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41.
42.
The present study aimed to produce small-diameter grafts made of a silk fibroin by electrospinning. In order to reinforce the electrospun silk fibroin graft (ES), the graft was coated with a silk sponge (ESSC). Physical properties such as a diameter of the electrospun silk fibers were influenced by a concentration of fibroin solution. Ultimate tensile strength (UTS) of the ESSC graft was improved compared to the ES graft. However, the ESSC graft was less compliant than the ES graft. Importantly, water permeability of the ESSC graft was within the range of which endothelialization was promoted in previous studies. 相似文献
43.
Michiko Fujita Mikio Kajiyama Akio Takemura Hirokuni Ono Hiroshi Mizumachi Shunji Hayashi 《应用聚合物科学杂志》1998,67(2):221-229
Natural rubber (NR) was blended in various ratios with 12 kinds of tackifiers that were prepared from petroleum. The blends were heated to various temperatures (20–120°C) to investigate their miscibility. The blends were visually observed for transparency or opacity at each temperature and further observed under an optical microscope for any existence of phase-separated structure. Miscibility of the blends is illustrated as phase diagrams in this article. NR/aliphatic resin systems and NR/aliphatic-aromatic copolymer systems showed phase diagrams of the lower critical solution temperature type, wherein the blends turned faintly cloudy over the binodal curves. The NR/hydrogenated petroleum resin system also showed a phase diagram of the lower critical solution temperature type. The miscible range of a blend system tends to become smaller as the molecular weight of a tackifier increases. Resins prepared by polymerization of pure aromatic monomers were completely immiscible with NR. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 221–229, 1998 相似文献
44.
FIR emissions in three directions from a FIR NH3 laser cavity having a zig-zag axis were observed when radiation from a pump CO 2 laser with multiple or single modes was linearly injected into the cavity. The temporal variation and Fabry-Perot interferogram of these emissions showed that the FIR zig-zag emission is dominated by a laser process due to a population inversion, while the other forward and backward emissions are due to a Raman process 相似文献
45.
Kawashima Hitoshi; Yamagishi Jun-ichi; Yamayoshi Michiko; Ohue Mayumi; Fukui Toshikazu; Kotani Hirotada; Yamada Masaaki 《Protein engineering, design & selection : PEDS》1992,5(2):171-176
To identify the sites important for the different biologicalactivities of human interleukin-l (hIL-1), 56 single-amino acid-substitutedmutants of hIL-l were produced in Escherichia coli using site-directedmutagenesis, and were examined for their biological activitiessuch as mouse lymphocyte activating factor activity (LAF activity),cytostatic activity against human melanoma cells A-375 (A375activity) and prostaglandin E2 (PGE2) inducing activity in humanosteosarcoma cells MG-63 (PEI activity). Two amino acid residues,Asp26 and Asp151, were found to be important for these activities.The replacement of Asp26 by Val caused a decrease in LAF andA375 activities by one or two orders of magnitude and a slightdecrease in A375 activity. The Tyr or Phe substitution for Asp151caused decreases in LAF and A375 activities by one or two ordersof magnitude and complete loss of PEI activity. The change fromAsp151 to Lys or Arg resulted in marked decrease in LAF activityand complete loss of A375 and PEI activities. Since Asp26 andAsp151 are close to each other in the three-dimensional structure,the region involving these amino acids seems to be importantfor the biological activities of hIL-1. 相似文献
46.
