Proton Pump Inhibitor Trapping Field (2D)

This is the 2D counterpart to the 3D proton-pump-inhibitor canaliculus simulator. Rather than animating discrete drug molecules diffusing through a 3D cutaway, it solves the same ion-trapping chemistry as a continuous reaction-diffusion field on a 2D grid: a mobile neutral-drug concentration diffuses across a spatial pH gradient from the neutral blood side toward the acidic canalicular membrane, converting locally into an immobile trapped form according to the Henderson-Hasselbalch equilibrium evaluated at each grid cell's own position. That trapped field then covalently disables proton pumps arrayed along the membrane, which recover only as fast as first-order protein synthesis allows once dosing stops. Watch the field itself pile up fastest right at the membrane where the local pH is lowest, and collapse instead when you raise canalicular pH toward neutral.