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1.
Mineo Hashizume Hiroaki Inoue Kiyofumi Katagiri Atsushi Ikeda Jun-Ichi Kikuchi 《Journal of Sol-Gel Science and Technology》2004,31(1-3):99-102
Morphological characterization of the organic-inorganic vesicular nanohybrids, Cerasomes, was performed in aqueous media from two aspects. Firstly, a novel Cerasome-forming lipid having two triethoxysilyl groups in the head moiety was synthesized and the physical property of the Cerasome was investigated. While the morphological stability of the Cerasomes, as evaluated from the vesicular collapse behavior against a micelle-forming nonionic surfactant, Triton-X 100, was extremely higher than that of the conventional phospholipid liposome, the stabilities were comparable to each other for the Cerasomes derived from the dual- and single-head lipids. On the other hand, the surface property of the Cerasome formed with the dual-head lipid more closely resembled the colloidal silica particles rather than that derived from the single-head lipid, as suggested by zeta-potential measurements. Secondly, the effect of the media pH on the morphological stability of the Cerasome formed with the single-head lipid was evaluated and appeared as a time difference in obtaining the morphological stability of the Cerasome. These morphological characteristics of the Cerasomes could be mainly owing to the development of the siloxane network on the vesicular surface. 相似文献
2.
This work consists of two parts. In Part I, we shall give a systematic study of Lorentz conformal structure from structural viewpoints. We study manifolds with split-complex structure. We apply general results on split-complex structure for the study of Lorentz surfaces.In Part II, we study the conformal realization of Lorentz surfaces in the Minkowski 3-space via conformal minimal immersions. We apply loop group theoretic Weierstrass-type representation of timelike constant mean curvature for timelike minimal surfaces. Classical integral representation formula for timelike minimal surfaces will be recovered from loop group theoretic viewpoint. 相似文献
3.
Jun-Ichi Anzai Yoko Sakata Yasuhiro Suzuki Akihiko Ueno Tetsuo Osa 《Journal of polymer science. Part A, Polymer chemistry》1983,21(3):855-864
Crown ether-modified polyethylenimines (PEI-CR) were prepared to elucidate their cation binding efficiency and selectivity by liquid-liquid and solid-liquid extraction methods. With alkali metal cations it was found that polyethylenimines containing benzo-15-crown-5 moieties (Ia and Ib) extracted all cations examined more efficiently than their monomeric analogs, especially in the cases of K+ and Rb+ cations. The solid-liquid extraction revealed clearly that the polymers complexed with K+ and Rb+ cations according to a 1:2 cation-to-crown stoichiometry. The high selectivities of the polymers for K+ and Rb+ were interpreted in terms of the favourable conformation of the polymer chain for the formation of intramolecular 1:2 complexes. On the contrary, these polymers bound alkali earth cations less effectively with low selectivities. 相似文献
4.
Masafumi Kobayashi Tetsuya Inoguchi Takashi Iida Takashi Tanioka Hiroshi Kumase Yasushi Fukai 《Journal of fluorine chemistry》2003,120(2):2838-110
Direct fluorination of 1,3-dioxolan-2-one with elemental fluorine was successfully carried out to provide 4-fluoro-1,3-dioxolan-2-one, which was expected as an additive for lithium ion secondary battery. 4-Fluoro-1,3-dioxolan-2-one was also further fluorinated with elemental fluorine to give three isomers of difluoro derivatives by the same methodology. Another topic is the preparation of trifluoromethanesulfonyl fluoride, an intermediate of lithium battery electrolyte, by the reaction of methanesulfonyl fluoride with elemental fluorine. The use of perfluoro-2-methylpentane as a solvent gave satisfactory selectivity of trifluoromethanesulfonyl fluoride. 相似文献
5.
Jun-Ichi Kikuchi Yukito Murakami 《Journal of inclusion phenomena and macrocyclic chemistry》1998,32(2-3):209-221
Steroid cyclophanes, bearing four bile acid moieties covalently placed on a tetraazaparacyclophane skeleton, were designed and synthesized as artificial cell-surface receptors. Guest-binding behavior of the steroid cyclophanes embedded in a bilayer membrane formed with a synthetic peptide lipid was clarified by means of fluorescence and circular dichroism spectroscopy. We found that the steroid cyclophane effectively bound aromatic guests in both bilayer membranes and aqueous solution. In addition, copper(II) ions acted as a guest species for the steroid cyclophane and a competitive inhibitor toward a NADH-dependent lactate dehydrogenase (LDH). On these grounds, we constituted a supramolecular assembly as an artificial signaling system in combination with the steroid cyclophane, a cationic peptide lipid, and LDH. As a consequence, the steroid cyclophane acted as an effective artificial cell-surface receptor being capable of transmitting an external signal to the enzyme in collaboration with copper(II) ions as a signal transmitter. 相似文献
6.
