• Korean Journal of Materials Research
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• v.32 no.12
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• pp.538-544
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• 2022

In existing ceramic mold manufacturing processes, inorganic binder systems (Si-Na, two-component system) are applied to ensure the effective firing strength of the ceramic mold and core. These inorganic binder systems makes it possible to manufacture a ceramic mold and core with high dimensional stability and effective strength. However, as in general sand casting processes, when molten metal is injected at room temperature, there is a limit to the production of thin or complex castings due to reduced fluidity caused by the rapid cooling of the molten metal. In addition, because sodium silicate generated through the vitrification reaction of the inorganic binder is converted into a liquid phase at a temperature of 1,000 ℃. or higher, it is somewhat difficult to manufacture parts through high-temperature casting. Therefore, in this study, a high-strength ceramic mold and core test piece with effective strength at high temperature was produced by applying a Si-Na-Ti three-component inorganic binder. The starting particles were coated with binary and ternary inorganic binders and mixed with an organic binder to prepare a molded body, and then heat-treated at 1,000/1,350/1,500 ℃ to prepare a fired body. In the sample where the two-component inorganic binder was applied, the glass was liquefied at a temperature of 1,000 ℃ or higher, and the strength decreased. However, the firing strength of the ceramic mold sample containing the three-component inorganic binder was improved, and it was confirmed that it was possible to manufacture a ceramic mold and core via high temperature casting.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.1
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• pp.57-65
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• 2023

A vibration response-based detection system was used to investigate the adhesive areas of single-lap joints using a nonlinear transformation approach for deep learning. In industry or engineering fields, it is difficult to know the condition of an invisible part within a structure that cannot easily be disassembled and the conditions of adhesive areas of adhesively bonded structures. To address these issues, a detection method was devised that uses nonlinear transformation to determine the adhesive areas of various single-lap-jointed specimens from the vibration response of the reference specimen. In this study, a frequency response function with nonlinear transformation was employed to identify the vibration characteristics, and a virtual spectrogram was used for classification in convolutional neural network based deep learning. Moreover, a vibration experiment, an analytical solution, and a finite-element analysis were performed to verify the developed method with aluminum, carbon fiber composite, and ultra-high-molecular-weight polyethylene specimens.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.2
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• pp.1-10
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• 2022

PURPOSE: This study examined the effects of the low dye taping technique on the static and dynamic balancing ability and navicular bone drop when the low dye taping technique was divided into elastic and non-elastic taping. METHODS: The subjects of the study were 31 volunteers without musculoskeletal disorders. The length (L) and anterior (A), posteromedial, and posterolateral values of the arch in the NO (normal eyes open), NC (normal eyes closed), PO (pillow with eyes open), and PC (pillow with close eyes closed) states were evaluated when barefoot and when Kinesio tape and non-elastic tape were applied. The measurements were analyzed using repeated ANOVA and an independent t-test. Post hoc tests were performed using a Fisher's LSD. RESULTS: A significant difference was found in the arch L and A values using a foot scanner (p < .05). In addition, there was a significant difference in dynamic balance in the three directions (p < .05), and no difference was found in the case of static balance. As a result, non-elastic tape application helps improve the dynamic balance ability and arch of the foot. CONCLUSION: The non-elastic tape technique is helpful for the foot arch function, and there is no difference in the static balance ability between Kinesio tape and non-elastic tape. Nevertheless, non-elastic tape is more helpful for the dynamic balance ability than Kinesio taping.

• The Journal of the Society of Stroke on Korean Medicine
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• v.9 no.1
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• pp.8-13
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• 2008

Objectives : This study was to investigated the correlation between average temperature & precipitation and pattern identification of the patients with stroke. Methods : 115 stroke patients within 30days of onset were registered during the study period. Pattern identification of stroke was classified into Fire and heat, Turbid phlegm and others. We took the mean of average temperature according to pattern identification and analyzed pattern identification into two groups according to climatological normal of average temperature in Seoul. We also analyzed pattern identification into two groups according to existence of precipitation. Results : Heat and fire, and other type of pattern identification had high frequency when average temperature was higher than 12.2℃. And there was no correlation between precipitation and pattern identification of stroke.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.2
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• pp.11-20
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• 2022

