High Risk of Non-Melanoma Skin Cancer in Actinic Keratosis Patients with Skin of Color: A Nationwide Register-Based Cohort Study.

INTRODUCTION: Actinic keratoses (AKs) are rough, scaly patches from UV exposure, increasing the risk of non-melanoma skin cancer (NMSC). This study examines AK incidence in Korea and its role as a risk factor for NMSC. METHODS: A retrospective nationwide register-based cohort study analyzed 2,917 AK patients and 14,585 controls from 2002 to 2019. Patients diagnosed with AK were followed until NMSC occurrence, death, emigration, or December 2019. RESULTS: AK incidence reached 44.8 per 100,000 person-years in 2019. The adjusted hazard ratio for NMSC in AK patients was 8.91 (95% confidence interval, 5.72-13.90). Higher NMSC risk was observed in female AK patients, those under 60 years, and those with lower income levels. The 16-year cumulative incidence of NMSC was 4.19% in AK patients versus 0.44% in controls. CONCLUSION: AK significantly increases the risk of NMSC in Koreans, highlighting the need for tailored surveillance and treatment strategies.

Impact of the COVID-19 pandemic on telogen effluvium: a nationwide multicentre interrupted time series study.

BACKGROUND: There is ongoing debate regarding the association between telogen effluvium (TE) and COVID-19, as well as COVID-19 vaccines. OBJECTIVES: To investigate the impact of the COVID-19 pandemic and vaccination on the development of TE among patients visiting dermatology clinics in South Korea. METHODS: Between 2017 and 2022, data regarding patients with TE and other types of hair loss were collected from 22 hospitals in South Korea. An interrupted time series analysis was conducted, dividing the time into periods before and after the COVID-19 pandemic, as well as before and after the COVID-19 vaccination. RESULTS: There was a significant slope change in the percentage of cases of TE during the postpandemic period (slope change 0.011, 95% confidence interval 0.005-0.017, P < 0.001), but no significant changes were observed after vaccination. The percentage of patients with other types of hair loss was not associated with COVID-19 or vaccination. The retrospective nature of the study may have limited the ability to establish causation. CONCLUSIONS: This multicentre study provides insights into the epidemiology of TE, showing a significant increase in cases of TE following the COVID-19 pandemic. However, there was no association between the occurrence of TE and COVID-19 vaccines.

A novel nerve block technique for nail surgery.

In pediatric patients, nail unit anesthesia is frequently required for procedures including matrixectomy or nail avulsion. However, nail unit anesthesia is very painful and requires a significant amount of time to take complete effect, causing a great deal of distress for most pediatric patients. By targeting the palmar and dorsal digital nerves in the distal part of the fingers, our method enables fast, simple, and less painful anesthesia.

Comparison of Melanocyte-Associated Immunohistochemical Markers in Acral Lentiginous Melanoma and Acral Benign Nevi.

ABSTRACT: Acral lentiginous melanoma (ALM) is a relatively rare clinicopathologic subtype of cutaneous malignant melanoma, but it is the most common type of melanoma among Asians. Although the research to identify immunohistochemical (IHC) markers to differentiate nevi from melanoma is being conducted, specific markers for ALM are not well-known. Therefore, we aimed to analyze and compare the differences in the expression of melanocyte-associated IHC markers between ALM and acral benign nevi (ABN). Two independent groups of 53 and 19 paraffin-embedded specimens (from patients with pathologically confirmed ALM and ABN, respectively) were subjected to IHC staining for MART-1, preferentially expressed antigen in melanoma (PRAME), SOX10, HMB-45, Ki-67, and p16. We performed a quantitative analysis of PRAME, SOX10, KI-67, and p16 expression and gradient pattern analysis of HMB-45 expression for each specimen. The PRAME (60.1% and 28.5%, P < 0.05) and Ki-67 (7.8% and 3.5%, P < 0.05) expression levels were significantly higher in the ALM group than in the ABN group. The p16 expression was significantly lower (14.2% and 19.4%, P < 0.05), and the absence of HMB-45 gradient was more frequent in the ALM group than in the ABN group. However, no statistical significance was noted in SOX10 (54.8% and 44.7%). Receiver operating characteristic curves showed that PRAME had the highest area under the curve value. In summary, among various IHC markers, PRAME was the most valuable marker for the diagnosis of ALM; however, further large-scale studies are needed to validate these findings.

