• Fisheries and Aquatic Sciences
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• v.10 no.2
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• pp.93-101
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• 2007

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in marine sediments from Mokpo coastal water of Korea. Total and toxic equivalent (TEQ) concentrations of PCDD/Fs ranged from 19.4 to 175pg/g dry weight and ranged from 0.195 to 2.87 pg WHO-TEQ/g dry weight, respectively. These PCDD/F concentrations were below the safety sediment value (20 pg TEQ/g dry weight) of chronic toxicity. A highly significant correlation between the concentrations of PCDD/Fs and total organic carbon (TOC) in marine sediments was observed. Overall PCDD/F concentrations in the sediments were elevated in rivers and at inner locations close to harbors, indicating that these contaminants derived from local discharges of human activities. PCDD/F concentrations measured in our study were lower than those in several industrialized areas in Korea. Nonparametric multidimensional scaling (MDS) ordination showed that combustion processes from industrial complexes are the major source of PCDD/Fs in Mokpo coastal water.

• Journal of Environmental Health Sciences
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• v.42 no.2
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• pp.102-111
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• 2016

Objectives: This study was conducted to evaluate the use of polyurethane foam disk passive air samplers (PUF PAS) for better measurement of atmospheric polychlorinared dibenzo-p-dioxins/furans (PCDD/Fs) concentrations compared to PUF PAS combined with high volume air samplers (HVS). Methods: Air samples were collected by a low volume air sampler (LVS) and PUF PAS. A total of two pairs were continuously collected for six months, but the PUF was replaced every two months. Results: A good correlation was shown ($R^2=0.8595$, p<0.0001) between atmospheric PCDD/Fs concentration measured by the LVS and PUF PAS. The average air sampling rate ($1.5m^3/day-sampler$) of all PCDD/Fs congeners showed a middle of the means which were measured using a HVS by other researchers in different cities. In addition, the air sampling rates of the LVS for each congener made less difference than did those of the HVS. Conclusion: It was found that measurements using the LVS were less influenced by atmospheric peak PCDD/Fs concentrations. However, trace POPs such as PCDD/Fs may involve relatively large analytical errors in measurement, and as a result the air sampling rate of the respective PCDD/Fs isomer is also likely to involve errors. The method of using a regression straight line between the concentrations obtained from the LVS and those from the PUF PAS was judged higher than the method using the air sampling rate, since the former compensated for the experimental errors in the process of evaluation of atmospheric PCDD/F concentrations using the PUF PAS.

• Korean Journal of Veterinary Research
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• v.24 no.1
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• pp.31-35
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• 1984

The hemoglobin phenotype and the gene frequencies of 44 Formosan deer(Cervus nippon) in Kyung-Gi area were examined by using cellulose acetate and starch gel electrophoresis. 1. The method of cellulose acetate electrophoresis was simplier, more clear and preserative than starch gel electrophoresis. 2. The hemoglobin phenotype was appeared 3 types as $Hb^F$ $Hb^{FS}$ and $Hb^S$. The frequencies of appearance were $Hb^F$ 47.7%, $Hb^{FS}$ 47.7% and $Hb^S$ 4.5%, respectively. 3. The genetic factors of hemoglobin were observed as $Hb^F$ and $Hb^S$ and the rates of gene frequencies were 71.6% and 28.4%, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.548-561
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• 2015

Atmospheric concentrations of polychlorinated dibezo-p-dioxins and furans (PCDD/Fs) were investigated at urban-residential (Group I: Suwon, Guri and Goyang), industrial (Group II: Ansan, Siheung and Bucheon), urban-rural mixed (Group III: Yangju, Pocheon and Dongducheon) and rural regions (Group IV: Yangpyeong) in Gyeonggi-do from February 2012 to November 2012 quarterly. The concentrations of PCDD/Fs ranged from 0.018 to $0.109pgTEQm^{-3}$ in Group I (mean value: $0.061pgTEQm^{-3}$), 0.059 to $0.367pgTEQm^{-3}$ in Group II (mean value: $0.179pgTEQm^{-3}$), 0.072 to $0.836pgTEQm^{-3}$ in Group III (mean value: $0.334pgTEQm^{-3}$) and 0.014 to $0.066pgTEQm^{-3}$ in Group IV (mean value: $0.034pgTEQm^{-3}$), respectively. In spite of the less PCDD/F emission sources than Group II (industrial regions), the level of PCDD/Fs in urban-rural mixed area showed the highest values with high fluctuation. It's likely that the Group III was affected by fugitive emissions such like biomass burning and unregulated open burning. The mean contribution of particle phase to total PCDD/F concentration was above 83% because most of PCDD/F congeners were partitioned into particle phase. We evaluated their gas-to-particles equilibriums with the regression between the particle-gas partition coefficient, $K_P(m^3{\mu}g^{-1})$ and corresponding subcooled liquid vapor pressure ($P_L$). The logarithm-$K_P$ of PCDD/Fs was poorly correlated with $P_L$ at low ambient temperature (below $10^{\circ}C$) and the slope (m) values for log-log plots of the $K_P$ vs. $P_L$ was steeper in the Group 2 and Group 3 than residential area. It implies that the slope values were likely influenced by both the direct emission source of PCDD/Fs and ambient temperature.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.201-206
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• 2004