Summary A high-performance liquid gel-permeation chromatographic method is described for the determination of human serum immunoglobulin G (IgG) by separating the fluorescent immuno complex from the free fluorescence-labeled antibody. Fluorescence-labeled antibody used in this study was fluorescein isothiocyanate (FITC)-labeled Fab fragment goat anti-human IgG (anti-IgG Fab). Immuno complexes and antibody of different molecular sizes can be separated. FITC-labeled anti-IgG Fab was added to the serum and the mixture is passed through the column. An immuno complex separates as well-delineated peak in the column void volume, and was measured by the fluorescence of the column eluate (Ex=490nm, Em=520nm). The total analysis time for a serum sample was approximately 15min. The minimum detection limit was 25 mg/dl. The relative standard deviation was below 2% (peak area). The results of the HPL-GPC analysis correlate well with those obtained by laser nephelometric assay (r=0.992). 相似文献
7.
Yano JI 《Chaos (Woodbury, N.Y.)》1994,4(2):287-297
Some basic theoretical issues of the Jovian atmospheric dynamics are discussed. Those include the depth of the motions, thermal convection both with deep and shallow configurations, the two-dimensional turbulence theory and its relevance. The refractive index analysis is suggested to interpret the coherent structures like Jupiter's Great Red Spot in terms of Charney-Drazin constraint based on the observations. A possibility of Jovian data assimilation is proposed as a future direction. 相似文献
8.
Akhtaruzzaman M Kamata N Nishida J Ando S Tada H Tomura M Yamashita Y 《Chemical communications (Cambridge, England)》2005,(25):3183-3185
Dithiazolylbenzothiadiazoles easily obtained have high electron affinity and the FET device of a trifluoromethylphenyl derivative exhibited a good n-type performance with high electron mobility. 相似文献
9.
Mineo Hashizume Isamu Saeki Masashi Otsuki Jun-Ichi Kikuchi 《Journal of Sol-Gel Science and Technology》2006,40(2-3):227-232
To extend the concept of the Cerasome, an organic-inorganic vesicular nanohybrid, this paper investigates the preparation
and characterization of a “mixed” Cerasome. The system consists of a Cerasome-forming lipid 1, a cationic synthetic lipid 2, and a zwitterionic phospholipid 3. Lipid mixtures of 1 and 2 or 1 and 3 were used to prepare the mixed Cerasomes. Their lipid distributions were examined using differential scanning calorimetry
(DSC), which showed that 1 and 2 (or 1 and 3) were phase-separated in the mixed Cerasomes. These results seem to be mainly attributable to the polymerizable nature of
1. Results of scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX) showed that 1 and 3 were both incorporated into a single Cerasome, not macroscopically separated to form separate vesicles from each lipid component.
Mixed Cerasomes of 1 and 2 showed high morphological stability against a membrane-solubilizing surfactant, incorporating up to 70% of 2. On the other hand, the mixed Cerasomes from 1 and 3 were less stable than the mixed Cerasomes from 1 and 2. This relative instability might be attributable to differences between the mixed Cerasomes from 1 and 2 and 1 and 3 in terms of their vesicular sizes, lipid domain sizes, and their relative effectiveness for siloxane network formation. These
results strongly support the formation of mixed Cerasomes that have lipid domains in-plane. Systems described in this study
are useful to prepare variously mixed Cerasomes that have different surface functionalities and in-plane lipid distribution,
but which have high morphological stability. 相似文献
10.
Talgat M. Inerbaev Vladimir R. Belosludov Rodion V. Belosludov Marcel Sluiter Yoshiyuki Kawazoe Jun-Ichi Kudoh 《Journal of inclusion phenomena and macrocyclic chemistry》2004,48(1-2):55-60
In this work, the electronic, structural, dynamic andthermodynamic properties of structure II, H and tetragonalAr clathrate hydrates have been calculated and the effectof multiple occupancy on their stability has been examinedusing first-principles and lattice dynamics calculations.The dynamic properties of these clathrates have beeninvestigated depending on the number of guest moleculesin a clathrate cage. It has been found that selectedhydrate structures are dynamically stable. The calculatedcell parameters are in agreement with experimental data.We also report the results of a systematic investigationof cage-like water structures using first-principles calculations. Ithas been observed that Ar clusters can be stabilized indifferent water cages and the stability is strongly dependenton the number of argon atoms inside the cages. 相似文献