Distribution Characteristics of Dioxins in Marine Sediment from Busan Port in Korea

Jeong, Tae-Uk,Seo, Dong-Cheol,Jeong, Seung-Ryul,Song, Bok-Joo,Cho, Jeong-Gu,Yoo, Pyung-Jong,Kim, Gi-Gon,Cho, Ju-Sik,Heo, Jong-Soo Korean Society of Soil Science and Fertilizer 2012 한국토양비료학회지 Vol.45 No.1

Eight marine sediments from Busan port in Korea were annually analyzed to examine the concentration distribution of dioxins from 2006 to 2010. Yearly mean concentration of dioxins ranged from 186.3 to $383.3pg\;g^{-1}$ in real values and 5.087 to 8.541 pg-TEQ (Toxicity equivalency) based on dry weight of samples. The dioxin concentration at the site near fishing market was the highest concentration among all sampling sites. Also the dioxin concentration at the sites with various pollutant sources such as large ships, sewage influx and thermal power station as well as fishing market was higher than that of the sites without specific pollutant sources. Another main factor that affects the dioxin concentration is topography characteristics of the bay. The bay has relatively high dioxin concentration because of the lack of the pollutant diffusion. This study demonstrated that the dioxin concentration in the site with pollutant sources and the lack of the pollutant diffusion was relatively high as compared with the other sites. As a result of contribution ratio of dioxin congeners, OCDD (Octachlorodibenzodioxin) in all sites was major contributor in real value, in contrast, dioxin congeners in TEQ values were dominated by 2,3,4,7,8-PeCDF.

Functional restoration of replicative senescent mesenchymal stem cells by the brown alga <i>Undaria pinnatifida</i>

Jeong, Sin-Gu,Oh, Youn Seo,Joe, I-Seul,Jeong, So Young,Cho, Hyo Moon,Lee, Jun Sik,Oh, Won Keun,Cho, Tae Oh,Cho, Goang-Won ZOOLOGICAL SOCIETY OF KOREA 2017 ANIMAL CELLS AND SYSTEMS Vol.21 No.2

<P><B>ABSTRACT</B></P><P>The brown alga <I>Undaria pinnatifida</I>, which is called Mi-Yoek in Korea, has been traditionally consumed as a health food in East Asian countries. Recent studies have reported that <I>U. pinnatifida</I> has beneficial effects on arteriosclerosis, inflammation, fat metabolism, and tumors<I>.</I> In this study, we examined the anti-senescence effects of ethanol extracts of <I>U. pinnatifida</I> (UP-Ex) in human bone marrow mesenchymal stem cells (hBM-MSCs). UP-Ex protected hBM-MSCs against oxidative injury, as determined by MTT assays. This effect was confirmed by immunoblot analysis of the oxidation-sensitive protein p53 and the apoptotic protein cleaved caspase-3. Excessive intracellular reactive oxygen species (ROS) accumulation induced by oxidative stress was moderated in UP-Ex-treated hBM-MSCs (UP-Ex-MSCs). Similarly, expression of the ROS-scavenging enzymes superoxide dismutase 1 (SOD1), SOD2, and catalase was recovered in UP-Ex-MSCs. Excessive ROS induced by long-term cell expansion (passage 17) was significantly decreased along with restoration of the senescence proteins p53, p21, and p16 in UP-Ex-MSCs. UP-Ex treatment also improved the ability of these replicative, senescent hBM-MSCs (passage 17) to differentiate into osteocytes or adipocytes, suggesting that UP-Ex ameliorates the functional decline of senescent stem cells and may provide better therapeutic efficacy in stem cell therapy.</P><P><B>Abbreviations:</B> hBM-MSCs: human bone marrow mesenchymal stem cells; DCF: 2′,7′-dichlorodihydrofluorescein; DCFH-DA: 2′,7′-dichlorofluorescein diacetate; MTT: 3-(4,5-dimethylthiazol-2-yl-)2,5-diphenyltetrazolium bromide; PBS: phosphate-buffered saline; PFA: paraformaldehyde; RIPA: radioimmunoprecipitation assay; ROS: reactive oxygen species; SOD1: superoxide dismutase 1; SOD2: superoxide dismutase 2.</P>

