베어링 윤활용 오일 거동에 관한 연구

김완기(Wangi Kim),문성현(Sunghyun Mun),한광진(Kwangjin Han) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11

In case of bearing lubricated by oil, it is important to predict flow rate of oil for estimating the temperature of bearing. In this paper, the oil flow was analized and the convective heat transfer coefficient of each bearing was derived to predict the bearing temperature by CFD. In order to verify the reliability for the analysis, the flow rate of oil through bearing was measured using the designed test equipment.

Encouraging Effect of Green Tea on the Growth of Akkermansia muciniphila

Hyun Woo Jeong(정현우),Jeong Kee Kim,A Young Kim,Donghyun Cho,Ji-Hae Lee,Jin Kyu Choi,Miyoung Park,Wangi Kim 한국식품영양과학회 2020 한국식품영양과학회 학술대회발표집 Vol.2020 No.10

AP 콜라겐 효소분해 펩타이드의 세포외기질 단백질 생성 및 피부 치밀도 개선 효과

정경미(Kyoungmi Jung),채민정(Minjung Chae),김승훈(Seung Hun Kim),김아름(A Reum Kim),임성환(Sung-Hwan Lim),문창용(Changyong Moon),노종화(Jonghwa Roh),김완기(Wangi Kim) 한국식품영양과학회 2023 한국식품영양과학회지 Vol.52 No.2

발전기 냉각성능 향상을 위한 통풍 유로 형상 변수에 관한 수치해석 연구

최장운(Jangun Choi),김완기(Wangi Kim),전무종(Moojong Jeon),류순기(Soongi Ryu) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

To develop high efficiency and lightweight generator, cooling system is needed considering internal heat loss. The flow network of single ended ventilation and IC01 type cooling system is comprised of radial ducts in lamination, gap between frame and stator, bypass, backward-curved fan, etc. The flow rate for cooling is determined by hydraulic loss of each airflow branch. The increasing hydraulic loss by saving weight of frame reduces flow rate and induces temperature rise in the winding. Consequently, generator efficiency and durability of insulation decreases. In this study, major geometric parameters of airflow passage are selected for cooling improvement as analyzing distribution of temperature rise and flow rate by CFD.

Heat-Killed Lactiplantibacillus plantarum APSulloc 331261 Enhances Lipid Catabolism Through AMPK Activation in HepG2 Cells

Hyun Woo Jeong,Donghyun Cho,Jonghwa Roh,Wangi Kim 건강기능식품미래포럼 2022 건강기능식품미래포럼 학술지 Vol.2 No.4

Fatty liver disease, a condition where excess triglyceride accumulates in the liver, has a high risk that develops into hepatic disorders such as cirrhosis and ultimately hepatic failure. Therefore, it is important to prevent the formation and progression of fatty liver for maintaining a healthy life. Recently, we identified Lactiplantibacillus plantarum APSulloc 331261, a novel strain of L. plantarum from the green tea (Camelia sinensis) field in Jeju Island and found a distinct property differed from other L. plantarum strains. In the present study, attempts were made to assess its potential as an anti-obesity agent by examining effects of heat-killed L. plantarum APSulloc 331261 (GTB1™) on lipid metabolism in the HepG2 cells, a human hepatoma cell line. The results were as follows. In the HepG2 human hepatoma cell line treated with oleic acid, GTB1™ was shown to prevent the accumulation of triglyceride, suppress the expression of lipogenic genes and stimulate the expression of lipid-catabolic genes as well as enhance the mitochondrial contents. In the same cells treated with ethanol, GTB1™ was observed to suppress oxidative stress and cytotoxicity. Interestingly, GTB1™ was shown to activate AMP-activated protein kinase (AMPK). The above effects of GTB1™ observed in HepG2 cells were reduced in the cells treated with an AMPK inhibitor and the cells transfected with AMPK-targeting siRNA. Regarding the pivotal role of AMPK in lipid metabolism, it is likely that GTB1™ exerts its action through the modulation of AMPK activity. All the in vitro results suggest that GTB1™ has a potential as an agent that help manage obesity and fatty liver.

Effect of Phenylalanine on Differentiation of Myoblast C1C12 and L6 Cells Into Myocytes

Hyun Woo Jeong,Jong Hyun Kim,Chan-Su Rha,Sohn Jonghee,Wangi Kim,Jonghwa Roh 건강기능식품미래포럼 2023 건강기능식품미래포럼 학술지 Vol.3 No.4

