Terrestrial n-alkanes and their carbon isotope records from the Hanon paleo-maar sediment, Jeju Island, Korea: Implications for paleoclimate and paleovegetation over the last 35 kyrs

Hyun, S.,Shin, K.H.,Lee, S.C.,Chang, S.W.,Nam, S.I. Pergamon Press 2017 QUATERNARY INTERNATIONAL Vol.441 No.1

<P>The carbon isotope of total carbon (delta C-13(org)), long-chain n-alkanes, and their compound-specific carbon isotope ratios (delta C-13(ALK)) were investigated in the Hanon paleo-maar sediment, Jeju Island of Korea to understand paleoclimate variabilities and their paleovegetation linkages. Based on the organic geochemical data (TOC (%), TN (%), and their delta C-13(org) and delta N-15), the core column stratigraphy was divided into three units, namely from the bottom to 14.5 ka (Unit I), from 14.5 ka to 3.01<a (Unit II), and from 3.0 ka to the core top (Unit III), respectively. In particular, delta C-13(org) showed marked fluctuation from -17.31%o to -28.68%o, suggesting different organic carbon sources. A relatively narrow range of variation in delta C-13(org) was observed in Unit III, and drastic changes in delta C-13(org) were observed from Unit I to Unit II. This may indicate a predominance of C-4 plants in Unit I, and drastic changes from terrestrial C-4 to C-3 in Unit II and predominance of C-3 plants in Unit III. The distributions of n-alkane were characterized by a continuous predominance of odd-numbered n-alkanes, particularly nC(29) and nC(31), and by high fluctuation of the total n-alkanes concentration. The average chain length (ACL), carbon preferences index (CPI), and paleoplant proxy (Paq) showed high fluctuation and glacial-interglacial variations with distinctive a high and low ratio at about 9.2 ka, corresponding to the switching points of delta C-13(org) and a high concentration of nalkane distribution. Individual n-alkane odd-numbered isotopes of delta C-13(Auc) ranged between -11.80%o in delta C-13n(21) and -34.93%o in delta C-13n(31), suggesting different sources of n-alkanes. The distribution of n-alkanes and their individual delta C-13(Auc), in particular delta C-13n(21), support paleovegetation changes, and their time dependent variations matched well with glacial-interglacial paleoclimate variations. Therefore, organic geochemical proxies recorded in Hanon paleo-maar sediment reflects paleoclimate variabilities as well as paleovegetation changes for the last 35 kyr in Jeju Island, Korea. (C) 2016 Elsevier Ltd and INQUA. All rights reserved.</P>

산란계 사료내 CLA 함유 Oil (CLAzen 80) 첨가가 난황내 지방산 조성에 미치는 영향

황보종,장종수,정일병,이병석,김동운,조성백,김희도,배해득,손진혁,홍의철,최낙진,Hwangbo J.,Chang J. S.,Chung I. B.,Lee B. S.,Kim D. U.,Cho S. B.,Kim H. D.,Bae H. D.,Son J. H.,Hong U. C.,Choi N. J. 한국가금학회 2005 韓國家禽學會誌 Vol.32 No.1

