• KSBB Journal
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• v.25 no.6
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• pp.507-512
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• 2010

In this study, we investigated the ability of luteolin, a plant derived flavonoid on hepatocarcinoma cell growth using HepG2 cell culture system. We found that luteolin increased the Smac/DIABLO releases, a mitochondrial protein that potentiates apoptosis. Luteolin also induced either transcriptional activity or expression of PPAR-gamma, a target of cancer growth that PPAR-gamma agonist sensitizes to apoptosis in certain cancer types. To find the possible upstream target molecules of PPAR-gamma activated by luteolin treatment, we used compound C, a specific inhibitor of AMP-activated protein kinase. Pre-treatment of Compound C significantly restored the activation or expression of PPAR-gamma stimulated by luteolin. This result indicated that AMPK signaling might be involved in the activation or expression of PPAR-gamma signaling pathway stimulated by luteolin. Moreover, we also found that luteolin inhibited the insulin-stimulated Akt phosphorylation as well as AICAR, a specific AMPK activator. These results propose that luteolin significantly induces cancer cell death through modulating survival signal pathways such as PPAR-gamma and Akt. AMPK signaling pathway may be an upstream regulator for survival signal pathways such as PPAR-gamma and Akt stimulated by luteolin.

• Proceedings of the Botanical Society of Korea Conference
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• 1996.06a
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• pp.50-63
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• 1996

Nitrogen (N) is an important regulator of the expression of genes involved in carbon and N assimilation pathways in plants by selectively altering the levels of proteins and/or mRNAs. These in C4 plants include genes for such as phosphoenolpyruvate carboxylase, carbonic anhydrase, and pyruvate-Pi dikinase. The C4 genes are regulated in mesophyll cells by N availability both transcriptionally and posttranscriptionally through cytokinins and glutamine as signals. The level of both the signals is up-regulated by N availability: cytokinins in roots and glutamine in leaves. The level of glutamine is controlled by the differential expression by N of glutamine synthetase and ferrdoxin-dependent glutamate synthase genes which locate in the mesophyll cells of C4 plants. The results is discussed as molecular mechanism for the greater N use efficiency of the plants as well as N partitioning is the photosynthetic cells.

• Nuclear Engineering and Technology
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• v.26 no.4
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• pp.536-547
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• 1994

The state feedback optimal control techniques are used in designing the reactor control system. The mathematical plant model with the temperature feedback effects is established from the one delayed neutron group point kinetics equation and the singly lumped thermal-hydraulic balance equations, and is expressed in terms of state variables. The LQR (Linear Quadratic Regulator) control system is designed, being followed by the LQG (Linear Quadratic Gaussian) design to determine the optimal conditions of rod movement for the desired reactor power responses. And two different servo control schemes, the ordinary feedback system and the order increased regulating system, are proposed for the purpose of input tacking. The general control characteristics such as stability margins and output responses are discussed. Comparing each other, it is found that the order increased regulating system has far better control characteristics than the ordinary feedback system.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1705-1716
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• 2021

Bangladesh, as a newcomer country, is expecting to start her nuclear power journey by 2022. Due to evident reasons, newcomer nuclear countries face several key challenges concerning the development of national nuclear safety infrastructure. The paper investigates the status of the 7 key safety infrastructure issues out of the 19 and readiness of the supportive organizations, laboratories, and workforces following the International Atomic energy Agency's status evaluation guide at milestone 3 and foreign countries' practice. Much progress has been achieved at phase 3 regarding the establishments of a few Acts, a regulator, and an operator. However, comprehensive regulatory frameworks, skilled workforces, establishments of a few supportive organizations, and laboratories for managing environmental radioactivity, radiological accidents, and radioactive wastes are yet to ready. Several suggestions are made for establishing and expediting radiation monitoring laboratories, a radiological emergency management center, a radioactive waste management company, and technical support organizations for the safety infrastructure. To avoid perceived risks, policymakers and competent authorities need to emphasize creating an optimized safety infrastructure before commissioning and operating the 1^st nuclear power plant safely, securely, and cost-sustainably.

