Development and accuracy validation of a fat fraction imaging biomarker for sialadenitis in the parotid gland.

BACKGROUND: The diagnosis of sialadenitis, the most frequent disease of the salivary glands, is challenging when the symptoms are mild. In such cases, biomarkers can be used as definitive diagnostic indicators. Recently, biomarkers have been developed by extracting and analyzing pathological and morphological features from medical imaging. This study aimed to establish a diagnostic reference for sialadenitis based on the quantitative magnetic resonance imaging (MRI) biomarker IDEAL-IQ and assess its accuracy. METHODS: Patients with sialadenitis (n = 46) and control subjects (n = 90) that underwent MRI were selected. Considering that the IDEAL-IQ value is a sensitive fat fractional marker to the body mass index (BMI), all subjects were also categorized as under-, normal-, and overweight. The fat fraction of parotid gland in the control and sialadenitis groups were obtained using IDEAL-IQ map. The values from the subjects in the control and sialadenitis groups were compared in each BMI category. For comparison, t-tests and receiver operating characteristic (ROC) curve analyses were performed. RESULTS: The IDEAL-IQ fat faction of the control and sialadenitis glands were 38.57% and 23.69%, respectively, and the differences were significant. The values were significantly lower in the sialadenitis group (P), regardless of the BMI types. The area under the ROC curve (AUC) was 0.83 (cut-off value: 28.72) in patients with sialadenitis. The AUC for under-, normal-, and overweight individuals were 0.78, 0.81, and 0.92, respectively. CONCLUSIONS: The fat fraction marker based on the IDEAL-IQ method was useful as an objective indicator for diagnosing sialadenitis. This marker would aid less-experienced clinicians in diagnosing sialadenitis.

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.

Harmonization of robust radiomic features in the submandibular gland using multi-ultrasound systems: a preliminary study.

OBJECTIVE: This study aimed to identify robust radiomic features in multiultrasonography of the submandibular gland and normalize the interdevice discrepancies by applying a machine-learning-based harmonization method. METHODS: Ultrasonographic images of normal submandibular gland of young healthy adults, aged between 20 and 40 years, were selected from two different devices. In a total of 30 images, the region of interest was determined along the border of gland parenchyma, and 103 radiomic features were extracted using A-VIEW. The coefficient of variation (CV) was obtained for individual features, and the features showing CV less than 10% were selected. For the selected features, the interdevice discrepancy was normalized using machine-learning method, called the ComBat harmonization. Median differences of the features between the two scanners, before and after harmonization, were compared using Mann-Whitney U-test; confidence interval of 95%. RESULTS: Among total 103 radiomic features, 17 features were selected as robust, showing CV less than 10% in both scanners. All values of selected features, except two, showed a statistical difference between the two devices. After applying the ComBat harmonization method, the median and distribution of the 16 features were harmonized to show no significant difference between the two scanners (p > 0.05). One feature remained different (p ≤ 0.05). CONCLUSION: On ultrasonographic examination, robust radiomic features for normal submandibular gland were obtained and interdevice normalization was efficiently conducted using ComBat harmonization. Our findings would be useful for multidevices or multicenter studies based on clinical ultrasonographic imaging data to improve the accuracy of the overall diagnostic model.

Impact of physiological parameters on the parotid gland fat fraction in a normal population.

Quantifying physiological fat tissue in the organs is important to further assess the organ's pathologic status. This study aimed to investigate the impact of body mass index (BMI), age, and sex on the fat fraction of normal parotid glands. Patients undergoing magnetic resonance imaging (MRI) of iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL-IQ) due to non-salivary gland-related disease were reviewed. Clinical information of individual patients was categorized into groups based on BMI (under/normal/overweight), age (age I/age II/age III), and sex (female/male) and an inter-group comparison of the fat fraction values of both parotid glands was conducted. Overall, in the 626 parotid glands analyzed, the fat fraction of the gland was 35.80%. The mean fat fraction value increased with BMI (30.23%, 35.74%, and 46.61% in the underweight, normal and overweight groups, respectively [p < 0.01]) and age (32.42%, 36.20%, and 41.94% in the age I, II, and III groups, respectively [p < 0.01]). The fat content of normal parotid glands varies significantly depending on the body mass and age regardless of sex. Therefore, the patient's age and body mass should be considered when evaluating fatty change in the parotid glands in imaging results.

