Successful cryopreservation of bovine oocytes is a very important technology for research and commercial applications. However, the survival and development rate of vitrified-thawed oocytes is lower than non-vitrified oocytes. Hydroxypropyl Cellulose supplementation (HPCs) has extremely high viscosity, which permits transitions to a glassy state at low temperatures. This characteristics of HPCs have been reported to help the survival of human oocytes. In this study, we investigated the survival rate, fertilization rate and ROS levels to confirm the effect of cryoprotectant solutions with HPC for oocyte vitrification in bovine. For vitrification, bovine MII oocytes were pretreated with EG10 (added 0, 10, 50 and 100 ㎍/㎖ HPC) for 5 min, exposed to EG30 (added 0, 10, 50 and 100 ㎍/㎖ HPC) for 30 sec, and then directly plunged into LN2. Thawing was taken by 4-step procedures [1 M sucrose and 10% FBS added D-PBS (SFD) -> 0.5 M SFD -> 0.25 M SFD -> 0.125 M SFD] for 1 min, respectively. After thawing, oocytes were washed with TL-HEPES, incubated in a droplet of previous cultured IVM medium for 1 h to recover. IVF drop (44 ㎕) contained 10 vitrified-thawed oocytes with sperm concentration of 1 × 106 cells ㎖, and then 2 ㎕ heparin and 2 ㎕ PHE were added. At 2 days after IVF, cleaved embryos were cultured in CR1aa + 3 mg/mL FAF-BSA for 48 h and cultured in CR1aa + 10% FBS for 4 days. In the results, in vitro survival rate of bovine vitrified-thawed MII oocyte was significantly higher in 50 (85.5%) and 100 ㎍/㎖ (80.2%) HPC groups than 0 (71.2%) and 10 ㎍/㎖ (71.3%) groups (p<0.05). The ROS level was lower in 50 ㎍/㎖ HPC group than in control group. After in vitro fertilization, cleavage rate and blastocyst development rate were not significantly different among treatment groups. Therefore, these results indicated that HPC treatment has a positive effect on the survival of vitrified-thawed bovine oocytes.

To improve survival rates of vitrified pig oocytes, the treatment of cytoskeletal stabilizer on an appropriate time is one of the possible approaches. However, the exact treatment timing and effect of cytoskeletal stabilizer such as cytochalasin B (CB) is not well known during oocyte vitrification procedures. Thus, the present study was conducted to determine optimal treatment timing of CB during vitrification and warming procedures. In experiment 1, the survival rates of the post-warming pig oocytes were analyzed by fluorescein diacetate (FDA) assay with 4 classifications. In results, post-warming oocytes showed significantly (p<0.05) decreased number of alive oocytes (31.8% vs. 86.4%) compared to fresh control. In detail, the significant difference (p<0.05) was found only in strong fluorescence (18.2% vs. 70.5%) not in intermediate fluorescence groups (13.6% vs. 15.9%). In experiment 2, CB was treated before (CB-Vitri) and after (Vitri-CB) vitrification. In results, group of Vitri-CB showed significantly (p<0.05) higher (91.6%) survival rates compared to group of CB-Vitri (83.7%), significantly (p<0.05) and comparable with group of Vitri Control (88.7%) by morphological inspection. In FDA assay results, group of Vitri-CB showed significantly (p<0.05) higher (44.2%) survival rates compared to groups of CB-Vitri (36.7%) and Vitri Control (35.1%). In conclusion, the increased survival rates of post-warming pig oocyte treated with Vitri-CB method are firstly described here. The main finding of present study is that the CB treatment during recovery could be helpful to refresh the post-warming pig oocyte resulting its improved survival rates.

해산로티퍼 (Brachionus plicatilis)의 생존 및 개체군 성장률 (r)을 사용하여 Zinc undecylenate (ZU)에 대한 독성평가를 실시하였다. 24 h 동안 ZU에 노출된 B. plicatilis의 생존율은 실험 최고농도 100 mg L-1에서도 영향이 나타나지 않았으나, ZU에 72 h 노출된 개체군 성장률 (r)은 농도 의존적으로 감소하는 경향을 나타내, 12.5 mg L-1 에서 유의적인 감소를 나타냈고 최고농도 50.0 mg L-1에서 개체군 성장률이 90% 이상 감소되었다. ZU에 노출된 B. plicatilis의 개체군 성장률의 반수영향농도 (EC50)값은 26.4 mg L-1, 무영향농도 (NOEC)는 6.3 mg L-1, 최소영향농도 (LOEC)는 12.5 mg L-1로 나타났다. 자연생태계 내에서 ZU 물질이 해수 중에서 12.5 mg L-1 이상을 초과하여 나타낼 때 B. plicatilis와 같은 동물성플랑크톤의 개체군 성장률이 영향을 받을 것으로 판단되며, 이러한 연구결과는 신방오도료물질의 생태안정성 평가를 위한 기준치 설정 및 다른 방오도료물질과의 독성치를 비교할 수 있는 유용한 자료로 활용될 것으로 판단된다.

