• 한국지반공학회논문집
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• 제38권9호
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• pp.53-67
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• 2022

마이크로파일은 소구경 현장타설말뚝으로, 시공방법이 간단하고 공사비용이 상대적으로 저렴하여 건축물을 비롯한 각종 구조물의 보수보강 및 증축 시 기초보강 등에 활용되고 있다. 시공이 용이하고 간단한 메커니즘의 구조체를 선단에 장착하여 지지력을 증대시키는 선단 확장형 마이크로파일이 개발되었으며, 이에 대한 수치해석, 내구성시험, 원심모형시험 등의 연구가 수행되어 왔다. 본 연구에서는, 기존에 수행된 수치모델링을 고도화하여 연직하중 재하에 의해 연결강봉 근입 시 고정 지압구가 활착되는 거동 메커니즘을 확인하고, 원심모형실험과 동일한 조건에서의 수치해석을 수행하여 그 결과를 비교하였다. 또한, Lab-scale 수치해석 결과를 바탕으로 고정 지압구의 형상 개선안을 도출하고, Field-scale 수치해석을 통해 일반 마이크로파일 대비 지지력 증대효과를 비교·검증하였다.

• 한국간호교육학회지
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• 제29권3호
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• pp.225-233
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• 2023

Purpose: The aim of this study was to identify factors related to the vaccination intentions of nursing students before clinical practice. Methods: A descriptive correlational study design was used. The participants were 129 nursing students who were enrolled in one college of nursing in Seoul and were scheduled for clinical training. Data collection was conducted from February 28 to March 7, 2022. The data were analyzed using descriptive statistics, a t-test, ANOVA, Pearson's correlation coefficient, and a latitudinal regression analysis using the IBM SPSS statistics version 26.0 program. Results: The intention to vaccinate showed a significant correlation with vaccination attitude (r=.72, p<.001), subjective norms (r=.68, p<.001), and perceived behavioral control (r=.63, p<.001). The influencing factors on three intent to vaccinate were vaccination attitude (β=.36 p<.001), subjective norms (β=.31, p<.001), and perceived behavioral control (β=.36, p<.001). The explanatory power of these variables was 69.6%. Conclusion: The vaccination rate before the clinical training of nursing students was related to economic burden, a lack of time, and transportation problems that nursing college students experienced during the vaccination process. Therefore, administrative and financial support is needed for improving the vaccination rates of nursing students.

• Fisheries and Aquatic Sciences
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• 제26권5호
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• pp.355-365
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• 2023

The Pacific abalone, Haliotis discus hannai, is a highly valued and industrially important aquaculture species with growing demands of the expanding abalone aquaculture industry. To explore the feasibility of using the brown alga, Sargassum horneri, as a potential substitute for abalone feed, it is important to identify the feed preference and attractant effect of S. horneri on Pacific abalone. Our experiments indicated that the feeding-associated movement of abalone could be detected using a video tracking system under indirect illumination with dim red light. To further analyze the attraction potentials of various test materials, preference analysis was performed using Avicel-coated glass plates with ground powders of various seaweeds (e.g., S. horneri, Saccharina japonica, and Undaria pinnatifida) and commercial abalone feed, together with coffee waste. Heat map analysis indicated greater attraction by the kelp S. japonica than by S. horneri and commercial feed, which showed similar preference levels. Feeding preference based on the area of Avicel eaten by abalone showed a significant preference for U. pinnatifida over S. horneri (feeding area: 68.6 ± 20.1% vs. 37.5 ± 22.4%, p < 0.05). Additionally, the feeding area was significantly greater for plates with S. japonica than for plates with S. horneri (44.0 ± 16.6% vs. 22.6 ± 15.4%, p < 0.05). There was no significant difference in feeding area between commercial feed and S. horneri (31.7 ± 11.6% vs. 31.6 ± 20.2%, p > 0.05). The methanol extracts attracted abalone in the following order: U. pinnatifida > S. horneri > S. japonica > commercial feed > coffee waste. To determine the attractive effects of the components of methanol extracts, mixtures of methanol extracts of commercial feed with increasing amounts of S. horneri were examined. The results showed a significant increase in feeding preference upon addition of S. horneri up to 50% and 75%, suggesting its potential for use as an appetite-enhancing feed additive. This study identified conditions that can be successfully used to monitor the movement of Pacific abalone; the results of preference analysis confirmed that abalone exhibited similar attraction and feeding preference for S. horneri, compared with commercial feed.

