Within the universe an influence creates processes and forms with helicity and spin, and there is a handedness bias. The scale of objects with helicity and spin goes from galaxies to miniscule atomic structures. A helical structure has chiral properties which allows helical structures of the same type at 180° to each other to effortlessly merge. Gravity with a helical electromagnetic field stru...

We perform direct numerical simulations of the equations of magnetohydrodynamics with external random forcing and in the presence of gravity. The domain is divided into two parts: a lower layer where the forcing is helical and an upper layer where the helicity of the forcing is zero with a smooth transition in between. At early times, a large-scale helical dynamo develops in the bottom layer. A...

Many jets exhibit twisted helical structures. Where superluminal motions are detected, jet orientation and pattern/flow speed are considerably constrained. In this case modeling efforts can place strong limits on conditions in the jet and in the external environment. This can be done by modeling the spatial development of helical structures which are sensitively dependent on these conditions. A...

The alpha-aminoisobutyric (Aib) residue has generally been considered to be a strongly helicogenic residue as evidenced by its ability to promote helical folding in synthetic and natural sequences. Crystal structures of several peptide natural products, peptaibols, have revealed predominantly helical conformations, despite the presence of multiple helix-breaking Pro or Hyp residues. Survey of s...

We show that diradicaloid helical conjugated molecules can display strong through-space bonding interactions. These interactions are analogous to π-stacking pancake bonding widely observed for dimers and other aggregates of stable π-conjugated radicals. We show that these multicenter interactions can have a significant stabilizing effect, but they depend in subtle ways on the specific overlap a...

We present Monte Carlo simulation results for square-well homopolymers at a series of bond lengths. Although the model contains only isotropic pairwise interactions, under appropriate conditions this system shows spontaneous chiral symmetry breaking, where the chain exists in either a left- or a right-handed helical structure. We investigate how this behavior depends upon the ratio between bond...

Sequence-specific binding of proteins to their DNA targets involves a complex spectrum of processes that often induce DNA conformational variation in the bound complex. The forces imposed by protein binding that cause the helical deformations are intimately interrelated and difficult to parse or rank in importance. To investigate the role of electrostatics in helical deformation, we quantified ...

Dimers of appropriately arranged anion-responsive π-conjugated moieties form helical structures by interaction with chiral anions. Terphenyl-bridged dimers of dipyrrolyldiketone boron complexes show chirality induced by binding l-amino acid anions, as observed by circular dichroism (CD) and circularly polarized luminescence (CPL). The preferred configurations of helical structures depend on the...

We have systematically compared structures of multi-helical DNA-binding domains (DBDs) which have been determined by crystallography or NMR spectroscopy. All the known multi-helical DBDs are very similar. The core of these structures consists of two alpha-helices in the helix-turn-helix combination, associated with one or two other helices. The structures can be classified according to either a...

Magnetohydrodynamic (MHD) equilibrium states with imposed axisymmetric boundary are computed in which a spontaneous bifurcation develops to produce an internal three-dimensional (3D) configuration with a helical structure in addition to the standard axisymmetric system. Equilibrium states with similar MHD energy levels are shown to develop very different geometric structures. The helical equili...