• 제목/요약/키워드: Chemical markers

검색결과 129건 처리시간 0.023초

Analysis of Organic Molecular Markers in Atmospheric Fine Particulate Matter: Understanding the Impact of "Unknown" Point Sources on Chemical Mass Balance Models

  • Bae, Min-Suk;Schauer, James J.
    • 한국대기환경학회지
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    • 제25권3호
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    • pp.219-236
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    • 2009
  • Particle-phase organic tracers (molecular markers) have been shown to be an effective method to assess and quantify the impact of sources of carbonaceous aerosols. These molecular markers have been used in chemical mass balance (CMB) models to apportion primary sources of organic aerosols in regions where the major organic aerosol source categories have been identified. As in the case of all CMB models, all important sources of the tracer compounds must be included in a Molecular Marker CMB (MM-CMB) model or the MMCMB model can be subject to biases. To this end, the application of the MM-CMB models to locations where reasonably accurate emissions inventory of organic aerosols are not available, should be performed with extreme caution. Of great concern is the potential presence of industrial point sources that emit carbonaceous aerosols and have not been well characterized or inventoried. The current study demonstrates that emissions from industrial point sources in the St. Louis, Missouri area can greatly bias molecular marker CMB models if their emissions are not correctly addressed. At a sampling site in the greater St. Louis Area, carbonaceous aerosols from industrial point sources were found to be important source of carbonaceous aerosols during specific time periods in addition to common urban sources (i.e. mobile sources, wood burning, and road dust). Since source profiles for these industrial sources have not been properly characterized, method to identify time periods when point sources are impacting a sampling site, needs to avoid obtaining biases source apportionment results. The use of real time air pollution measurements, along with molecular marker measurements, as a screening tool to identify when point sources are impacting a receptor site is presented.

Fast Microchip Electrophoresis Using Field Strength Gradients for Single Nucleotide Polymorphism Identification of Cattle Breeds

  • Oh, Doo-Ri;Cheong, Il-Cheong;Lee, Hee-Gu;Eo, Seong-Kug;Kang, Seong-Ho
    • Bulletin of the Korean Chemical Society
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    • 제31권7호
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    • pp.1902-1906
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    • 2010
  • A microchip electrophoresis (ME) method was developed using a programmed field strength gradients (PFSG) for the single nucleotide polymorphism (SNP) based fast identification of cattle breeds. Four different Korean cattle (Hanwoo) and Holstein SNP markers amplified by allele-specific polymerase chain reaction were separated in a glass microchip filled with 0.5% poly(ethyleneoxide) ($M_r$ = 8 000 000) by PFSG as follows: 750 V/cm for 0 - 14 s, 166.7 V/cm for 14 - 31 s, 83.3 V/cm for 31 - 46 s, and 750 V/cm for 46 - 100 s. The cattle breeds were clearly distinguished within 45 s. The ME-PFSG method was 7 times and 5 times faster than the constant electric field ME method and the capillary electrophoresis- PFSG method, respectively, with a high resolving power ($R_s$ = 5.05 - 9.98). The proposed methodology could be a powerful tool for the fast and simultaneous determination of SNP markers for various cattle breeds with high accuracy.

Microarray Profiling of Genes Differentially Expressed during Erythroid Differentiation of Murine Erythroleukemia Cells

  • Heo, Hyen Seok;Kim, Ju Hyun;Lee, Young Jin;Kim, Sung-Hyun;Cho, Yoon Shin;Kim, Chul Geun
    • Molecules and Cells
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    • 제20권1호
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    • pp.57-68
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    • 2005
  • Murine erythroleukemia (MEL) cells are widely used to study erythroid differentiation thanks to their ability to terminally differentiate in vitro in response to chemical induction. At the molecular level, not much is known of their terminal differentiation apart from activation of adult-type globin gene expression. We examined changes in gene expression during the terminal differentiation of these cells using microarray-based technology. We identified 180 genes whose expression changed significantly during differentiation. The microarray data were analyzed by hierarchical and k-means clustering and confirmed by semi-quantitative RT-PCR. We identified several genes including H1f0, Bnip3, Mgl2, ST7L, and Cbll1 that could be useful markers for erythropoiesis. These genetic markers should be a valuable resource both as potential regulators in functional studies of erythroid differentiation, and as straightforward cell type markers.

Clinical Application of Serum Tumor Associated Material (TAM) from Non-small Cell Lung Cancer Patients

  • Li, Cheng-Guang;Huang, Xin-En;Xu, Lin;Li, Ying;Lu, Yan-Yan
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권1호
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    • pp.301-304
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    • 2012
  • Objective: To explore the associations of serum tumor associated material (TAM) with other common tumor markers like carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125), carbohydrate antigen19-9 (CA19-9) and its clinical application in non-small cell lung cancer (NSCLC) patients. Methods: A total of 87 patients were enrolled into this study, all with histologically or cytologically confirmed NSCLC. With the method of chemical colorimetry, the level of TAM was determined and compared, while chemiluminescence was used to measure the levels of common tumor markers. Results: The level of TAM decreased after chemotherapy compared with before chemotherapy when CT or MRI scans showed disease control. Furthermore, it increased when disease progessed and there was no statistically significant difference in monitoring of TAM and common tumor markers (P>0.05). Conclusions: Detecting TAM in NSCLC patients has a higher sensitivity and specificity, so it can be used as an indicator for clinical monitoring of lung cancer chemotherapy.

