• Title/Summary/Keyword: Esr2a

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Detection of Radiation Degradation of LDPE by ESR Spectroscopy (전자스핀공명을 이용한 저밀도 폴리에틸렌의 방사선 열화 검지)

  • Kim Ki-Yup;Lee Chung;Ryu Boo-Hyung
    • Journal of the Korean Society of Safety
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    • v.20 no.1 s.69
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    • pp.81-86
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    • 2005
  • This study has investigated radiation degradation of low density polyethylene(LDPE). Samples were irradiated up to 800kGy using a $Co^{60}\;\gamma-ray$ at a dose rate of 5kGy/hr in the presence of air atmosphere at room temperature. After irradiation, storing for 2 weeks, free radical measurement of LDPE has established by electron spin resonance(ESR). ESR measurement showed that free radical concentration(FRC) was increased with radiation dose and decreased with the time. The radical types showed alkyl, allyl, and peroxy radical with the irradiation, these changed to peroxy radical with the time.

Electron Spin Resonance Study on the Miscibility of Poly(ethylene glycol) with Cathonic Dodecyl Trimethylammonium Bromide Micelle

  • Kim Jin-Soo;Lee Don-Keun;Kang Young-Soo
    • Journal of the Korean Magnetic Resonance Society
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    • v.9 no.2
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    • pp.155-162
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    • 2005
  • The interaction of poly(ethylene glycol)(PEG) with cationic dodecyl trimethyl ammonium bromide (DTAB)micelle was studied with electron spin resonance (ESR) by determining line widths of the ESR spectra and coupling constant of nitrogen($A_N$). The degree of ESR line shape change such as line widths and coupling constant indicated that PEG mixes well with DTAB micelle due to a great hydrophobic interaction with surfactant alkyl chains. This suggests that the PEG can be used as non-ionic surfactant to disperse the exposed oil in the ocean.

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Inflammatory Markers as Prognostic Factors for Patients with ARDS (급성 호흡곤란 증후군 환자에서 염증 표지자의 예후 예측인자로서의 역할)

  • Chung, Chae Uk;Hwang, Jae Hee;Park, Ji Won;Shin, Ji Young;Jung, Sun Yuong;Lee, Jeong Eun;Park, Hee Sun;Jung, Sung Soo;Kim, Ju Ock;Kim, Sun Young
    • Tuberculosis and Respiratory Diseases
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    • v.65 no.2
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    • pp.99-104
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    • 2008
  • Background: Acute respiratory distress syndrome (ARDS) is ultimately an inflammatory state. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level are inflammatory markers. The aim of this study was to evaluate the value of the ESR, CRP and APACHE II score as prognostic factors for patient with ARDS. Methods: We retrospectively analyzed the medical records of 87 ARDS patients. The predictors (APACHE II score, ESR and CRP) and outcomes (mortality and length of the total hospital stay, the ICU stay and mechanical ventilator care) were obtained from the patients' records. The patients were grouped according to survival as the Survivor and Non survivor groups. We compared the APACHE II score, the ESR and the CRP level between the survivor group and the nonsurvivor group. We evaluated the correlation between the predictors and the outcomes. The initial ESR, CRP level and APACHE II score were checked at the time of ICU admission and the second ESR and CRP level were checked $3.3{\pm}1.2$ days after ICU admission. Results: Thirty-eight (43.7%) patients remained alive and 49 (56.3%) patients died. The APACHE II score was significantly lower for the survivor group than that for the non survivor group ($14.7{\pm}7.6$ vs $19.6{\pm}9.1$, respectively, p=0.006). The initial ESR and CRP level were not different between the survivor and non-survivor groups (ESR $64.0{\pm}37.8mm/hr$ vs $63.3{\pm}36.7mm/hr$, respectively, p=0.93, CRP $15.5{\pm}9.6mg/dl$ vs $16.3{\pm}8.5mg/dl$, respectively, p=0.68). The decrement of the CRP level for the survivor group was greater than that for the non survivor group ($-8.23{\pm}10.0mg/dl$ vs $-1.46{\pm}10.1mg/dl$, respectively, p=0.003). Correlation analysis revealed the initial ESR was positively correlated with the length of the total hospital stay and the ICU stay (correlation coefficient of the total hospital days: R=0.43, p=0.001, correlation coefficient of the ICU stay: R=0.39, p=0.014). Conclusion: The initial APACHE II score can predict the mortality of ARDS patients, and the degree of the early CRP change can be a predictor of mortality for ARDS patients. The initial ESR has positive correlation with the ARDS patients' duration of the total hospital stay and the ICU stay.

