• Journal of Preventive Medicine and Public Health
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• v.39 no.2
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• pp.123-129
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• 2006

Objectives : The incidence of colorectal cancer increased greatly among the elderly in Korea, but the relationship between smoking and colon cancer remains controversial. Few studies have targeted Asian elderly people. We analyzed the smoking status, the amount smoked, and the smoking duration as risk factors of colorectal cancer to determine their association and causality. Methods: The cohort members (n=14, 103) consisted of 4,694 males and 9,409 females, and they were derived from the Korea Elderly Phamacepidemilogic Cohort (KEPEC), which was a population-based dynamic cohort. They were aged 65 years or more and they lived in Busan Metropolitan City between from 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). The baseline information was surveyed by a self-administered mailed questionnaire; after 8.7 person-years of mean follow up period, 100 cases of colorectal cancer occurred. The adjusted relative ratio (aRR) of smoking status, the smoking amount and the smoking duration were calculated from the Cox's proportional hazard model with the never-smokers as a reference group and the Cox model controlled for age, gender, precancerous lesions of CRC, medication history of NSAIDs & antibiotics, the alcohol drinking status and BMI. Results : Compared with the never smokers, the aRRs were 2.03 (95% CI=1.02-4.03) and 1.36 (95% CI=0.80-2.32) for the ex-smokers and current smokers, respectively. Statistical significant trends were not observed for the dose-relationship among the elderly, either for the mean daily amount smoked (p for trend=0.28) or for the total amount (p for trend=0.15). Still, the aRRs were 1.51 (95% CI=0.97-2.34) for the elderly who smoked less than 40 years and 2.35 (95% CI=1.16-4.74) for the elderly who had 40 years or more of smoking (p for trend=0.06). Smokers who started smoking before the age 20 had an increased aRR of 2.15 (95% CI=1.17-3.93) compared to the never smokers. Conclusions : After controlling for age, gender, precancerous lesion of CRC, medication history of NSAIDs & antibiotics, the alcohol drinking status and BMI, smoking increases the risk of colorectal cancer among elderly people. The age when starting smoking is also important.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.318-323
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• 2014

In order to analyze the effect of maleic anhydride (MAH) content and styrene monomer (SM)/MAH mole ratio on reactive extrusion of maleic anhydride grafted random polypropylenes (MAH-g-rPP), MAH-g-rPPs were prepared by using a twin screw extruder. MAH contents were 0.5, 1.0, 3.0, and 5.0 phr and SM/initiator mole ratio was 0.0, 1.0, and 2.0. Dicumyl peroxide (DCP) was used as an initiator. The graft degree of MAH was confirmed by the existence of carbonyl group (C = O) stretching peak at $1700cm^{-1}$ from FT-IR spectrum. The degree of graft reaction increased up to 3.0 phr MAH and showed the optimum value at 1.0 SM/MAH mole ratio from the area ratio of C = O and C-H stretching peak. Thermal and crystallization properties of MAH-g-rPP and PP/MAH-g-rPP/pulp composites were investigated by DSC, TGA, XRD, and POM. There was a decrease in non-isothermal crystallization temperature of PP/MAH-g-PP/pulp composites. Based on tensile properties and SEM pictures for the fractured surface of PP/MAH-g-PP/pulp composites, MAH content of 1.0 wt% and SM/MAH mole ratio of 1.0 were the optimum formulation as the compatibilizer. The rheological properties of the composites were measured by dynamic Rheometer to compare the processability of the composites with and without compatibilizer. The power law index showed slightly low value at the composites with compatibilizer.

• Journal of the Korea Society of Computer and Information
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• v.19 no.11
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• pp.137-147
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• 2014

The study aims at exploring motivation, rationale, and values in twitter users' retweet behavior. It proposes that diffusion of message is based on the complex interactional relationships among attributes of original message, user's rationale, and values. Based on a pilot study, we constructed a total of 34 questions asking message attributes, motivation, and values of retweeting. Then, twitter users participated in an online survey, in which they evaluate their own 5 retweet messages based on the constructed questions(5 messages ${\times}$ 34 questions = 170). Then, a factor analysis is done in order to see the dimensions of the concepts in retweet behavior; and understand how message attributes, motivations, and values are inter-related with each other. The main factors extracted were: (1) public fairness, (2) fun and playfulness, (3) communal help, (4) news and information, etc. Factor 2 and 4 show the traditional journalism characteristics; while factor 1 and 3 do alternative journalistic values. The latter may work as a rectifying factors for traditional journalism; however, backfiring mechanism for group polarization. In addition, (1) users' internal identities, (2) communal unity and (3) belongness were identified as rationales and values for retweet behavior.

