Creation of a Nanomodified Backfill Based on the Waste from Enrichment of Water-Soluble Ores

The paper analyzes losses during the development of low-value water-soluble ore deposits. The importance of development systems with backfill is shown. The use of industrial wastes of water-soluble ores to replace specially produced inert components in the preparation of backfill seems to be a good way to utilize the

Structural basis of metallo-β-lactamase inhibition by N-sulfamoylpyrrole-2-carboxylates

Metallo-β-lactamases (MBLs) can efficiently catalyze the hydrolysis of all classes of β-lactam antibiotics except monobactams. While serine-β-lactamase (SBL) inhibitors (e.g., clavulanic acid, avibactam) are established for clinical use, no such MBL inhibitors are available. We report on the synthesis and mechanism of inhibition of N-sulfamoylpyrrole-2-carboxylates (NSPCs) which are potent inhibitors of clinically relevant B1 subclass MBLs, including NDM-1. Crystallography reveals that the N-sulfamoyl NH2 group displaces the dizinc bridging hydroxide/water of the B1 MBLs. Comparison of crystal structures of an NSPC and taniborbactam (VRNX-5133), presently in Phase III clinical trials, shows similar binding modes for the NSPC and the cyclic boronate ring systems. The presence of an NSPC restores meropenem efficacy in clinically derived E. coli and K. pneumoniae blaNDM-1. The results support the potential of NSPCs and related compounds as efficient MBL inhibitors, though further optimization is required for their clinical development

A comparative study on the efficiencies of polyethylene compatibilizers by using theoretical methods

Functionalization of polyethylene chains by grafting of polar groups onto backbones is the most versatile way for preparing polyethylene based compatibilizers (PECs). In this work, a series of theoretical studies were performed to analyze the structure, adhesion and mixing behaviors of PECs. The effect of grafting different polar groups such as acrylic acid (AA), glycidyl methacrylate (GMA), maleic anhydride (MAH) and itaconic acid (IA) on the structure and cohesive properties of polyethylene chains were studied by Molecular Dynamics simulations. The mixing behavior of grafted polyethylenes with some commodity polymers such as polyetylene teraphthalate (PET), polyamide 6 (Nylon6), polyvinyl acetate (PVA) and polylactide (PLA) as well as with starch (ST) and starch acetate (STac) were investigated quantitatively by determining accurate interaction parameters using the modified Flory-Huggins Theory. We showed that the polar groups are the most reactive sites and they bind the chemically incompatible polymers by enabling the stronger interactions at the interfacial region