Unidirectional hopping transport of interacting particles on a finite chain

Particle transport through an open, discrete 1-D channel against a mechanical or chemical bias is analyzed within a master equation approach. The channel, externally driven by time dependent site energies, allows multiple occupation due to the coupling to reservoirs. Performance criteria and optimization of active transport in a two-site channel are discussed as a function of reservoir chemical potentials, the load potential, interparticle interaction strength, driving mode and driving period. Our results, derived from exact rate equations, are used in addition to test a previously developed time-dependent density functional theory, suggesting a wider applicability of that method in investigations of many particle systems far from equilibrium.Comment: 33 pages, 8 figure

Activity of the lipoxygenase inhibitor 1-phenyl-3-pyrazolidinone (phenidone) and derivatives on the inhibition of adhesion molecule expression on human umbilical vascular endothelial cells

Leukocyte adhesion contributes to perfusion abnormalities and tissue damage during trauma, shock or overwhelming inflammation. This study was performed to determine whether the lipoxygenase inhibitor phenidone and derivatives decrease the expression of adhesion molecules on tumor necrosis factor-α (TNF-α) stimulated endothelial cells and attenuate leukocyte-endothelial interactions under flow in vitro. TNF-α stimulated human umbilical venous endothelial cells (HUVECs) were incubated with phenidone, 4-methyl-phenidone, 4-4-dimethyl-phenidone, 5-methyl-phenidone, 5-phenyl-phenidone, and 5-methyl-1,(2,5-di-chloro-phenyl)-3-pyrazolidone. We tested the inhibition of adhesion molecule expression at different inhibitor concentrations before, during, and after the stimulation of HUVECs. The inhibition of endothelial cell expression on HUVECs was measured by flow cytometry. Rolling and firm adhesion of leukocytes to pretreated endothelium was examined in a parallel plate flow chamber. Phenidone inhibited the expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and endothelial-leukocyte adhesion molecule-1 on HUVECs when added prior to HUVEC stimulation. The inhibitory effect of phenidone was still observed when added simultaneously, but not when added after HUVEC stimulation. 4-4-dimethyl-phenidone and 5-phenyl-phenidone inhibited the expression of adhesion molecules more effectively than phenidone. The attenuation of leukocyte rolling under flow conditions was also significantly more effective with 4-4-dimethyl-phenidone than with phenidone. Lipoxygenase inhibitors might be of therapeutically interest for the treatment of overwhelming systemic inflammation during shock, trauma, and sepsis

Three-dimensional pathological size assessment in primary breast carcinoma

Maximal tumor diameter (MD) is traditionally an important prognostic factor in breast cancer. It must be questioned, however, how well a one-dimensional parameter alone can represent the actual morphologic condition of a three-dimensional body. Along with the pathologically assessed MD and two perpendicular diameters (PDs) of a lesion, eccentricity (EF) and the three-dimensional parameters tumor volume (TV) and surface area (TSA) of 395 ductal invasive breast carcinomas of limited size (10-40mm) were calculated. The dependent prognostic variable was axillary lymph node involvement (ALNI). MD, TV and TSA area were highly significant predictors of ALNI; these variables had similar levels of prediction accuracy (univariate analyses: MD: P=0.0003, TV: P=0.0009, TSA: P<0.0001; multivariate analyses: MD: P=0.0018, TV: P=0.0109, TSA: P=0.0009; pseudo R-squared values: MD: 0.42, TV: 0.39, TSA: 0.39). Despite certain variations in tumor shape, TV and TSA with similar MD, there is no evidence that three-dimensional pathologic measurements (TV/TSA) are more precise prognostic predictors of ALNI compared to the one-dimensional measurement alon