Effect of Welding Parameters on Al/Mg Dissimilar Friction Stir Lap Welding with and without Ultrasonic Vibration.

The amount of heat input during welding impacts the weld's thermal and mechanical behavior and the joint's properties. The current study involved conducting AA 6061 and AZ31B Mg dissimilar welding, using friction stir lap welding (FSLW) and ultrasonic vibration-enhanced FSLW (UVeFSLW). The comparison and analysis of the welding load, the weld's macro-microstructure, intermetallic compounds (IMCs), and joint properties were conducted by adjusting the process parameters. The study also examined the effect of ultrasonic vibration (UV) variations on welding heat input. The study demonstrated that it is possible to reduce the welding load by employing UV. Moreover, this impact becomes more pronounced as the welding heat input decreases. Additionally, the material flow in the weld, the width of the weld nugget zone, and the continuous IMC layer are significantly influenced by ultrasonic vibration, irrespective of the heat input during welding. However, the impact on large areas of irregular IMCs or eutectic structures is relatively small. Furthermore, achieving better joint properties becomes more feasible when a higher welding speed is employed for the Al alloy placed on top. Specifically, the impact of UV becomes more evident at higher welding speeds (≥220 mm/min).

Optimizing age-related hearing risk predictions: an advanced machine learning integration with HHIE-S.

OBJECTIVES: The elderly are disproportionately affected by age-related hearing loss (ARHL). Despite being a well-known tool for ARHL evaluation, the Hearing Handicap Inventory for the Elderly Screening version (HHIE-S) has only traditionally been used for direct screening using self-reported outcomes. This work uses a novel integration of machine learning approaches to improve the predicted accuracy of the HHIE-S tool for ARHL in older adults. METHODS: We employed a dataset that was gathered between 2016 and 2018 and included 1,526 senior citizens from several Taipei City Hospital branches. 80% of the data were used for training (n = 1220) and 20% were used for testing (n = 356). XGBoost, Gradient Boosting, and LightGBM were among the machine learning models that were only used and assessed on the training set. In order to prevent data leakage and overfitting, the Light Gradient Boosting Machine (LGBM) model-which had the greatest AUC of 0.83 (95% CI 0.81-0.85)-was then only used on the holdout testing data. RESULTS: On the testing set, the LGBM model showed a strong AUC of 0.82 (95% CI 0.79-0.86), far outperforming conventional techniques. Notably, several HHIE-S items and age were found to be significant characteristics. In contrast to traditional HHIE research, which concentrates on the psychological effects of hearing loss, this study combines cutting-edge machine learning techniques-specifically, the LGBM classifier-with the HHIE-S tool. The incorporation of SHAP values enhances the interpretability of the model's predictions and provides a more comprehensive comprehension of the significance of various aspects. CONCLUSIONS: Our methodology highlights the great potential that arises from combining machine learning with validated hearing evaluation instruments such as the HHIE-S. Healthcare practitioners can anticipate ARHL more accurately thanks to this integration, which makes it easier to intervene quickly and precisely.

Formation Mechanism of Thicker Intermetallic Compounds in Friction Stir Weld Joints of Dissimilar AA2024/AZ31B Alloys.

The hybrid structures of AA2024 aluminum alloy and AZ31B magnesium alloy have the advantages of being lightweight, having high specific strength, etc., which are of great application potentials in the aerospace industry. It is a key problem to realize the high-quality welding of these two dissimilar alloys. In this study, the friction stir welding (FSW) tests of AA2024 aluminum alloy and AZ31B magnesium alloy plates of thickness 3 mm were carried out. The intermetallic compounds (IMCs) at the bonding interface were characterized by scanning electron microscope, electron probe, and transmission electron microscope. It was found that the IMCs at the bonding interface in weld nugget zones of dissimilar AA2024/AZ31B FSW has a double-layer structure and a much larger thickness. During the welding process of AA2024/AZ31B, when the boundary of magnesium grains bulges and nucleates, the aluminum atoms diffuse into the magnesium grains, and the γ phase (Al12Mg17) nucleates at the bonding interface. The ß phase (Al3Mg2) then precipitates at the grain boundary of the γ phase and preferentially grows into γ phase grains. The continuous grain growth to the aluminum side makes the copper contained in AA2024 aluminum alloy concentrate on the side of ß phase, which reduces the nucleation work of recrystallization and phase transformation, and further promotes the nucleation and growth of IMCs grains. This is the main reason for the thicker IMCs in the FSW weld of dissimilar AA2024/AZ31B alloys.

