Epidemiology and Healthcare Utilization in Pediatric Multiple Sclerosis and Neuromyelitis Optica: A Nationwide Population-Based Study in South Korea (2016-2020).

Pediatric multiple sclerosis (MS) and neuromyelitis optica (NMO) are rare acquired demyelinating syndrome with limited epidemiological data available, particularly in non-Western setting. This study aimed to demonstrate the epidemiology of pediatric MS and NMO in South Korea and to analyze of healthcare utilization and economic burden associated with these conditions. Using a nationwide population-based database from the Korean Health Insurance Review and Assessment Service database, we identified pediatric cases (age < 20 years) of MS and NMO from 2016 to 2020. We analyzed incidence, prevalence, healthcare utilization and medical costs. The study found low age-standardized incidence and prevalence rates for pediatric MS and NMO in South Korea. There was a marked disparity in healthcare utilization between urban and rural areas. Most healthcare interactions occurred in tertiary hospitals in urban settings, particularly in Seoul. The study also highlighted the substantial economic burden associated with the management of rare diseases, with annual variability in medical costs. Pediatric MS and NMO are extremely rare in South Korea, with significant regional disparity in healthcare utilization. The findings emphasize the need for targeted healthcare policies to improve access and reduce disparities, particularly for chronic and rare diseases requiring specialized care.

Effectiveness of breath acetone monitoring in reducing body fat and improving body composition: a randomized controlled study.

When attempts to lose body fat mass frequently fail, breath acetone (BA) monitoring may assist fat mass loss during a low-carbohydrate diet as it can provide real-time body fat oxidation levels. This randomized controlled study aimed to evaluate the effectiveness of monitoring BA levels and providing feedback on fat oxidation during a three-week low-carbohydrate diet intervention. Forty-seven participants (mean age = 27.8 ± 4.4 years, 53.3% females, body mass index = 24.1 ± 3.4 kg m-2) were randomly assigned to three groups (1:1:1 ratio): daily BA assessment with a low-carbohydrate diet, body weight assessment (body scale (BS)) with a low-carbohydrate diet, and low-carbohydrate diet only. Primary outcome was the change in fat mass and secondary outcomes were the changes in body weight and body composition. Forty-five participants completed the study (compliance rate: 95.7%). Fat mass was significantly reduced in all three groups (allP< 0.05); however, the greatest reduction in fat mass was observed in the BA group compared to the BS (differences in changes in fat mass, -1.1 kg; 95% confidence interval: -2.3, -0.2;P= 0.040) and control (differences in changes in fat mass, -1.3 kg; 95% confidence interval: -2.1, -0.4;P= 0.013) groups. The BA group showed significantly greater reductions in body weight and visceral fat mass than the BS and control groups (allP< 0.05). In addition, the percent body fat and skeletal muscle mass were significantly reduced in both BA and BS groups (allP< 0.05). However, no significant differences were found in changes in body fat percentage and skeletal muscle mass between the study groups. Monitoring BA levels, which could have motivated participants to adhere more closely to the low-carbohydrate diet, to assess body fat oxidation rates may be an effective intervention for reducing body fat mass (compared to body weight assessment or control conditions). This approach could be beneficial for individuals seeking to manage body fat and prevent obesity.

Incidence of Pediatric Acute Disseminated Encephalomyelitis During the Coronavirus Disease 2019 Pandemic in South Korea.

BACKGROUND: Acute disseminated encephalomyelitis (ADEM) is an immune-mediated demyelinating disorder of the central nervous system that is usually triggered by infections. We aimed to determine the temporal trends in the incidence of ADEM before and during the pandemic and their correlation with viral epidemiology. METHODS: We conducted a nationwide, population-based, retrospective, ADEM cohort study by using the Health Insurance Review and Assessment Service database. New-onset ADEM was defined as a patient (age <19 years) who was hospitalized with a diagnostic code of G04.0, G36.8, and G36.9 and a prescription of intravenous methylprednisolone. The National Infectious Disease Surveillance System was used to collect the nationwide viral epidemics. RESULTS: A total of 185 new-onset pediatric ADEM cases were included. The mean patient age was 7.0 ± 4.9 years. The incidence of ADEM was 0.34 to 0.48 of 100,000 persons per year before the pandemic, which dropped to 0.22 of 100,000 persons per year during the first pandemic year. The risk of ADEM occurrence was approximately 1.74% higher during the prepandemic years compared with the first pandemic year (odds ratio = 1.017, P = 0.009). There was a weak positive correlation between acute respiratory viral infection and ADEM incidence (r = 0.28, P = 0.03). CONCLUSION: This study demonstrates how infection control during the early coronavirus disease 2019 (COVID-19) pandemic influenced the incidence of ADEM. The low incidence of ADEM in the early COVID-19 pandemic may be related to the decline in acute respiratory viral infections, which are potential triggers of ADEM.

