• Journal of Life Science
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• v.12 no.6
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• pp.812-820
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• 2002

In order to understand stress response of Leuconostoc mesenteroides against lactic acid, a new Leuconostoc sp. which has acid tolerance was isolated from various Kimchi samples. And it identified as Leuconostoc mesenteroides LM3 by comparing its fatty acid composition with reference strain. Its growth pattern was investigated by adding a given concentration of lactic acid at the lag phase to the stationary phase. In the DeMan, Rogosa, Sharpe (MRS) media containing over 0.4% (final v/v) lactic acid, this strain slowed slowly After exposure of the stationary phase cells to 4% of lactic acid for 60 min, this strain could survive, whereas a reference strain, Leuconostoc mesenteroides KCTC3505, showed no survival. And changes of trehalose concentration, the activity of trehalase and ATPase in the growth of Leuconostoc mesenteroides LM3 after addition of 0.6% (final v/v) lactic acid were investigated : After exposure to lartic acid, trehalose concentration in this strain was increased in comparison with no treatment, but its trehalase activity was not changed. And its ATPase activity was constant, and intracellular pH was almost constant. This result meant Leuconostoc mesenteroides LM3 should have a tolerance against lactic acid. It remains to further study the mechanism of this acid tolerance.

• The Journal of the Korea Contents Association
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• v.15 no.6
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• pp.62-72
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• 2015

The purpose of this study is to discuss new entrants' role in a business ecosystem and to analyze growth strategies of a new entrant in the movie industry. When participants of a business ecosystem complement one another with their own unique capabilities, they can coevolve and develop the business ecosystem. Especially, new entrants armed with competitive advantages are the key success factor for improving robustness of business ecosystem. Korean movie industry is dominated by a few large enterprises and thereby threatening fair trade. In an effort to encourage new entrants in the industry, this study analyzed success factors of a film distributor, Next Entertainment World(NEW). The success factors include unique criteria in selecting scenarios, quality management, rapid decision making process, and competent management team. Implications for the results and the future study are discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.331-338
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• 2000

The algicidal effects of marine bacteria were investigated and a strain, which had the strongest algicidal activity against the harmful dinoflagellate, Cochiodinim polykrikoides was selected. The bacterium was isolated in seawater during the period of blooming of C. polykrikoides in Masan Bay. This algicidal bacterium was identified as Micrococcus sp. LG-5 by means of morphological and biochemical tests. The optimal culture conditions of Micrococcus sp, LG-5 were $25^{\circ}C,\;pH 7.0\;and\;3.0{\%}$ NaCl concentration. The algicidal activity of Micrococcus sp. LG-5 was significantly increased to maximum value in the late of logarithmic phase of cell cuture. In addition, the culture filtrate ($pore size,\;0.1{\mu}m$) of Microcoocus sp. LG-5 showed strong algicidal effects. The cell numbers of C. polykikoides were decreased from $1.2{\times}10^4 cells/ml\;to\;less\;than\;2{\times}10^3\;cells/ml$ within 3, 6, 30 hours at the concentrations of culture filtrate $10{\%},\;5{\%}\;and\;1{\%}$, respectively. These results indicated that the algicidal effect was mediated by certain substances released from Microooccus sp. LG-5.

• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.46-51
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• 1999

Age, hatching date and growth in length of juvenile Limanda yokohamae were determined by analysis of microstructure in otoliths. Monthly samples were collected by a beach seine in the shallow water off Gaduk-do from January to December, 1998. The juveniles were collected between February and April. Mean total length was $22.6{\pm}1.77\;mm$ ($\pm$SD) in February, $23.6{\pm}3.86\;mm$ in March, and $38.2{\pm}8.38\;mm$ in April. The core of otoliths ranged from 18 to $21\;{\mu}m$ in diameter and the growth increments were deposited concentrically from the hatching mark. The secondary growth layer began to appear at the 48 to 56-th increment. It indicates that L. yokohamae larvae may be completed the metamorphosis at this time of ca. 52 d after hatching, and moved into the shallow water for demersal stage. The hatching date calculated from the number of daily increments was between late November and early January, showing a peak in December. The total length (L, mm) was related to otolith radius (R, ${\mu}m$); L=0.055 R+5.81 ($r^2=0.88$). The growth in total length was represented by the Gompertz growth curve; $L_t=3.39e^{4.51(1-e^{-0.0067t})}$ ($r^2=0.81$). Daily growth rate was 0.35 mm/d at the age of 70 d and increased up to 0.55 mm/d at the age of 120 d.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.85-93
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• 1995

