• Title/Summary/Keyword: directed evolution

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A Study of Development and Implementation of Problem-based Learning Program in Communication Curriculum of Nursing Education (문제중심 학습방법을 적용한 의사소통론 교과목 개발 및 적용)

  • Hyun, Myung-Sun;Kang, In-Ae;Kong, Seong-Sook
    • The Journal of Korean Academic Society of Nursing Education
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    • v.9 no.1
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    • pp.144-154
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    • 2003
  • Recently, in the academic disciplines critical thinking has been emphasized as the new evolution in education. Problem-based learning is suggested as the evolutionary learning method in developing critical thinking. In the nursing education, PBL is offered as an appropriate teaching method to prepare nurse student for professional. PBL is a student-centered learning strategy aimed at developing critical thinking, motivating self-directed study and attaining autonomy. The purpose of this study was to develop the communication curriculum of nursing education based on PBL and implementing of it. PBL module was developed focused on five communication situations. And learning strategies to facilitate the learning process and the guided questions to stimulate student inquiry were also developed. This PBL education was conducted for six students in the master's course during the 14 weeks from March, 2000 to June, 2000. The outcomes of the PBL education were examined based on the content analysis of the students reflective journal. As a result, it was found that students experienced the effect of it focused on self-oriented, group-oriented, and practice-oriented domain. In the self-oriented domain, the findings indicate that there were 5 kinds of concepts including 'motivation for self-directed study', 'transition toward certainty in knowledge acquisition', 'attempt to apply their prior knowledge into new situation', 'enhancement of self-image in real situation', 'self-growth with self reflection'. In the group-oriented domain, there were 3 kinds of concepts including 'cognitive work in group', 'perception of co-responsibility in attaining learning objectives', 'socialization with group members'. In the practice-oriented domain, there were 3 kinds of concepts including 'linkage theoretical knowledge with real situation', 'attempt to apply in real situation', 'development problem solving skill in real situation'. In conclusion, PBL had a significant effect on self, group, and clinical domain. And assessing PBL outcomes is challenging because standardized instrument do not develop yet. So the findings of this study can suggest the basic data for examining the PBL outcome.

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Geological Structures and Evolution of the Tertiary Chŏngja Basin, Southeastern Margin of the Korean Peninsula (울산군 강동면 제 3기 정자분지(亭子盆地)의 지질구조와 분지발달)

  • Son, Moon;Kim, In-Soo
    • Economic and Environmental Geology
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    • v.27 no.1
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    • pp.65-80
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    • 1994
  • The Tertiary $Ch{\check{o}}ngja$ basin is located in the southeastern coastal area of the Korean Peninsula. It is a lozenge shaped fault-bounded basin with circa $5{\times}5km$ areal extent, isolated from other Tertiary basins by the Cretaceous Ulsan Formation in-between. The northwestern boundary of the basin is a domino/listric type normal fault trending $N30^{\circ}E$, whereas its southwestern boundary is a dextral strike-slip fault (trending $N20^{\circ}W$) with a lateral offset of more than 1 km. The basin is bounded by the East Sea on the eastern margin. Basin-fills consist of extrusive volcanic rock (Tangsa Andesites) of Early Miocene (16~22 Ma in radiometric age), unconsolidated fluviatile conglomerate (Kangdong Formation) and shallow brackish-water sandstone ($Sinhy{\check{o}}n$ Formation). The latter yields abundant Vicarya-Anadara molluscan fossils of early Middle Miocene age. The Tertiary strata become younger toward the northwestern boundary-fault of the basin, showing a zonal distribution pattern parallel to the fault: the younger sedimentary formations occupy a narrow zone of 2 km width along the northwestern boundary-fault, whereas the older Tangsa Andesites underlie them unconformably in the eastern and southeastern portions of the basin. The strata in the basin, including the Tangsa Andesites, are tilted (about $20^{\circ}$) toward the northwestern boundary-fault Sedimentary strata thicken toward the boundary-fault, forming a wedge shaped half-graben structure. A number of small-scale syndepositional normal growth faults and graben structures are observed in the sedimentary strata. These extensional structures have the same trend as the normal northwestern boundary-fault which we interpret as a pull-apart detachment fault. These characteristics imply persistent extension during the basin evolution, caused by a NW-SE directed tensional force. The $Ch{\check{o}}ngja$ basin is, thus, a kind of syndepositional tectonic basin evolved in a strike-slip (pull-apart) regime. The latter was caused by a dextral simple shear associated with the NNW-SSE opening of the East Sea. In view of the fact that the normal growth faults do not cut through the uppermost portion of the youngest $Sinhy{\check{o}}n$ Formation, it is inferred that the tensional force came to be inactive in the early Middle Miocene. This is coincident in timing with the termination of the East Sea opening (15 Ma).