RAPD 분석법을 이용한 산삼, 웅담, 녹용 등의 한약재 판별연구 (Identification study of rare and high-priced natural products used for oriental medicine by RAPD analysis)

  • 조동욱
    • 한국한의학연구원논문집
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    • 제1권1호
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    • pp.471-476
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    • 1995
  • Natural products used for oriental medicine often come from various geographical sources, after several different distribution channels. Therefore some form of quality control procedure is required to safeguard naturl products for prescriptions purposes. To achieve this, systematic apprroaches such as morphological examination, microscopic analysis of powdered herbs and chemical analysis can be carried out. However, to ensure absolute criteria for quality assurance of natural products, DNA fingerprinting method such as RAPD(Random amplified polymorphism DNA) analysis can be used for authentication of natural products for authenticatin of natural products. In this study, warious oligonucleotide primers will be synthesized for the detection of RAPD markers and also parameters of affecting PCR(Polymerase Chain Reaction) in the detection of RAPD markers of rare and high-priced natural products will be studied with genomic DNA of chosen samples.

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TOPKAT®, Derek®, OECD toolbox를 활용한 화학물질 독성 예측 연구 (Toxicity Prediction using Three Quantitative Structure-activity Relationship (QSAR) Programs (TOPKAT®, Derek®, OECD toolbox))

  • 이진욱;박선영;장석원;이상규;문상아;김현지;김필제;유승도;성창호
    • 한국환경보건학회지
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    • 제45권5호
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    • pp.457-464
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    • 2019
  • Objectives: Quantitative structure-activity relationship (QSAR) is one of the effective alternatives to animal testing, but its credibility in terms of toxicity prediction has been questionable. Thus, this work aims to evaluate its predictive capacity and find ways of improving its credibility. Methods: Using $TOPKAT^{(R)}$, OECD toolbox, and $Derek^{(R)}$, all of which have been applied world-wide in the research, industrial, and regulatory fields, an analysis of prediction credibility markers including accuracy (A), sensitivity (S), specificity (SP), false negative (FN), and false positive (FP) was conducted. Results: The multi-application of QSARs elevated the precision credibility relative to individual applications of QSARs. Moreover, we found that the type of chemical structure affects the credibility of markers significantly. Conclusions: The credibility of individual QSAR is insufficient for both the prediction of chemical toxicity and regulation of hazardous chemicals. Thus, to increase the credibility, multi-QSAR application, and compensation of the prediction deviation by chemical structure are required.

Studies on the Small Body Size Mouse Developed by Mutagen N-Ethyl-N-nitrosourea

  • Zhang, Qian-Kun;Cho, Kyu-Hyuk;Cho, Jae-Woo;Cha, Dal-Sun;Park, Han-Jin;Yoon, Seok-Joo;Zhang, ShouFa;Song, Chang-Woo
    • Toxicological Research
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    • 제24권1호
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    • pp.69-78
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    • 2008
  • Mutant mouse which show dwarfism has been developed by N-ethyl-N-nitrosourea (ENU) mutagenesis using BALB/c mice. The mutant mouse was inherited as autosomal recessive trait and named Small Body Size (SBS) mouse. The phenotype of SBS mouse was not apparent at birth, but it was possible to distinguish mutant phenotype from normal mice 1 week after birth. In this study, we examined body weight changes and bone mineral density (BMD), and we also carried out genetic linkage analysis to map the causative gene(s) of SBS mouse. Body weight changes were observed from birth to 14 weeks of age in both affected (n = 30) and normal mice (n = 24). BMD was examined in each five SBS and normal mice between 3 and 6 weeks of age, respectively. For the linkage analysis, we produced backcross progeny [(SBS${\times}$C57BL/6J) $F_1{\times}$ SBS] $N_2$ mice (n = 142), and seventy-four microsatellite markers were used for primary linkage analysis. Body weight of affected mice was consistently lower than that of the normal mice, and was 43.7% less than that of normal mice at 3 weeks of age (P < 0.001). As compared with normal mice at 3 and 6 weeks of age, BMD of the SBS mice was significantly low. The results showed 15.5% and 14.1 % lower in total body BMD, 15.3% and 8.7% lower in forearm BMD, and 29.7% and 20.1% lower in femur BMD, respectively. The causative gene was mapped on chromosome 10. The map order and the distance between markers were D10Mit248 - 2.1 cM - D10Mit51 - 4.2 cM - sbs - 0.7 cM - D10Mit283 - 1.4cM - D10Mit106 - 11.2cM - D10Mit170.

Velocity measurements in complex flows of non-Newtonian fluids

  • Muller, Susan J.
    • Korea-Australia Rheology Journal
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    • 제14권3호
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    • pp.93-105
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    • 2002
  • Experimental methods for making quantitative measurements of velocity fields in non-Newtonian fluids are reviewed. Techniques based on light scattering spectroscopy - laser Doppler velocimetry and homodyne light scattering spectroscopy, techniques based on imaging the displacement of markers - including particle image velocimetry and molecular tagging velocimetry, and techniques based on nuclear magnetic resonance imaging are discussed. The special advantages and disadvantages of each method are summarized, and their applications to non-Newtonian flows are briefly reviewed. Example data from each technique are also included.

Environmental Tobacco Smoke의 이화학적 특성 (The physicochemical Characterization of ETS (Environmental Tobacco Smoke))

  • 이문수
    • 한국연초학회지
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    • 제17권1호
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    • pp.79-97
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    • 1995
  • On the basis of the literature, which is at present still scientific information improvable, the results of research done so far into the occurrence and analytical methodology of major markers of environmental tobacco smoke(ETS) have been summarized. Key areas addressed are: differences in physicochemical composition between mainstream smoke, sidestream smoke and ETS: techniques for field measurement of ETS: relationship between indoor air quality with ETS and its distribution view of US EPA and its problems: biological effects and concerning estimation of ETS exposure.

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