• Title/Summary/Keyword: vgb

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Production of methionine γ- lyase in recombinant Citrobacter freundii bearing the hemoglobin gene

  • Kahraman, Huseyin;Aytan, Emel;Kurt, Ash Giray
    • BMB Reports
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    • v.44 no.9
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    • pp.590-594
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    • 2011
  • The production of antileukemic enzyme methionine ${\gamma}$-lyase (MGL) in distinctly related bacteria, Citrobacter freundii and in their recombinants expressing the Vitresocilla hemoglobin (VHb) has been studied. This study concerns the potential of Citrobacter freundii expressing the Vitreoscilla hemoglobin gene (vgb) for the methionine ${\gamma}$- liyase production. Methionine ${\gamma}$- liyase production by Citrobacter freundii and its $vgb^-$ and $vgb^+$ bearing recombinant strain was studied in shake-flasks under 200 rpm agitation, culture medium and $30^{\circ}C$ in a time-course manner. The $vgb^+$ and especially the carbon type had a dramatic effect on methionine ${\gamma}$- liyase production. The $vgb^+$ strain of C. freundii had about 2-fold and 3.1-fold higher levels of MGL than the host and $vgb^-$ strain, respectively.

Assessment of the Relationship between Vigabatrin and Visual Field Defect in Children (항경련제 Vigabatrin이 시야에 미치는 영향)

  • Chung, Sa Jun;Chung, Yong Hwan;Cho, Eu Hyun
    • Clinical and Experimental Pediatrics
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    • v.45 no.12
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    • pp.1546-1550
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    • 2002
  • Purpose : The authors carried out this study to determine the relationship between vigabatrin (VGB) and visual field defect.. Methods : Seventy eight patients older than 8 years who had epilepsy which had developed and been diagnosed, and were receiving add-on therapy, were the subjects of this study. If suspicious results were obtained from the initial test with the Humphrey automatic perimeter, the patient was tested again with the Goldman perimeter. Follow-up examinations were performed on these patients after 6 months. Results : In this study, five of the 78 patients had suspicious primary test results, but upon the second examination they were all found to be normal. Thus there were no patients with visual field defects. Conclusion : VGB is a drug which may cause visual field defects, but in this study no patients presented with this symptom. Instead of limiting the use of VGB due to the adverse effect of visual field defect in the initial treatment of partial seizure and infantile spasm untreatable with other medication, if used with care it may not cause serious problems. Screening for visual defect is recommended, and in patients taking VGB regular examination is necessary.

Introduction of a Bacterial Hemoglobin Gene for Improving Bacterial Growth under Hypoxic Condition

  • Chung, Chung-Nam;Yoon, Suk-Ran;Jun, Woo-Jin;Shim, Sang-In;Park, In-Ho;Chung, Jin-Woong
    • Journal of agriculture & life science
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    • v.43 no.6
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    • pp.77-84
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    • 2009
  • Using recombinant DNA technology, the vector system containing minimal fragment of a bacterial hemoglobin gene (vgb) was constructed. When this vector was inserted into Escherichia coli, the growth of the host was significantly improved in both viable cell counts and absorbance measurement, compared to that of the wild type strain. In addition, by minimizing the size of bacterial hemoglobin in the vector, the ability of vgb in growth improvement was augmented, due to the reduction of metabolic burden from the maintenance and replication of the plasmid. By using this system, it is expected that the growth of microorganisms can be improved even in the hypoxic condition.

An Efficient and Stable Method for the Transformation of Heterogeneous Genes into Cephalosporium acremonium Mediated by Agrobacterium tumefaciens

  • XU WEI;ZHU CHUNBAO;ZHU BAOQUAN
    • Journal of Microbiology and Biotechnology
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    • v.15 no.4
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    • pp.683-688
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    • 2005
  • A transformation system mediated by Agrobacterium tumefaciens is routinely used for the genetic engineering of plants. Here, we report an efficient and stable method for transformation of heterogeneous genes into an industrial Cephalosporium acremonium by using a similar transformation system established in plants. Both the phleomycin-resistant gene and vgb gene were used as screening markers to confirm the success of transformation by either Southern hybridization or PCR amplification. It was found that acetosyringone (AS) was necessary only for protoplast transformation and the heterogeneous genes transferred were integrated into the genome of C. acremonium. The transformation efficiency obtained with this system was much higher than the conventional techniques used for transformation of C. acremonium.