Diagnostic Validity of Self-Reported Hearing Loss in Elderly Taiwanese Individuals: Diagnostic Performance of a Hearing Self-Assessment Questionnaire on Audiometry.

KEY POINTS: Question: Can the traditional Chinese version of the hearing handicap inventory for elderly screening (HHIE-S) checklist screen for age-related hearing loss (ARHL) in elderly individuals? FINDINGS: In this cross-sectional study of 1696 Taiwanese patients who underwent annual government-funded geriatric health checkups, the Chinese version of the HHIE-S had a sensitivity of 76.9% and a specificity of 79.8% with a cutoff score greater than 6 for identifying patients with disabled hearing loss (defined as a PTA > 40 dB). Meaning: The traditional Chinese version of the HHIE-S is an effective test to detect ARHL and can improve the feasibility of large-scale hearing screening among elderly individuals. PURPOSE: The traditional Chinese version of the hearing handicap inventory for elderly screening (TC-HHIE-S) was translated from English and is intended for use with people whose native language is traditional Chinese, but its effectiveness and diagnostic performance are still unclear. The purpose of this study was to evaluate the validity and reliability of the traditional Chinese version of the HHIE-S for screening for age-related hearing loss (ARHL). METHODS: A total of 1696 elderly people underwent the government's annual geriatric medical examination at community hospitals. In this cross-sectional study, we recorded average conducted pure-tone averages (PTA) (0.5 kHz, 1 kHz, 2 kHz, 4 kHz), age, sex, and HHIE-S data. Receiver operating characteristic (ROC) curve analysis was used to identify the best critical point for detecting hearing impairment, and the validity of the structure was verified by the agreement between the TC-HHIE-S and PTA results. RESULTS: The HHIE-S scores were correlated with the better-ear pure-tone threshold averages (PTAs) at 0.5-4 kHz (correlation coefficient r = 0.45). The internal consistency of the total HHIE-S score was excellent (Cronbach's alpha = 0.901), and the test-retest reliability was also excellent (Spearman's correlation coefficient = 0.60, intraclass correlation coefficient = 0.75). In detecting disabled hearing loss (i.e., PTA at 0.5-4 kHz > 40 dB), the HHIE-S cutoff score of > 6 had a sensitivity of 76.9% and a specificity of 79.8%. CONCLUSIONS: The traditional Chinese version of the HHIE-S is a valid, reliable, and efficient tool for large-scale screening for ARHL.

Risk of early-onset dementia among persons with tinnitus: a retrospective case-control study.

Higher rates of poor cognitive performance are known to prevail among persons with tinnitus in all age groups. However, no study has explored the association between tinnitus and early-onset dementia. We hypothesize that tinnitus may precede or occur concurrently with subclinical or early onset dementia in adults younger than 65 years of age. This case-control study used data from the Taiwan National Health Insurance Research Database, identifying 1308 patients with early-onset dementia (dementia diagnosed before 65 years of age) and 1308 matched controls. We used multivariable logistic regressions to estimate odds ratios (ORs) for prior tinnitus among patients with dementia versus controls. Among total 2616 sample participants, the prevalence of prior tinnitus was 18%, 21.5% among cases and 14.5% among controls (p < 0.001). Multivariable logistic regression showed and adjusted OR for prior tinnitus of 1.6 for cases versus controls (95% CI: 1.3 ~ 2.0). After adjusting for sociodemographic characteristics and medical co-morbidities, patients with early-onset dementia had a 67% higher likelihood of having prior tinnitus (OR = 1.628; 95% CI = 1.321-2.006). Our findings showed that pre-existing tinnitus was associated with a 68% increased risk of developing early-onset dementia among young and middle-aged adults. The results call for greater awareness of tinnitus as a potential harbinger of future dementia in this population.

