• 제목/요약/키워드: DCE

검색결과 132건 처리시간 0.036초

Development of 3D Mapping Algorithm with Non Linear Curve Fitting Method in Dynamic Contrast Enhanced MRI

  • Yoon Seong-Ik;Jahng Geon-Ho;Khang Hyun-Soo;Kim Young-Joo;Choe Bo-Young
    • 한국자기공명학회논문지
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    • 제9권2호
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    • pp.93-102
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    • 2005
  • Purpose: To develop an advanced non-linear curve fitting (NLCF) algorithm for dynamic susceptibility contrast study of brain. Materials and Methods: The first pass effects give rise to spuriously high estimates of $K^{trans}$ in voxels with large vascular components. An explicit threshold value has been used to reject voxels. Results: By using this non-linear curve fitting algorithm, the blood perfusion and the volume estimation were accurately evaluated in T2*-weighted dynamic contrast enhanced (DCE)-MR images. From the recalculated each parameters, perfusion weighted image were outlined by using modified non-linear curve fitting algorithm. This results were improved estimation of T2*-weighted dynamic series. Conclusion: The present study demonstrated an improvement of an estimation of kinetic parameters from dynamic contrast-enhanced (DCE) T2*-weighted magnetic resonance imaging data, using contrast agents. The advanced kinetic models include the relation of volume transfer constant $K^{trans}\;(min^{-1})$ and the volume of extravascular extracellular space (EES) per unit volume of tissue $\nu_e$.

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Dynamic Contrast-Enhanced MRI of the Prostate: Can Auto-Generated Wash-in Color Map Be Useful in Detecting Focal Lesion Enhancement?

  • Yoon, Ji Min;Choi, Moon Hyung;Lee, Young Joon;Jung, Seung Eun
    • Investigative Magnetic Resonance Imaging
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    • 제23권3호
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    • pp.220-227
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    • 2019
  • Purpose: To evaluate the usefulness of wash-in color map in detecting early enhancement of prostate focal lesion compared to whole dynamic contrast-enhanced MRI (DEC MRI) images. Materials and Methods: This study engaged 50 prostate cancer patients who underwent multiparametric MRI and radical prostatectomy as subjects. An expert [R1] and a trainee [R2] independently evaluated early enhancement and recorded the time needed to review 1) a wash-in color map and 2) whole DCE MRI images. Results: The review of whole DCE images by R1 showed fair agreement with color map by R1, whole images by R2, and color map by R2 (weighted kappa values = 0.59, 0.44, and 0.58, respectively). Both readers took a significantly shorter time to review the color maps as compared to whole images (P < 0.001). Conclusion: A trainee could achieve better agreement with an expert when using wash-in color maps than when using whole DCE MRI images. Also, color maps took a significantly shorter evaluation time than whole images.

확산 포집기로 공기중 혼합유기용제 포집시 온도와 상대습도가 포집효율에 미치는 영향 (Effects of temperature and relative humidity on the sampling efficiencies of mixed organic vapors measured by diffusion monitors)

  • 한진구;노영만;김현욱
    • 한국산업보건학회지
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    • 제5권2호
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    • pp.200-211
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    • 1995
  • This study was designed to evaluate the effects of temperature and humidity on the sampling efficiency of mixed organic vapors of l,2-DCE, benzene, and MIBK by 3 different types of diffusion monitors. Independent variables used for the study were temperatures ($25^{\circ}C$, $35^{\circ}C$), humidities (30%, 80%), and vapor concentrations (low, medium, and high). In addition, vapor concentrations measured by the traditional charcoal tube method were used as reference values and were compared with those of by diffusion monitors. The results were as follows: 1. The desorption efficiencies(DE) of 1,2-DCE and benzene from charcoal tubes and from diffusion monitors ranged from 98% to 105%. In contrast, the DEs of MIBK from charcoal tubes and diffusion monitors except DM1 ranged from 71% to 85%. The DE of MIBK from DM1 was 98%. 2. No statistically significant differences of 1,2-DCE concentrations and the sampling efficiencies regardless of temperatures and humidities studied between charcoal tube and 3 diffusion monitors were found. 3. At 80% humidity, increasing frequencies of 1,2-DCE breakthrough at higher temperature and higher vapor concentration measured by charcoal tubes were observed. 4. No statistically significant difference of benzene concentrations were found between charcoal tube and diffusion monitors except DM3. The sampling efficiencies of DM3 were statistically significantly lower at all experimental conditions except the $35^{\circ}C$ and 30% humidity condition. 5. No statistically significant difference of MIBK concentrations were found between charcoal tube and diffusion monitors except DM3. The sampling efficiencies of DM3 were statistically significantly higher at higher humidity conditions regardless of temperature. Although statistically not significant, sampling efficiency of MIBK showed positive correlation with humidity while negative correlation with concentration was observed. 6. For sampling 1,2-DCE and benzene, no significant variations of concentrations among three diffusion monitors regardless of temperature and humidity conditions were found. For MIBK sampling, however, wide variations with increasing humidity among diffusion monitors were obtained. In conclusion, this study suggests that diffusion monitors will be a reasonables substitute for the traditional charcoal tubes for sampling non-polar organic vapors at temperature and humidity conditions studied. For polar organic vapors, use of an alternative desorption solution other than CS2 is recommended because of its low desorption efficiency. In addition, since variable among diffusion monitors for polar organic vapors particularly at higher humidity conditions were observed, further study is recommended of the effects of humidity on the performance of diffusion monitors.