PURPOSE: This study investigated the immediate effects of gluteus medius strengthening training and relaxation therapy on the static balance, muscle strength asymmetry, and proprioception. METHODS: In this research, 38 healthy adults were assigned randomly to strengthening groups (SG) and relaxation groups (RG). The static balance, muscle strength asymmetry, and proprioception were measured as a pre-measurement. The same measurements were performed after the intervention and follow-up. An independent sample t-test was used to compare each group, and one-way repeated ANOVA was used to compare the changes within the group. RESULTS: In the static balance, the comparison between groups SG was more significant than RG, and only SG showed significant differences in the intra-group comparisons. There was no significant difference in muscle strength asymmetry between SG and RG. On the other hand, the comparison within the group revealed only SG to be significant. In proprioception, SG produced more significant results than RG, and only SG had significant values in the within-group comparison. CONCLUSION: Strengthening training affects the changes in static balance, muscle strength asymmetry, and proprioception.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.494-507
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• 2023

Vascular dementia (VaD) is characterized by progressive memory impairment, which is associated with microglia-mediated neuroinflammation. Polyphenol-rich natural plants, which possess anti-inflammatory activities, have attracted scientific interest worldwide. This study investigated whether Rubus fruticosus leaf extract (RFLE) can attenuate VaD. Sprague-Dawley rats were separated into five groups: SO, sham-operated and treated with vehicle; OP, operated and treated with vehicle; RFLE-L, operated and treated with low dose (30 mg/kg) of RFLE; RFLE-M, operated and treated with medium dose (60 mg/kg) of RFLE; and RFLE-H, operated and treated with high dose (90 mg/kg) of RFLE. Bilateral common carotid artery and hypotension were used as a modeling procedure, and the RFLE were intraorally administered for 5 days (preoperative 2 and postoperative 3 days). The rats then underwent memory tests including the novel object recognition, Y-maze, Barnes maze, and passive avoidance tests, and neuronal viability and neuroinflammation were quantified in their hippocampi. The results showed that the OP group exhibited VaD-associated memory deficits, neuronal death, and microglial activation in hippocampi, while the RFLE-treated groups showed significant attenuation in all above parameters. Next, using BV-2 microglial cells challenged with lipopolysaccharide (LPS), we evaluated the effects of RFLE in dynamics of proinflammatory mediators and the upstream signaling pathway. RFLE pretreatment significantly inhibited the LPS-induced release of nitric oxide, TNF-α, and IL-6 and upregulation of the MAPKs/NF-κB/iNOS pathway. Collectively, we suggest that RFLE can attenuate the histologic alterations and memory deficits accompanied by VaD, and these roles are, partly due to the attenuation of microglial activation.

• Korean Journal of Head & Neck Oncology
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• v.11 no.1
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• pp.30-35
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• 1995

Localized non-Hodgkin's lymphomas of head and neck are generally treated with radiation therapy with or without chemotherapy and the results of treatments are favorable, but the recurrences in the primary site or distant sites are a major contributor to failure, We experiened 19 cases of localized non-Hodgkin's lymphomas for 4-year period and retrogradely analized them. We treated patients with Ann Arbor stage I and low grade histology in Working formulation with radiation therapy and patients with Ann Arbor stage II, moderate to high grade histology or extensive tumor size with combination chemotherapy, The complete responses were occurred in 15 of 19 patients (radiation therapy, 5/6 (83.3%); chemotherapy 10/13(76.9%)). 3 relapses were occurred; 2 were in local relapses and 1 was in distant leptomeningeal relapse and the counter-therapeutic modalities were successful in 2 cases. Our results suggest that Ann Arbor stage is significant prognostic factor and appropriate staging with extensive methods is important to improve the results of treatment.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.230-240
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• 2012

