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Panagiota G. Fragouli Hermis Iatrou Nikos Hadjichristidis 《Journal of polymer science. Part A, Polymer chemistry》2004,42(3):514-519
A series of five tetrablock quarterpolymers of styrene, isoprene, dimethylsiloxane, and 2-vinylpyridine with molecular weights varying from 117 × 103 to 177 × 103 and having different compositions were synthesized. The synthesis was based on recent advances in the controlled high-vacuum anionic polymerization of hexamethylcyclotrisiloxane and on the selective linking of poly(dimethylsiloxane)lithium with the chlorosilane group of the heterofunctional linking agent chloromethylphenylethylene dimethylchlorosilane. Combined characterization results by size exclusion chromatography, membrane osmometry, and NMR spectroscopy suggested that the synthesized multiblock multicomponent polymers had a high degree of structural and compositional homogeneity. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 514–519, 2004 相似文献
3.
Dimitrios Tzovaras Nikos Grammalidis Michael G. Strintzis 《Signal Processing: Image Communication》1998,11(3):205-230
In the present paper techniques are examined for the coding of the depth map and disparity fields for stereo or multiview image communication applications. It is assumed that both the left and right channels of the multiview image sequence are coded using block- or object-based methods. A dynamic programming algorithm is used to estimate a disparity field between each stereo image pair. Depth is then estimated and occlusions are optionally detected, based on the estimated disparity fields. Spatial interpolation techniques are examined based on the disparity/depth information and the detection of occluded regions using either stereoscopic or trinocular camera configurations. It is seen that the presence of a third camera at the transmitter site improves the estimation of disparities, the detection of occlusions and the accuracy of the resulting spatial interpolation at the receiver. Various disparity field and depth map coding techniques are then proposed and evaluated, with emphasis given to the quality of the resulting intermediate images at the receiver site. Block-based and wireframe modeling techniques are examined for the coding of isolated depth or disparity map information. Further, 2D and 3D motion compensation techniques are evaluated for the coding of sequences of depth or disparity maps. The motion fields needed may be available as a byproduct of block-based or object-based coding of the intensity images. Experimental results are given for the evaluation of the performance of the proposed coding and spatial interpolation methods. 相似文献
4.
Panagiota G. Fragouli Hermis Iatrou Nikos Hadjichristidis Takuro Sakurai Akira Hirao 《Journal of polymer science. Part A, Polymer chemistry》2006,44(1):614-619
3‐Miktoarm star copolymers, 3μ‐D2V, with two poly(dimethylsiloxane) (PDMS) and one poly(2‐vinylpyridine) (P2VP) arm, were synthesized by using anionic polymerization–high vacuum techniques and (chloromethylphenylethyl)methyl dichlorosilane, heterofunctional linking agent, with two SiCl groups and one CH2Cl group. The synthetic strategy involves the selective reaction of the two ? SiCl groups with PDMSOLi living chains, followed by reaction of the remaining chloromethyl group with P2VPLi. Combined molecular characterization results (size exclusion chromatography, membrane osmometry, and 1H NMR spectroscopy) revealed a high degree of structural and compositional homogeneity. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 614–619, 2006 相似文献
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Tzanetos NP Dracopoulos V Kallitsis JK Deimede VA 《Langmuir : the ACS journal of surfaces and colloids》2005,21(20):9339-9345
A detailed study of the self-assembly ability of triblock coil-rod-coil copolymers containing a rigid di(styryl)-anthracene segment covalently linked to oxadiazole-based blocks and their binary blends with oxadiazole-based homopolymers is presented here. The self-organized microdomains seem to pack into a fascinating ordered hexagonal structure obtained at a critical concentration without any significant influence of the sample preparation method, based on evidence obtained by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fluorescence microscopy studies. The compatibilization efficiency of these coil-rod-coil copolymers in polymer blends composed of an electron-accepting polyoxadiazole and a luminescent polyanthracene-based pair was studied by atomic force microscopy (AFM). The common feature of all observed morphologies is the compatibilizing function of the rod-coil molecule, which intercalates between the incompatible domains to prevent the formation of well-defined phase separated nanostructured surfaces. 相似文献
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Oikonomakos NG 《Current protein & peptide science》2002,3(6):561-586
The regulation of the hepatic glucose output through glycogenolysis is an important target for type 2 diabetes therapy. Glycogenolysis is catalyzed in liver, muscle and brain by tissue specific isoforms of glycogen phosphorylase (GP). Because of its central role in glycogen metabolism, GP has been exploited as a model for structure-assisted design of potent inhibitors, which may be relevant to the control of blood glucose concentrations in type 2 diabetes. Several regulatory binding sites have been identified in GP, such as the catalytic, the allosteric, and the inhibitor binding sites. Protein crystallography has contributed significant structural information on the specificity and interactions that distinguish the binding sites, and also revealed a new unexpected binding site (new allosteric site). In this review, the kinetic, crystallographic binding, and physiological studies of a number of compounds, inhibitors of GP, are described, and the essential inhibitory and binding properties of specific compounds are analyzed in an effort to provide rationalizations for the affinities of these compounds and to exploit the molecular interactions that might give rise to a better inhibitor. These studies have given new insights into fundamental structural aspects of the enzyme enhancing our understanding of how the enzyme recognizes and specifically binds ligands, that could be of potential therapeutic value in the treatment of type 2 diabetes. 相似文献
9.
D. Thao Nguyen Matthias Freitag Christian Gutheil Dr. Kai Sotthewes Dr. Bonnie J. Tyler Dr. Marcus Böckmann Mowpriya Das Friederike Schlüter Prof. Dr. Nikos L. Doltsinis Prof. Dr. Heinrich F. Arlinghaus Prof. Dr. Bart Jan Ravoo Prof. Dr. Frank Glorius 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(32):13754-13759
10.
Marinos Pitsikalis Ekaterini Siakali-Kioulafa Nikos Hadjichristidis 《Journal of Polymer Science.Polymer Physics》1996,34(2):249-259
The dilute solution properties of linear polybutadienes with dimethylamine and zwitterionic end groups were studied by membrane osmometry (MO), low-angle laser light scattering (LALLS), viscometry, and dynamic light scattering (DLS) in cyclohexane. The polymers were prepared by anionic polymerization, under high vacuum conditions using [3-(dimethylamino)propyl]lithium as initiator. The dimethylamine groups were converted to zwitterions by reaction with cyclopropane sultone. No evidence of association was found for the amine-capped polymers, whereas the zwitterionic samples exhibited strong association in cyclohexane. The degrees of association increase by decreasing molecular weight of the base polymer due to the excluded volume repulsions. These aggregation numbers are of the same order as those found for ω-functionalized polyisoprenes, with the same polar groups in the same solvent. The hydrodynamic properties, measured by viscometry and dynamic light scattering, supported the conclusions drawn by LALLS and provide strong evidence that the aggregates behave hydrodynamically as star polymers. Comparison with theoretical models shows that the association behavior is best described by the linear head packing model. © 1996 John Wiley & Sons, Inc. 相似文献