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Now showing items 1 - 16 of 66

  • A comprehensive metabolic map for production of bio-based chemicals

    Lee, Sang Yup   Kim, Hyun Uk   Chae, Tong Un   Cho, Jae Sung   Kim, Je Woong   Shin, Jae Ho   Kim, Dong In   Ko, Yoo-Sung   Jang, Woo Dae   Jang, Yu-Sin  

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  • Microbial production of methyl anthranilate, a grape flavor compound

    Luo, Zi Wei   Cho, Jae Sung   Lee, Sang Yup  

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    A walking analysis system and method, and a computer-readable recording medium are disclosed. According to one embodiment of the present invention, the walking analysis method comprises the steps of: measuring lower limb joint angles of a walker through an inertial measurement device attached to the walker's body; extracting a walking event by using gyroscope data acquired through the inertial measurement device; detecting walking steps from the walking event, and subdividing the joint angles for each walking step; performing machine learning for the joint angles subdivided for each walking step, so as to classify the same into a plurality groups according to data characteristics; and determining the severity of a knee joint disease for the plurality of groups.
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  • Virtual Reality Training Improves da Vinci Performance: A Prospective Trial

    Cho, Jae Sung   Hahn, Koo Yong   Kwak, Jung Myun   Kim, Jin   Baek, Se Jin   Shin, Jae Won   Kim, Seon Hahn  

    Introduction: The DV-Trainer (TM) (a virtual reality [VR] simulator) (Mimic Technologies, Inc., Seattle, WA) is one of several different robotic surgical training methods. We designed a prospective study to determine whether VR training could improve da Vinci (R) Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA) performance. Subjects and Methods: Surgeons (n = 12) were enrolled using a randomized protocol. Groups 1 (VR training) and 2 (control) participated in VR and da Vinci exercises. Participants' time and moving distance were combined to determine a composite score: VR index = 1000/(time u moving distance). The da Vinci exercises included needle control and suturing. Procedure time and error were measured. A composite index (DV index) was computed and used to measure da Vinci competency. After the initial trial with both the VR and da Vinci exercises, only Group 1 was trained with the VR simulator following our institutional curriculum for 3 weeks. All members of both groups then participated in the second trial of the VR and da Vinci exercises and were scored in the same way as in the initial trial. Results: In the initial trial, there was no difference in the VR index (Group 1 versus Group 2, 8.9 +/- 3.3 versus 9.4 +/- 3.7; P =.832) and the DV index (Group 1 versus Group 2, 3.85 +/- 0.73 versus 3.66 +/- 0.65; P =.584) scores between the two groups. At the second time point, Group 1 showed increased VR index scores in comparison with Group 2 (19.3 +/- 4.5 versus 9.7 +/- 4.1, respectively; P =.001) and improved da Vinci performance skills as measured by the DV index (5.80 +/- 1.13 versus 4.05 +/- 1.03, respectively; P =.028) and by suturing time (7.1 +/- 1.54 minutes versus 10.55 +/- 1.93 minutes, respectively; P =.018). Conclusions: We found that VR simulator training can improve da Vinci performance. VR practice can result in an early plateau in the learning curve for robotic practice under controlled circumstances.
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  • Author Correction: A comprehensive metabolic map for production of bio-based chemicals

    Lee, Sang Yup   Kim, Hyun Uk   Chae, Tong Un   Cho, Jae Sung   Kim, Je Woong   Shin, Jae Ho   Kim, Dong In   Ko, Yoo-Sung   Jang, Woo Dae   Jang, Yu-Sin  

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  • CRISPR/Cas9-coupled recombineering for metabolic engineering of Corynebacterium glutamicum

    Cho, Jae Sung   Choi, Kyeong Rok   Prabowo, Cindy Pricilia Surya   Shin, Jae Ho   Yang, Dongsoo   Jang, Jaedong   Lee, Sang Yup  

    Genome engineering of Corynebacterium glutamicum, an important industrial microorganism for amino acids production, currently relies on random mutagenesis and inefficient double crossover events. Here we report a rapid genome engineering strategy to scarlessly knock out one or more genes in C. glutamicum in sequential and iterative manner. Recombinase RecT is used to incorporate synthetic single-stranded oligodeoxyribonucleotides into the genome and CRISPR/Cas9 to counter-select negative mutants. We completed the system by engineering the respective plasmids harboring CRISPR/Cas9 and RecT for efficient curing such that multiple gene targets can be done iteratively and final strains will be free of plasmids. To demonstrate the system, seven different mutants were constructed within two weeks to study the combinatorial deletion effects of three different genes on the production of.-aminobutyric acid, an industrially relevant chemical of much interest. This genome engineering strategy will expedite metabolic engineering of C. glutamicum.
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  • Metabolic engineering of Corynebacterium glutamicum for enhanced production of 5-aminovaleric acid

