• Journal of Ginseng Research
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• v.46 no.5
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• pp.621-627
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• 2022

Background: Panax ginseng (ginseng) is a traditional medicine that is reported to have cardioprotective effects; ginsenosides are the major bioactive compounds in the ginseng root. Methods: Magnetic molecularly imprinted polymer (MMIP) nanoparticles might be useful for both the extraction of the targeted (imprinted) molecules, and for the delivery of those molecules to cells. In this work, plant growth regulators were used to enhance the adventitious rooting of ginseng root callus; imprinted polymeric particles were synthesized for the extraction of ginsenoside Rb₁ from root extracts, and then employed for subsequent particle-mediated delivery to cardiomyocytes to mitigate hypoxia/reoxygenation injury. Results: These synthesized composite nanoparticles were first characterized by their specific surface area, adsorption capacity, and magnetization, and then used for the extraction of ginsenoside Rb₁ from a crude extract of ginseng roots. The ginsenoside-loaded MMIPs were then shown to have protective effects on mitochondrial membrane potential and cellular viability for H9c2 cells treated with CoCl₂ to mimic hypoxia injury. The protective effect of the ginsenosides was assessed by staining with JC-1 dye to monitor the mitochondrial membrane potential. Conclusion: MMIPs can play a dual role in both the extraction and cellular delivery of therapeutic ginsenosides.

• Journal of Korea Trade
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• v.23 no.7
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• pp.128-146
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• 2019

Purpose - The purpose of this paper is to investigate the relationship between internal control, economic policy uncertainty, and performance of cross-border merger and acquisition (M&A) based on the panel data of Chinese listed firms. The authors expected that internal control has a positive moderating effect on the performance of cross-border M&A and that it mainly occurs during periods when economic policies are relatively stable. In addition, the authors tried to find out the mechanism of internal control affecting cross-border M&A and the corporate performance. Design/methodology - The authors tested the hypotheses by a multivariate regression model based on the panel data of Chinese listed firms from 2009 to 2017. The dependent variable is the change value of business performance (DROA_1,2,3) and the explanatory variables are cross-border M&A (MA), China's uncertainty of economic policy (EPU), and internal control level (IC) respectively. Findings - The authors find that internal control has a positive moderating effect on the relationship between cross-border M&A and corporate performance. Further, the authors find that the moderating effect is more significant in state-owned enterprises and that it mainly occurs during periods when economic policies are relatively stable. Originality/value - This paper is the leading study that tries to analyze empirically the relationship between internal control, economic policy uncertainty, and performance of cross-border M&A. It provides a new avenue through which internal control might reasonably mitigate the risks of cross-border M&A and correspondingly improve the performance of cross-border M&A. It also confirms the moderating effect of internal control on the performance of cross-border M&A under the uncertainty of economic policy.

• Structural Engineering and Mechanics
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• v.78 no.2
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• pp.125-134
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• 2021

In this paper, the effects of Tuned Mass dampers (TMDs) on the reduction of the vertical vibrations of a real horizontally curved steel box-girder bridge due to different traffic loads are numerically investigated. The performance of TMDs to reduce the bridge vibrations can be affected by the parameters such as dynamic characteristics of TMDs, the location of TMDs, the speed and weight of vehicles. In the first part of this study, the effects of mass ratio, damping percentage, frequency ratio, and location of TMDs on the performance of TMDs to decrease vertical vibrations of different sections of bridge deck are evaluated. In the second part, the performance of TMD is investigated for different speeds and weights of traffic loads. Results show that the mass ratio of TMDs is the more effective parameter in reducing imposed vertical vibration in comparison with the damping ratio. Furthermore, it is found that TMD is very sensitive to its tuned frequency, i.e., with a little deviation from a suitable frequency, the expected performance of TMD significantly decreased. TMDs have a positive and considerable performance at certain vehicle speeds and this performance declines when the weight of traffic loads is increased. Besides, the results reveal that the highest impact of TMD on the reduction of the vertical vibrations is when free vibrations occur for the bridge deck. In that case, maximum reductions of 24% and 59% are reported in the vertical acceleration of the bridge deck for the forced and free vibration amplitudes, respectively. The maximum reduction of 13% is also obtained for the maximum displacement of the bridge deck. The results are mainly related to the resonance condition.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.173-184
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• 2021

