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        검색결과 10

        2.
        2003.12 구독 인증기관 무료, 개인회원 유료
        The effects of additions/deletions in glycosylated residues of recombinant human EPO (rhEPO) produced in CHO-K1 on their secretion were examined. hEPO cDNA was amplified from human liver mRNA and cloned into the pCR2.1 TOPO. Using overlapping-extension site-directed mutagenesis method, glycosylation sites at 24th, 38th, 83rd, and 126th were respectively or accumulatively removed by substituting its asparagine (or serine) with glutamine. To add novel glycosylation sites, 69 and 105th leucine was mutated to asparagine. Mutant and wild type rhEPO constructs were cloned into the pcDNA3 expression vector with CMV promoter and transfected into CHO cell line, CHO-K1, to produce mutant rhEPO mutant rhEPO proteins. Enzyme-linked immunosorbant assay (ELISA) and Western analysis with monoclonal anti-EPO antibody were performed using supernatants of the cultures showing transient and stable expressions respectively. Addition of novel glycosylation reduced rhEPO secretion dramatically while deletion mutants had little effect except some double deletion mutants (△24/83 and △38/83) and triple mutant (△24/38/83). This fact suggests that not single but combination of changes in glycosyl groups affect secretion of rhEPO in cell culture, possibly via changes in their conformations.
        4,000원
        3.
        2002.11 구독 인증기관·개인회원 무료
        The purpose of this study was to investigate the warming temperature and exposed time on the post-thaw survival rate and viability of bovine blastocyst cryopreserved by GMP vitrification. Groups of three bovine IVP blastocysts were sequentially placed into vitrification solution before being loaded into the GMP straws and immersed into LNwithin 20 to 25 sec. The warming rate was increased 2 times of warming temperature for improvement of post-thaw survival rates. The frozen embryos were warmed either at 35 or 70 for 1 or 2 sec and then diluted in sucrose solution. Post-thaw blastocysts were serially washed in 0.25 and 0.15 M sucrose in holding medium (HM: TCM199 supplemented with 10% FCS) and TCM-199 for each 5 min, respectively, and then cultured in TCM199 for 24 h. The rate of re-expanded blastocyst was significantly different fer 35 and 70 warming temporature (76.4 vs. 89.3%; P<0.05). The rate of re-expanded blastocyst at 70 for 1 sec was significantly higher than that for 2 sec (91.1 vs. 70.9%; P<0.05). The number of nuclei counted were significantly different among control, 35 and 70 (1218.5 vs. 10411.7 vs. 11410.3; P<0.05). These results indicated that the increasing of warming rate can provide high survival rates of bovine IVP blastocysts. Especially, the best viability of post-thaw blastocyst could be thaw at 70 for 1 sec. The warming temperature and exposed time far warming was considered to be limiting factors to the viability of bovine IVP embryos. he purpose of this study was to investigate the warming temperature and expose.
        4.
        2002.11 구독 인증기관 무료, 개인회원 유료
        The International Union for Conservation of Nature and Natural Resources (IUCN) considers the western/lowland bongo Tragelaphus eurycerus eurycerus to be a threatened species, and the eastern/mountain bongo Tragelaphus eurycerus isaaci an endangered species[1]. Although extinction is considered by many biologists to be a natural process during evolution, the exponential growth of the human population has drastically and prematurely reduced the numbers and genetic diversity of many species[2]. Species have evolved to adapt to a specific habitat or environment that meet their survival needs. Alteration or destruction of their habitat results in a species becoming incapable of adapting and hence becoming threatened with extinction. A widespread scientific and public consensus has emerged suggesting that governments should assign high priority to the maintenance of biological diversity via habitat preservation and management far species conservation[3]. Unfortunately, the loss of biological diversity far surpasses the available conservation resources and species are lost forever on a daily basis[4]. Notwithstanding the focus on habitat preservation and wildlife management, conservation biologists have also become increasingly interested in using the technologies of reproductive and developmental biology to help manage or rescue endangered species[5].
        4,000원
        6.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        The test was carried out at a test field at the Wanju Eco-Farming Complex from 2009 to 2010 to figure out the proper application of fertilizers when growing rice at the EcoFarming Complex. The result showed that when compared to the basal application of compost as fertilizer, applying supplementary compost after natural re-seeding of chinese milk vetch (CM씨 helped balance soìl nutrìtìon and maìntained rice yields.
        10.
        1995.12 서비스 종료(열람 제한)
        The wind generated circulation model describes the phenomenon based on the following physical assumptions: a) As the horizontal dimension of the flow domain is several orders of magnitude larger than vertical dimension, nearly horizontal flow is realistic. b) The time taken for circulation to develop may effect on the flow domain of the earth's rotation, the contribution of the Coriolis force. c) A flow domain of large dimension results in quite large Reynolds number and the Reynolds stresses are approximated by the turbulent mean velocity gradient. d) The circulation is forced by the shear stresses on the water surface exercised by the wind. Modification made to the depth average approximation of the convective terms and the bed shear stress terms by adopting a certain distribution of current over the depth and laboratory measurements for the bed shear expression. Modification circulation patterns, energy evolution and surface profile gave the significant differences comparing with the classical model results. The modified model results in higher free surface gradients balancing both the free surface shear and the bed shear and consequently to higher surface profiles along the coast.