• Title/Summary/Keyword: channel synthesis

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KCl Mediates $K^+$ Channel-Activated Mitogen-Activated Protein Kinases Signaling in Wound Healing

  • Shim, Jung Hee;Lim, Jong Woo;Kim, Byeong Kyu;Park, Soo Jin;Kim, Suk Wha;Choi, Tae Hyun
    • Archives of Plastic Surgery
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    • v.42 no.1
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    • pp.11-19
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    • 2015
  • Background Wound healing is an interaction of a complex signaling cascade of cellular events, including inflammation, proliferation, and maturation. $K^+$ channels modulate the mitogen-activated protein kinase (MAPK) signaling pathway. Here, we investigated whether $K^+$ channel-activated MAPK signaling directs collagen synthesis and angiogenesis in wound healing. Methods The human skin fibroblast HS27 cell line was used to examine cell viability and collagen synthesis after potassium chloride (KCl) treatment by Cell Counting Kit-8 (CCK-8) and western blotting. To investigate whether $K^+$ ion channels function upstream of MAPK signaling, thus affecting collagen synthesis and angiogenesis, we examined alteration of MAPK expression after treatment with KCl (channel inhibitor), NS1619 (channel activator), or kinase inhibitors. To research the effect of KCl on angiogenesis, angiogenesis-related proteins such as thrombospondin 1 (TSP1), anti-angiogenic factor, basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), pro-angiogenic factor were assayed by western blot. Results The viability of HS27 cells was not affected by 25 mM KCl. Collagen synthesis increased dependent on time and concentration of KCl exposure. The phosphorylations of MAPK proteins such as extracellular-signal-regulated kinase (ERK) and p38 increased about 2.5-3 fold in the KCl treatment cells and were inhibited by treatment of NS1619. TSP1 expression increased by 100%, bFGF expression decreased by 40%, and there is no significant differences in the VEGF level by KCl treatment, TSP1 was inhibited by NS1619 or kinase inhibitors. Conclusions Our results suggest that KCl may function as a therapeutic agent for wound healing in the skin through MAPK signaling mediated by the $K^+$ ion channel.

Channel Expansion Technology in MPEG Audio (MPEG 오디오의 채널 확장 기술)

  • Pang, Hee-Suk
    • Journal of Broadcast Engineering
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    • v.16 no.5
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    • pp.714-721
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    • 2011
  • MPEG audio uses the masking effect, high frequency component synthesis based on spectral band replication, and channel expansion based on parametric stereo for efficient compression of audio signals. In this paper, we present an overview of the state-of-the-art channel expansion technology in MPEG audio. We also present technical overviews and application examples to broadcasting services for HE-AAC v.2, MPEG Surround, spatial audio object coding (SAOC), and unified speech and audio coding (USAC) which are MPEG audio codecs based on the channel expansion technology.

Membrane Hyperpolarization Increases cAMP to Induce the Initiation of Sperm Motility in Salmonid Fishes, Rainbow Trout and Masu Salmon

  • Kho, Kang-Hee;Morisawa, Masaaki;Choi, Kap-Seong
    • Journal of Microbiology and Biotechnology
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    • v.13 no.6
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    • pp.833-840
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    • 2003
  • Sperm motility of salmonid fishes is suppressed by external $K^{+}$ and initiated by decrease of $K^{+}$ concentration surrounding the sperm. It was shown that the decrease in external $K^{+}$ concentration induced not only the initiation of sperm motility, but also hyperpolarization of the plasma membrane and synthesis of cAMP in the sperm of rainbow trout, steelhead trout, and masu salmon. Inhibitors of $K^{+}$ channels, especially voltage-dependent $K^{+}$ channels, inhibited these three reactions, and the inhibitions were abolished by subsequent addition of a $K^{+}$ ionophore, valinomycin, suggesting that $K^{+}$ efflux through the $K^{+}$ channel contributes to rapid changes in the membrane potential of sperm and cAMP synthesis, thereby resulting in the initiation of sperm motility of salmonid fishes.

The uniqueness of the plant mitochondrial potassium channel

  • Pastore, Donato;Soccio, Mario;Laus, Maura Nicoletta;Trono, Daniela
    • BMB Reports
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    • v.46 no.8
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    • pp.391-397
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    • 2013
  • The ATP-inhibited Plant Mitochondrial $K^+$ Channel ($PmitoK_{ATP}$) was discovered about fifteen years ago in Durum Wheat Mitochondria (DWM). $PmitoK_{ATP}$ catalyses the electrophoretic $K^+$ uniport through the inner mitochondrial membrane; moreover, the co-operation between $PmitoK_{ATP}$ and $K^+/H^+$ antiporter allows such a great operation of a $K^+$ cycle to collapse mitochondrial membrane potential (${\Delta}{\Psi}$) and ${\Delta}pH$, thus impairing protonmotive force (${\Delta}p$). A possible physiological role of such ${\Delta}{\Psi}$ control is the restriction of harmful reactive oxygen species (ROS) production under environmental/oxidative stress conditions. Interestingly, DWM lacking ${\Delta}p$ were found to be nevertheless fully coupled and able to regularly accomplish ATP synthesis; this unexpected behaviour makes necessary to recast in some way the classical chemiosmotic model. In the whole, $PmitoK_{ATP}$ may oppose to large scale ROS production by lowering ${\Delta}{\Psi}$ under environmental/oxidative stress, but, when stress is moderate, this occurs without impairing ATP synthesis in a crucial moment for cell and mitochondrial bioenergetics.

