• Korean Journal of Medicinal Crop Science
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• v.12 no.3
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• pp.203-208
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• 2004

Salidroside was isolated and purified from R. sachalinensis A. Bor. roots. Purified salidroside was obtained from repeated silicagel column chromatography and preparative HPLC, and identified by $^1H-NMR,\;^{13}C-NMR\;and\;^1H-^1H$ COSY spectra analyzer. Callus induction and cell suspension from R. sachalinensis leaf segments were established on 1/2MS solid medium and in $2B_5$ liquid medium containing 0.5 mg/l NAA and 1 mg/l, BA in the dark condition, respectively. The contents of salidroside for suspension culture were ranging from 0.12% to 0.41% in comparison with 0.17% for natural roots.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.169-175
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• 2014

Objective of this study was to investigate effects of pre-processing method and number of sampling leaves on stability of the reflectance measurement for Chinese cabbage and kale leaves. Chinese cabbage and kale were transplanted and cultivated in a plant factory. Leaf samples of the kale and cabbage were collected at 4 weeks after transplanting of the seedlings. Spectra data were collected with an UV/VIS/NIR spectrometer in the wavelength region from 190 to 1130 nm. All leaves (mature and young leaves) were measured on 9 and 12 points in the blade part in the upper area for kale and cabbage leaves, respectively. To reduce the spectral noise, the raw spectral data were preprocessed by different methods: i) moving average, ii) Savitzky-Golay filter, iii) local regression using weighted linear least squares and a $1^{st}$ degree polynomial model (lowess), iv) local regression using weighted linear least squares and a $2^{nd}$ degree polynomial model (loess), v) a robust version of 'lowess', vi) a robust version of 'loess', with 7, 11, 15 smoothing points. Effects of number of sampling leaves were investigated by reflectance difference (RD) and cross-correlation (CC) methods. Results indicated that the contribution of the spectral data collected at 4 sampling leaves were good for both of the crops for reflectance measurement that does not change stability of measurement much. Furthermore, moving average method with 11 smoothing points was believed to provide reliable pre-processed data for further analysis.

• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.105-108
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• 2015

To establish the anti-diabetic(α-glucosidase inhibitory) activity of D. lotus leaf extract, isolate and identify the constituents responsible for the activity. The methanolic extract of leaves was partitioned between water, n-butanol and ethyl acetate. Bio-assay guided fractionation, based on inhibition of ;${\alpha}$-glucosidase, allowed isolation and identification of the active components. Liquid chromatography/mass spectrometry(LC/MS), ¹ H-NMR and ¹³ C-NMR spectra analyses demonstrated that the active compound was myricetin-3-O-;${\alpha}$-L-rhamnoside(1). Compound 1 demonstrated a strong inhibition on the α-glucosidase, in vitro and ;${\alpha}$-glucosidase inhibitory value was calculated as 98.08%, when that of a reference drug, acarbose was estimated as 83.03%. The present study indicates compound 1 could be considered as an ;${\alpha}$-glucosidase inhibitor and developed as an important antidiabetes agent for type II diabetes therapy.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.9
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• pp.893-899
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• 2008

Changes in spectroscopic characteristics and pyrene binding coefficients of terrestrial dissolved organic matters(DOM) were investigated during microbial incubation. The incubation studies were conducted for 21 days using a leaf litter DOM and a soilderived DOM with an inoculum from a river. The dissolved organic carbon(DOC), the specific UV absorbance(SUVA), the synchronous fluorescence spectra, and the pyrene organic carbon-normalized binding coefficient(K$_{oc}$) of the DOM were measured at the incubation days of 0, 3, 7, 14 and 21. After the 21-day incubation, DOC were reduced to 61% and 51% of the original concentrations of the litter DOM and the soil-derived DOM, respectively. Comparison of the spectroscopic characteristics before and after the incubation revealed that the SUVA, the fulvic-like fluorescence(FLF), the humic-like fluorescence(HLF) of the different DOM were enhanced by the incubation whereas the protein-like fluorescence(PLF) was reduced. This indicates that more aromatic and humic-like compounds were enriched during the biodegradation process while biodegradable and weak carbon structures were depleted. Irrespective of the DOM sources, SUVA values showed a positive relationship with pyrene K$_{oc}$ with a correlation coefficient of 0.97. The FLF and HLF also exhibited good correlations with K$_{oc}$ values although different regression equations were obtained from the different DOM. Our results suggest that the selected spectroscopic characteristics could be good estimation indices for the changes of the binding reactivity of DOM for hydrophobic organic contaminants during biodegradation process.

