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>

Effect of low concentrations of hydrogen peroxide on the contractile responses of rat detrusor smooth muscle strips

Han, J.H.,Lee, M.Y.,Lee, S.Y.,Chang, I.H.,Kim, H.J.,Kim, W.,Myung, S.C. North-Holland ; Elsevier Science Ltd 2010 european journal of pharmacology Vol.638 No.1

This study was designed to determine how the contractility of rat detrusor smooth muscle strips changes in the presence of low concentrations of hydrogen peroxide (H<SUB>2</SUB><SUB>2</SUB>. The strips were dissected from the base of Sprague-Dawley rat bladders and their contractile responses to a cumulative increase in H<SUB>2</SUB><SUB>2</SUB>concentration (3x10<SUP>-6</SUP>3x10<SUP>-2</SUP>%) were measured. How the duration of exposure to the fixed concentration of 3x10<SUP>-4</SUP>% H<SUB>2</SUB><SUB>2</SUB>affected contractility was also examined. Moreover, the effect of 3x10<SUP>-4</SUP>% H<SUB>2</SUB><SUB>2</SUB>pretreatment on the response to cumulative increases in the concentrations of phenylephrine or acetylcholine (10<SUP>-8</SUP>10<SUP>-4</SUP>) was assessed. To elucidate the mechanism by which H<SUB>2</SUB><SUB>2</SUB>induced contraction, we examined the effect of pretreatment with 10nM Y-27632, 10μM indomethacin, 10μM SQ29548, 10μM verapamil, 10μM vitamin E, or 1μM Bay-K 8644 on the contractile responses generated by cumulatively increasing the concentration of H<SUB>2</SUB><SUB>2</SUB> H<SUB>2</SUB><SUB>2</SUB>induced contractile responses in Ca<SUP>2+</SUP>free physiological solution were also examined. Low concentrations of H<SUB>2</SUB><SUB>2</SUB>increased the contractile responses of the strips in a dose-dependent manner but increasing treatment duration decreased these responses. H<SUB>2</SUB><SUB>2</SUB>pretreatment significantly augmented the contraction induced by phenylephrine (P<0.05) but had no effect on the response to acetylcholine. Pretreatment with Y-27632, indomethacin, vitamin E, verapamil, and Bay-K 8644 significantly inhibited the H<SUB>2</SUB><SUB>2</SUB>induced contraction (P<0.05). SQ 29548-pretreatment had no effect. H<SUB>2</SUB><SUB>2</SUB>could not increase the contractile responses in Ca<SUP>2+</SUP>free physiological solution. Thus, low concentrations of H<SUB>2</SUB><SUB>2</SUB>may directly affect detrusor smooth muscles and thereby induce detrusor overactivity.

Changes in the Angstrom Exponent during Aerosol Coagulation and Condensation

Chang H. Jung,Ji Yi Lee,Yong P. Kim,김용표 한국대기환경학회 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

In this study, the Ångstrom exponent for polydispersed aerosol during dynamic processes was investigated. Log-normal aerosol size distribution was assumed,and a sensitivity analysis of the Ångstrom exponent with regards the coagulation and condensation process was performed. The Ångstrom exponent is expected to decrease because of the particle growth due to coagulation and condensation. However, it is difficult to quantify the degree of change. In order to understand quantitatively the change in the Ångstrom exponent during coagulation and condensation,different real and imaginary parts of the refractive index were considered. The results show that the Ångstrom exponent is sensitive to changes in size distribution and refractive index. The total number concentration decreases and the geometric mean diameter of aerosols increase during coagulation. On the while, the geometric standard deviation approaches monodispersed size distribution during the condensation process, and this change in size distribution affects the Ångstrom exponent. The degree of change in the Ångstrom exponent depends on the refractive index and initial size distribution, and the size parameter changes with the Ångstrom exponent for a given refractive index or chemical composition; this indicates that the size distribution plays an important role in determining the Ångstrom exponent as well as the chemical composition. Subsequently, this study shows how the Ångstrom exponent changes quantitatively during the aerosol dynamics processes for a log-normal aerosol size distribution for different refractive indices; the results showed good agreement with the results for simple analytic size distribution solutions.

