My research concentrates on establishing relations between the structure, chemistry and physical properties of transition-metal oxide nanostructures. The role of reduced dimensionality and the structure of interfaces, point defects, dislocations, etc, remains obscure in many cases but are central to macroscopic materials properties. Imaging interfaces and defects at sub-Angstrom resolution, chemical mapping at atomic level are some of the hot points to be addressed in materials science. The richness of an aberration corrected scanning transmission electron microscopy (STEM), in which a very tiny electron probe (of the order of 1 Å) is scanned over the specimen, is to collect several signals in parallel, allowing to combine structural imaging and spectroscopic imaging, electron energy loss spectroscopy (EELS) for example, with atomic resolution.