Wall stretch and thromboxane A2 activate NO synthase (eNOS) in pulmonary arterial smooth muscle cells via H2O2 and Akt-dependent phosphorylation

Kim, H. J.,Yoo, H. Y.,Jang, J. H.,Lin, H. Y.,Seo, E. Y.,Zhang, Y. H.,Kim, S. J. Springer Science + Business Media 2016 Pfl ugers Arch Vol.468 No.4

<P>Pulmonary arteries (PAs) have high compliance, buffering the wide ranges of blood flow. Here, we addressed a hypothesis that PA smooth muscle cells (PASMCs) express nitric oxide synthases (NOS) that might be activated by mechanical stress and vasoactive agonists. In the myograph study of endothelium-denuded rat PAs, NOS inhibition (L-NAME) induced strong contraction (96 % of 80 mM KCl-induced contraction (80K)) in the presence of 5 nM U46619 (thromboxane A(2) (TXA(2)) analogue) with relatively high basal stretch (2.94 mN, S(+)). With lower basal stretch (0.98 mN, S(-)), however, L-NAME application following U46619 (TXA(2)/L-NAME) induced weak contraction (27 % of 80K). Inhibitors of nNOS and iNOS had no such effect in S(+) PAs. In endothelium-denuded S(+) mesenteric and renal arteries, TXA(2)/L-NAME-induced contraction was only 18 and 21 % of 80K, respectively. Expression of endothelial-type NOS (eNOS) in rat PASMCs was confirmed by RT-PCR and immunohistochemistry. Even in S(-) PAs, pretreatment with H2O2 (0.1-10 mu M) effectively increased the sensitivity to TXA(2)/L-NAME (105 % of 80K). Vice versa, NADPH oxidase inhibitors, reactive oxygen species scavengers, or an Akt inhibitor (SC-66) suppressed TXA(2)/L-NAME-induced contraction in S(+) PAs. In a human PASMC line, immunoblot analysis showed the following: (1) eNOS expression, (2) Ser(1177) phosphorylation by U46619 and H2O2, and (3) Akt activation (Ser(473) phosphorylation) by U46619. In the cell-attached patch clamp study, H2O2 facilitated membrane stretch-activated cation channels in rat PASMCs. Taken together, the muscular eNOS in PAs can be activated by TXA(2) and mechanical stress via H2O2 and Akt-mediated signaling, which may counterbalance the contractile signals from TXA(2) and mechanical stimuli.</P>

