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71.
Simple and easy method to evaluate uptake potential of nanoparticles in mammalian cells using a flow cytometric light scatter analysis 总被引:1,自引:0,他引:1
Many classes of nanoparticles have been synthesized and widely applied, however, there is a serious lack of information concerning their effects on human health and the environment. Considering that their use will increase, accurate and cost-effective measurement techniques for characterizing "nanotoxicity" are required. One major toxicological concern is that nanoparticles are easily taken up in the human body. In this study, we developed a method of evaluating the uptake potential of nanosized particles using flow cytometric light scatter. Suspended titanium dioxide (TiO2) particles (5, 23, or 5000 nm) were added to Chinese hamster ovary cells. Observation by confocal laser scanning microscopy showed that the TiO2 particles easily moved to the cytoplasm of the cultured mammalian cells, not to the nucleus. The intensity of the side-scattered light revealed that the particles were taken up in the cells dose-, time-, and size-dependently. In addition, surface-coating of TiO2 particles changed the uptake into the cells, which was accurately reflected in the intensity of the side-scattered light. The uptake of other nanoparticles such as silver (Ag) and iron oxide (Fe3O4) also could be detected. This method could be used for the initial screening of the uptake potential of nanoparticles as an index of "nanotoxicity". 相似文献
72.
Yuko Kizu Ray Hasegawa Isao Amemiya Shuichi Uchikoga Hirofumi Wakemoto 《Journal of the Society for Information Display》2009,17(8):647-658
Abstract— A 9‐in. full‐color polymer‐stabilized OCB TFT‐LCD with stable bend alignment in the absence of an electric field was developed. The condition of the polymer stabilization, the characteristics of UV‐curable monomers, and their influence on the configurations of the polymer network in the cell were studied. Possible models of the configuration were proposed and their relationship to the electro‐optical properties was analyzed using a novel simulation method considering the distribution of anchoring effects from both alignment surfaces and the polymer network. It was suggested that a good performance such as high contrast ratio and fast response could be expected in the polymer network originating from newly developed monomers composed of multifunctional LC acrylates due to a relatively weak‐anchoring effect and presumably its localization near the alignment surfaces. By using the newly developed monomers under the optimized polymer‐stabilizing process, a high contrast ratio of 250:1 and fast response nearly equal to that of a conventional OCB cell were achieved. 相似文献
73.
Jianding Yu Yan Liu Xiuhong Pan Hongyang Zhao Velu Nirmal Kumar Mukannan Arivanandhan Yoshimi Momose Yasuhiro Hayakawa Xingwang Zhang Xinghong Luo Yasuhiro Okano Yuko Inatomi 《Microgravity science and technology》2016,28(2):143-154
The paper reviewed the previous microgravity experiment using Chinese recovery satellite, the in-situ measurement of composition profile in the solution by X-ray penetration method and homogeneous growth of InGaSb by temperature freezing method under terrestrial condition for making clear the effect of gravity on the growth of InGaSb ternary alloy semiconductor crystals. The previous experimental results showed that the shape of solid/liquid interfaces and composition profile in the solution were significantly affected by gravity. Based on the previous microgravity experimental results, experimental conditions were investigated to grow homogeneous In xGa 1?xSb with higher indium composition at Chinese recovery satellite SJ-10 in near future. 相似文献
74.
Viliame Savou Guido Grause Shogo Kumagai Yuko Saito Tomohito Kameda Toshiaki Yoshioka 《能源学会志》2019,92(4):1149-1157
Pyrolysis is a promising technique for the recovery of useful gas, tar, and solid products from biomass waste. However, the low tar yields obtained from lignocellulosic biomass are a significant drawback. To enhance tar yields, sugarcane bagasse, which is the most abundant agricultural waste in Fiji, was pretreated at ambient temperature and atmospheric pressure using various sulfuric acid (H2SO4) concentrations. Here, the ether bonds of cellulose, hemicellulose, and lignin were partially hydrolyzed. The pretreated samples were then pyrolyzed at 500 °C, and it was confirmed that H2SO4-pretreatment disrupted the bagasse cell structure, with the thermogravimetry and differential thermogravimetry results confirming that decomposition occurred at lower temperatures after pretreatment. In addition, tar yields were significantly enhanced from 5.6 wt% to 13.4 wt% for the untreated and 3 M H2SO4-pretreated samples respectively. The main components detected in this tar product were levoglucosan, andcellulose-and hemicellulose-derived products, whose proportions were increased following pretreatment. Thus, our work demonstrates that dilute acid pretreatment enhances tar production from sugarcane bagasse due to the production of shorter chain components via the partial hydrolysis of ether bonds. 相似文献
75.