The prevalence and demographic features of congenital cytomegalovirus infection in an urban area of East Asia: A population-based study.

Congenital cytomegalovirus (cCMV) infection is the leading environmental cause of childhood hearing impairment. However, its significance remains largely undocumented in many regions of the world. The purpose of this study was to investigate the prevalence and clinical features of cCMV infection in East Asia. Neonates born at a municipal hospital in Taipei were prospectively recruited and underwent concurrent hearing and CMV screenings. Those who failed the hearing screening or screened positive for CMV were subjected to a focused audiological and/or virological surveillance. The characteristics of the newborns and their mothers were compared between the CMV-positive and CMV-negative groups. Of the 1,532 newborns who underwent concurrent hearing and CMV screenings, seven (0.46%) were positive for cCMV infection. All seven CMV-positive newborns were asymptomatic at birth, and none of them developed hearing or other symptoms during a follow-up period of 14.4±6.3 months. The mothers of the CMV-positive newborns demonstrated higher gravidity (2.4 ± 1.4 vs. 2.1 ± 1.2) and parity (2.0 ± 1.2 vs. 1.6 ± 0.7) than those in the CMV-negative group; however, the difference did not reach statistical significance. The prevalence of cCMV infection in Taipei newborns was 0.46%, which is slightly lower than that of other populations and that of a previous report in the Taiwanese population. The relatively low prevalence in this study might be attributed to the improved public health system and decreased fertility rate in Taiwan.

Numerical Analysis of Keyhole and Weld Pool Behaviors in Ultrasonic-Assisted Plasma Arc Welding Process.

The acoustic radiation force driving the plasma jet and the ultrasound reflection at the plasma arc-weld pool interface are considered to modify the formulas of gas shear stress and plasma arc pressure on the anode surface in ultrasonic-assisted plasma arc welding (U-PAW). A transient model taking into account the dynamic changes of heat flux, gas shear stress, and arc pressure on the keyhole wall is developed. The keyhole and weld pool behaviors are numerically simulated to predict the heat transfer and fluid flow in the weld pool and dynamic keyhole evolution process. The model is experimentally validated. The simulation results show that the acoustic radiation force increases the plasma arc velocity, and then increases both the plasma arc pressure and the gas shear stress on the keyhole wall, so that the keyholing capability is enhanced in U-PAW.

A Nationwide Population-Based Study on the Incidence of Parapharyngeal and Retropharyngeal Abscess-A 10-Year Study.

This study aimed to investigate the annual incidence of parapharyngeal and retropharyngeal abscess (PRPA) based on 10-year population-based data. Patients with PRPA were identified from the Taiwan Health Insurance Research Database, a database of all medical claims of a randomly selected, population-representative sample of over two million enrollees of the National Health Insurance system that covers over 99% of Taiwan's citizens. During 2007-2016, 5779 patients received a diagnosis of PRPA. We calculated the population-wide incidence rates of PRPA by sex and age group (20-44, 45-64, and >64) as well as in-hospital mortality. The annual incidence rate of PRPA was 2.64 per 100,000 people. The gender-specific incidence rates per 100,000 people were 3.34 for males and 1.94 for females with a male:female gender ratio of 1.72. A slight increase in incidence rates among both genders over the study period was noted. Age-specific rates were lowest in the 20-44 age group with a mean annual incidence of 2.00 per 100,000 people, and the highest rates were noted in the age groups of 45-64 and >64 years with mean annual incidences of 3.21 and 3.20, respectively. We found that PRPA is common in Taiwan, males and older individuals are more susceptible to it, and incidence has increased in recent years.

Peripheral Vestibular Disorders: Nationwide Evidence From Taiwan.

