講座內容：Existing mathematical models of tumordevelopment are either discrete(cell-based) models or continuum models. Bothhave advantages anddisadvantages; the former allows for incorporation ofsignificantcell-level information but is computationally expensive whengrowthand mechanics are incorporated, whereas the latter is easy toformulateand computationally straightforward, but to date it has beendifficult toaccurately translate cell-level information into thecontinuum description. Inthis talk we introduce a hybrid model thatretains the advantages of both thediscrete and the continuummodels. In this model the surface layers of a growingmulticellularspheroid are described by a cell-based model, whereas theinteriorquiescent and necrotic zones (when present) are described by acontinuummodel, as is the extracellular matrix. We will discuss thetheoreticalfoundation of the model and the computational algorithmsdeveloped to analyzeit, and present numerical results for growingtumors.