본 연구는 oil 형태의 conjugated linoleic acid(CLAzen 80)를 산란계 사료에 수준별로 첨가 급여하였을 때 산란율과 난황내 지방산 조성의 변화를 조사하기 위하여 수행하였다. 59주령의 산란계 72수를 완전임의배치법으로 4개 처리구에 6주간 공시하였다. 처리구는 CLAzen 80를 첨가하지 않은 대조구와 각각 1, 2 및 $3\%$를 첨가구를 두었다. 연구 결과를 살펴보면 산란율은 처리구별 통계적 유의차가 없었지만, 난황내 지방산 조성은 CLAzen 80 첨가에 의하게 크게 영향을 받았다. 난황내 C16:0과 C18:0과 같은 포화 지방산 함량은 CLAzen 80 첨가에 의하여 증가하였으나, 일가불포화지방산인 C18:1 함량은 오히려 감소하였다. 한편, 난황내 C18:2와 C18:3와 같은 다가불포화지방산은 CLAzen 80 급여 2$\~$4주사이에는 모든처리구들에 있어서 그 함량이 일정하게 유지되었다. 그러나, 대조구와 비교하여 CLAzen 80 급여 6주 째에는 난황내 C18:2 함량이 감소하였다. 불포화지방산:포화지방산 비율과 n-6:n-3 불포화지방산 비율은 2$\~$4주 사이에는 처리구별간에 통계적 유의차가 없었고, 6주째 불포화지방산:포화지방산 비율이 CLAzen 80 첨가에 의하여 감소하였다. 한편, 난황내 CLA 함량은 CLAzen 80 첨가수준에 비례하여 증가하였다. 따라서, 산란계 사료 내 CLAzen 80 첨가는 난황내 CLA 함량을 증진시키는 것으로 요약할 수 있다. The objectives of the present study were to investigate the effects of varying levels of dietary oil containing conjugated linoleic acid (CLA) on the egg production and fatty acid composition of egg yolk. Seventy-two 59-wk-old ISA Brown laying hens were randomly allotted to four dietary treatments, each consisting of three replicates with six birds per replicate. There were four treatments that consist of diets containing 0, 1, 2, or $3\%$ commercial CLA-containing oil. Egg production was not significantly different among the dietary treatments at 0, 2, 4, and 6 week. The proportion of saturated fatty acids such as C16:0 and C18:0 in egg yolk were increased, but that of monounsaturated fatty acid C18:1 was decreased by feeding CLA-containing oil supplementation. However, the proportion of polyunsaturated fatty acids such as C18:2 and C18:3 in egg yolk were not different among dietary treatments at 2 and 4 wk of the experiment. At 6 week, the proportion of C18:2 in egg yolk was decreased by feeding CLA-containing oil compared with the control. Polyunsaturated fatty acid:saturated fatty acid (P:S) ratio and n-6:n-3 polyunsaturated fatty acid ratio were similar across the treatments between 2 and 4 week. The P:S ratio was decreased by dietary CLA-containing oil supplementation at 6 week. The proportion of CLA in egg yolk was linearly increased with increasing levels of CLA-containing oil supplementation. In conclusion, dietary supplementation of CLA-containing oil to laying hens increased beneficially increased CLA content in their egg yolk.

(S)YS-51, a novel isoquinoline alkaloid, attenuates obesity-associated non-alcoholic fatty liver disease in mice by suppressing lipogenesis, inflammation and coagulation

Park, E.J.,Kim, Y.M.,Kim, H.J.,Jang, S.Y.,Oh, M.H.,Lee, D.H.,Chang, K.C. North-Holland 2016 European journal of pharmacology Vol.788 No.-

<P>Obesity-associated non-alcoholic fatty liver disease (NAFLD) increases coagulation and inflammation. We hypothesized that (S)YS-51, an agent found to be beneficial in animal models of sepsis, may reduce NAFLD in high-fat diet (HFD) mice by reducing coagulation and inflammation. C57BL/6 mice were fed either a chow diet or HFD and each was supplemented with or without (S)YS-51 (10 mg/kg, daily, i.p.) for 16 weeks. The results showed that HFD caused significant increases in lipogenesis [CD36, fatty acid synthase (FAS) and sterol response element binding protein (SREBP)-1c mRNA and protein], inflammation [monocyte chemotactic protein (MCP)-1, tumor necrosis factor (TNIF)-alpha, intercellular cell adhesion molecule-1 (ICAM-1), TGF-beta, and procollagen type 1 mRNA, macrophage infiltration] and coagulation [tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) mRNA and thrombin antithrombin complex (TAT)] in the liver, adipose tissue and serum, which were significantly reduced by (S)YS-51. These results of (S)YS-51 were accompanied by significant reduction of weight gain, liver size, hepatic steatosis and fibrosis, blood cholesterol, hepatic triglyceride, and macrophage infiltration and inflammatory cytokines in adipose tissue without affecting food intake in HFD mice. Interestingly, (S)YS-51 increased SIRT1 mRNA and protein and AMPK expression in the liver of HFD mice by increasing both NAD(+)/NADH ratio and LKB1 phosphorylation. In HepG2 cells, (S)YS-51 activated SIRT1 followed by AMPK. Finally, (S)YS-51 improved glucose tolerance and insulin resistance in HFD mice. We concluded that (S)YS-51 attenuates NAFLD and insulin resistance in HFD mice by, at least, activation of SIRT1/AMPK signals. Thus, (S)YS-51 may be beneficial in NAFLD treatment. (C) 2016 Elsevier B.V. All rights reserved.</P>

