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61.
Biosensors based on the shift of whispering-gallery modes in microspheres accompanying protein adsorption are described by use of a perturbation theory. For random spatial adsorption, theory predicts that the shift should be inversely proportional to microsphere radius R and proportional to protein surface density and excess polarizability. Measurements are found to be consistent with the theory, and the correspondence enables the average surface area occupied by a single protein to be estimated. These results are consistent with crystallographic data for bovine serum albumin. The theoretical shift for adsorption of a single protein is found to be extremely sensitive to the target region, with adsorption in the most sensitive region varying as 1/R(5/2). Specific parameters for single protein or virus particle detection are predicted. 相似文献
62.
The time evolution of the concentration profile in a binary multi-layer film is investigated by using the Cahn-Hilliard equation, which is obtained on a basis of the lattice gas model treated within the framework of the layered mean-field approximation. For binary alloys with some ordered structures in the bulk equilibrium phase diagram, it is found that the corresponding structures appear and/or disappear with time, and then the system attains the thermal equilibrium state after an infinite time. It is also found that the time evolution strongly depends on the initial state. 相似文献
63.
We propose a physical mechanism based on breakdown of the Born‐Oppenheimer approximation to rationalize the ultrafast hydrogen migration in strong laser driven isomerization reactions. A three nuclei (proton, donor, and acceptor) model is employed to develop a three step solution scheme. The proton‐donor Coulomb repulsion is shown to be responsible for the high proton mobility. We identify a proton tunneling process and use the Keldysh‐Faisal‐Reiss theory to calculate the tunneling probability. The effect of laser parameters (intensity, frequency, polarization, and pulse duration) has been studied and found to be consistent with recent experiments. 相似文献
64.
Gold‐Catalyzed Enantioselective Synthesis,Crystal Structure,and Photophysical/Chiroptical Properties of Aza[10]helicenes 下载免费PDF全文
Maya Tanaka Dr. Yu Shibata Kyosuke Nakamura Kota Teraoka Prof. Dr. Hidehiro Uekusa Dr. Kazuko Nakazono Prof. Dr. Toshikazu Takata Prof. Dr. Ken Tanaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(28):9537-9541
The enantioselective synthesis of an aza[10]helicene, possessing two pyridone units, has been achieved by the gold‐catalyzed intramolecular quadruple hydroarylation of a tetrayne. This aza[10]helicene was successfully converted into a fully aromatic aza[10]helicene, possessing two pyridine units. Structure–photophysical and chiroptical properties relationship in a series of azahelicene isomers has also been disclosed. 相似文献
65.
X‐ray absorption fine structure study on the role of solvent on polymerization of 3‐hexylthiophene with solid FeCl3 particles 下载免费PDF全文
Tomoyasu Hirai Masanao Sato Makoto Kido Yusuke Nagae Katsuhiro Kaetsu Yudai Kiyoshima Shota Fujii Tomoyuki Ohishi Kevin L. White Yuji Higaki Yasutake Teraoka Maiko Nishibori Kazutaka Kamitani Kenji Hanada Takeharu Sugiyama Ryuichi Sugimoto Kazuhiko Saigo Ken Kojio Atsushi Takahara 《Journal of polymer science. Part A, Polymer chemistry》2015,53(18):2075-2078
66.
We examined the intradermal delivery of a hydrophilic polyphenol chlorogenic acid by in vitro study using excised guinea pig dorsal skin and Yucatan micropig skin. Skin accumulation as well as the solubility of chlorogenic acid in aqueous vehicles was much greater than for other polyphenols such as quercetin and genistein. However, since enhancement of skin delivery seemed to be necessary to exhibit its protective effects against oxidative damage of skin, we examined the effects of microemulsions as vehicles. Using microemulsions consisting of 150 mM NaCl solution, isopropyl myristate, polyoxyethylene sorbitan monooleate (Tween 80) and ethanol, skin accumulation as well as solubility of chlorogenic acid further increased. Enhancement effect of an oil-in-water (o/w-type) microemulsion was greater than that of a water-in-oil (w/o-type) microemulsion possibly due to the greater increase in solubility. This finding was quite different from previous findings on relatively hydrophobic polyphenols such as quercetin and genistein. Pretreatment of guinea pig dorsal skin with chlorogenic acid containing microemulsion gel prevented erythema formation induced by UV irradiation. These findings indicate the potential use of hydrophilic chlorogenic acid with o/w-type microemulsion as a vehicle to protect skin against UV-induced oxidative damage. 相似文献
67.
