• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.164-171
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• 2002

Morphological characteristics and growth pattern of 10 Polygonatum collections indigenous to Korea were examined to select the promising medicinal, edible resources and horticultural crops. Plant heights of I0 collections ranged from 15 to 102cm. Stem type was ascending or erect, and node numbers per a stem was 6.2 to 23.2. Phyllotaxis type was alternate or verticillate, and leaf shape was elliptical or linear. Leave numbers per a stem was 5.2 to 63.4, and bract types were classified into bracteate and nonbracteate. Flowers bloomed from May 7 to May 30, and flowering period was 5 to 13 days. Inflorescence types were classified into racemose, corymbose, and umbellate. Flower numbers per a stem was 1.5 to 125.2, and flower length was 13.1 to 30.2㎜. Perianth shapes were classified into tubular, constrict and urceolate. Surface colors of rhizome were pale yellow, pale brown, brown, and dark brown. As a result of this experiment, P. sibiricum, P. odoratum var. pluriflorum and P. odoratum var. thunbergii were thought to be useful as the medicinal and edible resources plants. On the other hand, P. odoratum var. pluriflorum 'Variegata', and P. odoratum var. maximowiczii, P. lasianthum. P. involucratum, P. desoulavyi, P. humile, and P. inflatum were thought to be useful as horticultural plants.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.203-210
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• 2002

In order to elucidate the growth mechanism of sulfide chimney formed as a result of seafloor hydrothermal mineralization, we carried out the mineralogical and fluid inclusion studies on the inactive, sulfide- and silica-rich chimney which has been recovered from a hydrothermal field in the Cleft segment of the Juan de Fuca Ridge. According to previous studies, many active and inactive vents are present in the Cleft segment. The sulfide- and silica-rich chimney is composed of amorphous silica, pyrite, sphalerite and wurtzite with minor amounts of chalcopyrite and marcasite. The interior part of the chimney is highly porous and represents a flow channel. Open spaces within chimneys are typically coated with colloform layers of amorphous silica. The FeS content of Zn-sulfides varies widely from 13.9 to 34.3 mole% with Fe-rich core and Fe-poor rims. This variation possibly reflects the change of physicochemical characteristics of hydrothermal fluids. Chemical and mineralogical compositions of the each growth zone are also varied, possibly due to a thermal gradient. Based on the microthermometric measurements of liquid-rich, two-phase inclusions in amorphous silica that was precipitated in the late stage of mineralization, minimum trapping temperatures are estimated to be about 1140 to 145$^{\circ}$C with the salinities between 3.2 and 4.8 wt.% NaCI equiv. Although the actual fluid temperatures of the vent are not available, this study suggests that the lowtemperature conditions were predominant during the mineralization in the hydrothermal field at Cleft segment. Comparing with the previously reported chimney types, the morphology, colloform texture, bulk chemistry, and a characteristic mineral assemblage (pyrite + marcasite + wurtzite + amorphous silica) of this chimney indicate that the chimney have been formed from a relatively low-temperature (<250$^{\circ}$C) hydrothermal fluid that was changed by sluggish fluid flow and conductive cooling.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.743-760
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• 2014

