• Molecules and Cells
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• 제45권12호
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• pp.896-910
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• 2022

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and potentially fatal virus. So far, most comprehensive analyses encompassing clinical and transcriptional manifestation have concentrated on the lungs. Here, we confirmed evident signs of viral infection in the lungs and spleen of SARS-CoV-2-infected K18-hACE2 mice, which replicate the phenotype and infection symptoms in hospitalized humans. Seven days post viral detection in organs, infected mice showed decreased vital signs, leading to death. Bronchopneumonia due to infiltration of leukocytes in the lungs and reduction in the spleen lymphocyte region were observed. Transcriptome profiling implicated the meticulous regulation of distress and recovery from cytokine-mediated immunity by distinct immune cell types in a time-dependent manner. In lungs, the chemokine-driven response to viral invasion was highly elevated at 2 days post infection (dpi). In late infection, diseased lungs, post the innate immune process, showed recovery signs. The spleen established an even more immediate line of defense than the lungs, and the cytokine expression profile dropped at 7 dpi. At 5 dpi, spleen samples diverged into two distinct groups with different transcriptome profile and pathophysiology. Inhibition of consecutive host cell viral entry and massive immunoglobulin production and proteolysis inhibition seemed that one group endeavored to survive, while the other group struggled with developmental regeneration against consistent viral intrusion through the replication cycle. Our results may contribute to improved understanding of the longitudinal response to viral infection and development of potential therapeutics for hospitalized patients affected by SARS-CoV-2.

• Journal of Food Hygiene and Safety
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• 제38권4호
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• pp.211-216
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• 2023

A total of 100 commercially available olive oil products were analyzed for 179 pesticide residues using gas chromatography-tandem mass spectrometry (GC/MS/MS). The olive oil samples were mixed with organic solvents, centrifuged and frozen to remove fat, and pesticide residues were analyzed using the "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) method. The determination coefficient (R²) of the analysis method used in this study was ≥0.998. The detection limit of the method ranged 0.004-0.006 mg/kg and its quantitative limit ranged 0.012-0.017 mg/kg. The recovery rate (n=5) measured at the level ranging 0.01-0.02, 0.1, and 0.5 mg/kg ranged 66.8-119.5%. The relative standard deviation (RSD) was determined to be ≤5.7%, confirming that this method was suitable for the "Guidelines for Standard Procedures for Preparing Food Test Methods". The results showed that a total of 151 pesticides (including difenoconazole, deltamethrin, oxyfluorfen, kresoxim-methyl, phosmet, pyrimethanil, tebuconazole, and trifloxystrobin) were detected in 64 of the 100 olive oil products. The detection range of these pesticide residues was 0.01-0.30 mg/kg. The percentage acceptable daily intake (%ADI) of the pesticides calculated using ADI and estimated daily intake (EDI) was 0.0001-0.1346, indicating that the detected pesticides were present at safe levels. This study provides basic data for securing the safety of olive oil products by monitoring pesticide residues in commercially available oilve oil products. Collectively, the analysis method used in this study can be used as a method to analyze residual pesticides in edible oils.

• Journal of the Korea Organic Resources Recycling Association
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• 제31권3호
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• pp.55-64
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• 2023

This batch experiment was conducted to investigate the patterns of major plant nutrients in the leachates from the soil that was incorporated with rice hull biochar adjusted pH with dry fish powder utilizing rice hull biochar for loading the soil microorganisms. The rice hull biochar adjusted pH between 6.0 and 7.0, and the mixture ratio of rice hull biochar and dry fish powder was 4:6. The treatments consisted of three; the soil incorporated with rice hull biochar non-adjusted pH with dry fish powder as control (RB + DF), the soil incorporated with rice hull biochar adjusted pH by pyroligneous acid solution and dry fish powder (RBP+DF), and the soil incorporated with rice hull biochar adjusted pH by citric acid solution and dry fish powder (RBC+DF). NH₄-N, NO₃-N, PO₄-P, and K concentrations in the leachates were analyzed during incubation. The accumulated NH₄-N and PO₄-P concentrations in the leachates from the RBC+DF treatment were the highest during leaching periods. The highest accumulated NO₃-N and K concentrations in the leachates from the RBP+DF treatment were observed. It observed that NH₄-N and PO₄-P were more released in the adjusted citric acid solution, but NO₃-N and K were less released than those in the pyroligneous acid solution due to their low absorption capacity. Furthermore, it is necessary to investigate crop growth responses to the soil incorporated with adjusted pH rice hull biochar and dry fish powder for loading soil microorganisms.

