Dalecki D, Child S Z, Raeman C H, Cox C, Penney D P, Carstensen E L
Department of Electrical Engineering, University of Rochester 14627, USA.
Ultrasound Med Biol. 1997;23(5):767-76. doi: 10.1016/s0301-5629(97)00071-9.
Thresholds for ultrasonically induced lung hemorrhage were determined in neonatal mice (24-36 h old), juvenile mice (14 d old) and adult mice (8-10 weeks old) to assess whether or not the threshold for lung hemorrhage is dependent upon age. Ultrasonic exposures were at 1.15 MHz with a pulse length of 10 microseconds, pulse repetition frequency of 100 Hz and a total exposure duration of 3 min. The threshold for lung hemorrhage occurred at a peak positive acoustic pressure of approximately 1 MPa for mice in all three age groups. Although the thresholds were similar for neonatal, juvenile and adult mice, the sizes of the suprathreshold hemorrhages were significantly larger in adult mice than in neonatal or juvenile mice.
为了评估肺出血阈值是否取决于年龄，研究测定了新生小鼠（24 - 36小时大）、幼年小鼠（14天大）和成年小鼠（8 - 10周大）超声诱导肺出血的阈值。超声暴露频率为1.15MHz，脉冲长度为10微秒，脉冲重复频率为100Hz，总暴露持续时间为3分钟。所有三个年龄组小鼠发生肺出血的阈值均出现在约1MPa的峰值正声压处。虽然新生、幼年和成年小鼠的阈值相似，但超阈值出血的大小在成年小鼠中明显大于新生或幼年小鼠。