Effect of purification conditions on gas storage and separations in a chromium-based metal-organic framework MIL-101

Lee, S.J.,Yoon, J.W.,Seo, Y.K.,Kim, M.B.,Lee, S.K.,Lee, U.H.,Hwang, Y.K.,Bae, Y.S.,Chang, J.S. Elsevier 2014 Microporous and mesoporous materials Vol.193 No.-

The effect of purification condition of a chromium terephthalate MIL-101 on gas storage (H<SUB>2</SUB>, CO<SUB>2</SUB>, and C<SUB>2</SUB>H<SUB>2</SUB>) and C2 hydrocarbon separations was investigated for MIL-101a, MIL-101b, and MIL-101c, which were obtained by three-step sequential purification using hot water/ethanol and aqueous NH<SUB>4</SUB>F solution treatments. MIL-101c was the best in terms of gas storage capacities among the three samples possibly due to the removal of free and coordinated terephthalic acids. Remarkably, MIL-101c exhibits among the highest total hydrogen uptake at 50bar and 77K (9.9 wt%) and shows considerably large deliverable capacity between 1.5 and 50bar (7.6 wt%). Moreover, MIL-101c shows among the highest C<SUB>2</SUB>H<SUB>2</SUB> storage capacity (6.4mmolg<SUP>-1</SUP>) and deliverable capacity (4.3mmolg<SUP>-1</SUP>) at 1bar and 313K. For C<SUB>2</SUB>H<SUB>2</SUB>/C<SUB>2</SUB>H<SUB>6</SUB>, C<SUB>2</SUB>H<SUB>2</SUB>/C<SUB>2</SUB>H<SUB>4</SUB>, and C<SUB>2</SUB>H<SUB>4</SUB>/C<SUB>2</SUB>H<SUB>6</SUB> separations, MIL-101c exhibits higher adsorption capacities, working capacities and adsorption figure of merit (AFM) values while MIL-101b shows higher selectivities and sorbent selection parameters. These results clearly show that a proper purification of MIL-101 is important for gas storage and gas separations.

Changes in the Ångstrom Exponent during Aerosol Coagulation and Condensation

Jung, Chang H.,Lee, Ji Yi,Kim, Yong P. Korean Society for Atmospheric Environment 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

In this study, the ${\AA}$ngstrom exponent for polydispersed aerosol during dynamic processes was investigated. Log-normal aerosol size distribution was assumed, and a sensitivity analysis of the ${\AA}$ngstrom exponent with regards the coagulation and condensation process was performed. The ${\AA}$ngstrom exponent is expected to decrease because of the particle growth due to coagulation and condensation. However, it is difficult to quantify the degree of change. In order to understand quantitatively the change in the ${\AA}$ngstrom exponent during coagulation and condensation, different real and imaginary parts of the refractive index were considered. The results show that the ${\AA}$ngstrom exponent is sensitive to changes in size distribution and refractive index. The total number concentration decreases and the geometric mean diameter of aerosols increase during coagulation. On the while, the geometric standard deviation approaches monodispersed size distribution during the condensation process, and this change in size distribution affects the ${\AA}$ngstrom exponent. The degree of change in the ${\AA}$ngstrom exponent depends on the refractive index and initial size distribution, and the size parameter changes with the ${\AA}$ngstrom exponent for a given refractive index or chemical composition; this indicates that the size distribution plays an important role in determining the ${\AA}$ngstrom exponent as well as the chemical composition. Subsequently, this study shows how the ${\AA}$ngstrom exponent changes quantitatively during the aerosol dynamics processes for a log-normal aerosol size distribution for different refractive indices; the results showed good agreement with the results for simple analytic size distribution solutions.

Follow-Up Study on CDX1 and CDX2 mRNA Expression in Noncancerous Gastric Mucosae After Helicobacter pylori Eradication

Shin, C. M.,Kim, N.,Chang, H.,Kim, J. S.,Lee, D. H.,Jung, H. C. Plenum Pub. Corp 2016 Digestive diseases and sciences Vol.61 No.4

<P>Changes in CDX1/CDX2 in gastric mucosae following Helicobacter pylori eradication have not been clarified yet. To evaluate the changes in CDX1/CDX2 expression after H. pylori eradication, in relation to the reversibility of intestinal metaplasia (IM). Time course of CDX1/CDX2 expressions was investigated in 176 subjects with various gastroduodenal disorders. Among them, 132 patients were H. pylori positives; H. pylori were eradicated in 107 of them; 13 failed to eradicate; and 12 did not receive H. pylori eradication therapy. Forty-four subjects were H. pylori negatives. Expression levels in CDX1 and CDX2 from noncancerous gastric mucosae of the corpus, as well as the histologic findings of gastric mucosae, were evaluated during the follow-up. Average follow-up duration was 33.7 months (range 2-97 months). Expression levels in both CDX1 and CDX2 mRNAs were correlated with IM grade in the corpus (rho = 0.633 and 0.554, respectively, all P < 0.001). Changes in CDX1/CDX2 mRNA expressions following H. pylori eradication showed only insignificant results; IM grade at the antrum and corpus showed a tendency to decrease after H. pylori eradication without statistical significance (P > 0.05). However, histologic improvement of IM at the corpus was associated with a decrease in CDX2 mRNA expression during the follow-up (linear mixed model, P for slope = 0.015). In this study, eradication of H. pylori did not show any beneficial effects on aberrant CDX1/CDX2 expressions or IM. Reversibility of IM may be associated with a decrease in CDX2 mRNA expression.</P>