    Shin, Jae Ho   Park, Seok Hyun   Oh, Young Hoon   Choi, Jae Woong   Lee, Moon Hee   Cho, Jae Sung   Jeong, Ki Jun   Joo, Jeong Chan   Yu, James  

    Background: 5-Aminovaleric acid (5AVA) is an important five-carbon platform chemical that can be used for the synthesis of polymers and other chemicals of industrial interest. Enzymatic conversion of l-lysine to 5AVA has been achieved by employing lysine 2-monooxygenase encoded by the davB gene and 5-aminovaleramidase encoded by the davA gene. Additionally, a recombinant Escherichia coli strain expressing the davB and davA genes has been developed for bioconversion of l-lysine to 5AVA. To use glucose and xylose derived from lignocellulosic biomass as substrates, rather than l-lysine as a substrate, we previously examined direct fermentative production of 5AVA from glucose by metabolically engineered E. coli strains. However, the yield and productivity of 5AVA achieved by recombinant E. coli strains remain very low. Thus, Corynebacterium glutamicum, a highly efficient l-lysine producing microorganism, should be useful in the development of direct fermentative production of 5AVA using l-lysine as a precursor for 5AVA. Here, we report the development of metabolically engineered C. glutamicum strains for enhanced fermentative production of 5AVA from glucose.Results: Various expression vectors containing different promoters and origins of replication were examined for optimal expression of Pseudomonas putida davB and davA genes encoding lysine 2-monooxygenase and delta-aminovaleramidase, respectively. Among them, expression of the C. glutamicum codon-optimized davA gene fused with His(6)-Tag at its N-Terminal and the davB gene as an operon under a strong synthetic H-36 promoter (plasmid p36davAB3) in C. glutamicum enabled the most efficient production of 5AVA. Flask culture and fed-batch culture of this strain produced 6.9 and 19.7 g/L (together with 11.9 g/L glutaric acid as major byproduct) of 5AVA, respectively. Homology modeling suggested that endogenous gamma-aminobutyrate aminotransferase encoded by the gabT gene might be responsible for the conversion of 5AVA to glutaric acid in recombinant C. glutamicum. Fed-batch culture of a C. glutamicum gabT mutant-harboring p36davAB3 produced 33.1 g/L 5AVA with much reduced (2.0 g/L) production of glutaric acid.Conclusions: Corynebacterium glutamicum was successfully engineered to produce 5AVA from glucose by optimizing the expression of two key enzymes, lysine 2-monooxygenase and delta-aminovaleramidase. In addition, production of glutaric acid, a major byproduct, was significantly reduced by employing C. glutamicum gabT mutant as a host strain. The metabolically engineered C. glutamicum strains developed in this study should be useful for enhanced fermentative production of the novel C5 platform chemical 5AVA from renewable resources.
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  • Systems metabolic engineering as an enabling technology in accomplishing sustainable development goals

    Yang, Dongsoo   Cho, Jae Sung   Choi, Kyeong Rok   Kim, Hyun Uk   Lee, Sang Yup  

    With pressing issues arising in recent years, the United Nations proposed 17 Sustainable Development Goals (SDGs) as an agenda urging international cooperations for sustainable development. In this perspective, we examine the roles of systems metabolic engineering (SysME) and its contribution to improving the quality of life and protecting our environment, presenting how this field of study offers resolutions to the SDGs with relevant examples. We conclude with offering our opinion on the current state of SysME and the direction it should move forward in the generations to come, explicitly focusing on addressing the SDGs.
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  • Systems Metabolic Engineering Strategies: Integrating Systems and Synthetic Biology with Metabolic Engineering

    Choi, Kyeong Rok   Jang, Woo Dae   Yang, Dongsoo   Cho, Jae Sung   Park, Dahyeon   Lee, Sang Yup  

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  • Markerless gene knockout and integration to express heterologous biosynthetic gene clusters in Pseudomonas putida.

