• 제목/요약/키워드: LC20

검색결과 645건 처리시간 0.031초

EQC모델을 이용한 Acetanilide의 환경중 분포예측 (Estimated Environmental Distribution of Acetanilide Using EQC Model)

  • 박광식;권민정;최윤호;송상환;박혜연;구현주
    • Environmental Analysis Health and Toxicology
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    • 제16권3호
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    • pp.133-137
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    • 2001
  • Acetanilide is a High Production Volume Chemical, which is produced about 2,300 tons/year in Korea as of 1998 survey. Most is used as an intermediate for synthesis of pharmaceuticals and dyes and the chemical is one of seven chemicals of which human and environmental risks are being assessed by National Institute of Environmental Research under the frame of OECD SIDS program. The chemical is water soluble (4 g/1 at 20$\^{C}$) and readily biodegradable (68.7%). Partition coefficiency (Log Pow) is 1.16 at 23$\^{C}$ so that the chemical has a low potential for bioaccumulation. The acute toxicities of algae, daphnia and fish are not high. The 72 hr-EbC50 of algae is 13.5 mg/1,48 hr-EC50 of daphnia is over 100 mg/1 and 96 hr-LC50 of Oryzias latipes is over 100mg/1. Regarding the exposure, levels in air, water, soil or sediment have not been monitored or estimated so that risk evaluation of acetanilide was not possible. In this study, distribution of the chemical among environmental media was estimated using EQC model based on the chemical-physical properties. In Level I and IIof which the chemical are hypothesized in equilibrium and no transfer through the media, more than 98% of acetanilide are estimated to be distributed in water. However, in Level Ⅲ of which non-equilibrium and intermedia transfer could be occurred, the chemical is estimated to distributed to soil as 51.8% and water as 47.8% as of total amount.

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Simple Purification of the Human Antimicrobial Peptide Dermcidin (MDCD-1L) by Intein-Mediated Expression in E. coli

  • Hong, In-Pyo;Kim, Yong-Seok;Choi, Shin-Geon
    • Journal of Microbiology and Biotechnology
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    • 제20권2호
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    • pp.350-355
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    • 2010
  • Among human antimicrobial peptides (hAMPs), DCD-1L has a broad spectrum of antimicrobial activity over a wide pH range and in high salt concentrations. It offers a promising alternative to conventional antibiotics. The 458-bp-long dermcidin cDNA was amplified by PCR using a human fetal cDNA library as a template. The 147-bp fragment of the MDCD-1L gene encoding an additional methionine residue was subcloned into the pTYB11 vector. Recombinant MDCD-1L was expressed as an intein fusion protein in E. coli, and then purified by affinity chromatography using chitin beads. A small peptide with a molecular mass of about 5 kDa was detected by tricine gel electrophoresis. The recombinant MDCD-1L peptide was purified from the gel and its amino acid sequence was determined by nanoLC-ESI-MS/MS analysis. The initiating amino acid, methionine, remained attached to the N-terminal region of recombinant MDCD-1L. Purified MDCD-1L showed antimicrobial activity against a Micrococcus luteus test strain.

카보푸란에 의한 송사리 acetylcholine esterase 및 monoamine oxidase의 활성조절 (Regulation of Acetylcholine Esterase and Monoamine Oxidase in Oryzias Latipes by Carbofuran)

  • Kim, Sung-Hee;Kim, Woo-Keun;Lee, Jeong-Soon;Koh, Sung-Cheol;Lee, Sung-Kyu;Chon, Tae-Soo;Kim, Jong-Sang
    • Environmental Analysis Health and Toxicology
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    • 제18권1호
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    • pp.21-25
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    • 2003
  • 카바메이트계 농약인 카보푸란은 어류에 대한 독성이 매우 높으며, 낮은 농도에서 어류의 척추기형이나 행동이상을 유발한다. 이러한 카보푸란의 독성기전을 밝히기 위한 일환으로 신경물질대사와 관련이 깊은 acetylcholine esterase(AChE)와 monoamine oxidase(MAO)에 미치는 농약의 효과를 송사리(Oryzias latipes; Medaka fish)를 이용하여 평가하였다. Medaka fish에 대한 카보푸란의 반수치사농도(LC$_{50}$)는 2.5 ppm이었으며, 1 ppb 카보푸란에 24시간 노출된 경우, AChE 효소활성이 머리와 몸통부위에서 각각 30, 20%씩 감소되었다. 한편, MAO 효소활성은 카보푸란의 농도가 증가함에 따라 머리부위에서는 감소한 반면, 몸통부위에서는 증가하는 경향을 보였다. 특히 카보푸란의 농도가 1 ppb에서도 송사리의 MAO 효소활성이 영향을 받는 것으로 나타나, 카보푸란에 의한 송사리의 행동이상은 AChE 활성 뿐 아니라 MAO활성의 변화에 의한 복합적인 효과일 가능성이 높다.

