• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.87-105
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• 2009

Nonlinear dynamic deformation characteristics, expressed in terms of normalized shear modulus reduction curve (G/$G_{max}-\log\gamma$, G/$G_{max}$ curve) and damping curve (D-$\log\gamma$), are important input parameters with shear wave velocity profile ($V_s$-profile) in the seismic analysis of (new or existing) fill dam. In this paper, the reasonable and economical methods to evaluate the nonlinear dynamic deformation characteristics for core zone and rockfill zone respectively are presented. For the core zone, 111 G/$G_{max}$ curves and 98 damping curves which meet the requirements of core material were compiled and representative curves and ranges were proposed for the three ranges of confining pressure (0~100 kPa, 100 kPa~200 kPa, more than 200 kPa). The reliability of the proposed curves for the core zone were verified by comparing with the resonant column test results of two kinds of core materials. For the rockfill zone, 135 G/$G_{max}$ curves and 65 damping curves were compiled from the test results of gravelly materials using large scale testing equipments. The representative curves and ranges for G/$G_{max}$ were proposed for the three ranges of confining pressure (0~50 kPa, 50 kPa~100 kPa, more than 100 kPa) and those for damping were proposed independently of confining pressure. The reliability of the proposed curves for the rockfill zone were verified by comparing with the large scale triaxial test results of rockfill materials in the B-dam which is being constructed.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.231-242
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• 2023

This study aims to provide basic data to reduce the incidence of radiation dermatitis and improve patient satisfaction by investigating the management status and satisfaction level of radiation dermatitis in patients undergoing radiation therapy. From October 28, 2022, to April 4, 2023, a survey was conducted on 137 breast cancer patients who received radiation therapy at G Hospital in Busan. The Radiation Therapy Oncology Group (RTOG) cutaneous acute radiotherapy toxicity score was used as the standard for measuring skin reactions, and the association between cancer stage and RTOG was analyzed. SPSS program (ver. 18.0) was used for statistical analysis. The frequency of radiation dermatitis occurrence was relatively low, with 73% in the RTOG 0-1 group and 27% in the 2-3 group. Patient satisfaction after radiation therapy varied significantly depending on the RTOG group, with lower levels of dermatitis resulting in higher satisfaction and higher levels resulting in dissatisfaction (p=0.001). Although there was no statistically significant difference in RTOG group and skin satisfaction depending on the frequency of aloe mist use (p=0.065), the group that used it 1-2 times a day (69.3%) showed a higher satisfaction level. The perceived effects of aloe mist use were statistically significant for decreasing heat sensation (p=0.001), pain (p=0.033), itching (p=0.001), and psychological stability (p=0.027), especially in the higher RTOG groups. Additionally, as cancer stage increased, the severity of radiation dermatitis also increased, which was statistically significant (p=0.001). In conclusion, radiation dermatitis is the most common side effect of radiation therapy, and it can appear in various forms depending on individual skin sensitivity and external factors during treatment. Adequate education before treatment and the use of MD Cream and aloe vera mist are recommended to reduce the incidence and manage radiation dermatitis effectively.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.89-96
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• 2023

This study was conducted to apply with an air duct for the cooling and a utilizing cultivating method that uses the fruiting node and the defoliation to the high-temperature vertical and hydroponic cultivation of the oriental melon. The lower fruiting node (LF) was to remove all third vines generated from 5 nodes of a secondary vine. The higher fruiting node (HF) was fruiting on the third vine generated from a first node of the third vine. The direction of the stem string; upward (UW), downward (DW). Four treatment conditions were applied with the LF-UW, LF-DW, HF-UW (control), and HF-DW. The leaf age of melon leaves was measured for photosynthesis at 3 days intervals, and the fruit characteristic was conducted on 79 fruits in each treatment. The photosynthesis rate steadily increased after leaf development, reaching 20.8 μmol CO₂·m^-2·s^-1 on the 10 days, gradually increasing to 21.3 μmol CO₂·m^-2·s^-1 on the 19 days, and reaching 23.4 μmol CO₂·m^-2·s^-1 on the 32 days. After that, it lowered to 16.8 μmol CO₂·m^-2·s^-1 on the 38 days and dropped significantly to 7.6 μmol CO₂·m^-2·s^-1 on the 47 days. As a result of the fruit characteristics by fruiting nodes, the treatments of the fruit length was 12.6-13.4 cm, respectively, which was significant, and the fruit width was 7.9- 8.6 cm, respectively, was not significant. The soluble content ranged from 12.9 to 15.7°Brix, and the significance of all treatments, and higher than of LF-DW and HF-UW. The photosynthesis rate of melon leaves was good until 32 days after leaf development, but after that, the rate decreased. As for fruit quality, it was conformed that melons can be cultivated at the LF because the fruit enlargement and soluble content dose not decrease even when set at the LF. Results indicated that those can be used for LF and defoliation in the development of vertical and hydroponic cultivation method in high-temperature season.

