• 대한수의학회지
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• 제38권2호
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• pp.394-400
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• 1998

Cryopreservation of embryos by vitrification is a simple method to preserve bovine embryos for subsequent embryo transfer, but embryonic viability after vitrification has been inconsistent and low compared with conventional slow freezing. The aim of the present study is to examine the effect of serum or serum albumin in a vitrification solution and epidermal growth factor(EGF) or fibroblast growth factor(FGF) on in vitro viability of bovine blastocysts frozen by vitrification. Bovine blastocysts were produced by in vitro maturation, fertilization of follicular oocytes and culture of embryos in a synthetic oviduct fluid medium(SOFM) containing BSA and 19 essential and nonessential amino acids. Blastocysts with excellent or good morphology were selected at 7 or 8 days after culture and utilized for vitrification. In experiment 1, blastocysts were vitrified in a solution containing semi-fetal calf serum(SFCS) or BSA(5 or 10mg/ml) and then their subsequent viabilities were examined by culturing thawed embryos in a SOFM containing BSA and 19 amino acids. Effect of EGF or FGF added to a SOFM containing polyvinyl alcohol(PVA) on the viability of vitrified-thawed blastocysts was investigated in experiment 2. BSA added at 5 or 10mg/ml to a vitrification solution showed significantly higher(p < 0.05) developmental rate to expanded and hatching blastocysts than SFCS, but there was no significant difference in the developmental rate to hatched blastocysts after thawing. Supplementation of a culture medium with EGF and/or FGF significantly increased(p < 0.05) embryo development to expanded blastocysts compared with control but showed no beneficial effect on the development to hatching or hatched blastocysts. Coculture of thawed embryos with granulosa cells in a TCM 199 containing 10% fetal calf serum(FCS) showed the highest developmental rate to expanded, hatching and hatched blastocysts among the groups tested. In conclusion, supplementation of a vitrification solution with BSA at 5mg/ml and culture of thawed blastocysts in a medium containing EGF and/or FGF can improve in vitro viability of bovine blastocysts frozen by vitrification.

• Clinical and Experimental Reproductive Medicine
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• 제20권2호
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• pp.165-176
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• 1993

These studies were carried out to investigate the optimal freezing protocol for 2 cell mouse embryos and to find the probability of quality control with 2-cell embryos frozen. The embryos showed the best survival by the protocol composed of a freezing solution with the cryoprotectants(1.5M propanediol + 0.1M sucrose), and a 2-steop thawing method(room temperature, 20 sec-37$^{\circ}C$, 20 sec). The developmental ability of frozen-thaw 2-cell embryos did not differ from that of fresh 2-cell embryos in m-KRB medium with 0.4% bovine serum albumin. But development of frozen-thaw embryos was depended on the supplements of the medium. In the albumin-free medium, the developmental rate(rate of blastocysts) was significantly reduced, compared with that in the medium with 0.4% BSA. Also, when frozen-thaw embryos were cultured in the meduim with human fetal cord serum(HCS), the developmental rate of frozen-thaw embryos was sligtly reduced, compared with that of fresh 2-cell embryos. Finally, frozen-thaw 2-cell mouse embryos were more sensitive to the toxic agent of disposable-plastic syringe. Therefore, toxicity of medium could be effectively detected by frozen-thaw 2-cell mouse embryos.

• Clinical and Experimental Reproductive Medicine
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• 제42권3호
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• pp.94-100
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• 2015

Objective: The goal of this study was to ascertain optimal assisted hatching (AH) method in frozen embryo transfer. We compared the effect of depending on whether mechanical or laser-AH was performed before or after the vitrification of embryo development rate and blastocyst cell numbers. Methods: In order to induce superovulation, pregnant mare's serum gonadotropin followed by human chorionic gonadotropin were injected into 4- to 5-week-old female mice. 2-cell embryos were then collected by flushing out the oviducts. The Expanded blastocysts were recovered after the collected embryos were incubated for 48 hours, and were then subjected to artificial shrinkage (AS) and cross-mechanical AH (cMAH) or quarter-laser zona thinning-AH (qLZT-AH) were carried out using the expanded blastocysts before or after vitrification. After 48 hours of incubation, followed by vitrification and thawing (V-T), and blastocysts were fluorescence stained and observed. Results: The rate of formation of hatched blastocysts after 24 and 72 hours of incubation was significantly higher in the AS/qLZT-AH/V-T group than in the other groups (p<0.05). The cell number of the inner cell mass was higher in AS/V-T/non-AH and AS/V-T/cMAH groups than those of others (p<0.05). In the control group, the number of trophectoderm and the total cell number were higher than in the AS-AH group (p<0.05). Conclusion: The above results suggest that AS and AH in vitrification of expanded blastocysts lead to the more efficient formation of hatched blastocysts in mice.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.533-536
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• 2008

