• 제목/요약/키워드: TENSION RELEASE

검색결과 136건 처리시간 0.023초

EFFECTS OF GINSENG SAPONIN ON ENDOTHELIUM - DEPENDENT VASCULAR RELAXATION IN RAT AORTA AND HYPERCHOLESTEROLEMIC RABBIT AORTA

  • Kim N.D.;Kang S.Y.
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1993년도 학술대회지
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    • pp.40-48
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    • 1993
  • Intravenous administration of saponin extracted from the root of Panax ginseng lowered the blood pressure dose-dependently (10-200 mg/kg, B.W) in anesthetized rats. Therefore, experiments were designed to study the hypothesis that the lowering of blood pressure is associated with the release of endothelium-derived relaxing factor and the accumulation of guanosine 3, 5-cyclic monophosphate (cGMP). Rings of thoracic aorta with and without endothelium were suspended for the measurement of isometric tension in organ chamber and the tissue content of cGMP was measured by radioimmunoassay. All experiments were performed in the presence of $indomethacin(10^{-5}M).$ Ginseng saponin $(10^{-5}-3{\times}10^{-6}g/ml)$ relaxed contractions induced by phenylephrine $10^{-6}M)$ in the aorta with endothelium but not in that without endothelium. Treatment of aortic rings with $N^G$ monomethyl-L-arginine (L-NMMA, $10^{-4}M$ for 30 min), a competitive inhibitor of nitric oxide synthase, and methylene blue $(MB,\;3{\times}10^{-7}M$ for 30 min). an inhibitor of soluble guanylate cyclase, diminished the relaxation induced by Ginseng saponin. Ginseng saponin $10^{-4}g/ml$ for 2 min) increased the accumulation of cGMP in rings with endothelium. L-NMMA and MB inhibited the accumulation of cGMP induced by Ginseng saponin. These data suggest that vascular relaxations induced by Ginseng saponin are mediated by release of endothelium-derived relaxing factor and the accumulation of cGMP. The effect of Ginseng saponin on endothelial function in hypercholesterolemic rabbits was examined. In hypercholesterolemic rabbits fed with $2\%$ cholesterol for 8 weeks, relaxation of aortic rings to acetylcholine was impaired. The impaired relaxations of aortic rings in hypercholesterolemic rabbits were improved by dietary supplementation of Ginseng saponin, probably because of an improved release of endothelium - derived relaxing factor.

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혈관평할근 세포에서의 칼륨이온과 카페인의 영향: 수축과 세포내 칼슘이온 농도에 대하여 (Effects of Potassium Ion and Caffeine on Contraction and Cytosolic Free $Ca^{2+}$ Levels in Vascular Smooth Muscle)

  • 안희열;H. 가라끼
    • 대한약리학회지
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    • 제24권2호
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    • pp.197-201
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    • 1988
  • 본 연구에서는 세포내의 칼슘이온과 결합하여 형광을 발하는 형광색소 fura 2를 이용하여 세포내의 칼슘이은 농도를 측정함과 동시에 장력을 측정하였으며 이에 대한 카페인과 고농도의 칼륨의 영향을 정토하였다. 72.7 mM의 칼륨 이온은 장력과 세포내 칼슘이온농도에서 각각 지속적 인 증가를 보여주었으며, 20 mM의 카페인은 일과성의 빠른 세포내의 칼슘이은농도의 증가에 이어 감소를 보여주었으나 기본치 보다는 높았다. 그러나, 장력에 있어서는 카페인은 일과성의 증가에 이어 기본 장력보다 낮은 감소를 보여주었다. 한편 칼슘이온 제거 용액에서 칼륨이온은 세포내의 갈륨이온 농도도 장력도 증가 시키지 못하였으나 카페인은 일과성의 세포내의 칼륨이온 농도와 장책의 증가를 보여주었다. 이상과 결과로부터 rat 대동맥에서의 고농도의 칼륨이은에 의한 수축은 세포 딴으로 부터의 칼슘이온 유입에 의한 것이며 반면에 카페인에 의한 수축은 세포내의 칼슘이온저장부위로 부터의 칼슘이온 유리에 의한 것임을 시사한다. 또한, 카페인은 세포내의 수축 단백의 칼슘 이온에 대한 감수성을 저하시키는 듯하다.

