• Title/Summary/Keyword: light-chain

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Trust, Long-term Orientation, and Relationship Performance: A Perspective of Distribution Management on Supply Chain

  • Changjoon LEE;Soohyo KIM
    • Journal of Distribution Science
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    • v.22 no.1
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    • pp.105-113
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    • 2024
  • Purpose: This study sheds light on the need for trust in buyer-seller relationships in supply chains and explores why long-term orientation is important. It also investigates the effect on relationship performance. This study provides implication on how to build robust supply chains. Methodology: A survey was conducted with firms with supply chains in South Korea. A total of 350 valid questionnaires were analyzed through Entrust Survey-a sampling company. Structural equation modeling (SPSS 18.0 and AMOS) was employed to test the hypotheses. Results: Cognitive trust had a positive effect on emotional trust. Emotional trust had a positive effect on long-term orientation but did not have a significant effect on relationship performance. Long-term orientation was proportionate to relationship performance. Conclusions: Trust is a critical factor in supply chains. As business environments are rapidly changing, the uncertainties are also meaningful. Supply chains have collapsed owing to COVID-19, the Russia-Ukraine war, and the U.S.-China trade war, and they are only just recently being rebuilt. Maintaining relationships with supply-chain partners is vital, and promoting cognitive and emotional trust is necessary.

Refolding of Fusion Ferritin by Gel Filtration Chromatography(GFC)

  • Kim, Hyung-Won;Kim, In-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.6
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    • pp.500-504
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    • 2005
  • Fusion ferritin (heavy chain ferritin, $F_H+$ light chain ferritin, $F_L$), an iron-binding protein, was primarily purified from recombinant Escherichia coli by two-step sonications with urea [1]. Unfolded ferritin was refolded by gel filtration chromatography (GFC) with refolding enhancer, where 50 mM Na-phosphate (pH 7.4) buffer containing additives such as Tween 20, PEG, and L-arginine was used. Ferritin is a multimeric protein that contains approximately 20 monomeric units for full activity. Fusion ferritin was expressed in the form of inclusion bodies (IBs). The IBs were initially solubilized in 4 M urea denaturant. The refolding process was then performed by decreasing the urea concentration on the GFC column to form protein multimers. The combination of the buffer-exchange effect of GFC and the refolding enhancers in refolding buffer resulted in an efficient route for producing properly folded fusion ferritin.

Fairness CSMA/CA MAC Protocol for VLC Networks

  • Huynh, Vu Van;Jang, Yeong-Min
    • International journal of advanced smart convergence
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    • v.1 no.1
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    • pp.14-18
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    • 2012
  • This paper presents a fair MAC protocol based on the CSMA/CA algorithm in visible light communication (VLC) networks. The problem of bandwidth sharing among differentiated priority in VLC networks can be solved by using number of backoff time and backoff exponent parameters with AIFS. The proposed algorithm can achieve fair allocation of the bandwidth resource among differentiated priority. The two dimension Markov chain is assisted for analyzing the proposed mechanism about throughput and delay metrics. Numerical results show that our proposed algorithm improves the fairness among different traffic flows.

Alternative Methods for Testing Botulinum Toxin: Current Status and Future Perspectives

  • Nepal, Mahesh Raj;Jeong, Tae Cheon
    • Biomolecules & Therapeutics
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    • v.28 no.4
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    • pp.302-310
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    • 2020
  • Botulinum toxins are neurotoxic modular proteins composed of a heavy chain and a light chain connected by a disulfide bond and are produced by Clostridium botulinum. Although lethally toxic, botulinum toxin in low doses is clinically effective in numerous medical conditions, including muscle spasticity, strabismus, hyperactive urinary bladder, excessive sweating, and migraine. Globally, several companies are now producing products containing botulinum toxin for medical and cosmetic purposes, including the reduction of facial wrinkles. To test the efficacy and toxicity of botulinum toxin, animal tests have been solely and widely used, resulting in the inevitable sacrifice of hundreds of animals. Hence, alternative methods are urgently required to replace animals in botulinum toxin testing. Here, the various alternative methods developed to test the toxicity and efficacy of botulinum toxins have been briefly reviewed and future perspectives have been detailed.