알코올 발효사료 급여가 한우의 육성성적 및 혈액의 생리적 변화에 미치는 영향

임광철,김창혁,오상집,성경일,김현숙,김종복,홍병주,신종서 한국동물자원과학회 2001 한국축산학회지 Vol.43 No.6

본 실험은 알코올 발효사료(alcohol 함량; 3.0∼3.2%, lactate 함량; 3.0∼3.5%) 처리가 한우 반추위내 혈액성분 및 비육능력에 미치는 영향을 검토하기 위하여 한우에 비지박 알코올 발효사료(Alcohol-fermented soybean curd dreg : AFS) 및 맥주박 알코올 발효사료(alcohol fermented brewery grain's : AFB)를 급여하여 평균체중이 329㎏인 한우 거세우 13두와 평균체중이 337㎏인 한우 비거세우 20두를 공시하여 증체량, 사료섭취량, 혈액성분, 혈중 알코올 함량을 측정하여 다음과 같은 결과를 얻었다. 거세우에서 비육전기의 일당증체량 및 사료효율은 알코올 발효사료 급여구들이 대조구에 비해 개선되는 경향을 보였으며, 비육후기의 일당증체량은 처리에 따른 유의적인 차이를 나타내지 않았으며, 비육후기의 사료효율은 알코올 발효사료 급여구가 개선되는 경향을 보였다. 비거세우에서 일당증체량 및 사료효율은 알코올 발효사료 급여로 개선되는 경향을 보였으나 유의성은 나타나지 않았으며, 비육 후기에는 개선효과가 없는 것으로 나타났다. 혈중 알코올 농도는 알코올 발효사료 급여구가 시험사료 급여 2시간 후에 유의적으로 높게 나타났으나(p<0.05), 사료급여 4시간째에는 급여전의 수준으로 낮아졌다. BUN 농도는 거세우가 비거세우에 비해 높았으며(14.3 vs 10.97 ㎎/㎗, p<0.05), 혈중 creatinine 농도는 거세우가 비거세우보다 낮았다(1.39 vs 1.49㎎/㎗, p<0.05). 혈중 cholesterol 농도는 전체적으로 체중이 증가함에 따라 증가하는 것으로 나타났고, 혈중 glucose 농도는 알코올 발효사료 급여로 비거세우에서는 감소하는 경향을 보인 반면 거세우에서는 증가하는 것으로 나타났다. 혈중 IP 농도는 알코올 발효사료 급여로 거세우 및 비거세우 모두 증가되었다.(p<0.05). This study was conducted to know the feeding effects of alcohol-fermented feedstuffs (alcohol concentration: 3.0∼3.2 %, lactate: 3.0∼3.5%) on the blood metabolites and fattening ability. Alcohol-fermented soybean curd dreg (AFS) and alcohol fermented brewery grain (AFB) were fed to 13 Korean steers (average body weight, 329㎏) and 20 Korean bulls (average 337㎏ B.W), and body weight gain, feed conversion rate, blood metabolites and blood alcohol concentration were analyzed. The feed conversion rates of steers at both fattening and finishing period were improved by feeding alcohol-fermented feedstuffs. However, improvement of daily body weight gain was observed only at fattening period. In bulls, body weight gains and feed conversion rate were also improved at fattening period (but not at finishing period) by feeding of alcohol-fermented feedstuffs, although a statistical significance was not detected. Blood alcohol concentrations of AFS and AFB group were significantly increased (p<0.05) at 2 hours after feeding, but dropped to the initial level at 4 hours after feeding. Blood urea nitrogen(BUN) concentrations of steers were higher than those of bulls (14.3 vs 10.97 ㎎/㎗), but creatinine was lower in steers than in bulls (1.39 vs 1.49㎎/㎗). Blood cholesterol concentration was generally proportional to the increment of body weight. While the blood glucose content was decreased in bulls by feeding alcohol-feedstuffs, it was increased in steers. Blood inorganic phosphorus(IP) level was increased in both steers and bulls.

DISCOVERY OF X-RAY PULSATION FROM THE GEMINGA-LIKE PULSAR PSR J2021+4026

Lin, L. C. C.,Hui, C. Y.,Hu, C. P.,Wu, J. H. K.,Huang, R. H. H.,Trepl, L.,Takata, J.,Seo, K. A.,Wang, Y.,Chou, Y.,Cheng, K. S. IOP Publishing 2013 ASTROPHYSICAL JOURNAL LETTERS - Vol.770 No.1

<P>We report the discovery of an X-ray periodicity of similar to 265.3 ms from a deep XMM-Newton observation of the radio-quiet gamma-ray pulsar, PSR J2021+4026, located at the edge of the supernova remnant G78.2+2.1 (gamma-Cygni). The detected frequency is consistent with the gamma-ray pulsation determined by the observation of the Fermi Gamma-ray Space Telescope at the same epoch. The X-ray pulse profile resembles the modulation of a hot spot on the surface of the neutron star. The phase-averaged spectral analysis also suggests that the majority of the observed X-rays have thermal origins. This is the third member in the class of radio-quiet pulsars with significant pulsations detected from both X-ray and gamma-ray regimes.</P>

DISCOVERY OF X-RAY PULSATIONS FROM THE NEXT GEMINGA, PSR J1836+5925

Lin, L. C. C.,Hui, C. Y.,Li, K. T.,Takata, J.,Hu, C. P.,Kong, A. K. H.,Yen, D. C. C.,Chou, Y. IOP Publishing 2014 ASTROPHYSICAL JOURNAL LETTERS - Vol.793 No.1

<P>We report recent XMM-Newton investigations of PSR J1836+5925, the 'next Geminga,' which determined an X-ray pulsation of similar to 173.3 ms. Its X-ray periodicity is consistent with the gamma-ray ephemeris at the same epoch. The X-ray folded light curve has a sinusoidal structure that is different from the double-peaked gamma-ray pulse profile. We have also analyzed the X-ray phase-averaged spectra which shows that the X-ray emission from PSR J1836+5925 is thermal dominant. This suggests that the X-ray pulsation mainly originates from the modulated hot spot on the stellar surface.</P>