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Analysis of Metacommunicative Episodes between Nurses and Children

  • 신현숙
    • Child Health Nursing Research
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    • 제15권1호
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    • pp.53-60
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    • 2009
  • Purpose: The purpose of this study was to analyze metacommunicative episodes comprised of nurses' metacommunicative behavior and children's responses occurring in the dyads of nurse-child within the context of an inpatient pediatric unit. Methods: Twelve dyads of nurses and children were videotaped for four hours each day over a two-day period as they interacted with each other on the inpatient unit. The metacommunicative episodes were recorded from the videotapes. The metacommunicative behavior was categorized within Shin's metacommunicative behaviors. Results: The total number of episodes between the nurses and children included in this study was 242. The most frequently used metacommunicative behavior was 'reflection', followed by tagging, baby talk, approaching, mediating eye level, friendly demand, encouraging, description of acts, symbolization, turnabouts, touching, and mimic voice, respectively. The most common response to the nurses' metacommunicative behavior was agreeing, followed by tension release. Conclusion: Young children responded positively to metacommunicative behavior by the nurses. Understanding metacommunicative behavior may help nurses approach their young patients more easily and with confidence.

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유리섬유/폴리프로필렌 복합재에서 섬유 함유비가 파괴특성에 미치는 영향에 대한 연구 (A Study of Fiber Content Effect on the Fracture Behavior of Glass/Polypropylene Composites)

  • 이경엽;신동혁;이중희
    • 한국자동차공학회논문집
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    • 제9권5호
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    • pp.173-178
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    • 2001
  • This study investigates the effect of fiber content on the fracture behavior of thermoplastic composites (glass fiber/polypropylene). The fiber contents used were 20%, 30%, and 40% by weight. Fracture tests were performed using compact tension (CT) specimens made of composite sheets of three fiber contents (20%, 30%, 40%). The results showed that compliance, fracture load, and fracture toughness were affected by the fiber content. The compliance decreased with fiber content while the fracture load increased as the fiber content increased. The fracture toughness also increased as fiber content increased. Specifically, the fracture toughness increased 14% as the fiber content increased from 20% to 40%.

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A modified method for corner mouth lift in scarprone patients

  • Min, Kyung Hee;Lee, Hyun Jic;Jeong, Chang Ho;Jeong, Tae Kwang
    • Archives of Plastic Surgery
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    • 제47권6호
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    • pp.622-625
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    • 2020
  • Corner mouth lift is in increasing demand among young patients in East Asia. Although various surgical methods exist for corner mouth lift, many patients are reluctant to undergo surgery due to fears of postsurgical scarring. We present a new technique aimed at reducing postoperative scarring. The technique involves triangular excision of the corner of the mouth and incision of the commissure with transposition of a lateral vermilion flap to lift the corner of the mouth. The muscle around the corner of the mouth is dissected to release tension. The corner mouth lift was successfully performed in all patients. It can be effectively used even in patients, such as young Asian women, who are susceptible to hypertrophic scars.

웹툰 이용동기와 계획행동이론 변인이 웹툰 관련 행동의도에 미치는 영향: 영화관람, 유료 콘텐츠 전환시 이용, 캐릭터 상품 구매의도의 비교 (The Influence of Webtoon Usage Motivation and Theory of Planned Behavior on Intentions to Use Webtoon: Comparison between movie viewing, switching to paid content, and intention for buying character products)

