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Singular and N onsingular Circulant Asymmetric Digraphs

Abstract

This paper describes two special types of digraphs which arc r-regular, circulant and asymmetric. These graphs are denoted by Crn ‘and dCn. Specifically, this paper shows which of these special classes of r-egular, asymmetric and circulant digraphs are singular and which are non-singular. Read More

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Diterpenes from the Soft Coral Clavularia inflata (Coelenterata, Octocorallia, Stolonifera)

Abstract

Three diterpenes were isolated from the dichloromethane extract of the Stolonifer Clavularia inflata. The structure of (3S,4S)-clavulara-l (15), 17- diene-3,4-diol 1 was elucidated by 1 D and 2D NMR spectroscopy while the structures of (4R)-clavulara-l(l5),17-diene-4-o1 2 and (lR,4R)clavulara- 17-ene-l,4-dioI3 were determined by comparing their proton NMR spectra with those previously reported. Read More

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Genomic Characterization and Physical Mapping of Shigella flexneri Serotype-Specific Antigen V Temperate Bacteriophage

Abstract

Shigella flexneri hosts a temperate bacteriophage SfV responsible for the conversion of serotype Y strains (3,4) to serotype Sa (V; 3,4) through its glucosyl transferace gene. This enzyme mediated conversion effects a molecular antigenic conversion in glucosyl or glycosylic moiety attachment generating a corresponding immunogenic shift in the O-antigen component of the outer membrane lipopolysaccharide immune response among Shigellosis patients. With respect to vaccine development, further investigation into SfV’s complete genome is crucial to explore and distinctly locate other genetic horizontal transfer contributing immunogenicity aside from the somatic antigen and proteins encoded by the invasion plasmid. Read More

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Synthesis of sugar functionalized tetrathiafulvalene

Abstract

The synthesis and chemistry of the water soluble sugar functionalized tetrothiafulvalenes are discussed. The use of a suitable protecting group for the coupling between oxone and thiones is given along with deprotection and subsequent nucleophilic substitution with halosugars. The potential applications of these promising sugar derivatized tetrathiafulvalenes are hereby enumerated. Read More

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A Flavone from Vitex parviflora

Abstract

The chloroform extract of the air-dried leaves of Vitex parviflora afforded retusin by silica gel chromatography. Its structure was elucidated by extensive ID and 2D NMR spectroscopy. Antimicrobial tests indicated that retusin has moderate activity against the fungi, A. niger and low activity against the bacteria, P. aeruginosa. It was found inactive against the fungi, C. albicans and T. mentagrophytes and the bacteria: E. coli, S. aureus and B. subtilis. Read More

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Some Related Designs of Paley 2-designs of QN-type

Abstract

Paley 2-designs of QN-type are symmetric 2- (2q+ I, q . a-1/2) designs where q is a prime power such that q= 1 (mod 4). The main results of this paper show that the Paley 2-designs of QN-type and their complements are self-dual. Read More