• Title/Summary/Keyword: Destabilization

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LIGHT is Expressed in Foam Cells and Involved in Destabilization of Atherosclerotic Plaques through Induction of Matrix Metalloproteinase-9 and IL-8

  • Kim, Won-Jung;Lee, Won-Ha
    • IMMUNE NETWORK
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    • v.4 no.2
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    • pp.116-122
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    • 2004
  • Background: LIGHT (TNFSF14) is a member of tumor necrosis factor superfamily and is the ligand for TR2 (TNFRSF14/HVEM). LIGHT is known to have proinflammatory roles in atherosclerosis. Methods: To find out the expression pattern of LIGHT in atherosclerotic plaques, immunohistochemical analysis was performed on human carotid atherosclerotic plaque specimens. LIGHT induced atherogenic events using human monocytic cell line THP-1 were also investigated. Results: Immunohistochemical analysis revealed expression of LIGHT and TR2 in foam cell rich regions in the atherosclerotic plaques. Double immunohistochemical analysis further confirmed the expression of LIGHT in foam cells. Stimulation of THP-1 cells, which express TR2, with either recombinant LIGHT or immobilized anti-TR2 monoclonal antibody induced interleukin-8 and matrix metalloproteinase(MMP)-9. Electrophoretic mobility shift assay demonstrated that LIGHT induces nuclear localization of transcription factor, nuclear factor $(NF)-{\kappa}B$. LIGHT induced activation of MMP-9 is mediated by $NF-{\kappa}B$, since treatment of THP-1 cells with the $NF-{\kappa}B$ inhibitor PDTC (pyrrolidine dithiocarbamate) completely blocked the activation of MMP-9. Conclusion: These data indicate that LIGHT is expressed in foam cells in atherosclerotic plaques and is involved in atherogenesis through activation of pro-atherogenic cytokine IL-8 and destabilization of plaque by inducing matrix degrading enzyme.

Instability and Self-Sustained Oscillation of the Flow between Three-Dimensionally Cross-corrugated Plates (3차원 교차 주름판 내 유동의 불안정성 및 자활 진동)

  • Lee Seung Youp;Choi Young Don
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.679-682
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    • 2002
  • Energy dissipations in a general PHE flow are the compounded effects of the piled corrugate geometries and its wall pressure and temperature distributions. In addition, although the exchangers are substantial pieces of engineering equipment, they are composed of a very large number of nominally identical and small geometrical elements. In the present numerical study, the three-dimensionally complicated energy dissipation fields and those wall-shape-induced flow destabilization are investigated in the cross-corrugated passages, which result in high energy transports with comparatively low pressure drop. We revealed the critical conditions as $Re=157.3 for the wall-shape-induced flow destabilization in a general PHE element by initial value method, or shooting method, and compare its value to that of analytical solution of plane Poiseille flow, two-dimensional grooved flow and so on. We also observed the detailed variation of flow field and energy transportation with changes in time and flow variables such as Reynolds number. Lastly, we considered the flow natural frequency, or Strouhal number, with variation of hydrodynamic conditions for the best use of active control, such as forced mass flow rate pulsative flow, to enhance energy transportation.

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The α-Effect in SNAr Reaction of 1-Fluoro-2,4-dinitrobenzene with Hydrazine: Ground-State Destabilization versus Transition-State Stabilization

  • Cho, Hyo-Jin;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.8
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    • pp.2371-2374
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    • 2014
  • A kinetic study is reported on SNAr reaction of 1-fluoro-2,4-dinitrobenzene with a series of primary amines including hydrazine in $H_2O$ at $25.0^{\circ}C$. The plots of $k_{obsd}$ vs. [amine] are linear and pass through the origin, indicating that general-base catalysis by a second amine molecule is absent. The Br${\o}$nsted-type plot exhibits an excellent linear correlation with ${\beta}_{nuc}$ = 0.46 when hydrazine is excluded from the correlation. The reaction has been suggested to proceed through a stepwise mechanism, in which expulsion of the leaving group occurs after the rate-determining step (RDS). Hydrazine is ca. 10 times more reactive than similarly basic glycylglycine (i.e., the ${\alpha}$-effect). A five-membered cyclic intermediate has been suggested for the reaction with hydrazine, in which intramolecular H-bonding interactions would facilitate expulsion of the leaving group. However, the enhanced leaving-group ability is not responsible for the ${\alpha}$-effect shown by hydrazine because expulsion of the leaving group occurs after RDS. Destabilization of the ground-state of hydrazine through the electronic repulsion between the nonbonding electron pairs is responsible for the ${\alpha}$-effect found in the current $S_NAr$ reaction.