최근 농촌의 생활환경 개선 및 소득기반 조성을 위한 문화마을, 밭 기반 정비사업의 도로포장사업에서는 토양 고형화를 이용한 기계화 경작로 시공이 이루어지고 있다. 기계화 경작로 포장은 도로로서의 기능을 장기적으로 유지할 수 있는 소요강도 및 내구성을 확보할 수 있어야 하며, 금후 추진될 사업량에 대비하여 경제성, 내구성, 유지관리의 용이성, 환경 친화성 등을 만족시킬 수 있는 공법의 개발이필요하다. 본 연구는 이러한 농어촌 기계화 경작로를 대상으로 속경성이며, 수화 특성이 우수한 인산염 마그네시아 시멘트의 토양 고화재로서의 적용여부에 대해 연구하였다. 연구 결과 인산염 마그네시 시멘트 배합은 인산염 마그네시아(MAP:MgO)의 배합이 4 : 6에서 W/B = 50 wt%일 때 14MPa로 가장 큰 압축강도와 높은 수화열 특성을 나타냈으며, 대상토-고화재 동결융해 저항성 실험 결과, 인산염마그네시아 시멘트(MAP:MgO=4:6), W/B=50wt%를 기준으로 치환시료(점성토:표준사=4:6, 3:7) 배합이가장 우수하였으며, 인산염 마그네시아 시멘트(MAP:MgO=4:6):대상토의 비율이 4:6과 5:5 배합이 동결융해 후의 압축강도 값이 7.0 MPa 이상으로써 가장 우수한 것으로 나타났다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권5호
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• pp.393-399
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• 2004

Useful genes can be Screened from various environments by construction of metagenomic DNA libraries. In this study, water samples were collected from several lakes in mid Korea, and analyzed by T-RFLP to examine diversities of the microbial communities. The crude DNAs r were extracted by the SDS-based freezing-thawing method, and then further purified using an $UltraClean^{TM}$ kit (MoBio, USA). The metagenomic libraries were constructed with the DNAs partially digested with EcoR I, BamH I, and Sac II in Escherichia coli DH 10B using the pBACe3.6 vector. About 44.0 Mb of metagenomic libraries were obtained with average inserts 13-15 kb in size. The bphC genes responsible for degradation of aromatic hydrocarbons via mets-cleavage were identified from the metagenomic libraries by colony hybridization using the bphC specific sequence as a probe. The 2,3-dihydroxybiphenyl (2, 3-DHBP) dioxygenase gene (bphC ), capable of degradation of 2,3-DHBP, was cloned and its nucleotide Sequences analyzed. The genes consisted of 966 and 897 base pairs with an ATG initiation codon and a TGA termination codon. The activity of the 2,3-DHBP dioxygenase was highly expressed to 2,3-DHBP and Showed a broad substrate range to 2,3-DHBP, catechol, 3-methylcatechol and 4-methylcatechol. These results in-dicated that the bphC gene identified from the metagenomes derived from lake water might be useful in the development of a potent strain for degradation of aromatic pollutants.

• 한국양식학회지
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• 제11권1호
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• pp.67-75
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• 1998

감성돔 (Acanthopagrus schlegeli) 정자의 냉동 보존시 정자의 생리활성과 보존효과를 비교하기 위하여, 순환여과 사육시스템에서 사육한 전장 $25.9{\pm}1.7$ cm, 체중$292.8{\pm}53.7$ g의 성어로부터 얻은 정액을 재료로 하여 희석액별, 동해방지제별 해동후 정자의 활성, 생존율 및 알에 대한 수정능력을 평가하였다. 희석액별 냉동보존에서 해동정자의 생존율은 3% sodium citrate에서 $80{\pm}1.4$%로 가장 높았으나, 수정률은 5.4% glucose에서 $63.4{\pm}4.4$%로 가장 높았다. 동해방지제별 냉동보존에서 해동정자의 수정률은 5~15% glycerol을 동해방지제로 사용하였을 때, 50.1~69.4%로 DMSO 보다 나은 효과를 보였다. 감성돔 정자의 냉동보존을 위한 적정 희석액과 동해방지제는 5% glucose와 5% glycerol이었다. 냉동하지 않은 감성돔 정자의 머리는 구형으로 직경 $1.5{\pm}0.1$ ${\mu}$m, 길이 $1.3{\pm}0.1$${\mu}$m였으며, 치밀한 핵질로 채워져 있었다. 편모는 전형적인 9+2 구조를 나타냈다. 그러나 냉동후 해동시킨 정자중에서는 염색질의 과립화, 세포막의 이탈에 의한 그 용적이 커지는 구조변화를 보였다.