Influence of Dental Titanium Implants with Different Surface Treatments Using Femtosecond and Nanosecond Lasers on Biofilm Formation.

This study aimed to evaluate the impact of different surface treatments (machined; sandblasted, large grit, and acid-etched (SLA); hydrophilic; and hydrophobic) on dental titanium (Ti) implant surface morphology, roughness, and biofilm formation. Four groups of Ti disks were prepared using distinct surface treatments, including femtosecond and nanosecond lasers for hydrophilic and hydrophobic treatments. Surface morphology, wettability, and roughness were assessed. Biofilm formation was evaluated by counting the colonies of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Prevotella intermedia (Pi) at 48 and 72 h. Statistical analysis was conducted to compare the groups using the Kruskal-Wallis H test and the Wilcoxon signed-rank test (α = 0.05). The analysis revealed that the hydrophobic group had the highest surface contact angle and roughness (p < 0.05), whereas the machined group had significantly higher bacterial counts across all biofilms (p < 0.05). At 48 h, the lowest bacterial counts were observed in the SLA group for Aa and the SLA and hydrophobic groups for Pg and Pi. At 72 h, low bacterial counts were observed in the SLA, hydrophilic, and hydrophobic groups. The results indicate that various surface treatments affect implant surface properties, with the hydrophobic surface using femtosecond laser treatment exerting a particularly inhibitory effect on initial biofilm growth (Pg and Pi).

Corrigendum: Incidence of Guillain-Barré syndrome in South Korea during the early COVID-19 pandemic.

[This corrects the article DOI: 10.3389/fneur.2023.1125455.].

Incidence of Guillain-Barré syndrome in South Korea during the early COVID-19 pandemic.

Objectives: Guillain-Barré syndrome (GBS) is an immune-mediated polyradiculoneuropathy, often triggered by infection. We aimed to investigate how the incidence of GBS changed in the early stages of the coronavirus 2019 (COVID-19) pandemic when nationwide infections declined due to non-pharmaceutical interventions. Methods: We conducted a nationwide population-based retrospective GBS cohort study using data from the Health Insurance Review and Assessment Service of Korea. Patients with new-onset GBS were defined as those who were first hospitalized between 1 January 2016 and 31 December 2020 with an International Classification of Disease, 10th Revision code, for GBS (G61.0) as a primary diagnosis. The incidence of GBS in the pre-pandemic years (2016-2019) was compared with that in the first pandemic year (2020). Nationwide epidemiological data for infections were collected from the national infectious disease surveillance system. A correlation analysis was performed to determine the incidence of GBS and nationwide trends of various infections. Results: Overall, 3,637 new-onset GBS cases were identified. The age-standardized incidence of GBS in the first pandemic year was 1.10 (95% confidence interval, 1.01-1.19) per 100,000 persons. Compared to the first pandemic year, the incidence of GBS during the pre-pandemic years (1.33-1.68/100,000 persons/year) was significantly higher, with incidence rate ratios of 1.21-1.53 (P < 0.001). Nationwide cases of upper respiratory viral infections were significantly reduced in the first pandemic year; however, Campylobacter infections peaked in the summer of the pandemic. The nationwide epidemiology of parainfluenza virus, enterovirus, and Campylobacter infections correlated positively with GBS incidence. Conclusion: The overall GBS incidence decreased in the early stages of the COVID-19 pandemic, which can be attributed to the dramatic reduction in viral illnesses due to public measures.

Clinical application of the optimized X-ray parameter model through analysis of disease risk and image quality when combining the ion chamber of automatic exposure control of digital radiography.

