  We present data of transport measurements through a metallic nanobridge
exhibiting diffusive electron transport. A logarithmic temperature dependence
and a zero-bias anomaly in the differential conductance are observed,
independent of magnetic field. The data can be described by a single scaling
law. The theory of electron-electron interaction in disordered systems, adapted
to the case of finite-size systems in non-equilibrium, yields quantitative
agreement with experiment. Measurements of universal conductance functuations
support the assumptions of the theory about the electronic phase coherence.
