Development of ReaxFF Reactive Force Field for Aqueous Iron-Sulfur Clusters with Applications to Stability and Reactivity in Water.

Iron-sulfur clusters serve unique roles in biochemistry, geochemistry, and renewable energy technologies. However, a full theoretical understanding of their structures and properties is still lacking. To facilitate large-scale reactive molecular dynamics simulations of iron-sulfur clusters in aqueous environments, a ReaxFF reactive force field is developed, based on an extensive set of quantum chemical calculations.

Systematic Evaluation of ReaxFF Reactive Force Fields for Biochemical Applications.

Four established ReaxFF force fields, trained on biochemical systems, have been systematically benchmarked on 20 proteinogenic amino acids and 11 dipeptides. The force fields were compared with respect to geometries, energetics, and atomic charges of conformers for the amino acids. To assess the performance with respect to reactivity, the condensation reactions for the formation of dipeptides were investigated by calculating the reaction energetics and pathways.

Lieb-Oxford bound and pair correlation functions for density-functional methods based on the adiabatic-connection fluctuation-dissipation theorem.

Compliance with the Lieb-Oxford bound for the indirect Coulomb energy and for the exchange-correlation energy is investigated for a number of density-functional methods based on the adiabatic-connection fluctuation-dissipation (ACFD) theorem to treat correlation. Furthermore, the correlation contribution to the pair density resulting from these methods is compared with highly accurate reference values for the helium atom and for the hydrogen molecule at several bond distances. For molecules, the Lieb-Oxford bound is obeyed by all considered methods.

Systemic depletion of macrophages by liposomal bisphosphonates reduces neointimal formation following balloon-injury in the rat carotid artery.

Objectives: Macrophage depletion by liposomal clodronate inhibits neointimal formation after balloon-injury. The present study examined bisphosphonates (BPs) potency-effect relationship and the role of systemic versus local monocytes in vascular repair.

Methods And Results: Liposomal preparations of clodronate, pamidronate, alendronate, and ISA-13-1 inhibited RAW-264 macrophages growth in a dose-response manner.

Macrophage depletion by clodronate-containing liposomes reduces neointimal formation after balloon injury in rats and rabbits.

Background: Inflammation is critical to vascular repair after mechanical injury. Excessive inflammation enhances neointimal formation and restenosis. We examined whether transient systemic inactivation of macrophages at the time of vascular intervention could attenuate the degree of expected restenosis.