• 한국산학기술학회논문지
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• 제16권2호
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• pp.1200-1206
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• 2015

신약 개발의 주요 표적이 되는 G-protein coupled receptor (GPCR)은 대부분의 생리적 활동에 관여하며 다양한 질병과 질환들에 관련되어 있다. GPCR을 타겟으로 하는 의약개발 연구에서 필수적인 실험방법으로 많이 활용되고 있는 세포기반 스크리닝 기술들은 사용되는 세포의 상태에 따라 데이터의 질이 좌우되는데 최근, 실험에 사용할 세포를 매번 배양하면서 소모되는 비용과 데이터의 변동을 줄이기 위해 냉동보관 세포를 적용하는 추세이다. 이에 본 연구에서는 단일 세포를 많은 양으로 배양하고 냉동 보관한 다음 사용되는 세포의 반응을 최적화하기 위하여 칼슘 검출을 위한 광 단백질이 포함된 세포주에 calcium sensing receptor와 urotensin II receptor가 안정적으로 발현되는 안정화 세포를 제작하고 $-80^{\circ}C$에서 보관한 다음 7 일 간격으로 실험했을 때 효능제와 길항제 반응을 비교하였다. 실험결과 보관기간이 증가함에 따라 세포 신호 값이 감소하였지만 $EC_{50}$와 $IC_{50}$ 값의 변화는 나타나지 않았다($EC_{50}:3.46{\pm}1.36mM$, $IC_{50}:0.49{\pm}0.15{\mu}M$). 그러나 액체질소에서 보관한 세포의 경우에서는 비냉동 세포와 비교하여 세포 신호 값이 감소했지만 보존기간에 따른 변화가 나타나지 않았으며 기간에 따른 $IC_{50}:0.49{\pm}0.15{\mu}M$와 $IC_{50}$의 변화도 없었다. 보관기간이 경과 될수록 세포의 신호 값이 감소하는 것은 세포 손상도 증가가 원인인 것으로 판단되며, 이러한 결과들로부터 장기간 냉동 보관을 위해서는 액체질소를 이용하는 것이 가장 효과적이고 한 달 이내 단기간 사용의 목적으로는 $-80^{\circ}C$ 보관조건도 가능할 것으로 판단된다. 이와 같이 냉동세포의 적극적인 활용을 통하여 초기 스크리닝 과정에서 나타나는 실험 유동성을 감소시킬 수 있을 것으로 예상된다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.74-74
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• 2003

In present study, attempts were made to preserve abalone (Haliotis discus hannai) sperm in liquid form at low temperature, to evaluate the effect of various diluents in short-term storage on sperm, and cryopreservation procedures were optimized for the cryoprotectants as well as freezing rates, in terms of the motility and survival rate, and the ultrastructural changes of sperm after short-term storage and cryopreservation were observed. The abalone sperm reached maximum motility until about 4min after activation. The motility was constant for about 16min, after which it dropped gradually, and about 50min later all motility ceased. Threshold activation of sperm was found in 40% artificial seawater (ASW), and motility increased as the concentration of ASW increased. In Hanks balanced salt solution without calcium (Ca-Free HBSS, 300 and 400 mOsmol/kg) and 10%, 20%, and 30% ASW the sperm was immotile, and motility once again restored incompletely only in HBSS of 300 and 400 mOsmol/kg, 20% and 30% ASW after 100% ASW was added. Sperm motility was extended following 20 days of cold storage only in 70% and 100% ASW. A high motility index of 3.5-4.5 was observed for the first 8 days in 70% and 80% ASW. In other diluents sperm motility was constant less than 10 days, and the motility index was obviously lower than that of sperm in 70% and 100% ASW. After 20 days of cold storage survival rates of 10.2%-20.7% were obtained in ASW and 300 mOsmol/kg HBSS, and that in 400 HBSS (65.3%) was significantly higher than others. The constant period of sperm motility stored in 70% ASW was longer obviously than that in 100% ASW after 6 days of storage, and the time to maximum motility of sperm stored in 70% increased gradually, while the difference in which of sperm in 100% ASW was not significant. The sperm plunged into liquid nitrogen all died except that sperm using 15% glycerol as cryoprotectant restored 10.4% of motility. The highest motility index (3.4) was obtained with 5% glycerol and freezing procedure: $50^{\circ}C$/min from $20^{\circ}C$ to $-80^{\circ}C$.