Metabolism and Excretion Study of DW116, A New Fluoroquinolone, in Rats

  • Jung, Byung-Hwa;Park, Young-Han;Park, Jongsei;Chung, Bong-Chul
    • Archives of Pharmacal Research
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    • 제20권4호
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    • pp.358-362
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    • 1997
  • Metabolite identification and urinary and biliary excretion of the new fluoroquinolone antibacterial agent DW116 [1-(5-fluoro-2-pyridyl)-6-fluoro-7-(4-methyl-1 -piperazinyl)-1, 4-dihydro-4-oxoquinoline-3-carboxylic acid, hydrochloride] after oral administration have been studied in Sprague-Dawley rats. The excretion kinetics were monoexponential. Most of the drug was eliminated via the hepatic and renal routes. Mean renal clearance of DW116 was 73.4 ml/hr/kg and mean biliary clearance was 83.8 ml/hr/kg. The major metabolite excreted in the bile was identified as the glucuronide ester of the parent drug using base-hydrolysis of the conjugate metabolite followed by co-HPLC with standard compound, $^{19}$ F-NMR and LC-MS methods. The glucuronide conjugate was also found in urine. The mean urinary recoveries of free and total (free plus glucuronide ester) DW116 were $28.6{\pm}2.7% $and $36.4{\pm}1.8%$ of the administered dose and the corresponding biliary recoveries were $14.4{\pm} 5.5%$ and $37.0{\pm}7.6%$, respectively.

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정보보안 분야의 위협정보 개체명 인식 시스템 개발을 위한 데이터셋 구축 (Development of Tagging Dataset for Named Entity Recognition in Security)

  • 김경민;허윤아;김규경;임희석
    • 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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    • 한국정보과학회언어공학연구회 2018년도 제30회 한글 및 한국어 정보처리 학술대회
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    • pp.669-671
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    • 2018
  • 개체명 인식(Named Entity Recognition)은 주로 인명(PS), 지명(LC), 기관명(OG) 등의 개체를 인식하기 위한 방식으로 많이 사용되어왔다. 그 이유는 해당 개체들이 데이터에서 중요한 의미를 가진 키워드이기 때문이다. 그러나 다른 도메인이 달라진다면 그동안 사용된 개체보다 더욱 중요한 의미를 갖는 개체가 존재할 수 있다. 특히 정보보안 분야에서는 악의적으로 사용되는 위협정보가 문서 내에서 중요한 의미를 갖는다. 보안 문서는 해시값, 악성코드명, IP, 도메인/URL 등 위협정보에 중요한 단서가 될 수 있는 다양한 정보를 담고 있다. 본 논문에서는 정보보안 분야의 위협정보를 탐지할 수 있는 개체명 시스템 개발을 위해 4개의 클래스와 20가지 속성으로 정의한 구축 방식을 구축하고 그 구축 방식에 대해 제안한다.

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연령 변화에 따른 치조골의 디지탈 방사선학적 특성비교 (Comparison of digitized radiographic alveolar features with age)

  • 이건일
    • 치과방사선
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    • 제27권1호
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    • pp.17-24
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    • 1997
  • The purpose of the present study was to use digital profile image features and digital image analysis of fixed-dimension bone regions, extracted from standardized periapical radiographs of the maxilla, to determine whether differences exist in alveolar bone of younger women(mean age: 59.23±7.34 years) and just menopaused women(mean age: 59.23±7.34). Periapical films were used from two groups of 20 randomly selected women. None of the subjects had a remarkable medical history. To simplify protocol, we chose one interproximal bone area between the maxillary right canine and lateral incisor for study. Ech film was digitized into a 1312 x 1024 pixel x 8 bit depth matrix by means of a Nikon 35 mm film scanner(LS-35lOAF, Japan) with fixed gain and internal dark current correction to maintain constant illumination. The scanner was interfaced to a Macintosh LC III computer(Apple Computer, Charlotte, N.C.). Area and profile orientation were selected with a NIMH Image 1.37(NIH Research Services Branch, Bethesda, Md.). Histogram features were extracted from each profile and area. The results of this study indicate that mean pixel intensities didn't differ significantly between two groups and there was a high correlarion-coefficient between digitized radiographic profile features and area features.

