  We deal with the three-dimensional Gross-Pitaevskii equation, which is used
to describe a cloud of dilute bosonic atoms that interact under competing two-
and three-body scattering potentials. We study the case where the cloud of
atoms is strongly confined in two spatial dimensions, allowing us to build an
unidimensional nonlinear equation, controlled by the nonlinearities and the
confining potentials that trap the system along the longitudinal coordinate. We
focus attention on specific limits, dictated by the cubic and quintic
coefficients, and we implement numerical simulations to help us to quantify the
validity of the procedure.