• Journal of the korean academy of Pediatric Dentistry
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• 제50권1호
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• pp.75-88
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• 2023

The aim of this retrospective study was to evaluate the demographic characteristics of pediatric dental patients who underwent dental treatment under general anesthesia (DTGA) at the Seoul National University Dental Hospital from January 2011 through December 2020 and compare the patterns of repeated DTGA between dental patients with severe disabilities (DSD) and non-DSD (healthy or medically compromised patients without DSD). There were 1,857 DTGAs among 1,719 patients (mean age = 5.1 years; males = 59.3%; ASA 2 or above = 52.9%; DSD = 26.8%). Overall, 6.6% of patients underwent repeated DTGA, and the rate of repeated DTGA over a 10-year period was 7.4%. ASA 2 or above (p < 0.0001) and DSD (p < 0.0001) were more likely to undergo repeated DRGA compared to ASA 1 and non-DSD. At both GA1 and GA2, DSD received significantly more restorative treatment on permanent teeth than non-DSD (p = 0.002, p < 0.0001, respectively). There has been an increasing demand for DTGA in pediatric dentistry over the last 10 years. Regular check-ups and preventive oral health care are necessary for pediatric dental patients with severe disabilities to reduce the possibility of repeated DTGA.

• Journal of the Korean Society of Earth Science Education
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• 제16권2호
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• pp.247-260
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• 2023

In this study, when applying the 'geological structure' content element of high school earth science I developed according to the 2015 curriculum to the STEAM program using a web-based expert system using 3D data of Google Earth and drones, the creative problem-solving ability of high school students, attitudes toward STEAM, and the results of this study are as follows. First, after applying the STEAM program, high school students' creative problem-solving ability showed meaningful results at the p<.001 level. Second, STEAM attitudes showed a significant value at the p<.001 level, confirming that they had a positive impact on high school students' attitudes towards STEAM. It was judged that web-based class activities using Google Earth and drones were useful for integrated thinking such as learners' sense of efficacy and value recognition for usefulness of knowledge. High school students' satisfaction with the STEAM program was 3.251, showing a slightly high average. It was confirmed that web-based class activities such as drones and Google Earth had a positive impact on learners' class satisfaction. However, it was interpreted that the lack of time for class activities limited the ability of the learners to increase their interest in class. The proposal of this research is as follows. First of all, in consideration of the production of presentation materials and practical training in the STEAM program, activities such as block time and advance instruction for class understanding before class are necessary. Secondly, in order to revitalize STEAM education in the high school curriculum, we judge that research on the development of various integrated education programs that can be applied to the high school grade system is necessary.

• Journal of the Korean Society of Radiology
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• 제17권4호
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• pp.607-614
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• 2023