Relation of Dynamic Changes in Interfacial Tension to Protein Destabilization upon Emulsification

  • Sah, Hong-Kee;Choi, Soo-Kyoung;Choi, Han-Gon;Yong, Chul-Soon
    • Archives of Pharmacal Research
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    • v.25 no.3
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    • pp.381-386
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    • 2002
  • The objective of this study was to link conformational changes of proteins at a water/methylene chloride interface to their destabilization upon emulsification. When 4 aqueous protein solutions (bovine serum albumin, $\beta$-lactoglobulin, ovalbumin, or ribonuclease) were emulsified in methylene chloride, considerable proportions of all the proteins became water insoluble aggregates. There were also noticeable changes in the compositions of their water-soluble species. A series of water/methylene chloride interfacial reactions upon the proteins was considered a major cause of the phenomena observed. Based on this supposition, the interfacial tension was determined by a Kruss DVT-10 drop volume tensiometer under various experimental conditions. It substantiated that the interfacial tension was high enough to cause the adsorption of all the proteins. Under our experimental conditions, their presence in the aqueous phase resulted in reductions of the interfacial tension by the degrees of 8.5 - 17.1 mN $m^{-1}$. In addition, dynamic changes in the interfacial tension were monitored to compare relative rates at which the adsorbed proteins underwent conformational, structural rearrangements at the interface. Such information helped make a prediction about how easily proteins would denature and aggregate during emulsification. Our study indicated that emulsifying aqueous protein solutions in organic solvents should be handled with care, due to adverse interfacial effects.

Foreign Investors' Abnormal Trading Behavior in the Time of COVID-19

  • KHANTHAVIT, Anya
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.63-74
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    • 2020
  • This study investigates the behavior of foreign investors in the Stock Exchange of Thailand (SET) in the time of coronavirus disease 2019 (COVID-19) as to whether trading is abnormal, what strategy is followed, whether herd behavior is present, and whether the actions destabilize the market. Foreign investors' trading behavior is measured by net buying volume divided by market capitalization, whereas the stock market behavior is measured by logged return on the SET index portfolio. The data are daily from Tuesday, August 28, 2018, to Monday, May 18, 2020. The study extends the conditional-regression model in an event-study framework and extracts the unobserved abnormal trading behavior using the Kalman filtering technique. It then applies vector autoregressions and impulse responses to test for the investors' chosen strategy, herd behavior, and market destabilization. The results show that foreign investors' abnormal trading volume is negative and significant. An analysis of the abnormal trading volume with stock returns reveals that foreign investors are not positive-feedback investors, but rather, they self-herd. Although foreign investors' abnormal trading does not destabilize the market, it induces stock-return volatility of a similar size to normal trade. The methodology is new; the findings are useful for researchers, local authorities, and investors.

Quality characteristics of plant-based whipped cream with ultrasonicated pea protein

  • Insun Kim;Kwang-Deog Moon
    • Food Science and Preservation
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    • v.31 no.1
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    • pp.64-79
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    • 2024
  • The rise in popularity of vegetarian and plant-based diets has led to extensive research into plant-based whipped creams. Whipped cream is an oil-in-water emulsion that creates foam through whipping, stabilizing the foam with proteins and fats. Pea protein is an excellent emulsifier and foaming agent among plant-based proteins, but its application in whipped cream is currently limited. The objective of this study was to investigate the quality characteristics of plant-based whipped cream made with ultrasonicated pea protein. The whipped creams were evaluated based on their quality characteristics. A commercially available dairy whipped cream (CON) was used as a control. Plant-based creams were evaluated using pea protein solution, cocoa butter, and canola oil to produce un-ultrasonicated pea protein whipped cream (PP) and ultrasonicated pea protein whipped cream (UPP) at 360 W for 6 min. UPP significantly reduced whipping time and foam drainage compared with CON and PP, resulting in significantly increased overrun, fat destabilization, and hardness. Optical microscopy showed that UPP had smaller fat globules and bubble size than PP. The fat globules of UPP and CON were mostly below 5 ㎛, whereas those of PP were distributed at 5-20 ㎛. Finally, ultrasonication significantly improved the overrun, foam drainage, fat destabilization, and hardness of UPP, which are significant quality characteristics of whipped creams. Therefore, ultrasonicated plant-based pea protein whipped cream is believed to be a viable alternative to dairy whipped cream.

