• 치과방사선
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• 제23권1호
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• pp.71-85
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• 1993

The purpose of the study was to investigate the effects of the single and fractionated irradiation on the microvascular structure of the submandibular gland in rats. For this study, 90 Sprague-Dawley strain rats were irradiated to their neck region with equal split doses of 9Gy for a 4 hours interval and 15Gy single dose by 6MV X-irradiation and sacrificed on the 1st, 3rd, 7th, 14th and 27th day after irradiation. The author observed histological changes at Hematoxylin and Eosin staining and PAS staining under a light microscope, and also observed distribution and structural changes of the microvasculature in rat submandibular gland using a scanning electron microscope by forming vascular resin casting. The results were as follows: 1. In the light microscopic examination, the microvasculature was slightly dilated and decreased in number on the 1st day after irradiation, and increase in number of microvasculature was observed on the 3rd day after irradiation. And then distribution of microvasculature was markedly increased on the 7th day after iradiation, but decreased on th 14th day after irradiation again. Such changes were greater in the single irradiated group than in the fractionated irradiated group. 2. The reaction to PAS staining on glandular cell was decreased on the 1st and the 3rd day after irradiation, and recovered on the 7th day after irradiation. The reaction was decreased on the 14th day after irradiation again, and recovered on the 28th day after irradiation. Changes were more apparent in the single irradiated group. 3. In the scanning electron microscopic examination, early changes of microvasculature were decreased capillary density, dilation of conduits and meandering. Increased capillary dentsity or anastomosis due to vascular reproduction and smooth curved running were observed on the 7th and 14th day after irradiation. Decreased capillary and smooth running tendency were observed on the 28th day after irradiation again. Such changes were greater in the single irradiated group than in the fractionated irradiated group.

• 한국식품과학회지
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• 제4권4호
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• pp.259-264
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• 1972

국산(國産) 라면제품을 형광등조사구(螢光燈照射區) 고온암소구(高溫暗所區) 자외선조사구(紫外線照射區) 등의 처리구(處理區)로 나누어 20주(週)동안 저장하고, 경시적(經時的)으로 산가(酸價) 과산화물가(過酸化物價) carbonyl가(價) TBA가(價) 지방산조성(脂肪酸組成) 옥도가(沃度價) 등의 지방산화현상(脂肪酸化現象)을 살펴 본 바 다음과 같은 결과를 얻었다. 전반적으로 형광등조사구(螢光燈照射區) 및 고온암소구(高溫暗所區)의 라면은 완만한 산화현상(酸化現象)을 보였으며, 저장 16주(週)에 변패취(變敗臭)를 확인하였고, 자외선조사구(紫外線照射區)의 라면은 저장초(初)부터 급격한 산화(酸化)가 일어났으며, 저장 4주(週)에 변패취(變敗臭)를 확인하였다. 2) 산가(酸價) 과산화물가(過酸化物價) TBA가(價)등은 각처리구(名處理區) 공(共)히 전실험기간동안 증가하였으며 자외선조사구(紫外線照射區)에서 그 증가현상(增加現象)은 현저하였다. 특히 TBA가(價)는 자외선조사구(紫外線照射區)에서 저장 4주(週)이후 급격히 증가하여 10주(週)에 그 정점(頂點)을 이루고 다시 감소하였다. 이 때의 bound malonaldehyde는 14주(週)까지 증가하다가 그 이후 완만히 변화하였다. 3) 저장초(貯藏初) 그리고 저장(貯藏) 12주(週)의 고온암소구(高溫暗所區) 및 자외선조사구(紫外線照射區)의 라면유지(油脂)에 대한 지방산조성(脂肪酸組成)을 살펴 본 결과 고온암소구(高溫暗所區)에선 큰 변화가 없었으며, 자외선조사구(紫外線照射區)에선 저장초(貯藏初)의 지방산조성(脂肪酸組成)에 비(比)하여 linoleic acid 등 불포화 지방산의 상대적(相對的)인 감소현상을 볼 수 있었으며 저장 중 옥도가(沃度價)의 감소(減少)가 이러한 사실(事實)을 뒷받침하고 있다.

