• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1344-1350
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• 2003

This study was performed to investigate the antioxidative effect as the inhibition of malondialdehyde (MDA) and bovine serum albumin (BSA) conjugation reaction, inhibition of lipid peroxidation and the scavenging effect on 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical, and antimutagenic capacities as the Ames test in 7 common vegetables taken by Korean for suggestion of prevention and dietetic treatment of chronic diseases and development of antioxidative and antimutagenic functional food. The water fractions of perilla leaves and sedum were most effective in the inhibition of MDA and BSA conjugation reaction showing 62.5% of inhibition rate among 7 vegetables. The inhibition rates of ethanol fractions of sedum and wild water dropwort on the lipid peroxidation were 67.1% and 61.5%, respectively. The ethanol fractions of crown daisy and wild water dropwort showed the most effective results among 7 vegetables in the DPPH radical scavenging capacities showing inhibition rate of 78.8% and 73.6%, respectively. The indirect and direct antimutagenic effects of ethanol extract of 7 vegetables were examined by Ames test using Salmonella typimurium TA98 and TA100. Inhibitory effects of wild water dropwort was superior to the other vegetables on the Ames test. These results suggest that common 7 vegetables taken by Korean are believed to be a possible antioxidative and antimutagenic capacities, although the results were different, more or less, according to the assay method and vegetables used.

• Korean Journal of Plant Resources
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• v.24 no.4
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• pp.413-418
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• 2011

This study was carried out to establish a proper cultivation site and diagnose the drought-tolerance of Aster scaber and Synurus deltoides leaves by using Pressure-volume curves. In order to measure pressure-volume (P-V) curves, Aster scaber and Synurus deltoides were cut off above ground part and the tip of the cutting were placed in water, which was covered with a plastic bag. Samples were kept overnight (about 12 hours) in darkness at room temperature (20~25$^{\circ}C$) to achieve maximal turgor (full saturation). The pressure in the chamber was gradually increased from 0.3MPa to 1.8MPa by nitrogen gas. After measured, leaf samples were dried at 80$^{\circ}C$ for 48 hours and dry weight of each samples were determined. The result of the original bulk osmotic potential at maximum turgor ${\Psi}^{sat}_o$ sat was lower -0.8 MPa in Aster scaber leaves than -0.7 MPa Synurus deltoides leaves. Also the osmotic potential at incipient plasmolysis ${\Psi}^{tlp}_o$ in Aster scaber leave was -0.9 MPa. In contrast, the value of maximum bulk modulus of elasticity $E_{max}$ of Aster scaber leaves were approximately two folds higher than that of Synurus deltoides leaves. The values of the relative water content at incipient plasmolysis $RWC^{tlp}$ are all above 90% showing that the function of osmoregulation is somewhat better, and Vo/DW, Vt/DW, Ns/DW of Synurus deltoides leaves were approximately 1~2 times higher than that of Aster scaber leaves. Thus, responses to water relations of Aster scaber and Synurus deltoides such as ${\Psi}^{sat}_o$, ${\Psi}^{tlp}_o$, $E_{max}$, ${\Psi}_{P,max}$, $RWC^{tl}$ were shown that the Aster scaber leaves was slightly higher drought-tolerance than Synurus deltoides leaves. However, in both of Aster scaber and Synurus deltoides, occurring incipient plasmolysis at the high water content, have a relatively lower drought-tolerance property indicating that growth of these plants are cultivated appropriate in high moisture soil sites.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.625-636
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• 2010

The geophysical characteristics and geological structure of the northeastern part of the Ulleung Basin were investigated from interpretation of geophysical data including gravity, magnetic, bathymetry data, and seismic data. Relative correction was applied to reduce errors between sets of gravity and magnetic data, obtained at different times and by different equipments. The northeastern margin of the Ulleung Basin is characterized by complicated morphology consisting of volcanic islands (Ulleungdo and Dokdo), the Dokdo seamounts, and a deep pathway (Korea Gap) with the maximum depth of -2500 m. Free-air anomalies generally reflect the topography effect. There are high anomalies over the volcanic islands and the Dokdo seamounts. Except local anomalous zones of volcanic edifices, the gradual increasing of the Bouguer anomalies from the Oki Bank toward the Ulleung Basin and the Korea Gap is related to higher mantle level and denser crust in the central of the Ulleung Basin. Complicated magnetic anomalies in the study area occur over volcanic islands and seamounts. The power spectrum analysis of the Bouguer anomalies indicates that the depth to the averaged Moho discontinuity is -16.1 km. The inversion of the Bouguer anomaly shows that the Moho depth under the Korea Gap is about -16~17 km and the Moho depths towards the Oki Bank and the northwestern part of Ulleung Island are gradually deeper. The inversion result suggests that the crust of the Ulleung Basin is thicker than normal oceanic crusts. The result of 20 gravity modeling is in good agreement with the results of the power spectrum analysis and the inversion of the Bouguer anomaly. Except the volcanic edifices, the main pattern of magnetization distribution shows lineation in NE-SW. The inversion results, the 2D gravity modeling, and the magnetization distribution support possible NE-SW spreading of the Ulleung Basin proposed by other papers.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.67-76
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• 2016