This study aimed to isolate and identify freshwater algae from the organic agricultural ecosystems and investigate its biological characteristics to study the possibility of utilizing a biomass freshwater algae in organic farming. In the survey area, average water temperature was $12.4{\sim}28.2^{\circ}C$ and the pH ranges were from 6.1 to 8.5. The solid culture method is more suitable than liquid culture method for isolation of freshwater algae with lower contamination level and higher isolation frequency. A total of 115 strains were isolated from six freshwater algae habitats in nine regions in Korea. BGMM (BG11 Modified Medium) amended with NaNO3 and $KNO_3$ as a nitrogen, and $Na_2CO_3$ as carbon source was designed to isolate and culture freshwater algae. Absorbance of freshwater algae culture has increased dramatically to four days and decreased after eight days after inoculation. CHK008 of the seven isolates showed the highest absorbance in seven days after culturing in BGMM. The optimal pH of BGMM for culturing freshwater algae was pH 6-7. As light intensity increased, growth of freshwater algae increased. Among the five kinds of carbon sources, glucose and galactose promoted good growth of freshwater algae in BGMM. The colony color of purified 16 green algae isolates showed a separation of green, dark and light green, and of them, eleven algae strains showed a strong fluorescent light under fluorescence microscopy. Cell size of the green algae showed a wide range of variation depending on the species. General morphology of the green algae strains was spherical. Chlamydomonas sp. was elliptical, and Chlorella sorokiniana was ellipsoidal and cylindrical. All strains of the green algae except for Chlamydomonas sp. did not have flagella. One isolate of Chlamydomonas sp. and five isolates of C. sorokiniana secreted mucus. Sixteen isolates of 16 green algae were identified as two family and six species, Chlorella vulgalis, C. sorokiniana, C. pyrenoidosa, C. kessleri, C. emersonii, and Chlamydomonas sp. based on their morphological characteristics.

• Journal of Korean Society of Forest Science
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• v.62 no.1
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• pp.24-42
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• 1983

To develop Ilex cornuta which grow naturally in the southwest seaside district as new ornamental tree, the author chose I. cornuta growing in the four natural communities and those cultivated in Kwangju city as a sample, and investigated its ecology, morphology and characteristics. The results obtained was summarized as follows; 1) The natural distribution of I. cornuta marks $35^{\circ}$43'N and $126^{\circ}$44'E in the southwestern part of Korea and $33^{\circ}$20'N and $126^{\circ}$15'E in Jejoo island. This area has the following necessary conditions for Ilex cornuta: the annual average temperature is above $12^{\circ}C$, the coldness index below $-12.7^{\circ}C$, annual average relative humidity 75-80%, and the number of snow-covering days is 20-25 days, situated within 20km of from coastline and within, 100m above sea level and mainly at the foot of the mountain facing the southeast. 2) The vegetation in I. cornuta community can be divided that upper layer is composed of Pinus thunbergii and P. densiflora, middle layer of Eurya japonica var. montana, Ilex cornuta and Vaccinium bracteatum, and the ground vegetation is composed of Carex lanceolata and Arundinella hirta var. ciliare. The community has high species diversity which indicates it is at the stage of development. Although I. cornuta is a species of the southern type of temperate zone where coniferous tree or broad leaved, evergreen trees grow together, it occasionally grows in the subtropical zone. 3) Parent rock is gneiss or rhyolite etc., and soil is acidic (about pH 4.5-5.0) and the content of available phosphorus is low. 4) At maturity, the height growth averaged $10.48{\pm}0.23cm$ a year and the diameter growth 0.43 cm a year, and the annual ring was not clear. Mean leaf-number was 11.34. There are a significant positive correlation between twig-elongation and leaf-number. 5) One-year-old seedling grows up to 10.66 cm (max. 18.2 cm, min. 4.0 cm) in shoot-height, with its leaf number 12.1 (max. 18, min), its basal diameter 2.24 mm (max. 4.0 mm, min. 1.0 mm) and shows rhythmical growth in high temperature period. There were significant positive correlations between stalk-height and leaf-number, between stalk-height and basal-diameter, and between number and basal diameter. 6) The flowering time ranged from the end of April to the beginning of May, and the flower has tetra-merouscorella and corymb of yellowish green. It has a bisexual flower and dioecism with a sexual ratio 1:1. 7) The fruit, after fertilization, grows 0.87 cm long (0.61-1.31 cm) and 0.8 cm wide (0.62-1.05 cm) by the beginning of May. Fruits begin to turn red and continue to ripen until the end of October or the beginning of November and remain unfading until the end of following May. With the partial change in color of dark-brown at the beginning of the June fruits begin to fall, bur some remain even after three years. 8) The seed acquision ratio is 24.7% by weight, and the number of grains per fruit averages 3.9 and the seed weight per liter is 114.2 gram, while the average weight of 1,000 seeds is 24.56 grams. 9) Seeds after complete removal of sarcocarp, were buried under ground in a fixed temperature and humidity and they began to develop root in October, a year later and germinated in the next April. Under sunlight or drought, however, the dormant state may be continued.

