• Title/Summary/Keyword: Side Channel

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Effects of Paroxetine on a Human Ether-a-go-go-related Gene (hERG) K+ Channel Expressed in Xenopus Oocytes and on Cardiac Action Potential

  • Hong, Hee-Kyung;Hwang, Soobeen;Jo, Su-Hyun
    • International Journal of Oral Biology
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    • v.43 no.1
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    • pp.43-51
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    • 2018
  • $K^+$ channels are key components of the primary and secondary basolateral $Cl^-$ pump systems, which are important for secretion from the salivary glands. Paroxetine is a selective serotonin reuptake inhibitor (SSRI) for psychiatric disorders that can induce QT prolongation, which may lead to torsades de pointes. We studied the effects of paroxetine on a human $K^+$ channel, human ether-a-go-go-related gene (hERG), expressed in Xenopus oocytes and on action potential in guinea pig ventricular myocytes. The hERG encodes the pore-forming subunits of the rapidly-activating delayed rectifier $K^+$ channel ($I_{Kr}$) in the heart. Mutations in hERG reduce $I_{Kr}$ and cause type 2 long QT syndrome (LQT2), a disorder that predisposes individuals to life-threatening arrhythmias. Paroxetine induced concentration-dependent decreases in the current amplitude at the end of the voltage steps and hERG tail currents. The inhibition was concentration-dependent and time-dependent, but voltage-independent during each voltage pulse. In guinea pig ventricular myocytes held at $36^{\circ}C$, treatment with $0.4{\mu}M$ paroxetine for 5 min decreased the action potential duration at 90% of repolarization ($APD_{90}$) by 4.3%. Our results suggest that paroxetine is a blocker of the hERG channels, providing a molecular mechanism for the arrhythmogenic side effects of clinical administration of paroxetine.

Ameliorating Effects of Sulfonylurea Drugs on Insulin Resistance in Otsuka Long-Evans Tokushima Fatty Rats

  • Park, Jeong-Kwon;Kim, Sang-Pyo;Song, Dae-Kyu
    • The Korean Journal of Physiology and Pharmacology
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    • v.12 no.1
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    • pp.7-12
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    • 2008
  • OLETF (Otsuka Long-Evans Tokushima Fatty) rats are characterized by obesity-related insulin resistance, which is a phenotype of type 2 diabetes. Sulfonylurea drugs or benzoic acid derivatives as inhibitors of the ATP-sensitive potassium $(K_{ATP})$ channel are commercially available to treat diabetes. The present study compared sulfonylurea drugs (glimepiride and gliclazide) with one of benzoic acid derivatives (repaglinide) in regard to their long-term effect on ameliorating insulin sensitivity in OLETF rats. Each drug was dissolved and fed with drinking water from 29 weeks of age. On high glucose loading at 45 weeks of age, response of blood glucose recovery was the greatest in the group treated with glimepiride. On immunohistochemistry analysis for the Kir6.2 subunit of $K_{ATP}$ channels, insulin receptor ${\beta}$-subunits, and glucose transporters (GLUT) type 2 and 4 in liver, fat and skeletal muscle tissues, the sulfonylurea drugs (glimepiride and gliclazide) were more effective than repaglinide in recovery from their decreased expressions in OLETF rats. From these results, it seems to be plausible that $K_{ATP}$-channel inhibitors containing sulfonylurea moiety may be much more effective in reducing insulin resistance than those with benzoic acid moiety. In contrast to gliclazide, non-tissue selectivity of glimepiride on $K_{ATP}$ channel inhibition may further strengthen an amelioration of insulin sensitivity unless considering other side effects.

Study on Concentration Variation of 222Rn for Various Scintillators Using Low-Level Liquid Scintillation Counter (저 준위 액체섬광계수기를 이용한 섬광체 종류에 따른 222Rn 농도 변화 연구)

  • Jeon, JaeWan;Lee, Deuk-Hee;Kim, Jin-Seop
    • Journal of the Korean Society of Radiology
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    • v.13 no.6
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    • pp.847-856
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    • 2019
  • The various environmental issues arose with the development of today's economy. naturally, people were increased interest in environment and the importance of research on drinking water and contamination are emerging especially. A number of country areas, uranium and 222Rn in ground water have been detected to people using as drinking water. So this study evaluated the way for more accurate measurements than when measuring 222Rn concentrations in the ground water containing. the experiment was performed using the low-level liquid scintillation counter with an alpha, beta analysis easy PSA function of pulse. the scintillator as the preparation of the ground water samples are mixed, the measure value detection is lowered over prepare period and expiration date. Energy spectrum was also moved to a lower side channel. As a long time to buy the scintillator and over time after opening, it was confirmed that detection is lowered. if the purpose is to use a different scintillator can see the energy through the channel change.