• Journal of Ginseng Research
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• 제47권4호
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• pp.552-560
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• 2023

Background: Ginseng Radix (Panax ginseng Meyer, Araliaceae) has been used medicinally to treat the brain and nervous system problems worldwide. Recent studies have revealed physiological effects that could potentially benefit cognitive performance or mood. The present study aimed to investigate the antidepressant effects of Korean red ginseng water extract (KGE) and its active component in an unpredictable chronic mild stress (UCMS)-induced animal model and elucidate the underlying mechanisms. Methods: The antidepressant potential of the UCMS model was evaluated using the sucrose preference test and open field tests. The behavioral findings were further corroborated by the assessment of neurotransmitters and their metabolites from the prefrontal cortex and hippocampus of rats. Three doses of KGE (50, 100, and 200 mg/kg) were orally administered during the experiment. Furthermore, the mechanism underlying the antidepressant-like action of KGE was examined by measuring the levels of brain-derived neurotrophic factor (BDNF)/CREB, nuclear factor erythroid 2-related factor 2 (Nrf2), and Kelch-like ECH-associated protein 1 (Keap1) proteins in the prefrontal cortex of UCMS-exposed rats. Results: KGE treatment normalized UCMS-induced depression-related behaviors. Neurotransmitter studies conducted after completing behavioral experiments demonstrated that KGE caused a reduction in the ratio of serotonin and dopamine, indicating a decrease in serotonin and dopamine turnover. Moreover, the expression of BDNF, Nrf2, Keap1 and AKT were markedly increased by KGE in the prefrontal cortex of depressed rats. Conclusion: Our results provide evidence that KGE and its constituents exert antidepressant effects that mediate the dopaminergic and serotonergic systems and expression of BDNF protein in an animal model.

• 한국식생활문화학회지
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• 제21권1호
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• pp.57-64
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• 2006

The purpose of this study was to measure the pizza purchasing behavioral characteristics of respondents and importances of factors affecting pizza purchase, to estimate the effects of attributes on pizza restaurant choice, and to predict probability of selecting a particular pizza restaurant. The questionnaire consisted of two parts: The paired experimental profiles, purchasing behavior and importances of factors affecting pizza purchase. This study generated profiles of 16 hypothetical pizza restaurant based on the seven attributes. The profiles comprised 16 discrete sets of variables, each of which had two levels. For this study, researcher randomly selected 150 students of university as respondents. Twenty students did not complete the survey instrument, resulting in a final sample size of 129. All estimations were carried out using frequencies, $X^2$, independent samples t-test, phreg procedure of SAS package. The results are as follows. Some purchasing behavioral characteristics and importances of factors affecting pizza purchase were significantly different by gender. Based on the estimated models developed for male student group and female student group, the Chi-square statistics were significant at p<0.001. The parameter estimate for late delivery time with male student group was highest, and the parameter estimate for price with female student group was highest. The pizza restaurant that charged \20,000, offered 100% discount on eleventh pizza, promised to deliver pizza in 40 mins, usually delivered the pizza as promised time, offered only 1 type of pizza crust, delivered warm pizza, offered the money-back guarantee was favored by each of male student group and female student group. The results from this study suggested that there was an opportunity to increase market share and profit by improving operations so that customers receive discount and money-back guarantee simultaneously, and by reducing price, delivery time.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.1094-1104
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• 2023

Aggression in horses may cause serious accidents during riding and non-riding activities. Hence, predicting the temperament of horses is essential for selecting suitable horses and ensuring safety during the activity. In certain animals, such as hamsters, plasma melatonin concentrations have been correlated with aggressive behavior. However, whether this relationship applies to horses remains unclear. To address this research gap, this study aimed to evaluate differences in the plasma melatonin concentrations among horses of different breeds, ages, and sexes and examine the correlation between plasma melatonin concentrations and the temperament of the horses, including docility, affinity, dominance, and trainability. Blood samples from 32 horses were collected from the Horse Industry Complex Center of Jeonju Kijeon College. The docility, affinity, dominance, and trainability of the horses were assessed by three professional trainers who were well-acquainted with the horses. Plasma melatonin concentrations were measured using an enzyme-linked immunosorbent assay. The consequent values were compared between the horses of different breeds, ages, and sexes using a three-way analysis of variance and least significant difference post hoc test. Linear regression analysis was employed to identify the relationship between plasma melatonin concentrations and docility, affinity, dominance, and trainability. The results showed that the plasma melatonin concentrations significantly differed with breeds in Thoroughbred and cold-blooded horses. However, there were no differences in the plasma melatonin concentrations between the horse ages and sexes. Furthermore, plasma melatonin concentrations did not exhibit a significant correlation with the ranking of docility, affinity, dominance, and trainability.

• Nutrition Research and Practice
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• 제17권5호
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• pp.1019-1027
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• 2023