For the current organizations, retaining executive members is one of the most important functions of human resource management. Given that importance, although executives' mobility becomes prevalent, most prior studies tended to focus on involuntary turnover of executive members. To fill this gap, the current theoretical paper suggests a model of executive voluntary turnover, drawing on the lierature of employee mobility and entrepreneurship. First, running a new business as a CEO negatively affects prior-firm performance, but collaboration between two firms mitigate the negative association. Second, spin-off positively affects prior-firm performance, but this is weakened as spin-off firm performance decreases. Finally, moving to a competitor negatively, while moving to a collaborator positively affects prior-firm performance.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.4
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• pp.277-283
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• 2020

Objective: The sperm DNA fragmentation index (DFI) guides the clinician's choice of an appropriate assisted reproductive technology (ART) procedure. The DFI can be determined using commercially available methodologies, including sperm chromatin dispersion (SCD) kits and sperm chromatin structure assay (SCSA). Currently, when DFI is evaluated using SCD kits, the result is analyzed in reference to the SCSA-derived threshold for the choice of an ART procedure. In this study, we compared DFI values obtained using SCSA with those obtained using SCD and determined whether the difference affects the choice of ART procedure. Methods: We compared SCSA to two SCD kits, CANfrag (n=36) and Halosperm (n=31), to assess the DFI values obtained, the correlations between tests, the technical repeatability, and the impact of DFI on the choice of ART. Results: We obtained higher median DFI values using SCD kits than when using SCSA, and this difference was significant for the CANfrag kit (p<0.001). The SCD kits had significantly higher coefficients of variation than SCSA (p<0.001). In vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) would be chosen for a significantly higher proportion of patients if a decision were made based on DFI derived from SCD rather than DFI determined using SCSA (p=0.003). Conclusion: Our results indicate that SCD kit-specific thresholds should be established in order to avoid the unnecessary use of IVF/ICSI based on sperm DNA damage for the management of infertility. Appropriate measures should be taken to mitigate the increased variability inherent to the methods used in these tests.

• Wind and Structures
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• v.35 no.1
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• pp.55-66
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• 2022

Tall buildings are often subjected to steady and unsteady forces due to external wind flows. Measurement and mitigation of these forces becomes critical to structural design in engineering applications. Over the last few decades, many approaches such as modification of the external geometry of structures have been investigated to mitigate wind-induced load. One such proven geometric modification involved the rounding of sharp corners. In this work, we systematically analyze the impact of rounded corner radii on the reducing the flow-induced loading on a square cylinder. We perform 3-Dimensional (3D) simulations for high Reynolds number flows (Re=1 × 105) which are more likely to be encountered in practical applications. An Improved Delayed Detached Eddy Simulation (IDDES) method capable of capturing flow accurately at large Reynolds numbers is employed in this study. The IDDES formulation uses a k-ω Shear Stress Transport (SST) model for near-wall modelling that prevents mesh-induced separation of the boundary layer. The effects of these corner modifications are analyzed in terms of the resulting variations in the mean and fluctuating components of the aerodynamic forces compared to a square cylinder with no geometric changes. Plots of the angular distribution of the mean and fluctuating coefficient of pressure along the square cylinder's surface illustrate the effects of corner modifications on the different parts of the cylinder. The windward corner's separation angle was observed to decrease with an increase in radius, resulting in a narrower and longer recirculation region. Furthermore, with an increase in radius, a reduction in the fluctuating lift, mean drag, and fluctuating drag coefficients has been observed.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.528-542
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• 2021

The purpose of this study is to examine the commonalities and differences that appear across the types of perceptions toward job changes according to the Industrial 4.0. among job seekers and workers. For an approach to subjective beliefs, viewpoints and preferences, the data investigated using Q methodology, was analyzed using the QUANL program for PC. From the Q-methodology, the types of perception toward job changes due to Industrial 4.0 and their features were drawn. The perception types were classified as four types: negative perception type, neutral perception type, high evaluation about quality of jobs, and employment increase perception type. The results found that views toward job transition due to Industrial 4.0 are were diverse beyond the dichotomy and institutional and educational efforts should be required to mitigate job insecurity and cope with job changes caused by technological advance.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.3
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• pp.145-155
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• 2022

