These study was carried out to investigate the effects of the recovery time, diameter of oocytes on in vitro fertilization or intracytoplasmic sperm injection (ICSI). The in vitro maturation rates to MII stage of oocytes recovered at the inactive, follicular and luteal stages matured for 72 h were 1.4±0.0%, 43.4±3.2% and 10.8±2.7%, respectively. The fertilization rates of in vitro cultured oocytes recovered from ovaries at the in active, follicular and luteal stages were 0.0±0.0%, 15.7±3.4% and 7.6±3.5%, respectively. The in vitro maturation rate of oocytes recovered from ovaries at the follicular stage of the reproductive cycle was significantly higher than those at the inactive and luteal stages (p<0.05). The penetration rate determined that the percentages of oocytes with diameters in the <100 μm, 100 to 100 μm and 110 to 120 μm ranges were 17.5±4.7%, 43.9±4.5%, 21.3±3.4%, respectively. The penetration rate of oocytes with diameters between 100 to 110 μm was significantly higher than that of oocytes whose diameters were 100< μm and 110～120 μm (p<0.05). The penetration rate of oocytes determined that the percentages of ovaries with diameters between 1 to 5 mm and 6 to 10 mm were 32.9±3.2% and 17.5±3.7%, respectively. Thus, the diameters of the ovaries were significantly higher at 1 to 5 mm (p<0.05). A total of 264 oocytes were fixed and stained after co-incubation with sperm, of which 72 had identifiable nuclear material. After in vitro fertilization for 20 hrs, 27.3% of oocytes were penetrated by spermatozoas. Oocytes were fixed and stained after ICSI, of which 38 oocytes contained identifiable nuclear material. After in vitro fertilization and ICSI for 20 hrs, to 27.3% and 67.9% of oocytes were penetrated by spermatozoas. The in vitro fertilization rates by ICSI was significantly higher than that in vitro fertilization method (p<0.05).

The purpose of this study was to investigate the effects of the collection time, co-culture and sperm penetration of canine oocytes on in vitro maturation and fertilization. The oocytes were cultured in TCM-199 media containing hormonal supplements (10% FCS, 10 IU/ml HCG, 10 IU/ml PMSG) at 5% CO2, 95% air, 38℃. The in vitro maturation rate to MⅡ stage of in vitro oocytes recovered from ovaries that collected at follicular, luteal and inactive phases of the reproductive phase for 44～72 hrs were 19.2%, 12.2%, and 6.0%, respectively. Follicular phases oocytes had a significantly higher in vitro maturation rate than oocytes collected at luteal and anestrus stage (p<0.05). The in vitro maturation rates to the MII stage of canine oocytes after 48 hrs of culture with glutathione, pyruvate, or glutathione + pyruvate were 12.5%, 10.7%, and 17.5%, respectively. This was higher than that in both alone or the combination of the two compared to the control group (19.0%). The sperm penetration rates of in vitro matured oocytes by fresh and frozen semen were 29/80 (36.3%) and 18/80 (22.5%), respectively. Although there are limited reports about canine oocytes co-culture and in vitro fertilization, our results on in vitro maturation is comparable to the results from other researches.

In the present studies, we have intended to compare the EDS (20% EG + 20% DMSO + 0.4 M sucrose + 10% FCS) and EDT (20% EG + 20% DMSO + 0.3 M trehalose 10% FCS) methods for vitrification of canine oocytes, in order to improve the vitrification methods. The survival rate of vitrified‐thawed oocytes using the EDS method was 15.1±1.8% (p<0.05), which was lower than that of the control group (66.7±2.5%). About 45～55% of the vitrified‐warmed oocytes showed normal morphology, as assessed by PI staining. However, the ratio of survival rate of oocytes showed lower than that of normal morphology in comparison between EDS method and control group. The survival and developmental rates of vitrified‐warmed oocytes by the EDS and EDT methods were 16.7±1.4% and 11.1±0.8% and 8.3±1.4% and 4.4±1.8%, respectively (p<0.05). The results were significantly lower than the control group (66.7±2.5% and 16.7±3.7%). However, the survival rate of vitrified‐warmed oocytes using EDS method showed higher than that in the ETS group.

Manufacturing technologies of compound semiconductor are similar to the process of memory device, but management technology of manufacturing process for compound semiconductor is not enough developed. Semiconductor manufacturing environment also has been

원양어선 제501 오룡호는 황천 중인 베링해에서 조업 후 피항하던 중 개구부를 통한 침수로 인하여 침몰하였으며 많은 선원들이 사망하고 실종되었다. 본 연구에서는 사고선박 침몰사고의 진행상황 별 유동수 영향과 어획물 배치 등을 고려한 선박복원성 계산을 KST-SHIP (선박안전기술공단 선박계산시스템)을 사용하여 수행하고 사고선박의 침몰사고 시의 침수 후 선박복원성을 분석하였다. 먼저 만재출항상태 (Full Load Departure Condition)에서의 사고선박의 비손상 복원성 계산서와 KST-SHIP을 사용한 비손상 선박복원성 계산 결과를 비교하여 검증하고, 사고선박의 출항 시부터 사고 직전까지의 배수량에 따른 비손상 복원성 계산을 수행하여 비손상 복원성을 분석하였다. 또한 사고선박 침몰사고 시의 진행상황 별 침수 후 선박복원성 계산을 수행하여 침수 후 복원성도 분석하였다.

Most indica rice varieties show a low efficiency of transformation because of difficulties in callus formation and low-regeneration frequencies in conventional culture such as MS16 or N6 medium. Recently, some improved methods were reported for Agrobacterium-mediated transformation using mature elite indica seeds however, these procedures take a long time (5–7 months) to obtain transgenic plants and still with significantly low efficiency. In this study, we provide additional improvements in the indica rice transformation protocol introducing new selection method by tosoflavin/tflA which was based on bacterial photosensitizer and its degrading enzyme pair. We introduced direct in planta transformation using early stage of germinating rice seeds instead of usual embryogenic callus. Methods that use embryos as a starting material for inoculation with Agrobacterium are also used for comparison with the new protocol using rice seeds. Transformed cells proliferated from rice seeds obtain toxoflavin resistance, and transgenic plants are eventually regenerated from those proliferated tissues. However, we found out that tissue proliferation from indica seeds and shooting and rooting are very sensitive to minor salt nutrients in the media and need to pay attention to use indica rice specific nutrient media. The use of naturally occurring photosensitizers such as toxoflavin as selection agents appears to give rapid and unambiguous selection results owing to their unique phytotoxic mode of action. In particular, the toxoflavin/tflA selection system might be useful for generating transgenic indica rice cultivar where high false-positive backgrounds with current selection marker systems are problematic.