    Choi, Kyeong Rok   Cho, Jae Sung   Cho, In Jin   Park, Dahyeon   Lee, Sang Yup  

    Pseudomonas putida has gained much interest among metabolic engineers as a workhorse for producing valuable natural products. While a few gene knockout tools for P. putida have been reported, integration of heterologous genes into the chromosome of P. putida, an essential strategy to develop stable industrial strains producing heterologous bioproducts, requires development of a more efficient method. Current methods rely on time-consuming homologous recombination techniques and transposon-mediated random insertions. Here we report a RecET recombineering system for markerless integration of heterologous genes into the P. putida chromosome. The efficiency and capacity of the recombineering system were first demonstrated by knocking out various genetic loci on the P. putida chromosome with knockout lengths widely spanning 0.6-101.7=E2=80=AFkb. The RecET recombineering system developed here allowed successful integration of biosynthetic gene clusters for four proof-of-concept bioproducts, including protein, polyketide, isoprenoid, and amino acid derivative, into the target genetic locus of P. putida chromosome. The markerless recombineering system was completed by combining Cre/lox system and developing efficient plasmid curing systems, generating final strains free of antibiotic markers and plasmids. This markerless recombineering system for efficient gene knockout and integration will expedite metabolic engineering of P. putida, a bacterial host strain of increasing academic and industrial interest. Copyright =C2=A9 2018 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.
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  • Reconstruction of context-specific genome-scale metabolic models using multi-omics data to study metabolic rewiring

    Cho, Jae Sung   Gu, Changdai   Han, Taehee   Ryu, Jae Yong   Lee, Sang Yup  

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  • Rostral Agranular Insular Cortex Lesion with Motor Cortex Stimulation Enhances Pain Modulation Effect on Neuropathic Pain Model

    Jung, Hyun Ho   Shin, Jaewoo   Kim, Jinhyung   Ahn, Seung-Hee   Lee, Sung Eun   Koh, Chin Su   Cho, Jae Sung   Kong, Chanho   Shin, Hyung-Cheul   Kim, Sung June   Chang, Jin Woo  

    It is well known that the insular cortex is involved in the processing of painful input. The aim of this study was to evaluate the pain modulation role of the insular cortex during motor cortex stimulation (MCS). After inducing neuropathic pain (NP) rat models by the spared nerve injury method, we made a lesion on the rostral agranular insular cortex (RAIC) unilaterally and compared behaviorally determined pain threshold and latency in 2 groups: Group A (NP + MCS; n =3D 7) and Group B (NP + RAIC lesion + MCS; n =3D 7). Also, we simultaneously recorded neuronal activity (NP; n =3D 9) in the thalamus of the ventral posterolateral nucleus and RAIC to evaluate electrophysiological changes from MCS. The pain threshold and tolerance latency increased in Group A with "MCS on" and in Group B with or without "MCS on." Moreover, its increase in Group B with "MCS on" was more than that of Group B without MCS or of Group A, suggesting that MCS and RAIC lesioning are involved in pain modulation. Compared with the "MCS off" condition, the "MCS on" induced significant threshold changes in an electrophysiological study. Our data suggest that the RAIC has its own pain modulation effect, which is influenced by MCS.
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  • Textile and Clothing Safeguards: from the ATC to the Future Sung Jae Kim

    Sung Jae Kim   Kenneth A. Reinert  

    The Agreement on Textiles and Clothing established the textile and clothing safeguards regime from 1995 to 2004. The current safeguards regime for these products is defined in terms of the Agreement on Safeguards, the China Textile Safeguards, and the China Product-specific Safeguards. This article examines each of these three current safeguard options and assesses them in terms of a number of relevant dimensions. It also reviews safeguard actions to date to provide a sense of continued managed trade in this area.
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    The present invention relates to a method for preparing a bacteria mutant strain, comprising the steps of: (a) primarily transforming a normal bacteria into an enzyme-expressing vector which has temperature sensitivity or antibiotic sensitivity and expresses (i) a recombinase; (b) making the primarily transformed bacteria obtained in step (a) to be a competent cell; (c) secondarily transforming the competent cell obtained in step (b) by introducing (i) a single-stranded oligodeoxyribonucleic acid (ssODN) which binds complementarily to the target gene and (ii) a first vector which expresses a guide (RNA) and has antibiotic sensitivity or temperature sensitivity; and (e) removing the inserted enzyme-expressing vector and the first vector from the secondarily transformed bacteria, wherein at least one of the enzyme-expressing vector and the first vector expresses a Cas protein. A method according to the present invention can delete a target gene effectively, select a recombinant microorganism rapidly and at high efficiency, and remove all foreign vectors from the finally selected recombinant microorganism, finding very useful applications in the industrial use of recombinant Corynebacterium.
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  • The utilization of Doppler ultrasonography with color flow mapping in the diagnosis and evaluation of malignant trophoblastic tumors

    Park, Yong Won   Kim, Dong Kyu   Cho, Jae Sung   Kim, Haeng Soo   Park, Young Ja   Kim, Jae Wook   Park, Tchan Kyu  

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  • Studies on Korean in Community Schoolsby Dong Jae Lee; Sookeun Cho; Miseon Lee; Min Sun Song; William O'Grady

    Review by: Nam-Kil Kim  

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