Mathematical Modeling Reveals the Role of Hypoxia in the Promotion of Human Mesenchymal Stem Cell Long-Term Expansion

Figure 2

Illustration of the logistic function. It is the form of the state transition rate in the two-compartment model, where is the midpoint and specifies the upper bound, while can be used to tune the steepness of the sigmoid curve. The slope of the tangent, that is, the derivative of at , is also shown by the dashed line.