Medium sized carbocycles are particularly difficult to synthesize. Ring closing metathesis reactions (RCM) have recently been applied to construct eight-membered carbocycles, but trisubstituted double bonds in the eight-membered rings are more difficult to produce using RCM reactions. In this review, model examples and our own results are cited and the importance of the preparation of suitably ...

We study basic properties of quiescent and rotating multipole-mode solitons supported by axially symmetric Bessel lattices in a medium with defocusing cubic nonlinearity. The solitons can be found in different rings of the lattice and are stable when the propagation constant exceeds the critical value, provided that the lattice is deep enough. In a high-power limit the multipole-mode solitons f...

Evaporation-induced self-assemblies (EISAs) with various morphologies were selectively fabricated by drying a solution containing polypyrrole nanoparticles. The morphogenesis of EISAs was strongly dependent upon the solvent evaporation rate and the nanoparticle concentration. In the case of fast evaporation, 2-D dendrites or pseudo 1-D dendrites were observed. When the liquid medium evaporated ...

The title compound, [Fe(C(5)H(5))(C(17)H(11)BrN(3))], was synthesized by the reaction of 4-bromo-benzaldehyde, acetyl-ferrocene and ammonium acetate in an aqueous medium. The crystal packing is stabilized by inter-molecular N-H⋯N hydrogen bonds. The dihedral angles between the phenyl ring and the pyridine and cyclopentadienyl rings are 51.67 (13) and 12.12 (21)°, respectively.

A versatile and metal-free approach for the synthesis of carbocycles and of heterocycles bearing seven- and eight-membered rings is described. The strategy is based on ring expansion of 1-vinylcycloalkanols (or the corresponding silyl or methyl ether) mediated by the hypervalent iodine reagent HTIB (PhI(OH)OTs). Reaction conditions can be easily adjusted to give ring expansion products bearing ...

The design of concentric ring arrays for isoflux radiation is presented in this paper. This design considers the reduction of the side lobe level and isoflux radiation requirements for Medium Earth Orbit (MEO) satellites. The optimization problem considers the spacing among rings and levels of amplitude excitations. The well-known method of Particle Swarm Optimization (PSO) is utilized for this...

Let R be a ring. Let σ be an automorphism of R. We define a σ-divided ring and prove the following. (1) Let R be a commutative pseudovaluation ring such that x ∈ P for any P ∈ Spec(R[x,σ]) . Then R[x,σ] is also a pseudovaluation ring. (2) Let R be a σ-divided ring such that x ∈ P for any P ∈ Spec(R[x,σ]). Then R[x,σ] is also a σ-divided ring. Let now R be a commutative Noetherian Q-algebra (Q i...

Bleomycin (BLM) is a glycopeptide antibiotic and anti-tumor agent that targets primarily the furanose rings of DNA and in the presence of ferrous ions produces oxidative damage and DNA strand breaks. Escherichia coli cells growing in broth medium and exposed to low concentrations of BLM contain double-strand breaks and require homologous recombination to survive. To a lesser extent, the cells a...

The objective of this study was to elucidate the mechanisms associated with the reciprocal relation between magnesium and calcium on vascular smooth muscle tone in bovine pulmonary artery and vein. Rapid removal of magnesium from Krebs-bicarbonate medium used to bathe isolated rings of precontracted artery or vein caused transient endotheliumand calciumdependent relaxation and cyclic GMP accumu...

The objective of this study was to elucidate the mechanisms associated with the reciprocal relation between magnesium and calcium on vascular smooth muscle tone in bovine pulmonary artery and vein. Rapid removal of magnesium from Krebs-bicarbonate medium used to bathe isolated rings of precontracted artery or vein caused transient endothelium- and calcium-dependent relaxation and cyclic GMP acc...