• Molecules and Cells
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• v.45 no.5
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• pp.294-305
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• 2022

E3 ligase BRUTUS (BTS), a putative iron sensor, is expressed in both root and shoot tissues in seedlings of Arabidopsis thaliana. The role of BTS in root tissues has been well established. However, its role in shoot tissues has been scarcely studied. Comparative transcriptome analysis with shoot and root tissues revealed that BTS is involved in regulating energy metabolism by modulating expression of mitochondrial and chloroplast genes in shoot tissues. Moreover, in shoot tissues of bts-1 plants, levels of ADP and ATP and the ratio of ADP/ATP were greatly increased with a concomitant decrease in levels of soluble sugar and starch. The decreased starch level in bts-1 shoot tissues was restored to the level of shoot tissues of wild-type plants upon vanadate treatment. Through this study, we expand the role of BTS to regulation of energy metabolism in the shoot in addition to its role of iron deficiency response in roots.

• Korean Journal of Weed Science
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• v.9 no.1
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• pp.56-68
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• 1989

aA series of experiments were conducted to investigate the effect of plant growth regulator treatments on the growth and lateral root formation in soybean sprouts in order to establish the effective method of producing root-less or short-rooted soybean sprouts with larger diameter in the hypocotyl. Major results can be summarized as follows. 1. Soybean sprouts showed fairly uniform elongation rate from 3 to g days after imbibition with daily increase of 3.8cm. The speed of elongation of hypocotyl was reduced whereas that of root accelerated 7 days after imbibition. Lateral roots began to emerge fairly evenly from 5 to 9 days after imbibition with a daily increase of 4.4. 2. Auxins(IAA, IBA, NAA, 2,4-D) inhibited hypocotyl elongation and formation of lateral roots and increased hypocotyl diameter without influencing root length and hook diameter at higher concentrations. The dry weight of cotyledon was increased significantly as compared to that of hypocotyl and root. Among the tested auxins, 2, 4-D was the most effective. 3. BA and 4PU-30 significantly reduced elongation of hypocotyl and root and resulted in the biggest diameter of hypocotyl when treated at higher concentrations. The lowest effective concentration of BA to prevent the formation of larval gal roots was 12.5ppm. The formation of lateral roots could be completely prevented by BA and 4PU-30 treatment but kinetin, zeatin, zeatin riboside resulted in many lateral roots and increased thickness of soybean sprouts with little influence. Cotyledon deformation was found in soybean sprouts treated by 4PU-30. 4. 2, 4-D was the most effective for increasing the hypocotyl diameter while 4PU-30 was the most effective for reducing no. of lateral roots. 5. It can be concluded that among the plant growth regulators tested, BA was effective in reducing root length and increasing hypocotyl diameter. BA 12.5 ppm or 15 ppm may thus be the more practical for production of soybean sprouts. 6. ABA showed no significant effect of growth parameter, however ABA 25 ppm inhibited only no of lateral roots with little influence on the growth of seedling. 7. Ethephon inhibited the elongation of hypocotyl and root and increased hypocotyl diameter at higher concentrations. 8. The combined effect of cytokinins and ethephon was very similar to result of BA treatment alone. As the ethephon concentration increased, hypocotyl diameter and dry weight of cotyledon tended to increase.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.517-526
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• 2023

The harvest time of the late-ripening 'Fuji' apple (Malus × domestica) is variable, depending on the coloration of the fruit skin. Ethephon, a plant growth regulator, promotes the ethylene production and induces physiological responses associated with fruit maturation in climacteric fruit crops, such as apples. This study aimed to investigate the effect of ethephon treatment on fruit characteristics after fruit enlargement, with the objective of proposing an economical and stable harvest control method for 'Fuji'/M.26 apples. Fruit characteristics were assessed at 10-days intervals following the application of 100 mg/L ethephon and mixture of 100 mg/L ethephon and 0.5% CaCl₂ at 145 days after full bloom (DAFB). Starch contents of ethephon-treated (ET) and ethephon with CaCl₂-treated (EC) apples began to decrease from 155 DAFB, and the starch contents of ET and EC at 10 days before harvest were similar to those of control at harvest time. Red coloration of fruit skin in EC was lower compared to ET but higher than control. The average fruit firmness was low in ET, while the control and EC exhibited similar levels of firmness. Fruit sugar acid ratios did not show significant differences between treatments. However, the titratable acidity of EC was significantly lower than that of the control at 10 days before harvest. Moreover, fruit sugar acid ratio of ET and EC at 10 days before harvest in 2021 was similar to their sugar acid ratio at harvest time. Therefore, it was thought that fruit maturation and skin coloration could be accelerated by 10 days from the harvest time through the combined treatment of 100 mg/L ethephon and 0.5% CaCl₂ at the end of fruit enlargement in 'Fuji'/M.26.

