• Journal of Ginseng Research
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• v.17 no.3
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• pp.232-235
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• 1993

We investigated the effect of antioxidants (ascorbate, glutathione, and sodium azide), which efEectively inhibited the chlorophyll bleaching of Panax ginseng CA Meyer under the high light intensity, treated by folilar wiping on the early stage of photosynthesis and transpiration of ginseng in the 5000 $\mu$mol photon.$m^{-2}$.$s^{-1}$. Ascorbate and glutathione, endogenous antioxidant, completely recovered ginseng from the photoinhibition, but sodium azide, synthetic quencher, showed negative effect. We assumed that endogenous antioxidants could be available to the protection of the leaf-burning phenomenon of ginseng.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.4-8
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• 2000

최근 양방향 전송에 기반을 둔 양방향 파장 분할 다중 방식(WDM: wavelength division multiplexing) 광통신망$^{(1-3)}$ 이 제안되고 있다. 양방향 파장 분할 다중 방식 광통신망은 광섬유의 수나 광증폭기의 수 등 경제적 비용을 경감할 수 있고 비선형 현상을 줄일 수 있다는 장점을 갖는다. 그러나 이러한 양방향 광통신망에서는 Rayleigh 역산란이나 다중 광반사, 각종 소자의 누화에 의한 상대 강도 잡음(RIN: relative intensity noise)에 의해 시스템의 성능과 통신망의 확장성이 심각하게 저하될 수 있다$^{(4)}$ . 따라서 상대 강도 잡음을 억제하면서도 양방향 광통신망의 장점을 살릴 수 있는 광증폭기 및 애드/드롭 모듈의 설계가 필수적이다. (중략)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.248-248
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• 2009

GaN 기반 LED 소자의 ITO 표면에 sol-imprinting 기술을 이용하여 잔여층 없이 $TiO_2$ 나노 패턴을 형성하였다. 알콕사이드 계열의 $TiO_2$ sol과 Si 몰드로부터 복제된 PDMS 몰드를 사용하여 표면에 패턴을 형성하고, 이 후 annealing을 통해 내부에 남아있던 불순물을 제거하고 다결정 $TiO_2$을 형성하였다. 표면에 형성된 $TiO_2$ 나노 패턴이 LED 소자 내부에서 발생한 빛의 전반사를 억제하기 때문에 소자의 광추출 효율이 증가하였다.

• Proceedings of the SCSK Conference
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• 1996.07a
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• pp.10-14
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• 1996

최근 오존층의 파괴로 인한 지구 자외선량의 증가로 피부암 및 광노화의 발생가능성이 증가되고있다. 광노화의 주요한 현상중의 하나는 탄력섬유상 물질이 축적되는 일광탄력 섬유증이다. 자외선은 탄력소 유전자의 전사과정증가를 유도하며 결국 비정상적인 탄력소의 증가를 유발한다는 보고가 있다. 본 연구에서는 피부 섬유아세포 및 각질형성세포를 배양하여 자외선이 탄력소 유전자발현에 미치는 영향 및 전사조절인자에 미치는 영향을 알아보고자 하였다. 피부섬유아세포에 UVB를 30mJ-200J/m 조사하여 nothern blotting한 결과 UV양이 증가함에 따라 탄력소 전사물이 증가되었고, 1001/$m^2$ 에서 최대의 증가를 보였다. 탄력소 promoter와 CAT을 접합시킨 pEP62 vector을 섬유아세포에 형질전환 시키고 UV에 의한 Promoter 활성을 본 결과 UV조사량이 증가할수록 활성이 증가되었고 200J/$m^2$ 에서 대조군에 비해 5배의 활성 증가를 보였다. 이 system에 광노화 억제물질로 알려진 retinoid를 5 $\times$ $10^{-6}$M처리하였을 때 UV에 의한 탄력소 promoter활성을 약 1/3로 감소시켰다. 각질 형성세포에서 UVB에 의한 transcription factor의 활성을 mobility shift assay에 의해 조사한 결과 AP-1 및 NFkB가 활성화됨을 볼 수 있었다.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.365-376
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• 2006

