An energy feed structure includes a first tube having an open end and a closed end, a second tube to pierce the closed end, and a solid dielectric material to cover the open end. In order to enhance a device of this type such that the cleaning is simplified, a cleaning mechanism be provided for the exterior of the feeding line, which comprises a rinsing area for holding the portion of the feeding line that is to be cleaned. The invention further relates to methods for producing a corn plant containing in its genetic material one or more transgenes and to the transgenic plants produced by that method and to methods for producing other inbred corn lines derived from the inbred MV7100. One embodiment provides a method of modifying the surface of a tissue in a living organism. The solid lubricant is applied onto the sliding surface of a sliding member made of a metal, any of various resins, etc.