This study was conducted to examine the optimal environmental condition for promoting the growth of sowthistle as affected by light quality and photoperiod in a closed-type plant production system. Seeds were sown in 240-cell plug trays and then germinated for 3 days at a 24-hour photoperiod in a closed-type plant production system with LED lights (R:B:W = 8:1:1). Seedlings were transplanted and grown under 3 types of LED (R:B:W = 8:1:1, R:W = 3:7, or R:B = 8:2) and 4 photoperiods (24/0, 16/8, 8/16, or 4/20 hours) with $230{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity at a density of $20cm{\times}20 cm$. The experimental design was a randomized complete block design. Plants were cultured for 40 days un der the condition of $21{\pm}2^{\circ}C$ and $70{\pm}10%$ relative humidity after transplanting. Plants were fed with a recycling nutrient solution (pH 7.0 and EC $2.0dS{\cdot}m^{-1}$) contained in a deep floating tank. Fresh weight and dry weight of shoot or root, leaf length, and leaf area were the greatest in the photoperiod of 24/0 (light/dark) with RW LED. The highest number of leaves occurred in the photoperiod of 16/8 (light/dark) with RB LED, while the incidence of tip burn was higher in the photoperiod of 24/0 (light/dark) compared to the other treatments. Chlorophyll value was the highest in the 16/8 (light/dark) photoperiod and there was no significant difference by light quality. Chlorophyll fluorescence was the lowest in the photoperiod of 24/0 (light/dark) compared with other treatments. Therefore, in terms of economic feasibility and productivity for Ixeris dentata Nakai cultivation in a closed-type plant production system, the results obtained suggest that plants grew the best when kept in a photoperiod of 16/8 (light/dark) and light quality of combined LED RW (3:7).

• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.195-206
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• 2021

In 2020, South Korea initiated research and development of a longitudinal connectivity evaluation between upstream and downstream based on stream ecosystem health. This study analyzed the migration of upstream and downstream migratory fish species, fish distribution characteristics, trophic guilds, tolerance guilds, and species composition changes from 2015 to 2020 at Songrim weir in Yeongok stream, where the cross-structure of an ice harbor-type fishway for fish movement was recently improved. A total of 5,136 fish, including 36 species, were collected and three major migratory fishes were identified, namely, Tribolodon hakonensis, Plecoglossus altivelis altivelis, and Oncorhynchus keta. According to the comparative analysis before (Pre-I) and after (Post-I) improvement of the fishway, the relative abundance of primary freshwater fish increased in the upstream section, while the number of migratory fishes decreased. The fish species that used the fishway in the Songrim weir were Tribolodon hakonensis (58.4%) and Plecoglossus altivelis altivelis(11.8%). According to the Wilcoxon Signed-Rank Test migratory fish showed a statistically significant difference (p<0.05) in the upstream and downstream, showing a biological improvement effect of the crossstructure. On the other hand, the annual change of migratory fish based on the MannKendall trend test did not significantly increase or decrease (p>0.05). Therefore, in the fish passage improvement project, it is necessary not only for physical, hydrological, and structural tests, but also for pre- and post-biological tests on the use and improvement effect of fishway.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.297-305
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• 2022

The goal of this study was to evaluate the anti-obesity effect of radish leaf extracts (MU-C) and radish leaf extracts with 3% citric acid (MU-CA) in a high-fat diet (HFD)-induced C57BL/6 mice. The effects of radish leaf extracts on adipogenesis were also investigated using 3T3-L1 adipocytes. As determined by Oil red O staining, MU-C inhibited adipogenesis in 3T3-L1 adipocytes. Four-week-old male C57BL/6 mice were fed an HFD for 6 weeks and then treated with radish leaf extracts (500 mg/kg, p.o.) for 6 weeks. Then, the serum levels of Aspartate aminotransferase, Alanine aminotransferase, Total cholesterol, Triglyceride and low-density lipoprotein cholesterol in the mice were measured using an automatic chemical analyzer and enzyme-linked immunosorbent assay. Administration of MU-C significantly reduced the fat weight when compared with HFD controls. As confirmed by histopathologic analysis, adipose tissue size markedly decreased in mice treated with MU-C. Therefore, this study could provide a basis for investigating the clinical use of MU-C as an agent for preventing obesity.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.123-135
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• 2012

