• Analytical Science and Technology
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• v.25 no.2
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• pp.133-145
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• 2012

The quantitative composition of total suspended particulates (TSP) in the atmosphere is identified to consist mainly of ions, organic carbon (OC), element carbon (EC), and metals. In terms of environmental analysis, the rest of the TSP composition may be defined as unknown fraction (${\Sigma}X$) which is yet difficult to analyze both quantitatively and qualitatively. In this study, the major components of TSP were measured at an urban residential area (Gang Seo) in Seoul, Korea from February to December 2009. These TSP data were analyzed in various respects to explain the relationship between known and unknown constituents. During this study period, TSP was comprised mainly of unknown compounds (48.6%) followed by ions, OC, EC, and metals. The results of this study indicate that the distribution of ${\Sigma}X$ exhibits a strong similarity with ${\Sigma}Anions$, as they both increase with increasing TSP levels. However, if the concentrations of ${\Sigma}X$ and ${\Sigma}Anion$ are normalized against TSP, they exhibit a strong inverse correlation with each other due probably to larges differences in solubility. To establish a better strategy for air quality control in urban atmosphere, more efforts are needed to characterize unidentified proportion of particulate matters.

• Journal of Microbiology
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• v.43 no.4
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• pp.345-353
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• 2005

The complex ecosystem of intestinal micro flora is estimated to harbor approximately 400 different microbial species, mostly bacteria. However, studies on bacterial colonization have mostly been based on culturing methods, which only detect a small fraction of the whole microbiotic ecosystem of the gut. To clarify the initial acquisition and subsequent colonization of bacteria in an infant within the few days after birth, phylogenetic analysis was performed using 16S rDNA sequences from the DNA iso-lated from feces on the 1st, 3rd, and 6th day. 16S rDNA libraries were constructed with the amplicons of PCR conditions at 30 cycles and $50^{\circ}C$ annealing temperature. Nine independent libraries were produced by the application of three sets of primers (set A, set B, and set C) combined with three fecal samples for day 1, day 3, and day 6 of life. Approximately 220 clones ($76.7\%$) of all 325 isolated clones were characterized as known species, while other 105 clones ($32.3\%$) were characterized as unknown species. The library clone with set A universal primers amplifying 350 bp displayed increased diversity by days. Thus, set A primers were better suited for this type of molecular ecological analysis. On the first day of the life of the infant, Enterobacter, Lactococcus lactis, Leuconostoc citreum, and Streptococcus mitis were present. The largest taxonomic group was L. lactis. On the third day of the life of the infant, Enterobacter, Enterococcus faecalis, Escherichia coli, S. mitis, and Streptococcus salivarius were present. On the sixth day of the life of the infant, Citrobacter, Clostridium difficile, Enterobacter sp., Enterobacter cloacae, and E. coli were present. The largest taxonomic group was E. coli. These results showed that microbiotic diversity changes very rapidly in the few days after birth, and the acquisition of unculturable bacteria expanded rapidly after the third day.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.768-773
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• 2014

In this study, experimental and numerical studies for the synthesis of carbon nanotube(CNT) in methane counterflow diffusion flame have been performed. Methane mixed with acetylene($C_2H_2$) was used as a fuel gas and ferrocene was used as a catalyst for synthesis of CNT. The major parameters was $C_2H_2$ mixing rate and mixing rates were 2 %, 6 %, and 10 %. Characteristics of CNT formation on grid were analyzed from SEM images. the chemical reaction mechanism adopted is GRI-MECH 3.0. Numerical results showed that flame temperature and CO mole fraction were increased with increasing acetylene mixing rate. Experimental results showed that the CNT synthesis in 2% acetylene mixture flame better than that of 6% and 10% acetylene mixture flames. It can be considered that 6% and 10% acetylene mixture flames generated the excessive carbon source and then it interrupted the supplement of the carbon source into ferrocene catalyst. It can be found that the supply of appropriate quantity of carbon source can make effect to synthesis of high purity of CNT.

