• Environmental Mutagens and Carcinogens
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• v.8 no.1
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• pp.13-21
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• 1988

Mutagenic actions of aflatoxin B$_1$ (AFB$_1$) in the presence of various concentrations of L-ascorbIc acid (AA) in Salmonella typhimurium strains TA 100 and TA98 were studied. Spontaneous revertants per plate of the tester strains TA100 and TA98 were 121-125 and 25-30 with or without S9 mix, respectively. The negative controls used in the study did not show any mutagenesis in the tester strains. AFB$_1$ revealed strong mutagenicity at the dose levels of 0.05, 0.1 and 0.25 ${\mu}$g/plate with metabolic activation system in both strains. However, it showed a toxic effect when the levels were more than 0.5 ${\mu}$g/plate. When lower concentrations of AA (5-20 ${\mu}$g/plate) were added to AFB$_1$ in the Ames assay system with S9 mix the mutagenic action of AFB$_1$ decreased in both strains. About 70-90% of mutagenicity of AFB$_1$ disappeared in strain TA100 when 20${\mu}$g of AA was added to 0.05 ${\mu}$g of AFB$_1$. The inhibitory effect was greatly increased by the addition of higher concentrations of AA to AFB$_1$ in TA100 strain. The mutagenicity of AFB$_1$ was completely inhibited when 100 ${\mu}$g and 500 ${\mu}$g of AA were added to 0.05 ${\mu}$g and 0.1 ${\mu}$g of AFB$_1$, respectively, However, this protective effect of AA on AFB$_1$ mediated mutagenesis was less effective in TA98 strain than that in TA100.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.431-435
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• 2009

This study was conducted to compare the effect of various LED and UVa light to enhanced coloration of paprika fruits cultivars; 'Special', 'Helsinki'. Immatured paprika fruits were irradiated with red LED, blue LED and UVa lights which were high intensity (red: $50{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, blue: $70{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, UVa: $3{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and low intensity (red: $20{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, blue: $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, UVa: $0.25{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). The coloration of 'Special' cultivar was increased the fastest in high intensity UVa light for 2 days after treatment. There were no significantly difference among treatments except the low intensity UVa light. The coloration of 'Helsinki' was increased the fastest in blue LED light, and followed by red LED light and UVa light for 2 days after treatment. The $a^*/b^*$ value of 'Special' and $b^*$ value of 'Helsinki' that indicated the paprika fruit coloration were generally higher high intensity LED and UVa lights than low intensity LED and UVa lights. We couldn't find out any significantly different coloration effect among all treatments in final days of coloration. and rather than UVa treatment fruit shrunk the surface of paprika fruits.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.329-335
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• 2005

In order to investigate the effects of Saussurea involucrata on (relationship between) aging (and Saussurea involucrata), we examined the activities of antioxidation, in vitro MMP inhibition and UVA-induced MMP-1 expression in human dermal fibroblasts. S. involucrata showed scavenging activities radicals and reactive oxygen species (ROS) with the $IC_{50}$ values of $3.89{\mu}g/mL$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and $67.29{\mu}g/mL$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. At the concentration of $1000{\mu}g/mL$, S. involucrata showed 93.27% inhibition on lipid peroxidation of linoleic acid. S. involucrata inhibited the activities of MMP-1 in a does-dependent manner and the $IC_{50}$ value calculated from semi-log plots was $97.18{\mu}g/mL$. Also, UVA induced MMP expression in human dermal fibroblasts was reduced 42.86% by treatment with S. involucrata, and MMP-1 mRNA expression was reduced in a dose-dependent manner. Therefore S. involucrata was able to significantly inhibit MMP expression in protein and mRNA level. All these results suggested that S. involucrata might act as an anti-aging agent by antioxidation and reducing UVA-induced MMP-1 production.