A Coherent Phase Sequence Detection Scheme for SLM-based OFDM Systems without Side Information (위상 신호에 대한 부가 정보가 없는 SLM 기반 OFDM 시스템을 위한 동기식 위상 신호 검출 방식)

  • Ryu, Chang Su;Joo, Jung Suk
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.6
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    • pp.15-20
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    • 2016
  • In this paper, we consider selective mapping (SLM) based OFDM systems without side information, where SLM is one of the promising peak-to-average power ratio (PAPR) reduction techniques due to its simplicity and no distortion in the transmitted signal. First, we construct a new phase sequence where a part of phase sequence is replaced by an orthogonal sequence. Based on the proposed phase sequence, we propose a new scheme for detecting coherently the index of the phase sequence used in transmitter without side information. Computer simulation shows that the proposed detection scheme performs well in SLM-based OFDM systems, and specifically outperforms the existing ones when channel variation is relatively small between sub-carriers used in phase sequence detection.

AN ELECTROMYOGRAPHIC STUDY ON THE TREATMENT OF BRUXISM AND TEMPOROMANDIBULAR JOINT DYSFUNCTION PATIENTS (Bruxism과 악관절(顎關節) 기능장애자(機能障碍者)의 치료(治療)에 관(關)한 근전도학적(筋電圖學的) 연구(硏究))

  • Ro, Chang-Sup;Choi, Boo-Byung
    • The Journal of Korean Academy of Prosthodontics
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    • v.22 no.1
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    • pp.85-94
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    • 1984
  • The purpose of this study was to investigate treatment effectiveness of TENS and bite plane for bruxism and TMJ dysfunction patients. The electromyograms were made on males aged 23 to 25 with sound stomatognathic system, 5 males bruxism aged 24 to 27, and 1 male and 4 females TMJ dysfunction patients (right TMJ pain) aged 14 to 33. The electromyographic study was limited to the middle of masseter muscle and anterior temporal muscle. The electromyographic study was carried out with 8-channel EM2 (Myotronics Research Inc.) and was taken 5 mandibular positions of clinical rest position, clench intercuspal position, clench protruded, cluch right, clench left. The 2 pairs of surface electrodes were used exactly, with the ear lobe as reference point. The recording were subjected to determine the mean voltage. The results were as follows; 1. In the clinical rest position, the muscle activities of bruxism and TMJ dysfunction patients were higher than those of normal at the before treatment, but that were lower or similar to those of normal at the TENS after and after bite plane wearing. 2. In the clench I.C.P., the muscle activities of TMJ dysfunction patients were decreased as the order of the before treatment, after TENS, after occlusal bite plane wearing, but those of bruxism were irregular. 3. In the clench right and the clench left, the muscle activities of the middle of masseter muscle of the non-working side of bruxism were higher than those of the working side at the before treatment and after TENS, but the muscle activities of after occlusal bite plane wearing were similar to those of the normal. 4. In the clench right and the clench left, the muscle activities of the middle of masseter muscle and anterior temporal muscle of the working side of TMJ dysfunction patients were higher than those of non-working side as like the normal at the before treatment, after TENS, and after occlusal bite plane wearing.

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Incision and Geomorphic Development of Rivers on Eastern and Western Sides of the Northern Sobaek Mountains (소백산맥 북부 영동영서 하천의 하각과 지형 발달)

  • Cho, Young-Dong;Park, Chung-Sun;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.2
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    • pp.27-40
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    • 2017
  • This study tries to analyze topographic distribution and characteristics of as well as formative age and incision rate of fluvial terraces in Danyang River on western side and Geum River on eastern side of the northern Sobaek Mountains and to estimate geomorphic development during the late Quaternary in the mountains regarded as one of the uplift axes in the Korean Peninsula. OSL age dating shows that the fluvial terrace I with an altitude above riverbed of approximately 7~13 m in Danyang River has a formative age of approximately 18 ka (MIS 2) and incision rate in the river is approximately 0.156~0.194 m/ka based on the age. Altitudes above riverbed of the fluvial terrace I in Geum River range from approximately 7 to 14 m and the terrace is thought to be older than 70 ka based on age result from aeolian sediments above the terrace deposits, suggestive of an incision rate less than approximately 0.10 m/ka. These results indicate lower uplift rate in the northern Sobaek Mountains than in the Taebaek Mountains. Moreover, it can be suggested that the northern Sobaek Mountains has experienced asymmetric uplift during the late Quaternary, because the river on western side of the northern Sobaek Mountains shows greater uplift rate than the eastern side river does. Low incision rate in Geum River can be attributed to low altitude of the river basin with little difference in altitude from the base level as well as to gentle river slope due to influence of Nakdong River.