• 한국약용작물학회지
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• 제5권2호
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• pp.131-138
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• 1997

초롱꽃과 약음작물 재배에서의 문제점은 발아의 불안정에 기인한 입묘율(立苗率) 불량(不良)이라 할 수 있다. 초롱꽃과 약용작물중에서 농가에서 주로 재배되고 있는 도라지, 더덕 및 만삼의 발아 및 유근신장에 미치는 광질(光質), 일중조명시간(日中照明時間) 및 저온처리(低溫處理) 기간(期間)의 영향을 추적하여 초기입묘에 관한 정보를 제공하고자 본 시험을 실시하였던 바 그 결과를 요약하면 다음과 같다. 1. 공시종(供試種)의 발아율은 광질(光質), 일중조명시간(日中照明時間) 또는 저온처리(低溫處理)에 관계없이 도라지에서 가장 높고 만삼에서 가장 낮았으며, 광질(光質)에 따른 발아율은 일중조명시간(日中照明時間) 및 저온처리(低溫處理)에 따라 변화되었던 반면, 일중(日中) 12시간의 조명(照明)이 초기 발아율을 향상시켰으나 4일에서 8일로 저온처리 기간을 증가시킴으로서 발아율은 향상되었다. 2. 일중조명시간(日中照明時間)에 관계없이 도라지의 발아율은 백색광(白色光)에서 높았으나 더덕은 오히려 가장 낮은 결과를 보인 반면, 만삼은 일일 12시간 이상의 조명(照明)하에서 더덕과 동일한 결과를 보였다. 이러한 광질효과(光質效果)는 저온처리로 인하여 현저히 소멸되는 것으로 나타났다. 3. 치상 후 9일에 조사된 공시종(供試種)의 유근장은 광질(光質), 일중조명시간(日中照明時間) 또는 저온처리(低溫處理)에 관계없이 더덕에서 가장 길고 만삼에서 가장 짧았고, 광질(光質)에 따른 유근장은 일중조명시간(日中照明時間) 및 저온처리(低溫處理)에 따라 변화되었던 반면, 일중 8시간의 조명(照明)에서 가장 길고 4일에서 8일로 저온처리 기간을 증가시킴으로서 길어지는 경향을 보였다. 4. 유근장은 무처리(無處理)에 비하여 저온처리를 4일 또는 8일 동안 가할 경우 발아기간에 관계없이 도라지와 더덕에서는 길어졌던 반면, 만삼에시는 8일 간의 저온처리에서만 이러한 현상이 관찰되었다.

• 대한소아치과학회지
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• 제25권2호
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• pp.368-382
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• 1998

The purpose of this study is to evaluate and compare the results of argon laser for 5 seconds, argon laser for 10 seconds, and visible light for 40 seconds photo-polymerization in compressive strength, microhardness, curing depth, temperature rising during polymerization, and polymerization shrinkage. Hybrid type composite resin(Z-100) and compomer(Dyract) were used to be compared. The compressive strength was measured by an Instron(1mm/min cross head speed) in 60 specimens and the microhardness of the surface was expressed by Vickers Hardness Number(VHN) in 30 specimens. The curing depth was evaluated comparing the different values of upper and lower VHN according to irradiation time and thickness for the light source polymerization in 60 specimens. The temperature rising during photopolymerization was observed by the temperature change with thermocouple sensitizer beneath 40 specimens at the argon laser for 10 seconds and visible light 40 seconds irradiation. The polymerization shinkage was evaluated by calculating the decrease of % volume by using a dilatometer in 30 specimens. The results were as follows ; 1. In the case of compressive strength, the argon laser polymerization groups were higher than visible light group in Z-100 (p<0.05). In Dyract, the argon laser 5 seconds group did not show a significant difference with the visible light 40 seconds group. The argon laser 10 seconds group showed the markedly low value when compared with other groups (p<0.05) 2. In microhardness, Z-100 was better than Dyract when comparing by VHNs (p<0.05); however, there was not a significant difference between two materials in the visible light 40 seconds group and the argon laser 10 seconds group. 3. In the study of curing depth, Z-100 showed the consistent polymerization in argon laser irradiation because there was no difference in the VHN decrease according to the thickness change. Over the thickness control, the results did not show a significant difference between visible light and argon laser group in Z-100; however, in the case of Dyract, the visible light 40 seconds group was better than the argon laser groups(p<0.05). 4. There was a significant difference between the two materials in temperature rising during polymerization (p<0.05), but not a significant difference between irradiation times, 5. There was not a significant difference between the two materials in polymerization shrink age. The argon laser 5 seconds group was smaller than the other groups (p<0.05). It could be concluded that Z-100 polymerization was recommended to use the argon laser for reduction of the irradiation time while Dyract was recommended to use the visible light polymerization.

• 한국광학회지
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• 제31권4호
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• pp.183-190
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• 2020

본 논문에서는 넓은 조사 면적에 단거리 조사시에도 균일한 조명도 분포를 가지도록 하는 비대칭 배광의 조명 광학계에 대한 연구를 진행하였다. 단거리에 설치되는 조명의 경우 조사 거리가 짧기 때문에 충분한 배광 분포 형성이 되지 못해 조명의 균일도를 만족하기 어렵다. 또한 시인성을 위해 조명기기가 기울어져 설치되기 때문에 비대칭 배광의 조명 설계가 요구된다. 이러한 문제점을 해결하기 위해 비대칭 배광을 가지는 조명 광학계 설계를 통해 근거리 조사 시에도 대상 표면에 균일한 조명도를 얻을 수 있었으며, 이를 근거리 조명 중 하나인 라이선스 램프에 적용하여 법규 기준을 만족하는 것을 확인하였다.