• 한국식품영양학회지
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• 제17권3호
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• pp.322-327
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• 2004

단백질 함량이 다른 밀가루로 데니쉬 페이스트리를 직날법으로 제조 후 급속 냉동시켜 냉동고에 12주간 저장하면서 4주 간격으로 해동ㆍ발효ㆍ굽기 한 제품의 부피, 수분함량, 조직감 및 품질평가의 결과는 다음과 같다. 1. 단백질 함량이 높은 밀가루로 만든 냉동 생지 제품의 부피가 가장 컸다. 2. 단백질 함량이 높은 밀가루로 만든 냉동 생지 제품의 수분함량이 높게 나타났으나 그 차이는 크지 않았다. 3. 단백질 함량이 높은 밀가루로 만든 냉동 생지 제품의 경도가 높게 나타났다. 4. 종합적인 품질평가는 단백질 함량이 높은 밀가루로 만든 냉동 생지 제품에서 높은 점수를 얻었다. 이상의 결과로 데니쉬 페이스트리 냉동 생지 제조시 단백질 함량이 높은 밀가루를 사용할 때 제품의 부피, 수분 함량, 품질 평가 등에서 우수한 효과를 나타냈으나 경도에는 그렇지 않았다.

• 한국터널지하공간학회 논문집
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• 제8권3호
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• pp.237-247
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• 2006

터널의 장기 내구성을 향상시키고 싱글쉘 터널공법을 적용하기 위해서는 고성능 숏크리트 라이닝의 사용이 필수적이라고 할 수 있다. 숏크리트에 적용되는 혼화재료 가운데, 실리카 흄과 같은 포졸란 재료들이 숏크리트의 강도와 내구성을 향상시키는데 주된 영향을 미친다고 할 수 있다. 또한 시멘트 광물계 급결제는 기존 급결제와 비교하여 응결이 빠르며 친환경적인 것으로 알려져 있다. 따라서 본 연구에서는 포졸란 재료인 메타카올린과 칼슘 알루미네이트 시멘트 광물계 급결제를 적용하여 습식 숏크리트의 성능을 향상시키는데 목표를 두었다. 메타카올린과 실리카 흄의 적용에 따른 성능을 비교하기 위하여 각각의 사용량을 시멘트 중량의 4%와 8%로 적용하였다. 또한 메타카올린과 실리카 흄을 시멘트 중량의4% 및 8%로 병용 혼입한 경우에 대해서도 검토하였다. 각 배합조건에 대해 배합된 숏크리트의 응결시간, 압축강도, 휨강도, 투수성 및 동결융해저항성을 측정한 결과, 숏크리트의 고성능화를 위해 실리카 흄의 대체 재료로서 메타카올린을 적용할 수 있음을 확인하였다.

• Clinical and Experimental Reproductive Medicine
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• 제29권1호
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• pp.37-44
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• 2002

Objective : Heat shock protein family is related to protective mechanism of cells by environmental changes. This study was performed to evaluate the effect of cryopreservation on the heat shock protein 90 (Hsp90) expression in mouse ovarian tissue. Methods : Cryopreservation of mouse ovarian tissue was carried out by slow freezing method. The mRNA level of Hsp90 expression in both fresh and cryopreserved mouse ovarian tissue was analyzed by RT-PCR. The protein expression of Hsp90 was evaluated by Western blot analysis and immunohistochemistry. Results: The mRNA and protein of Hsp90 were expressed in both fresh and cryopreserved mouse ovarian tissue. The amount of Hsp90 mRNA was increased in cryopreserved ovarian tissue after 60 and 90 minutes after thawing and incubation. The amount of Hsp90 protein was increased in the cryopreserved ovarian tissue after 6 hours of the incubation in Western blot analysis. In immunohistochemical study, Hsp90 protein was localized in cytoplasm of oocytes and granulosa cells. Significant level of immunoreactive Hsp90 protein was detected in theca cells contrast to the weak expression in ovarian epithelial cells. Conclusion: This results showed the increase of Hsp90 expression in both mRNA and protein level in the cryopreserved mouse ovarian tissue. It can be suggested that Hsp90 may play a role in the protective or recovery mechanism against the cell damage during cryopreservaion.

• KSBB Journal
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• 제23권2호
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• pp.125-130
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• 2008

해수클로렐라 (Chlorella elliposidea C020) 에탄올 추출물로부터 항균 및 항곰팡이 활성, 항산화활성, tyrosinase inhibitory 활성 (미백효과)과 용혈활성을 실험하였다. 효율적인 추출을 위해서 동결건조 후 95% 에탄올로 2시간 추출하는 것이 가장 좋다는 것을 알 수 있었다. 해수클로렐라 에탄올 추출물의 항균 및 항곰팡이에 대한 활성을 측정한 결과, B. subtilis PM125와 B. licheniformis, V. parahemolyticus와 E. tarda NUF251에서 활성을 나타내었다. 그러나, 곰팡이인 C. albicanse에 대하여서는 활성을 나타내지 않았으며, 인간의 적혈구로 용혈활성 실험한 결과, 아주 낮은 활성을 나타내었다. DPPH방법을 이용하여 항산화 능력을 측정한 결과, 2 mg/mL에서 75% 라디칼 소거능력을 나타내었다. 해수클로렐라 에탄올 추출물의 tyrosinase 저해활성 $IC_{50}$는 10.87 mg/mL로 나타났다. 이러한 결과를 바탕으로 해수클로렐라 에탄올 추출물로부터 다양한 생리활성물질을 개발하여 고부가가치 제품을 창출할 수 있을 것으로 판단된다.