Objective To analyze the characteristics of hearing loss at different frequencies among noise-exposed workers in a lithium battery manufacturing enterprise. Methods A total of 1 954 noise-exposed workers from a large lithium battery manufacturing enterprise were selected as the study subjects using the judgmental sampling method. Pure-tone audiometry, individual noise exposure level monitoring, and workplace noise intensity measurement were conducted. Results The overall detection rate of hearing loss among the study subjects was 39.0%. The detection rates of unilateral and bilateral hearing loss were 21.0% (410/1 954) and 18.0% (352/1 954), respectively. The detection rate of hearing loss in the right ear was higher than that in the left ear (30.1% vs 26.9%, P<0.05). The detection rates of elevated hearing thresholds at high frequencies and speech frequencies were 38.8% and 1.1%, respectively. Comparisons of the detection rates of elevated hearing thresholds across different frequencies between the left and right ears showed significant differences (all P<0.01); specifically, the detection rate at 4.0 kHz in the right ear was higher than that in the left ear (P<0.01). The detection rates of elevated hearing thresholds at 2.0, 4.0, and 6.0 kHz increased with longer duration of noise exposure (all P<0.05). Except at 1.0 kHz, the detection rates of elevated hearing thresholds at 0.5, 2.0, 3.0, 4.0, and 6.0 kHz showed increasing trends with age (all P<0.05). Conclusion Hearing loss among noise-exposed workers in the lithium battery manufacturing industry is predominant in the high-frequency type, with the highest sensitivity at 4.0 kHz and greater susceptibility in the right ear. The detection rate of high frequency hearing loss increases with longer noise exposure duration and advacing age. Health surveillance should focus on workers with longer noise exposure duration and older age. Noise control measures should be strengthened.

Bilateral vestibulopathy（BVP） is one of the common diseases in the vestibular nervous system, with an incidence rate of about 4%-7% in the population, which can lead to a variety of body dysfunctions. At present, there are two main treatment methods for BVP. One is vestibular rehabilitation. However, only part of BVP patients can finally benefit from vestibular rehabilitation, and most patients will remain with permanent vestibular dysfunction. Benefiting from the maturity of cochlear implant technology, European and American countries took the lead in the development of vestibular prosthesis（VP） technology to restore the vestibular function in patients with BVP. This review will focus on the development history, principles, future applications and the related research progress of VP in China.
Humans ; Bilateral Vestibulopathy/therapy* ; Cochlear Implants ; Vestibule, Labyrinth ; Cochlear Implantation ; China

Objective:The aim of this study was to design and perform "Tap-hammer"system that can be used to elicit vestibular evoked myogenic potentials (VEMP) in normal adults and to report the preliminary results of this system.Methods:A triggered Tap-hammer was designed, made and connected with an electric recording system, to form as a system for Tap-VEMP recording. Twenty healthy adult volunteers (7 males and 13 females, aged 20 to 37 years, 40 ears in total) were recruited for air-conducted sound VEMP (ACS-VEMP) and Tap-VEMP examinations. Waveforms and parameters of both VEMPs were recorded and analyzed. SPSS 22.0 software was used for statistical analysis.Results:The response rates of ACS-, Tap-ocular VEMP (oVEMP) and ACS-, Tap-cervical VEMP (cVEMP) were both 100% (40/40). The mean±SD n1 latency, p1 latency, n1-p1 interval, amplitude, and asymmetry ratio (AR%) of Tap-oVEMP were (9.80±2.51)ms, (13.90±3.26)ms, (4.09±1.43)ms, (16.43±9.61)μV, (22.68±17.35)% respectively. The mean±SD p1 latency, n1 latency, p1-n1 interval, amplitude, and asymmetry ratio (AR%) of Tap-cVEMP were (13.26±2.07)ms, (21.84±2.89)ms, (8.58±2.10)ms, (457.65±274.94)μV, (20.42±13.46)% respectively. Both n1 latency and p1 latency of Tap-VEMPs were shorter than those in ACS-VEMPs ( P<0.05). No statistical difference could be found between the two stimulation methods in the parameters of n1-p1 interval, amplitude, and asymmetry ratio( P>0.05). Conclusion:The Tap-hammer system can elicit VEMP responses in healthy young people. This system can be used as an alternative stimulation method for bone conduction VEMP.

Objective To investigate the protective effects of (-)-epigallocatechin gallate ( EGCG ) on daunorubicin ( DNR)-induced cardiotoxicity in mice. Methods The qualified mice were randomly divided into four groups:normal control group, myocardial injured model control group,high dose group (80 mg·kg-1 ) and low dose group (40 mg·kg-1 ) of EGCG. EGCG was administered intragastrically once daily for 7 days,followed by a single intraperitoneal injection of DNR (15 mg·kg-1 ) except in the normal control group. The electrocardiogram,myocardial enzymes and TNT-Hs in serum,cardiac ultrastructure of mice were detected after 48 h. Results In DNR model control group,the incidence of arrhythmia was 64. 7%. The activity of serum cardic enzymes including CK,CK-MB,LDH,α-HBDH and ALT,AST, level of TNT-Hs were significantly higher than those in the normal control group(P<0. 01),and myocardial ultrastructure was injured remarkably. The incidence of arrhythmia was 44. 4% in mice treated with high dose of EGCG and 31. 6% in mice with low dose of EGCG. Compared to the model control group, the activity of CK,CK-MB,LDH,α-HBDH and ALT,AST, level of TNT-Hs in serum decreased remarkably in EGCG groups( P<0. 05 or P<0. 01). Low can EGCG alleviated the injury to the ultrastructure of myocardium compared to the model control group. Conclusion EGCG can prevent the cardiac toxicity induced by DNR in mice.