Neural stem cells injured by oxidative stress can be rejuvenated by GV1001, a novel peptide, through scavenging free radicals and enhancing survival signals

Park, H.H.,Yu, H.J.,Kim, S.,Kim, G.,Choi, N.Y.,Lee, E.H.,Lee, Y.J.,Yoon, M.Y.,Lee, K.Y.,Koh, S.H. Elsevier BV 2016 NeuroToxicology Vol.55 No.-

<P>Oxidative stress is a well-known pathogenic mechanism of a diverse array of neurological diseases, and thus, numerous studies have attempted to identify antioxidants that prevent neuronal cell death. GV1001 is a 16-amino-acid peptide derived from human telomerase reverse transcriptase (hTERT). Considering that hTERT has a strong antioxidant effect, whether GV1001 also has an antioxidant effect is a question of interest. In the present study, we aimed to investigate the effects of GV1001 against oxidative stress in neural stem cells (NSCs). Primary culture NSCs were treated with different concentrations of GV1001 and/or hydrogen peroxide (H2O2) for various time durations. The H2O2 decreased the viability of the NSCs in a concentration-dependent manner, with 200 mu M H2O2 significantly decreasing both proliferation and migration. However, treatment with GV1001 rescued the viability, proliferation and migration of H2O2 injured NSCs. Consistently, free radical levels were increased in rat NSCs treated with H2O2, while co-treatment with GV1001 significantly reduced these levels, especially the intracellular levels. In addition, GV1001 restored the expression of survival-related proteins and reduced the expression of death associated ones in NSCs treated with H2O2. In conclusion, GV1001 has antioxidant and neuroprotective effects in NSCs following treatment with H2O2, which appear to be mediated by scavenging free radicals, increasing survival signals and decreasing death signals. (C) 2016 Elsevier B.V. All rights reserved.</P>

Peroxiredoxin II promotes hepatic tumorigenesis through cooperation with Ras/Forkhead box M1 signaling pathway

Park, Y-H,Kim, S-U,Kwon, T-H,Kim, J-M,Song, I-S,Shin, H-J,Lee, B-K,Bang, D-H,Lee, S-J,Lee, D-S,Chang, K-T,Kim, B-Y,Yu, D-Y Macmillan Publishers Limited 2016 Oncogene Vol.35 No.27

<P>The current study was carried out to define the involvement of Peroxiredoxin (Prx) II in progression of hepatocellular carcinoma (HCC) and the underlying molecular mechanism(s). Expression and function of Prx II in HCC was determined using H-ras(G12V)-transformed HCC cells (H-ras(G12V)-HCC cells) and the tumor livers from H-ras(G12V)-transgenic (Tg) mice and HCC patients. Prx II was upregulated in H-ras(G12V)-HCC cells and H-ras(G12V)-Tg mouse tumor livers, the expression pattern of which highly similar to that of forkhead Box M1 (FoxM1). Moreover, either knockdown of FoxM1 or site-directed mutagenesis of FoxM1-binding site of Prx II promoter significantly reduced Prx II levels in H-ras(G12V)-HCC cells, indicating FoxM1 as a direct transcription factor of Prx II in HCC. Interestingly, the null mutation of Prx II markedly decreased the number and size of tumors in H-ras(G12V)-Tg livers. Consistent with this, knockdown of Prx II in H-ras(G12V)-HCC cells reduced the expression of cyclin D1, cell proliferation, anchorage-independent growth and tumor formation in athymic nude mice, whereas overexpression of Prx II increased or aggravated the tumor phenotypes. Importantly, the expression of Prx II was correlated with that of FoxM1 in HCC patients. The activation of extracellular signal-related kinase (ERK) pathway and the expression of FoxM1 and cyclin D1 were highly dependent on Prx II in H-ras(G12V)-HCC cells and H-ras(G12V)-Tg livers. Prx II is FoxM1-dependently- expressed antioxidant in HCC and function as an enhancer of Ras(G12V) oncogenic potential in hepatic tumorigenesis through activation of ERK/FoxM1/cyclin D1 cascade.</P>

Deep hole traps in undoped n-GaN films grown by hydride vapor phase epitaxy

Lee, In-Hwan,Polyakov, A. Y.,Smirnov, N. B.,Govorkov, A. V.,Usikov, A. S.,Helava, H.,Makarov, Yu. N.,Pearton, S. J. American Institute of Physics 2014 JOURNAL OF APPLIED PHYSICS - Vol.115 No.22

Deep hole traps were studied in bulk free-standing GaN crystals and in thinner (10-20 mu m) GaN films prepared by hydride vapor phase epitaxy (HVPE) on sapphire. Six hole traps in different combinations were detected in these crystals, H1 (activation energy 0.92-0.94 eV), H2 (0.55 eV), H3 (0.65-0.7 eV), H4 (0.85-0.9 eV), H5 (1.1-1.2 eV), and H6 (0.95-1.05 eV). The dominant traps in all samples were the H5 and H6 traps that were attributed, respectively, to gallium vacancy complexes with oxygen (V-Ga-O) and substitutional carbon related centers. We associate the H5 hole traps with the red luminescence bands, the H4 hole traps with the green luminescence bands, and the H6 hole traps with the yellow luminescence bands often observed in HVPE GaN. These attributions are based on the low energy thresholds of the deep traps optical excitation spectra and the depth of the respective trap levels. (C) 2014 AIP Publishing LLC.

