• The Journal of Engineering Geology
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• v.31 no.1
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• pp.103-118
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• 2021

For management and preservation measures of lava tube, it is studied how the blasting vibration by constructions near Geomunoreum lava tubes in Jeju affect lava tube. 11 boreholes were drilled in study area, and in-situ blasting tests were conducted by changing from 0.5 kg to 10 kg charge per delay in those boreholes. The vibration velocity, which meets the regulatory vibration criterion during daytime, was estimated as below 0.276 cm/sec by analyzing the relationship between vibration velocity and vibration level. In addition, SRE and CRE were calculated from the results of in-situ blasting tests, and k-values were shown as 130.04 in SRE, 199.71 in CRE, respectively. Also, n-values were shown as -1.717 in SRE, -1.711 in CRE, respectively. Charge per delay were assessed based on these equations, and charges per delay had ranges of 0.57~7.42 kg/delay in estimation equation of vibration velocity, 0.21~5.29 kg/delay in SRE, and 0.04~5.51 kg/delay in CRE, considering the 0.2 kine vibration criterion for cultural heritage and the 20~100 m distance from vibration source. Additionally, the relationships which meet the criteria of 0.2 kine, were calculated by combining CRE in this study with the result of previous study. Allowable charges per delay, which meet the criteria of 0.2 kine, were evaluated as 1.07 kg/delay in 50 m, 5.13 kg/delay in 100 m and 22.26 kg/delay in 200 m distances. These relationships for each vibration velocity are useful to deduce charge per delay for the ground near Geomunoreum lava tube.

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.24-33
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• 2021

For this study, we surveyed concentrations of 8 mycotoxins (aflatoxin B1, B2, G1, G2, ochratoxin A, fumonisin B1, B2 and zearalenone) in agricultural products used for food and medicine by liquid chromatography-tandem mass spectrometry and conducted a risk assessment. Samples were collected at the Yangnyeong Market in Seoul, Korea, between January and November 2019. Mycotoxins were extracted from these samples by adding 0.1% formic acid in 50% acetonitrile and cleaned up by using an ISOLUTE Myco cartridge. The method was validated by assessing its matrix effects, linearity, limit of detection (LOD), limit of quantification (LOQ), recovery and precision using four representative matrices. Matrix-matched standard calibration was used for quantification and the calibration curves of all analytes showed good linearity (r2>0.9999). LODs and LOQs were in the range of 0.02-0.11 ㎍/kg and 0.06-0.26 ㎍/kg, respectively. Sample recoveries were from 81.2 to 118.7% and relative standard deviations lower than 8.90%. The method developed in this study was applied to analyze a total of 187 samples, and aflatoxin B1 was detected at the range of 1.18-7.29 ㎍/kg (below the maximum allowable limit set by the Ministry of Food and Drug Safety, MFDS), whereas aflatoxin B2, G1 and G2 were not detected. Mycotoxins that are not regulated presently in Korea were also detected: fumonisin (0.84-14.25 ㎍/kg), ochratoxin A (0.76-17.42 ㎍/kg), and zearalenone (1.73-15.96 ㎍/kg). Risk assessment was evaluated by using estimated daily intake (EDI) and specific guideline values. These results indicate that the overall exposure level of Koreans to mycotoxins due to the intake of agricultural products used for food and medicine is unlikely to be a major risk factor for their health.

• Journal of Nutrition and Health
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• v.54 no.1
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• pp.76-94
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• 2021

