• 한국환경성돌연변이발암원학회지
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• 제22권1호
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• pp.1-11
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• 2002

• 천문학회보
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• 제31권2호
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• pp.25.1-25.1
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• 2006

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2001년도 임시총회 및 제18차 학술발표회 발표논문초록집
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• pp.94-94
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• 2001

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.133.1-133.1
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• 2002

• 천문학회보
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• 제40권1호
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• pp.61.1-61.1
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• 2015

We performed a monitoring campaign of a Jupiter-Family comet 17P/Holmes, which underwent the dramatic outburst on 23.3 October 2007 at $r_h=2.44AU$, to investigate the secular change in activity and subsequent physical properties of the inner dust coma before and after the 2014 perihelion passage. The monitoring observation was carried out over two years: from May to July 2013, from July to November 2014, and January 2015 with ~weekly cadence. We conducted photometry monitoring in Rc band using four ground-based telescopes, which are the Ishigakijima Astronomical Observatory 105cm telescope, the Okayama Astrophysical Observatory 50cm telescope, the Nishi-Harima Astronomical Observatory 2m telescope, and the T30 51cm i-telescope, respectively. In order to examine the dust production rate, we put a constraint upon the physical distance from the center of the nucleus as rho=2500km and conducted aperture photometry. We found that the average absolute Rc magnitude over the period between July to November 2014 was mR(1,1,0)~12.29, which was approximately 1.5 magnitudes fainter than those of 2013 data. Accordingly, comet 17P/Holmes seemed to become dormant, although a minor eruption was detected on January 26, 2015. In this presentation, we will introduce our ongoing project for 17P/Holmes and discuss why the nucleus becomes dormant within one orbital period.

• 천문학회보
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• 제40권1호
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• pp.61.2-61.2
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• 2015

15P/Finlay is one of the Jupiter-Family Comets that has long been known since the late 19 century. The comet maintains the perihelion around 1.0 AU over a century, without showing any prominent activities (i.e. fragmentation or eruption) since the discovery. According to reports in unpublished observations, the comet exhibited an outburst in the middle of 2014 December. We conducted a imaging observation of 15P/Finlay just after the report, from 2014 December 23 to 2015 February 18 using three telescopes (the Okayama Astrophysical Observatory 50-cm telescope, the Ishigakijima Astronomical Observatory 105-cm telescope, and the Nishi-Harima Astronomical Observatory 2-m telescope), which constitute a portion of the OISTER (an inter-university observation network in the optical and infrared wavelengths). As a result of the frequent observations, we witnesses the second outburst around UT 2015 January 16. Such cometary outbursts draw the attention to researchers on ground that they could offer insight into the internal structure of comets, following a historical outburst occurred at 17P/Holmes on 2007 October 23. Although cometary outbursts have been often reported mostly in unpublished observations or unreviewed reports, it should be emphasized that there are not a sufficient number of astrophysical research which characterizes the physical properties by observing the aftermaths. This presentation provides a new observational result of 15P/Finlay outburst. Based on the morphological development of the dust cloud as well as the near-nuclear magnitude, we will derive the kinetic energy of the outburst. Finally we plan to compare the results of 15P/Finlay with those of analogical events at 17P/Holmes and P/2010 V1 (Ikeya-Murakami).

• 한국환경성돌연변이발암원학회지
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• 제21권2호
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• pp.128-134
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• 2001

Single cell gel electrophoresis (SCGE) assay, also called comet assay, is a rapid and sensitive method to detect DNA damage in single cell level. To evaluate the DNA damage of lymphocytes of pesticides sprayers, SCGE assay was carried out for 50 pesticides sprayer and 58 control subjects. They were interviewed with structured questionnaire to get the information about the kinds and amount of pesticide. Insecticides and fungicides were predominant among pesticides. Major components of pesticides were organophosphorus, organosulfate, cartap, carbamates, and triazole. Sprayed pesticides were classified into two groups. Group I included organophosphorus, organoarsenic, organotin, tetrazine, triazole and gramoxone, which were known to cause DNA damages. Group II pesticide were carbamates, surfactants, organosulfates, etc., which were not found as DNA damaging agents in scientific documents. Olive tail moments of 100 lymphocytes were measured by KOMET 3.1 program for each person. The means of tail moments were compared between farmers exposed to pesticides and control subjects. Farmers showed higher tail moments than control subjects (2.07$\pm$1.40 vs 1.53$\pm$0.77, p<0.05). The means of tail moments also were compared among group I sprayers (n=36), group II sprayers (n=24) and, control subject, and the means or tail moments were 3.4s$\pm$3.2o, 2.66$\pm$2.20 and 1.53$\pm$0.77 respectively. The difference between means of group I sprayers and controls was statistically significant (p<0.05). In conclusion, this study showed higher DNA damage in farmers exposed to pesticides than control subjects, and comet assay could be useful as a biological monitoring method of genotoxic pesticides for farmers.