• Composites Research
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• v.31 no.2
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• pp.43-50
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• 2018

The effects of deposition temperature on chemical vapor deposited silicon carbide (CVD-SiC) were studied to obtain high deposition rates and excellent bending strength characteristics. Silicon carbide prepared at $1250{\sim}1400^{\circ}C$ using methyltrichlorosilane(MTS : $CH_3SiCl_3$) by hot-wall CVD showed deposition rates of $95.7{\sim}117.2{\mu}m/hr$. The rate-limiting reaction showed the surface reaction at less than $1300^{\circ}C$, and the mass transfer dominant region at higher temperature. The activation energies calculated by Arrhenius plot were 11.26 kcal/mole and 4.47 kcal/mole, respectively. The surface morphology by the deposition temperature changed from $1250^{\circ}C$ pebble to $1300^{\circ}C$ facet structure and multi-facet structure at above $1350^{\circ}C$. The cross sectional microstructures were columnar at below $1300^{\circ}C$ and isometric at above $1350^{\circ}C$. The crystal phases were all identified as ${\beta}$-SiC, but (220) peak was observed from $1300^{\circ}C$ or higher at $1250^{\circ}C$ (111) and completely changed to (220) at $1400^{\circ}C$. The bending strength showed the maximum value at $1350^{\circ}C$ as densification increased at high temperatures and the microstructure changed from columnar to isometric. On the other hand, at $1400^{\circ}C$, the increasing of grain size and the direction of crystal growth were completely changed from (111) to (220), which is the closest packing face, so the bending strength value seems to have decreased.

• Development and Reproduction
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• v.12 no.1
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• pp.31-39
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• 2008

Neural tissue has limited intrinsic capacity of repair after injury, and the identification of alternate sources of neural stem cells has broad clinical potential. We isolated mesechymal-like stem cells from human adipose tissues (AT-MSCs), and studied on transdifferentiation-promoting conditions in neural cells. Dopaminergic and cholinergic neuron induction of AT-MSCs was also studied. Neural differentiation was induced by adding bFGF, EGF, dimethyl sulphoxide (DMSO) and butylated hydroxyanisole(BHA) in N2 Medium and N2 supplement. The immunoreactive cells for $\beta$-tubulin III, a neuron-specific marker, GFAP, an astrocyte marker, or Gal-C, an oligodendrocyte marker, were found. AT-MSCs treated with bFGF, SHH and FGF8 were differentiatied into dopaminergic neurons that were immunopositive for TH antibody. Differentiation of MSCs to cholinergic neurons was induced by combined treatment with basic fibroblast growth factor (bFGF), retinoic acid (RA) and sonic hedgehog (Shh). AT-MSCs treated with DMSO and BHA rapidly assumed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including neuro D1, $\beta$-tubulin III, GFAP and nestinwas markedly elevated during this acute differentiation. While the stem cell markers such as SCF, C-kit, and Stat-3 were not expressed after preinduction medium culture, we confirmed the differentiation of dopaminergic and cholinergic neurons by TH/$\beta$-tubulin III or ChAT/ $\beta$-tubulin III positive cells. Conclusively, AT-MSCs can be differentiated into dopaminergic and cholinergic neuronsand these findings suggest that AT-MSCs are alternative cell source of treatment for neurodegenerative diseases.