The purpose of this study was to evaluate the efficacy of blocking the oxygen in the air during the polymerization of sealant. All curing were performed with various light curing units under the application of oxygen gel barrier, stream of nitrogen and carbon dioxide gas for inhibition of oxygen diffusion into sealant surface. The results of present study can be summarized as follows : 1. The amount of eluted TEGDMA form the specimens cured with all the three different light units in the stream of $N_2$ and $CO_2$ gas and application of Oxygen gel barrier($DeOx^{(R)}$) were significantly lower than in the room-air atmosphere (Control) (p<0.05). 2. In the $DeOx^{(R)}$ application, the amount of eluted TEGDMA the specimen cured with PAC light for 10seconds was less than that cured in the stream of $N_2$ and $CO_2$ atmospheric conditions (p<0.05) 3. In the LED using 10 or 20sec irradiation times under the stream of $N_2$ and $CO_2$, the eluted TEGDMA showed to be no statistically significant difference (p>0.05). 4. The microhardness from the specimens cured with all the three different light units under each treated conditions were significantly higher than in the room-air atmosphere (p<0.05). 5. The surface treatment by $DeOx^{(R)}$, $N_2$ and $CO_2$ reduces the thickness of oxygen inhibited layer by sp proximately 49% of the untreated control value.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.75.1-75.1
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• 2011

화석연료의 고갈과 온실가스 배출의 증가로 지속 가능한 친환경 에너지 생산이 요구되는 가운데, 태양광 발전은 이러한 조건을 만족시키는 에너지 생산 방안으로 주목받고 있다. 태양광 발전은 태양 직사광을 이용한 발전 방법 때문에 실외에 설치되어야 하며 이에 따라 외부의 충격이나 오염물질로부터 태양전지 패널을 보호하기 위한 보호층이 필수적이다. 그러나 보호층에 의한 입사광의 반사 및 먼지나 황사에 의한 보호층의 오염 등은 태양전지의 발전 효율을 감소시키는 요인으로 작용하여 이에 대한 대응이 필요하다. 본 연구에서는 PET 필름에 나노 임프린트 리소그래피 및 핫 엠보싱 공정을 이용하여 moth-eye 반사방지 패턴을 형성함으로써 보호층에서의 입사광 반사를 억제하였다. 또한, 이러한 반사방지 패턴에 초소수성 자기조립단분자막을 코팅하여 표면 에너지를 낮춤으로써 먼지 및 황사에 의해 오염되었을 경우에도 빗물에 의해 오염 물질이 쉽게 씻겨 내릴 수 있는 자정기능을 부여하였다. 이러한 반사방지를 통한 입사광 투과량의 향상 및 초소수성 표면에 의한 자정작용에 의하여 태양전지의 발전 효율이 증가되었다.

• Applied Biological Chemistry
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• v.46 no.1
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• pp.60-65
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• 2003

MMP-1 inhibitory compounds were isolated from 120 Korean traditional edible plants. UP- 1 activity significantly increased linearly with increasing UVB dose in normal human foreskin fibroblast HS68 cell, showing maximum activity at approximately 35 $mJ/cm^2$, whereas in HaCaT cell, normal human keratinocyte, no increase was observed. Maximum secretion of MMP-1 after UVB treatment occurred around 36-48 k after treatment. MMP-1 inhibitory compound isolated from cold-water fraction of Cataegus pinnatifida Bunge showed the mort potent activity. The MMP-1 inhibitory compound was deduced as a peptide based on the fact that pronase digestion decreased the activity whereas periodate oxidation did not. The most potent UP- 1-inhibitory protein, CP-2Va-2, showing an activity of 88.5% against MMP-1, was isolated through sequential column chromatography on DEAE-Toyopearl 650C, Butyl-Toyopearl 650M, and Bio-Gel P-30. Molecular weight of CP-2Va-2 determined through high performance liquid chromatography and SDS PACE was 19 and 20 kDa. respectively, signifying a monomeric structure.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.150-159
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• 1996