Y. ItoY. Teraoka 《Solid State Communications》2003,127(4):275-278
Using spin density functional theory within the framework of the local spin density approximation with Perdew-Zunger type exchange-correlation energy, ferromagnetism in a quasi-two-dimensional electron gas (Q-2DEG) is studied. The electronic and magnetic structures of a thin film are calculated as a function of film thickness and electron density. Ferromagnetism in the Q-2DEG is found to appear at a higher electron density than in the three-dimensional electron gas. Unless a film is very thin, with decreasing electron density, a magnetic phase transition occurs from a spin-unpolarized fluid to a Wigner film with surface magnetism, in which the spin polarization localizes only in the neighborhood of surfaces. Further decreasing density induces another transition to a fully spin-polarized ferromagnetic Wigner film. 相似文献
68.
Izumi Iwakura Miho Hatanaka Ai Kokura Haruna Teraoka Taketo Ikeno Takushi Nagata Tohru Yamada 《化学:亚洲杂志》2006,1(5):656-663
The key reactive intermediate of borohydride reduction catalyzed by Schiff base–cobalt complexes is proposed to be the dichloromethylcobalt hydride with a sodium cation, based on experimental and theoretical studies. It was revealed that chloroform is not the solvent but the reactant that activates the cobalt catalyst. The substrate carbonyl compounds are fixed and activated by the alkali cation, which is captured by the oxygen atoms of the planar ligand and the chlorine atom of the axial ligand, and attacked by the hydride on the cobalt atom via a six‐membered‐like transition state to afford the corresponding alcohol. 相似文献
69.
Kobayashi H Shimamura K Akaida T Sakano K Tajima N Funazaki J Suzuki H Shinohara E 《Journal of chromatography. A》2003,990(1-2):169-178
Continuous free flow electrophoresis of proteins was carried out in a microfabricated free flow electrophoresis (mFFE) module with the 30-μm thick slit of the separation. The newly developed micromodule fraction separator (MFS) was attached to the down-stream end site of the separation chamber of mFFE. By using the MFS, electrolyte solution from the separation chamber was introduced to the peristaltic pump without disturbing the electrolyte solution flow at the bottom side of the chamber. The separation of protein mixture samples was achieved by a hydroxypropylmethylcellulose pretreatment coating of the separation chamber. The pretreatment of the sample chamber effectively suppressed electroosmotic flow. All fractionated samples were collected using the MFS after continuous elecrophoresis and analyzed by reversed-phase HPLC. From the results of HPLC analyses none of the cytochrome c fractions at the other ports revealed cross talk phenomena at adjacent ports. A similar result occurred for the myoglobin. This means that these proteins were completely separated from each other by continuous mFFE, and the MFS functioned efficiently during continuous electrophoresis. 相似文献
70.
Kisho Mori Mitsuhiro Hirase Takahiro Morishige Eri Takano Hirobumi Sunayama Yukiya Kitayama Sachiko Inubushi Ryohei Sasaki Masakazu Yashiro Toshifumi Takeuchi 《Angewandte Chemie (International ed. in English)》2019,58(6):1612-1615
Exosomes are small (30–100 nm) membrane vesicles that serve as regulatory agents for intercellular communication in cancers. Currently, exosomes are detected by immuno‐based assays with appropriate pretreatments like ultracentrifugation and are time consuming (>12 h). We present a novel pretreatment‐free fluorescence‐based sensing platform for intact exosomes, wherein exchangeable antibodies and fluorescent reporter molecules were aligned inside exosome‐binding cavities. Such antibody‐containing fluorescent reporter‐grafted nanocavities were prepared on a substrate by well‐designed molecular imprinting and post‐imprinting modifications to introduce antibodies and fluorescent reporter molecules only inside the binding nanocavities, enabling sufficiently high sensitivity to detect intact exosomes without pretreatment. The effectiveness of the system was demonstrated by using it to discriminate between normal exosomes and those originating from prostate cancer and analyze exosomes in tear drops. 相似文献