• Applied Biological Chemistry
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• 제43권3호
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• pp.196-201
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• 2000

시금장 대량생산을 위한 기초자료로써 보리메주의 발효기간에 따른 향기성분을 조사하였다. pH는 발효기간에 따라서 pH $5.2{\sim}5.6$로 별차이가 없었다. L값과 b값은 발효기간이 지남에 따라서 점차 감소하였으며, a값은 발효 5일째까지는 점차 증가 하였으며 15일차이후에는 점차 감소하였다. 보리메주에서 분리 동정된 향기성분은 총 75종이었다. 관능기별로는 aldehyde와 ketone류가 각각 10종이 동정되어 다수를 차지하였고, acid와 phenol류가 각각 9종, alcohol류와 hydrocarbon류가 7종, ester류는 6종, pyrazine류는 3종, 질소함유화합물과 furan류가 각각 2종, 그리고 기타 11종이 동정되었다. 함량별로는 ethyl acetate가 $67.8{\sim}89.1%$로 가장 많은 함량을 차지하였으며, hexadecanoic acid($1.21{\sim}12.00%)$, tetramethylpyrazine($0.06{\sim}12.30%$) 등의 순으로 많았다.

• 공학논문집
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• 제6권2호
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• pp.141-151
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• 2004

금합금계 매몰재 재료의 물리적 특성은 각각 열팽창계수과 압축강도, 입도 분포에 크게 좌우된다. 일반적으로 금합금계 매몰재는 cristobalite와 quartz, plaster로 주성분을 구성하고 있다. 그리고 cristobalite와 quartz의 열팽창계수는 $2.6\times10^{-6}/^\circC$, $2.32\times10^{-6}/^\circC$, 로 이 두 재료의 혼합비가 매몰재의 열팽창 계수를 변화시키는 매우 중요한 역할을 하고 있다. 현재 국내에서는 금합금계 매몰재는 전량 수입에 의존하고 있고 그 시장 수요 또한 대단히 크다. 따라서 균일한 입도 분포를 가지는 cristobalite와 quartz의 개발과 주조금속의 열팽창과 냉각에 따른 수축력을 고려한 열팽창계수를 가지면서 매몰재의 요구강도에 적합한 압축강도를 가지는 금합금계 매몰재의 개발이 필수적이다. 따라서 본 연구에서는 먼저 균일한 입도를 갖는 cristobalite와 quartz 분체의 제조와 cristobalite와 quartz의 혼합비에 따른 열팽창계수와 압축강도를 비교 분석하였다. 본 연구의 결과로 표면이 매끄럽고 균일한 입도 분포를 갖는 cristobalite와 quartz를 제조하였으며, cristobalite와 quartz의 혼합비가 45:25가 열팽창계수와 압축강도에서 매몰재가 요구하는 조건을 만족하였다.

• 한국융합학회논문지
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• 제9권12호
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• pp.81-88
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• 2018

사람치은섬유모세포(human gingival fibroblast, HGF)는 치은조직에 존재하는 주요한 세포의 형태 중 하나로 외부 자극에 반응하여 다양한 염증대사물질을 생산한다. 본 연구에서는 돌김에탄올추출물(PYEE)이 Porphyromonas gingivalis로부터 분리한 lipopolysaccharide로 염증이 유도된 HGF-1 cell에서 항염 효과를 보이는지 분석하고자 하였다. LPS-PG에 의해 과발현된 iNOS와 COX-2는 PYEE의 처리에 의해 농도 의존적으로 발현이 감소되었고, nuclear factor $(NF)-{\kappa}B$ 또한 동일한 양상으로 활성이 억제되었다. 신호전달물질 중 c-Jun $NH_2$-terminal kinase (JNK)의 인산화만이 PYEE에 의해 억제되었다. 그리고 항염 작용에 관여하는 것으로 알려진 2상 효소 중 하나인 NAD(P)H:quinone dehydrogenase (NQO)-1도 분석하였고, 이 효소는 PYEE의 처리에 의해 강하게 발현이 유도가 되었다. 결론적으로 돌김에탄올추출물은 치주질환 에방과 치료를 위한 후보물질로 활용 가능할 것으로 사료된다.

• 융합정보논문지
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• 제8권6호
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• pp.9-14
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• 2018

본 연구는 2013-2015년 국민건강영양조사 자료를 사용하여 한국 노년층을 대상으로 과거흡연기간과 상실치아의 관련성을 평가하였다. 조사 대상은 만 65세 이상 노인 4,037명(남자 1,737명, 여자 2,300명)이었다. 통계분석은 SPSS/WIN 22.0을 이용하여, 가중치를 산출한 후 복합표본 분석을 시행하였다. 본 연구에서 종속변수로 사용된 한국 노년층의 평균 상실치아는 11.14개로, 이를 기준으로 11개 미만과 11개 이상으로 재분류하였다. 과거흡연 기간에 따른 상실치아의 관련성을 분석한 결과, 과거흡연기간 10년 미만을 기준으로 비교했을 때 과거흡연기간이 30년 이상이 상실치아가 11개 이상일 위험성이 2배 이상 높게 나타났다. 결론적으로 과거흡연기간이 30년 이상인 경우 상실치아가 평균보다 유의하게 증가함을 확인하였다. 그러므로 금연정책과 금연교육을 통해 지속적인 구강건강관리가 필요할 것으로 보인다.

