• Title/Summary/Keyword: Isolated node

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Effect of Na, K, Ca and Mg ions on the Action Potential of the Sinoatrial Node in the Rabbit (토끼 동방결절 활동전압에 대한 Na, K, Ca 및 Mg 이온의 영향)

  • Lee, Jeong-Ryeol;Eom, Yung-Ui
    • Journal of Chest Surgery
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    • v.18 no.1
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    • pp.1-6
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    • 1985
  • Isolated sinus node cells of the rabbit were used to assess the effects of extracellular Na, K, Ca and Mg concentrations on cardiac pacemaker activity. With intracellular glass micro-electrodes spontaneous action potentials of SA node were recorded and the effects of various ions and their blockers were analyzed in terms of the cycle length, the amplitude and the duration of action potentials, the results obtained were as follows. 1. Sodium reduction [up to 30%] decreased the amplitude of action potential and lengthened the cycle length. TTX, specific blocker of Na channel slightly lengthened the cycle length. 2. Increasing potassium ion concentration, the duration of action potential decreased and the frequency increased in 6mM, however, spontaneous action potential was stopped in 24 mM. Barium ion known to be decreasing K conductance increased the duration of action potential but no significant change in the cycle length was noticed. 3. Calcium ion has shortening effect on the duration and the cycle length of action potential but not with dose-dependent manner. Cadmium ion .[0.02mM] lengthened cycle length and the duration of action potential. 4. Increasing the concentration of magnesium ion the cycle length was lengthened, significantly.

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Scutellaria baicalensis Modulates Cytokine Production, T Cell Population and Immunoglobulin Level by Mesenteric Lymph Node Lymphocytes in Experimental Mice with Colitis (한약재인 황금의 궤양성 실험동물에 대한 장간막 임파절 임파구의 면역글로블린 수준, T세포집단, 사이토카인 생성의 조절작용)

  • Lim, Beong-Ou;Park, Pyo-Jam;Choi, Wahn-Soo;Kim, Jong-Dai
    • Korean Journal of Medicinal Crop Science
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    • v.16 no.2
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    • pp.100-105
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    • 2008
  • We previously examined extracts, isolated from Scutellaria baicalensis (SB), chemical mediators, and IgE by mesenteric lymph node (MLN) lymphocytes in rats. The present study was to evaluate the effects of extracts of SB on the MLN lymphocytes function of mice given orally by 20 mg/kg for 2 weeks with dextran sulfate sodium (DS)-induced colitis. Results show that IgE levels in MLN lymphocytes was low, while IgA was high, in mice given SB compared to that fed water. Concentrations of $Inteferon-{\gamma}$ and interleukin (IL)-2 of T cells by concanavalin A treatment was significantly higher in the SB fed group than the normal group. Activation-induced IL-4 and IL-10 secretion was lower in SB fed mice compared control mice after DS-induced colitis. These results suggested that SB suppresses the inflammation in DS-induced colitis through the modulation of Th1/Th2 balance to down-regulate $Th_2$ response in MLN lymphocytes.

Supporting Node Connectivity with Dixon's Test for ZigBee-based WSN (ZigBee 기반의 WSN을 위한 Dixon 테스트를 통한 노드 연결 지원)

  • Yoo, Seung-Eon;Lee, Tae-Ho;Lee, Byung-Jun;Kim, Kyung-Tae;Youn, Hee-Yong
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2019.01a
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    • pp.95-97
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    • 2019
  • 본 논문에서는 ZigBee 기반의 WSN과 노드 연결을 위한 새로운 기법을 제안한다. 이 기법은 통신 노드 간에 격리된 노드의 수를 최소화하기 위해 수신신호강도(RSSI) 샘플에 적용된 딕슨 테스트(Dixon's test)를 사용하여 ZigBee 기반의 WSN을 위한 새로운 노드 연결 구조로써 특이점(outlier)을 제거하여 적은 수의 RSSI 값으로도 정확한 노드 연결이 가능하다. 본 논문에서는 시뮬레이션을 통하여 제안하는 기법이 기존의 RSSI 기반의 기법보다 더 높은 정확도를 유지하면서 처리 시간은 줄어든 것을 증명하였다.

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A Case of Papillary Thyroid Carcinoma Arising in Thyroglossal Duct Cyst (갑상설관 낭종에서 발생한 유두상 선암 1예)

  • Lee Kyoung-Keun;Ahn Hae-Sun;Lee Kwang-Man
    • Korean Journal of Head & Neck Oncology
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    • v.16 no.1
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    • pp.83-86
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    • 2000
  • Thyroglossal duct cyst is common midline mass, which is related to hyoid bone and may show signs of inflammation. Carcinoma arising in the thyroglossal duct cyst is rare, occuring in less than 1% of thyroglossal duct cyst. Papillary adenocarcinoma is the most common histologic type(75-85%). The initial treatement of choice is wide excision of the tumor bearing tissue(Sistrunk procedure), resection of associated lymph node alone is enough when they are small and isolated, but a modified neck dissection must be done if regional involvement is more extensive. Its prognosis is excellent(the incidence of regional lymph node metastasis is 7% compare to 89% for papillary cancer of thyroid gland proper).

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Performance Improvement of Multilayer Perceptrons with Increased Output Nodes (다층퍼셉트론의 출력 노드 수 증가에 의한 성능 향상)

  • Oh, Sang-Hoon
    • The Journal of the Korea Contents Association
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    • v.9 no.1
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    • pp.123-130
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    • 2009
  • When we apply MLPs(multilayer perceptrons) to pattern classification problems, we generally allocate one output node for each class and the index of output node denotes a class. On the contrary, in this paper, we propose to increase the number of output nodes per each class for performance improvement of MLPs. For theoretical backgrounds, we derive the misclassification probability in two class problems with additional outputs under the assumption that the two classes have equal probability and outputs are uniformly distributed in each class. Also, simulations of 50 isolated-word recognition show the effectiveness of our method.