This study was conducted to investigate the inhibition of protox activity and the PPIX accumulation of the oxyfluorfen-tolerant and-susceptible rice cultivars with barnyardgrass, a typical susceptible weed in accordance by oxyfluorfen treatment. The susceptible rice cultivars and barnyardgrass showed more inhibition of protox activity due to the treatment of oxyfluorfen than the tolerant rice cultivars. Especially in the concentration at $10^{-6}$M treatment, protox activity of the susceptible rice cultivars and barnyardgrass were the completely inhibited but the tolerant rice cultivars kept 32~59% of activity compared to the control. As the treatment concentration increased, the content of PPIX accumulation increased and it increased untill four hours of light exposure but it tended to decrease these after. The content of PPIX accumulation by the treatment of oxyfluorfen was more pronounced in the light condition than in the dark. Under the light and dark conditions, the susceptible rice cultivars and barnyardgrass showed more PPIX accumulation than the tolerant rice cultivate. Especialiy the susceptible barnyardgrass had more than the rice. With the treatment of GC and DA, tetrapyrrole biosynthesis inhibitor, the herbicidal activity by oxyfluorfen was inhibited, and the susceptible rice cultivars and barnyardgrass tended to have less effective than the tolerant rice cultivars and the content of chlorophyll or PPS accumulation tended to be similar.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.173-179
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• 2003

This study was established to control the overgrowth of cucumber and tomato plug seedlings by controlling of irradiation timings light intensities of red (R) light. Compared with the control, end-of-day (EOD) timing of R irradiation significantly reduced the seeding heights by 21.3% and 14.2% in cucumber and tomato, respectively. In addition, both plant seedlings treated with R light at EOD timing had the thickest stem diameter. Tomato seedlings treated with R light at EOD showed th highest chlorophyll content and the smallest leaf size. Dry weights of above ground plant tissue in both plant seedlings were significantly reduced by EOD R light treatment. And both plant seedlings treated with EOD treatment had the lowest T/R ratio, and the highest compactness rates. The increased intensities of R light resulted in the shorter plant heights in cucumber and tomato plant seedlings. It also reduced the length of hypocotyls and internodes and the size of leaves in the both seedlings. Elevated R light intensities tended to increase the stem diameter and chlorophyll contents. Dry weights of above ground plant tissue and roots in both plant seedlings were reduced by the elevated R irradiation. Cucumber seedlings treated with 2 and 8 $mol{\cdot}m^{-2}{\cdot}s^{-1}$ and tomato seedlings treated with 8 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ had significantly lower T/R ratio the other treatments tested.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.224-228
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• 2012

BACKGROUND: This experiment was conducted to investigate the effects of red light on inhibition of flowering and vegetative growth of perilla (Perilla Frutescens. L). METHODS AND RESULTS: To determine red light intensity for inhibiting floral induction of perilla 6h light plus daylength extension (17:00-23:00) with three different intensity of red lights 0.046, 0.114 and $0.177{\mu}mol/m^2/s$ were treated respectively, and control plants were grown under 11(06:00-17:00)/13(17:00-06:00)h light/dark environment. Red(660nm) and far-red(730nm) light were irradiated for night break treatment subsequently to investigate photoreversible flowering response of perilla 'Manchu'. The flowering was inhibited by night break with red light, but sequential far-red light induced floral induction of perilla. Perilla not flowered by red light intensity over $0.177{\mu}mol/m^2/s$. Red light of $0.2{\mu}mol/m^2/s$ was irradiated for 6 hours (20:00-02:00) with LEDs device in plastic house. Perilla not flowered and continued the vegetative growth by red light treatment and the plant length, number of leaves, fresh weight, and leaf area of perilla were increased by 3%, 7%, 21%, and 19%, respectively, compared to incandescent control. CONCLUSION: These results showed that red(660nm) light for daylength extension could be used to control flowering and to enhance production of perilla leaf.