• Title/Summary/Keyword: single chain

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Solution Structure of an Active Mini-Proinsulin, M2PI: Inter-chain Flexibility is Crucial for Insulin Activity

  • Cho, Yoon-Sang;Chang, Seung-Gu;Choi, Ki-Doo;Shin, Hang-Cheol;Ahn, Byung-Yoon;Kim, Key-Sun
    • BMB Reports
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    • v.33 no.2
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    • pp.120-125
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    • 2000
  • M2PI is an active single chain mini-proinsulin with a 9-residue linker containing the turn-forming sequence 'YPGDV' between the B- and A-chains, but which retains about 50% of native insulin receptor binding activity. The refolding efficiency of M2PI is higher than proinsulin by 20-40% at alkaline pH, and native insulin is generated by the enzymatic conversion of M2PI. The solution structure of M2PI was determined by NMR spectroscopy. The global structure of M2PI is similar to that of native insulin, but the flexible linker between the B- and A-chains perturbed the N-terminal A-chain and C-terminal B-chain. The helix in the N-terminal A-chain is partly perturbed and the ${\beta}$-turn in the B-chain is disrupted in M2PI. However, the linker between the two chains was completely disordered indicating that the designed turn was not formed under the experimental conditions (20% acetic acid). Considering the fact that an insulin analogue, directly cross-linked between the C-terminus of the B-chain and the N-terminus of the A-chain, has negligible binding activity, a flexible linker between the two chains is sufficient to keep binding activity of M2PI, but the perturbed secondary structures are detrimental to receptor binding.

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Blockchain Interoperability Mechanism (블록체인 상호호환성 메커니즘)

  • Zhou, Qing;Lee, Young-seok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.11
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    • pp.1676-1686
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    • 2021
  • In this paper, we propose a general cross-chain solution based on the idea of modularity, abstraction, and layering, which decoupling the cross-chain function from the consensus algorithm and specific application logic, and utilize a Merkle proof to ensure the validity and legality of cross-chain operations. Since the underlying implementations of homogeneous and heterogeneous blockchains are different, we treat them separately. For homogeneous blockchains, we suggest a TCP-like cross-chain transport protocol (CCTP). While for heterogeneous blockchains, we present a method to construct the relay chain to realize the cross-chain function. The proposed scheme can enable the correct, effective, reliable, orderly, and timely transmission of cross-chain data. However, the essential difference between the operations within a single blockchain and the interoperability between different blockchains is that the trust domain is different. Cross-chain interoperation itself breaks the completeness of the blockchain, therefore, some efficiency and safety must sacrifice to trade-off.

Development of Analytical Tools for the Bullwhip Effect Control in Supply Chains : Quantitative Models and Decision Support System (공급사슬에서 채찍효과 관리를 위한 분석도구의 개발 : 정량화 모형과 의사결정지원시스템)

  • Shim, Kyu-Tak;Park, Yang-Byung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.32 no.1
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    • pp.117-129
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    • 2009
  • The bullwhip effect is known as the significant factor which causes unnecessary inventory, lost sales or cost increase in supply chains. Therefore, the causes of the bullwhip effect must be examined and removed. In this paper, we develop two analytical tools for the bullwhip effect control in supply chains. First, we develop the quantitative models for computing the bullwhip effect in a three-stage supply chain consisted of a single retailer, a single distributor and a single manufacturer when the fixed-interval replenishment policy is applied at each stage. The quantitative models are developed under the different conditions for the demand forecasting and share of customer demand information. They are validated through the computational experiments. Second, we develop a simulation-based decision support system for the bullwhip effect control in a more diverse dynamic supply chain environment. The system includes a what-if analysis function to examine the effects of varying input parameters such as operating policies and costs on the bullwhip effect.

Slipchip Device Development in Molecular Diagnostics

  • Qingtian Yin;Huiwen Bai;Ruijie Li;Youngung Seok
    • Korean Journal of Materials Research
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    • v.34 no.2
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    • pp.63-71
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    • 2024
  • Slipchip offers advantages such as high-throughout, low cost, and simple operation, and therefore, it is one of the technologies with the greatest potential for high-throughput, single-cell, and single-molecule analyses. Slipchip devices have achieved remarkable advances over the past decades, with its simplified molecular diagnostics gaining particular attention, especially during the COVID-19 pandemic and in various infectious diseases scenarios. Medical testing based on nucleic acid amplification in the Slipchip has become a promising alternative simple and rapid diagnostic tool in field situations. Herein, we present a comprehensive review of Slipchip device advances in molecular diagnostics, highlighting its use in digital recombinase polymerase amplification (RPA), loop-mediated isothermal amplification (LAMP), and polymerase chain reaction (PCR). Slipchip technology allows users to conduct reliable droplet transfers with high-throughput potential for single-cell and molecule analyses. This review explores the device's versatility in miniaturized and rapid molecular diagnostics. A complete Slipchip device can be operated without special equipment or skilled handling, and provides high-throughput results in minimum settings. This review focuses on recent developments and Slipchip device challenges that need to be addressed for further advancements in microfluidics technology.

