• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.264-274
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• 1993

This study was carried out to assess the agronomic characters and physicochemical properties of floury and chalky-endosperm mutant lines induced by chemical mutagen treatment to rice varieties, Hwacheongbyeo and IR24. Linkage analysis of a floury-endosperm gene was carried out using linkage testers. The grain size of brown rice of the mutants was smaller than that of the original varieties. The l, 000-grain and 1$\ell$ weight were lighter in the mutants compared with those in the original varieties. The compound starch granules in the endosperm cell of the mutants showed a loosely-packed crystalline structure. Amylose contents in mutants ranged from 16.9 to 28.5%. Crude protein contents of the mutants were not significantly different from the original rice variety, Hwacheongbyeo, but white core mutant(line 47106) derived from IR24 showed higher protein(l1.32%) compared with IR24(8.30%). The mutants showed slightly harder gel characteristics, and much lower viscosity in Amylograph than original varieties. Steamed rice-cakes from mutant lines showed greater volume than those from original varieties. During the process of alcohol fermentation, Brix in the mutants(especially floury mutants) decreased faster and the alcohol production after 10-day fermentation was much greater in the mutants than in the original varieties. Three different gene loci for floury endosperm characteristics were identified from the allelism test among mutant lines, and the genes were tentatively symbolized as flo-a, flo-b and flo-c, respectively. A floury gene, flo-a, was linked with lg(liguleless) gene in the linkage group N, with R.V. 5.76$\pm$1.72%.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.145-158
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• 2023

Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.1
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• pp.87-96
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• 2023

This study was conducted to discover substances that regulate skin surface acidification using human epidermal keratinocyte cell lines, and to investigate their effects on the moisturizing ability and skin barrier function of the stratum corneum. Prunella vulgaris (P. vulgaris) is an herb widely distributed in Northwest Africa and North America that has been studied for its anti-apoptotic, antioxidant, and anti-inflammatory effects. However, research on the regulation of NHE1 expression and the restoration of skin barrier function has not been conducted. Analysis of P. vulgaris revealed the presence of rosmarinic acid and caffeic acid as active ingredients, which were tested for toxicity in human epidermal keratinocyte cell lines (HaCaT), and showed no toxic effects were observed at high concentarion (100 ㎍/mL or 100 µM). It is known that sodium-hydrogen ion exchange pumps (NHE1) decrease in expression in aging skin to maintain the acidic pH of the stratum corneum, and it is hypothesized that this decrease plays an important role in the impaired restoration of skin barrier function in aging skin. P. vulgaris extract and caffeic acid increased the expression of NHE1 in keratinocytes, increased the expression of natural moisturizing factor (NMF) precursor filaggrin and ceramide synthesis enzyme serine palmitoyl transferase (SPT). In addition, P. vulgaris and caffeic acid decreased the extracellular pH of keratinocytes, indicating a direct effect on skin pH regulation. Taken together, these results suggest that P. vulgaris and caffeic acid can regulate skin pH through NHE1 modulation, and may help to restore skin barrier function by increasing NMF and ceramide synthesis. These results show the possibility that honeysuckle and caffeic acid can have a positive effect on skin health, and can be the basis for the development of new skin protection products using them.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.258-263
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• 2023

In this study, conductive polymers and the enzyme tyrosinase (Tyr) were deposited on the surface of a screen printed carbon electrode (SPCE), which can be fabricated as a disposable sensor chip, and applied to the detection of bisphenol F (BPF), an endocrine disruptor with proven links to male diseases and thyroid disorders, using electrochemical methods. On the surface of the SPCE working electrode, which was negatively charged by oxygen plasma treatment, a positively charged conductive polymer, poly(diallyldimethyl ammonium chloride) (PDDA), a negatively charged polymer compound, poly(sodium 4-styrenesulfonate) (PSS), and another layer of PDDA were layered by electrostatic attraction in the order of PDDA, PSS, and finally PDDA. Then, a layer of Tyr, which was negatively charged due to pH adjustment to 7.0, was added to create a PDDA-PSS-PDDA-Tyr sensor for BPF. When the electrode sensor is exposed to a BPF solution, which is the substrate and target analyte, 4,4'-methylenebis(cyclohexa-3,5-diene-1,2-dione) is generated by an oxidation reaction with the Tyr enzyme on the electrode surface. The reduction process of the product at 0.1 V (vs. Ag/AgCl) generating 4,4'-methylenebis(benzene-1,2-diol) was measured using cyclic and differential pulse voltammetries, resulting in a change in the peak current with respect to the concentration of BPF. In addition, we compared the detection performance of BPF using an ionic liquid electrolyte as an alternative to phosphate-buffered saline, which has been used in many previous sensing studies. Furthermore, the selectivity of bisphenol S, which acts as an interfering substance with a similar structure to BPF, was investigated. Finally, we demonstrated the practical applicability of the sensor by applying it to analyze the concentration of BPF in real samples prepared in the laboratory.