Vascular endothelial growth factor (VEGF), plays a key role in angiogenesis. Many endogenous factors can affect angiogenesis in endothelial cells. VEGF is known to be a strong migration, sprouting, survival, and proliferation factor for endothelial cells during angiogenesis in endothelial cells. Searching for novel genes involved in VEGF signaling during angiogenesis, we carried out differential display polymerase chain reaction on RNA from VEGF-stimulated human umbilical vein endothelial cells (HUVECs). In this study, follistatin (FS) differentially expressed in VEGF-treated HUVECs, compared with controls. Addition of VEGF (10ng/L) produced an approximately 11.8-fold increase of FS mRNA. F5 or VEGF produced approximately 1.8- or 2.9-fold increases, respectively, in matrix metalloproteinase-2 (MMP-2) secretion for 12h, compared to the addition of a control buffer. We suggest that VEGF may affect the angiogenic effect of HUVECs, through a combination of the direct effects of VEGF itself, and the indirect effects mediated via induction of FS in vitro.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.1-9
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• 1973

The purpose of this paper is to investigate the mechanism of Diels-Alder reaction by assuming pseudo molecular complex (PMC) which has characters both of ionic and radical bonds. We treated this complex quantum-chemically as an intermediate between the configuration without charge transfer (radical bond character) and the configuration corresponding to the charge transfer from Diene (R) to Dienophile (S) (ionic bond character). The wave function for the complex could be expressed as: ${\psi}_{complex} = {\psi}(R,S) +{ \rho}{\psi}(R^+,S^-)$ where ${\rho}$ is the extent of charge transfer which is a constant to measure the ionic character of PMC. It has been noticed that${\rho}$is related to the difference between Fr + Fr' and Fs + Fs' in free valence (F) when R is united to S through atom r in R to atom s in S and atom r' in R to atom s' in S, That is, ${\rho}{\alpha}$ ${\Delta}F = (Fr + Fr') - (Fs + Fs')$. We have calculated ${\Delta}F$values for more than forty Diels-Alder reactions. The calculated values of ${\Delta}F$ is reversely proportional to the values of Brown's paralocalization energy (Lp) as well as Dewar's differences of delocalization energy$({\Delta}Edeloc.)$ with good linearity. This approach also presents a way of predicting the possibility and the easiness of diene synthesis between any two conjugate compounds. According to the considerations, it could be concluded that Diels-Alder reaction takes place through the united ionic-radical mechanism rather than the separated ionic or radical mechanism.

• Korean Journal of Materials Research
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• v.32 no.2
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• pp.107-113
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• 2022

Fibrous supercapacitors (FSs), owing to their high power density, good safety characteristic, and high flexibility, have recently been in the spotlight as energy storage devices for wearable electronics. However, despite these advantages, FCs face many challenges related to their active material of carbon fiber (CF). CF has low surface area and poor wettability between electrode and electrolyte, which result in low capacitance and poor long-term stability at high current densities. To overcome these limits, fibrous supercapacitors made using surface-activated CF (FS-SACF) are here suggested; these materials have improved specific surface area and better wettability, obtained by introducing porous structure and oxygen-containing functional groups on the CF surface, respectively, through surface engineering. The FS-SACF shows an improved ion diffusion coefficient and better electrochemical performance, including high specific capacity of 223.6 mF cm^-2 at current density of 10 ㎂ cm^-2, high-rate performance of 171.2 mF cm^-2 at current density of 50.0 ㎂ cm^-2, and remarkable, ultrafast cycling stability (96.2 % after 1,000 cycles at current density of 250.0 ㎂ cm^-2). The excellent electrochemical performance is definitely due to the effects of surface functionalization on CF, leading to improved specific surface area and superior ion diffusion capability.

