• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.3
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• pp.132-145
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• 2016

In case of the seabed around and under gravity structures such as submerged breakwater is exposed to a large wave action long period, the excess pore pressure will be generated significantly due to pore volume change associated with rearrangement soil grains. This effect will lead a seabed liquefaction around and under structures as a result from decrease in the effective stress. Under the seabed liquefaction occurred and developed, the possibility of structure failure will be increased eventually. In this study, to evaluate the liquefaction potential on the seabed quantitatively, numerical analysis was conducted using the expanded 2-dimensional numerical wave tank model and the finite element elasto-plastic model. Under the condition of the regular wave field, the time and spatial series of the deformation of submerged breakwater, the pore water pressure (oscillatory and residual components) and pore water pressure ratio in the seabed were estimated.

• The Korea Journal of Herbology
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• v.29 no.6
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• pp.63-71
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• 2014

Objectives : Lonicerae japonicae Flos(LJF) has been reported to exhibit anti-oxidant, anti-inflammatory, anti-viral, anti-rheumatoid properties. However, it is still largely unknown whether LJF inhibits the ultraviolet(UV)B-induced oxidative damage in human HaCaT keratinocytes. Therefore in this paper, we investigated the anti-oxidative capacity and protective effect of LJF against UVB-induced oxidative demage in human HaCaT keratinocytes. Methods : To evaluate the anti-oxidative activity of LJF extracts, we measured total phenolic contents, total flavonoid contents, antioxidant capacity, and superoxide scavenging activity. To give an oxidative stress to HaCaT cells, UVB was irradiated with $200mJ/cm^2$ to HaCaT cells. To detect the protective effect of LJF against UVB, we measured cell viability, DNA fragmentation and reactive oxygen species (ROS) production. In addition, we performed high-performance liquid chromatography (HPLC) analysis to find a major component of LJF. Results : LJF contained phenolic and flavonoid contents, and showed the anti-oxidant and superoxide scavenging activity. The UVB-induced oxidative conditions led to the cell death, DNA fragmentation and reactive oxygen species (ROS) production. However, pretreatment with LJF reduced oxidative conditions, including inhibition of cell death, DNA fragmentation and ROS production. In addition, we found out chlorogenic acid as major component of LJF. Conclusions : These results could suggest that LJF contained anti-oxidative contents and exhibited protective effects against UVB on human HaCaT keratinocytes. And the effective compound of LJF which could show protective activities against UVB is chlorogenic acid. Thus, LJF and chlorogenic acid would be useful for the development of drug or cosmetics treating skin troubles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2189-2198
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• 2014

Paraquat (PQ) is a very effective and widely used herbicide that was commercially introduced in 1962. In this study, instead of using antioxidants like in the past, to inhibit the formation of PQ-induced ROS, we attempted to reduce the oxygen concentration by using non-lethal hypoxia therapy. Therefore, we studied the toxicity of PQ in vivo, analyzed the major effects of ROS on the targeted lung tissue and compared the results with the gross histological changes after the cell protective effect of non-lethal hypoxia therapy. In vivo studies demonstrated that low-concentration oxygen therapy (i.e., 10-12% oxygen) in rats administered with PQ was associated with a higher survival rate than in rats that received only PQ. In vivo non-lethal hypoxia treatment showed better survival and less lung tissue damage. Using a hypoxic/anaerobic incubator with integrated multifaceted molecular analysis, including MDA assay, glutathione assay, and SOD assay, we established an optimal, significantly reduced in vivo non-lethal hypoxia treatment by exploiting the PQ-induced cytotoxicity responses.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.952-961
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• 2003

