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51.
Some tetracycline (TC) antibiotics, including TC and anhydrotetracycline, have been found to enhance specific binding of low
density lipoprotein (LDL) to both LDL receptor-positive and-negative cells at relatively higher concentrations. When incubated
at 37°C, the ability of LDL receptor-negative human fibroblasts to bind 125I-LDL was increased from<2 to 45 ng/mg by 170 μM TC. In normal human fibroblasts and Hep G2 cells, 125I-LDL binding was elevated 1.4- to 2-fold by 113 μM TC. The 125I-LDL binding in the presence of TC was diminished by both heparin and EDTA. The enhancement by TC was not observed when 125I-LDL binding was assayed at 4°C. TC enhanced LDL binding to paraformaldehyde-fixed Hep G2 cells, excluding LDL receptor induction
in the mechanism. These results demonstrated that TC enhanced cellular LDL binding through a process not involving functional
LDL receptors. 相似文献
52.
Izumi Kita Tomohiro Shibata Yuki Kamiya Daishi Kato Kazuo Kunieda Keiji Yamada Kazushi Ikeda 《Artificial Life and Robotics》2009,14(3):375-378
To increase the productivity of knowledge workers, it is necessary to manage their organization so that they are motivated
to collaborate with each other for their synergy. However, it is difficult for managers to grasp the explicit interactions
of workers in the organization all the time. Owing to advanced communications technology, and the reduced size and improved
capabilities of computers, we are able to record group behaviors as logging data in the office. The aim of this study is to
extract features of group behavior from long-range office-logging data. We apply principal component analysis to the data
matrix whose element is the mean travel velocity calculated from an individual’s trajectory per day. The results demonstrate
the feasibility of our approach, since nontrivial informative group features can be extracted. 相似文献
53.
Tomohisa Yamashita Keiji Suzuki & Azuma Ohuchi 《International Transactions in Operational Research》2001,8(1):75-88
In our research, we propose the solution to the 'Distributed Social Dilemma' as an extended social dilemma model. In this model, in order to prevent the players from becoming freeloaders, we introduce competitive meta-players. Our purpose is to evaluate, through agent-based simulation, how the meta-players effect to increase cooperation amongst players in a distributed social dilemma. In order to examine our proposed solution, we introduce the preference of the players to cooperate as the measure of the effect of the meta-players. On the basis of the result of the simulations, we show the degree of the effect of the competitive meta-players on the distribution social dilemma. 相似文献
54.
Hironobu Yamada Teruki Hasegawa Yudai Ishihara Toshihiko Kiwa Keiji Tsukada 《NDT & E International》2008,41(2):108-111
We examined the difference in the detection limits of flaws in the depths of multi-layered and continuous aluminum plates using low-frequency eddy current testing. The detection limits were measured by using a magneto-resistive sensor. Comparing the frequency of an applied magnetic field, the detection limit at 50 Hz is deeper than that at 1 kHz. Comparing the sample structure, the detection limit in the multi-layered samples is deeper than that in the continuous samples. These results are likely due to the differences in the skin depth and conductivity of the sample. 相似文献
55.
Improved heat and solvent resistance of a pressure‐sensitive adhesive thermally processable by isocyanate dimer dissociation 下载免费PDF全文
Methods that do not involve use of an organic solvent are being considered for manufacturing environmental‐friendly pressure‐sensitive adhesive tapes. Among these methods, the hot‐melt method exhibits high productivity but is somewhat limited in terms of performance. Hot‐melt‐fabricated pressure‐sensitive adhesives require heating fluidization and cooling solidification, and it is extremely difficult to improve their heat resistance. We examine thermally processable pressure‐sensitive adhesives with a completely new structure, fabricated based on the thermal dissociation of the isocyanate dimer. This enables thermal processing of materials softened by thermal dissociation. Fabrication of crosslinkable pressure‐sensitive adhesive becomes possible through a reaction of isocyanate caused by dissociation of its dimer. It is found that improving thermal and solvent resistances, which are disadvantages associated with conventional hot‐melt pressure‐sensitive adhesives, is potentially possible with the pressure‐sensitive adhesive reported here. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41444. 相似文献
56.
Eisuke Watanabe Junko Fujii Kaori Kojima Satoshi Iwatsuki Masahiko Inamo Hideo D. Takagi Koji Ishihara 《Inorganic chemistry communications》2010,13(12):1406-1409
Kinetic studies were performed on the reactions of phenylboronic acid with L-lactic acid and mandelic acid in acidic aqueous and alkaline solutions in order to specify reactive species in these reactions. It was confirmed that the diprotonated ligand (H2L: L-lactic acid or mandelic acid) is less reactive than the monoprotonated ligand (HL?: L-lactate ion or mandelate ion), which made possible direct determination of the rate constants of phenylboronic acid (PhB(OH)2) and its conjugate base, phenylboronate ion (PhB(OH)3?). It was found that PhB(OH)2 is more reactive than PhB(OH)3?. On the basis of kinetic results, it was concluded that the most reactive species are PhB(OH)2 and HL? at physiological pH 7.4, so the reaction in the boronic acid-based sensor for L-lactate mainly would occur between these species. 相似文献
57.
