This disclosure includes flow spool riser segment assemblies that are suitable for managed pressure drilling and that can be lowered through a rotary of a drilling rig. The control circuit is configured to store at least one erase indicator. The catheter comprises a flexible biocompatible tubular portion terminating in a free distal end. One stent coating includes a blend of a faster releasing PLA-PEO copolymer and a slower releasing PLA-PCL copolymer. In another embodiment a system may comprise an interface configured to communicate with a content provider, and an anchor point circuit configured to bind a digital property received from the content provider to the anchor point circuit such that the digital property can only be used in conjunction with the anchor point circuit.