• Journal of Radiation Protection and Research
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• v.40 no.1
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• pp.65-72
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• 2015

The basic concepts of radiation-induced skin damage have been established, the biological mechanism has not been studied. In this study, we have examined the effects of gamma rays on skin injury and cyclooxygenase(COX)-2 expression. Gamma irradiation induced clinicopathological changes in a dose- and time-dependent manner in mini-pig skin. The histological changes were consistent with the changes in gross appearance at 12 weeks after irradiation. After three days' irradiation, apoptotic cells in the basal layer were found more frequently in irradiated skin than in normal skin, with the magnitude of the effect being dose-dependent. The thickness of the epidermis transiently increased 3 days after irradiation, and then gradually decreased, although changes in the epithelial thickness of the irradiated field were not observed with irradiation doses over 50 Gy. In the epithelium, there was an initial degenerative phase, during which the rate of basal cell depletion was dependent on the radiation dose (20-70 Gy). One week after irradiation, COX-2 expression was mostly limited to the basal cell layer and was scattered across these cells. High COX-2 expression was detected throughout the full depth of the skin after irradiation. The COX-2 protein is upregulated after irradiation in mini-pig skin. These histological changes associated with radiation exposure dose cause the increased COX-2 expression in a dose-dependent fashion.

• Journal of Energy Engineering
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• v.25 no.2
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• pp.37-44
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• 2016

The demand for electricity has a considerable impact on various energy sectors since electricity is generated from various energy sources. This paper attempts to estimate the electricity demand function and obtain some quantitative information on price and income elasticities of the demand. To this end, we apply a lagged dependent variable model to derive long-run as well as short-run elasticities using the time-series data over the period 1991-2014. Our dependent variable is annual electricity demand. The independent variables include constant term, real price of electricity, and real gross domestic product. The results show that the short-run price and income elasticities of the electricity demand are estimated to be -0.142 and 0.866, respectively. They are statistically significant at the 5% level. That is, the electricity demand is in-elastic with respect to price and income changes in the short-run. The long-run price and income elasticities of the electricity demand are calculated to be -0.210 and 1.287, respectively, which are also statistically meaningful at the 5% level. The electricity demand is still in-elastic with regard to price change in the long-run. However, the electricity demand is elastic regarding income change in the long-run. Therefore, this indicates that the effect of demand-side management policy through price-control is restrictive in both the short- and long-run. The growth in electricity demand following income growth is expected to be more remarkable in the long-run than in the short-run.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.9 no.1
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• pp.1-14
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• 2003

Objective : Ikiyangeumhaedoc-tang(IYHT) has an effect of nourishing Yin(陰) and Jin(津), and has been used to cancer patient effectively. In order to prove the anticancer's and antimetastic effect of IYHT experimentally, studies were done. Methods : We evaluated the cytotoxic activity on HT-1080 cells as well as inhibitory effect on activity of DNA topoisomerase Ⅰ, cell adhesion, cell invasion and proliferation of HUVEC cells induced by bFGF and measured the expression of mRNA(uPA, MMP2, TIMP2), p-ERK protein, recovery effect of gap junctional intercellular communication by $H_{2}O_2$ and survival time of ICR mice bearing sacoma-180. Results : IYHT showed the inhibitory effect on DNA topoisomerase Ⅰ in the concentration of $100{\mu}g/ml,\;500{\mu}g/ml$ and the dosage-dependent inhibitory effect on the adhesion of HT-1080. The concentration of 1mg/ml of IYHT inhibited 15% of adhesion compared with control. IYHT decreased the expression of uPA, but not in MMP2, TIMP2 by RT-PCR and inhibited the expression of p-ERK effectively in the concentration of more than $500{\mu}g/ml.$ IYHT recovered the inhibited gap junctional intercellular communication by $H_{2}O_2$ to the level of 60% of normal control in the concentration of $400{\mu}g/ml$ but, did not extended the mean survival time of sarcoma 180-bearing mouse. Conclusions : It was concluded that IYHT could be applied usefully for prevention and treatment of human cancer, And also experimental study for the evaluation of molecular biological study and antimetastatic research would be recommended in the near future.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.379-402
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• 2022

