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New role of E3 ubiquitin ligase in the regulation of necroptosis

  • Seo, Jinho;Lee, Eun-Woo;Song, Jaewhan
    • BMB Reports
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    • v.49 no.5
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    • pp.247-248
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    • 2016
  • Necroptosis is a well-known form of caspase-independent cell death. Necroptosis can be triggered by various extrinsic stimuli, including death ligands in the presence of receptorinteracting protein kinase 3 (RIPK3), a key mediator of necroptosis induction. Our recent studies have revealed that C-terminus HSC-70 interacting protein (CHIP), an E3 ligase, can function as an inhibitor of necroptosis. CHIP−/− mouse embryonic fibroblast showed higher sensitivity to necrotic stimuli than wild-type mouse embryonic fibroblast cells. Deleterious effects of CHIP knockout MEFs were retrieved by RIPK3 depletion. We found that CHIP negatively regulated RIPK3 and RIPK1 by ubiquitylation- and lysosome- dependent degradation. In addition, CHIP−/− mice showed postnatal lethality with intestinal defects that could be rescued by crossing with RIPK3−/− mice. These results suggest that CHIP is a negative regulator of RIPK1 and RIPK3, thus inhibiting necroptosis.

Proposition of a Predicting Equation for Shear Capacity of HSC Beam (단면의 모멘트를 이용한 고강도 콘크리트 보의 전단강도 예측식의 제안)

  • Choi Jeong Seon;Lee Chang Hoon;Lee Joo Ha;Yoon Young Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.375-378
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    • 2005
  • In the mechanism of beam shear failure, beam action and arch action always exist simultaneously. According to a/d ratio, the proportion and contribution between these two actions to shear capacity are merely changed. Moreover, the current codes recommendations are founded on the experimental results with normal strength concrete, the applicable range of $f'_{c}$ must be extended. Based on this mechanism and new requirement, an analytical equation is proposed for shear capacity prediction of reinforced concrete beams without stirrups. To reflect contribution change of two actions, stress variation in longitudinal reinforcement along the span is considered with Jenq and Shah Model. Dowel action and shear friction are also taken into account. Size effect is included to derive more precise equation. It is shown that the proposed equation is more accurate than other empirical equations and codes. So, it can be possible that wide range of a/d ratio is considered by one equation.

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An improved method to determine hydroxyproline in an immortalized rat liver stellate cell line (HSC-T6)

  • Lee, Eun-Su;Kwak, Wie-Jong;Lee, Eung-Seok;Soh, Yun-Jo
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.154.1-154.1
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    • 2003
  • Hydroxyproline (HYP) is a post-translational product of proline hydroxylation catalyzed by an enzyme prolyl 4-hydroxylase which plays a crucial role in the synthesis of all collagens, because the 4-hydroxyproline residues are essential for the folding of the newly synthesized collagen polypeptide chains into triple-heical molecules. Considering the role of collagen and its significance in many clinically important diseases such as liver cirrhosis, a great deal of attention has been directed toward the development of an assay at cell-based system. (omitted)

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Experimental Verification of Resistance-Demand Approach for Shear of HSC Beams

  • El-Sayed, Ahmed K.;Shuraim, Ahmed B.
    • International Journal of Concrete Structures and Materials
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    • v.10 no.4
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    • pp.513-525
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    • 2016
  • The resistance-demand approach has emerged as an effective approach for determining the shear capacity of reinforced concrete beams. This approach is based on the fact that both the shear resistance and shear demand are correlated with flexural tensile strain from compatibility and equilibrium requirements. The basic shear strength, under a given loading is determined from the intersection of the demand and resistance curves. This paper verifies the applicability of resistance-demand procedure for predicting the shear capacity of high strength concrete beams without web reinforcement. A total of 18 beams were constructed and tested in four-point bending up to failure. The test variables included the longitudinal reinforcement ratio, the shear span to depth ratio, and the beam depth. The shear capacity of the beams was predicted using the proposed procedure and compared with the experimental values. The results of the comparison showed good prediction capability and can be useful to design practice.

Expression of O-acetyl disialoganglioside synthase in experimental rat and human liver fibrosis

  • Lee, Sung-Hee;Choi, Jeong-Yong;Park, Eun-Jeon;Zhao, Yu-Zhe;Park, Young-Nyun;Chae, Keon-Sang;Sohn, Dong-Hwan
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.300.3-301
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    • 2003
  • The activation of the hepatic stellate cell (HSC) is a key step in liver fibrogenesis. Utilizing large scale sequencing of a 3' -directed cDNA library, we investigated expression profiles of quiescent and activated rat HSCs. During the activation process, O-acetyl disialoganglioside synthase (OAcGD3S) was identified as one of the significant upregulated factors. Upregulation of OAcGD3S in cultured HSCs was confirmed by both northern and western blot analyses. (omitted)

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Ballistic behavior of steel sheet subjected to impact and perforation

  • Jankowiak, Tomasz;Rusinek, Alexis;Kpenyigba, K.M.;Pesci, Raphael
    • Steel and Composite Structures
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    • v.16 no.6
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    • pp.595-609
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    • 2014
  • The paper is reporting some comparisons between experimental and numerical results in terms of failure mode, failure time and ballistic properties of mild steel sheet. Several projectile shapes have been considered to take into account the stress triaxiality effect on the failure mode during impact, penetration and perforation. The initial and residual velocities as well as the failure time have been measured during the tests to estimate more physical quantities. It has to be noticed that the failure time was defined using a High Speed Camera (HSC). Thanks to it, the impact forces (average and maximum level), were analyzed using numerical simulations together with an analytical description coupled to experimental observations. The key point of the model is the consideration of a shape function to define the pulse loading during perforation.