In the first part of the study, rates of estrus occurrence and success of A.I. service in the Thai-native and Friesian crossbred, and purebred Friesian cows fed in the National Dairy Training and Applied Research Institute in Chiang Mai, Thailand were traced monthly throughout a year. An electric fan and a water sprinkler cooled the stall for the purebred cows during the hot season (March-September). Both rates in pure Friesians were at their highest in the cold-dry season (October- February), but they decreased steadily during the hot-dry season (March-May) and were at their lowest in the hot-wet season (June-September). Seasonal change of a similar pattern was observed in the incidence of estrus, but not in the success rate of insemination in the crossbred cows. By the use of reproductive data, compiled in the same institute, on the 75 % cross- and purebred Friesian cows, and climatological data in Chiang Mai district, effects of ambient temperature and humidity on the reproductive traits of cows were examined by regression analysis in the second half of the study. Significant relationships in the crossbred, expressed by positive-linear and parabola regressions, were found between reproductive parameters such as days to the first estrus (DTFE), A.I. service (DTFAI), and conception, the number of A.I. services required for conception and some climatic factors. However, regarding this, no consistent or intelligible results were obtained in purebred cows, perhaps because electric fans and water sprinklers were used for this breed in the hot season. Among climatic factors examined, the minimum temperature (MINT) in early lactation affected reproductive activity most conspicuously. As the temperature during one or two months prior to the first estrus and A.I. service rose, DTFE and DTFAI steadily became longer, although, when MINT depleted below $17-18^{\circ}C$, the reproductive interval tended to be prolonged again on some occasions. The maximum temperature also affected DTFE and DTFAI, but only in limited conditions. The effect of humidity was not clear, although the inverse relationship between DTFE and minimum humidity during 2 months before the first estrus in the crossbred seemed to be significant. Failure to detect any definite effect of climate on the reproductive traits of pure Friesians seemed to indicate that forced ventilation by electric fans and water sprinklers were effective enough to protect the reproductive ability of this breed from the adverse effects of a hot climate.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.213-220
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• 2015

CFT column has a lot of structural advantages due to the composite behavior between in-filled concrete and steel tube. This paper deals with the development of an effective numerical model which can consider the bond-slip behavior between both components of concrete matrix and steel tube without taking double nodes. Since the applied axial load to in-filled concrete matrix is delivered to steel tube by the confinement effect and the friction, the governing equation related to the slip behavior can be constructed on the basis of the force equilibrium and the compatability conditions. In advance, the force and displacement relations between adjacent two nodes make it possible to express the slip behavior with the concrete nodes only. This model results in significant savings in the numerical modeling of CFT columns to take into account the effect of bond-slip. Finally, correlation studies between numerical results and experimental data are conducted to verifying the efficiency of the introduced numerical model.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.449-457
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• 2016

This study was aimed at exploring the meaning and essence of the conflict experiences of clinical dental hygienists. In-depth interviews with 13 dental hygienists working in a dental clinic were conducted. Giorgi's method was used for qualitative analysis of the data. Conflict experiences of clinical dental hygienists were categorized into four central meaning as task conflicts, interpersonal conflicts, organizational environment conflicts, and conflict management style. Participants felt more sensitive towards the attitudes of people than treatment itself. Further studies on the multifaceted approach to conflict experiences of dental hygienists should be made. Additional research is necessary to develop effective measures and program to prevent and reduce conflict and stress in the work environment of dental hygienists.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.172-177
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• 2016

The phenolic compounds, antioxidant activity and neuronal cell protective effect of Cirsium japonicum extract were evaluated in this study. High performance liquid chromatography mass analysis showed that C. japonicum was composed of chlorogenic acid, linarin, and pectolinarin. C. japonicum extract showed its antioxidant activity with half-maximal inhibitory concentrations of 567 and $130{\mu}g/mL$ by DPPH and ABTS radical scavenging activity, respectively. The total antioxidant capacities of C. japonicum via DPPH, ABTS, and FRAP assays were 11.32, 100.15, and $12.76{\mu}g/mL$ trolox equivalents, respectively. In addition, the neuroprotective effect of C. japonicum extract was investigated by measuring cell viability via MTT, LDH and DCF-DA assay using $H_2O_2-damaged$ PC12 cells. C. japonicum extract showed neuronal cell protective effects in a dose-dependent manner. These results indicated that C. japonicum extract has potent antioxidant and neuronal protective effects. Therefore, C. japonicum can be regarded as an effective and safe functional food resource as natural antioxidants, and may decrease the risk of neurodegenerative disorders.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.334-346
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• 2017

