The Long-Term Stability of Fat-Graft Myringoplasty in the Closure of Tympanic Membrane Perforations and Hearing Restoration.

BACKGROUND/AIMS: This study was conducted to evaluate the long-term stability of fat-graft myringoplasty (FGM) for chronic tympanic membrane perforations, analyzing the perforation closure rate and re-gained hearing outcome with respect to the size and location of the perforations. METHODS: Between August 2007 and June 2018, a total of 193 patients who underwent FGM due to chronic tympanic membrane perforation at a tertiary referral center were enrolled and analyzed. RESULTS: The mean follow-up was 14.6 months (range 6-39). The complete perforation closure rate after FGM was 89.6%, with no statistical difference among the perforation size groups. The mean postoperative air-bone gap (ABG) was 11.0 dB and mean ABG improvement was 4.9 dB. CONCLUSION: Our FGM technique had a favorable tympanic closure rate for small to large perforations, and yielded relatively good hearing improvement in the mid-size perforation cases over long-term follow-up periods. According to the topographic evaluation of FGM, this procedure resulted in a reliable perforation closure rate and audiological results regardless of the perforation site.

Rate and Product Studies with 1-Adamantyl Chlorothioformate under Solvolytic Conditions.

A study was carried out on the solvolysis of 1-adamantyl chlorothioformate (1-AdSCOCl, 1) in hydroxylic solvents. The rate constants of the solvolysis of 1 were well correlated using the Grunwald-Winstein equation in all of the 20 solvents (R = 0.985). The solvolyses of 1 were analyzed as the following two competing reactions: the solvolysis ionization pathway through the intermediate (1-AdSCO)+ (carboxylium ion) stabilized by the loss of chloride ions due to nucleophilic solvation and the solvolysis-decomposition pathway through the intermediate 1-Ad+Cl- ion pairs (carbocation) with the loss of carbonyl sulfide. In addition, the rate constants (kexp) for the solvolysis of 1 were separated into k1-Ad+Cl- and k1-AdSCO+Cl- through a product study and applied to the Grunwald-Winstein equation to obtain the sensitivity (m-value) to change in solvent ionizing power. For binary hydroxylic solvents, the selectivities (S) for the formation of solvolysis products were very similar to those of the 1-adamantyl derivatives discussed previously. The kinetic solvent isotope effects (KSIEs), salt effects and activation parameters for the solvolyses of 1 were also determined. These observations are compared with those previously reported for the solvolyses of 1-adamantyl chloroformate (1-AdOCOCl, 2). The reasons for change in reaction channels are discussed in terms of the gas-phase stabilities of acylium ions calculated using Gaussian 03.

Clinical efficacy of standard simple elliptical incision following drain-less and subcutaneous suture technique in preauricular sinus surgery.

BACKGROUND: The purpose of this study was to review our surgical strategy and outcomes of drain-less, subcutaneous suture technique in standard simple elliptical incision on preauricular sinus (PAS) cases. METHODS: The clinical records of 198 patients (247 ears) with PASs who were operated via standard simple elliptical incision with drain-less, subcutaneous suture technique by a single surgeon (K.H.P.) between January 2008 and December 2018 were reviewed for analysis. Patients' demographics, location of PASs, previous incision and drainage (I&D) history, previous surgical excision history, duration of follow-up, postoperative infection after surgery, and recurrence after surgery were analysed. RESULTS: Out of 247 PASs, 18 (7.3%) cases had postoperative infections and 11 (4.5%) cases showed recurrence. Postoperative infection rate were higher in previous I&D groups (PIDGs, 9.8%) and previous fistulectomy groups (PFGs, 10%), and also recurrence rates of PFGs (10%) was higher than those of fresh cases. However, there were no statistically significant differences between these groups. In addition, PAS patients with postoperative complications such as infection and recurrence were more common in male patients. CONCLUSION: We report a method of drain-less standard simple elliptical incision for the surgical removal of PAS and the outcomes of the surgery. Our method showed a low recurrence rate and low chance of wound infection postoperatively not only in fresh cases but also in pre-operative I&D cases and even previous fistulectomy cases. In conclusion, our method is proposed as an effective and safe method in all kind of patient groups, without presenting post-operative discomfort to patients.