Analytical Properties of Electron Spin Resonance after Irradiation of Seasonings with Different Radiation Sources (조미료의 방사선 조사선원에 따른 전자스핀공명 분석 특성)

  • Ahn, Jae-Jun;Kim, Gui-Ran;Jin, Qiong-Wen;Kwon, Joong-Ho
    • Food Science and Preservation
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    • v.16 no.3
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    • pp.385-391
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    • 2009
  • Analytical electron spin resonance (ESR) parameters were investigated in irradiated seasonings after exposure to different radiation sources. Two commercial seasonings (SS-1 and SS-2) were irradiated with 0.20 kGy under ambient conditions using a $^{60}Co$ gamma-ray irradiator or an electron beam accelerator. Crystalline sugar-induced multi-component signals with g-values of 2.031, 2.021, 2.017, 2.009, 2.002, 1.990, and 1.980 were observed in both irradiated samples, whereas singlet signals were detected in non-irradiated materials, thereby distinguishing irradiated from control samples. Under the same analytical conditions, the ESR signal intensity of electron beam-irradiated samples was greater than that of gamma-irradiated materials. Determination coefficients (R2 values) between irradiation doses and corresponding ESR responses were 0.9916-0.9973 for all samples, and the magnetic field of specified g-values for irradiated samples remained constant. The predominant ESR signals of g2 (2.021), g4 (2.009), g5 (2.002), and g6 (1.990) showed high correlations with the corresponding irradiation doses (R2=0.8243 - 0.9929).

Multistep Identification of γ-Irradiated Boiled-Dried Anchovies by Analysis of Thermoluminescence, Electron Spin Resonance, Hydrocarbon and 2-Alkylcyclobutanone (건멸치의 방사선 조사 확인을 위한 열발광, 전자스핀공명, Hydrocarbon 및 2-Alkylcyclobutanone의 다중분석)

  • 노정은;권중호
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.1
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    • pp.8-14
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    • 2003
  • Multistep detection was peformed to identify irradiated dried anchovy. In thermoluminescence (TL) analysis, non-irradiated samples represented a lower peak at about 28$0^{\circ}C$, but irradiated samples showed a higher peak at around 20$0^{\circ}C$. The normalization with a re-irradiation step at 1 kGy could verify the identification results. Electron spin resonance (ESR) spectroscopy for bones separated from irradiated anchovy revealed specific signals (g=2.002,1.998) derived from a hydroxyapatite radical, which intensities were in proportion to the irradiation doses and still detectable even after 6 months of storage at -2$0^{\circ}C$. Six kinds of hydrocarbons (HC) were observed in dried anchovy samples and 1,7-hexadecadiene and 1-hexadecene were only detected in irradiated anchovy at 1 kGy or more. Also among 3 kinds of radiation-induced 2-alkylcyclobutanones (2-ACB) observed, 2-dodecylcy-clobutanone and 2-tetradecylcyclobutanone were unique in irradiated anchovy. As a result, the concentration of radiation-induced HCs and 2-ACBs were dependent on the irradiation dose and detectable after 6 months of storage. However, TL and ESR analyses were found simpler than the other methods for identification of irradiated boiled-dried anchovy.

Detection and Absorbed-Dose Estimation of Electron Beam-Irradiated Dried Vegetable Using ESR Spectroscopy (ESR Spectroscopy에 의한 전자선 조사 건조 채소의 검지와 흡수선량 예측)

  • 권중호;정형욱
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.4
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    • pp.882-885
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    • 1999
  • Along with the increasing demands for food irradiation technology, proper detection methods for controlling irradiated foods are required. Dried vegetable(chunggyungchae), which is permitted to be irradiated in Korea, was subjected to a detection study by ESR spectroscopy. Pre established threshold value was successfully applicable to the detection of 50 coded unknown samples of dried clean vege tables, both nonirradiated and electron beam irradiated. Three calibration curves obtained from the samples irradiated at 2.5~15 kGy were not practically adopted to estimate actual absorbed doses ranging from 4 to 7 kGy.

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Detection of Gamma-Irradiated Wheat Flour and Glutinous Rice Flour by Measuring Free Radical (Free radical의 측정을 통한 감마선 조사된 밀가루와 찹쌀가루의 검지)

  • Lee, Eun-Jeong;Yang, Jae-Seung
    • Korean Journal of Food Science and Technology
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    • v.34 no.2
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    • pp.170-173
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    • 2002
  • Electron spin resonance (ESR) spectroscopy was used to detect free radicals in irradiated wheat flour and glutinous rice flour. They were irradiated with doses of 0, 0.1, 0.5, 1 and 2 kGy at room temperature using a Co-60 irradiator. Free radicals detected for irradiated wheat flour and glutinous rice flour were higher than those of unirradiated ones. Since concentration of free radicals linearly increased with applied doses $(0.1{\sim}2\;kGy)$, highly positive correlation coefficients $(R^2=0.9995{\sim}0.9998)$ were obtained between irradiation doses and free radical concentrations right after irradiation. Although concentration of free radicals slowly decreased with storage time, the characteristic ESR signals of free radical in irradiated samples were observed even after 4 weeks of storage at room temperature.