• Journal of Powder Materials
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• v.28 no.2
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• pp.143-149
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• 2021

In this study, (GaN)_1-x(ZnO)_x solid solution nanoparticles with a high zinc content are prepared by ultrasonic spray pyrolysis and subsequent nitridation. The structure and morphology of the samples are investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The characterization results show a phase transition from the Zn and Ga-based oxides (ZnO or ZnGa₂O₄) to a (GaN)_1-x(ZnO)_x solid solution under an NH3 atmosphere. The effect of the precursor solution concentration and nitridation temperature on the final products are systematically investigated to obtain (GaN)_1-x(ZnO)_x nanoparticles with a high Zn concentration. It is confirmed that the powder synthesized from the solution in which the ratio of Zn and Ga was set to 0.8:0.2, as the initial precursor composition was composed of about 0.8-mole fraction of Zn, similar to the initially set one, through nitriding treatment at 700℃. Besides, the synthesized nanoparticles exhibited the typical XRD pattern of (GaN)_1-x(ZnO)_x, and a strong absorption of visible light with a bandgap energy of approximately 2.78 eV, confirming their potential use as a hydrogen production photocatalyst.

• Radiation Oncology Journal
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• v.18 no.2
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• pp.133-137
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• 2000

Purpose :To investigate whether combined beta-carotene with X-Irradiation has more enhanced radition response than X-irradiation or not, we peformed a experiment about in vitro cytotoxlcity of beta-carotene and/or X-irradiation in the fibrosarcoma cells, tumor growth delay of combined beta-caroten with/or X-irradiation in the mouse fibrosarcoma. Materials and Methods : 2$\%$ emulsion of beta-carotene was serially diluted and used. X-Irradiation was given by 6 MeV linear accelerator. The cytotoxicity of beta-carotene in vitro was evaluated from clonogenic assay. To compare the cytotoxiclty between combined beta-carotene with X-irradiation and X-irradiation group, 2 mg/ml of beta-carotene was contacted to fibrosarcoma (FSall) cells for 1 hour before X-irradiation. For the tumor growth delay, single 20 Gy was given to FSall tumor hearing C3H/N mice whic was classified as beta-crotene with X-irradiation group (n=5) and X-irradiation alone group (n=5). 0.2 ml of 20 mg/kg of beta-carotene were i.p. injected to mice 30 minute before X-irradiation in the beta-crotene with X-irradiation group. The tumor growth delay defined as the time which reach to 1,000 mm$^{3}$ of tumor volume. Results : (1) Cytotoxicity in vitro: 1) survival fraction at beta-carotene concentration of 0.002,0.02,0.2 and 2 mg/ml were 0.69$\pm$0.07, 0.59$\pm$0.08, 0.08$\pm$0.008 and 0.02$\pm$0.006, respectively. 2) each survival fraction at 2, 4, 6 and 8 Gy in the 2 mg/ml of beta-carotene + X-irradiation group were 0.13$\pm$0.05, 0.03$\pm$0.005, 0.01 $\pm$0.002 and 0.009$\pm$0.0008, respectively. But each survival fraction at same irradiation dose in the X-irradiation group were 0.66$\pm$0.05, 0.40$\pm$0.04, 0.11$\pm$0.01 and 0.03$\pm$0.006, respectively(p<0.05). (2) The time which reach to 1,000 mm$^{3}$ of tumor volume of beta-carotene + X-irradiation group and X-irradiation alone group were 18, 19 days, respectively(p>0.05) Conclusion : The contact of beta-caroten to Fsall cells showed mild cytotoxicity which 띤as increased according to concentration. The cytotoxicity of combined beta-carotene with X-irradiation more increased than that of X-irradiation, additionally, And there was significant difference of cytotoxicity between two groups. But there were no significant difference of the growth delay of fibrosarcoma between two groups.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.80-109
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• 2020