Purpose: This study was implemented to develop and validate a semi-quantitative food frequency questionnaire (SQ-FFQ) to assess the dietary intake of married migrant women in multicultural families. Methods: The SQ-FFQ consisting of 41 food items was selected based on the information of frequently consumed foods from the preliminary studies on dietary intake survey for married migrant women or a Korean Health and Nutrition Examination survey. Thirty-five subjects who visited the Multicultural Family Support Center in Seoul and Daejeon area completed their three-day diet records and SQ-FFQ 2 times. The reproducibility and relative validity of SQ-FFQ were assessed by comparing the 1st and 2nd SQ-FFQ and by comparison with the three-day diet records, respectively. Results: The reliability of SQ-FFQ, which was examined 1-2 weeks apart, showed no significant difference in the energy and macronutrient intake (carbohydrate, fat, protein), while the average intakes of vitamin A, riboflavin, calcium, and potassium were slightly higher in the 2nd than 1st SQ-FFQ. All correlation coefficients for the reliability for nutrients were statistically significant, ranging from 0.453 to 0.885. The mean intakes of energy, carbohydrate, vitamin C, thiamin, folate, vitamin B12, calcium, and sodium obtained from the SQ-FFQ were greater than those of the 3-day dietary records. The Spearman's correlation coefficient between the 2 methods was the highest for plant fat (r = 0.602; p < 0.001) and relatively higher for energy, carbohydrate, fat, and thiamin ranging from 0.512 to 0.599; and protein, riboflavin, niacin, folate ranging from 0.335 to 0.499, while no significant correlation was observed for vitamin A, C, calcium, iron, and sodium. Conclusion: The developed SQ-FFQ for married migrant women in multicultural families in this study appears to be useful for estimating the nutritional status, particularly energy, carbohydrates, fat, and vitamin B group.

• Journal of Life Science
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• v.31 no.1
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• pp.37-46
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• 2021

The effects of freeze-dried powder from fresh and black garlic hot water extracts on the lipid metabolism in Sprague-Dawley rats fed a high-cholesterol diet were analyzed. The experimental group was classified into the normal group (NG), the high-fat (HF) and high-cholesterol diet group (CG), the HFC and 1% fresh garlic hot water extract powder-added diet group (FGEG), and the HFC and 1% black garlic hot water extract powder-added diet group (BGEG), respectively. The serum total lipid content was 381.52±7.30 mg/ml and 368.80±4.40 mg/ml in the FGEG and the BGEG, respectively, and was significantly lower than that of the CG. The total cholesterol and triglyceride contents of the FGEG and BGEG were also significantly lower than that of the CG. The high-density lipoprotein (HDL) cholesterol was significantly higher, and the low-density lipoprotein (LDL) and the very low-density lipoprotein (VLDL) cholesterol content was lower in the FGEG and BGEG than in the CG. The serum ALT and AST activities were significantly lower than those of the CG, and especially the BGEG was lower. The total cholesterol content and the triglyceride levels of the liver tissue were 36.0% and 14.3% lower in the BGEG than in the CG, respectively. The thiobarbituric acid reactive substance (TBARS) concentrations in the serum and the liver tissue were higher in the CG than in the FGEG and BGEG, but there was no difference between them. Based on these results, garlic extract powders significantly reduced the lipid profile and increased the antioxidant activity in rats in vivo. The black garlic hot water extract powder was more effective than raw garlic because of the total number of phenolic compounds and browning substances in the black garlic.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.610-615
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• 2020

Edible insects might be used as a means to solve food insecurity caused by population growth. Many studies have investigated the biological activity of insects; however, few studies have investigated the nutritional value of insects. Therefore, the aim of this study was to investigate the nutritional value of Allomyrina dichotoma larva protein (ADP) as a source of protein replacement. In vivo studies were conducted to determine the food efficiency ratio (FER), protein efficiency ratio (PER), and true digestibility (TD) of ADP. Experiments were conducted in 3 groups of 8 animals per group using twenty-four 4-week-old SD rats. The experimental groups included the general diet group (Con), in which 20% of the total Kcal in the diet was composed of casein protein, and the ADP group (ADP), in which 20% of the total Kcal was composed of ADP protein, and a non-protein diet group (NP) to measure the protein (metabolic fecal nitrogen) excreted by metabolic processes in the body. As a result of this experiment, we found that the FERs were 0.52 and 0.41 in the casein protein intake (Con) and ADP groups, respectively, thus showing a significantly lower level in the ADP group. The PERs of ADP and Con were 2.39 and 2.63, respectively. The TD of Con and ADP were 91% and 80%, respectively.

