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We have developed a magnetic levitation type seismic isolation device. The device could remove any horizontal vibrations very effectively. Three-layer structure was adopted in the device. The bottom layer was composed of permanent magnets. The middle layer comprised HTS bulks and permanent magnets. The top layer consisted of HTS bulks. The horizontal vibration characteristics in the middle layer depended on the air gap between the bottom and middle layers; the air gap was closely related to the load weight distribution in the top and middle layers. Inhomogeneous load weight distribution caused the different air gap in each bulk. Horizontal levitation against the inhomogeneous load weight distribution, however, could be obtained by adjusting the initial offset angle of each bulk in field-cooling process. The smaller initial air gap was effective in realizing horizontal levitation; the difficulty of horizontal levitation increased with the initial air gap. Independent of the load weight distribution, almost the same characteristics of horizontal vibration were obtained in the small initial air gap. [ABSTRACT FROM AUTHOR]

: Background Previously, we have demonstrated that surgical stress rapidly induced transient hyporesponsiveness of blood cells to endotoxin and that monocyte mCD14 and HLA-DR expression decreased soon after the start of surgery under general anaesthesia. This study was designed to investigate the effects of epidural anaesthesia on surgical stress-induced immunosuppression in patients undergoing upper abdominal surgery. : Methods After having obtained informed consent, patients were randomly allocated to receive general anaesthesia (Group G) or general anaesthesia with epidural anaesthesia (Group E). Perioperative changes in neutrophil phagocytic activity, neutrophil respiratory burst activity, monocyte mCD14 and HLA-DR expression, plasma IL-10 concentration, and the LPS-induced TNF-a production in whole blood were measured. : Results Surgical stress rapidly depressed neutrophil phagocytic activity, monocyte mCD14 and HLA-DR expression, and LPS-induced TNF-a production ex vivo (P < 0.05 vs preoperation) in both Group G and Group E. In contrast, the plasma IL-10 concentration increased significantly 2 h after the start of surgery (P < 0.05) in both groups. There were no significant differences between the two groups. The neutrophil respiratory burst activity did not change during the operation in either group. : Conclusion This study showed that the innate immune system is suppressed from the early period of upper abdominal surgery. Subgroup analysis suggested that epidural anaesthesia to T4 dermatome as well as general anaesthesia may not protect patients from this immunosuppression. These results in part explain the impairment of host-defense mechanisms seen in the perioperative period. [ABSTRACT FROM AUTHOR]