• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.4
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• pp.247-257
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• 2018

Background/Aims: The aim of this study was to analyze the trend of the prevalences of atrophic gastritis (AG) and intestinal metaplasia (IM) from 2011 to 2016~2017 in Korea. And, the risk factors of AG and IM were compared between 2011 and 2016~2017. Materials and Methods: A total of 4,023 subjects in 2011 and 2,506 subjects in 2016~2017 were enrolled. AG and IM were diagnosed on the basis of endoscopic findings. Multivariate analysis was performed for risk factors of AG and IM. Seventeen factors were analyzed. Results: The seroprevalence of Helicobacter pylori decreased from 2011 (59.8%; 2,407/4,023) to 2016~2017 (51.6%; 1,293/2,506; P<0.001). The prevalence of AG decreased from 2011 to 2016~2017 (P=0.018), but that of IM increased (P<0.001). The risk factors of AG in 2011 were male sex, old age, H. pylori immuoglobulin G (IgG) positivity, family history of gastric cancer (GC), and high-salt diet. For IM in 2011, the risk factors were male sex, old age, H. pylori IgG positivity, and family history of GC. Risk factors of AG in 2016~2017 were old age, H. pylori IgG positivity, and country of residence. For IM in 2016~2017, the risk factors were male sex, old age, family history of GC, high fasting glucose level (${\geq}126mg/dL$), H. pylori IgG positivity, and low income level. Conclusions: The difference in prevalence trends of AG and IM between 2016~2017 and 2011 could be the result of the different risk factors of AG and IM, such as decreased prevalence of H. pylori infection.

• The Korean Journal of Archival Studies
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• no.54
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• pp.179-210
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• 2017

By redefining the concept of history, my colleagues and I have reformed our department in terms of curriculum and faculty members. This paper is a report of some of the conclusions that we have obtained from this procedure. Despite a long relationship, two disciplines do not seem to match or complement each other in the Korean education system. We believe that this is due to the fact that the Department of Korean History has focused on "national history (NH)." By conferring a privilege on NH, persons, families, societies, regions, and others were removed from NH. To make matters worse, a biased view that history is just an interpretation has prevailed, and the empiricism of history was weakened, which brought about an indifference in keeping records and archives. In East Asia, "history" means both modern history and archives. The concern about the authenticity of records did not come from H. Jenkinson or L. Duranti, and not even from the electronic environment or the Public Records Act of 1998. Key concepts such as records, documents-archives, manuscripts, authenticity, compilation-appraisal, arrangement, and description are different from their signifiant but are same or similar to their $signifi{\acute{e}}$. In case of "provenance" and "original order," they are used in education and practice in the traditional archives. History includes the recording, archiving, and the story or historiography of an event. In this context, the Department of Korean History should contain a more archives-oriented curriculum and select an archival-trained faculty. On the other hand, the department has accumulated long-term experience with appraisal and description of records; thus, archival science should absorb the criticism of the material. History will be shaken without the help of archives, while archives will lose their root without history. We are at the point in which we need to be reminded why we want to be a historian or an archivist, and for this, the more colleagues, the better.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.146-154
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• 2021