특집:녹색선박 SCR시스템 기술개발 현황 - 선박용 질소산화물 저감장치 개발의 필요성 및 규제현황

  • Jeong, Gyeong-Yeol;Park, Chang-Dae;Im, Byeong-Ju;Kim, Seong-Yun;Kim, Min
    • 기계와재료
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    • v.24 no.2
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    • pp.28-36
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    • 2012
  • IMO의 해양오명 방지협약(MARPOL 73/78)에 의하면 선박 배기가스에 포함된 질소산화물(NOx)과 황산화물(SOx)의 배출 제한을 강화한 IMO Tier III 기준이 2010년에 발효되어 2016년부터 신조선에 적용되며, NOx는 85% 이상 저감할 것을 요구하고 있다. 국제적으로 적용되는 선박배출가스 기준을 국내에 적용하고, 검증하기 위해서는 이를 시험할 수 있는 시험/검증 절차와 방법을 개발하는 것 또한 시급한 문제이다. 선진국들은 이미 오염물질 배출 저감 장비를 채택하고 대기 중 오염물질 측정 장치 도입을 추구하는 추세이며, 친환경 선박 기자재 개발로 차세대 녹색선박기술 선점을 주력하고 있다. 대한전기협회에서는 독일 VGB사의 "VGB-R 302 He 1998 $2^{nd}$ Revised edition" 2010년 판을 참고하여 발전소에 대한 SCR 시스템의 성능시험 및 진단 권장지침을 만들어 이용하고 있지만, 선박 SCR 시스템에 대한 내용은 정해진 바 없으며, 이를 개발하는 것 또한 중요하다.

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Enhanced Biodegradation of Environmental Allergen by a vgb-containing Burkholderia cepacia

  • Kim, Mi-Sun;Yoon, Suk-Ran;Jun, Woo-Jin;Park, So-Young;Yang, Young;Shim, Sang-In;Hwang, Kwang-Woo;Chung, Jin-Woong
    • Molecular & Cellular Toxicology
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    • v.1 no.4
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    • pp.262-267
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    • 2005
  • Using genetic engineering, the Vitreoscilla (bacterial) hemoglobin gene (vgb) was integrated stably into the chromosomes of and Burkholderia cepacia. Similar to previous results, the wild type VHb improved growth for Burkholderia cepacia and degradation of benzoic acid under both normal and low aeration conditions. The stable expression of VHb enhanced these parameters. The results demonstrate the possibility that the positive effects provided by VHb may be augmented by protein engineering.

An Empirical Study on the Measurement of Clustering and Trend Analysis among the Asian Container Ports Using the Variable Group Benchmarking and Categorical Variable Models (가변 그룹 벤치마킹 모형과 범주형 변수모형을 이용한 아시아 컨테이너항만의 클러스터링측정 및 추세분석에 관한 실증적 연구)

  • Park, Rokyung
    • Journal of Korea Port Economic Association
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    • v.29 no.1
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    • pp.143-175
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    • 2013
  • The purpose of this paper is to show the clustering trend by using the variable group benchmarking(VGB) and categorical variable(CV) models for 38 Asian ports during 9 years(2001-2009) with 4 inputs(birth length, depth, total area, and number of crane) and 1 output(container TEU). The main empirical results of this paper are as follows. First, clustering results by using VGB show that Shanghai, Qingdao, and Ningbo ports took the core role for clustering. Second, CV analysis focusing on the container throughputs indicated that Singapore, Keelong, Dubai, and Kaosiung ports except Chinese ports are appeared as the center ports of clustering. Third, Aqaba, Dubai, Hongkong, Shanghai, Guangzhou, and Ningbo ports are recommended as the efficient ports for the target of clustering. Fourth, when the ports are classified by the regional location, Dubai, Khor Fakkan, Shanghai, Hongkong, Keelong, Ningbo, and Singapore ports are the core ports for clustering. On the whole, other ports located in Asia should be clustered to Dubai, Khor Fakkan, Shanghai, Hongkong, Ningbo, and Singapore ports. The policy implication of this paper is that Korean port policy planner should introduce the VGB model, and CV model for clustering among the international ports for enhancing the efficiency of inputs and outputs.

