• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.20-20
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.97-97
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• 한국세라믹학회지
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• 제28권11호
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• pp.897-907
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• 1991

This study was conducted to research the formation and the color development of CoO-ZnO-Fe2O3-TiO2-SnO2 system for the purpose of synthesizing the spinel pigments which are stable at high temperature. After preparing CoO-ZnO-Fe2O3, in which CoO causes the color, as a basic composition, $\chi$CoO.(1-$\chi$)ZnO.Fe2O3 system, $\chi$CoO.(1-$\chi$)ZnO.TiO2 system and $\chi$CoO.(1-$\chi$)ZnO.SnO2 system were prepared with $\chi$=0, 0.2, 0.5, 0.7, 1.0 mole ratio respectively. The manufacturing was carried out at 128$0^{\circ}C$ for 90 minutes. These specimens were analyzed by the reflectance measurement and the X-ray diffraction analysis and the results were summarized as follows: 1. All of the specimens formed the spinel structure and were colored with stable yellow or blue. 2. As the content of CoO and Fe2O3 in the specimens being increased, the reflectance of each specimen was measured becoming lower and the colors were changed from yellow to greyish blue and from blue to dark blue. 3. As the substituting amount of Co2+ ion for Zn2+ ion in $\chi$CoO-ZnO-TiO2-SnO2 system being increased, the colors were changed from blue to greyish blue. The colors were changed from yellow to grayish green owing to the tetrahedral Co2+ ions being increased, the octahedral Co2+ ions being decreased with increasing the amount of Sn4+ ions. 4. CoO-ZnO-Fe2O3-TiO2-SnO2 system, in which Zn2+ was substituted with Co2+ and Fe3+ was substituted with Ti4+ and Sn4+, easily formed the spinel structure without regard to the amount of substitution or the ion owing to the selectivity of the coordination number: 4 of Zn2+, 4 of Co2+, 6 of Fe3+ or 6 of Ti4+ and Sn4+.

• 구강회복응용과학지
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• 제32권2호
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• pp.117-122
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• 2016

목적: 치은 미백은 치과치료의 목적으로 심미적 장애를 위한 치료에 가깝다. 기존의 치은미백술은 고출력 다이오드 레이저를 이용하여 박피술에 의한 치료를 했왔다. 그러나 이러한 치료법은 시술 후 감염 및 통증에서 자유로울 수 없기에, 우리는 저출력 LED 레이저를 이용하여 치은미백술을 진행하고자 하였다. 연구 재료 및 방법: 돼지고기 표면에 레이저를 조사하여 출력전력, 온도변화, 피부 변성 등의 안정성을 측정하였다. 15 - 20 kg 비글의 구강내 점막 색소에 비손 365 nm LED 레이저를 15분씩, 1 - 2주간 1, 2회씩 각각 조사하였다. 헤마토실린-에오신 염색을 통하여 색소의 손실여부를 확인하였다. 결과: 365 nm LED 레이저 조사 부위의 멜라닌 색소가 줄어드는 것을 확인 할 수 있었다. 결론: 본 연구에서 제시하는 365 nm LED 레이저는 수술적 기술 및 다이오드 레이저를 이용한 탈색화 효과를 대처 할 수 있을 것이라고 사료 된다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권11호
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• pp.1605-1610
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• 2012

Two experiments were conducted to study the effects of red pepper (Capsicum frutescens) powder or red pepper pigment on the performance and egg yolk color of laying hens. In Exp. 1, 210, thirty-wk old, Hy-line Brown laying hens were fed one of seven diets containing 0.3, 0.6, 1.2, 2.0, 4.8 or 9.6 ppm red pepper pigment or 0.3 ppm carophyll red. Each diet was fed to three replicate batteries of hens with each battery consisting of a row of five cages of hens with two hens per cage (n = 3). In Exp. 2, 180, thirty-wk old, Hyline Brown laying hens, housed similarly to those in Exp. 1, were fed an unsupplemented basal diet as well as treatments in which the basal diet was supplemented with 0.8% red pepper powder processed in a laboratory blender to an average particle size of $300{\mu}m$, 0.8% red pepper powder processed as a super fine powder with a vibrational mill ($44{\mu}m$) and finally 0.8% red pepper powder processed as a super fine powder with a vibrational mill but mixed with 5% $Na_2CO_3$ either before or after grinding. A diet supplemented with 0.3 ppm carophyll red pigment was also included (n = 3). In both experiments, hens were fed the red pepper powder or pigment for 14 days. After feeding of the powder or pigment was terminated, all hens were fed the basal diet for eight more days to determine if the dietary treatments had any residual effects. In Exp. 1, there were no differences in egg-laying performance, feed consumption or feed conversion ratio due to inclusion of red pepper pigment in the diet. Average egg weight was higher (p<0.05) for birds fed 1.2, 2.4 or 9.6 ppm red pepper pigment than for birds fed the diet containing 0.3 ppm red pepper pigment. On d 14, egg color scores increased linearly as the level of red pepper pigment in the diet increased. In Exp. 2, feeding red pepper powder did not affect egg-laying performance, feed consumption or feed conversion ratio (p>0.05). However, compared with the control group, supplementation with all of the red pepper powder treatments increased egg weight (p<0.05). All the red pepper powder treatments also increased (p<0.05) the yolk color score compared with the control. The results of the present study suggest that both red pepper powder and pigment are effective feed additives for improving egg yolk color for laying hens.

