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        검색결과 50

        22.
        2010.09 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the survival rate of frozen-thawed spermatozoa in equine by glycerol concentration and freezing speed. Two stallions (1 Thoroughbred-13 year old and 1 Arab-7 year old) bred in Korea Racing authority was examined for 1 times in a couple of weeks. Semen was collected by condom method standing heated mare and were centrifuged 650 g for 15 min. and isolated the seminal plasma. Thick fraction of semen was diluted EDTA-Lactose-egg yolk diluents to 1:1 and contained in 0.5 ml straw as 6~14×107cells/ml. Final concentrations of glycerol were 3, 5 and 7% in cryopreseved diluents and added 4 times for 2 hours equilibration. For the freezing, equilibrated straws were located 3 or 5 cm above LN2 gas for 5 or 10 min. Survival rates of pre-frozen sperm were 65.0±13.2%, 68.3±10.4%, 66.7±11.5% and post-frozen were 53.3±23.1%, 45.0±15.0%, 50.0±18.0% in 3, 5, 7% glycerol concentration, respectively. There was no difference between glycerol concentrations. Survival rates of frozen-thawed sperm on freezing speed were 36.7±10.4%, 40.0±7.1%, 30.0±13.2% at 3 cm-5 min and 33.3±11.5%, 31.7± 2.9%, 21.7±10.4% at 3 cm-10 min in 3, 5, 7% glycerol concentration, respectively. Survival rates of frozen-thawed sperm on freezing speed were 43.3±15.3%, 32.0±17.9%, 22.3±15.7% at 5cm-5 min and were 47.5±15.0%, 43.3±12.6%, 48.3±15.3% at 5cm-10 min in 3, 5, 7% glycerol concentration, respectively. There were significantly different between groups (p<0.05). These results suggest that glycerol concentration did not affect cryopreservation of stallion semen within 3~7% but freezing speed affects. In our experiment, the best cryopreservation condition was at 5 cm above LN2 gas for 10 min for pre-freezing and 7% of glycerol concentration. These results lead to commercial AI with frozen-thawed stallion semen.
        3,000원
        23.
        2010.09 구독 인증기관 무료, 개인회원 유료
        This study was performed to investigate the characteristics within ages and freezing tolerance of spermatozoa in Jindo Dog. Experimental animals were selected 12 herds within 1~8 year’s old and collected semen for 2 times in a week. Collected semen was evaluated whole volume and sperm number with CASA system (SIAS, Medical Supply, Korea). Then seminal plasma were separated and diluted with modified Tris-egg yolk extender and added 4, 6 and 8% glycerol for 4 times to final concentration and equilibrated for 1.5 hrs. Before and after freezing, equilibrated semen were evaluated the survival rates. Total volume of sperm at 1~2 year old group is as 5.2×108 cells/ ml largest and there were no significance among groups. The motility of 1~2 year old group is highest as 90.9% and there were significance among groups. Abnormal sperm showed similar among groups. The survival rate in terms of pre-freezing and post-freezing were decreased all levels of glycerol and reveled 87.0% to 64.5% in 4%, 87.5% to 51.9% in 6% and 73.4% to 29.7% in 8%, there were significant difference among the groups (p<0.05). These results suggest that the optimal sperm-freezing methods in Jindo Dog are utilized with modified Tris egg-yolk extender with 4% glycerol and were improve the reproductive activity by these methods.
        3,000원
        24.
        2010.09 구독 인증기관 무료, 개인회원 유료
        The objective of this study was investigate the superovulation treatment and to relate concentrations of blood urea nitrogen(BUN) in Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg PGF2α was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received 100 μg GnRH at the time of 1st insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Cows with BUN <10, 11~18 and ≥19 mg/dl had return of estrus of 34.6, 30.5 and 30.4 days respectively. Return of estrus after superovulation treatment was not significantly lower for cows with blood urea nitrogen (BUN) above 10 mg/dl than for cows with BUN below 10 mg/dl. Cows with BUN <10, 11~18 and ≥19 mg/dl had number of transferable embryos of 3.2±1.2, 5.4±1.9 and 4.1±2.1 respectively.
