• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.6-15
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• 2024

Background: People's activities have been restricted due to the COVID-19 pandemic. These changes in activity patterns may lead to a decrease in fine particulate matter (PM_2.5) concentrations. Additionally, the level of population exposure to PM_2.5 may be changed. Objectives: This study aimed to analyze the impact of population movement and meteorological factors on the distribution of PM_2.5 concentrations before and after the outbreak of COVID-19. Methods: The study area was Guro-gu in Seoul. The research period was selected as January to March 2020, a period of significant population movement changes caused by COVID-19. The evaluation of the dynamic population was conducted by calculating the absolute difference in population numbers between consecutive hours and comparing them to determine the daily average. Ambient PM_2.5 concentrations were estimated for each grid using ordinary kriging in Python. For the population exposure assessment, the population-weighted average concentration was calculated by determining the indoor to outdoor population for each grid and applying the indoor to outdoor ratio to the ambient PM_2.5 concentration. To assess the factors influencing changes in the ambient PM_2.5 concentration, a statistical analysis was conducted, incorporating population mobility and meteorological factors. Results: Through statistical analysis, the correlation between ambient PM_2.5 concentration and population movement was positive on both weekends and weekdays (r=0.71, r=0.266). The results confirmed that most of the relationships were positive, suggesting that a decrease in human activity can lead to a decrease in PM_2.5 concentrations. In addition, when population-weighted concentration averages were calculated and the exposure level of the population group was compared before and after the COVID-19 outbreak, the proportion of people exceeding the air quality standard decreased by approximately 15.5%. Conclusions: Human activities can impact ambient concentrations of PM_2.5, potentially altering the levels of PM_2.5 exposure in the population.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1152-1162
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• 2021

Objective: This study aimed to determine whether there are regional differences in the blood-brain barrier (BBB) permeability of cognitively normal elderly participants and to identify factors influencing BBB permeability with a clinically feasible, 10-minute dynamic contrast-enhanced (DCE) MRI protocol. Materials and Methods: This IRB-approved prospective study recruited 35 cognitively normal adults (26 women; mean age, 64.5 ± 5.6 years) who underwent DCE T1-weighted imaging. Permeability maps (K_trans) were coregistered with masks to calculate the mean regional values. The paired t test and Friedman test were used to compare Ktrans between different regions. The relationships between K_trans and the factors of age, sex, education, cognition score, vascular risk burden, vascular factors on imaging, and medial temporal lobar atrophy were assessed using Pearson correlation and the Spearman rank test. Results: The mean permeability rates of the right and left hippocampi, as assessed with automatic segmentation, were 0.529 ± 0.472 and 0.585 ± 0.515 (K_trans, x 10^-3 min^-1), respectively. Concerning the deep gray matter, the K_trans of the thalamus was significantly greater than those of the putamen and hippocampus (p = 0.007, p = 0.041). Regarding the white matter, the K_trans value of the occipital white matter was significantly greater than those of the frontal, cingulate, and temporal white matter (p < 0.0001, p = 0.0007, p = 0.0002). The variations in K_trans across brain regions were not related to age, cognitive score, vascular risk burden, vascular risk factors on imaging, or medial temporal lobar atrophy in the study group. Conclusion: Our study demonstrated regional differences in BBB permeability (K_trans) in cognitively normal elderly adults using a clinically acceptable 10-minutes DCE imaging protocol. The regional differences suggest that the integrity of the BBB varies across the brains of cognitively normal elderly adults. We recommend considering regional differences in K_trans values when evaluating BBB permeability in patients with neurodegenerative diseases.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.1
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• pp.1-10
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• 2006

Previous studies on zooplankton in Asan Bay were mostly based on samples collected seasonally with three months intervals. Present study was aimed to know the temporal variation of meso-zooplankton distribution using the data collected monthly. Relationships between zooplankton abundances and environmental factors such as seawater temperatures, salinities and chlorophyll-a contents were also studied. Seawater temperature showed typical pattern of seasonal variation found in temperate waters. The fluctuations of environmental factors ranged relatively wider In the inner part of the bay than those in outer part of the bay. Salinity was very low right after the summer rainy period due to the sporadic outflow of freshwater from the adjacent artificial lakes. Sudden changes in salinity seemed to have significant impact on zooplankton assemblages. Chlorophyll-a contents were increased in general when compared with previous reports probably due to the recent human exploitations in the coastal zone, which might enhance the nutrients level . The timing and duration of spring bloom showed geographical differences. In the inner part of the bay it began earlier (February) and last longer (three months) while in the outer part of the bay it began late (April) and last just one month. Zooplankton abundance, especially most abundant taxon Acartia hongi, showed weak but significant positive correlation with chlorophyll-a contents. The difference in temporal variation found with two different sampling intervals indicated the necessity of shorter time interval samplings.

