• 제목/요약/키워드: Knock-out

검색결과 182건 처리시간 0.027초

FWKO 유수분리공정을 이용한 오일-물 혼합물의 분리특성 (Characteristics of Water Separation for Oil-Water Mixture in a FWKO Vessel)

  • 권순철;박근익;윤성민;김주연;박찬영;배위섭;이영우
    • Korean Chemical Engineering Research
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    • 제49권6호
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    • pp.823-828
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    • 2011
  • 오일-물 혼합물에서 물을 제거하기 위하여 FWKO(Free Water Knock Out) vessel에서의 물 분리특성에 대해 연구하였다. 오일을 모사하기 위해 데칸, 톨루엔, 아스팔트를 사용하였다. 데칸을 이용하여 프로토타입 vessel에서 기초실험을 수행하였으며, 기초실험결과를 토대로 최적 water cut이 0.8인 것을 알게 되었다. 이에 이어 톨루엔을 이용하여 성능평가를 실행한 결과로 최적 체류시간이 1,200 sec인 것을 알 수 있었고 아스팔트를 사용하여 방해판의 개수, 실험온도를 변수로 FWKO vessel에서의 최적의 물 분리조건에 대해 조사하였다. 최적의 분리조건은 방해판 3개, 온도 $45^{\circ}C$였다.

Developmental Characteristics of SCNT Pig Embryos Knocked-out of Alpha-1,3-Galactosyltransferase Gene

  • Shim, Joo-Hyun;Park, Mi-Rung;Yang, Byoung-Chul;Ko, Yeoung-Gyu;Oh, Keon-Bong;Lee, Jeong-Woong;Woo, Jae-Seok;Park, Eung-Woo;Park, Soo-Bong;Hwang, Seong-Soo
    • Reproductive and Developmental Biology
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    • 제33권3호
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    • pp.157-162
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    • 2009
  • This study was performed to comprehend the developmental characteristics of cloned embryos knocked out (KO) of $\alpha$-1,3-galactosyltransferase (GalT) gene. Immature oocytes were collected and cultured for 40 hrs (1-step) or 20hrs (with hormone) + 20hrs (without hormone) (2-step). The embryos transferred with miniature pig ear fibroblast cell were used as control. The reconstructed embryos were cultured in PZM-3 with 5% $CO_2$ in air at $38.5^{\circ}C$ for 6 days. To determine the quality of the blstocysts, TUNEL and quantitative realtime RT-PCR were performed. The embryos were transferred to a surrogate (Landrace) at an earlier stage of the estrus cycle. The maturation rate was significantly higher in 2-step method than that of 1-step (p<0.05). The blastocyst development of GalT KO embryos was significantly lower than that of normal cloned embryos (p<0.05). The total and apoptotic cell number of GalT KO blastocysts was not different statistically from control. The relative abundance of Bax-$\alpha$/Bcl-xl ratio was significantly higher in both cloned blastocysts than that of in vivo blastocysts (p<0.05). Taken together, it can be postulated that the lower developmental potential and higher expression of apoptosis related genes in GalT KO SCNT embryos might be a cause of a low efficiency of GalT KO cloned miniature pig production.

Putative fructose-1,6-bisphosphate aldolase 1 (AtFBA1) affects stress tolerance in yeast and Arabidopsis

  • Moon, Seok-Jun;Shin, Dong-Jin;Kim, Beom-Gi;Byun, Myung-Ok
    • Journal of Plant Biotechnology
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    • 제39권2호
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    • pp.106-113
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    • 2012
  • Glycolysis is responsible for the conversion of glucose into pyruvate and for supplying reducing power and several metabolites. Fructose-1,6-bisphosphate aldolase (AtFBA1), a central enzyme in the glycolysis pathway, was isolated by functional complementation of the salt-sensitive phenotype of a calcineurin (CaN)-deficient yeast mutant. Under high salinity conditions, aldolase activity and the concentration of NADH were compromised. However, expression of AtFBA1 maintained aldolase activity and the NADH level in yeast cells. AtFBA1 shares a high degree of sequence identity with known class I type aldolases, and its expression was negatively regulated by stress conditions including NaCl. The fusion protein GFP-AtFBA1 was localized in the cytosol of Arabidopsis protoplasts. The seed germination and root elongation of AtFBA1 knock-out plants exhibited sensitivity to ABA and salt stress. These results indicate that AtFBA1 expression and aldolase activity is important for stress tolerance in yeast and plants.

