• 제목/요약/키워드: Slow and rapid methods

검색결과 79건 처리시간 0.024초

회분식 생물반응기를 이용한 BDOCrapid와 BDOCslow 결정 (Determination of BDOCrapid and BDOCslow using Batch Bio-reactor)

  • 손희종;노재순;강임석
    • 한국물환경학회지
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    • 제20권4호
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    • pp.357-364
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    • 2004
  • In this study, biodegradable organic matter was divided into a rapidly biodegradable fraction($BDOC_{rapid}$) and a slowly biodegradable fraction($BDOC_{slow}$) for various waters with different types of DOC. These fractions($BDOC_{rapid}$ and $BDOC_{slow}$) were defined by using a shaking incubation method modified from Carlson's method. Also, in this study, optimum incubation time and accuracy were investigated to determine $BDOC_{rapid}$ and $BDOC_{slow}$. When suspended bacteria obtained from raw water and BAC effluent, or attached bacteria from BAC was respectively used as an inoculum, the difference in total BDOC($BDOC_{total}$) was minimal. Therefore, total BDOC was determined in 7~8 days by the shaking method, which is comparable with Servais's method by which BDOC was determined in 28 days. In addition, the difference of BDOC between these two methods was within 7%. Although $BDOC_{rapid}$ and $BDOC_{slow}$ were effectively determined by a method defined by Klevens, the difference in optimal incubation time was significant for different water samples. However, when using the shaking method, optimal incubation time for $BDOC_{rapid}$ was found to be 3 days, therefore, the $BDOC_{rapid}$ was defined as the difference between $DOC_0$ and $DOC_{3days}$, and $BDOC_{slow}$ was defined as the difference between $BDOC_{total}$ and $BDOC_{rapid}$. As a conclusion, for determining the fraction of BDOC using the shaking method, the concentrations of an inoculurns and optimal incubation times used in this study were very effective.

구강상피세포의 냉동보관 방법에 따른 세포생존률 비교 (COMPARISON OF VIABILITY OF ORAL EPITHELIAL CELLS STORED BY DIFFERENT FREEZING METHODS)

  • 백도영;이승종;정한성;김의성
    • Restorative Dentistry and Endodontics
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    • 제34권6호
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    • pp.491-499
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    • 2009
  • 본 연구의 목적은 구강상피세포를 배양한후 각기 다른 조건의 냉동 보존법으로 6일간 보존시 각각의 세포의 활성도를 Cell counting, WST-1, Clonogenic capacity의 방법을 이용하여 비교 평가하기 위함이다. 각 실험군당 $1\times10^6$개의 세포를 다음의 방법으로 6일간 냉동 보존한다. Freezing container에 담아 $1^{\circ}C$/min의 냉동속도로 $-70^{\circ}C$까지 냉동 후 $-196^{\circ}C$에 냉동하여 보관한 일반 냉동 보존군, 세포를 바로 $-196^{\circ}C$의 액화질소에 넣어 냉동한 급속 냉동 보존군, $4^{\circ}C$에서 $-35^{\circ}C$까지 $-0.5^{\circ}C$/min속도로 서서히 냉동시킨 뒤 $-196^{\circ}C$에 냉동한 저속 냉동 보존군, 2 Mpa, 3 Mpa의 압력을 가하고 $-0.5^{\circ}C$/min속도로 $4^{\circ}C$에서 $-35^{\circ}C$까지 서서히 냉동시킨 뒤 $-196^{\circ}C$에 냉동한 2 Mpa, 3 Mpa압력 저속 냉동 보존군으로 나누었다. 6일 후 냉동되었던 세포를 급속 해빙하여 각각의 Cell counting, WST-1, Clonogenic capacity 값을 측정하여 비교하였다. 실험 결과 2 Mpa혹은 3 Mpa의 압력을 이용한 저속 냉동법이 저속 냉동법 및 급속 냉동법 보다 세포 활성도에 있어 우수한 경향을 나타내었다.

생쥐배아의 냉동보존에 있어서 여러 조건의 평가 - 저속 처리단계와 급속 처리단계, 배양액, 세포기 (The Evaluation of Various Conditions in the Cryopreservation of Mouse Embryos - Rapid and Slow Method of Cryopreservation, Culture Media and Cell Stages)