• Conservation Science in Museum
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• v.29
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• pp.133-152
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• 2023

This study references preceding studies to examine the history of paint application techniques using various paints in the past, with the aim to contribute to the long-term preservation of large military cultural heritage assets situated outdoors. To this end, the study compared the findings of preceding research with the findings of an analysis conducted on a H-13 helicopter housed at the War Memorial of Korea. Upon collecting and analyzing samples from three grounded WWII aircraft from above-ground by preceding studies, it was confirmed from each sample that the various chemical properties of chrome ensured the effectiveness of the protective coating. The compound was first tested as a corrosion-inhibiting pigment in the early 1940s and proved its excellent moisture-resistant properties over the course of 80 years, despite the deterioration of the paint layer and long-term exposure to the natural environment. For this reason, it has been widely used as a corrosion inhibitor for aluminum alloys in the aviation industry. In other word, the most widely-used material for preventing corrosion was an organic primer containing chromate. In this study, based on the paint analysis of a H-13 helicopter operated in the Korean War, it was shown that the second layer, consisting of the primer, contains chromium oxide (Cr₂O₃). In addition, it was estimated that red lead tetraoxide (Pb₃O₄) was used for the vehicle. Analysis results and data from previous studies can help to confirm the continued effectiveness of corrosion prevention function provided by chromate. Meanwhile, the result of infrared spectroscopy analysis confirmed the use of alkyd resin. In the future, comparisons with a more diverse range of artifacts will allow the identification of changes in the manufacturing technology of paints used to protect alloys from corrosion.

• Korean Journal of Heritage: History & Science
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• v.56 no.2
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• pp.136-146
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• 2023

Biological materials, such as stuffed specimens, can release various acids or volatiles. There has been no research carried out on the emission characteristics of organic compounds generated from the preservatives used in taxidermy specimens or associated manufacturing materials and methods. Therefore, in order to identify the organic compounds generated from taxidermy specimens, a degradation experiment was conducted on specimens for each material and for storage specimens. To produce Ogye chicken specimens, naphthalene and borax were used as preservatives, and planer sawdust, newspaper, and polystyrene foam were used as the core body materials. The deterioration experiment was conducted for 2 weeks in a high-temperature environment(50℃) and a high-humidity environment (95%), with an Ogye chicken specimen (year 2015) kept in an animal storage facility. Results indicated that the concentration of organic compounds generated by the specimen in the high-temperature environment tended to be greater than that in the high-humidity environment. The preservatives benzene, toluene, xylene, and p-dichlorobenzene were detected in the specimens using naphthalene, confirming that naphthalene is a major organic compound release factor, and the specimens that used sawdust, newspaper, and polystyrene foam also exhibited organic compounds. This appears to have been due to degradation of the material. In addition, ammonia was detected in the specimens for each material due to decay. In particular, the specimens using borax at high temperature were subject to approximately 9 times higher rates of ammonia-related deterioration than the specimens using naphthalene. These results can be considered to result from the prevention of biological damage through insecticidal effects by accelerating the sublimation of naphthalene in a high-temperature environment. Naphthalene is a potentially carcinogenic substance, and when used as a preservative, proper use management is required. Taxidermy specimens can release various organic compounds depending on the manufacturing techniques used, so a systematic preservation management plan is required that depends on conditions such as the applicable manufacturing materials and preservatives.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.68-76
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• 1996

To elucidate the optimum fertilizer level and application method for band application under puddled-soil drill seeding in Jeonbuk series of fluvio-marine alluvial soil at National Honam Agricultural Experiment Station in 1995, using Dongjinbyeo, slow releasing compound fertilizer of 100％ and 80％ to conventional application level was applied totally as basal fertilizer simultaneously with seeding under 3cm and 5cm depth from soil surface in a distance of 4cm from the seeded row. Plant height was taller and tiller number was higher in band application than conventional application but ratio of effective tiller was vice versa. Panicle number was more but ratio of effective tiller ratio was lower in 100％ than 80％ level of band application and they were higher in 3cm than 5cm depth from soil surface. Leaf area index and dry weight was higher in conventional application at early growth stage but was vice versa after maximum tillering stage, and they were higher in 3cm depth at early growth stage but 5cm depth after maximum tillering stage. NH$_4$-N in soil was higher in conventional application at 25 days after seeding but, thereafter was lower than band application and it was higher in 3cm than 5cm depth till 40 days after seeding but was versa, thereafter. Lodging degree was slightly higher in band application, 100％ level and 5cm depth than in their counterparts. Panicle number and grain number per $m^2$ was lower in conventional application than 80％ or 100％ level of band application without significant difference between band application levels or application methods. Yield was higher at 80％ level of band application under 3cm depth than conventional application, but no significantly different among other application methods. Therefore, 80％ level of band application under 3cm depth of soil surface was more effective for puddled-soil drill seeding on the basis of the reduction of application efforts, better plant growth and higher yield in rice.

