• Title/Summary/Keyword: TENSION RELEASE

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

  • Kim N.D.;Kang S.Y.
    • Proceedings of the Ginseng society Conference
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    • 1993.09a
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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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Effects of Potassium Ion and Caffeine on Contraction and Cytosolic Free $Ca^{2+}$ Levels in Vascular Smooth Muscle (혈관평할근 세포에서의 칼륨이온과 카페인의 영향: 수축과 세포내 칼슘이온 농도에 대하여)

  • Ahn, H.Y.;Karaki, H.
    • The Korean Journal of Pharmacology
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    • v.24 no.2
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    • pp.197-201
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    • 1988
  • Effects of high concentration of KC1 and caffeine on cytosolic $Ca^{2+}$ level $([Ca^{2+}]_{cyt})$, measured simultaneously with muscle tension using a fluorescent intracellular $Ca^{2+}$ indicator fura 2, were examined in isolated smooth muscle of rat aorta. High $K^+$ (72.7 mM) solution induced sustained increase in both $([Ca^{2+}]_{cyt})$ and tension. In contrast to this, caffeine (20 mM) induced a rapid increase in $([Ca^{2+}]_{cyt})$ followed by a decrease to a level which was higher than the resting level. However, muscle tension showed only a transient increase followed by a decrease below the resting level. In a $Ca^{2+}-free$ solution, high $K^+-induced$ neither $([Ca^{2+}]_{cyt})$ nor tension, whereas caffeine induced a transient increase in both $([Ca^{2+}]_{cyt})$ and muscle tension. These results suggest that high $K^+-induced$ contraction in vascular smooth muscle of rat aorta is due to $Ca^{2+}$ influx whereas caffeine-induced contraction is due to $Ca^{2+}$ release from cellular store. Further, caffeine seems to have an additional effect to decrease the sensitivity of the contractile elements to $Ca^{2+}$.

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Analysis of Metacommunicative Episodes between Nurses and Children

  • Shin, Hyun-Sook
    • Child Health Nursing Research
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    • v.15 no.1
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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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A Study of Fiber Content Effect on the Fracture Behavior of Glass/Polypropylene Composites (유리섬유/폴리프로필렌 복합재에서 섬유 함유비가 파괴특성에 미치는 영향에 대한 연구)

  • 이경엽;신동혁;이중희
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.5
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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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    • v.47 no.6
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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.

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 (웹툰 이용동기와 계획행동이론 변인이 웹툰 관련 행동의도에 미치는 영향: 영화관람, 유료 콘텐츠 전환시 이용, 캐릭터 상품 구매의도의 비교)

  • Lee, Jeong Ki;Lee, You Jin;Kim, Byung Gue;Kim, Bo Mi;Choi, Sun Ryul;Koo, Ja Young;Koleva, Vanya Slavche
    • Korean Journal of Communication Studies
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    • v.22 no.2
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    • pp.89-121
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    • 2014
  • In order to suggest a strategy for continuous growth of webtoon, this article examined webtoon usage motivation and tried to make a prediction about culture content products and services connected with webtoon, including intention for viewing movies, based on webtoon; intention for switching to paid webtoon content, and intention for buying webtoon character products. From the point of view of Uses and Gratification Theory intentions for using webtoon and human sociocultural behavior intention are already predicted but with the usefulness of Theory of Planned Behavior Integrated Model this study extended the explanation power of prediction about webtoon related behavioral intention. Results found 5 motivational factors for webtoon usage i.e. 'seeking information', 'entertainment and access availability', 'webtoon genre characteristics', 'influence from a friend or acquaintance', and 'escapism and tension release'. Among them the ones that influenced the intention for viewing movies, based on webtoon, were found to be 'webtoon genre characteristics', 'escapism and tension release' and the 3 variables from Theory of Planned Behavior. 'Seeking information', 'entertainment and access availability', 'webtoon genre characteristics', and all the 3 variables from Theory of Planned Behavior were found to influence the intention for switching to paid webtoon content. The intention for buying webtoon based character products was affected by the motivational factors 'seeking information', 'escapism and tension release' and the behavior and subjective norms variables from Theory of Planned Behavior. Based on the uncommon results from the research several suggestions were made for the continuous growth of webtoon.

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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    • v.28 no.6
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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.

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

  • Park, Kang-Geun;Kim, Ie-Sung
    • Journal of Korean Association for Spatial Structures
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    • v.9 no.3
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    • pp.67-74
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    • 2009
  • Presently means of utilizing sensors such as Piezoelectric(PZT) Element for evaluating the affect of oscillator, strain gauge for analyzing physical changes and use of Fiber Bragg Grating(FBG) Sensor are widely practiced in the field. In this study, PZT and FBG sensors were used to tearing damage of cable systems in these sensors. Cable systems are a construction of elements carrying only tension and no compression or bending in membrane structure. But damage detection of cable systems by using existing safety diagnosis is difficult to detect the characteristic change of overall structural action. If cable snaps are occurred to cable release and tear in tension structures, these are set up a vibration. So, we used piezo-electric materials and result of experiment using this was compared with result of experiment using FBG sensors The purpose of this research is to develop of damage detection method of cable system in tensile stress.

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

  • Park, Chal-Sook;Kim, Jun-Yong;Kwan, Han;Kim, Min-Jo;Choi, Yu-Kyung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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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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    • v.2 no.1
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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.