• Journal of agriculture & life science
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• v.51 no.1
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• pp.35-43
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• 2017

This research was carried out to excessive water tolerance test among corn accessions collected from India to breed corn cultivars targeting India market. The corn accessions were 20 Inbred lines and cultivars from India as well as Korean cultivars Gwangpyungok and Chaloksusu. Excessive water tolerance test was done in the green house by immerging the pots containing corn seedlings for two weeks. Then, the plant heights were measured to compare the control plants that were not grown in the immerging state. The results showed that seven accessions of high tolerance in flooding; H2(92.9%), H18(88.8%), CN114A(98.1%), CN351A(94.3%), Super900M(95.3%), P3394(98.8%), 31N27(96.7%) in which the percent is comparison to the control plants. Whereas nine accessions showed high damage by immerging; H1(78.9%), H8(73.4%), H10(77.1%), H19(79.0%), H26(74.1%), H31(75.7%), H34(77.5%), H36(77.4%), H40(74.6%). However, the reduction on the contents of chlorophyll a, chlorophyll b, carotenoids in leaf revealed contrast results to the flooding tolerance. Particularly, H36($7.249{\mu}g{\cdot}mg^{-1}$) and H40($7.642{\mu}g{\cdot}mg^{-1}$) showed rapid reduction in the chlorophyll a content during the flooding treatment. Whereas two Indian commercial varieties 37N27($0.630{\mu}g{\cdot}mg^{-1}$) and P3394($1.208{\mu}g{\cdot}mg^{-1}$) showed slight reduction. The reduction of chlorophyll a and carotenoid contents was positively correlated during the excessive water stress.

• Journal of Life Science
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• v.31 no.5
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• pp.488-495
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• 2021

The aim of this study was to investigate the possible antioxidant effect of Spirodela polyrhiza (SP) on rats fed a high fat and high cholesterol diet supplemented with either 5% (SPA group) or 10% (SPB group) SP for 4 weeks. The hepatic SOD activity of the HF group significantly decreased compared to that of the N group, but that of the SPA and SPB groups significantly increased. The GPx activity of the SPA and SPB groups in the liver was significantly greater than that of the HF group, and the hepatic catalase activity of the SPA and SPB groups significantly increased compared to the HF group. The hepatic superoxide radical content of the mitochondria and microsomes of the HF group significantly increased compared to that of the N group, but the contents were reduced in the group that took SP powder. The hepatic hydrogen peroxide content in the cytosol and mitochondria of the SP powder group was lower than in the HF group. The carbonyl content in the mitochondria and microsomes of the SPA and SPB groups was significantly lower than in the HF group. The TBARS values in the liver significantly decreased in the SPA and SPB groups. Spirodela polyrhiza was thus effective in reducing oxidative stress by regulating the hepatic antioxidant enzymes and the free radicals in rats fed high fat and high cholesterol diets.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.750-761
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• 2021

This study was performed to observe the responses of angiogenesis-related protein expression in skeletal muscle of aged rats by regular resistance exercise training with aerobic exercise. For the purpose of the study, naturally aged SD rats (20-24 months, N=18) were used and divided into control (CON, n=6), resistance exercise (RE, n=6), and resistance + aerobic exercise (RE + AE, n=6) groups. RE group performed 3 sets × 4 exercises each session using a ladder for laboratory animals, and RE +AE group performed 2 sets × 3 times of ladder climbing and additional treadmill running (30 min) each session. After 8 weeks of exercise training, soleus muscle and extensor digitorum longus muscle (EDL) were extracted and used for analysis. Western blot was performed to analyze the expression levels of angiogenesis-related proteins (HIF-1α, VEGF, FLK-1, Ang-1, Ang-2) in skeletal muscle. As a result of the study, the expression of HIF-1α, VEGF, FLK-1, Ang-1, and Ang-2 proteins in soleus muscle (type I muscle) was higher in RE +AE than in CON group, and HIF-1α, VEGF, Ang-1, Ang-2 protein expression of RE group was higher than that of CON group. Furthermore, Ang-2 to Ang-1 ratio of RE + AE group was higher than that of RE group, showing differences by exercise type. In EDL muscle (type II muscle), HIF-1α was increased only by RE group, whereas VEGF and FLK-1 protein expressions were increased in both training types, and no difference was observed between the types of exercise training. In addition, there was no difference in angiopoieitin protein expressions in EDL muscle by exercise training. Therefore, in aging, regular exercise training induces skeletal muscle angiogenic response regardless of exercise type, and in particular, the combination of aerobic exercise with resistance exercise may have an additional positive effect on angiogenesis in type I muscle.

