Abstract: The present disclosure provides an adapter circuit including a bus capacitor, a PMOS power transistor, and a sampling control module; a positive terminal of the bus capacitor is connected to a DC bus voltage, and a negative terminal of the bus capacitor is connected to a drain of the PMOS power transistor; a gate of the PMOS power transistor is connected to a drive signal, and a source of the PMOS power transistor is grounded; the sampling control module is used to obtain the drive signal by detecting an AC mains input voltage and a power-down voltage when the bus discharges, so as to turn off the PMOS power transistor after the AC mains input voltage reaches a peak value, and turn on the PMOS power transistor after the power-down voltage reaches a set voltage; the drive signal includes a PMOS Turn-on signal and a PMOS Turn-off signal.

Abstract: This invention relates to the use of a quantitative functional MRI (fMRI)—arterial spin-labeling perfusion MRI or absolute T2 mapping MRI or a combination thereof in the non-invasive neuroimaging of a subject's brain in response to stress-inducing psychological stimuli, which can be utilized to predict individual stress reactivity as well as to be used as a human model for testing or optimizing psychopharmacological agents.