OBJECTIVES/HYPOTHESIS: This study aimed to evaluate the prevalence of peripheral vestibular disorders in an Asian population of predominantly Han Chinese ethnicity. STUDY DESIGN: Cross-sectional study. METHODS: Patients with a peripheral vertigo disorder were identified from the Taiwan Health Insurance Research Database, a database of all medical claims of a randomly selected, population-representative sample of 2 million enrollees of Taiwan's National Health Insurance system covering over 99% of Taiwan's citizens. In 2016, 59,986 patients received a diagnosis of peripheral vestibular disorders in Taiwan. We calculated the population-wide prevalence rates of peripheral vestibular disorders in 2016 by sex and age group (20 to 24, 25 to 29, 30 to 34, 35 to 39, 40 to 44, 45 to 49, 50 to 54, 55 to 59, 60 to 64, 65 to 69, and ≥ 70 years) stratified into five urbanization levels. RESULTS: The prevalence rate of peripheral vestibular disorders was 2,833.4 per 100,000 population during the year. Prevalence of Meniere's disease was 70.4 per 100,000, benign paroxysmal positional vertigo, 446.4, vestibular neuritis 307.2, and other or unspecified peripheral vestibular dizziness, 2,009.5 per 100,000. Prevalence rates steadily increased with age for every type of peripheral vestibular disorder, and were higher among females compared to males. The female-to-male gender ratios were 1.84, 1.89, and 1.93 for Meniere's disease, vestibular neuritis, and other peripheral vestibular dizziness, respectively. Counties with the lowest urbanization level had the highest prevalence rates of all types of peripheral vestibular disorders except vestibular neuritis. CONCLUSIONS: Results showed that peripheral vestibular disorders are common in Taiwan, increase with age, are predominantly female, and show higher prevalence in rural areas. LEVEL OF EVIDENCE: 2b Laryngoscope, 131:639-643, 2021.

A population-based case-control study of the association between cervical spondylosis and tinnitus.

OBJECTIVE: This population-based study aimed to study the association between tinnitus and cervical spondylosis. DESIGN: A case-control study. STUDY SAMPLE: We retrieved data from the Taiwan Longitudinal Health Insurance Database. We identified 2465 patients with tinnitus (cases) and 7395 comparison patients by propensity score matching. Multivariable logistic regressions were conducted to estimate the odds (OR) of a diagnosis of cervical spondylosis preceding the tinnitus diagnosis relative to controls. RESULTS: We found that 1596 (16.19%) of 9860 sample patients had received a diagnosis of cervical spondylosis before the index date, significantly different between the tinnitus group and control group (17.20% vs. 15.85%, p < 0.001). Logistic regression analysis showed an adjusted OR for prior cervical spondylosis of 1.235 for cases vs. controls (95% confidence interval [CI]: 1.088-1.402). Further, the adjusted ORs were 1.246 (95% CI: 1.041-1.491) and 1.356 (95% CI: 1.016-1.811), respectively, among patients aged 45 ∼ 64 and >64 groups. No difference in cervical spondylosis likelihood between cases and controls was found among patients aged 18 ∼ 44 groups. CONCLUSIONS: In conclusion, the study shows a positive association between cervical spondylosis and tinnitus. The findings call for greater awareness among physicians about a possible somatosensory component of cervical spine function which may contribute to tinnitus.

Numerical Simulation of Arc and Droplet Behaviors in TIG-MIG Hybrid Welding.

Tungsten inert gas-metal inert gas hybrid welding (TIG-MIG) combines the advantages of tungsten and metal inert gas welding. It can efficiently produce high-quality weld joints that meet modern manufacturing quality and efficiency requirements. Based on heat transfer, fluid dynamics, and electromagnetic theory, a three-dimensional coupled transient model of arc-droplet interactions in TIG-MIG hybrid welding was established. In this study, the temperature field, flow field, electromagnetic force, pressure, and current density parameters were analyzed in the arc space. The results show that introducing TIG welding has a significant impact on MIG welding.

Correction to: Increased risk of tinnitus following a trigeminal neuralgia diagnosis: a one-year follow-up study.

An amendment to this paper has been published and can be accessed via the original article.

Association of cervical spondylosis with obstructive sleep apnea.

