• Clinical and Molecular Hepatology
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• v.24 no.4
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• pp.384-391
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• 2018

Backgrounds/Aims: The objective of our study was to determine the epidemiological, laboratory, and serological characteristics of patients with chronic hepatitis B virus (HBV) infection and normal transaminases. The study also aimed to evaluate liver damage by measuring the liver fibrosis (LF) grade and to identify possible factors associated with the presence of fibrosis. Methods: A retrospective observational study was conducted in patients with chronic HBV infection and classified as inactive carriers or immune-tolerant. Epidemiological variables of age, sex, immigrant, alcohol consumption, and body mass index (BMI), as well as virological variables (HBV DNA) and transaminase level were collected throughout the follow-up. The LF grade was evaluated by transient elastography. The cutoff value for significant fibrosis (SF) was liver stiffness ${\geq}7.9kPa$. Results: A total of 214 patients were included in the analysis, and 62% of them had a BMI ${\geq}25kg/m^2$. During follow-up, 4% of patients showed transaminase elevation (<1.5 times normal). Most patients had a viral DNA level <2,000 IU/mL (83%). Data on LF were available in 160 patients; of these, 14% had SF, 9% F3, and 6% F4. The variables associated with the presence of SF were transaminase alteration during follow-up, as 23% of patients with SF had elevated transaminases versus 3% of patients without SF (P<0.005), and BMI, as the vast majority of patients with SF (88%) had a BMI ${\geq}25kg/m^2$ versus 56% of patients without SF (P<0.05). Conclusions: In patients with chronic HBV infection and normal transaminases, liver damage does not seem to be related to DNA levels, alcohol consumption, or immigrant status. SF seems to be associated with transaminase alteration during follow-up and elevated BMI. It is therefore recommended to measure LF grade with validated non-invasive methods in such patients.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.6
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• pp.367-375
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• 2020

Background: Intraosseous anesthesia (IO) allows the anesthetic solution to be injected directly into the cancellous bone. The anesthetic solution immediately reaches the periapical region, and thus the axonal area of the nerve, where it can temporarily disable the sodium pump. The effect is felt almost without any time delay, and only a small amount of anesthetic solution is required. Methods: This study aims to investigate the efficacy of IO using the AnestoⓇ device after infiltration anesthesia (IA) and/or inferior alveolar nerve block anesthesia (IANB) failed to work in symptomatic irreversible pulpitis (hot tooth). The 33 patients included in the study were treated additionally with 1.7 ml articaine hydrochloride with 1:100,000 epinephrine hydrochloride (UltracainⓇ D-S, Sanofi-Aventis, Frankfurt, Germany) IO. Results: The electrical pulp test showed that 95.76% of the volunteers reacted positively to the combination of IANB or IA with the IO. In women, the additive IO was effective at 97.22%. In men, the IO led to pain elimination in 94.00% of cases. The duration of the IO was less than a quarter of an hour (13.03 min). The IO worked longer in women than in men (13.61 min vs. 12.33 min). Overall, more than every third tooth that needed trepanation was located in the posterior area of the mandible (36.4%). Treatment of hot teeth in this area was associated with an increased pulse rate and increased residual pain. There was a moderate correlation (Spearman-Rho [IRI] = 0.280) between the Visual Analog Scale (VAS) score and bone density, and a significant correlation (IRI = 0.612) between subjective residual pain and bone width. The IO resulted in a moderate, transient increase in the pulse rate by approximately 20 bpm. This is similar to the temporary increase in heart rate after conventional anesthesia techniques in non-preloaded patients and can be considered clinically irrelevant. Conclusion: IO with the AnestoⓇ device as an extension and deepening of local pain elimination is recommended for the treatment of hot teeth.

• Journal of Korean Neurosurgical Society
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• v.64 no.4
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• pp.562-574
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• 2021

