83,878 research outputs found
K-theory for group C*-algebras
No full textThese notes are based on a lecture course given by the first author in the Sedano Winter School on K-theory held in Sedano, Spain, on January 22-27th of 2007. They aim at introducing K-theory of C*-algebras, equivariant K-homology and KK-theory in the context of the Baum-Connes conjectur
Search for eta(c) decays into pi pi and K(K)over-bar
No full textUsing 58 million J/psi) events taken with the BESII detector, a search for eta(c) CP violating decays into pi pi and K (K) over bar has been performed. No clear 77, signal is observed, and upper limits for B(eta(c) -> pi pi) and B(eta(c) -> K (K) over bar) are given at the 90% confidence level, B(J/psi -> gamma eta(c)) center dot B(eta(c) -> pi(+)pi(-)) < 1.1 x 10(-5), B(J/psi -> gamma eta(c)) center dot B(eta(c) -> pi(0)pi(0)) < 0.71 x 10(-5), B(J/psi -> gamma(eta c)) center dot B(eta(c) -> K+K-) < 0.96 x 10(-5), and B(J/psi -> gamma eta(c)) center dot B(eta(c) (KSKS0)-K-0) < 0.53 x 10(-5).Physics, Particles & FieldsSCI(E)1ARTICLE2337-3414
Elaborate Supramolecular Architectures Formed by Co-Assembly of Metal Species and Peptoid Macrocycles
No full textPeptoids are a family of sequence-specific oligomers capable of mimicking the structure and function of polypeptides. The innate folding and self-assembly capabilities of peptoid oligomers can be enhanced by the presence of coordinated metal ions. In this work, we explore the co-assembly of water-soluble hexameric and tetrameric peptoid macrocycles with Na+ and K+ ions. Solid-state structures were solved for six cyclopeptoid-metal coassemblies by X-ray diffraction using single crystals grown from fully aqueous solutions. Subtle variations in the peptoid oligomer composition give rise to dramatic alterations in the supramolecular assemblies. Some structures feature extensively hydrated porous architectures that include unusual metal ion clusters. The ability to study the metallopeptoid structure at an atomic resolution in crystals obtained from an aqueous solution is an important advancement, as most previous peptoid crystal structures were obtained from nonaqueous or cosolvent solutions. These results will facilitate the design of peptoids and other foldamers for the assembly of supramolecular frameworks
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