• Journal of Digital Convergence
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• v.15 no.4
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• pp.1-11
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• 2017

The purpose of the study is to develop an online measurement scale for diagnosing self-directed learning ability for students in Korea. In order to achieve the goal, literature review, case analyses, and experts interview were carried out and finalized the blended-learning based SMMIS model. A total of 1,626 elementary, middle and high school students participated in the scale survey to validate the credibility and validity. Based on these results, an online measurement tool for self-directed learning was developed. The tool can be used in blended-learning environment to maximize its effectiveness. In conclusion, we discussed about implications and strategies for the blended-learning based on self-directed learning program model for young students, and suggested future vision and further research.

• Journal of Ginseng Research
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• v.46 no.3
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• pp.496-504
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• 2022

Background: Cigarette smoke (CS) is considered a principal cause of chronic obstructive pulmonary disease (COPD) and is associated with mucus hypersecretion and airway inflammation. Ginsenoside compound K (CK), a product of ginsenoside metabolism, has various biological activities. Studies on the effects of CK for the treatment of COPD and mucus hypersecretion, including the underlying signaling mechanism, have not yet been conducted. Methods: To study the protective effects and molecular mechanism of CK, phorbol 12-myristate 13-acetate (PMA)-induced human airway epithelial (NCI-H292) cells were used as a cellular model of airway inflammation. An experimental mouse COPD model was also established via CS inhalation and intranasal administration of lipopolysaccharide. Mucin 5AC (MUC5AC), monocyte chemoattractant protein-1, tumor necrosis factor-α (TNF-α), and interleukin-6 secretion, as well as elastase activity and reactive oxygen species production, were determined through enzyme-linked immunosorbent assay. Inflammatory cell influx and mucus secretion in mouse lung tissues were estimated using hematoxylin and eosin and periodic acid-schiff staining, respectively. PKCδ and its downstream signaling molecules were analyzed via western blotting. Results: CK prevented the secretion of MUC5AC and TNF-α in PMA-stimulated NCI-H292 cells and exhibited a protective effect in COPD mice via the suppression of inflammatory mediators and mucus secretion. These effects were accompanied by an inactivation of PKCδ and related signaling in vitro and in vivo. Conclusion: CK suppressed pulmonary inflammation and mucus secretion in COPD mouse model through PKC regulation, highlighting the compound's potential as a useful adjuvant in the prevention and treatment of COPD.

• Journal of Ginseng Research
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• v.31 no.1
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• pp.23-33
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• 2007

Ginsenosides are one of the most well-known traditional herbal medicines frequently used for the treatment of cardiovascular symptoms in korea. The anti-ischemic effects of the mixture of ginsenoside $Rg_3$, and CK on ischemia-induced isolated rat heart were investigated through analyses of changes in hemodynamics ; blood pressure, aortic flow, coronary flow, and cardiac output. The subjects in this study were divided into four groups: normal control, the mixture of ginsenoside $Rg_3$ and CK, an ischemia-induced group without any treatment, and an ischemia-induced group treated with the mixture of ginsenoside $Rg_3$ and CK. There were no significant differences in perfusion pressure, aortic flow, coronary flow and cardiac output between them before ischemia was induced. The supply of oxygen and buffer was stopped for five minutes to induce ischemia in isolated rat hearts, and the mixture of ginsenoside $Rg_3$ and CK was administered during ischemia induction. Treatments of the mixture of ginsenoside $Rg_3$ and CK significantly prevented decreases in perfusion pressure, aortic flow, coronary flow, and cardiac output under ischemic conditions. In addition, hemodynamics (except heart rate) of the group treated with the mixture of ginsenoside $Rg_3$ and CK significantly recovered 60 minutes after reperfusion compared to the control group (mixture+ischemia vs ischemia - average perfusion pressure: 74.4${\pm}$2.97% vs. 85.1${\pm}$3.01%, average aortic flow volume: 49.11${\pm}$2.72% vs. 59.97${\pm}$2.93%, average coronary flow volume: 58.50${\pm}$2.81% vs. 72.72${\pm}$2.99%, and average cardiac output: 52.47${\pm}$2.78% vs. 63.11${\pm}$2.76%, p<0.01, respectively). These results suggest that treatment of the mixture of ginsenoside $Rg_3$ and CK has distinct anti-ischemic effects in ex vivo model of ischemia-induced rat heart.

