• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.103-107
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• 2003

The inductively coupled plasma(ICP) etching process was selected to fabricate RF Surface Acoustic Wave(SAW) filters and a Pt thin film was sputtered on a $LiTaO_3$ substrate applied to electrode materials to reduce the spurious response and improve the power durability. Steep sidewall pattern was achieved employing $C_4F_8/Ar/Cl_2$ gas chemistry. We investigated an etching mechanism and parameter dependence of the Pt thin film about $C_4F_8$ addition. Sidewall etch angle was about $80^{\circ}$ at the $C_4F_8$ 20% mixing ratio. Fabricated SAW filter is consists of some series and parallel arm SAW resonators which work as impedance elements and show capacitance characteristics at out of the passband. It can be modified for $800{\sim}900\;MHz$ RF filters. External matching circuits were unnecessary.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.51-59
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• 2005

To examine the influence of aging on the mechanism of muscle fatigue, we compared the magnitude of central and peripheral fatigue in young and old women before, during and after a sustained submaximaI isometric contraction of elbow flexor muscles. Twelve women (6 young. $20.7{\pm}1.2$ years and 6 old, $68.8{\pm}29$ years) performed a contraction at 20% of maximal voluntary contraction (MVC) torque with their non-dominant arm. The old women were weaker than the young women, however their endurance time for the 20% contraction was longer compared with the young women ($1822{\pm}444$ vs. $1061{\pm}678$ sec, P <. 05). Both groups had a similar reduction in voluntary activation ratio (VA) during and after the fatiguing contraction. However, the old women showed much greater variability in VA before and after the contraction ($91.61{\pm}4.54%$ and $76.70{\pm}19.55\;%$ range of $79{\sim}99$ to $87{\sim}99%$ respectively) compared with the young women ($95.71{\pm}1.86\;%$ and $83.46{\pm}7.57\;%$ range of $39{\sim}75$ to $69{\sim}90%$, respectively). Furthermore, the EMG activity of the elbow flexor muscles and triceps brachii was greater for the old women compared with the young women throughout the fatiguing contraction, indicating different activation strategies with age. Indices of peripheral fatigue including twitch properties, showed that fatigue within the muscle was more rapid for the young women compared with the old women. These results suggest that although old women are weaker than young women, they have greater endurance due to mechanisms within muscle. Furthermore, old women showed great variability in their ability to optimally activate all muscle fiber compared with young women for an isometric contraction.

• The korean journal of orthodontics
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• v.49 no.6
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• pp.381-392
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• 2019

Objective: The objective of this two-arm parallel trial was to compare the type of tooth movement during en masse retraction of the maxillary anterior teeth using labial versus lingual biocreative therapy. Methods: Twenty-eight subjects were randomized in a 1 : 1 ratio to either the labial or lingual group. En masse anterior retraction was performed using labial biocreative therapy in group A and lingual biocreative therapy in group B. Cone beam computed tomography scans were taken before and after retraction and the primary outcome was the type of tooth movement during anterior retraction. Data were analyzed using paired t-tests for comparisons within each group and independent-sample t-test for comparison of the mean treatment changes between the two groups. Results: Significant differences were found between the two groups in relation to the type of tooth movement (labiolingual inclination of the central incisor; mean difference, $5.85{\pm}1.85^{\circ}$). The canine showed significant distal tipping in the lingual group (mean difference, $6.98{\pm}1.25^{\circ}$). The canine was significantly more intruded in the lingual group (mean difference, $1.67{\pm}0.49mm$). Good anchorage control and significant soft tissue changes occurred in both groups. No serious adverse effects were detected. Conclusions: With a 10-mm retraction hook, the labial biocreative technique with the reverse curve overlay provided anterior retraction with good torque control, while in the lingual group, anterior retraction occurred with controlled tipping movement with significant distal tipping and intrusion of the canine (trial registration: The trial was registered at ClinicalTrials.gov [NCT03239275]).

