• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3581-3586
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• 2014

Aim: To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action. Methods: The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-${\kappa}Bp65$, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Results: TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-${\kappa}Bp65$ and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-${\kappa}Bp65$ and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01). Conclusion: TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-${\kappa}Bp65$, cyclinD1 and p16 may also play important roles in the regulation mechanisms.

• Asia-Pacific Journal of Business
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• v.6 no.2
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• pp.81-95
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• 2015

This study is an investigative study into the effects that the 'travel motivations' of participants on walking tourism has on their 'degree of satisfaction' by identifying tourist motivations for selecting walking tour among many types of tourism and their effects on hikers' degree of satisfaction. This study was conducted with hikers affiliated with 'walking on beautiful roads '-one of Busan's preliminary social enterprises- with a total of 176 copies used for a final effective sample. Data collected was analyzed using SPSS WIN 18.0 to conduct a frequency analysis of the sample. Along with exploratory factor analysis, Cronbach's ${\alpha}$ coefficient was used as an estimate of the validity and reliability of each factor. Multiple regression analysis was done for an analysis of travel motivations and their effects on satisfaction. The scale rates items in the questionnaire in the following categories: 'Motivations' for walking tours consist of 5 factors- vacation, soul-searching, social get-togethers, nature tour, community experience-with a total of 20 items. 'The degree of satisfaction' is made up of a factor with a total of 4 items. The results of the study are as follows: with respect to the hypothesis that motivations for walking tour would have a positive effect on the degree of satisfaction, test results show that 'motivations' have significant partial effects on the 'degree of satisfaction'. Motivations affect the degree of satisfaction in the order of nature tour and soul-searching except for experience and social get-togethers- an indication that participants on walking tours tend to travel for the attractiveness of nature, wanting time for reflection and meditation. As the first investigative study into participants in walking tours products offered by travel agencies, the study has the following implications for marketers: First, travel agencies selling walking tour products and government institutions concerned about the development of hiking trails need to discuss ways to make the most of natural resources as they are- rather than using development-oriented approaches. The study has its own limitation: it is that with the lack of domestic and international studies on walking tours, the study has not gained access to precedent studies on the subject so it has not established a systemic approach to the emerging type of tourism. Hopefully, this study will make a small contribution to its development.

• Journal of Science Education
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• v.36 no.1
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• pp.106-119
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• 2012

In order to promote national competition on knowledge based-society in 21centuries, it is important for us to train talented people who have much creativity. Comparing curriculums and contents studied in SECG (Science Education Center for the Gifted) and other organizations is object of this thesis. Finding implications of proper GATE(gifted and talented education) by understanding the present conditions is also a part of this thesis. We select 5 Science Education Centers for the Gifted and devise framework for analysis in order to analyze chemical textbooks in GATE programs. The framework consists of 6 categories including the contents, the level of activities, the opening extent of experiments, and the ability to think creatively. In our study of textbooks, we have found that the contents of chapters are divided properly but lacked the field of frontier and convergence science. Their activity types will have to develop programs which consist of various activities such as lectures and experiments. Precedent studies and study activities to promote scientific thinking were rated highly in general ratio. The level of studies that we analyzed lacked creative activities very much. In the opening extent of experiments, activities in the level 2 and the level 3 were low-rate. And in our study of thinking creatively, activities of promotion for expanded and related-ability to think seemed to lack. In order to achieve specific education for the gifted children, developments of GATE program is required. In the in-depth analysis from the questionnaires of Likert's method's descriptions, narrations, and interviews, it is divided into two answers in depth: contents of program, management of program. These also divided into two answers by attitude: positive answer or negative answer. According to the responses of the contents of program, the result of analysis shows that most respondents have positive reactions to not only contents and the managing method of SECG programs, but also to individual enhancing-abilities overall.

• Journal of Gifted/Talented Education
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• v.22 no.3
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• pp.779-800
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• 2012

This study is to understand gifted students' suicidal ideation and its related variables among gifted students. For this, this study explores the relationship between maladaptive perfectionism of gifted students and suicidal ideation, confirming mediating effects of depression and academic stress. For the study 320 middle school students who were identified as the gifted at a gifted education center affiliated with the university. The results are summarized as follows. First, the fit of measurement model was found to be ${\chi}^2$=228.571(df=110, p=.000), CFI=.972, TLI=.966, RMSEA=.058, indicating most of fit indexes were acceptable. Second, suicidal ideation was found a significant positive relationship with maladaptive perfectionism, depression, academic stress. Third, as a result of examining path coefficient, it was found to be influenced significantly by all of the path from maladaptive perfectionism to depression and academic stress, the path from depression to suicidal ideation, the path from academic stress to suicidal ideation. However, the path from maladaptive perfectionism to suicidal ideation was found to be statistically insignificant. Fourth, the result showed that depression and academic stress worked as complete mediators between maladaptive perfectionism and suicidal ideation. These findings give useful information about affective aspects of gifted adolescents in hard circumstances. The results of the study will be helpful in devising consultation and educational programs for the gifted who are in danger of suicide.