Forkhead Genes are Key Regulators of Developmental Processes in Aspergillus nidulans

  • Oh, Dong-Soon;Kim, Jong-Hwa;Han, Dong-Min;Han, Kap-Hoon
    • 한국균학회소식:학술대회논문집
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    • 한국균학회 2014년도 춘계학술대회 및 임시총회
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    • pp.39-39
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    • 2014
  • In a homothallic filamentous fungus Aspergillus nidulans, sexual and asexual developments are largely affected by the genetic and environmental factors. To regulate the complex subsets of genes involved in the developmental processes accurately, tight regulations of transcription factors are required. The forkhead type transcription factors are the class of regulators that function in a broad spectrum of cellular and developmental processes in many species from yeast to human. Here, we identified the fkhA and fkhB genes that encode a conserved forkhead transcription factors. The fkhA deletion resulted in the complete loss of fruiting body formation under all conditions favoring sexual development, suggesting that the fkhA gene is required for sexual development in A. nidulans. Overexpression of fkhA resulted in enhanced formation of fruiting bodies under induction condition not only in the normal condition but also in the condition of presence of 0.6 M KCl, which strongly inhibits sexual development. To know the function of the fkhB gene, we also generated fkhB knock-out strain in A. nidulans. Deletion of fkhB resulted in abnormal conidiophore formation under standard conditions and delayed sexual development process, suggesting that the fkhB gene plays an important role in conidiophore morphogenesis Taken together, these results suggest that the fkhA gene is necessary and sufficient for regulating sexual development and the fkhB gene is a transcription factor related in asexual developmental process in A. nidulans.

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생쥐의 자궁, 난소, 태아에 있어서 아라키돈산에 특이적인 acyl-CoA synthetase 4 유전자의 발현

  • 박효영;문선정;양정미;이상미;정영희;문승주;강만종
    • 한국발생생물학회:학술대회논문집
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    • 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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    • pp.96-96
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    • 2003
  • Acyl-CoA synthetase 4는 생쥐에 있어서 거의 모든 조직에서 발현하며 아라키돈산에 특이적인 효소이다. 아라키돈산은 세포막의 인지질로부터 cPLA2에 의하여 유리되고 cyclooxygenase-1, -2에 의하여 eicosanoid로 변환된다. 이렇게 생산된 prostaglandin과 같은 eicosanoid는 배란, 수정, 임신에 있어서 중요한 기능을 수행하고 있다. 그러나 세포막으로부터 유리된 아라키돈산은 acyl-CoA synthetase 4에 의하여 다시 세포막으로 재에스테르화되어 eicosaniod의 생산을 조절하는 것으로 생각되어지고 있다. 또한 acyl-CoA synthetase 4 유전자 한쪽이 knock-out된 heterozygote mouse에서는 사산, 유산과 난소에 있어서 황체 수의 증가 등을 보고하고 있다. 그러므로 본 연구에서는 정상 생쥐 (C57BL/6) 임신 기간 중 acyl-CoA synthetase 4 유전자의 발현을 확인하기 위하여 자궁, 난소, 태아에서 RT-PCR을 수행하였다. 또한 cPLA2, cyclooxygenase-1, cyclooxygenase-2 유전자의 발현 양상을 분석하여 eicosanoid 생산에 관여하는 유전자 상호간의 발현 을 확인하였다. acyl-CoA synthetase 4는 임신 0 day에서부터 19.5 day까지 자궁과 난소에서 모두 발현하고 있었다. 또한 5.5 day에서부터 19.5 day까지의 태아에서도 그 발현이 확인되었다. 그리고 cPLA2와 cyclooxygenase-1은 acyl-CoA synthetase 4와 유사한 양상을 보였으나 cyclooxygenase-2는 임신기간 중의 자궁, 난소, 태아에서 전혀 발현하지 않았다. 그러므로 임신 중 생쥐 자궁, 난소, 태아에 있어서 eicosanoid 생산에는 cPLA2, cyclooxygenase-1, acyl-CoA synthetase 4 유전자가 관여하고 있는 것으로 생각된다.

