• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.342-354
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• 2018

Suaeda japonica is a halophytic plant that lives in mudflat at intertidal zone of western and southern coastal areas of Korea. The seawater-living plants showed a purple color during their whole life. In contrast, freshwater-living plants displayed a green color in leaves. When seawater-living plants were transferred to potting soil, the purple color was gradually changed to green in the leaves. The extracted purple pigment compound exhibited typical characteristics of betacyanin that were represented by water solubility, pH- and temperature-dependent color changes, sensitivity to light, UV-Vis spectra, and gel electrophoretic migration pattern. The LC-MS analysis of the extracted pigment compound showed the presence of two major protonated molecular ions ($[M+H]^+$) at m/z 651.1 and m/z 827.1. Antioxidant activity of the pigment compound was determined using stable free radical DPPH assay. It was found to have an antioxidant activity that is linearly increased in proportion to the reaction time for up to 30 min, and the activity was comparable to that of control BHA at 9.0 mg/ml. The anticancer activity against several tumor cell lines was also examined following the MTT assay. The significant growth inhibitory effect was observed on two tumor cell lines, SW-156 (human kidney carcinoma) and HEC-1B (human endometrial adenocarcinoma). Probably, the pigment compound may function as an osmolyte to uphold halotolerant physiological processes in saline environment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.s01
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• pp.98-114
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• 1988

This study was conducted to investigate the status and prospects of seed quality researches in rapeseed. Rapeseed Quality was mainly related to oil and protein content, fatty acid composition and glucosinolate content. Hence, breeding for improvement of rapeseed Quality has been emphasized as follows: 1) inheritance mode, 2) investigation of germplasm, 3) establishment of analysis technique, 4) establishment of selection method, 5) idealization of cultural technique. The oil quality is determined by its fatty acids. Fatty acids have been determined by gas chromatography. To improve oil quality was emphasized for zero erucic acid, the highest possible linoleic acid and the lowest possible linolenic acid content. Rapeseed meal is not considered as top quality feed ingredient although it has higher protein content and well-balanced amino acid composition. This is mainly because of the presence of considerable amounts of glucosinolates. Thus the reduction of glucosinolate content in rapeseed meal is of great importance. In breeding for meal quality, low glucosinolate lines (plants) were selected and analyzed by gas chromatography and UV-spectrophotometer. Current problems and future researches of rapeseed quality in Korea are 1) improvement of researcher's number and facilities, 2) depression of animal feeding trials, 3) unsatisfied relationship between research and manufacturing and products field, 4) improvement of fertility for yellow and thin seed coat lines crossed between mustard and rapeseed, 5) establishment of new rapid analysing system for rapeseed quality.

• The Korean Journal of Applied Statistics
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• v.27 no.4
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• pp.543-552
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• 2014

High bandwidth RF such as Bluetooth, GPRS, EDGE, 3GSM, HSDPA is papular in the mobile phone market. A non-conducting metal coating process requires an e-beam deposition of metal, two steps of UV hard coating primer and top coating; however, it is inefficient. We navigate to the electron beam irradiation conditions(resin surface treatment conditions) in the PC/ABS resin injection process. By analyzing the experimental results, we find the optimum development conditions for the electro deposition pre-treatment process and mass production lines using the plasma generated electron beam source.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.542-547
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• 1994

To find out the most reasonable analysis conditions of paeoniflorin, different paeoniflorin extraction methods and various UV detector wavelengths were conducted with paeonia radix of 4-year old Euisung local variety. The most reasonable paeoniflorin extraction time by reflux apparatus was 1hr. and by ultrasonic apparatus was 3hrs. and those methods were completed only once. Concentration of paeoniflorin by reflux apparatuses at 1hr. and 2hrs. of extracting time were higher than those of ultrasonic apparatus, and the differences were highly significant. However, the differences of paeoniflorin concentration at 3hrs. and 4hrs. in two methods were not significant. In comparing paeoniflorin concentration of many lines, ultrasonic extracting apparatus was more simple and effective than the reflux apparatus. Paeoniflorin was more reasonable sensitivity at 240nm, and albiflorin was 254nm by HPLC. When paeoniflorin and albiflorin were analyzed simultaneously, 254nm was more stable than any other wavelength.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.64.2-64.2
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• 2019

HD 81817 is known as a hybrid star. Hybrid stars have both cool stellar wind properties and UV or even X-ray emission features of highly ionized atoms in their spectra. A white dwarf companion has been suggested as the source of UV or X-ray features. HD 81817 has been observed since 2004 as a part of our radial velocity (RV) survey program to search for exoplanets around K giant stars using the Bohyunsan Observatory Echelle Spectrograph (BOES) at the 1.8 m telescope of Bohyunsan Optical Astronomy Observatory (BOAO) in Korea. We obtained 84 RV measurements between 2004 and 2018 for HD 81817 and found two periodic RV variations. The obtained amplitudes of RV periods are around 200 m/s, which are significantly lower than that expected from a white dwarf companion. Furthermore, our re-analysis of the IUE spectra used by Reimers (1984) shows that the excess in UV emission can easily be explained by a pseudo-continuum of unresolved emission lines originating in the extended chromosphere of the star. We thus conclude that there are no companions of stellar mass to HD 81817. Meanwhile, we analyzed two periodicities in RV measurements and conclude that the period of 627.9 days is caused by intrinsic stellar activities based on H alpha equivalent width (EW) variations of a similar period. On the other hand, the period of 1047.8 days is likely to be caused by substellar companion which has a minimum mass of 27.6 M_JUP, a semi-major axis of 3.3 AU, and an eccentricity of 0.17 assuming the stellar mass of 4.3 M_⊙ for HD 81817. The inferred mass puts HD 81817 b in the brown dwarf desert.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.70.3-70.3
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• 2016