• The Korean Journal of Pain
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• v.34 no.4
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• pp.463-470
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• 2021

Background: Although neuropathic pain is a severe and common pain, its pathophysiology has not been elucidated yet. Studies in recent years have focused on the immune system's role in the pathogenesis of neuropathic pain. The aim of this study was to investigate the role of immunological mechanisms in neuropathic pain and the effect of pregabalin by measuring immunological marker levels in peripheral blood before and after pregabalin treatment in postherpetic neuralgia (PHN) patients with neuropathic pain. Methods: Forty patients diagnosed with PHN were included in the study. CD4, T follicular cells (Tfh: CD4⁺CXCR5⁺PD1⁺), Th17 (CD4⁺CCR6⁺ and CD4⁺IL17A⁺), regulatory T cells (Treg: CD4⁺ CD25⁺foxp3⁺), Th1 (CD4⁺ CXCR3⁺ and CD4⁺ IFN-γ⁺) and Th2 (CD4⁺ IL-4⁺) cell ratios were measured in peripheral blood samples before treatment and after 3 months of treatment. Results: When immunological marker and inflammation parameter levels were compared before and after treatment, the helper T cell ratio (CD3⁺, CD4⁺) was 30.28 ± 12.27% before treatment and 34.93 ± 11.70% after treatment, so there was a statistically significant increase (P = 0.028). Th17 was 4.75 ± 5.02% before treatment and 5.80 ± 3.13% after treatment, and there was a statistically significant increase (P = 0.036). Conclusions: Immunological mechanisms play an essential role in the pathogenesis of neuropathic pain, immunologically based treatment approach will be the critical point of treatment.

• The Journal of Industrial Distribution & Business
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• v.12 no.11
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• pp.33-50
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• 2021

Purpose: In South Korea, two kinds of mandatory insurance, Fierce Liability Insurance and Outdoor Advertising Liability Insurance sells as of February 2021 according to relevant codes. This study analyzed third party liability and personal living liability insurance in terms of various risks not corporation side but personal side arising from normal living and life. Research design, data and methodology: Some cases of drone accident hit man and fierce dog accident were taken into analysis to verify blame ratio and insurance claim money. The former case is that on the way down the elevator, the dog, American pit bull terrier rushed in and bit the lower part of the knee against the visitor. The latter case is that while flying in the sky as usual, the drone suddenly crashed, fell, and hit the head of a young child while walking on the street. Further previous studies such as third party liabilities, liability insurance, mandatory insurance were deeply analyzed. Results: Based on some case studies and previous studies, the author suggested valuable comments in turn realization of insurer as provider, exhaustive creation and operation of mandatory insurance, realization of insured as demanded, and arrangements of laws and systems in special consideration of amendment of companion animal and exhaustive execution of mandatory insurance by the government. Conclusions: This study was about third party liability, personal living liability insurance and expansion of mandatory insurance caused by relevant laws by the government. In this study the author verified what issues were observed from two cases drone accident and fierce dog accident and then suggested some valuable comment as above both systemic plans and practical plans. First of all, the individual should get Comprehensive Property Insurance(CPI) that covers the risks of his/her own property arising from the everyday life. And then the individual should further buy Personal Living Liability Insurance(PLLI) in order to prepare 'accidents that may happen when, where, or how' and overcome the said accidents. Moreover, the individual should take a look every single insurance contract whether he/she has a special terms and conditions of Personal Living Liability Insurance(PLLI) or not.

