Enhancement of immune activities of Dioscorea japonica Thunberg in in vivo and ex vivo models

Lim, Seokwon,Kim, Na-Hyung,Cho, Hi-Jae,Jeong, Hyun-Ja Korean Society of Food Science and Technology 2019 한국식품과학회지 Vol.51 No.4

Dioscorea japonica Thunberg (DJ) has been widely used as a healthy food in Korea for the enhancement of physical stamina. Hence, the present study evaluated the immune-enhancing effect of DJ in forced swim test of mouse model. The immobility time of the group treated with DJ for 7 days was significantly reduced in comparison with that of the control group. After a forced swimming test, the changes in blood biochemical parameters and splenic T lymphocyte populations induced by the administration of DJ were assessed. Serum levels of lactic dehydrogenase, creatine phosphokinase, and aspartate aminotransferase were significantly decreased in DJ-administered group compared to the control group. However, administration of DJ did not affect the splenic T lymphocyte populations. Moreover, DJ significantly increased the production of interferon-g and interleukin-2 compared to the media control in splenocytes. Collectively, it may be concluded that DJ is useful for enhancement of physical and immune function.

식품소재화를 위한 Calendula officinalis L. 꽃잎의 항피부노화 기능성 규명 및 비효소적 연화 기술 연구

임석원(Seokwon Lim),최성빈(Sungbin Choi),이범주(Pomjoo Lee),김형섭(Hyung-sup Kim),이다영(Da-young Lee),변상균(Sanguine Byun) 한국식품과학회 2019 한국식품과학회지 Vol.51 No.3

UVB에 의한 MMP-1의 과발현이 카렌듈라 꽃잎을 처리하여 주면 농도의존적으로 감소하였다. 이를 통해 연화시킨 카렌듈라 꽃잎이 UVB에 의한 피부의 광노화를 억제시킬 수 있다는 것을 확인하였다. 가열과 산처리의 복합처리를 통한 카렌듈라 꽃잎의 연화에서 처리시간, 온도, pH에 따른 연화 수준을 punctual test를 통해 비교 분석하였다. Hardness 값의 비료 분석을 통해 연화특성 및 효과가 처리 조건들에 의해 다름을 확인할 수 있었으며, 70℃ 이상의 높은 온도에 의한 연화효과가 산처리에 의한 효과보다 더 큰 것을 확인할 수 있었다. 하지만 열처리에 의한 연화의 경우 에너지 소비가 큰 것을 고려할 때, pH 2.1에서는 50℃, 30분의 열처리만으로도 70℃ 이상의 열처리 효과가 나타나므로, 이 연화처리 조건이 경제적으로 가장 효율적이라 판단되었다. Calendula (Calendula officinalis L.) petals are edible flowers which have been used as a decorative ingredient in dishes or as a medicinal food. In this study, the anti-skin aging potential of calendula petals was investigated. Additionally, the texture was softened by non-enzymatic methods to broaden their application as a food or cosmetic agent. Treatment of calendula prevented ultraviolet-induced matrix metalloproteinase-1 expression in skin cells. We investigated whether heating-based processing could soften calendula petals. The results from the punctual test demonstrated significant changes in the hardness of calendula petals depending on the pH, heating temperature, and time. Although there were minor differences among various processing conditions, the largest alteration in hardness was observed when the petals were softened by incubation at 80°C and pH 2.3 for 120 min. Collectively, these results show that the application of proper processing conditions can soften calendula petals without using enzymes.

Evaluation of an IVR-ERVC strategy for a high power reactor using MELCOR 2.1

Lim, Kukhee,Cho, Yongjin,Whang, Seokwon,Park, Hyun Sun Elsevier 2017 Annals of nuclear energy Vol.109 No.-