Subjective Listening Test based on Frontal Loudspeaker Array Reproduction System (전방 스피커 어레이 재생 방식 기반 음향 재현 성능 평가)

  • Yoo, Jae-hyoun;Jang, Daeyoung;Lee, Taejin
    • Journal of Broadcast Engineering
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    • v.20 no.5
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    • pp.667-675
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    • 2015
  • As the interest on the high-definition and high-quality broadcasting is increased, the request on the high quality sound signal is enlarged as well as on the video signal's quality. One factor contributing to the high-quality of audio signal is an expansion of reproduction channels like 10.2channel and 22.2channel, but there is a problem of speaker installation issue of these many channels. One solution to solve this problem, we can use frontal loudspeaker array reproduction technique making virtual surround sound. So in this paper, we introduce theocratical analysis on the Wave Field Synthesis used for speaker array based sound reproduction and also present the result about the subjective listening test of reproduction performance based on this technique to check the perfoemance of this system. As a result, we showed WFS based frontal loudspeaker array reproduction method could provide sufficient performance compared to conventional discrete 5.1 channel reproduction method.

Improved Synthesis Method of Negative Inter-channel Correlation Parameter Based on Anti-phase Primary Component (반위상 주요성분에 기반을 둔 개선된 음수 채널간 상관도 파라미터 합성 기법)

  • Hyun, Dong-Il;Lee, Seok-Pil;Park, Young-Cheol;Youn, Dae-Hee
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.6
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    • pp.410-418
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    • 2012
  • Parametric stereo(PS) and MPEG surround(MPS) are major spatial audio coding(SAC) tools. In this paper, the problem of the inter-channel correlation(ICC) synthesis in the conventional SAC is analyzed. Conventional methods assume that ambient components mixed to two output channels are anti-phased, while the primary components are assumed to be in-phased. This assumption can cause excessive ambient mixing for a negative-valued ICC. As a remedy to this problem, we propose a new ICC synthesis method based on an assumption that the primary components are anti-phased each other for a negative ICC. The proposed method is also applied to the approximation which works in practice. The performance of the proposed method was evaluated by computer simulations and the subjective listening tests verified that the proposed method is effective in not only headphones but also loudspeakers playback.

Synthesis of Antithypertensive Agents via Couping Reaction of Benzothiazepinone and 1,4-Dihydropyridine Derivatives

  • Ham, Won-Hun;Yang, Jae-Gwon;Lim, Tae-Gyun;Jung, Yun-Ho;Chung, Yun-Sung
    • Archives of Pharmacal Research
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    • v.17 no.2
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    • pp.119-123
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    • 1994
  • The synthesis of 3a, 3b, 7a fro Benzpthiazepinone and 1,4-dihyropyridine derivatives is described. Benzothiazepinone nad 1,4-dihydropyridine derivatives were prepared according to literature procedure. The key reactions involve esterification and amidation of benzothize-pinone nad 1,4-dihydropyridine derivatives.

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Realization of Multi-Channel Active Filters by Using Operational Amplifiers (연산 증폭기를 사용한 다중 챈넬능동휠타의 구현)

  • Chung Duk Kim
    • 전기의세계
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    • v.24 no.4
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    • pp.80-82
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    • 1975
  • This paper presents a synthesis procedure of multi-channel active filters, which realizes an arbitrary N*N matrix of real rational functions in the complex variable s as a voltage transfer matrix. The resultant network reveals a transformerless grounded active RC(2N+1)-terminal network. The active network is consisted of six 2N-port RC networks with 2N single-ended operational amplifiers.

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Combustion synthesis of carbon nanotubes using their self-catalytic behavior (자기촉매 특성을 이용한 탄소나노튜브의 연소합성 연구)

  • Woo, Sang-Kil;Hong, Young-Taek;Kwon, Oh-Chae
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1815-1820
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    • 2008
  • Self-catalytic behavior of combustion-synthesized carbon nanotubes (CNTs) is evaluated using a double-faced wall stagnation flow burner with a CNT-deposited stainless steel plate wall. CNT formation is observed using field-emission scanning and transmission electron microscopies and Raman spectroscopy. A self-catalytic behavior of multi-walled CNTs (MWCNTs) shows the enhanced ratio of channel diameter to tube wall thickness and the enhanced intensity ratio of G-band to D-band in Raman spectroscopy, implying that the quality of metal-catalytic, flame-synthesized MWCNTs can be much improved via a CNT self-catalytic flame-synthesis process. Thus, using a DWSF burner through the self-catalytic process has potential in mass production of CNTs having much improved quality.

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