The Effect of the ortho Nitro Group in the Solvolysis of Benzyl and Benzoyl Halides.

A kinetic study was carried out on the solvolysis of o-nitrobenzyl bromide (o-isomer, 1) and p-nitrobenzyl bromide (p-isomer, 3), and o-nitrobenzoyl chloride (o-isomer, 2) in a wide range of solvents under various temperatures. In all of the solvents without aqueous fluoroalcohol, the reactions of 1 were solvolyzed at a similar rate to those observed for 3, and the reaction rates of 2 were about ten times slower than those of the previously studied p-nitrobenzoyl chloride (p-isomer, 4). For solvolysis in aqueous fluoroalcohol, the reactivity of 2 was kinetically more reactive than 4. The l/m values of the extended Grunwald-Winstein (G-W) equation for solvolysis of 1 and 2 in solvents without fluoroalcohol content are all significantly larger than unity while those in all the fluoroalcohol solvents are less than unity. The role of the ortho-nitro group as an intramolecular nucleophilic assistant (internal nucleophile) in the solvolytic reaction of 1 and 2 was discussed. The results are also compared with those reported earlier for o-carbomethoxybenzyl bromide (5) and o-nitrobenzyl p-toluenesulfonate (7). From the product studies and the activation parameters for solvolyses of 1 and 2 in several organic hydroxylic solvents, mechanistic conclusions are drawn.

Expression of polysialylated neural cell adhesion molecules on adult stem cells after neuronal differentiation of inner ear spiral ganglion neurons.

During brain development, polysialylated (polySia) neural cell adhesion molecules (polySia-NCAMs) modulate cell-cell adhesive interactions involved in synaptogenesis, neural plasticity, myelination, and neural stem cell (NSC) proliferation and differentiation. Our findings show that polySia-NCAM is expressed on NSC isolated from adult guinea pig spiral ganglion (GPSG), and in neurons and Schwann cells after differentiation of the NSC with epidermal, glia, fibroblast growth factors (GFs) and neurotrophins. These differentiated cells were immunoreactive with mAb's to polySia, NCAM, ß-III tubulin, nestin, S-100 and stained with BrdU. NSC could regenerate and be differentiated into neurons and Schwann cells. We conclude: (1) polySia is expressed on NSC isolated from adult GPSG and on neurons and Schwann cells differentiated from these NSC; (2) polySia is expressed on neurons primarily during the early stage of neuronal development and is expressed on Schwann cells at points of cell-cell contact; (3) polySia is a functional biomarker that modulates neuronal differentiation in inner ear stem cells. These new findings suggest that replacement of defective cells in the inner ear of hearing impaired patients using adult spiral ganglion neurons may offer potential hope to improve the quality of life for patients with auditory dysfunction and impaired hearing disorders.

Prevalence and associated factors of tinnitus: data from the Korean National Health and Nutrition Examination Survey 2009-2011.

BACKGROUND: Tinnitus is a common condition and frequently can be annoying to affected individuals. We investigated the prevalence and associated factors for tinnitus in South Korea using the data from the Korea National Health and Nutrition Examination Surveys (KNHANES) during 2009-2011. METHODS: KNHANES is a cross-sectional survey of the civilian, non-institutionalized population of South Korea (n = 21 893). A field survey team that included an otolaryngologist moved with a mobile examination unit and performed interviews and physical examinations. RESULTS: Among the population over 12 years of age, the prevalence of any tinnitus was 19.7% (95% CI 18.8%-20.6%). Tinnitus was more prevalent in women, and the prevalence rate increased with age (P < 0.001). Among those with any tinnitus, 29.3% (95% CI 27.3%-31.3%) experienced annoying tinnitus that affected daily life. Annoying tinnitus also increased with age (P < 0.001), but no sex difference was demonstrated (P = 0.25). In participants aged 40 years or older, age, quality of life, depressive mood, hearing loss, feeling of dizziness, and rhinitis were associated with any tinnitus (P < 0.05). Age, hearing loss, history of cardiovascular disease, and stress were associated with annoying tinnitus (P < 0.05). CONCLUSIONS: Tinnitus is a common condition, and a large population suffers from annoying tinnitus in South Korea. Public understanding of associated factors might contribute to better management of tinnitus.

