• Title/Summary/Keyword: ERG

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Ferromagnetic Resonance of Amorphous $Co_{1-\chi}Hf_\chi$ Thin Films (비정질 $Co_{1-x}Hf_x$ 박막의 강자성 공명)

  • 백종성;김약연;이성재;임우영;이수형
    • Journal of the Korean Magnetics Society
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    • v.7 no.3
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    • pp.129-133
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    • 1997
  • To investigate the influence of the Hf concentration and the annealing effect in $Co_{1-x}Hf_x$(X=0.16, 0.24 at.%) systems, ferromagnetic resonance experiments have been carried out. Spin wave resonance spectra for all samples consist of several volume modes and one (or two) surface mode. It is suggested that both surfaces of the film have a perpendicular hard axis to the film plane (negative surface anisotropy). The surface anisotropy $K_{s2}$ at substrate-film interface is varied slowly from -0.07 to -0.32 erg/$\textrm{cm}^2$ and the surface anisotropy $K_{s1}$ at film-air interface is varied from 0.18 to -0.47 erg/ $\textrm{cm}^2$ with increasing annealing temperature in the amorphous $Co_{84}Hf_{16}$ thin films. Also, the surface anisotropy $K_{s2}$ is varied slowly from -0.31 to -0.41 erg/$\textrm{cm}^2$ and the surface anisotropy $K_{s1}$is varied from -0.19 to -0.60 erg/$\textrm{cm}^2$ with increasing annealing temperature in the amporphous $Co_{84}Hf_{16}$ thin films. We conjecture that the variation of surface anisotropy $K_{s1}$ is due to the increase of Co concentration resulted from Hf oxidation for low temperature annealing(150~175 $^{\circ}C$) and the diffusion of Co atoms near the film surfaces for high temperature annealing (200~225 $^{\circ}C$).

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2D-QSAR analysis for hERG ion channel inhibitors (hERG 이온채널 저해제에 대한 2D-QSAR 분석)

  • Jeon, Eul-Hye;Park, Ji-Hyeon;Jeong, Jin-Hee;Lee, Sung-Kwang
    • Analytical Science and Technology
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    • v.24 no.6
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    • pp.533-543
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    • 2011
  • The hERG (human ether-a-go-go related gene) ion channel is a main factor for cardiac repolarization, and the blockade of this channel could induce arrhythmia and sudden death. Therefore, potential hERG ion channel inhibitors are now a primary concern in the drug discovery process, and lots of efforts are focused on the minimizing the cardiotoxic side effect. In this study, $IC_{50}$ data of 202 organic compounds in HEK (human embryonic kidney) cell from literatures were used to develop predictive 2D-QSAR model. Multiple linear regression (MLR), Support Vector Machine (SVM), and artificial neural network (ANN) were utilized to predict inhibition concentration of hERG ion channel as machine learning methods. Population based-forward selection method with cross-validation procedure was combined with each learning method and used to select best subset descriptors for each learning algorithm. The best model was ANN model based on 14 descriptors ($R^2_{CV}$=0.617, RMSECV=0.762, MAECV=0.583) and the MLR model could describe the structural characteristics of inhibitors and interaction with hERG receptors. The validation of QSAR models was evaluated through the 5-fold cross-validation and Y-scrambling test.

Der Realisierungsmechanismus der fakultativen $Erg\"{a}nzung$ - Ist die $Fakultativit\"{a}t\;der\;Erg\"{a}nzung$ ein idiosynkratisches $Ph\"{a}nomen$? (수의적 보족어의 실현 메커니즘- 보족어의 수의성은 예측 불가능한 개별 어휘적 특성인가?)

