Stathmin is a microtubule-destabilizing protein ubiquitously expressed in vertebrates and highly expressed in many cancers. In several cell types, stathmin regulates the partitioning of tubulin between unassembled and polymer forms, but the mechanism responsible for partitioning has not been determined. We examined stathmin function in two cell systems: mouse embryonic fibroblasts (MEFs) isolat...

We performed molecular dynamics (MD) simulations of nucleation from vapor at temperatures below the triple point for systems consisting of 10(4)-10(5) Lennard-Jones (L-J) type molecules in order to test nucleation theories at relatively low temperatures. Simulations are performed for a wide range of initial supersaturation ratio (S(0) ≃ 10-10(8)) and temperature (kT = 0.2-0.6ε), where ε and k a...

We study the phenomenon of decay of a supercurrent in a superconducting thin film due to the spontaneous homogeneous nucleation of quantized vortex-antivortex pairs in the absence of an external magnetic field and in the presence of a periodic pinning potential. We describe the vortex nucleation by means of a Schwinger-type path-integral calculation including the effects of quantum dissipation....

Crystallization of supersaturated liquids usually starts by epitaxial growth or by heterogeneous nucleation on foreign surfaces. Herein, we review recent advances made in modeling heteroepitaxy and heterogeneous nucleation on flat/modulated surfaces and nanoparticles within the framework of a simple dynamical density functional theory, known as the phase-field crystal model. It will be shown th...

The formation of string-gels of dipolar colloidal particles is investigated using molecular dynamics simulations. The characteristic gelation time consistently increases as the temperature of the system increases; it also increases as the density of the system increases. This latter result suggests that the gel formation is not a simple nucleation process. In particular, the energy barriers sep...

– Phenomenological nucleation theories are considered from the viewpoint of Gibbs’ surface thermodynamics. We point out, in defining the critical nucleus, that it is important to make a distinction between the number of molecules enclosed by the surface of tension and the excess number of molecules over the uniform vapor phase. We show that the Kelvin equation should be employed in determining ...

We present preliminary results from large scale molecular dynamics (MD) simulations of homogenous vapor to liquid nucleation. The simulations contain between one and eight billion LennardJones atoms and were run for up to 56 million time-steps. The large particle numbers (over 104 times larger than previous simulations, see e.g. [2]) have several advantages: i) Resolving and quantifying nucleat...

The synthesis of wafer-scale single crystal graphene remains a challenge toward the utilization of its intrinsic properties in electronics. Until now, the large-area chemical vapor deposition of graphene has yielded a polycrystalline material, where grain boundaries are detrimental to its electrical properties. Here, we study the physicochemical mechanisms underlying the nucleation and growth k...

The mechanism by which Cu catalyst pretreatments control graphene nucleation density in scalable chemical vapor deposition (CVD) is systematically explored. The intrinsic and extrinsic carbon contamination in the Cu foil is identified by time-of-flight secondary ion mass spectrometry as a major factor influencing graphene nucleation and growth. By selectively oxidizing the backside of the Cu fo...

We have used an extension of our slow light technique to provide a method for inducing small density defects in a Bose-Einstein condensate. These sub- resolution, micrometer-sized defects evolve into large-amplitude sound waves. We present an experimental observation and theoretical investigation of the resulting breakdown of superfluidity, and we observe directly the decay of the narrow densit...