We investigate theoretically electron spin states in one dimensional (1D) and two dimensional (2D) hard-wall mesoscopic rings in the presence of both the Rashba spin-orbit interaction (RSOI) and the Dresselhaus spin-orbit interaction (DSOI) in a perpendicular magnetic field. The Hamiltonian of the RSOI alone is mathematically equivalent to that of the DSOI alone using an SU(2) spin rotation transformation. Our theoretical results show that the interplay between the RSOI and DSOI results in an effective periodic potential, which consequently leads to gaps in the energy spectrum. This periodic potential also weakens and smoothens the oscillations of the persistent charge current (CC) and spin current (SC) and results in the localization of electrons. For a 2D ring with a finite width, higher radial modes destroy the periodic oscillations of persistent currents.

A novel series of compounds obtained by fusing the cholinesterase inhibitor donepezil and the antioxidant ebselen were designed as multi-target-directed ligands against Alzheimer's disease. An in vitro assay showed that some of these molecules did not exhibit highly potent cholinesterase inhibitory activity but did have various other ebselen-related pharmacological effects. Among the molecules, compound 7d, one of the most potent acetylcholinesterase inhibitors (IC50 values of 0.042 μM for Electrophorus electricus acetylcholinesterase and 0.097 μM for human acetylcholinesterase), was found to be a strong butyrylcholinesterase inhibitor (IC50 = 1.586 μM), to possess rapid H2O2 and peroxynitrite scavenging activity and glutathione peroxidase-like activity (ν0 = 123.5 μM min(-1)), and to be a substrate of mammalian TrxR. A toxicity test in mice showed no acute toxicity at doses of up to 2000 mg/kg. According to an in vitro blood-brain barrier model, 7d is able to penetrate the central nervous system.

No abstract

No abstract