• Journal of radiological science and technology
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• v.34 no.1
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• pp.43-50
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• 2011

In this study we modeled the varian 2100C/D linear accelerator head and multi-leaf collimator by simulation with the GEANT4 Monte Carlo toolkit. Then central axis percentage depth dose profiles and lateral dose profiles within homogeneous water phantom($50{\times}50{\times}50\;cm^3$) were evaluated with 6 MV photon beam. The simulations were performed in two stages. In the first stage, photon energy spectrum at the target were computed were computed. Then spectra data was directly irradiated in the water phantom using sampling techniques. The simulation data were compared with experimental data to evaluate the accuracy of the model. Results showed that two data were matched within 2% error boundary. The proposed method will be applied for simulation of dose calculation and dose distribution study.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.60-68
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• 1993

It has been known that the silk degumming treated by hot alkali solution is easy to handle but is liable to yield poor-quality silk due to the degree of degumming loss, incomplete-degumming or over-degumming. Therefore, many studies have been carried out on the silk degumming by enzyme in order to improve the quality of silk. However, no attention has been paid to the physicochemical analysis of enzymatic degummed silk. In this paper, two different degumming methods, soap and enzymatic, are compared in aqueous solution state of silk fibroin. The results can be summarized as follows: There was no significant difference between two solutions on the bases of polarizing microscopy, TEM observation and SDS-PAGE. Spherulite of silk fibroin was not observed in polarizing microscopy, however the leaf-shape fibril structure was developed upon solidification. The size of spherulites of silk fibroin in TEM observation were 30~120nm with a wide range of size distribution. The intrinsic viscosity of enzymatic degummed fibroin solution was lower than that of soap degummed solution. This can be explained that the silk fibroin was more degraded by enzymatic degumming method compared with the soap degumming method. SDS-polyacrylamide gel electrophoresis showed that the fibroin molecule was composed of large component of molecule weight above 50 kd and small component of molecule weight about 20 kd. There was no difference in crystallinity between two degumming methods on the bases of results of DSC thermograms and IR spectra.

• Korean Journal of Remote Sensing
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• v.27 no.2
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• pp.191-201
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• 2011

Soybean has widely grown for its edible bean which has numerous uses. Microwave remote sensing has a great potential over the conventional remote sensing with the visible and infrared spectra due to its all-weather day-and-night imaging capabilities. In this investigation, a ground-based polarimetric scatterometer operating at multiple frequencies was used to continuously monitor the crop conditions of a soybean field. Polarimetric backscatter data at L, C, and X-bands were acquired every 10 minutes on the microwave observations at various soybean stages. The polarimetric scatterometer consists of a vector network analyzer, a microwave switch, radio frequency cables, power unit and a personal computer. The polarimetric scatterometer components were installed inside an air-conditioned shelter to maintain constant temperature and humidity during the data acquisition period. The backscattering coefficients were calculated from the measured data at incidence angle $40^{\circ}$ and full polarization (HH, VV, HV, VH) by applying the radar equation. The soybean growth data such as leaf area index (LAI), plant height, fresh and dry weight, vegetation water content and pod weight were measured periodically throughout the growth season. We measured the temporal variations of backscattering coefficients of the soybean crop at L, C, and X-bands during a soybean growth period. In the three bands, VV-polarized backscattering coefficients were higher than HH-polarized backscattering coefficients until mid-June, and thereafter HH-polarized backscattering coefficients were higher than VV-, HV-polarized back scattering coefficients. However, the cross-over stage (HH > VV) was different for each frequency: DOY 200 for L-band and DOY 210 for both C and X-bands. The temporal trend of the backscattering coefficients for all bands agreed with the soybean growth data such as LAI, dry weight and plant height; i.e., increased until about DOY 271 and decreased afterward. We plotted the relationship between the backscattering coefficients with three bands and soybean growth parameters. The growth parameters were highly correlated with HH-polarization at L-band (over r=0.92).