Diagnostic value and clinical significance of stress hormones in patients with tinnitus.

Tinnitus has been found to be modulated by stress and is also closely related to the emotional state and the limbic system. In the present study, we evaluated the diagnostic and clinical values of several stress hormones in a large number of tinnitus patients. This study included 344 patients with sensorineural tinnitus and 87 normal controls. A questionnaire about tinnitus was administered to the participants, and blood levels of norepinephrine (NE), epinephrine (Epi), a metabolite of serotonin (5-hydroxyindoleacetic acid, 5-HIAA) and cortisol were compared between groups. In results, the mean values of Beck's depression inventory (BDI), Brief Encounter Psychosocial Instrument (BEPSI), NE, and 5-HIAA levels were higher in the tinnitus group, although there was no statistical significance. But, the proportion of participants with elevated 5-HIAA was significantly higher in the tinnitus group (21.8 vs. 8.0 %, P < 0.05), and the 5-HIAA level significantly correlated with the duration of tinnitus, NE and cortisol. Elevated stress-related hormones, as well as hearing loss, BDI, and BEPSI were the most related factors with tinnitus in multiple regression test with age adjustment. However, levels of stress-related hormones did not correlate with subjective measures including BDI, BEPSI and severity of tinnitus. In conclusion, blood stress hormones seemed to have some diagnostic and clinical value in patients with tinnitus, and serotonin is supposed to be the most important hormone in tinnitus. Further studies about the values of stress and stress hormones in tinnitus patients may lead to new approaches regarding diagnosis and clinical management of the disease.

Protective effect of unilateral and bilateral ear plugs on noise-induced hearing loss: functional and morphological evaluation in animal model.

The aim of the following study is to evaluate immediate protective effect of ear plug from noise morphologically and functionally. An 1-month aged 29 male C57BL/6 mice. Subjects were divided into four groups as normal control(G1), bilaterally plugged group (G2), unilaterally plugged group (G3) and noise control group (G4) and later 3 groups were exposed to 110 sound pressure level white noise for 60 min. Immediately after noise exposure, audiologic tests were performed and cochlear morphology and expression levels of a-synuclein in the cochlea were investigated. There were no functional changes in G2 and plugged ears of G3 after noise exposure, whereas unplugged ears of G3 and G4 showed significant hearing loss. In morphological study, there were a significant degeneration of the organ of Corti and mean number and diameter of efferent buttons, in unplugged ears of G3 and G4. Plugged ears of G3 also showed mild changes in morphological study. Reduction of a-synuclein was observed at the efferent terminals or cochlear extracts after noise exposure. The protective effect of ear plug on noise exposure was proven morphologically and functionally in the animal model of noise-induced hearing loss. Further study on cellular or ultrastructural level with ear plug will be needed to reveal more precise mechanism.

The Effects of Music-Based Auditory Training on Hearing-Impaired Older Adults With Mild Cognitive Impairment.