• Journal of Gifted/Talented Education
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• v.26 no.3
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• pp.515-539
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• 2016

The purpose of this study is to develop the integrated curriculum for gifted elementary students based on ICM (Integrated Curriculum Model) and to apply it for analysis of the relationship between creativity and creative problem solving skills. An integrated curriculum for gifted students attending a university-affiliated institute was developed and applied to twenty mathematically gifted 5th and 6th grade students. TTCT language test and CAT test for students' products from activities were conducted. In addition, tape-recorded group discussions and activities during instruction, and interview with students and teacher, activity sheets were analyzed. As results, their language abilities shown TTCT test have been improved. Furthermore, the correlation between the test results of automata and language creativity, the average of two projects and language creativity, and future problem solving and the average of TTCT showed significant correlations. Results showed the gifted students' understanding of high level concepts and cooperation among groups were needed in order to improve creative problem solving. It suggested a further study research the integrated curriculum applying creativity and giftedness to real-life problem situations for gifted students to make them grow into essential competent persons in the future.

• Journal of The Korean Association For Science Education
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• v.41 no.4
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• pp.283-295
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• 2021

This study attempts to explore the nature of science anxiety experienced by science-gifted middle school students based on Giorgi's phenomenological research method. Among the first-year middle school students selected by the University-affiliated Science Education Institute for the Gifted, six science-gifted students with high levels of science trait anxiety and science state anxiety experience were selected. Two interviews related to experience of science anxiety were conducted with participants. As a result of the analysis, science anxiety experienced by science-gifted students was caused by setting the ideal self-concept, lack of confidence, past experiences, difficulty in contents, and something valuable. Students complained of physical·physiological, cognitive, emotional·psychological discomfort when they felt science anxiety, and recognized it as an opportunity for growth. In addition, science-gifted students were shown to cope with various ways such as confronting uneasy situations directly or refining their minds to overcome various uncomfortable symptoms that arise when science anxiety is triggered. Some students thought that no special efforts were required to lower their level of anxiety because anxiety was relieved over time. The students had both negative and positive meanings for science anxiety. The results of this study will help teachers in-depth understanding of middle school science-gifted students who experience science anxiety and provide a theoretical basis for what kind of educational environment should be created and educational programs should be provided in relation to science anxiety.

• Journal of Korean Society of Rural Planning
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• v.24 no.4
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• pp.121-134
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• 2018

By using the raw data of the 2015 Agriculture, Forestry and Fishery Consensus that surveyed the farmers engaged in agriculture, forestry and fishery in 2015, this study investigated the effects of the characteristics of the farms in Gangwon-do on the utilization of the digital devices, which was classified into computers usage only, smartphones usage only, both computers and smartphones usage, and no digital device usage. This study used the Multinomial Logit Model for the above purpose. Moreover, the IIA(Independence of Irrelevant Alternatives) method of the Multinomial Logit Model was analyzed to be suitable. Upon the result of the analysis, when all the other variables were constant in the average, the probability of choosing both computers and smartphones increased by 0.02% as the family member living together with the farm owner increased by 1 person. In addition, the farms with agricultural machineries have 0.03% increased probability of using smartphones to sell their agricultural products, when compared with the farms without agricultural machinery. Moreover, for the farms with high sales profit of the agricultural products, the probability of using computers and the probability of using smartphones increased by 0.04% and 0.01%, respectively, and the probability of using both computers and smartphones increased by 0.02%. On the other hand, for the farms affiliated with the agricultural organization, the probability of using both computers and smartphones increased by 0.17%, and the probability of using only smartphones and the probability of using only computers increased by 0.16% and 0.15%, respectively. In case of selling to the National Agricultural Cooperative Federation(NACF), the probability of using smartphones increased by 0.11% if all other variables were to be constant in the average. In particular, the farms participating in the agriculture-related industries have 1.09% increased probability of using computers, have 0.92% increased probability of using smartphones, and 0.85% increased probability of using both computers and smartphones. Therefore, the implications suggested based on the results of the analysis are as follows. First, the farms' choices of the digital devices are made independently. Hence, the future agricultural industry business platform establishment should necessarily consider the types of farms' choices of the digital devices in the future. Second, since the usage of digital devices has a generally positive influence on the farm household income, digital education to improve farmers' ability to use the digital devices should be urgently provided in order to improve the farm household income in the farms in Gangwon-do. Third, because the digital devices used to sell agricultural products differ depending on the age of the farm owner, it would be desirable to target the younger generation of the farm owners rather than establishing the agricultural industry business platform for the farms in the aged farm villages. Fourth, it would be advisable for the future agricultural business platform to consider the characteristics of agricultural products sales source.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.325-333
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• 2021