Anti-diabetic Constituent from the Node of Lotus Rhizome (Nelumbo nucifera Gaertn)

  • Lee, Min-Won;Kim, Jun-Sik;Cho, Su-Min;Kim, Ji-Hun;Lee, Jae-Seung
    • Natural Product Sciences
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    • v.7 no.4
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    • pp.107-109
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    • 2001
  • To investigate anti-diabetic component from the node of lotus rhizome (Nelumbo nucifera; Nymphaeaceae), activity guided isolation was conducted. One amino acid was isolated from active fraction of the aqueous methanolic extract. The structure of this compound was identified as tryptophan (1) by the analysis of spectroscopic evidences and comparisons with the data of authentic samples. Tryptophan reduced the blood glucose level significantly in glucose-fed hyperglycemic mice compared with glucose-treated group and exhibited 44.3% of activity compared with tolbutamide,.

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GATING MECHANISM AND VOLTAGE-DEPENDENT BLOCK BY EXTERNAL DIVALENT CATIONS OF THE DELAYED RECTIFIER K CHANNEL IN RABBIT SINO-ATRIAL NODE CELLS

  • Ho, Won-Kyung;Lee, Suk-Ho;Earm, Yung-E
    • Proceedings of the Korean Biophysical Society Conference
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    • 1996.07a
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    • pp.5-5
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    • 1996
  • In sino-atrial node cells which act as the normal pacemaker of the heart, K conductance in resting state is minimal due to the absence of inward rectifier K channels K conductance only increases when the membrane is depolarized by the activation of the delayed rectifier K current I$\_$k/. In the present study, we investigated the gating mechanism of$\_$k/ using the whole cell patch clamp technique in isolated single sinoatrial cells of the rabbit. (omitted)

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Temperature-dependency of $Ca^{2+}$ Effect on the Electrical Activity of Rabbit SA Node (동방결절 전기적 특성에 대한 $Ca^{2+}$ 효과의 온도에 따른 변화)

  • Ho, Won-Kyung;Kim, Ki-Whan;Hwang, Sang-Ik
    • The Korean Journal of Physiology
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    • v.21 no.1
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    • pp.1-12
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    • 1987
  • There is evidence that the effect of extracellular $Ca^{2+}$ on heart rate is temperature-dependent: at $38^{\circ}C$ excess $Ca^{2+}$ induces positive chronotropic response, whereas at $30^{\circ}C$ there is no significant chronotropic effect of $Ca^{2+}$. The cause of this temperature-dependency, however, remains still unclear. Therefore, this study was undertaken to investigate the chronotropic effect of external $Ca^{2+}$ at different temperature in the isolated rabbit atria and in the small strips of SA node cut perpendicularly to crista terminalis. In the isolated atria, the $Ca^{2+}$ effect was temperature-dependent: at $35^{\circ}C$ excess $Ca^{2+}$ evoked positive chronotropic response, while at $30^{\circ}C$ there was no significant changes in sinus rate. On the contrary, in the small SA strips external $Ca^{2+}$ induced negative chronotropic effect. At $35^{\circ}C$ changes in $Ca^{2+}$ concentration from 2 to 4, 6, and 10 mM decreased the sinus rate by $2.7{\pm}1.6%$, $11.2{\pm}3.7%$ and $23.2{\pm}8.1%$ respectively. Lowering the temperature to $30^{\circ}C$, the negative chronotropic effect of $Ca^{2+}$ became greater. With intracellular microelectrodes transmembrane potential was recorded in the small SA strips at $30^{\circ}C$, $35^{\circ}C$ and $38^{\circ}C$. As temperature increased from 30 to $38^{\circ}C$, sinus rate was accelerated by $13/min/^{\circ}C$, $APD_{50}$(action ptential duration from peak to 50% repolarization) decreased by $5\;msec/^{\circ}C$, and amplitude of action potential was slightly decreased. With an increase in $Ca^{2+}$ concentrations from 0.5 to 6 mM, overshoot increased and MDP decreased. These $Ca^{2+}$ effects on the overshoot and MDP of action potentials were not altered by temperature. But the $Ca^{2+}$ effects on the rates of diastolic depolarization, systolic depolarization and repolarization were modified by temperature. Discrpancy of the chronotropic effects of $Ca^{2+}$ between isolated atria and small SA strips was discussed.

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Increasing Output Nodes for Performance Improvement of Multilayer Perceptrons (다층퍼셉트론의 성능향상을 위한 출력노드 수 증가)

  • Oh, Sang-Hoon
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.13-15
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    • 2006
  • When we use multilayer perceptron model for pattern classification probmems, we allocate one output node for each class. In this paper, we increase the number of output nodes for each class and investigate the performance of multilayer perceptrons through the simulation of isolated-word recognition problems.

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2 Cases of Nasopharyngeal Tuberculosis (비인강결핵 2례)

  • 문동숙
    • Korean Journal of Bronchoesophagology
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    • v.6 no.2
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    • pp.196-200
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    • 2000
  • Nasopharyngeal tuberculosis is a rare pathological condition. It is most often associated with lymph node and pulmonary lesions, but it may be an isolated lesion. The clinical manifestation may resemble a malignant tumor of the nasopharynx and the nasopharyngeal tuberculosis is occurred occasionally primary infection but more frequently secondary infection to pulmonary tuberculosis. The nasal endoscopic evaluation of nasopharynx is necessary in patient with possible pulmonary or extrapulmonary tuberculosis. The author reports two cases of nasopharyngeal tuberculosis in a 45-years old and 34-years old woman with a review of the literature.

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