• Restorative Dentistry and Endodontics
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• v.35 no.4
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• pp.246-256
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• 2010

The purpose of this study was to evaluate a rotational stability of endodontic electronic motors by comparing the changes of rotational speed, depending on the number of usages and with/without static load. Twelve new endodontic electronic motors were used in this study. Non contact type digital tachometer was used for measuring the rotational speed of handpiece. True RMS Multimeter was used for measuring the voltages and the electric currents. All measurements were recorded every 10 seconds during 10 minutes and repeated 9 times. Five repetition was done per each electronic motor. To statistical analysis, student t-test, repeated measures and Scheffe's post-hoc tests were performed. In the same motor group, there was no significant difference in all measurements. In all groups, there was no significant difference in the amount of rotational speed changes depending on the number of usages and with/without static load. In the limitation of this study, the results showed that all kinds of endodontic electronic motors in this study had an established rotational stability. Therefore they could be safely used in root canal treatment with a reliable maintenance of rotational speed, regardless of the number of usages and with/without load.

• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.378-386
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• 2022

Scenedesmus obliquus ABC-009 is a microalgal strain that accumulates large amounts of lutein, particularly when subjected to growth-limiting conditions. Here, the performance of this strain was evaluated for the simultaneous production of lutein and biofuels under three different modes of cultivation - photoautotrophic mode using BG-11 medium with air or 2% CO₂ and heterotrophic mode using YM medium. While it was found that the highest fatty acid methyl ester (FAME) level and lutein content per biomass (%) were achieved in BG-11 medium with CO₂ and air, respectively, heterotrophic cultivation resulted in much higher biomass productivity. While the cell concentrations of the cultures grown under BG-11 and CO₂ were largely similar to those grown in YM medium, the disparity in the biomass yield was largely attributed to the larger cell volume in heterotrophically cultivated cells. Post-cultivation light treatment was found to further enhance the biomass productivity in all three cases and lutein content in heterotrophic conditions. Consequently, the maximum biomass (757.14 ± 20.20 mg/l/d), FAME (92.78 ± 0.08 mg/l/d), and lutein (1.006 ± 0.23 mg/l/d) productivities were obtained under heterotrophic cultivation. Next, large-scale lutein production using microalgae was demonstrated using a 1-ton open raceway pond cultivation system and a low-cost fertilizer (Eco-Sol). The overall biomass yields were similar in both media, while slightly higher lutein content was obtained using the fertilizer owing to the higher nitrogen content.

• Journal of Environmental Science International
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• v.32 no.11
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• pp.745-756
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• 2023

Growing stringent global regulations in Korea poses a threat to corporate sustainability. Companies must respond strategically to navigate these regulations and avoid greenwashing. Objective of this research was to analyze how Korean companies are responding to the global trend of reducing plastic use and propose improved management strategies. Seven indicators were developed to assess companies' post-plastic strategies and applied to analyze the sustainability reports of Amore Pacific and LG Household & HealthCare. These indicators included, 1) disclosure of plastic raw materials used by weight or volume, 2) disclosure of recycled plastic raw materials used by weight or volume, 3) disclosure of waste recycling, reuse amounts, and disposal using waste treatment method 4) strategies to reduce environmental impact of plastics, 5) plastic packaging, reduce, recycle, reuse, and composting (in the real environment), 6) plastic management roadmap for the circular economy, and 7) education for sustainable plastic management. Based on the review of considered companies, we propose in-listed sustainable plastics management strategies: disclosing the ratio of plastic raw materials and recycled raw materials for all products, considering recycling rate throughout the product value chain, and not only for the production phase, reviewing carbon dioxide emissions based on life cycle assessment rather than reducing plastic consumption, studying the biodegradability of biodegradable plastics in natural environment such as soil, considering the consumer's perspective.

• Journal of Preventive Medicine and Public Health
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• v.57 no.1
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• pp.55-64
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• 2024

