• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.449-455
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• 2012

Greenhouse and laboratory experiments were conducted to determine the effects of shade treatment and substrate components on plant growth and physiological activity of Taraxacum officinale. Substrates combined with coco peat and perlite (ratio 70 : 30 and 50 : 50, v/v) showed higher growth and yield than their single substrates (p<0.05). Shade treatment also significantly reduced plant height, root length, root diameter, leaf area, chlorophyll content, and fresh weight (p<0.05), compared to no shade. Contents of total phenolics [mg chlorogenic acid equivalents (CAE) $kg^{-1}$ DW] and total flavonoids [mg naringin equivalents $kg^{-1}$ DW] showed higher amounts in shoot parts than root parts of T. officinale, with shade than no shade. The antioxidant potential of the methanol extracts from the plants dose-dependently increased. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was higher in leaf parts than in root parts of the plants, and no shade than with shade.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.5
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• pp.79-87
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• 2014

The enrichment with nutrients in rivers and lakes becomes serious problems in Korea. As the environmental friendly solution, the phytoremediation are getting more attention and the water hyacinth could be a strong candidate plant for this. Water hyacinth is a free floating freshwater plant proven to be a effective plant used for a purification of a polluted lakes, sewage wastewater, and livestock wastewater. The biggest obstacles for application of water hyacinth in Korea could be the disposal of the water hyacinth before winter, because there is no feasible use for the water hyacinth until now. In this study, the characteristics of water hyacinth were deeply investigated for providing background data to develop appropriate application of the water hyacinth. The water hyacinth was fractioned three parts, leaf, air blader, root of which morphological properties were evaluated with microscope and field emission scanning electron microscope (FE-SEM). The water contents of each parts of the water hyacinth were 87% for leaf, 96.5% for air bladder, 94.6% for root. The chemical compositions of each parts were also measured and showed around 29% of hot water extract in leaf and air bladder, 42% holocellulose for leaf, 47% holocellulose for air bladder. The application of water hyacinth biomass without root parts to papermaking provided bulkier structure, but the tensile strength was decreased.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.62-62
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• 2023

Zanthoxylum piperitum ("chopi" in Korean) has been used as traditional medicinal plants with high anti-inflammatory, antioxidant, and antifungal activities. The aims of the study were to identify marker compounds and to investigate metabolites variation of chopi according to different parts and harvest times. Every month from June to September, chopi were harvested with three different parts: leaves, leaf-twig mixtures, twigs. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), two main marker compounds (quercitrin and quercetin-3-O-glucoside) were characterized in 70% ethanol extracts of chopi. Quantification of the two marker compounds were subsequently conducted by high performance liquid chromatography (HPLC), representing that contents of these compounds were higher in leaves and leaf-twig mixtures rather than twigs. For the comprehensive analysis of metabolites associated with production of marker compounds, 35 primary metabolites were identified using gas chromatography-mass spectrometry (GC-MS). Multivariate analysis results represented that plant parts were main contributors to the separation of chopi. However, significant differences were not observed between leaves and leaf-twig mixtures samples. The partial least square (PLS) predictive model revealed that monosaccharides (fructose, galactose, glucose, mannose, xylose) and branched-chain amino acids (isoleucine, valine, leucine) were important determinants for the production of marker compounds together with alanine, inositol, GABA, and theronic acid. This study could be extended to stabilize and utilize chopi as an industrial material, as well as to find good candidates with various nutritional traits.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1470-1473
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• 2003

In this paper the networked control systems (NCS) problem is discussed where plants and controllers are distributed and interconnected by a common network. NCS is designed with LQ regulator and applied to an inverted pendulum accounting for the multiple time delays. We are to deals with a networked control system with a single controller, multiple sensors and multiple actuators. Since these parts are distributed, they are interconnected by communication networks. An NCS with LQ regulator is designed and applied to an inverted pendulum as a benchmark plant to check its performance under time delays induced by the network. Network induced delays are composed of two parts. One is the delay from controller to plant, and another is from plant to controller. They are assumed to be constant in this paper, and the plant and controller are discretized. To apply the LQ regulator the NCS model is transformed to a standard model with delayed states as state variable. And real network induced delay is measuring in TCP/IP network assuming that two delays are constant.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.101-107
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• 2010

An efficient plant regeneration system has been developed for figleaf gourd (Cucurbita ficifolia Bouch$\'{e}$), which is exclusively used as a rootstock for cucumber. The protocol is based on results obtained from a series of culture experiments involving different parts of the cotyledons and various media. The culture of cotyledon explants was critical for the enhancement of shoot regeneration frequency. The lower parts of the cotyledon excised at the plumule base were found to display a markedly enhanced production of adventitious shoots compared to other cotyledon regions. Culture in silver nitrate-supplemented Murashige and Skoog (MS) medium was not beneficial for shoot regeneration and suppressed root regeneration. Efficient shoot regeneration was obtained on MS medium containing 1.0 $mg\;l^{-1}$ zeatin and 0.1 $mg\;l^{-1}$ indole-3-acetic acid. Regenerated shoots successfully elongated and rooted in medium containing 0.1 $mg\;l^{-1}$ 1-naphthalene-acetic acid after 10-15 days of subculturing. The plantlets were satisfactorily acclimatized in a greenhouse and grew into normal plants without any morphological alterations.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.184-188
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• 2001

