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111.
Microfluidic trapping technology has been widely applied for single-cell observation in order to reveal characteristic cell behaviors. However, this strategy has yet to be tested for monitoring highly motile cells, which are often biologically important. In this paper, we seek the conditions that enable effective and long-term trapping of a prominent model ciliate Tetrahymena thermophila within a hydrodynamic microfluidic device. Although motility and flexibility of T. thermophila make it difficult to avoid escaping from the trap, we show that tuning some key parameters in the hydrodynamic circuit was effective to achieve approximately 40 h cell retention, which is long enough to monitor cell behaviors over several generations. Here, we demonstrate the real-time observation of cell division and phagocytic digestion, revealing interesting phenomena such as a wide distribution in doubling time in a poor synthetic medium and heterogeneous time courses in digestion processes. Our results present a strategy for trapping highly motile ciliate cells in order to study the dynamic behaviors of single cells. 相似文献
112.
3,6‐Diethylphthalonitrile ( 3 ) with a tetrathiafulvalene (TTF) unit at 4,5‐positions was prepared from 4,5‐xylylenedithio‐3,6‐diethylphthalonitrile ( 1a ) via elimination of the xylylene group, connection of a carbonyl group to benzenedithiolate generated, and condensation of 4,5‐bis(methylthio)‐1,3‐dithiole‐2‐thione with benzo‐1,3‐dithiole‐2‐one ( 2‐O ) produced. A 1:1 mixture of phthalonitrile ( 3 ) and 4,5‐bis(benzylthio)‐3,6‐diethylphthalonitrile ( 1b ) was treated with lithium in n‐hexanol at 120°C to produce hexakis (benzylthio)mono(tetrathiafulvaleno)phthalocyanine ( 5 ), tetrakis(benzylthio)bis(tetrathiafulvaleno)phthalocyanine ( 6 ), and bis(benzylthio)tris(tetrathiafulvaleno)phthalocyanine ( 7 ). The structures of 5 , 6 , and 7 were determined by 1H NMR, FAB MS, MALDI‐TOF MS (matrix assisted laser desorption ionization time‐of‐flight mass spectrometry), and UV‐‐vis spectroscopy. Compound 6 is a mixture of trans and cis isomers ( 6‐ trans and 6‐ cis ). The UV‐‐vis spectrum of 5 measured in chloroform changed by addition of trifluoroacetic acid (TFA). The Q band absorption at λmax = 755 nm (chloroform) decreased in intensity and resulted in a new absorption at λmax = 740 nm (chloroform/TFA). The electrochemical properties of 5 , 6 , and 7 were determined by cyclic voltammetry using Ag/AgNO3 as a reference electrode. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:605–611, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20694 相似文献
113.
Sakamoto M Tanaka D Tsunoyama H Tsukuda T Minagawa Y Majima Y Teranishi T 《Journal of the American Chemical Society》2012,134(2):816-819
The structures of nanomaterials determine their individual properties and the suprastructures they can form. Introducing anisotropic shapes and/or interaction sites to isotropic nanoparticles has been proposed to extend the functionality and possible suprastructure motifs. Because of symmetric anisotropy, Platonic solids with regular polygon faces are one of the most promising nanoscale structures. Introduction of Platonic solid anisotropy to isotropic nanomaterials would expand the functionality and range of possible suprastructure motifs. Here, we demonstrate a novel strategy to obtain nano-Platonic solids through the face coordination of square porphyrins on an inscribed Au sphere with adequate size. The face coordination of the multidentate porphyrin derivatives, with four acetylthio groups facing the same direction, on the Au cluster encased the Au cluster in a Platonic hexahedron with six porphyrin faces. Transmission electron microscopy, mass spectrometry, elemental analysis, and scanning tunnelling microscopy were used to confirm the formation of the nano-Platonic hexahedron. 相似文献
114.
Hiroaki Katsuki 《Journal of solid state chemistry》2009,182(7):1749-1753
Na-A and/or Na-X zeolite/porous carbon composites were prepared under hydrothermal conditions by NaOH dissolution of silica first from carbonized rice husk followed by addition of NaAlO2 and in situ crystallization of zeolites i.e., using a two-step process. When a one-step process was used, both Na-A and Na-X zeolites crystallized on the surface of carbon. Na-A or Na-X zeolite crystals were prepared on the porous carbonized rice husk at 90 °C for 2-6 h by changing the SiO2/Al2O3, H2O/Na2O and Na2O/SiO2 molar ratios of precursors in the two-step process. The surface area and NH4+-cation exchange capacity (CEC) of Na-A zeolite/porous carbon were found to be 171 m2/g and 506 meq/100 g, respectively, while those of Na-X zeolite/porous carbon composites were 676 m2/g and 317 meq/100 g, respectively. Na-A and Na-X zeolites are well-known microporous and hydrophilic materials while carbonized rice husk was found to be mesoporous (pores of ∼3.9 nm) and hydrophobic. These hybrid microporous-mesoporous and hydrophilic-hydrophobic composites are expected to be useful for decontamination of metal cations as well as organic contaminants simultaneously. 相似文献
115.
