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Lee, Soojin,Pyo, Heesoo,Chung, Bong Chul,Kim, Haidong,Lee, Jeongae Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.11
Alkoxyalcohols are used as solvents or preservatives in various consumer products such as wet wipes. The metabolites of alkoxyalcohols are known to be chronically toxic and carcinogenic to animals. Thus, an analytical method is needed to monitor alkoxyalcohols in wet wipes. The aim of this study was to develop a simultaneous analytical method for 14 alkoxyalcohols using headspace gas chromatography coupled with mass spectrometry to analyze the wet wipes. This method was developed by comparing with various headspace extraction parameters. The linear calibration curves were obtained for the method ($r^2$ > 0.995). The limit of detection of alkoxyalcohols ranged from 2 to $200ng\;mL^{-1}$. The precision of the determinative method was less than 18.20% coefficient of variation both intra and inter days. The accuracy of the method ranged from 82.86% to 119.83%. (2-Methoxymethylethoxy)propanol, 2-phenoxyethanol, and 1-phenoxy-2-propanol were mainly detected in wet wipes.
Discovery of Urinary Biomarkers in Patients with Breast Cancer Based on Metabolomics
( Jeongae Lee ),( Han Min Woo ),( Gu Kong ),( Seok Jin Nam ),( Bong Chul Chung ) 한국질량분석학회 2013 Mass spectrometry letters Vol.4 No.4
A metabolomics study was conducted to identify urinary biomarkers for breast cancer, using gas chromatographymass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), analyzed by principal components analysis (PCA) as well as a partial least squares-discriminant analysis (PLS-DA) for a metabolic pattern analysis. To find potential biomarkers, urine samples were collected from before- and after-mastectomy of breast cancer patients and healthy controls. Androgens, corticoids, estrogens, nucleosides, and polyols were quantitatively measured and urinary metabolic profiles were constructed through PCA and PLS-DA. The possible biomarkers were discriminated from quantified targeted metabolites with a metabolic pattern analysis and subsequent screening. We identified two biomarkers for breast cancer in urine, β-cortol and 5- methyl-2-deoxycytidine, which were categorized at significant levels in a student t-test (p-value < 0.05). The concentrations of these metabolites in breast cancer patients significantly increased relative to those of controls and patients after mastectomy. Biomarkers identified in this study were highly related to metabolites causing oxidative DNA damage in the endogenous metabolism. These biomarkers are not only useful for diagnostics and patient stratification but can be mapped on a biochemical chart to identify the corresponding enzyme for target identification via metabolomics.
Lee, Ji-Young,Kim, Seungki,Lee, Jong-Tae,Choi, Jong-Ho,Lee, Jeongae,Pyo, Heesoo Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.12
Headspace (HS) and headspace solid-phase microextraction (HS-SPME) were studied for extracting volatile organic compounds (VOCs) from whole blood, with chemical and instrumental variables being optimized for maximum sensitivity: incubation at $60^{\circ}C$, equilibration for 30 min, pH 11, and 2 mL injection volume. Both techniques provided accurate analyses, with detection limits of 0.05-0.1 ng $mL^{-1}$ and 0.05-0.5 ng $mL^{-1}$. HS showed better sensitivity, reproducibility, and analysis times than HS-SPME. Overall levels of chloroform in whole blood were found to be 0.05-5.84 ng $mL^{-1}$; detected levels of benzene were 0.05-2.20 ng $mL^{-1}$.
Measurement of Age - Related Changes in Bone Matrix Using ²H₂O Labeling
Jeongae Lee,Yoo Kyeong Kim 한국식품영양과학회 2005 Preventive Nutrition and Food Science Vol.10 No.1
Age-related changes in bone metabolism are well established by biochemical markers of bone matrix in serum and urine, but analysis of the residual bone matrix, which is still turning over, has not been investigated. In the present study, we measured in vivo rates of bone protein synthesis using a precursor-product method based on the exchange of ²H from ²H₂O into amino acids. Four percent ²H₂O was administered to mice in drinking water after intraperitonial (i.p) bolus injection of 99.9% ²H₂O. Mice were divided into the two groups: growing young mice were administered 4% ²H₂O for 12 weeks after an i.p bolus injection at 5 week of age, whereas weight stable adult mice started drinking 4% ²H₂O 8 weeks later than the growing group and continued 4% ²H₂O drinking for 8 weeks. Mass isotopomer abundance in alanine from bone protein was analyzed by gas chromatography/mass spectrometry. Body ²H₂O enrichments were in the range of 1.88~2.41% over the labeling period. The fractional synthesis rates (ks) of bone protein were 2.000±0.071%/d for growing mice and 0.243±0.014%/d for adult mice. These results demonstrate that the bone protein synthesis rate decreases with age and present direct evidence of age-related changes in bone protein synthesis.
Non-Target Screening: A powerful tool for selecting environmental pollutants
Jeongae Lee(이정애),Hee Soo Pyo,Bong CHul Chung 한국분석과학회 2021 학술대회논문집 Vol.2021 No.11
An immense number of chemicals is produced, marketed, used by modern society and can be released into the environment through different pathways. Identification and quantitative determination of the emerging substances released into the environment through different pathways is still an analytical challenge for scientists since neither chemical nor spectral databases nor analytical standards are available. Gas and liquid chromatography hyphenated to a variety of accurate mass analyzers based on the use of high-resolution have been used for this purpose. We present an overview of the basic principles, promises and challenges of suspect and non-targeted screening (NTS) approaches current approaches based on high resolution accurate mass spectrometry (HRAMS) analysis, particularly based on software tools for data acquisition and data processing used for the identification of unknown the environmental pollutants. NTS has great potential for treatment assessment and pollutant prioritization within regulatory applications. We would like to introduce the main activities and especially harmonized protocols of the European Human Biomonitoring Initiative.
Discovery of Urinary Biomarkers in Patients with Breast Cancer Based on Metabolomics
Lee, Jeongae,Woo, Han Min,Kong, Gu,Nam, Seok Jin,Chung, Bong Chul Korean Society for Mass Spectrometry 2013 Mass spectrometry letters Vol.4 No.4
A metabolomics study was conducted to identify urinary biomarkers for breast cancer, using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), analyzed by principal components analysis (PCA) as well as a partial least squares-discriminant analysis (PLS-DA) for a metabolic pattern analysis. To find potential biomarkers, urine samples were collected from before- and after-mastectomy of breast cancer patients and healthy controls. Androgens, corticoids, estrogens, nucleosides, and polyols were quantitatively measured and urinary metabolic profiles were constructed through PCA and PLS-DA. The possible biomarkers were discriminated from quantified targeted metabolites with a metabolic pattern analysis and subsequent screening. We identified two biomarkers for breast cancer in urine, ${\beta}$-cortol and 5-methyl-2-deoxycytidine, which were categorized at significant levels in a student t-test (p-value < 0.05). The concentrations of these metabolites in breast cancer patients significantly increased relative to those of controls and patients after mastectomy. Biomarkers identified in this study were highly related to metabolites causing oxidative DNA damage in the endogenous metabolism. These biomarkers are not only useful for diagnostics and patient stratification but can be mapped on a biochemical chart to identify the corresponding enzyme for target identification via metabolomics.