Ryo Inagaki Fumika Ito Yuko Shimamura 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2019,36(2):236-243
The effects of the presence of chloride on the formation of 3-monochloro-1,2-propanediol fatty acid esters (3-MCPDEs) and glycidol fatty acid esters (GEs) in saltwater fish, meats and acylglycerols (diacylglycerol and triacylglycerol) during heating were investigated in this study. Five saltwater fish species (salmon, saury, yellowtail, mackerel and Spanish mackerel) were grilled with a fish griller. 3-MCPDEs and GEs were detected in all of the grilled fish samples. The total amount of GEs was higher than 3-MCPDEs. Beef and pork patties with or without sodium chloride (1.5%) were cooked using gaseous fuel. The formation of 3-MCPDEs was significantly increased by the addition of sodium chloride to the meat patties, whereas the concentration of GEs in the cooked meat patties was not changed by the content of sodium chloride. Hexadecane solutions of diacylglycerol or triacylglycerol containing FeCl3 were heated at 240°C. The formation of 3-MCPDEs was greatly increased by adding FeCl3 to the solutions of triacylglycerol. The amounts of 3-MCPDEs decreased with the extension of the heating time. From these results, it is suggested that 3-MCPDEs and GEs are formed in saltwater fish and meats by cooking, and that the formation of 3-MCPDEs was affected by chloride in foodstuffs. 相似文献
76.
Kalidas Shetty Masahiro Ohshima Taka Murakami Katsuji Oosawa Yuko Ohashi 《Food Biotechnology》2013,27(2):111-128
Abstract Melon (Cucumis melo L.) is an important fruit crop cultivated widely in every region of the world. Our laboratory is targeting this species for production of novel proteins important to food industry. Prior to expression of protein of interest in transgenic melon an efficient genetic transformation system has to be developed. In this context we are testing a wide variety of promoters fused to reporter gene for β‐glucuronidase (GUS) for expression specifically in melon fruits. In this study in melon, salicylic acid‐inducible promoter region of pathogenesis‐related protein gene (PR1a) of tobacco fused to β‐glucuronidase (GUS) gene was introduced into melon via Agrobacterium‐mediated gene transfer using a binary vector system. Gene transfer was effective when Agrobacterium virulence factors like acetosyringone (100 μM) and low pH (5.2) were provided during the co‐culture step. Transformed shoots were recovered from benzyladenine‐induced cut cotyledons using kanamycin gene as a selective marker. Regeneration of shoots from cotyledons was stimulated by providing 10 mM proline in the shoot organogenesis medium. Southern and Northern blot analysis of transformants confirmed the presence of β‐glucuronidase gene in two selected clones J‐3 and PR‐G. The transformants also showed high β‐glucuronidase activity after salicylic acid treatment. Thiamine, a previously known inducer of pathogenesis‐related protein, stimulated β‐glucuronidase in J‐3 but not PR‐G melon transformants tested in this study. These studies showed that tobacco PR1a promoter region can be expressed in melon and it was stimulated by salicylic acid. This indicates the potential to use the promoter region of tobacco PR1a for genetic improvement of melon for specific food processing‐related characteristics or for expression of novel food‐related proteins. The promoter region could be used to drive specific target genes under stress or salicylic acid induced conditions. 相似文献
77.
Lipase from Candida antarctica was entrap-immobilized in cellulose acetate-TiO2 gel fiber (fiber-immobilized lipase) by the sol-gel method. Syntheses of geranyl acetate and citronellyl acetate catalyzed
by the fiber-immobilized lipase were studied in heptane solution. Conversions reached 85% for geranyl acetate after 100 h,
and 75% for citronellyl acetate after 80 h, and these values were almost identical to those for syntheses catalyzed by nonimmobilized
lipase, although the reaction rate was decreased by immobilization. Compared to those of the non-immobilized lipase and commercially
available immobilized lipase (Novozyme 435), the activity of the fiber-immobilized lipase was not particularly affected by
changes in reaction conditions, such as bulk water content or substrate concentration. The fiber-immobilized lipase retained
a high level of activity after six repeated uses, and almost no enzyme leakage from fiber was observed. However, the reactivity
of the fiber-immobilized lipase was depressed at higher temperature, presumably due to dehydration by thermal contraction
of the gel fiber. 相似文献
78.
