Comparative Study of Thermal and Plasma-Enhanced Atomic Layer Deposition of Iron Oxide Using Bis(N,N'-di-butylacetamidinato)iron(II).

Only a few iron precursors that can be used in the atomic layer deposition (ALD) of iron oxides have been examined thus far. This study aimed to compare the various properties of FeOx thin films deposited using thermal ALD and plasma-enhanced ALD (PEALD) and to evaluate the advantages and disadvantages of using bis(N,N'-di-butylacetamidinato)iron(II) as an Fe precursor in FeOx ALD. The PEALD of FeOx films using iron bisamidinate has not yet been reported. Compared with thermal ALD films, PEALD films exhibited improved properties in terms of surface roughness, film density, and crystallinity after they were annealed in air at 500 °C. The annealed films, which had thicknesses exceeding ~ 9 nm, exhibited hematite crystal structures. Additionally, the conformality of the ALD-grown films was examined using trench-structured wafers with different aspect ratios.

Monday peak is unique to suicide? Comparison of weekly distribution by causes of death using national representative cohort database.

INTRODUCTION: The excess suicide mortality on Monday was reported in numerous studies. However, it is uncertain that the uneven weekly distribution of deaths is observed among suicide, or common among various causes of death. METHODS: Weekly distributions of suicide and other causes of death from 2012 to 2017 in South Korea were compared. Logistic regression models were fitted to investigate the association between causes of death and day-of-the-week effects. We also fitted conditional logistic regression models after age and gender matching. RESULTS: A total of 1,622,213 deaths, including 80,492 suicide decedents, were analyzed. A total of 16.0% of suicide deaths occurred on Monday, whereas 12.4% on Saturday and 13.0% on Sunday. Suicide decedents were more likely to die on Monday than other causes of deaths after controlling sociodemographic factors in unmatched data. However, there was no evidence of excess suicide deaths on Mondays than other days in contrast to matched death controls. CONCLUSION: While the increase in mortality on Mondays was not unique to suicide, our findings have suicide prevention implications. Mental health practitioners should consider providing additional mental health resources on earlier working days. Workplace mental health programs to reduce psychological burdens of employees could help to prevent suicide during working days.

Smart glasses and telehealth services by professionals in isolated areas in Korea: Acceptability and concerns.

BACKGROUND: Smart glass technology offers remote interaction between health professionals for telehealth, alleviating healthcare disparities in isolated areas. OBJECTIVE: To evaluate the professionals' perceptions of smart glass technology as a tool for telehealth and distance learning. METHOD: This mixed-method study on health professionals in 10 different island areas in Korea involved participants experiencing a smart glass-based telehealth system using the scenario of clinical consultation with remote specialists. A group pre- and post-test design was used to examine the change in attitude and perceived importance among health professionals about using smart glasses in telehealth. RESULTS: Forty-seven participants completed both pre-and post-evaluation of smart glasses. A positive, statistically significant change in participants' perceptions of smart glasses regarding their implications for telehealth and distance learning (p< 0.05) was found. Fifty-one health workers provided feedback on smart glasses, and a majority expressed their expectations of quality care with telehealth using advanced technology. The main concerns were patients' privacy issues and inadequate technology for seamless application. CONCLUSION: The incorporation of smart glass technology offers great potential to enrich telehealth as well as distance learning for unskilled health professionals in isolated areas. Future studies are needed to increase efforts to secure a high level of acceptance for clinical consultation with remote specialists on this newly developed device.

Effects of Filler Functionalization on Filler-Embedded Natural Rubber/Ethylene-Propylene-Diene Monomer Composites.

Natural rubber (NR) presents a number of advantages over other types of rubber but has poor resistance to chemicals and aging. The incorporation of ethylene propylene diene monomer (EPDM) into the NR matrix may be able to address this issue. Mineral fillers, such as carbon black (CB) and silica are routinely incorporated into various elastomers owing to their low cost, enhanced processability, good functionality, and high resistance to chemicals and aging. Other fillers have been examined as potential alternatives to CB and silica. In this study, phlogopite was surface-modified using 10 phr of compatibilizers, such as aminopropyltriethoxysilane (A1S), aminoethylaminopropyltrimethoxysilane (A2S), or 3-glycidoxypropyltrimethoxysilane (ES), and mixed with NR/EPDM blends. The effects of untreated and surface-treated phlogopite on the mechanical properties of the rubber blend were then compared with those of common fillers (CB and silica) for rubbers. The incorporation of surface-modified phlogopite into NR/EPDM considerably enhanced various properties. The functionalization of the phlogopite surface using silane-based matters (amino- and epoxide-functionalized) led to excellent compatibility between the rubber matrix and phlogopite, thereby improving diverse properties of the elastomeric composites, with effects analogous to those of CB. The tensile strength and elongation at break of the phlogopite-embedded NR/EPDM composite were lower than those of the CB-incorporated NR/EPDM composite by 30% and 10%, respectively. Among the prepared samples, the ES-functionalized phlogopite showed the best compatibility with the rubber matrix, exhibiting a tensile strength and modulus of composites that were 35% and 18% higher, respectively, compared with those of the untreated phlogopite-incorporated NR/EPDM composite. The ES-functionalized phlogopite/NR/EPDM showed similar strength and higher modulus (by 18%) to the CB/NR/EPDM rubber composite, despite slightly lower elongation at break and toughness. The results of rebound resilience and compression set tests indicated that the elasticity of the surface-modified phlogopite/NR/EPDM rubber composite was higher than that of the silica- and CB-reinforced composites. These improvements could be attributed to enhancements in the physical and chemical interactions among the rubber matrix, stearic acid, and functionalized (compatibilized) phlogopite. Therefore, the functionalized phlogopite can be utilized in a wide range of applications for rubber compounding.