The purpose of this study was to identify the inner characteristics of nurses that contributed to their overcoming work-related stress and continuing to work in hospitals. We sought to identify strategies nurses used to reduce early turn-over intention and promote job retention. Twelve nurses with at least five years of work experience were recruited from two tertiary-level hospitals and three general hospitals in Seoul and Gyeonggi for focus group interviews. Data were collected from January 27 to April 20, 2016. Qualitative data were analyzed using content analysis. Based on the results, the inner characteristics and strengths of these nurses were classified into four categories and 13 sub-categories. The four categories wereas follows: "efforts to overcome self," "positive attitude," "effective communication and support from surroundings," and "aim to grow as a nursing professional." The results of this study indicate that the strength of nurses should be enhanced to facilitate a continued desire to work. Training for self-reflective practice is recommended to improve resilience, positive attitudes, and communication skills, as well as to establish job identity.

• Journal of dental hygiene science
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• v.17 no.1
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• pp.12-19
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• 2017

The aim of this study was to investigate adult individuals' perceptions on the association between chronic diseases and oral health provide basic data required for motivating individuals to follow ideal oral health behaviors and boost their interests in oral disease prevention and treatment. Subjects in their 20s to 50s were selected through the convenience sampling method and eleven questions were set as factors and answered via self-administered questionnaires. To determine statistical significance, analysis of variance was used with the level of significance set at 0.05. The subjects' perception of the association between chronic diseases and oral health were analyzed with respect to their health behaviors. Individuals with relatively higher stress levels demonstrated higher levels of perception levels (p<0.05). Public education regarding the association between chronic diseases and oral health has not been ideally effective in South Korea. Thus, the general public's perceptions of the association between chronic diseases and oral health should be revised. In addition aspects regarding this matter should be enhanced within oral health education programs which often only focus on demonstrating the importance of oral health management so that individuals can get sufficient information on the association between chronic diseases and oral health.

• Journal of Korean Public Health Nursing
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• v.15 no.2
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• pp.262-274
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• 2001

This study was undertaken to grasp the relationship between perceived health status, health conception and health promoting behavior in the elderly. The subjects for this study were 157 old persons in Kyung-ju city. Data were collected by interview with questionnaires from August 24 to October 10, 1999. Analysis of the data was done by SPSS program using descriptive statistics, t-test, ANOVA, Pearson Correlation Coefficient, stepwise multiple regression. The results were summarized as follows 1. For the practice of health promoting behavior. the mean score was 2.52. The factor of the highest mean score was nutrition(3.02) and factor of the lowest mean score was exerciset(2.03). 2. According to age(F=3.35, P=.012), sex(t=2.26, P=.025), marital status (F=5.08, P=.007), education(F=4.22, P=.003), family numbed(F=5.31, P= .006), people living together (F=2.77, P=.044), economic status(F=7.10, P=.00l), average monthly pocket money (F=3.35, P=.012), there were differences of health promoting behavior. 3. According to age(F=3.40, P=.01l), sex(t=4.30, P=.000), education(F=8.55, P=.000), economic status(F=12.59, P=.000), average monthly pocket money(F=4.26, P=.003), present disease(t=-8.41, P=.000), there were differences of perceived health status. According to marital status(F=3.36, P=.037), education(F=2.89, P=.038), there were differences of health conception. 4. Performance in the health promoting behavior was significantly correlated with perceived health status(r=.272, P=.00l), health conception(r=.345, P=.000) 5. The combination of well-being health conception and average monthly pocket money explained $24.7\%$ of the variance of health-promoting behavior. On the basis of the above findings the following recommendations are made; Nursing interventions enhancing exercise or activity, accountability for health, stress management of the elderly must be provided. And Cost-effective health promoting program for the elderly must be developed.