The oxicity assesment of Phenanthrene (PHE) has been investigated by using the rate (r) of survival and population growth in rotifer Brachionus plicatilis. The survival rate was determined after 24 h of exposure to PHE. The survival rate of PHE had no effect at a maximum of 300 mg L-1. The r was determined after 72 h of exposure to PHE. It was observed that r in the controls (absence PHE) was greater than 0.5, but that it suddenly decreased with an increased concentration of PHE. PHE reduced r in a dose-dependent manner and a significant reduction occurred at a concentration of greater than 37.5 mg L-1. The EC50 value of r in PHE exposure was 63.7 mg L-1. The no-observed-effect-concentration (NOEC) of r in PHE exposure was 18.8 mg L-1. The lowest-observed-effect-concentration (LOEC) of r in the PHE exposure was 37.5 mg L-1. From the results, the concentration of PHE (greater than 37.5 mg L-1) has a toxic effect on the r of B. plicatilis in natural ecosystems. These results (including NOEC, LOEC and EC50) might be useful for the Polycyclic aromatic hydrocarbons (PAHs) toxicity assessment in marine ecosystems.

For the effective seedling production of the hard shelled mussel, Mytilus coruscus, this study assessed the effects of the dietary value of live food, density, water temperature and salinity on growth and survival rate of the larvae. The optimal survival rate and growth rate were examined under differing conditions of water temperature, salinity, and rearing density for 30 days. The three groups were provided different feeding organisms, such as Isochrysis galbana and Teleaulax suecica. The mixtures were provided at a rate of 5×104 cell mL-1. The best growth was observed in the group with conditions 21℃ water temperature (16.2±9.1 μm), 33 psu of salinity (16.82±3.9 μm), 2500 individual m-2 (17.2±5.9 μm), and fed with 5×104 cell mL-1 of I. galbana and T. suecica mixture (16.0±7.3 μm). The highest survival rate was found in the group at conditions 18℃ water temperature (66.4%), 33 psu of salinity (24.4%), 2500 individual m-2 (65.8%), and fed with 5×104 cell mL-1 of I. galbana and T. suecica mixture (58.8%). We therefore conclude that the suitable culture conditions for the stable production of hard shelled mussel artificial seedlings was at 18 to 21℃ of temperature, 30 to 33 psu of salinity, 2500 to 5000 individual m-2 of rearing density, and feeding supplement of 5×104 cell mL-1 of I. galbana and T. suecica mixture under semi running water system.

This study was conducted to evaluate the effect of transfer temperature of epididymis on survival rate of semen and development ability of B6D2F1 mice embryos. No significant differences were noted in the survival rate of semen (59.0% ± 0.1 vs. 47.6% ± 0.1), in vitro fertilization rate (90.7% ± 0.1 vs. 90.7% ± 0.1), developmental rate (90.0% ± 0.1 vs. 90.0% ± 0.1), and blastocysts formation rate (53.1% ± 0.2 vs. 52.3% ± 0.2) between groups. (NS; P>0.05). However, the zona hatched rate was significantly higher in the 4°C group compared to those of the 37°C group (47.8% ± 0.1 vs. 25.6% ± 0.2; p<0.05). When it comes to cell numbers of blastocysts, the % ICM (/total cells) was significantly higher in the group of 4°C compared to the 37°C (27.0% ± 0.1 vs. 18.3% ± 0.1; p<0.05). However there were no differences in total cell numbers (72.7 ± 31.6 vs. 62.0 ± 36.6), ICM cell numbers (17.0 ± 7.8 vs. 14.6 ± 8.6), TE cell numbers (55.8 ± 29.8 vs. 64.0 ± 24.4), the ratio of ICM:TE (1:4.2 ± 4.1 vs. 1:6.4 ± 7.2) between two groups (NS; P>0.05).Taken altogether, it is expected to achieve the best developmental ability of B6D2F1 mice embryos in the transfer temperature of epididymis. Also these results can provide fundamental data to maximize culture condition for in vitro fertilization on B6D2F1 mice. In future, therefore, it is expected that results herein might be applied for in vitro culture of human embryos.