Geometrical Influence on Particle Transport in Cross-Flow Ultrafiltration: Cylindrical and Flat Sheet Membranes.

Cross-flow membrane ultrafiltration (UF) is used for the enrichment and purification of small colloidal particles and proteins. We explore the influence of different membrane geometries on the particle transport in, and the efficiency of, inside-out cross-flow UF. For this purpose, we generalize the accurate and numerically efficient modified boundary layer approximation (mBLA) method, developed in recent work by us for a hollow cylindrical membrane, to parallel flat sheet geometries with one or two solvent-permeable membrane sheets. Considering a reference dispersion of Brownian hard spheres where accurate expressions for its transport properties are available, the generalized mBLA method is used to analyze how particle transport and global UF process indicators are affected by varying operating parameters and the membrane geometry. We show that global process indicators including the mean permeate flux, the solvent recovery indicator, and the concentration factor are strongly dependent on the membrane geometry. A key finding is that irrespective of the many input parameters characterizing an UF experiment and its membrane geometry, the process indicators are determined by three independent dimensionless variables only. This finding can be very useful in the design, optimization, and scale-up of UF processes.

Effects of Sling-Based Thoracic Active Exercise on Pain and Function and Quality of Life in Female Patients with Neck Pain: A Randomized Controlled Trial.

This study aimed to investigate the effects of sling-based thoracic active exercise on pain, function, and quality of life in female patients with neck pain. A total of 27 female patients with neck pain were divided into the sling-based thoracic active exercise group (n = 14) and the control group (n = 13). The study group performed a sling-based thoracic active exercise with cervical manual therapy for 50 min a day, twice a week for 4 weeks, whereas the control group performed a placebo exercise with cervical manual therapy in the same manner as the study group. Evaluation of the degree of pain before and after treatment was based on the pressure pain threshold and numeric pain rating scale scores. The craniovertebral angle and neck disability index (NDI) were used to evaluate neck function, and quality of life was measured using the Short Form-36. Afterwards, the patients' pressure pain thresholds were significantly increased, and the numeric pain rating scale score was significantly decreased in both groups (p < 0.05). In terms of function, the craniovertebral angle was significantly increased in both groups (p < 0.05), and neck dysfunction significantly decreased (p < 0.05). The quality of life significantly increased in both groups (p < 0.05). The pressure pain threshold, craniovertebral angle, neck dysfunction index, and quality of life scores (p < 0.05) were significantly different between groups, except the numeric pain scale score. Our results showed that sling-based thoracic active exercise is effective in reducing pain and improving function and quality of life in female patients with neck pain, thus emphasizing the need for thoracic treatment for such patients.

Fluoroquinolone and no risk of Achilles-tendinopathy in childhood pneumonia under eight years of age-a nationwide retrospective cohort.

BACKGROUND: The emergence of macrolide-resistant Mycoplasma pneumoniae pneumonia (MRMP) has made its treatment challenging. A few guidelines have recommended fluoroquinolones (FQs) as second-line drugs of choice for treating MRMP in children under the age of eight, but concerns about potential adverse events (i.e., Achilles tendinopathy; AT) have been raised. The aim of this study was to investigate the relationship between the use of FQs and the risk of AT in pneumonia in children under eight years of age. METHODS: Children hospitalized with pneumonia (total of 2,213,807 episodes) from 2002 to 2017 were enrolled utilizing the Korean National Health Insurance Sharing Service (NHISS) database. The independent risk of FQs for AT was analyzed by a generalized estimating equation with adjustment for age, sex, and underlying diseases. RESULTS: Among 2,213,807 episodes of pneumonia hospitalization, children in a total of 6,229 episodes (0.28%) were treated with FQs (levofloxacin 40.9%, ciprofloxacin 36.1%, moxifloxacin 11.6%, and others 11.4%). The FQ-exposure group showed a 0.19% (12/6,229) incidence of AT within 30 days after the first administration of FQ. The use of FQs increased the risk of AT (OR 3.00; 95% CI: 1.71-5.29), but became null after adjusting for age, sex, and underlying diseases (aOR 0.85; 95% CI: 0.48-1.51). All AT related to the use of FQs occurred after the use of ciprofloxacin or levofloxacin, and not in children under eight years of age. CONCLUSIONS: AT was a rare adverse event of FQ use for childhood pneumonia, particularly under eight years of age. Clinicians could consider using FQs as a second-line option in the treatment of childhood pneumonia when there are no alternative therapeutic options.