Clear overlapping of the bilateral epicondyle and proper separation of the elbow joint are crucial for obtaining accurate lateral general radiographs of the elbow. However, due to the complex anatomical structure of the elbow, achieving optimal positioning is challenging, leading to the need for repeated x-ray examinations. Therefore, the purpose of this study was to investigate the angle of the forearm in patients where accurate lateral images of the elbow joint can't be obtained after vertical incidence using a styrofoam device during elbow joint lateral x-ray imaging. Twenty patients were enrolled in our study following the established protocol. First, a vertical x-ray at an angle of 0° between the forearm and the table was taken (control group). Here, if the lateral image of the elbow joint was deemed inadequate, the forearm angle was adjusted using custom-made styrofoam supports with 5° and 10° inclinations (experimental groups). For the evaluation method, two assessors utilized a 5-point Likert scale to assess the images. The reliability of the assessments was analyzed using Cronbach's alpha coefficient. As a result, patients with inadequate overlap of the bilateral epicondyle and separation of the elbow joint in the initial examination (control group) were able to obtain the best images when setting a 10° angle between the forearm and the table. The subjective evaluation was 1.6 ± 0.8 points at 0°, 2.7 ± 0.8 points at 5°, and 4.4 ± 1.3 points at 10°, respectively. The reliability analysis for the angles of 0°, 5°, and 10° yielded Cronbach's alpha values of 0.867, 0.697, and 0.922, respectively. In conclusion, when it is not possible to obtain accurate images using the conventional position and X-ray beam direction, it is considered that by initially acquiring images with an angle of 10° between the forearm and the table, and gradually decreasing the angle while obtaining images, it would be possible to achieve the optimal image while reducing the number of repeat examinations.

• Journal of the Korean Society of Radiology
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• 제17권4호
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• pp.489-495
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• 2023

Radiation shielding facilities are constructed in locations where diagnostic radiation generators are installed, with the aim of preventing exposure for patients and radiation workers. The purpose of this study is seek to compare and validate the trend of attenuation thickness of lead, the primary material in these radiation shielding facilities, at different maximum tube voltages by Monte Carlo simulations and measurement. We employed the Monte Carlo N-Particle 6 simulation code. Within this simulation, we set a lead shielding arrangement, where the distance between the source and the lead sheet was set at 100 cm and the field of view was set at 10 × 10 cm². Additionally, we varied the tube voltages to encompass 80, 100, 120, and 140 kVp. We calculated energy spectra for each respective tube voltage and applied them in the simulations. Lead thicknesses corresponding to attenuation rates of 50, 70, 90, and 95% were determined for tube voltages of 80, 100, 120, and 140 kVp. For 80 kVp, the calculated thicknesses for these attenuation rates were 0.03, 0.08, 0.21, and 0.33 mm, respectively. For 100 kVp, the values were 0.05, 0.12, 0.30, and 0.50 mm. Similarly, for 120 kVp, they were 0.06, 0.14, 0.38, and 0.56 mm. Lastly, at 140 kVp, the corresponding thicknesses were 0.08, 0.16, 0.42, and 0.61 mm. Measurements were conducted to validate the calculated lead thicknesses. The radiation generator employed was the GE Healthcare Discovery XR 656, and the dosimeter used was the IBA MagicMax. The experimental results showed that at 80 kVp, the attenuation rates for different thicknesses were 43.56, 70.33, 89.85, and 93.05%, respectively. Similarly, at 100 kVp, the rates were 52.49, 72.26, 86.31, and 92.17%. For 120 kVp, the attenuation rates were 48.26, 71.18, 87.30, and 91.56%. Lastly, at 140 kVp, they were measured 50.45, 68.75, 89.95, and 91.65%. Upon comparing the simulation and experimental results, it was confirmed that the differences between the two values were within an average of approximately 3%. These research findings serve to validate the reliability of Monte Carlo simulations and could be employed as fundamental data for future radiation shielding facility construction.

• Korean Journal of Communication Studies
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• 제22권2호
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• pp.89-121
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• 2014