No Association Between First Exposure to General Anaesthesia and Atopic Dermatitis in the Paediatric Population.

General anaesthesia could affect various immune responses, including Th1 and Th2 immunity, which might also affect cells that play an important role in the pathogenesis of atopic dermatitis. However, the relationship between general anaesthesia exposure and atopic dermatitis remains unknown. The aim of this study was to investigate the risk of developing atopic dermatitis after first exposure to general anaesthesia in the paediatric population (18 years or under). A retrospective cohort study, including those exposed (n = 7,681) and unexposed (n = 38,405; control participants) to general anaesthesia (1:5 ratio), was conducted using national sample cohort data from 2002 to 2015. All participants were followed up for 2 years after cohort entry. The 2-year cumulative incidences of atopic dermatitis in the exposed and unexposed groups were 2.3% and 2.2%, respectively. In the subgroup analysis by age, the cumulative incidence was not significantly different between these cohorts. The risks of atopic dermatitis were not significant in the exposed group in the univariate model (hazard ratio 1.05; confidence interval 0.88-1.24) and in the multivariate model, wherein all covariates were adjusted (adjusted hazard ratio, 1.03; 95% confidence interval 0.87-1.23). The results suggest that children's exposure to general anaesthesia was not associated with increased or decreased risk of atopic dermatitis.

A prospective study to evaluate the treatment effect of pulsed dye laser on thyroidectomy hypertrophic scars using 3D imaging analysis.

OBJECTIVES: The pulsed dye laser (PDL) is an effective modality for preventing and improving hypertrophic scars (HSs). However, the heterogeneity of the parameter settings of the laser and subjective scar assessment methods used in most studies resulting in uncertainty with treatment plans. Therefore, we investigated the treatment effect of the PDL (V-beam; Candela Laser Corporation) on HSs in post-thyroidectomy patients using three-dimensional imaging analysis and intended to provide a systemic and optimal treatment protocol. METHODS: Nineteen patients with HS after thyroidectomy underwent eight treatment sessions with the 595 nm PDL (with the dose gradually increased by 0.5 J/cm2 ) at 4- to 6-week intervals. Patients with an elevated lesion also received intralesional corticosteroid (ICS) treatment. After every two treatment sessions, we assessed the patients' HS using the Vancouver Scar Scale (VSS), a patient satisfaction questionnaire, and with a three-dimensional (3D) skin imaging device (Antera 3D™; Miravex Limited). RESULTS: In repeated-measures analysis of variance, the mean VSS and patient satisfaction significantly improved (p < 0.001), with significant differences in these values observed until the sixth and eighth treatment sessions, respectively. In the quantitative analysis using Antera 3D™, the mean height, pigmentation, and vascularity scores were observed to be significantly improved (p < 0.001). Significant differences in these values were observed until the fourth, second, and eighth treatment sessions, respectively. Subgroup analysis according to ICS treatment showed no significant differences in scar characteristics between those with and without ICS treatment. CONCLUSIONS: In this study, we found that the PDL was effective in reducing scar height, vascularity, and pigmentation in patients with thyroidectomy HS using 3D imaging analysis. Furthermore, we have suggested a cost-effective treatment plan with the 595 nm PDL.

Photobiomodulation therapy with an 830-nm light-emitting diode for the prevention of thyroidectomy scars: a randomized, double-blind, sham device-controlled clinical trial.

This randomized, double-blind, and sham device-controlled trial aimed to evaluate the efficacy and safety of home-based photobiomodulation therapy using an 830-nm light-emitting diode (LED)-based device for the prevention of and pain relief from thyroidectomy scars. Participants were randomized to receive photobiomodulation therapy using an LED device or a sham device without an LED from 1 week postoperatively for 4 weeks. Scars were assessed using satisfaction scores, the numeric rating scale (NRS) score for pain, Global Assessment Scale (GAS), and Vancouver Scar Scale (VSS) scores. The scars were also assessed using a three-dimensional (3D) skin imaging device to detect color, height, pigmentation, and vascularity. Assessments were performed at the 1-, 3-, and 6-month follow-ups. Forty-three patients completed this trial with 21 patients in the treatment group and 22 patients in the control group. The treatment group showed significantly higher patient satisfaction and GAS scores and lower NRS and VSS scores than the control group at 6 months. Improvements in color variation, height, pigmentation, and vascularity at 6 months were greater in the treatment group than in the control group, although the differences were not significant. In conclusion, early application of 830-nm LED-based photobiomodulation treatment significantly prevents hypertrophic scar formation and reduces postoperative pain without noticeable adverse effects.

