• IMMUNE NETWORK
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• v.6 no.4
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• pp.185-191
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• 2006

Background: Based on outstanding progresses in animal experiments, vaccines for some human tumors have been developed. However, clinical effects of these vaccines have been far below than expected. This discrepancy might come from differences between animal models and human patients with respect to immunocompetency. The immune status of mice after tumor inoculation has not been well studied, which make us cautious in interpreting and applying the results from mice to human. We evaluated cell-mediated immune responses in mice after tumor cell inoculation. Methods: Mice were inoculated with TA3Ha, CT26, or 4T1. Delayed-type hypersensitivity (DTH) responses were induced 2-4 weeks after inoculation using 2,4-dinitro-1-fluorobenzene as an antigen. The relationships between the severity of DTH responses and the duration of tumor inoculation or the size of tumor mass were analyzed. Results: In T A3Ha groups, DTH response was elevated 2 weeks after inoculation, but depressed after 4 weeks, compared to the control group. When analyzed based on the sizes of tumor masses elicited, DTH responses were inversely related to the mass size, especially in those greater than 10 mm in diameter. In CT26 groups, while the duration after inoculation did not affect the severity of DTH responses, those with large mass showed depressed responses regardless the duration of inoculation. 4T1 cells grew so slowly that the size of tumor mass was small even 4 weeks after inoculation, and this group showed much higher DTH responses compared to that of tumor-free group. Conclusion: At least in an experimental setting where tumor model was induced by inoculating tumor cell lines into immunologically competent mice, the host immune response was elevated in early stage, and then depressed in late stage when the mass grew over a critical size.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.66-72
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• 2016

In this study, a sulfonated poly(arylene ether ketone) block copolymer was prepared from hydrophilic oligomer and hydrophobic oligomer. The structure of the prepared membrane was characterized by $^1H$-NMR, FT-IR and GPC. The $M_w$(weight-average molecular weights) of the polymer was $209,700g\;mol^{-1}$ and the molecular weight distribution($M_w/M_n$) of 1.25 was obtained. The prepared membrane showed excellent thermal stability with gradual weight loss up to $200^{\circ}C$. The proton conductivity of SPAEK block copolymer reached the maximum of $9.0mS\;cm^{-1}$ at $90^{\circ}C$ under 100% relative humidity (RH). From the observed results, it is necessary to do more aggressive attempt to study the possibility of application as an ion-conductive composite electrolyte.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.510-519
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• 2021

Volatile Organic Compounds (VOCs) in sediments, which can cause human health problems, have been monitored in Korea since 2014. Measured VOC concentrations can be affected by matrix type and the volatility of target substances. In this study, (1) VOCs volatility and the influence of matrix interference were confirmed, and (2) internal standards (IS) method was applied to improve analytical method. For these purposes, method detection limit (MDL), calibration linearity, precision and accuracy of VOCs were compared in various matrices using the IS. Some of VOCs in sediments showed different peak areas and reduced rates compared to water matrix. It was suggested that adsorption properties of sediments hindered the migration to vapor during heat pretreatment in headspace method. A calibration curve was created in clean sand. Recovery rates for the calibration curve method and IS applying method were 64.1~83.1% and 99.1~119.3%, respectively. Relative standard deviations ranged from 11.1% to 21.6% for the calibration curve method and those for IS ranged 4.7% to 13.7%. In case of real sediment, calibration curve and 1,2-Dichlorobenzene-d4 (ODCB) among IS were not suitable. The average recovery rate of Fluorobenzene (FBZ) increased by 56.4% and Relative Standard Deviation (RSD) by 4.7%. However, the recovery rate was increased in the samples with large values of igniting intensity. This study confirmed that influence of the matrix of VOCs in sediment, and addition of IS materials improved precision and accuracy. Although IS corrects volatilization and adsorption, it is recommended that more than two types of IS should be added rather than single.