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941.
M. Matsumoto C. E. McNamee D. P. Bossev M. Nakahara T. Ogawa 《Colloid and polymer science》2000,278(7):619-628
Tetraethylammonium perfluorooctyl sulfonate (TEAFOS; critical micelle concentration, 1 mM), which forms a threadlike micelle
in its pure solution, was adopted to study the structure of salted-out, solubilized micelles and microemulsions by cryogenic
transmission electron microscopy. The concentration of the surfactant was kept constant at 60 mM. The micelle solution salted
out with LiNO3 provided a surfactant phase in the presence of a clear interface. The surfactant phase was studded, being formed of homogeneously
dispersed spherical micelles, and had no obvious threadlike forms. The micelles, which solubilized the maximum amount of perfluorinated
oil, were spherical and had the same size as isolated spherical micelles in pure TEAFOS solution. The microemulsions were
formed in the presence of perfluorinated alcohol as cosurfactant and the particles were rotund even when the concentration
of the perfluorinated oil was equivalent to that for solubilization and the sizes increased with increasing oil content. The
difference in size between the solubilized micelles and microemulsions with the same amount of oil suggested that the oil
molecules had been solubilized between palisades of perfluorinated alkyl chains in the micelles and had dissolved in the cores
of the microemulsions.
Received: 10 September 1999/Accepted: 2 December 1999 相似文献
942.
943.
Akira Matsumoto Tomonori Ohashi Hiroaki Oe Hiroyuki Aota Jun‐Ichi Ikeda 《Journal of polymer science. Part A, Polymer chemistry》2000,38(24):4396-4402
As an extension of our work on the elucidation of the mechanism and control of 3‐dimensional network formation in the free‐radical crosslinking polymerization and copolymerization of multivinyl compounds with the aim to molecularly design vinyl‐type network polymers, novel amphiphilic polymers were prepared as crosslinked polymer precursors. Thus, benzyl methacrylate, a nonpolar monomer, was copolymerized radically with 5 mol % of triicosaethylene glycol dimethacrylate [CH2C(CH3)CO(OCH2CH2)23OCOC(CH3)CH2], a polar monomer, in the presence of lauryl mercaptan as a chain transfer agent. The resulting prepolymers (i.e., vinyl‐type network‐polymer precursors or amphiphilic polymers) were characterized mainly by viscometry using t‐butylbenzene (t‐BB) and a t‐BB/MeOH (80/20) mixture as solvents. The viscosities in the t‐BB/MeOH (80/20) mixture were quite high compared with those in t‐BB, and completely reversed concentration dependencies were observed in the solvents. These are discussed by considering the difference in conformation and the shrinkage of polar, flexible polyoxyethylene units or the entanglement of nonpolar, rigid primary chains. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4396–4402, 2000 相似文献
944.
Akira Matsumoto Akiyoshi Ueda Hiroyuki Aota Jun‐ichi Ikeda 《Macromolecular rapid communications》2000,21(10):701-703
The preliminary study of the effect of physical crosslinking on the gelation in monovinyl/divinyl copolymerizations is described. Thus, mono(2‐methacryloyloxyethyl) succinate was added to the crosslinking copolymerization of butyl methacrylate with 1,6‐hexanediol dimethacrylate and the gelation was explored in terms of the effect of hydrogen bonds formed between carboxyl groups introduced into the primary polymer chain. 相似文献
945.
946.
947.
Toshihiro Ichino Morihiko Matsumoto J. Steven Rutt Shiro Nishi 《Journal of polymer science. Part A, Polymer chemistry》1993,31(7):1701-1707
A new dual-phase solid polymer electrolyte system has been proposed. In this system, a network of ion pathways is formed in a low-polarity, host polymer matrix. A series of electrolytes were prepared from styrene-butadiene copolymer latices with dissolved lithium salts. Polymer films were formed from these latices, and then impregnated with γ-butyrolactone (γ-BL) or γ-butyrolactone/dimethoxyethane mixture (γ-BL/DME), giving latex polymer electrolytes. The ionic conductivity of the polymer electrolyte system increased with increasing solvent content, although a distinct percolation threshold was not measured. Ionic conductivity also increased with the use of DME cosolvent, with the highest conductivity being 1.4 × 10?4S/cm. Complex impedance diagrams are discussed. The diagrams show significant deviations from the ideal. TEM/SEM observations are consistent with the desired dual-phase morphology. © 1993 John Wiley & Sons, Inc. 相似文献
948.
Targeted proteo-glycomics analysis of Sialyl Lewis X antigen expressing glycoproteins secreted by human hepatoma cell line. 总被引:2,自引:0,他引:2
Sialyl Lewis X (SLEX) antigen, Neu5Acalpha2-3Galbeta1-4 (Fucalpha1-3) GlcNAc-R, plays important roles in cell-to-cell interaction: for example, the E- and P-selectin-mediated influx of SLEX expressing leukocytes into inflamed areas. A human hepatocellular carcinoma cell line, HepG2 cells, was highly expressed SLEX on secreted glycoproteins and cell surface, in contrast with HuH-7 cells. We identified SLEX expressing glycoproteins in HepG2 cultured medium by two-dimensional polyacrylamide gel electrophoresis, followed by in gel digestion and peptide mass fingerprint using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOFMS), including transferrin, alpha1-antitrypsin, alpha2-HS glycoprotein and beta-glycoprotein. We analyzed N-glycans of these glycoproteins by MALDI-TOFMS in combination with exoglycosidase digestion; our results indicate increases in poly-fucosylated and high-branched N-glycans. High alpha1,3-fucosylation in glycoproteins would be caused by increased expression of alpha1,3-fucosyltransferase activities in HepG2 cells. 相似文献
949.
A simple, rapid, and reliable method for the determination of residual sulphonamide antibacterials (SAs) (sulfadiazine, sulfamerazine, sulfadimidine, sulfamethoxypiridazine, sulfisozole, sulfamonomethoxine, sulfamethoxazole, sulfisoxazole, sulfadimethoxine, and sulfaquinoxaline) in animal liver and kidney was developed using a combination of clean-up on a Bond Elut PSA cartridge and HPLC with UV detection. The SAs were extracted with ethyl acetate and then dissolved in 5 ml of 50 v/v% ethyl acetate-n-hexane after being evaporated to dryness. For clean-up of the crude sample, the resuspended extract was applied to a Bond Elut PAS (primary/secondary amine cartridge), and then SAs were eluted from the cartridge using 5 ml of 20 v/v% acetonitrile-0.05 M ammonium formate before being analysed by HPLC. Recoveries of the SAs at the levels of 0.5 and 0.1 microg/g were 70.8-98.2%, the rerative standard deviation were less than 7.0%, and the detection limits were 0.03 microg/g. The present analysis method of SAs in animal kidney and liver using HPLC with a clean-up procedure was demonstrated to be highly applicable to the direct LC-MS-MS analysis without any modification. 相似文献
950.
Shuichi Matsumura Takeshi Okamoto Keisuke Tsukada Kazunobu Toshima 《Macromolecular rapid communications》1998,19(6):295-298
Oxiranes, such as glycidyl phenyl ether (GPE) and benzyl glycidate (BG), were copolymerized with succinic anhydride (SA) by lipase at a temperature between 60 and 80°C to yield the corresponding polyesters bearing carboxyl or phenyl groups. Bulk polymerization, especially at the temperature of 80°C, and preferably using porcine pancreatic lipase gave biodegradable polyesters with a molecular weight greater than 5000. 相似文献