Akiyama M Murakami K Ikeda M Iwatsuki K Wada A Tokuno K Onishi M Iwabuchi H 《Journal of food science》2007,72(7):C388-C396
ABSTRACT: Headspace volatiles of freshly brewed drip coffee were investigated by gas chromatography/mass spectrometry (GC/MS) and gas chromatography/olfactometry (GC/O, CharmAnalysis™) analyses. For this purpose, a solid-phase microextraction (SPME) sampling method for the headspace volatiles of freshly brewed drip coffee was developed. SPME fiber coated with divinylbenzene (DVB)/carboxen/polydimethylsiloxane (PDMS) was selected from 6 types, and sampling time was determined at 2 min. The headspace coffee volatiles stayed constant in proportion for the first 2 min to keep the freshness of the brewed coffee aroma. Using this sampling method, the headspace volatiles of freshly brewed drip coffee (Ethiopian arabica coffee, roast degree: L value; 23) were examined by GC/MS and GC/O analyses. From the GC/O results, 1-(3,4-dihydro-2 H -pyrrol-2-yl)-ethanone (nutty-roast odor) and 4-(4'-hydroxyphenyl)-2-butanone (raspberry ketone, sweet-fruity odor) were newly detected as components in the aroma of coffee. 相似文献
58.
Muneki Nakada Changho Chong Atsushi Morosawa Keiji Isamoto Takuya Suzuki Hiroyuki Fujita Hiroshi Toshiyoshi 《IEEJ Transactions on Electrical and Electronic Engineering》2014,9(4):448-458
This paper presents a novel device architecture for optically actuated microelectromechanical systems (MEMS) endoscopes for optical coherence tomography (OCT) measurement. A 10‐mW infrared light beam at a wavelength of 1.5 µm is transferred through the single‐mode fiber to provide a scanning MEMS mirror with the drive voltage (maximum 11 V) by exciting a photovoltaic cell, while also providing with a secondary light beam at a wavelength of 1.3 µm for the OCT measurement. An electrostatic vertical comb‐drive optical scanner (1.5 mm × 2.0 mm × 0.5 mm) has been developed by using the deep reactive ion etching (DRIE) of a silicon‐on‐insulator (SOI) wafer. The design of the scanner module is discussed, along with the experimental results of electrostatic operation. An equivalent circuit model for the optical scanner is developed to explain the behavior of the optically powered actuation mechanism, including the hysteresis loop in the frequency response and the voltage dependence of oscillating angle (mechanical peak ±3.2°/7 V around the resonance frequency of 250 Hz). OCT measurement of a tissue is demonstrated to reconstruct the cross‐sectional image of a fingerprint at a resolution of lateral 40 µm × vertical 8 µm and penetration depth of 2.5 mm. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
59.
In this paper, a back propagation neural network (BPNN) has been applied to predict the corner wear of a high speed steel (HSS) drill bit for drilling on different workpiece materials. Specially defined static and dynamic features extracted by a wavelet packet transform (WPT) from the resultant force converted from thrust and torque together with the cutting conditions (workpiece material, spindle speed, drill diameter, feed rate) are used as inputs to train the network to obtain a better output, drill corner wear. Drilling experiments have been carried out over a wide range and, features newly defined and conventional ones, features extracted from different frequency bands are compared. 相似文献
60.
Antioxidant Effects of Herbal Tea Leaves from Yacon (Smallanthus sonchifolius) on Multiple Free Radical and Reducing Power Assays,Especially on Different Superoxide Anion Radical Generation Systems 下载免费PDF全文
Shintaro Sugahara Yuto Ueda Kumiko Fukuhara Yuki Kamamuta Yasushi Matsuda Tatsuro Murata Yasuhiro Kuroda Kiyotaka Kabata Masateru Ono Keiji Igoshi Shin Yasuda 《Journal of food science》2015,80(11):C2420-C2429
Yacon (Smallanthus sonchifolius), a native Andean plant, has been cultivated as a crop and locally used as a traditional folk medicine for the people suffering from diabetes and digestive/renal disorders. However, the medicinal properties of this plant and its processed foods have not been completely established. This study investigates the potent antioxidative effects of herbal tea leaves from yacon in different free radical models and a ferric reducing model. A hot‐water extract exhibited the highest yield of total polyphenol and scavenging effect on 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH) radical among four extracts prepared with hot water, methanol, ethanol, and ethylacetate. In addition, a higher reducing power of the hot‐water extract was similarly demonstrated among these extracts. Varying concentrations of the hot‐water extract resulted in different scavenging activities in four synthetic free radical models: DPPH radical (EC50 28.1 μg/mL), 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) cation radical (EC50 23.7 μg/mL), galvinoxyl radical (EC50 3.06 μg/mL), and chlorpromazine cation radical (EC50 475 μg/mL). The yacon tea‐leaf extract further demonstrated superoxide anion (O2?) radical scavenging effects in the phenazine methosulfate‐NADH‐nitroblue tetrazolium (EC50 64.5 μg/mL) and xanthine oxidase assay systems (EC50 20.7 μg/mL). Subsequently, incubating human neutrophilic cells in the presence of the tea‐leaf extract could suppress the cellular O2? radical generation (IC50 65.7 μg/mL) in a phorbol 12‐myristate 13‐acetate‐activated cell model. These results support yacon tea leaves may be a good source of natural antioxidants for preventing O2? radical‐mediated disorders. 相似文献