Estimation of a sediment attenuation coefficient using mid-frequency bottom-interacting signals in Jinhae Bay, Southeast Korea.

The inversion results of geoacoustic parameters using bottom-interacting signals in Jinhae Bay, South Korea, were presented in March 2019 by Kwon, Choi, Ryang, Son, and Jung [J. Acoust. Soc. Am. 145, 1205-1211 (2019)]. At site 1 in this study area, where the surficial sediment was dominated by mud, bottom-loss estimates were typical of losses in sediment with a sound speed lower than that of the water column. In this case, because most of the energy incident on the bottom at the angle of intromission is transmitted into the sediment, scattering may dominate the bottom-path energy, which can lead to an underestimate of bottom loss and an overestimate of the sediment attenuation coefficient. Here, we attempt to provide an accurate estimate of the sediment attenuation coefficient by comparing the difference in amplitudes between the bottom-reflected and sub-bottom-reflected signals over a frequency band of several kHz. To verify the inversion results, measurements of sediment attenuation at the site were also taken by repeatedly transmitting and receiving continuous acoustic waves of 120-180 kHz using four stake transducers embedded in the sediment. The inversion results are in reasonable agreement with the sediment attenuation coefficients measured in situ.

A Hybrid Newton-Raphson and Particle Swarm Optimization Method for Target Motion Analysis by Batch Processing.

Bearing-only target motion analysis (BO-TMA) by batch processing remains a challenge due to the lack of information on underwater target maneuvering and the nonlinearity of sensor measurements. Traditional batch estimation for BO-TMA is mainly performed based on deterministic algorithms, and studies performed with heuristic algorithms have recently been reported. However, since the two algorithms have their own advantages and disadvantages, interest in a hybrid method that complements the disadvantages and combines the advantages of the two algorithms is increasing. In this study, we proposed Newton-Raphson particle swarm optimization (NRPSO): a hybrid method that combines the Newton-Raphson method and the particle swarm optimization method, which are representative methods that utilize deterministic and heuristic algorithms, respectively. The BO-TMA performance obtained using the proposed NRPSO was tested by varying the measurement noise and number of measurements for three targets with different maneuvers. The results showed that the advantages of both methods were well combined, which improved the performance.

Passive Source Localization Using Acoustic Intensity in Multipath-Dominant Shallow-Water Waveguide.

The array invariant technique has been recently proposed for passive source localization in the ocean. It has successfully estimated the source-receiver horizontal range in multipath-dominant shallow-water waveguides. However, it requires a relatively large-scale hydrophone array. This study proposes an array invariant method that uses acoustic intensity, which is a vector quantity that has the same direction as the sound wave propagating through a water medium. This method can be used to estimate not only the source-receiver horizontal range, but also the azimuth to an acoustic source. The feasibility of using a vector quantity for the array invariant method is examined through a simulation and an acoustic experiment in which particle velocity signals are obtained using a finite difference approximation of the pressure signals at two adjacent points. The source localization results estimated using acoustic intensity are compared with those obtained from beamforming of the acoustic signals acquired by the vertical line array.

Batch Processing through Particle Swarm Optimization for Target Motion Analysis with Bottom Bounce Underwater Acoustic Signals.

A target angular information in 3-dimensional space consists of an elevation angle and azimuth angle. Acoustic signals propagating along multiple paths in underwater environments usually have different elevation angles. Target motion analysis (TMA) uses the underwater acoustic signals received by a passive horizontal line array to track an underwater target. The target angle measured by the horizontal line array is, in fact, a conical angle that indicates the direction of the signal arriving at the line array sonar system. Accordingly, bottom bounce paths produce inaccurate target locations if they are interpreted as azimuth angles in the horizontal plane, as is commonly assumed in existing TMA technologies. Therefore, it is necessary to consider the effect of the conical angle on bearings-only TMA (BO-TMA). In this paper, a target conical angle causing angular ambiguity will be simulated using a ray tracing method in an underwater environment. A BO-TMA method using particle swarm optimization (PSO) is proposed for batch processing to solve the angular ambiguity problem.