  • 이정기;이유진;김병규;김보미;최선률;구자영;바냐 콜레바
    • 커뮤니케이션학 연구
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    • 제22권2호
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    • pp.89-121
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    • 2014
  • 본 연구는 웹툰의 지속적 성장 전략을 이끌어 내기 위해 웹툰의 이용동기를 규명하고, 웹툰과 관련된 파생 문화 콘텐츠 상품 및 서비스, 즉 웹툰 기반 영화 관람의도, 웹툰 유료 전환시 구매의도, 웹툰 캐릭터 상품 구매의도를 예측해 내고자 했다. 특히 본 연구는 이용과 충족이론의 관점에서 웹툰 이용동기와 인간의 사회문화적 행동의 도를 예측하는데 유용성을 보이는 계획행동이론을 융합한 모델을 통해 웹툰 관련 행동의도 예측의 설명력을 확장해 내고자 했다. 분석결과 웹툰 이용동기는 정보 추구 동기, 오락 및 접근 용이성 동기, 웹툰의 장르적 특성 동기, 친구나 지인의 영향 동기, 현실도피 및 긴장해소 동기 등 5개로 나타났다. 웹툰 기반 영화 개봉시 관람의도에 영향을 미치는 변인은 웹툰 동기 중 웹툰의 장르적 특성 동기, 현실도피 및 긴장해소 동기, 계획행동이론의 3가지 변인인 것으로 나타났다. 웹툰 유료 서비스 이용의도에 영향을 미치는 변인은 웹툰 이용동기 중 정보 추구 동기, 오락 및 접근 용이성 동기, 웹툰의 장르적 특성 동기, 계획행동이론의 3가지 변인인 것으로 나타났다. 웹툰 기반 캐릭터 상품 구매의도에 영향을 미치는 변인은 웹툰 이용동기 중 정보 추구 동기, 현실 도피 및 긴장해소 동기, 계획행동이론 변인 중 태도와 주관적 규범인 것으로 나타났다. 본 연구는 이상의 연구결과를 바탕으로 웹툰의 지속적 성장을 위한 몇 가지 제언을 수행했다.

Induces Vasodilatation of Rat Mesenteric Artery in vitro Mainly by Inhibiting Receptor-Mediated $Ca^{2+}$ -Influx and $Ca^{2+}$ -Release

  • Cao Yong-Xiao;Zheng Jian-Pu;He Jian-Yu;Li Jie;Xu Cang-Bao;Edvinsson Lars
    • Archives of Pharmacal Research
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    • 제28권6호
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    • pp.709-715
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    • 2005
  • The purpose of this study was to investigate the effect of atropine on peripheral vasodilation and the mechanisms involved. The isometric tension of rat mesenteric artery rings was recorded in vitro on a myograph. The results showed that atropine, at concentrations greater than 1$\mu$M, relaxed the noradrenalin (NA)-precontracted rat mesenteric artery in a concentration-dependent manner. Atropine-induced vasodilatation was mediated, in part, by an endothelium-dependent mechanism, to which endothelium-derived hyperpolarizing factor may contribute. Atropine was able to shift the NA-induced concentration-response curve to the right, in a non-parallel manner, suggesting the mechanism of atropine was not mediated via the ${\alpha}_1$-adrenoreceptor. The $\beta$-adrenoreceptor and ATP sensitive potassium channel, a voltage dependent calcium channel, were not involved in the vasodilatation. However, atropine inhibited the contraction derived from NA and $CaCl_2$ in $Ca^{2+}$-free medium, in a concentration dependent manner, indicating the vasodilatation was related to the inhibition of extracellular $Ca^{2+}$ influx through the receptor-operated calcium channels and intracellular $Ca^{2+}$ release from the $Ca^{2+}$ store. Atropine had no effect on the caffeine-induced contraction in the artery segments, indicating the inhibition of intracellular $Ca^{2+}$ release as a result of atropine most likely occurs via the IP3 pathway rather than the ryanodine receptors. Our results suggest that atropine-induced vasodilatation is mainly from artery smooth muscle cells due to inhibition of the receptor-mediated $Ca^{2+}$-influx and $Ca^{2+}$-release, and partly from the endothelium mediated by EDHF.