        4,000원
        25.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This studies were conducted to investigate the survival rate of frozen-thawed spermatozoa of Jindo Dog by monosaccharide and freezing rates. Experimental animals were prepared 12 males within 1~8 year's old and collected once in a couple of weeks by digital manuplation methods. Collected semen was diluted 1:1 with Tris-egg yolk extender and added 4, 6 or 8% of glycerol and none, 4 mM glucose or 4 mM fructose as cryoprotectant and was equilibrated for 2 hrs in . In monosaccharide groups, the freezing rate was 5 cm-5 min. above . The survival rates without monosaccharide were , , in 4, 6 or 8% glycerol, respectively. In addition of glucose, the survival rates were , , in 4, 6 or 8% glycerol, respectively and in fructose, were , , in 4, 6 or 8% glycerol, respectively. There showed significantly different between glycerol groups and monosaccharides groups (p<0.05). The survival rates of freezing rate in 5 cm-5 min. group was , , and in 10 cm-10 min. group was , , in 4, 6 or 8% glycerol, respectively. There were significantly different between freezing rates (p<0.05). These results suggest that the addition of fructose with 6%-glycerol and slow freezing improve the survival of frozen-thawed sperm in Jindo Dog.
        4,000원
        26.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the effects of abnormal ovarian cycles after superovulation treatment of Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received GnRH at the time of Ind insemination. Embryos were recovered 7 or 8 days after the 1st insemination. The cows were considered to have resumed ovarian cyclicity on the day of ovulation if followed by regular ovarian cycles. 50.0 percentage of the cows (18/36) had normal resumption of ovarian cyclicity (resumption within 40 days after superovulation), and 50.0% (18/36) had delayed resumption(resumption did not occur until>40 days after superovulation). Delayed resumption Type II (first ovulation did not occur until 40 days after superovulation, i.e. delayed first ovulation 33.3%) were the most common types of delayed resumptions. The mean numbers of total ova from < 10 and 10 of corpora lutea (CL) was 7.3 and 13.9, respectively. The number of transferable embryos differed between < 10 and 10 CL was 4.2 and 5.1, respectively. 11.1 percentage of the cows (4/36) did not resumption their ovarian cyclicity until 60 days after superovulation treatment.
        4,000원
        28.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oxygen consumption has been regarded as a useful indicator for assessment of mammalian embryo quality. However, there was no standard criterion to measure the oxygen consumption of embryos. Here, we measured oxygen consumption of bovine embryos at various developmental stages was measured using a scanning electrochemical microscopy (SECM). We found that the oxygen consumption significantly increased in blastocyst-stage embryos compared to other stage embryos (from 2-cell-stage to morula-stage), indicating that oxygen consumption reflects the cell number ( versus , p<0.05). In the morula-stage embryos, the oxygen consumption of in vivo derived embryos was significantly higher than that of in vitro produced embryos ( versus , p<0.05). However, there was no significant difference in consumption of oxygen by in vivo and in vitro-derived bovine blastocyst-stage embryos (p>0.05). In the frozen-thawed blastocyst-stage embryos, live embryos showed significantly higher oxygen consumption than dead embryos ( versus , p<0.05). These results indicate that the measuring oxygen consumption by SECM can be used to evaluate bovine embryo quality.