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물/1,2-Dichloroethane 계면에서 Cefotiam 약물 이온의 전이 반응 연구 및 약물 센서에 응용 (Electrochemical Study on Transfer Reaction of Ionizable Cefotiam across a Water/1,2-dichloroethane Interface and Drug Sensing Applications)

  • 리우샤오원;신타제시카;이혜진
    • 공업화학
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    • 제29권5호
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    • pp.581-588
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    • 2018
  • 본 논문은 편극화된 물/1,2-dichloroethane (1,2-DCE) 계면에서 세포티암(cefotiam, CTM) 항생제 약물의 전이 반응을 전기화학적 방법으로 조사하였다. CTM 약물은 물의 pH에 따라 서로 다른 전하를 가지고 이온화되며 각 pH에서 이들 이온의 전이 반응을 연구함으로써 처음으로 CTM 약물이 좀 더 우세하게 물 또는 유기층에 분배되는 정도를 나타내는 상 분배 도표를 세웠다. 이를 바탕으로 CTM 약물의 형식 전이 전위값 및 형식 Gibbs 전이 에너지 값을 포함한 열역학적 정보와 함께 분배 계수를 포함한 중요한 약물동태학 정보를 얻었다. 특히 pH 3.0 수용액에서 양전하를 띠는 CTM 이온의 전이 반응을 순환전압전류법으로 조사한 결과 CTM 농도에 따라 측정한 전류 값이 비례하여 증가한다는 점을 확인하였다. 이를 바탕으로 CTM 이온을 정량 분석 가능한 센서를 개발하였다. 휴대성과 이동성을 보완하기 위해 polyethylene terephthalate 필름에 마이크로홀을 만들어 지지체로 사용하고, 1,2-DCE 유기용매를 polyvinylchloride-2-nitrophenyloctylether (PVC-NPOE) 유기성 젤로 대체하여 도포하는 방식으로 센서를 제작하였다. 상기 센서를 이용하여 CTM 약물을 $1{\mu}M$에서 $10{\mu}M$까지 정량 분석할 수 있었다.

Aerobic Degradation of Tetrachloroethylene(PCE) by Pseudomonas stutzeri OX1

  • Ryoo, Doohyun;Shim, Hojae;Barbieri, Paola;Wood, Thomas K.
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2000년도 추계학술대회
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    • pp.207-208
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    • 2000
  • Since trichloroethylene (TCE), dichloroethylene (DCE), and vinyl chloride (VC) arise from anaerobic degradation of tetrachloroethylene (PCE) and TCE, there is interest in creating aerobic remediation systems that avoid the highly toxic VC and cis-DCE which predonominate in anaerobic degradation. However, it seemed TCE could not be degraded aerobically without an inducing compound (which also competitively inhibits TCE degradation). It has been shown that TCE induces expression of both the toluene dioxygenase of p. putida F1 as well as toluene-p-monooxygenase of P.mendocina KRI. We investigated here the ability of PCE, TCE, and chlorinated phenols to induce toluene-o-xylene monooxygenase (ToMO) from P.stutzeri OX1. ToMO has a relaxed regio-specificity since it hydroxylates toluene in the ortho, meta, and para positions; it also has a broad substrate range as it oxidizes o-xylene, m-xylene, p-xylene, toluene, benzene, ethylbenzene, styrene, and naphthalene; chlorinated compounds including TCE, 1, 1-DCE, cis-DCE, trans-DCE, VC, and chloroform : as well as mixtures of chlorinated aliphatics (Pseudomonas 1999 Maui Meeting). ToMO is a multicomponent enzyme with greatest similarity to the aromatic monooxygenases of Burkholderia pickettii PKO1 and P.mendocina KR1. Using P.sturzeri OX1, it was found that PCE induces P.mendocina KR1 Using P.situtzeri OX1, it was found that PCE induces ToMO activity measured as naphthalene oxygenase activity 2.5-fold, TCE induces 2.3-fold, and toluene induces 3.0 fold. With the mutant P.stutzeri M1 which does not express ToMO, it was also found there was no naphthalene oxygenate activity induced by PCE and TCE; hence, PCE and TCE induce the tow path. Using P.putida PaW340(pPP4062, pFP3028) which has the tow promoter fused to the reporter catechol-2, 3-dioxygenase and the regulator gene touR, it was determined that the tow promoter was induced 5.7-, 7.1-, and 5.2-fold for 2-, 3-, 4-chlorophenol, respectively (cf. 8.9-fold induction with o-cresol) : however, TCE and PCE did not directly induce the tou path. Gas chromatography and chloride ion analysis also showed that TCE induced ToMO expression in P.stutzeri OX1 and was degraded and mineralized. This is the first report of significant PCE induction of any enzyme as well as the first report of chlorinated compound induction of the tou operon. The results indicate TCE and chlorinated phenols can be degraded by P.stutzeri OX1 without a separate inducer of the tou pathway and without competitive inhibition.

