Recent discovery of mesoscopic electronic structures, in particular the carbon nanotubes, made necessary an investigation of what effect may helical symmetry of the conductor (metal or semiconductor) have on the persistent current oscillations. We investigate persistent currents in helical structures which are non-decaying in time, not requiring a voltage bias, dissipationless stationary flow o...

Tensegrity grids composed of tensegrity units that form double layer cable nets of single or double curvature can find applications in architecture as surface structures. In this paper a parametric process for the geometric configuration and representation of double layer tensegrity structures of helical shape is discussed. Departing from the geometric construction process, an algorithm that fa...

A combination of conformational search, energy minimization, and energetic evaluation using a continuum solvent treatment has been employed to study the stability of various conformations of the DNA fragment d(CGCAGAA)/d(TTCGCG) containing a single adenine bulge. The extra-helical (looped-out) bulge conformation derived from a published x-ray structure and intra-helical (stacked bulge base) mod...

Ribonucleic acid structure determination by NMR spectroscopy relies primarily on local structural restraints provided by H–H NOEs and J-couplings. When employed loosely, these restraints are broadly compatible with Aand B-like helical geometries and give rise to calculated structures that are highly sensitive to the force fields employed during refinement. A survey of recently reported NMR stru...

the automatic assignment of protein secondary structure from three dimensional coordinates is an essentialstep in the characterization of protein structure.although, the recognition of secondary structures suchas alpha-helices and beta-sheets seem straightforward, but there are many different definitions, eachregarding different criteria. we have developed a newalgorithm for protein helix assig...

Helical structures, ubiquitous in nature, have inspired design and manufacturing of helical devices with applications in nanoelecromechanical systems, morphing structures, optoelectronics, microrobotics and drug delivery devices. Meanwhile, multi-stable structures have attracted increasing attention for their applications in bio-inspired robots and deployable aerospace components. Here we show ...