Periodic Elastic Motion in a Self-Assembled Monolayer under Spontaneous Oscillations of Surface Tension: Molecules in a Scrum Push Back a Marangoni Flow.

Regularly recurring phenomena are a common and important part of life. Such rhythmic behaviors are often seen in nonliving systems under far-from-equilibrium conditions. The study of simple nonliving systems provides clues for improving our understanding of the origin of biological rhythms. Here, we focus on the spontaneous oscillation of surface tension associated with an intermittent Marangoni convective flow generated by two types of surfactants, those that are partially soluble (long chain alcohols) and insoluble (lipids) in water. In this system, we find that the collective motions of two surfactants interact with each other in a systematic manner to control a stable periodic motion: the alcohol molecules (donor) produce a Marangoni flow, and the lipid molecules (acceptor) in a monolayer push the flow back. The shape of the surface tension oscillation can be explained by the viscoelastic properties of the acceptor surfactant, whereas the period of the surface tension oscillation has been explained by the physical properties of the donor surfactant. A recently developed time-resolved X-ray surface scattering technique enables the dynamic structure of the water surface under flow to be determined. We have repeatedly observed that lipid molecules at the air-water interface become regularly oriented normal to the surface at every onset of the Marangoni convective flow.

[Trial of the Profit Optimization of the Department of Cardiac Surgery in the Local National University Hospital].

In recent years economic sense is required in hospital management, the national university hospital is also no exception. We performed duty improvement efforts as well as the current state analysis in the department of cardiac surgery for the purpose of revenue optimization in our hospital. At result, we succeeded in the improvement of the medical index as well as medical profit and found the key of solution to the serious problem that national university hospital has.