Electrochemical properties of Si/(FeSiB) anode materials prepared by high-energy mechanical milling

Yu, H.T.,Loka, C.,Lee, K.S.,Cho, J.S.,Lee, S.H. Elsevier 2013 Materials science & engineering. B, Advanced funct Vol.178 No.20

Nano-structured composite with overall atomic composition Si<SUB>60</SUB>/(FeSiB)<SUB>40</SUB> has been synthesized by high-energy mechanical milling (HEMM) for Lithium-ion rechargeable batteries as anode material. Crystal structure, microstructure, electrochemical properties, elastic modulus and Vickers hardness (H<SUB>V</SUB>) have been observed by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), electrochemical test and nano-indentation test. With increasing milling time from 6 to 10h, we observed a relatively homogeneous structure comprised of nano-crystalline active silicon (Si) embedded in less active FeSiB matrix phase. Electrochemical properties of 10h milled nano-composite powder offers low capacity fade, high coulombic efficiency from 3rd cycle (540mAhg<SUP>-1</SUP>) to until 102nd cycle (495mAhg<SUP>-1</SUP>). The coulombic efficiencies of both 6 and 10h milled powders are 98% and 99%, respectively. Coin cell cross sections of 6 and 10h milled powders showed evidence for the void formation during lithiation and delithiation. Nano-indentation results exhibited that the amorphous FeSiB flakes have 2.96 times higher recoverable energy than Si. Resultant composite powders showed high irreversible capacity and stable lithiation and delithiation due to the reduced particle size, increased surface area and the highly elastic FeSiB matrix phase. Research reveals that the obtained nano-composite can be a promising candidate for lithium-ion rechargeable batteries.

척수손상 환자를 위한 병원기반 사회복귀지원 프로그램의 개발 및 효과

호승희(S. H. Ho),유소연(S. Y. Yu),김예순(Y. S. Kim),방문석(M. S. Bang),이범석(B. S. Lee),김동아(D. A. Kim),김은주(E. J. Kim),김현경(H. K. Kim) 한국재활복지공학회 2015 재활복지공학회논문지 Vol.9 No.2

본 연구는 척수손상 환자를 대상으로 병원기반 사회복귀 지원프로그램을 개발하고, 프로그램 시행 전·후를 비교 분석함으로써 프로그램의 효과성을 평가하고자 하였다. 재활병원에 입원해 있는 25명의 척수손상 환자를 대상으로 2~3개월 동안 일주일에 2번 평균 6.1개의 프로그램을 실시하였다. 프로그램 시행 전, 후 COPM, HADS, AD-R, WHOQOL-BREF를 통해 작업 수행도 및 만족도, 불안과 우울, 장애수용, 삶의 질을 비교하였으며, 퇴원 시 CIQ로 지역사회통합 수준과 퇴원 후의 사회복귀여부를 측정하였다. 자료분석은 기술통계와 대응표본 t검정(paired t-test)을 실시하였다. 연구결과 병원기반 사회복귀 지원프로그램 실시 후 작업 수행도 및 만족도, 장애수용, 삶의 질에 향상을 보였다(p<0.05). 또한 퇴원 후 25명의 척수손상 환자 중에서 10명이 가정, 학업, 직업으로 복귀하였다. 이를 통해 병원기반 사회복귀 지원프로그램이 척수손상 환자들이 퇴원 후 그들이 속한 지역사회로 돌아가는데 효과적임을 알 수 있었다. 척수손상 환자들이 가정과 사회로의 빠른 복귀를 위해서는 사회복귀를 위한 다양한 프로그램 개발과 더불어 체계적인 사회복귀 연계시스템이 이루어져야 할 것으로 사료된다. The purpose of this research attempted to developed the Community Reintegration support Program(H-CRsP) on patients with Spinal Cord Injury(SCI) and identity the effect. To assess the effectiveness of a Hospital based H-CRsP with a comprehensive team approach for treating inpatients with Spinal Cord Injury(SCI), offered by the Korea National Rehabilitation Hospital. Participants with SCI were recruited from the Korean National Rehabilitation Hospital. Twenty-five participants who met inclusion criteria were provided with a H-CRsP. A H-CRsP with modules related to the training of daily living skills, driving, vocations and school support activities, leisure or recreational activities, peer counseling, sexual rehabilitation, and others support activities. The 25 enrolled patients had been treated with average of 6.1 programs 2 times a week for over 2 or 3months. COPM, HADS, WHOQOL-BREF, AD-R were administered before the treatment(pre-test) and also at the time of discharge(post-test) to compare the treatment outcomes in the 25 program participants. Measured level of community integration by CIQ at discharge. The data were analyzed by such statistical methods as frequency and paired t-test analysis. Significant improvements were found on the Occupational Performance and Satisfaction, Acceptance of Disability, Quality of Life score in the COPM, AD-R, WHOQOL-BREF (p<0.05). In addition, 10 of the 25 patients returned to home, work or school. These results demonstrated the effectiveness of the H-CRsP in helping patients with SCI return their communities to which they belong. It considered development of the variety of programs and prepare systematically related system.