• The Journal of the Petrological Society of Korea
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• v.9 no.4
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• pp.211-237
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• 2000

Major element zoning has been analyzed in garnet porphroblasts obtained from the Grt-St and Ky-Grt-St grade assemblages in Zones I on the northern flank of the Pelham Dome, north central Massachusetts. These porphyroblasts grew during multiple phases of deformation and meta-morphism revealed by the inclusion trail geometry plus the chemical zoning patterns within garnet porphyroblasts. Unusual zoning patterns, including zoning reversals and gradient changes in XMn, zlgzag patterns in Fe/(Fe +Mg) and staircase-shaped patterns in XCa, are coincident with textural truncations and other changes in microstructure within the garnet porphrublasts. Chemical variations in plagioclase, biotite, muscovite and staurolite combined with inclusion trail geometry and petrography reveal that the garnet zoning patterns are modified by combinations of the following. (1) Uni-and divariant reactions involving garnet consumption(Grt+ Chl+Ms=St+Bt+Qtz + $H_2$O) and production(St+Ms + Qtz= Bt+ Grt +A1$_2$$SiO_{5}$ + $H_2$O). (2) Deformation induced episudic ionit dissolution, preferential diffusion and re-distribution during foliation development. (3) P-T changes during growth of the porphyroblasts. The P-T paths combined with petrographic and inclusion trail morphology observations consist of two pattens; (1) heating/compression during NW-SE shortening; and (2) decompression with cooling during NNW-SSE shortening. Based on temperature-time(T-t) geochronological data and late-Paleozoic tectonic model, Alleghanian metamorphism, which is the result of heterogeneous shearing concentrated along the boundary between the Abalone Terrane(Pelham dome) and cover rocks(Bronson Hill Terrane), has produced Ky-St-Ms mineral assemblage during Pennsylvanian(290-300 Ma) in Shutesbury area. However, temperature of alleghanian metamorphism was not high enough to form garnet and staurolite in the Northfiled syncline area. Alleghanian metamorphism has affected only the matrix due to heterogeneous shearing in the study area.

• KSBB Journal
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• v.22 no.5
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• pp.297-304
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• 2007

For large and rapid screening of high-yielding mutants of lovastatin produced by filamentous fungal cells of Aspergillus terreus, one of the most important stage is to test as large amounts of mutated strains as possible. For this purpose, we intended to develop a miniaturized cultivation method using $7m{\ell}$ culture tube instead of traditional $250m{\ell}$ flask (working volume $50m{\ell}$). For obtaining large amounts of conidiospores to be used as inoculums for miniaturized cultures, 4 components i.e., glucose, sucrose, yeast extract and $KH_2PO_4$ were intensively investigated, which had been observed to show positive effect on enhancement of spore production through Plackett-Burman design experimet. When optimum concentrations of these components that were determined through application of response surface method (RSM) based on central composite design (CCD) were used, maximum spore numbers amounting to $1.9\times10^{10}$ spores/plate were obtained, resulting in approximately 190 fold increase as compared to the commonly used PDA sporulation medium. Using the miniaturized cultures, intensive strain development programs were carried out for screening of lovastatin high-yielding as well as highly reproducible mutants. It was observed that, for maximum production of lovastatin, the producers should be activated through 'PaB' adaptation process during the early solid culture stage. In addition, they should be proliferated in condensed filamentous forms in miniaturized growth cultures, so that optimum amounts of highly active cells could be transferred to the production culture-tube as reproducible inoculums. Under these highly controlled fermentation conditions, compact-pelleted morphology of optimum size (less than 1 mm in diameter) was successfully induced in the miniaturized production cultures, which proved essential for maximal utilization of the producers' physiology leading to significantly enhanced production of lovastatin. As a result of continuous screening in the miniaturized cultures, lovastatin production levels of the 81% of the daughter cells derived from the high-yielding producers turned out to be in the range of 80%$\sim$120% of the lovastatin production level of the parallel flask cultures. These results demonstrate that the miniaturized cultivation method developed in this study is efficient high throughput system for large and rapid screening of highly stable and productive strains.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.1
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• pp.1-12
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• 2002

