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首页> 外文期刊>IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control >Superthreshold behavior and threshold estimation of ultrasound-induced lung hemorrhage in pigs: Role of age dependency
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Superthreshold behavior and threshold estimation of ultrasound-induced lung hemorrhage in pigs: Role of age dependency

机译：超声诱发猪肺出血的超阈行为和阈值估计：年龄依赖性的作用

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Age-dependent threshold and superthreshold behavior of ultrasound-induced lung hemorrhage were investigated with 116 2.1 ± 0.3-kg neonate crossbred pigs (4.9 ± 1.6 days old), 103 10 ± 1.1-kg crossbred pigs (39 ± 5 days old), and 104 20 ± 1.2-kg crossbred pigs (58 ± 5 days old). Exposure conditions were: 3.1 MHz, 10-s exposure duration, 1-kHz pulse repetition frequency (PRF), and 1.2-Μs pulse duration. The in situ (at the pleural surface) peak rarefactional pressure ranged between 2.2 and 10.4 MPa with either eight or nine acoustic pressure groups for each of the three pig ages (12 pigs/exposure group) plus sham exposed pigs. There were no lesions in the shams. Pigs were exposed bilaterally with the order of exposure (left then right lung, or right then left lung) and acoustic pressure both randomized. Pig age was not randomized. Individuals involved in animal handling, exposure, and lesion scoring were blinded to the exposure condition. Logistic regression analysis was used to examine the dependence of the lesion incidence rates on in situ peak rarefactional pressure, left versus right lung exposure, order of exposure (first versus second), and age in three age groups. Likewise, lesion depth and lesion root surface area were analyzed using Gaussian tobit regression analysis. A significant threshold effect on lesion occurrence was observed as a function of age; younger pigs were less susceptible to lung damage given equivalent in situ exposure. Overall, the oldest pigs had a significantly lower threshold (2.87 ± 0.29 MPa) than middle-aged pigs (5.83 ± 0.52 MPa). The oldest pigs also had a lower threshold than neonate pigs (3.60 ± 0.44 MPa). Also, an unexpected result was observed. The ultrasound exposures were bilateral, and the threshold results reported above were based on the lung that was first exposed. After the first lung was exposed, the pig was turned over and the other lung was exposed to the same acoustic pressure. There was a significant decrease (greater than the confidence limits) in occurrence thresholds: 3.60 to 2.68, 5.83 to 2.97, and 2.87 to 1.16 MPa for neonates, middle-aged, and oldest pigs, respectively, in the second lung expos- ed. Thus, a subtle effect in lung physiology resulted in a major effect on lesion thresholds.
机译：研究了116头2.1±0.3千克新生杂种猪（4.9±1.6天），103头10±1.1千克新生杂种猪（39±5天）和年龄依赖性的超声诱发肺出血的阈值和超阈行为104 20±1.2公斤杂种猪（58±5天大）。曝光条件为：3.1MHz，10s曝光持续时间，1-kHz脉冲重复频率（PRF）和1.2μs脉冲持续时间。原位（在胸膜表面）峰值稀疏压力在2.2到10.4 MPa之间，对于三个猪龄（每头猪12头）和假暴露的猪，分别有八个或九个声压组。残渣中没有病变。猪以暴露的顺序（从左至右肺，或从右至左肺）进行双侧暴露，声压均是随机的。猪的年龄不是随机的。涉及动物处理，接触和病变评分的个体对接触条件不了解。使用Logistic回归分析来检查病变发病率与原位峰值稀疏压，左与右肺部暴露，暴露顺序（第一与第二）以及三个年龄组的年龄之间的相关性。同样，使用高斯tobit回归分析来分析病变深度和病变根表面积。观察到随着年龄的增长，对病变发生的显着阈值影响；在相同的原位暴露条件下，年幼的猪对肺部损伤的敏感性较低。总体而言，最老的猪的阈值（2.87±0.29 MPa）明显低于中年猪（5.83±0.52 MPa）。最老的猪的阈值也比新生猪低（3.60±0.44 MPa）。另外，观察到意外结果。超声暴露是双侧的，上面报告的阈值结果基于首次暴露的肺。在第一个肺暴露后，将猪翻身，另一个肺暴露在相同的声压下。发生阈值显着降低（大于置信限）：第二次肺部暴露的新生儿，中年和最老的猪分别为3.60至2.68、5.83至2.97和2.87至1.16 MPa。因此，对肺生理的微妙影响导致对病变阈值的重大影响。

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