• Journal of Aquaculture
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• v.18 no.4
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• pp.299-304
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• 2005

Laboratory culture of the native kelp Kjelimaniella crassifolia and the introduced species Laminaria japonica in east coast of Korea were compared at each stage of their life cycles. In the zoospore stage, L. japonica grows optimally at a water temperature of $15{\~}20^{\circ}C$ achieving $95\%$ spore release in 24 hours, whereas K. crassifolia requires 48 hours to achieve $90\%$ spore release in these conditions. Good growth of gametophytes occurred at $10^{\circ}C$ and $15^{\circ}C$ in both species. L. japonica grows optimally under high light intensity ($80{\~}120{\mu}mol{\cdot}m^{-2}s^{-1}$) while K. crassifolia grows best under low light intensity ($40{\~}60{\mu}mol{\cdot}m^{-2}s^{-1}$). Growth of juvenile sporophytes of L. japonica was good in various water temperatures ($10{\~}20^{\circ}C$) and light levels ($40{\~}120{\mu}mol{\cdot}m^{-2}s^{-1}$) while K. crassifolia grew to optimal blade length only under specific conditions ($10{\~}40{\mu}mol{\cdot}m^{-2}s^{-1}$). While the optimal culture conditions for K. crassifolia were more constrained than those of L. japonica which tolerated a wide range of water temperatures and light intensities, the laboratory culture conditions for both of these species reflect the natural environment in which these species are found.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.321-326
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• 2014

The aim of this study was to investigate which hydroponic system is the optimum for growth and photosynthetic characteristics of Angelica gigas during experiment. Angelica gigas 'Manchu' were sowed and managed under a growth room chamber. The environmental conditions (temperature $22^{\circ}C/18^{\circ}C$ (day/night), relative humidity 50-70%, photosynthetic photon flux density (PPFD) $120{\pm}6{\mu}mol\;m^{-2}s^{-1}$) were maintained for 3 weeks. Forty eight seedlings with 4-5 leaves were transplanted in deep flow technique (DFT), substrate, and spray culture systems [culture bed: 800 (L) ${\times}$ 800 (W) ${\times}$ 400 mm(H)] under $150{\pm}5{\mu}mol\;m^{-2}s^{-1}$ PPFD provided with fluorescence lamps and cultivated for 11 weeks. At the end of the experiment, fresh and dry weights, leaf lenghth and width, SPAD, root fresh, and dry weights, and root volume of Anglica gigas were measured. Photosynthetic rate of Anglica gigas were measured with portable photosynthesis systems to investigate optimum PPFD, $CO_2$ concentration, and air temperature conditions. Fresh and dry weights of Anglica gigas grown in substrate were significantly greater than DFT-treated, but there were not significant with spray treatment. Leaf photosynthesis of Anglica gigas showed the tendency to sharply increase as PPFD was increased from 50 to $200{\mu}mol\;m^{-2}s^{-1}$. Though $CO_2$ saturation point was around $1000-1200{\mu}mol\;mol^{-1}$, increase in air temperature from 16 to $26^{\circ}C$ did not quite affect photosynthesis of Anglica gigas. In conclusion, Anglica gigas may be optimally cultivated with a spray culture system as air temperature, PPFD, and $CO_2$ concentration for environment are controlled at $20{\pm}3^{\circ}C$, $150{\mu}mol\;m^{-2}s^{-1}$, and around $1000{\mu}mol\;mol^{-1}$ for mass production.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.12-15
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• 2000

In this paper, we have fabricated the PHEMT's with AlGaAs/InGaAs/GaAs and measured characteristics of DC and frequencies. The PHEMT's has a 0.35$\mu\textrm{m}$ gate length, gate width of 60$\mu\textrm{m}$ and 80$\mu\textrm{m}$, and fingers of 2 and 4. From the measurements results for the 60$\mu\textrm{m}$ ${\times}$ 2 PHEMT's, we obtained 1.2V of Vk, -3.5V of Vp, 46mA of Idss, 221mS/mmof gm, and 3.6dB of S$\sub$21/ gain, 45GHz of f$\sub$T,/ 100GHz of fmax. And, in case of 80$\mu\textrm{m}$ ${\times}$ 4 PHEMT's, we obtained 1.2V of Vk, -4.5V of Vp, 125mA of Idss, 198mS/mm of gm, and 2.0dB of S$\sub$21/ gain. 44GHz of f$\sub$T/, 70GHz of fmax at 35GHz frequency. Also, MAG are decreased as a number of finger are Increased.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.424-439
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• 1998

