsCl structures. Comparisons of the present results with theoretical calculations by Birch and Anderson are presented. 相似文献
65.
66.
The J = 1 ← 0 and J = 2 ← 1 transitions and the l-doubling transitions of J = 2 – 6 of 12CH3F in the ν2 and ν5 states were analyzed by taking into account the Coriolis interaction between the two modes. The molecular constants which are derived are: ν5 - ν2, 252 412 ± 112; , 25 611.60 ± 0.40; Aζ5, ?38 772 ± 116; , 25 432.52 ± 0.33; D, 21 838.4 ± 8.2; , 39.58 ± 0.30 MHz; in addition to a few other minor constants. The present result is completely consistent with the recent Raman data of Escribano, Mills, and Brodersen, J. Mol. Spectrosc.61, 249 (1976). Molecular constants in the ν3 and ν6 states have also been obtained: B3, 25 197.570 ± 0.020; B6, 25 418.917 ± 0.047; Aζ6ηJ, ?0.562 ± 0.030; |q6|, 8.70 ± 0.13 MHz. Errors are 2.5 times the standard deviations. 相似文献
67.
Microwave spectrum of monodeuterated diacetylene (HCCCCD), which is nonpolar in the equilibrium configuration, was observed in various excited states of bending vibrations. Dipole moments in the ν6, 2ν6, and ν6 + ν9 vibrational states were determined from the Stark effect measurement to be 0.0907(6), 0.1681(14), and 0.0900(4) D with uncertainties in parentheses, where ν6 and ν9 denote respectively the CCH bending and lowest frequency bending vibrations. The l-type doubling constant in the ν6 state is 2.1316(28) MHz. Rotational constants were determined in MHz; ν6(Π), 4086.2165(44); 2ν6(Δ), 4087.6963(58); ν6 + ν9(Δ), 4097.7537(50); 2ν8(Δ), 4094.4786(103); ν6 + ν7(Δ), 4092.9074(176); ν7 + ν8(Δ), 4095.8925(354); 2ν6 + ν9(Φ), 4098.9505(339). 相似文献
68.
Demonstration of a PDMS-based bio-microactuator using cultured cardiomyocytes to drive polymer micropillars 总被引:1,自引:0,他引:1
Tanaka Y Morishima K Shimizu T Kikuchi A Yamato M Okano T Kitamori T 《Lab on a chip》2006,6(2):230-235
Natural cellular functions are increasingly exploited for integrated chemical systems such as biochemical reactors and biosensors. We propose to utilize the intrinsic mechanical function of cardiomyocytes, converting chemical energy into mechanical energy. In this report, we demonstrate the working principle of our proposed poly(dimethylsiloxane) (PDMS) based cardiomyocyte bio-microactuator using fabricated PDMS micropillars driven to repetitive motion by attached pulsating cardiomyocytes. Sheets of PDMS embedded with an array of micropillars were fabricated and modified for cardiomyocyte attachment in culture. Primary neonatal rat cardiomyocytes were cultured on the array, attaching to the micropillars and substratum successfully, and exhibiting their typical spontaneous, pulsatile phenotype. Micropillars beat with the coupled cells spontaneously without any triggers. The beat frequency was 1.4 Hz at 37 degrees C and the displacement of the top of the pillar that beat most strongly in our observation was 2.8+/-0.2 microm. From this result, contractile forces of cultured cardiomyocytes were estimated to exceed 3.5 microN. The estimated force is far greater than that of a previously described hydrogel-based cardiomyocyte bio-microactuator (K. Morishima et al., in Micro Total Analysis Systems 2003, ed. M. A. Northrup et al., The Transducers Research Foundation, San Diego, CA, vol. 2, pp. 1125-1128). PDMS compatibility as a base material for bio-microactuator design using cultured cardiomyocytes was verified. This PDMS-based cell microactuator worked for about one week without exchange of the culture medium, and this system could be developed for various purposes in the future as self-actuated and efficient mechanochemical transducers without external energy source requirements. 相似文献
69.
70.
[reaction: see text] A series of modified gamma-cyclodextrins (CDs) with a flexible or rigid cap, synthesized and used as chiral supramolecular hosts for mediating the enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylic acid, significantly improved the chemical and optical yields of chiral head-to-head cyclodimer 3, while the gamma-CD with a rigid cap dramatically inverted the stereochemical outcomes and further improved the enantioselectivities of both head-to-tail and head-to-head dimers 2 and 3. 相似文献