  • Choi Kyun-Ho
    • Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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    • v.2
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    • pp.101-128
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    • 2000
  • In der vorliegenden Arbeit wurde der Realisierungsmechanismus der fakultativen $Erg\"{a}nzung$ aufgrund des zweidimensionalen Valenzmodells und des zweistufigen Semantikmodlells behandelt. Dabei wurde die $Fakultativit\"{a}t\;der\;Erg\"{a}nzung$ nicht als ein $Ph\"{a}nomen$ im Lexikon angesehen, sondern als ein $Ph\"{a}nomen$ auf der Ebene der Valenzrealisierung, das als Resultat des Zusammenspiels von valenzunabhangigen Faktoren zu betrachten ist. In der bisherigen Valenzforschung wurde die $Fakultativit\"{a}t\;als\;eine\;ausschlie{\ss}lich$ idiosynkratische Eigenschaft des einzelnen Verbs interpretiert, die man bei jedem Verb erlernen $mu{\ss}$. Gegen diese Auffassung wandte die vorliegende Arbeit ein, dass die $Fakultativit\"{a}t$ keine unvoraussagbare idiosynkratische Eigenschaft des einzelnen Verbs ist: Die $Fakultativit\"{a}t\;der\;Erg\;"{a}nzung$ kann durch $Regularit\"{a}ten$ allgemein vorausgesagt werden. Anhand der statischen Lokalisierungsverben im Deutschen wurde gezeigt, dass die $Fakultativit\"{a}t\;der\;lokalen\;Erg\;"{a}nzung$ von den konzeptuellen Prozessen $abh\"{a}ngt:$ Bei dem $Lokalisierungsproze{\ss}$ ist die Realisierung der lokalen $Erg\"{a}nzung$ notwendig. Dagegen ist die Realisierung der lokalen $Erg\"{a}nzung$ bei dem $Delokalisierungsproze{\ss}$ optional. Wenn man die $Fakultativit\"{a}t$ durch allgemeine $Regularit\"{a}ten\;erkl\"{a}ren$ kann, dann ist es nicht $n\"{o}tig,\;die\;Fakultativit\"{a}t$ bei jedem Verb im Lexikon zu markieren. Dadurch kann das mentale Lexikon enorm entlastet werden. Dies bedeutet $f\"{u}r$ deutschlernende $Ausl\"{a}nder$ eine $gro{\ss}e$ Erleichterung.

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Inhibitory Effect of Nicardipine on hERG Channel

  • Chung, Eun-Yong;Cho, Hea-Young;Cha, Ji-Hun;Kwon, Kyoung-Jin;Jeon, Seol-Hee;Jo, Su-Hyun;Kim, Eun-Jung;Kim, Hye-Soo;Chung, Hye-Ju
    • Biomolecules & Therapeutics
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    • v.18 no.4
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    • pp.448-453
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    • 2010
  • Drug-induced long QT syndrome is known to be associated with the onset of torsades de pointes (TdP), resulting in a fatal ventricular arrhythmia. QT interval prolongation can result from blocking the human ether-a-go-go-related gene (hERG) channel, which is important for the repolarization of cardiac action potential. Nicardipine, a Ca-channel blocker and antihypertensive agent, has been reported to increase the risk of occasional serious ventricular arrhythmias. We studied the effects of nicardipine on hERG $K^+$ channels expressed in HEK293 cells and Xenopus oocytes. The cardiac electrophysiological effect of nicardipine was also investigated in this study. Our results revealed that nicardipine dose-dependently decreased the tail current of the hERG channel expressed in HEK293 cells with an $IC_{50}$ of 0.43 ${\mu}M$. On the other hand, nicardipine did not affect hERG channel trafficking. Taken together, nicardipine inhibits the hERG channel by the mechanism of short-term channel blocking. Two S6 domain mutations, Y652A and F656A, partially attenuated (Y652A) or abolished (F656A) the hERG current blockade, suggesting that nicardipine blocks the hERG channel at the pore of the channel.

