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Electrostatic Fields with Different Directions Affect Growth and Cell Division of Tomato Seedlings
Dahae Kim,Myung-Min Oh 한국원예학회 2021 한국원예학회 학술발표요지 Vol.2021 No.10
An electric field, one of the essential factors for plants’ life, exists in the natural environment and is self-generated in plants. Many studies have demonstrated that electric field positively affects various physiological responses in plants, including seed germination and plant growth and development. However, there is still limited information to understand how plants respond to the external electric field. In this study, we explored the effect of external electrostatic fields with different directions on the growth of tomato seedlings. The 18-day-old tomato seedlings were grown in growth chambers with electrostatic fields applied vertically or horizontally, which were generated using stainless steel meshes as electrodes and a high voltage generator. The electrostatic fields of 5 kV/m were treated for 3 weeks. Plant height was significantly increased in all treatments by 10 ‒ 30% compared with the control. The number of nodes showed a similar pattern as plant height. The number of leaves was also increased in all treatments compared with the control. However, the horizontal electrostatic field decreased leaf area by about 30% compared to the control. The vertical electrostatic fields increased shoot fresh weight, while the horizontal field increased root fresh weight. Furthermore, cell division was activated in electrostatic field treatments by 28 ‒ 80% compared with the control, which supports the results of plant height and leaf number. In conclusion, our results show that the directions of the electrostatic field applied to tomato seedlings can change its morphogenesis, and promote growth and cell division. Electric fields could be a new component to control the plant responses although we need more research in the future.
Protective effect of Korean Red Ginseng against FK506-induced damage in LLC-PK1 cells
Dahae Lee,Ki Sung Kang,Jae Sik Yu,Jung-Yoon Woo,Gwi Seo Hwang,Dae-Woon Eom,Seung-Hoon Baek,Hye Lim Lee,Ki Hyun Kim,Noriko Yamabe 고려인삼학회 2017 Journal of Ginseng Research Vol.41 No.3
Background: Compound FK506 is an immunosuppressant agent that is frequently used to prevent rejection of solid organs upon transplant. However, nephrotoxicity due to apoptosis and inflammatory response mediated by FK506 limit its usefulness. In this study, the protective effect of Korean Red Ginseng (KRG) against FK506-induced damage in LLC-PK1 pig kidney epithelial cells was investigated. Methods: LLC-PK1 cells were exposed to FK506 with KRG and cell viability was measured. Western blotting and RT-PCR analyses evaluated protein expression of MAPKs, caspase-3, and KIM-1. TLR-4 gene expression was assessed. Caspase-3 activities were also determined. The number of apoptotic cells was measured using an image-based cytometric assay. Results: The reduction in LLC-PK1 cell viability by 60mM FK506 was recovered by KRG cotreatment in a dose-dependent manner. The phosphorylation of p38, p44/42 MAPKs (ERK), KIM-1, cleaved caspase-3, and TLR-4 mRNA expression was increased markedly in LLC-PK1 cells treated with 60mM FK506. However, with the exception of p-ERK, elevated levels of p-p38, KIM-1, cleaved caspase-3, and TLR-4 mRNA expression were significantly decreased after cotreatment with KRG. Activity level of caspase-3 was also attenuated by KRG cotreatment. Moreover, image-based cytometric assay showed that apoptotic cell death was increased by 60mM FK506 treatment, whereas it was decreased after cotreatment with KRG. Conclusion: Taken together, these results suggest that the molecular mechanism of KRG in the FK506-induced nephrotoxicity may lead to the development of an adjuvant for the inhibition of adverse effect FK506 in the kidney.
