High-resolution studies of lung surfactant collapse.

Survanta is a replacement lung surfactant (LS) used in the treatment of respiratory distress syndrome (RDS), the fourth leading cause of infant mortality in the United States. It consists of purified LS from bovine sources and retains the surfactant proteins (SP) SP-B and SP-C, both thought to be important in proper respiratory function. As such, it provides a useful and biologically relevant model system to probe the structure and function of natural LS.

Structure of a soft-sphere fluid at a soft repulsive wall: a comparison of weighted density-functional theories.

Density-functional theory is used to investigate the structure of a soft-sphere fluid at a soft wall. The fluid is modeled by an inverse sixth-power repulsive pair potential and the fluid particles interact with a flat stationary wall defined by an inverse-twelth power repulsive external potential. For comparison we examine results using three weighted density approximations (WDA), namely those due to Phys.