OBJECTIVE: The study objective was to evaluate the association between cervical spondylosis (CS) and a subsequent diagnosis of obstructive sleep apnea (OSA) in light of the expected constricting impact of CS-associated cervical spine changes on the pharyngeal airway space, a key contributor to OSA. METHODS: Data were retrieved from the Taiwan National Health Insurance Research Dataset. A total of 98,234 patients who newly received a diagnosis of OSA were identified. We identified four propensity score-matched controls per OSA patient (n = 392,936). Chi-square tests were used to compare cases and controls on sociodemographic characteristics, and multivariable logistic regression modelling to examine the association of OSA with prior CS. RESULTS: Of the 98,234 sampled patients, 18,070 (18.4%) patients had a prior CS diagnosis, significantly different among cases compared to controls, being 18.4% and12.1%, respectively, p < 0.001. Logistic regression analysis showed an adjusted odds ratio (OR) of prior CS of 1.778 (95% confident interval (CI): 1.744-1.814) relative to controls. The adjusted odds of prior CS without myelopathy was 1.764 for cases relative to controls (95% CI: 1.727-1.801), and for prior CS with myelopathy (adjusted OR: 1.778, 95% CI: 1.721-1.837). Analysis stratified by age showed that in the 45-64- and >64-year age groups, the adjusted ORs of CS were 1.803 (95% CI: 1.758-1.850) and 1.634 (95% CI: 1.568-1.703), respectively, for cases relative to controls. CONCLUSIONS: Our results suggest that OSA is associated with prior CS. The results call for professionals to be alert to the possibility of subsequent development of OSA among patients with CS.

Increased risk of tinnitus following a trigeminal neuralgia diagnosis: a one-year follow-up study.

BACKGROUND: Tinnitus due to hyperactivity across neuronal ensembles along the auditory pathway is reported. We hypothesized that trigeminal neuralgia patients may subsequently suffer from tinnitus. Using nationwide, population-based data and a retrospective cohort study design, we investigated the risk of tinnitus within 1 year following trigeminal neuralgia. METHODS: We used the Taiwan National Health Insurance Research Dataset, a claims database, to identify all patients diagnosed with trigeminal neuralgia from January 2001 to December 2014, 12,587 patients. From the remaining patients, we identified 12,587 comparison patients without trigeminal neuralgia by propensity score matching, using sex, age, monthly income, geographic region, residential urbanization level, and tinnitus-relevant comorbidities (hyperlipidemia, diabetes, coronary heart disease, hypertension, cervical spondylosis, temporomandibular joint disorders and injury to head and neck and index year). All study patients (n = 25,174) were tracked for a one-year period to identify those with a subsequent diagnosis of tinnitus over 1-year follow-up. RESULTS: Among total 25,174 sample patients, the incidence of tinnitus was 18.21 per 100 person-years (95% CI = 17.66 ~ 18.77), the rate being 23.57 (95% CI = 22.68 ~ 24.49) among patients with trigeminal neuralgia and 13.17 (95% CI = 12.53 ~ 13.84) among comparison patients. Furthermore, the adjusted Cox proportional hazard ratio for tinnitus in the trigeminal neuralgia group was 1.68 (95% CI = 1.58 ~ 1.80) relative to the comparison cohort. CONCLUSIONS: We found a significantly increased risk of tinnitus within 1 year of trigeminal neuralgia diagnosis compared to those without the diagnosis. Further studies in other countries and ethnicities are needed to explore the relationship between trigeminal neuralgia and subsequent tinnitus.

Is the risk of idiopathic sudden sensorineural hearing loss higher in nasopharyngeal carcinoma than in hypopharyngeal cancer? A population-based study.

BACKGROUND: The aim of this study was to compare the risk of developing sudden sensorineural hearing loss (SSHL) in patients with hypopharyngeal cancer with that in patients with nasopharyngeal carcinoma (NPC). METHODS: A population-based, retrospective cohort study was performed using the Taiwan National Health Research Database databank. Patients selected for this study were diagnosed with hypopharyngeal cancer or NPC and treated with radiotherapy in the period from 2001 to 2004. Routine follow-up was conducted for 8 years (2004-2012), and the incidence of SSHL was calculated at the final follow-up. RESULTS: There was no significant difference in the risk of developing SSHL between the hypopharyngeal cancer group and its control group (p = 1.000). In hypopharyngeal cancer and NPC groups, the rates of SSHL were 0.12% and 1.00%, respectively (p < 0.001). The cumulative hazard of SSHL during the follow-up period was significantly higher in the NPC group than in the control group (p < 0.001). CONCLUSION: Radiotherapy in patients with hypopharyngeal cancer did not increase the risk of developing SSHL, but postirradiation NPC was significantly associated with an increased incidence of SSHL.

