• Journal of the Korean Magnetics Society
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• v.8 no.6
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• pp.341-345
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• 1998

Magnetic shielding effect of cylinderical ahields made of commericial amorphous ribbons has been studied. The shell-arrangement-order of double shell shield has been found to show a striking differencein shielding factor. In low applied field region, a 2605CO-2705M-shield (outer shell: 2605CO, inner shell: 2705M) yields two times higher shielding factor than a 2705M-2605CO-shield (outer shell: 2705M, inner shell: 2605CO). The reasons are as follows: In case of 2605CO-2705M-shield, the outer shell is not easily saturated and effectively shields the applied field. In addition, the inner shell shows high shielding factor in the field shielded by the outer shell. In case of 2705M-2605CO-shield, the outer shell is saturated at very low-field as well as the inner shell shows low shielding factor in the field shielded by the outer shell.

• Journal of Acupuncture Research
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• v.19 no.6
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• pp.97-110
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• 2002

목적 : 본 연구는 (a) 저빈도 전침의 만성 단발성 관절염에 대한 치료 효과와 (b) 척수에서 동통과 관련되는 지표인 P 물질과 trk A mRNA의 발현조절에 미치는 영향을 연구하기 위해 실행되었다. 방법 : Complete Freund's adjuvant를 실험동물의 우측 경족근관절에 주입하여 관절염을 유발시키고 9주 동안 관찰하였다. 만성 관절염의 최적의 치료조건을 찾기 위하여 각각 세 종류의 경혈(환도, 용천, 족삼리)과 전침자극강도(0.5, 1, 2 mA)를 사용하여, 행동학적 지표로서 동통을 측정하였다. 측정 결과 가장 큰 효과를 나타낸 군을 선택하여 RT-PCR 방법을 사용하여 P 물질 및 trk A mRNA의 변화를 척수 후각과 후근신경절에서 측정하였다. 결과 : 관절의 굴신을 통한 통증 검사와 족과관절 둘레 길이 측정을 통하여 관찰한 결과 원위부에 위치한 환도에 저강도의 자극을 시행한 경우(환도, 0.5 mA)가 가장 우수한 치료 효과를 나타내었다. RT-PCR을 시행한 결과, 환측 후근신경절의 P물질이 관절염 유발 대조군의 경우 정상군에 비해 증가하였고 환도-0.5mA 군에서 다시 감소하는 것을 관찰하였으며, trk A는 관절염 유발군의 경우 척수 후각에서 양측성 증가를 나타내었고 이는 전침치료에 의해 다시 감소되는 것을 관찰하였다. 결론 : 환도 0.5mA의 저빈도 전침은 관절염을 효과적으로 감소시킬 뿐 아니라 관절염으로 증가된 후근신경절의 P 물질과 척수후각의 trk A mRNA 발현을 효과적으로 감소시켰으며, 이는 원위취혈로 선혈된 환도혈의 만성관절염에 대한 치료효과를 분명히 보여준다고 할 수 있다.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.191-198
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• 2017

Hyaluronidase inhibitory activity as inflammatory factor of Koreinsis chinensis leaf ethanol extract was showed higher inhibitory activity than water extract. 29.5% inhibitory activity was shown at concentration of $200{\mu}g/mL$ phenolics. Lipopolysaccharide (LPS)-stimulated Raw 264.7 cells were treated with different concentrations ($5-25{\mu}g/mL$) of Koreinsis chinensis leaf extract and the amount of nitric oxide (NO) was determined; LPS-treated cells produced 3 times more NO than non-LPS treated cells. Moreover, the NO production in cells treated with Koreinsis chinensis leaf extract showed inhibitory effect in a concentration-dependent manner. Due to the stimulant-induced NO production is regulated by the inducible nitric oxide synthase (iNOS), we determined the iNOS protein level to elucidate the mechanism by which the NO production was inhibited. It was reduced by 40% with a Koreinsis chinensis leaf extract concentration of $25{\mu}g/mL$ and identified iNOS inhibition in dose-dependent manner. The prostaglandin $E_2$ production in cells treated with Koreinsis chinensis leaf extract was reduced by 26.2% at concentration of $25{\mu}g/mL$. The protein expression of cyclooxygenase-2 in LPS-treated Raw 264.7 cells was inhibited by 64% at $25{\mu}g/mL$ of Koreinsis chinensis leaf extract. Koreinsis chinensis leaf extract had a concentration-dependent inhibitory effect on the production of tumor necrosis factor-${\alpha}$ and interleukin-6 as pro-inflammatory cytokine in LPS-treated Raw 264.7 cells at $25{\mu}g/mL$ of Koreinsis chinensis leaf extract. Their levels were decreased by 61.7 and 62% respectively.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.6
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• pp.49-63
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• 2017