Objective : This study is to evaluate the efficacy and safety of demineralized bone matrix (DBM) gel versus DBM gel with recombinant human bone morphogenetic protein-2 (rhBMP-2) used in transforaminal lumbar interbody fusion (TLIF). Methods : This study was designed as a prospective, multi-center, double-blind method, randomized study. All randomized subjects underwent TLIF with DBM gel with rhBMP-2 group (40 patients) as an experimental group or DBM gel group (36 patients) as a control group. Post-operative observations were performed at 12, 24, and 48 weeks. The spinal fusion rate on computed tomography scans and X-rays films, Visual analog scale pain scores, Oswestry disability index and SF-36 quality of life (QOL) scores were used for the efficacy evaluation. The incidence rate of adverse device effects (ADEs) and serious adverse device effects (SADEs) were used for safety evaluation. Results : The spinal fusion rate at 12 weeks for the DBM gel with rhBMP-2 group was higher with 73.68% compared to 58.82% for the DBM gel group. The 24 and 48 weeks were 72.22% and 82.86% for the DBM gel with rhBMP-2 group and 78.79% and 78.13%, respectively, for the DBM gel group. However, there were no significant differences between two groups in the spinal fusion rate at 12, 24, and 48 weeks post-treatment (p=0.1817, p=0.5272, p=0.6247). There was no significant difference between the two groups in the incidence rate of ADEs (p=0.3836). For ADEs in the experimental group, 'Pyrexia' (5.00%) was the most common ADE, followed by 'Hypesthesia', 'Paresthesia', 'Transient peripheral paralysis', 'Spondylitis' and 'Insomnia' (2.50%, respectively). ADEs reported in control group included 'Pyrexia', 'Chest discomfort', 'Pain', 'Osteoarthritis', 'Nephropathy toxic', 'Neurogenic bladder', 'Liver function analyses' and 'Urticaria' (2.86%, respectively). There was no significant difference between the two groups in the incidence rate of SADEs (p=0.6594). For SADE in the experimental group, ''Pyrexia' and 'Spondylitis' were 2.50%. SADE reported in the control group included 'Chest discomfort', 'Osteoarthritis' and 'Neurogenic bladder'. All SADEs described above were resolved after medical treatment. Conclusion : This study demonstrated that the spinal fusion rates of DBM gel group and DBM gel with rhBMP-2 group were not significantly different. But, this study provides knowledge regarding the earlier postoperative effect of rhBMP-2 containing DBM gel and also supports the idea that the longer term follow-up results are essential to confirm the safety and effectiveness.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.3
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• pp.167-174
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• 2021

Recent investigation into the integrity of nuclear containment buildings has highlighted the importance of developing an elaborate diagnostic method to evaluate the distribution and size of cavities inside concrete walls. As part of developing such a method, this paper presents a finite element approach to modeling elastic waves propagating in the containment building walls of a nuclear power plant. We introduce a perfectly matched layer (PML) wave-absorbing boundary to limit the large-scale nuclear containment wall to the region of interest. The formulation results in a semi-discrete form with symmetric damping and stiffness matrices. The transient elastic wave equations for a mixed unsplit-field PML were solved for displacement and stresses in the time domain. Numerical results show that the sensitivity of displacement, velocity, acceleration, and stresses is large depending on the size and location of the cavity. The dynamic response of the wall slightly differs depending on the existence of the containment liner plate. The results of this study can be applied to a full-waveform inversion approach for characterizing cavities inside a containment wall.

• Journal of Wetlands Research
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• v.23 no.2
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• pp.122-132
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• 2021

We reviewed the methods employed in Korean tidal flat surveys to measure the local abundance of the endangered wildlife and marine protected species, the fiddler crab, Austruca lactea. A complete census for infinite population is impossible even in a limited habitat within a tidal flat, and density estimates from samples strongly vary due to diverse biological and ecological factors. The habitat boundaries and areas shift with periodicities or rhythmic activities of organisms as well as measurement errors. Hence the local abundance calculated from density and habitat areas should be regarded as transient. This conjecture was valid based on the spatio-temporal variations of the density averages, standard error ranges, and spatial distribution of the crab, A. lactea observed for 3 years (2015-2017) in Songdo tidal flat in Incheon. We proposed the potential habitat areas using the occurrence probability of 50% from logistic regression model, reflecting the importance of habitat conservation value as an alternative to local abundance. The spatial shape of potential habitat predicted from a generalized model would remain constant over time unless the species' critical environmental conditions change rapidly. The species-specific model is expected to be used for the introduction of desired species in future habitat restoration/creation projects.

• Journal of Korean Society of Disaster and Security
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• v.14 no.1
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• pp.9-21
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• 2021

Recently, the importance of eco-friendly power generation facility using renewable energy has newly appeared. Hydropower plant is a very important source of electricity generation and supply which is very important to secure safety because it is commonly connected with multi facility and operated on a large scale. In this study, a scenario-based analysis method was suggested to assess vulnerability of a penstock system caused by water hammer commonly occurred in the operation of hydropower plants. A hypothetical hydropower plant was used to demonstrate the applicability of a transient analysis model. In order to verify reliability of the model, the prediction of pressure behaviors were compared with the results of commercial model (SIMSEN) and measured data, then a real hydroelectric power plant was applied to develop all potential water hammer scenarios during the actual operation. The scenario-based simulation and vulnerability assessment for water hammer in the penstock system were performed with internal and external load conditions. The simulation results indicated that the vulnerability of a penstock system was varied with the operating conditions of hydropower facilities and significantly affected by load combination consisting of different load scenarios. The proposed numerical method could be an useful tool for the vulnerabilityty assessment of the hydropower plants due to water hammer.

