• Journal of Radiation Industry
• /
• v.17 no.3
• /
• pp.283-292
• /
• 2023

Spent nuclear fuel corresponds to high-level radioactive waste that has high decay heat and radioactivity. Accordingly, Spent nuclear fuel withdrawn from the reactor core is primarily stored and managed in a spent nuclear fuel pool in the nuclear power plant to reduce decay heat and radioactivity. In Korea, most nuclear power plant store all spent nuclear fuel in a spent nuclear fuel pool. For wet storage, there are no defense in depth different with reactor core. The study related to spent nuclear fuel pool accident should be carried out to ensure safety. Therefore, it is necessary to analyze previous study cases related to safety of spent nuclear fuel pool and accident cases to build foundational knowledge. The Objective of this study is to analyze study cases of safety assessment and cases for spent nuclear fuel pool accident. For analyzing study cases of safety assessment, possible phenomena when spent nuclear fuel pool accident occurring identified, Subsequently, study cases for safety assessment about each phenomena were investigated, and materials & methods and results for each study are analyzed. For analyzing cases for spent nuclear fuel pool accident, we analyzed accident cases caused by loss of cooling and loss of coolant in spent nuclear fuel pool. Subsequently, causes and change of water level and temperature by each accident case are analyzed. As a result of the analysis on study cases of spent nuclear fuel pool accident, the results of the study conducted by each research institute were vary depending on the computer code, materials & methods of experiment and major assumptions used in the study. As a result of analyzing cases for spent nuclear fuel pool accident, it was found that accident cases for loss of cooling is more than cases for loss of coolant accident. Even though the types of accident in spent nuclear fuel pool were similar, the specific causes were different by each accident case. All the accident cases analyzed did not lead to severe accidents, such as nuclear fuel being exposed to the air. The result of this study will be used as fundamental data for study on spent nuclear fuel pool accident that will be conducted in the future.

• Journal of Plant Biotechnology
• /
• v.46 no.3
• /
• pp.189-204
• /
• 2019

In this study, we analyzed the changes in glucosinolate content and gene expression in TO1000DH3 and Early big seedling upon methyl jasmonate (MeJA) treatment. Analysis of glucosinolate contents after MeJA treatment at $200{\mu}M$ concentration showed that the total glucosinolate content increased by 1.3-1.5 fold in TO1000DH3 and 1.3-3.8 fold in Early big compared to those before treatment. Aliphatic glucosinolates, progoitrin and gluconapin, were detected only in TO1000DH3, and the changes in the content of neoglucobrassicin were the greatest at 48 hours after MeJA treatment in TO1000DH3 and Early big. The transcriptomic analysis showed that transcripts involved in stress or defense reactions, or those related to growth were specifically expressed in TO1000DH3, while transcripts related to nucleosides or ATP biosynthesis were specifically expressed in Early big. GO analysis on transcripts with more than two-fold change in expression upon MeJA treatment, corresponding to 12,020 transcripts in TO1000DH3 and 13,510 transcripts in Early big, showed that the expression of transcripts that react to stimulus and chemical increased in TO1000DH3 and Early big, while those related to single-organism and ribosome synthesis decreased. In particular, the expression increased for all transcripts related to indole glucosinolate biosynthesis, which is associated with increase in glucobrassicin and neoglucobrassicin contents. Upon MeJA treatment, the expression of AOP3 (Bo9g006220, Bo9g006240), TGG1 (Bo14804s010) increased only in TO1000DH3, while the expression of Dof1.1 (Bo5g008360), UGT74C1 (Bo4g177540), and GSL-OH (Bo4g173560, Bo4g173550, Bo4g173530) increased specifically in Early big.

• Korean Journal of Poultry Science
• /
• v.49 no.4
• /
• pp.211-220
• /
• 2022

Poultry are exposed to extremely high levels of oxidative stress as a consequence of the excessive production of reactive oxygen species (ROS) induced by endogenous and exogenous stressors, such as high-stocking densities, thermal stress, environmental and feed contamination, along with factors associated with intensive breeding systems. Oxidative stress promotes lipid peroxidation, DNA damage, and inflammation, which can have detrimental effects on the health of birds. During the course of evolution, birds have developed antioxidant defense mechanisms that contribute to maintaining homeostasis when exposed to endogenous and exogenous stressors. The primary antioxidant defense systems are enzymatic and non-enzymatic in nature and play roles in protecting cells from ROS attack. Recently, plant flavonoids, which have been established to reduce oxidative stress, have been attracting considerable attention as potential feed additives. Flavonoids are a group of polyphenolic compounds that can be stabilized by binding structural compounds with ROS, and can promote the elimination of ROS by inducing the expression of antioxidant enzymes. However, although flavonoids can contribute to reducing lipid peroxidation and thereby enhance the antioxidant capacity of birds, they have low solubility in the gastrointestinal tract, and consequently, it is necessary to develop a delivery technology that can facilitate the effect intestinal absorption of these compounds. Furthermore, it is important to determine the dietary levels of flavonoids by assessing the exact antioxidant effects in the gastrointestinal tract wherein the concentrations of dietary flavonoids are highest. It is also necessary to examine the expression of transcriptional factors and vitagenes associated with the efficient antioxidant effects induced by flavonoids. It is anticipated that the application of flavonoids as natural antioxidants will become a particularly important field in the poultry industry.