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Novel Antioxidants and Atherosclerosis

  • Parthasarathy Sampath;Santanam Nalini
    • 한국식품영양과학회:학술대회논문집
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    • 한국식품영양과학회 2004년도 Annual Meeting and International Symposium
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    • pp.265-270
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    • 2004
  • Coronary heart disease (CHD) has been the number one killer in western society for a long time, and CHD in most instances is due to atherosclerosis. One of the earliest events in atherogenesis is the intracellular accumulation of lipids, particularly cholesterol esters, in the aortic intima. The lipids presumably came from the uptake of plasma lipoproteins, particularly from LDL. These foam cells were identified as being predominantly as macrophages. Currently, it is believed that oxidation of low density lipoprotein (LDL) might contribute to the generation of foam cells. An outcome of the oxidation hypothesis is that the consumption of antioxidants would be beneficial. In this study, Boldine, an alkaloid of Peumus boldus was tested for their antioxidant potency both in, in vitro oxidation system and in mouse models. Boldine decreased the ex-vivo oxidation of Low-density lipoprotein (LDL). In vivo studies were performed to study the effect of these compounds on the atherosclerotic lesion formation in LDL r-/- mice. Three groups of LDL r-/- mice (N=12 each) were fed an atherogenic diet. Group 1 was given vehicle and group 2 and 3 were given 1 and 5 mg of Boldine/day in addition to the atherogenic diet. The results indicated that there was a decrease in lesion formation reaching a 40% reduction due to Boldine compared to controls. The in vivo tolerance of Boldine in humans (has been used as an herbal medicine in other diseases) should make it an attractive alternative to vitamin E.

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Gene Targeting of the Acyl-CoA Synthetase Specific to Arachidonate

  • Kang, Man-Jong
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2000년도 국제심포지움
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    • pp.3-4
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    • 2000
  • The synthesis of acyl-CoA catalyzed by acyl-CoA synthetase (ACS, EC 6.2.1.3) from fatty acid, ATP, and CoA is a crucial reaction in mammalian fatty acid metabolism. In arachidonate metabolism, acyl-CoA synthetase(ACS) plays a key role in the esterification of free arachidonate into membrane phospholipids. Following its release by the action of calcium dependent phospholipase, free arachidonate is believed to be rapidly converted to arachidonoyl-CoA and reesterified into phospholipids in order to prevent excessive synthesis of eicosanoids. In previous studies, we have characterized five ACSs (designated as ACS1-5) with different tissue distribution. ACS1, ACS2, and ACS5 are similar in structure and fatty acid preference, and completely different from ACS3 and ACS4. The latter are arachidonate-preferring enzymes closely related in structure but expressed in different tissues: ACS3 mRNA is highly expressed in the brain and the mRNA for ACS4 is expressed in steroidogenic tissues including adrenal gland, ovary, and testis. To learn more about the potential function of ACS4 in arachidonate metabolism, we have produced knock-out mice for ACS4 gene. ACS4+/- females become pregnant less frequently and produce small litters with extremely low transmission of the disrupted alleles. Striking morphological changes including extremely enlarged uterine filled with numerous proliferative cysts of various size were detected in ACS4+/- females. Furthermore, marked accumulation of prostaglandins were seen in the uterus of heterozygous females. These results indicate that ACS4 is critical for the uterine arachidonate metabolism and heterozygous disruption of its gene lead to impaired pregnancy.