A Study of N-IDS Detection regarding a DoS Attack and Packet Analysis (DoS공격에 대한 N-IDS 탐지 및 패킷 분석 연구)

  • Chun, Woo-Sung;Park, Dae-Woo
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2008.06a
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    • pp.175-182
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    • 2008
  • 2008년에 있었던 우리나라 금융기관과 정부기관에 대한 DoS 공격에 대한 연구이다. 실험실 환경에서 실제 DoS 공격 툴을 이용하여 공격을 실시한다. DoS 공격을 탐지하기 위하여 네트워크 상에서 Snort를 이용한 N-IDS를 설치하고, 패킷을 탐지하기 위한 Winpcap과 패킷의 저장 및 분석하기 위한 MySQL, HSC, .NET Framework 등을 설치한다. e-Watch 등의 패킷 분석 도구를 통해 해커의 DoS 공격에 대한 패킷량과 TCP, UDP 등의 정보, Port, MAC과 IP 정보 등을 분석한다. 본 논문 연구를 통하여 유비쿼터스 정보화 사회의 역기능인 사이버 DoS, DDoS 공격에 대한 자료를 분석하여 공격자에 대한 포렌식자료 및 역추적 분석 자료를 생성하여 안전한 인터넷 정보 시스템을 확보하는데 의의가 있다.

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Reinforced high-strength concrete square columns confined by aramid FRP jackets -part II: modeling

  • Wu, Han-Liang;Wang, Yuan-Feng;Ma, Yi-Shuo
    • Steel and Composite Structures
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    • v.11 no.4
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    • pp.325-340
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    • 2011
  • Based on the experimental data presented in part I of these companion papers, a semi-empirical model is proposed for axial stress-strain curves of reinforced high-strength concrete square columns confined by aramid fiber reinforced polymer (FRP) jackets. Additionally, a three-dimensional finite element model is developed to simulate the mechanical behaviors of the columns. In the finite element model, both material nonlinear and contact nonlinear are taken into account. Moreover, the influence of contact nonlinear (i.e., the end friction on the contact surface between test machines and specimens) is investigated deeply. Predictions from both the semi-empirical model and the finite element model agree with the experimental results, and it is also demonstrated that the friction coefficient of end friction notably affect the properties of columns when it ranges from 0.00 to 0.25.

Seismic Performance of High-Strength Concrete Columns

  • Hwang Sun-Kyoung;Yun Hyun-Do;Han Byung-Chan;Park Wan-Shin;Kim Sun-Woo;Han Min-Ki
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.41-44
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    • 2004
  • This experimental investigation was conducted to examine the behaviour of eight one-third scale columns made of high-strength concrete (HSC). The columns were subjected to a constant axial load corresponding to 30 per cent of the column axial load capacity and a cyclic horizontal load-inducing reversed bending moment. The variables studied in this research are the volumetric ratio of transverse reinforcement, tie configuration and tie yield strength. Columns with 42 per cent higher amounts of transverse reinforcement than that required by seismic provisions of ACI 318-02 showed ductile behaviour. Relationships between the calculated damage index and the observed damage such as initial crack, spalling of concrete, buckling of longitudinal bar, and crushing of concrete are propose.

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Strength and durability of ultra fine slag based high strength concrete

  • Sharmila, Pichaiya;Dhinakaran, Govindasamy
    • Structural Engineering and Mechanics
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    • v.55 no.3
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    • pp.675-686
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    • 2015
  • The use of ground granulated blast furnace slag (GGBFS) from steel industries waste is showing perspective application in civil engineering as partial substitute to cement. Use of such waste conserves natural resources and minimizes the space required for landfill. The GGBFS used in the present work is of ultra fine size and hence serves as micro filler. In this paper strength and durability characteristics of ultra fine slag based high strength concrete (HSC) (with a characteristic compressive strength of 50 MPa) were studied. Cement was replaced with ultra fine slag in different percentages of 5, 10, and 15% to study the compressive strength, porosity, resistances against sulfate attack, sorptivity and chloride ion penetration. The experiments to study compressive strength were conducted for different ages of concrete such as 7, 28, 56, and 90 days. From the detailed investigations with 16 mix combinations, 10% ultra fine slag give better results in terms of strength and durability characteristics.