OBJECTIVES: The present study aimed to determine the effect of music-based auditory training on older adults with hearing loss and decreased cognitive ability, which are common conditions in the older population. METHODS: In total, 20 older adults diagnosed with both mild-to-moderately severe hearing loss and mild cognitive impairment (MCI) participated. Half of this group were randomly assigned to the auditory training group (ATG), and the other half were designated as the control group (CG). For the ATG, a 40-minute training session (10 minutes for singing a song, 15 minutes for playing instruments, and 15 minutes for playing games with music discrimination) was conducted twice a week for 8 weeks (for a total of 16 sessions). To confirm the training effects, all participants were given tests pre- and post-training, and then a follow-up test was administered 2 weeks after the training, using various auditory and cognitive tests and a self-reporting questionnaire. RESULTS: The ATG demonstrated significant improvement in all auditory test scores compared to the CG. Additionally, there was a notable enhancement in cognitive test scores post-training, except for the digit span tests. However, there was no statistically significant difference in the questionnaire scores between the two groups, although the ATG did score higher post-training. CONCLUSION: The music-based auditory training resulted in a significant improvement in auditory function and a partial enhancement in cognitive ability among elderly patients with hearing loss and MCI. We anticipate that this music-based approach will be adopted for auditory training in clinical settings due to its engaging and easy-to-follow nature.

Evaluation of the reliability and validity of the upright head roll test for lateral semicircular canal benign paroxysmal positional vertigo.

BACKGROUND: The upright head roll test (UHRT) is a recently introduced diagnostic maneuver for lateral semicircular canal benign paroxysmal positional vertigo (LSC-BPPV). OBJECTIVE: This study aimed to evaluate the reliability and validity of the UHRT. METHODS: Two separate studies were conducted. Study 1 analyzed 827 results of videonystagmography (VNG) to assess UHRT reliability, and Study 2 analyzed 130 LSC-BPPV cases to evaluate UHRT validity. RESULTS: The inter-test reliability between UHRT and the supine head roll test (SHRT) showed substantial agreement (Cohen's kappa = 0.753) in direction-changing positional nystagmus (DCPN) and almost perfect agreement (Cohen's kappa = 0.836) in distinguishing the direction of DCPN. The validity assessment of UHRT showed high accuracy in diagnosing LSC-BPPV (80.0%) and in differentiating the variant types (74.6%). UHRT was highly accurate in diagnosing the canalolithiasis type in LSC-BPPV patients (Cohen's kappa = 0.835); however, it showed only moderate accuracy in diagnosing the cupulolithiasis type (Cohen's kappa = 0.415). The intensity of nystagmus in UHRT was relatively weaker than that in SHRT (P < 0.05). CONCLUSION: UHRT is a reliable test for diagnosing LSC-BPPV and distinguishing subtypes. However, UHRT has a limitation in discriminating the affected side owing to a weaker intensity of nystagmus than SHRT.

Clinical significance of orthostatic dizziness in the diagnosis of benign paroxysmal positional vertigo and orthostatic intolerance.

PURPOSE: Orthostatic dizziness (OD) and positional dizziness (PD) are considerably common conditions in dizziness clinic, whereas those two conditions are not clearly separated. We aimed to evaluate the clinical significance of simple OD and OD combined with PD for the diagnosis of benign paroxysmal positional vertigo (BPPV) and orthostatic intolerance (OI). PATIENTS AND METHODS: Patients presenting with OD (n=102) were divided into two groups according to their symptoms: group PO, presenting with PD as well as OD; group O, presenting with OD. A thorough medical history, physical examination, and vestibular function tests were performed to identify the etiology of the dizziness. Orthostatic vital sign measurement (OVSM) was used to diagnose OI. RESULTS: The majority of patients were in group PO (87.3%). BPPV was the most common cause of OD for entire patients (36.3%) and group PO (37.1%), while OI was most common etiology for group O (38.5%). Total of 17 (16.7%) OI patients were identified by OVSM test. Orthostatic hypotension (n=10) was most frequently found, followed by orthostatic hypertension (n=5), and orthostatic tachycardia (n=2). Group O showed significantly higher percentage (38.5%) of OI than group PO (13.5%) (P=0.039). CONCLUSION: It is suggested that orthostatic testing such as OVSM or head-up tilt table test should be performed as an initial work up for the patients with simple OD. Positional tests for BPPV should be considered as an essential diagnostic test for patients with OD, even though their dizziness is not associated with PD.

