• Title/Summary/Keyword: $(K,{\rho})$-stability

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Chronophin activation is necessary in Doxorubicin-induced actin cytoskeleton alteration

  • Lee, Su Jin;Park, Jeen Woo;Kang, Beom Sik;Lee, Dong-Seok;Lee, Hyun-Shik;Choi, Sooyoung;Kwon, Oh-Shin
    • BMB Reports
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    • v.50 no.6
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    • pp.335-340
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    • 2017
  • Although doxorubicin (Dox)-induced oxidative stress is known to be associated with cytotoxicity, the precise mechanism remains unclear. Genotoxic stress not only generates free radicals, but also affects actin cytoskeleton stability. We showed that Dox-induced RhoA signaling stimulated actin cytoskeleton alterations, resulting in central stress fiber disruption at early time points and cell periphery cortical actin formation at a later stage, in HeLa cells. Interestingly, activation of a cofilin phosphatase, chronophin (CIN), was initially evoked by Dox-induced RhoA signaling, resulting in a rapid phosphorylated cofilin turnover leading to actin cytoskeleton remodeling. In addition, a novel interaction between CIN and $14-3-3{\zeta}$ was detected in the absence of Dox treatment. We demonstrated that CIN activity is quite contrary to $14-3-3{\zeta}$ binding, and the interaction leads to enhanced phosphorylated cofilin levels. Therefore, initial CIN activation regulation could be critical in Dox-induced actin cytoskeleton remodeling through RhoA/cofilin signaling.

Experiments for Amour Stability of Low Crested Structure Covered by Rocks (저 마루높이 구조물의 피복재 안정성 실험: 피복석 피복 조건)

  • Lee, Jong-In;Bae, Il Rho;Moon, Gang Il
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.1
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    • pp.35-41
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    • 2020
  • In this study, the stability of low crested structure armoured by rock has been investigated using two-dimensional hydraulic model tests. The effect of wave steepness and freeboard on the rock stability on crest, front, and the rear slope has been investigated. Rocks were mostly damaged near the upper part of the seaward slope and the crest of the seaward side. From the experimental data, the new empirical formula for the stability coefficients of the rocks was proposed.

Experiments for Amour Stability of Low Crested Structure covered by Tripod Block (저 마루높이 구조물의 피복재 안정성 실험: Tripod 피복 조건)

  • Lee, Jong-In;Bae, Il Rho;Lim, Ho Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.1
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    • pp.43-49
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    • 2020
  • In this study, the stability of the low crested structure armoured by Tripod block has been investigated using two-dimensional hydraulic model tests. The effect of wave steepness and freeboard on the rock stability on crest, front, and the rear slope has been investigated. From the experimental data, the new empirical formula for the stability coefficients of the Tripod block was proposed. But Tripod is not proper to use the armour block of the low crested structure because the uplift force of this block is greater than that of Tetrapod and rock.

Mechanism of the Hydrolysis of Phenyl N-(p-chlorobenzoyl)Chloroformimidate Derivatives in Acid Media (산성용액 중에서 Phenyl N-(p-chlorobenzoyl)chloroformimidate 유도체의 가수분해 반응 메카니즘)

  • Nack-Do Sung;Young-Gu Cheun;Ki-Sung Kwon;Tae-Rin Kim
    • Journal of the Korean Chemical Society
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    • v.31 no.4
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    • pp.352-358
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    • 1987
  • Rate constants for the hydrolysis of para-substituted phenyl N-(p-chlorobenzoyl)chloroformimidate (I) derivatives in 1 : 4 dioxane-water at $25^{\circ}C$ have been determined. Rate data, substituent effect $(\rho\>{\rho}^+)$, product analysis and MO calculation indicate that the uncatalyzed reaction proceeds through an $S_N1$ mechanism involving the formation of azocarbonium ion (II) below pH 3.0, and the base-catalyzed reaction proceeds through an $S_N2$ mechanism via transition state (III) above pH 4.0. The relative stability of four peri planar conformational isomers were (E-ap) > (Z-ap) > (E-sp) > (Z-ap), respectively, and the most stable stereo structures shows that the Y-substituted phenyl group $(C_6H_4-Y)$ occupy vertical $(90^{\circ})$ position on the plane of the benzimidochloroformyl group in (E-ap) conformer. The nucleophilic substitution of water molecule occurs by sigma attack to the activatived azomethine carbon atom of (I) derivatives.

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A Study on the Small-Signal Stability Improvement Method Using Static Var Compensator (무효전력보상기를 이용한 미소신호안정도 개선방안에 관한 연구)

  • Lee, Su-Hyun;Rho, Kyu-Min;Kim, Deok-Young;Kwon, See-Hyuk
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1064-1066
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    • 1997
  • This paper proposes an efficient algorithm of designing PSS and CSS. First, the stabilizer input variable is selected using the participation matrix. Secondly, the stabilizer constants are decided using first order eigenvalue sensitivity. The proposed method was validated to sample power system.