Yosuke Tanaka Tatsutoshi Shioda Takashi Kurokawa Junji Oka Kazuyuki Ueta Toshiharu Fukuoka 《Optical Review》2009,16(3):257-261
We propose a novel power-line-monitoring system using optical fibers for transmitting power as well as signal. The principle
is experimentally confirmed with a system composed of a monitoring side with a 1.5-μm laser diode, transmission line of a
single mode fiber, and a sensing side having an efficient photovoltaic (PV) cell, electrical junction sensor, and low power
liquid crystal optical modulator (LCOM). The PV cell generates the electrical power in the sensing side with a conversion
efficiency of 20%. The LCOM is driven with low power of less than 50 μW, modulates the laser light with a signal indicating
the power line condition, and transmits the optical signal. The developed sensing unit produces an optical signal having an
extinction ratio of 15 dB with low optical power of 1.8 mW. Five systems were in operation for two years, faithfully monitoring
the oil pressure in electrical cables every 20 min without incident. 相似文献
116.
Toshiharu Iwasaki Wataru Takarada Takeshi Kikutani 《Journal of Macromolecular Science: Physics》2017,56(9):709-723
The effect of heat sealing temperature on peelable heat seal strength (HSS) before and after the sterilization, often used industrially, was investigated for one of either polyethylene (PE) multilayered films with various inner sealant layers consisting of two high density PEs (HDPEs), a linear low density PE (LLDPE) or low density PE (LDPE). To attain similar HSS, heat sealing at a temperature close to the melting peak temperature (Tm-p) was needed only in the case of LDPE. Heat sealing behavior at higher temperatures, to attain higher HSS, was also investigated for HDPE and LDPE. High HSS, as well as suppressed reduction of HSS after the sterilization, was achieved for HDPE at a heat sealing temperature well below its Tm-p. An Increase of HSS with the increase of dwell time was also observed. On the other hand, for LDPE, high HSS and its stability after the sterilization were achieved only when the heat sealing temperature was increased to the value equivalent to its Tm-p. Improvement of the processing conditions for the shortening of the processing period was also investigated. For HDPE, higher sealing bar temperature was needed to gain similar HSS when the dwell time of the heat sealing was shortened from 4 to 2 s, whereas the attained maximum temperature at the interface was found to be similar. The characteristics of the heat sealed portion, judged from the relation between HSSs before and after the sterilization, were not affected by the dwell time of heat sealing, indicating that the shortening of the processing time by appropriate raising of the sealing bar temperature is possible. 相似文献
117.
Toshiharu Irisawa Kiiko Matsumoto Koichi Sudoh Hiroshi Iwasaki Makio Uwaha 《Surface science》2008,602(17):2880-2885
Smoothing of an atomically rough vicinal surface of SrTiO3 is studied by scanning tunneling microscope (STM) observation and by Monte Carlo (MC) simulation. A complex step pattern that resembles a two-dimensional phase separation pattern is observed on the surface. Analysis of the step pattern during annealing obtained by the STM in comparison with the MC simulation reveals an asymmetry of the relaxation pattern between islands and holes. The asymmetry is attributed to the difference of the mobility of an adatom and an atomic hole, and the asymmetry is enhanced by the step edge diffusion barrier. Values of an effective bond energy and an effective diffusion barrier as well as the surface diffusion coefficient are deduced from the relaxation pattern. 相似文献
118.
119.
Hirohito Yamazaki Shinji Kimura Mutsumi Tsukahara Keiko Esashika Toshiharu Saiki 《Applied Physics A: Materials Science & Processing》2014,115(1):53-56
In this paper, we propose a new optical detection scheme for nanopore-based DNA sequencing with high resolution towards eventual base identification. We use ultraviolet light for excitation of a fluorescent probe attached to DNA and a nanopore in the silicon membrane that has a significantly large refractive index and an extinction coefficient at ultraviolet wavelengths. In this study, numerical electromagnetic simulation revealed that the z-polarization component (perpendicular to the membrane plane) of the electric field was dominant near the nanopore and generated a large electric field gradient at the nanopore exit, typically with a decay length of 2 nm for a nanopore with diameter of 7 nm. The large extinction coefficient contributed to reduction in background noise coming from fluorophore-labeled DNA strands that remain behind the membrane (the cis side of the membrane). We observed a high signal-to-noise ratio of single DNA translocation events under the application of an electric field. 相似文献
120.
用两波混频方法在514.5nm(氩离子激光器)对BSO晶体中光折变增益与入射面情况的依赖关系进行了研究,由于BSO晶体围绕<110>轴旋转时受主能级状态的影响,从而光折变增益将取决于衍射效率的改变。 相似文献