The Sacheonwangsa Temple in Silla is an esoteric temple that was founded provisionally in 670, and was completed in 679. This study attempted to elucidate the planning method of the Sacheonwangsa Temple based on the results of research on excavations and investigations into its construction processes and construction measures thereof. The research results are as follows. (1) In the site construction, assuming the size of one Bang (坊) on the south of Nangsan Mountain, after dividing the north-south width into three equal parts, there is a possibility that two of these parts were set to the flat portion. (2) In the 'Jochang (祖創, 670)', it is estimated that an area of 300 cheoks by 300 cheoks was postulated on the flat surface, and, as an initial conception, the mandala's plane design of the outer square 2 hasta (3 cheoks) and inner square 1 hasta (1.5 cheoks) was originally devised for the setting of 'Mudra (神印)', and an area 100 times greater has been set as the basis in the scale and layout planning of the central block. (3) During 'Gaechang (攺刱, ~679)', it is judged that because of the narrowness of the distance between the Pagoda and Geumdang Hall, which occurs when the center of the Geumdang Hall coincides with the center of 'the first stage of the foundation (先築基壇)', the scale and layout planning were adjusted from the initial conception. (4) The arrangement of the building was determined by dividing the fixed size of the central block (280 cheoks by 320 cheoks). Specifically, the east-west direction is set on the quartile's line of the east-west width of the central block, and in contrast, the north-south direction is based on the structural characteristics of the central block. It is presumed that the position of the transept was determined through the division and adjustment of the column spacing of the east-west corridor, then the Geumdang Hall and Altar were based on this. (5) The scale of the Geumdang Hall and Pagoda is determined by the petition of the division by the unit fraction starting from the quartile's line of the central block's east-west width. This planning is understood to be based on the self-similarity, which is rooted in the mandala's plane design as the model.

• Journal of the Mineralogical Society of Korea
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• v.32 no.3
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• pp.163-172
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• 2019

A long core (RS15-LC48) was collected at a site in the continental rise between the Southern Ocean and the Ross Sea (Antarctica) during the 2015 Ross Sea Expedition. The mineralogical characteristics and the origin of clay minerals in marine sediments deposited during the Quaternary in the Ross Sea were determined by analyzing sedimentary facies, variations in grain size, sand fraction, mineralogy, clay mineral composition, illite crystallinity, and illite chemical index. Core sediments consisted mostly of sandy clay, silty clay, or ice rafted debris (IRD) and were divided into four sedimentary facies (units 1-4). The variations in grain size distribution and sand content with depth were very similar to the variations in magnetic susceptibility. Various minerals such as smectite, chlorite, illite, kaolinite, quartz, and plagioclase were detected throughout the core. The average clay mineral composition was dominated by illite (52.7 %) and smectite (27.7 %), with less abundant clay minerals of chlorite (11.0 %) and kaolinite (8.6 %). The IC and illite chemical index showed strong correlation trends with depth. The increase in illite and chlorite content during the glacial period, together with the IC and chemical index values, suggest that sediments were transported from the bedrocks of the Transantarctic Mountains. During the interglacial period, smectite may have been supplied by the surface current from Victoria Land, in the western Ross Sea. High values for IC and the illite chemical index also indicate relatively warm climate conditions during that period.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1383-1389
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• 2004

The nutritive value and utilization of whole crop rice silage (WCRS), Hamasari, at yellow mature stage was determined by three studies. In first study, chemical composition, in vivo digestibility and metabolizable energy (ME) content of WCRS was determined by Holstein steers. WCRS contains 6.23% CP, its digestibility is 48.4% and estimated TDN is 56.4%. Its ME content was 1.91 Mcal/kg DM. Gross energy (GE) retention (% of GE intake) in steers is only 22.7% most of which was lost through feces (44.7% of GE intake). It takes 81 minutes to chew a kg of WCRS by steers. In another study, the effect of Hamasari at yellow mature stage at three stages of lactation (early, mid and late lactation) and two levels of concentrate (40 or 60%) on voluntary intake, ME content and ME intake, milk yield and composition using lactating Holstein dairy cows were investigated. Total intake increased with the concentrate level in early and mid lactation, but was similar irrespective of concentrate level in late lactation. WCRS intake was higher with 40% concentrate level than with 60% concentrate. ME intake by cows increased with the concentrate level and WCRS in early lactating cows with 40% concentrate can support only 90% of the ME requirement. Milk production in accordance with ME intake increased with the increase in concentrate level in early and mid lactating cows but was similar in late lactating cows irrespective of concentrate level. Fat and protein percent of milk in mid and late lactating cows were higher with for 60% concentrate than 40%, but reverse was in early lactating cows. Solids-not-fat was higher with for 60% concentrate than 40% concentrate. Finally in situ degradability of botanical fractions such as leaf, stem, head and whole WCRS, Hamasari at yellow mature stage was incubated from 0 to 96 h in Holstein steers to determine DM and N degradability characteristics of botanical fractions and whole WCRS. Both DM and N solubility, rate of degradation and effective degradability of leaf of silage was lower, but slowly degradable fraction was higher compared to stem and head. Solubility of DM and N of stem was higher than other fractions. The 48 h degradability, effective degradability and rate of degradation of leaf were always lower than stem or head. In conclusion, voluntary intake of silage ranged from 5 to 12 kg/d and was higher with low levels of concentrate, but milk yield was higher with high levels of concentrate. Fat corrected milk yield ranged from 19 to 37 kg per day. For consistency of milk, early lactating cows should not be allowed more than 40% whole crop rice silage in the diet, but late lactating cows may be allowed 60% whole crop rice silage.

