PHYSICAL FACTORS INVOLVED IN ULTRASONICALLY INDUCED CHANGES IN LIVING SYSTEMS .1. IDENTIFICATION OF NON-TEMPERATURE EFFECTS
PHYSICAL FACTORS INVOLVED IN ULTRASONICALLY INDUCED CHANGES IN LIVING SYSTEMS .1. IDENTIFICATION OF NON-TEMPERATURE EFFECTS
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DOI：
10.1121/1.1906707
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发表时间：
1950-01-01
影响因子：
2.4
通讯作者：
FRY, FJ
中科院分区：
文献类型：
--
作者：
FRY, WJ;WULFF, VJ;FRY, FJ
特别参考温度，讨论了伴随液体介质中高强度超声扰动的物理变量的变化，这些变化对于理解这种扰动对组织的影响显得很重要。超声（35 w./sq. cm.，频率 1 mc.）即使在长时间暴露后也不会对兴奋性、尖峰电位的波形或切除的周围神经的传播速度产生影响。暴露于超声波的切除的小龙虾腹神经索在暴露几秒后表现出自发活动减少，并在超声波关闭后约一分钟恢复其原始活动。青蛙的位置使得超声波入射到脊髓腰椎增大处的背侧表面，4.3秒后表现出后腿麻痹。在室温下暴露。 7.3 秒后。暴露在 1°-2°C 下。坐骨神经的组织学检查显示神经广泛变性，脊髓显示下运动神经元的明显病理学。温度。测量结果表明，周围神经和小龙虾腹神经索的最高温度升高了 1-2°C。而完整青蛙的脊髓则表现出温度。温度升高。 25℃左右。超声波对所研究系统的影响是由温度以外的物理因素产生的。在这些因素中，空化是最容易控制的，并将在未来进行研究。提出了一种通过测量初始温度变化率来获得吸声系数的方法。在各种测试对象中。
The changes in physical variables which accompany a high intensity ultrasonic disturbance in liquid media and which appear important in understanding the effects of such disturbances on tissue are discussed with special reference to temp. Ultrasound (35 w./sq. cm., frequency 1 mc.) is without effect on excitability, wave form of the spike potential, or propagation velocity of excised peripheral nerve, even after prolonged exposures. The excised crayfish ventral nerve cord exposed to ultrasound exhibits a reduction of spontaneous activity after several seconds exposure and recovers its original activity about one minute after the ultrasound is turned off. Frogs positioned so that ultrasound is incident on the dorsal surface over the lumbar enlargement of the spinal cord exhibit paralysis of the hind legs after 4.3-sec. exposure at room temp. and after 7.3-sec. exposure at 1[degree]-2[degree]C. Histological examination of the sciatic nerves shows extensive degeneration of nerves, and the spinal cord shows marked pathology of the lower motor neurones. Temp. measurements indicate that peripheral nerve and crayfish ventral nerve cord exhibit a maximal rise of 1-2[degree]C. whereas the spinal cord of intact frogs exhibit temp. increases in temp. of the order of 25[degree]C. The effect of ultrasound on the system studied is produced by physical factors other than temp. Of these factors, cavitation is the one most easily controlled and will be investigated in the future. A method is presented for obtaining acoustic absorption coefficients by measuring the initial rate of change of temp. in various test objects.