In the present study, we aimed to find any essential amino acids (EAAs) that can promote muscle protein synthesis. For this purpose, we examined how the removal of each EAA from the differentiation-inducing medium (Diff.) that is the Dulbecco’s Modified Eagle’s Medium with 2% horse serum affects the differentiation of C2C12 (mouse myoblasts) or L6 (rat myoblasts) cells into mature myocytes. This method was chosen because muscle protein synthesis is significantly enhanced during the differentiation process. This rationale was confirmed by the observation that C2C12 cells showed increased expressions of myosin heavy chain when induced to differentiate by culturing them in the Diff.. When we induced the C2C12 or L6 cells in the Diff. with each EAA depletion, we found that their differentiation rate and the expression of myogenic marker proteins (MyoD and MyoG) was blunted. This decreases were most noticeable when cultured in the Diff. with phenylalanine removed (Diff.-Phe). This effect was comparable to that of leucine. Further, the phenylalanine-removing effect could be recovered by supplementing this EAA back to the Diff.-Phe but not by adding tyrosine, indicating that the effect on differentiation is due to phenylalanine itself. These findings suggest that phenylalanine plays a role in the differentiation of myoblasts, particularly when muscle protein synthesis is enhanced, implying that phenylalanine could contribute to the promotion of muscle protein synthesis. Based on these findings, it is expected that phenylalanine, like leucine, could provide benefits in preventing the loss of muscle mass.

AP 콜라겐 효소분해 펩타이드에 의한 자외선 손상으로부터 피부세포 보호 및 광노화 억제 효능

이지해(Ji-Hae Lee),채민정(Minjung Chae),최진규(Jin Kyu Choi),김완기(Wangi Kim),박미영(Miyoung Park) 한국식품영양과학회 2021 한국식품영양과학회지 Vol.50 No.2

태양광선에 포함된 자외선에 의한 광노화는 내인성 노화에 비해 굵고 깊은 주름과 많은 잔주름이 발생하며, 피부에 불규칙적인 색소침착과 함께 피부가 매우 거칠고, 건조해지며 탄력성이 감소하여 피부가 처지는 특징이 있다. 특히 노화된 피부의 진피 내 교원질량의 감소는 섬유아세포에서 교원질합성이 감소하거나 MMPs와 같은 효소에 의한 교원질 분해가 증가한 경우에 발생하며, 지속적인 자외선 노출이 주원인으로 알려져 있다. 피부를 구성하는 주요 성분인 콜라겐 펩타이드의 보충은 피부 노화 증상을 완화하는 데 도움이 될 수 있다. 본 실험에서는 실꼬리돔(N. virgatus)의 비늘에서 유래한 AP 콜라겐 효소분해 펩타이드가 실제 in vitro와 in vivo 실험에서 UV 광노화에 의한 주름, 건조, 탄력 저하 현상을 완화하는지 확인하고자 하였다. 섬유아세포에 UVB 조사 후 감소한 type I 콜라겐과 TGFβ1의 유전자 발현이 AP콜라겐 효소분해 펩타이드뿐 아니라 지표 성분인 GPH에 의해서도 회복되는 것을 확인하였다. 12주간 진행된 무모생쥐를 이용한 in vivo 실험에서 AP 콜라겐 효소분해 펩타이드 섭취군은 UV 노출에 의한 주름 형성(총 주름의 면적, 수, 길이, 물리학적 형태인자), 진피 내 교원섬유/탄력섬유의 변성 및 감소, 피부 표피 및 진피의 두께 증가, 탄력 저하, 피부 장벽 손상에 따른 수분량 감소에 의한 건조 등의 피부변화를 완화하는 것으로 확인되었다. 이와 같은 결과를 통해 AP 콜라겐 효소분해 펩타이드의 섭취는 자외선에 의한 피부손상으로부터 주름과 보습에 대한 피부 건강 개선 효능을 갖는 기능성식품 소재로 이용 가능성이 높음을 확인할 수 있었다. Extrinsic factors including chronic ultraviolet (UV) radiation, smoking, and other pollutants may cause skin damage and aging. Oral supplementation of collagen, a major component in the skin dermis can have a photo-protective effect and help improve skin conditions. This study examined the effects of AP collagen peptides (APCP) containing glycine-proline-hydroxyproline (GPH) on UVB radiation in both human skin fibroblast and SKH-1 hairless mice. In UVB-irradiated fibroblast, APCP and GPH improved collagen type I and transforming growth factor-β1 gene expression in a dose-dependent manner. To evaluate the effects of APCP on skin photo-aging in vivo, hairless mice were exposed to UVB irradiation and administered APCP orally for 12 weeks. In the APCP-treated group, the mouse skin showed improved wrinkle indices (total wrinkle area, number of wrinkles, total length of wrinkles and mean foam factor) and histopathological changes (collagen and elastic fiber, and epidermal and dermal thickness) with a better skin barrier status (transepidermal water loss, subcutaneous hydration) and elasticity (gross elasticity, net elasticity, a portion of the visco-elasticity, and a portion of the elasticity) compared to the mouse skin of the control group. These results suggest that APCP is a potent candidate for an anti-photoaging ingredient.

