• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.447-451
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• 2007

This study was carried out to examine the antioxidant activity of Gynostemma pentaphyllum Makino. Using the DPPH method, we found that free radical scavenging activity was strong in all the fractions except the water fraction of the water extract (GPW) and ethanol extract (GPE) of G pentaphyllum Makino. Pseudo-SOD activity was highest in the diethyl ether fraction of the ethanol extract, while the other fractions of the ethanol and water extracts were lower. For xanthine oxidase inlribition activity, the diethyl ether fraction and butanol fraction of GPW, and the diethyl ether fraction and butanol fraction of GPE, showed activities over 80%. Nitrite scavenging ability was strong (over 60%) in all the GPW and GPE fractions. The diethyl ether fraction and butanol fraction of GPW had more effective nitrite scavenging abilities than the other extract fractions. These results suggest that the extracts of G pentaphyllum Makino can be used as a functional material in a tea or drink.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.353-359
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• 1988

Variations in photosynthetic capacities of leaves differing in thickness were explained on the basis of relationships between gas exchange and internal leaf structure. The relative importance of gas diffusion and of biochemical processes as limiting for leaf photosynthesis was also determined. Mesophyll cell surface was considered to be the limiting internal site for gas diffusion. and cell volume to be indicative of the sink capacity for CO$_2$ fixation. Increases in cell surface area were assumed to reduce proportionately mesophyll resistance to the liquid phase diffusion of CO$_2$. Increased cell volume was thought to account for a proportional increase in reaction rates for carboxylation, oxygenation. and dark respiration. This assumption was tested using chamber-grown Glycine max (L.) Merr. cv. Amsoy plants. Plants were grown under 200, 400, and 600 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR to induce development of various leaf thickness. Photosynthetic CO$_2$ uptake rates were measured on the 3rd and 4th trifoliolate leaves under 1000 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR and at the air temperature of 28 C. A pseudo -mechanistic photosynthesis model was modified to accommodate the concept of cell surface area as well as both cell volume and surface area. Both versions were used to simulate leaf photosynthesis. Computations based on volume and surface area showed slightly better agreement with experimental data than did those based on the surface area only. This implies that any single factor, whether it is photosynthetic model utilized in this study was suitable for relating leaf thickness to leaf productivity.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.342-351
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• 1999

The forest vegetation developing on Mt. Inwang, an isolated forestland in Seoul, Korea was analyzed phytosociologically and its spatial distribution mapped out. Using the vegetation map, The characteristics of landscape structures in terms of the number and size of patches are discussed. Forest vegetation of the study area was classified into ten communities, ten groups, and eighty subgroups. Landscape element types were classified into secondary forests, relict communities, introduced plantations, and other elements including urbanized area. Pinus densiflora community, natural forest and Robinia pseudo-acacia community, plantation, formed matrix and some secondary forest elements, relict communities and the ether plantations of small size tended to distribute as small patches in such matrix. The number of patches per unit area in secondary forest elements was more than that in plantation elements. The result in patch size was vice versa. The vascular plant species richness of the landscape element types in Mt. Inwang was found to he positively related to their size. As the results of landscape ecological analyses, it was estimated that differentiation of patches recognized in community level would be related to human interference a and those in subordinate levels to natural process such as progression of succession.

• KSBB Journal
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• v.22 no.2
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• pp.109-113
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• 2007

Suspension culture of recombinant Chinese hamster ovary (CHO) cells producing follicle-stimulating hormone was performed to investigate the effect of glycine betaine on cell growth and FSH production at low culture temperature. At 28$^{\circ}C$, cell growth was suppressed, but cell viability remained high for a longer culture period. When the culture temperature was lowered from 37$^{\circ}C$ to 28$^{\circ}C$, more than 14-fold increase in the maximum FSH titer was achieved. In batch culture at 28$^{\circ}C$, the use of 15 mM glycine betaine (GB) to culture medium resulted in the enhancement of maximum cell density and FSH titer by 11% and 17%, respectively, compared to the culture without GB. In pseudo-perfusion culture at 28$^{\circ}C$ with the exchange of fresh medium containing 15 mM GB, a final FSH of $2,058{\mu}g$ which is approximately 1.4-fold higher as compared to the culture without GB was obtained. This enhanced FSH production with 15 mM GB was not just because of enhanced specific FSH productivity (qFSH), but mainly because of the extended culture longevity. Taken together, this result demonstrates that the application of GB at low culture temperature is feasible to enhance the production of recombinant proteins in rCHO cells.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.198-206
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• 1981