• Journal of Animal Science and Technology
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• v.61 no.3
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• pp.138-146
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• 2019

Vitamin $B_3$ (niacin) is essential for all living cells and plays a central role in energy metabolism and oxidative phosphorylation. Vitamin $B_3$, a water-soluble vitamin, is present in the form of nicotinic acid and nicotinamide, a monocarboxylic acid derivative of pyridine. While nicotinic acid is commonly effective in lowering cholesterol levels, unlike nicotinic acid, nicotinamide is ineffective on lipids. Presence rates of nicotinic acid and nicotinamide, which are the available forms of vitamin $B_3$, are different for each food. However, the studies in the literature are generally based on the analysis of total amount of vitamin $B_3$ in foods and the studies determining the profile of vitamin $B_3$ in foods are limited. The aim of the study was to determine the vitamin $B_3$ profiles of 10 kinds of animal based food and 10 different plant based food samples. In this study, 10 kinds of animal based food samples consisting of veal (veal steak fillet), chicken (breast), turkey meat (thigh), goat meat (leg, belly), lamb (leg, back, arm), mutton (belly), bovine meat (loin) and 10 different plant based food samples namely; barley, rye, wheat (bread), wheat (durum), oat, rice, dried pea, green lentil, red lentil and chickpea were studied by high performance liquid chromatography using post-column derivatization system. The presence rates of nicotinic acid and nicotinamide were determined in the meat samples as 30% and 70% and as 87% and 13% in the cereal and legume samples, respectively. Nicotinic acid levels were found in low amounts in the meat samples. The amounts of nicotinic acid in the cereal and legume samples were significantly higher than the meat samples. Consequently, the plant based foods such as cereals and legumes, with a ratio of 87% nicotinic acid presence, standout as the best source of nicotinic acid and encouraging regular intake of those cereals and legumes containing rich nicotinic acid would remove nicotinic acid deficiency in human.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.1
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• pp.39-45
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• 2022

Normal strategy of structure optimization procedure has been minimum cost or weight design. Minimum weight design satisfying an allowable stress has been used for the ship and offshore structure, but minimum cost design could be used for the case of high human cost. Natural frequency analysis and forced vibration one have been used for the strength estimation of marine structures. For the case of high precision experiment facilities in marine field, the structure has normally enough margin in allowable stress aspect and sometimes needs high natural frequency of structure to obtain very high precise experiment results. It is not easy to obtain a structure design with high natural frequency, since the natural frequency depend on the stiffness to mass ratio of the structure and increase of structural stiffness ordinary accompanies the increase of mass. It is further difficult at the grillage structure design using the profiles, because the properties of profiles are not continuous but discrete, and resource of profiles are limited at the design of grillage structure. In this paper, the grillage structure design system under the constraint of high natural frequency is introduced. The design system adopted genetic algorithm to realize optimization procedure and can be used at the design of the experimental facilities of marine field such as a towing carriage, PMM, test frame, measuring frame and rotating arm.

• Journal of Korean Neurosurgical Society
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• v.65 no.5
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• pp.730-740
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• 2022

Objective : Although several commercialized bone cements are used during percutaneous vertebroplasty (PVP) for patients with osteoporotic vertebral compression fracture (OVCF), there are no reports using domestic products from South Korea. In this study, we investigated the safety and efficacy of Spinofill^® (Injecta Inc., Gunpo, Korea), a new polymethyl methacrylate product. Methods : A prospective, single-center, and single-arm clinical trial of 30 participants who underwent PVP using Spinofill^® for painful thoracolumbar OVCF was performed with 6-months follow-up. Clinical and surgical outcomes included the Visual analog scale (VAS), Korean-Oswestry disability index (K-ODI), and Odom's criteria, complication rate, and recurrence rate. Radiological outcomes were evaluated by measuring the findings of postoperative computed tomography and simple radiograph. Results : The pain of VAS (from 8.95±1.05 to 4.65±2.06, p<0.001) and the life quality based on K-ODI (from 33.95±5.84 to 25.65±4.79, p<0.001) improved significantly, and successful patient satisfaction were achieved in 20 patients (66.7%) 1 day after surgery. These immediate improvements were maintained or more improved during the follow-up. There was no surgery- or product-related complications, but OVCF recurred in two patients (6.7%). Favorable cement interdigitation was reported in 24 patients (80.0%), and extra-vertebral cement leakage was reported in 13 patients (43.0%). The mean vertebral height ratio (from 60.49%±21.97% to 80.07%±13.16%, p<0.001) and segmental kyphotic angle (from 11.46°±8.50° to 7.79°±6.08°, p=0.002) improved one day after surgery. However, these short-term radiological findings somewhat regressed at the end. Conclusion : The overall outcomes of PVP using Spinofill^® were as favorable as those of other conventionally used products.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.450-461
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• 2022