Tinnitus in patients with profound hearing loss and the effect of cochlear implantation.

The objectives of this study were to characterize the features of tinnitus in patients with profound sensorineural hearing loss and to evaluate the effect of cochlear implantation (CI) on their tinnitus. Medical records were reviewed for 35 patients who underwent CI, and completed tinnitus questionnaire between March 2003 and August 2011. Of them, 22 had tinnitus prior to CI (62.9 %) and the tinnitus group was older than the non-tinnitus group (47.5 ± 15.1 vs. 28.9 ± 15.2). The mean tinnitus handicap inventory (THI) score of the tinnitus group was 50.5 ± 28.7 before surgery, and the mean THI score and visual analogue scale (VAS) scores for loudness, annoyance, effect on life, and awareness decreased significantly after CI, with a mean follow-up period of 10.7 months. Tinnitus was completely eliminated in ten patients (45.5 %) and THI scores decreased in all patients. In a correlation analysis of the decrease in THI scores, preoperative VAS scores for loudness, awareness, effect on life, and annoyance, as well as preoperative THI scores, were highly correlated with the degree of decrease in THI scores postoperatively. The auditory performance of patients older than 40 years did not differ from that of younger patients, but their tinnitus was more improved after CI. In conclusion, tinnitus is a common complaint in patients with cochlear implants, and is more prevalent in elderly implantees. In the present study, CI improved tinnitus in all patients, although the most severe cases had the greatest benefit.

The cover of an ear thermometer probe as a split-thickness skin graft mold in external auditory canal reconstruction.

Maintaining the patency of the external auditory canal (EAC) during reconstruction is important because of its physiological role in hearing and immunological protective functions. The curved shape of the EAC presents a challenge when performing a skin graft. One of the key points for a successful skin graft is to ensure compression on the wound bed, and many novel methods, including prefabricated ear molds, have been reported for this purpose. In this study, we present a case of a skin graft performed to reconstruct a skin defect following excision of actinic keratosis in the EAC, using the cover of an ear thermometer probe as a mold for the graft to match the curvature of the EAC. This is an economical and practical method for secure compression dressing of a skin graft in the EAC.

Association between HbA1c and hearing loss: a tertiary care center-based study.

The purpose of this study was to investigate the correlation between glycated hemoglobin (HbA1c) levels and hearing loss (HL) using data from a tertiary hospital. Our hypothesis regarding the relationship between HL and HbA1c levels was that elevated HbA1c levels are associated with an increased risk of HL. We retrospectively reviewed the medical charts of patients diagnosed with sensorineural HL or diabetes between 2006 and 2021 at the Catholic Medical Center (CMC). Data were collected from the CMC's Clinical Data Warehouse. Participants were selected from patients who were prescribed pure-tone audiometry and an HbA1c blood test. The survey was completed for 5287 participants. The better ear pure-tone audiometry (PTA) for air conduction thresholds at 500, 1000, 2000, and 4000 Hz was calculated. Sensorineural HL was defined as a better ear PTA of 25 dB or higher. We used the HbA1c level as a diagnostic criterion for diabetes. The following criteria were used to define the HbA1c level: normal, HbA1c level below 5.6%; prediabetes, level between 5.6 and 6.4%; and diabetes, level of 6.5% or more. Among 5287 participants, 1129 were categorized as normal, 2119 as prediabetic, and 2039 as diabetic. The diabetic group was significantly older (p < 0.05). The PTA also significantly deteriorated in the diabetes group (p < 0.05). We analyzed the effects of age, sex, and HbA1c level on frequency-specific hearing using multiple regression. The hearing thresholds at all frequencies deteriorated significantly with increasing age and HbA1c level (p < 0.05). A case-control study was also performed to facilitate a comprehensive comparison between distinct groups. The participants were categorized into two groups: a case (PTA > 25 dB) and control group (PTA ≤ 25 dB), based on their PTA threshold of four frequencies. After adjusting for age and sex, we found no significant odds ratio (OR) of HL between the prediabetes group and the normal group. Notably, the OR of HL was significantly higher in the diabetes group with each PTA threshold and frequency. The 6.3% HbA1c level cutoff value was determined by analyzing the receiver operating characteristic curve for predicting hearing impairment > 25 dB. Diabetes was associated with hearing loss in all frequency ranges, particularly at high frequencies. Screening for HL is strongly recommended for patients with elevated HbA1c levels.