BACKGROUND/OBJECTIVES: Sustainability has become one of the top priorities in the foodservice industry. With an increase in consumer interest in sustainability and educational opportunities in higher education, it is important to know what sustainable practices are implemented in campus dining and how sustainable practices affect consumers' responses. This study aims to identify the key sustainable practices in the campus dining context, and investigate the relationship by applying the stimulus-organism-response framework to determine whether the key sustainable practices influence consumers' perception and behavioral intentions. SUBJECTS/METHODS: The self-administered online survey was distributed to college students in 8 dining halls at a large southeastern university in the United States from September 20-October 10, 2019. A total of 382 valid questionnaires were collected, and factor analysis and multiple regressions were utilized to test the research model. RESULTS: This study identified 4 dimensions of campus sustainability with a total of sustainable practices: sustainable food, waste management, energy/water conservation, and recycling/reuse. Three dimensions of sustainable campus practices (i.e., sustainable food, waste management, recycling/reuse) played a significant role in consumers forming a perceived value while energy/water conservation did not significantly influence the consumers' perceived value toward the campus dining. Waste management was identified as the most important practice to enhance consumers' perceived value (β = 0.330). Using sustainable food and recycling/reuse were ranked second and third, respectively (β = 0.262, β = 0.154). The findings confirmed the significant positive relationship between perceived value and revisit intentions. CONCLUSIONS: The findings support the inclusion of dining sustainability as a critical component in explaining college students' perceived value and revisit intention toward campus dining. Furthermore, this study provides practical implications for university administrators and foodservice operators to consider the key sustainable practices to meet the consumers' value and revisit intentions.

• 대한약침학회지
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• 제27권2호
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• pp.70-81
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• 2024

Objectives: Cognitive impairments, ranging from mild to severe, adversely affect daily functioning, quality of life, and work capacity. Despite significant efforts in the past decade, more than 200 promising drug candidates have failed in clinical trials. Herbal remedies are gaining interest as potential treatments for dementia due to their long history and safety, making them valuable for drug development. This review aimed to examine the mechanisms behind the effect of Polygonum multiflorum on cognitive function. Methods: This study focused primarily on the effects of Polygonum multiflorum and its chemical constituents on cognitive behavioral outcomes including the Morris water maze, the passive avoidance test, and the Y maze, as well as pathogenic targets of cognitive impairment and Alzheimer's disease (AD) like amyloid deposition, amyloid precursor protein, tau hyperphosphorylation, and cognitive decline. Additionally, a thorough evaluation of the mechanisms behind Polygonum multiflorum's impact on cognitive function was conducted. We reviewed the most recent data from preclinical research done on experimental models, particularly looking at Polygonum multiflorum's effects on cognitive decline and AD. Results: According to recent research, Poligonum multiflorum and its bioactive components, stilbene, and emodin, influence cognitive behavioral results and regulate the pathological target of cognitive impairment and AD. Their mechanisms of action include reducing oxidative and mitochondrial damage, regulating neuroinflammation, halting apoptosis, and promoting increased neurogenesis and synaptogenesis. Conclusion: This review serves as a comprehensive compilation of current experiments on AD and other cognitive impairment models related to the therapeutic effects of Polygonum multiflorum. We believe that these findings can serve as a basis for future clinical trials and have potential applications in the treatment of human neurological disorders.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제35권3호
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• pp.210-217
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• 2024

Objectives: South Korea has the highest suicide rate among Organisation for Economic Co-operation and Development countries; there is an increasing trend in suicide attempts among middle and high school students. Various factors contribute to the risk of suicide among adolescents, and the perception of suicide prevention has emerged as a significant factor. This study aimed to investigate the association between emotional and behavioral difficulties among middle and high school students and their perceptions of suicide prevention and to explore differences in suicide perception according to age. Methods: A survey was conducted among community middle and high school students, including 530 participants, between 2020 and 2021. Emotional and behavioral difficulties were assessed using the Strengths and Difficulties Questionnaire-Korean version, and participants were asked to complete a questionnaire on the importance and possibility of suicide prevention. A correlation test and analysis of variance were used to examine the relationships between the variables, and suicide awareness was compared according to age. Results: The participants who displayed higher strength or lower difficulty were more likely to respond positively to suicide prevention measures. They also exhibited high strength and low difficulty levels, thus agreeing with the importance of suicide prevention. Regarding age-related perceptions of suicide, adults aged 20-29 years reported the lowest probability of suicide prevention. Conclusion: Suicide perceptions influence the incidence of suicide. Therefore, active societal engagement through suicide prevention campaigns and related education is essential to improve such perceptions. Continuous attention and support are required to address this issue.

• Animal cells and systems
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• 제7권4호
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• pp.303-307
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• 2003

The aim of this study is to investigate whether alcohol alters learning and memory processes pertaining to emotional and spatial factors using the active avoidance and T-maze task in zebrafish. In the active avoidance task, zebrafish were trained to escape from one compartment to another to avoid electric shocks (unconditioned stimulus) following a conditioned light signal. Acquisition of active avoidance task appeared to be normal in zebrafish that were treated with 1% alcohol for 30 min for 17 days until the end of the behavioral test, and retention ability of learned behavior, tested 2 days later, was the same as control group. In the T-maze task, the time to find a reservoir was compared. While the latency was similar during the 1 st training session between control and alcohol-treated zebrafish, it was significantly longer in alcohol-treated zebrafish during retention test 24 h later. Furthermore, when alcohol was treated 30 min after 2nd session without prior treatment, zebrafish demonstrated similar retention ability compared to control. These results suggest that chronic alcohol treatment alters spatial learning of zebrafish, but not emotional learning.