Preparation, Ferroelectric and Electrical Properties of Lead Germanate Pb5Ge3O11 thin films prepared by sol-gel methods

C.H. Chang,J.S. Kim,H.S. Lee,J.K. Kim,S.S. Kim,T.K. Song 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1

Lead germanate Pb5Ge3O11 (PGO) thin flms were prepared by sol-gel methods and their electrical properties were obtained. Single phase of prepared PGO thin flm was confrmed by X-ray diraction peaks. PGO thin lms with c-axis oriented grains were prepared on (111) Pt-coated Si substrates when heat treated at 450C 600C for 1 h. Grains showed a plate like shape and grain size was increased with increasing annealing temperature. PGO thin lms were found to be ferroelectric at room temperature, and remanent polarization was about 4 C/cm2 at a coercive feld of 100 kV/cm. In this work, preparation, ferroelectric and electrical properties of PGO thin flms were investigated.

Modeling and simulation of HTS cables for scattering parameter analysis

Bang, S.S.,Lee, G.S.,Kwon, G.Y.,Lee, Y.H.,Chang, S.J.,Lee, C.K.,Sohn, S.,Park, K.,Shin, Y.J. North-Holland 2016 Physica. C, Superconductivity Vol.530 No.-

<P>Most of modeling and simulation of high temperature superconducting (HTS) cables are inadequate for high frequency analysis since focus of the simulation's frequency is fundamental frequency of the power grid, which does not reflect transient characteristic. However, high frequency analysis is essential process to research the HTS cables transient for protection and diagnosis of the HTS cables. Thus, this paper proposes a new approach for modeling and simulation of HTS cables to derive the scattering parameter (S-parameter), an effective high frequency analysis, for transient wave propagation characteristics in high frequency range. The parameters sweeping method is used to validate the simulation results to the measured data given by a network analyzer (NA). This paper also presents the effects of the cable-to-NA connector in order to minimize the error between the simulated and the measured data under ambient and superconductive conditions. Based on the proposed modeling and simulation technique, S-parameters of long-distance HTS cables can be accurately derived in wide range of frequency. The results of proposed modeling and simulation can yield the characteristics of the HTS cables and will contribute to analyze the HTS cables. (C) 2016 Elsevier B.V. All rights reserved.</P>

Comprehensive study on critical role of surface oxygen vacancies for 2DEG formation and annihilation in LaAlO3/SrTiO3 heterointerfaces

Moon, S. Y.,Moon, C. W.,Chang, H. J.,Kim, T.,Kang, C. Y.,Choi, H. J.,Kim, J. S.,Baek, S. H.,Jang, H. W. Springer Science + Business Media 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.2

<P>Here we report comprehensive study of 2DEG at a-LAO/STO interfaces in comparison with 2DEG at crystalline LaAlO3 (c-LAO)/STO interfaces. We observe that the oxygen deficient environment during the deposition of LAO overlayer is essentially required to create 2DEG at LAO/STO interface regardless of growth temperature from 25 degrees C to 700 degrees C, indicating that the oxygen-poor condition in the system is more important than the crystallinity of LAO layer. The critical thickness (2.6 nm) of 2DEG formation at a-LAO/STO heterostructure is thicker than (1.6 nm) that at c-LAO/STO. Upon ex-situ annealing at 300 degrees C under 300 mTorr of oxygen pressure, 2DEG at a-LAO/STO interface is annihilated, while that in c-LAO/STO interface is still maintained. With combing these findings and scanning transmission electron microscope (STEM) analysis, we suggest that oxygen vacancies at the LAO surface is attributed to the origin of 2DEG formation at the LAO/STO and the crystallinity of the LAO overlayer plays a critical role in the annihilation of 2DEG at a-LAO/STO interface rather than in the formation of 2DEG. This work provides a framework to understand the importance of prohibiting the LAO surface from being oxidized for achieving thermally stable 2DEG at a-LAO/STO interface.</P>