OBJECTIVE: To present an optimized examination model by analyzing the risk of disease and image quality according to the combination of the ion chamber of automatic exposure control (AEC) with digital radiography (DR). METHODS: The X-ray quality was analyzed by first calculating the percentage average error (PAE) of DR. After that, when using AEC, the combination of the ion chambers was the same as the left and centre and right, right and centre, left and centre, centre, right, and left, for a total of six. Accordingly, the entrance surface dose (ESD), risk of disease, and image quality were evaluated. ESD was obtained by attaching a semiconductor dosimeter to the L4 level of the lumbar spine, and then irradiating X-rays to dosimeter centre through average and standard deviation of radiation dose. The calculated ESD was input into the PCXMC 2.0 programme to evaluate disease risk caused by radiation. Meanwhile, image quality according to chamber combination was quantified as the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) through Image J. RESULTS: X-ray quality of DR used in the experiment was within the normal range of±10. ESD of six ion chamber combinations was 1.363mGy, 0.964mGy, 0.946mGy, 0.866mGy, 0.748mGy, 0.726mGy for lumbar anteroposterior (AP), and the lumbar lateral values were 1.126mGy, 0.209mGy, 0.830mGy, 0.662mGy, 0.111mGy, and 0.250mGy, respectively. Meanwhile, disease risk analyzed through PCXMC 2.0 was bone marrow, colon, liver, lung, stomach, urinary and other tissue cancer, and disease risk showed a tendency to increase in proportion to ESD. SNR and CNR recorded the lowest values when three chambers were combined and did not show proportionality with dose, while showed the highest values when two chambers were combined. CONCLUSION: In this study, combination of three ion chambers showed the highest disease risk and lowest image quality. Using one ion chamber showed the lowest disease risk, but lower image quality than two ion chambers. Therefore, if considering all above factors, combination of two ion chambers can optimally maintain the disease risk and image quality. Thus, it is considered an optimal X-ray examination parameter.

Highly Sensitive and Selective Detection of Hydrogen Using Pd-Coated SnO2 Nanorod Arrays for Breath-Analyzer Applications.

We report a breath hydrogen analyzer based on Pd-coated SnO2 nanorods (Pd-SnO2 NRs) sensor integrated into a miniaturized gas chromatography (GC) column. The device can measure a wide range of hydrogen (1-100 ppm), within 100 s, using a small volume of human breath (1 mL) without pre-concentration. Especially, the mini-GC integrated with Pd-SnO2 NRs can detect 1 ppm of H2, as a lower detection limit, at a low operating temperature of 152 °C. Furthermore, when the breath hydrogen analyzer was exposed to a mixture of interfering gases, such as carbon dioxide, nitrogen, methane, and acetone, it was found to be capable of selectively detecting only H2. We found that the Pd-SnO2 NRs were superior to other semiconducting metal oxides that lack selectivity in H2 detection. Our study reveals that the Pd-SnO2 NRs integrated into the mini-GC device can be utilized in breath hydrogen analyzers to rapidly and accurately detect hydrogen due to its high selectivity and sensitivity.

Effects of the Frying and Drying Conditions on the Furan Formation in Instant-Noodle Manufacturing.

In this study, furan analysis was conducted in instant fried and dried noodles manufactured under various frying and drying conditions, respectively. Instant fried noodles were manufactured via five different frying durations (30-150 s). The levels of furan formed in the fried noodles during the manufacturing process ranged from 4.26 to 41.8 ng/g. The instant dried noodles were manufactured at four different temperatures (80-130 °C). The levels of furan formed in the dried noodles ranged from 3.99 to 4.11 ng/g. The black-bean paste, which is the main ingredient of the black-bean sauce, had the highest furan level (16.5-2484 ng/g) in instant noodles. Our results showed that the furan formation increased with the frying temperature and duration of the black-bean paste (p < 0.05). The activation energy (Ea) in the black-bean paste was estimated at 58.627 kJ/mol by using the Arrhenius formula. The calculated Ea was similar to the Ea of the general chemical reaction. The results of this study might be useful to minimize the furan formation in the manufacture of instant noodles.

Effect of healthcare benefits on short-term adherence of positive airway pressure therapy.

