“According to Yonatan Dubi and Massimiliano Di Ventra of the University of California, San Diego. They have calculated that provided some points along the wire's length stay below the threshold temperature, the material will superconduct.”
It might have something to do with frequency. As you might know, at DC, electricity fills the entire cross-section of the wire. However, as the frequency increases, the electrons move farther away from the center of the wire. It is known as the skin effect and is the result of eddy currents in the wire. Now if the areas where most of the eddy currents are found are kept at a lower temperature, you might be able to achieve superconduction in those areas. Just a guess.