Detecting malicious behaviors in MMORPG by applying motivation theory (모티베이션 이론을 이용한 온라인 게임 내 부정행위 탐지)

  • Lee, Jae-hyuk;Kang, Sung Wook;Kim, Huy Kang
    • Journal of Korea Game Society
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    • v.15 no.4
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    • pp.69-78
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    • 2015
  • As the online game industry has been growing rapidly, more and more malicious activities to gain economic benefits have been reported as well. Game bot is one of the biggest problems in the online game industry. So we proposed a bot detection method based on the ERG theory of motivation for the first time. Most of the previous studies focused on behavior-based detection by monitoring patterns of the specific actions. In this paper, we applied the motivation theory to analyze user behaviors on a real game dataset. The result shows that normal users in the game followed the ERG theory of motivation in the same way as it works in real world. But in the case of game bots, the theory could not be applied because the game bot has specific reasons, unlike normal game users. We applied the ERG theory to users to distinguish game bot users from normal users. We detected the game bot with high accuracy of 99.78% by applying the theory.

Comparison of ERG Denoising Performance according to Mother Function of Wavelet Transforms (웨이브렛 변환의 모함수에 따른 ERG의 잡음제거 성능 비교)

  • Seo, Jung-Ick;Park, Eun-Kyoo;Jang, Jun-Young
    • Journal of Korean Clinical Health Science
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    • v.4 no.4
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    • pp.756-761
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    • 2016
  • Purpose. Noise occurs at measuring Electoretinogram(ERG) signals as the other bio-signal measurement. It is compared the denoising performance according to the mother function of wavelet transforms. Methods. The ERG signal that generated power supply noise and white noise was used as a sampling signal. The noise of ERG signal was filtered by using haar, db7, bior mother function. The filtering performance of each mother functions was compared using Fourier transform spectrum and SNR(signal to noise ratio). Results. In the haar functioin, the result of the Fourier transform spectrum was that the power supply noise is removed and the white noise performance is not good. The SNR was 27.0404. In the db7 function, the results of Fourier transform spectrum was that the power supply noise is removed and the white noise performance is good. The SNR was 35.1729. In the db7 function, the results of Fourier transform spectrum was that the power supply noise is removed and the white noise performance is the bset. The SNR was 35.4445. Conclusions. The db7, bior function was good results in power supply noise and white noise filtered. The bior function is suitable for filtering noise of the ERG signal.

Gap Junction Contributions to the Goldfish Electroretinogram at the Photopic Illumination Level

  • Kim, Doh-Yeon;Jung, Chang-Sub
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.3
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    • pp.219-224
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    • 2012
  • Understanding how the b-wave of the electroretinogram (ERG) is generated by full-field light stimulation is still a challenge in visual neuroscience. To understand more about the origin of the b-wave, we studied the contributions of gap junctions to the ERG b-wave. Many types of retinal neurons are connected to similar and different neighboring neurons through gap junctions. The photopic (cone-dominated) ERG, stimulated by a small light beam, was recorded from goldfish (Carassius auratus) using a corneal electrode. Data were obtained before and after intravitreal injection of agents into the eye under a photopic illumination level. Several agents were used to affect gap junctions, such as dopamine D1 and D2 receptor agonists and antagonists, a nitric oxide (NO) donor, a nitric oxide synthase (NOS) inhibitor, the gap junction blocker meclofenamic acid (MFA), and mixtures of these agents. The ERG b-waves, which were enhanced by MFA, sodium nitroprusside (SNP), SKF 38393, and sulpiride, remained following application of a further injection of a mixture with MFA. The ERG b-waves decreased following $N^G$-nitro-L-arginine methyl ester (L-NAME), SCH 23390, and quinpirole administration but were enhanced by further injection of a mixture with MFA. These results indicate that gap junction activity influences b-waves of the ERG related to NO and dopamine actions.