Efficient Channel Assignment Scheme Based on Finite Projective Plane Theory

  • Chen, Chi-Chung;Su, Ing-Jiunn;Liao, Chien-Hsing;Woo, Tai-Kuo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.2
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    • pp.628-646
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    • 2016
  • This paper proposes a novel channel assignment scheme that is based on finite projective plane (FPP) theory. The proposed scheme involves using a Markov chain model to allocate N channels to N users through intermixed channel group arrangements, particularly when channel resources are idle because of inefficient use. The intermixed FPP-based channel group arrangements successfully related Markov chain modeling to punch through ratio formulations proposed in this study, ensuring fair resource use among users. The simulation results for the proposed FPP scheme clearly revealed that the defined throughput increased, particularly under light traffic load conditions. Nevertheless, if the proposed scheme is combined with successive interference cancellation techniques, considerably higher throughput is predicted, even under heavy traffic load conditions.

Liquid Crystal Alignment and Generation of Pretilt Angle by Using Photo-alignment Techniques on Different Polymer Moleculars (광배향기술을 이용한 액정배향의 기구 및 폴리이미드의 분자구조가 프리틸트각에 미치는 영향)

  • 황율연;이창훈;박지호;서대식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.112-115
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    • 1997
  • In this paper, we investigated the liquid crystal(LC) alignment and generation of pretilt angle by using photo-alignment techniques on two kinds of polyimide(Pl) surface. It was found that the uniform alignment for nematic(N) LC is obtained in a cell with slanted UV light irradiation on PI surface without side-chain. We successfully observed that the pretilt angle of NLC is generated about 3.3 degrees in a cell with an incidence angle of 70 degrees on PI surface without side chain. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecular and the polymer.

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Improved Coexpression and Multiassembly Properties of Recombinant Human Ferritin Subunits in Escherichia coli

  • Lee, Jung-Lim;Levin, Robert E.;Kim, Hae-Yeong
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.926-932
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    • 2008
  • Human heavy chain (H-) and light chain (L-) ferritins were amplified from a human cDNA library. Each ferritin gene was inserted downstream of the T7 promoter of bacterial expression vectors, and two types of coexpression vectors were constructed. The expression levels of recombinant ferritins ranged about 26-36% of whole-cell protein. H-ferritin exhibited a lower expression ratio compared with L-ferritin, by a coexpression system. However, the coexpression of HL-ferritins was significantly increased above the expression ratio of H-ferritin by cultivation without IPTG induction overnight. Purified recombinant H-, L-, HL-, and LH-ferritins were shown to be homo- and heteropolymeric high molecular complexes and it was indicated that their assembled subunits would be able to work functionally in the cell. Thus, these results indicate an improvement in the expression strategy of H-ferritin for heteropolymeric production and studies of ferritin assembly in Escherichia coli.

Energy Status of Neurospora crassa Mutant nap in Relation to Accumulation of Carotenoids

  • Belozersk, Tatyana A.;Potapova, Tatyana V.;Isakova, Elena P.;Shurubor, Eugene I.;Savel'eva, Ludmila V.;Zvyagilskaya, Renata A.
    • Journal of Microbiology
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    • v.41 no.1
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    • pp.41-45
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    • 2003
  • N crassa mutant strain nap showed reduced growth rate, decreased electric membrane potential, and elevated intracellular ATP content in comparison to the wild type. Blue light induced a hyperpolarization of the membrane potential in both strains. The analysis of oxidative and phosphorylation activities of mitochondria isolated from the two strains has revealed that nap utilized more efficient oxidative pathways. The higher intracellular ATP content in the nap was presumably due to impaired transport systems of the plasma membrane, and to a lesser extent to the functioning of the fully competent respiratory chain. The excess ATP possibly accounts for carotenoid accumulation in the mutant.