• Journal of Plant Biotechnology
• /
• v.43 no.3
• /
• pp.359-366
• /
• 2016

Tradescantia is a perennial plant in the family of Commelinaceae. It is known to be sensitive to radiation. In this study, Tradescantia BNL 4430 was irradiated with gamma radiation at doses of 50 to 1,000 mGy in a phytotron equipped with a $^{60}Co$ radiation source at Korea Atomic Energy Research Institute, Korea. At 13 days after irradiation, we extracted RNA from irradiated floral tissues for RNA-seq. Transcriptome assembly produced a total of 77, 326 unique transcripts. In plantlets exposed to 50, 250, 500, and 1000 mGy, the numbers of up-regulated genes with more than 2-fold of expression compared that in the control were 116, 222, 246, and 308, respectively. Most of the up-regulated genes induced by 50 mGy were heat shock proteins (HSPs) such as HSP 70, indicating that protein misfolding, aggregation, and translocation might have occurred during radiation stress. Similarly, highly up-regulated transcripts of the IQ-domain 6 were induced by 250 mGy, KAR-UP oxidoreductase 1 was induced by 500 mGy, and zinc transporter 1 precursor was induced by 1000 mGy. Reverse transcriptase (RT) PCR and quantitative real time PCR (qRT-PCR) further validated the increased mRNA expression levels of selected genes, consistent with DEG analysis results. However, 2.3 to 97- fold higher expression activities were induced by different doses of radiation based on qRT-PCR results. Results on the transcriptome of Tradescantia in response to radiation might provide unique identifiers to develop in situ monitoring kit for measuring radiation exposure around radiation facilities.

• Korean Journal of Plant Resources
• /
• v.37 no.2
• /
• pp.120-129
• /
• 2024

Alcoholic liver disease (ALD) is a significant risk factor in the global disease burden. The stem bark of the Betulaceae plant Alnus japonica, which is indigenous to Korea, has been used as a popular folk medicine for hepatitis and cancer. However, the preventive effect of Alnus japonica leaf extracts on alcohol-related liver damage has not been investigated. The objective of this study was to investigate the hepatoprotective effects of the extracts of Alnus japonica leaf (AJL) against ethanol-induced liver damage in HepG2/2E1 cells. Treatment with AJL significantly prevented ethanol-induced cytotoxicity in HepG2/2E1 cells by reducing the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). This protective effect was likely associated with antioxidant potential of AJL, as evidenced by the attenuation of reactive oxygen species (ROS) and malondialdehyde (MDA) production and restoration of the depleted glutathione (GSH) levels in ethanol-induced HepG2/2E1 cells. Our findings suggest that FCC might be considered as a useful agent in the prevention of liver damage induced by oxidative stress by increasing the antioxidant defense mechanism.

• Analytical Science and Technology
• /
• v.32 no.6
• /
• pp.252-261
• /
• 2019

Pyrrolizidine alkaloids (PAs) are a group of secondary metabolites that are produced by plants all over the world as a defense mechanism against herbivores. To date, over 660 PAs have been identified from more than 6,000 plant species that have been reported to be widely present in plants belonging to Asteraceae, Boraginaceae, and Fabaceae. This study describes an analytical method based on UPLC-MS/MS for the quantitation of 7 pyrrolizidine alkaloids (Lycopsamine, Echimidine, Retrorsine, Retrorsine N-oxide, Senecionine, Heliotrine, and Trichodesmine) in honey, and was applied to 84 honey samples for validation. Quantitation was performed based on a matrix-matched calibration to compensate for the matrix effect on the electrospray ionization. Good linear calibrations were obtained for all 7 PAs in the spiked honey samples (2.575-202.14 ㎍/kg; R² ≥ 0.998). The extraction recoveries for most of the PAs in the honey samples were in the range of 81 %-108 %. The analysis showed that 6 of the 84 honey samples were contaminated by the PAs with the mean total sum of PAs being 47.19 ㎍/kg, and the concentrations of the PAs were observed to be in the range of 1.76-202.1 ㎍/kg. The retronecine type compounds (Echimidine, Lycopsamine) were the most frequently found PAs in honey. These data provide useful information for the assessment of human risk posed by the consumption of honey contaminated PAs.