AP 콜라겐 효소분해 펩타이드 섭취가 피부 주름, 탄력 및 보습 개선에 미치는 효과

정경미(Kyoungmi Jung),양미숙(Mi-Suk Yang),김승훈(Seung Hun Kim),노종화(Jonghwa Roh),김완기(Wangi Kim) 한국식품영양과학회 2021 한국식품영양과학회지 Vol.50 No.5

본 연구에서는 40~60세 성인 여성을 대상으로 APCP의 피부 주름, 탄력 및 보습 개선에 대한 이중눈가림, 무작위배정, 대조식품 비교 인체적용시험을 진행하였다. 눈가 주름 부위의 육안평가 및 Visiometer를 이용한 피부 주름 개선 평가에서 APCP 1,000 mg 및 1,500 mg 섭취군 모두 12주에 대조식품 섭취군 대비 유의적인 개선 효과를 보였고, 섭취종료 후 2주까지 피부 주름 개선이 유지됨을 확인할 수 있었다. 피부 탄력 개선 평가에서 R2, R5 및 R7 지표에 대해 APCP 1,000 mg 및 1,500 mg 섭취군 모두 6주부터 대조식품 섭취군 대비 유의적인 개선 효과를 보였고 12주까지 통계적으로 유의한 차이를 나타내었다. 피부 보습 개선 평가에서도 APCP 1,000 mg 및 1,500 mg 섭취군 모두 12주에 대조식품 섭취군 대비 유의적인 개선 효과를 보였고 섭취종료 후 2주까지 피부 보습 개선 상태가 유지되었다. 연구를 진행하는 동안 이상반응, 임상실험실 검사 및 활력징후 검사에서 유의미한 변화는 나타나지 않아 APCP의 안전성을 확인할 수 있었다. 본 인체적용시험 결과를 통해 APCP는 피부주름, 거칠기, 탄력 및 보습과 같은 피부 건강 개선에 도움을 줄 수 있는 건강기능식품임을 확인하였다. Collagen is a component of the human body, known to have a beneficial effect on human health when consumed as a food or dietary ingredient. This double-blinded, randomized, placebo-controlled study aimed to evaluate the efficacy and safety of AP collagen peptides (APCP) containing 3% glycine-proline-hydroxyproline, on improving skin wrinkles, elasticity and hydration. Totally, 105 subjects with crow’s-feet wrinkles were randomly assigned to receive either placebo, APCP 1,000 mg or APCP 1,500 mg, once daily for 12 weeks. Efficacy endpoints of skin wrinkles, elasticity and hydration were measured at baseline, 6 and 12 weeks, and at the 2-week follow-up visit. Compared to the placebo group, the visual evaluations and R3 (average roughness) values of crow’s-feet wrinkles were significantly decreased in both APCP groups at 12 weeks, and these effects were maintained until 2 weeks after completion of ingestion. During the intake period at 6 and 12 weeks, three parameters for skin elasticity (R2, R5, R7) showed significant improvement in both APCP groups, as compared to the placebo group. The APCP groups also showed a statistically significant difference in skin hydration compared to the placebo group, at 12 weeks and at 2 weeks after the end of intake. No adverse effects were encountered during the study period. These results indicate that APCP 1,000 mg and 1,500 mg can be used as a functional food ingredient to improve human skin conditions related to skin aging and hydration.

Oral Ingestion of AP Collagen Peptide Leads to Systemic Absorption of Gly-Pro-Hyp, Alleviating H2O2-Induced Dermal Fibroblast Aging

Minjung Chae,Chang Yong Moon,Sung-Hwan Lim,Yusuke Yamashita,Hiroaki Yamada,Masahiro Ide,Chan Woong Park,Jonghwa Roh,Wangi Kim 한국식품영양과학회 2023 Journal of medicinal food Vol.26 No.5

Collagen-derived dipeptides and tripeptides have various physiological activities. In this study, we compared the plasma kinetics of free Hyp, peptide-derived Hyp, Pro-Hyp, cyclo(Pro-Hyp), Hyp-Gly, Gly-Pro-Hyp, and Gly-Pro-Ala after ingestion of four different collagen samples: AP collagen peptide (APCP), general collagen peptide, collagen, and APCP and γ-aminobutyric acid (GABA) combination. Each peptide was measured by high-performance liquid chromatography and triple quadrupole mass spectrometer. We found that, among all the peptides that were analyzed, only Gly-Pro-Hyp was significantly increased after ingestion of APCP compared with that of general collagen peptides and collagen. In addition, ingestion of the APCP and GABA combination improved the absorption efficiency of Gly-Pro-Ala. Finally, we reveal that Gly-Pro-Hyp was effective for preventing H2O2-induced reduction in extracellular matrix (ECM)-related genes, COL1A, elastin, and fibronectin, in dermal fibroblasts. Taken together, APCP significantly enhances the absorption of Gly-Pro-Hyp, which might act as an ECM-associated signaling factor in dermal fibroblasts, and the APCP and GABA combination promotes Gly-Pro-Ala absorption. Clinical Trial Registration number: UMIN000047972.