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Development of Screening Method for the Soluble Recombinant Protein using β-Lactamase as a Fusion Partner (β-Lactamase 접합 단백질 발현 시스템을 이용한 가용성 재조합 단백질 탐색 기술 개발)

  • Lee, Jae-Hun;Hwang, Bum-Yeol;Kim, Byung-Gee;Lee, Sun-Gu
    • Korean Chemical Engineering Research
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    • v.47 no.5
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    • pp.624-629
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    • 2009
  • It is the most important step to screen soluble and insoluble proteins when we attempt to improve the solubility of recombinant proteins through directed evolution approach. Here we show that the solubility of a recombinant protein in vivo can be examined by expressing the recombinant protein with beta-lactamase as a fusion partner. First we constructed an expression system which can produc a fusion protein with the C-terminal of beta-lactamase. Two soluble proteins, i.e. adenine deaminase and aspartate aminotransferase, and insoluble GlcNAc-2-epimerase were cloned into the developed expression vector, respectively. We investigated the effect of the expression of the three recombinant fusion proteins on the growth of E. coli, and confirmed that the solubilities of the recombinant proteins correlated with cell growth rates.

Functional expression of CalB in E.coli (대장균에서의 Candida antarctica lipase B 최적 발현)

  • Kim, Hyun-Sook;Kim, Yong-Hwan
    • KSBB Journal
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    • v.23 no.5
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    • pp.445-448
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    • 2008
  • Candida antarctica lipase B (CalB) is an efficient biocatalyst for many organic synthesis reactions. To make full use of CalB, we need effective expression system. Previously recombinant CalB was successfully expressed in the methylotropic yeast Pichia pastoris. In addition, we succeed in the functional expression of CalB in the Escherichia coli cytoplasm. This CalB expression system in E.coli has many considerable advantages in comparison with other expression systems and enables high-throughput screening of gene libraries as those derived from directed evolution experiments. To optimize E.coli system, we investigate comparing between OrigamiB (DE3) and BL21 (DE3) and observing effect of IPTG amount.

Optimizing the binding activity of the AP2/ERF transcription factor with the GCC box element from Brassica napus by directed evolution

  • Jin, Xiao-Fen;Zhu, Bo;Peng, Ri-He;Jiang, Hai-Hua;Chen, Jian-Min;Zhuang, Jing;Zhang, Jian;Yao, Quan-Hong;Xiong, Ai-Sheng
    • BMB Reports
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    • v.43 no.8
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    • pp.567-572
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    • 2010
  • In this study, we cloned the ERF-B3 subfamily transcription factor gene BnaERF-B3-hy15 from Brassica napus L. Huyou15. This 600 bp gene encodes a 199 amino acid classic ethylene responsive factor (ERF), which shown no binding or very weak binding GCC box-binding activity by the yeast one-hybrid assay. We used gene shuffling and the yeast one-hybrid system to obtain three mutated sequences that can bind to the GCC box. Sequence analysis indicated that two residues, Gly156 in the AP2 domain and Phe62 at the N-terminal domain were mutated to arginine and serine, respectively. Changes of Gly156 to arginine and Phe62 to serine increased the GCC-binding activity of BnaERF-B3-hy15 and the alter of Gly156 to arginine changed the AP2-domain structure of BnaERF-B3-hy15.

