Ashkenazi I E, Ribak J, Avgar D M, Klepfish A
Aviat Space Environ Med. 1982 Apr;53(4):342-6.
The daily fluctuations in the levels of some physiological and performance parameters have been assessed in three young subjects. The assessment was carried out before and after exposing them to the combined effect of two stressors, reduced barometric pressure and hypoxia. The exposure was effectuated by a simulated flight in a low pressure chamber for 30 min. The measured altitude in the chamber was 25000 ft (7620 m). During the simulated flight, each of the individuals experienced 2-3 min of hypoxia. The examined parameters (oral temperature, peak expiratory flow, grip strength, 2 and 6 digits recognition test, addition, counting backward, and odd-even addition test) exhibited circadian rhythms whose acrophases shifted significantly after exposure to the combined effect of the two stressors. The phases continued to shift for 4 d in a concordantly synchronized pattern. On the fourth day, they exhibited a tendency to resume their original phase.
在三名年轻受试者中评估了一些生理和性能参数水平的每日波动情况。评估在他们暴露于两种应激源（气压降低和低氧）的联合作用之前和之后进行。通过在低压舱中进行30分钟的模拟飞行来实现暴露。舱内测量的高度为25000英尺（7620米）。在模拟飞行期间，每个个体经历了2 - 3分钟的低氧状态。所检查的参数（口腔温度、呼气峰值流量、握力、2和6指识别测试、加法、倒数和奇偶加法测试）呈现出昼夜节律，其高峰相位在暴露于两种应激源的联合作用后发生了显著变化。这些相位以一致同步的模式持续变化了4天。在第四天，它们呈现出恢复到原始相位的趋势。
