Rare earth metal compounds, particularly lanthanum, cerium, and yttrium, are formed as porous particles and are effective in binding metals, metal ions, and phosphate. This invention discloses a critical ratio or balance between loading of contained graft material through the hollow center or central passage of the implant and the implant’s frictional load bearing or contact area with e. Application data and related ECC data are advantageously stored in a common page within a common DRAM device.