Objective: In order to acquire the technique for the establishment of human embryonic stem cells (ESe) derived from the human frozen-thawed embryos produced in IVF-ET program, this study was performed to establish mouse ESC derived from the in vitro fertilized embryos. Materials and Methods: After Fl hybrid (C57BL female $\times$ CBA mael) female mice were superovulated with PMSG and hCG treatment, their oocytes were retrieved and inseminated, and the fertilized embryos were cultured for 96-120 hours until the expected stages of blastocysts were obtained. To isolate the inner cell mass (ICM), either the blastocysts were treated with immunosurgery, or the whole embryos were cultured for 4 days. Isolated ICMs were then cultured onto STO feeder cell layer, and the resultant ICM colonies were subcultured with trypsin-EDTA treatment. During the subculture process, ESC-like cell colonies were observed with phase contrast microscopy. To identify ESC in the subcultured ESC-like cell colonies, alkaline phosphatase activity and Oct-4 (octamer-binding transcription factor-4) expression were examined by immunohistochemistry and RT-PCR, respectively. To examine the spontaneous differentiation, ESC-like cell colonies were cultured without STO feeder cell layer and leukemia inhibitory factor (LIF). Results: Seven ESC-like cell lines were established from ICMs isolated from the in vitro fertilized embryos. According to the developmental stage, the growth of ICMs isolated from the expanded blastocysts was significantly better than that of ICMs isolated from the hatched blastocysts (80.3% vs. 58.7%, p<0.05). ESC-like cell colonies were only obtained from ICMs of expanded blastocysts. However, the ICMs isolated from the embryos treated with immunosurgery were poorly grown and frequently differentiated during the culture process. The established ESC-like cell colonies were positively stained with alkaline phosphatase and expressed Oct-4, and their morphology resembled that observed in the previously reported mouse ESC. In addition, following the extended in vitro culture process, they maintained their expression of cell surface markers characteristic of the pluripotent stem cells such as alkaline phosphatase and Oct-4. When cultured without STO feeder cell layer and LIF, they were spontaneously differentiated into the various types of cells. Conclusion: The findings of this study suggest that the establishment of mouse ESC can be successfully derived from the in vitro fertilized embryos. The established ESC-like cells expressed the cell surface markers characteristic of the pluripotent stem cells and spontaneously differentiated into the various types of cells.

• Journal of fish pathology
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• v.2 no.1
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• pp.1-18
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• 1989

In Korea, studies on a Nematode, Anguillicola crassa parasitic in the air bladder of eel are not yet reported. This reason led the author to study the parasitic species, state and life history of the A. crassa parasitized in the air bladder of eel in order to take effective control measures against its damage. The size of fully developed eggs was 80 to $92(86.7){\times}62$ to $71(67.4)\;{\mu}m$, larva was 210 to $240(225){\times}18$ to $23(20.6)\;{\mu}m$. The intermediate host of A. crassa was Thermocyclops hyalinus, it was capable for parasitizing the eel after 4 days of invasion and then the size of larva was 360 to $420(390){\times}28$ to $35(31)\;{\mu}m$. Fifty days after eel had ingested the Thermocyclops hyalinus infected with larva of A. crassa, the larvae matured into adult worms in the air bladder of eel. The size of detected adult worms was 7.3 to $31.0(16.5){\times}0.5$ to 2.2(1.2) mm, 4.9 to $13.3(8.3){\times}0.3$ to 0.9(0.4) mm. Investigating the morphology of the worms, they were identified as A. crassa. Monthly the parasitic rate of the worms in the eel was high in June, September and December, but low in January to March. After the investigation on the significance between non-parasitic fish and parasitic fish, it was not significant, therefore it can be considered that there is no effect of infection in the growth of eel. Any abnormality of eels air bladder tissue was not seen by the infection of A. crassa. At 25.0 to $26.7^{\circ}C$ of water temperature the death time of Thermocyclops hyalinus by masoten treatment was 14 hours in 0.5 ppm, 20 hours in 0.4 ppm, 22 hours in 0.3 ppm, 30 hours in 0.2 ppm and 42 hours in 0.1 ppm.