494 research outputs found

    Strategies For Manufacturing Servitization Of Korean SMEs: By Using Data Envelopment Analysis

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    This study examines the efficiency of Korean manufacturing SMEs through data envelopment analysis. We divide business processes into support activities (e.g., business management and product planning) and primary activities (e.g., production and sales and after-sales services) to measure the efficiency of each process by product module. Moreover, we verify the effect of manufacturing servitization by comparing between the efficiency of servitized and non-servitized firms. The result shows that support activities are generally more efficient than primary activities and that standardized mass production with option (module 2) and totally customized production (module 4) is more efficient than either standardized mass production without option (module 1) or customized assembly after standardized production (module 3). The results suggest that, as SMEs are small, they have an advantage in support activities but also lack production and sales channel infrastructure. Moreover, modules 2 and 4 are relatively efficient because they can increase their product values via product differentiation. In addition, servitized firms are more efficient than non-servitized firms in almost every process and module, implying that servitization in manufacturing is an effective way to improve product value. Finally, module 1 and the production process are relatively inefficient, while servitized firms have higher efficiency scores than do non servitized firms. Likewise, module 3 and sales and after-sales services are relatively inefficient, while servitized firms have higher efficiency scores than do non servitized firms. There results imply that servitization can be used by Korean manufacturing SMEs to develop efficiently and effectively

    Folding machineries displayed on a cation-exchanger for the concerted refolding of cysteine- or proline-rich proteins

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    <p>Abstract</p> <p>Background</p> <p><it>Escherichia coli </it>has been most widely used for the production of valuable recombinant proteins. However, over-production of heterologous proteins in <it>E. coli </it>frequently leads to their misfolding and aggregation yielding inclusion bodies. Previous attempts to refold the inclusion bodies into bioactive forms usually result in poor recovery and account for the major cost in industrial production of desired proteins from recombinant <it>E. coli</it>. Here, we describe the successful use of the immobilized folding machineries for <it>in vitro </it>refolding with the examples of high yield refolding of a ribonuclease A (RNase A) and cyclohexanone monooxygenase (CHMO).</p> <p>Results</p> <p>We have generated refolding-facilitating media immobilized with three folding machineries, mini-chaperone (a monomeric apical domain consisting of residues 191–345 of GroEL) and two foldases (DsbA and human peptidyl-prolyl <it>cis-trans </it>isomerase) by mimicking oxidative refolding chromatography. For efficient and simple purification and immobilization simultaneously, folding machineries were fused with the positively-charged consecutive 10-arginine tag at their C-terminal. The immobilized folding machineries were fully functional when assayed in a batch mode. When the refolding-facilitating matrices were applied to the refolding of denatured and reduced RNase A and CHMO, both of which contain many cysteine and proline residues, RNase A and CHMO were recovered in 73% and 53% yield of soluble protein with full enzyme activity, respectively.</p> <p>Conclusion</p> <p>The refolding-facilitating media presented here could be a cost-efficient platform and should be applicable to refold a wide range of <it>E. coli </it>inclusion bodies in high yield with biological function.</p

    Parameter-robust linear quadratic Gaussian technique for multi-agent slung load transportation

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    This paper copes with parameter-robust controller design for transportation system by multiple unmanned aerial vehicles. The transportation is designed in the form of string connection. Minimal state-space realization of slung-load dynamics is obtained by Newtonian approach with spherical coordinates. Linear quadratic Gaussian / loop transfer recovery (LQG/LTR) is implemented to control the position and attitude of all the vehicles and payloads. The controller's robustness against variation of payload mass is improved using parameter-robust linear quadratic Gaussian (PRLQG) method. Numerical simulations are conducted with several transportation cases. The result verifies that LQG/LTR shows fast performance while PRLQG has its strong point in robustness against system variation

    PGAP6, a GPI-specific phospholipase A2, has narrow substrate specificity against GPI-anchored proteins

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    Gun-Hee Lee, Morihisa Fujita, Hideki Nakanishi, Haruhiko Miyata, Masahito Ikawa, Yusuke Maeda, Yoshiko Murakami, Taroh Kinoshita, PGAP6, a GPI-specific phospholipase A2, has narrow substrate specificity against GPI-anchored proteins, Journal of Biological Chemistry, Volume 295, Issue 42, 2020, Pages 14501-14509, ISSN 0021-9258, https://doi.org/10.1074/jbc.RA120.014643

    Functional and structural characteristics of anticancer peptide Pep27 analogues

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    BACKGROUND: A secreted peptide Pep27 initiates the cell death program in S. pneumoniae through signal transduction. This study was undertaken to evaluate the relation between the structure and cytotoxic activity of Pep27 and its analogues on cancer cells. RESULTS: Pep27anal2 characterized substituting ((2)R→W), ((4)E→W), ((11)S→W) and ((13)Q→W) in native Pep27, exhibited greater hydrophobicity and anticancer activity than Pep27 and other analogues. The IC(50 )values of Pep27anal2 were approximately 10 – 30 μM in a number of cell lines (AML-2, HL-60, Jurkat, MCF-7 and SNU-601). Confocal microscopy showed that Pep27anal2-FITC was localized in the plasma membrane, and then moving from the membrane to subcellular compartments with the initiation of membrane blebbing. Flow cytometric analysis using propidium iodide and Annexin V also revealed that Pep27anal2 induced apoptosis with minor membrane damage. Electron microscopy revealed that Pep27 induced apoptosis in Jurkat cells. The anticancer activity of Pep27anal2 was neither abrogated by pan-caspase inhibitor (Z-VAD-fmk) nor related to cytochrome c release from mitochondria. The 3D solution structures of these two Pep27 peptides revealed that both form a random coil conformation in water; however, they adopted stable α-helical conformations in solutions. CONCLUSION: The results indicate that Pep27anal2 can penetrate the plasma membrane, and then induce apoptosis in both caspase-and cytochrome c-independent manner. The hydrophobicity of Pep27anal2 appears to play an important role in membrane permeabilization and/or anticancer properties. The structure-functional relationships of these peptides are also discussed. It is proposed that Pep27anal2 is a potential candidate for anticancer therapeutic agents

    STATIC AND DYNAMIC CHARACTERISTICS OF AIR FOIL THRUST BEARING CONSIDERING TILTING PAD CONDITION

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    ABSTRACT The thrust pad of the rotor is used to sustain the axial force generated due to the pressure difference between the compressor and turbine sides of turbomachinery such as the gas turbines and turbochargers. Furthermore, this thrust pad has a role to maintain and determines the attitude of the rotor. In a real system, it also helps reinforce the stiffness and damping of the journal bearing. This study was performed for the purpose of analyzing the characteristics of the air foil thrust bearing. The model for the air foil thrust bearing used in this study is composed of two parts: one is an inclined plane, which plays a role to increase the load carrying capacity using the physical wedge effect, and the other is a flat plane. This study mainly consists of three parts. First, the static characteristics were obtained over the region of the thin air film using the finite difference method (FDM) and the bump foil characteristics using the finite element method (FEM). Second, the analysis of the dynamic characteristics was conducted by perturbation method. For more exact calculation, the rarefaction gas coefficients perturbed about the pressure and film thickness were taken into consideration. At last, the static and dynamic characteristics of the tilting condition of the thrust pad were obtained. Furthermore, the load carrying capacity and torque were calculated for both tilting and not-tilting conditions. From this study, several results were presented: 1) the stiffness and damping of the bump foil under the condition of the various bump parameters, 2) the load carrying capacity and bearing torque at the tilting state, 3) the bearing performance under various bearing parameters, 4) the effects considering the rarefaction gas coefficients
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