We simulate the bond and site percolation models on a simple-cubic lattice with linear sizes up to L = 512, and estimate the percolation thresholds to be pc(bond) = 0.248 811 82(10) and pc(site) = 0.311 607 7(2). By performing extensive simulations at these estimated critical points, we then estimate the critical exponents 1/ν = 1.141 0(15), β/ν = 0.477 05(15), the leading correction exponent yi = −1.2(2), and the shortest-path exponent dmin = 1.375 6(3). Various universal amplitudes are also obtained, including wrapping probabilities, ratios associated with the cluster-size distribution, and the excess cluster number. We observe that the leading finite-size corrections in certain wrapping probabilities are governed by an exponent ≈ −2, rather than yi ≈ −1.2.

A self-adjusting, blood vessel-mimicking, multilayered tubular structure with two polymers, poly(ε-caprolactone) (PCL) and poly(dl-lactide-co-glycolide) (PLGA), can keep the shape of the scaffold during biodegradation. The inner (PCL) layer of the tube can expand whereas the outer (PLGA) layers will shrink to maintain the stability of the shape and the inner space of the tubular shape both in vitro and in vivo over months. This approach can be generally useful for making scaffolds that require the maintenance of a defined shape, based on FDA-approved materials.

No abstract

No abstract

No abstract