• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.9-15
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• 2021

Sargassum serratifolium is a rich source of antioxidant meroterpenoids. The optimal extraction temperature and time for obtaining maximal antioxidant yield, antioxidant activity, and phenolic content from Sargassum serratifolium were determined using response surface methodology (RSM). The ranges of the independent variables for extraction temperature and time were 30-70℃ and 12-36 h, respectively. With increasing temperature and time, the yield increased significantly, while DPPH (2,2-dipheny-1-picrylhydrazyl) radical-scavenging activity and total phenolic content decreased significantly. The optimal extraction temperature and time obtained by RSM were 54℃ and 7 h, respectively, providing a yield of 8.2%, DPPH radical-scavenging activity of 60%, and total phenolic content of 163 mg GAE/g. The findings of this study provide useful information for the development of Sargassum serratifolium extraction processes for the food and cosmetic industries.

• Korean Journal of Adult Nursing
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• v.23 no.3
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• pp.298-307
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• 2011

Purpose: The purpose of this study was to examine the effects of physical activity on glycemic control among Koreans with type 2 diabetes. Methods: A total of 215 patients with type 2 diabetes (82 male and 133 female) were recruited (mean age = $59.0{\pm}9.7$ years). The amounts of physical activity was assessed using the physical activity scale for elderly (PASE). Fasting blood glucose (FBG), Hemoglobin A1c ($HbA_1c$), and 2 hours post-prandial glucose (2hrPG) were measured. Results: The highest PASE score was housework-related physical activity. However, the amounts of walking was significantly higher in good FBG level (Z = 1.39, p=.041) and the amounts of leisure-time physical activity was higher in good HbA1 and 2hrPG level than in the poor glycemic control group (Z = 2.29, p<.001; Z = 1.99, p=.001). A logistic regression analysis showed that patients with leisure-time physical activity in the top quartile more likely presented with good glycemic control in $HbA_1c$, OR=3.84 (95% Confidence Interval (CI) = 1.65~8.95) and in 2hrPG, OR=4.06 (95%CI = 1.77~9.27), compared to patients in the lowest quartile. Conclusion: Leisure-time physical activity is effective for controlling the glucose levels, especially $HbA_1c$ and 2hrPG among type 2 diabetic patients. It is suggested that health providers need to more focus on providing aggressive recommendations on physical activity considering physical activity patterns by individuals.

• Journal of Preventive Medicine and Public Health
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• v.41 no.6
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• pp.427-433
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• 2008

Objectives: This study was performed to assess the association between physical activity and the clustering of metabolic abnormalities among Korean children. The effect of substituting moderate to vigorous physical activity for the time spent in inactivity was examined as well. Methods: The study subjects were comprised of 692 (354 boys, 338 girls) 4th grade elementary school students. We used a modified form of the physical activity questionnaire that was developed in the Five-City Project. The subjects with clustering of metabolic abnormalities were defined as having two or more of the following five characteristics: waist circumference ${\geq}90\;%$, systolic or diastolic blood pressure ${\geq}90\;%$, fasting glucose ${\geq}110\;mg/dl$, triglycerides ${\geq}110\;mg/dl$ and HDL cholesterol ${\geq}40\;mg/dl$. We calculated the odds ratios to assess the effect of substituting moderate to vigorous physical activity for time spent in inactivity. Results: The risk of clustered metabolic abnormalities was inversely correlated with the increased time spent on moderate to vigorous physical activity, but the correlation was not significant. The odds ratio for clustering of metabolic abnormalities that represented the effect of substituting moderate to vigorous physical activity for 30minutes of sedentary activity was 0.87(95% Cl=0.76-1.01). Conclusions: These findings suggest that substituting moderate to vigorous physical activity for sedentary activity could decrease the risk of clustered metabolic abnormalities.