Lipid emulsion attenuates apoptosis induced by a toxic dose of bupivacaine in H9c2 rat cardiomyoblast cells

Ok, S-H,Yu, J,Lee, Y,Cho, H,Shin, I-W,Sohn, J-T Scientific & Medical Division,Macmillan Press 2016 Human & experimental toxicology Vol.35 No.9

<P>The goal of this in vitro study was to investigate the effect of lipid emulsion on apoptosis induced by a toxic dose of bupivacaine (BPV) in H9c2 rat cardiomyoblast cell lines. The effect of lipid emulsion on the decreased cell viability and count induced by BPV or mepivacaine (MPV) in the H9c2 cells was assessed using an 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide assay or a cell count assay. The effect of BPV or lipid emulsion combined with BPV on cleaved caspase 3, caspase 8, and Bax in H9c2 cells was investigated using Western blotting. A terminal deoxynucleotidyl transferase dUTP2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL) assay was performed to detect apoptosis of H9c2 cells treated with BPV alone or lipid emulsion combined with BPV. The magnitude of lipid emulsion-mediated attenuation of decreased cell viability induced by BPV was higher than that of lipid emulsion-mediated attenuation of decreased cell viability induced by MPV. Lipid emulsion attenuated the increases in cleaved caspase 3, caspase 8 and Bax induced by BPV. Lipid emulsion attenuated the increases in TUNEL-positive cells induced by BPV. These results suggest that lipid emulsion attenuates a toxic dose of BPV-induced apoptosis via inhibition of the extrinsic and intrinsic apoptotic pathways. The protective effect of lipid emulsion may be partially associated with the relatively high lipid solubility of BPV.</P>

Effects of O3 and H2O as oxygen sources on the atomic layer deposition of HfO2 gate dielectrics at different deposition temperatures

Lee, S.,Kim, H.,Lee, J.,Yu, I. H.,Lee, J. H.,Hwang, C. Royal Society of Chemistry 2014 Journal of Materials Chemistry C Vol.2 No.14

Variations in the growth behavior, physical and electrical properties, and microstructure of the atomic layer deposited (ALD) HfO2 gate dielectrics were examined with two types of oxygen sources: O-3 and H2O for the given Hf-precursor of Hf[N(CH3)(C2H5)](4). The ALD temperature windows for O-3 and H2O were 240-320 degrees C and 200-280 degrees C, respectively, with the growth rate of HfO2 using O-3 being higher than that of the films using H2O within the ALD window. While the film density of HfO2 using O-3 decreased, the film density of HfO2 using H2O increased with the decreasing ALD temperature. As the deposition temperature decreased, the amount of impurity in the HfO2 film with the O-3 oxidant increased due to the insufficient reaction, which led to the crystallization of the HfO2 film into the tetragonal structure after the post-deposition annealing at 600 degrees C. The films with a lower density and a higher carbon-impurity concentration retained the portion of the tetragonal phase (similar to 30%) to the highest annealing temperature of 1000 degrees C. However, the HfO2 films grown at 200 degrees C with H2O showed the best electrical performance, which could be ascribed to the highest density, low impurity concentration, and negligible involvement of the interfacial low dielectric layer.

