• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.4
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• pp.19-30
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• 2002

The stability of slope using root-pile like to the reinforcements is affected by the interaction behavior mechanism of soil-reinforcements. Through the studying on the interaction in joint of its, therefore, the control roles can be find out in installed slope. In study, the stress level ratio based on the insert angle of installed reinforcements in soil used to numerical analysis, which was results from the duty direct shear test in Lab. The maximum shear strain variation on the reinforcements was observed at insert angle, which was approximately similar to the calculated angle based on the equation proposed by the Jewell. The elasto-plastic joint model on the contact area of soil-reinforcements was presumed, the reinforced soil assumed non-linear elastic model and the reinforcements supposed elastic model, respectively. The finite element analysis of assumed models was performed. The shear strain variation of non-reinforced state obtained by the FEM analysis including elasto-plastic joint elements were shown the rationality of general limit equilibrium analysis for the slope failure mode on driving zone and resistance zone, which based on the stress level step according to failure ratio. Through the variation of shear strain for the variation of inserting angle of reinforcements, the different mechanism on the bending and the shear resistance of reinforcements was shown fair possibility.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5619-5625
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• 2012

Gastric carcinoma is a leading cause of cancer death in the world and multi-drug resistance (MDR) is an essential aspect of gastric carcinoma chemotherapy failure. Recent studies have shown that integrin-linked kinase (ILK) is involved in metastasis of human tumors, expression silencing of ILK inhibiting the metastasis of several types of cultured human cancer cells. However, the role and potential mechanism of ILK to reverse the multi-drug resistance in human gastric carcinoma is not fully clear. In this report, we focused on roles of expression silencing of ILK in multi-drug resistance reversal of human gastric carcinoma SGC7901/DDP cells, including increased drug sensitivity to cisplatin, cell apoptosis rates, and intracellular accumulation of Rhodamine-123, and decreased mRNA and protein expression of multi-drug resistance gene (MDR1), multi-drug resistance-associated protein (MRP1), excision repair cross-complementing gene 1 (ERCC1), glutathione S-transferase -${\pi}$ (GST-${\pi}$) and RhoE, and transcriptional activation of AP-1 and NF-${\kappa}B$ in ILK silenced SGC7901/DDP cells. We also found that there was a decreased level of p-Akt and p-ERK. The results indicated that ILK might be used as a potential therapeutic strategy to combat multi-drug resistance through blocking PI3K-Akt and MAPK-ERK pathways in human gastric carcinoma.

• International Journal of Concrete Structures and Materials
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• v.10 no.sup3
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• pp.87-96
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• 2016

This numerical study investigated the effects of different reinforcing details in beam-column joints on the blast resistance of the joints. Due to increasing manmade and/or natural high rate accidents such as impacts and blasts, the resistance of critical civil and military infrastructure or buildings should be sufficiently obtained under those high rate catastrophic loads. The beam-column joint in buildings is one of critical parts influencing on the resistance of those buildings under extreme events such as earthquakes, impacts and blasts. Thus, the details of reinforcements in the joints should be well designed for enhancing the resistance of the joints under the events. Parameters numerically investigated in this study include diagonal, flexural, and shear reinforcing steel bars. The failure mechanism of the joints could be controlled by the level of tensile stress of reinforcing steel bars. Among various reinforcing details in the joints, diagonal reinforcement in the joints was found to be most effective for enhancing the resistance under blast loads. In addition, shear reinforcements also produced favourable effects on the blast resistance of beam-column joints.

• Archives of Pharmacal Research
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• v.29 no.11
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• pp.1018-1023
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• 2006

Chemoresistance remains the major obstacle to successful therapy of cancer. In order to understand the mechanism of multidrug resistance (MDR) that is frequently observed in lung cancer patients, here we studied the contribution of MDR-related proteins by establishing lung cancer cell lines with acquired resistance against etoposide. We found that human H460 lung cancer cells responded to etoposide more sensitively than A549 cells. Among MDR-related proteins, the expression of p-glycoprotein (Pgp) and lung resistance protein (LRP) were much higher in A549 cells compared with that in H460 cells. When we established H460-R1 and -R2 cell lines by progressive exposure of H460 cells to increasing doses of etoposide, the response against etopbside as well as doxorubicin was greatly reduced in R1 and R2 cells, suggesting MDR induction. Induction of MDR was not accompanied by a decrease in the intracellular accumulation of etoposide and the expression of MDR-related proteins that function as drug efflux pumps such as Pgp and MRP1 was not changed. We found that the acquired resistance paralleled an increased expression of LRP in H460 cells. Taken together, our data suggest the implicative role of LRP in mediating MDR in lung cancer.

• Environmental Engineering Research
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• v.11 no.2
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• pp.91-98
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• 2006

There is a possibility of the production of the air bubbles in membrane pores due to the reduction in pressure during membrane filtration. The effect of fine air bubbles from dissolved gases on microfiltration was investigated in the submerged membrane bio-reactor (SMBR). The $R_{air}$ (air bubble resistance) was defined as the filtration resistance due to the air bubbles formed from the gasification of dissolved gases. From the results of filtration tests using pure water with changes in the dissolved oxygen concentration, the air bubbles from dissolved gases were confirmed to act as a foulant and; thus, increase the filtration resistance. The standard pore blocking and cake filtration models, SPBM and CFM, respectively, were applied to investigate the mechanism of air bubble fouling on a hollow fiber membrane. However, the application of the SPBM and CFM were limited in explaining the mechanism due to the properties of air bubble. With a simple comparison of the different filtration resistances, the $R_{air}$ portion was below 1% of the total filtration resistance during sludge filtration. Therefore, the air bubbles from dissolved gases would only be a minor foulant in the SMBR. However, under the conditions of a high gasification rate from dissolved gases, the effect of air bubble fouling should be considered in microfiltration.

