We study the nucleation of blebs, i.e., protrusions arising from a local detachment of the membrane from the cortex of a cell. Based on a simple model of elastic linkers with force-dependent kinetics, we show that bleb nucleation is governed by membrane peeling. By this mechanism, the growth or shrinkage of a detached membrane patch is completely determined by the linker kinetics, regardless of...

Grand canonical molecular dynamics (GCMD) is applied to the nucleation process in a metastable phase near the spinodal, where nucleation occurs almost instantaneously and is limited to a very short time interval. With a variant of Maxwell's demon, proposed by McDonald [Am. J. Phys. 31, 31 (1963)], all nuclei exceeding a specified size are removed. In such a steady-state simulation, the nucleati...

Climate models show that particles formed by nucleation can affect cloud cover and, therefore, the earth's radiation budget. Measurements worldwide show that nucleation rates in the atmospheric boundary layer are positively correlated with concentrations of sulfuric acid vapor. However, current nucleation theories do not correctly predict either the observed nucleation rates or their functional...

We performed molecular dynamics simulations of the nucleation of water vapor in order to test nucleation theories. Simulations were performed for a wide range of supersaturation ratios (S = 3-25) and water temperatures (T(w) = 300-390 K). We obtained the nucleation rates and the formation free energies of a subcritical cluster from the cluster size distribution. The classical nucleation theory ...

We combine density-functional theory with the string method to calculate the minimum free energy path of bubble nucleation in two polymer–CO2 mixture systems, poly(methyl methacrylate) (PMMA)–CO2 and polystyrene (PS)–CO2. Nucleation is initiated by saturating the polymer liquid with high pressure CO2 and subsequently reducing the pressure to ambient condition. Below a critical temperature (Tc),...

Aerosol nucleation events observed worldwide may have significant climatic and health implications. However, the specific nucleation mechanisms remain ambiguous. Here, we report case studies of eight nucleation events observed during an intensive field campaign at a boreal forest site (Hyytiälä, Finland) in spring 2005. The present analysis is based on comprehensive kinetic simulations using an...

Crystallization is one of the most important phase transformations of first order. In the case of metals and alloys, the liquid phase is the parent phase of materials production. The conditions of the crystallization process control the as-solidified material in its chemical and physical properties. Nucleation initiates the crystallization of a liquid. It selects the crystallographic phase, sta...

poly(ethylene adipte) and poly(ethylene adipate)/silica nanocomposite (pead/sio2) containing 3 wt. % sio2  were prepared by an in situ method. the examinations on the non-isothermal crystallization kinetic behavior have been conducted by means of differential scanning calorimeter (dsc). the avrami, ozawa, and combined avrami and ozawa equations were applied to describe the crystallization kinet...

We measured the nucleation rates of lysozyme protein crystals using microfluidically produced emulsion drops containing supersaturated protein solution. The technique involves quenching several thousand independent nanoliter drops by rapidly lowering the temperature and then counting the number of drops that have not nucleated as a function of time at constant temperature. We fit the number dis...

Neurons have highly polarized arrangements of microtubules, but it is incompletely understood how microtubule polarity is controlled in either axons or dendrites. To explore whether microtubule nucleation by γ-tubulin might contribute to polarity, we analyzed neuronal microtubules in Drosophila containing gain- or loss-of-function alleles of γ-tubulin. Both increased and decreased activity of γ...