Phytophthora-induced diseases on citrus in Jeju island have been considered of minor importance because of the use as root stock of trifoliate orange, which is immune to Phytophthora. However, brown rot on fruit, which severely occurred in 1998 and 1999, has become a great threat to citrus production in the island. About one-half of the surveyed orchards were infected in 1998 and 4 out of 19 infected fields showed over 20% fruit infection rate. The disease was less severe in 1999, with an estimated infected area and total fruit reduction of 3,155 ha and 15,300 tons, respectively. Typical gummosis was also occasionally observed on cv. Shiranugi, which is mostly cultivated under plastic film houses. Two types of Phytophthora were consistently isolated from various plant parts, identified as P. citrophthora and P. nicotianae. The former was isolated from the aerial parts of the fruit, young leaf, and shoot in the fields. Meanwhile, the latter was only isolated from the basal stem showing gummosis in plastic film houses.

• Korean Journal of Pharmacognosy
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• v.29 no.2
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• pp.79-85
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• 1998

Six antioxidative compounds in the aerial parts of Potentilla fragarioides were isolated by a bioassay guided purification using a DPPH free radical. They were identified as (+)-catechin, isoquercitrin, quercitrin, $quercetin-3-O-{\beta}-D-glucopyranosyl-{\beta}-D-xylopyranoside$, caffeic acid, and 4-O-caffeoyl-L-threonic acid on the basis of $^{1}H$ and $^{13}C-NMR$ and MS data. The DPPH radical scavenging activity of five compounds $(RC_{50}:\;7.5{\sim}10.5\;{\mu}g)$ except for quercitrin $(16\;{\mu}g)$ was more effective than those of ${\alpha}-tocopherol$ $(12\;{\mu}g)$ and BHA $(14\;{\mu}g)$.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.405-410
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• 2006

A series of aqueous or methanol extracts from four different Korean salad plants were assayed to determine their allelopathy and antioxidant activity. The extracts applied on filter paper in a Petri-dish bioassay significantly inhibited root growth of against alfalfa (Medicago sativa) seedlings. Leaf extracts from 40 g dry tissue $L^{-1}$ of Aster yomena was most phytotoxic to alfalfa root growth, and followed by that of Cirsium japonicum, Taraxacum officinale, and Ixeris dentate. Methanol extracts of plants dose-dependently increased DPPH free radical scavenging activity in vitro. Antioxidant activity of methanol extracts from the same plant species was investigated, and the result showed high DPPH free radical scavenging activity in Cirsium japonicum, Aster yomena, and Ixeris dentate, however, in Taraxacum officinale was least activity. By means of HPLC analysis, chlorogenic acid, p-coumaric acid, and total phenolics with 7.68, 17.47 and 18.64 mg, $100g^{-1}$, respectively, showed the highest amounts in methanol extracts from Cirsium japonicum leaves. These results suggest that Compositae salad plants contain water-soluble substances with allelopathic potential as well as antioxidant activity.

• Korean Journal of Medicinal Crop Science
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• v.19 no.4
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• pp.227-232
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• 2011

The roots of Platycodon grandiflorum has been widely used as a crude drug or a food stuff. Unfortunately, the output and the quality is not regular and highly dependent on the cultivation area and cultivation method. Therefore, seedling cultivation study of this plant under structure with various fertilizer supply was performed. As a result, significant big difference between ammonia nitrogen and nitrate nitrogen content was shown in the root at seedling stage while the difference was not significant in the aerial parts. Fresh weight of the root (7.73 g plant$^{-1}$) was higher in the group treated with three major nutrients (N, P and K) than in those treated with three major nutrients and calcium or magnesium or both calcium and magnesium, and non-treated group (2.69 g plant$^{-1}$). Total nitrogen content was recognized to be significantly correlated with root weight, plant height, number of leaves and weight of aerial parts. Ammonium nitrogen content was more correlated the growth of P. grandiflorum than nitrate nitrogen. For phosphoric acid, significant correlation was also shown with the four growth factors.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.747-752
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• 2007

This study was carried out to identify and quantify the flavonoids from 6 different plant parts of Allium victorialis var. platyphyllum (AVP), including the flower, leaf, root, stem, flower stalk, and flower seed, using liquid chromatography/ mass spectrometry. Two major flavonoids were structurally identified as quercetin (3,5,7,3'4,'-pentahydroxyflavone) and kaempferol (3,5,7,4'-tetrahydroxyflavone) at contents of 11.8-25.8 and $6.0-64.4\;{\mu}g/mL$, respectively. In particular, the flower and root plant parts contained the highest amounts of quercetin and kaempferol compared to the other parts. We also assessed the recovery effects of each plant-part extract of AVP on gap junctional intercellular communication (GJIC) in WB-F344 cells by the scrape-loading and dye transfer (SL/DT) method. According to the results, GJIC was reduced by approximately 70.2% ($62.3{\pm}12.5$ cells) compared to the control ($209{\pm}9.5$ cells, 100%) when 12-O-tetradecanoylphorbol-13-acetate (TPA) was treated alone in the WB-F344 rat liver epithelial cells. However, the stem extract (0.2 mg/mL) restored GJIC to basal levels (92%, $204{\pm}2.3$ cells, p<0.01) and the flower extract (0.2 mg/mL) stimulated GJIC to 82.5% ($172.6{\pm}8.3$ cells, p<0.05), when applied together with the TPA.