A field research was conducted to evaluate the effects of inoculation of Rhizobium meliloti and lime application on the early growth of alfalfa, var. Luna, in an acid soil. Alfalfa seeds were inoculated by lime-peat pelleting method with $A_3$ strain isolated from alfalfa roots. Both inoculated and noninoculated seeds were sown in acid soil (pH 5.5) with three levels of lime application (1, 3, 6 ton/ha) on mid-April. Inoculated seeds produced many effective nodules in early stage and increased nitrogen and chlorophyll contents of leaf, consequently stimulating alfalfa growth. Pseudo nodules were found in noninoculated, while they were seldom formed in inoculated. Lime application increased soil pH, plant height, root length, and shoot and root weight. Liming effect on nodulation was significant at first cut, but no longer after then. Both inoculation and liming increased the forage yield of alfalfa. Inoculation and liming of 6 ton/ha together produced the highest yield. As compared to control plot of nitrogen application, the effect of seed inoculation only could be equal to about 120 kg/ha nitrogen application. The total nitrogen contents of forage were little affected by number or weight of nodules and amounts of lime application.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.497-506
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• 2010

This study intended to investigate the environmental factors including soil and vegetation in order to better understand the environmental and ecological characteristics of ten different habitats of $Hanabusaya$ $asiatica$. These habitats, according to investigations, are mostly located on the slopes of mountains facing north at an altitude of 580 m to 1,396 m above sea level with angles of inclination ranging from 5 degrees to 80 degrees. A total of 146 vascular plant taxa are identified in 32 quadrates of the ten habitats. The importance value of $H.$ $asiatica$ is 8.87%, and 5 highly ranked species such as $Carex$ $siderosticta$ (8.67%), $Ainsliaea$ $acerifolia$ var. $subapoda$ (7.10%), $Calamagrostis$ $arundinacea$ (6.79%), $Athyrium$ $yokoscense$ (5.33%), $Astilbe$ $rubra$ (3.11%) are considered to be an affinity with $H.$ $asiatica$ in their habitats. Dominant species of woody plants in ten habitats are represented as $Quercus$ $mongolica$ in tree layer (T1), $Acer$ $pseudo$-$sieboldianum$ in subtree layer (T2), $Rhododendron$ $schlippenbachii$ and $Tripterygium$ $regelii$ in shrub layer (S). The degree of their average species diversity is 1.30, and that of dominance and evenness are 0.08 and 0.88, respectively. The type of soil is sandy loam, loam and loamy sand, and the average field capacity of soil is 23.95%. Their average organic matter is 12.28%, soil pH 5.79, and available phosphorus is 25.48%. Correlation coefficients analysis based on environmental factors, vegetation and soil analysis shows that the coverage of tree layers is correlated with richness, diversity, dominance, evenness and coverage of $H.$ $asiatica$.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.135-141
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• 2011

This research was conducted to provide basic data of surplus heat for designing solar heat-storage systems. The surplus heat is defined as the heat exhausted by forced ventilations from the greenhouses to control the greenhouse temperature within setting limits. Various simulations were performed to compare the differences of thermal behaviors among greenhouse types as well as among several domestic areas by using pseudo-TMY (Typical Meteorological Year) data manipulated based both on the weather data supplied from Korean Meteorological Administration and the TMY data supplied from The Korean Solar Energy Society. Additional analyses were carried out to examine the required heating energy together with some others such as the energy balances in greenhouses to be considered. The results of those researches are summarized as follows. Regional surplus solar heats for the nine regions with 4-type were analyzed. The results showed that the ratio of surplus solar energy compared to heating energy was the highest in Jeju (about 212.0~228.0%) for each greenhouse type. And followed by Busan, Kwangju, Jinju, Daegu, Daejeon, Jeonju, Suwon and Daekwanryung. And irrespective of greenhouse types, surplus solar energy alone could cover up nearly all of the required supplemental heating energy except for a few areas.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.442-448
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• 2021

In this work, the (K_1-xAg_x)(Ta_0.8Nb_0.2)O₃ (x=0.1-0.4) ceramics were fabricated using mixed-oxide method, and their structural and electrical properties were measured. All specimens represented a pseudo cubic structure with the lattice constant of 0.3989 nm. When 0.4 mol of Ag was added, second phases induced from metallic Ag and K₂(Ta,Nb)₆O₁₆ phase were observed. Dielectric constant and dielectric loss of K(Ta_0.8Nb_0.2)O₃ specimen doped with 0.3 mol of Ag were 2,737 and 0.446, respectively. The curie temperature was about -5℃, which does not change with Ag addition. The remanent polarization began to decrease sharply around 12~15℃, and the temperature at which the remanent polarization began to decrease as the applied voltage increased shifted to the high temperature side. The electrocaloric effect (ΔT) and electrocaloric efficiency (ΔT/ΔE) of the (K_0.7Ag_0.3)(Ta_0.8Nb_0.2)O₃ ceramics were 0.01024℃ and 0.01825 KmV^-1, respectively.

