• Journal of Conservation Science
• /
• v.37 no.6
• /
• pp.689-700
• /
• 2021

This study aims to optimize the measurement conditions of handmade Hanji paper to reduce the time required for measurement while meeting folding endurance standards, for various basis weights. Thirteen types were selected, including 12 types of Hanji with grammages of 17 g/m², 30 g/m², and 45 g/m², and one type of 75 g/m² copy paper, and 24 sheets were prepared in the laid and chain directions. Subsequently, folding endurance experiments at different load (14.72 N, 9.81 N, 4.91 N) and specimen width conditions (15 mm, 10 mm, 5 mm) were performed, using a 4-MIT folding endurance tester. The results showed that, for specimen widths of 15 mm and 10 mm under a load of 4.91 N, the folding endurance falls within the reference range (10~10000 times). In particular, reduced folding endurance range and measurement time were observed at a width of 10 mm under a load of 4.91 N. Moreover, the endurance trend lines based on the average values of load and specimen width ranges enabled the prediction of the folding endurance within those ranges, according to the decreasing slope. Furthermore, for a specimen width of 15 mm under a load of 4.91 N, the folding endurance in the comparison group (35 to 17723 times) significantly exceeds the upper limit of the reference range (10~10000 times). Therefore, the measurement conditions of 4.91 N with a specimen width of 10 mm are proposed.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.21 no.1
• /
• pp.15-21
• /
• 2021

Purpose: Urea cycle disorder (UCD) is an inherited inborn error of metabolism, acting on each step of urea cycle that cause various phenotypes. The purpose of the study was to investigate the long-term clinical consequences in different groups of UCD to characterize it. Methods: Twenty-two patients with UCD genetically confirmed were enrolled at Pusan National University Children's hospital and reviewed clinical features, biochemical and genetic features retrospectively. Results: UCD diagnosed in the present study included ornithine transcarbamylase deficiency (OTCD) (n=10, 45.5%), argininosuccinate synthase 1 deficiency (ASSD) (n=6, 27.3%), carbamoyl-phosphate synthetase 1 deficiency (CPS1D) (n=3, 13.6%), hyperornithinemia-hyperammonemia-homocitrullinuria syndrome (HHHS) (n=2, 9.1%), and arginase-1 deficiency (ARG1D) (n=1, 4.5%). The age at the diagnosis was 32.7±66.2 months old (range 0.1 to 228.0 months). Eight (36.4%) patients with UCD displayed short stature. Neurologic sequelae were observed in eleven (50%) patients with UCD. Molecular analysis identified 37 different mutation types (14 missense, 6 nonsense, 6 deletion, 6 splicing, 3 delins, 1 insertion, and 1 duplication) including 14 novel variants. Progressive growth impairment and poor neurological outcomes were associated with plasma isoleucine and leucine concentrations, respectively. Conclusion: Although combinations of treatments such as nutritional restriction of proteins and use of alternative pathways for discarding excessive nitrogen are extensively employed, the prognosis of UCD remains unsatisfactory. Prospective clinical trials are necessary to evaluate whether supplementation with BCAAs might improve growth or neurological outcomes and decrease metabolic crisis episodes in patients with UCD.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.38 no.3
• /
• pp.150-161
• /
• 2022

Purpose: To determine the effects of the microgroove-fibronectin complex surface on the expression of various genes related to cellular activity in human gingival fibroblasts. Materials and Methods: Smooth titanium specimens (NE0), acid-treated titanium specimens (E0), microgroove and acid-treated titanium specimens (E60/10), fibronectin-fixed smooth titanium specimens (NE0FN), acid-treated and fibronectin-immobilized titanium specimens (E0FN), and microgroove and acid-treated titanium specimens immobilized with fibronectin (E60/10FN) were prepared. Real-time polymerase chain reaction experiments were conducted on 44 genes related to cell behavior of human gingival fibroblasts. Results: Adhesion and proliferation of human gingival fibroblast on microgroove-fibronectin complex titanium were activated through four types of signaling pathway. Integrin α5, Integrin β1, Integrin β3, Talin-2, which belong to the focal adhesion pathway, AKT1, AKT2, NF-κB, which belong to the PI3K-AKT signaling pathway, MEK2, ERK1, ERK2, which belong to the MAPK signaling pathway, and Cyclin D1, CDK4, CDK6 genes belonging to the cell cycle signaling pathway were upregulated on the microgroove-fibronectin complex titanium surface (E60/10FN). Conclusion: The microgroove-fibronectin complex titanium surface can up-regulate various genes involved in cell behavior.