PURPOSE: The objective of this study was to assess the impact of healthcare benefits on adherence to positive airway pressure (PAP) therapy in obstructive sleep apnea (OSA) patients. METHODS: Medical records of OSA patients at the Veterans Health Service Medical Center were retrospectively reviewed. OSA patients were assigned to two groups as the date of prescribing PAP: after (=Group A) and before (=Group B) July 1, 2018 when PAP therapy starts to be included in healthcare insurance coverage for OSA patients in South Korea. PAP adherence was compared over a 3-month period between the two groups; subjective improvement after therapy was evaluated using the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index scores. In addition, we evaluated a number of OSA patients who chose to start PAP therapy without healthcare benefit (from July 2018 to December 2018). RESULTS: Each of the 50 patients in the Group A and B exhibited PAP adherence rates of 82% and 26%, respectively (P < .001). Age did not affect PAP adherence in the Group A. The mean apnea-hypopnea index (from 36.7 to 1.34, P < .001) and ESS (from 7.6 to 5.6, P = .004) scores of patients in the Group A had significantly improved within the first three months. Twenty-three (23 out of 334, 6.9%) OSA patients did not have any healthcare insurance, but they medically needed PAP therapy. However, only one of the 23 patients began PAP treatment. CONCLUSION: Short-term PAP adherence significantly improved after PAP therapy was included in healthcare insurance coverage.

Quantitative Analysis Methods Using Histogram and Entropy for Detector Performance Evaluation According to the Sensitivity Change of the Automatic Exposure Control in Digital Radiography.

The purpose of this study is to evaluate detector performance using histogram and entropy analysis according to the sensitivity change of the automatic exposure control (AEC). The experiment was performed as follows: The sensitivity of the detector was analyzed through a normalized histogram with sensitivities of S200, S400, S800, and S1000 of the AEC; the entropy of the image was then analyzed, and the signal volume of the detector was evaluated according to the sensitivity change. As the sensitivity of the AEC was increased from S200 to S1000, the histogram showed underflow, quantization separation, and dynamic range discrepancy. In addition, entropy showed a decrease as sensitivity was set higher; in particular, entropy degradation was more prominent at sensitivities above S800. Through the histogram and entropy analysis, it was concluded that the detector does not reproduce the sensitivity and signal volume accurately when the sensitivity of the AEC is set high in performance evaluation.

ATP degradation products as freshness indicator of flatfish during storage.

In this study, the ATP degradation products and microbial growth during storage of flatfish were measured for assessing its freshness. LOD and LOQ of the ATP degradation products including ADP, AMP, IMP, HxR and Hx were 0.01-0.11 and 0.02-0.37 µg/g respectively, and the recovery ranged from 35.8 to 98.8%. The Hx level increased significantly during the storage period, regardless of storage temperature (p < 0.05). The initial Hx level was 245.27 µg/g, and this rapidly increased to 2563.72, 6643.69, and 4236.65 µg/g at 4, 10, and 25 °C at 14 days, 8 days, and 12 h, respectively. The correlation coefficient (R 2) between microbial growth and Hx percentage ranged from 0.7709 to 0.8939. Based on the nitroblue tetrazolium colorimetric assay, the optical density of flatfish stored at 4 °C increased from 2.45 to 13.29 at 82 h of storage, which was equivalent to 442% increment.

Water Filling and Emptying Kinetics in Two-Dimensional Hexagonal Mesoporous Silica of the Same Pore Diameter but Different Pore Lengths.

The effect of pore length on the water filling and emptying rates was studied using mesoporous silica (MPS) with same pore diameter but different pore lengths. The pore diameter of the synthesized MPS was ∼8 nm, whereas the average pore lengths were 460, 1,770, and 4000 nm. The gravimetric method was employed to record the time course of the adsorbed mass of water in MPS at 298 K and 1 atm. In both the filling and emptying processes, the relaxation curves (time course of adsorbed mass of water per unit mass of sample) were not significantly related to the pore length. This independence of the initial adsorption and desorption rates on the pore length suggests that the surface of the MPS aggregates is the bottleneck in the overall adsorption and desorption processes and that the initial mass flux in each nanopore is inversely proportional to the pore length. Furthermore, because the relaxation times to reach the equilibrium state were independent of the pore length, the mass flux of water uptake, release, and transport probably increase with an increase in the pore length during the entire adsorption and desorption processes. A transport model to describe these phenomena was proposed.