Malignant Otitis Externa is Associated with Diabetes: A Population-Based Case-Control Study.

OBJECTIVE: Despite studies reporting a possible association between malignant otitis externa (MOE) and diabetes, there are no large-scale population-based empirical studies. This nationwide, population-based case-control study explored the association of MOE occurrence with previously diagnosed diabetes. METHODS: Data were retrieved from Taiwan's National Health Insurance Research Database, 753 patients with MOE (cases) and 2 259 propensity score-matched patients without MOE (controls). Multiple logistic regressions were conducted to examine the association of MOE with previously diagnosed diabetes. RESULTS: In total, 728 (24.2%) out of 3 012 sample patients had diabetes prior to the index date. Chi-square test revealed a significant difference in diabetes prevalence among cases and controls (54.8% vs 13.9%, p < 0.001). Simple logistic regression showed the odds ratio for prior diabetes among cases versus controls was 7.50 (95% CI, 6.22~9.03). The adjusted odds ratio of prior diabetes for cases versus controls was 10.07 (95% CI, 8.15~12.44) after adjusting for patient demographics and medical co-morbidities. CONCLUSIONS: This study found an association between MOE and diabetes. One clinical practice implication of our study is that when a patient with diabetes complains of otalgia or otorrhea, and physical examination shows swelling of the ear canal or granulation growth, physicians should consider the possibility of MOE.

Association between pioglitazone use and head and neck cancer: Population-based case-control study.

BACKGROUND: This study aimed to evaluate the association between pioglitazone use and the occurrence of head and neck cancer. METHODS: Data for this case-control study were retrieved from the Taiwan National Health Insurance Research Database. A total of 21 464 diabetic patients newly diagnosed with head and neck cancers were identified. We used propensity score matching to select 64 392 comparison patients (3:1 ratio). Multiple logistic regression modeling was used to examine the association of head and neck cancer with pioglitazone use in the 5 years preceding the cancer diagnosis. RESULTS: Bivariate analysis showed a significant difference in the prevalence of prior using pioglitazone between cases and controls (19.3% vs 18.5%, P < .001) was observed. Multiple regression analysis showed adjusted odds of pioglitazone use of 1.06 (95% CI: 1.02-1.10) among cases relative to controls. CONCLUSIONS: Prior pioglitazone use was associated with oral cavity cancer.

Association between mitral valve prolapse and sudden sensorineural hearing loss: A case-control population-based study.

This study aimed to evaluate the relationship between sudden sensorineural hearing loss (SSNHL) and MVP using a population-based dataset. Data for this case-control study were retrieved from the Taiwan Longitudinal Health Insurance Database. In total, 3399 cases of newly diagnosed SSNHL were identified. We used propensity score matching to select 3399 comparison patients (one for every case) from the same dataset. The selected matching variables included age, sex, monthly income, geographical location, urbanization level of the patient's residence, hypertension, diabetes, and hyperlipidemia. Chi-squared tests were used to compare differences in sociodemographic characteristics, while conditional logistic regression analyses were used to examine the association of SSNHL with previously diagnosed MVP. Of the 6798 sampled subjects, 131 (1.93%) patients had received a diagnosis of MVP prior to the index date. A significant difference in the prevalence of prior MVP between cases and controls (2.41% vs. 1.44%, p = 0.004) was observed. The conditional logistic regression analysis conditioned on gender, age, monthly income, urbanization level, geographic region, hyperlipidemia, diabetes, and hypertension suggested that the odds ratio of prior MVP for cases was 1.69 (95% confidence interval (CI): 1.18~2.42) compared to controls. Our study found that patients with MVP had a 1.69-fold higher risk of getting SSNHL compared to patients without MVP.