Molecular simulations of gas transport in hydrogenated nitrile butadiene rubber and ethylene-propylene-diene rubber.

Diffusion and sorption of five gases (H, N, O, CO, CH) in hydrogenated nitrile butadiene rubber (HNBR) and ethylene-propylene-diene rubber (EPDM) have been investigated by molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations. The diffusion coefficients of gas molecules in HNBR and EPDM are well correlated with the effective penetrant diameter except for CO. CO shows a lower diffusion coefficient due to its linear shape.

Use of power Doppler sonography for differential diagnosis of small hepatocellular carcinoma and adenomatous hyperplastic nodule.

Objective: To evaluate applicability of power Doppler sonography (PDS) in differential diagnosis of small hepatocellular carcinoma (SHCC) and adenomatous hyperplastic nodule (AHN).

Methods: Twenty-two cases of SHCC and 15 cases of AHN were investigated by PDS and the findings were compared with those of digital subtraction angiography (DSA).

Results: The rates of arterial and portal flow in an afferent tumor vessel were 86.