Transient-evoked otoacoustic emission signals predicting outcomes of acute sensorineural hearing loss in patients with Ménière’s disease

Abstract

Background: Fluctuating hearing loss is characteristic of Ménière’s disease (MD) during acute episodes. However, no reliable audiometric hallmarks are available for counselling the hearing recovery possibility.

Aims/objectives: To find parameters for predicting MD hearing outcomes.

Material and methods: We applied machine learning techniques to analyse transient-evoked otoacoustic emission (TEOAE) signals recorded from patients with MD. Thirty unilateral MD patients were recruited prospectively after onset of acute cochleo-vestibular symptoms. Serial TEOAE and pure-tone audiogram (PTA) data were recorded longitudinally. Denoised TEOAE signals were projected onto the three most prominent principal directions through a linear transformation. Binary classification was performed using a support vector machine (SVM). TEOAE signal parameters, including signal energy and group delay, were compared between improved (PTA improvement: ≥15?dB) and nonimproved groups using Welch’s t-test.

Results: Signal energy did not differ (p?=?.64) but a significant difference in 1-kHz (p?=?.045) group delay was recorded between improved and nonimproved groups. The SVM achieved a cross-validated accuracy of >80% in predicting hearing outcomes.

Conclusions and significance: This study revealed that baseline TEOAE parameters obtained during acute MD episodes, when processed through machine learning technology, may provide information on outer hair cell function to predict hearing recovery.     

Prediction modelling using routine clinical parameters to stratify survival in Malignant Pleural Mesothelioma patients undergoing cytoreductive surgery

Introduction

Malignant pleural mesothelioma (MPM) is an uncommon cancer with a poor prognosis and heterogeneous survival. Surgery for MPM is offered in some specialist centers to highly selected patients. A previously described classification and regression tree (CART) model stratified survival in unselected MPM patients using routinely collected clinical data. This study aimed to examine the performance of this CART model on a highly selected surgical population.

Effects of Asymmetric Quantum Wells on the Structural and Optical Properties of InGaN-Based Light-Emitting Diodes

A metalorganic vapor phase epitaxy-grown InGaN/GaN multiple-quantum-well (MQW) with three graded-thickness wells (the first-grown well had the greatest width) near the n-GaN was used as the active layer of an LED. For LEDs with an asymmetric quantum well (AQW), high-resolution X-ray diffraction and transmission electron microscopic reveal that the modified MQWs with a reasonable crystalline quality were coherently strained on the underlying GaN epilayers without any relaxation. In addition, the slight increase of indium segregation in the LED with an AQW may be attributed to variations in indium contents experienced during epitaxial growth of the wide well-containing MQWs. By preventing the energetic electrons from accumulating at the topmost quantum well nearest the p-GaN, the presence of light intensity roll-off in the LED with an AQW is shifted to higher currents and the corresponding maximum light output power is increased with a ratio 7.9% higher than that of normal LEDs. Finally, similar emission wavelengths were observed in the electroluminescence spectra of both LEDs, suggesting that light emitted mostly from the top quantum wells (near the p-GaN) while the emissions from the AQW region were insignificant.