  The occurrence of superconductivity in proximity to various strongly
correlated phases of matter has drawn extensive focus on their normal state
properties, to develop an understanding of the state from which
superconductivity emerges. The recent finding of superconductivity in layered
nickelates raises similar interests. However, transport measurements of doped
infinite-layer nickelate thin films have been hampered by materials limitations
of these metastable compounds - in particular, a relatively high density of
extended defects. Here, by moving to a substrate
(LaAlO$_{3}$)$_{0.3}$(Sr$_{2}$TaAlO$_{6}$)$_{0.7}$ which better stabilizes the
growth and reduction conditions, we can synthesize the doping series of
Nd$_{1-x}$Sr$_{x}$NiO$_{2}$ essentially free from extended defects. This
enables the first examination of the 'intrinsic' temperature and doping
dependent evolution of the transport properties. The normal state resistivity
exhibits a low-temperature upturn in the underdoped regime, linear behavior
near optimal doping, and quadratic temperature dependence for overdoping. This
is strikingly similar to the copper oxides, despite key distinctions - namely
the absence of an insulating parent compound, multiband electronic structure,
and a Mott-Hubbard orbital alignment rather than the charge-transfer insulator
of the copper oxides. These results suggest an underlying universality in the
emergent electronic properties of both superconducting families.
