The changes of hair cells after acute radiation injury to cochlea were studied with scanning electron microscope in guinea pigs. Outer hair cell cilia were disordered, fused, and lost in the early stage after 40Gy ?-ray irradiation of the bullae of guinea pigs. From 15 to 30d after radiation, reconstruction of cilia besides early changes, and ball shape materials on the side of inner hair cells were found. The possible mechanism of these changes is also discussed

The effects of different doses of r-ray on cochlea are reported in this paper. Significant hearing loss and severe cochlea hair cells injury were found while radiation dose was more than 80 Gy. With 40 Gy to 60 Gy, slight hearing loss, but cochlea hair cells and support cells impairment were observed. With 20 Gy, no hearing loss and no hair cell damage were found. The results indicated that the damage increases with a dose of radiation and there is a delay effect of radiation on cochles.

Objective:To evaluate a self-designed intelligent robot-assisted minimally invasive reduction system in the reduction of unstable pelvic fractures by a cadaveric anatomic study.Methods:Ten unembalmed cadavers (7 male and 3 female ones) were used in this study. In each cadaveric specimen an unstable pelvic fracture was created in accordance with clinical case models (3 cases of type B1, 4 cases of type B2 and 3 cases of type C1 by the Tile classification). A self-designed intelligent robot-assisted minimally invasive reduction system was used to assist the reduction in the cadaveric models. Intraoperative registration and navigation time, autonomous reduction time, total operation time and reduction error were measured.Results:Effective reduction was completed in 10 bone models with the assistance of our self-designed intelligent robot-assisted minimally invasive reduction system. The time for intraoperative registration and navigation averaged 47.4 min (from 32 to 74 min), the autonomous reduction time 73.9 min (from 48 to 96 min), and the total operation time 121.3 min (from 83 to 170 min). The reduction error averaged 2.02 mm (from 1.67 to 2.62 mm), and the reduction results met the clinical requirements.Conclusion:Our self-designed intelligent robot-assisted minimally invasive reduction system is a new clinical solution for unstable pelvic fractures, showing advantages of agreement with clinical operative procedures, high reduction accuracy and operational feasibility, and reduced radiation exposure compared to a conventional operation.