In order to examine the effect of testosterone of the cell growth, using a primary rabbit kidney proximal tubule cell culture system, we observed the effect of 3 growth factors and testosterone supplementation on the growth of primary rabbit kidney proximal tubule cells in the serum-free medium. 1 nM of testosterone showed a potentiation of the effect on the growth of the proximal tubule cell in serum-free medium, but higher concentration (>10 nM) of testosterone indeed inhibited the growth. In the absence of hydrocortisone as a growth supplement in serum-free medium, testosterone caused to potentiate the growth of the cell. In the presence of hydrocortisone, testosterone also potentiated the grwoth of the proximal tubule cells. According to the Northern analysis, testosterone increased significantly the level of ${\beta}-actin$ mRNA in proximal tubular cells of rabbit kidney. Consequently we may suggest that growth stimulatory effect of testosterone on the primary rabbit kidney proximal tubule cell in serum-free and hormonally defined media ascribed to increase the synthesis of ${\beta}-actin$, which is an important protein consisting of cellular microfilament.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.6-18
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• 2001

Larvae of the gunnel Pholis fangi were collected in coastal waters off Daecheon with a bag net from March to June, 1988, and with a ring larva net in February 1989. Maturity and spawning period were analyzed by examination of the gonads of adult fish collected with a bag net from May 1998 through November 1999. In February, the larvae were widely distributed in the outer and inner Cheonsu Bay. From March to April the larvae were present mainly the inner bay; they were absent there in May and found mainly in the outer bay. After June, few gunnel larvae were collected in the study area. This suggests a seaward movement of gunnel from the nursery grounds of the bay to offshore feeding grounds. The otolith of larvae smaller than 10 mm in total length did not show a distinct growth stop. The growth stop is believed to be formed in the early larval stage when the total length is about 10 mm. This period coincides with the time of shoreward migration, suggesting a metabolic change during this period. At a total length of 30 to 40 mm, the shape of the otolith changes from spherical to elongate. Daily growth rate in length was estimated by the Gompertz equation, which is represented as follows: TL = 6.702exp{2.925"1-exp (-0.008 t)"} ($r^2=0.94$, N = 92) Assuming daily deposition of growth increments in the otolith, the time of first growth increment formation was shown to be from December to January. Gonad observations show that Pholis fangi spawns from November to December. So, the hatching time is thought to be about one month.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.6
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• pp.282-288
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• 2017

In this paper, GaAs/AlGaAs multi-layer structure was grown by liquid phase epitaxy with graphite sliding boat, which can be used as a device structure of a photocathode image sensor. The multi-layer structure was grown on an n-type GaAs substrate in the sequence as follows: GaAs buffer layer, Zn-doped p-type AlGaAs layer as etching stop layer, Zn-doped p-type GaAs layer, and Zn-doped p-type AlGaAs layer. The Characteristics of GaAs/AlGaAs structures were analyzed by using scanning electron microscope (SEM), secondary ion mass spectrometer (SIMS) and hall measurement. The SEM images shows that the p-AlGaAs/p-GaAs/p-AlGaAs multi-layer structure was grown with a mirror-like surface on a whole ($1.25mm{\times}25mm$) substrate. The Al composition in the AlGaAs layer was approximately 80 %. Also, it was confirmed that the free carrier concentration in the p-GaAs layer can be adjusted to the range of $8{\times}10^{18}/cm^2$ by hall measurement. In the result, it is expected that the p-AlGaAs/p-GaAs/p-AlGaAs multi-layer structure grown by the LPE can be used as a device structure of a photoelectric cathode image sensor.