  • 이승연;권주택;송희원;조윤희;이기숙;류철희;김종덕
    • Clinical and Experimental Reproductive Medicine
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    • 제26권2호
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    • pp.127-135
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    • 1999
  • Cryopreservation is able to store the surplus pre-embryos for freezing and furthermore thawing and transfer in a subsequent cycle. Cryopreserving cells which are maintaining their viability are the very complex process. This study has been carried out in order to find the effects of cryopreservation steps, freezing media and embryonic stages on the rates of viability and development of cryopreserved mouse embryos. Female ICR mice ($6{\sim}8$ weeks old) were induced to superovulate by sequential intraperitoneal injection of 5 IU PMSG and 5 IU hCG 48h apart. Mouse embryos were collected according to its developmental stage after the injection of hCG. Embryos were cryopreserved not only by cryoprotectant step (1 step${\sim}$4 step) but also in a variety of media (HTF, IVF medium, D-PBS) and cell stage. The results were as follows: There is no clear advantage in these freezing media of rapid method, but 4 cell and 8 cell of slow method (2, 3, 4 step) have advantage in D-PBS. The development of embryos according to cell stage become greater in 8 cell stage. In the treatment steps of cryopreservation, the development of embryo to blastocyst was similar among rapid method, but the development of 4 cell and 8 cell embryos to blastocyst according to slow method was better than rapid method.

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Association of CYP2E1 and NAT2 Polymorphisms with Lung Cancer Susceptibility among Mongolian and Han Populations in the Inner Mongolian Region

  • Zhang, Jing-Wen;Yu, Wan-Jia;Sheng, Xiao-Min;Chang, Fu-Hou;Bai, Tu-Ya;Lv, Xiao-Li;Wang, Guang;Liu, Su-Zhen
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권21호
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    • pp.9203-9210
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    • 2014
  • Purpose: To explore associations of CYP2E1 and NAT2 polymorphisms with lung cancer susceptibility among Mongolian and Han populations in the Inner Mongolian region. Materials and Methods: CYP2E1 and NAT2 polymorphisms were detected by PCR-RFLP in 930 lung cancer patients and 1000 controls. Results: (1) Disequilibrium of the distribution of NAT2 polymorphism was found in lung cancer patients among Han and Mongolian populations (p=0.031). (2) Lung cancer risk was higher in individuals with c1, D allele of CYP2E1 RsaI/PstI, DraI polymorphisms and slow acetylation of NAT2 (c1 compared with c2, OR=1.382, 95%CI: 1.178-1.587, p=0.003; D compared with C, OR=1.241, 95%CI: 1.053-1.419, P<0.001; slow acetylation compared with rapid acetylation, OR=1.359, 95%CI:1.042-1.768, p=0.056) (3) Compared with c2/c2 and rapid acetylation, c1/c1 together with slow acetylation synergetically increased risk of lung cancer 2.83 fold. (4) Smokers with CYP2E1 c1/c1, DD, and NAT2 slow acetylation have 2.365, 1.916, 1.841 fold lung cancer risk than others with c2/c2, CC and NAT2 rapid acetylation, respectively. (5) Han smokers with NAT2 slow acetylation have 1.974 fold lung cancer risk than others with rapid acetylation. Conclusions: Disequilibrium distribution of NAT2 polymorphism was found in lung cancer patients among Han and Mongolian populations. Besides, Han smokers with NAT2 slow acetylation may have higher lung cancer risk compared with rapid acetylation couterparts. CYP2E1 c1/c1, DD and NAT2 slow acetylation, especially combined with smoking, contributes to the development of lung cancer. CYP2E1 c1/c1 or DD genotype and NAT2 slow acetylation have strong synergistic action in increasing lung cancer risk.

농촌지역의 효율적인 간이 상수처리에 관한 연구 (A Study on Efficient Simple Water Supply System in Rural Areas)

  • 이홍근;백남원;백도현
    • 한국환경보건학회지
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    • 제22권3호
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    • pp.103-115
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    • 1996
  • The purpose of this study was to establish acceptable criteria for the design of simple water treatment plant in rural areas. To develop efficient simple water treatment methods for rural areas, water quality in the study areas was investigated and rapid and slow filtrations in pilot-scale were tested under various conditions. The main results of this study are as follows. It was found that the water qualities of the study areas exceed the drinking water standards, which implies that some treatments are required in rural areas. Treatment efficiencies of both rapid sand and dual-media (sand and anthracite) filtration without pre-treatment such as flocculation and sedimentation are very low, which were turned out to be unadequate for the rural areas. Treatment efficiencies of both vertical and horizontal slow filtration without chlorination are very high for consumed $KMnO_4, NH_3-N, NO_3-N$, turbidity, and very low for coliform and bacteria. Treatment efficiencies of both vertical and horizontal slow filtration with chlorination are very high over the most pollutants. A slow filtration with chlorination is efficient for the rural areas. An adequate depth of sand layer is over 60 cm. A horizontal filtration is more economical than a vertical filtration. A horizontal filtration can be operated for a relatively long periods of time without sand washing or replacement because clogging is removed by simple back-washing.

