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61.
A wavelength-scanning heterodyne interference confocal microscope has proved to provide the tomographic image of the refractive indices of transparent and turbid media on the scale of geometrical depth when weakly reflected light with an optical power as low as of the order of 10(-14) W is used. The refractive indices of the transparent object and the turbid media were measured with accuracies of -0.5% and approximately 3%, respectively. This imaging method is advantageous for evaluating quantitative refractive indices and internal structures. 相似文献
62.
Mitsutoshi Jikei Yuuki Kobayashi Kazuya Matsumoto Makoto Hirokawa Shigeharu Ueki 《应用聚合物科学杂志》2019,136(1):46910
The surface properties and antiplatelet adhesion behavior of terminally functionalized hyperbranched poly(l -lactide)s (HB PLLAn-Glu, n = 5, 10, 20) were examined. Contact angle changes and X-ray photoelectron spectroscopic measurements indicated that the hydrated glutamic acid units in HB PLLAn-Glu films migrated to the surface during immersing in water and unique microdomains were observed from the HB PLLA10-Glu film after water immersion. HB PLLA10-Glu and HB PLLA5-Glu prevented platelet adhesion, but HB PLLA20-Glu showed the typical platelet adhesion response for a hydrophobic surface. Both the high hydrophilicity and microdomain formation of HB PLLAn-Glu contributed to the efficient antiplatelet adhesion behavior. The glutamic acid-terminated HB PLLA10-Glu films were more effective at preventing platelet adhesion than the 2-methoxyethoxy-terminated HB PLLA10 films. This study is the first example of platelet adhesion properties being controlled by the terminal functional groups and branching density of hyperbranched polymers. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46910. 相似文献
63.
A wavelength-scanning heterodyne interference confocal microscope quickly accomplishes the simultaneous measurement of the thickness and the refractive index of a sample by detection of the amplitude and the phase of the interference signal during a sample scan. However, the measurement range of the optical path difference (OPD) that is obtained from the phase changes is limited by the time response of the phase-locked loop circuit in the FM demodulator. To overcome this limitation and to improve the accuracy of the separation measurement, we propose an OPD detection using digital signal processing with a Hilbert transform. The measurement range is extended approximately five times, and the resolution of the OPD is improved to 5.5 from 9 microm without the electrical noise of the FM demodulator circuit. By applying this method for simultaneous measurement of thickness and the refractive index, we can measure samples 20-30-microm thick with refractive indices between 1 and 1.5. 相似文献
64.
Imamura K Kawasaki Y Nagayasu T Sakiyama T Nakanishi K 《Journal of Bioscience and Bioengineering》2007,103(1):7-12
The adsorption characteristics of octapeptides, containing different numbers of aspartic acid, lysine, and alanine residues (i.e., D(4)K(0)A(4), D(4)K(1)A(3), D(4)K(3)A(1), D(4)K(4)A(0), and D(0)K(4)A(4)) on the surface of titanium (Ti) particles were investigated in the pH range of 3.0-8.8 at 30 degrees C. The adsorption isotherms for octapeptides having four plural aspartic acid residues with or without lysine residues showed two distinct adsorption modes, i.e., irreversible and reversible modes, at pHs 3.0-6.5; at pH 7.0 or higher, the adsorption mode was reversible. Increasing the number of lysine residues at a fixed number of aspartic acid residues (i.e., 4) decreased the amount of peptides adsorbed in both modes. D(4)K(4)A(0) adsorbed irreversibly at pHs 3.0-6.5, due to the fact that negatively charged carboxyl groups directly interact with a positively charged Ti surface, whereas positively charged amino groups of lysine residues are directed in an opposite direction toward the solution side, as predicted by molecular mechanics/dynamics calculations. 相似文献
65.
Chemical Synthesis of the Epimeric (23R)‐ and (23S)‐Fluoro Derivatives of Bile Acids via Horner–Wadsworth–Emmons Reaction
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Kaoru Omura Yuuki Adachi Yuuki Kobayashi Shoutaro Sekiguchi Biao Zhou Takashi Iida 《Lipids》2015,50(9):919-926
A method for the synthesis of two (23R)‐ and (23S)‐epimeric pairs of 23‐fluoro‐3α,7α,12α‐trihydroxy‐5β‐cholan‐24‐oic acid and 23‐fluoro‐3α,7α‐dihydroxy‐5β‐cholan‐24‐oic acid is described. The key intermediates, 23,24‐dinor‐22‐aldehyde peracetates were prepared from cholic and chenodeoxycholic acids via the 24‐nor‐22‐ene, 24‐nor‐22ξ,23‐epoxy, and 23,24‐dinor‐22‐aldehyde derivatives. The Horner–Wadsworth–Emmons reaction of the 23,24‐dinor‐22‐aldehydes using triethyl 2‐fluoro‐2‐phosphonoacetate in the presence of LiCl and 1,8‐diazabicyclo[5,4,0]undec‐7‐ene (DBU), and subsequent hydrogenation of the resulting 23ξ‐fluoro‐22‐ene ethyl esters, followed by hydrolysis, gave a mixture of the epimeric (23R)‐ and (23S)‐fluorinated bile acids which were resolved efficiently by preparative RP‐HPLC. The stereochemical configuration of the fluorine atom at C‐23 in the newly synthesized compounds was confirmed directly by the X‐ray crystallographic data. The 1H and 13C NMR spectral differences between the (23R)‐ and (23S)‐epimers were also discussed. 相似文献
66.