Objectives: This study investigated the prevalence and characteristics of comorbid conditions in patients exposed to ionizing radiation and those who were involved in the Soviet-Afghan war. Methods: This study analyzed the frequency and spectrum of morbidity and comorbidity in patients over a long-term period (30-35 years) following exposure to ionizing radiation at the Semipalatinsk nuclear test site or the Chornobyl nuclear power plant, and among participants of the Soviet-Afghan war. A cohort study, both prospective and retrospective, was conducted on 675 patients who underwent comprehensive examinations. Results: Numerical data were analyzed using the Statistica 6 program. The results are presented as the mean±standard deviation, median, and interquartile range (25-75th percentiles). The statistical significance of between-group differences was assessed using the Student t-test and Pearson chi-square test. A p-value of less than 0.05 was considered statistically significant. We found a high prevalence of cardiovascular diseases, including hypertension (55.0%) and cardiac ischemia (32.9%); these rates exceeded the average for this age group in the general population. Conclusions: The cumulative impact of causal occupational, environmental, and ultra-high stress factors in the combat zone in participants of the Soviet-Afghan war, along with common conventional factors, contributed to the formation of a specific comorbidity structure. This necessitates a rational approach to identifying early predictors of cardiovascular events and central nervous system disorders, as well as pathognomonic clinical symptoms in this patient cohort. It also underscores the importance of selecting suitable methods and strategies for implementing treatment and prevention measures.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.165-171
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• 2023

Potato dry rot is one of the potato storage diseases caused by Fusarium species and is a representative pathological disorder that induced post-harvest loss during storage. Chlorpropham treatment for sprouting inhibition is mainly used for room temperature storage of potatoes for processing. In this study, the inhibitory effect of chlorpropham on Fusarium-induced dry rot of potato 'Dano'. To investigate the mycelial growth rate of the dry rot fungus (Fusarium solani Appel & Wollenw), mycelial growth was investigated in a chlorpropham (5.0, 50.4, 503.8, and 5,038 ppm) and prochloraz (0.1, 1.0, 10.0, and 100.0 ppm) medium containing F. oxysporum mycelia. Mycelia were more inhibited as the concentration of chlorpropham and prochloraz increased during incubation at 20℃, and the inhibition rate was 98.2% and 100% when treated with 503.8 ppm of chlorpropham and 10ppm of prochloraz in 14 days, respectively. Potato Dano tubers inoculated with F. oxysporum were dipped in chlorpropham (5.0, 50.4, and 503.8 ppm) and prochloraz (100 ppm) to investigate the effect of preventing dry rot during cold storage at 20℃ and 4℃ in vivo. The disease diameter of potatoes stored at room temperature (about 20℃) was reduced to 13.0 mm in the prochloraz 100 ppm teatment, and 10.7 mm in the chlorpropham 50.4 ppm treatment compared to 13.7 mm in the control tuber at 70 days of storage. The disease progression in all treatments including control was similar with no statistically significant difference at 4℃ air temperature. From the results of this study, it is considered that treatment with 50.4 ppm of chlorpropham after harvest will be useful for suppressing dry rot of stored potatoes.

• Research in Plant Disease
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• v.28 no.2
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• pp.82-91
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• 2022

Recently, several in vitro studies have reported antiviral activity of agents of systemic acquired resistance against plant virus infection, but the approach has not been applied in a wide range of agricultural fields. The objective of this study was to evaluate the inhibitory effect of the exogenous application of salicylic acid (SA), chitosan (CH), or eugenol (EG) in tomato yellow leaf curl virus (TYLCV) infection of greenhouse-grown tomato plants. In vitro, the initial time of symptom was observed in TYLCV-infected plants (VP) of the resistant cultivar 'Superdotaerang' at 12 days post inoculation (dpi) after application of antiviral agents. At 32 dpi, the disease rate of TYLCV in the CHT+VP (0.1% chitosan and virus infected control) treated plants was 87.5%, lower than that of the other treatment. However, the virus content in the CHT+VP treated plants was higher than those of the other treatments, and SA, EG, and CH did not show significant effect on plant height or shoot and root fresh weight. Our results from summer-cultivated greenhouse-grown tomatoes show that none of the tested agents had an inhibitory activity on viral infection or yield of tomato 'Dotaerangsola'cultivar. In contrast, all treated 'TY Giants' cultivars that possessed TYLCV resistance genes Ty-1 and Ty-3a did not show typical symptoms and the virus content was remarkably lower than those in the TYLCV treated plants in 'Superdotaerang'. The results of this research indicated that the planting of resistant tomato cultivars was effective method instead of using SA, EG, and CH (known as resistance-inducing factors for control) of TYLCV in the field.