        4,000원
        29.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of present experiment was to examine commercial synthetic extender(AndroMed) for semen cryopreservation of Korean Black Bull. Semen was collected from a Korean Black Bull using an artificial vagina and transported to the laboratory. The semen was diluted 1:1 by AndroMed. The pellect was diluted to final sperm concentration of by doubling in every 10 minutes at cold chamber. The semen was equilibrated for 1 hr at cold chamber and packed to 0.5 ml straw. The semen straws were located above 5 cm of liquid nitrogen for 5 minutes, above 5 cm for 10 minutes and above 10 cm for 10 min. And then the frozen straw was plunged to . The presented straws were examined the viability and motility after thawed at water bath. Hanwoo semen was used as KPN (Korea Proven Bull Number) in this experiment. The survival rates was significantly higher in fresh semen than frozen semen (). However, the motility rates was similar (80.7% and 66.4%). The survival and motility rates were higher in 5cm, 10 min treatment group than the other two groups in straw-located height and duration above ( and 70.7% vs, 33.18% and vs, 30.14% and 65.7%, respectively). The development rates to cleavage was higher in Black Cow than Hanwoo semen (62.2%, 64.4%), However, The development rates to blastocyst was higher in Hanwoo than Black cow semen (25.9%, 23.0%). In conclusion. The present results that acceptable fertilization and cryopreservation could be obtained by in vitro fertilization with frozen-thawed semen using a synthetic semen extender (AndroMed).
        4,000원
        30.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to investigate the effective genetic resources preservation system using the frozen boar semen. The porcine oocytes were matured for 44 hours in NCSU-23 medium with or without 10% Porcine Follicle Fluid (PFF), 0.5 porcine FSH, 0.5 equine LH, 1.0 17 -estradiol () and 10 ng/ml Epidermal Growth Factor (EGF) under mineral oil at in humidified atmosphere of 5% in air. After 44 h of culture, the oocytes were inseminated with frozen-thawed semen and fresh semen prepared with mTBM medium for 6 h. Later, set of 50 presumptive zygotes were transferred into 4-well dish (500 ) of IVC medium. for embryos freezing, slow-freezing and vitrification methods were used as a cryopreservation. Differences among treatments were analyzed using General Linear Model Procedure by SAS Package (version 6.12) differences were considered significant when p<0.05. Following IVF and IVC, the rates of cleavage and blastocysts formation were significantly higher (p<0.05) in hormone supplemented group than that of hormone-free group (25.7 vs, 12.1). The development rates to cleavage and blastocysts were significantly higher in PZM-5 group than NCSU-23 group (60.3%, 46.6% vs 27.4%, 11.1%). Further improvement was achieved when PZM-5 was supplemented with FBS. Cleavage rates was significantly higher in fresh semen source group than frozen semen (66.7% vs 43.7%). However in blastocysts rates was similar two groups. Post-thaw survival rates of embryos were 1.2% and 2.2% in slow-frezing and vitrification groups, respectively. The results of our study suggest that it is still possible to improve the culture conditions and boar semen cryopreservation for enhance reproductive technology and animal genetic resources conservation.
        4,000원
        31.
        2009.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is not easy for porcine embryos produced by in vitro systems to develop into blastocysts with high quality. To solve this problem, many researchers have developed novel culture methods. However, the formation of blastocysts with high quality is still low. In this study, we aimed to produce piglet following transfer of in vitro produced early embryos ( cell stage embryos) or morula and blastocyst. The cell stage embryos were transferred to five estrus-synchronized recipients (200 embryos per recipient). One of the five sows farrowed three piglets, which contain two live piglets and one dead piglet, 114 days after embryo transfer. However, two recipients transferred with morula and blastocysts did not farrow. Microsatellite analysis confirmed that the genomic DNA of two live piglets were not genetically identical to that of the recipient. These results indicate that it is possible to obtain piglets by transfer of early embryos produced by in vitro production (IVP) systems.
        4,000원
        34.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서 돼지 난포란에서 채취된 난모 세포들을 체외성숙 후 형태적으로 선별하거나 극체 방출란을 선별하여 활성화 처리 후 48시간째에 분할란을 선별할 때 배발달율이 어느정도 향상되는지를 검토하였다. 난모 세포를 48시간 성숙 배양 후 형태적 선별과 극체의 방출 유무를 검사하고, 선별된 난모 세포들을 시간 추가 배양한 후 7% ethanol로 활성화시키고 cytochalasin B에 5시간 노출 후 PZM-5 배 양액으로 7일간 배양하였으며, 배양 중
        4,000원
        36.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 염소 액상 정액의 활용에 적합한 희석액을 검토하여, 국내 염소 인공수정 실용화를 위한 기초 자료를 확보하기 위하여 실시되었다. 두 마리의 흑염소 수컷으로부터 전기 자극법으로 정액을 채취하였다. 채취된 정액은 BTS로 희석하여 500g에서 5분간 원심분리하여 정장을 제거하고, BTS, Modena, Triladyl로 희석하여 냉장고나 온장고에서 8일간 보관되었다. BTS와 Modena로 희석된 정자의 운동성은 하루 만에 소멸되었으며, BTS로
        4,000원
        38.
