• 한국환경보건학회지
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• 제26권2호
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• pp.108-115
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• 2000

The mass fraction of PM10 had a bimodal distribution in the middle of between 2.1 ${\mu}{\textrm}{m}$, and the average mass fraction of particles less than 2.1~3.1 ${\mu}{\textrm}{m}$ was 54.1% for Pb and 890.8 ng/㎥ for Fe, respectively. For the concentration of PM10 and metallic elements by seasonal variation, PM10 showed bimodal distribution, while metallic elements showed different distributions by their sources. The ratios of fine particles to total mass were 0.45 for PM10, 0.41 for Cr, and 0.20 for Fe, 0.57 for Zn, 0.68 for Cd and 0.63 for Pb, respectively. That facts indicated that PM10, Zn, Cd, Cr and Pb were from anthropogenic sources, and Fe was from natural source. The geometric means and geometric standard deviations by seasonal variations were 3.6 ${\mu}{\textrm}{m}$ , 2.31 ${\mu}{\textrm}{m}$ in winter, 3.0 ${\mu}{\textrm}{m}$ , 2.49 ${\mu}{\textrm}{m}$ in spring, 2.7 ${\mu}{\textrm}{m}$ , 2.03 ${\mu}{\textrm}{m}$ in summer respectively. And, total efficiency of cascade impactor by seasonal variations were 49.6% in winter, 45.9% in spring and 44.5% in summer.

• 한국식품조리과학회지
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• 제13권1호
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• pp.56-63
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• 1997

천연물에 존재하는 항균성 물질을 이용하여 천연식품보존제를 개발하고자 한약재 및 민간요법으로 사용되어온 우리나라 전통 향신료인 산초의 항균성을 검색한 결과 클로로포름 분획 에서 B. subtilis, E. coli, L.plantarum 및 S. aureus 등 4종의 균주에 대해 모두 l000 $\mu\textrm{g}$/$m\ell$에서 가장 큰 저해능을 보였으며, 에틸아세테이트 분획 또한 B. sutilis와 E. coli에 대해서 각각 1000 $\mu\textrm{g}$/$m\ell$과 500 $\mu\textrm{g}$/$m\ell$에서 성장이 억제되었다. 가장 큰 활성을 보인 클로로포름층을 다시 분획하여 4그룹으로 나누어 항균성을 검색한 결과 3번 분획에서 4균주에 대해 750 $\mu\textrm{g}$/$m\ell$에서 성장저해 효과를 보였다. chloroform 2차 분획에서 활성이 높게 나타난 subfraction No. 2는 IR, NMR, 그리고 Gchfs를 이용하여 분석한 결과 hexadecanoic acid로 동정되었다.

• 한국환경과학회지
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• 제11권12호
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• pp.1299-1305
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• 2002

Thirty sediment samples of the <63${\mu}{\textrm}{m}$ fraction collected from the southwestern coast of Korea were analysed for their heavy metal (Fe, Mn, Cr, Co, Cu, Ni, Zn and Pb) concentration. The results show that sediment texture plays a controlling role on the total metal concentrations and their spatial distribution. A single lM HCl extraction procedure was used in order to assess the environmental risk of heavy metals in bottom sediments. The non-residual fraction was the most abundant pool for Mn and Pb in most samples, which means that this metals are highly avaliable in these sediments. Cr, Ni, Fe, Co, Zn and Cu were mainly associated with the residual fraction, suggesting that their concentrations are controlled significantly by transport processes with the fine particles as carriers from diffuse pollution source. Concentration enrichment ratios(CER) were calculated from the non-residual contents and their values allowed us to classify the sediments according to their environmental risk.

• 한국재료학회지
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• 제10권12호
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• pp.799-806
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• 2000

63Sn-37Pb에 Cu$_{6}$Sn$_{5}$를 분산시킨 760$\mu\textrm{m}$크기의 솔더범프를 Au(0.5$\mu\textrm{m}$)/Ni(5$\mu\textrm{m}$)/Cu(27$\pm$20$\mu\textrm{m}$) BGA 기판에 스크린)/Ni(5im)/Cu(27:201m) B3GA 기판에 스크린 프린팅법으로 제조하여, 리플로우 피크온도 유지시간, 15$0^{\circ}C$ 시효처리 시간에 따른 전단강도를 분석하였다. Cu$_{6}$Sn$_{5}$를 첨가한 솔더범프는 피크온도에서 30초간 유지시에는 63Sn-37Pb 솔더범프보다 높은 전단강도를 나타내었으나, 피크온도 유지시간을 60초 이상으로 증가시킴에 따라 전단강도가 63Sn-37Pb 솔더범프보다 저하하였다. 전단시험 후 솔더범프의 파단면은 초기에 전단 균열의 점진적인 전파에 의해 발생된 파괴부위와 점진적 균열전파에 의한 면적 감소로 솔더범프가 급격히 떨어져 나가면서 발생한 파괴부위로 구분할 수 있었다 피크온도 유지시간, 15$0^{\circ}C$ 시효처리 시간 및 Cu$_{6}$Sn$_{5}$ 첨가량에 무관하게 점진적 파괴모드에 의한 균열 전파길이가 증가할수록 솔더범프의 전단강도가 감소하였다.감소하였다.