• Research in Plant Disease
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• v.26 no.2
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• pp.103-108
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• 2020

Evaluations were made for the effects of cheese whey treatment on infection of pepper plants by cucumber mosaic virus-Vch (CMV-Vch) and pepper mottle virus-Kr (PepMoV-Kr). In a greenhouse, pepper plants sprayed with whey, prior to inoculation by CMV-Vch using aphids, showed a viral infection rate significantly lower (6.6%) than for the control (23.3%). In an open field experiment, in which CMV infection relied on natural transmission by aphids, pepper plants were sprayed with undiluted whey once a week, starting on the transplanting date (May 2) to the end of June. On June 5, these whey-sprayed plants showed a CMV infection rate reduced by 18.9% and 16.7%, compared to untreated and pesticide-treated plants, respectively. In the greenhouse, pepper plants inoculated with PepMoV-Kr mixed with whey showed a viral infection rate decreased by 60% compared to the control. The accumulated amount of PepMoV-Kr coat protein was less than that for the virus-only control at 6 days post inoculation (dpi), but increased up to a similar level as the control at 9 dpi. This study showed that cheese whey is effective in reducing infection of both CMV and PepMoV in pepper plants.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.162-167
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• 1986

This experiment was conducted to determine the effect of light, organophosphorus compounds and plant growth regulators on phytotoxicity of pendimethalin (3,4-dimethyl-2,6-dinitro-N-1-ethyl propylamine) in rice (Oryza saliva L.). The phytotoxicity of pendimethalin on post-germination growth of rice was greatly reduced by light treatment. This effect resulted from photodecomposition of pendimethalin. Antidoting activity on phytotoxicity of pendimethalin varied with the kind of organophosphorus compounds used and the application time. The greatest antidoting effect was obtained from edifenphos (0-3thy1 S,S-diphenylphosphorothioate). However, the effect was not observed when edifenphos was applied prior to pendimethalin. There was no antidoting effect of indole acetic acid (IAA), gibberellic acid ($GA_3$) and kinetin used alone, but combinations of 3 ppmw IAA + either 3 or 5 ppmw $GA_3$ and 1 ppmw kinetin + 10 ppmw $GA_3$ reduced the phytotoxicity of pendimethalin.

• Korean Journal of Pharmacognosy
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• v.36 no.2 s.141
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• pp.109-115
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• 2005

The herb of Allium victorialis var. platyphyllum (Liliaceae) has been used as an edible wild herb and to treat heart failure and gastritis. We have already reported antihyperlipidemic anti-tumor effects of this plant. To enlarge the commercial availability of this food, it was investigated whether the extracts of A. victorialis var. platyphyllum reduce hyperlipidemia and obesity or not. The plants tested in this experiment were collected from two eco-types of Is. Ullung and Mt. Odae cultivated at Pyongchang. Extracts were prepared by extracting the fresh leaves and those dried at $36^{\circ}C$ and $90^{\circ}C$, respectively. Pretreatment with the ethanolic extracts for two weeks(p.o.) reduced serum triglyceride-, total cholesterol- and LDL-cholesterol contents in rats induced by Triton WR-1339, respectively. Furthermore, oral administration of the extracts also inhibited the hyperlipidemia induced with oral diet of 30% corn oil. In the other attempt to find to alleviate the obesity, the model rats with obesity were induced by the high fat-diet for six weeks. Post-treatment with the extracts for two weeks significantly reduced the hyperlipidemia. Retroperitoneal-, epidymal- and total abdominal fat pad weights were considerably reduced at 100 mg/kg oral administration of the extracts. Increased feces lipid contents were also found in the rat treated with the extracts. The extract may lead to the higher activity in treatment of hyperlipidemia and obesity than of the dried one.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.240-249
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• 2011

The potential of juglone a plant naphthoquinone as a natural herbicide on new target, 7-keto-8-amino pelargonic acid synthetase (KAPAS) in the early step of biotin biosynthesis pathway, was performed in vitro and in vivo. Juglone effectively inhibited KAPAS activities in vitro and the $IC_{50}$ was $9.5{\mu}M$. Foliar application of juglone showed very good herbicidal activity to the eight-tested weed species. Among them, Solanum nigrum was completely controlled at a concentration of $250{\mu}g\;mL^{-1}$ with main symptoms of desiccation or burndown. Digitaria sanguinalis and Aeschynomene indica were also sensitive to juglone treatment. All eight weed species were controlled by 90~100% at a concentration of $500{\mu}g\;mL^{-1}$. However, soil application of juglone to Digitaria sanguinalis did not show any herbicidal symptoms. Cellular leakage from cucumber leaf squares treated with juglone increased depending on the concentrations increased from 6.25 to $100{\mu}M$ after 24 hours incubation with or without light. However, chlorophyll loss in cucumber leaf squares was negligible. Biotin supplements significantly rescued the inhibition of germination rate of Arabidopsis thaliana seeds previously inhibited by the juglone. Our results suggest that the juglone is a possible environmental friendly herbicide candidate with a new target KAPAS inhibiting activity.