Water Treatment of Low Pressure Steam turbine Generation on Small MSW Incinerationp Plant (중소형폐기물소각설비의 발전용 용수처리에 관한 연구)

  • Jeon, Kuem-Ha;Ha, Choon-Rai;Kim, Nack-Joo
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.836-839
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    • 2009
  • 중소형 폐기물소각설비의 저압 저질의 포화증기를 이용한 폐열발전용 용수처리에 관한 연구를 수행 하였다. 기존 소각설비에 적용된 강산성 이온교환수지형 연수기에 역삼투압 멤브레인 처리와 강염기성 이온교환수지형 용수처리를 연결하여 보일러 용수를 처리한 결과, KS B6209의 30 $kg/cm_2$ 증기 압력의 보일러 용수기준에는 적합하였고, 증기의 비체적으로 증기 농도로 환산하면. 역삼투압법처리에 의한 방법보다는 강염기성이온교환수지형 용수처리를 연계 처리한 결과가 중소형폐기물소각설비의 저압증기터빈발전에 보다 적합한 것으로 나타났다.

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Ultimate behavior of reinforced concrete cooling tower: Evaluation and comparison of design guidelines

  • Noh, Hyuk-Chun;Choi, Chang-Koon
    • Structural Engineering and Mechanics
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    • v.22 no.2
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    • pp.223-240
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    • 2006
  • Taking into account the geometrical and material nonlinearities, an ultimate behavior of reinforced concrete cooling tower shell in hyperbolic configuration is presented. The design wind pressures suggested in the guidelines of the US (ACI) and Germany (VGB), with or without the effect of internal suction, are employed in the analysis to examine the qualitative and quantitative characteristics of each design wind pressure. The geometrical nonlinearity is incorporated by the Green-Lagrange strain tensor. The nonlinear features of concrete, such as the nonlinear stress-strain relation in compression, the tensile cracking with the smeared crack model, an effect of tension stiffening, are taken into account. The biaxial stress state in concrete is represented by an improved work-hardening plasticity model. From the perspective of quality of wind pressures, the two guidelines are determined as highly correlated each other. Through the extensive analysis on the Niederaussem cooling tower in Germany, not only the ultimate load is determined but also the mechanism of failure, distribution of cracks, damage processes, stress redistributions, and mean crack width are examined.

Modeling wind ribs effects for numerical simulation external pressure load on a cooling tower of KAZERUN power plant-IRAN

  • Goudarzi, Mohammad-Ali;Sabbagh-Yazdi, Saeed-Reza
    • Wind and Structures
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    • v.11 no.6
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    • pp.479-496
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    • 2008
  • In this paper, computer simulation of wind flow around a single cooling tower with louver support at the base in the KAZERUN power station in south part of IRAN is presented as a case study. ANSYS FLOTRAN, an unstructured finite element incompressible flow solver, is used for numerical investigation of wind induced pressure load on a single cooling tower. Since the effects of the wind ribs on external surface of the cooling tower shell which plays important role in formation of turbulent flow field, an innovative relation is introduced for modeling the effects of wind ribs on computation of wind pressure on cooling tower's shell. The introduced relation which follows the concept of equivalent sand roughness for the wall function is used in conjunction with two equations ${\kappa}-{\varepsilon}$ turbulent model. In this work, the effects of variation in the height/spacing ratio of external wind ribs are numerically investigated. Conclusions are made by comparison between computed pressure loads on external surface of cooling tower and the VGB (German guideline for cooling tower design) suggestions.