We recorded temperature-dependent high-resolution 13C NMR spectra of dry and swollen poly(acrylate)s [poly(2-methoxyethyl acrylate) (PMEA), poly(2-hydroxyethyl methacrylate) (PHEMA), and poly(tetrahydrofurfuryl acrylate) (PTHFA)] by dipolar decoupled-magic angle spinning (DD-MAS) and cross-polarization-magic angle spinning (CP-MAS) methods, to gain insight into their network structures and dynamics. Suppressed or recovered intensities (SRI) analysis of 13C CP-MAS and DD-MAS NMR was successfully utilized, to reveal portions of dry and swollen polymers which undergo fast and slow motions with fluctuation frequencies in the order of 108 Hz and 104-105 Hz, respectively. Fast isotropic motions with frequency higher than 108 Hz at ambient temperature were located to the portions in which 13C CP-MAS NMR signals of swollen PMEA were selectively suppressed. In contrast, low-frequency motion was identified to the portions in which 13C DD-MAS (and CP-MAS) signals are most suppressed at the characteristic suppression temperature(s) Ts. Network of PMEA gels (containing 7 wt% of water) turns out to be formed by partial association of backbones only, as manifested from their Ts gradient at lowered temperature, whereas networks of PHEMA (containing 40 wt% of water) and PTHFA (9 wt% of water) gels are tightly formed through mutual inter-chain associations of both backbones and side-chains, as viewed from the raised Ts values for both near at ambient temperature. It is also interesting to note that flexibility of gel network (PMEA > PTHFA > PHEMA) characterized by the suppression temperature Ts (PMEA < PTHFA < PHEMA) is well related with a characteristic parameter for biocompatibility such as the production of TAT (thrombin-antithrombin III complex) as a marker of activation of the coagulation system. 相似文献
79.
Negative-ion fragmentation of N-glycans has been proven to be more informative than that of positive-ion. In particular, it defines structural features such as the specific composition of the two antennae and the location of fucose. However, negative-ion formation of neutral N-glycans by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) remains a challenging task, and the detection limit of N-glycans in negative-ion mode is merely at the subpicomole level. Thus, practical applications are limited. In this study, combinations of five liquid matrices and nine anions were used to ionize N-glycans as anionic adducts, and their performances for sensitive analyses were evaluated. The best results were obtained with anion-doped liquid matrix G(3)CA, which consists of p-coumaric acid and 1,1,3,3-tetramethylguanidine; the detection limits of anion adducted N-glycans were 1 fmol/well for NO(3)(-), and 100 amol/well for BF(4)(-). Negative-ion MS(2) spectra of 1 fmol N-glycans were successfully acquired with a sufficient signal-to-noise ratio and were quite useful for MS-based structural determination. The anion-doped G(3)CA matrix opens the way for sensitive and rapid analysis of neutral N-glycans in negative-ion MALDI at a low femtomole level. 相似文献
80.
K Abe T Kumagai C Takahashi A Kezuka Y Murakami Y Osawa H Motoki T Matsuo M Horiuchi K Sode S Igimi K Ikebukuro 《Analytical chemistry》2012,84(18):8028-8032
We constructed a novel bacterial genome detection system using zinc finger protein (ZF) fused with firefly luciferase (ZF-luciferase). Taking advantage of the direct recognition of double-stranded DNA (dsDNA) by ZF, we previously constructed bacterial genome detection systems that did not require dehybridization processes. To detect polymerase chain reaction (PCR) products rapidly and with a high sensitivity, we constructed two kinds of ZF-luciferase, Sp1-fused luciferase (Sp1-luciferase), and Zif268-fused luciferase (Zif268-luciferase). ZF-luciferase not only maintains luciferase activity but also shows dsDNA-binding ability and specificity. Furthermore, we succeeded in the detection of 10 copies of the genome of Legionella pneumophila and Escherichia coli O157. ZF-luciferase would be a useful tool for highly sensitive detection of pathogenic bacterial genome. 相似文献