Background: Alzheimer's disease (AD) is one of the most prevalent neurodegenerative disorders. Enhancing hippocampal neurogenesis by promoting proliferation and differentiation of neural stem cells (NSCs) is a promising therapeutic strategy for AD. 20(S)-protopanaxadiol (PPD) and oleanolic acid (OA) are small, bioactive compounds found in ginseng that can promote NSC proliferation and neural differentiation in vitro. However, it is currently unknown whether PPD or OA can attenuate cognitive deficits by enhancing hippocampal neurogenesis in vivo in a transgenic APP/PS1 AD mouse model. Here, we administered PPD or OA to APP/PS1 mice and monitored the effects on cognition and hippocampal neurogenesis. Methods: We used the Morris water maze, Y maze, and open field tests to compare the cognitive capacities of treated and untreated APP/PS1 mice. We investigated hippocampal neurogenesis using Nissl staining and BrdU/NeuN double labeling. NSC proliferation was quantified by Sox2 labeling of the hippocampal dentate gyrus. We used western blotting to determine the effects of PPD and OA on Wnt/GSK3β/β-catenin pathway activation in the hippocampus. Results: Both PPD and OA significantly ameliorated the cognitive impairments observed in untreated APP/PS1 mice. Furthermore, PPD and OA significantly promoted hippocampal neurogenesis and NSC proliferation. At the mechanistic level, PPD and OA treatments resulted in Wnt/GSK-3β/β-catenin pathway activation in the hippocampus. Conclusion: PPD and OA ameliorate cognitive deficits in APP/PS1 mice by enhancing hippocampal neurogenesis, achieved by stimulating the Wnt/GSK-3β/β-catenin pathway. As such, PPD and OA are promising novel therapeutic agents for the treatment of AD and other neurodegenerative diseases.

• Tuberculosis and Respiratory Diseases
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• v.87 no.2
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• pp.176-184
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• 2024

Background: Results of studies investigating the association between body mass index (BMI) and mortality in patients with coronavirus disease-2019 (COVID-19) have been conflicting. Methods: This multicenter, retrospective observational study, conducted between January 2020 and August 2021, evaluated the impact of obesity on outcomes in patients with severe COVID-19 in a Korean national cohort. A total of 1,114 patients were enrolled from 22 tertiary referral hospitals or university-affiliated hospitals, of whom 1,099 were included in the analysis, excluding 15 with unavailable height and weight information. The effect(s) of BMI on patients with severe COVID-19 were analyzed. Results: According to the World Health Organization BMI classification, 59 patients were underweight, 541 were normal, 389 were overweight, and 110 were obese. The overall 28-day mortality rate was 15.3%, and there was no significant difference according to BMI. Univariate Cox analysis revealed that BMI was associated with 28-day mortality (hazard ratio, 0.96; p=0.045), but not in the multivariate analysis. Additionally, patients were divided into two groups based on BMI ≥25 kg/m² and underwent propensity score matching analysis, in which the two groups exhibited no significant difference in mortality at 28 days. The median (interquartile range) clinical frailty scale score at discharge was higher in nonobese patients (3 [3 to 5] vs. 4 [3 to 6], p<0.001). The proportion of frail patients at discharge was significantly higher in the nonobese group (28.1% vs. 46.8%, p<0.001). Conclusion: The obesity paradox was not evident in this cohort of patients with severe COVID-19. However, functional outcomes at discharge were better in the obese group.

• KDI Journal of Economic Policy
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• v.35 no.2
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• pp.1-39
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• 2013

Considering the relationship between state-owned enterprise (SOE) CEOs and political circles, this study examines the performance impacts of CEO's succession type, board chair separation, and industry expertise and finance expertise of CEOs and outside directors. I propose the definition of political independence in SOE CEOs based on the independence in appearance that might affect general people's perception. It means that there are no relationships or circumstances that might affect SOE CEO's judgment, activity, and report. The definition is able to overcome the limitations of the prior research that could not discover the CEOs who were affiliated to political circles because the research just distinguished the CEOs following their pre-jobs. This study focused on the performance impacts of political independence impaired CEO as well as the CEO's impacts on the relationship between the performance and other corporate governance variables. I selected as dependent variables the average return on asset as operating income divided by total assets and the average customer satisfaction rate evaluated by Korean government during the first three years following the year of the events of explanatory variables. My theory and evidence from the various CEO's personal background and financial information from SOEs in Lee Myung-bak Administration and Rho Moo-hyun Administration suggest the following important things. First, the analysis based on whether or not a SOE CEO keeps political independence shows that a political independence impaired CEO made a significantly negative impact on customer satisfaction rate. Second, the separation between a board chair and a CEO in SOEs introduced by Korean Act on Management of Public Institutions made a significantly positive impact on customer satisfaction rate. However, the positive impact of the board chair separation was removed in a political independence impaired CEO's SOE. Third, outside director's industry expertise made a significantly positive impact on return on asset. However, the positive impact of the outside director's industry expertise was removed in a political independence impaired CEO's SOE. Fourth, the comparison between Lee Myung-bak Administration and Roh Moo-hyun Administration on the corporate governance and performance of SOEs shows that the ratio of political independence impaired CEO was significantly higher in Lee Administration and the ratio of outside director's industry expertise and finance expertise were respectively significantly higher in Roh Administration. Based on these results, I suggested a few policy alternatives for CEO's improved political independence and requirements for executive's expertise in SOEs.