        1997.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        석탄계 핏치의 열처리 온도 및 압력에 따른 결정화도와 기공도 그리고 산화저항성 등을 관찰하였으며, hexagonal type 4D 탄소/탄소 복합재를 석탄계 핏치로 가압함침 및 탄화시킨 다음 가해준 압력이 고밀도화에 미치는 영향을 관찰하였다. 석탄계 핏치의 가압탄화 압력이 흑연화도에 크게 영향을 미치지 않았으며, 기공면적비에 있어서는 압력을 600bar로 상승시켜 줌으로써 상압 처리한 경우 보다 1.5배 정도 감소 하였다. 650˚C까지 열처리하여 얻은 코우크스의 산화반응 개시온도는 처리압력이 증가함에 따라서 지연되었다. 탄소/탄소 복합재의 함침압력을 100bar에서 600bar로 상승시켜 줄 경우 밀도 증가율이 크게 향상 되었으며 기공도는 감소하였다.
        4,000원
        39.
        2019.09 KCI 등재 서비스 종료(열람 제한)
        본 연구는 2019년 영화진흥위원에서 발표한 국내 영화산업에서 BIG 5(롯데컬처웍스, 씨제이이앤엠㈜, ㈜넥스트엔터테인먼 트월드(NEW), ㈜쇼박스, 메가박스중앙㈜플러스엠)로 불리는 국내 영화제작 및 투자배급사의 리더 필름 영상에 관한 연구로, 국내 5대 영화배급사의 리더 필름 영상을 선행연구를 바탕으로 영상의 비주얼메타포의 적합성, 비주얼메타포의 이해도, 영상의 호감도, 영상의 브랜드 인지도, 영상의 주목효과로 구분하였고 이에 대한 비주얼 메타포 효과를 검증하였다. 분석결과 회사별 리더 필름 영상의 은유적 표현의 적합성은 리더 필름 영상별 차이를 발견할 수 없었지만, 영상의 이해도, 영상의 호감도, 브랜드 인지도, 영상의 주목도에서는 유의미한 차이가 있는 것으로 나타났다. 영상의 이해도는 메가박스중앙㈜플 러스엠과 씨제이이앤엠㈜이 가장 높게 나타났으며, 영상의 호감도와 브랜드 인지도에서는 NEW와 롯데컬처웍스 순으로 높게 나타났다. 그리고 영상의 주목도에서는 씨제이이앤엠㈜와 NEW순으로 높게 나타났다. 최종적으로 ㈜넥스트엔터테인 먼트월드(NEW)의 리더 필름 영상이 비주얼메타포의 표현효과가 가장 높았으며, 메가박스중앙㈜플러스엠의 리더 필름 영상이 비주얼메타포의 표현효과가 가장 낮은 결과를 보였다. 이와 같은 연구결과를 바탕으로 효과적인 리더 필름 영상제작을 논의하고 영상디자인의 실무적 시사점을 제안하였다.
        40.
        2019.04 서비스 종료(열람 제한)
        In order to improve the traffic congestion on the road, it is essential to construct overpasses and highways in big cities. In particular, in order to facilitate traffic flow within the overpass route, it is necessary to construct a curved bridge because the plane shape of the bridge itself must be aligned with the road alignment. Therefore, in this study, we have developed a precast PSC curved girder of concrete hollow box type with excellent bending moment, shear force and torsional moment resistance, and perform performance evaluation by structural test to confirm applicability to curved bridge.
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