Biomedical subjects

Allan S Myerson

Publications and source records attributed to Allan S Myerson.

4 recordsLinked to original sources

PubMed2005

Crystallization on confined engineered surfaces: a method to control crystal size and generate different polymorphs.

Patterned glycine crystals nucleated on functionalized metallic square islands. This approach can be used to fabricate particles with micron dimensions and screen solid forms under different conditions. The size of the glycine crystals is controlled by the dimensions of the islands. High energy metastable beta-glycine crystallizes on small metallic islands, whereas for large islands, the polymorphic outcome becomes biased toward the alpha-form.

Crystallization↗

PubMed2005

Strong dc electric field applied to supersaturated aqueous glycine solution induces nucleation of the gamma polymorph.

Applying a strong static electric field to supersaturated aqueous glycine solutions resulted in the nucleation of the gamma polymorph. This is the first report of a strong dc field inducing the nucleation of a neutral solute in a supersaturated solution. We attribute this effect to the electric-field-induced orientation of the highly polar glycine molecules in large preexisting solute clusters, helping them organize into a crystalline structure. This result also lends further support to our proposed optical-Kerr mechanism for nonphotochemical laser-induced nucleation.

Crystallization↗

PubMed2004

Molecular dynamics study of the interactions of ice inhibitors on the ice {001} surface.

The interactions of antifreeze protein (AFP) type I, antifreeze glycoproteins, polyvinyl pyrrolidone (PVP), and various amino acids with ice are investigated using Cerius2, a molecular modelling tool. Binding energies of these additives to a major ice crystal face {001} are computed. Binding energy comparison of threonine molecules (by themselves) and as threonine residues within AFP type I demonstrate their role in improving AFP's binding ability to the ice crystal face. The shifts in onset points of ice crystallization with AFP type I, PVP, and amino acids are measured using differential scanning calorimetry. These values when correlated with their respective binding energies reveal a direct proportionality and demonstrate AFP's effectiveness in inhibiting growth and nucleation of ice, over amino acids.

Antifreeze Proteins↗

PubMed2002

Polarization switching of crystal structure in the nonphotochemical light-induced nucleation of supersaturated aqueous glycine solutions.

By switching between linear and circular polarization in the irradiation of supersaturated solutions of the amino acid glycine in water with intense nanosecond pulses of near-infrared laser light, we have obtained the gamma and alpha phases, respectively, through nonphotochemical light-induced nucleation (NPLIN). This is the first report of light polarization controlling crystal structure. The intensity dependence of NPLIN in aqueous urea is also reported.

Glycine↗