• Safety and Health at Work
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• v.12 no.3
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• pp.311-316
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• 2021

Background: The present study investigated the association between two domains of physical activity (occupational physical activity [OPA] and leisure-time physical activity [LTPA]) and sleep duration. Methods: We investigated 3,421 paid workers from the Korea National Health and Nutrition Examination Survey, 2014-2015. Sleep duration was categorized into three categories (short for less than 5 h, optimal for 5-9 h, and long for more than 9 h). OPA and LTPA were defined in terms of answers to relevant questions. Odds ratios were calculated for sleep duration according to each physical activity domain using multinomial logistic regression models. Results: There were 464 subjects (13.6%) who showed short sleep duration, and 169 subjects (4.9%) who showed long sleep duration. Prevalence of OPA and LTPA was higher in male workers than in female workers (for OPA: 3.67% and 1.76%, respectively, p = 0.0108; for LTPA: 16.14% and 6.07%, respectively, p < 0.0001). The odds ratio of OPA for long sleep duration in female workers was 3.35 (95% confidence interval, 1.37-8.21). Otherwise, LTPA was not associated with sleep duration in female paid workers, nor both physical activity domains in male paid workers. Conclusion: Female paid workers with work-related physical activity were at risk of oversleeping. These findings also suggested that physical activity has distinct associations with sleep duration according to the physical activity domains and sex.

• Journal of Environmental Health Sciences
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• v.44 no.2
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• pp.143-152
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• 2018

Objectives: The purpose of this study was to provide basic data for air pollutant exposure modelling and understanding the contribution of respective microenvironments by assessing the time-activity patterns of Korean students according to variables such as grade, sex, weekday, and weekend. Methods: In this study, we compared the residential time of 521 (both weekday and weekend) lower elementary students, 1,735 (1,054 on weekdays, 681 on weekends) upper elementary students, 2,210 (1,294 on weekdays, 916 on weekends) middle school students, and 2,366 (1,387 on weekdays, 979 on weekends) high school students in different microenvironments according to grade, sex, weekday, and weekend. We used data from the 2014 Time-Use Survey by the Korean National Statistical Office for upper elementary students through high school students, and surveyed time-activity patterns of 521 lower elementary students aged 7-9 years. Each microenvironment was divided into indoor, outdoor, and transport. Indoor environments were divided into home, school, and other places. In addition, the results of previous studies were compared to this study. Results: Weekday time-activity patterns of Korean students indicated that lower elementary students spent $16.02{\pm}2.53hr$ in the home and $5.37{\pm}2.32hr$ in school. Upper elementary students spent $14.11{\pm}1.79hr$ in the home and $6.27{\pm}1.37hr$ in school. Middle school students spent $12.83{\pm}2.22hr$ in the home and $7.48{\pm}1.88hr$ in school. High school students spent $10.65{\pm}2.86hr$ in the home and $10.23{\pm}2.86hr$ in school on weekdays. High school students spent the least amount of time in the home and the most time in school compared to other grades Conclusions: Students spent most of their time indoors, including in the home, school, and other indoors. On weekdays, as the grade increases, home residential times were decreased and school residential times were increased. Differences in time-activity patterns according to sex were not found for either weekdays or weekends. It is estimated that Korean students could be affected by school indoor air quality. High school students could be most affected by school indoor air quality since they spent the most time at school.

• Journal of Korea Planning Association
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• v.53 no.6
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• pp.19-38
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• 2018

The purpose of this study is to examine the impacts of neighborhood sports activity facilities on the exercise time and subjective health level using the National Sport Participation Survey data(2013-2015) in Seoul, Korea. We conducted path analysis including exercise time, subjective health level and various environmental factors. From the survey data, we extracted individual's characteristics including subjective health and exercise time. In addition, we calculated physical environment variables of neighborhood units. The results of this study are as follow. First, most of moderating variables such as gender, age, income and job showed expected relationships with exercise time or subjective health level. Second, the perceived level regarding neighborhood sports facilities such as public sports facilities had a strong positive association with exercise time and subjective health level. Third, the area of public sports facility, neighborhood park and the number of schools had positive effects on the exercise time and subjective health level. Lastly, land use mix and the number of intersections showed a positive effects on exercise time. To sum up, the results indicated that public sports facility, neighborhood park and perceived environment on neighborhood sports facility are critical factors of residents' exercise time and subjective health level.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.895-899
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• 2002