• Journal of Life Science
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• v.28 no.3
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• pp.293-299
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• 2018

Viticis fructus (fruits of Vitex rotundifolia) is the dried fruit from Vitex rotundifolia; is a traditional medicine for treating inflammation, migraines, chronic bronchitis, headaches, eye pain, and gastrointestinal infections; and demonstrates various bioactivities, including anti-allergic, anti-cancer, and anti-inflammatory effects, which are partly due to its phenolic compound content. This study examines the inhibitory effects of viticis fructus (fruits of Vitex rotundifolia) on MMP-2 and MMP-9 expression using gelatin zymography and RT-PCR in phorbol-12-myristate-13-acetate (PMA)-induced HT-1080 fibro-sarcoma cells. Fruits of Vitex rotundifolia were extracted twice using dichloromethane ($CH_2Cl_2$) and methanol (MeOH). The combined crude extracts ($CH_2Cl_2$ and MeOH) significantly inhibited MMP-2 and MMP-9 activities in gelatin zymography. The combined extracts were fractionated into n-hexane, 85% aqueous methanol (85% aq. MeOH), n-butanol, and water, successively according to polarity. Among all solvent-partitioned fractions, 85% aq. MeOH fractions showed the strongest inhibition on the activation of MMP-2 and MMP-9 in gelatin zymography. In PMA-stimulated HT-1080 cells, the expression levels of MMP-2 and MMP-9 mRNA were also greatly inhibited by the 85% aq. MeOH fraction. These results suggest that viticis fructus can be used as an excellent source for anti-invasive agents.

• Journal of Preventive Medicine and Public Health
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• v.36 no.4
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• pp.373-376
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• 2003

Objectives : Peripheral blood-buffy coat fractions (N=14,956) have been stored at $-70^{\circ}C$ in the headquarter of the Korean Multicenter Cancer Cohort (KMCC), since 1993. To study the future molecular etiology of cancers using specimens of the cohort, properly stored specimens are necessary, Therefore, the DNA-viability of the bully coat samples was investigated. Methods : Buffy coat fraction samples were randomly selected from various collection areas and years (N=100). The DNA viability was evaluate from the UV-absorbent ratios at 260/280nm and the PCH for $\beta$-globin was performed with genomic DNA isolated from the buffy coat. Results : PCR products were obtained from 85 and 98% of the C and H area-samples, respectively, using 50 or $100{\mu}l$ of the buffy coat. There were significant differences in the yields of the PCR-amplifications from the C and H areas (p<0.05), which was due to differences in the homogenization of the buffy coat fractions available as aliquots. The PCR-products were obtained from all of the samples (N=7) stored at the C area-local confer, but the other aliquots stored at the headquarter were not PCR-amplified, Therefore, the PCR products in almost all the samples, even including the DNA-degraded samples, were obtained. In addition, an improvement in the DNA isolation, i,e. approx. 1.6 fold, was found after using extra RBC lysis buffer. Conclusions : PCR products for $\beta$-globin were obtained from nearly all of the samples. The regional differences in the PCR amplifications were thought to have originated from the different sample-preparation and homogenization performance. Therefore, the long term-stored buffy coat species at the KMCC can be used for future molecular studies.