Biology of vascular inflammation and therapeutic application (혈관염증의 분자생물학적특성 및 제어기술)

  • Jeon, Byeong-Hwa
    • 순환기질환의공학회:학술대회논문집
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    • 2006.10a
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    • pp.10-13
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    • 2006
  • Inflammation plays an important role in the progression of atherosclerosis and plaque destabilization converting a chronic process into an acute disorder with ensuing thromboembolism. Current therapeutic effective in preventing atherosclerosis and stroke such as statins, ASS and RAS inhibitors my exert part of their effects by modulating inflammatory responses in the vessel walls. As alternative approaches, discovery to find having inhibitory action of MMP activity, COX-2, macrophage infiltration, such as APE1/ref-1 and fusion technology for cell permeable protein may provide a new antiatherosclerotic therapy in the future.

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Direct Observation of an Antihomoaromatic Bicyclooctadienyl Cation

  • Shin Jung-Hyu
    • Bulletin of the Korean Chemical Society
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    • v.3 no.2
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    • pp.66-70
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    • 1982
  • The question of the bicyclohomoaromatic stabilization and destabilization is examined. The chemistry of bicyclo(3.2.1)octa-3,6-dienide anion has been studied on order to test these concepts. The bicyclooctadienide anion is shown to be stable delocalized ion which undergoes a facile proton-deuterium exchange reaction. The solvolysis of bicyclo(3.2.1)octa-3,6-dienyl p-nitrobenzoate is much slower than the monoene analog. We have made direct observation of the bicyclooctadienyl and octenyl cations by $^{19}F$-nmr spectroscopy, and were able to demonstrate that the bicyclooctadienyl cation was bishomoantiaromatic.

Destabilization and Subversion of Racial Identity on Stage: Eugene O'Neill, Charles Gilpin, and The Wooster Group in The Emperor Jones

  • Park, Chung-Yeol
    • English Language & Literature Teaching
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    • v.13 no.3
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    • pp.117-132
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    • 2007
  • Playwright Eugene O'Neill's expressionistic text-based approach to The Emperor Jones, with an emphasis on fixity, was at odds with African American actor Charles Gilpin's improvisational performance technique, stressing rupture, spontaneity, and discontinuity. The contemporary avant-garde performance troupe The Wooster Group likewise produces subversive and interrogative forms of identity in performing the play, which challenge the normative approach to gender, race, and an imagined orientation. The historical foundation of subversion and destabilization laid by O'Neill and Gilpin were manifold in the Wooster Group's production of The Emperor Jones, and not only formed a backdrop to it but also played a central role in the group's representation of race and even gender on the stage. In this essay, I use O'Neill's play, The Emperor Jones, a crucial example of racialized fantasies of identification, to explore how the modernist stage through the performances of Gilpin and The Wooster Group constructed racialized subjects of both its performers and audiences. Gilpin and the Wooster Group's strategies each shared a similar complexity in the portrayal of black identity in performance. Offering an examination of how ideologies of race and gender overlap in The Emperor Jones, I hope to show how each performance signifies a range of subversions and differences simultaneously and sometimes oppositionally that needs to be explored both holistically and in detail to offer a fuller picture of these remarkable attempts. Through this approach, I examine Gilpin's creative adaptations of O'Neill's text and illuminate how it is that the Wooster Group's appropriative use of blackface in their performance has come to gain critical acceptance.

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