• Journal of Korean Society of Forest Science
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• v.110 no.1
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• pp.53-63
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• 2021

Sophora koreensis Nakai is an indigenous plant in Koreawith a restricted natural range, part of which is in Gangwon province. The species is known to contain phytochemicals that have beneficial effects on human health, and it is economically important in bioindustry. Because of the limited number of plants in a small range of habitats, the mass-propagation method should be developed for use and conservation. In vitro tissue culture is a reliable method in terms of mass propagation from selected clones of the species. We investigated the optimal conditions of the medium in this process, especially focusing on the concentrations of plant growth regulators(PGRs) in the culture of stem-containing axillary buds. Three statistical methods, i.e., ANOVA, response surface method(RSM), and fuzzy clustering were used to analyze the plant growth, number of shoots induced, and shoot length with various combinations of PGRs. Results from the RSM differed from those of the other two methods; thus, the method was not suitable. ANOVA and fuzzy clustering showed similar results. However, more accurate results were obtained using fuzzy clustering because it provided a probability for each treatment. On the basis of the fuzzy clustering analysis, stem tissue produced the greatest number of shoots(11.03 per explant; 63.33%) on a medium supplemented with 5-��M 6-benzylaminopurine and 2.5-��M thidiazuron(TDZ). Proliferation of shoots(2.18 ± 0.21 cm, 63.33%) was attained on a medium supplemented with 2.5-��M BA, 2.5-��M TDZ, and 2.5-��M gibberellic acid.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.65-71
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• 2021

This study was carried out to investigate the effect of the final irrigation timing (FIT) before packaging for long-term transportation on growth, flowering, and crop quality of Phalaenopsis after simulated dark shipping (SDS). Phalaenopsis Sogo Yukidian 'V3' plants grown in 11 cm-diameter plastic pots filled with potting media (sphagnum moss + bark or only sphagnum moss) were packaged in paper boxes for export at 3.5, 7, 10 days (FIT 3.5, 7,10; Experiment 1) and 4, 6, 8, 10 days (FIT 4, 6, 8, 10; Experiment 2) after the final irrigation and then stored in a growth chamber at 20 ± 1℃ and 70 ± 3% RH created for SDS. After 4 weeks, the plants were taken out and grown in a greenhouse at 23 ± 3℃ and 70 ± 5% RH, and crop characteristics were measured during cultivation. In Experiment 1, the survival rate of FIT 3.5 plants was lower than that of FIT 7 and FIT 10. There was no difference between treatments in days to first flower, the number of florets, and the elongation rate of flower stalks. In Experiment 2, the percentage of rotted leaves was lowest in FIT 6 when before forcing and at 12 weeks after forcing, and that of FIT 8 was similar to FIT 6 when before forcing, but slightly increased after 12 weeks. The percentage of rotted leaves of FIT 10 was highest and that of FIT 4 was also high. There was little difference in flowering characteristics among treatments. In conclusion, the FIT before packaging for long-term (4 weeks) transportation of potted Phalaenopsis 'V3' affected the leaf rot rather than the post-shipping growth and flowering. And it was considered appropriate to set the volumetric water content of the potting media just before packaging to about 30%.