Physiological and Behavioral Studies on the Stimulating Effect of Strobe Light-IV Electroretinogram of Jack Mackerel by Strobe Light Frequency and Intensity (스트로보광의 위협효과에 관한 행동생리학적 연구-IV 스트로보광의 섬광빈도 및 강도에 의한 전갱이의 망막활동전위)

  • An, Yeong-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.2
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    • pp.132-137
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    • 2004
  • In order to assess electrophysiological responses of fish, a recording of Electroretinogram (ERG) was made on the dark-adapted eyes of anesthetized jack mackerel Trachurus japonicus in the strobe-flash frequency range of 1.7~25 Hz and in the intensity range of 56~415 lx.s. The amplitude change of the ERG is highest at the moment when the strobe light is irradiated and becomes weakest soon after, then gradually increases and becomes stable. The amplitude of the ERG by strobe flash frequencies looked stable tendency after about 12~17 minutes elapsed. During the test duration of 30 minutes, the maximum of amplitude change and stimulation amount over all the tested frequencies was found at 10 Hz. The reduction of the flash intensity caused the decrease in the amplitude and stimulation amount.

Taxifolin Glycoside Blocks Human ether-a-go-go Related Gene $K^+$ Channels

  • Yun, Jihyun;Bae, Hyemi;Choi, Sun Eun;Kim, Jung-Ha;Choi, Young Wook;Lim, Inja;Lee, Chung Soo;Lee, Min Won;Ko, Jae-Hong;Seo, Seong Jun;Bang, Hyoweon
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.1
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    • pp.37-42
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    • 2013
  • Taxifolin glycoside is a new drug candidate for the treatment of atopic dermatitis (AD). Many drugs cause side effects such as long QT syndrome by blocking the human ether-a-go-go related gene (hERG) $K^+$ channels. To determine whether taxifolin glycoside would block hERG $K^+$ channels, we recorded hERG $K^+$ currents using a whole-cell patch clamp technique. We found that taxifolin glycoside directly blocked hERG $K^+$ current in a concentration-dependent manner ($EC_{50}=9.6{\pm}0.7{\mu}M$). The activation curve of hERG $K^+$ channels was negatively shifted by taxifolin glycoside. In addition, taxifolin glycoside accelerated the activation time constant and reduced the onset of the inactivation time constant. These results suggest that taxifolin glycoside blocks hERG $K^+$ channels that function by facilitating activation and inactivation process.

TMPRSS2:ETS Fusions and Clinicopathologic Characteristics of Prostate Cancer Patients from Eastern China

  • Dong, Jun;Xiao, Li;Sheng, Lu;Xu, Jun;Sun, Zhong-Quan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.7
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    • pp.3099-3103
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    • 2014
  • TMPRSS2:ERG gene fusions in prostate cancer have a dominant prevalence of approximately 50.0%, but infomration is limited on differences among ethnic and geographical groups. Some studies focusing on Japanese and Korean patients reported a lower incidence. Investigations concerning Chinese revealed controversial results. We evaluated TMPRSS2:ERG, TMPRSS2:ETV1 and TMPRSS2:ETV4 fusions in more than 100 Eastern Chinese prostate cancer patients. Paraffin blocks of needle biopsy and radical prostatectomy were collected from 91 and 18 patients respectively. All patients' clinicopathologic factors were gathered. TMPRSS2:ERG, TMPRSS2:ETV1 and TMPRSS2:ETV4 fusions were tested by multi-probe fluorescence in situ hybridization (FISH) assay. TMPRSS2:ERG fusions was present in 14.3% biopsy specimens and 11.1% radical prostatectomy patients. Neither TMPRSS2:ETV1 nor TMPRSS2:ETV4 fusion was found in any case. Altogether, 13 (86.7%) TMPRSS2:ERG fusion positive cases possessed deletion pattern and 7 (46.6%) and insertion pattern. Some 5 cases had both deletion and insertion patterns. While 38.5% (5/13) patients with deletion pattern had distant metastasis, except for one metastatic case harboring both deletion and insertion, there were no patients with insertion pattern accompanied with metastasis. There were no differences between fusion positive and negative cases in the distribution of age, PSA, Gleason score and TNM stage. Eastern Chinese prostate cancer patients have a significantly low incidence of TMPRSS2:ERG fusion. They also lack TMPRSS2:ETV1 and TMPRSS2:ETV4 fusion. There are more deletion pattern than insertion pattern in TMPRSS2:ERG positive cases. Fusion positive and negative patients have no clinicopathologic factor differences.