Yumeng Zheng Masafumi Fujimoto Yuuki Sato Shinzo Yoshikado 《Journal of the European Ceramic Society》2021,41(9):4841-4849
The effects of Cr2O3 and/or NiO addition to Y2O3-doped Bi-based high-voltage ZnO varistors were investigated, including crystal structure and interface states analysis. Incorporating 0.35 mol% Cr2O3 in Y-doped varistors increased the single-grain varistor voltage VNNGB from 2.6 to 3.3 V and decreased the leakage current density by a factor of 40, from 2 × 10?5 to 5 × 10-7 A/cm2. The nonlinearity index α before and after degradation increased from 21 to 35. 1.2 mol% NiO increased VNNGB to 4 V. Highest varistor voltage was 1500 V for 0.3 mol% NiO. Resistance to electrical degradation improved with optimal amounts of Cr or Ni by reduction of grain boundary oxygen vacancies. Though the donor density was changed prominently by addition of Cr and/or Ni, changes in the barrier height were suppressed by the change in interface state density. As a result, the change in VNNGB was related mainly to the empty interface state under no bias. 相似文献
67.
Kazuhiko Ishihara Kyoko Fukazawa Yuuki Inoue Jun Koyama Yoshiyuki Mori Toru Kinoshita Katsumi Hiranuma Noboru Yasuda 《应用聚合物科学杂志》2018,135(30)
Plastic substrates have been widely applied in clinical settings for dental treatments. These substrates should be strong enough for long‐term implantation in the oral cavity and should be resistant to biofouling. We developed a new photoreactive phospholipid polymer to reduce biofouling on dental plastics via a photochemical reaction. Poly(methyl methacrylate) (PMMA) and poly(ether ether ketone) (PEEK) were used as dental plastics. To determine the antibiofouling properties on the polymer surface, the phospholipid polymer was covalently immobilized on the substrates by UV irradiation. We evaluated the antibiofouling properties by observing the protein adsorption and cell and bacterial adhesion. Significant protein adsorption and cell adhesion appeared on the bare PMMA and PEEK substrates but decreased dramatically after surface modification with the phospholipid polymer. Thus, this photoreactive polymer shows potential for conferring dental plastics with antibiofouling properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46512. 相似文献
68.
Hiroki Hasegawa Yasuhiro Hoshino Takeshi Kasamoto Yuuki Akaida Takaya Kowatari Yasuhiro Shiroki Hiroyuki Shibata Hiromichi Ohta Yoshio Waseda 《Metallurgical and Materials Transactions B》2012,43(6):1405-1412
The thermal conductivities of some synthetic slags containing Al2O3, CaO, and SiO2 have been determined in the temperature range between 1623?K (1350?°C) and 1823?K (1550?°C) by applying a front-heating front-detection laser-flash method. In this method, the temperature response curve is measured in the short initial time period immediately after irradiating a laser pulse. The resultant values obtained by this method are unaffected by the radiative heat transfer. The temperature dependence of the thermal conductivity values were found not to be significant for all slag samples currently investigated. The thermal conductivity (??) of samples is represented with standard deviation less than 2?pct of its value as a function of compositions as follows: $$ \lambda = - 0.48\left[ {{\text{Al}}_{ 2} {\text{O}}_{ 3} } \right] - 0.57\left[ {\text{CaO}} \right] - 0.55\left[ {{\text{SiO}}_{2} } \right] + 57.1{\text{ W m}}^{ - 1} {\text{ K}}^{ - 1} $$ where [Al2O3], [CaO], and [SiO2] are molar percent of Al2O3, CaO and SiO2, respectively. The equation is suggested to cover the region of the following compositions: 8.0?mol pct < Al2O3 <21.0?mol pct, 31.5?mol pct < CaO <41.5?mol pct and 43.0?mol pct < SiO2 <58.1?mol pct. The addition of Al2O3 to slags with a constant CaO/SiO2 molar ratio resulted in an increase in thermal conductivity. In contrast, the effects of addition of SiO2 and CaO are found to be insignificant. 相似文献
69.
Removal kinetic model of oil droplet from o/w emulsion by adding methylated milk casein in flotation
In this study, o/w emulsion flotation experiments were conducted by adding methylated milk casein (MeSC). Emulsion used in this study was prepared by ultrasonic emulsification of heavy oil (bunker-A) and sodium dodecyl sulfate (SDS) solution. A simple kinetic model was proposed to estimate the removal rate of the oil droplets within the column. The model was based on main assumption that adsorption of single droplet adsorbed MeCS or floc onto bubble surface within flotation column. Removal rate constant, K, was defined by kaXs (Sbτ/V), where ka and Xs are overall adsorption rate and saturated adsorption density of oil droplet or floc, Sb, τ and V are bubble surface production rate, retention time of bubble swarms and emulsion volume within the column, respectively. The experiments were conducted with varying operating conditions; superficial gas velocity, column dimension and emulsion volume. K was evaluated from slope value of obtained straight line by plotting time versus ln (T/T0), where T/T0 is relative turbidity. K was mostly proportional to (Sbτ/V), which corresponds to specific surface area of bubble swarms per unit volume within the column, in the present experimental region. This result suggested that efficiency of this removal process was mainly controlled by the specific surface area of bubble swarms, and proposed model was fundamentally verified. 相似文献
70.