• Journal of Ginseng Research
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• v.47 no.2
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• pp.274-282
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• 2023

Background: Ginsenoside compound K (CK) stimulated activation of the PI3K-Akt signaling is one of the major mechanisms in promoting cell survival after stroke. However, the underlying mediators remain poorly understood. This study aimed to explore the docking protein of ginsenoside CK mediating the neuroprotective effects. Materials and methods: Molecular docking, surface plasmon resonance, and cellular thermal shift assay were performed to explore ginsenoside CK interacting proteins. Neuroscreen-1 cells and middle cerebral artery occlusion (MCAO) model in rats were utilized as in-vitro and in-vivo models. Results: Ginsenoside CK interacted with recombinant human PTP1B protein and impaired its tyrosine phosphatase activity. Pathway and process enrichment analysis confirmed the involvement of PTP1B and its interacting proteins in PI3K-Akt signaling pathway. PTP1B overexpression reduced the tyrosine phosphorylation of insulin receptor substrate 1 (IRS1) after oxygen-glucose deprivation/reoxygenation (OGD/R) in neuroscreen-1 cells. These regulations were confirmed in the ipsilateral ischemic hemisphere of the rat brains after MCAO/R. Ginsenoside CK treatment reversed these alterations and attenuated neuronal apoptosis. Conclusion: Ginsenoside CK binds to PTP1B with a high affinity and inhibits PTP1B-mediated IRS1 tyrosine dephosphorylation. This novel mechanism helps explain the role of ginsenoside CK in activating the neuronal protective PI3K-Akt signaling pathway after ischemia-reperfusion injury.

• Carbon letters
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• v.14 no.4
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• pp.234-242
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• 2013

Potassium hydroxide-activated carbons (CK21, CK11, and CK12) were prepared from pistachio nutshells. Physicochemical properties of activated carbons were characterized by TGA, $pH_{pzc}$, Fourier transform infrared spectroscopy, scanning electron microscopy, and $N_2$-adsorption at $-196^{\circ}C$. The examinations showed that activated carbons have high surface area ranging between 695-1218 $m^2/g$, total pore volume ranging between 0.527-0.772 mL/g, and a pore radius around 1.4 nm. The presence of acidic and basic surface C-O groups was confirmed. Batch adsorption experiments were carried out to study the effects of adsorbent dosage, temperature, initial concentration of adsorbate, and contact time on deltamethrin adsorption by activated carbons. The kinetic studies showed that the adsorption data followed a pseudo-second order kinetic model. The Langmuir model showed a maximum adsorption capacity of 162.6 mg/g at $35^{\circ}C$ on CK12. Thermodynamic studies indicated that adsorption was spontaneous and increased with temperature, suggesting an endothermic process.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.1
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• pp.43-50
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• 2016

This paper introduces an appearance-based facial expression recognition method using ASM landmarks which is used to acquire a detailed face region. In particular, EHMM-based algorithm and SVM classifier with histogram feature are employed to appearance-based facial expression recognition, and performance evaluation of proposed method was performed with CK and JAFFE facial expression database. In addition, performance comparison was achieved through comparison with distance-based face normalization method and a geometric feature-based facial expression approach which employed geometrical features of ASM landmarks and SVM algorithm. As a result, the proposed method using ASM-based face normalization showed performance improvements of 6.39% and 7.98% compared to previous distance-based face normalization method for CK database and JAFFE database, respectively. Also, the proposed method showed higher performance compared to geometric feature-based facial expression approach, and we confirmed an effectiveness of proposed method.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.231-239
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• 2013

BACKGROUND: The disease resistant (OsCK1) rice was generated by inserting choline kinase (CK1) and phosphinothricin acetyltransferase (PAT) genes isolated from Oriza sativa and Streptomyces hygroscopicus into the genome of rice (Nakdongbyeo). With the potential problems of safety, the non-target organism evaluation is required as an essential element for the environmental risk assessment of genetically modified (GM) crops. In present study, we studied the effects on survival of Misgurnus anguillicaudatus and Cyprinus carpio, commonly used as a model organism in ecotoxicological studies. METHODS AND RESULTS: The M. anguillicaudatus and C. carpio were fed on disease resistant (OsCK1) rice and non-genetically modified (non-GM) rice (Nakdongbyeo) to 0, 10, 100, 1,000 and 5,000 mg/L, as treatment concentration respectively. The OsCK1 rice used for the test was confirmed to have the OsCK1/PAT gene expression by the PCR and ELISA analysis. Feeding test showed that no significant differences in cumulative immobility and abnormal response of M. anguillicaudatus and C. carpio fed on between OsCK1 rice and non-GM rice. The 96hr-$LC_{50}$ values showed no difference between OsCK1 rice (>5,000 mg/L) and non-GM rice (>5,000 mg/L). CONCLUSION(S): The results of this study suggested that there was no significant difference in toxicity for M. anguillicaudatus and C. carpio between OsCK1 rice and non-GM counterparts.