Deep learning synthesis of cone-beam computed tomography from zero echo time magnetic resonance imaging.

Cone-beam computed tomography (CBCT) produces high-resolution of hard tissue even in small voxel size, but the process is associated with radiation exposure and poor soft tissue imaging. Thus, we synthesized a CBCT image from the magnetic resonance imaging (MRI), using deep learning and to assess its clinical accuracy. We collected patients who underwent both CBCT and MRI simultaneously in our institution (Seoul). MRI data were registered with CBCT data, and both data were prepared into 512 slices of axial, sagittal, and coronal sections. A deep learning-based synthesis model was trained and the output data were evaluated by comparing the original and synthetic CBCT (syCBCT). According to expert evaluation, syCBCT images showed better performance in terms of artifacts and noise criteria but had poor resolution compared to the original CBCT images. In syCBCT, hard tissue showed better clarity with significantly different MAE and SSIM. This study result would be a basis for replacing CBCT with non-radiation imaging that would be helpful for patients planning to undergo both MRI and CBCT.

Radiomics-based sialadenitis staging in contrast-enhanced computed tomography and ultrasonography: a preliminary rat model study.

OBJECTIVE: The aim of this study was to measure the ability of radiomics analysis to diagnose different stages of sialadenitis, compare the diagnostic accuracy of computed tomography (CT) and ultrasonography (US), and suggest radiomics features selected through 3 machine learning algorithms that would be helpful in discriminating between stages of sialadenitis with both imaging systems. STUDY DESIGN: Wistar rats were treated to induce acute and chronic sialadenitis in the left and right submandibular glands, respectively. Contrast-enhanced CT and US of the glands were performed, followed by extirpation and histopathologic confirmation. Radiomics feature values of the glands were obtained from all images. Based on 3 feature selection methods, an optimal feature set was defined after a comparison of the receiver operating characteristic area under the curve (AUC) of each combination of 3 deep learning algorithms and 3 classification models. RESULTS: The attribute features for the CT model were 2 gray-level run length matrices and 2 gray-level zone length matrices. In the US model, there were 2 gray-level co-occurrence matrices and 2 gray-level zone length matrices. The most accurate diagnostic models of CT and US yielded outstanding (AUC = 1.000) and excellent (AUC = 0.879) discrimination, respectively. CONCLUSIONS: The radiomics diagnostic model using gray-level zone length matrices-based features conferred clinically outstanding discriminating ability among stages of sialadenitis using CT and excellent discrimination with US in almost all combinations of machine learning feature selections and classification models.

Refinement of image quality in panoramic radiography using a generative adversarial network.

OBJECTIVE: We aimed to develop and assess the clinical usefulness of a generative adversarial network (GAN) model for improving image quality in panoramic radiography. METHODS: Panoramic radiographs obtained at Yonsei University Dental Hospital were randomly selected for study inclusion (n = 100). Datasets with degraded image quality (n = 400) were prepared using four different processing methods: blur, noise, blur with noise, and blur in the anterior teeth region. The images were distributed to the training and test datasets in a ratio of 9:1 for each group. The Pix2Pix GAN model was trained using pairs of the original and degraded image datasets for 100 epochs. The peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM) were obtained for the test dataset, and two oral and maxillofacial radiologists rated the quality of clinical images. RESULTS: Among the degraded images, the GAN model enabled the greatest improvement in those with blur in the region of the anterior teeth but was least effective in improving images exhibiting blur with noise (PSNR, 36.27 > 32.74; SSIM, 0.90 > 0.82). While the mean clinical image quality score of the original radiographs was 44.6 out of 46.0, the highest and lowest predicted scores were observed in the blur (45.2) and noise (36.0) groups. CONCLUSION: The GAN model developed in this study has the potential to improve panoramic radiographs with degraded image quality, both quantitatively and qualitatively. As the model performs better in refining blurred images, further research is required to identify the most effective methods for handling noisy images.

Efficacy of corticosteroid ductal irrigation in acute salivary gland inflammation induced in a rat model.

