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21.
It has been confirmed, from observations with an electron microscope after staining negatively with aqueous uranyl acetate
solutions and using a flourescent microscope, that sucrose fatty acid esters form closed vesicles. The range of particle size
of the vesicle, consisting of chromatographically fractionated sucrose dilaurate, was apparently 70–700 nm in the longer diameter
of individual vesicles based on the transmission electron microscopic (TEM) observation. The weight-average particle size
was 424 nm as shown by means of the photon-correlation method. The amounts of 6-carboxyfluorescein trapped in the vesicles
of sucrose fatty acid esters were determined, and it was ascertained that the volumes of the central water phase depended
upon the acyl chain lengths of fatty acid residues. Further, the effect of the additives [cholesterol and dicetyl phosphate
(DCP) was examined. As an example, the vesicle of sucrose stearate had a central water phase of 1.7 one water/mol ester, and
showed a slow release of 6-carboxyfluorescein from the central water phase after preparation of the vesicle. 相似文献
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X Wang AA Thant K Machida Y Hiraiwa H Iwata S Matsuda M Hamaguchi 《Canadian Metallurgical Quarterly》1998,12(5):1097-1101
We found that ectopic expression of N-cadherin in 3Y1 caused tight association of cells and, thereby, substantially suppressed cell growth. N-cadherin expression inhibited neither tyrosine phosphorylation of cellular proteins, GTP uptake onto Ras, nor activation of MAP kinase, suggesting that it does not directly interfere the Ras-MAP kinase pathway. However, co-expression of N-cadherin with dominant negative Ras, S17N Ras, showed synergestic growth inhibitory effect, suggesting that N-cadherin signaling antagonizes the Ras-MAP kinase signaling. In addition, we found that N-cadherin yielded cell-cycle arrest at G0/G1 phase. These results strongly suggest that N-cadherin cell adhesion machinery works as a negative controller of cell cycle in 3Y1 and this growth suppressive function of cadherin is distinct from the epithelial morphogenetic function. 相似文献
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Akio Katsuki Hiromichi Onikura Takao Sajima Satoshi Machida Kazuhiro Oda 《Precision Engineering》1994,16(4):296-301
A laser-guided BTA tool has been developed to prevent axial hole deviations. Four kinds of experiments were conducted to examine the performance of this tool in detail and to determine its practical application using a duralumin (A2017-T4) workpiece with a prebored 108-mm diameter hole. The first experiment was performed to examine the conditions of the hole deviation in the case of normal deep-hole boring. The second was to examine whether the tool corrects for the stated hole deviation. The third was to examine whether the tool can go straight through to the target without shifting toward a thin wall (t = 0.7 mm) on one side of the workpiece. The fourth was to examine whether the tool can be guided toward the target without affecting a prebored hole, which was inclined to radial direction at 100 μm for a hole length of 100 mm. The experiments were performed with a rotating tool-stationary workpiece system. Rotational speed was 270 rpm and feed ws 0.125 mm/rev. Tool diameter was 110 mm. The results show that the tool can be guided to go straight through toward the target despite the disturbances. 相似文献
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There exist proper orthogonal elliptical polarisation states, which are maintained over long fibre length without converting. When one of the proper polarisation states is excited, orthogonal polarisation less than ?40 dB is confirmed after 5 km single-mode fibre transmission. It is also proposed that twisted single-mode fibres show a high degree of polarisation for any incident polarisation state. The polarisation characteristics are hardly affected by external perturbations. 相似文献
29.
A microscopic theory of superconductors containing a magnetically polarizable medium is given. By taking into account the
Zeeman effect, we derive the crossover behavior from a second- to a first-order phase transition, the magnetization curve
in the high-field region, and the magnetization jump at the first-order phase transition temperature. The theory gives a qualitative
account of the magnetic behavior, including the remarkable convex curvature of the magnetization curves, observed in the ferromagnetic
superconductor ErRh4B4 with applied external field parallel to the magnetic easy axis. 相似文献
30.
Naotsugu Itoh Takuya Machida Wei-Chun Xu Hisamichi Kimura Tsuyoshi Masumoto 《Catalysis Today》1995,25(3-4):241-247
Amorphous PdxSi1-x(x=0.8,0.825,0.85) in the form of ribbon was prepared by a single-roller melt spinning technique to examine hydrogen permeability and catalytic activity for dehydrogenation. As a result, it was found that the amorphous specimens had higher tenacity and higher permeability of hydrogen than its crystallized form. Also, the surface of the amorphous specimen showed a catalytic activity for dehydrogenation of cyclohexane, while no activity was observed in the untreated. Taking advantage of both hydrogen permeability and catalytic activity, the amorphous PdxSi1-x would be expected to be a candidate for a catalytic membrane. 相似文献