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작은 표면균열의 성장특성에 의한 수명예측 (A Fatigue Life Prediction by Growth Characteristics of a Small Surface Crack)

  • 서창민;임창순;강용구
    • 한국해양공학회지
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    • 제3권2호
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    • pp.617-617
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    • 1989
  • This paper deals with a fatigue life prediction of a surface crack based on the experimentally obtained relationship between surface crack length ratio $a/a_{f}$ and cycle ratio $N/N_{f}$ using micro computer. Firstly $a/a_{f}$-$N/N_{f}$ curves obtained from experimental tests, were assumed as three curves UC(the upper limit curve), LC(the lower limit curve) and MC(the middle curve), and these were utilized to predict the fatigue life. Comparing the calculated values which represent the characteristics of crack growth behaviors from the three assumed curves with the experimental ones, it has been found that in the stable crack growth region, they coincide reasonably well each other. And the differences between the fatigue lives obtained from the assumed curves and the experimental fatigue life did not exceed 20%. Using the characteristics of $a/a_{f}$-$N/N_{f}$ curves, it is possible to predict the da/dN-Kmax curves and the S-$N_{f}$ curves.

작은 표면균열의 성장특성에 의한 수명예측 (A Fatigue Life Prediction by Growth Characteristics of a Small Surface Crack)

  • 서창민;임창순;강용구
    • 한국해양공학회지
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    • 제3권2호
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    • pp.108-117
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    • 1989
  • This paper deals with a fatigue life prediction of a surface crack based on the experimentally obtained relationship between surface crack length ratio $a/a_{f}$ and cycle ratio $N/N_{f}$ using micro computer. Firstly $a/a_{f}$-$N/N_{f}$ curves obtained from experimental tests, were assumed as three curves UC(the upper limit curve), LC(the lower limit curve) and MC(the middle curve), and these were utilized to predict the fatigue life. Comparing the calculated values which represent the characteristics of crack growth behaviors from the three assumed curves with the experimental ones, it has been found that in the stable crack growth region, they coincide reasonably well each other. And the differences between the fatigue lives obtained from the assumed curves and the experimental fatigue life did not exceed 20%. Using the characteristics of $a/a_{f}$-$N/N_{f}$ curves, it is possible to predict the da/dN-Kmax curves and the S-$N_{f}$ curves.

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Double tuned matching에 의한 MMIC 광대역 전력 증폭기의 설계 (Design of MMIC power amplifier using double tuned matching)

  • 김진성;채연식;윤용순;이진구
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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    • pp.150-153
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    • 2000
  • In this paper, we have designed a 2 stage MMIC power amplifier which has flat gains of in-band and reasonable out-band cutoff characteristics using 0.5$\mu\textrm{m}$ MESFET libra교 of ETRI. For the 1st stave, we obtaind P$_{1dB}$ of 9.2 dBm and gain 10.8 dB using 6 finger D-MESFET and P$_{1dB}$ of 18.4 dBm and gain of 10.8 dB using 14 finger D-MESFET for the 2nd stage, which is power matched using LIBRA's embedded TUNER. Also in-band gain flatness and out-band cutoff characteristics are obtained by attaching LC tank in the output matching circuit. The designed 2 stage MMIC power amplifier has bandwidth of 0.95~2.8 GHz, gain of 20 dB and P$_{1dB}$of 17.2 dBm. Especially gain flatness of $\pm$0.8dB was obtained in 1.8~2.5 GHz frequency ranges. And chip size is 1.4$\times$1.4 mm..4 mm.

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가정식 음식의 아크릴아마이드 함량분석 (Acrylamide monitoring in home-made food products)

  • 이미선;박재영;오상석
    • 한국식품조리과학회지
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    • 제20권6호
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    • pp.708-711
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    • 2004
  • Swedish research in 2002 indicated that acrylamide formation was particularly associated with traditional high temperature cooking processes of certain carbohydrate-rich foods. Since the Swedish report, similar findings have been reported by researchers in numerous other countries. In 2003, three hundred and twenty seven domestic food products, selected on the basis of annual sales in Korea, were analyzed. The results were similar to those from other countries. In this study, the monitoring of acrylamide was expanded to include Korean traditional food products. Samples were purchased from local markets, prepared and then analyzed using LC/MS/MS methods. The categorized food products analyzed included cooked rices and porridges, soup products, fried products, boiled down products, seasoned products, roasted products and coffee. The acrylamide concentrations of the samples were $ND\~18ppb$ in cooked rices and porridges, $ND\~28ppb$ in soup products, $ND\~22ppb$ in fried products, $ND\~218ppb$ in boiled down products, <10ppb in seasoned and roasted products, and <10\~11ppb in brewed coffee and coffee drinks.