The purpose of this study was to verify the effectiveness of the employee metacognition and it's positive effect on employee agility. Also it aims to investigate the mechanism through the cascading multi-mediating effect through the role breadth self-efficacy and learning agility in such a relationship. In order to solve the common-method bias, independent and dependent variables were measured with time lag, and the relationship between variables was clearly verified by applying the position and the length of time worked with the supervisor as control variables. In testing the hypothesis, 478 questionnaires collected from whom worked at the company has more than 300 office workers in various industries were analyzed. As the result, firstly metacognition had a significant positive(+) effect on employee agility. Second, role breadth self-efficacy was found to positively mediate the relationship between metacognition and employee agility. Third, learning agility was found to mediate metacognition and employee agility positively(+). Fourth, metacognition serially mediates role breadth self-efficacy and learning agility, and the positive(+) effect on employee agility was verified. In addition, metacognition had a greater effect on member agility when passing through role breadth self-efficacy and learning agility rather than the direct effect on employee agility.

• Journal of Korean Society for Quality Management
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• v.46 no.2
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• pp.351-374
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• 2018

Purpose: The collective civil complaint problem is considered as important obstructive factor of the nuclear power plant construction project's success and quality. Therefore, this study demonstrate the factors which can affect the settling collective civil complaints, and also suggest the improvement of the resolution. Methods: This study collected the data of Kori Nuclear Power Division staff, local residents and Hanul Nuclear Power Division staff, local residents, and use them for analysis. Results: The results are twofold in the study: First, the 'Situation Recognition' and 'Mutual Cooperation' which are independent variables for solving collective civil complaints have proved to give positive influence on both the nuclear staff and the local residents about the complaint resolution outcome of the dependent variable. Second, the moderation variable 'Expected Benefit' on the influential relationship between the collective civil complaint resolution factor and the civil complaints resolution outcome proved to have a moderating effect only on the nuclear staff. On the other hand, moderation variables 'Time of SOC Business Implementation' and 'Time of Compensation' proved to have a moderating effect only for the local residents. Conclusion: According to the results, the staff have a positive opinion on the benefits of the nuclear power plant construction, while residents feel strongly that they do not get any benefit from the construction despite of tremendous investment and expected benefit in local area. As this results, policy implementation which is superable different understanding is required.

• The Journal of Korean Medicine
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• v.31 no.4
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• pp.79-100
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• 2010

Objective: Production of ROS from glucose toxicity results in injury of pancreatic $\beta$-cells in diabetes models. This study was undertaken to examine the influence of Lespedeza Cuneata extract (LCE) on cytoprotective effects on glucose toxicity, insulin secretion and gene expression in RIN-m5F cells. Methods: First, we measured LCE's antioxidant activity by DPPH free radical-scavenging activity and SOD activity. After the various concentrations of LCE were added to the RIN-m5F cells, we measured cell viability with glucose stimulation by MTT assay and glucose-stimulated insulin secretion. We analyzed gene expression with Agilent whole mouse genome 44K oligo DNA microarray and searched for related pathways in KEGG (Kyoto Encyclopedia of Genes and Genomes). Lastly we measured INS-1, INS-2, INS-R, IRS-1, IRS-2, IRS-3, GLP-1R, and GLP-2R mRNA expression by real time RT-PCR. Results: Free radical-scavenging activity, SOD activity and insulin secretion increased dependent on LCE concentration, but LCE did not show considerable cytoprotective effect on RIN-m5F cells. More than twice expressed gene was 6362 in Oligo DNA chip. In KEGG, the most related pathway was the metabolic pathway. In the insulin signaling pathway, up expressed genes were Irs1, Mapk8, Akt1, and Lipe and down expressed genes were Rhoq, Fbp2, Prkar2b, Gck, and Prkag1. In real time RT-PCR, IRS-2, and IRS-3 expression increased significantly compared to the control group on LCE $12{\mu}g/m{\ell}$ concentration and GCK expression decreased significantly compared to the control group. Conclusions: These results show that LCE encourages insulin secretion and insulin metabolism by complicated gene mechanisms. Further mechanism study and clinical study seem to be necessary about Lespedeza Cuneata.