• Journal of Industrial Convergence
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• v.22 no.1
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• pp.21-31
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• 2024

The purpose of this study is to analyze the impact of middle school students' perceived parenting attitudes (positive parenting attitude, negative parenting attitude) on career adaptability and to verify the mediating effect of grit in these influence relationships. For this purpose, 2,235 first-year middle school students from the Korea Children and Youth Panel Survey 2021 were selected as research subjects. Data analysis methods included frequency analysis, descriptive statistical analysis, correlation analysis, and regression analysis using the SPSS 26.0 program. The main research results are as follows: First, in the impact of parenting attitude on career adaptability, positive parenting attitude was significant as positive (+), and negative parenting attitude was negative (-). Second, in the effect of parenting attitude on grit, positive parenting attitude was significant as positive (+), and negative parenting attitude was negative (-). Third, grit was positively (+) significant to career adaptability. Fourth, in the relationship between parenting attitude and career adaptability, the mediating effect of grit was found to be a complete mediating effect with positive parenting attitude and a partial mediating effect with negative parenting attitude. Through this, practical suggestions were provided to improve middle school students' career adaptability.

• Journal of Korean Academy of Rural Health Nursing
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• v.19 no.1
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• pp.25-34
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• 2024

Purpose: This study investigates the relationship between job stress and burnout among primary healthcare practitioners during COVID-19 pandemic through mixed methods study. Methods: Data were collected from October to November 2022 using Qualtrix, a web-based survey platform. 1,082 primary health care practitioners participated in the survey. Quantitative data were analyzed using correlation analysis using IBM SPSS/WIN 27.0. Qualitative data were analyzed using content analysis through open-ended questions. Results: Job stress and burnout among primary healthcare practitioners during COVID-19 were positively correlated. Four categories and seven subcategories were identified. Conclusion: Based on these findings, it is necessary to develop a support system for primary healthcare practitioners according to the type of residential area and the number of peopleto reduce job stress and burnout.

• Industry Promotion Research
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• v.9 no.1
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• pp.179-187
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• 2024

This study aims to develop policies and programs to improve self-differentiation that will have an impact on establishing a positive view of marriage among college students by examining and confirming the impact of college students' self-differentiation on their views on marriage among college students in early adulthood. This is an attempted research study. For this purpose, a self-report online survey was conducted and analyzed among 204 college students attending a university in northern Gyeonggi Province. The analysis method used SPSS 25.0 program to calculate internal consistency, frequency analysis to identify the general characteristics of the research subject, descriptive statistical analysis to determine the level of the research variable, and differences in research variables according to the characteristics of the research subject. To find out, an independent samples t-test, analysis of variance, and post hoc test were conducted, and analysis using SPSS Process Macro was conducted to verify the mediation effect. The results of the analysis showed a positive (+) correlation between self-differentiation and views on marriage, which suggests that self-differentiation has a significant impact on establishing a positive view on marriage, and for this purpose, it is necessary to establish a positive view on marriage among college students. To this end, we aimed to provide basic data to support education for healthy families through national policy.