Masanobu Onishi Michiko Inoue Tetsuya Araki Hisakatsu Iwabuchi Yasuyuki Sagara 《Food and Bioprocess Technology》2012,5(4):1228-1237
The sampling parameters to simulate retronasal aroma during the mastication of white bread has been optimized using a retronasal
aroma simulator (RAS) to compare the retronasal bread aroma with the conventional headspace aroma. The volatile composition
in breath was compared with that in the effluent from a RAS using proton transfer reaction mass spectrometry, and the optimized
RAS parameters were as follows: 2.5 g of bread sample, 250 mL of buffer, 1 L/min of N2 gas stream, 350 rpm of rotating speed, and 38 °C of water jacket temperature. The increased sensitivity and high reproducibility
of RAS enabled detailed measurements of flavor release in the mouth during the mastication of bread. The simulated retronasal
aroma was compared with the conventional headspace aromas by gas chromatography/olfactometry (GC/O), and the results demonstrated
that the caramel note odorant of 2,5-dimethyl-4-hydroxy-3(2H)-furanone was found to show the highest contribution to the headspace aroma; however, it showed little contribution to the
simulated retronasal aroma. These differences appeared to be caused by the volume of buffer added in RAS experiments. The
odorant concentrations in the RAS effluent were found to decrease with the increase of the buffer volume, and the decreasing
rates appeared to be associated with the chemical types of odorants. Flavor release of typical odorants in a RAS was measured
at various ratios of buffer volume, and the results indicated that flavor release in mouth appeared to be influenced by the
physicochemical properties of odorants. The results would help flavor chemists to make better prediction of bread aroma in
mouth during the mastication. 相似文献
47.
A simple hybrid system exhibiting chaos is developed and a chaos control method realised. It is shown that, since the dynamics can be expressed by a return map, the system has an observable chaos. The control method, which is based on the pole assignment technique, can stabilise any unstable periodic orbit in the chaos. The theoretical result is verified by laboratory experiments 相似文献
48.
Kazuko Katsuki Hidenori Suzuki Masatoshi Hasegawa Michiko Heike Noriko Hosomachi Yuya Yamashita Yuta Nakamura 《Journal of Porous Materials》2007,14(4):443-448
The effects of reaction period, temperature, and iron species on the zeolite framework type were studied in this work. Gismondine
(GIS) is usually synthesized by hydrothermal method at 80°C from sodium metasilicate and aluminum nitrate as starting materials
preferentially independent of the presence/absence of iron source. However, the present work revealed that pure analcime (ANA)
could be formed at temperatures more than 120°C. A large polyhedral ANA crystal with a diameter of 180 μm was obtained even
at a comparatively low temperature such as 150°C at a short reaction period of 1 week. The presence of iron source promoted
the formation of pure ANA. Infrared spectroscopy, X-ray diffraction, and ICP-OES analysis suggested that the iron component
added as a reactant was incorporated into the ANA framework through the isomorphous substitution for Al. 相似文献
49.
α-Lipoic acid (ALA) is an essential cofactor in mitochondrial multi-enzyme complexes related to energy production. However, it is unstable under light or heat, and its decomposition is accompanied by an unpleasant odor. Therefore, its stabilization by complex formation with the cationic polymer chitosan (CS) was investigated. The ALA dissolved in demineralized water was efficiently adsorbed on the precipitated insoluble CS particles, and an ALA–CS complex was obtained. The amount of ALA adsorbed on CS was affected by the CS species and the quantity ratio of ALA to CS. The ALA from the ALA–CS complex was released immediately by changing the pH. When ALA was incubated at 65 °C, it melted and polymerized. In addition, some decomposition of ALA was also observed in the physical mixture of ALA with CS. However, the ALA–CS complex did not decompose at all under the same conditions. Thus, the stabilization of ALA was achieved by complex formation with CS. CS is useful as a material for the stabilization of ALA, leading to its clinical use. 相似文献
50.
Summary
Inverse gas chromatography (IGC) has been applied to observe the interaction between poly(vinylidene fluoride) (PVDF) and
organic solvent systems under conditions approaching infinite dilution of the volatile component.
The specific retention volumes (Vg
0) were calculated from the retention volumes of the PVDF/solvent systems. The retention diagrams (RDs) which were plotted
as ln Vg
0 vs. reciprocal temperature, corresponded with the thermodynamic behavior of PVDF. PVDF dissolves well in carbonyl-containing
solvents at high temperatures. In these systems, the solution is converted easily to a thermoreversible gel by standing at
room temperature. The Flory-Huggins interaction parameter (χ12) and molar heat of sorption of probe absorbed by the amorphous part of PVDF (Δ H1
s) calculated from the retention values indicated that the characteristics of the interaction between PVDF and the solvent
(probe) varied with temperature and probe properties. The results of IGC of PVDF/solvent systems were discussed in relation
to the dissolution and gelation behavior of PVDF.
Received: 29 September 1999/Revised version: 30 November 1999/Accepted: 9 December 1999 相似文献