• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.725-731
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• 2015

Electron spin resonance (ESR) analysis was conducted for eight different kinds of dried seafood products to investigate their gamma-irradiation status. The specimens consisted of 0~10 kGy-irradiated bones, which included five dried fishes (plaice, hairtail, saury, herring, and dried filefish) and three dried mollusks (beca squid, dried squid, and mitra squid) without flesh or marrow. ESR analysis showed that irradiated specimens exhibited typical asymmetric signals as compared to non-irradiated specimens. ESR signal intensities of all dried fishery samples significantly increased depending on irradiation dose, whereas hydroxyapetite radicals clearly appeared in irradiated plaice, saury, and hairtail. In comparing hydroxyapatite (HA) ratio, irradiated hairtail showed a greater hydroxyapatite-radical generation rate than plaice and saury, and the HA ratio significantly increased with elevated irradiation dose. However, all irradiated plaice and hairtail samples, including 5 and 10 kGy-irradiated saury, showed radiation-derived radicals, whereas filefish and mollusks did not. From the results, ESR spectroscopy was found to have potential to be applied for identifying irradiated plaice, hairtail, and saury, which all contained bones.

• Journal of the Korean Chemical Society
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• v.38 no.1
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• pp.13-20
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• 1994

Substituted anthrasemiquinone radical anions, which were formed by laser flash photoreduction of the substituted anthraquinone (1,4-DHAQ, 1,5-DHAQ, 1,8-DHAQ, 1,8-DCAQ), were studied by the electron spin resonance spectroscopy in the mixed solvents of the 2-propanol and the triethylamine. Hyperfine splitting constants (hfsc) were determined by simulating the ESR spectra. Extended Huckel Molecular Orbital (EHMO) calculations were performed to obtain $\pi$ spin densities for these quinones. The hyperfine splitting constants could be assigned to specific protons on the basis of $\pi$ spin densities.

• Tuberculosis and Respiratory Diseases
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• v.45 no.5
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• pp.992-999
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• 1998

Background: To correlate the emphysema score for quantification of the overall extent of emphysema in both lungs by CT with physiologic fingings and to get more objective and simple method to assess the extent of emphysema. Method: Thin-section CT and pulmonary function test(PFT) were performed in 17 patients with emphysema (all males, mean age, 62 years). Emphysema score was obtained as percentage of emphysematous lung area, dividing the total area of the emphysema(voxels with attenuation value less than -880, -900, -920HU, respectively) by the overall area of both lungs(voxels with attenuation value less than -400HU) with highlighting voxels using "Density mask" program. Emphysema score was calculated from whole lung(ESV) and 5 representative scans(ESR) using "Density mask", Visual emphysema score(ESV) was obtained by visual assessment from 5 representative scans. Correlation of these emphysema scores(ESW, ESR, ESV) and physiologic findings were performed, comparing the ESW with ESR and ESV. Results: ESW had correlation with DLCO(r=0.53-0.64) and $FEV_1/FVC$(r=0.42-0.57) among PFT parameters. ESR had good correlation with ESW and with PFT parameters as well. ESV did not correlate with PFT parameters except DLCO. Conclusion: CT quantification of emphysema using "density mask" correlated well with physiologic findings. To assess the severity of emphysema, both ESW and ESR are more reliable than ESV, and ESR is recommended in routine practice as it is objective, simple and reliable.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.1
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• pp.16-21
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• 2005

To find out the effectiveness of clinical examination for detection of dermatophagoides farinae allergen asthma disease, 50 patients (control group) and 50 healthy persons matched by sex and age to the control group, were tested for allergen asthma. The results of the study follow. The ESR there was significantly different from the comparisons of the patients' normal reference values, 95.3 % in ESR, patient groups allergen asthma and heamatology values with control group. The ESR level of allergen asthma patients, $62.23{\pm}35.09$ mm/hr, was higher than that of the controls, $9.47{\pm}5.36$ mm/hr (p<0.001). The eosinophil count level of the patients, $370.65{\pm}365.45mm^3$, was higher than that of the controls with $171.99{\pm}131.80mm^3$ (p<0.001). The IgE level of the patients, $1137.79{\pm}784.69IU/ml$, was higher than that of the controls with $71.29{\pm}14.28 IU/ml$ (p<0.001).

• The Plant Pathology Journal
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• v.21 no.3
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• pp.283-287
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• 2005

Since the discovery of generation of $O_2^-$ in plant, many evidence for the oxidative burst (OXB) has been accumulated in various combinations of plant and pathogen or elicitor systems. $O_2^-$ generating system responsible for the OXB was coupled with oxidation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) in microsomal fraction isolated from sliced aged potato tuber slices which were treated by hyphal wall components elicitor from Phytophthora infestans (HWC). We developed new assay method for quantitative measurement of oxygen radical $O_2^-$ by using electron spin resonance (ESR) analysis during elicitor­induced OXB on the surface of plant tissues. The ESR analysis using an $O_2^-$ trapper, Tiron (1,2-dihydroxy-3,5­benzenedisulfonic acid), provided a convenient assay for detecting only $O_2^-$ during elicitor-induced OXB producing various active oxygen species (AOS) on plant tissue surface. Tiron was oxidized to Tiron semiquinon radical by $O_2^-$. Quantity of the radical signal was measured by specific spectra on ESR spectroscopy. The level of $O_2^-$ was high in from surface of potato tuber tissue treated with hyphal cell wall elicitor (HWC) from Phytophthora infestans. There was no secondary OXB induction by $H_2O_2$ treatment in plant.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.423-426
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• 1995