• Journal of Neurogastroenterology and Motility
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• v.26 no.1
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• pp.106-116
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• 2020

Background/Aims Emerging evidence shows that the mechanism of irritable bowel syndrome (IBS) is associated with neurotrophic factors and tight junction proteins (TJPs). It is known that there are sex differences in the pathophysiology of IBS. The aim of the present study is to determine expression levels of neurotrophic factors, TJPs, and cytokines according to IBS subtype and sex. Methods From 59 IBS (33 IBS-constipation, 21 IBS-diarrhea, and 5 IBS-mixed) and 36 control patients, colonic mucosa mRNA expression levels of transient receptor potential vanilloid-1 (TRPV1), nerve growth factor (NGF), glial cell-derived neurotrophic factor (GDNF), and various TJPs were assessed by real-time polymerase chain reaction. Western blot was performed to determine levels of zonular occludens-1 (ZO-1). Serum levels of cytokines were measured by enzyme-linked immunosorbent assay. Results TRPV1, GDNF, and NGF mRNA levels were significantly increased in those with IBS-constipation compared to those in controls (all P < 0.05). However, they showed no significant difference between those with IBS-diarrhea and controls. Expression level of TRPV1 correlated with that of GDNF (r = 0.741, P < 0.001) and NGF (r = 0.935, P < 0.001). ZO-1 RNA expression levels were lower (P = 0.021) in female IBS-diarrhea than those in controls, although they showed no significant differences between male IBS-diarrhea and controls. Serum IL-1β levels in female IBS were significantly higher than those of male IBS, especially in IBS-constipation (P < 0.001). Conclusion Our results suggest that neurotrophic factors and IL-1β are closely related to IBS-constipation and that decrease of ZO-1 is an important factor in female with IBS-diarrhea.

• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.66-73
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• 2021

In this study, The full load test and WHTC mode test were performed to examine the effect on a heavy duty natural gas engine according to the type of standard gas for certification to check engine performance and exhaust characteristics. Two types of standard gas (G_r, G₂₃) and commercially available natural gas were applied as the fuel used. As a result of the test results of three natural gases with different fuel compositions, G₂₃ with a high nitrogen content was inferior in torque, fuel consumption, and thermal efficiency conditions. In addition, when evaluated in the WHTC mode it was possible to obtain a result that satisfies the EURO VI regulation. However, compared to the other two fuels, the emission characteristics of G₂₃ decreased CO2 and CO, but increased CH4, NOx and PN emissions.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.100-115
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• 2022

In this study, integrated hybrid system (IHS) composed of two alternatively-operating UV/photocatalytic reactor (AOPR) process and biofilter processes of a biofilter system having two units (i.e., R_up and R_dn) with an improved design (R reactor) and a conventional biofilter (L reactor) was constructed, and its transient behavior was observed to perform the successful treatment of waste air containing ethanol and hydrogen sulfide (H₂S). At the IHS-operating stages of HA1, HA2 and HA3T of reversed feed direction, the AOPR process showed not only ethanol-removal efficiencies of 55, 50 and 45%, respectively, but also H₂S-removal efficiencies of 70, 60 and 37%, respectively. In particular, a drastic decrease of H₂S-removal efficiency at the stage of HA3T was observed due to a doubling of H₂S-inlet concentration fed to AOPR from 10 ppmv to 20 ppmv at the stage of HA3T. The order of ethanol-breakthroughs and the order of the magnitude of ethanol-removal efficiencies at the sampling ports of each unit of R reactor at the stages of HA1, HB1, HA2, HB2, and the first half of HA3T, were reversed, respectively, at the stages of the second half of HA3T and HB3T. In case of H₂S, R reactor did not show H₂S-breakthrough as prominent as the ethanol-breakthrough, but showed the trend similar to the ethanol-breakthrough.

• Journal of Convergence for Information Technology
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• v.12 no.5
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• pp.183-193
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• 2022

The purpose of this study is to analyze the effect of black consumer behavior perception on the anger expression and turnover intention of beauty workers. For data collection, the final 392 copies were used by distributing questionnaires to 400 people for three months from November 1, 2021 to January 31, 2022, centering on beauty service workers in Seoul, Gyeonggi, and Incheon. For data analysis, SPSS 25.0 program was used. Frequency analysis was performed to identify demographic characteristics, and factor analysis and reliability analysis were performed to understand the validity of the measurement tool. Correlation analysis, A regression analysis was performed. As a result of the analysis, the transient and deterrence of black consumers had a positive (+) effect on anger expression, anger suppression, and turnover intention, and anger expression and anger control had a positive (+) effect on turnover intention. Therefore, it is necessary to raise excessive problems of black consumers or eradicate forced services, and it is believed that proper customer response methods and programs for stress relief should be provided by members.