Purpose: It is essential to minimize the movement of tumor due to respiratory movement at the time of respiration controlled radiotherapy of non-small cell lung cancer patient. Accordingly, this Study aims to evaluate the usefulness of restricted respiratory period by comparing and analyzing the treatment plans that apply free and restricted respiration period respectively. Materials and Methods: After having conducted training on 9 non-small cell lung cancer patients (tumor n=10) from April to December 2011 by using 'signal monitored-breathing (guided- breathing)' method for the 'free respiratory period' measured on the basis of the regular respiratory period of the patents and 'restricted respiratory period' that was intentionally reduced, total of 10 CT images for each of the respiration phases were acquired by carrying out 4D CT for treatment planning purpose by using RPM and 4-dimensional computed tomography simulator. Visual gross tumor volume (GTV) and internal target volume (ITV) that each of the observer 1 and observer 2 has set were measured and compared on the CT image of each respiratory interval. Moreover, the amplitude of movement of tumor was measured by measuring the center of mass (COM) at the phase of 0% which is the end-inspiration (EI) and at the phase of 50% which is the end-exhalation (EE). In addition, both observers established treatment plan that applied the 2 respiratory periods, and mean dose to normal lung (MDTNL) was compared and analyzed through dose-volume histogram (DVH). Moreover, normal tissue complication probability (NTCP) of the normal lung volume was compared by using dose-volume histogram analysis program (DVH analyzer v.1) and statistical analysis was performed in order to carry out quantitative evaluation of the measured data. Results: As the result of the analysis of the treatment plan that applied the 'restricted respiratory period' of the observer 1 and observer 2, there was reduction rate of 38.75% in the 3-dimensional direction movement of the tumor in comparison to the 'free respiratory period' in the case of the observer 1, while there reduction rate was 41.10% in the case of the observer 2. The results of measurement and comparison of the volumes, GTV and ITV, there was reduction rate of $14.96{\pm}9.44%$ for observer 1 and $19.86{\pm}10.62%$ for observer 2 in the case of GTV, while there was reduction rate of $8.91{\pm}5.91%$ for observer 1 and $15.52{\pm}9.01%$ for observer 2 in the case of ITV. The results of analysis and comparison of MDTNL and NTCP illustrated the reduction rate of MDTNL $3.98{\pm}5.62%$ for observer 1 and $7.62{\pm}10.29%$ for observer 2 in the case of MDTNL, while there was reduction rate of $21.70{\pm}28.27%$ for observer 1 and $37.83{\pm}49.93%$ for observer 2 in the case of NTCP. In addition, the results of analysis of correlation between the resultant values of the 2 observers, while there was significant difference between the observers for the 'free respiratory period', there was no significantly different reduction rates between the observers for 'restricted respiratory period. Conclusion: It was possible to verify the usefulness and appropriateness of 'restricted respiratory period' at the time of respiration controlled radiotherapy on non-small cell lung cancer patient as the treatment plan that applied 'restricted respiratory period' illustrated relative reduction in the evaluation factors in comparison to the 'free respiratory period.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.62-72
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• 1986

At present, the definition and chemical analysis method of available soil phosphorus for plants have not been standardized because of the complexity of crop and soil characteristics in Korea and many analysis methods have been suggested with different extraction conditions. Suitable analytical method of available soil P should be established by the trial of various methods based on crop nutrition and soil conditions. To establish the most suitable analysis method of available soiIP, a pot experiment with young maize was conducted over 44 different upland soils collected over the land of Korea. The amount of uptaken P by the plant was determined by ten different chemical methods for the available soil P. The results obtained were as follows: 1. Total phosphorus content in the sample soils ranged ranged $533{\sim}4917\;ppm$, and showed significant positive correlation with the content of organic matter. 2. The P content was relatively low in the acid sulfate soil and very high in the volcanic ash soil although both types of soil contained high level of orgic matter. 3. The amount of extractable P determined by ten different methods were varied more or less, and the ratios of the extractable P to the total soil P were in the range of $1{\sim}48%$. 4. The relative values to the amount of extractable soil P by different methods were in the order of $H_2O(5\;min.)\;1.0\;<\;H_2O(60min.)\;2.27\;<\;NH_4HCO_3\;5.57\;<\;NaHCO_3\;7.42\;<\;Double\;lactate\;9.71\;<\;Bray\;No.1\;12.53\;<\;Lancaster\;17.63\;<\;Nelson\;25.96\;<\;AcOH\;27.6\;<\;CAL-method\;50.27$ 5. The amount of extractable P determined by all of applied methods was very low in acid sulfate soil, volcanic ash soil and coarse textured soil. 6. Soil pH and total soil P generally showed significant positive correlation with the chemically extracted P, and soil organic matter was negatively correlated with the determined by Nelson-and CAL-method. Olsen method which showed significant correlation with exchangeable calcium seemed to be recommendable for calcareous soils. 7. Total amount of uptaken P by Young maize through continuos twice cropping was 4.05% of total soil P in average, and the uptake in the second cropping was twice as much as that of the first cropping. 8. Three determination methods, i.e. Soltanpour-, Double lactate and Bray No. 1-method seemed to be more suitable than Lancaster method which is widely practiced at present in Korea. However, further study should be carried out with other crops and soils to most adequate chemical method for determination of available soil P.