The purpose of this study is to analyze the effects of the collective characteristics of SMEs on M&A activity on the disclosure effect of mergers and long-term business performance after mergers. From 2000 to 2012, we examine 717 cases of small and medium-sized enterprises (SMEs) using multiple regression analysis and difference analysis. The results of this study are as follows. First, it is confirmed that the effect on the merger announcement effect is the same as the previous study on the Korean capital market listed companies except for the effect of diversification, listing effect, and cross-border effect. In addition, we have found that firms with higher performance in the past have higher excess returns in the disclosure effect of mergers and acquisitions. Second, unlike the previous studies that non-related mergers have a positive effect on long-term operating performance, for the characteristics of SMEs with lower market competitiveness than that of average listed companies, SMEs merging with same industry group companies have a positive effect on long-term operating performance. This study provides a new perspective on the merger and acquisition of SMEs by examining the effects of M&A announcement and long-term performance.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1487-1495
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• 2018

In this study, we investigated collagen production and hyaluronic acid production effects for wrinkle improvement test on 50 kinds of land plants and 10 kinds of marine plants native to Jeju Island as a part of developing customized cosmetic materials. Collagen and hyaluronic acid are recognized as major factors affecting skin aging. Cerastium holosteoides var. hallaisanense Mizushima extract ($100{\mu}g/mL$) produced more than 190% of collagen in the extracts of 50 kinds of land plants. Vicia angustifolia var. segetilis K. Koch. extract ($100{\mu}g/mL$) produced more than 160% of collagen. Ftsia japonica Decne. et Planch. extract ($100{\mu}g/mL$), Euonymus japonica Thunb. extract ($100{\mu}g/mL$), Suaeda malacosperma H.Hara extract ($100{\mu}g/mL$), Elaeagnus umbelellata Thunb. extract ($100{\mu}g/mL$), Sedum oryzifolium Makino extract ($100{\mu}g/mL$), Vicia unijuga A. Br. extract ($100{\mu}g/mL$), and Brassica juncea var. integrifolia Sinsk. extract ($100{\mu}g/mL$) showed more than 140% collagen production effect. Among the 10 species of marine plants, Sargassum macrocarpum C. Agardh extract ($50{\mu}g/mL$) produced more than 190% of collagen, and Carpopeltis angusta (Harvey) Okamura extract ($100{\mu}g/mL$), Codiumcoactum Okamura extract ($100{\mu}g/mL$), and Codium tenuifolium S. Shimada, T. Tadano & J. Tanaka extract ($100{\mu}g/mL$) showed more than 140% collagen production. Suaeda malacosperma H.Hara extract ($100{\mu}g/mL$) showed the effect of producing hyaluronic acid more than 140%, and Ftsia japonica Decne. et Planch. extract ($20{\mu}g/mL$) and Wistaria floribunda A.P. DC extract ($100{\mu}g/mL$) showed more than 130% hyalunonic acid production effect. Among the 10 species of marine plants, Peyssonnelia capensis Montagne extract ($100{\mu}g/mL$) was the most effective. Carpopeltis angusta (Harvey) Okamura extract ($100{\mu}g/mL$), Codiumcoactum Okamura extract ($100{\mu}g/mL$), and Codium tenuifolium S. Shimada, T. Tadano & J. Tanaka extract ($100{\mu}g/mL$) showed more than 120% hyalunonic acid production. Jeju resources, which have good collagen and hyaluronic acid production, showed the potential to be applied to solve the skin troubles of customized cosmetics in the future.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.323-328
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• 2015

Control efficacy was investigated with fungicides as 3 copper compound, 3 antibiotic fungicides and one fungicide containing to quinolone against the growth of Ralstonia solanacearum on NA medium and the disease occurrence on pepper seedlings. Among 7 fungicides, oxytetracycline was shown the highest activity against a growth of the pathogen in the agar diffusion method, but validamycin showed no activity against the pathogen. With $1000{\mu}g\;mL^{-1}$ of each copper fungicide as copper hydroxide, copper oxychloride+ dithianone and copper sulfate, 2.2, 1.3 and 1.5 mm in size of clear zone only could be found, respectively. In pepper seedling test, oxytetracycline showed a perfect activity in all treatments 7 days after inoculation. However, its activity was decreased from $500{\mu}g\;mL^{-1}$ of treatment over the time. Copper fungicides showed the control efficacy lower than antibiotic fungicides except for validamycin. Based on the results, it was suggested that it would be better to use antibiotic fungicides than copper fungicides to control pepper bacterial wilt in the fields.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.845-853
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• 2014

In this study, we measured the dose reaching the OSLD dosimeter by using the regular lead apron, and air gap apron through 3 experiments, and researched the reductive effect of air gap apron on exposure dose based on the 140 keV gamma ray radiating from $^{99m}technetium$, which is the most commonly used in nuclear medicine. As a result, when the gap between the dosimeter and 0.2mm lead plate is 0 Cm, the average value of 10 dosimeters was 0.515 mSv, and when the gap between the dosimeter and lead plate is 20 Cm, the average value of 10 dosimeters was 0.138 mSv, which shows reductive effect of dose as much as 0.388 mSv. When the gap between the dosimeter and 0.5mm lead plate is 0 Cm, the average value of 10 dosimeters was 0.296 mSv, and when the gap between the dosimeter and lead plate is 20 Cm, the average value of 10 dosimeters was 0.075 mSv, which shows reductive effect of dose as much as 0.221 mSv. As we check the cumulative dosage for 3 days, the lead apron without air layer shows average 0.239 mSv, and the air gap apron shows 0.176 mSv, which is actually reduced by 0.062 mSv. As we check the cumulative dosage for a month, the lead apron without air layer shows 0.59 mSv, and the air gap apron shows 0.54 mSv, which is reduced by 0.05 mSv.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1396-1402
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• 2000