Enhanced PCR efficiency of high-fidelity DNA polymerase from Thermococcus waiotapuensis

Cho, S.S.,Yu, M.,Kim, S.H.,Kwon, S.T. IPC Science and Technology Press ; Elsevier Scienc 2014 Enzyme and microbial technology Vol.63 No.-

Twa DNA polymerase from hyperthermophilic archaeon Thermococcus waiotapuensis has exceedingly high fidelity among family B DNA polymerases. However, Twa DNA polymerase has significant shortcomings in terms of a low extension rate and poor processivity. To resolve these weaknesses, we focused on two amino acid residues (N565 and H633) in the palm and thumb subdomains of the Twa DNA polymerase. These two residues were replaced by site-directed mutagenesis and the enzymatic properties of the mutants were analyzed. Here, Twa H633R DNA polymerase showed significantly improved polymerase function compared to wild-type Twa DNA polymerase in terms of processivity (2-fold), extension rate (1.5-fold) and PCR efficiency. Kinetic analysis using DNA as a template revealed that the k<SUB>cat</SUB> value of the Twa H633R mutant was similar to that of wild-type, but the K<SUB>m</SUB> of the Twa H633R mutant was about 1.6-fold lower than that of the wild-type. These results showed that the Arg residue substitution at H633 located in the thumb subdomain has a positive effect on processivity, extension rate and PCR efficiency, suggesting that the Twa H633R mutant allows a conformational change for easy access of the primer-template to the binding site of the polymerase domain.

Photochemical tuning of ultrathin TiO2/p-Si p-n junction properties via UV-induced H doping

Lee, S. Y.,Kim, J.,Ahn, B.,Cho, I. S.,Yu, H. K.,Seo, H. Springer Science + Business Media 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.2

<P>We report a modified TiO2/p-Si electronic structure that uses ultraviolet exposure for the incorporation of H. This structure was characterized using various photoelectron spectroscopic techniques. The ultraviolet (UV) exposure of the TiO2 surface allowed the Fermi energy level to be tuned by the insertion of H radicals, which induced changes in the heterojunction TiO2/p-Si diode properties. The UV exposure of the TiO2 surface was performed in air. On UVexposure, a photochemical reaction involving the incorporation of UV-induced H radicals led to the creation of a surface Ti-O-OH group and caused interstitial H doping (Ti-H-O) in the bulk, which modified the electronic structures in different ways, depending on the location of the H. On the basis of the band alignment determined using a combined spectroscopic analysis, it is suggested that the UV-induced H incorporation into the TiO2 could be utilized for the systematic tuning of the heterojunction property for solar cells, photocatalytic applications, and capacitors.</P>

청주 사뇌사지 청동기의 과학 분석(1)

강형태,유혜선,문선영,권혁남 국립중앙박물관 2000 박물관보존과학 Vol.2 No.-

청주 사뇌사지에서 출토된 청동기 12점에 대한 과학 분석을 실시하였다. 이들 각 시료의 금속조직에 나타난 결정 입자의 형태, 크기, 분포와 관련하여 검토한 결과 식기류, 제기류, 타명기류로 나타났는데 성분조성에 따른 분류 결과와도 일치하였다. 식기류는 주로 단조품으로서 성분조성비는 Cu:Sn:Pb=8:2:0, 제기류는 주조품으로서 Cu:Sn:Pb=7:1:2, 타명기류는 Cu:Sn:Pb=85:10:5/9:1:0이었다. 즉, 원료의 배합비는 제품의 용도 및 제작방법과 밀접한 관계가 있다는 것을 알 수 있었다. Cu와 상관계수가 높은 원소는 Co, Fe, As이었는데 이는 Cu 광물에 불순물로 함께 분포한다는 것을 의미하며 As 함량은 식기류, 제기류, 타명기류 순으로 증가한다는 것을 알 수 있었다. 또한 납 함유량이 높은 청동기 3점의 납동위원소비를 분석하고 원료의 산지를 추정한 결과 일본·중국산 납을 사용한 것으로 나타났다. 땜납의 성분조성은 Cu:Sn:Pb=83:12:5이었으며 Pb의 결정이 작고 고르게 분포하고 있었다. This study is a scientific analysis of 12 bronze materials which were excavated from Sanoisa temple in Chongju. Analysis of crystalline shape, size and distribution of the each sample metal sug gested that they can be classified as tableware(wrought), vessels for memorial service(casting) and bell bronze, which is the same result as classification based on elemental composition. Most of the tableware are forging wares with composition of 8:2:0 in Cu:Sn:Pb, and vessels for memorial service are casting wares whose composition is 7:1:2 in Cu:Sn:Pb, and bell bronze's composition is Cu:Sn:Pb=85:10:5/9:1:0. The result clearly shows that composition is closely related with usage and manufacturing method of wares. Trace elements such as Co, Fe and As are the elements with high correlation coefficient with Cu, which means they exist as impurities in Cu, and the content of As showed an increase in the order of tableware, memorial service vessels and bell bronze. In addition, the analysis of lead isotope ratio showed that 3 bronze materials with high lead content were made from the lead coming from Japan and China. The composition of the solder was Cu:Sn:Pb=83:12:5 where small Pb crystals were distributed evenly.