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411.
Takeda N Gotoh M Matsuoka T 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2011,28(9):1168-1174
An efficient LC method was developed for screening the presence of quinolones (QLs)--comprising fluoroquinolones (FQs) and acidic quinolones (AQs)--residues in various livestock and fishery products. Targeted analytes were for nine FQs of marbofloxacin (MAR), ofloxacin (OFL), norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENR), danofloxacin (DAN), orbifloxacin (ORB), difloxacin (DIF) and sarafloxacin (SAR), and three AQs of oxolinic acid (OXA), nalidixic acid (NAL) and flumequine (FMQ). Samples comprised ten different food products covering five matrices: muscle (cattle, swine and chicken), liver (chicken), raw fish (shrimp and salmon), egg (chicken), and processed food (ham, sausage and fish sausage). This method involved a simple extraction with (1:1) acetonitrile-methanol, a highly selective clean-up with an immobilised metal chelate affinity column charged with Fe(3+), a fast isocratic LC analysis using a short column (20 mm × 4.6 mm, 3 μm) with a mobile phase of (15:85:0.1) methanol/water/formic acid, and fluorescence detection (excitation/emission wavelengths of 295 nm/455 nm for FQs (495 nm for MAR), and 320 nm/365 nm for AQs). Among FQs, pairs of NOR/OFL, ORB/DIF and ENR/DAN were incompletely resolved. A confirmatory LC run with a Mg(2+) containing methanolic mobile phase was also proposed for the samples suspected of being positive. The optimised method gave satisfactory recoveries of 88.5% (56.1-108.6%) and 78.7% (44.1-99.5%) for intra- and inter-day assays with relative standard deviations of 7.2% (0.7-18.4%) and 6.8% (1.4-16.6%), respectively. Limits of quantitation ranged from 0.8 μg kg(-1) (DAN) to 6.5 μg kg(-1) (SAR). This method was successfully employed to analyse 113 real samples and two positive samples were found: fish sausage (CIP 990 μg kg(-1)) and shrimp (ENR 20 μg kg(-1)). 相似文献
412.
High strength polyvinyl alcohol (PVA) fibers with a conventional degree of polymerization of 1500 were prepared by doping iodine with PVA spinning solution. The iodine‐doped PVA (I‐PVA) aqueous solution was extruded into cold methanol that provides dark purple PVA‐iodine complex gel fibers. Only a small amount of iodine was required to enhance drawability and molecular orientation by reducing the interaction between PVA chains. An increase of ca. 10% in the maximum draw ratio of the doped fibers compared with that of undoped PVA translated into values for the tensile strength, 2.2 Giga‐Pascal (GPa), and initial modulus (47 GPa) that were more than 30% higher than those of the neat PVA fiber. Easier chain slippage of molecules in the amorphous segments of the I‐PVA fiber during drawing leads to increased orientation in these segments, which is believed to be the source of the improvements in mechanical properties. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers 相似文献
413.
Piyanuch Sommani Hiroshi TsujiHiroyuki Kojima Hiroko SatoYasuhito Gotoh Junzo IshikawaGikan Takaoka 《Surface & coatings technology》2011,206(5):897-899
The fine adhesion pattern of mesenchymal stem cells (MSCs) on polytyrene (PS) was investigated by carbon negative-ion implantation with decreasing the implanted line-width. The carbon negative ions with certain ion fluence of 3 × 1014 ions/cm2 and ion energy of 10 keV were implanted through the ridge-pattern mask having slit aperture from 0 to 40 μm. After 2 days of culture of rat MSCs on the modified PS, the MSCs elongated and adhered along the implanted region due to the lowering of contact angle after the ion implantation. The cells stained with fluorescent dye of DAPI were used to observe the position of cell adhesion on the modified line-width. By decreasing the line-width from 40 to 3 μm, we found the adhesion arrangements from the gathering cells to the individual cells. The most probable adhesions of the gathering cells in a lateral direction of the line were found at a wider width than 20 μm, while that of the individual cells were found at a width of about 10 μm. The adhesion arrangement of individual cells helped to increase the distances of cell-to-cell due to the elongated adhesion of cells along the narrowed implanted line-width. The number of adhered cells decreased with a decrease in the implanted line-width, and almost all of them had the same direction of their nucleus at the narrower line-width than 12 μm. Therefore, the controls of the individual cell-adhesion arrangement in a line and the nuclei direction could be achieved by decreasing the implanted line-width to about 10 μm. 相似文献
414.
Takashi Minemoto Masanori Toda Shingo Nagae Masahiro Gotoh Akihiko Nakajima Kenji Yamamoto Hideyuki Takakura Yoshihiro Hamakawa 《Solar Energy Materials & Solar Cells》2007,91(2-3):120-122
Effects of spectral irradiance distributions on the outdoor performance of amorphous Si//thin-film crystalline Si stacked photovoltaic (PV) modules installed at Shiga-prefecture in Japan have been investigated. Outdoor solar spectrum measurements revealed that more than 95% of annual total spectra were blue-rich compared to AM1.5 standard solar spectrum. The outdoor performance of the modules had a higher spectral dependence than that of polycrystalline Si modules. Also, the peak of the histogram of annual spectral indexes well corresponded to the peak of the outdoor performance. The results indicate that the actual spectral irradiance distribution is important in designing stacked PV modules. 相似文献
415.