The effects of Coptis chinensis Franch(CCF) extract on the growth, acid production, cell adherence and glucosyltransferase(GTase) activity of Streptococcus mutans JC-2 were investigated. Methanol extract from CCF showed a strong inhibitory effect on the growth of S. mutans. The minimal inhibition concentration(MIC) of the methanol extract was determined as $130\;{\mu}g/mL$, whereas MIC of water extract was $200\;{\mu}g/mL$. MICs of berberine and palmatine were $50\;{\mu}g/mL$ and $110\;{\mu}g/mL$, respectively, showing stronger antimicrobial activities than the extracts of CCF. Antimicrobial activities of methanol extract, berberine and palmatine were not decreased by heating at $121^{\circ}C$ for 15 min, suggesting that the antimicrobial components including berberine and palmatine are heat-stable. Acid production of S. mutans was decreased by methanol and water extracts, berberine and palmatine. The activity of GTase was inhibited by methanol extract, berberine and palmatine at $300\;{\mu}g/mL$ with 23.2%, 46.1% and 17.1%, respectively, but was not inhibited by water extract. The water extract and palmatine at sub-MICs inhibited the adherence of S. mutans to glass surface by 59.2% and 41.7%, respectively. These results suggest that CCF extracts have anticariogenic effects and could be used as an anticariogenic food additive.

• The Korean Journal of Pharmacology
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• v.32 no.1
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• pp.1-11
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• 1996

Since it has been reported that the depolarization-induced norepinephrine (NE) release is inhibited by activation of presynaptic $A_1-adenosine$ heteroreceptor in hippocampus, a large body of experimental data on the post-receptor mechanism of this process has been accumulated. But, the post-receptor mechanism of presynaptic $A_1-adenosine$ receptor on the NE release has not been clearly elucidated yet. Therefore, it was attempted to clarify the post-receptor mechanisms of the $A_1-adenosine$ receptor-mediated control of NE release in this study. Slices from rat hippocampus were equilibrated with $^3H-norepinephrine$ and the release of the labelled products was evoked by electrical stimulation (3 Hz, 5 $Vcm^{-1}$, 2 ms, rectangular pulses), and the influence of various agents on the evoked tritium-outflow was investigated. Adenosine, in concentrations ranging from $1{\sim}30{\mu}M$, decreased the NE release in a dose-dependent manner, without affecting the basal rate of release. The adenosine effects were significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, $2{\mu}M$), a selective $A_1-receptor$ antagonist. The responses to N-ethylmaleimide (NEM, 10 & $30{\mu}M$), a SH-alkylating agent of G-protein, were characterized by increments of the evoked NE-release and the basal release, and the adenosine effects were completely abolished by NEM pretreatment. $4{\beta}-Phorbol$ 12,13-dibutyrate (PDB, $1{\mu}M$), a specific protein kinase C (PKC) activator, increased the evoked NE release, whereas polymyxin B sulfate (PMB,0.1 mg), a PKC inhibitor, decreased the release, and the adenosine effects were inhibited by these agents. Nifedipine $(1{\mu}M)$, a $Ca^{2+}-channel$ blocker of dihydropyridine analogue, did not affect the adenosine effect. Tetraethylammonium (TEA, 3 mM) increased the evoked NE release, and inhibited the adenosine effects, but glibenclamide, a ATP dependent $K^+-channel$ blocker, did not. Finally, 8-bromo cyclic AMP (100 & $300{\mu}M$), a membrane-permeable analogue of cAMP, did not alter the NE release, but adenosine effects were inhibited by pretreatment with 8br-cAMP. These results suggest that the decrement of the evoked NE-release by $A_1-adenosine$ receptor is mediated by the C-protein, which is coupled to protein kinase C, adenylate cyclase system and TEA sensitive $K^+-channel$, and that nifedipine-sensitive $Ca^{2+}-channel$ and glibenclamide-sensitive $K^+-channel$ are not involved in this process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.8-12
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• 2005

This study was performed to determine the inhibitory effects on cell survival and Quinone reductase induced activity of Aster yomena (AY) on human cancer cells which, using methanol, was extracted and fractionated into five different solvent types: hexane (AYMH), ethylether (AYMEE), ethylacetate (AYMEA), butanol (AYMB) and aqueous (AYMA) partition layers. The experiment was conducted to determine cytotoxicity of various Aster yomena partition layers on HepG2, HeLa and MCF-7 cells by MTT assay. Among various partition layers of Aster yomena, A YMEE and A YMEA showed the strong cytotoxic effects on all cancer cell lines we used. The Quinone reductase (QR) induced activity on HepG2 cells, A YMH at a does of 100 $\mu$g/mL was 2.46 times more effective compared to the control value of 1.0.