This study was conducted to determine the degree of reduction in the yield of sweetpotato subjected to different shading treatments according to the growing season of the typical viscous sweetpotato 'Hogammi' and the powdery sweetpotato 'Jinyulmi'. Shading was provided using commercially available shading nets (55% and 75% shading level), and the treatments were applied at the following stages of storage root growth: SFS: the storage root formation stage (planting-50^th day), SSS: the storage root swelling stage (50-90^th day), and SAS: the storage root actively swelling Stage (90-120^th day). The growth characteristics according to shading treatments during each growth period, the number of tubers obtained at harvest, and sugar contents were investigated. For both assessed cultivars, there was no significant difference between the control group and the 55% shading treated group with respect to the maximum quantum yield (Fv/Fm) of photosystem II under different shading treatments, whereas the 75% shading group showed slightly higher values than the control group. In both cultivars, the contents of chlorophyll a and b tended to increase in plants subjected to shading treatments compared with the control plants, particularly that of chlorophyll b. Compared with the control group, the chlorophyll b content of 'Hogammi' subjected to 55% and 75% shading increased by 47% and 41%, respectively, whereas that of 'Jinyulmi' increased by 39% and 34%, respectively. We also detected reductions in the dry weights of the above- and belowground parts of the two varieties in response to shading compared with the control, with the reduction in the dry weight of belowground parts being significant. Furthermore, in both varieties, the T/R rate tended to increase in response to shading treatment. Owing to the lack of sunlight, both cultivars tended to suppress the formation and enlargement of tuber roots. Consequently, post-harvest yield analysis revealed that under shading treatments, both cultivars were characterized by poor tuber root growth according to growing season, with the yield of 'Hogammi' showing a greater reduction compared with that of 'Jinyulmi'. In addition, we found that the higher shading level also significantly reduced yields. Compared with the storage root formation and storage root actively swelling stages, shading treatments during the storage root swelling stage significantly affected yield reduction in both varieties.

• Journal of Nutrition and Health
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• v.54 no.3
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• pp.277-291
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• 2021

Purpose: This study was undertaken to identify the alcohol drinking status of industrial workers, their health care practice, and dietary behavior, as well as their nutrient intake. Methods: In July 2019, 220 male subjects working in the Chungnam area were enrolled in the study. Their alcohol drinking status was evaluated by applying the Alcohol Use Disorder Identification-K (AUDIT-K) system. Demographic characteristics, status of health care practice, and dietary behaviors were assessed using a self-administered questionnaire; nutrient intakes were analyzed using 24-hour recalls. Data were analyzed by applying χ²-test, ANOVA, Duncan test, and Pearson's correlation analysis with SPSS v. 25.0. Results: Workers were classified by their alcohol drinking status as 'normal' (84, 38.2%), 'problem drinker' (45, 20.5%), 'alcohol dependence I' (60, 27.3%), and 'alcohol dependence II' (31, 16.0%). The alcohol drinking status showed significant differences with age (p < 0.05), monthly income (p < 0.05), smoking status (p < 0.05), and need for weight control (p < 0.05). Moreover, increased alcohol intake resulted in significantly decreased levels of health care practice and dietary behaviors (p < 0.05, p < 0.01, respectively). The energy intake was highest in the 'alcohol dependence I' group, followed by 'alcohol dependence II', 'problem drinker', and 'normal drinker' (p < 0.05). Intakes of vitamin E, vitamin C, and niacin in the 'alcohol dependence I' group were found to be higher than the other groups (p < 0.05). A negative correlation was obtained between alcohol drinking status, health care practice, and dietary behaviors, whereas a positive correlation was determined between alcohol drinking status, energy and water intakes. Conclusion: Considering these results, we conclude the necessity to consider nutritional and alcoholic education programs for improving the quality of work life of industrial workers, based on their alcohol drinking status.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.10-24
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• 2021

Purpose: The purpose of this study is to determine the dangers of biodiesel and general diesel mixtures currently used as alternative fuels by equipment (tag method and penski Marten method) and to determine the difference between flash point and combustion point (closed, open) according to test methods. It is intended to be used as a reference material for identification and evaluation of firecausing substances by confirming the risk of mixtures by comparative analysis and measurement, and establishing a risk assessment method for chemical substances. Method: Flash point test method and result treatment were tested based on ASTM and KS M mode, which are tag sealing and pen schematense test methods used as flash point and combustion point test methods for crude oil and petroleum products. The manufacturer of the equipment used in this experiment was a test equipment that satisfies the test standards of KS M 2010 with equipment produced by TANAKA of Japan. The flash point and combustion point were measured, and the flash point according to the test method of biodiesel and general diesel mixture ( Closed, open), and the ignition point of a mixture of biodiesel and general diesel was compared and analyzed for ignition risk compared with conventional diesel. Results: Looking at the experimental results, first, as an analysis of the risk of flammability of the mixture, the flash point of a substance containing 70% biodiesel was found to be about 92℃ based on general diesel with a flash point of 64.5℃, and gasoline and biodiesel or When the biodiesel mixture was synthesized, it was confirmed that the flash point tends to decrease. In addition, the difference between the flash point and the combustion point was analyzed as about 20 ~ 30℃, and when a small amount of gasoline or methanol was mixed, the flash point was lowered, but it was confirmed that the combustion point was similar to that of the existing mixture. Conclusion: In this study, in order to secure the effectiveness of the details of the criteria for judging dangerous materials in the existing Dangerous Materials Safety Management Act, and to secure the reliability and reproducibility of the judgment of dangerous materials, we confirm the criteria for judging the risk of the mixture through an experimental study on flammable mixtures. It will be able to provide reference data for experimental criteria for flammable liquids that are regulated in the field. In addition, if this study accumulates know-how on experiment by test method, it is expected that it can be used as a basis for research on risk assessment and research on dangerous goods.

