• Title/Summary/Keyword: K channel

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Effects of $Cl^-$ Channel Blockers on the Cardiac ATP-sensitive $K^+$ Channel

  • Kwak, Yong-Geun
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.3
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    • pp.305-313
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    • 1999
  • To explore whether $Cl^-$ channel blockers interact with the ATP-sensitive $K^+\;(K_{ATP})$ channel, I have examined the effect of two common $Cl^-$ channel blockers on the $K_{ATP}$ channel activity in isolated rat ventricular myocytes using patch clamp techniques. In inside-out patches, 4,4'-diisothio-cyanatostilbene- 2,2'-disulfonic acid (DIDS) and niflumic acid applied to bath solution inhibited the $K_{ATP}$ channel activity in a concentration-dependent manner with $IC_{50}$ of 0.24 and 927 ${\mu}M,$ respectively. The inhibitory action of DIDS was irreversible whereas that of niflumic acid was reversible. Furthermore, DIDS-induced block was not recovered despite exposure to ATP (1 mM). In cell-attached and inside-out patches, DIDS blocked the pinacidil- or 2,4-dinitrophenol (DNP)-induced $K_{ATP}$ channel openings. In contrast, niflumic acid did not block the pinacidil-induced $K_{ATP}$ channel openings in inside-out patches, but inhibited it in cell-attached patches. DIDS and niflumic acid produced additional block in the presence of ATP and did not affect current-voltage relationship and channel kinetics. All these results indicate that DIDS among $Cl^-$ channel blockers specifically blocks the cardiac $K_{ATP}$ channel.

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The Literatural Study on Medical treatment with Acupuncture Point of Flank pain (협통(脇痛)의 치료혈(治療穴)에 관한 문헌적(文獻的) 고찰(考察))

  • Moon, Jung-Won;Oh, Min-Suck
    • Journal of Haehwa Medicine
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    • v.14 no.1
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    • pp.149-154
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    • 2005
  • I have come to next conclusions in consequence of documentary study about medical books of many generations regarding Medical treatment with Acupuncture Point of Flank pain. The urinary bladder channel of foot-taiyang is most used. Next there are the ren channel, the gall baldder channel of foot-shaoyang, the liver channel of foot-jueyin, the triple-warmer channel of hand-shaoyang, the kidney channel of foot-shaoyin, the stomach channel of foot-yangming, the spleen channel of foot-taiyin, the pericardium channel of hand-jueyin, the lung channel of hand-taiyin, the small intestine channel of hand-taiyang, the large intestine channel of hand-yangming, the heart channel of hand-shaoyin in the order of frequency in used channel among the twelve channels. The liver channel of foot-jueyin is most used. The gall baldder channel of foot-shaoyang, the urinary bladder channel of foot-taiyang, the triple-warmer channel of hand-shaoyang, the spleen channel of foot-taiyin, the stomach channel of foot-yangming, the ren channel, the small intestine channel of hand-taiyang, the kidney channel of foot-shaoyin, the pericardium channel of hand-jueyin, the large intestine channel of hand-yangming, the lung channel of hand-taiyin, the heart channel of hand-shaoyin in the order of frequency in used point among the twelve channels.

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The Literatural Study on Acupuncture and Moxibustion Therapy of Arthalgia Syndrome (비증(痺症)의 침구치료(鍼灸治療)에 관한 문헌적(文獻的) 고찰(考察))

  • Je, Byung Sun;Lim, Lark cheol;Oh, Min Suck
    • Journal of Haehwa Medicine
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    • v.13 no.1
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    • pp.61-69
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    • 2004
  • I have come to next conclusions in consequence of documentary study about medical books of many generations regarding acupuncture and moxibustion therapy of arthalgia syndrome. 1. Jing point of regular channels is most used. Next there are extraordinary point, ashi point in the acupuncture and moxibustion therapy of arthalgia syndrome. 2. The gall baldder channel of foot-shaoyang is most used. Next there are the urinary bladder channel of foot-taiyang, the large intestine channel of hand-yangming, the stomach channel of foot-yangming, the small intestine channel of hand-taiyang, the spleen channel of foot-taiyin, the liver channel of foot-jueyin, the triple-warmer channel of hand-shaoyang, the du channel, the lung channel of hand-taiyin, the kidney channel of foot-shaoyin, the pericardium channel of hand-jueyin, the heart channel of hand-shaoyin, the ren channel in the order of frequency in used channel among the twelve channels. 3. Three yang channels of foot is most used. Next there are three yang channels of hand, three yin channels of hand, three yin channels of foot in the order of frequency in use among the twelve channels. 4. The gall baldder channel of foot-shaoyang is most used. Next there are the urinary bladder channel of foot-taiyang, the large intestine channel of hand-yangming, the triple-warmer channel of hand-shaoyang, the stomach channel of foot-yangming, the small intestine channel of hand-taiyang, the liver channel of foot-jueyin, the lung channel of hand-taiyin, the spleen channel of foot-taiyin, the kidney channel of foot-shaoyin, the du channel, the pericardium channel of hand-jueyin, the ren channel the heart channel of hand-shaoyin in the order of frequency in used point among the twelve channels. 5. Huantiao is most used. Next there are Weizhong, Quchi, Yangfu, Chize Feiyang Xiyangguan Xiguan Tianjing, Sanli Xiaoluo in the order of frequency in use. 6. Jing point in the order of frequency of use, expel wind-evil and remove wetness-evil on the Acupuncture and Moxibustion Therapy of Arthalgia Syndrome.