Shu Gotoh Takashi Ueda Hiroaki Kakinuma Masahiro Akiyama 《Solar Energy Materials & Solar Cells》1998,50(1-4):281-288
The annealing characteristics of GaAs tunnel junctions using carbon (C) as a p-type dopant were studied through current-voltage measurement and secondary-ion mass spectroscopy (SIMS). After annealing (750°C, 20 min), diodes fabricated with a C-doped p+-GaAs/Si-doped n+-GaAs tunnel junction showed an excellent tunnel peak current density (JP) of 114 mA/cm2, which is a larger value than ever reported for structures using Be or Zn as a p-type dopant. Degradation of JP, in diodes after annealing was found to drastically improve when the tunnel junction was sandwiched between p- and n-AlGaAs layers. The inserted n-AIGaAs layer was more effective in suppressing JP, degradation than the p-AIGaAs layer. SIMS results revealed that Si diffusion, which causes JP, degradation, was suppressed at the interfaces of the p+-GaAs/n+-GaAs tunnel junction and the GaAs/AIGaAs heterojunction. An excellent JP value of 1.7 A/cm2 at 55 mV was obtained after annealing (750°C, 20 min) through structural optimization. 相似文献
416.
Satoh T Ruslan RI Gotoh S Akitsu T 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(4):788-797
In this work we propose a novel circuit design: a double-resonance oscillator. Its oscillation shows two oscillation modes: frequency locking to the quartz crystal resonance and LC resonance oscillation. Transition of the oscillation mode and the strength of oscillation are analyzed and reviewed for the fundamental mode in comparison with a Colpitts oscillator. The experimental results support the estimates of negative resistance for the double-resonance oscillator compared with the LC oscillator. 相似文献
417.
Yuki Fujii Tsunayoshi Takehara Takeyuki Suzuki Hiromichi Fujioka Satoshi Shuto Mitsuhiro Arisawa 《Advanced Synthesis \u0026amp; Catalysis》2015,357(18):4055-4062
N‐Alkyl‐N‐(2‐vinylbenzyl)prop‐2‐en‐1‐amine derivatives undergo a one‐pot olefin isomerization/aliphatic enamine ring‐closing metathesis (RCM)/oxidation/1,3‐dipolar cycloaddition sequence with the ruthenium complex, Ru(CO)HCl(PPh3)3, a second generation Hoveyda–Grubbs catalyst, and a 1,3‐dipolarophile. Overall, in a single operation the reaction sequence converts simple benzylamine derivatives into isoindolo[1,2‐a]isoquinolines with a π‐conjugated four‐ring system, through three unique ruthenium‐catalyzed transformations.
418.
Axonal transport plays a crucial role in neuronal morphogenesis, survival and function. Despite its importance, however, the molecular mechanisms of axonal transport remain mostly unknown because a simple and quantitative assay system for monitoring this cellular process has been lacking. In order to better characterize the mechanisms involved in axonal transport, we formulate a novel computer-assisted monitoring system of axonal transport. Potential uses of this system and implications for future studies will be discussed. 相似文献
419.
Md. Majibur Rahman Khan Yasuo Gotoh Hideaki Morikawa Mikihiko Miura 《应用聚合物科学杂志》2008,110(3):1358-1365
The effect of iodine treatment on the carbonization behavior of tussah silk fibroin (SF) fiber from a wild cocoon, Antheraea pernyi (A. pernyi), was investigated, and the carbon yield, fiber morphology, structural characteristics, and mechanical properties were evaluated. The SF fiber was treated with iodine vapor at 100°C for 12 h and was heated to 800°C under a multistep heating program as carbonization process, which corresponds to the constant thermal degradation rate of SF determined by dynamic thermogravimetric analysis (TGA). The carbon yield was ca. 39 wt %, which is much higher than those for untreated A. pernyi. Scanning electron microscopic (SEM) observation showed that obtained carbon fibers from iodinated SF were structurally intact, and the strength was higher than that from untreated SF. Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction, and Raman spectroscopy revealed that the structures of the carbon fibers obtained from both untreated and iodinated SF were almost the same and amorphous. At the early stage of carbonization of SF, amide bonding of SF molecules was begin to collapse at temperatures higher than 350°C and was completely dissociated by carbonization at 800°C. Dynamic viscoelastic measurements showed that with heating above 270°C the iodine component introduced intermolecular crosslinking of SF and the melt flow of the SF was inhibited, which enhances higher carbon yield and better performance of silk based carbon fiber. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献