• 한국축산시설환경학회지
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• 제14권1호
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• pp.15-22
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• 2008

본 연구는 효소복합체 처리가 양돈분뇨의 액비화 과정의 악취제어 가능성을 조사하기 위하여 액비저장 탱크에 4주간 저장하면서 효소복합체 처리, 폭기 처리, 효소와 폭기 동시 처리 및 대조구로 나누어 비교하였다. 또한 효소복합체를 돈사에 살포하여 돈사내 공기의 질과 양돈장 부지경계선에서의 복합악취농도를 조사하였는데, 그 결과를 요약하면 다음과 같다. 효소복합체와 폭기 처리는 양돈분뇨의 액비화 과정의 암모니아와 황화수소 농도에 영향을 미치는 것으로 조사되었으며, 암모니아와 황화수소 농도는 4주간의 액비화 과정 동안 지속적으로 감소되었다. 효소복합체의 일정 수준 처리는 양돈분뇨 액비화 과정의 악취저감을 위한 효율적인 수단이 될 수 있을 것으로 판단된다. 효소복합체와 폭기 처리는 양돈분뇨의 액비화 과정의 총질소, 총인 및 암모니아성 질소 농도에 영향을 미치는 것으로 조사되었으며, 효소복합체 처리는 양돈분뇨 액비의 품질 유지와 악취저감을 위한 하나의 기술적 대안으로 충분한 것으로 보인다. 효소복합체 살포는 돈사내 공기의 질을 개선하고 양돈장의 부지경계선에서의 복합악취 저감에도 효과적으로 작용하는 것으로 나타났다. 이상의 결과를 요약하면, 효소복합체 처리는 양돈분뇨 액비화 과정의 악취제어와 고품질 액비제조 가능성이 인정되며, 돈사 내부 및 양돈장 환경개선과 악취저감 효과가 있는 것으로 판단된다.

• 한국자원식물학회지
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• 제33권6호
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• pp.689-695
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• 2020

This study was conducted to improve and supplement the system of cryopreservation for adventitious bulbs induced by tissue cultured bulb-scales of lily (Lilium spp.) cvs. 'Milky way'. The explants, bulblets and bulb-scale-bulblets, were treated to low temperature (4℃) for 7 days prior to the pre-culture. The adventitious bulbs were pre-cultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3 and 0.7M). The pre-cultured adventitious bulbs were treated to loading solution (LS1 or LS2, C4 or C6) containing 35% of PVS3 (LS1, C4) or 40% of PVS3 (LS2, C6) for 40 min and exposed to dehydration solution (PVS3, B1) containing 50% glycerol and 50% sucrose for 60 min at 25℃. The adventitious bulbs were moved onto droplets containing 3 µl PVS3 on sterilized aluminum foils, and then soaked into liquid nitrogen (LN) for 60 min. The result of highest regrowth rate as 65.7% was obtained in cold treatment (4℃), osmoprotected with LS1 solution, and cultured in PCM3 medium by using bulb-scale-bulblet for cryopreservation. This result shows that droplet-vitrification could be used as a promising method for long-term storage of lily genetic resource.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.35-35
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• 2021

This study was conducted to improve and supplement the system of cryopreservation for adventitious bulbs induced by tissue cultured bulb-scales of lily (Lilium spp.) cvs. 'MilkyWay'. The explants, bulblets and bulb-scale-bulblets, were treated to low temperature (4℃) for 7 days prior to the pre-culture. The adventitious bulbs were pre-cultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3 and 0.7M). The pre-cultured adventitious bulbs were treated to loading solution (LS1 or LS2, C4 or C6) containing 35% of PVS3 (LS1, C4) or 40% of PVS3 (LS2, C6) for 40 min and exposed to dehydration solution (PVS3, B1) containing 50% glycerol and 50% sucrose for 60 min at 25℃. The adventitious bulbs were moved onto droplets containing 3 ㎕ PVS3 on sterilized aluminum foils, and then soaked into liquid nitrogen (LN) for 60 min. The result of highest regrowth rate as 65.7% was obtained in cold treatment (4℃), osmoprotected with LS1 solution, and cultured in PCM3 medium by using bulb-scale-bulblet for cryopreservation. This result shows that droplet-vitrification could be used as a promising method for long-term storage of lily genetic resource.

