[ Eq(Derivative(x1, t), (1*k51*(k1*(1 + k36*(k33*t**k34/(k35**k34 + t**k34)/k44)**k38)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k44)**k38) + k2*x6)*(1 + 1/10/(3/10)*(k33*t**k34/(k35**k34 + t**k34)/k45)**k41)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k45)**k41) + (-1)*k51*x1*log(2)/k3)/k51),
  Eq(Derivative(x2, t), 1*k51*1000000000/602300000000000000000000*k49*201/10*3600*x2/(k5 + x2)/k51),
  Eq(Derivative(x3, t), (1*k51*k10*k6/(1 + k9*x4/k43)*(x2 + x8)/(k7 + x2 + x8)*x12/(2*(k11 + x12)) + (-1)*k51*x3*log(2)/k12)/k51),
  Eq(Derivative(x4, t), (1*k51*(k13*(1 + k36*(k33*t**k34/(k35**k34 + t**k34)/k44)**k38)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k44)**k38) + k14*x3)*(1 + 1/10/(3/10)*(k33*t**k34/(k35**k34 + t**k34)/k45)**k41)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k45)**k41) + (-1)*k51*x4*log(2)/k15)/k51),
  Eq(Derivative(x5, t), (1*k51*(k16*x3 + 3600*89/1000000000000*x6)*(1 + 1/10/(3/10)*(k33*t**k34/(k35**k34 + t**k34)/k45)**k41)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k45)**k41) + (-1)*k51*x5*log(2)/k18)/k51),
  Eq(Derivative(x6, t), 1*k51*k19*x5*(1 + k36*(k33*t**k34/(k35**k34 + t**k34)/k44)**k38)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k44)**k38)/k51),
  Eq(Derivative(x7, t), (1*k51*k20*x6*(1 + 1/10/(3/10)*(k33*t**k34/(k35**k34 + t**k34)/k45)**k41)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k45)**k41) + (-1)*k51*x7*log(2)/k21)/k51),
  Eq(Derivative(x8, t), 1*k51*1000000000/602300000000000000000000*k49*201/10*3600*x7/(k5 + x7)/k51),
  Eq(Derivative(x9, t), (1*k51*(1 + 1/10/(3/10)*(k33*t**k34/(k35**k34 + t**k34)/k45)**k41)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k45)**k41)*(k22*(1 + k36*(k33*t**k34/(k35**k34 + t**k34)/k44)**k38)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k44)**k38) + k23*x10/(k24 + x10)) + (-1)*k51*x9*log(2)/k25)/k51),
  Eq(Derivative(x10, t), 1*k51*1000000000/602300000000000000000000*k49*46*3600*x9/(k27 + x9)/k51),
  Eq(Derivative(x11, t), (1*k51*(k28*(1 + k36*(k33*t**k34/(k35**k34 + t**k34)/k44)**k38)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k44)**k38) + 3600*1/200000*x3)*(1 + 1/10/(3/10)*(k33*t**k34/(k35**k34 + t**k34)/k45)**k41)/(1 + (k33*t**k34/(k35**k34 + t**k34)/k45)**k41) + (-1)*k51*x11*log(2)/k30)/k51),
  Eq(Derivative(x12, t), (1*k51*k31*x11 + (-1)*k51*x12*log(2)/k32)/k51) ]