A combined experimental/computational approach to the characterization of polymer-clay nanocomposites based on PEO-diacrylate macromolecules

Wed, 06/29/2022 - 05:51 By Anonymous

Titolo: A combined experimental/computational approach to the characterization of polymer-clay nanocomposites based on PEO-diacrylate macromolecules

Hydrogen sulphide removal from biogas by zeolite adsorption: part I. GCMC molecular simulations

Wed, 06/29/2022 - 05:51 By Anonymous

Titolo: Hydrogen sulphide removal from biogas by zeolite adsorption: part I. GCMC molecular simulations
Abstract: In this work Grand Canonical Monte Carlo (GCMC) simulations have been used to study hydrogen sulfide (H2S) removal from biogas streams by different zeolites such as FAU (Faujasite, NaX and NaY), LTA (zeolite A (Lynde division, Union Carbide)) and MFI (Zeolite Socony Mobil – five). Additionally, quantum mechanics (QM) molecular simulations have been performed to obtain structures and partial charges of some sorbates. The computational procedure adopted has been validated by comparison with experimental data available for H2S removal in atmospheric environment by zeolite NaY. In order to obtain a priority list in terms of both H2S isotherms and adsorption selectivity, adsorption simulations for pure H2S at low pressures and for a prototype biogas mixture (i.e., CO2, CH4, and H2S) have been performed and compared. The adsorption mechanisms and competition for accessible adsorption sites in terms of thermodynamic behavior have been also examined. Overall, the results obtained in this work could be routinely applied to different case studies, thus yielding deeper qualitative and quantitative insights into adsorption pollutant removal processes in environmental fields.

Through the open door: Preferential binding of dasatinib to the active form of BCR-ABL unveiled by in silico experiments

Wed, 06/29/2022 - 05:51 By Anonymous

Titolo: Through the open door: Preferential binding of dasatinib to the active form of BCR-ABL unveiled by in silico experiments
Abstract: Dasatinib is a second-generation BCR-ABL inhibitor approved for the treatment of patients with chronic myeloid leukemia, both in the frontline and in the imatinib-resistant/intolerant settings. The high affinity of dasatinib for the protein is currently assumed to result from its ability to bind both the active and inactive conformations of the BCR-ABL kinase. In the present work, using state of the art molecular simulation techniques we prove that dasatinib exhibits a highly selective preference for the active (open) BCR-ABL conformation. By using three different BCR-ABL conformations (active, inactive, and intermediate inactive) we show that, from a thermodynamic standpoint, the affinity of dasatinib for BCR-ABL drastically decreases in the order: active > alternative inactive > inactive, as a result of differential contributions from the single residues lining the kinase binding pocket and the concomitant stabilization/destabilization of the kinase hydrophobic spine. Molecule-pulling experiments also corroborate this trend as significantly lower forces and smaller times are required to extract dasatinib from its inactive BCR-ABL complexes with respect to the active complex counterparts. Importantly, our results support recent NMR solution results demonstrating no evidence of dasatinib bound to the inactive form of BCR-ABL.