NO₂Sensing Properties of CuPc and H₂Pc LB Films

Kwon, H.J.,Lee, Y.-J.,Chang, Y.K.,Kim, J.-D. 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

Characteristics of CuPc and H_(2)Pc Langmuir-Blodgett(LB) films were examined and their NO_(2) sensing properties were investigated on a gas sensor using 9 MHz quartz crystal microbalance(QCM). The monolayer behavior of H_(2)Pc in air-water interface was observed by inspecting its UV absorption spectra as the surface pressure was increased. On ellipsometry measurement for CuPc and H_(2)Pc LB films, the thickness of H_(2)Pc LB film was almost twice as thick as that of CuPc. X-ray photoelectronic spectroscopy (XPS) spectra of CuPc LB film showed that Cu2p(1/2) and Cu2p(3/2) peak shifts arised from new bond formation by NO_(2) adsorption. Both CuPc and H_(2)Pc LB film produced significant frequency changes in low ppm range of NO_(2).

Temperature and air pollution affected tree ring δ¹³C and water-use efficiency of pine and oak trees under rising CO₂ in a humid temperate forest

Kwak, J.H.,Lim, S.S.,Lee, K.S.,Viet, H.D.,Matsushima, M.,Lee, K.H.,Jung, K.,Kim, H.Y.,Lee, S.M.,Chang, S.X.,Choi, W.J. Elsevier 2016 Chemical geology Vol.420 No.-

<P>To better predict forest productivity under rising atmospheric CO2 concentration ([CO2]), it is critical to understand how intrinsic water-use efficiency (WUEi) and its relationship with tree growth are affected by the concomitant changes in environmental conditions such as precipitation, temperature, and air pollution that either enhance or undermine any potential CO2 fertilization effect. We investigated changes in delta C-13 and WUEi in annual rings and basal area increment (BAI) of Pinus densiflora (from 1968 to 2007) and Quercus variabilis (from 1970 to 2007) trees in relation to precipitation, temperature, and air pollution in a humid temperate forest. The WUEi of P. densiflora increased by 39.9%, whereas that of Q. variabilis did not change over time in the study period. The WUEi was not affected by precipitation for both species but increased (P < 0.001) with temperature for P. densiflora and with SO2 emissions for both species. Multiple regression models suggested that the effect of [CO2] on tree growth was much higher than temperature; however, for the period (1998 to 2007) when SO2 emissions data were available, SO2 emission was the driver of changes in BAI and WUEi, and temperature effects became stronger than [CO2]. Overall, BAI and WUEi were positively (P < 0.001) correlated for P. densiflora, but not for Q. variabilis. We conclude that temperature and air pollution rather than precipitation were key determinants of WUEi at the study site and that the two species had contrasting responses to environmental changes. (C) 2015 Elsevier B.V. All rights reserved.</P>

한우 어미소와 송아지의 행동 특성

한지훈,김동주,전중환,장홍희,구자민,김은정,이효종,연성찬 한국동물자원과학회 2004 한국축산학회지 Vol.46 No.1

This study was performed to investigate the behavioral characteristics of Hanwoo(Bos taurus coreanae) cows and their calves. Four cows and their calves were placed in pens. The behaviors of each cow and calf were recorded using a time lapse VCR from 07:00 h to 18:00 h for 6 days and were analyzed using the scan point sampling method. The cow's behaviors in order of frequency were LD(lying down, 25%), ST(standing, 23%), EA(eating, 13%), LR(lying down rumination, 10%) and SR(standing rumination, 7%). The cows spent less than 3% of their time PG(pairwise grooming) and SF(sniffing). The calves mainly showed LD(52%), ST(28%), LF(lying flat, 4%), EA(3%) and WA(walking, 3%). The calves spent less than 2% of their time SF(sniffing) and SUK(sucking). The behavioral patterns of cows and calves at 07:00 h, 12:00 h and 18:00 h were different, especially in ST and LD.

스위칭 수 저감을 위한 다중레벨 인버터

이인혁(I-H Lee),송성근(S-G Song),이상훈(S-H. Lee),박성준(S-J Park),남해곤(H-G Nam),정해덕(H-D Chung),장영학(Y-H Chang) 전력전자학회 2005 전력전자학술대회 논문집 Vol.- No.-

In this paper, we proposed the electric circuit using one common arm of H-Bridge Inverters to reduce the number of switching component in multi-level PWM inverter combined with H-Bridge Inverters and Transformers. and we proposed the switching method that can be same rate of usage at each transformer. Also, we tested the proposed prototype inverter to clarify the proposed electric circuit and reasonableness of control signal.