Langmuir-Blodgett technique offers a convenient and elegant way to organic conducting systems for ultra thin films. In conducting systems based on LB films, TCNQ derivatives have been extensively studied as electron acceptor molecules in a large number of organic conducting systems.[1] A very interesting UV-visible spectra of octadecylviologen-$(TCNQ^-)_2$ was obtained from a methylenechloride and acetonitrile mixture, and from Langmuir-Blodgett films. The ESR characteristics of octadecylviologen-$(TCNQ^-)_2$ were studied to understand conducting mechanism and structure of LB films. The ESR spectra infer that the N-dococylquinolinium-TCNQ LB films has anisotropic property. But octadecylviologen-$(TCNQ^-)_2$ does not show angular dependence. As the temperature increases from 350K to 450K, the ESR signal of LB films becomes sharp. Scanning calorimetry(DSC) of octadecylviologen-$(TCNQ^-)_2$ provides the endothermic reaction temperature of the films, 340K, which corresponds to the temperature, 365K, of the new ESR signal.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.374-378
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• 2009

Three physical methods, photostimulated luminescence (PSL), thermoluminescence (TL), and electron spin resonance (ESR), have been applied to detect the irradiation treatment for the non- and steamed sesame seed samples. PSL successfully screened the irradiated samples from the non-irradiated control by comparing their photon counts (PCs) with the lower (less than 700 count/60 sec) and upper threshold values (higher than 5,000 count/60 sec). TL signals were still detected in all irradiated samples even after steaming, which was reconfirmed with TL ratios [integrated area of $TL_1$ (the first glow)/$TL_2$ (the second glow)] through re-irradiation step. ESR spectrometry showed that radiation-induced cellulose radicals were detected in all the irradiated samples irrespective of steaming treatment. Identification of the irradiated sesame seeds was possible even after steaming by analyzing PSL, TL, and ESR.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1076-1081
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• 2001

Gamma-irradiated peanuts, Korean and Chinese origins, were investigated on detection properties by thermoluminescence (TL), electron spin resonance (ESR), and DNA comet assay (single cell gel electrophoresis). TL measurement showed that the non-irradiated sample revealed a glow curve with low intensity at about 25$0^{\circ}C$, while the irradiated samples showed higher intensity around at 18$0^{\circ}C$. TL ratio (TL$_1$/TL$_2$) of area for TL$_1$ glow curve to TL$_2$ was below 0.05 for the non-irradiated sample and 0.2 or more for the irradiated ones, thus identifying each other. ESR spectroscopy for the irradiated peanuts using outer skin showed negligible signals induced by irradiation, indicating ESR is little applicable to the detection of irradiated peanuts. In DNA comet assay, the non-sample had no or very short tails, whereas the irradiated samples revealed the cells with long tails. Significance in the increase of their lengths depending on irradiation dose (r=0.761/Korean, r=0.768/Chinese) was also found. There was no remarkable difference in detection properties by origins of samples in all determinations, It is concluded that TL analysis or DNA comet assay is suitable for detection of irradiated peanuts and a combined method is recommendable for enhancing the reliability of detection results.

• Biomaterials and Biomechanics in Bioengineering
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• v.1 no.2
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• pp.105-116
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• 2014

Synthesis of interpenetrating polymer network (IPN) of chitosan-gelatin (Cs-Ge) (as a primary network) and N-isopropylacrylamide (NIPAAm) monomer (as the secondary network) was carried out with different ratio. Its structure was characterized by FT-IR, which indicated that the IPN was formed. The memberanes were studied by swelling, weight loss with time. The interior morphology of the IPN hydrogels was revealed by scanning electron microscopy (SEM); the IPN hydrogels showed a interpenetrated network of NIPAAm/chitosan has layers with more minute stoma and canals compared to interpenetrated network of NIPAAm/gelatin. Lower critical solution temperature (LCST), equilibrium swelling ratio (ESR) and deswelling kinetics were measured. The DSC results noticed that LCST of IPN hydrogels with different ratio of Cs/Ge/PNIPAAm are around $33{\pm}2^{\circ}C$. The ESR obtained results showed that with a ratio of Cs/Ge/NIPAAm: 1/1/6, the swelling ratio increased drastically from room temperature to $36^{\circ}C$ but with a ratio of Cs/Ge/PNIPAAm: 1/3/6, decrease significantly at the same condition. Therefore the hydrogels have been changed from a hydrophilic structure to a hydrophobic structure. Furthermore with an increase in temperature from room to the LCST, the ESR of IPN with higher concentration of (PNIPAAm) and (Ge) decreases but de-swelling kinetics of them are faster. Due to the suitable and different kinetics of de-swelling and the equilibrium swelling ratio (ESR) in various proportions, and because of the morphology inside the mass which confirms other tests, these hydrogels are very appropriate as a smart thermosensitive hydrogels with rapid response.

• Journal of the Korean Ceramic Society
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• v.48 no.6
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• pp.577-583
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• 2011

Stabilized biocompatible superparamagnetic iron oxide nanoparticles (SPIONs) were prepared by controlled coprecipitation method for hyperthermia application. ESR measurements determined that all of the interactions in the individual SPIONs (1 nm and 11 nm) were antiferromagnetic in nature because the ions contributed to the magnetization with a range of magnetic moments. In-situ monitoring of the temperature increment was performed, showing that the microwave absorption rate of the SPIONs was dispersed in an appropriate host media (polar or non-polar solvents) during microwave irradiation. Microwave absorption energy rates and heat loss of SPIONs in solvent were calculated by non-linear data fitting with an energy balance equation. The microwave absorption rates of SPIONs dispersed in solvent linearly increases when the concentration of SPIONs increases, implying that the microwave absorption rate can be tunable by changing the concentration of SPIONs.