The survival rate and number of parasitized host of Encarsia formosa Gahan and Eretmocerus eremicus Rose were observed at low temperature conditions (6, 8, 10 and 12 ± 1oC, RH 70 ± 10%, in dark condition. Mummy of Encarsia formosa was stored at 12oC, for 70% of the mummies survived for 10 days. After 6-days storage at 12oC, number of parasitized host of the parasitoids was decreased to 35.9 (67.6%, compared to control). Mummy of Eretmocerus eremicus was stored at 12oC, and 70% of the mummies survived for 14 days. After 6-days storage at 12oC, number of parasitized host was decreased to 31.6 (83.6%, compared to control). Our results suggest that 12oC was most suitable temperature for storage of Encarsia formosa and Eretmocerus eremicus.

본 연구는 미세조류 및 해조류 유주자의 피막화가 이들의 생장 및 생존에 미치는 영향을 파악할 목적으로 수행되었다. 갈조류의 세포벽을 구성하는 녹말과 알긴산을 다양한 비율로 혼합하여 친환경 피막소재로 이용하였으며, 염화칼슘 수용액에 적하(form a drop)한 후 피막의 형성 여부를 확인하였고, 미세조류 Nannochloropsis salina와 해조류 Ulva australis의 유주자를 피막화하여 생존율 및 성장률을 측정하였다. 미세조류와 해조류 피막은 녹말과 알긴산의 배합비 (무게비)가 5:5, 2:8, 0:10일 때에만 형성되었으며, 10:0과 8:2에서는 형성되지 않았다. 형성된 피막 중 녹말과 알긴산의 5:5 배합비에서 미세조류 개체수가 8.74×105 cells mL-1로 최대 증가를 보였으나, 알긴산만을 이용한 피막에서는 4.92×105 cells mL-1로 가장 낮았다. 따라서, 녹말과 알긴산의 혼합으로 구성된 피막에서 녹말의 함량이 증가할수록 미세조류 및 해조류 유주자의 생존 및 생장율은 증가되지만 알긴산이 50% 이하인 배합비에서는 물성이 약한 것으로 나타났다. 또한, 인공어초 표면에 응용한 결과, 99 개체 cm-2가 발아하는 것으로 나타났다. 본 연구는 해양생태계 복원을 위한 해조류 유주자의 생존율 및 생장률을 향상 시킬 수 있는 다양한 기초자료가 될 것으로 사료되어진다.

일반 상선과 달리 해양플랜트 시설은 발주자가 직접 고용한 인원과 조선소에서 파견된 시운전 종사자들은 2교대로 해양플랜트공사가 종료될 때까지 혼재되어 승선한다. 그러므로 많은 인원들이 안전하게 거주할 수 있는 별도의 해양플랜트 전용생활부선을 사용하는 것이 일반적이다. 따라서 이 연구에서는 인명 안전의 관점에서 해양플랜트 전용생활부선 거주자의 생존율 향상을 위한 방법을 제시하고자 한다. 이를 위해 해양플랜트 전용생활부선에서 발생할 수 있는 다양한 종류의 사고 중 가장 많이 발생할 것으로 판단되는 화재 사고를 가정하였다. 이를 위해 국내·외 규정에 근거한 화재시뮬레이션 전산 모형을 제작하여 종사자들에 대한 피난 안전성을 분석하였다. 특히, 해양플랜트 전용생활부선에서 화재가 발생할 경우 지속적으로 훈련을 받은 선원들과는 달리 다양한 직종, 인종, 문화를 갖고 있는 인력들의 비정형화된 피난 행위로 인하여 위험성이 높아질 것으로 판단되므로 생존가능시간인 유효 피난시간을 증가시키고, 실제 피난에 소요되는 필요 피난시간을 감소시켜 생존율을 향상시킬 수 있는 구조개선 및 안전설비 설치에 대해 제안하였다.

Makgeolli is a health beneficial food for diabetes compared to other alcoholic beverages. We examined the effect of Makgeolli on blood glucose level and survival rate in a streptozotocin (STZ)-induced diabetic mouse model. We force fed 30 male STZ-induced diabetic ICR mice Makgeolli consisting of 6% alcohol (DM-MAK), 6% ethanol (DM-EtOH), or distilled water (DM-DW) for 4 weeks. In the DM-MAK group, food intake and water intake were higher than those of other groups after 4 weeks. Body weight, however, was not different among the experimental groups. We also found no significant difference in blood glucose level among the experimental groups. In normal ICR mice fed Makgeolli for 1 week, the area of the blood glucose curve was higher than those of other groups fed 6% ethanol, 2% glucose, or distilled water. Survival rates of STZ-induced diabetic mice fed Makgeolli, 6% ethanol, or DW for 4 weeks were 100%, 25%, and 62.5%, respectively. In conclusion, Makgeolli had no beneficial effect on blood glucose in a STZ-induced diabetic mouse model, although their survival rate was high. These results show that Makgeolli has an effect on type 1 diabetes through other mechanisms than blood glucose control.