Hearing restoration in a deaf animal model with intravenous transplantation of mesenchymal stem cells derived from human umbilical cord blood.

OBJECTIVE: This study was performed to confirm the effect of transplantation of human umbilical cord blood mesenchymal stem cells (UCB-MSCs) on hearing restoration in a sensorineural hearing loss (SNHL) animal model. MATERIAL AND METHODS: UCB was collected from pregnant women after obtaining consent, and mesenchymal stem cells (MSCs) were extracted. We established an SNHL model and transplanted UCB-MSCs through the brachial vein of the guinea pigs. The animals were divided into 4 groups: animals with normal hearing, animals with SNHL, animals with SNHL and injected with saline, and animals with SNHL and transplanted with UCB-MSCs. Hearing tests were conducted at 1, 3, and 5 weeks, and the results were compared by grading auditory brainstem response (ABR) recordings and distortion product otoacoustic emissions (DPOAEs) for each treatment. Lastly, cochlear pathological features were examined, and surface preparations and morphological changes in each animal model were compared using hematoxylin and eosin staining and light microscopy studies. RESULTS: In SNHL group, decreased DPOAEs and increased ABR threshold were noted. Furthermore, in the SNHL group, ABR hearing thresholds were unconverted and were similar to those observed in deafness. The transplanted UCB-MSC group showed a significant improvement in hearing threshold (40 dB) compared to that in all the SNHL group (80-90 dB). Examination of the SNHL animals' cochlear morphological features demonstrated a noticeable lack of spiral ganglion cells and also showed degenerated outer hair cells. However, the transplanted UCB-MSCs showed an increase in spiral ganglion and hair cells. CONCLUSION: Intravenous transplantation of UCB-MSCs can enhance hearing thresholds, outer-hair cells and increase the number of spiral ganglion neurons (SGNs).

Preauricular sinus: advantage of the drainless minimal supra-auricular approach.

OBJECTIVES: We performed this study to introduce our minimal supra-auricular approach for the surgical management of a preauricular sinus (PAS) and to evaluate the advantages of this drainless technique. STUDY DESIGN: This was a retrospective study. SETTING: The study was done in a tertiary referral center. METHODS: We enrolled 94 patients (101 ears) with a PAS who underwent surgical treatment via a minimal supra-auricular approach performed by one surgeon between April 1999 and May 2010. After removing the specimen, meticulous subcutaneous suturing and no drain were used in 83 patients (89 ears) and a postoperative drain was inserted in 11 patients (12 ears). Surgical outcomes of this technique were compared between the groups with and without postoperative drain insertion. RESULTS: With a good surgical view and meticulous subcutaneous mattress sutures in our minimal supra-auricular approach for PAS excision, there was no postoperative recurrence or other serious complication. In the drain group, previous operation history was more frequent (P = .010), and the rate of preoperative infection was higher than in the drainless group (P = .018). Postoperatively, a compression dressing was required more frequently (P = .002) and for longer in the drain group (P = .001). The rate of immediate postoperative wound infection was higher in the drain group (P = .003). CONCLUSION: Our drainless minimal supra-auricular approach for the surgical removal of a PAS has advantage in terms of good surgical results of no recurrence and is more comfortable for patients because of the reduced need for a compression dressing. We suggest that this technique is effective and safe for PAS excision.

Analysis of the Knowledge, Attitudes, and Practice Model of Healthcare Professionals on Hearing Loss at Elderly Dementia Residences in Korea.