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Analysis of cross magnetizing effect on the generator characteristics (발전기 특성에 미치는 교차자화 포화현상의 영향 해석)

  • Kim, Deok-Young;Rho, Kyu-Min;Kwon, Sae-Hyuk
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.1224-1227
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    • 1998
  • This paper presents an effect of cross magnetization to the generator characteristics in synchronous machine infinite bus system. Eigenvalues, synchronous torque and damping torque are investigated as the operating condition of the system is changed variously. The simulation results show that cross magnetization has an important effect to the generator characteristics in steady state stability analysis.

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A STUDY ON THE STABILITY, EFFICACY, AND EFFECT OF COLLOIDAL SILVER EMULSION

  • Yun, Kyung-Rho;Ji, Hong-Geun;Seo, Bong-Seok
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.25 no.4 s.34
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    • pp.75-95
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    • 1999
  • A colloid refers to dispersed particles of a solid or liquid having the diameter of about $10^{-5}-10^{-7}cm$. Such colloidal silver is produced by electrolysis. In this paper, colloidal silvers of various concentrations according to charge amount and time are produced, and their anti-microbial activities are measured. And optimum conditions for emulsion are measured by varying the concentration of colloidal silvers. Further, stability of the emulsion is measured with a Zeta potential, chrome meter by applying colloidal silvers to creams (W/Si, O/W, MLV).

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A STUDY ON THE STABILITY, EFFICACY, AND EFFECT OF COLLOIDAL SILVER EMULSION

  • Yun, Kyung-Rho;Ji, Hong-Geun;Seo, Bong-Seok
    • Proceedings of the SCSK Conference
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    • 1999.10a
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    • pp.75-95
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    • 1999
  • A colloid refers to dispersed particles of a solid or liquid having the diameter of about $10^{-5}$ - $10^{-7}$. Such colloidal silver is produced by electrolysis. In this paper. colloidal silvers of various concentrations according to charge amount and time are produced, and their anti-microbial activities are measured. And optimum conditions for emulsion are measured by varying the concentration of colloidal silvers. Further, stability of the emulsion is measured with a Zeta potential. chrome meter by applying colloidal silvers to creams (W/Si. O/W, MLV).

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Effect of Load Characteristics in Small-Signal Stability Analysis in Multimachine Power Systems (다기계통의 미소신호안정도해석시 부하특성의 영향)

  • Kwon, Sae-Hyuk;Rho, Kyu-Min;Jang, Kil-Soo
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.189-191
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    • 1993
  • A systematic procedure for the elements of system matrix in multimachine systems with loads is suggested for the small-signal stability studies. Synchronous machines are represented by either a two-axis model or classical model. The interrelationship of submatrices of system matrix is investigated. Once elements of one submatrix are determined, they can be used to calculate the elements of the other submatrix. It is illustrated for three machine and nine bus multimachine systems with constant impedance loads, constant MVA load, constant current and power factors.

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Investigation of gamma radiation shielding capability of two clay materials

  • Olukotun, S.F.;Gbenu, S.T.;Ibitoye, F.I.;Oladejo, O.F.;Shittu, H.O.;Fasasi, M.K.;Balogun, F.A.
    • Nuclear Engineering and Technology
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    • v.50 no.6
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    • pp.957-962
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    • 2018
  • The gamma radiation shielding capability (GRSC) of two clay-materials (Ball clay and Kaolin)of Southwestern Nigeria ($7.49^{\circ}N$, $4.55^{\circ}E$) have been investigated by determine theoretically and experimentally the mass attenuation coefficient, ${\mu}/{\rho}(cm^2g^{-1})$ of the clay materials at photon energies of 609.31, 1120.29, 1173.20, 1238.11, 1332.50 and 1764.49 keV emitted from $^{214}Bi$ ore and $^{60}Co$ point source. The mass attenuation coefficients were theoretically evaluated using the elemental compositions of the clay-materials obtained by Particle-Induced X-ray Emission (PIXE) elemental analysis technique as input data for WinXCom software. While gamma ray transmission experiment using Hyper Pure Germanium (HPGe) spectrometer detector to experimentally determine the mass attenuation coefficients, ${\mu}/{\rho}(cm^2g^{-1})$ of the samples. The experimental results are in good agreement with the theoretical calculations of WinXCom software. Linear attenuation coefficient (${\mu}$), half value layer (HVL) and mean free path (MFP) were also evaluated using the obtained ${\mu}/{\rho}$ values for the investigated samples. The GRSC of the selected clay-materials have been compared with other studied shielding materials. The cognizance of various factors such as availability, thermo-chemical stability and water retaining ability by the clay-samples can be analyzed for efficacy of the material for their GRSC.