Active galactic nuclei (AGNs) typically show a non-thermal continuum locally represented by a power-law and many prominent emission lines in the UV and optical regions. AGNs are classified by two types, where Type I AGNs exhibit both broad and narrow lines and only narrow lines are observed in Type 2 AGNs. The unification models of AGNs invoke the existence of a molecular torus just outside of the broad line region. In the presence of a high column HI region associated with the molecular torus, we propose that significant fraction of broad line photons near Lyman series can be scattered by atomic hydrogen in the torus. In particular, $Ly{\alpha}$ being the strongest emission line, strong linear polarization may develop around $Ly{\alpha}$ through Rayleigh scattering. We adopt a Monte Carlo technique to investigate the polarized transfer of $Ly{\alpha}$ in a thick HI region with the shape of a torus. We consider the range of HI column density N_HI = 1020-23 with fixed geometric parameters of the torus such as the inner and outer radii and the height. We present the polarized spectra and angular distribution of Rayleigh scattered radiation around $Ly{\alpha}$. We find that the $Ly{\alpha}$ core part is polarized in the direction perpendicular to the symmetry axis whereas in the far wing part it is polarized in the parallel direction. It is concluded that the unification of AGNs implies that $Ly{\alpha}$ can be uniquely polarized through Rayleigh scattering.

• Biomedical Science Letters
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• v.17 no.1
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• pp.55-60
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• 2011

Skin is a physical barrier against diverse injury and damages. Exposure to ultraviolet (UV) radiation causes detrimental skin injuries such as inflammation and cell death. The value of natural pigments could be applied to many usages including cosmetics. This study was conducted to examine the protective effect of natural pigments extracted from mulberry, balsam pear, purple-colored sweet potato, pehmannia root, gardenia fruit, and black rice against UV-induced cell death in HaCaT cells, human keratinocyte cell lines. In the present study, the exposure of 50 mJ/$cm^2$ UV-B for 24 hr induced cell death in HaCaT cells, which was prevented by the pretreatment of extracts of mulberry, balsam pear, purple-colored sweet potato, rehmannia root, gardenia fruit, and black rice. In addition, the exposure of 50 mJ/$cm^2$ UV-B for 24 hr also increased lipid peroxide (LPO) formation, compared to control in HaCaT cells, which was prevented by the pretreatment of extracts of mulberry, balsam pear, purple-colored sweet potato, rehmannia root, gardenia fruit, and black rice. In conclusion, the extracts of mulberry, balsam pear, purple-colored sweet potato, rehmannia root, gardenia fruit, and black rice prevented the UV-B-induced cell apoptosis via the inhibition of oxidative stress in HaCaT cells.

• Journal of Microbiology and Biotechnology
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• v.6 no.4
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• pp.245-249
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• 1996

A cytotoxic compound, 8461 was isolated from the culture of Streptomyces sp. strain MCY846 by its cytotoxicity against gastric cancer cell line SNU-l. The IR, UV and NMR spectra of 8461 were identical to those of elaiophylin. This compound showed moderate cytotoxicity against several cell lines and exerted strong inhibitory effect on the synthesis of nitric oxide in the lipopolysaccharide stimulated-Raw 264.7 cells.

• Journal of The Korean Astronomical Society
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• v.33 no.3
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• pp.159-163
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• 2000

We have investigated one dimensional steady flow model of a typical magnetic flux tube in the solar transition region constrained to observed Differential Emission Measure (DEM) for the average quiet-Sun deduced by Raymond & Doyle (1981) with a flux tube geometry conforming to Doppler shifts of UV lines measured by Chae, Yun & Poland (1998). Because local heating and filling factor in the transition region are not well known, we considered two extreme cases, one characterized by the filling factor= 1 ('filled-up model') and the other set by local heating=0 ('not-heated model'). We examined how much the heating is required for the flux tube by recomputing a model through adjustment of the filling factor in such a way that 'not-heated model' accounts for the observed DEM.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.37.1-37.1
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• 2012

We present mid-IR (MIR) and near-UV (NUV) properties of red sequence galaxies defined by optical color-magnitude relation. We use the Wide-field Infrared Survey Explorer (WISE) preliminary released data matched with the SDSS DR7/GALEX GR6. The red sequence galaxies with little emission lines show a wide spread of MIR (3.4um-12um) colors, implying a variety of MIR excess emission. We focus on the properties of the red sequence galaxies with MIR excess, comparing the properties of post-starburst galaxies to trace how galaxies migrate to the red sequence.