Due to a lack of knowledge about age-related hearing loss, its early identification and appropriate intervention are not being carried out in the field of dementia care. Since the untreated hearing loss of the elderly leads to a more rapid cognitive decline, the present study aimed to understand the hearing-related knowledge, attitudes, and practices of healthcare professionals in long-term care (LTC) facilities in Korea. A total of 557 workers (104 facility managers and 453 healthcare professionals) in residential LTC participated in this cross-sectional multicenter survey study. The Korean version of the knowledge, attitudes, and practice (KAP) on-line survey with a five-point scale or yes/no response was applied as the experimental tool. The results of structural equation modeling showed that knowledge significantly affected the attitudes and health-seeking practices of the facility manager, and allied healthcare professionals demonstrated similar results, which showed the significant effects of that knowledge on attitudes and health-seeking practices. This clearly indicated that sufficient knowledge is the driving force for the health-seeking practices and positive attitudes of both the facility manager and the healthcare professionals. Thus, we suggest that a further step, such as the development of comprehensive and professional guidelines regarding hearing care information for these professionals in residential LTC facilities, should be followed, and believe that this effort could lead to improving hearing-related knowledge, attitudes, and practices in order to clinically and politically care for the elderly population.

Association of dietary factors with noise-induced hearing loss in Korean population: A 3-year national cohort study.

Noise-induced hearing loss (NIHL) is a hearing impairment (HI) caused by various clinical factors. Identifying the relationship between NIHL and nutrient consumption could help in reducing the prevalence of hearing loss. The aim of this study was to analyze the relationship between NIHL and dietary factors using data of the Korea National Health and Nutrition Examination survey (KNHANES). The data were collected from The Fifth KNHANES 2010-2012. The survey was taken by a total of 10,850 participants aged 20-65 years. Air conduction audiometry was measured at 500, 1000, 2000, and 4000 Hz in both ears. Metabolic syndrome, noise exposure, alcohol consumption, smoking, income level, marital status, and nutritional intake were evaluated. The differences between non-HI and HI participants in the noise-exposed group showed statistically significant differences in age, sex, marital and smoking status, alcohol consumption, and fasting glucose and triglyceride levels (p<0.05). In a multiple regression analysis of the noise-exposed group, age showed a significant association with HI (OR: 0.604; 95% CI: 0.538-0.678) after adjusting for confounders. In multivariate analysis for dietary factors affecting HI in noise-exposed groups, retinol (OR: 1.356; 95% CI: 1.068-1.722), niacin (OR: 1.5; 95% CI: 1.022-2.201), and carbohydrates (OR: 0.692; 95% CI: 0.486-0.985) showed a significant association with NIHL. Age was identified as the only factor significantly affecting NIHL. When the dietary factors of the noise-exposed group were analyzed, high intake of niacin and retinol and low intake of carbohydrates appeared to reduce the risk of hearing loss.

Fast switching of long-pitch cholesteric liquid crystal device.

We propose a long-pitch cholesteric liquid crystal (ChLC) device capable of operation in both the dynamic mode and the memory mode. Fast switching between the homeotropic state and the focal conic state allows the display of moving pictures at a low operating voltage. In addition, we can write text messages on the proposed ChLC device by applying an external pressure locally to switch it from the focal conic state to the planar state.

High performance transflective liquid crystal display associated with fringe-field switching device.

The outdoor readability of the most popular portable liquid crystal display (LCDs) viz. fringe field switching has been addressed both in single and dual cell gap transflective devices. The devices use dual orientation, such as, homogeneous alignment in transmissive (T) part and 64° twisted alignment in reflective (R) part. The dark states of the proposed devices are achieved by controlling phase retardation in T part and polarization rotation in R part and the white state is realized by rotating optic axis of liquid crystal and removing phase retardation in T and R parts, respectively. The devices show high light efficiency without requiring any optical compensation films, exhibiting strong potential for portable display applications.