• 대한통합의학회지
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• 제6권4호
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• pp.101-110
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• 2018

Purpose : This study aimed to analyze the relationship between local residents' experience of public health education on smoking, drinking, and nutrition and their perceptions of health and happiness, thereby providing data for improving the levels of residents' perceptions of health and happiness through the expansion of public health education. Methods : This study used 2017 data on the health of local communities in Gyeongsangnam-do. SPSS (version 25.0) was employed for the statistical analysis. A t-test and an analysis of variance were conducted in order to examine the levels of local residents' perceptions of health and happiness according to their general characteristics and whether or not they had received public health education on smoking, drinking, and nutrition. Results : Those who resided in a city, were younger, earned money, had high educational background, and had high income level had much experience on smoking, drinking, and nutrition education. Those who lived in a county, were males, were younger, had a high level of education, earned money, and had high income level felt a high level of subjective happiness. Residents who had experienced smoking, drinking, and nutrition education had a high level of subjective perception of general health and oral health. The subjects' experience of public health education was positively correlated with their levels of perception of their health and happiness. Conclusion : Education on smoking, drinking, and nutrition for local residents does not merely provide them with knowledge but also it is conductive to improving their quality of life. Therefore, more opportunities for a larger number of people to receive public health education on diverse topics should be given to increase their levels of happiness.

• 대한통합의학회지
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• 제8권4호
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• pp.163-169
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• 2020

Purpose : This study aimed to investigate the anti-allergic effect of Persicaria perfoliata water extract (PPWE) on IgE stimulated rat basophilic leukemia (RBL-2H3) cell line. Methods : P. perfoliata (L.) H. Gross has been used in traditional medicine as an anti-allergic agent, antipyretic, and diuretic and for respiratory disorders. To analyze the anti-allergic activity of PPWE, release of β-hexosaminidase in RBL-2H3 cells was estimated by enzyme linked immunosorbant assay (ELISA). Also, the cytotoxic effect of PPWE was identified by WST assay, and nuclear factor (NF)-κB and its upstream signaling molecules were assessed by western blot analysis. Results : PPWE treatment significantly attenuated β-hexosaminidase release in a dose dependent manner without any cytotoxicity. PPWE inhibited β-hexosaminidase activity by 38.4±1.2, 36.6±0.6, 32.5±2.2 and 26.5±1.2 at 500, 250, 100, and 50 ㎍/㎖ of PPWE, respectively, compared with the control group. In addition, an analysis of the expression level of NF-κB, an inflammation transcription factor, in RBL-2H3 cells upon IgE stimulation provided reults consistent with the results of β-hexosaminidase release. The phosphorylated status of upstream signaling molecules for transcription factor, mitogen activated protein kinases (MAPKs), was also analyzed. The results showed that PPWE treatment dose-dependently inhibited phosphorylation of extracellular regulatory kinase (ERK) and c-Jun N-terminal kinase (JNK). These results show that PPWE had a strong IgE-mediated degranulation inhibitory effect on RBL-2H3 cells. Conclusion : P. perfoliata ameliorated IgE-mediated allergic reaction via the modulation of MAPK and NF-κB signaling pathway in RBL-2H3 cells. These results indicate that P. perfoliata could be a potential candidate for a treatment strategy against various allergic disorders.

• Journal of Periodontal and Implant Science
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• 제52권5호
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• pp.383-393
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• 2022

Purpose: Aloe-emodin (AE), a natural anthraquinone abundant in aloe plants and rhubarb (Rheum rhabarbarum), has long been used to treat chronic inflammatory diseases. However, AE's underlying mechanisms in periodontal inflammation have not been fully elucidated. Acidic mammalian chitinase (AMCase) is a potential biomarker involved in bone remodeling. This study aimed to evaluate AE's effect on periodontitis in rats and investigate AMCase expression. Methods: Eighteen Sprague-Dawley rats were separated into the following groups: healthy (group 1), disease (group 2), vehicle (group 3), AE high-dose (group 4), and AE low-dose (group 5). Porphyromonas gingivalis ligatures were placed in rats (groups 2-5) for 7 days. Groups 4 and 5 were then treated with AE for an additional 14 days. Saliva was collected from all groups, and probing pocket depth was measured in succession. Periodontal pocket tissues were subjected to histomorphometric analysis after the rats were sacrificed. Bone marrow-derived macrophages and murine macrophages were stimulated with receptor activator of nuclear factor-κB ligand (RANKL) and treated with different concentrations of AE. AMCase expression was detected from the analysis of saliva, periodontal pocket tissues, and differentiated osteoclasts. Results: Among rats with P. gingivalis-induced periodontitis, the alveolar bone resorption levels and periodontal pocket depth were significantly reduced after treatment with AE. AMCase protein expression was significantly higher in the disease group than in the healthy control (P<0.05). However, AE inhibited periodontal inflammation by downregulating AMCase expression in saliva and periodontal pocket tissue. AE significantly reduced RANKL-stimulated osteoclastogenesis by modulating AMCase (P<0.05). Conclusions: AE decreases alveolar bone loss and periodontal inflammation, suggesting that this natural anthraquinone has potential value as a novel therapeutic agent against periodontal disease.