• Journal of Food Hygiene and Safety
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• v.38 no.2
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• pp.46-54
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• 2023

In this study, we examined the residual amounts of formaldehyde in hygiene products to determine the safety of these products in Gyeonggi-do. Formaldehyde is among the harmful substances that may remain within certain hygiene products. On the basis of an analysis of formaldehyde in a total of 222 items (6 disposable paper straws, 9 disposable paper napkins, 21 toilet papers, 13 disposable dishcloths, 16 disposable paper towels, 32 wet wipes for food service restaurants, 25 disposable cotton swabs, and 100 disposable diapers), we detected traces in three wet wipes for food service restaurants (1.87 to 4.45 mg/kg), which is approximately 9% to 22% of the standard level (20 mg/kg). We established that all the hygiene products assessed in the study met the individual standards for formaldehyde, thereby confirming that safe products are being distributed. In the standards and specifications for hygiene products, the formaldehyde test method is regulated for application with respect to three categories based on the type of product. The samples used in this study were of types for which method 1 or method 2 is applied, and the limits of detection, limits of quantification, linearity, and recovery rates were reviewed to verify the validity of each test method. When method 2 was applied, we experienced interference when performing analysis at a wavelength of 412 nm, which was associated with the influence of impurities in some samples of disposable cotton swabs and disposable diapers. Consequently, in these cases, the results were compared after analysis using method 1. By comparing the results obtained using method 2 with those obtained using method 1, the latter of which were unaffected by the interference of impurities, we were able to detect formaldehyde at low concentrations. These findings accordingly highlight the necessity to standardize the formaldehyde test method for future analyses.

• The Journal of Korean Medicine
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• v.44 no.1
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• pp.65-75
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• 2023

Objectives: Objectives: In this study, we define a medical service type that combines Western medicine, Korean medicine, and complementary and alternative medicine (CAM) as an integrated medical service. This study, as part of tertiary hospital-based integrated medical service model and clinical field application, aims to collect status and opinions on integrated medical service for medical staff in the field. Methods: This is a survey study, and was conducted on doctors from Kyung Hee University Hospital and Korean medicine doctors from Kyung Hee University Korean Medicine Hospital. Respondents were recruited on a first-come, first-served basis until the number of respondents reached 120. The investigation was conducted for a total of 16 days from October 4, 2021 to October 19, 2021 by e-mail. Results: Recognition of integrated medical services was confirmed to be 45.8%, and 49.2% responded positively to the necessity of it. As a group of diseases that require the establishment of integrated medical services in the future, 'disorders of musculoskeletal systems and connective tissues' was the highest. The most expected advantages of providing integrated medical services were 'increased satisfaction of patients and guardians' and 'increased treatment effects.' Conclusions: In this study, we investigated the perception of doctors and Korean medicine doctors on integrated medical services that combine Western medicine, Korean medicine, and CAM. It has been confirmed that medical staff generally have a positive perception of integrated medical services, and if the scientific basis for the effect of integrated medical services is supported, the rate of positive perception is expected to increase.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.2
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• pp.90-96
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• 2023

The aim of this study was to investigate the effect of application rate of rice straw compost on soil chemical properties and soil organic carbon stock (SOC stock). The experiments were performed with no fertilizer (NF), inorganic fertilizer (NPK), NPK + rice straw compost 7.5 ton ha^-1 (NPKC7.5), NPK + rice straw compost 15 ton ha^-1 (NPKC15), NPK + rice straw compost 22.5 ton ha^-1 (NPKC22.5), and NPK + rice straw compost 30 ton ha^-1 (NPKC30). The SOC and SOC stock were highest in the NPKC30 treatment at 22.8 g kg^-1 and 71.2 Mg C ha^-1, respectively. Rice production was in the range of 621.2-654.4 kg 10a^-1 in NPKC22.5 and NPKC30 treatments, which was higher than that in the NPK treatment. However, with increase in compost application, the exchangeable K and Ca of the soil increased, and the exchangeable K and Ca were higher than the optimum range in NPKC22.5 and NPKC30 treatments. Excessive application of compost can have negative impacts on the environment, including nutrient accumulation in the soil and water pollution from nutrient runoff. Therefore, applying the standard amount of compost according to the agricultural environment would be appropriate, despite the relatively lower rice production and SOC stock than that observed with the application of 22.5 and 30 ton ha^-1.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.413-422
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• 2022

Barnea manilensis is a bivalve which bores soft rocks, such as, limestone or mudstone in the low intertidal zone. They make burrows which have narrow entrances and wide interiors and live in these burrows for a lifetime. In this study, the morphology and the microstructure of the valve of rock-boring clam B. manilensis were observed using a stereoscopic microscope and FE-SEM, respectively. The chemical composition of specific part of the valve was assessed by energy dispersive X-ray spectroscopy (EDS) analysis. 3D modeling and structural dynamic analysis were used to simulate the boring behavior of B. manilensis. Microscopy results showed that the valve was asymmetric with plow-like spikes which were located on the anterior surface of the valve and were distributed in a specific direction. The anterior parts of the valve were thicker than the posterior parts. EDS results indicated that the valve mainly consisted of calcium carbonate, while metal elements, such as, Al, Si, Mn, Fe, and Mg were detected on the outer surface of the anterior spikes. It was assumed that the metal elements increased the strength of the valve, thus helping the B. manilensis to bore sediment. The simulation showed that spikes located on the anterior part of the valve received a load at all angles. It was suggested that the anterior part of the shell received the load while drilling rocks. The boring mechanism using the amorphous valve of B. manilensis is expected to be used as basic data to devise an efficient drilling mechanism.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.1
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• pp.35-41
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• 2023

