Brayman A A, Azadniv M, Miller M W, Chen X
Department of Biophysics, School of Medicine and Dentistry, University of Rochester, New York 14642.
J Acoust Soc Am. 1994 Aug;96(2 Pt 1):627-33. doi: 10.1121/1.410302.
An exposure system producing interleafed pulses of 1-MHz ultrasound from balanced, opposing transducers was used to test the bubble recycling hypothesis (as formulated with respect to rotating exposure vessels) in a stationary exposure vessel containing P388 cell suspensions. Cell lysis was measured in cell suspensions which had been exposed or sham-exposed to 1-MHz ultrasound (5 W/cm2 spatial peak pulse average intensity) delivered in continuously alternating, opposing pulses. The opposing pulse cycle frequency (i.e., gating frequency) varied from 0.1 Hz to 100 kHz, corresponding to single pulse durations ranging from 5 microseconds to 5 s. Unequivocal support for the bubble recycling hypothesis was obtained. Lytic yield increased as the gating frequency increased, passing through a maximum at gating frequencies of 100 Hz-1 kHz. As the gating frequency increased further, lytic yield declined rapidly. The results are discussed in relation to recent theoretical estimates of bubble translation speeds in an ultrasound field, and are found to be consistent with those estimates.
使用一个曝光系统，该系统通过平衡的、相对的换能器产生1兆赫超声的交错脉冲，以在含有P388细胞悬浮液的固定曝光容器中测试气泡循环假说（如针对旋转曝光容器所阐述的）。在已暴露或假暴露于以连续交替、相对脉冲形式传递的1兆赫超声（空间峰值脉冲平均强度为5瓦/平方厘米）的细胞悬浮液中测量细胞裂解情况。相对脉冲周期频率（即门控频率）从0.1赫兹变化到100千赫，对应单脉冲持续时间从5微秒到5秒。获得了对气泡循环假说的确凿支持。裂解产率随着门控频率的增加而增加，在100赫兹至1千赫的门控频率下达到最大值。随着门控频率进一步增加，裂解产率迅速下降。结合近期超声场中气泡平移速度的理论估计对结果进行了讨论，发现与那些估计结果一致。