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Study on the Gi Boo Lon of Su Wen (《소문ㆍ기부론》에 대한 연구)

  • Oh Yi Soo;Kim Bo Hun;Roh Seung Jo;Cheon Sang Muk;Kim Jong Ho;Jeong Hyun Jong;Lee Jong Soon;Jeong Heon Young;Keum Kyung Soo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.5
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    • pp.1275-1284
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    • 2004
  • This paper discuss the acupoints and flowing of channel. The Acupoints issued from the Foot Taiyin channel's energy are seventy three. The acupoints issued from the Foot Shaoyang channel's energy are sixty two. The acupoints issued from the Foot Yangming channel's energy are sixty eight. The acupoints issued from the Hand Taiyang channel's energy are thirty six. The acupoints issued from the Hand Yangming channel's energy are twenty two. The acupoints issued from the Hand Shaoyang channel's energy are thirty two. The acupoints issued from the Du channel's energy are twenty eight. The acupoints issued from the Ren channel's energy are twenty eight. The acupoints issued from the Chong channel's energy are twenty two. The acupoints issued from the Foot Shaoyin channel are the Lianquan points of kidney channel on each side under the tongue. The total points above amount of three hundred and sixty five. Urinary Bladder Channel of Foot-Taiyang: The number of acupoints is 67. Gall Bladder Channel of Foot-Shaoyang: The number of acupoints is 44. Stomach Channel of Foot-Yangming: The number of acupoints is 45.

Channel Estimation for Mobile OFDM systems by LS Estimator based Kalman Filtering Algorithm

  • Bae, Sang-Jun;Jang, Yoon-Ho;Nam, Sang-Kyun;Kwak, Kyung-Sup
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.12C
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    • pp.1208-1215
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    • 2009
  • In OFDM systems, mobile channel degrades the system performance seriously. Therefore, channel estimation technique is required to compensate for the degradation from the channel effects. However, conventional channel estimations in frequency domain induce ICI which is induced from Doppler frequency. In addition, a linear interpolation method causes inaccurate channel estimation. In order to minimize the effect of the interference and interpolation error, the proposed method combines LS method and Kalman filtering algorithm. Channel impulse response is adaptively tracked by Kalman filtering based on the information from LS estimator. Simulation results are presented to verify the performance of the proposed channel estimation over mobile channel environment. Simulation results show that the proposed method can effectively compensate for channel degradation.

Analysis of Channel Access Delay in CR-MAC Protocol for Ad Hoc Cognitive Radio Wireless Sensor Networks without a Common Control Channel

  • Joshi, Gyanendra Prasad;Nam, Seung Yeob;Acharya, Srijana;Kim, Sung Won
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.3
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    • pp.911-923
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    • 2014
  • Ad hoc cognitive radio wireless sensor networks allow secondary wireless sensor nodes to recognize spectrum opportunities and transmit data. Most existing protocols proposed for ad hoc cognitive radio wireless sensor networks require a dedicated common control channel. Allocating one channel just for control packet exchange is a waste of resources for channel-constrained networks. There are very few protocols that do not rely on a common control channel and that exchange channel-negotiation control packets during a pre-allocated time on the data channels. This, however, can require a substantial amount of time to access the channel when an incumbent is present on the channel, where the nodes are intended to negotiate for the data channel. This study examined channel access delay on cognitive radio wireless sensor networks that have no dedicated common control channel.

Random Access Channel with Retransmission Gain

  • Shi, Junmin;Sun, Yi;Zhang, Xiaochen;Xiao, Jizhong
    • IEIE Transactions on Smart Processing and Computing
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    • v.2 no.3
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    • pp.148-159
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    • 2013
  • An analysis of the throughput and stability region of random access systems is currently of interest in research and industry. This study evaluated the performance of a multiuser random access channel with a retransmission gain. The channel was composed of a media access control (MAC) determined by the transmission probabilities and a multiuser communication channel characterized by the packet reception probabilities as functions of the number of packet transmissions and the collision status. The analysis began with an illustrative two-user channel, and was extended to a general multiuser channel. For the two-user channel, a sufficient condition was derived, under which the maximum throughput was achieved with a control-free MAC. For the channel with retransmission gain, the maximum steady throughput was obtained in a closed form. The condition under which the random access channel can acquire retransmission gain was also obtained. The stability region of the general random access channel was derived. These results include those of the well-known orthogonal channel, collision channel and slotted Aloha channel with packet reception as a special instance. The analytical and numerical results showed that exploiting the retransmission gain can increase the throughput significantly and expand the stability region of the random access channel. The analytical results predicted the performance in the simulations quite well.

