Compounds, pharmaceutical compositions and methods are provided that are useful in the treatment of CDK4-mediated disorders, such as cancer. The PPI is electrically connected to the metal pad. An end wall at a distal end of the adjusting portion includes a through passage coaxial with the channel and an upwardly opening cavity. The methods and systems can be used to advertise products to consumers, which can be purchased for personal use or for gifting. In one exemplary embodiment, the methods and devices are effective to mimic the natural function of the spine by allowing flexion, extension, and lateral bending of the spine, while substantially restricting posterior-anterior shear and rotation of the spine.