Cytotoxic Effects on HL-60 Cells of Myosin Light Chain Kinase Inhibitor ML-7 Alone and in Combination with Flavonoids

  • Lee, Joong-Won;Kim, Yang-Jee;Choi, Young-Joo;Woo, Hae-Dong;Kim, Gye-Eun;Ha, Tae-Kyung;Lee, Young-Hyun;Chung, Hai-Won
    • Toxicological Research
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    • v.25 no.4
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    • pp.181-188
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    • 2009
  • Uncontrolled cell growth and increased cell proliferation are major features of cancer that are dependent on the stable structure and dynamics of the cytoskeleton. Since stable cytoskeleton structure and dynamics are partly regulated by myosin light chain kinase (MLCK), many current studies focused on MLCK inhibition as a chemotherapeutic target. As a potent and selective MLCK inhibitor, ML-7 [1-(5-iodonaphthalene-1-sulfonyl)-1 H-hexahydro-1,4-diazapine hydrochloride] is a promising candidate for an anticancer agent, which would induce apoptosis as well as prevents invasion and metastasis in certain types of cancer cells. This study assessed cytotoxic effects of ML-7 against HL-60 cells and therapeutic efficacy of ML-7 as a potential antileukemia agent. Trypan-blue exclusion assays showed dose- and time- dependent decreases in ML-7 treated HL-60 cells (p<0.05). Comet assays revealed a significant increase in DNA damage in HL-60 cells after treatment with $40{\mu}M$ ML-7 for 2h. Sub-G1 fractions, analyzed by flow cytometry increased in a dose-dependent manner, suggesting that ML-7 can induce apoptotic cell death in HL-60 cells. ML-7 was selectively cytotoxic towards HL-60 cells; not affecting normal human lymphocytes. That selective effect makes it a promising potential anti-leukemia agent. In addition, anticancer efficacy of ML-7 in combination with flavonoids (genistein or quercetin) or anticancer drugs (cisplatin or Ara-C) against HL-60 cells was assessed. Combination of ML-7 with flavonoids increased the anti-cancer effect of ML-7 to a greater extent than combination with the anticancer drugs. This implies that ML-7 in combination with flavonoids could increase the efficacy of anticancer treatment, while avoiding side effects cansed by conventional anticancer drug-containing combination chemotherapy.

The Vasodilating Mechanism of Sodium Nitroprusside and Forskolin on Phorbol dibutyrate-Induced Contractions in Rat Aorta (Sodium nitroprusside와 Forskolin의 Phorbol ester 수축에 대한 혈관이완작용의 기전)

  • Ahn, Hee-Yul
    • The Korean Journal of Pharmacology
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    • v.31 no.3
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    • pp.291-297
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    • 1995
  • The objectives of this study is to compare the inhibitory mechanism of sodium nitroprusside and forskolin on the phorbol ester, activator of protein kinase C (PKC), -induced contractions in rat aorta. $0.1\;{\mu}M$ phorbol dibutyrate (PDBu) induced sustained contractions and increased phosphorylations of myosin light chain (MLC) time-dependently. At 30 min, the contractions and phosphorylations of MLC by PDBu were augmented maximally and remained constant. Moreover, $^{45}Ca^{2+}$ uptake was increased 30 min after PDBu stimulation from resting values. Sodium nitroprusside which activates guanylyl cyclase followed by increasing cGMP, inhibited the PDBu-induced contractions concentration-dependently. On the other hand, forskolin which activates adenylyl cyclase followed by increasing cAMP, also inhibited the PDBu-induced contractions concentration-dependently. However, sodium nitroprusside was more potent to inhibition of the PDBu-induced contractions than forskolin. Sodium nitroprusside inhibited $^{45}Ca^{2+}$ uptake by PDBu stimulation. Forskolin also inhibited $^{45}Ca^{2+}$ uptake by PDBu stimulation. Sodium nitroprusside and forskolin inhibited the phosphorylations of MLC by PDBu, respectively. However, sodium nitroprusside was more potent to inhibition of phosphorylations of MLC by PDBu than forskolin. From these results, Sodium nitroprusside via cGMP or forskilin via cAMP may reduce myoplasmic $Ca^{2+}$ followed by suppression of phosphorylations of MLC of PKC-mediated contractions, which results in vasodilation. However, cGMP may play a role more importantly than cAMP on the regulation of protein kinase C-mediated contraction in vascular smooth muscle.

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