Distributed Target Tracking in Challenging Environments Using Multiple Asynchronous Bearing-Only Sensors.

In the multiple asynchronous bearing-only (BO) sensors tracking system, there usually exist two main challenges: (1) the presence of clutter measurements and the target misdetection due to imperfect sensing; (2) the out-of-sequence (OOS) arrival of locally transmitted information due to diverse sensor sampling interval or internal processing time or uncertain communication delay. This paper simultaneously addresses the two problems by proposing a novel distributed tracking architecture consisting of the local tracking and central fusion. To get rid of the kinematic state unobservability problem in local tracking for a single BO sensor scenario, we propose a novel local integrated probabilistic data association (LIPDA) method for target measurement state tracking. The proposed approach enables eliminating most of the clutter measurement disturbance with increased target measurement accuracy. In the central tracking, the fusion center uses the proposed distributed IPDA-forward prediction fusion and decorrelation (DIPDA-FPFD) approach to sequentially fuse the OOS information transmitted by each BO sensor. The track management is carried out at local sensor level and also at the fusion center by using the recursively calculated probability of target existence as a track quality measure. The efficiency of the proposed methodology was validated by intensive numerical experiments.

Measurements of mid-frequency bottom-interacting signals and geoacoustic inversion in Jinhae Bay, Southeast Korea.

Measurements of bottom-interacting signals over a frequency range of 4-12 kHz were made at two different sites in shallow water off the southeast coast of Korea. Although the distance between the sites was less than 20 km, the geological properties of surficial sediments were different. The surficial sediment at the site located on the north side was dominated by mud, and the measured bottom loss showed typical characteristics of sediment with a sound speed lower than the water sound speed. In addition, some interesting arrivals, which seemed to be reflected from a sub-sediment interface, were observed immediately following bottom arrivals in the frequency range of 4-8 kHz of some datasets. In contrast, sediment at the site located to the south was dominated by sandy mud, and the bottom loss showed typical characteristics of sediment with a higher sound speed. Geoacoustic parameters of surficial sediment were estimated using a simulated annealing method with an objective function comparing the measured bottom loss data with the Rayleigh reflection model. Surficial layer thickness was estimated based on arrival-time differences between bottom reflected and sub-bottom reflected signals. Inversion results are discussed in comparison with a bottom model constructed based on seismic data and core samples.

Optimal Deployment of Vector Sensor Nodes in Underwater Acoustic Sensor Networks.

Underwater acoustic sensor networks have recently attracted considerable attention as demands on the Internet of Underwater Things (IoUT) increase. In terms of efficiency, it is important to achieve the maximum communication coverage using a limited number of sensor nodes while maintaining communication connectivity. In 2017, Kim and Choi proposed a new deployment algorithm using the communication performance surface, which is a geospatial information map representing the underwater acoustic communication performance of a targeted underwater area. In that work, each sensor node was a vertically separated hydrophone array, which measures acoustic pressure (a scalar quantity). Although an array receiver is an effective system to eliminate inter-symbol interference caused by multipath channel impulse responses in underwater communication environments, a large-scale receiver system degrades the spatial efficiency. In this paper, single-vector sensors measuring the particle velocity are used as underwater sensor nodes. A single-vector sensor can be considered to be a single-input multiple-output communication system because it measures the three directional components of particle velocity. Our simulation results show that the optimal deployment obtained using single-vector sensor nodes is more effective than that obtained using a hydrophone (three-channel vertical-pressure sensor) array.

Measurements of Normal Incidence Reflection Loss as a Function of Temperature at the Water-Castor Oil Interface.

