The two-step nucleation model for crystal nuclei formation explains several experimental and theoretical results better than the classical nucleation theory. We report here direct visualization of the two-step nucleation model for organic molecular crystallization. Evaporative crystallization from a solution of a dibenzoylmethane boron complex that displays mechanofluorochromism, a fluorescence...

At first order phase transitions the transition proceeds through droplet nucleation and growth. We discuss a lattice method for calculating the droplet nucleation rate, including the complete dynamical factors. The method is especially suitable for very strongly suppressed droplet nucleation, which is often the case in physically interesting transitions. We apply the method to the 3-dimensional...

The critical cluster is the threshold size above which a cluster will be more likely to grow than to evaporate. In field and laboratory measurements of new particle formation, the number of molecules of a given species in the critical cluster is commonly taken to be the slope of the log-log plot of the formation rate versus the concentration of the species. This analysis is based on an approxim...

1) As also the authors note, the role of ion induced nucleation and even the possible ion-induced nucleation mechanisms are somewhat unresolved. Taking this into account, the authors treat the subject from a slightly too narrow and purpose-oriented point of view. Because of these clear discrepancies between different studies, the authors should very carefully demonstrate e.g. their model calcul...

We demonstrate extreme superheating and single bubble nucleation in an electrolyte solution within a nanopore in a thin silicon nitride membrane. The high temperatures are achieved by Joule heating from a highly focused ionic current induced to flow through the pore by modest voltage biases. Conductance, nucleation, and bubble evolution are monitored electronically and optically. Temperatures n...

We present a computer simulation study on crystal nucleation and growth in supersaturated suspensions of mono-disperse hard spheres induced by a triangular lattice substrate. The main result is that compressed substrates are wet by the crystalline phase (the crystalline phase directly appears without any induction time), while for stretched substrates we observe heterogeneous nucleation. The sh...

It is demonstrated that laser-induced nucleation enables preferential crystallization of metastable anhydrous solids from solution.

Cell motility depends on the rapid growth of cortical actin filaments whose barbed ends are capped in the resting cell. High speed supernates (HSS) of dilute neutrophil lysates contain actin monomers and/or oligomers that can be induced to polymerize by certain stimuli. We questioned whether some of the actin remaining in the supernate after high speed centrifugation exists as occult nucleation...

The Nck adaptor protein recruits cytosolic effectors such as N-WASP that induce localized actin polymerization. Experimental aggregation of Nck SH3 domains at the membrane induces actin comet tails--dynamic, elongated filamentous actin structures similar to those that drive the movement of microbial pathogens such as vaccinia virus. Here we show that experimental manipulation of the balance bet...