• 한국식품영양과학회지
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• 제32권7호
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• pp.1071-1075
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• 2003

차가버섯 분획물의 항산화활성과 유전독성 억제효과를 규명하기 위하여 차가버섯으로부터 조다당, 불용성 조다당 I과 II를 각각 추출하였으며 그 여액에서 저분자 물질과 에틸 아세테이트, 물 분획물을 얻었다. 얻어진 시료들은 DPPH free radical 소거능으로 항산화 활성을 측정하였으며, 마우스를 이용한 소핵실험으로 유전독성 억제효과를 검토하였다. 실험결과, 에틸 아세테이트 분획물의 RC$_{50}$ 이 46.5 $\mu\textrm{g}$으로 월등히 높았으며, 물 분획물과 수용성 다당도 각각 78.3$\mu\textrm{g}$과 77.4$\mu\textrm{g}$으로 다른 분획물에 비해 높은 항산화 효과를 나타내었다. 그리고 유전독성 억제효과에서는 양성대조군에 비하여 최고 농도인 80 mg/mg에서 저분자 물질과 에틸 아세테이트 분획물, 물 분획물, 수용성 다당 그리고 불용성 다당 I 및 II에서 각각 63.9%, 72.2%, 63.9%, 88.9%, 80.6% 그리고 81.5%의 소핵생성 억제효과를 나타내었으며 다당 분획물들이 80% 이상의 높은 억제율을 나타내었다.

• 한국대기환경학회지
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• 제16권5호
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• pp.431-443
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• 2000

The purpose of this experimental study is to investigate seasonal deposition flux variations and deposition velocities of the total dusfall and various inorganic elements in it. Total 41 dustfall and TSP samples were collected from November, 1997 through December, 1998 in Kunsan. Each sample was analyzed by and AAS to determine he levels of 5 inorganic elements: Zn, Cd, Cr, Fe and Pb. Deposition fluxes, soluble/total fractions and deposition velocities for each element were extensively investigated. Estimated dry deposition fluxes of dustfall and elements in Kunsan were in the range of 14.6~48.8(mean 25.6) ton/$\textrm{km}^2$/yr for dustfall, 14.5~72.6(mean 44.1)kg/$\textrm{km}^2$/yr for Zn, 0.9~0.5(mean 3.0) kg/$\textrm{km}^2$/yr for Cd, 2.1~239.2(mean 63.9) kg/$\textrm{km}^2$/yr for Cr, 331.6~1,082.7(mean 873.9) kg/$\textrm{km}^2$/yr for Fe, 5.2~178.4(mean 49.2) kg/$\textrm{km}^2$/yr for Pb, respectively. And the concentra-tion of TSP and elements in Kunsan were 71$\mu\textrm{g}/m^3$ for TSP, $29.9ng/m^3$ for Zn, $0.6ng/m^3$ for Cd, $0.1 ng/m^3$ for Cr, $1,061.0 ng/m^3$ for Fe, $4.0 ng/m^3$ for Pb, respectively. And the estimated deposition velocity of dustfall and elements in Kunsan were 1.13$\times$ 10(sup)-2 cm/sec for dustfall, 4.67$\times$ 10(sup)-2 cm/sec for Zn, 16.92 cm/sec for Cd, 15.69 cm/sec for Cr, 1.72$\times$ 10(sup)-2 cm/sec for Fe, 0.36 cm/sec for Pb, respectively.

• Journal of Microbiology
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• 제35권1호
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• pp.1-9
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• 1997

Distribution of airborne microorganisms was determined with two different types of air samplers, the Anderson cascade sampler and the Aerobioscope sampler, in the vicinity of Taejon. The size distribution of particles carrying bacteria and fungi was concurrently measured. The concentration of detected viable airborne particles was greatly varied. It was observed that the number of microbial particles increased in April and October. The most isze o particles carrying bacteria was larger than 4.7 .mu.m in mean aerodiameter, which made up 69.8% of the total particle fraction. About 63.2% of fungi-carrying particles were smaller than 4.7 .mu.m in aerodiameter. The distribution of particles on Yellow Sand Phenomena days was also analyzed. The number of fine particles having mass median aero-diameter from 1.0 to 10.mu.m increased on Yellow Sand Phenomena days to about 6 times that on normal days and the n umber of colony forming unit (CFU/$\textrm{m}^3$) of airborne bacteria also increased by 4.3 times in April. The reuslts from the Anderson sampler showed that the concentration of bacteria increased greatly on the fraction of fine particles ranging from 0.6 $\mu$m to 4.7 $\mu$m in diameter. Unlike the increase in bacterial floraon Yellow Sand Phenomena days, the fungal concentration slightly decreased and showed a normal size distribution parttern. This study suggests that a long-range transmission of bacteria results form bacteria adsorbing onto the fine particles during the Yellow Sand Phenomena.