• KSBB Journal
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• v.19 no.1
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• pp.17-26
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• 2004

In this study the extracellular production of 5-aminolevulinic aicd (ALA) by recombinant E. coli BL2l (DE3) pLysS harboring the plasmid pFLS45 are investigated. Optimum concentrations of succinic acid and glycine for cell growth and ALA production were found to be 30 mM and 15 mM, respectively. Levulinic acid (LA) as an inhibitor of ALAD was added to the culture medium in the end of exponential cell growth phase and its optimum concentration was 30 mM. Growth of recombinant E. coli BL2l (DE3) pLysS (pFLS45) was largely dependent upon the pH value of culture medium. When the pH of culture medium was in the range of 6.0 and 6.5, high cell mass and ALA production were obtained. IPTG induction for the expression of the fusion gene did not enhance the production of ALA. Recombinant cell grew at 30't faster than at 37$^{\circ}C$, but ALA productivity was lower than at 37$^{\circ}C$. Repeated addition of glycine, succinic acid, and LA increased the production of ALA and the inhibition of intracellular ALA dehydratase activity, with up to 1.3 g/L ALA having been produced in the cultivation.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.73-83
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• 1993

In order to examine the effect of ${\beta}-estradiol$ on the cell growth, using a primary rabbit kidney poximal tubule cell culture system. We investigated the effect of ${\beta}-estradiol$ on alpha 1 (IV) collagen and ${\beta}-actin$ mRNA levels from primary rabbit kidney cell cultures, and also the effects of 3 growth factors and ${\beta}-estradiol$ supplementation on the growth of primary rabbit kidney proximal tubule cells in the serum-free medium. 1 nM of ${\beta}-estradiol$ showed a sizable potentiation effect on the growth of the proximal tubule cell in serum-free medium, but higher concentration (> 10 nM) of estradiol indeed inhibited the growth. In the absence of hydrocortisone as a growth supplement in serum-free medium, ${\beta}-estradiol$ caused to potentiate the growth of the cell. In the presence of hydrocortisone, ${\beta}-estradiol$ also potentiated the growth of the proximal tubule cells. According to the Northern analysis, ${\beta}-estradiol$ increased the level of ${\beta}-actin$ mRNA, although mRNA level of the alpha I(IV) collagen was not changed significantly.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.3
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• pp.13-24
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• 2006

Purpose : 이 연구는 MCF-7 인간 유방암 세포주에 대한 활락효령단(活絡效靈丹) 추출물의 증식억제효과, 세포독성효과, 세포사 유발효과를 확인하기 위하여 이루어졌다. Methods : MCF-7 인간 유방암 세포주는 Dulbecco's modified Eagle's medium/F12 (DMEM/F12)에 10% fetal bovine serum (FBS)와 항생제를 가하여 만든 배지를 이용하여 배양하였고 MCF-7 세포를 96-well plate에 접종한 후 다양한 농도 (0 ${\sim}$ 2000 g/ml)의 활락효령단(活絡效靈丹)이 든 배지로 처리한 후 72시간 동안 배양하였고 또한 1000g/ml의 활락효령단(活絡效靈丹)이 든 배지로 처리한 후 48, 96, 192 시간동안 배양하여 각각 MTS assay kit로 세포생존율을 측정하였다. 세포독성은 Sulforhodamine B assay 방법을 이용해 측정하였고 세포사 과정에서 MCF-7 세포에서의 caspase 활성화를 측정하기 위해 Western blotting을 수행하여 poly ADP ribose polymerase (PARP)의 절단을 확인하였다. Results : 실험결과 활락효령단(活絡效靈丹) 추출물에 의한 세포성장 및 독성효과는 시간 및 농도에 비례하는 것으로 나타났고 세포고사과정에서 작용하는 caspase의 전기질인 PARP 절단량이 활락효령단(活絡效靈丹) 처리 농도에 비례에 증가하였다. Conclusions : 활락효령단(活絡效靈丹)은 다양한 기전에 의해서 유방암 세포에 대한 억제효과를 가질 수 있는 것으로 인식할 수 있다.