Post annealing effect of flexible polymer solar cells to improve their electrical properties

Gong, S.C.,Jang, S.K.,Ryu, S.O.,Jeon, H.,Park, H.H.,Chang, H.J. Elsevier 2010 CURRENT APPLIED PHYSICS Vol.10 No.4

Flexible polymer solar cells with an ITO/PEDOT/P3HT:PCBM/Al structure were fabricated using regioregular poly(3-hexylthiophene) (P3TH) polymer:(6,6)-phenyl C61-butyric acid methyl ester (PCBM) fullerene polymer as the photovoltaic (PV) bulk hetero-junction layer. The P3HT and PCBM used as the electron donor and electron acceptor materials were spin cast on indium tin oxide (ITO) coated polyethylene naphthalate (PEN) substrates. The optimum mixing concentration ratio of the P3HT:PCBM PV layer was found to be 4:4 wt.%, at which the maximum short circuit current density (J<SUB>SC</SUB>), open circuit voltage (V<SUB>OC</SUB>), fill factor (FF) and power conversion efficiency (PCE) values were about 3.8 mA/cm<SUP>2</SUP>, 427 mV, 36.6% and 0.66%, respectively. To investigate the effects of the post annealing treatment, the as-prepared flexible polymer solar cells were post annealed at temperatures ranging from 150 <SUP>o</SUP>C to 180 <SUP>o</SUP>C for 5 min. The J<SUB>SC</SUB> and V<SUB>OC</SUB> values increased with increasing post annealing temperature from 150 <SUP>o</SUP>C to 170 <SUP>o</SUP>C, which may be due to the improvement of the light absorption coefficient of P3HT and improved ohmic contact between the PV layer and Al electrode film. The maximum J<SUB>SC</SUB>, V<SUB>OC</SUB>, FF and PCE values of the flexible polymer solar cell, which was post annealed at 170 <SUP>o</SUP>C for 5 min, were found to be about 4.3 mA/cm<SUP>2</SUP>, 616 mV, 32.6% and 0.86%, respectively.

혈청 Creatine Kinase측정 표준화에 관한 연구(Ⅵ)

이창규,이승관,조경진,정수경,박종성,박상숙,류정록,남현철,김상섭,김석수,장철수,최명재 高麗大學校 倂設 保健大學 保健科學硏究所 1998 保健科學論集 Vol.24 No.1

In European countries or Japan they made an attempt for the standardization of assays in AST, ALT, ALP, CK, LD and GGT 10 years ago. For the actualization of the trial, they managed to succeeded in development of certified reference material and enzyme reference material. And they are now forecasting the unification of test results produced differently under the respective situatons. Then, through the highly developed communication system, someone can access any test results whenever or whereever only if they want to. It means that we can expect much greater improvements in medical services through the information exchanges. In this study the authors tried to ascertain the interchangeability comparing the obtained results of the CK tests between two general hospitals. Fortunately, the data got in the internal QC programs came to fall within the normal tolerances. The reference intervals for the CK test were different accarding to the chosen reagents and the results from the pooled serum were also shown differently each other. However, from the two hospitals, we could get glucose K factors, upon which the measurements were obtained and compared. Using K factors we measured the CKs, then we multiply the CK values by correction coefficients. We could found that the two results were showing good coincidence in the comparison. The main purpose of the standardization of enzyme assays is the creation of a new unified value which can be expressed differently otherwise. Using the standardized values we can exploit the data everywhere, reduce the medical costs from repeated or duplicated tests, save the foreign exchanges preventing the diversification of impart connections.