Multidrug resistance of tumors has been a severe obstacle to the success of cancer chemotherapy. The study wants to investigate the reversal effects of imperatorin (IMP) on doxorubicin (DOX) resistance in K562/DOX leukemia cells, A2780/Taxol cells and in NOD/SCID mice, to explore the possible molecular mechanisms. K562/DOX and A2780/Taxol cells were treated with various concentrations of DOX and Taol with or without different concentrations of IMP, respectively. K562/DOX xenograft model was used to assess anti-tumor effect of IMP combined with DOX. MTT assay, Rhodamine 123 efflux assay, RT-PCR, and Western blot analysis were determined in vivo and in vitro. Results showed that IMP significantly enhanced the cytotoxicity of DOX and Taxol toward corresponding resistance cells. In vivo results illustrated both the tumor volume and tumor weight were significantly decreased after 2-week treatment with IMP combined with DOX compared to the DOX alone group. Western blotting and RT-PCR analyses indicated that IMP downregulated the expression of P-gp in K562/DOX xenograft tumors in NOD/SCID mice. We also evaluated glycolysis and glutamine metabolism in K562/DOX cells by measuring glucose consumption and lactate production. The results revealed that IMP could significantly reduce the glucose consumption and lactate production of K562/DOX cells. Furthermore, IMP could also remarkably repress the glutamine consumption, α-KG and ATP production of K562/DOX cells. Thus, IMP may sensitize K562/DOX cells to DOX and enhance the antitumor effect of DOX in K562/DOX xenograft tumors in NOD/SCID mice. IMP may be an adjuvant therapy to mitigate the multidrug resistance in leukemia chemotherapy.

• BMB Reports
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• v.55 no.11
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• pp.547-552
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• 2022

Sorafenib, originally identified as an inhibitor of multiple oncogenic kinases, induces ferroptosis in hepatocellular carcinoma (HCC) cells. Several pathways that mitigate sorafenib-induced ferroptosis confer drug resistance; thus strategies that enhance ferroptosis increase sorafenib efficacy. Orphan nuclear receptor estrogen-related receptor γ (ERRγ) is upregulated in human HCC tissues and plays a role in cancer cell proliferation. The aim of this study was to determine whether inhibition of ERRγ with DN200434, an orally available inverse agonist, can overcome resistance to sorafenib through induction of ferroptosis. Sorafenib-resistant HCC cells were less sensitive to sorafenibinduced ferroptosis and showed significantly higher ERRγ levels than sorafenib-sensitive HCC cells. DN200434 induced lipid peroxidation and ferroptosis in sorafenib-resistant HCC cells. Mechanistically, DN200434 increased mitochondrial ROS generation by reducing glutathione/glutathione disulfide levels, which subsequently reduced mTOR activity and GPX4 levels. DN200434 induced amplification of the antitumor effects of sorafenib was confirmed in a tumor xenograft model. The present results indicate that DN200434 may be a novel therapeutic strategy to re-sensitize HCC cells to sorafenib.

• Journal of Animal Science and Technology
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• v.64 no.4
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• pp.603-620
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• 2022

Human activities have caused an increase in greenhouse gas emissions, resulting in climate change that affects many factors of human life including its effect on water and food quality in certain areas with implications for human health. CH₄ and N₂O are known as potent non-CO₂ GHGs. The livestock industry contributes to direct emissions of CH₄ (38.24%) and N₂O (6.70%) through enteric fermentation and manure treatment, as well as indirect N₂O emissions via NH₃ volatilization. NH₃ is also a secondary precursor of particulate matter. Several approaches have been proposed to address this issue, including dietary management, manure treatment, and the possibility of inhibitor usage. Inhibitors, including urease and nitrification inhibitors, are widely used in agricultural fields. The use of urease and nitrification inhibitors is known to be effective in reducing nitrogen loss from agricultural soil in the form of NH₃ and N₂O and can further reduce CH₄ as a side effect. However, the effectiveness of inhibitors in livestock manure systems has not yet been explored. This review discusses the potential of inhibitor usage, specifically of N-(n-butyl) thiophosphoric triamide, dicyandiamide, and 3,4-dimethylpyrazole phosphate, to reduce emissions from livestock manure. This review focuses on the application of inhibitors to manure, as well as the association of these inhibitors with health, toxicity, and economic benefits.