Reflection loss at the water-castor oil interface as a function of temperature was measured in a direction normal to the interface using a 200-kHz acoustic signal. The acoustic impedance of water increases with temperature, whereas that of castor oil decreases. The measured reflection losses varied from 30 to 65 dB, and a sharp rising peak in reflection loss was observed at the temperature at which the acoustic impedance of water became equal to that of castor oil. This temperature is called the temperature of intromission in this paper. These measurements were compared with the model predictions based on a Rayleigh-reflection model using the measured sound speeds of both fluids. The sound speeds in water and castor oil as functions of temperature are the input parameters of the Rayleigh-reflection model, and were measured directly using an arrival time difference method in the temperature range of 5 to 30 °C. The comparison results imply that temperature is an important factor affecting the reflection at the interface separating the two fluids.

Racial/ethnic variation and risk factors for allopurinol-associated severe cutaneous adverse reactions: a cohort study.

OBJECTIVES: To examine associations of race/ethnicity and purported risk factors with hospitalised allopurinol-associated severe cutaneous adverse reactions (AASCARs). METHODS: We used US Medicaid data to identify incident allopurinol users between 1999 and 2012. We examined the risk of hospitalised AASCARs according to race/ethnicity and purported key risk factors and calculated relative risks (RR). RESULTS: Among 400 401 allopurinol initiators, we documented 203 hospitalised AASCAR cases (1 in 1972 initiators). The average AASCAR hospitalisation was 9.6 days and 43 individuals (21%) died. The multivariable-adjusted RRs for AASCARs among blacks, Asians and Native Hawaiians/Pacific Islanders compared with whites or Hispanics were 3.00 (95% CI 2.18 to 4.14), 3.03 (95% CI 1.72 to 5.34) and 6.68 (95% CI 4.37 to 10.22), respectively. Female sex, older age (≥60 years), chronic kidney disease and initial allopurinol dose (>100 mg/day) were independently associated with a 2.5-fold, 1.7-fold, 2.3-fold and 1.9-fold higher risk of AASCAR, respectively. In our combined demographic analysis, older women (≥60 years) of a high-risk race/ethnicity (blacks, Asians or Native Hawaiians/Pacific Islanders) had over a 12-fold higher risk of hospitalised AASCARs than younger men of a low-risk race/ethnicity (whites or Hispanics) (multivariable-adjusted RR, 12.25; 95% CI 6.46 to 23.25). CONCLUSIONS: This racially diverse (yet mostly white) cohort study indicates that the risk of hospitalised AASCAR is rare overall, although blacks, Asians and Native Hawaiians/Pacific-Islanders have a substantially higher risk of hospitalised AASCARs, particularly among older women. These data also support the practice of initiating allopurinol at a low dose (eg, ≤100 mg/day).

Medications as a potential source of exposure to parabens in the U.S. population.

INTRODUCTION: Use of paraben-containing medications has been shown to be associated with urinary paraben concentrations among couples undergoing fertility treatment, but it is unknown whether this association is also present among the general population. METHODS: A list of prescription medications of interest was developed based on their likelihood of containing parabens and the ability to identify users in the National Health and Nutrition Examination Survey (NHANES); alendronate, escitalopram oxalate, fluoxetine, and olanzapine were chosen. Participants reported whether they had used each medication in the past month. Linear regression models were used to compare model-based mean urinary concentrations of each paraben among users and non-users of these four medications. RESULTS: A total of 10,302 respondents were included in the analysis, 265 (2.6%) of whom had reported using a paraben-containing prescription medication in the previous month. Users of alendronate had mean concentrations of ethyl paraben that were approximately three-fold higher than non-users (p ≥ 0.001 in unadjusted and adjusted models), which was likely due to three participants with very high concentrations. No other differences in paraben concentrations were found for any of the medications of interest (all p ≥ 0.13). Compared to non-users, a significantly greater proportion of alendronate users had butyl and ethyl paraben concentrations above the 95th percentile (17.8% and 12.3%, respectively) compared to non-users (5.0% and 5.0%, respectively; both p ≤ 0.01), despite ethyl paraben not being an expected ingredient in the brand name formulation of alendronate. CONCLUSION: Despite previous work showing that medications can be an important source of paraben exposure, there was no clear overall evidence of associations between the use of paraben-containing medications and increases in urinary paraben concentrations among participants in NHANES 2005-2012. These results highlight the difficulties inherent in proper assessment of exposures with short half-lives based on a single cross-sectional biologic sample.