Engineering CotA Laccase for Acidic pH Stability Using Bacillus subtilis Spore Display

  • Sheng, Silu;Jia, Han;Topiol, Sidney;Farinas, Edgardo T.
    • Journal of Microbiology and Biotechnology
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    • v.27 no.3
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    • pp.507-513
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    • 2017
  • Bacillus subtilis spores can be used for protein display to engineer protein properties. This method overcomes viability and protein-folding concerns associated with traditional protein display methods. Spores remain viable under extreme conditions and the genotype/phenotype connection remains intact. In addition, the natural sporulation process eliminates protein-folding concerns that are coupled to the target protein traveling through cell membranes. Furthermore, ATP-dependent chaperones are present to assist in protein folding. CotA was optimized as a whole-cell biocatalyst immobilized in an inert matrix of the spore. In general, proteins that are immobilized have advantages in biocatalysis. For example, the protein can be easily removed from the reaction and it is more stable. The aim is to improve the pH stability using spore display. The maximum activity of CotA is between pH 4 and 5 for the substrate ABTS (ABTS = diammonium 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate). However, the activity dramatically decreases at pH 4. The activity is not significantly altered at pH 5. A library of approximately 3,000 clones was screened. A E498G variant was identified to have a half-life of inactivation ($t_{1/2}$) at pH 4 that was 24.8 times greater compared with wt-CotA. In a previous investigation, a CotA library was screened for organic solvent resistance and a T480A mutant was found. Consequently, T480A/E498G-CotA was constructed and the $t_{1/2}$ was 62.1 times greater than wt-CotA. Finally, E498G-CotA and T480A/E498G-CotA yielded 3.7- and 5.3-fold more product than did wt-CotA after recycling the biocatalyst seven times over 42 h.

A Review on Membranes and Catalysts for Anion Exchange Membrane Water Electrolysis Single Cells

  • Cho, Min Kyung;Lim, Ahyoun;Lee, So Young;Kim, Hyoung-Juhn;Yoo, Sung Jong;Sung, Yung-Eun;Park, Hyun S.;Jang, Jong Hyun
    • Journal of Electrochemical Science and Technology
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    • v.8 no.3
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    • pp.183-196
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    • 2017
  • The research efforts directed at advancing water electrolysis technology continue to intensify together with the increasing interest in hydrogen as an alternative source of energy to fossil fuels. Among the various water electrolysis systems reported to date, systems employing a solid polymer electrolyte membrane are known to display both improved safety and efficiency as a result of enhanced separation of products: hydrogen and oxygen. Conducting water electrolysis in an alkaline medium lowers the system cost by allowing non-platinum group metals to be used as catalysts for the complex multi-electron transfer reactions involved in water electrolysis, namely the hydrogen and oxygen evolution reactions (HER and OER, respectively). We briefly review the anion exchange membranes (AEMs) and electrocatalysts developed and applied thus far in alkaline AEM water electrolysis (AEMWE) devices. Testing the developed components in AEMWE cells is a key step in maximizing the device performance since cell performance depends strongly on the structure of the electrodes containing the HER and OER catalysts and the polymer membrane under specific cell operating conditions. In this review, we discuss the properties of reported AEMs that have been used to fabricate membrane-electrode assemblies for AEMWE cells, including membranes based on polysulfone, poly(2,6-dimethyl-p-phylene) oxide, polybenzimidazole, and inorganic composite materials. The activities and stabilities of tertiary metal oxides, metal carbon composites, and ultra-low Pt-loading electrodes toward OER and HER in AEMWE cells are also described.

