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. Author manuscript; available in PMC: 2015 Feb 3.
Published in final edited form as: Mol Cell Biomech. 2013 Jun;10(2):159–182.

Table 1.

Disc tissue properties used in the numerical model.

NP AF CEP
Initial water content Ø0w
(Water content: Øw=(Ø0w+e)/(1+e))
0.86 a 0.75 a Normal:0.6 b,
Calcified:0.45
Elastic constant λ
(MPa)
0.02 c 0.2 c 0.1 d
Elastic constant µ
(MPa)
0.015 c 0.15 c 0.2 d
Cell density
(cells/mm3)
Normal:4000 e,
Cell based therapy:
6000, 8000, 10000
9000 e 15000 e
Parameter for hydraulic
permeability
k = α1ws)b1
a1=0.00339 nm2 f,
b1=3.24 f
a1=0.00044 nm2 g,
b1=7.193 g
a1=0.0248 nm2 h,
b1=2.154 h
Parameter for diffusivity
DαD0α=exp[a2(rsαk)b2]
α: ions and nutrient solutes
a2=1.25 nm i,
b2=0.681 i
a2=1.29 nm i,
b2=0.372 i
a2=1.29 nm i,
b2=0.372 i

Where rsα is hydrodynamic radius of ions and nutrient solutes (rs+=0.197nm;rs=0.142nm;rsoxy=0.1nm;rslac=0.255nm;rsglu=0.3nm), D0α is diffusivity of ions and nutrient solutes in aqueous solution (D0+=1.28109m2/s,D0=1.77109m2/s,D0oxy=3.0109m2/s,D0lac=1.28109m2/s,D0glu=0.92109m2/s).

a

Yao and Gu, 2007.

b

Roberts et al., 1989; Setton et al., 1993.

c

Yao and Gu, 2006.

d

Mow et al., 2002; Yao and Gu, 2004.

e

Maroudas et al., 1975.

f

Gu et al., 2003, from agarose gels.

g

Gu and Yao, 2003, from porcine AF tissue.

h

Maroudas et al., 1975; Yao and Gu, 2004.

i

Gu et al., 2004, from porcine AF tissue and agarose gels.