• 제목/요약/키워드: Isolated node

검색결과 92건 처리시간 0.025초

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

  • 이정렬;엄융의
    • Journal of Chest Surgery
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    • 제18권1호
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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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한약재인 황금의 궤양성 실험동물에 대한 장간막 임파절 임파구의 면역글로블린 수준, T세포집단, 사이토카인 생성의 조절작용 (Scutellaria baicalensis Modulates Cytokine Production, T Cell Population and Immunoglobulin Level by Mesenteric Lymph Node Lymphocytes in Experimental Mice with Colitis)

  • 임병우;박표잠;최완수;김종대
    • 한국약용작물학회지
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    • 제16권2호
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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.

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

  • 유승언;이태호;이병준;김경태;윤희용
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2019년도 제59차 동계학술대회논문집 27권1호
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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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갑상설관 낭종에서 발생한 유두상 선암 1예 (A Case of Papillary Thyroid Carcinoma Arising in Thyroglossal Duct Cyst)

  • 이경근;안해선;이광만
    • 대한두경부종양학회지
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    • 제16권1호
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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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다층퍼셉트론의 출력 노드 수 증가에 의한 성능 향상 (Performance Improvement of Multilayer Perceptrons with Increased Output Nodes)

  • 오상훈
    • 한국콘텐츠학회논문지
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    • 제9권1호
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    • pp.123-130
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    • 2009
  • 일반적으로 다층퍼셉트론을 패턴인식 문제에 적용할 경우 클래스 당 하나의 출력 노드를 배정하고, 이 출력 노드의 인덱스가 입력 패턴의 클래스를 뜻하도록 한다. 이 논문에서는 이와 달리 다층퍼셉트론의 성능 향상을 위하여 클래스 당 출력노드 수를 증가시키는 방법을 제안한다. 두 개의 클래스 문제를 대상으로 클래스 발생확률이 동일하고 각 클래스 내에서 출력노드가 균일분포를 지닌다는 가정 하에, 이 방법의 효용성을 확률론적인 유도를 통하여 증명하였다. 그리고, 50개의 고립단어 인식의 시뮬레이션으로 출력노드를 증가 시킬 경우 성능이 향상됨을 확인하였다.

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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    • 제7권4호
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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
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1996년도 정기총회 및 학술발표회
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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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동방결절 전기적 특성에 대한 $Ca^{2+}$ 효과의 온도에 따른 변화 (Temperature-dependency of $Ca^{2+}$ Effect on the Electrical Activity of Rabbit SA Node)

  • 호원경;김기환;황상익
    • The Korean Journal of Physiology
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    • 제21권1호
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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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다층퍼셉트론의 성능향상을 위한 출력노드 수 증가 (Increasing Output Nodes for Performance Improvement of Multilayer Perceptrons)

  • 오상훈
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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    • pp.13-15
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    • 2006
  • 다층퍼셉트론을 패턴인식 문제에 적용하는 경우 대부분 하나의 클래스 당 하나의 출력노드를 할당한다. 이 논문에서는 class 당 출력노드 수를 증가시키는 경우에 다층퍼셉트론의 성능이 향상되는 지 고립단어 인식 문제의 시뮬레이션을 통하여 고찰하였다. 시뮬레이션 결과 출력노드 수가 하나인 경우보다 증가시킨 경우 더 나은 성능을 얻었다.

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비인강결핵 2례 (2 Cases of Nasopharyngeal Tuberculosis)

  • 문동숙
    • 대한기관식도과학회지
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    • 제6권2호
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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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