The diffusion of a molecule in a tissue is studied by measuring the uptake of labeled protein into the tissue of thickness L =8 um. Initially, there is no labeled protein in the tissue. At t=0, the tissue is placed in a solution with a molecular concentration of C1=9.4 uM, so the surface concentration at x=0 is maintained at C1. Assume the tissue can be treated as a semi-infinite medium. Surface area of the tissue is A = 4.2 cm2. Calculate the flux into the tissue at x=0 and t=5 s. Please give your answer with a unit of umol/cm2 s. Assuming the diffusion coefficient is known of D=1*10-9 cm2/s