An exploration of the antioxidant effects of garlic saponins in mouse-derived C2C12 myoblasts

Kang, J. S.,Kim, S. O.,Kim, G.-Y.,Hwang, H. J.,Kim, B. W.,Chang, Y.-C.,Kim, W.-J.,Kim, C. M.,Yoo, Y. H.,Choi, Y. H. Spandidos Publications 2016 INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE Vol.37 No.1

<P>In this study, we aimed to confirm the protective effects of garlic saponins against oxidative stress-induced cellular damage and to further elucidate the underlying mechanisms in mouse-derived C2C12 myoblasts. Relative cell viability was determined by 3-(4.5-dimethylthiazol-2-yl)-2.5 diphenyltetrazolium bromide assay. Comet assay was used to measure DNA damage and oxidative stress was determined using 2 ',7 '-dichlorofluorescein diacetate to measure intracellular reactive oxygen species (ROS) generation. Western blot analysis and small interfering RNA (siRNA)-based knockdown were used in order to investigate the possible molecular mechanisms. Our results revealed that garlic saponins prevented hydrogen peroxide (H2O2)-induced growth inhibition and exhibited scavenging activity against intracellular ROS. We also observed that garlic saponins prevented H2O2-induced comet tail formation and decreased the phosphorylation levels of gamma H2AX expression, suggesting that they can prevent H2O2-induced DNA damage. In addition, garlic saponins increased the levels of heme oxygenase-1 (HO-1), a potent antioxidant enzyme associated with the induction and phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2) and the translocation of Nrf2 from the cytosol into the nucleus. However, the protective effects of garlic saponins on H2O2-induced ROS generation and growth inhibition were significantly reduced by zinc protoporphyrin IX, an HO-1 competitive inhibitor. In addition, the potential of garlic saponins to mediate HO-1 induction and protect against H2O2-mediated growth inhibition was adversely affected by transient transfection with Nrf2-specific siRNA. Garlic saponins activated extracellular signal-regulated kinase (ERK) signaling, whereas a specific ERK inhibitor was able to inhibit HO-1 upregulation, as well as Nrf2 induction and phosphorylation. Taken together, the findings of our study suggest that garlic saponins activate the Nrf2/HO-1 pathway by enabling ERK to contribute to the induction of phase II antioxidant and detoxifying enzymes, including HO-1 in C2C12 cells.</P>

Suppression of c-Myc induces apoptosis via an AMPK/mTOR-dependent pathway by 4-O-methyl-ascochlorin in leukemia cells

Shin, J. M.,Jeong, Y. J.,Cho, H. J.,Magae, J.,Bae, Y. S.,Chang, Y. C. Springer Science + Business Media 2016 Apoptosis Vol.21 No.5

<P>4-O-Methyl-ascochlorin (MAC) is a methylated derivative of the prenyl-phenol antibiotic ascochlorin, which was isolated from an incomplete fungus, Ascochyta viciae. Although the effects of MAC on apoptosis have been reported, the underlying mechanisms remain unknown. Here, we show that MAC promoted apoptotic cell death and downregulated c-Myc expression in K562 human leukemia cells. The effect of MAC on apoptosis was similar to that of 10058-F4 (a c-Myc inhibitor) or c-Myc siRNA, suggesting that the downregulation of c-Myc expression plays a role in the apoptotic effect of MAC. Further investigation showed that MAC downregulated c-Myc by inhibiting protein synthesis. MAC promoted the phosphorylation of AMP-activated protein kinase (AMPK) and inhibited the phosphorylation of mammalian target of rapamycin (mTOR) and its target proteins, including p70S6 K and 4E-BP-1. Treatment of cells with AICAR (an AMPK activator), rapamycin (an mTOR inhibitor), or mTOR siRNA downregulated c-Myc expression and induced apoptosis to a similar extent to that of MAC. These results suggest that the effect of MAC on apoptosis induction in human leukemia cells is mediated by the suppression of c-Myc protein synthesis via an AMPK/mTOR-dependent mechanism.</P>