Blood eosinophils may predict radiographic sinus opacification in patients with chronic rhinitis.

BACKGROUND: The association between chronic rhinosinusitis (CRS) and chronic rhinitis remains unclear. The aim of this study was to estimate the predictive factors for sinus opacification in chronic rhinitis patients without obvious CRS. METHODS: We retrospectively studied a total of 332 adult patients with chronic rhinitis who visited our clinic from January 2015 to December 2017. All of the patients underwent endoscopic examination, allergy test, and osteomeatal-unit computed tomography. The subjects were assigned to the normal sinus (NS) group (Lund-Mackay score [LMS] <5) and sinus opacification (SO) group (LMS ≥5). RESULTS: A total of 288 patients were eligible for this study. Of them, 183 (63.5%) were classified in the NS group and 105 (36.5%) in the SO group. Total immunoglobulin E (IgE) level and peripheral blood eosinophil count were significantly higher in the SO than NS group (p = 0.031 and p < 0.0001, respectively). Using Pearson correlation coefficients, we determined that eosinophil count had a positive correlation with the LMS (r = 0.282). In logistic analysis, the interquartile range increase (0.19 × 109 /L) of the eosinophil count was significantly associated with SO (odds ratio [OR] 1.76; 95% confidence interval [CI], 1.30 to 2.39). After adjusting for age, gender, smoking, drinking, and underlying disease, the interquartile range increase of the eosinophil count increased the odds of SO to 1.69-fold; this increase was statistically significant (p = 0.007; 95% CI, 1.17 to 2.43). CONCLUSION: Peripheral blood eosinophil count is an independent predictor of CRS in patients with chronic rhinitis.

Theory of Transport-Induced-Charge Electroosmotic Pumping toward Alternating Current Resistive Pulse Sensing.

In this work, we study transport-induced-charge electroosmosis toward alternating current resistive pulse sensing for the next generation of biomedical applications. Transport-induced-charge electroosmosis, being a new class of electrokinetic phenomenon, occurs as a salt concentration gradient works in synergy with an electric field in ultrathin nanopores. Apart from the conventional electric double layer-governed electroosmotic flow in which the flow behavior is subject to the surface charge, it is found that the transport-induced-charge electroosmotic flow behaves independently of surface charge magnitude but can be linearly regulated by the bulk salt concentration bias. The reversal of the electric field simultaneously inverses the induced charge allowing the establishment of a unidirectional flow under the application of a periodic alternating current field. This unique phenomenon permits continuous water and nanoparticles pumping through a two-dimensional material nanopore in spite of the reversal of the electric field. Built upon this mechanism, we propose a theoretical prototype of alternating current resistive pulse sensing in a two-dimensional nanopore system.

Molecular simulations of water adsorption and transport in mesopores with varying hydrophilicity arrangements.

The adsorption and transport of water in an open cylindrical mesopore with two different inner surface arrangements of hydrophilicities were examined by molecular simulations. The first model has a weak hydrophilic surface at both entrances of the pore and a stronger hydrophilic surface in the mid-section. The second pore has stronger hydrophilic surfaces at the entrances and weaker in the middle region. The simulation results show that the water adsorption isotherms obtained from Grand Canonical Monte Carlo simulations and pore filling curves acquired from Grand Canonical Molecular Dynamics simulations change depending on the arrangement of the strong and weak hydrophilic surfaces. In the first model, water condensation focuses on the mid-section forming a liquid bridge or a film, which creates a concave meniscus accelerating subsequent adsorption within the pore. Two bridges form in the entrance regions, where a cavity naturally occurs in between the films, in the second model. The different filling and emptying mechanisms clearly change the adsorption-desorption characteristics for the two pore types, but the second type generally showed faster transitions overall. Flux and meniscus analysis also reveals a circulating flow at the menisci of the interfaces within the pore. The results are expected to be valuable in understanding the effects of interior surface modification of nanopores in future applications.

Thermal dependence of nanofluidic energy conversion by reverse electrodialysis.

