We present a flexible and highly reproducible method using three-dimensional (3D) multicellular tumor spheroids to quantify chemotherapeutic and nanoparticle penetration properties in vitro. We generated HeLa cell-derived spheroids using the liquid overlay method. To properly characterize HeLa spheroids, scanning electron microscopy, transmission electron… (More)
Mutations in the parkin gene have been identified as one of the important genetic factors for the etiology of PD. However, pathogenicities of parkin mutations, especially of those heterozygotes, remain controversial, possibly due to confusions caused by the "mixed" effects of all types of mutations. Here we report a study on the independent effects of… (More)
Our aim in this paper is to investigate the behavior of positive solutions for the following systems of rational difference equations: x n+1 = A/x n y n (2), and y n+1 = By n /x n-1 y n-1, n = 0,1,…, where x -1, x 0, y -1, and y 0 are positive real numbers and A and B are positive constants.
In this paper we study the oscillatory property of solutions for a class of partial difference equation with constant coefficients. In order to study the oscillation results, we find the regions of nonexistence of positive roots of its characteristic equation which is equivalent to the oscillation results. We derive some necessary and sufficient conditions… (More)
It is expected in this paper to investigate the existence and uniqueness of positive solution for the following difference equation: -Δ(2) u(t - 1) = f(t, u(t)) + g(t, u(t)), t ∈ ℤ 1, T , subject to boundary conditions either u(0) - βΔu(0) = 0, u(T + 1) = αu(η) or Δu(0) = 0, u(T + 1) = αu(η), where 0 < α < 1, β > 0, and η ∈ ℤ 2,T-1. The proof of the main… (More)
Sciatic nerve tissue was obtained from the gluteus maximus muscle segment of normal human cadavers and amniotic membrane tissue was obtained from healthy human puerperant placentas. Both tissues were analyzed for their stress relaxation and creep properties to determine suitability for transplantation applications. Human amniotic membrane and sciatic nerve… (More)