• Korean Journal of Ecology and Environment
• /
• v.55 no.2
• /
• pp.120-131
• /
• 2022

Microcystins (MCs) are cyano-toxins mainly produced by cyanobacteria in the genera of Microcystis, Anabaena, and Oscillatoria. The concentrations of MCs in the water bodies and fish tissues taken from the four weirs (Ipo, Gangjeong-goryeong, Baekje, and Juksan) in the four main rivers in Korea, and the health risk of human due to consumption of toxin-detected fish was examined. The maximum values of MCs concentration in the water samples were as follows: Juksan (3.261 ㎍ L^-1), Gangjeong-goryeong (1.014 ㎍ L^-1), Baekje (0.759 ㎍ L^-1), and Ipo (0.266 ㎍ L^-1) weirs. The MC-RR concentration was the highest among the MCs, and MC-YR was not detected. MCs of 0.222~9.808 ㎍ g^-1 dry weight were detected in the liver of 3 out of 215 fishes of 16 species, and below the detection limit in muscle. As a result of comparing the feeding characteristics of the collected fishes and toxin concentrations in water and fish tissue, it was concluded that the biomagnification of MCs through the food chain did not occur. It was judged that there was no health risk due to the consumption of the fish detected the toxin, based on the amount of the fish intake of the Korean people and the allowable daily intake of MCs. However, in order to reduce the health risk due to MCs, further studies should be conducted to analyze the concentration of MCs contained in fish tissues collected at various times in the area dominated by harmful cyanobacteria to obtain data on the exposure of MCs due to fish consumption. In addition, it is necessary to establish the management guidelines for MCs in fish tissues.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.67 no.4
• /
• pp.253-264
• /
• 2022

In this study, we investigated the occurrence of viral diseases in the early growth stage of soybean to establish management practices. We collected 83 soybean samples showing abnormal symptoms, approximately 3-4 weeks after seeding in the breeding field of the National Institute of Crop Science. Viruses were detected in the collected samples using reverse transcription polymerase chain reaction (RT-PCR) and metatranscriptome analysis of all those samples. The incidence of viral diseases in the field was less than 1% overall and up to 50% in certain cultivars and lines. RT-PCR and metatranscriptome analysis detected Soybean yellow mottle mosaic virus (SYMMV), Soybean mosaic virus (SMV), Soybean yellow common mosaic virus, Peanut stunt virus, and soybean geminivirus A (SGVA). Among these detected viruses, SYMMV and SMV were identified as major viruses causing infection in the early growth stage of soybean, with detection rates of 53.7% and 42.6%, respectively. Soybeans infected with SYMMV showed typical mosaic symptoms, whereas those infected with SMV showed a variety of symptoms such as mosaic, mottle, stunt, and chlorotic spots. Transmission characteristics of these viruses are variable, such that SMV is primarily transmitted by seeds, whereas SYMMV could be transmitted by insects, soil, and seeds. In this study, SGVA was detected in the early growth stage of soybean, and research on the current status and its effects on soybean after the early growth stage should be conducted.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.31 no.3
• /
• pp.15-25
• /
• 2023

In this study, silicon sludge from semiconductor dicing process is recycled to fabricate silica nanoparticles, which are applied as dispersing materials for electro-responsive (ER) smart fluid. In specific, metal impurities are removed from silicon sludge by acid washing to obtain the high-purity silicon powder. And then, silica nanoparticles are synthesized by facile hydrothermal method employing the silicon powder as reactant material. To control the size of silica nanoparticles, the reaction time of hydrothermal method is varied as 8, 15, 20, and 30 hours are applied to control the size of silica nanoparticles. Sizes of silica nanoparticles are increased proportionally to the reaction time owing to the increased numbers of hydrolysis and condensation reactions. As-synthesized silica nanoparticles are prepared as electro-responsive smart fluids by dispersing into silicon oil. Silica nanoparticles synthesized by 30 hours of hydrothermal reaction (SiO₂-H30) exhibit the highest shear stress of 21.4 Pa under an applied electric field strength of 3.0kV mm^-1. Such enhancement in ER performance of SiO₂-H30 among various silica nanoparticles are attribute to the reinforcing effect originated from the mixed particle size, which allowing the formation of rigid chain-like structures. Accordingly, this study successfully propose a recycling method of silicon sludge to synthesize silica nanoparticles and their derived ER fluids, which may suggest new possibility to ESG management emphasizing the eco-friendliness.