• The Korean Journal of Food And Nutrition
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• v.36 no.5
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• pp.379-386
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• 2023

The objective of this study was to investigate the distribution of functional compounds in perilla leaves of various genetic resources and their antioxidant activities. A comprehensive analysis of functional compounds was conducted for 90 genetic resources, focusing on total polyphenol content (TPC), total flavonoid content (TFC), individual phenolic content (IPC), and lutein. Their antioxidant activities were then analyzed based on their radical scavenging capacity using ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl). The TPC content exhibited a range of 13.19 to 35.85 mg gallic acid equivalent/g, whereas the TFC content varied from 11.74 to 46.51 mg catechin equivalent/g. Total IPC was detected in a range of 6,310.98 to 40,491.82 ㎍/g. Lutein was detected at levels between 70.97 and 597.97 ㎍/g. ABTS and DPPH radical scavenging activities of perilla leaves ranged from 30.39 to 58.58 mg trolox equivalent (TE)/g and from 7.74 to 46.56 mg TE/g, respectively. Furthermore, correlation analysis demonstrated that rosmarinic acid, a phenolic acid, exhibited a significantly positive correlation with antioxidant activity. These findings suggest that various genetic resource of perilla leaves could effectively mediate antioxidant capacity. Results of this study provide valuable information for use of perilla leaves in Korea as functional food materials.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.193-203
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• 2023

Ethyl formate (EF) is a naturally occurring insecticidal compound and is used to control pests introduced from abroad, in quarantine, by a fumigation method. In particular, it is mainly used as a substitute for methyl bromide and is less toxic to humans and less harmful to plants. This study aimed to investigate the possible acute toxicity of EF to useful organisms, and how to reduce phytotoxicity in watermelon, zucchini, and oriental melon. After fumigation with EF for 2 h, the LC₅₀ values for earthworms, honey bees, and silkworms were 39.9, 7.09, and 17.9g m^-3, respectively. The degree of susceptibility to EF was in the order of earthworms, silkworms, and honey bees based on the LC₅₀ value, and EF fumigation induced stronger acute toxicity to honey bees. Phytotoxicity was observed in watermelon leaves treated with a concentration of 7.5 g m^-3 EF, and when treated with a concentration of 10.0g m^-3, it was confirmed that the edges of watermelon leaves were charred and seemed to be damaged by acids. Zucchini and melon, and other cucurbits, showed strong damage to the leaves when treated with a concentration of 10 g m^-3, and sodium silicate, at concentrations of 10% and 20%, was used to reduce phytotoxicity. Therefore, acute toxicity towards nontarget organisms and phytotoxicity during the fumigation of EF should be reduced for efficient agricultural pest control.

• Food Science and Preservation
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• v.30 no.5
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• pp.833-846
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• 2023

Onions are essential vegetables for Koreans' diet and have various physiological activities. However, problems arise every year due to the imbalance between production and demand. Therefore, in this study, nutritional and functional components, and antioxidant activity were analyzed for each growth period in order to utilize onions at the disposal period. Whole onions harvested before June showed higher values of general ingredients, inorganic ingredients, organic acids, spiraeoside, quercetin, total chlorophyll, and antioxidant activity than bulbs harvested in June. On the other hand, the free sugar content was higher in the bulb of the harvest season in June than in whole onions. The total thiosulfinate content was similar to that of whole onions and bulbs in the early stages of growth. In addition, as a result of comparing the flavonoid compound and antioxidant activity of each onion variety, whole onions harvested at 25 weeks were higher in content than onion bulbs harvested in June. In conclusion, onions before the harvest season in June had excellent utilization value as food. Harvesting before 21 weeks is desirable for growing onions with excellent nutritional value, while harvesting after 23 weeks is recommended for excellent functional components and antioxidant activity in onions.