Purpose: We aimed to compare the transport time, the proportion of direct hospital visit and the emergency procedures between the current mountain rescue helicopter emergency medical service (HEMS) and physician-staffed mountain-rescue HEMS. Methods: During weekends from October 2, to November 21, 2010, 9 emergency physicians participated as HEMS staff in the mountain-rescue HEMS program of the Seoul fire department. Patient demographic data, transport time, proportion of direct hospital visits, and emergency procedures were recorded. We also collected data on HEMS mountain-rescued patients from June 1, to September 1, 2010, and we compared them to those for the study patients. After an eight-week trial of the HEMS, we performed a delphi survey to determine the attitude of the physician staff, as well as the feasibility of using a physician staff. Results: Twenty-four(24) patients were rescued from mountains by physician-staffed HEMS during the study period, and 35 patients were rescued during the pre-study period. Patient demographic findings were not statistically different between the two groups, but the transport time and the emergency procedures were. During the study period, the time from call to take-off was $6.1{\pm}4.1min$ (vs. $12.1{\pm}8.9min$ during the pre-study period, p-value=0.001), and the time from call to arrival at the scene was $15.0{\pm}4.8min$ (vs. $22.3{\pm}8.1min$ during the pre-study period, p-value=0.0001). The proportions of direct hospital visit were not different between the two groups, but more aggressive emergency procedures were implemented in the study group. The delphi survey showed positive agreement on indications for HEMS, rapidity of transport and overall satisfaction. Conclusion: A pilot trial of physician-staffed HEMS for mountain rescue showed rapid response and more aggressive performance of emergency procedures with high satisfaction among the attending physicians.

• Journal of Trauma and Injury
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• v.27 no.4
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• pp.133-138
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• 2014

Purpose: If the survival of patients suffering from severe blunt trauma is to be improved, appropriate interventions should be taken immediately. The purpose of this study is to evaluate the clinical utility of end-tidal carbon dioxide ($ETCO_2$) as a surrogate marker for predicting both the need for intervention and the prognosis. Methods: This is a prospective observational study. Nasal cannula was applied to measure $ETCO_2$, and the following parameters, which are known to be related to the prognosis for a patient, were recorded: injury severity score (ISS), revised trauma score (RTS), arterial blood gas (ABG), lactate, and hemoglobin (Hb). To evaluate the outcome, we investigated the details of emergent interventions and expired patients. Results: A total of 93 patients were enrolled in this study. Emergent intervention was significantly associated with systolic blood pressure (sBP, p-value=0.001), $ETCO_2$ (p-value<0.001), serum lactate level (p-value<0.001), pH (p-value< 0.003), $HCO_3$ (p-value=0.004), base excess (p-value<0.002), ISS (p-value<0.001) and RTS (p-value=0.005). In the multivariate logistic regression, only $ETCO_2$ (odds ratio (OR): 0.897, 95% confidence interval (CI): 0.792-0.975, p-value= 0.048) and ISS (OR: 1.132, 95% CI: 1.053-1.233, p-value=0.002) were associated with emergent intervention whereas $ETCO_2$ (p-value=0.973) and ISS (p-value=0.511) were not statistically significant in predicting the survival of patients in the univariate analysis. An optimal ETCO cut-off of 29 mmHg on the ROC curve was determined, with the area under the ROC curve (AUC) being 0.824 (0.732-0.917)]. Conclusion: This study has revealed that $ETCO_2$, which can be rapid and easily measured through a nasal cannula, and the ISS may be prognostic indicators of emergent interventions in Emergency Departments.

• Journal of Life Science
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• v.31 no.7
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• pp.654-661
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• 2021

In this study, in order to isolate excellent whitening agents from fungal cultural broth, various fungi were collected from wild areas in South Korea and then screened for tyrosinase inhibition activity, as tyrosinase is a precursor for the biosynthesis of melanin in regulating skin color. A fungus strain that inhibits tyrosinase activity has been identified and confirmed as Trichoderma viridescens (later renamed T. viridescens SW-1) via ITS sequencing. In T. viridescens SW-1, tyrosinase inhibitory activity was strongest on day three of culture. A 5% culture broth showed a tyrosinase inhibitory activity greater than 90% and exhibited high thermostability on day three. At 10% culture broth, the accumulations of intra- and extracellular melanin were inhibited above 27.1% and 7.5%, respectively. In summary, the physical and functional properties of the tyrosinase inhibitory substances of T. viridescens SW-1 included high levels of inhibition of melanin synthesis and antioxidative activity as well as thermostability. Therefore, we suggest that the whitening substance identified from the cultural broth of T. viridescens SW-1 has potential for application as a functional cosmetic ingredient.