<P><B>Abstract</B></P> <P>The IVR-ERVC (In-Vessel Retention of molten corium through External Reactor Vessel Cooling) is an effective severe accident management strategy for reducing the possibility of a reactor containment failure by terminating the severe accident progress inside a reactor. However, the technical applicability and feasibility of the IVR-ERVC design for an advanced high-power reactor should still be validated considering the uncertainties of physical models, the initial conditions and assessment methodologies. In this paper, the severe accident progress of the APR1400 for a large break loss-of-coolant accident is analyzed using MELCOR 2.1 when the reactor cavity is fully flooded. The chronology of events, the thermal hydraulic behaviors and the core degradation behaviors are analyzed. As a result of the MELCOR calculation, a relatively large portion of particulate debris is relocated to the bottom of the lower head at the end of the debris-quench mode, preventing effective heat transfer to the ex-vessel wall. Because the lower head wall cannot be ablated by melting in the MELCOR, the in-vessel wall temperature is increased as compared to the melting point of the lower head. The heat flux is maximized at approximately 3.5e4s and it is compared to the results from the lumped parameter method.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The MELCOR 2.1 calculation of the IVR-ERVC for the APR1400 is carried out. </LI> <LI> The analysis result using MELCOR is compared to the LPM results. </LI> <LI> Absence of wall ablation model causes the very high temperature of in-vessel wall. </LI> </UL> </P>

Prandtl number effect on thermal behavior in volumetrically heated pool in the high Rayleigh number region

Whang, Seokwon,Park, Hyun Sun,Lim, Kukhee,Cho, Yong Jin Elsevier 2019 Nuclear engineering and design Vol.351 No.-

<P><B>Abstract</B></P> <P>The in-vessel retention by external reactor vessel cooling (IVR-ERVC) is a severe accident management strategy to hold or mitigate the molten radioactive material in the reactor pressure vessel (RPV). Highly turbulent natural convection is one of the most important phenomenon determining the thermal behavior of the molten pool. In the safety evaluation of IVR-ERVC, thermal behavior of the corium pool has been determined using experimental correlations. Property differences between the experimental simulant and the corium have been considered negligible. The effect of property differences represented by Prandtl number (Pr) on the thermal behavior of oxide pool is numerically investigated. The algebraic heat flux model (AFM) is used to simulate the turbulent natural convection and is validated with the BALI experiment. The Pr effect on the flow characteristics and the thermal behavior is investigated in the high Rayleigh number region. The present results show that the upward heat transfer tends to increase at the same Ra<SUP>′</SUP> in the case of the molten pool which is lower Pr fluid than the simulant material.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Property effect on the flow and thermal behavior of oxide pool is investigated. </LI> <LI> The algebraic heat flux mode is used to simulate the turbulent natural convection. </LI> <LI> Thermal behavior of simulant and corium is different in the same Rayleigh number. </LI> </UL> </P>

Uncertainty analysis of in-vessel retention in a high power reactor during severe accident

Whang, Seokwon,Park, Hyun Sun,Moriyama, Kiyofumi,Lim, Kukhee,Cho, Young Jin,Kim, Moo Hwan Elsevier 2017 Nuclear engineering and design Vol.319 No.-

<P><B>Abstract</B></P> <P>The in-vessel retention by external reactor vessel cooling (IVR-ERVC) is one of the severe accident management strategies for mitigation or termination of the accident by holding the radioactive material in the reactor vessel. We made a lumped parameter based computer code to evaluate the thermal load on the reactor vessel, and applied the code for a probabilistic analysis for a high power (>1000MWe) reactor assuming the APR1400 condition. The present analysis showed the focusing effect in most of cases. The heat transfer models, especially the critical heat flux correlation, showed a significant impact on the result. Consideration of the multidimensional heat conduction effect in the vessel wall can reduce the excessive conservatism in the vessel failure criterion by assuming the same heat fluxes at inside and outside of the vessel wall. The influence of the probability distribution profiles for the uncertainty parameters was also investigated.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Uncertainty analysis of IVR-ERVC strategy is carried out for a high power reactor, APR1400. </LI> <LI> Significant influence of heat transfer models: oxide layer heat transfer and outside critical heat flux correlations. </LI> <LI> Multidimensional heat conduction effect in vessel wall moderate conservatism of failure criterion. </LI> </UL> </P>

협력적 필터링과 연관규칙 알고리즘을 활용한 도서추천 시스템

이석원(SeokWon Lee),임세희(Sehee Lim),양지훈(Jihoon Yang) 한국정보과학회 2016 한국정보과학회 학술발표논문집 Vol.2016 No.12