Purpose: This study aimed to compare the therapeutic effects of corticosteroid irrigations and normal saline irrigations in the early inflammatory state of the salivary gland. Materials and Methods: Adult male Wistar rats were divided into experimental (n=6) and control (n=3) groups. Inflammation was induced in the experimental subjects on both sides of the submandibular gland with ligation. After 14 days, both sides of the glands were de-ligated and retroductal irrigation using saline (n=3) and a corticosteroid (n=3) was performed on the left sides only. The controls (n=3) were used to normalize the gland state for the effects of diet and aging. Magnetic resonance imaging was performed to confirm inflammation and post-irrigation gland recovery by measuring relative signal intensity (SI). The glands were excised for histological examination. Results: All experimental animals showed inflamed glands with increased SI and subsequent recovery of the gland with decreased SI to varying degrees. The SI of the controls showed no significant changes during the overall period. The mean SI change of the irrigated gland was higher than that of the non-irrigated side, without a significant difference. The corticosteroid-irrigated glands showed a greater change in SI than that of the saline-irrigated glands. Histology revealed that inflammation was not observed in most of the irrigated glands, while mild to moderate quantities inflammatory cells were found in non-irrigated glands. Conclusion: Corticosteroid irrigation mitigated the early stages of salivary gland inflammation more effectively than normal saline.

Deep learning neural networks to differentiate Stafne's bone cavity from pathological radiolucent lesions of the mandible in heterogeneous panoramic radiography.

This study aimed to develop a high-performance deep learning algorithm to differentiate Stafne's bone cavity (SBC) from cysts and tumors of the jaw based on images acquired from various panoramic radiographic systems. Data sets included 176 Stafne's bone cavities and 282 odontogenic cysts and tumors of the mandible (98 dentigerous cysts, 91 odontogenic keratocysts, and 93 ameloblastomas) that required surgical removal. Panoramic radiographs were obtained using three different imaging systems. The trained model showed 99.25% accuracy, 98.08% sensitivity, and 100% specificity for SBC classification and resulted in one misclassified SBC case. The algorithm was approved to recognize the typical imaging features of SBC in panoramic radiography regardless of the imaging system when traced back with Grad-Cam and Guided Grad-Cam methods. The deep learning model for SBC differentiating from odontogenic cysts and tumors showed high performance with images obtained from multiple panoramic systems. The present algorithm is expected to be a useful tool for clinicians, as it diagnoses SBCs in panoramic radiography to prevent unnecessary examinations for patients. Additionally, it would provide support for clinicians to determine further examinations or referrals to surgeons for cases where even experts are unsure of diagnosis using panoramic radiography alone.

Automated cortical thickness measurement of the mandibular condyle head on CBCT images using a deep learning method.

This study proposes a deep learning model for cortical bone segmentation in the mandibular condyle head using cone-beam computed tomography (CBCT) and an automated method for measuring cortical thickness with a color display based on the segmentation results. In total, 12,800 CBCT images from 25 normal subjects, manually labeled by an oral radiologist, served as the gold-standard. The segmentation model combined a modified U-Net and a convolutional neural network for target region classification. Model performance was evaluated using intersection over union (IoU) and the Hausdorff distance in comparison with the gold standard. The second automated model measured the cortical thickness based on a three-dimensional (3D) model rendered from the segmentation results and presented a color visualization of the measurements. The IoU and Hausdorff distance showed high accuracy (0.870 and 0.928 for marrow bone and 0.734 and 1.247 for cortical bone, respectively). A visual comparison of the 3D color maps showed a similar trend to the gold standard. This algorithm for automatic segmentation of the mandibular condyle head and visualization of the measured cortical thickness as a 3D-rendered model with a color map may contribute to the automated quantification of bone thickness changes of the temporomandibular joint complex on CBCT.

Accuracy of digital model generated from CT data with metal artifact reduction algorithm.

This study investigated whether metal artifact reduction (MAR) applied computed tomography (CT) scans could be used to generate precise digital models and explored possible correlations between the amount of metal artifact and model accuracy. Thirty maxillofacial CT scans were randomly selected and a MAR algorithm was applied. By subtracting the original and MAR-applied CT images, the amount of metal artifact was quantified. Digital models were generated from the original and the MAR-applied CT data. Paired digital models were superimposed and shape deviation in planar surface was measured at 10 points in 4 planes. Statistical analyses were performed to compare deviations and to assess correlations between the amount of artifact and deviation. The MAR algorithm reduced metal artifact in all cases. The overall mean deviation of the MAR-applied models was 0.0868 mm, with no significant difference according to the reference plane. The amount of artifact did not significantly influence the accuracy of the digital models. MAR-applied CT is a convenient source for digital modeling with clinically acceptable accuracy. The MAR algorithm can be used regardless of the amount of metal artifact, which are generated by dental prostheses, for the quick and convenient manipulation of dental digital models.

