Oxygen vacancy-assisted recovery process for increasing electron mobility in n-type BaSnO3 epitaxial thin films

The scattering of charge carriers with line defects, i.e., threading dislocations, needs to be decreased to further enhance electron mobility of lattice-mismatched epitaxial films and heterostructures for the application of high-performance electronic devices. Here, we report a strategy to post-treat epitaxial La-doped BaSnO3 films by delicately controlling oxygen partial pressure p(O2), which achieved significant increase in room temperature electron mobility to 122 cm2∙V−1∙s−1. This mobility enhancement is attributed to an oxygen vacancy-assisted recovery process that reduces the density of dislocations by accelerating the movement of dislocations in ionic crystals under p(O2)-controlled treatment, despite an increase in the density of charged point defects

G-protein-coupled receptor inactivation by an allosteric inverse-agonist antibody

G-protein-coupled receptors are the largest class of cell-surface receptors, and these membrane proteins exist in equilibrium between inactive and active states1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13. Conformational changes induced by extracellular ligands binding to G-protein-coupled receptors result in a cellular response through the activation of G proteins. The A2A adenosine receptor (A2AAR) is responsible for regulating blood flow to the cardiac muscle and is important in the regulation of glutamate and dopamine release in the brain14. Here we report the raising of a mouse monoclonal antibody against human A2AAR that prevents agonist but not antagonist binding to the extracellular ligand-binding pocket, and describe the structure of A2AAR in complex with the antibody Fab fragment (Fab2838). This structure reveals that Fab2838 recognizes the intracellular surface of A2AAR and that its complementarity-determining region, CDR-H3, penetrates into the receptor. CDR-H3 is located in a similar position to the G-protein carboxy-terminal fragment in the active opsin structure1 and to CDR-3 of the nanobody in the active β2-adrenergic receptor structure2, but locks A2AAR in an inactive conformation. These results suggest a new strategy to modulate the activity of G-protein-coupled receptors