Urinary cadmium is used as a sensitive indicator for internal Cd dose, and increased excretion of $N-acetyl-\beta-D-glucosaminidase(NAG)$, $\beta_2-microglobulin(MG)$ and total protein are useful indices for renal dysfunction by chronic exposure to Cd. The target group was 184 inhabitant(82 men and 102 women) in an abandoned mine area known as exposure to low level Cd. The control group was took 160 individuals(64 men and 96 women) in Cd not-exposed area. Urinary Cd concentration was significantly higher in the target group than the control. The geometric mean of urinary Cd for male was $2.56{\mu}g/\ell,\;2.80{\mu}g/g$ creatinine and $2.50{\mu}g/S.G.$ in the target group and $1.19{\mu}g/\ell,\;1.36{\mu}g/g$ creatinine and $1.17{\mu}g/S.G.$ in the control. For female $2.69{\mu}g/\ell,\;3.94{\mu}g/g$ creatinine and $2.63{\mu}g/S.G.$ in the target group and $1.27{\mu}g/\ell,\;1.97{\mu}g/g$ creatinine and $1.25{\mu}g/S.G.$ in the control, respectively. In addition, urinary Cd of the target group had affected by the period of residence and dietary habit for the rice and the vegetables from the target area. These findings suggest the chronic exposure to Cd of the target population. Mean excretion of urinary NAG, $\beta_2-MG$ and total protein were not significant between two groups. In the target group, urinary NAG activity and total protein were significantly correlated with urinary Cd, but $\beta_2-MG$ was not related. Urinary excretion of NAG, $\beta_2-MG$ and total protein were significantly increased in $10\leqq$ than in <2 of urinary Cd level. In $2\sim10$ group of urinary Cd level, the excretion of NAG significantly increased while not showed for $\beta_2-MG$. In present study, urinary excretion of NAG was relatively sensitive than $\beta_2-MG$ in chronic exposure population to low level Cd.

• Korean Journal of Optics and Photonics
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• v.11 no.4
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• pp.294-298
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• 2000

The output characteristics of intracavity frequency doubling of laser-diode end-pumped Nd:S-VAP laser were investigated. Nd:S-VAP is suitable for a microchip laser medium, which has a low threshold property because of a very high value of the stimulated emission cross-section and lifetime product. The threshold energy measured was 81 J.ll. The second harmonic output energy measured was $126\mu\textrm{J}$at a pump energy of $2\mu\textrm{J}$. We described for intracavity frequency doubling by using theoretical calculations. Q-switched second harmonic energy measured was $15\mu\textrm{J}$per pulse with a pulse-width of 26 ns. at a pump energy of 2 mJ and an $M^2$ of 1.47 represented a good beam quality. ality.

• The Journal of Internal Korean Medicine
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• v.35 no.4
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• pp.455-471
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• 2014

Objectives: This experiment was done for investigating antimicrobial activity of Hwangryunheadok-tang and Scutellariae Radix extract, Phellodendri Cortex extract, Coptis Rhizoma extract, Gardenia Jasminoides extract against Staphylococcus aureus. Methods: After administering S. aureus on a bacterial culture media plate, antimicrobial activity was tested by dripping $80{\mu}l$ diluted Hwangryunheadok-tang and Scutellariae Radix extract, Phellodendri Cortex extract, Coptis Rhizoma extract, and Gardenia Jasminoides extract (100%, 50%, 10%, 1%) on plates that were cultivated for a span of time from 16 to 72 hours. Also, minimal inhibitory concentration (MIC) was tested by dripping the minimum dilution density solution that has antimicrobial activity between $80{\mu}l$ and $20{\mu}l$ ($80{\mu}l$, $60{\mu}l$, $40{\mu}l$, $20{\mu}l$) in measure of density. Antimicrobial activity of Hwangryunheadok-tang and four kinds of extracts against S. aureus was continually displayed. Results: 1. S. aureus (Standard Microorganism, ATCC) (1) Antimicrobial activity was displayed for Hwangryunheadok-tang, Scutellariae Radix extract, and Phellodendri Cortex extract respectively in the undiluted solution and 50% of diluted magnification. Gardenia Jasminoides extract showed its activity only in the undiluted solution; Coptis Rhizoma extract showed its activity down to 10% of diluted magnification. The antimicrobial activity of the undiluted solution was increased when the volume of inoculation increased. But, there was no difference when time was extended for cultivation. (2) MIC of Hwangryunheadok-tang, Scutellariae Radix extract was 50%, $20{\mu}l$. Coptis Rhizoma extract was 10%, $20{\mu}l$, Phellodendri Cortex extract was 50%, $80{\mu}l$ and Gardenia Jasminoides extract was 100%, $60{\mu}l$. 2. S. aureus isolated from diarrheal patients (1) When compared to standard microorganism, MIC has decreased. As a result, their antimicrobial activity has increased. (2) Antimicrobial activity of Hwangryunheadok-tang and four extracts was continually shown in extending of the time, 16, 24 and 72 hours. Conclusions: The author comes to the conclusion that Hwangryunheadok-tang, and four kinds of extracts have antimicrobial activity against S. aureus. Especially, when comparing standard microorganisms with S. aureus isolated from diarrheal patients, some cases showed that antimicrobial activity of all the extracts were better than antibiotics. Thus, if a further study is performed, the use of Hwangryunheadok-tang, and four kinds of extracts will be valuable and beneficial in clinical treatments.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.11a
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• pp.107-115
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• 2002