Modeling cross-flow ultrafiltration of permeable particle dispersions.

Cross-flow ultrafiltration is a pressure-driven separation and enrichment process of small colloidal particles where a colloidal feed dispersion is continuously pumped through a membrane pipe permeable to the solvent only. We present a semi-analytic modified boundary layer approximation (mBLA) method for calculating the inhomogeneous concentration-polarization (CP) layer of particles near the membrane and the dispersion flow in a cross-flow filtration setup with a hollow fiber membrane. Conditions are established for which unwarranted axial flow and permeate flow reversal are excluded, and non-monotonic CP profiles are observed. The permeate flux is linked to the particle concentration on the membrane wall using the Darcy-Starling expression invoking axially varying osmotic and trans-membrane pressures. Results are discussed for dispersions of hard spheres serving as a reference system and for solvent-permeable particles mimicking non-ionic microgels. Accurate analytic expressions are employed for the concentration and solvent permeability dependent dispersion viscosity and gradient diffusion coefficient entering into the effective Stokes flow and advection-diffusion equations. We show that the mBLA concentration and flow profiles are in quantitative agreement with results by a finite element method. The mBLA results are compared with predictions by an earlier CP layer similarity solution, showing the higher precision of the former method.

Biportal endoscopic discectomy for high-grade migrated lumbar disc herniation.

OBJECTIVE: Although endoscopic procedures for lumbar disc herniation have improved greatly and offer many advantages, the indications are limited mostly to nonmigrated or low-grade migrated disc herniation. Endoscopic application in migrated disc herniation cases is still challenging and technically demanding. The goal in this study was to determine the feasibility of biportal endoscopic discectomy for removal of high-grade migrated disc herniation. METHODS: A retrospective review was performed in 262 patients who had undergone biportal endoscopic discectomy after the diagnosis of lumbar herniated disc. According to preoperative MRI findings, disc herniation was classified into 5 zones based on the direction and distance from the disc space. Patients were divided into 2 groups-a high-grade migration group and a low-grade migration group. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI), visual analog scale (VAS), and modified Macnab criteria, and those outcomes and operation time were compared between the 2 groups. RESULTS: There were 10 patients with "high-grade up," 8 with "low-grade up," 98 with disc-level, 102 with "low-grade down," and 44 with "high-grade down" herniation, thereby yielding 54 patients in the high-grade group and 208 in the low-grade group. Demographic data for the 2 groups showed no significant difference. There was no significant difference between the 2 groups in ODI, VAS, and modified Macnab criteria. Operation time between the 2 groups was not significantly different (60.74 vs 65.63 minutes, p > 0.05). CONCLUSIONS: Biportal endoscopic discectomy can be effective for high-grade migrated lumbar disc herniation with no prolonged operation time and satisfactory clinical outcomes.

Estimating Nationwide Prevalence of Live Births with Down Syndrome and Their Medical Expenditures in Korea.

BACKGROUND: This study aimed to estimate the nationwide prevalence of live births with Down syndrome (DS) and its trends and compare the observed and model-based predicted prevalence rates. Further, we compared the direct medical expenditures among DS and non-DS patients. METHODS: Using the health administrative data of Health Insurance Review and Assessment in Korea, we selected 2,301 children with DS who were born between 2007 and 2016 to estimate the prevalence of live births with DS, and 12,265 non-DS children who were born between 2010 and 2014 to compare the direct medical expenditures among patients. RESULTS: The prevalence of live births with DS was 5.03 per 10,000 births in 9 years, and 13% of children with DS were medical aid recipients during the study period. The medical expenditure of children with DS was about 10-fold higher than that of non-DS children and their out-of-pocket expenditure was about twice as high. CONCLUSION: The prevalence of live birth with DS is high in the low socioeconomic group and the healthcare costs for the children with DS are significantly higher than those for non-DS children. Therefore, health authorities should help mothers at lower socioeconomic levels to receive adequate antenatal care and consider the cost of medical care for children with DS.

Effect of Pregnancy on Quantitative Medication Use and Relation to Exacerbations in Asthma.

BACKGROUND: The quantification of asthma medication reduction and its relation to an aggravation of asthma during pregnancy at an individual level are unclear. METHODS: We conducted a nationwide retrospective cohort study of asthmatic pregnant women in South Korea. All of the asthma medications were ranked from 1 to 4 according to the guideline-based stepwise approach. We assessed the daily sums of the ranks of the asthma medications and their association with exacerbations during three phases based on the individual's delivery date: before, during, and after pregnancy. RESULTS: The study cohort included 115,169 asthmatic pregnant women who gave birth between 2011 and 2013. The subjects were clustered into four groups according to the daily rank sums of their asthma medication. Asthma medications were rapidly reduced at the beginning of the pregnancy and then slowly increased after delivery. Exacerbations were more frequent in the group with higher rank-sum values than in the group with lower values. Overall exacerbations were reduced during pregnancy compared to before or after delivery. CONCLUSIONS: Asthmatic pregnant women tended to reduce their asthma medication use during pregnancy. This led to a greater number of exacerbations in a small part of the study population.