• 생물환경조절학회지
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• 제19권3호
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• pp.171-176
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• 2010

본 연구는 단감 '부유' 품종을 대상으로 과실 비대 및 착색에 대한 성숙기에 결과지의 잎 제거 정도의 영향을 구명하기 위해 수행하였다. 잎 제거 정도에 따라 과실 주변의 조도는 자연광의 70.1klux에 대하여 무처리구에서는 7.9%, 20% 처리구에서는 13.6%, 50% 처리구에서는 16.4%, 그리고 100% 처리구에서는 30.0% 수준이었다. 과피색 a값은 무처리구 및 20% 처리구에서 수확직전까지 일정 수준으로 꾸준히 증가하였고, Chroma 값은 모든 처리구에서 증가하다가 처리 7주 이후 떨어지는 경향을 나타내었다. 수확된 과실의 무게와 직경은 100% 처리구에서 유의하게 가볍고 짧았다. 과형지수는 무처리구와 다른 처리구들 간 유의한 차이를 나타내었다. 과실 당도는 무처리구보다 다른 처리구들에서 낮은 경향으로 50% 처리구에서 유의하게 낮았다. 과피색 a값은 무처리구 및 20% 처리구에서 높았고, 과피색 b값과 Chroma 값은 20% 처리구에서 유의하게 낮았다. 과피 내 베타 카로틴 및 라이코펜 함량은 잎의 제거 비율이 높은 처리구일수록 낮은 경향이었고, 총 엽록소 함량은 이와 반대의 경향을 나타내었다. 따라서 과실 성숙기에 과실 주변 잎을 제거하는 처리는 과실 착색 증진에 다소 효과가 있는 것으로 생각된다.

• 한국수산과학회지
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• 제35권6호
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• pp.671-675
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• 2002

우렁쉥이 껍질에서 추출한 autoclave 추출구와 neutrase 추출구는 지방흡수력의 경우 대조시료인 chitin과 chitsan에 비해 떨어지는 대략 250$\~$$300\%$ 정도이었으나, 포말성은 각각 0.70과 0.67로, 포말안정성은 0.50과 0.38로 우수하였다 Autoclave 추출구 및 neutrase 추출구의 유화능은 각각 $49.2\%$와 $47.1\%$, 유화안정성의 경우 각각 $48.3\%$와 $44.8\%$ 정도였으며 특히, 색소흡착능은 각각 $85.2\%$와 $85.6\%$로 대조시료에 비해 다소 우수하였다 항혈액응고능은 모든 시료에서 hPn 저 지효과는 나타났으나 PT값은 약 14.5초로 일정하여 혈액응고저지 효과가 거의 없었다. 특히 autoclave 처리구를 DEAE-cellulose ion exchange chromatography하여 얻은 F4 (획분4)는 APTT가 75초로 가장 효과적 이 었으며, Sephadex G-100의 $F_2$가 70초 정도였다. ACE저해능은 모든 시료에서 ACE 저해효과가 있었으며, 채택된 실험방법에 따라 동일시료 경우에 있어서도 저해효과 값이 차이가 났으며, 특히 DEAE-cellulose 이온교환 처리한 $ F_4$ (획분4)가 $35.7\%$로 가장 효과적이었다.

• 한국수산과학회지
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• 제15권3호
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• pp.233-240
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• 1982