• Journal of the Korean Regional Science Association
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• v.35 no.2
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• pp.33-47
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• 2019

The purpose of this study is to examine the effect of urban decline on Subjective Well-being(SWB). According to the scale of the city, the municipal districts of Korea are classified into metropolitan cities, middle cities, and small cities. The SWB in the growth area, the maintenance area, and the declining area according to the degree of relative decline of each city group was examined. In addition, in order to consider the complex nature of urban decline, SWB was divided into overall life satisfaction, household income satisfaction, and housing environment satisfaction. Panel models were also used to identify the dynamic relationship between the progress of urban decay and the change in SWB. The empirical analysis of this study examined the effect of decline on the SWB for the local residents. As a result, it was confirmed that the effect of urban decline on the SWB of the residents varies according to the size of the city where the individual resides, according th the SWB by the division. In the case of metropolitan inhabitants, the decline of the housing environment of the residents due to deterioration of the physical environment was confirmed as a result of the decline of the city, but the overall life satisfaction was increased due to the decrease of the social costs such as congestion in an overcrowded area. On the contrary, in the case of the residents of the small cities, it is confirmed that the decline of the city reduces the overall life satisfaction, household income satisfaction, and housing environment satisfaction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.155-164
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• 2019

In this study, the soil-structure interaction(SSI) effect on the seismic response of LNG storage tanks was investigated according to the type of foundation. For this purpose, a typical of LNG storage tank with a diameter of 71m, which is constructed on a 30m thick clay layer over bedrock was selected, and nonlinearity of the soil was taken into account by the equivalent linearization method. Four different types of foundations including shallow foundation, piled raft foundation, and pile foundations(surface and floating types) were considered. In addition, the effect of soil compaction in group piles on seismic response of the tank was investigated. The KIESSI-3D, which is a SSI analysis package in the frequency domain, was used for the SSI analysis. Stresses in the outer tank, and base shear and overturning moment in the inner tank were calculated. From the comparisons, the following conclusions could be made: (1) Conventional fixed base seismic responses of outer tank and inner tank can be much larger than those of considering the SSI effect; (2) The influence of SSI on the dynamic response of the inner tank and the outer tank depends on the foundation types; and (3) Change in the seismic response of the structure by soil compaction in the piled raft foundation is about 10% and its effect is not negligible in the seismic design of the structure.

• Journal of The Korean Association For Science Education
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• v.42 no.2
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• pp.201-214
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• 2022

The purpose of this study is to examine the characteristics of model of the experiment in students' open inquiry. The research is a reinterpretation of the data collected from the performance of a three-year research project under the theme of 'school science inquiry' the perspective of model of the experiment. The inquiry activities of a focus group made up of four students have been recorded seven times. The recorded files and transcribed copies were analyzed according to interpretive methods. Students' activities were divided into three modeling of the experiment units, considering the modeling unit that includes the process of starting from the problem until it gets solved. The results of the study include illuminating the dynamic process and characteristics of modeling of the experiment and discussing its educational meaning as a distributed cognitive system at each modeling unit. First, students, instruments, and the primitive form of calculation represented by the interaction between them turned out to be important factors in the distributed cognitive system that constitutes model of the experiment. Second, in the early stages, non-verbal activities were carried out in which students became familiar with instruments, and verbal quantitative signs were created when the activities were sufficiently carried out. The generated quantitative signs became a source of data and confidence that can be referenced in subsequent activities. Third, the specialization of instrumentalization occurred, and factors that were important in inquiry, such as variable control, appeared. The results of the study provide new implications for science education research and education, which have been centered on explanatory models, by unfolding the characteristics of model of the experiment that have not been noticed in science education through students' inquiry.

• Science of Emotion and Sensibility
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• v.25 no.3
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• pp.117-126
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• 2022

This study seeks to identify usage behaviors and improvement factors to increase the academic and practical application of value the of color image scales. For this purpose, the authors discuss the positive and negative perspectives on the evaluation of previous studies on color image scales. Furthermore, a survey was conducted with 25 color experts who have been working in the field for over five years, and in-depth interviews were conducted with five of them. The contents of the survey are usage behaviors, evaluation, and the improvement of Kobayashi and IRI color image scales. In this process, emotional adjectives that need improvement were derived, and the opinions of experts related to improvements were collected. The analysis results are as follows. 1) As a result of the usage behaviors, 92% were aware of both color image scales. Moreover, 44% used both, and 56% used only one. 2) Regarding familiarity and trust, IRI was higher than Kobayashi. 3) A total of 88% of respondents stated that color image scales were necessary. A total of 43.6% of respondents, the largest group of respondents, indicated that color image scales are necessary in the field of practice. 4) Regarding the need for improvement, 88% responded that IRI color image scales need improvement. 5) The highest response to the factors requiring improvement was the reflection of the times, which was 31.9% for Kobayashi and 30.9% for IRI. 6) When improving color image scales, the adjectives that need to be treated as the most important were shown to be modern (15.8%) → natural, romantic, wild (8.8%) → dynamic (7.0%) → classic, casual, chic (5.3%). In conclusion, limitations were identified in the use of color image scales in practice and in the research areas, and there was a demand for correction and supplementation. The results of this study will serve as a foundational study related to color image scales, and it is expected that subsequent research related to color image scales will follow.