• Journal of Korean Home Economics Education Association
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• v.36 no.2
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• pp.51-63
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• 2024

The purpose of this study was to examine the relationships among parental perception of home-based fine motor experiences in early childhood, home environment, and frequency of fine motor activities, and to investigate a mediating role of home environment in the process of parental perception influencing early childhood's frequency of fine motor activities. The data from 214 five-year-old children and their parents from six early childhood education centers in Gyeonggi province were collected and analyzed. The data were processed using IBM SPSS Statistics 23 and analyzed with descriptive statistics, independent samples t-tests, correlation analysis, multiple regression analysis, and bootstrapping analysis. The major findings were as follows: First, gender differences in parental perception, home environment, and frequency of fine motor activities existed in that values across all three variables were higher for girls than for boys. Second, parental perception, home environment and frequency of fine motor activities were positively correlated. Third, partial mediating effects of home environment on the relation between parental perception and the frequency of fine motor activities were found. These findings show an existence of gender differences in early childhood's fine motor activities. This research also affirms the significance of increasing the frequency of fine motor activities by enhancing parental perceptions for balanced motor development of boys and girls, and establishing a home environment conducive to fine motor activities at any time and in any location.

• Journal of Industrial Convergence
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• v.22 no.8
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• pp.63-72
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• 2024

This study attempted to explore the impact of sense of humor and stress coping styles among nursing students on adaptation to clinical practice. The study included 180 nursing students as participants, and data collection was conducted using self-administered questionnaires from April 15 to 26, 2024. The collected data underwent t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression analysis. The research findings revealed that the sense of humor scored 3.52, stress coping styles scored 3.40, and adaptation to clinical practice scored 3.46. Adaptation to clinical practice according to general characteristics showed statistically significant differences based on major satisfaction (F=29.80, p<.001), clinical practice satisfaction (F=40.46, p<.001), relationships with peers in clinical practice (F=5.05, p<.001), and personality (t=-3.41, p<.05). Adaptation to clinical practice showed statistically significant positive correlations with sense of humor (r=.31, p<.001) and stress coping styles (r=.43, p<.001). The factors influencing adaptation to clinical practice were clinical practice satisfaction(β=.34, p<.001), stress coping styles (β=.29, p<.001), and major satisfaction (β=.23, p<.05), explaining 42% of the total variance.

• Journal of Mushroom
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• v.9 no.4
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• pp.145-154
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• 2011

Shiitake mushroom (Lentinula edodes) is usually cultivated on the oak log. Log cultivation of this mushroom is getting difficult to get oak logs and has a weak point of its long cultivation period. Recently sawdust cultivation is getting increase. It is important to make mycelia browning on the substrate surface. This browned surface in sawdust cultivation plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. The development of methods for the rapid mycelia browning is quite required. In this article we would like to find cultural characteristics of collected strains and to see the correlation with mycelial browning. Mycelial growth in the media was different according to kinds of media and strains. The optimal temperature on mycelial growth was $20-25^{\circ}C$. Browning patterns of mycelium under 200 Lux seemed to be used for a key to differentiate the strains for sawdust cultivation. Browning period was 30-40 days in the agar media and 70-100 days in the sawdust bag cultivation. When we considered the productivity and the other characteristics, ASI 3046 is the best for the bag cultivation. Significance between mycelial growth and browning was not accepted, but that of mycelial growth between on PDA and sawdust was accepted. Browning period on the PDA and sawdust showed a strong relationships. These results suggested that the browning habits could not be depend on the difference of media, but on their own properties. To select the strain showed fast browning can be done by using agar media for saving time.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.27-33
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• 2012

This study aimed to investigate the responses of plant growth and blossom-end rot (BER) incidence to calcium (Ca) and its three kinds of antagonistic cations (K, Mg, and $NH_4$-N) with various ratios in nutrient solution for sweet paper (Capsicum annuum L. 'RZ208'). Both Ca to each cation and Ca to a series of cation combinations, such as potassium (K), ammonium nitrate ($NH_4$), or magnesium (Mg) were more influential to the fruit growth and quality than plant growth. Especially, the BER incidence was significantly influenced by the ratio treatments. For examples, when Ca:(K + Mg) or Ca:(K + Mg + $NH_4$) ratio was 1:2 the highest incident rate of BER about 70.3 or 86.3% was observed, lowering the marketable yield to 19 or 13.7% of the total yield, respectively. The correlation coefficiencies (= r) to relationships between the BER and K as well as BER and $NH_4$ were 0.82 (P < 0.05) and 0.65 (P < 0.05), respectively. Combination only with the Mg element was not correlated with the BER incidence. However, when both of the K and Mg concentrations were 0.65 (P < 0.05). The highest correlation coefficiency, 0.92 (P < 0.05), was found to a relationship between the BER and the tree elemental combination.