압전소자와 광섬유센서를 이용한 케이블의 손상평가 (Estimation of Cable Damages using Piezo Disk and Optical Fiber Sensors)

  • 박강근;김이성
    • 한국공간구조학회논문집
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    • 제9권3호
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    • pp.67-74
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    • 2009
  • 가진력의 영향을 평가하기 위해 이용되는 압전소자와 물체의 변형량을 분석하기 위해 사용되는 광섬유 센서와 변형 게이지는 각종 시험과 실험에 널리 사용되고 있다. 본 연구에서는 케이블 시스템에서 발생한 손상을 검토하기 위해 압전소자와 광섬유센서를 이용하였다. 케이블 시스템은 압축이나 휨이 발생하지 않고 막구조에서 단지 인장력을 분담한다. 그러나 기존의 안전진단법을 이용하여 케이블 시스템의 손상을 판단하는 것은 전체구조의 특이한 구조거동 등으로 검토하기 어렵다. 인장부재에서 케이블의 풀림과 할렬이 발생하면 진동을 유발하기 때문에 압전소자를 케이블의 손상을 검토하기 위해 이용하였으며, 이를 광섬유 센서를 이용한 실험의 결과와 비교하였다. 본 연구는 인장응력 하에 케이블 시스템의 손상을 검토하는 방법을 제안하기 위한 실험적 연구이다.

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터널의 굴착을 위한 수직사면의 안정대책 방안 수립 및 시행 (Slope stability method establish and carry out in vertical slope for tunnel excavation)

  • 박철숙;김준용;곽한;김민조;최우경
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.992-1006
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    • 2008
  • The tunnel type spillways is under construction to increasing water reservoir capacity in Dae-am dam. Cutting-slope adjacent to outlet of spillways had been originally designed to be 63 degrees and about 65m in height. Examination is carried out in preceding construction that it is caused to some problems possibility which of machine for slope cutting couldn't approach to the site, blasting for cutting slope might have negative influence on highway and roads nearby, and fine view along the Tae-hwa river would be eliminated. In order to establish stability of tunnel and more friendly natural environment that we are carry out detailed geological surface survey and analysis of slope stability. So, we are design and construct for tunnel excavation with possible method that it is keep up natural slope. The result of survey and analysis that natural slope was divided 3 zone(A, B, C zone). In A and B zone, in first removed floating rock, high tensile tension net is install that it prevent of release and falling of rock, in order to security during under working. In addition to, pre-stressed rock anchor is install purpose of security during tunnel excavation because of fault zone near vertical developed above excavation level. Zone C is relatively good condition of ground, design is only carry out random rock bolt. All zone are designed and constructed drainage hole for groundwater and surface water is easily drain. Desinged slpoe is harmony with near natural environment. Successfully, construction is completed.

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In Silico Screening for Angiogenesis-Related Genes in Rat Astrocytes

  • Kim, Soo-Young;Lee, Sae-Won;You, Sung Yong;Rha, Sun Young;Kim, Kyu-Won
    • Genomics & Informatics
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    • 제2권1호
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    • pp.36-44
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    • 2004
  • Astrocytes play supportive roles for neurons in the brain. Recently, they have been accepted to have various functions in the vascular system as well as in the nervous system. We investigated the differential gene expression in rat astrocytes according to the oxygen tension, which is a crucial factor for angiogenesis. A cDNA microarray was performed to find the genes whose expression was sensitive to oxygen tension. We found 26 genes in the astrocyte were found and classified into 4 groups. In order to show the genes' relevancy to angiogenesis, seven of the 26 genes were investigated to see whether they have capabilities of interaction with angiogenesis­related factors in AngioDB. Through this investigation, we found interactions of three proteins with angiogenesis-related factors. These genes were further investigated with a new focus on the vascular endothelial growth factor (VEGF) expression in an astrocyte based on our hypothesis that astrocytes can have effects on endothelial angiogenesis via the release of VEGF. Collectively, we identified several genes whose expressions were dependent on the oxygen concentration of the astrocyte. Furthermore, the relevancy of astrocytes to angiogenesis was investigated using preexisting information of AngioDB, and suggested a possible signaling pathway for VEGF expression in the aspects of brain endothelial angiogenesis by astrocytes.