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.234-246
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• 1992

This study was conducted to determine the toxic effects of air pollutants on landscaping tress, Pinus densiflora, Pinus koraiensis, Ginkgo biloba, Liriodendron tulipifera, Platanus occidentalis and their resistance to the pollutant toxicity in urban and industrial regions of Seoul and Taejon, Korea. Total sulfur contents and enzyme activities such as superoxide dismutase and peroxidase were analyzed in tree foliage of Pinus densiflora, Pinus koraiensis, Ginkgo biloba, Liriodendron tulipifera, Platanus occidentalis. In addition, POD activity was analyzed in the foliage on tree seedlings, i.e. Pinus densiflora, Pinus koraiensis, Ginkgo biloba, Lirioderdron tulipifera, with the fumigation of $SO_2$ in gas chamber 4 hours a day for six days. In Ginkgo biloba total sulfur content and POD activity had a negative correlation while other species had a positive relationship in total sulfur content and enzyme activity. Air pollutants accumulated in tree tissues were supposed to enhance the enzyme activity like POD providing the resistance mechanisms. Especially Pinus koraiensis and Platanus occidentalis had higher POD activity than other species. The increase of temporary POD activity against environmental stress appeared in sensitive trees and prolonged increase of POD activity played an important role in resistance mechanism. SOD and POD activities in all species had a positive correlation except Ginkgo biloba. Changes of SOD and POD activities were different between species and in most species SOD as well as POD seemed to participate in resistance mechanism.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.360-365
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• 1992

Clinical isolates of 8 ofloxacin resistant Staphylococcus auresu (ORSA) were subjected to MIC test, Southern analysis on gyrA locus and nucleotide sequence analysis of 290 bp of gyrA gene (gyrA-290) spanning amino acid 26 to 121 in order to understand the mechanism of quinolone resistance in Staphylococcus aureus. ORSAs showed highlevel resistance against quinolones (8-250 fold increase of MICs) and also significant resistance agianst ${\beta}-lactams$ (2-32 fold increase of MICs). However, ORSs did not show any change in sensitivity agianst vancomycin. Southern analysis of ORSAs with HindIII, PstI and AluI revealed RFLPs on gyrA locus. In order to further analyze the gyrA gene, gyrA-290 was amplified by PCR and cloned to pTZ vector. Subsequent nucleic acid sequence analysis of gyrA-290 demonstrated a point mutation of C to T resulting amino acid change of Ser-84 to Leu-84 in all 8 ORSA strains. The substitution at 84th amino acid of tyrase A might confer one mechanism of high level quinolone resistance in Staphylococcus aureus.

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.57.1-57.1
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• 1998

• Journal of Pharmaceutical Investigation
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• v.24 no.4
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• pp.281-287
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• 1994

The effects of oleic acid, propylene glycol and 5% (w/w) oleic acid in propylene glycol on the electrical properties of hairless mouse skin were studied and the results were compared. The complex electrical impedance was measured as a function of frequency, and resistance and capacitance were determined from the Nyquist plot. Immediately after the treatment with oleic acid, resistance was 145% of the pretreatment value. However it decreased with time and, after 20 hours, it was about 25% of its pretreatment value. Capacitance increased; immediately after the treatment, it was about 125% of pretreatment value and it seemed to increase slowly with time. When the skin was treated with propylene glycol, resistance decreased about 5O% and capacitance increased about 65%. Similar results were observed when the skin was treated with 5% (w/w) oleic acid in propylene glycol, except that the magnitude of resistance drop was much larger. Oleic acid acted synergistically with propylene glycol. Together with the flux data in the literature, the results obtained in this work indicate that electrical resistance is closely related to the permeability of drug molecules through the skin. The results are discussed in terms of the mechanism of action of these penetration enhancers. Overall, this work provided further mechanistic insight into the role of SC lipids in skin resistance and capacitance.

• Biomolecules & Therapeutics
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• v.25 no.1
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• pp.44-56
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• 2017

Insulin resistance is characterized by the reduced ability of insulin to stimulate tissue uptake and disposal of glucose including cardiac muscle. These conditions accelerate the progression of heart failure and increase cardiovascular morbidity and mortality in patients with cardiovascular diseases. It is noteworthy that some conditions of insulin resistance are characterized by up-regulation of the sympathetic nervous system, resulting in enhanced stimulation of ${\beta}$-adrenergic receptor (${\beta}$AR). Overstimulation of ${\beta}$ARs leads to the development of heart failure and is associated with the pathogenesis of insulin resistance in the heart. However, pathological consequences of the cross-talk between the ${\beta}$AR and the insulin sensitivity and the mechanism by which ${\beta}$AR overstimulation promotes insulin resistance remain unclear. This review article examines the hypothesis that ${\beta}$ARs overstimulation leads to induction of insulin resistance in the heart.