• Biomolecules & Therapeutics
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• 제7권2호
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• pp.153-157
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• 1999

The anticancer effect of medicinal plants against two oral carcinoma cells, A253 and SCC-25 were investigated in this study. Methanol extracts from 63 medicinal plants, which have anticancer activities against other cancers such as stomach, hepatocellular or colon carcinomas, were prepared and screened for their anti- oral cancer activity by using MTT assay. Thirty one samples showed anti-oral cancer activity against either cell line used, however, other 32 samples had no anti-oral cancer activity. Among these samples methanol extract of Caesalpinia sappan revealed the strongest anti-oral cancer activity. The $IC_{50}$/ values of this extract against A253 and SCC-25 cells were 16 and 25 $\mu$g/m1, respectively. Fractions of n-hexane, dichloromethane, ethylacetate, n-buthanol and water were prepared from methanol extracts of Caesalpinia sappan, Anthriscus sylvestris, Rhus japonica, Curcuma arowatica, Inula helenium, Sinoarnudinaria reticulata, and Polygonum cuspidatum, respectively. Among these 35 fractions the n-hexane fraction of Inula helenium showed the strongest anti-oral cancer activity, the $IC_{50}$/ value was 1.6$\pm$0.3 $\mu\textrm{g}$/ml. Ten other fractions showed $IC_{50}$/ values lower than 10 $\mu\textrm{g}$/ml.

• 한국환경보건학회지
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• 제27권4호
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• pp.63-71
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• 2001

PM 2.5/ samples were measured at two sites, Hadan(suburban site) and Anrak (roadside site) in Busan area. PM 2.5/ sampling was performed for 24-hour intervals by the FH9.5 particulate sampler. Aerosol samples were collected on PTFE filter. A total of 60 particulate samples were collected, dad samples were measured for Particulate mass concentration, metallic elements (Cr, Mn, Ni. Cu. Se, Fe, Pb, and Zn) and waer-soluble elements (C $l^{[-10]}$ , N $O_{3}$$^{[-10]}$ ,S $O_{4}$$^{2-}$, N $H_{4}$$^{+}$, $Ca_{2}$$^{+}$, $Mg_{2}$$^{+}$ and $^{+}$.Mass concentration in Hadan ranged 24.23~57.12 $\mu\textrm{g}$/㎥ and 60.22~72.12 $\mu\textrm{g}$/㎥m Yellow Sand Events. Major cations in Hadan and Anrak site is N $H_{4}$$^{+}$and N $a^{+}$ respectively. SO42$^{[-10]}$ was the abundant specie in the PM 2.5 fraction for Hadan site an dAnrak site. Hadan site showed igher concentration in S $O_{4}$$^{2.1}$ and N $H_{4}$ $^{+}$ In Anrak site the concentration of S $O_{4}$/sip 2-/and N $a^{+}$ was higher than other ions Prominent metallic elements were Fe and Pb in two sites. Principal component analysis showed that main source of PM 2.5 aerosol particles was non-metal related source which was resulted in relating elements as Cr, Ni, and Pb at Hadan site, Anrak site also has resulted PM2.5 aerosol paricles source, which was related its element like Zn, and Ni,. The SAS package analysis also showed that long-range transport effect at Hadan area due to Yellow Sand Event by the prevailing weaterlies.ling weaterlies.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.375-380
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• 2000

The preliminary screening of several cyanobacteria, using mice bioassay, reveale the production of a hepatotoxin by the cyanobacterium Scytonema sp. strain BT 23 isolated from soil. An intraperitoneal injection of the crude toxin (LD50 56 mg/kg body wt) from this strain caused the death of the mice within 40 min, and the anmals showed slinical signs of mice within 40 min, and the animals showed clinical signs of hepatotoxicity. The toxin was purified and partially characterized. The active fraction appears to be nonpolar in nature and shows absorption peaks at 240 and 285 nm. The purified toxin had an LD50 of TEX>$100<\mu\textrm{g}/kg$ body wt and the test mice died within 40 min of toxin administration. The toxin-treated mice showed a 1.65-fold increase in liver weight at 40 min and the liver color chnged to dark red due to intrahepatic hemorrhage and pooling of blood. Furthermore, the administration of the toxin to test mice induced a 2.58, 2.63, and 2.30-fold increse in the activity of the serum enzymes alanine aminotransferase, lactate dehydrogenase, and alkaline phosphatase, respectively. Further experiments with the 14C-labeled toxin revealed a maximum accumulation of the toxin in the liver. The clinical symptoms in the mice were similar to those produced by microcystin-L.R. These results suggest that hepatotoxins may also be produced in non bloom-forming planktonic cyanobacteria.