• Journal of Intelligence and Information Systems
• /
• v.29 no.3
• /
• pp.287-316
• /
• 2023

As global energy crisis and the COVID-19 pandemic have emerged as social issues, there is a growing demand for companies to move away from profit-centric business models and embrace sustainable management that balances environmental, social, and governance (ESG) factors. ESG activities of companies vary across industries, and industry-specific weights are applied in ESG evaluations. Therefore, it is important to develop strategic management approaches that reflect the characteristics of each industry and the importance of each ESG factor. Additionally, with the stance of strengthened focus on ESG disclosures, specific guidelines are needed to identify and report on sustainable management activities of domestic companies. To understand corporate sustainability strategies, analyzing ESG reports and news articles by industry can help identify strategic characteristics in specific industries. However, each company has its own unique strategies and report structures, making it difficult to grasp detailed trends or action items. In our study, we analyzed ESG reports (2019-2021) and news articles (2019-2022) of six companies in the 'Finance,' 'Manufacturing,' and 'IT' sectors to examine the sustainability strategies of leading domestic ESG companies. Text mining techniques such as keyword frequency analysis and topic modeling were applied to identify industry-specific, ESG element-specific management strategies and issues. The analysis revealed that in the 'Finance' sector, customer-centric management strategies and efforts to promote an inclusive culture within and outside the company were prominent. Strategies addressing climate change, such as carbon neutrality and expanding green finance, were also emphasized. In the 'Manufacturing' sector, the focus was on creating sustainable communities through occupational health and safety issues, sustainable supply chain management, low-carbon technology development, and eco-friendly investments to achieve carbon neutrality. In the 'IT' sector, there was a tendency to focus on technological innovation and digital responsibility to enhance social value through technology. Furthermore, the key issues identified in the ESG factors were as follows: under the 'Environmental' element, issues such as greenhouse gas and carbon emission management, industry-specific eco-friendly activities, and green partnerships were identified. Under the 'Social' element, key issues included social contribution activities through stakeholder engagement, supporting the growth and coexistence of members and partner companies, and enhancing customer value through stable service provision. Under the 'Governance' element, key issues were identified as strengthening board independence through the appointment of outside directors, risk management and communication for sustainable growth, and establishing transparent governance structures. The exploration of the relationship between ESG disclosures in reports and ESG issues in news articles revealed that the sustainability strategies disclosed in reports were aligned with the issues related to ESG disclosed in news articles. However, there was a tendency to strengthen ESG activities for prevention and improvement after negative media coverage that could have a negative impact on corporate image. Additionally, environmental issues were mentioned more frequently in news articles compared to ESG reports, with environmental-related keywords being emphasized in the 'Finance' sector in the reports. Thus, ESG reports and news articles shared some similarities in content due to the sharing of information sources. However, the impact of media coverage influenced the emphasis on specific sustainability strategies, and the extent of mentioning environmental issues varied across documents. Based on our study, the following contributions were derived. From a practical perspective, companies need to consider their characteristics and establish sustainability strategies that align with their capabilities and situations. From an academic perspective, unlike previous studies on ESG strategies, we present a subdivided methodology through analysis considering the industry-specific characteristics of companies.

