• Journal of Microbiology and Biotechnology
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• v.31 no.12
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• pp.1615-1623
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• 2021

Picropodophyllotoxin (PPT), an epimer of podophyllotoxin, is derived from the roots of Podophyllum hexandrum and exerts various biological effects, including anti-proliferation activity. However, the effect of PPT on colorectal cancer cells and the associated cellular mechanisms have not been studied. In the present study, we explored the anticancer activity of PPT and its underlying mechanisms in HCT116 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to monitor cell viability. Flow cytometry was used to evaluate cell cycle distribution, the induction of apoptosis, the level of reactive oxygen species (ROS), assess the mitochondrial membrane potential (Δψm), and multi-caspase activity. Western blot assays were performed to detect the expression of cell cycle regulatory proteins, apoptosis-related proteins, and p38 MAPK (mitogen-activated protein kinase). We found that PPT induced apoptosis, cell cycle arrest at the G1 phase, and ROS in the HCT116 cell line. In addition, PPT enhanced the phosphorylation of p38 MAPK, which regulates apoptosis and PPT-induced apoptosis. The phosphorylation of p38 MAPK was inhibited by an antioxidant agent (N-acetyl-L-cysteine, NAC) and a p38 inhibitor (SB203580). PPT induced depolarization of the mitochondrial inner membrane and caspase-dependent apoptosis, which was attenuated by exposure to Z-VAD-FMK. Overall, these data indicate that PPT induced G1 arrest and apoptosis via ROS generation and activation of the p38 MAPK signaling pathway.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.335-340
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• 2004

On a liquid propellant PPT, the discharge processes that discharge was initiated and plasma was accelerated was observed by using a ultra high speed camera. Liquid propellant PPT is a pulsed plasma thruster using liquid as propellant. Our past study showed the successful operation of liquid propellant PPT and the thruster showed high specific impulse. However, its acceleration mechanism has not been clarified. In this study we observed the plasma acceleration processes in order to deepen our understanding of the acceleration mechanism.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.164-164
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• 2002

에스트로젠을 처리한 송사리의 간으로부터 choriogenin vitellogenin estrogen receptor의 발현량을 전사수준에서 Real-time을 사용하여 정량.비교하였다. 시험어종으로는 부화 후 5개월 이상된 성숙한 수컷 송사리(Oryzias latipes)를(체중 약 250mg/마리)를 사용하여 17$\beta$-estradiol(25ppt, 50ppt, 100ppt)에 24시간 노출시켰다. Fluorescence dye는 choriogenin vitellogenin estrogen receptor의 경우 FAM (6-carboxyfluorescein)을 사용하였으며, $\beta$-actin의 경우는 VIC를 사용하였다. 프로브에 사용하는 quencher dye는 TAMRA(6-carboxy-N',N',N',N'-tetramethyl rhodamine)을 사용하였다. Internal control로 사용된 $\beta$-actin은 17$\beta$-estradiol의 농도에 상관 없이 0~10pM 범위에서 일정하게 발현됨을 보여주었다. vitellogenin choriogenin L 및 choriogenin H는 17$\beta$-estradiol의 농도에 의존하여 발현이 증가되는 용량-반응양상(Dose-dependent)을 나타내었다. 반면, estrogen receptor는 모든 처리군에서 $10^{-2}$pM 정도로 발혐됨에 따라 본 시험농도의 17$\beta$-estradiol에 의해서는 거의 유도발현이 되지 않음을 보여주었다. choriogenin L, choriogenin H, vitellogenin I 및 estrogen receptor 발현감수성을 비교한 결과, 25ppt 및 50ppt의 17$\beta$-esoadiol 농도에서는 ChgL > ChgH > VTG I >ER의 순으로 감수성이 높았으며, 100ppt 노출에서는 ChgL > VTG I > Chg H > ER의 순으로 감수성이 높게 나타났다. 결론적으로 choriogenin이 에스트로젠물질에 의한 가장 민감한 생체지표임을 알 수 있었다.

• The Journal of Economics, Marketing and Management
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• v.10 no.5
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• pp.15-24
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• 2022

Purpose: The purpose of this study is to find a way to improve and overcome the psychological treatment limited to the negative factors dealt with in psychology from a positive psychological point of view. To this end, this study aims to verify whether a positive psychotherapy program can improve happiness, resilience, and post-traumatic growth along with improvement of psychological symptoms such as depression. Research design, data and methodology: To this end, in this study, mean difference analysis was conducted using t-test on 10 participants in the 16th PPT program and 14 in the control group. Also, after setting the main variables, we tried to confirm the effectiveness through simple regression analysis and multiple regression analysis of the causal relationship model. Results: As a result of the independent sample t-test and the paired sample t-test, it was confirmed that the group participating in the PPT program had higher flourish, happiness, resilience, post-traumatic growth, and lower depression. In addition, as a result of regression analysis, it was confirmed that post-traumatic growth had a positive effect, and that depression was a life-threatening factor. Conclusions: Since the PPT program has a positive effect on the participants with relatively negative psychological symptoms, it is necessary to expand it. In addition, it is necessary to introduce various preventive programs such as PPT as well as traditional psychological treatment for negative symptoms such as depression.

