2,597 research outputs found

    Bochner and conformal flatness on normal complex contact metric manifolds

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    We will prove that normal complex contact metric manifolds that are Bochner flat must have constant holomorphic sectional curvature 4 and be Kähler. If they are also complete and simply connected, they must be isometric to the odd-dimensional complex projective space CP 2n+1(4) with the Fubini-Study metric. On the other hand, it is not possible for normal complex contact metric manifolds to be conformally flat

    Isotropic-medium three-dimensional cloaks for acoustic and electromagnetic waves

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    We propose a generalization of the two-dimensional eikonal-limit cloak derived from a conformal transformation to three dimensions. The proposed cloak is a spherical shell composed of only isotropic media; it operates in the transmission mode and requires no mirror or ground plane. Unlike the well-known omnidirectional spherical cloaks, it may reduce visibility of an arbitrary object only for a very limited range of observation angles. In the short-wavelength limit, this cloaking structure restores not only the trajectories of incident rays, but also their phase, which is a necessary ingredient to complete invisibility. Both scalar-wave (acoustic) and transverse vector-wave (electromagnetic) versions are presented.Comment: 17 pages, 12 figure

    Acetazolamide-based fungal chitinase inhibitors

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    Chitin is an essential structural component of the fungal cell wall. Chitinases are thought to be important for fungal cell wall remodelling, and inhibition of these enzymes has been proposed as a potential strategy for development of novel anti-fungals. The fungal pathogen Aspergillus fumigatus possesses two distinct multi-gene chitinase families. Here we explore acetazolamide as a chemical scaffold for the inhibition of an A. fumigatus ‘plant-type’ chitinase. A co-crystal structure of AfChiA1 with acetazolamide was used to guide synthesis and screening of acetazolamide analogues that yielded SAR in agreement with these structural data. Although acetazolamide and its analogues are weak inhibitors of the enzyme, they have a high ligand efficiency and as such are interesting leads for future inhibitor development

    A Darboux theorem for generalized contact manifolds

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    We consider a manifold M equipped with 1-forms η1,...,ηsη1, ..., ηs which satisfy certain contact like properties. We prove a generalization of the classical Darboux theorem for such manifolds
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