• Phonetics and Speech Sciences
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• v.12 no.4
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• pp.27-36
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• 2020

The aim of this study is to investigate the perceptive aspects of the polysemic sentence final ending "-(eu)lgeol" produced by Chinese Korean learners. "-(Eu)lgeol" has two different meanings, that is, a guess and a regret, and these different meanings are expressed by the different prosodic features of the last syllable of "-(eu)lgeol". To examine how Korean native speakers perceive "-(eu)lgeol" sentences produced by Chinese Korean learners and the most saliant prosodic variable for the semantic discrimination of "-(eu)lgeol" at the perceptive level, we performed a perceptual experiment. The analysed material constituted four Korean sentences containing "-(eu)lgeol" in which two sentences expressed guesses and the other two expressed regret. Twenty-five Korean native speakers participated in the perceptual experiment. Participants were asked to mark whether "-(eu)lgeol" sentences they listened to were (1) definitely regrets, (2) probably regrets, (3) ambiguous, (4) probably guesses, or (5) definitely guesses based on the prosodic features of the last syllable of "-(eu)lgeol". The analysed prosodic variables were sentence boundary tones, slopes of boundary tones, pitch difference between sentence-final and penultimate syllables, and pitch levels of boundary tones. The results show that all the analysed prosodic variables are significantly correlated with the semantic discrimination of "-(eu)lgeol" and among these prosodic variables, the most salient role in the semantic discrimination of "-(eu)lgeol" is pitch difference between sentence-final syllable and penultimate syllable.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.383-391
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• 2021

To develop a cultivation method for the mass production of sweetpotato cultivars, 'Juhwangmi' (orange tuber) and 'Sinjami' (puple tuber), the yield of tuber roots and content of various functional substances were analyzed according to planting intervals and growing periods. For 'Juhwangmi, the total yield of tubers was increased by respectively 36% and 54% and the yield of tubers over 300 g was increased by respectively 170% and 221% in the 140-day and 160-day cultivation plots compared with that in the 120-day cultivation plot at the 70×20 cm planting interval. Similarly, the total content of beta-carotene in the tubers increased as the cultivation period was extended. In particular, beta-carotene content at the 70×20 cm planting interval was the highest. For 'Sinjami', at the same planting interval, the total yield of tubers and yield of tubers over 300 g significantly increased as the growing period was extended. Within the same cultivation period, the yield of tubers over 300 g and the total anthocyanin content of 'Sinjami' were higher at the 70×30 and 70×35 cm planting intervals than at the 70×20 and 70×25 cm planting intervals in the 140-day and 160-day cultivation plots. Moreover, the total polyphenol and flavonoid content was significantly higher in 'Sinjami' than in 'Juhwangmi', and the values were the highest in the 160-day cultivation plots. In particular, the content of these two functional substances in tubers over 300 g was the highest at the 70×30 and 70×35 cm planting intervals.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.61-72
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• 2022