Lysozyme activity in buffalo milk in relation to the period of lactation, parity of animal, weather conditions and udder infections was studied. Effect of storage and heat processing of milk on lysozyme activity was determined. Lysozyme activity was higher in buffalo milk than in cow milk. Buffalo colostrum showed lysozyme activity 5 times of that in mature milk. Lysozyme activity in buffalo milk was not influenced by the parity of animal and the stage of lactation, however, it increased during extreme whether conditions (winter and summer). Lysozyme in both cow and buffalo milk exhibited maximum activity at pH 7.4. Buffalo milk lysozyme was fully stable while the cow milk lysozyme was partly inactivated by pasteurization (low temperature-long time as well as high temperature-short time treatments). Lysozyme in buffalo milk was more stable than in cow milk during storage and heat treatment. A 10 to 50-fold increase in milk lysozyme activity was observed in mastitic cows. An assay of lysozyme activity in milk can be used to diagnose mastitis in cattle but not in buffaloes. Some buffaloes exhibited 1000 fold greater lysozyme activity and moderately raised somatic cell count in milk, but there was no sign of mastitis in these animals. A possible role of milk lysozyme in prevention of mastitis in buffaloes is discussed.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.14-25
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• 2018

Chemical compositions, trypsin inhibitory activity, and gelling properties of albumen from duck egg during salting of 30 days were studied. As the salting time increased, moisture content decreased, the salt content and surface hydrophobicity increased (p<0.05). Trypsin inhibitory activity and specific activity were continuously decreased throughout the salting time of 30 days (p<0.05). This coincided with the decrease in band intensity of inhibitor with molecular weight of 44 kDa as examined by inhibitory activity staining. Nevertheless, no differences in protein patterns were observed in albumen during the salting of 30 days. Based on texture profile analysis, hardness, springiness, gumminess, chewiness, and resilience of albumen gel decreased with increasing salting time. Conversely, salted albumen gels exhibited higher cohesiveness and adhesiveness, compared to those of fresh albumen. Scanning electron microscopic study revealed that gel of salted albumen showed the larger voids and less compactness. In general, salting lowered trypsin inhibitory activity and gelling property of albumen from duck egg to some extent. Nevertheless, the salted albumen with the remaining inhibitor could be an alternative additive for surimi or other meat products to prevent proteolysis.

• Journal of Astronomy and Space Sciences
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• v.30 no.1
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• pp.43-48
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• 2013

The geomagnetic activity shows the semiannual variation stronger in vernal and autumnal equinoxes than in summer and winter solstices. The semiannual variation has been explained by three main hypotheses such as Axial hypothesis, Equinoctial hypothesis, and Russell-McPherron Effect. Many studies using the various geomagnetic indices have done to support three main hypotheses. In recent, Oh & Yi (2011) examined the solar magnetic polarity dependency of the geomagnetic storm occurrence defined by Dst index. They reported that there is no dependency of the semiannual variation on the sign of the solar polar fields. This study examines the solar magnetic polarity dependency of quiet time geomagnetic activity. Using Dxt index (Karinen & Mursula 2005) and Dcx index (Mursula & Karinen 2005) which are recently suggested, in addition to Dst index, we analyze the data of three-year at each solar minimum for eight solar cycles since 1932. As a result, the geomagnetic activity is stronger in the period that the solar magnetic polarity is anti-parallel with the Earth's magnetic polarity. There exists the difference between vernal and autumnal equinoxes regarding the solar magnetic polarity dependency. However, the difference is not statistically significant. Thus, we conclude that there is no solar magnetic polarity dependency of the semiannual variation for quiet time geomagnetic activity.

• Korean Journal of Pharmacognosy
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• v.51 no.3
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• pp.199-206
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• 2020

The aim of this study was to investigate the potential of Chaenomeles sinensis as a content of protocatechuic acid and physiological activities. The analyzed the content of protocatechuic acid of Chaenomeles sinensis water extract (CSW) according to different extract temperature and time for extraction. It was analyzed as 0.14±0.00 mg/g in the extract at 100℃ for 3 h. Protocatechuic acid content increased as extraction time and temperature increased. The activity of the CSW at 100℃ for 3 h was measured. As a result of measuring DPPH, ABTS radical scavenging activity and SOD activity, antioxidant activity was found and α-glucosidase inhibition activities. Cell viability was shown for RAW 264.7 cells, and NO (nitric oxide) production was also inhibited. Finally, content of protocatechuic acid increased with increasing extraction time and extraction temperature, and exhibited antioxidant activity, inhibition of NO production, and anti-diabetic activity. It is believed that the Chaenomeles sinensis is likely to be developed as a functional material.