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수도권 광역전철 개선방안 - 급행화, 운전, 배선을 중심으로- (Methods of Improvement of Metropolitan Electric Railways - For Express Trains, Operations and Tracks -)

  • 한우진
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 춘계학술대회 논문집
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    • pp.1146-1152
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    • 2005
  • Now many metropolitan electric railways are being constructed on the metropolitan area. But railways now in service have some inefficiency. These railways are operated like subways, for example, all slow trains and fixed train set. So this paper proposes the methods of improvement. For making rapid train, it is showed ' philosophy of rapid train ' that makes rapid train to be main service. And for effective operation, it is introduced flexible train set and 'separation-unification operation'. And for smart railway tracks, it is introduced making loop track and direct connection track between radiating and circular railways. By these methods, a master plan of improvement of metropolitan electric railways is made and vision of the railways becomes common to passengers.

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김치저장성 향상을 위한 동결방법이 배추조직의 물성변화에 미치는 영향 (Effect of Freezing Methods for Kimchi Storage Stability on Physical Properties of Chinese Cabbage)

  • 양진한;박소희;유진현;임호수;황성연;조재선
    • 한국식생활문화학회지
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    • 제18권2호
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    • pp.105-110
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    • 2003
  • 김치를 $10^{\circ}C$에서 8일간 숙성시켜 산도 $0.6{\sim}0.7%$로 숙성된 김치를 $-70^{\circ}C$$-20^{\circ}C$로 냉동하여 $-20^{\circ}C$에서 저장하면서 배추 조직의 elasticity, hardness, 세포 조직의 변화, 드립양을 실험한 결과는 다음과 같다. $-70^{\circ}C$에서 급속 동결한 것과 $-20^{\circ}C$에서 완만동결한 냉동 김치중 배추조직의 elasticity는 냉동저장 15일까지 감소하다 일정하게 유지되었고 hardness는 거의 변화가 없었으며 냉동 방법에 따른 변화도 거의 나타나지 않았다. 투과 전자현미경으로 관찰한 결과 control의 경우 세포벽이 매우 두꺼우며 세포의 모양들이 잘 보존되어 있는 것을 볼 수 있었고 $-20^{\circ}C$로 냉동 처리하여 해동시킨 세포벽들은 많이 손상되어 있음을 볼 수 있었으며 $-70^{\circ}C$로 급속 냉동 시료의 경우 세포벽의 손상 정도가 $-20^{\circ}C$로 냉동 처리한 시료보다 덜 파괴되어 있음을 볼 수 있었다. 한편 냉동 저장기간 동안 드립의 손실량의 변화는 $-70^{\circ}C$로 냉동 처리한 시료의 드립양은 $3{\sim}4%$정도로 $-20^{\circ}C$로 냉동 처리한 시료의 $5{\sim}6%$에 비해 적은 것을 알 수 있었다.

DGGE 기법을 이용한 생물활성탄 공정의 부착 박테리아 군집분석 (Analysis of Attached Bacterial Communities of Biological Activated Carbon Process Using DGGE Method)

  • 손희종;최진택;손형식;이상준
    • 대한환경공학회지
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    • 제34권8호
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    • pp.533-540
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    • 2012
  • BAC 공정 운전초기부터 부착 박테리아들의 생체량이 정상상태(steady-state)에 도달한 이후까지 $BDOC_{total/rapid/slow}$ 제거율의 변화와 DGGE와 ATP 분석을 통하여 부착 박테리아들의 군집과 생체량을 평가하였다. 용존 유기물질 제거율 평가에 따른 BAC 공정의 정상상태 도달 여부 평가결과를 보면 DOC의 경우 운전 bed volume 27,500 부근에서 BAC 공정이 정상상태에 도달하였고, $BDOC_{rapid}$$BDOC_{total/slow}$의 경우는 각각 운전 bed volume 15,000 부근과 32,000 부근에서 정상상태에 도달하였다. BAC 공정의 운전기간 증가에 따른 HPC 및 ATP 농도 분석을 통한 부착 박테리아들의 생체량 평가결과 bed volume 22,500 이후로 거의 일정한 생체량을 유지하였으며, 이 때 HPC와 ATP 농도는 각각 $3.3{\times}10^8$ cells/g 및 $2.14{\mu}g/g$ 정도로 나타났다. DGGE를 이용하여 운전기간 증가에 따른 BAC 부착 박테리아들의 군집분석 결과 운전초기(bed volume 8,916)의 경우 분석가능한 DGGE band 개수가 5개였으나 운전기간 증가에 따라 분석가능한 DGGE band 개수는 최대 11개로 증가하였다. 또한, DGGE를 이용한 박테리아 군집분석 결과 BAC 운전기간의 증가에 따라 다양한 박테리아 그룹들이 존재하였고, Pseudomonas fluorescens, Acinetobacteria와 유사한 uncultured bacterium, uncultured Novosphingobium sp. 및 Flavobacterium frigidarium은 운전초기 단계부터 지속적으로 부착 박테리아 군집을 형성하였고, 전체적으로 Proteobacteria 그룹이 비교적 높은 비율로 우점하였다.