공간다중화 MIMO 시스템에서 비트 오차율 성능향상을 위한 신호 설계 및 복호 방법

이석원(Seokwon Lee),주형식(Hyungsik Ju),임성묵(Sungmook Lim),한재민(Jaemin Han),오은성(Eunsung Oh),홍대식(Daesik Hong) 한국통신학회 2009 한국통신학회 학술대회논문집 Vol.2009 No.11

UPPAAL을 사용한 VANET환경 안전메시지 전송 검증

최석원(Seokwon Choi),안소진(Sojin Ahn),임지훈(Jihoon Lim),최진영(Jinyoung Choi) 한국정보과학회 2016 한국정보과학회 학술발표논문집 Vol.2016 No.6

Enhancing the Stability of Lipid Nanoparticle Systems by Sonication during the Cooling Step and Controlling the Liquid Oil Content

Ban, Choongjin,Lim, Seokwon,Chang, Pahn-Shick,Choi, Young Jin American Chemical Society 2014 Journal of agricultural and food chemistry Vol.62 No.47

<P>Aggregation of unstable particles in water limits the application of lipid nanoparticle (LNP) systems to foods despite the capability to encapsulate lipophilic bioactive components. This study exploits a preparation process that can reduce the aggregation of LNPs. Sonication during the cooling step (postsonication) for 4, 5, or 6 min was applied to increase the covering effect of Tween 20 on the particle. Additionally, LNPs were prepared using fully hydrogenated canola oil (FHCO) blended with 0–30 wt % liquid canola oil (LCO) of the lipid phase. Surfactant surface load data indicate that the postsonication might make nonemulsifying Tween 20 diffuse from the aqueous phase to droplet surfaces, which could decrease the crystallinity index (CI) of LNPs due to the inhibition of lipid crystallization. Moreover, the LCO content in lipid matrix could decrease the CI, which could reduce the formation of hydrophobic patches on the particle surface. Therefore, the postsonication and the LCO addition in the matrix could effectively prevent aggregation among hydrophobic patches. This improved colloidal stability of LNPs was verified by the particle shape in transmission electron microscopy and the gelation test. Consequently, LNPs fabricated using 6 min postsonication and 30 wt % LCO in the lipid exhibited the greatest stability (size, 202.3 nm; CI, 57.5%; Tween 20 surface load, 10.29 mg m<SUP>–2</SUP>). This study may serve as a basis for further research that aims to develop delivery systems for functional foods.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2014/jafcau.2014.62.issue-47/jf503489v/production/images/medium/jf-2014-03489v_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jf503489v'>ACS Electronic Supporting Info</A></P>

Isolation of a Natural β-d-Glucosidase Inhibitor in Jujube Leaf Extract

Youngje Jo,Seokwon Lim,Young Jin Choi 한국산업식품공학회 2016 학술대회 및 심포지엄 Vol.2016 No.10

The glucosidase inhibitors are currently interested owing to their promising therapeutic potential in the treatment of disorders such as diabetes, human immunodeficiency virus (HIV) infection, metastatic cancer, and lysosomal storage diseases. Among them, β-d-glucosidase inhibitors can be used to elucidate the mechanisms of various biochemical reactions and to treat the Gaucher disease as potential therapeutics. In this study, the natural β-glucosidase inhibitor was isolated from jujube leaf extract. The isolation and purification are vital for the structure analysis. The jujube leaf was extracted with hot water (95°C, 15 min). Then the natural β-glucosidase inhibitor was isolated using size exclusion chromatography and semi-preparative HPLC. In the first purification process, the 35 fractions were collected according to molecular size using PD-10 column packed with Sephadex G-25 medium. The strongest inhibition on the activity of β -glucosidase was observed at 6 and 7 fractions. The chromatogram of these samples showed that 3 peaks were observed comparing with baseline. For further purification, the strongest inhibitory activity peak was isolated using semi-preparative HPLC with VDS C18 column. Highly purified inhibitor, which can be used for structure analysis and characterization, was obtained. Further study is necessary to identify the natural β-glucosidase inhibitor in the jujube leaf extract.