• Current Optics and Photonics
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• 제6권3호
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• pp.227-235
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• 2022

To investigate the aging-related physiological functions of organic light-emitting diodes (OLEDs), we examined mRNA expression changes in aging-related genes due to oxidative stress inhibition by 630-nm red light OLEDs. As a result of irradiating 630-nm OLED with an intensity of 5 mW/cm² for 15 min, the viability of dermal fibroblasts significantly increased by 1.3-fold. In addition, reactive oxygen species generated by H₂O₂ were significantly reduced about 4.9-fold by irradiation with 630-nm OLED. Quantitative reverse-transcription polymerase chain reaction results showed that 630-nm OLEDs altered aging-related gene mRNA expression levels through antioxidant activity. The mRNA expression levels of matrix metalloproteinase1 (MMP1) and MMP9 decreased significantly, by about 2.2- and 2.5-fold, compared to the control group, whereas those of collagen, type I, and alpha 1 increased significantly, by 4.9-fold. The mRNA expression levels of cancer suppression genes p16 and p53 in dermal fibroblasts were also significantly reduced by 630-nm OLED irradiation, by about 1.4- and three-fold, respectively, compared to the control. Overall, it was confirmed that 630-nm OLED irradiation lowered the level of ROS formation induced by H₂O₂ in dermal fibroblasts, and that this antioxidant effect could regulate the mRNA expression levels of aging- and tumor suppression-related genes. This study shows a link between 630-nm OLED irradiation and anti-aging physiological functions such as antioxidant function, and suggests the potential of OLEDs as a useful light source for skin care.

• 농업과학연구
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• 제50권3호
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• pp.417-425
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• 2023

Because an irradiation of 405 nm violet light could have a strong energy, it was used to be sterilized against various microbes in the indoor air condition or fresh food. Escherichia coli is a representative bio-pollutant in the indoor air-borne bacteria, and a hygienic microbe in the horticultural food. This study evaluated the inactivation influences on E. coli DS5α after exposure to 405 nm violet-light (VL) by investigating irradiating time, and the vertical and horizonal distance from light source. The illumination of 405 nm VL was inversely proportional to the distance from the VL source. E. coli DS5α on nutrient agar (NA) was inactivated approximately 50% more than the control when irradiated at 65 cm from 405 nm VL for 3 hours. When compared to the control, E. coli DS5α was inactivated approximately 50% within 70 cm from 405 nm VL for 3 hours. As it was irradiated for 3 hours 70 cm away from 405 nm VL, the horizonal distance from the point was negatively correlated to the inactivation of E. coli DS5α. These results indicated that the inactivation of E. coli DS5α grown on NA medium needs to be irradiated with 405 nm within 70 cm from the light source for 3 hours.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.220-223
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• 2002

본 연구에서는 자체 제작한 2L 규모의 bubble-column photobioreactor에서 H. pluvialis의 배양을 시도하였고 astaxanthin의 축적량 증가를 유도하기 위하여 배양시작 20일 후에 light stress를 주었다. 이 방법을 통하여 대조구에 비하여 68%의 건조균체중량 증가와 215%의 astaxanthin 축적량 증가를 유도할 수가 있었고, bubble-column photobioreactor를 이용한 유도배양이 H. pluvialis의 배양에 적합함을 알 수가 있었다.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.179-183
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• 2002

Lycopene as a natural antioxidant may provide protection against a broad range of epithelial cancers and chronic diseases. Lycopene concentrate extracted from tomatoes can be used as functional food. Lycopene would undergo degradation via isomerization and oxidation under different processing conditions, which impact its bioactivity and reduce the fuuctionality for health benefits. Heat and light induce lycopene oxidation and isomerization of all-trans form to cis form. The effects of thermal treatment and light irradiation on the stability of lycopene were determined. Results have shown that lycopene stability depends on the extent of oxidation and isomerization. Cir-isomers are less stable than trans-isomers. The level of cis-isomers increased as treatment time increased but only for a short period during the beginning of the treatment. The major effect of thermal treatment and light irradiation was a significant decrease in the total lycopene content. A true assessment of health benefits of lycopene concentrate depends on the lycopene content and the composition of all trans-isomers and cia-isomers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1882-1884
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• 1999

The photoisomerization of functional polyimide was investigated in the various temperatures and UV(360nm) & visible(450nm) light irradiation. The absorption spectrum of azobenzene containing polyamic acid in a mixture of N,N-dimethylacetamide and benzene(1:1 by volume) solution was induced photoisomerization by UV and visible light irradiation. The absorption spectrum of LB films are also induced photoisomerization by UV and visible light irradiation.