• Steel and Composite Structures
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• v.28 no.5
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• pp.589-606
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• 2018

The previous studies reflected the significant effect of neutral-axis position and coupling of in-plane and out-of-plane displacements on behavior of functionally graded (FG) nanobeams. In thin FG beam, this coupling can be eliminated by a proper choice of the reference axis. In shear deformable FG nanobeam, not only this coupling can't be eliminated but also the position of neutral-axis is dependent on through-thickness distribution of shear strain. For the first time, in this paper it is avoided to guess a shear strain shape function and the exact shape function and consequently the exact position of neutral axis for arbitrary gradation of higher order nanobeam are obtained. This paper presents new methodology based on differential transform and collocation methods to solve coupled partial differential equations of motion without any simplifications. Using exact position of neutral axis and higher order beam kinematics as well as satisfying equilibrium equations and traction-free conditions without shear correction factor requirement yields to better results in comparison to the previously published results in literature. The classical rule of mixture and Mori-Tanaka homogenization scheme are considered. The Eringen's nonlocal continuum theory is applied to capture the small scale effects. For the first time, the dependency of exact position of neutral axis on length to thickness ratio is investigated. The effects of small scale, length to thickness ratio, Poisson's ratio, inhomogeneity of materials and various end conditions on vibration and buckling of local and nonlocal FG beams are investigated. Moreover, the effect of axial load on natural frequencies of the first modes is examined. After degeneration of the governing equations, the exact new formulas for homogeneous nanobeams are computed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.3 s.333
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• pp.9-16
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• 2005

The mobility in strained Si inversion layer on $Si_{1-x}Ge_x$ is calculated considering a quantum effect(subband energy and wavefunction) in inversion layer and relaxation time approximation. The quantum effect in inversion layer is obtained by using self-consistent calculation of $Schr\ddot{o}dinger$ and Poisson equations. For the relaxation time, intravalley and intervalley scatterings are considered. The result shows that the reason for the enhancement in mobility as Ge mole fraction increases is that the electron mobility in 2-폴드 valleys is about 3 times higher than that of 4-폴드 valleys and most electrons are located in 2-폴드 valleys as Ge mole fraction increases. Meanwhile, for the phonon-limited mobility the fitting to experimental data, Coulomb and surface roughness mobilities are included in total mobility, Deformation potentials are selected for the calculated effective field, temperature, and Ge mole fraction dependent mobilities to be fitted to experimental data, and then upgraded data can be obtained by considering nonparabolicity in Si band structure.

• International Journal of Oral Biology
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• v.45 no.3
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• pp.115-125
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• 2020

Resveratrol has been reported to exert anticancer activity via modulation of multiple pathways and genes. In this study, we examined the effect of resveratrol on YD-10B human oral squamous cell carcinoma cells and its molecular mechanisms of action. We found that resveratrol inhibited the proliferation of YD-10B cells in a dose- and time-dependent manner. The suppressive effect of resveratrol was accompanied by a reduction in Bmi-1 gene expression. We observed that silencing the Bmi-1 gene by small interfering RNA effectively downregulated the levels of GLUT1 mRNA and protein, which were also repressed by resveratrol. Bmi-1 silencing increased the number of YD-10B cells in S-phase arrest by approximately 2.3-fold compared with the control. In conclusion, the results of the present study demonstrate, for the first time, that resveratrol suppresses Bmi-1-mediated GLUT1 expression in human oral squamous cell carcinoma cells and suggest that the specific molecular targeting of Bmi-1 and/or GLUT1 expression can be combined with a chemotherapeutic strategy to improve the response of oral cancer cells to resveratrol.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1791-1795
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• 2013

Aims and Background: Prostate cancer is one of the most common malignant tumors in the male reproductive system, which causes the second most cancer deaths of males, and control of angiogenesis in prostate lesions is of obvious importance. This study assessed the effect of apogossypolone (ApoG2) on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs). Subjects and Methods: HUVECs were treated with different concentrations of ApoG2. The survival rate of HUVECs were determined by MTT assay. Utrastructural changes of HUVECs were assessed with transmission electron microscopy. Apoptosis in HUVECs was analyzed by flow cytometry and cell migration by Boyden chamber assay. Matrigel assays were used to quantify the development of tube-like networks. Results: ApoG2 significantly inhibited HUVEC growth even at 24 h (P<0.05). The inhibitory effect of ApoG2 is more obvious as the concentration and the culture time increased (P<0.05). These results indicate that ApoG2 inhibits the proliferation of HUVECs in a time- and concentration-dependent manner with increase of the apoptosis rate. Besides, ApoG2 reduced the formation of total pseudotubule length and network branches of HUVECs. Conclusions: The results suggest that ApoG2 inhibits angiogenesis of HUVECs by growth inhibition and apoptosis induction.