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패랭이꽃 추출물의 항산화, Nitric Oxide 생성저해, 암세포 성장 및 부착 억제 활성 (Antioxidant Activities of Dianthus chinensis L. Extract and Its Inhibitory Activities against Nitric Oxide Production and Cancer Cell Growth and Adhesion)

  • 이중재;서영교;이준호;주지형
    • 한국식품영양과학회지
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    • 제45권1호
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    • pp.44-51
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    • 2016
  • 본 연구에서는 패랭이꽃의 항산화 성분 함량을 측정하고 패랭이꽃 에탄올 추출물의 항산화, 항염, 항암 활성을 in vitro 수준에서 평가하고자 하였다. 패랭이꽃의 총 폴리페놀, 총 플라보노이드, 총 카로티노이드 함량은 각각 19.0 mg GAE/g, 65.7 mg QE/g, $95.0{\mu}g/g$으로 측정되었다. 패랭이꽃 추출물($1,000{\mu}g/mL$)의 DPPH radical 소거 활성은 44.1%, 철환원력은 51.1%로 같은 농도의 ascorbic acid의 활성보다는 낮았지만 의미 있는 수준의 활성을 나타내었다. 패랭이꽃 추출물은 RAW 264.7 대식세포의 NO 생성을 대조구 대비 7~23% 수준으로 억제하는 농도 의존적 활성을 나타내었고, H1299 폐암세포와 HCT116 대장암세포의 성장을 대조구 대비 각각 2~81%(48~96시간 처리 시점)와 10~80%(72시간 처리시점)로 억제하는 농도 의존적 활성 또한 나타내었다. 패랭이꽃 추출물은 암세포의 부착을 억제하는 활성이 H1299와 HCT116 세포에서 모두 나타났으나 HCT116 세포에서 나타난 활성($250{\sim}1,000{\mu}g/mL$ 이상의 농도 처리시 대조구 대비 26~40% 부착 수준)이 H1299 세포에서 나타난 활성($1,000{\mu}g/mL$ 농도 처리 시 대조구 대비 55% 부착 수준)보다 컸다. 이상의 연구 결과를 통하여 패랭이꽃 추출물은 항산화 성분 함량 및 활성이 유의미한 수준이고 세포 수준의 항염 및 항암 활성을 가지는 것으로 생각된다. 앞으로 이와 같은 연구 결과가 in vivo 수준에서 재현되는지 여부를 검증하고 관련 기전을 탐색하는 심도 있는 연구가 필요할 것으로 생각된다.

나노튜브전극을 사용한 전압전류법에 의한 식물잎에서 살충제 검출 (Detection of Pesticide Thiram in Plant Leafs Using Voltammetric at Nanotube Electrode)

  • 이장현;이수영
    • 한국환경과학회지
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    • 제19권12호
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    • pp.1335-1341
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    • 2010
  • Voltammetric diagnostics of pesticide thiram was studied in plant leafs in vivo fluid with DNA immobilized on a carbon nanotube electrode (DCE). Sensor properties of carbon nanotube (CE) and DNA immobilized nanotube were compared. DCE was more effective than CE in target detecting. The parameters such as pH strength, stripping accumulation, amplitude, and increment potential were examined to find the optimum condition for detection of pesticide thiram in a sesame leaf. The optimized conditions were as follows 550 Hz frequency, 0.15 V amplitude, 0.005 V increment potential, -1.2 V initial potential, 4.78 pH, 500 sec accumulation time. Under optimum condition, the detection limit of thiram was attained at 0.01ng/L.

혐기성 PCE 탈염소화 관련 미생물 군집 특성

  • 이태호;문부영;박태주
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.133-137
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    • 2004
  • Tetrachloroethylene(PCE) dechlorination was investigated in an anaerobic enrichment culture from landfill soil. Anaerobic PCE dechlorinating microorganisms could convert 150mg/L of PCE via trichloroethylene(TCE) to cir-1,2-dichloroethylene(CDCE) within 2 days at the optimum temperature of 30 to 35$^{\circ}C$. The enrichment culture could dechlorinate TCE but did not degrade other chlorinated aliphatic compounds, such as cDCE, trans-1,2-dichloroethylene, 1,1-dichloroethylene, 1,1-dichloroethane, 1,2-dichloro- ethane, and 1,1,1-trichloroethane during 5 days incubation. Several isolates from the enrichment culture did not show dechlorinating activity of PCE. Microbial analysis of the dechlorinating enrichment culture by using Polymerase chain reaction-Denaturing gradient gel electrophoresis (PCR-DGGE) method showed that at least three microorganisms were related to the anaerobic PCE dechlorination in the enrichment

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