ABSTRACT
We present the pressure tensor of an associating Lennard-Jones (LJ) fluid confined in a spherical cavity of hard wall, where a high-order density correlation has been taken into account. To give the two-body association potential for calculating the pressure tensor, an angle-average of site-site attraction over all orientations of two particles is performed. Furthermore, the classical density functional theory is employed to obtain the density profile of the confined fluid, by which the normal and tangential pressure profiles are illustrated under various conditions to show the dependence of the pressure tensor on the association strength, number of associating sites, radius of cavity, and bulk density. As an application, the corresponding surface tension is calculated. It is shown that under a strong association interaction (both association strength and the number of associating sites are large), the pressure profiles are depleted from the wall of the cavity instead of the oscillatory behavior under a weak association interaction. Such a tendency is mainly determined by the competition between association interaction and excluded volume interaction. Therefore, the aggregation state and related properties of an associating LJ fluid within a confinement of nanoscale can be efficiently regulated by the association interaction.
ABSTRACT
AIM: To study the effect of the recombined human growth hormone(rhGH) on secretory immunoglobulin A (sIgA), epidermal growth factor (EGF) in rats with obstructive jaundice. METHODS: Sixty Wistar rats were randomly divided into four groups, sham-operated (group A), common biliary duct-ligated (group B), biliary duct-ligated plus rhGH-treat for one week (group C), biliary duct-ligated plus rhGH-treat for two weeks (group D), each group had 15 rats. Except group A, the rats of other groups were operated with biliary duct-ligated. Until two weeks after operation, the rats of group A and B were killed. After operation, the rats of group C were treated with rhGH hypodermic injection (0.75 U x kg(-1) x d(-1)) for one week, and then killed. The rats of D group were treated with rhGH hypodermic injection (0.75 U x kg(-1) x d(-1)) for two weeks, and then killed. All procedures were performed aseptically. Total bilirubin (TB), alkaline phosphatase (ALP), prealbumin(PA), insulin-like growth factor (IGF-1), sIgA, EGF were measured. RESULTS: Compared with group A, in group B, C, D, serum level of PA, IGF-1 and sIgA, EGF level of gastric and intestinal juice were lower, but TB, ALP were higher, there were significant difference. Compared with group B, the rats with treatment of rhGH in group C and D had higher sIgA and EGF and lower intestinal bacterial translocation. CONCLUSION: In objective jaundice rats, rhGH can protect their hepatic function, intestinal physical-barrier function and immune-barrier function, and reduce intestinal bacterial translocation.