본 연구는 해양 식물플랑크톤에 지속성 유기오염물질의 영향을 이해하기 위한 목적으로, 연안역에서 우점하는 식물플랑크톤 주요 5종 즉, 규조류 Skeletonema costatum, 침편모조류 Heterosigma akashiwo, 와편모류 prorecentrum dentatum, Prorocentrum minimum, Akashiwo sanguinea를 이용하여을 benzo[a]pyrene (PAHs)에 72시간동안 노출시킨 다음 각 종의 성장 및 저해, 회복능력 등을 조사하였고, benzo[a]Pyrene의 농도 0.1, 1, 5, 10 $\mu\textrm{g}$/l에 Heterosigma akashiwo(Raphidophyceae)를 노출시켜 시간에 따른 광합성률의 변화를 측정하였다. benzo[a]Pyrene에 72시간 노출시킨 후 S. costatum, P. minimum, P. dentatum, akashiwo의 세포수는 1-10 $\mu\textrm{g}$/l의 농도범위에서 극적인 감소를 보인 반면, A. sanguinea는 0.1-1 $\mu\textrm{g}$/l의 낮은 농도범위에서 지수함수적인 감소를 나타냈다. 성장저해 농도 ($IC_{50}$/)는 A. sanguinea가 0.43 $\mu\textrm{g}$/l로 가장 낮았고, H akashiwo(1.17 $\mu\textrm{g}$/l) S. costatum (3.34 $\mu\textrm{g}$/l), p dentatum (3.97 $\mu\textrm{g}$/l), p minimum (7.24 $\mu\textrm{g}$/l)의 순서로 증가하였다. BenEo[a]pyrene의 낮은 농도(1 $\mu\textrm{g}$/l)에 노출되었던 세포들은 5종 모두 시간이 경과함에 따라 회복하는 경향을 나타냈으나 고농도(10, 100 $\mu\textrm{g}$/l)에 노출시에는 P. minimum을 제외하고는 회복되지 않았다. 이러한 결과들은 조사된 5종 중에서 유각 와편모류 P. minimum이 benzo[a]pyrene에 가장 내성이 강하며, 무각 와편모류 A. sangulinea가 가장 약함을 의미한다. benzo[a]pyrene의 여러 농도수준에 노출시켰을 때 H. akashiwo의 광합성 능력은 낮은 농도들에서는 대조구와 유사하였으나, 5 $\mu\textrm{g}$/l의 높은 농도에서는 초기에 매우 낮은 광합성 능력을 보이다가 시간이 경과하면서 대조군보다 더 높은 경향을 나타냈다. 이러한 결과는 식물플랑크톤이 benso[a]pyrene의 낮은 농도에서 노출될 때는 이 물질을 탄소원으로 사용할 가능성이 있음을 시사한다. 본 연구의 결과들은 연안해역에 benso[a]pyrene과 같은 지속성 유기오염물질이 유입되었을 때 내정여부에 따라 식물플랑크톤 군집내 종 천이와 일차생산력에 크게 영향을 미칠 수 있음을 시사한다.