• Journal of Aquaculture
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• v.18 no.1
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• pp.52-59
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• 2005

The productivity of cyclopoid copepod, Apocyclops royi fed by various diets (Isochrysis galbana, Tetraselmis suecica, Phaeodactylum tricornutum, concentrated freshwater Chlorella and baker's yeast) was investigated at tile different temperatures ($16-36^{\circ}C$) with different salinities (5-34 ppt). A. royi was cultured in 6 ml vessels (12 wells culture plate). Total production (188 inds.) and daily production (13.4 inds.) of nauplii by A. royi female at $32^{\circ}C$ were significantly higher than those of nauplii at the different temperatures (P<0.05). Development time from nauplii to copepodite and from nauplii to adult tended to increase with increasing water temperature up to 32. And total production (169 inds.) and daily production (9 inds.) of nauplii by A. royi female at 10 ppt were significantly higher than those of nauplii at the different salinities (P<0.05). The fastest development time from nauplii to copepodite and from nauplii to adult was observed at 10 ppt and 15 ppt, respectively (P<0.05). The highest total production of A. royi nauplii and fastest development time from nauplii to adult were obtained in females fed Isochrysis galbana (P<0.05). These results may indicate that the optimum culture temperature and salinity for A. royi are $32^{\circ}C$ and 10 ppt, respectively, and Isochrysis galbana is one of the suitable diets for this copepod.

• Korean Journal of Microbiology
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• v.30 no.1
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• pp.47-52
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• 1992

This study describes isolation and identification of a soil bacterium which is degradable of phosphinothricin and improvement of the isolated strain by using mutagenesis and spheroplast fusion. The experiment was performed to search for a possibility of development of a new strain which is both PPT-degradable and glyphosate-resistant by using interspecies cell fusion between the PPT-degrading bacterium. Pseudornonu.\ puucimohlis and a glyphosate -resistant strain, Pseudornonu.~ cc,pucicl. Auxotrophic mutants were obtained by the treatement of P. puucimohili.\ with ethylmethanosulfate, and used to cell fusion. Lysozyme and EDTA were used to spheroplast formation and regeneration rates :)f the spheroplast were 6.5'%1 in P. pauc.irnohili.\ and 8.8% in P.ci,j~u[,i(lr, espctively. Polyethylenglycol 5.000 was used to cell fusion as fusogen. The fusant\ulcorner F1. F2. F\ulcorner and F4 werc- obtained by the intra- and interspecies cell fusion. The fusant Fl of intraspecies cell fusion was higher to the wild type by 1 I'%l in PPT degrading ability, and the fusant F3 of inierspesis cell fusion developed plyphosatc-resistant and PPI-dcgrading ability which were propertics of two parental strains.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.86-97
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• 2021

Background: Panax ginseng Meyer has been used as a nourishing edible herb in East Asia for thousands of years. 25-OH-PPT was first discovered as a natural rare triterpenoid saponin in ginseng stems and leaves by our group. Research found that it showed strong inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, and protected cardiocytes (H9c2) through PI3K/Akt pathway. Methods: In the research, in order to optimize the 25-OH-PPT enrichment process, optimal macroporous resins and optimal purification conditions were studied. Meanwhile, the hypoglycemic effect and mechanism of 25-OH-PPT were evaluated by using STZ to establish insulin-dependent diabetic mice and the spontaneous type 2 diabetes DB/DB mice. Results and Conclusion: Research found that 25-OH-PPT can reduce blood glucose and enhance glucose tolerance in STZ model mice. It increases insulin sensitivity by upregulating GLUT4 and AMPK in skeletal muscle, and activating insulin signaling pathways. In DB/DB mice, 25-OH-PPT achieves hypoglycemic effects mainly by activating the insulin signaling pathway. Meanwhile, through the influence of liver inflammatory factors and lipids in serum, it can be seen that 25-OH-PPT has obvious anti-inflammatory and lipid-lowering effects. These results provide new insights into the study of ginseng as a functional food.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.02a
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• pp.40-40
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• 1999

• Proceedings of the Korean Vacuum Society Conference
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• 1999.02a
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• pp.58-58
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• 1999

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.142-143
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• 2002