Fear of Falling and Mortality among Older Adults in Korea: Analysis of the Korean Longitudinal Study of Aging.

BACKGROUND: The fear of falling (FOF) has been reported in a high percentage of elderly people. An excessive FOF is a major concern among the elderly because it can lead to permanent disability. However, the impact of FOF on mortality has been insufficiently studied. The aim of this study was to investigate the impact of FOF on mortality among the elderly in Korea. METHODS: This was a prospective study carried out using the database of the Korean Longitudinal Study of Aging, a nationwide study of community-dwelling adults in Korea. Study participants included 3,421 adults, aged 65 years or older, without either severe cognitive impairment (Korean version of Mini-Mental Status Examination ≥10), or previous history of cancer. We used Cox proportional hazards models to investigate the association between FOF and all-cause mortality. RESULTS: This study included 1,474 men and 1,947 women. Cox regression showed that participants with FOF had an increased risk of mortality (mild: hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.01-1.54; moderate: HR, 1.59; 95% CI, 1.23-2.05) after adjusting for confounding variables. In a subgroup analysis, FOF was still a significant risk factor of mortality for patients with no previous history of falling after adjusting for other risk factors, as in the full model, except for history of falling (HR, 1.65; 95% CI, 1.27-2.13). CONCLUSION: We found that FOF was a significant risk factor for mortality in the elderly in Korea. Further studies on the effects and mechanism of FOF on mortality are needed.

Quantitative analysis of metal artifact reduction using the auto-edge counting method in cone-beam computed tomography.

The metal artifact reduction (MAR) algorithm is used in most CBCT unit to reduce artifact from various dental materials. The performance of MAR program of a CBCT unit according to the dental material type under different imaging mode was evaluated as introducing automatic quantification of the amount of artifact reduced. Four customized phantoms with different dental prostheses (amalgam, gold, porcelain-fused-metal, zirconia) underwent CBCT scanning with and without the MAR option. The imaging was performed under varied scanning conditions; 0.2 and 0.3 mm3 voxel sizes; 70 and 100 kVp. The amount of artifacts reduced by each prosthesis and scanning mode automatically counted using canny edge detection in MATLAB, and statistical analysis was performed. The overall artifact reduction ratio was ranged from 17.3% to 55.4%. The artifact caused by the gold crown was most effectively reduced compared to the other prostheses (p < 0.05, Welch's ANOVA analysis). MAR showed higher performance in smaller voxel size mode for all prostheses (p < 0.05, independent t-test). Automatic quantification efficiently evaluated MAR performance in CBCT image. The impact of MAR was different according to the prostheses type and imaging mode, suggesting that thoughtful consideration is required when selecting the imaging mode of CBCT.

CT-like MRI using the zero-TE technique for osseous changes of the TMJ.

OBJECTIVE: This study was conducted to assess the clinical usability of the zero-echo time (ZTE) technique of MRI for evaluating bone changes of the temporomandibular joint (TMJ) in comparison with CBCT. METHODS: Twenty patients with TMJ disorder who underwent both CBCT and MRI were randomly selected. CBCT images were obtained with an Alphard 3030 device (Asahi Roentgen Ind., Co. Ltd, Kyoto, Japan). MRIs were obtained using a 3.0 T scanner (Pioneer; GE Healthcare, Waukesha, WI, USA) and a 21-channel head coil. An isotropic three-dimensional proton-density-weighted ZTE sequence was acquired. Two radiologists evaluated 40 joints of 20 patients for the presence of the following osseous changes: flattening, erosion, osteophyte and sclerosis of the condyle; and flattening, erosion and sclerosis of the articular fossa. CBCT and ZTE-MRI assessments were performed at a 2-month interval. The prevalence-adjusted and bias-adjusted κ statistic was used to analyse interexaminer and intraexaminer agreement and the agreement between ZTE-MRI and CBCT. RESULTS: Intraexaminer and interexaminer agreement analyses of ZTE-MRI showed high reproducibility (κ>0.80), which was comparable to that of CBCT. Flattening, osteophyte and sclerosis of the condyle and all types of bone changes in the mandibular fossa showed nearly perfect agreement between CBCT and ZTE-MRI (κ = 0.80-0.90). Erosion of the condyle showed substantial agreement between both sets of images (κ = 0.65-0.70). CONCLUSIONS: It is suggested that ZTE-MRI provides clinically reliable images for bone assessment in TMJ disorder. MRI may become a beneficial diagnostic tool for patients with both TMJ disc and bone pathology, with advantages involving medical costs and radiation dose.