한국재래닭 (오계) 원시생식세포의 완만동결과 급속동결의 비교 (Comparison of Vitrification and Slow Freezing for the Cryopreservation of Chicken Primordial Germ Cell (Ogye))

  • 김성우;고응규;변미정;도윤정;한재용;김동훈;성환후;김현
    • Journal of Animal Science and Technology
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    • 제55권5호
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    • pp.417-425
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    • 2013
  • 동결 닭 PGCs의 생식계열 키메라를 이용한 생체에의 복원을 실용화 하기 위해서는, 닭 PGCs의 동결보존기술의 향상에 의해 동결 및 융해 후의 많은 생존세포를 확보 하는 것과, 생식계열 키메라의 제작효율을 높이는 것이 반드시 필요하다. 닭 PGCs는 배양 5.5일령의 닭 원시생식선으로부터 채취하고, ACS 방법에 의해서 순수 닭 PGCs를 분리했다. 닭 PGCs의 동결보존실험결과 다음의 4종류의 동결방법을 각각 비교 검토했다. 1. 플라스틱 스트로에 의한 완만동결법 (SF), 동결보호물질은 2M 에틸렌 글리콜 (EG), 2. 스트로에 의한 급속동결법 (RF), 8M EG + 7% PVP, 3. 동결용 Cryotube에 의한 SF, 2M EG, 4. 튜브에 의한 SF, 10% DMSO. 동결 및 융해 후의 PGCs의 생존율은 각각 76.4%, 70.6%, 80.5%, 78.1%로 관찰되었다.

생쥐배아의 동결보존에 관한 실험적 연구 (The Experimental Study on Cryopreservation of Mouse Embryo)

  • 이여일;권영숙;박현정
    • Clinical and Experimental Reproductive Medicine
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    • 제28권1호
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    • pp.55-63
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    • 2001
  • Objectives: This study was carried out to evaluate the effects of embryonic stage, cryoprotectant, and freezing-thawing method on the rates of survival and development of the cryopreserved mouse early embryo and finally to establish the cryopreservation method of surplus embryos obtained during assisted reproductive technology (ART). Materials and Methods: Two to eight cell embryos were obtained from oviducts of mated $F_1$ hybrid female mice superovulated by pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Two-step 1,2-propanediol (PROH), dimethylsulfoxide (DMSO) and 4-step PROH DMSO were used as cryoprotectant and dehydration and rehydration method of embryos, and slow-cooling or rapid-cooling method was used as frozen program. The survival rates of embryos were measured after thawing and rehydration, and the developmental rates of embryos were compared and observed during culturing embryos for 24, 48, 72, 96 hrs. Results: As for the survival and development rates of embryos according to embryonic stage, the survival rate of 2 cell stage in PROH and DMSO was significantly higher than 4-8 cell (64.5% versus 62.1 %,79.7% versus 73.2%) (p<0.01, p<0.01), but the development rates of 4-8 cell embryos in PROH and DMSO were significantly higher than 2 cell embryos for whole culture period (p<0.01) and the development rates of 4-8 cell embryos in PROH were significantly higher than 2 cell embryos in DMSO (p<0.01). As for the survival and development rates of embryos according to cryoprotectant, the survival rate of 2 cell embryo in DMSO was significantly higher than that in PROH (74.4% versus 64.5%) (p<0.01), whereas the development rate of embryos was not differ till 24 hrs. The developmen1 rate from morular to hatching blastocyst, however, was significantly higher in PROH than in DMSO during 48 hr (p<0.01). The survival rate of 4-8 cell embryo was 62.1% in PROH and 73.2% in DMSO. The development rates of embryo in PROH were significantly higher for whole culture periods (p<0.01, 0.05). In respect to the effect of freezing and thawing program on the survival and development rates of embryos, method of slow cooling and rapid thawing was more effective than that of rapid cooling and rapid thawing. Conclusions: The survival rate of embryo in 2 cell stage was higher than in 4-8 cell stage, and PROH appears more effective cryoprotectant than DMSO because PROH showed better development rates of embryos in 2 and 4-8 cell stage. Moreover, slow cooling and rapid thawing method was considered as the best cryopreservation program.

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