The Effect of Economic Indicators on the Stock Returns by Industry

Jeong-Gu Seo,Jin-Soo Lee,Seong-Gab Kim 한국인터넷전자상거래학회 2017 인터넷전자상거래연구 Vol.17 No.5

This study analyzed value relevance of financial performance including the economic factors such as exchange rates, economic growth, interest rates and other macro economic variables. The empirical results are as follows. Regarding the KOSPI, US(Japanese, Chinese) exchange rates are found to significantly influence. But European exchange rates did not show a statistically significant result. In addition, for the economic growth rate, Korea(US, European, Chinese) growth rates are found to significantly influence. But Japanese growth rates showed no significant results. And among other economic indicators, employment rates, interest rates, unemployment rates, inflation, savings rates, and manufacturing inventories showed significant influence. By the industrial analysis of the relevance for each economic indicators, the independent variables appeared to affect differently on the corporate value. According to this study, the equity capital market participants must take into account exchange rate, economic growth rate, interest rate and many other economic indicators. It also shows that the main variables are be considered a industry-specific impact on the firm value. In this study, the effect of the economic indicators as the main variables on stock return were studied for each industry controlling for the effects of accounting variables. This is meaningful to help investors make reasonable decisions by referring to the important economic indicators. This paper provides useful information to investors and creditors.

Distribution Characteristics of Dioxins in Soils under Different Land Use in Busan, Korea

Jeong, Tae-Uk,Seo, Dong-Cheol,Jeong, Seung-Ryul,Cho, Jeong-Gu,Yoo, Pyung-Jong,Kim, Gi-Gon,Cho, Ju-Sik,Heo, Jong-Soo Korean Society of Soil Science and Fertilizer 2011 한국토양비료학회지 Vol.44 No.4

In this study, distribution characteristics of dioxins in soils in Busan, Korea were investigated regarding different land use types. Soil sampling sites that distributed through the Busan city showed dioxin concentration ranging from 0.489 to $322.736pg-TEQ\;g^{-1}$ dry weight with a mean value of $26.257pg-TEQ\;g^{-1}$ dry weight. The mean dioxin concentrations of investigated soils ranged from 1.554 to $50.357pg-TEQ\;g^{-1}$ dry weight in consideration of each land use type. That in metal refinery sites with $50.357pg-TEQ\;g^{-1}$ dry weight was higher than any other sites, followed by waste incinerator sites with $44.285pg-TEQ\;g^{-1}$ dry weight. The majority of soil samples had the same dioxin congener profiling despite the different range of dioxin concentration. Octa-CDD was the major contributor among seventeen dioxin congeners with the range from 29.5 to 70.1% in real values. In contrast to real values, dioxin congener profiles in TEQ values were dominated by 2,3,4,7,8-PeCDF which contributed about 35.3~43.8% to the total dioxin concentrations. It was judged by these results that penta-CDF was the major contributor of soil samples in Busan city. The mean ratio of PCDFs/PCDDs in real values was about 0.71, but that in TEQ values was, in contrast to it, approximately 3.03.

O-GlcNAc Biology

Jeong Gu Kang,Sang Yoon Park,Suena Ji,In Sook Jang,Su Jin Park,Hyeon Gyu Seo,Hanbyeol Kim,Eun Ah Kim,Ho Jung Seo,Yang Shin Lee,Jürgen Roth,Jin Won Cho 한국당과학회 2010 한국당과학회 학술대회 Vol.2010 No.1

The O-GlcNAc modification is a quite different fro m conventional glycosylation in two aspects. First, it occurs in cytoplasm and nucleus and does not in endoplasmic reticulum or Golgi apparatus. Second, this is a single sugar modification and is not a long chain oligosaccharide modification. O-GlcNAc is covalently modified on hydroxyl group of serine and threonine and usually this modification affects or competes with phosphorylation. Thus this modification might modulate many cellular events due to inhibiting or sometimes accelerating phosphorylation. O-GlcNAc transferase and O-GlcNAcase are two important enzymes for modifying proteins with O-GlcNAc. More than 800 proteins have been identified as O-GlcNAcylated proteins. Today I am going to summarize results obtained last 10 years and discuss about future aspects in O-GlcNAc biology.

N-Stack 기술을 적용한 듀얼 구조를 갖는 SCR 기반 ESD 보호회로에 관한 연구

정승구(Jeong Seung Gu),백승환(Baek Seung Hwan),이정민(Lee Jeong Min),서우열(Seo Woo Yeol),구용서(Yong-Seo Koo) 대한전자공학회 2022 대한전자공학회 학술대회 Vol.2022 No.11

세무조사기업의 특성에 관한 연구 - 재무 및 지배구조 특성을 중심으로 -

서정구 ( Seo Jeong-gu ),문상현 ( Moon Sang-hyun ),이진수 ( Lee Jinsoo ) 한국세무회계학회 2018 세무회계연구 Vol.0 No.55