• BMB Reports
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• v.39 no.4
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• pp.426-431
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• 2006

Embryonic stem cells (ESCs), representing a population of undifferentiated pluripotent cells with both self-renewal and multilineage differentiation characteristics, are capable of spontaneous differentiation into cardiomyocytes. The present study sought to define the kinetic characterization of lactate dehydrogenase (LDH) and creatine kinase (CK) of ESC- and neonatal-derived cardiomyocytes. Spontaneously differentiated cardiomyocytes from embryoid bodies (EBs) derived from mouse ESC line (Royan B1) and neonatal cardiomyocytes were dispersed in a buffer solution. Enzymes were extracted by sonication and centrifugation for kinetic evaluation of LDH and CK with spectrophotometric methods. While a comparison between the kinetic properties of the LDH and CK of both groups revealed not only different Michaelis constants and optimum temperatures for LDH but also different Michaelis constants and optimum pH for CK, the pH profile of LDH and optimum temperature of CK were similar. In defining some kinetic properties of cardiac metabolic enzymes of ESC-derived cardiomyocytes, our results are expected to further facilitate the use of ESCs as an experimental model.

• Journal of Ginseng Research
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• v.43 no.3
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• pp.460-474
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• 2019

Background: Ginsenoside compound K (CK) is a promising drug candidate for rheumatoid arthritis. This study examined the impact of polymorphisms in NR1I2, adenosine triphosphate-binding cassette (ABC) transporter genes on the pharmacokinetics of CK in healthy Chinese individuals. Methods: Forty-two targeted variants in seven genes were genotyped in 54 participants using Sequenom MassARRAY system to investigate their association with major pharmacokinetic parameters of CK and its metabolite 20(S)-protopanaxadiol (PPD). Subsequently, molecular docking was simulated using the AutoDock Vina program. Results: ABCC4 rs1751034 TT and rs1189437 TT were associated with increased exposure of CK and decreased exposure of 20(S)-PPD, whereas CFTR rs4148688 heterozygous carriers had the lowest maximum concentration ($C_{max}$) of CK. The area under the curve from zero to the time of the last quantifiable concentration ($AUC_{last}$) of CK was decreased in NR1I2 rs1464602 and rs2472682 homozygous carriers, while $C_{max}$ was significantly reduced only in rs2472682. ABCC4 rs1151471 and CFTR rs2283054 influenced the pharmacokinetics of 20(S)-PPD. In addition, several variations in ABCC2, ABCC4, CFTR, and NR1I2 had minor effects on the pharmacokinetics of CK. Quality of the best homology model of multidrug resistance protein 4 (MRP4) was assessed, and the ligand interaction plot showed the mode of interaction of CK with different MRP4 residues. Conlusion: ABCC4 rs1751034 and rs1189437 affected the pharmacokinetics of both CK and 20(S)-PPD. NR1I2 rs1464602 and rs2472682 were only associated with the pharmacokinetics of CK. Thus, these hereditary variances could partly explain the interindividual differences in the pharmacokinetics of CK.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.106-112
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• 2017

This paper presents a mathematical model derived from the upper-bound theorem of concrete plasticity to rationally evaluate the shear friction strength of concrete interfaces with a construction joint. The upper limit of the shear friction strength was formulated from the limit state of concrete crushing failure on the strut-and-tie action along the construction joints to avoid overestimating the shear transfer capacity of a transverse reinforcement with a high clamping force. The present model approach proposed that the cohesion and coefficient of friction of concrete can be set to be $0.27(f_{ck})^{0.65}$ and 0.95, respectively, for rough construction joints and $0.11(f_{ck})^{0.65}$ and 0.64, respectively, for smooth ones, where $f_{ck}$ is the compressive strength of concrete. From the comparisons with 155 data compiled from the available literature, the proposed model gave lower values of standard deviation and coefficient of variation of the ratios between predictions and experiments than AASHTO and fib 2010 equations, indicating that the proposed model has consistent trends with test results, unlike the significant underestimation results of such code equations in evaluating the shear friction strength.