• Pediatric Infection and Vaccine
• /
• v.30 no.2
• /
• pp.73-83
• /
• 2023

Purpose: This study aimed to investigate the viral load dynamics in children with underlying malignancies diagnosed with symptomatic coronavirus disease 2019 (COVID-19). Methods: This was a retrospective longitudinal cohort study of patients <19 years old with underlying hemato-oncologic malignancies that were diagnosed with their first symptomatic severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (PCR)-confirmed COVID-19 infection during March 1 to August 30, 2022. Review of electronic medical records and telephone surveys were undertaken to assess the clinical presentations and transmission route of the patients. Thresholds of negligible likelihood of infectious virus was defined as E gene reverse transcription (RT)-PCR cycle threshold (Ct) value ≥25. Results: During the 6-month study period, a total of 43 children with 44 episodes of COVID-19 were included. Of the 44 episodes, the median age of the patients included was 8 years old (interquartile range [IQR], 4.9-10.5), and the most common underlying disease was acute lymphoid leukemia (n=30, 68.2%), followed by patients post-hematopoietic stem cell transplantation (n=8, 18.2%). Majority of the patients had mild COVID-19 (n=32, 72.7%), and three patients (7.0%) had severe/critical COVID-19. Furthermore, 2.3% (n=1) died of COVID-19 associated acute respiratory distress syndrome. The largest percentage of the patients showed E gene RT-PCR Ct value ≥25 between 15-21 days (n=13, 39.4%), followed by 22-28 days (n=10, 30.3%). In 15.2% (n=5), E gene RT-PCR Ct value remained <25 beyond 28 days after initial positive PCR. Refractory malignancy status (β, 67.0; 95% confidence interval, 7.0-17.0; P=0.030) was significantly associated with prolonged duration of E gene RT-PCR <25. A patient with prolonged duration of E gene RT-PCR Ct value <25 was suspected to have infectivity shown by the transmission of the virus to his mother at day 86 after his initial positive test. Conclusions: Children that acquire symptomatic COVID-19 during refractory malignancy state are at a high risk for prolonged shedding warranting PCR-based transmission precautions in this cohort of patients.

• Research in Plant Disease
• /
• v.29 no.1
• /
• pp.23-38
• /
• 2023

The fire blight caused by Erwinia amylovora (Ea) is a devastating disease of Rosaceae plants, including commercially important apple and pear trees. Since the first report in Korea in May 2015, it has been spreading to neighboring regions gradually. Host plants can be infected by pollinators like bees, rainfall accompanied by wind, and cultural practices such as pruning. Many studies have revealed that wild Rosaceae plants such as Cotoneaster spp., Crataegus spp., Pyracantha spp., Prunus spp., and Sorbus spp. can be reservoirs of Ea in nature. However, wild Rosaceae plants in Korea have not been examined yet whether they are susceptible to fire blight. Therefore, the susceptibility to fire blight was examined with 25 species in 10 genera of wild Rosaceae plants, which were collected during 2020-2022, by artificial inoculation. Bacterial suspension (10⁸ cfu/ml) of Ea type strain TS3128 was inoculated artificially in flowers, leaves, stems, and fruits of each plant species, and development of disease symptoms were monitored. Moreover, the presence of Ea bacteria from inoculated samples were checked by conventional polymerase chain reaction. Total 14 species of wild Rosaceae plants showed disease symptoms of fire blight, and Ea bacteria were detected inside of inoculated plant parts. These results suggest that wild Rosaceae plants growing nearby commercial apple and pear orchards in Korea can be Ea reservoirs, and thus they should be monitored regularly to minimize the damage by Ea infection and spreading.

• The Korean Journal of Mycology
• /
• v.50 no.4
• /
• pp.281-289
• /
• 2022

Fusarium head blight is an important disease of small grains. It is mainly caused by members of the Fusarium graminearum species complex (FGSC). Barley and wheat growers spray fungicides, especially demethylation-inhibitor fungicides, to suppress the disease. The objective of this study was to examine the changes in the sensitivity of the FGSC population to the triazole fungicide, propiconazole. A total of 124 and 350 isolates of FGSC were obtained from barley and wheat in Jeolla Province during 2010-2016 and 2020-2021, respectively. The species identity and trichothecene chemotypes of the FGSC isolates were determined based on polymerase chain reaction assays targeting translation elongation factor 1-alpha and TRI12 genes, respectively. Sensitivity to propiconazole was determined based on the effective concentration that reduced 50% of the mycelial growth (EC₅₀) using the agar dilution method. Of all isolates, F. asiaticum with the nivalenol chemotype was the most common (83.9% in 2010-2016 and 96.0% in 2020-2021), followed by F. asiaticum with the 3-acetyl deoxynivalenol chemotype (12.1% in 2010-2016 and 2.9% in 2020-2021). The EC₅₀ values of the isolates collected in 2010-2016 and 2020-2021 ranged from 0.0180 to 11.0166 ㎍/mL and 1.3104 to 17.9587 ㎍/mL, respectively. The mean EC₅₀ value of the isolates increased from 3.8648 ㎍/mL in 2010-2016 to 5.9635 ㎍/mL in 2020-2021. The baseline resistance to propiconazole was determined to be 7 ㎍/mL, based on the EC₅₀ value of isolates collected in 2010-2016, and the ratio of resistant isolates increased from 9.7% in 2010-2016 to 28.6% in 2020-2021.