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주의력결핍 과잉운동장애에서 도파민 수송체 유전자 다형성 (Dopamine Transporter Gene Polymorphism in ADHD)

  • 신동원
    • 생물정신의학
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    • 제9권1호
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    • pp.8-14
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    • 2002
  • Patients with attention deficit hyperactivity disorder(ADHD) have symptoms of inattention, hyperactivity, impulsivity. Symptoms of ADHD are responsive to medications such as methylphenidate, dextroamphetamine, pemoline, and bupropion. The functional change of the dopamine transporter is related to the therapeutic effect of these drugs. This can be one reason for the dopamine transporter to be emphasized in the research field of ADHD. ADHD has a genetic tendency. Since dopamine transporter gene(DAT1) knock out mice were reported to be several times more active than normal mice in a novel situation, lights has been shed on DAT1 as a candidate gene for ADHD. Though there have been several studies which reported an association between DAT1 and ADHD, the association between DAT1 and ADHD is not conclusive. Since Vandenbergh reported the DAT1 polymorphism with variable number of tandem repeats(VNTR), and the racial differences in allelic frequencies of the DAT1, wide ethnic variation in the distribution of the DAT1 polymorphism had been confirmed. Wide ethnic variation in the distribution of the DAT1 suggested that there might be ethnic difference in the association between DAT1 and ADHD. Before applying previous findings to Koreans, verification might be needed for Korean patients with ADHD.

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NF-κB and Therapeutic Approach

  • Lee, Chang-Hoon;Kim, Soo-Youl
    • Biomolecules & Therapeutics
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    • 제17권3호
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    • pp.219-240
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    • 2009
  • Since NF-${\kappa}B$ has been identified as a transcription factor associated with immune cell activation, groups of researchers have dedicated to reveal detailed mechanisms of nuclear factor of ${\kappa}B$ (NF-${\kappa}B$) in inflammatory signaling for decades. The various molecular components of NF-${\kappa}B$ transcription factor pathway have been being evaluated as important therapeutic targets due to their roles in diverse human diseases including inflammation, cystic fibrosis, sepsis, rheumatoid arthritis, cancer, atherosclerosis, ischemic injury, myocardial infarction, osteoporosis, transplantation rejection, and neurodegeneration. With regards to new drugs directly or indirectly modulating the NF-${\kappa}B$ pathway, FDA recently approved a proteasome inhibitor bortezomib for the treatment of multiple myeloma. Many pharmaceutical companies have been trying to develop new drugs to inhibit various kinases in the NF-${\kappa}B$ signaling pathway for many therapeutic applications. However, a gene knock-out study for $IKK{\beta}$ in the NF-${\kappa}B$ pathway has given rise to controversies associated with efficacy as therapeutics. Mice lacking hepatocyte $IKK{\beta}$ accelerated cancer instead of preventing progress of cancer. However, it is clear that pharmacological inhibition of $IKK{\beta}$ appears to be beneficial to reduce HCC. This article will update issues of the NF-${\kappa}B$ pathway and inhibitors regulating this pathway.

포장자재 풀시스템 도입을 통한 제관(CAN병).제병(PET병)업계 물류효율화에 관한 연구 (A study on the logistics effectiveness in the receptacles & bottles manufacturers by introducing Packing resource Pool System)

  • 박인술;권안식;강경식
    • 대한안전경영과학회지
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    • 제9권3호
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    • pp.63-71
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    • 2007
  • Recently, many companies knock themselves out to reduce logistics costs. However, they have reached the limit on cost reducing by improving the manufacturing process. In addition, Customers are growing more and more particular about the quality. Also the firms, which provide foods & beverages manufacturer with vacant receptacles and bottles, make zealous efforts to save costs. They have tried to seek for the resolution by own investment and improving system, but they haven't found certainly substitutions. In this study, we analyze problems of the vacant receptacles manufacturers and present introduction of pool system by standardization of Packing Resource. This PPS(Packing resource Pool System) will enable to reduce logistics cost that is challenge for the receptacles & bottles manufacturers, be helpful reducing environmental disruption which are the pollution of alien substances, wasted paper sheets because the system cleans retrieved Packing resources and reuses them.