The primary pathogenic event of sickle cell anemia is the polymerization of the mutant hemoglobin (Hb) S within the red blood cells, occurring when HbS is in deoxy state in the venous circulation. Polymerization is known to start with nucleation of individual polymer fibers, followed by growth and branching via secondary nucleation, yet the mechanisms of nucleation of the primary fibers have ne...

The nucleation and growth of sol-gel derived TiO2 colloidal nanoparticles have been studied using  experiment and theory as well. In this study, the temperature effect on the formation of TiO2 nanoparticles was discussed and some effective parameters such as the supply rate of solute (Q0), the mean volumic growth rate of stable nuclei during the nucleat...

This article reviews recent ­ ndings on internal and surface nucleation in silicate glasses. The internal homogeneous nucleation rates sharply decrease and the induction times increase with the Tg=TL ratio (Tg is the glass-transition temperature and TL is the liquidus temperature). Only systems that have Tg=TL < 0:58 display measurable internal nucleation rates on a laboratory time-scale. Numer...

The nitrate-regulated promoter of narG in Escherichia coli was fused to promoterless ice nucleation (inaZ) and green fluorescent protein (GFP) reporter genes to yield the nitrate-responsive gene fusions in plasmids pNice and pNgfp, respectively. While the promoter of narG is normally nitrate responsive only under anaerobic conditions, the L28H-fnr gene was provided in trans to enable nitrate-de...

Physical and biochemical aspects of protein crystal nucleation can be distinguished in an appropriately designed experimental setting. From a physical perspective, the diminishing number of nucleation-active particles (and/or centers), and the appearance of nucleation exclusion zones, are two factors that act simultaneously and retard the initially fast heterogeneous nucleation, thus leading to...

Formin proteins and their associated factors cooperate to assemble unbranched actin filaments in diverse cellular structures. The Saccharomyces cerevisiae formin Bni1 and its associated nucleation-promoting factor (NPF) Bud6 generate actin cables and mediate polarized cell growth. Bud6 binds to both the tail of the formin and G-actin, thereby recruiting monomeric actin to the formin to create a...

Systems with long-range interactions when quenched into a metastable state near the pseudospinodal exhibit nucleation processes that differ from classical nucleation seen near the coexistence curve. In systems with long-range elastic forces the description of the nucleation process can be quite subtle due to the presence of bulk and surface elastic compatibility constraints. We analyze the nucl...

The kinetics of nucleation of one-component gas hydrates in aqueous solutions are analyzed. The size of the hydrate nucleus and the work for nucleus formation are determined as functions of the supersaturation Dm: Expressions for the stationary rate J of hydrate nucleation are derived. These expressions describe the JðDmÞ dependence for homogeneous nucleation and for heterogeneous nucleation at...

The division of semi-crystalline polymeric material into small domains is an effective tool for studying crystal nucleation. The scaling behavior of the nucleation rate as a function of domain size can reveal important information about the mechanism responsible for the birth of a crystal nucleus. We have investigated the process of crystal nucleation in a system of dewetted polyethylene drople...