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111.
Kim Y Kim KS Kounovsky KL Chang R Jung GY dePablo JJ Jo K Schwartz DC 《Lab on a chip》2011,11(10):1721-1729
Fully stretched DNA molecules are becoming a fundamental component of new systems for comprehensive genome analysis. Among a number of approaches for elongating DNA molecules, nanofluidic molecular confinement has received enormous attentions from physical and biological communities for the last several years. Here we demonstrate a well-optimized condition that a DNA molecule can stretch almost to its full contour length: the average stretch is 19.1 μm ± 1.1 μm for YOYO-1 stained λ DNA (21.8 μm contour length) in 250 nm × 400 nm channel, which is the longest stretch value ever reported in any nanochannels or nanoslits. In addition, based on Odijk's polymer physics theory, we interpret our experimental findings as a function of channel dimensions and ionic strengths. Furthermore, we develop a Monte Carlo simulation approach using a primitive model for the rigorous understanding of DNA confinement effects. Collectively, we present a more complete understanding of nanochannel confined DNA stretching via the comparisons to computer simulation results and Odijk's polymer physics theory. 相似文献
112.
113.
Sang Soo Lee Hyun Woo Cho Sang Kyu Lim Ki Ho Han Jin Soo Han Moo Jung Chu Je Soo Ko Kyeong-Mo Yoon Yong-Gi Lee 《光学学报》2003,23(Z1)
Transmission of 40Gbit/s NRZ signal was successfully demonstrated over 219km of installed SMF in KT's Daejeon area network. After transmission, the measured power penalty was 0.5dB for all the tributary channels. 相似文献
114.
Ki Chul Park Masatsugu Fujishige Susumu Arai Morinobu Endo 《Journal of Physics and Chemistry of Solids》2008,69(10):2481-2486
High-speed agitation by a mixing blade has efficiently achieved the cutting of a large diameter (100-150 nm) of multi-walled carbon nanotubes. The cutting process is caused by an inter-collision of the nanotubes with high transfer energy. The collision-induced cutting allows for the shortening of the nanotubes without serious damage of the original graphitic layers due to the cutting effect being limited to the collision points. Furthermore, the operation under ambient atmosphere introduces oxygen-containing functional groups to the cut nanotubes. The estimated length distribution has indicated that high-speed agitation achieves a large cutting effect during a short duration of several minutes. 相似文献
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116.
Il Kim Hong Ki Choi Taek Kyu Han Seong Ihl Woo 《Journal of polymer science. Part A, Polymer chemistry》1992,30(10):2263-2271
A series of monoester catalysts has been studied, each catalyst prepared by the reaction of magnesium diethoxide with benzoyl chloride [BzCOCl, to produce ethyl benzoate (EB) in situ] in the presence of excess titanium tetrachloride. Solid product and catalysts obtained by subsequent treatments with titanium tetrachloride were characterized by elemental analysis, IR spectroscopy, x-ray diffraction, BET measurement, and thermal gravimetric analysis. The catalysts yielded very high activity (above 20 kg polymer/g Ti h atm) for the polymerization of propylene in slurry reactions. From the results of polymerization as well as catalyst characterization, the effects of internal and external Lewis bases on the isospecificity and stability of catalysts are discussed in detail. © 1992 John Wiley & Sons, Inc. 相似文献
117.
We prove the semigroup generated by four binary relations contains all regular binary relations. 相似文献
118.
We present a model of social systems as special types of games in extensive form in which perception and learned strategies play an important role. We discuss personality, emotions, and the relation of utility to Maslow's hierarchy of values. We also formulate a new class of games, partially cooperative games, and attempt to define a solution concept for these. 相似文献
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120.
A new pteridine compound was isolated from green sulfur photosynthetic bacteria, Chlorobium limicola f. thiosulfatophilum NCIB 8327. The structure of this pterin derivative was established to be 1-O-(L -erythro-5,6,7,8- tetrahydropterin-2′-yl)-β-N-acetylglucosamine ( 1 ) from 1H-NMR and CD spectra as well as from various mass spectrometric techniques and chemical-cleavage techniques. Upon acid hydrolysis of 1 , equimolar amounts of biopterin ( 2 ) and N-acetylglucosamine were produced. The structure of the hydrolysis product 2 was confirmed by comparing its NMR, UV, CD, and MS and its chromatographical behavior with those of an authentic specimen. N-Acetylglucosamine was identified by an enzymatic hydrolysis experiment as well as by NMR and thin layer chromatography. Electrospray (ES), fast-atom-bombardment (FAB), and thermospray (TS) mass spectrometry of 1 yielded an MH+ at m/z 441. Periodate-oxidation experiments of the intact molecule 1 and of its hydrolysis product 2 are consistent with the proposed structure. Differential I2 oxidation experiments with the native compound showed that the in vivo oxidation state of this pterin is its tetrahydro form. We propose the trivial name ‘limipterin’ for this new compound. 相似文献