• Journal of Life Science
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• v.31 no.5
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• pp.502-510
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• 2021

The objective of this study was to develop a novel ticagrelor-loaded self-nanoemulsifying drug delivery system with an enhanced solubility and dissolution rate. Numerous oils and surfactants were screened, then medium chain triglyceride (MCT) oil and the surfactants polyoxyethylene sorbitan monooleate (Tween 80) and Labrafil M1944CS were selected for the preparation of the ticagrelor-loaded self-nanoemulsifying drug delivery system. A pseudo-ternary phase diagram was constructed to detect the nanoemulsion region. Of the various formulations tested, the liquid SNEDDS, composed of MCT (oil), Tween 80 (surfactant), and Labrafil M1944CS (cosurfactant) at a weight ratio of 20/70/10 produced the smallest emulsion droplet size (around 20.56±0.70 nm). Then, particle size, polydispersity, and zeta potential were measured using drugs containing liquid SNEDDS. The selected ticagrelor-loaded liquid SNEDDS was spray-dried to convert it into a ticagrelor-loaded solid SNEDDS with a suitable inert carrier, such as silicon dioxide, calcium silicate, or magnesium aluminometasilicate. The solid SNEDDS was characterized by scanning electron microscopy, transmission electron microscopy, and in vitro dissolution studies. SEM, PXRD, and DSC results suggested that amorphous ticagrelor was present in the solid SNEDDS. Also, the solid SNEDDS significantly increased the dissolution rate of ticagrelor. In particular, the emulsion particle size and the polydispersity index of the solid SNEDDS using silicon dioxide (SS1) as a carrier was the smallest among the evaluated solid SNEDDS, and the flowability and compressibility result of the SS1 was the most suitable for the manufacturing of solid dosage forms. Therefore, solid SNEDDS using silicon dioxide (SS1) could be a potential nano-sized drug delivery system for the poorly water-soluble drug ticagrelor.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.54-71
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• 1991

To classify and analyze the forest communities and their structures, the vegetation in Mt. Joghe was investigated from July, 1980 to August, 1989. The results obtained are as follow ; 1. A total of 750 kinds of vascular plant(49 orders, 122 families, 434 genera, 627 species, 1 subspecies, 111 varieties and 11 forma)were observed in Mt. Ioghe. The newly observed plant species were Dioscorea quingueloba, Spiranthes sinensis, Cephalanthera falcata, Angelica gigas, Clematis patents, Paeonia obovata, Hibiscus mulabilis, Ainsliaea acerifolia, Dictamnus dasycarpus, Cynachum ascyrifolia, Vaccinium koreanum, Erythrortium japonicum, Indigofera kirilowii (17species), Broussonetia kazinoki var, humillis, Euonymus, fortunei var. radicans, Juniperus communis var, nippnnica, Callicarpa japonica var. radicans, Joniperus communis var. rzipponica, Callicarpa japonica var. taquetii (4 varieties) and L indera obtusiloba for. billosum (1 forma). 2. The life spectrum of flora in Mt. Joghe was classified into $CH-D_1-R_5-e$ type. Distribution area was identical to Southern type by Nakai, Lee, and Yim. A few subtropical species were also observed. 3. Simpson's species diversity index(Ds) was 0.9 and Shannon-Weiner's diversity index (H') was 1.004. These indice suggest that the vegetation in Mt. Joghe is of complicated forest communities. 4. Pte-Q was 1.81 which was higher than the nationwide mean of 1.68. Urbanization Index (UI) was 28.75 for naturalized plant species, and 17.49 for exotic woody plant species, which were similar to those of Mt. Baekun and Mt. Naejang. 5. The forest vegetation of Mt. Joghe was grouped in 3 vegetation types : 7 natural plant Communities dominated by Quercus serrat, Quercus acutissima, Quercus variabilis, Carpinus laxiflora, Pinus derasiflora and Platycarya strobilacea, 8 substitutional plant communities Styrax japonica, Stewartia koreana, Lindera erytlrrocarpa, Zelkova serrata, Rhtrs chinensis, Controversa, and Frzrxirtus manrlshurica, and 7 plantation Communities composed of Pinus koraiensis, Pinus rigida, Magnolia nbnvata, Chamecyparis obkrsa, Larie ieptolepis, Castanea crenata and Cryptomeria japonica. 6. Actual vegetation maps and profile diagrams were made by phytosocialogical classification. 7. As the important and unique species in Mt. Joghe, Lindera sericea, Penicaria tilitorme, Hex macropoda, Hex macropoda for. pseudo-macropoda, Steroartia koreana, Adenopkora palustris and Corylop.,is coreana, which were also seported by Lee(1977), Kim and Yark(1989), were identified and Vaccinium coreanum, Cremastra appendiculinium, Juniperus comminis van. nipponica, Cephalanthera falcata, Broussortetia kazinoki var. humilis, paeonia obovata, Deutzia prunifolia, Dictamnus dasyarpus, Angelica gigics and Bupleurum falcatum were odditionally observed.