Alveolar bone height according to the anatomical relationship between the maxillary molar and sinus.

PURPOSE: The aim of this study was to investigate the available alveolar bone height between the maxillary molars and the sinus floor according to their anatomical relationship using cone-beam computed tomographic (CBCT) images. METHODS: A total of 752 maxillary first (M1) and second molars (M2) on CBCT scans of 188 patients were selected. First, each maxillary molar was categorized as type 1, 2, 3, or 4 according to the relationship of the molar root with the maxillary sinus floor. The frequency distribution of each type was analyzed. Second, the shortest vertical distance (VD) of each molar was measured from the furcation midpoints of the roots to the lowest point of the sinus floor by 2 observers. Intraclass correlation coefficients and the t-test were calculated for the VD measurements. RESULTS: For M1, type 3 was the most frequent, followed by type 2. For M2, type 3 was the most common, followed by type 1. The VD measurements of type 1 were 9.51±3.68 mm and 8.07±2.73 mm for M1 and M2, and those of type 3 were 3.70±1.52 mm and 4.03±1.53 mm for M1 and M2, respectively. The VD measurements of M2 were significantly higher in female patients than in male patients. CONCLUSIONS: Type 3 was the most frequent anatomical relationship in the maxillary molars, and showed the lowest alveolar bone height. This information will help clinicians to prevent complications related to the maxillary sinus during maxillary molar treatment and to predict the available bone height for immediate implant planning.

Factors Related to Employment Situation among Korean Cancer Survivors: Results from a Population-Based Study

Background: Due to the increased incidence and survival rate of cancer, the number of cancer survivors has been increasing. In addition, many problems have been reported regarding the employment of these survivors. Therefore, this study aims to investigate the employment situation of cancer survivors and associated factors. Methods: We analyzed data from the Korean National Health and Nutrition Examination Survey (2010-2014), which is a nationwide cross-sectional health survey, and included a total of 1,060 participants who were diagnosed with cancer. Multivariate logistic regression analysis was conducted to investigate the factors associated with the participants' employment situation. Results: The employment rate among cancer survivors was 42.0%. The variables found to be associated with being employed were male gender, younger age, higher household income level, educational level at middle school level or under, and not having activity limitations. Conclusion: These findings suggest that, in addition to cancerrelated factors, general characteristics such as gender, age, household income, and education level are important factors associated with the employment status of Korean cancer survivors.

Care Needs of Patients at the End of Life With a Noncancer Diagnosis Who Live at Home.

BACKGROUND: As the population ages, the prevalence of various chronic diseases increases. Palliative care for patients at the end of life with a noncancer diagnosis is currently limited because of the difficulties of demarcating the boundaries of the end-of-life care period and of determining the various care needs of patients at the end of life. PURPOSE: This study aimed to investigate the levels of importance and difficulty of the multidimensional care needs for patients with a noncancer diagnosis during various end-of-life stages. METHODS: This study is a retrospective survey. Home healthcarenurse specialists (HHNS) reviewed medical and nursing records and responded to a structured questionnaire. The caring experiences of HHNS with 115 patients, who were 40 years or older, had received home care nursing throughout the stable (between the onset of the end-of-life stage and 1 week before death) and near-death (1 week before death) stages at Seoul St. Mary's Hospital in Korea, and had died between September 1, 2014, and December 31, 2015, were analyzed. RESULTS: The care needs of "coordination among family or relatives" and "support for fundamental needs" were more important in the stable stage than in the near-death stage. The care need of "loss, grief care" was more important in the near-death stage than in the stable stage. The care need of "physical symptoms management" was the most difficult to meet in both stages. Lower Palliative Performance Scale score was associated with a higher level of care need, particularly in the "management of physical symptoms" and "psychological support" realms in the stable stage and in the "coordination among family or relatives" realm in both stages. CONCLUSIONS: End-of-life stage and initial score on the Palliative Performance Scale were found to have a significant influence on the multidimensional care needs of patients with a noncancer diagnosis. Thus, healthcare professionals should assess patient care needs according to disease trajectory to provide continuous and holistic care.