The Detection of Irradiated Composite Seasoning Foods by Analyzing Photostimulated Luminescence (PSL), Electron Spin Resonance (ESR) and Thermoluminescence (TL) (PSL, ESR 및 TL 측정에 의한 복합조미식품의 방사선 조사여부 검지)

  • Kwon Joong-Ho;Kim Mi-Yeung;Kim Byeong-Keun;Chung Hyung-Wook;Kim Tae-Cheol;Kim Soo-Jin
    • Food Science and Preservation
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    • v.13 no.1
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    • pp.55-60
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    • 2006
  • Two kinds of composite seasoning products (beef broth powder, polk bone extract powder) were used for a detection trial of gamma irradiation treatment up to 10 kGy by analyzing photostimulated luminescence (PSL), electron spin resonance (ESR) and thermoluminescence(TL). PSL results showed that the photon counts of non-irradiated samples were lower than 700, while those of irradiated samples were higher than 5000, which makes it possible to screen irradiated composite seasoning products at 1 kGy or over from the non-irradiated control. ESR signals measured for both irradiated samples were not irradiation-specific, even though they were dose dependent in the signal intensity. Radiation-induced TL glow curves were found in irradiated beef broth powder and furthernmore, TL ratio $(TL_4/TL_2)$ obtained by a re-irradiation step could verify the detection result of TL1 glow curves, showing ratios lower than 0.05 in the non-irradiated sample and higher than 1.00 in irradiated ones.

Detection Characteristics of TL, ESR and DNA Comet for Irradiated Soybeans (열발광, 전자스핀공명 및 DNA Comet 분석에 의한 대두의 방사선 조사 여부 검지 특성)

  • Lee, Eun-Young;Jeong, Jae-Young;Noh, Jung-Eun;Jo, Deok-Jo;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.34 no.1
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    • pp.18-23
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    • 2002
  • The detection characteristics of gamma-irradiated $(0{\sim}4\;kGy)$ soybeans produced in Korea and China were investigated by thermoluminescene (TL), electron spin resonance (ESR), and DNA comet assay. The TL glow curves were shown at around $200^{\circ}C$ for irradiated soybeans, while that at $280^{\circ}C$ for the non-irradiated one. The normalization with a re-irradiation step at 1 kGy could verify the above detection results. The Korean soybean showed higher glow curves than Chinese did. The ESR spectroscopy for husks of irradiated soybeans revealed specific signals (g = 2.02374, 1.98715) derived from cellulose radical, which intensities were proportional to irradiation does, with the higher peaks in Chinese sample than Korean one. The DNA comet for the non-irradiated sample showed no or little tails, while those for irradiated samples above 0.5 kGy were remarkably changed in their length, size, and concentration, thus resulting in distinguishing non-irradiated from irradiated samples. As a result, TL, ESR, and DNA comet determinations were found suitable for the detection of irradiated soybean at 0.5 kGy or more, and negligible differences were observed between Korean and Chinese origins in their detection characteristics.

ESR Study of Paramagnetic Defects of the ${\gamma}$-irradiated Potassium Sulfate Single Crystal (${\gamma}$-선에 조사된 황산칼륨 단결정의 상자성 결함에 관한 전자스핀공명 연구)

  • Yo Chul Hyun;Chung Won Yang;Jong In Hong;Eun Ok Kim;Jung Sung Yang
    • Journal of the Korean Chemical Society
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    • v.25 no.6
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    • pp.367-375
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    • 1981
  • Single crystals of Potassium Sulfate ($K_2SO_4$) have been grown from the saturated solution by the evaporation method at the optimum conditions. Radiation damages in the crystal by ${\gamma}$-irradiation of about $12{\times}10^6$ Roentgen have given rise to paramagnetic centers or paramagnetic defects. Electron spin resonance (ESR) spectra of the centers are obtained with the X-band EPR spectrometer at room temperature. The ESR peaks of the paramagnetic species are found to be anisotropic but the peak of $SO_3-$ radical is an isotropic of Gaussian shape at g = 2.0036. A number of ESR spectra of the crystal for angular variation of the anisotropic peaks are recorded at various orientations of rotation about a, b and c crystallographic axes respectively. The g-values are calculated from the line position between anisotropic peaks and the isotropic one and then principal g-values and its direction cosines of the species are obtained by diagonalization of 9 matrix elements of the corresponding g-values. All the paramagnetic defects are identified by the characteristic principal g-values and its direction cosines.

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