세무조사의 목적은 납세자의 탈세여부를 조사하는 것이며 탈세 유형은 일반적으로 고의적 장부상 수익(매출)을 누락하거나 실제 발생하지 않은 비용을 해당사업에 지출한 것으로 처리하여 소득금액을 줄이고 과세표준을 감소시켜 실제 지출하는 세금을 줄이기 위한 것이다. 이러한 탈세행위는 국가재정에 직접적 타격을 주고 국민후생지출에 따른 감소를 유발시켜 나라전체의 사회적 문제가 되어 소득재분배와 자원배분에 따른 문제점을 야기 시킨다. 본 연구는 세무조사기업과 비 세무조사기업의 재무적 특성과 기업지배구조 특성의 차별점을 연구하고자 한다. 분석결과 첫째, 재무적 특성은 T-test 검증과 로지스틱 회귀분석(Logistic Regression) 검증 결과 당좌비율, 매출액 총이익률, 단기차입금 비율, 부채비율의 특성변수가두 검증 모두 유의수준내의 결과를 보였다. 둘째, 기업지배구조 특성으로 T-test 검증과 로지스틱 회귀분석(Logistic Regression) 검증 결과 BIG4, 대주주 지분율, 사외이사비율, 세무전문인 여부가 유의한 결과를 보였다. 본 연구의 한계점은 재무적 특성이외의 기업의 질적특성을 고려하지 못하였고, 정기세무조사 기업을 표본에서 제외하여 세무조사 전체기업을 표본으로 구성하지 못했다는데 한계점이 있다. 이러한 한계점에도 불구하고 선행연구에서 고려하지 않았던 특성변수를 추가하여 분석하였고 검증 방법을 T-test 검증과 로지스틱 회귀분석(Logistic Regression) 검증의 두 가지 방법을 상호보완적으로 사용하여 분석하였으며 세무조사 선정가능성에 기초적인 정보를 제공할 것으로 기대되며, 재무구조와 기업지배구조특성에 변화에 따른 세무조사 가능성에 대한 관련성이 있다는 실증적 증거를 제시하였다는데 공헌점이 있다. The purpose of the tax investigation is to investigate the taxpayer's tax evasion. Tax evasion misses sales or spares costs. Thus, by reducing the amount of income and reducing taxation standards, it is to reduce the tax that is actually spending. Such tax evasion acts directly against national finances. And it leads to a reduction of public welfare spending, which becomes a social problem for the whole country. It also causes problems related with the income redistribution and the resource allocation. This study investigates the difference between the financial characteristics and corporate governance characteristics of tax investigation companies and non-tax investigation companies. The results of the analysis are as follows. First, the financial characteristics are as follows. As a result of the T-test and the logistic regression analysis, the characteristics of the current ratio, the gross profit margin, the short-term borrowing ratio, and the debt-to-equity ratio were within the significance level. Second, T-test and logistic regression analysis show that BIG4, outside directors ratio, tax professionals are significant. The limitations of this study are not considering the qualitative characteristics of firms other than financial characteristics. In addition, there is a limit to the fact that the regular tax investigation companies are excluded from the sample.

Difference of resistance to Streptococcus pneumoniae in mouse

Dong-Gu Jeong,Eui-Suk Jeong,Kyoung-Sun Lee,Jin-Hee Seo,Yang-Kyu Choi 한국실험동물학회 2010 한국실험동물학회 학술발표대회 논문집 Vol.2010 No.8

Difference in Resistance to Streptococcus pneumoniae Infection in Mice

Dong-Gu Jeong,Eui-Suk Jeong,Jin-Hee Seo,Seung-Ho Heo,Yang-Kyu Choi 한국실험동물학회 2011 Laboratory Animal Research Vol.27 No.2

Streptococcus pneumoniae is a major pathogen that causes various diseases, including pneumonia and sepsis, as millions of people suffer from S. pneumoniae infection worldwide. To better understand the immune and inflammatory responses to S. pneumoniae, we produced murine models. To investigate the differences between intranasal and intratracheal infection, BALB/c mice were infected with S. pneumoniae D39 intranasally or intratracheally. Mice showed no significant differences in survival rates, body weight changes, and bacterial loads. To investigate resistance and susceptibility among mouse strains, BALB/c, C57BL/6J, tumor necrosis factor-α (TNF-α) knockout, and interleukin-10 (IL-10) knockout mice were infected with S. pneumoniae D39 via intranasal or intravenous routes. In this study, BALB/c and C57BL/6J mice were resistant, IL-10 knockout mice were intermediate, and TNF-α knokout mice were susceptible to S. pneumoniae infection. These data show that intranasal and intratracheal infection induced similar results after S. pneumoniae infection, and the genetic background of mice must be considered when studying S. pneumoniae infection in vivo.

Multiple Organ Failure and Impaired Bacterial Clearance after Streptococcus pneumoniae Sepsis in Tumor Necrosis Factor-Alpha-deficient mice

Dong-Gu Jeong,Eui-Suk Jeong,Jin-Hee Seo,Seung-Ho Heo,Yang-Kyu Choi 한국실험동물학회 2011 한국실험동물학회 학술발표대회 논문집 Vol.2011 No.2