外柱细胞软化对Corti器感音影响的生物力学研究

Corti器的感音过程容易受到内部结构属性变化的影响。外柱细胞血管舒张刺激磷蛋白缺失会减缓肌动蛋白丝的形成，从而产生听力延迟。本研究运用COMSOL建立三维有限元模型研究肌动蛋白缺失导致外柱细胞软化时，Corti器感音过程中基底膜和外毛细胞与Deiters细胞结合点的力学行为变化。结果表明，外柱细胞软化会削弱外毛细胞主动力对基底膜位移增益的放大作用，但削弱作用并不会立即产生，Corti器存在维持正常功能的“缓冲”阶段。在100 dB和120 dB之间可能存在一个声压级临界值，在该临界值两侧外柱细胞软化对基底膜应力变化的影响是截然相反的。另外外柱细胞软化对不同外毛细胞与Deiters细胞结合点力学行为的影响也不同，位移增益优先级会因此产生改变。

Effects of a new intelligent ventilation mode on clinical respiratory mechanics in patients with acute respiratory distress syndrome

Abstract: Objective To explore the effects of a new intelligent ventilation mode on clinical respiratory mechanics in patients with acute respiratory distress syndrome (ARDS). Methods A total of 84 patients with ARDS were divided into observation group (42 cases) and control group (42 cases) according to the simple random number table method. New intelligent ventilation mode (intelligent trigger + adaptive minute ventilation) was adopted in observation group, and conventional ventilation mode (synchronous intermittent command + pressure support ventilation) in control group. The mechanical ventilation-related indexes, respiratory mechanics indexes and blood gas indexes were compared between two groups. Results The ventilation time, manual operation frequency, ventilator alarm frequency and mechanical energy in observation group were less than those in control group (P<0.05). After ventilation, the respiratory rate, minute ventilation and static lung compliance of two groups of patients were increased and there were drops in peak airway and airway closure pressure (P<0.05). The respiratory frequency and static lung compliance of observation group after ventilation were significantly higher than those of control group (P<0.05), but there was no statistically significant difference between two groups in minute ventilation, airway peak and airway closure pressure (P>0.05). The pH of two groups of patients after ventilation was close to that before ventilation (P>0.05). After ventilation, PaO2 of two groups of patients was higher than that before ventilation, and PaCO2 was lower (P<0.05) and the differences between two groups in pH and PaO2 after ventilation were trivial (P>0.05) and the PaCO2 of observation group after ventilation was significantly lower than that of control group (P<0.05). Conclusion The new intelligent ventilation mode used in the treatment of ARDS can shorten ventilation time, reduce mechanical energy and lessen the workload of medical care. Moreover, it can effectively improve the blood gas index and respiratory mechanics index of patients, and protect the lung function.