The thermal dependence of salinity-gradient-driven energy conversion by reverse electrodialysis using a mesoporous silica thin film with pores ca. 2-3 nm in diameter was studied in a temperature range of 293-333 K. As the temperature increases, the surface charge density of mesopores increases owing to an increase in the zeta potential of the pore walls, which in turn increases the concentration of counter-ions in the electrical double layer. The ion mobility also increases with increasing temperature owing to a decrease in the liquid viscosity. As a result, the temperature increase improves the ion conductance of mesopores both in the surface-charge-governed regime at low ion concentrations and in the bulk regime at high ion concentrations. However, further increases in temperature induce bubble nucleation. In particular, in highly concentrated salt solutions, hydrophobic patches appear on the pore surfaces because of the salting-out effect and mask the surface charge. The weakened polarity in mesopores allows more co-ions to enter them, decreasing the potential difference across the film, resulting in a serious deterioration of the energy conversion efficiency. The thermal dependence of the performance characteristics of mesoporous-silica-based nanofluidic devices was also evaluated.

Enhanced energy harvesting by concentration gradient-driven ion transport in SBA-15 mesoporous silica thin films.

Nanofluidic energy harvesting systems have attracted interest in the field of battery application, particularly for miniaturized electrical devices, because they possess excellent energy conversion capability for their size. In this study, a mesoporous silica (MPS)-based nanofluidic energy harvesting system was fabricated and selective ion transport in mesopores as a function of the salt gradient was investigated. Aqueous solutions with three different kinds of monovalent electrolytes-KCl, NaCl, and LiCl-with different diffusion coefficients (D+) were considered. The highest power density was 3.90 W m-2 for KCl, followed by 2.39 W m-2 for NaCl and 1.29 W m-2 for LiCl. Furthermore, the dependency of power density on the type of cation employed indicates that the harvested energy increases as the cation mobility increases, particularly at high concentrations. This cation-specific dependency suggests that the maximum power density increases by increasing the diffusion coefficient ratio of cations to anions, making this ratio a critical parameter in enhancing the performance of nanofluidic energy harvesting systems with extremely small pores ranging from 2 to 3 nm.

Effect of Various Food Additives on the Levels of 4(5)-Methylimidazole in a Soy Sauce Model System.

In this study, the effect of food additives such as iron sulfate, magnesium sulfate, zinc sulfate, citric acid, gallic acid, and ascorbic acid on the reduction of 4(5)-methylimidazole (4(5)-MI) was investigated using a soy sauce model system. The concentration of 4(5)-MI in the soy sauce model system with 5% (v/v) caramel colorant III was 1404.13 µg/L. The reduction rate of 4(5)-MI level with the addition of 0.1M additives followed in order: iron sulfate (81%) > zinc sulfate (61%) > citric acid (40%) > gallic acid (38%) > ascorbic acid (24%) > magnesium sulfate (13%). Correlations between 4(5)-MI levels and the physicochemical properties of soy sauce, including the amount of caramel colorant, pH value, and color differences, were determined. The highest correlations were found between 4(5)-MI levels and the amount of caramel colorant and pH values (r(2) = 0.9712, r(2) = 0.9378). The concentration of caramel colorants in 8 commercial soy sauces were estimated, and ranged from 0.01 to 1.34% (v/v).

Effect of withdrawal speed on film thickness and hexagonal pore-array dimensions of SBA-15 mesoporous silica thin film.

Two-dimensional hexagonal mesoporous silica thin films of SBA-15 were synthesized on Si substrates via dip-coating using an evaporation-induced self-assembly process. The effect of the withdrawal speed on the thicknesses, one-dimensional pore alignments, and two-dimensional hexagonal pore arrays of the films was elucidated. Detailed analyses of FE-SEM and TEM images and XRD and XRR patterns of the synthesized thin films clarified that the pore sizes, interplanar spacings, and film thicknesses depend on the withdrawal speed. Furthermore, the same films were synthesized on Si substrates with microtrenches. The local flow of coating solutions around microtrenches affects the pore direction as well as the film thickness. In order to form well-ordered mesoporous silica thin films with large surface areas, it is important to control the synthetic conditions such as the local flow of the coating solutions as well as the physicochemical properties of the silica precursor solutions or template molecules.