Development and validation of an LC-MS/MS method for quantifying a new G protein selective μ-opioid receptor agonist YZJ-4729 and its major metabolite M10 in human plasma to support a phase I study in healthy subjects.

The use of conventional opioids that act on μ-receptors is a recognized care agent for moderate-to-severe acute treatment. However, recent attention has shifted to a new class of μ-receptor agonists which can selectively activate the G-protein pathway and thus have better efficacy and fewer side effects. Recently, YZJ-4729 was developed as a new G protein selective μ-opioid receptor agonist.

Performance characterization of a self-made terahertz photoconductive antenna.

A terahertz (THz) photoconductive antenna is prepared using, to the best of our knowledge, a novel method, which has high yield and strong stability. It eliminates the stripping process of a thin-film THz antenna and effectively prevents the toxicity of the corrosion solution, the easy damage in the transfer process, and the weak bonding with the substrate. First, a 200 µm copper wire is bundled on a low-temperature GaAs epitaxial wafer, and then the electrode of the photoconductive antenna is fabricated using the vacuum evaporation method.