梅尼埃病患者宽频声导抗吸收率的特征

目的:探讨宽频声导抗吸收率在梅尼埃病中的特征。方法:对36例单侧梅尼埃病患者进行宽频声导抗、纯音测听、耳蜗电图和内听道MRI检查,并收集39例正常成年人宽频声导抗结果进行对比。从宽频声导抗数据库中调出鼓室图峰压值对应的各频率吸收率数值,计算吸收率相对面积;计录耳蜗电图中总和电位和动作电位的比值(-SP/AP);鼓室内注射钆造影剂后行内听道核磁共振,判断有无膜迷路积水。使用配对t检验对单侧梅尼埃病患者吸收率面积、吸收率峰值进行比较;使用单因素方差分析对各期患耳吸收率面积、吸收率峰值以及双耳间吸收率面积差值进行比较。结果:单侧梅尼埃病患者双耳间吸收率面积患侧均大于健侧,差异有统计学意义;双耳间吸收率峰值无显著差异;各期梅尼埃病患耳间吸收率峰值、吸收率面积及双耳间吸收率面积差值均无显著差异;正常成年人与单侧梅尼埃病患者双耳吸收率面积差值无显著差异。单侧梅尼埃病患耳内听道钆造影显示内淋巴积水比例为95.24%,耳蜗电图中-SP/AP>0.4为61.11%。结论:单侧梅尼埃病患者宽频声导抗患侧吸收率相对面积大于健侧,敏感性高,但非特异性。

Absorption of sulfur dioxide using membrane and enhancement of desorption with ultrasound

The absorption of sulfur dioxide in simulated flue gas by using liquid-containing membrane was investigated.The process of sulfur dioxide desorption from the absorbent of citrate solution was explored.The influence of the gas-phase,and the liquid-phase on absorption efficiency of sulfur dioxide and the influence of ultrasonic frequency,ultrasonic power and stirring speed on desorption efficiency of sulfur dioxide were examined.The results indicate that the absorption efficiency decreases with increasing flow velocity and sulfur dioxide content in gas-phase,and can be improved by increasing the concentration and the pH value of citrate solution.It is concluded that lower ultrasonic frequency results in a better degassing efficiency.The using of ultrasound in desorbing sulfur dioxide from citrate solution improves the desorbing efficiency in the some conditions,without changing the essence of chemical reaction.

Research on the sensitivity for the coal mine gas concentration detection by laser spectrum absorption

Because of the former gas chemistry examination method defects, tunable diode laser absorption spectrum technology （TDLAS） was used. It used an isolated absorption spectrum of the gas molecule to measure the gas absorption spectrum in order to distinguish the gas conveniently. The second harmonic （20 was measured in this system. Due to the fact which the harmonious signal is proportional to the concentration of the absorption gas, the gas concentration may be obtained through examining harmonious signal. The theoretical analysis and the experimental result indicate that under the same level of pressure, survey with the signal-to-noise ratio（SNR） of 2fsignal increases the accuracy by one order of magnitude and may reach 10 ^-3 and the sensitivity may reach the 10^-6 level compared to that of direct absorption. 5% methane density and a 30 cm absorption cell were used in the experiment. It has several advantages including high sensitivity, best resolution, and faster response and so on. The gas concentration monitoring of coal mine may be accomplished.

神经网络分析梅尼埃病患者的宽频声导抗特点

目的:基于神经网络构建宽频声导抗对梅尼埃病的预测模型,并评价其预测性能。方法:纳入64例确诊梅尼埃病患者,内耳钆增强磁共振造影均提示患耳膜迷路积水,同时选取40例正常青年人作为对照。分析梅尼埃病患者和正常青年人的宽频声导抗测试结果,采用MATLAB 2021a软件建立神经网络模型,通过准确率、阳性预测值、阴性预测值、约登指数、灵敏度、特异度、受试者工作特征曲线及曲线下面积(AUC)评估模型的性能。结果:成功建立了用宽频声导抗预测梅尼埃病的单隐层前馈神经网络模型,其输入层有104个特征值,隐层有13个神经元节点,输出层有1个输出神经元。该模型准确率83.2%,阳性预测值为80.7%,阴性预测值为84.3%,灵敏度为76.5%,特异度为83.7%,约登指数为0.602,模型AUC为0.855。结论:基于神经网络,根据宽频声导抗测试结果构建了准确率较高的梅尼埃病预测模型,为诊断梅尼埃病提供了参考。