The Study of Relationship between Berm Width and Debris Flow at the Slope (사면에서 토석류와 소단폭의 관계성에 관한 연구)

  • Kim, Sungduk;Oh, Sewook;Lee, Hojin
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.11
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    • pp.5-12
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    • 2013
  • The purpose of this study is to estimate the behavior and the mechanism of debris flow at the end of mountain side when a berm was set on the inclined plane. The numerical model was performed by using the Finite Difference Method(FDM) based on the equation for the mass conservation and momentum conservation. In order to measure the behavior of the debris flow, the debris flow of a straight channel slope and the debris flow of channel slope with 3 types of berms were compared. First, the flow discharge and the sediment volume concentration at the downstream of the channel slope, depending on the various berm width and the different inflow discharges at the upstream of the channel were analyzed. The longer the berm width, the flow discharge at the downstream of the channel was decreased and the high flow fluctuation was reduced by a berm. And it means that a berm can effect for the delay of the debris flow. Through Root Mean Square ratio(RMS) comparison, the flow discharge of the channel slope with a berm was lower than that of a straight channel slope. The longer the berm width, for the sediment volume concentration, an inflection point did not show but mild curve. Because the low sediment concentration with water mixture by a berm continuously flow at the downstream end, it will be effect for reducing the disaster caused by debris flow. The results of this study will provide useful information in predicting and preventing disaster caused by the debris flow.

Investigation of Device Characteristics on the Mechanical Film Stress of Contact Etch Stop Layer in Nano-Scale CMOSFET (Nano-Scale CMOSFET에서 Contact Etch Stop Layer의 Mechanical Film Stress에 대한 소자특성 분석)

  • Na, Min-Ki;Han, In-Shik;Choi, Won-Ho;Kwon, Hyuk-Min;Ji, Hee-Hwan;Park, Sung-Hyung;Lee, Ga-Won;Lee, Hi-Deok
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.4
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    • pp.57-63
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    • 2008
  • In this paper, the dependence of MOSFET performance on the channel stress is characterized in depth. The tensile and compressive stresses are applied to CMOSFET using a nitride film which is used for the contact etch stop layer (CESL). Drain current of NMOS and PMOS is increased by inducing tensile and compressive stress, respectively, due to the increased mobility as well known. In case of NMOS with tensile stress, both decrease of the back scattering ratio ($\tau_{sat}$) and increase of the thermal injection velocity ($V_{inj}$) contribute the increase of mobility. It is also shown that the decrease of the $\tau_{sat}$ is due to the decrease of the mean free path ($\lambda_O$). On the other hand, the mobility improvement of PMOS with compressive stress is analyzed to be only due to the so increased $V_{inj}$ because the back scattering ratio is increased by the compressive stress. Therefore it was confirmed that the device performance has a strong dependency on the channel back scattering of the inversion layer and thermal injection velocity at the source side and NMOS and PMOS have different dependency on them.

A Study on Leaching Characteristics Change for Sediment Dredging in Yongwon Channel, Busan New Port (부산신항 용원수로에서의 퇴적물 준설에 의한 용출특성 변화 연구)

  • Choo, Min Ho;Kim, Young Do;Jeong, Weon Mu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.3
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    • pp.541-547
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    • 2017
  • In Yongwon channel, its natural flow of seawater is blocked by the construction of Busan Newport including the container berth. The channel was transformed into a narrow and long one, where it is possible that ships are only allowed to pass through the north-side channel of Gyeonmado located at the point of river mouth to Songjeongcheon. So it is considered that the changes in the terrain characteristics of Yongwon channel is likely to alter the circulation of sea water, thereby changing its water quality. Contaminants are accumulated from the sediment release. In this study, before and after dredging the sediment release test was performed. As a result, after the sediment dredging is performed, the reduction rate was higher at the same point. The results show that the water quality can be improved by dredging. Each group (A~C) reduction rate of the evaluation of the reduction rate of 4.64% T-N, 18.00%, 18.59%, respectively. T-P rate of 24.75% reduction, 24.17%, 44.08%, respectively. COD reduction rate was 18.57%, 19.76%, 38.08%, respectively. These results can be used as basic data for controlling the contamination by dredging in Yongwon channel.

An Adaptive Joint Precoding for Multi-user MIMO Systems (다중 사용자 MIMO 시스템을 위한 적응적 결합 프리코딩)

  • Park, Ju Yong;Hanif, Mohammad Abu;Song, Sang Seob;Lee, Moon Ho
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.12
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    • pp.3-11
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    • 2014
  • Multiple antennas can provide huge capacity gains when the transmitter knows the channel state information (CSI). Precoding is a technique that exploits CSI at the transmitter side. In this paper, an adaptive precoding scheme is proposed, called a hybrid multiple-input multiple-output (MIMO) precoding (HMP). HMP is a combination of linear and nonlinear precoding. The number of transmit antennas less than or equal to four is as same as the conventional antenna selection scheme. Therefore, the HMP scheme uses more than four transmit antennas. The good channel means that the channels must be selected to maximize the channel capacity among the given channels, and the rest channels are called bad channel. In HMP scheme, we use the nonlinear precoding in the good channels and the linear precoding in the bad channels. The well-known Tomlinson-Harashima precoding (THP) is considered as nonlinear precoding. The system throughput and MSE (minimum square error) are shown for the performance of HMP scheme compared to the conventional schemes which are BD (block diagonalization), antenna selection and THP.