Evolution of Vertical Integration in the Korea Broiler Industry (한국육계산업의 수직통합(계열화) 전개상황)

  • 박영인
    • Korean Journal of Poultry Science
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    • v.18 no.1
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    • pp.57-66
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    • 1991
  • The broiler industry in Korea has been gradually changing its structure of independent operation into integrated and coordinated production and marketing system. It was in 1960s when the broiler industry first tried the integrated effort, but never succeeded as it was expected since due mainly to growers' attitudes favorable for traditional operation and agribusiness' passive response on structure change. Until mid 1980s, however, a bit of partially integrated system had been evolved by several factor suppliers. Recent years have furthered its progress toward completely integrated pattern, the ultimate goal of broiler integration. It is true that the external factors including the GATT Negotiations through the Uruguay Round stimulated the people involved in the industry to find the way of making it competitive to survive in the open, liberalized world economic system rapidly emerging through the process of globalization. Once the industry realized the necessity of reducing the cost of production and improving the quality of it, the conclusion tended to come to the point of an entire structural alteration by means of integration rather than an improvement of a certain segment such as marketing. It is very obvious. therefore. that the movement toward the complete integration will speed up in a coming few years under the leadership of not only entrepreneurs but also producers group. According to a report. there were three almost complete integrators and thirteen partial integrators as of December, 1990, all of which eagerly directed toward the completely integrated system in due course . Among others as an advantage of integrated structure. the cost saving must be pointed out as the greatest one In a survey, it was estimated that the cost of dressed and ready-to-eat chicken could be lowered by 31.8 percent and 41.5 percent, respectively, over that to be under the independent, non-integrated system. As long as everybody concerned about the future of the industry in the open market mechanism realizes the importance of the structure change through an integration, the broiler sector of Korean agriculture shall be moving toward the direction of vertically and completely integrated structure in order to make it competitive, even to export, hopefully before 1995 or by the end of this century in any case.

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A Simulation Model for the Application of Concurrent Engineering to Design Phase in Construction (건설공사 설계단계에서의 동시공학 적용을 위한 시뮬레이션 모델)

  • Han, Jin-Taek;Lee, Jae-Seob
    • Korean Journal of Construction Engineering and Management
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    • v.10 no.3
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    • pp.102-110
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    • 2009
  • Although several research efforts have been directed to fast-tracking to reduce the total delivery time, few researches have been studied on concurrent engineering in construction projects. The focus of fast-tracking is primarily on overlapping independent activity pairs. In comparison, the focus of concurrent engineering is on overlapping dependent activity pairs. Dependent activities are much harder to overlap successfully. This paper presents a simulation-based Concurrent Engineering methodology to optimize the overall duration of a set of design activities in a project by modelling key factors that determine the duration of individual activities and overlap between dependent activities. This methodology involves determining how much to overlap activities, how to decide which activities to overlap and the corresponding cost and time tradeoffs using a discrete event model solution. This simulation model, therefore, can be used as a reference on decision-making to define optimum point between time and cost.

A Study on the Evaluation of Load Carrying Capacity of Highway Bridges based on Structural Reliability Methods (구조신뢰성(構造信賴性) 방법에 의한 도로교(道路橋)의 내하력(耐荷力) 평가(評價)에 관한 연구(硏究))

  • Shin, Jae Chul;Cho, Hyo Nam;Chang, Dong Il
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.7 no.2
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    • pp.107-120
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    • 1987
  • This study is directed for the evolution of the rational approaches to the systematic evaluation of the load carrying capacity of bridges based on the practical and second moment reliability methods. A new approach for the evaluation of load carrying capacity of exsisting bridges is proposed in this study. The key idea behind this approach is in the fact that the load carrying capacity of an existing bridges under extreme traffic truck loadings may be measured by evaluating and classifying the reliability state of the bridge in terms of reliability index(${\beta}$). The rating formulas developed in this study are applied for the evaluation of load carrying capacity of the several actual deteriorated bridges inspected and tested for the capacity rating, and the results are compared with those calculated by using the current rating formulas. It may be concluded that the proposed rating formulas which is derived based on reliability methods, have to eventually replace the current rating formula when the basic statistical data for the resistance and load effects become available in the near future.

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