This experiment was carried out to examine double cropping system using Italian ryegrass (IRG) 'Kowinearly', whole crop rice 'Yeongwoo' and barnyard millet 'Jeju native' during the Oct. 2020 to Oct. 2022. Three kinds of forage crops were cultivated at paddy field in Livestock Institute, Jeollanamdo Agricultural Research and Extension Services, Jeollanamdo, South Korea. Whole crop rice (WCR) was sown in late May and barnyard millet (BM) sown early June each year after harvesting IRG. We examined dry matter yield and feed value of forage crops depending on harvest time of forage crops during the experimental period. The plant height in heading stage of IRG ranged from 108 to 112cm and dry matter yield ranged from 6,783 to 11,530 kg ha^-1. The crude protein (CP) of IRG ranged from 6.0 to 8.44%, acid detergent fiber (ADF) ranged from 55.6 to 60.2% and neutral detergent fiber (NDF) ranged from 32.58 to 36.7%, The dry matter yield of WCR increased as the harvest stage was delayed (14,310 kg ha^-1 in milk, 16,167 kg ha^-1 in yellow ripen, and 18,891 kg ha^-1 in mature). Similar to results of dry matter yield of WCR, dry matter yield of BM increased as the harvest stage was delayed (11,194 kg ha^-1 in late heading. and 14,308 kg ha^-1 in mature), However nutrient content of WCR and BM showed a decreasing trend. As shown in above results, the productivity of WCR after harvesting IRG was shown to be high at paddy field in the southern region. However, BM also was appeared to have potential as summer forage crops.

• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.203-211
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• 2022

Melanogenesis is the production of melanin from tyrosine by a series of enzyme-catalyzed reactions, in which tyrosinase and DOPA oxidase play key roles. The melanin content in the skin determines skin pigmentation. Abnormalities in skin pigmentation lead to various skin pigmentation disorders. Recent research has shown that the expression of EMP2 is much lower in melanoma than in normal melanocytes, but its role in melanogenesis has not yet been elucidated. Therefore, we investigated the role of EMP2 in the melanogenesis of MNT1 human melanoma cells. We examined TRP-1, TRP-2, and TYR expression levels during melanogenesis in MNT1 melanoma cells by gene silencing of EMP2. Western blot and RT-PCR results confirmed that the expression levels of TYR and TRP-2 were decreased when EMP2 expression was knocked down by EMP2 siRNA in MNT1 cells, and these changes were reversed when EMP2 was overexpressed. We verified the EMP2 gene was knocked out of the cell line (EMP2 CRISPR/Cas9) by using a CRISPR/Cas9 system and found that the expression levels of TRP-2 and TYR were significantly lower in the EMP2 CRISPR/Cas9 cell lines. Loss of EMP2 also reduced migration and invasion of MNT1 melanoma cells. In addition, the melanosome transfer from the melanocytes to keratinocytes in the EMP2 KO cells cocultured with keratinocytes was reduced compared to the cells in the control coculture group. In conclusion, these results suggest that EMP2 is involved in melanogenesis via the regulation of TRP-2 expression.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.3
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• pp.21-29
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• 2023

In this study, the stress characteristics of temporary fixed steel rods were analyzed in the "temporary fixing system using internal prestressing tension", which is mainly applied to the construction of superstructures by FCM. It was difficult to confirm the changes in initial tensile force in this system because the steel rod was internally connected to the pier and the PSC BOX. Therefore, measurement was performed before and after the completion of each segment using an FBG sensor to measure the change in the micro length of the steel rod. The results of the analysis showed that 75% to 90% of the maximum vertical contraction of the steel rod that occurred until the completion of the cantilever segment occurred in the fixing ~ 1segment, and the maximum loss of initial prestressing force was 39%. Such excessive loss of tension force to 1 segment means that tension is needed to improve the precision of construction during the fixation, and re-tension is needed to secure stability for conduction of cantilever segments after the completion of 1segment. In the 2 ~ last segment, the stress of the steel rod decreased gradually, and in the summer, the decrease in stress tended to partially recover due to the increase in the length of the steel rod corresponding to the increase in the vertical volume of PSC BOX. The dominant factor in the stress change in 2~ last segment in this phenomenon is judged to be the change in the length of the steel rod according to the temperature. Unlike the change in length, the relaxation was 1.2-2.7%, which was mostly offset by the opposite stress corresponding to the temperature stress. Therefore, a plan was proposed to improve the internal stress, such as adjusting the fixation time.