• Journal of the Korean Geotechnical Society
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• v.38 no.6
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• pp.17-28
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• 2022

The effect of the soil-structure interaction (SSI) on has been recently evaluated in shaking table tests. However, most of these tests were conducted on single-degree-of-freedom (SDOF) superstructures and a single-pile. This study investigates the inertial interaction effect of a multi-degree-of-freedom (MDOF) superstructure system with a group piles on a large-scale shaking table test. Whereas the SDOF superstructure system shows a single-frequency amplification tendency, the MDOF superstructure system exhibited amplification tendencies of the acceleration phase and frequency responses for multiple frequencies. In addition, the amplification phenomenon between the footing and the column-type superstructure exceeded that between the footing and the wall-type superstructure, indicating a greater inertial interaction effect of the column-type superstructure. The relationship between shear force and inertial force, the relative vertical and horizontal displacements on the footing was figured out. Also, the ananlysis of dynamic p-y curve at each depth was conducted. In summary, the MDOF and SDOP superstructure systems exhibited different behaviors and the column-type superstructure exerted a higher interaction effect than the wall-type superstructure.

• Journal of Pharmacopuncture
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• v.27 no.1
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• pp.1-13
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• 2024

Background: Diabetic nephropathy (DN) is one of the major complications of chronic hyperglycaemia affecting normal kidney functioning. The ayurvedic medicine curcumin (CUR) is pharmaceutically accepted for its vast biological effects. Objectives: The Curcuma-derived diferuloylmethane compound CUR, loaded on Poly (lactide-co-glycolic) acid (PLGA) nanoparticles was utilized to combat DN-induced renal apoptosis by selectively targeting and modulating Bcl2. Methods: Upon in silico molecular docking and screening study CUR was selected as the core phytocompound for nanoparticle formulation. PLGA-nano-encapsulated-curcumin (NCUR) were synthesized following standard solvent displacement method. The NCUR were characterized for shape, size and other physico-chemical properties by Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS) and Fourier-Transform Infrared (FTIR) Spectroscopy studies. For in vivo validation of nephro-protective effects, Mus musculus were pre-treated with CUR at a dose of 50 mg/kg b.w. and NCUR at a dose of 25 mg/kg b.w. (dose 1), 12.5 mg/kg b.w (dose 2) followed by alloxan administration (100 mg/kg b.w) and serum glucose levels, histopathology and immunofluorescence study were conducted. Results: The in silico study revealed a strong affinity of CUR towards Bcl2 (dock score -10.94 Kcal/mol). The synthesized NCUR were of even shape, devoid of cracks and holes with mean size of ~80 nm having -7.53 mV zeta potential. Dose 1 efficiently improved serum glucose levels, tissue-specific expression of Bcl2 and reduced glomerular space and glomerular sclerosis in comparison to hyperglycaemic group. Conclusion: This study essentially validates the potential of NCUR to inhibit DN by reducing blood glucose level and mitigating glomerular apoptosis by selectively promoting Bcl2 protein expression in kidney tissue.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.383-397
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• 1999

Bone is a dynamic tissue which is constantly remodelled by subsequent cycles of bone resorption and formation. Glucocorticoid and vitamine $D_3$ are known as regulating substances in bone metabolism. In vitro experiments using bone tissue, it was suggested that glucocorticoid inhibits bone resorption, whereas the effect of glucocorticoid on bone formation are complex- increasing or decreasing effect. The active form of vitamin $D_3$, 1,25-dihydroxycholecalciferol[1.25-$(OH)_2D_3$], has been reported to stimulate osteoblastic activities including the production of ALP, type I collagen, and osteoclacin. The purpose of this study was to evaluate the effect of admixture of vitamin $D_3$ and dexamethasone, one of glucocorticoids, on osteoblastic cell line(MC3T3-E1). Alkaline phosphatase(ALP) and MTT assay were conducted in the cultivated cells with 1, 10, 100nM/ml of 1,25-$(OH)_2D_3$ and/or 10nM/ml, 100nM/ml, $1{\mu}M/ml$ of dexamethasone. The observed results were as follows. 1. The activity of osteoblastic cells with $1{\mu}M/ml$ of dexamethasone was significantly increased at 1-day cultivation with comparison to control group, but was decreased afterwards. But the activity of ALP was greatest in $1{\mu}M/ml$ of dexamethasone and increased with time lapsed. 2. The activity of osteoblastic cells with vitamin $D_3$ was significantly increased dose-dependently at 1-day cultivation, but was significantly decreased in l00nM/.ml at 2-day cultivation, and was a little increased again at 3-day cultivation. The activity of ALP was increased in 10nM/ml or 100nM/ml at 2-day or 3-day cultivation, and was greatest in 100nM/ml at 3-day cultivation. 3. In case of admixture of dexamethasone and vitamin $D_3$, the cellular activity was decreased in any concentration of vitamin $D_3$ at 2-day cultivation, but was increased again at 3-day cultivation, which was greater than that in control or dexamethasone only group. The activity of ALP was decreased at 1-day cultivation, but was increased in the admixture of 10nM/ml or 100nM/ml of dexamethasone with 100nM/ml of vitamin $D_3$ at 2-day cultivation, and was again decreased at 3-day cultivation.