Modifications of nucleons in nuclei and other consequences of the quark substructure

In this review I address the possibility that quarks manifest themselves in nuclei through modifications of intrinsic properties of the nucleons embedded in the nuclear medium. This means that we investigate theoretical descriptions of nuclei that assume that the color degrees of freedom are frozen in ''bound hadrons''. However, the properties of the ''bound hadrons'' are not necessarily identical to those of the ''free hadrons''. The most relevant of the bound hadrons are the nucleons, proton and neutron, but also pions, delta's and multiquark (like six-quark) hadrons could be relevant and can be discussed in the same framework. (orig.) With 194 refs