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        검색결과 15

        2.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to analyze the transgenic efficiency and sex ratio in -1,3-galactosyltransferase (GalT) knock-out (KO) transgenic pigs according to generation. GalT KO piglets were produced by artificial insemination or natural mating. The transgenic confirmation of GalT KO was evaluated by PCR amplification using specific primers. After electrophoresis, three types of bands were detected such as 2.3 kb single band (Wild), 2.3 and 3.6kb double bands (GalT KO -/+; heterozygote), and 3.6kb single band (GalT KO -/-; homozygote). Transgenic efficiency in F1 generation was 64.5% (23/35) of GalT KO (-/+). In F2 generation, GalT KO transgenic efficiency was 36.4% (21/57, Wild), 47.5% (28/57, GalT KO -/+), and 16.1% (8/57, GalT KO -/-), respectively. Interestingly, no homozygote piglets were born in 6 deliveries among total 11 deliveries, although they were pregnant between male (M) and female (F) heterozygote. In the 5 litters including at least one GalT KO -/- piglet, the transgenic efficiency was 13.3% (2/24, Wild), 51.3% (14/24, GalT KO -/+), and 35.3% (8/24, GalT KO -/-), respectively. The sex ratio of M and F was 40:60 in and 49:51 in generation, respectively. Based on these results, GalT KO transgenic pigs have had a reproductive ability with a normal range of transgenic efficiency and sex ratio.
        4,000원
        7.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The picking process in distribution center is one of the most difficult and time-consuming process. The improvement of picking productivity is a core element which decides efficiency of the distribution center. The time to shipping on vehicles from receiving depends on the arrangement of items or picking methods. The Pick to Light system typically is used to improve the efficiency of order picking. In some cases the layout design of Pick to Light system has been performed rather than scientific analysis by a common experience. Therefore, this study analyzed the impact of picking performance by the zone arrangement method in order picking process of Pick to Light system.
        4,000원
        8.
        2005.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 임상 조건하에서 수정란이식의 효율성 증대를 위하여 이식 시술자 측면의 숙련도, 난이도, 소요시간, 주입 위치, 자궁의 출혈 및 위치 조절이 체외수정란이 이식된 수란우의 임신과 유산에 미치는 효과를 검토하였다. 임신율은 숙련된 시술자, 자궁각 2/3 지점에 이식 및 위치 조절군이 유의하게 높은 경향이었으나, 이식 난이도, 소요시간 및 출혈에 따른 차이는 인정되지 않았다. 한편 시술자 측의 요인에 따른 유산율은 유사한 경향이었다.
        4,000원
        9.
        2003.09 구독 인증기관 무료, 개인회원 유료
        hFSH는 α와 β subunit으로 구성된 heterodimer로서 두 subunit의 조합은 활성을 지닌 호르몬의 생산에 있어서 매우 중요한 단계이다. 이 조합과정의 효율을 증대하기 위하여 본 연구에서는 hFSH를 단일사슬의 단백질로 구축하고자 하였으며, 이의 일환으로 각 subunit 대한 cDNA단편을 연결하는 서열로 CTP linker를 도입하였다. 재조합한 hFSH-CTP 유전자는 pseudotype의 retrovirus vector system을 이용하여 CHO 세포와 닭의 배로 각각 전이되었다. CHO 세포에서의 FSH의 생산은 α와 β를 각각 전이한 경우에 비해 hFSH-CTP를 전이한 경우에서 17배 이상 높은 것으로 나타났다. 닭에서는 유전자 전이를 시도한 62개체 중에서 11마리가 부화하였으며 그 중 10마리가 형질전환된 닭인 것으로 RT-PCR을 통하여 확인되었다. 그러나 개체의 혈중 FSH의 생산은 확인하지 못하였다. 이상의 실험 결과를 바탕으로 하여 재조합된 hFSH-CTP는 FSH의 발현에 매우 효율적인 구조로 생각되며, 또한 retrovirus를 이용한 유전자 전이 방법은 형질전환 가금의 생산에 있어서 매우 적절한 방법으로 사료된다.
        4,000원
        13.
        2000.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was undertaken to optimize enucleation and reconstitution methods for the production of cloned mice by somatic cell nuclear transfer Outbred ICR mouse oocytes at the metapahse- II stage were retrieved from female mice superovulated by PMSG and hCG. In Experiment 1, oocytes were enucleated in medium supplemented with cytochalasin B (CCB) of 3 levels (0, 7.5 or 15 /mL), and higher rate of encleation was obtained at 7.5 and 15 /mL than at /mL. In Experiment 2, oocytes enucleated in 7.5 /mL CCB-containing medium were reconstituted with different types of somatic cell by following methods; 1) cumulus cells by direct cell injection, 2) cumulus cells by electric fusion (1.25 kV/cm, 2 pulses for each 70 ) or 3) STO cells by the electrofusion. Electrofusion of STO cells with enucleated oocytes yielded the greatest (P<0.05) rate of reconstitution without lysis (76%) than any other combinations. Although significant decrease in the rate of somatic cell introduction was found, the electrofusion of cumulus cells yielded better rate of reconstitution than direct injection (0 vs. 18%). In Experiment 3, the duration of electric stimulation for the fusion was changed to either 50 or 90 , but no significant improvement of reconstitution efficacy was obtained. In conclusion, this study showed that ICR mouse oocytes could be used for the production of reconstituted oocytes and a fusion method of 1.25 KV/cm with 2 pulses using 570 cell was the optimal.
        4,000원