• 한국식품위생안전성학회지
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• 제31권5호
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• pp.356-364
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• 2016

식물에서 흔히 존재하는 isoquercetin의 유전독성을 평가하기 위하여 최종평가항목인 DNA 절단 및 염색체 손상을 quercetin과 비교 평가하였다. 7주령의 수컷 ICR 마우스를 사용하였고 3일 동안 시험물질을 경구로 투여하였다. 부형제로 0.5% carboxymethylcellulose를 사용하였고 isoquercetin과 quercetin은 각각 250, 500 mg/kg/day로 투여하였으며, 양성대조물질로 ethyl methanesulfonate 200 mg/kg/day를 사용하였다. 일차 투여 후 48시간에 그리고 마지막 투여 후 3시간 내에 부검하였고 조직을 적출하였다. DNA 손상은 Comet assay를 사용하여 위와 간세포에서 관찰하였고, 소핵시험은 골수세포에서 소핵 분석방법을 사용하여 평가하였다. 두 가지 유전독성 시험을 동일 마우스를 사용하여 수행하였다. 그 결과, isoquercetin과 quercetin의 경구 투여는 500 mg/kg/day에서도 위와 간에서 DNA 손상을 초래하지 않았으며 골수세포에서 소핵을 유발하지 않았다. 따라서 본 연구에서 사용한 플라보노이드는 본 실험 조건하에서 유전독성을 유발하지 않는 것으로 사료된다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2011년도 한국우주과학회보 제20권1호
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• pp.20.1-20.1
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• 2011

We present the results of far-ultraviolet (FUV) observations of comet C/2001 Q4 (NEAT) obtained with Far-ultraviolet Imaging Spectrograph (FIMS) on board the Korean microsatellite STSAT-1, which operated at an altitude of 700 km in a sun-synchronous orbit. FIMS is a dual-channel imaging spectrograph (S channel 900-1150 ${\AA}$, L channel 1350-1750 ${\AA}$, ${\lambda}/{\Box}{\lambda}$ ~ 550) with large image fields of view (S: $4^{\circ}.0{\times}4'.6$, L: $7^{\circ}.5{\times}4'.3$, angular resolution 5'-10') optimized for the observation of diffuse emission of astrophysical radiation. Comet C/2001 Q4 (NEAT) was observed with a scanning survey mode when it was located around the perihelion between 8 and 15 May 2004. Several important emission lines were detected including S I (1425, 1474 ${\AA}$), C I (1561, 1657 ${\AA}$) and several emission lines of CO $A1{\cap}-X1{\sum}+$ system in the L channel. We estimated QCO = ($2.58\;{\pm}\;0.64)\;{\times}\;1028$ s-1 from the production rate of CO 1510 ${\AA}$. We obtained L-channel image which have map size of $5^{\circ}{\times}5^{\circ}$. The image was constructed for the wavelength band of L-channel (1350-1750 ${\AA}$).We also obtained radial profile of S I, C I, CO with line fitting from central coma.

• Environmental Analysis Health and Toxicology
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• 제20권4호통권51호
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• pp.365-374
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• 2005

Ambient air particulate matters are classified into two distinct modes in sire distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effect on human populations has long been recognized. However, the toxicology of these adverse efforts has not been clarified. We investigated the genotoxic effect of PM 2.5 collected from urban area in Seoul by comet assay (A549 cells), CBMN assay (CHO-K1 cells) and EROD-microbioassay (H4IIE cells). Results from in vitro micronucleus assay and comet assay showed that PM 2.5 samples collected from traffic area, residential area and indoor air induced chromosomal damage and DNA breakage in a non-cytotoxic dose. The complex mixture effect of these PM 2.5 extracts was quantified by EROD-microbioassay in terms of its bio-TEQ (biologiral -TCDD equivalent concentration) which was 70.87$\pm$28.07, 93.55$\pm$21.80 and 14.31 $\pm$ 1.10 ng/g-PM 2.5 in traffic area, residental area and indoor air samples, respectively. Conclusively, we suggested that PM 2.5 collected from traffic area and residential area contains CYPIA inducer and genotoxic materials.