Mode Change of a Gamma-Ray Pulsar, PSR J2021+4026

Zhao, J.,Ng, C. W.,Lin, L. C. C.,Takata, J.,Cai, Y.,Hu, C.-P.,Yen, D. C. C.,Tam, P. H. T.,Hui, C. Y.,Kong, A. K. H.,Cheng, K. S. American Astronomical Society 2017 The Astrophysical journal Vol.842 No.1

<P>A glitch of a pulsar is known as a sudden increase in the spin frequency and spin-down rate (frequency time derivative), and it can be caused by a sudden release of the stress built up in the solid crust of the star or pinned vortices in the superfluid interior. PSR J2021+4026 is the first pulsar that shows a significant change in the gamma-ray flux and pulse profile at the glitch that occurred around 2011 October 16. We report the results of timing and spectral analysis of PSR J2021+4026 using similar to 8 yr Fermi. Large Area Telescope data. We find that the pulsar stayed at a high spin-down rate (similar to 4% higher than the pre-glitch value) and a low gamma-ray state (similar to 18% lower) for about 3 yr. after the glitch. Around 2014 December, the spin-down rate and gamma-ray flux gradually returned to pre-glitch values within a timescale of a. few months. The phase-resolved spectra and pulse profiles after the relaxation are also consistent with those before the glitch. The observed long-term evolution of the spin-down rate and the gamma-ray flux indicates that the glitch triggered a mode change in the global magnetosphere. We speculate that the glitch changed. the local magnetic field structure around the polar cap and/or the inclination angle of the. dipole axis, leading to. a change in the electric current circulating in the. magnetosphere.</P>

X-Ray Study of Variable Gamma-Ray Pulsar PSR J2021+4026

Wang, H. H.,Takata, J.,Hu, C.-P.,Lin, L. C. C.,Zhao, J. American Astronomical Society 2018 The Astrophysical journal Vol.856 No.2

<P>PSR J2021+4026 showed a sudden decrease in the gamma-ray emission at the glitch that occurred around 2011 October 16, and a relaxation of the flux to the pre-glitch state at around 2014 December. We report X-ray analysis results of the data observed by XMM-Newton on 2015 December 20 in the post-relaxation state. To examine any change in the X-ray emission, we compare the properties of the pulse profiles and spectra at the low gamma-ray flux state and at the post-relaxation state. The phase-averaged spectra for both states can be well described by a power-law component plus a blackbody component. The former is dominated by unpulsed emission and probably originated from the pulsar wind nebula as reported by Hui et al. The emission property of the blackbody component is consistent with the emission from the polar cap heated by the back-flow bombardment of the high-energy electrons or positrons that were accelerated in the magnetosphere. We found no significant change in the X-ray emission properties between two states. We suggest that the change of the X-ray luminosity is at an order of similar to 4%, which is difficult to measure with the current observations. We model the observed X-ray light curve with the heated polar cap emission, and we speculate that the observed large pulsed fraction is owing to asymmetric magnetospheric structure.</P>

6면 프리즘 렌즈가 장착된 Lensmeter에서 시험 렌즈의 편심 위치 계산

Maria Lin,박종대,,조창호,김현규 배재대학교 자연과학연구소 2005 自然科學論文集 Vol.16 No.1

6면 프리즘 렌즈가 장착된 렌즈메터에서 상점의 위치로부터 시험렌즈의 편심의 위치를 알아 낼 수 있는 알고리즘을 개발하였다. 6개의 프리즘에 의해 형성되는 6개의 상점은 시험렌즈의 편심의 극좌표에 의해 변하게 되며, 비틀린 광선 추적으로 계산할 수 있다. 광학 설계 프로그램인 Code V를 사용하여 렌즈메터 광학계를 분석하고, 시험렌즈의 위치에 따른 상점의 위치 변화를 함수로 나타내서 역으로 상점의 위치로부터 시험렌즈의 편심의 위치를 알아낼 수 있는 방법을 개발하였다. We have developed an algorithm to determine the decenter position from the image points in a lensmeter with 6-sided prism lens. The positions of the image points which are formed by six prisms depends on the decenter position of a test lens and can be calculated by skew ray tracing. The optical characteristics of the lens meter was analyzed using the Code V program and the positions of the image points was expressed as a function of the decenter position of the test lens. By minimizing the expectation error, we can determine the decenter position of a test lens from the image positions.