남해안 서부에 위치한 득량만과 가막양에서 1981년 하계 중 해수의 클로로필-a양과 저이 중 COD, 강열감대, 파오파이틴양 그리고 황화물양을 측정하였다. 노경노은 약 $300km^2$로서 근래 피조개의 채묘 및 양성이 급증하고 있고, 가업양은 약 $150km^2$로서 수하식에 의한 굴 선성이 많다. 득량만 해수 중 클로로필-a양은 9월에 많아 $1.0\sim5.0{\mu}g/l$로서 평균 $2.5{\mu}g/l$이었다. 양적인 분포에선 득량만의 서북쪽에서 많았다. 저이 중 유기물양은 양서 모두, COD$5.0\sim10.0mg/g$, 강열감양$5.0\sim9.0\%$,체페오파이틴양 $2.0\sim 5.0{\mu}g/g$ 건이이었으며 황화물양은 $0.1\sim0.3mg/g$ 건이이었다. 유기물과 황화물양 모두, 득량만에서는 만입구에서 깊숙히 들어갈수록 증가하였고, 가막양에서는 만의 서편과 서북쪽에 많았다. 상기의 모든 양은 낙산$\cdot$거제만의 양들과 비슷하거나 약간 적었다. 클로로필-a양에 의한 해수의 부영선화는 제산$\cdot$거제만과 같이 중간 수준인데 비해, 저이의 부영양화는 초기단계이었다. 저이중 COD와 페오파이틴양으로부터 산출한 저오염도는$6\sim11$로서, 낙산$\cdot$거제만의 $7\sim18$, 진해서의 $11\sim30$에 비해 낮았다. 이는, COD양이 적다는 이유도 있지만, 굴 양성을 많이 하는 낙산$\cdot$거제만이나 진해만 서부해역과는 달리 페오파인틴양이 COD양보다 적었기 때문이다.

• Ocean and Polar Research
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• 제25권4호
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• pp.427-435
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• 2003

Growth and pigment responses to different levels of solar radiation with or without ultraviolet (UV)-B component $({\lambda}=280-315nm)$ were investigated in Antarctic rhodophytes, Kallymenia antarctica and Palmaria decipiens, collected around King George Island during the summer of 2000. In K. antarctica specific growth rate, based on thallus area or fresh weight, decreased with increasing solar irradiances while P. decipiens were relatively insensitive to the effects of light. It is noticeable that the presence or absence of UV-B had no significant effect on growth for either species. However, K. antarctica showed a more pronounced reduction in chlorophyll (Chl a) concentrations at higher irradiances in the presence of UV-B. In P. decipiens, Chl a concentrations did not differ despite radiation level fluctuations being lower albeit than initial measurements. Thallus thickness was greater in K. antarctica than in P. decipiens. There were higher relative amounts of UV-absorbing pigments (UVAPs) in P. decipiens than in K, antarctica. The single absorbance peak obtained from the methanol extracts was resolved into three (316,332 and 346nm) in K. antarctica and four peaks (315,326,333 and 349 nm) in Palmaria as a result of the fourth-derivative. After 7 days exposure to solar radiation, the amount of UVAPs in K. antarctica was significantly reduced to a similar degree at all light levels, whereas that of P. decipiens remained unchanged except at 5% of surface irradiance. High performance liquid chromatography (HPLC) analysis of purified extracts indicated that P. decipiens possesses porphyra-334 in addition to three other mycosporine-like anlino acids (MAAs; asterina-330, palythine, shinorine), which are commonly present in K. antarctica. Significantly lower tolerance of K. antarctica to high levels of solar radiation may be connected with its usual absence in the eulittoral, while the active growth and elastic pigment responses of P. decipiens over a wide range of solar irradiance levels up to full sunlight seems to correspond well with its wide vertical distribution from rock pools down to 25-30m.

• 한국식품영양과학회지
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• 제26권1호
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• pp.10-16
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• 1997

김의 유용성분을 식품가공에 응용키 위한 기초적 연 구로 건조김과 배소김을 에탄을 농도를 달리 하여 추출하고 추출물의 수율, 단백질, 다당, 핵산, 타우린, 클로로필 및 카로티노이드의 함량, 갈색도 및 주요 추출처리구의 관능적 특성을 검토하였다. 단백질, 다당질 및 핵산 성분은 에탄을 농도가 낮을수록 높은 추출성을 보였으나 단백질의 경우 건조김이, 다당 및 핵산의 경우에는 배소김이 상대적으로 3배 이상 높은 추출성을 보였다 타우린은 건조김이나 배소김에 관계없이 0~70%에탄을 범위에서 1,000mg%이상의 높은 추출성 을 보였다. 카로티노이드의 경우는 95% 에탄을 농도에서 건조김 146.6mg%, 배소김 138.4mg%로서 최대를 보였으나 이 수준은 메탄올/아세톤을 혼합용매로 추출하는 경우의 66~80% 수준이었다. 유리 당과 아미노산 의 반응을 반영하는 갈변도는 배소김을 대상으로 한 경 우 50~60% 에탄을 추출물이 가장 높게 나타난 반면 추출수율은 물만을 용매로 한 경우가 26.3~27.5%로 최대를 보였다. 한편 주요추출물의 관능특성을 조사한 결과, 배소김의 추출물이 맛과 향 등 관능적 측면에서 우수한 것으로 판단되어 배소김을 대상으로 한 물/에탄을 추출물이 각종 식품소재로서 응용가치가 클 것으로 평가되었다.