• BMB Reports
• /
• v.36 no.5
• /
• pp.450-455
• /
• 2003

Antioxidant enzymes are scavenger reactive-oxygen intermediates and are involved in many cellular defense systems. We previously reported that a crude extract of Garnoderma lucidum, a medicinally potent mushroom, profoundly increased the catalase gene expression and enzyme activities in mouse livers (Park et al., J. Biochem. Mol. Biol. 34. 144-149, 2001). In this study, we elucidated the detailed mechanism whereby G. lucidum stimulates the catalase activity and expression. The major active fraction was isolated from G. lucidum and methyl linoleate was considered the most major component of the fraction. In order to determine whether methyl linoleate increases mRNA and protein synthesis of catalase, Northern and Western blot analyses were performed in vivo with methyl linoleate-treated mouse liver homogenate after feeding methyl linoleate to the mice. Northern and Western blot analyses of the crude liver homogenates in the mice that were administered methyl linoleate revealed that the expression catalase was significantly increased when compared to the untreated controls. In addition, the catalase protein levels and enzymatic activities increased in the mouse liver homogenates. These results suggest that methyl linoleate that is produced by G. lucidum stimulates the catalase expression at the transcription level.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.23 no.2
• /
• pp.23-32
• /
• 1997

Melanin pigmentation in human skin is a major defense mechanism against ultraviolet light of the sun. Tyrosinase(EC 1.14.18.1) plays a key role in the biosynthesis of ultraviolet of melanin. This is why much researches have been focused on its regulation in controlling the epidermal melanization. We have found that the water-extract of Banha(Pinelliae ternate B.), an oriental medicinal plant, has no tyrosinase inhibitory activity, but does inhibit the melanin biolsynthesis in B16 mouse melanin cells. We also found that Banha extract lowers the tyrosinase activity in cultured cells. To elucidate the action mechanism of Banha extract we have investigated its effect on the tyrosinase mRNA level using reverse transcription-polymerase chain reaction technique. It was revealed that Banha extract reduced the tyrosinase mRNA level in dose dependent manner; when B16 mouse melanoma cells were cultured with 2mg/ml and 5mg/ml of Banha extract, there were 20% and 44% decrease in tyrosinase mRNA level, respectively. These data suggest that the Banha extract exerts its melanogenic inhibitory effect through the transcriptional regulation of tyrosinase mRNA.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.8
• /
• pp.985-991
• /
• 2008

This study was to investigated the changes of physiologically active components in germinated brown rice treated with chitosan (CGBR) and its anti-obesity effect in rat fed a high fat diet. Contents of physiologically active compounds such as total phenolic compounds, total dietary fiber, $\gamma$-aminobutyric acid (GABA), and total phytic acid in CGBR were significantly higher than those of traditional germinated brown rice (GBR). Lipase inhibitory activity of CGBR was higher than those of GBR and brown rice (BR). High fat diets containing CGBR, GBR, and BR were administered to three groups of male Sprague-Dawley rats for four weeks. All groups showed no significant difference in body weight, total abdominal fat, and plasma lipid levels. However, CGBR group appeared to have lower body weight gain and total abdominal fat level than other groups fed high fat diets containing GBR and BR. Total cholesterol and LDL-cholesterol contents in plasma of CGBR group were also lower than those of other groups. Thus, new germination method of brown rice using chitosan is a useful process, which utilizes plant defense responses to elevate the production of secondary metabolites and anti-obesity effect.

• Journal of Life Science
• /
• v.13 no.5
• /
• pp.658-667
• /
• 2003

Antioxidative enzymes (superoxide dismutase; SOD, ascorbate peroxidase; APX, glutathione reductase; GR) play major roles in scavenging mechanism of reactive oxygen species which were involved in various stress conditions including salt. In order to investigate the relation between their growth responses (dry weight) and the changes of antioxidative enzymes activity, salt-tolerant spinach beet having 15cm of shoot length were treated with various salt levels (0, 50, 200, 1000 mM NaCl) for 24 hours. Spinach beet exhibited an increase in the activity of antioxidative enzymes by salt, the maximal activity at 200 mM NaCl and the lowest activity at 50 mM NaCl in 2 hrs. after treatments. As a result of PAGE, it has been confirmed that spinach beet contained 3 isoforms (Fe-SOD, CuZn-SOD and Mn-SOD) of SOD and main isoform was CuZn- SOD form. In case of APX, isoforms of the low molecular weight(No. 7, 8) were showed strong expression especially at 200 and 400 mM NaCl treatment. Meanwhile, GR did not show specific pattern of isoforms among the salt treatments. Especially, in case of 50 mM treatment, plant showed the lowest activity of SOD with the best growth, a low enzyme activity was induced by inactivation of the Mn-SOD. Therefore, we suggested that the decrease of SOD activity at a low salt level (50 mM NaCl) or the increase of enzyme activity at a high salt level (200 mM NaCl) may be related to expression of the Mn-SOD isoform. These antioxidative enzymes showed the increase of activity in a short time by salt addition. So, it is considered that spinach beet copes effectively with a stressful condition such as salt by operating effective antioxidative defense mechanism rapidly under high salt level.