• Structural Engineering and Mechanics
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• 제83권4호
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• pp.551-561
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• 2022

In this paper, the effect of fire conditions according to ISO 834 standard on the behavior of carbon fibre-reinforced plastic (CFRP) reinforced steel beams coated with gypsum-based mortar has been investigated numerically. To study the efficiency of these beams, 3D coupled temperature-displacement finite element analyzes have been conducted. Mechanical and thermal characteristics of three different parts of composite beams, i.e., steel, CFRP plate, and fireproof coating, were considered as a function of temperature. The interaction between steel and CFRP plate has been simulated employing the adhesion model. The effect of temperature, CFRP plate reinforcement, and the fireproof coating thickness on the deformation of the beams have been analyzed. The results showed that within the first 120 min of fire exposure, increasing the thickness of the fireproof coating from 1 mm to 10 mm reduced the maximum temperature of the outer surface of the steel beam from 380℃ to 270℃. This increase in the thickness of the fireproof layer decreased the rate of growth in the temperature of the steel beam by approximately 30%. Besides excellent thermal resistance and gypsum-based mortar, the studied fireproof coating method could provide better fire resistance for steel structures and thus can be applied to building materials.

• 대한통합의학회지
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• 제10권3호
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• pp.27-36
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• 2022

Purpose : This study was aimed to analyze the effects of cosmetics containing Persicaria perfoliata water extract (PPWE) on the skin moisturizing and improvement of skin condition in clinical trials. Methods : Clinical trial was conducted for five weeks after IRB approval at Dong-Eui University. Out of a total of 64 people, 15 people each were assigned to four groups as follows; control group A, B, C and the experimental group A that using cosmetic containing PPWE. Skin condition was measured two times, before and after clinical trial, by a professional skin analyzer, SDM (skin diagnosis system). Moisture and oil value of participants was analyzed twice, each morning and evening, using a portable device on their cheeks. In addition, the survey was investigated subjective satisfaction on change in skin condition and the satisfaction on the use of cosmetics. Result : The experimental group exhibited subjectively significant changes before and after clinical trials on skin its dryness (p=.039), blush (p=.017), and redness (p<.001). In addition, subjective evaluation was also the highest satisfaction in aspects of number of application (p=.003), amount of application (p=.002), moisture maintenance, and skin scratching frequency. The satisfaction on the use of cosmetics was the highest in the intention to repurchase (p=.045), recommendation willingness to others (p=.020), and intention to use various products (p=.001). Skin moisture of the clinical trial participants using the SDM, moisture level and elasticity of the experimental group increased by 12.94 and 10.28. Moisture level, which was measured by a portable device, was the most potently increased in the experimental group. Conclusion : Consequently, PPWE containg cosmetics exhibited the effects of moisturization and attenuated skin dryness in clinical trials, which might be utilized as a fundamental data to develop numerous lines of cosmetics.

• 한국산업융합학회 논문집
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• 제26권4_2호
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• pp.561-570
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• 2023

This study was to evaluate the effect of different rinsing times and methods on the accuracy of temporary prostheses fabricated by 3D printing method. Sixty temporary prostheses were fabricated with LCD types of 3D printer(Halot-Sky, Creality, Shenzhen, China) and divided into six groups (n = 10) based on rinsing times and methods. All specimens were rinsed with 99% isopropanol alcohol for 5 and 10 min using three methods-hand washed, ultrasonic cleaning, and automated washing. All specimens were polymerized for 3 minutes under the same conditions. The marginal and internal gaps of specimens were examined using a replica technique. The light-body silicone thickness was measured at 6 reference points(Absolute marginal discrepancy, Marginal, Chamfer, Axial, Angle, and Occlusal gap). All measurements were performed by a stereomicroscope. Reference point images were taken at 100× magnification and then measured using an image analysis program. Statistical analysis was performed using Two-way ANOVA, One-way ANOVA, and the Kruskal-Wallis test (p = .05). The marginal and internal gaps were statistically different according to the rinsing methods and rinsing times(p < .001). In the rinsing time, the temporary prosthesis rinsed for 5 minutes group showed higher accuracy than 10 minutes group. In the rinsing method, the hand washing group showed higher accuracy than the automated washing group.