In order to suggest a strategy for continuous growth of webtoon, this article examined webtoon usage motivation and tried to make a prediction about culture content products and services connected with webtoon, including intention for viewing movies, based on webtoon; intention for switching to paid webtoon content, and intention for buying webtoon character products. From the point of view of Uses and Gratification Theory intentions for using webtoon and human sociocultural behavior intention are already predicted but with the usefulness of Theory of Planned Behavior Integrated Model this study extended the explanation power of prediction about webtoon related behavioral intention. Results found 5 motivational factors for webtoon usage i.e. 'seeking information', 'entertainment and access availability', 'webtoon genre characteristics', 'influence from a friend or acquaintance', and 'escapism and tension release'. Among them the ones that influenced the intention for viewing movies, based on webtoon, were found to be 'webtoon genre characteristics', 'escapism and tension release' and the 3 variables from Theory of Planned Behavior. 'Seeking information', 'entertainment and access availability', 'webtoon genre characteristics', and all the 3 variables from Theory of Planned Behavior were found to influence the intention for switching to paid webtoon content. The intention for buying webtoon based character products was affected by the motivational factors 'seeking information', 'escapism and tension release' and the behavior and subjective norms variables from Theory of Planned Behavior. Based on the uncommon results from the research several suggestions were made for the continuous growth of webtoon.

• Journal of International Area Studies (JIAS)
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• 제15권1호
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• pp.61-82
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• 2011

Public resistance is an essential factor of the democratization process. Due to this, public resistance has been recognized as an important element in discussing the democratization of China. Recently in China, and a new era of resistance especially the agrarian resistance has been being expanded. This paper identifies trends and characteristics of that. With searching changes in the relationship between the nation and the societies in China, we will check whether democratization can be built from the whole bottom of the nation's ideology or not. It is a paradox of china's economic growth that the peasant uprising increased is a factor to the growth. The farmers' smoldering discontent exploded with rage because rural communities have been forced to sacrifice during the growth. The authoritarian party-state system in China has been faced with the limits in calming the peasant revolt down with the traditional suppression and restriction. Even though the party-state system in China has accepted farmers' dissatisfaction somewhat, and it has tried to improve its image of a benevolent government and pursued buying stability strategy, the gap between urban and rural areas has been expanded in the sustainable economic development and modernization process, therefore the authorities could not soothe the farmers' sense of alienation. Accordingly, the peasant revolt has not flickered out easily, and has been getting uncontrolled across China. Resistance characteristics of Chinese farmers have also changed. In the past, they had been sporadic and indirect ways, whereas in recent years, they have changed into organized and active ways. Of course, it is generally evaluated that the party-state system has sustained a strong social control so far. Buying stability strategy has prevented farmers' complaints from spreading to a threat to its regime, because civil societies in rural areas have still weak foundations from being formed. The party-state system, because of tensions and conflicts, will control the growing powers of civil societies in rural areas with institutionalization of interaction between the nation and the societies, and they will induce street protests to legalized struggle for a while. However, the relationship between the state and the societies has already started new rearrangement, in terms of that the conflicts between the state and rural communities have continued, and the changes of resistance ways.

• Journal of Practical Agriculture & Fisheries Research
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• 제13권1호
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• pp.103-114
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• 2011

The present survey was conducted to investigate effects of weaning age on market weights of steers and calf mortality in Hanwoo. Eight hundred and sixty-two Hanwoo cow-calf operations from all nine provinces were surveyed via personal interviews. The number of farms categorized by herd (heifer plus cow) size were 188, 364, 227 and 83 for <20 heads, 20~49 heads, 50~99 heads and >100 heads, respectively. Approximate 40% of farms surveyed weaned calves at three months of age. The percentages of farms weaning calves over three months of age were 53.5%, 37.5%, 43.7% and 39.0% for <20 heads, 20~49 heads, 50~99 heads and >100 heads, respectively. The herd size did not affect market weights of Hanwoo steers. However weaning age was negatively correlated to carcass weight of Hanwoo steers, showing that as weaning age decreased, carcass weights of Hanwoo steers increased. The average calf mortality was 5.6% and the herd size did not affect calf mortality. But weaning age was shown to be positively correlated to calf mortality and the rate of diarrhea that caused calf death, suggesting that as weaning age decreased, calf mortality and the rate of diarrhea decreased. Overall, the results of present study suggest that a decrease of calf weaning age in Hanwoo can increase the profit of Hanwoo cow-calf operations by increasing carcass weight of Hanwoo steers and by decreasing calf mortality.