Moreover, this behaviour persists to room temperature, whereas "high-temperature" superconductors only lose their resistance below about 150K or -120 C. ... Instead she calls it “a strange conduction phenomenon called negative resistance.”

What is the problem with superconductors?

Many superconducting materials were soon discovered, but practical applications were another matter. These superconductors shared one problem – they needed to be cooled down. The amount of energy needed to cool a material down to its superconducting state was too expensive for daily applications.

Why do superconductors have to be cold?

If a superconductor is too hot, the electrons are jiggling around too violently to maintain electron-electron bonds. Since the bonding between electrons is so weak, you have to have a very low temperature to avoid breaking the bonds.