Search results for "conjugate"
showing 10 items of 644 documents
Informatics in Descriptive Geometry. Didactic Experience
2009
This study is centred in the environment of the research into solutions of the problems of graphic representation, expressing theoretical considerations which allow the carrying out of geometric-descriptive procedures decoded in informatics language, for implementing CAD commands.
A generalization of groups with many almost normal subgroups
2010
A subgroup $H$ of a group $G$ is called almost normal in $G$ if it has finitely many conjugates in $G$. A classic result of B. H. Neumann informs us that $|G : Z(G)|$ is finite if and only if each $H$ is almost normal in $G$. Starting from this result, we investigate the structure of a group in which each non- finitely generated subgroup satisfies a property, which is weaker to be almost normal.
Anti-$PC$-groups and Anti-$CC$-groups
2007
A groupGhas Černikov classes of conjugate subgroups if the quotient groupG/coreG(NG(H))is a Černikov group for each subgroupHofG. An anti-CCgroupGis a group in which each nonfinitely generated subgroupKhas the quotient groupG/coreG(NG(K))which is a Černikov group. Analogously, a groupGhas polycyclic-by-finite classes of conjugate subgroups if the quotient groupG/coreG(NG(H))is a polycyclic-by-finite group for each subgroupHofG. An anti-PCgroupGis a group in which each nonfinitely generated subgroupKhas the quotient groupG/coreG(NG(K))which is a polycyclic-by-finite group. Anti-CCgroups and anti-PCgroups are the subject of the present article.
Synthesis of sialyl-Tn antigen. Regioselective sialylation of a galactosamine threonine conjugate unblocked in the carbohydrate portion
1994
Abstract Regioselective and stereocontrolled formation of the sialyl-Tn antigen conjugate 6 was achieved by reacting the NeuNAc-2-xanthate 2 with the GalNAc threonine acceptor 5 bearing three hydroxy groups. Complete deprotection afforded the sialyl-Tn antigen structure 11 .
Tris- and tetrakis-[oligo(phenylenevinylene)]silanes: synthesis and luminescence behaviour
2002
Abstract The connection of three or four monodisperse oligo(phenylenevinylene)s to a central silicon atom is performed via Wittig–Horner reactions. The terminal rings are substituted with alkoxy side chains. Depending on the ratio of the lengths of the rigid conjugated units and the flexible side chains, transparent films can be obtained from several of these trigonal-pyramidal or tetrahedral molecules. An intense fluorescence in the blue-green region is emitted by molecules of either shape. These compounds are interesting as active materials for electro-optical applications due to their intense fluorescence and improved film forming capability.
Commutators, C0-semigroups and resolvent estimates
2004
Abstract We study the existence and the continuity properties of the boundary values on the real axis of the resolvent of a self-adjoint operator H in the framework of the conjugate operator method initiated by Mourre. We allow the conjugate operator A to be the generator of a C 0 -semigroup (finer estimates require A to be maximal symmetric) and we consider situations where the first commutator [ H ,i A ] is not comparable to H . The applications include the spectral theory of zero mass quantum field models.
Synthesis, Characterization, and Saccharide Binding Studies of Bile Acid − Porphyrin Conjugates
2007
Synthesis and characterization of bile acid-porphyrin conjugates (BAPs) are reported. Binding of saccharides with BAPs in aqueous methanol was studied by monitoring changes in the visible absorption spectral of the porphyrin-moieties. Although these studies clearly showed absorbance changes, suggesting quite high if non-selective binding, the mass spectral studies do not unambiguously support these results.
Exponential and bayesian conjugate families: Review and extensions
1997
The notion of a conjugate family of distributions plays a very important role in the Bayesian approach to parametric inference. One of the main features of such a family is that it is closed under sampling, but a conjugate family often provides prior distributions which are tractable in various other respects. This paper is concerned with the properties of conjugate families for exponential family models. Special attention is given to the class of natural exponential families having a quadratic variance function, for which the theory is particularly fruitful. Several classes of conjugate families have been considered in the literature and here we describe some of their most interesting feat…
Synthesis and structure-activity relationship studies of cytotoxic cinnamic alcohol derivatives.
2011
Three series of di- and trisubstituted derivatives of cinnamic alcohol and its conjugated dienol analogues were designed and synthesised. The derivatives were screened for cytotoxicity against nine tumour cell lines: KB, A549, Hela, CNE, PC-3, BEL-7404, HL-60, BGC823 and P388D1. Most of the cinnamic alcohol derivatives showed cytotoxic activity. The compound 7-(4',5'-dichlorobenzyloxy)-6,8-dihydroxycinnamic alcohol (55) exhibited significant cytotoxicity to seven human tumour cell lines on a micromolar range, especially with regard to the KB and P388D1 cell lines, showing IC(50) values of 0.4 and 0.5 µM, respectively. The structure-activity relationships of the derivatives are discussed.