• Korean Journal of Medicinal Crop Science
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• v.22 no.3
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• pp.231-236
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• 2014

This experiment was carried out to establish the optimum cutting time, plant growth regulator, and bed-soil for rooting by greenwood cutting of Schisandra chinensis. Approximately 7 cm long-shoots of greenwood cuttings were transplanted by various cutting times, plant growth regulators, and bed-soils in the plastic-film house. The rooting rate of greenwood cutting was 12.5% in the April 5th, 73.5% in the May 8th, and 75.5% in the August 5th. The number and length of primary root in greenwood cutting were more in the early May than those in the early August. For mass propagation of Schisandra chinensis. using greenwood cutting, shoots were treated with plant growth regulators on May to increase rooting rate. Rooting rate was 100% with IAA $50mg/{\ell}$, 92.9% with NAA $100mg/{\ell}$, and NAA $1,000mg/{\ell}$, for 60 min. To select effective media for rooting, various medias for bed-soil were treated by single and mixture form for 100 days after cutting. Rooting rate was 91.8% in the single treatment of peat moss or decomposition of granite soil, and this result was better than those in other treatment. The treatment by 1 : 1 mixture of peat moss and horticulture bed soil was rooting with 94.0% best rooting rate.

• Korean Journal of Medicinal Crop Science
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• v.10 no.5
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• pp.344-352
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• 2002

This study was conducted to determine the optimum planting dates and density of one year old Bupleurum falcatum L. to improve its quality. Furthermore, the effect of cultural methods and plant growth regulators$(GA_3,\;IAA,\;Kinetin)$ on the quality of B. falcatum were also investigated. In this study, Jeongseon cultivar collected in Korea and Mishima cultivar introduced from Japan were used. Some of the results obtained are as follows. Jeongseon cultivar showed less stem branches and shoot weight compared to Mishima. However, Jeongseon cultivar showed tall plant height, high root fresh and dry weight, and high levels of SSa and TSS, but low SSc content than that of Mishima. Although fresh and dried root weight of both cultivars were not affected by plant growth regulators treatment. compared with the untreated one, increasement of TSS content were made by $GA_3$ 100 ppm, IAA 50 ppm or 10 ppm and kinetin 10 ppm treatment in Jeongseon cultivar, and by $GA_3$ 10 ppm and IAA 100 ppm or 10ppm treatment in Mishima cultivar applied on June 1.

• Korean Journal of Medicinal Crop Science
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• v.12 no.6
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• pp.508-514
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• 2004

Chrysanthemum boreale M. is an important medicinal plant that has been historically used in herbal medicine and in the health food throughout East Asia. This study was conducted to investigate the influence of abscisic acid (ABA) and salicylic acid (SA) on plant growth, mineral content and effective components, such as essential oil, amino acid and cumambrin A, by means in order to increase the productivity and the quality of flowerheads in the plant. Yields of flowerheads were increased by 12.7%, 21.7% and 15.5% by ABA, SA and both treatments, respectively, as compared with the control. Inorganic nutrient content was changed by PGRs; SA treatment was increased by nitrogen, phosphorus and magnesium content but decreased by potassium of C. boreale M. flowerheads. Total content of amino acid was increased by SA but decreased by ABA treatment. Essential oil content and yields were increased to 9.7% and 33.8% by SA treatment. Moreover, the content of terpene, monoterpenoids and sesquiterpenoids, were improved by ABA treatment, especially, germacrene-D content was increased by 39.1%, as compared to control. In addition, yields of cumambrin A, sesquiterpene compound exhibiting blood-pressure activity, increased in all PGRs treatments, but its concentration in the C. boreale M. flowerheads only increased by ABA and both treatment. The experiment suggests that PGRs using ABA and SA could increase the yields and quality of C. boreale M. flowerheads.