Design and Performance Evaluation of Load-Modulation MIMO System Using High-Order Modulation (고차 변조를 사용하는 Load-Modulation MIMO 시스템 설계와 성능 평가)

  • Lee, Dong-Hyung;An, Changyoung;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.11
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    • pp.2121-2130
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    • 2015
  • In this paper, we analyze LM-MIMO (load-modulation multiple-input multiple-output) system with single RF chain. And then, we confirm that load modulation technique can support generation of high-order m-PSK modulation and m-QAM modulation in LM-MIMO system. Finally we evaluate performance of LM-MIMO system with load modulation. Conventional MIMO system requires a number of RF chains for expansion of MIMO dimension. A number of RF chains can cause various problems. On the other hand, although LM-MIMO system is expanded, LM-MIMO system requires single RF chain only. Therefore, LM-MIMO system has low-complexity and low power consumption. As results, we can confirm that load modulation of T-model can modulate high-order m-PSK and m-QAM singal. Also, we can confirm that $4{\times}4$ LM-MIMO system using load modulation has a similar performance to conventional $4{\times}4$ MIMO system.

Transfer and Expression of the Recombinant hFSH Gene in CHO Cells and Transgenic Chickens using Retrovirus Vector System (CHO 세포와 형질전환 닭에 있어서 Retrovirus Vector System에 의한 hFSH 재조합 유전자의 전이와 발현)

  • 권모선;구본철;심호섭;박창식;이성호;김태완
    • Korean Journal of Animal Reproduction
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    • v.27 no.3
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    • pp.197-206
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    • 2003
  • hFSH (human follicle stimulating hormone) is heterodimer consisting of $\alpha$ and $\beta$ subunits. Since assembly of the both subunits in the cell is often the rate-limiting step in production of functional hormone, single-chain hormones have been engineered by genetically linking two different cDNA fragments with a linker sequence. Using retrovirus vector system, the resulting recombinant hFSH gene was transferred in CHO cells and chicken embryos, and the expression of the gene was investigated. In CHO cells, protein synthesis from the single-chain FSH gene was 17 fold higher than that from the heterodimeric counterpart. In the study of transgenic chickens, ten of the eleven chicks hatched from 62 embryos manupulated with recombinant retrovirus stock was determined to carry transgenic genes. RT-PCR analyses confirmed transcription of the single-chain FSH gene, however, no recombinant FSH was detected from the blood samples.

Expression and Characterization of a Single-Chain Variable Fragment against Human LOX-1 in Escherichia coli and Brevibacillus choshinensis

  • Hu, Wei;Xiang, Jun-Yan;Kong, Ping;Liu, Ling;Xie, Qiuhong;Xiang, Hongyu
    • Journal of Microbiology and Biotechnology
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    • v.27 no.5
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    • pp.965-974
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    • 2017
  • The single-chain variable fragment (scFv) against lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a promising molecule for its potential use in the diagnosis and immunotherapy of atherosclerosis. Producing this scFv in several milligram amounts could be the starting point for further engineering and application of the scFv. In this study, the abundant expression of the anti-LOX-1 scFv was attempted using Escherichia coli (E. coli) and Brevibacillus choshinensis (B. choshinensis). The scFv had limited soluble yield in E. coli, but it was efficiently secreted by B. choshinensis. The optimized fermentation was determined using the Plackett-Burman screening design and response surface methodology, under which the yield reached up to 1.5 g/l in a 5-L fermentor. Moreover, the properties of the scFvs obtained from the two expression systems were different. The antigen affinity, transition temperature, and particle diameter size were 1.01E-07 M, $55.2{\pm}0.3^{\circ}C$, and 9.388 nm for the scFv expressed by B. choshinensis, and 4.53E-07 M, $52.5{\pm}0.3^{\circ}C$, and 13.54 nm for the scFv expressed by E. coli. This study established an efficient scale-up production methodology for the anti-LOX-1 scFv, which will boost its use in LOX-1-based therapy.