Dahae Lee,Ranhee Kim,So-Ri Son,Ji-Young Kim,Sungyoul Choi,Ki Sung Kang,Dae Sik Jang The Korean Society of Ginseng 2023 Journal of Ginseng Research Vol.47 No.2
Background: Here, we aimed to assess the inhibitory effect of a new compound from Panax ginseng on the migration of human ovarian cancer cells and tube formation of human umbilical vein endothelial cells (HUVECs). Methods: A new compound, ginsenglactone A (1), was isolated from ginseng roots, together with seven known compounds (2-8). Spectroscopic data were used to elucidate the chemical structure of 1. The tubular structure formation in HUVECs was assessed by Mayer's hematoxylin staining. The migration of A2780 cells was evaluated using the scratch wound healing assay. Results: HUVECs treated with 1 had the statistically significant decrease in tubular structure formation compared to the HUVECs treated with compounds 2-8. This effect was enhanced by co-treatment with inhibitors for phosphatidylinositol 3-kinase (PI3K) (LY294002) and extracellular signal-regulated kinase (ERK) (U0126). Treatment with 1 decreased the expression of phosphorylation of ERK, PI3K, vascular endothelial growth factor receptor2 (VEGFR2), Akt, and mammalian target of rapamycin (mTOR). In addition, the ability of A2780 cells to cover the scratched area were also decreased. This effect was enhanced by co-treatment with U0126. Lastly, treatment with 1 decreased the phosphorylation of ERK, matrix metalloproteinase-9 (MMP-9), and MMP-2. Conclusion: These results suggest that ginsenglactone A is a potential inhibitor of HUVEC tubular structure formation and A2780 cellular migration, which may be helpful for understanding its anticancer mechanism.
Dahae Lee,Ki Sung Kang,Sanghyun Lee,Eun Ju Cho,Hyun Young Kim 한국식품영양과학회 2016 Preventive Nutrition and Food Science Vol.21 No.4
Reactive oxygen species are tumorigenic by their ability to increase cell proliferation, survival, and cellular migration. The purpose of the present study was to compare the antioxidant activity and cytotoxic effects of 3 berry extracts (strawberry, Korean raspberry, and mulberry) in A2780 human ovarian carcinoma cells. Except for raspberry, the ethyl acetate or methylene chloride fractions of berries containing phenolic compounds exerted dose dependent free radical scavenging activities. In the raspberry fractions, the hexane fraction also exhibited potent antioxidant activity. The cytotoxic effects of berries extracts in A2780 human ovarian carcinoma cells were measured using the 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide assay. Surprisingly, co-treatment with n-butanol (BuOH) fractions of berries showed stronger cytotoxic effects compared to the other fractions. These findings suggest that potent anticancer molecules are found in the BuOH fractions of berries that have stronger cytotoxic activity than antioxidants.
How Does Crisis Shape Cultural Policy? - Changing Cultural Policy response during the COVID-19 Era
( Dahae Jung ) 한국행정학회 2021 한국행정학회 학술발표논문집 Vol.2021 No.-
This study classifies the role of modern national government in cultural policy by country and tests how the direction and characteristics of each country's cultural policy have changed before and after the COVID-19 crisis. This study classifies and analyzes three countries. France, the United Kingdom, and the United States have high cultural competence depending on the degree of intervention in national cultural policy and the direction of cultural policy. Then, by understanding the cultural policies of each country before and after COVID-19, differences and similarities between countries according to the role of the government and the direction of cultural policy are derived. As a result, the cultural policies of the three countries before COVID-19 appeared similar according to global trends (decentralization, 4th industrial revolution-digitalization, measurement of economic value of art, etc.) In the UK, the Ministry of Culture was centered, and in the US, the non-profit organization was centered, but there were various and individual differences. Interestingly, however, after COVID-19, government intervention in all countries increased under the guise of a national crisis, and it was found that financial support for survival was the center of the cultural policy that was operated previously.
An Efficient Scheme to Acquire the Maximum Power Multipath Component in UWB Systems
Dahae Chong,Sanghun Kim,Suk Chan Kim,Sun Yong Kim,Seokho Yoon 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7
In this paper, we propose a novel two-stage acquisition scheme in ultra-wideband (UWB) systems. The proposed scheme aims to find the maximum power multipath component. In the first stage, we obtain a timing candidate using bit reversal search (BRS) scheme and in the second stage, we find the maximum power multipath component based on the result from the first stage. Simulation results show that the proposed scheme gives better performance than that of the BRS scheme.