THE TAIWANESE-AMERICAN OCCULTATION SURVEY PROJECT STELLAR VARIABILITY. II. DETECTION OF 15 VARIABLE STARS

Mondal, S.,Lin, C. C.,Chen, W. P.,Zhang, Z.-W.,Alcock, C.,Axelrod, T.,Bianco, F. B.,Byun, Y.-I.,Coehlo, N. K.,Cook, K. H.,Dave, R.,Kim, D.-W.,King, S.-K.,Lee, T.,Lehner, M. J.,Lin, H.-C.,Marshall, S. American Institute of Physics 2010 The Astronomical journal Vol.139 No.5

<P>The Taiwanese-American Occultation Survey (TAOS) project has collected more than a billion photometric measurements since 2005 January. These sky survey data—covering timescales from a fraction of a second to a few hundred days—are a useful source to study stellar variability. A total of 167 star fields, mostly along the ecliptic plane, have been selected for photometric monitoring with the TAOS telescopes. This paper presents our initial analysis of a search for periodic variable stars from the time-series TAOS data on one particular TAOS field, No. 151 (R.A. = 17<SUP>h</SUP>30<SUP>m</SUP>6<img entity='fs' SRC='http://ej.iop.org/icons/Entities/fs.gif' ALT='fs' ALIGN='BASELINE' />7, decl. = 27°17'30'', J2000), which had been observed over 47 epochs in 2005. A total of 81 candidate variables are identified in the 3 deg<SUP>2</SUP> field, with magnitudes in the range 8 < R < 16. On the basis of the periodicity and shape of the light curves, 29 variables, 15 of which were previously unknown, are classified as RR Lyrae, Cepheid, δ Scuti, SX Phonencis, semi-regular, and eclipsing binaries.</P>

DISCOVERY OF AN ULTRACOMPACT GAMMA-RAY MILLISECOND PULSAR BINARY CANDIDATE

Kong, Albert K. H.,Jin, Ruolan,Yen, T.-C.,Hu, C.-P.,Hui, C. Y.,Tam, P. H. T.,Takata, J.,Lin, L. C. C.,Cheng, K. S.,Park, S. M.,Kim, C. L. IOP Publishing 2014 ASTROPHYSICAL JOURNAL LETTERS - Vol.794 No.2

<P>We report multi-wavelength observations of the unidentified Fermi object 2FGL J1653.6-0159. With the help of high-resolution X-ray observations, we have identified an X-ray and optical counterpart to 2FGL J1653.6-0159. The source exhibits a periodic modulation of 75 minutes in the optical and possibly also in the X-ray. We suggest that 2FGL J1653.6-0159 is a compact binary system with an orbital period of 75 minutes. Combining the gamma-ray and X-ray properties, 2FGL J1653.6-0159 is potentially a black-widow-/redback-type gamma-ray millisecond pulsar (MSP). The optical and X-ray light curve profiles show that the companion is mildly heated by the high-energy emission and that the X-rays are from intrabinary shock. Although no radio pulsation has yet been detected, we estimated that the spin period of the MSP is similar to 2 ms based on a theoretical model. If pulsation can be confirmed in the future, 2FGL J1653.6-0159 will become the first ultracompact rotation-powered MSP.</P>

TRANSPORT OF SOLAR WIND H ⁺ AND He ⁺⁺ IONS ACROSS EARTH’S BOW SHOCK

Parks, G. K.,Lee, E.,Fu, S. Y.,Kim, H. E.,Ma, Y. Q.,Yang, Z. W.,Liu, Y.,Lin, N.,Hong, J.,Canu, P.,Dandouras, I.,Rè,me, H.,Goldstein, M. L. American Astronomical Society 2016 ASTROPHYSICAL JOURNAL LETTERS - Vol.825 No.2

<P>We have investigated the dependence of mass, energy, and charge of solar wind ( SW) transport across Earth's bow shock. An examination of 111 crossings during quiet SW in both quasi-perpendicular and quasi-parallel shock regions shows that 64 crossings had various degrees of heating and thermalization of SW. We found 22 crossings where the SW speed was <400 km s(-1). The shock potential of a typical supercritical quasi-perpendicular shock estimated from deceleration of the SW and cutoff energy of electron flat top distribution is similar to 50 Volts. We find that the temperatures of H+ and He++ beams that penetrate the shock can sometimes be nearly the same in the upstream and downstream regions, indicating little or no heating had occurred crossing the bow shock. None of the models predict that the SW can cross the bow shock without heating. Our observations are important constraints for new models of collisionless shocks.</P>