Vitamin D and the characteristics associated with risk for knee pain among Korean older adults: Findings from a nationally representative survey.

AIM: To explore vitamin D and the risk factors associated with knee pain in a representative population of Korean older adults METHODS: Data were analyzed from the Korean National Health and Nutrition Examination Survey (2010-2013). A total of 3874 participants (1728 men, 2146 women) aged 65 years and older who had a measured serum 25-hydroxyvitamin D level were evaluated. Multivariate logistic regression was used to investigate the relationship between serum vitamin D and knee pain severity RESULTS: Sex, age, obesity, education, knee radiographic osteoarthritis, hip pain and back pain were associated with having knee pain. Also, the level of serum 25-hydroxyvitamin D was not significantly associated with knee pain severity. After controlling for confounding factors, the level of serum 25-hydroxyvitamin D was not significantly associated with knee pain, and severity levels of mild, moderate and severe. CONCLUSIONS: The results show that the serum vitamin D did not have a significant effect on knee pain in older adults in Korea. Geriatr Gerontol Int 2017; 17: 1278-1285.

Prevalence, risk factors and comorbidities of allergic rhinitis in South Korea: The Fifth Korea National Health and Nutrition Examination Survey.

BACKGROUND: There has been no nationwide epidemiological investigation of allergic rhinitis (AR) that was diagnosed by both questionnaires and laboratory tests in Korea. This study investigated the prevalence, risk factors, and comorbidities of AR in South Korea. METHODS: The Korean National Health and Nutritional Examination Survey examined a representative sample of the Korean population. A total of 2305 participants underwent immunoradiometric assay for specific IgE antibodies against common indoor allergens. Healthy, atopy only, and AR groups were defined according to the results of allergen test. The weighted prevalence for each group was calculated. Risk factors including food and comorbidities were identified using univariate or multivariate analyses. The patients were also categorized into four subgroups according to the Allergic Rhinitis and Its Impact on Asthma (ARIA) classification and associated comorbidities were analyzed. RESULTS: The prevalence of atopy only and AR was 30.0 ± 1.2% and 16.2 ± 1.0%, respectively. The multivariate analysis showed that the prevalence was influenced by sex (p < 0.01) for atopy only and sex (p = 0.09), age (p = 0.02), marital status (p = 0.24), and stress level (p = 0.30) for AR. Compared with the healthy group, asthma (odds ratio [OR] = 4.77), nasal polyp (NP; OR = 3.44), chronic rhinosinusitis (OR = 13.93), and olfactory dysfunction (OR = 4.88) were more prevalent in the AR group. Based on the ARIA guideline, intermittent mild rhinitis was most common (58.1%). Asthma was correlated to severity and atopic dermatitis and NPs was associated with persistency. Daily intake of less mackerel and more carrots, bread, and bean curd were associated with the increased risk of AR. CONCLUSION: Prevalence, risk factors, and comorbidities of AR were evaluated in the general Korean population, which will contribute to prevention and treatment of AR and its comorbidities in Koreans.

Wafer-scale production of uniform InAs(y)P(1-y) nanowire array on silicon for heterogeneous integration.

One-dimensional crystal growth allows the epitaxial integration of compound semiconductors on silicon (Si), as the large lattice-mismatch strain arising from heterointerfaces can be laterally relieved. Here, we report the direct heteroepitaxial growth of a mixed anion ternary InAsyP1-y nanowire array across an entire 2 in. Si wafer with unprecedented spatial, structural, and special uniformity across the entire 2 in. wafer and dramatic improvements in aspect ratio (>100) and area density (>5 × 10(8)/cm(2)). Heterojunction solar cells consisting of n-type InAsyP1-y (y = 0.75) and p-type Si achieve a conversion efficiency of 3.6% under air mass 1.5 illumination. This work demonstrates the potential for large-scale production of these nanowires for heterogeneous integration of optoelectronic devices.