Ultrasound Microbubbles Enhance the Efficacy of Insulin-Like Growth Factor-1 Therapy for the Treatment of Noise-Induced Hearing Loss

The application of insulin-like growth factor 1 (IGF-1) to the round window membrane (RWM) is an emerging treatment for inner ear diseases. RWM permeability is the key factor for efficient IGF-1 delivery. Ultrasound microbubbles (USMBs) can increase drug permeation through the RWM. In the present study, the enhancing effect of USMBs on the efficacy of IGF-1 application and the treatment effect of USMB-mediated IGF-1 delivery for noise-induced hearing loss (NIHL) were investigated. Forty-seven guinea pigs were assigned to three groups: the USM group, which received local application of recombinant human IGF-1 (rhIGF-1, 10 µg/µL) following application of USMBs to the RWM; the RWS group, which received IGF-1 application alone; and the saline-treated group. The perilymphatic concentration of rhIGF-1 in the USM group was 1.95- and 1.67- fold of that in the RWS group, 2 and 24 h after treatment, respectively. After 5 h of 118 dB SPL noise exposure, the USM group had the lowest threshold shift in auditory brainstem response, least loss of cochlear outer hair cells, and least reduction in the number of synaptic ribbons on postexposure day 28 among the three groups. The combination of USMB and IGF-1 led to a better therapeutic response to NIHL. Two hours after treatment, the USM group had significantly higher levels of Akt1 and Mapk3 gene expression than the other two groups. The most intense immunostaining for phosphor-AKT and phospho-ERK1/2 was detected in the cochlea in the USM group. These results suggested that USMB can be applied to enhance the efficacy of IGF-1 therapy in the treatment of inner ear diseases.     

声学随机共振实验

在特定的非线性系统中,噪声的存在能够增强信号的响应, 这种现象为随机共振. 本文实验通过观察噪声对听觉阈限的影响,使学生了解声学中的随机共振现象.     

Ebselen and Analogues: Pharmacological Properties and Synthetic Strategies for Their Preparation

Ebselen is the leader of selenorganic compounds, and starting from its identification as mimetic of the key antioxidant enzyme glutathione peroxidase, several papers have appeared in literature claiming its biological activities. It was the subject of several clinical trials and it is currently in clinical evaluation for the treatment of COVID-19 patients. Given our interest in the synthesis and pharmacological evaluation of selenorganic derivatives with this review, we aimed to collect all the papers focused on the biological evaluation of ebselen and its close analogues, covering the timeline between 2016 and most of 2021. Our analysis evidences that, even if it lacks specificity when tested in vitro, being able to bind to every reactive cysteine, it proved to be always well tolerated in vivo, exerting no sign of toxicity whatever the administered doses. Besides, looking at the literature, we realized that no review article dealing with the synthetic approaches for the construction of the benzo[d][1,2]-selenazol-3(2H)-one scaffold is available; thus, a section of the present review article is completely devoted to this specific topic.     

PROGRESS IN MECHANICS OF THE COCHLEA

耳蜗力学是听觉科学和生理声学研究的核心话题,同时也是一个极具代表性的生物力学话题. 深入总结和揭示耳蜗力学特性能够推动相关问题的深入研究和促进心理声学的发展与应用. 该文分宏观力学和微观力学两部分进行综述,然后结合近几年的研究动态,总结耳蜗力学的发展趋势和应用前景. 表明耳蜗作为一个杰出的频率选择和高灵敏度的声信号感应器官,可以对20~20 000 Hz 这样跨度达千倍的频率做出精确响应,且刺激信号可以放大4 000 倍以上.     

汉语降频助听算法的实验分析与改进

降频助听算法是改善听障患者声音辨识能力的最安全有效的方法. 本文以主观测试实验为手段, 通过分析当前算法的声音识别能力的不足, 提出一种自适应慢放降频算法. 算法结合慢放算法和频移算法的优点, 并能根据信号的频谱结构, 自适应调整慢放因子, 降低时域不同步性. 并且, 通过分析含噪信号和噪声信号的频谱关系, 提出一种噪声下的慢放因子评估方法. 实验结果显示, 同其他降频算法相比, 该算法可以提高15%到20%的识别率. 在对听障患者的测试中, 同传统的助听设备相比, 平均识别率也获得显著改善.     

Experiments on authenticity and plausibility of binaural reproduction via headphones employing different recording methods

Major criteria for a successful binaural reproduction are not only a suitable localization performance, but also the authenticity and plausibility of the presented scene. It is therefore interesting to examine whether the binaural reproduction can be perceptually distinguished from a real source. The aim of the presented investigation is to compare the quality of the binaural reproduction via headphones with two different microphone setups (miniature microphone in Open-Dome and ear plug) for individual head-related-transfer-function (HRTF) and headphone-transfer-function (HpTF) measurements. Listening tests with a total of 80 subjects were carried out focusing on plausibility and authenticity. In the examination of plausibility detection rates showed that subjects were not able to match the reproduced pink noise to its reproduction system (real source vs. binaural reproduction via headphones). The authenticity of the static binaural reproduction was highly dependent on the stimulus. Pink noise could often be distinguished due to coloration in higher frequencies and small differences in location. A difference between microphone setups could not be found in neither of the listening tests.     

A snapshot of young adults’ noise exposure reveals evidence of ‘Binge Listening’

There have been several previous studies into daily noise exposure levels in modern urban communities, which typically report mean noise exposure levels (L_Aeq) for adults between 73 and 79 dB. In this study, rather than focus on group mean exposures across a wide age range, individual patterns of noise exposure over 4- and 5-day periods were examined in a group of 45 young adults aged 18–35 years. The main objective of the study was to determine the extent to which young adults exhibit a ‘binge listening’ pattern of noise exposure, i.e., high weekend leisure noise vs. low weekday work noise exposure. A secondary objective was to identify the types of activities that generate the highest noise exposures. The results showed that although most participants (60%) were exposed to low daily noise levels, 33% of participants exhibited a ‘binge listening’ exposure pattern characterized by one or two high-noise days, usually a Friday, Saturday or Sunday, preceded or followed by much quieter days. The most notable high-noise activities were playing an instrument solo or in a band; attending a nightclub; and attending a pop concert, each of which recorded average noise levels greater than 100 dB. Future research is needed to determine whether ‘binge listening’ is more or less harmful than the chronic exposure presupposed in traditional risk models, however, under the equal-energy principle, repeated ‘binge’ noise exposures from weekend visits to nightclubs, live music events and other high-noise events represent a significant risk to long-term hearing health.     

人耳听阈曲线的测定实验设计

为了医学生物理实验的改革创新,我实验室引进了BD-Ⅱ-116型听觉实验仪,为学生开设＂人耳听阈曲线的测定＂的医用物理实验,在此给出声强级、听阈曲线、响度等概念,设计目的、实验器材、实验原理、实验内容与步骤等,学生通过本实验掌握了实验理论,同时对医学内容也有了一定了解。     

基于PMMA毛细管电泳芯片的多位点突变检测研究

利用基于激光诱导荧光(LIF)检测的芯片毛细管电泳平台,批量制作了低成本聚甲基丙烯酸甲酯(PMMA)芯片,通过修饰管道,优化有效分离距离、分离介质等条件,可在90s内完成DNA片段的分离检测,实现单碱基分离,并在此平台上成功地对遗传性耳聋三个常见突变位点实现分型检测,为这种低成本的PMMA芯片应用于分型相关的临床诊断领域奠定了基础。