Investigation of fullerene cluster growth mechanisms by carbon atom addition using classical molecular dynamics.

The mechanisms of carbon sticking reactions to C36 and C-C80 fullerenes were investigated with molecular dynamics simulations (MD) using the Second-generation Reactive Empirical Bond Order (SREBO) and Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) potentials that were specifically optimized for carbon-carbon interactions. Results showed the existence of three possible sticking configurations where the projectile atom can stick either to one, two or three atoms of the target fullerene. They also showed that although the two potentials give similar magnitudes for the sticking cross-sections, they yield fairly different results as far as sticking mechanisms and configurations at thermal collision-energies, i.

Metabolic Stress Impairs Pericyte Response to Optogenetic Stimulation in Pancreatic Islets.

Pancreatic islets are highly vascularized micro-organs ensuring whole body glucose homeostasis. Islet vascular cells play an integral part in sustaining adequate insulin release by beta cells. In particular, recent studies have demonstrated that islet pericytes regulate local blood flow velocity and are required for maintenance of beta cell maturity and function.

Stochastic models of systems for Nanotechnology: from micro to macro scale.

Computer modeling technique based on the theory of stochastic processes have been used in order to provide a realistic simulation of the behavior of nanoscopic systems, related in particular to plasma reactors in microelectronic device production. Basing on decades of experience, we show here, with new results, that the universality of such methods allows the development of codes with the highest reusability and versatility, crossing the barrier of scale. At the smallest scale, the quantum calculations of the potential energy surface of hydrogen species under nano-confinement conditions display the effects due to the dimension and the symmetry of the confining potential well.

Structure-Activity Relationship Studies of Retro-1 Analogues against Shiga Toxin.

High-throughput screening has shown that Retro-1 inhibits ricin and Shiga toxins by diminishing their intracellular trafficking via the retrograde route, from early endosomes to the Golgi apparatus. To improve the activity of Retro-1, a structure-activity relationship (SAR) study was undertaken and yielded an analogue with a roughly 70-fold better half-maximal effective concentration (EC) against Shiga toxin cytotoxicity measured in a cell protein synthesis assay.