The present study was conducted to examine the effect of soybean silage as a crude protein supplement for corn silage in the diet of Hanwoo steers. The first experiment was conducted to evaluate the effect of replacing corn silage with soybean silage at different levels on rumen fermentation characteristics in vitro. Commercially-purchased corn silage was replaced with 0, 4, 8, or 12% of soybean silage. Half gram of the substrate was added to 50 mL of buffer and rumen fluid from Hanwoo cows, and then incubated at 39℃ for 0, 3, 6, 12, 24, and 48 h. At 24 h, the pH of the control (corn silage only) was lower (p<0.05) than that of soybean-supplemented silages, and the pH numerically increased along with increasing proportions of soybean silage. Other rumen parameters, including gas production, ammonia nitrogen, and total volatile fatty acids, were variable. However, they tended to increase with increasing proportions of soybean silage. In the second experiment, 60 Hanwoo steers were allocated to one of three dietary treatments, namely, CON (concentrate with Italian ryegrass), CS (concentrate with corn silage), CS4% (concentrate with corn silage and 4% of soybean silage). Animals were offered experimental diets for 110 days during the growing period and then finished with typified beef diets that were commercially available to evaluate the effect of soybean silage on animal performance and meat quality. With the soybean silage, the weight gain and feed efficiency of the animal were more significant than those of the other treatments during the growing period (p<0.05). However, the dietary treatments had little effect on meat quality except for meat color. In conclusion, corn silage mixed with soybean silage even at a lower level provided a greater ruminal environment and animal performances, particularly with increased carcass weight and feed efficiency during growing period.

• Journal of Life Science
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• v.32 no.4
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• pp.310-317
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• 2022

Recently, interest in the harmful factors of particulate matter (PM), a major component of air pollution, has been increasing. In particular, PM_2.5 with a diameter of less than 2.5 ㎛ is well known to induce oxidative stress accompanied by autophagy in human lung epithelial cells. However, studies on whether PM_2.5 increases autophagy under oxidative stress and whether this process is reactive oxygen species (ROS)-dependent are insufficient. Therefore, in this study, we investigated whether PM_2.5 promotes autophagy through the generation of ROS in human alveolar epithelial A594 cells. According to our results, cells co-treated with PM_2.5 and hydrogen peroxide (H₂O₂) showed a lower cell viability than cells treated with each alone, which was associated with increased total and mitochondrial ROS production. The co-treatment of PM_2.5 and H₂O₂ also increased autophagy induction, which was confirmed through Cyto-ID staining, and the expression of autophagy biomarker proteins increased. However, when ROS generation was artificially blocked by N-acetyl-L-cysteine pretreatment, the reduction in cell viability and induction of autophagy by PM_2.5 and H₂O₂ co-treatment were markedly attenuated. Therefore, the present results suggest that PM_2.5-induced ROS generation may play a critical role in autophagy induction in A549 cells.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.342-361
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• 2022

In order to evaluate the effect of nitrogen application levels on yield and quality of rice varieties, a field experiment was conducted at National Institute of Crop Science of Korea from 2018 to 2020. Five levels (0, 3, 5, 7, and 9 kg/10a) of nitrogen fertilizer were treated to 21 Korean rice varieties. Yield, yield component, appearance quality, and protein content in rice were analyzed. The average head rice yield for 3 years decreased by 28%, 22%, 11%, and 8%, respectively, when cultivated with 0, 3, 5, and 7 kg/10a nitrogen application compared to cultivation with a standard nitrogen application amount, 9 kg/10a. The number of panicles per hill increased as the amount of nitrogen application increased, but there was no significant change in the number of grains per panicle and 1000-grains weight, and the number of panicles per hill showed relatively small annual variation compared to other yield components. There was no significant difference in the head rice ratio according to the nitrogen application amount, the broken rice ratio slightly decreased, and the floury rice ratio increased. The protein content of rice decreased with increasing nitrogen application in 2018 and 2019, and was the lowest at 7 kg/10a of nitrogen application, and showed a tendency to increase again at 9 kg/10a. In the case of 2020, as the amount of nitrogen application increased, the protein content showed a tendency to continuously increase. In terms of varieties, 13 varieties, including Chilbo, seemed to be capable of low-nitrogen cultivation because loss of the head rice yield was less and the protein content could be lowered to 6% or less according to 7 kg/10a nitrogen application.