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A Novel Routing Algorithm Based on Load Balancing for Multi-Channel Wireless Mesh Networks

  • Liu, Chun-Xiao;Chang, Gui-Ran;Jia, Jie
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.4
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    • pp.651-669
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    • 2013
  • In this paper, we study a novel routing algorithm based on load balancing for multi-channel wireless mesh networks. In order to increase the network capacity and reduce the interference of transmission streams and the communication delay, on the basis of weighted cumulative expected transmission time (WCETT) routing metric this paper proposes an improved routing metric based on load balancing and channel interference (LBI_WCETT), which considers the channel interference, channel diversity, link load and the latency brought by channel switching. Meanwhile, in order to utilize the multi-channel strategy efficiently in wireless mesh networks, a new channel allocation algorithm is proposed. This channel allocation algorithm utilizes the conflict graph model and considers the initial link load estimation and the potential interference of the link to assign a channel for each link in the wireless mesh network. It also utilizes the channel utilization percentage of the virtual link in its interference range as the channel selection standard. Simulation results show that the LBI_WCETT routing metric can help increase the network capacity effectively, reduce the average end to end delay, and improve the network performance.

Effects of Adenosine on the Ionic Channel Activated by Metabolic Inhibition in Rabbit Ventricular Myocytes

  • Han, Jin;Kim, Eui-Yong;Ho, Won-Kyung;Earm, Yung-E
    • The Korean Journal of Physiology
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    • v.30 no.1
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    • pp.1-9
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    • 1996
  • The objective of the present study was to characterize the role of adenosine in regulation of ATP-sensitive $K^+\;channel\;(K_{ATP}\;channel)$ activity in isolated rabbit ventricular myocytes using the patch clamp technique. Internal adenosine had little effects on KaTr channel activity. In an outside-out patch with intrapipette GTP and ATP, external adenosine stimulated $K_{ATP}\;channel$ activity. In an inside-out Patch with intrapipette adenosine, ATP reduced $K_{ATP}\;channel$ activity, and GTP stimulated $K_{ATP}\;channel$ activity. Adenosine receptor activation shifted the half-maximal inhibition Of $K_{ATP}\;channel\;from\;70\;to\;241\;{\mu}m$. These results Suggest that activation of adenosine receptors stimulates $K_{ATP}\;channels$ in rabbit ventricular myocytes by reducing the apparent affinity of the channel for ATP. The effect may be important for activating $K_{ATP}\;channels$ during early phase of myocardial ischemia.

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Effect of Prostaglandins $D_2,\;E_2\;and\;I_2\;on\;the\;Regulation\;of\;K_{ATP}$ Channel Activity in Rat Cardiac Myocytes

  • Ju, Jeong-Min;Nah, Seung-Yeol;Kim, Jae-Ha
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.5
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    • pp.507-512
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    • 1999
  • Contribution of prostaglandins $D_2,\;E_2\;and\;I_2\;(PGD_2,\;PGE_2\;and\;PGI_2)$ on the regulation of ATP-sensitive $K^+$ channel $(K_{ATP}\;channel)$ was investigated in isolated single rat ventricular cardiac myocytes using the patch clamp technique. $PGD_2,\;PGE_2\;and\; PGI_2$ did not affect $K_{ATP}$ channel activity in the inside-out patch, but increased channel activity in a dose-dependent manner when the channel activities were attenuated by the administration of 100 ${\mu}M$ ATP to the internal solution in the inside-out patch. Channel activations by the prostaglandins were abolished by 50 ${\mu}M$ glibenclamide, a $K_{ATP}$ channel blocker. Dose-response curves of relative channel activity against the ATP concentrations of internal solution in the inside-out patch were shifted to the right in the presence of those three prostaglandins. The rank order of the channel stimulatory potencies $(as\;IC_{50}\;for\;ATP)$ calculated from the dose-response curves were $PGI_2\;>\;PGD_2\;>\;PGE_2.$ Conductance of the channel was not changed by those three prostaglandins. In conclusion, we suggest that prostaglandins $D_2,\;E_2\;and\;I_2$ are involved in the regulation of $K_{ATP}$ channel activity in certain circumstances, and that those three prostaglandins may cause myocardial relaxation by opening $K_{ATP}$ channels, thus protecting the heart from ischema.

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