• Korean Journal of Agricultural Science
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• v.22 no.2
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• pp.170-179
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• 1995

This study was conducted to investigate the genetic constitution of blood proteins and enzymes in 238 Korean Native cattle reared at Korean Native Cattle Breeding Center, National Livestock Cooperative Federation. The genetic polymorphisms of post-transferrin-2(pTf-2), transferrin(Tf), post-albumin(pAlb), albumin(Alb), ceruloplamin(Cp), amylase-I(Am-I) and hemoglobin(Hb) were analyzed by using PAGE(polyacrylamide gel electrophoresis) and STAGE(starch gel electrophoresis). The genotypes and gene frequencies were estimated at these loci for each blood proteins and enzymes. The results obtained from this study were summarized as follows : 1. The pTf-2 locus were identified to be genetically controlled by codominant alleles designated pTf-2 F and S, and the distribution of genotypes were 46.22, 46.64 and 7.14% for pTf-2 FF, FS and SS types, and the gene frequencies of the pTf-2 F and S allele were 0,695 and 0.305, respectiveley. 2. The Tf locus were found to be controlled by Tf A, D1, D2 and E alleles, and the distributioin of genotypes were 0.84, 13.87, 13.03, 10.92, 22.27, 12.61, 2.94, 15.51, 6.72 and 1.68% for Tf AA, AD1, AD2, AE, D1D1, D1D2, D1E, D2E and EE types, and the gene frequencies of Tf A, D1, D2 and E were 0.197, 0.430, 0.191 and 0.081, respectively. 3. The pAlb locus were observed to be controlled by two alleles, pAlb F and S, and the distribution of genotypes were 42.86, 33.19 and 23.95% for pAlb FF, FS and SS types, and the gene frequencies were 0.595 and 0.405 for Tf F and S allele, respectively. Also the gene frequencies of Alb was 1.000 of Alb A allele. 4. The Cp locus were identified to be controlled by Cp F and S allele, and the distribution of genotypes were 23.11, 34.87 and 42.02% for Cp FF, FS and SS types, and the gene frequencies were 0.405 and 0.595 for Cp F and S allele, respectively. 5. The Am-I locus were observed to be genetically controlled by Am-I B and C allele, and the distribution of genotypes were 51.26, 16.81 and 31.92% for Am-I BB, BC and CC types, and the gene frequencies of Am-I B and C alleles were 0.597 and 0.403, respectively. 6. The Hb locus were found to be controlled by Hb A and B alleles, and the distribution of genotypes were 93.19, 16.39 and 0.42% for Hb AA, AB and BB types, and the gene frequencies of Hb A and B alleles were 0.914 and 0.086, respectively.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.9
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• pp.77-86
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• 1998

A two-chip humidity sensor system has been developed which consists of a capacitive sense element die and a CMOS interface chip. The sense element was fabricated using thin polyimide films on (100) silicon substrate and showed excellent linearity(0.72%FS), low hysteresis (<3%) and low temperature coefficient(-0.0285 ~-0.0542pF/K) over a wide range of relative humidity and temperature. The capacitance-relative humidity characteristic exhibited a drift of 2~3% after 9 weeks of exposure to 4$0^{\circ}C$/90%RH. The signal-conditioning circuitry was fabricated using an 1.2- ${\mu}{\textrm}{m}$, one poly double metal CMOS process. The measured output voltage of the sensor system was directly proportional to relative humidity and showed good agreement with theory.

• The Journal of Korean Academic Society of Nursing Education
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• v.21 no.2
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• pp.246-255
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• 2015

Purpose: The purpose of this study was to investigate differences in the states of anger, depression, resilience and self-esteem according to type of school violence involving elementary school students. Methods: The participants were 257 elementary school students in the 4th, 5th and 6th grades. Data was collected by structured questionnaires, and analyzed using descriptive statistics, ${\chi}^2$-test, t-test, ANOVA, and Pearson correlation coefficients with the SPSS/WIN 20.0 program. Results: There were significant differences among the states of anger (Fs=16.66, p<.001), depression (Fs=18.04, p<.001), resilience (F=12.77, p<.001) and self-esteem (F=10.39, p<.001) according to the type of school violence. Of all the groups, bully-victim exhibited the highest score for anger and depression, and the lowest score for resilience and self-esteem. Conclusion: Based on the findings, developing intervention programs that consider the psychological characteristics of elementary school students is necessary. Also, the results of this study suggest that integrative programs for students that can enhance resilience and self-esteem, such as self-discovery programs, and reduce anger, such as anger control programs, need to be developed.