Purpose: DNA damage and repair responses are induced by metabolic diseases and environmental stress. The balance of DNA repair response and the antioxidant system play a role in modulating the entire body's health. This study uses a high-fat and high-calorie (HFC) drink to examine the new roles of a plant-based multivitamin/mineral supplement with phytonutrients (PMP) for regulating the antioxidant system and cellular DNA repair signaling in the body resulting from metabolic stress. Methods: In a double-blind, randomized, parallel-arm, and placebo-controlled trial, healthy adults received a capsule containing either a PMP supplement (n = 12) or a placebo control (n = 12) for 8 weeks. Fasting blood samples were collected at 0, 1, and 3 hours after consuming a HFC drink (900 kcal). The blood samples were analyzed for the following oxidative stress makers: areas under the curve reactive oxygen species (ROS) levels, plasma malondialdehyde (MDA), erythrocytes MDA, urinary MDA, oxidized low-density lipoprotein, and the glutathione:oxidized glutathione ratio at the time points. We further examined the related protein levels of DNA repair signaling (pCHK1 (Serine 345), p-P53 (Serine 15), and 𝛄H2AX expression) in the plasma of subjects to evaluate the time-dependent effects of a HFC drink. Results: In a previous study, we showed that PMP supplementation for eight weeks reduces the ROS and endogenous DNA damage in human blood plasma. Results of the current study further show that PMP supplementation is significantly correlated with antioxidant defense. Compared to the placebo samples, the blood plasma obtained after PMP supplementation showed enhanced DNA damage response genes such as pCHK1(Serine 345) (a transducer of DNA response) and 𝛄H2AX (a hallmark of DNA damage) during the 8 weeks trial on metabolic challenges. Conclusion: Our results indicate that PMP supplementation for 8 weeks enhances the antioxidant system against oxidative stress and prevents DNA damage signaling in humans.

• The korean journal of orthodontics
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• v.54 no.1
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• pp.16-25
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• 2024

Objective: To compare the effectiveness of laser-engineered copper-nickel titanium (SmartArch) and superelastic nickel-titanium (SENT) archwires in aligning teeth and inducing root resorption and pain experienced by patients. Methods: Two-arm parallel groups with a 1:1 allocation ratio were used. The participants were patients aged 11.5 years and older with 5-9 mm of mandibular anterior crowding who were indicated for non-extraction treatment. The primary outcome was alignment effectiveness, assessed using Little's irregularity index (LII) over 16 weeks with a single wire (0.016-inch) in the SmartArch group and 2 wires (0.014- and 0.018-inch) in the SENT group (8 weeks each). Secondary outcomes included root resorption evaluated by pre- and post-intervention periapical radiographs and pain levels recorded by the participants during the first week. Results: A total of 40 participants were randomly allocated into 2 groups; 33 completed the study and were analyzed (16 in the SmartArch group and 17 in the SENT group, aged 16.97 ± 4.05 years). The total LII decrease for the SmartArch and SENT groups was 5.63 mm and 5.29 mm, respectively, which was neither statistically nor clinically significant. Root resorption was not significantly different between the groups. The difference in pain levels was not statistically significant for the first 5 days following wire placement; however, there was a significant difference favoring the SENT group in the final 2 days. Conclusions: SmartArch and SENT archwires were similarly effective during the alignment phase of orthodontic treatment. Root resorption should be observed throughout the treatment with either wire. SmartArch wires demonstrated higher pain perception than SENT wires.