• 대한기계학회논문집B
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• 제40권1호
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• pp.1-7
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• 2016

환원제를 이용하여 배기가스 내의 NOx를 질소로 환원시키는 요소수 SCR 시스템은 다른 후처리 장치들 중에서 가장 효율적인 장치로 알려져 있다. 차량에 적용되는 SCR 장치는 32.5wt%의 공융혼합물을 이용한다. 이러한 혼합물의 가장 큰 장점 중의 하나는 $-11.7^{\circ}C$에서 얼기 때문에 추운 환경에서 응고를 피할 수 있다는 것이다. 한편, 이러한 추운 환경에서 시동시 필요한 수용액을 충분히 공급하기 위해서는 고체상을 가열해야 한다. 따라서 본 연구에서는 Fluent 상용코드를 이용하여 3차원 비정상 전산해석을 통한 냉각수 및 전기가열 방식에 따른 고체상 요소수의 시간에 따른 액상비 및 온도분포와 같은 해동 및 열전달 특성을 고찰하였다. 본 연구를 통하여 전기히터 가열 방식이 냉각수 방식보다 효율적임을 확인하였다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.73-73
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• 2003

The present study examined the possibility of long term storage, by cryopreservation in liquid nitrogen, of the sperm of Filefish (Thamnaconus septentrionalis), and the changes in motility, survival rate and ultrastructure of the sperm after freezing and thawing. The sperm was collected by stripping and stored on ice until experiments. For selection of the immobilizing solution, diluted artificial seawater (ASW) of 20, 30 and 40% were tested. The sperm motility was significantly inhibited in 30% ASW, and restored entirely after 100% ASW was added again. Two cryoprotectants, dimethyl sulfoxide ($Me_2$SO) and glycerol, were added to 30% ASW to formulate the extenders at the concentrations between 5 to 20% by volume for freezing. The sperm was diluted at the ratio of 1 :6 with the extenders, inserted into 0.5ml plastic straws and frozen at a freezing rate of $50^{\circ}C$/min to $-100^{\circ}C$ after equilibration for 10 min at room temperature, followed by plunging into liquid nitrogen. The straws were thawed in a $30^{\circ}C$ water bath for 15 sec. The highest post-thawed sperm motility and survival rate were obtained with 5% glycerol Afterward, the effect of different freezing rates was examined using 5% glycerol as a cryoprotectant, and the rate of $20^{circ}C/min to $-80^{\circ}C$ showed the best result Some ultrastructural changes of sperm, such as the detachment of plasmatic and nuclear membranes, destruction of mitochondria, were observed after cryopreservation. Morphological normality of the sperm in 5% glycerol frozen at the ratio of 1$0^{\circ}C$/min to $-80^{\circ}C$ was better than that of others.

• Journal of Forest and Environmental Science
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• 제32권3호
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• pp.311-322
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• 2016

Since forest trees form the basis of forest ecosystem, their prolong subsistence is crucial for various flora and fauna. The foremost challenges to sustain the forest ecosystem comprise of the declining forest tree population accompanied with structural changes due to afforestation and exploitation of forest area, environment changes, pests, pollution, and introgressive hybridization. For ex situ conservation approach, in vitro techniques encompass basic role for conserving tree genetic resources, predominantly where natural propagules like recalcitrant seed might not be appropriate for long-term conservation. The practice includes restricted growth techniques, conventional micropropagation, production and storage of synthetic seeds, and cryopreservation. Even though these practices have been applied chiefly to herbaceous species, but recently, woody species were also focused upon. Key conceptions, challenges and techniques for forest tree seed conservation are discussed briefly in this review with special emphasis on some successful cryopreservation approaches for long-term storage.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.399-403
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• 2002

Squeeze film dampers (SFDs) are designed and analyzed for radial superconducting bearings. The designed SFDs are mounted on the superconductors submerged in liquid nitrogen such that the dampers should supply additional damping to the relatively underdamped superconducting bearing support . Basic theory of SFD assembled with superconductors is introduced. Rotordynamic simulations are provided to support the feasibility of the superconducting bearings mounted on SFDs for a horizontal flywheel energy storage system.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권9호
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• pp.442-445
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• 2006

In order to realize the commercial application of HTSC materials, it is necessary to develop the fabrication process of high Tc oxide superconductor materials with desired shape and for practical application and high critical current density as well as good mechanical strength which can withstand high lorenz force generated at high magnetic field. Much studies have been concentrated to develop the fabrication technique for high critical current density but still there are a lot of gap which should be overcome for large scale application of HTSC materials at liquid nitrogen temperature. Recently some new fabrication techniques have been developed for YBaCuO bulk superconductor with high mechanical strength and critical current density. In this project, the establishment of fabrication condition and additive effects of second elements were examined so as to improve the related properties to the practical use of YBaCuO superconductor, and we reported the production of the YBaCuO high Tc superconductor by the pyrolysis method.