• Title/Summary/Keyword: relaxation times

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Elucidation of the profound antagonism of contractile action of phenylephrine in rat aorta effected by an atypical sympathomimetic decongestant

  • Rizvic, Eldina;Jankovic, Goran;Savic, Miroslav M.
    • The Korean Journal of Physiology and Pharmacology
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    • v.21 no.4
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    • pp.385-395
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    • 2017
  • Vasoconstrictive properties of sympathomimetic drugs are the basis of their widespread use as decongestants and possible source of adverse responses. Insufficiently substantiated practice of combining decongestants in some marketed preparations, such are those containing phenylephrine and lerimazoline, may affect the overall contractile activity, and thus their therapeutic utility. This study aimed to examine the interaction between lerimazoline and phenylephrine in isolated rat aortic rings, and also to assess the substrate of the obtained lerimazoline-induced attenuation of phenylephrine contraction. Namely, while lower concentrations of lerimazoline ($10^{-6}M$ and especially $10^{-7}M$) expectedly tended to potentiate the phenylephrine-induced contractions, lerimazoline in higher concentrations ($10^{-4}M$ and above) unexpectedly and profoundly depleted the phenylephrine concentration-response curve. Suppression of NO with NO synthase (NOS) inhibitor $N^w$-nitro-L-arginine methyl ester (L-NAME; $10^{-4}M$) or NO scavanger $OHB_{12}$ ($10^{-3}M$), as well as non-specific inhibition of $K^+$-channels with tetraethylammonium (TEA; $10^{-3}M$), have reversed lerimazoline-induced relaxation of phenylephrine contractions, while cyclooxygenase inhibitor indomethacin ($10^{-5}M$) did not affect the interaction between two vasoconstrictors. At the receptor level, non-selective 5-HT receptor antagonist methiothepin reversed the attenuating effect of lerimazoline on phenylephrine contraction when applied at $3{\times}10^{-7}$ and $10^{-6}M$, but not at the highest concentration ($10^{-4}M$). Neither the 5-$HT_{1D}$-receptor selective antagonist BRL 15572 ($10^{-6}M$) nor 5-$HT_7$ receptor selective antagonist SB 269970 ($10^{-6}M$) affected the lerimazoline-induced attenuation of phenylephrine activity. The mechanism of lerimazoline-induced suppression of phenylephrine contractions may involve potentiation of activity of NO and $K^+$-channels and activation of some methiothepin-sensitive receptors, possibly of the 5-$HT_{2B}$ subtype.

Influence of Bornyl Acetate on Blood Pressure and Aortic Strips Contractility of the Rat

  • Lim, Dong-Yoon;Ki, Young-Woo;Na, Gwang-Moon;Kang, Moo-Jin;Kim, Byeoung-Cheol;Kim, Ok-Min;Hong, Soon-Pyo
    • Biomolecules & Therapeutics
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    • v.11 no.2
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    • pp.119-125
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    • 2003
  • The present study was conducted to investigate the effects of bornyl acetate on arterial blood pressure and vascular contractile responses in the normotensive rats and to establish the mechanism of action. Both phenylephrine (an adrenergi$\alpha$-receptor agonist) and high potassium (a membrane-depolarizing agent) caused greatly contractile responses in the isolated aortic strips. These phenylephrine (10$^{-5}$ M)-induced contractile responses were depressed in the presence of high concentrations of bornyl acetate (10∼20 $\mu\textrm{g}$/ml), but not affected in low concentrations of bornyl acetate (2.5∼5$\mu\textrm{g}$/ml). High potassium (5.6 ${\times}$ 10$^{-2}$ M)-induced contractile responses were also greatly inhibited in the presence of bornyl acetate (2.5∼20 $\mu\textrm{g}$/ml) in a dose-dependent fashion. Bornyl acetate (1∼10 mg/kg) given into a femoral vein of the normotensive rat produced a dose-dependent depressor response, which is transient (data not shown). Interestingly, the infusion of a moderate dose of bornyl acetate (3mg/kg/30 min) made a significant reduction in pressor responses induced by intravenous norepinephrine. Collectively, these results obtained from the present study demonstrate that intravenous bornyl acetate causes a dose-dependent depressor action in the anesthetized rat at least partly through the blockade of adrenergic $\alpha$$_1$-receptors. bornyl acetate also causes vascular relaxation in the isolated aortic strips of the rat via the blockade of adrenergic $\alpha$$_1$-receptors, in addition to the unknown mechanism of direct vasorelaxation.

The Analysis of Drainage Time and Resolution of the Quasi-dynamic and Dynamic Wetness Index (배수시간과 격자크기와 반동력학적 또는 동력학적 습윤지수에 대한 연구)

  • Kim, Sang-Hyun;Han, Ji-Young;Lee, Ga-Young;Kim, Nam-Won
    • Journal of Korea Water Resources Association
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    • v.36 no.6
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    • pp.949-960
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    • 2003
  • The resolution issue of wetness index with relaxation of the steady state assumption is explored on the platform of Digital Elevation Model (DEM). The variabilities of the quasi-dynamic wetness index and the dynamic wetness index are discussed on the base of the spatial and statistical aspects depending upon resolutions of DEM and the drainage time. The organization patterns of the wetness index can be observed upon various drainage times and pixel size. The transient behaviour of wetness patterns of the Sulmachun watershed are shown in the relatively short drainage time. The statistical analysis of the quasi-dynamic and dynamic wetness analysis provide the convergence of analysis results to the steady state characteristics later than 10,000 hours drainage time. The probability density functions of the quasi-dynamic and the dynamic wetness index shows the existence of the threshold pixel size of DEM which provide stability and consistency in the computation result of these two wetness index.

A Survey of the Role of Thalassotherapy Program in SPA Salon (스파살롱내 딸라소테라피 프로그램에 대한 연구)

  • Hong, Ran-Hi;Heo, Eun-Young
    • Journal of the Korean Society of Fashion and Beauty
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    • v.4 no.1 s.7
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    • pp.51-59
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    • 2006
  • Today, SPA fills many of the same needs as they did thousands of years ago, including relaxation, wellness and stress relief by incorporating many of the same methods embraced by the ancients such as a multitude of hydrotherapy treatments, thalassotherapy and massage therapy, one of the most widely used SPA treatments. The definition is as follows: SPA is entities devoted to enhancing overall well-being through a variety of professional services that encourage the renewal of mind, body and spirit. It was from here that the concept of modernday SPA evolved, incorporating full health and beauty services along with sport, aquatic and rest facilities. Todays SPA, a absolute concept, is being specialized and spread as fast as undefinable just in a word. Thalassotherapy, a kind of SPA therapy, contains minerals and trace elements. Born more than 4,000 years ago in ancient Egypt, thalassotherapy comes from the Greek words for thalasso(sea water) and therapeia(to heal). Thalassa was the Greek personification of the Mediterranean Sea that surrounded them and gave them so much of their sustenance. It helps to nourish, hydrate and refine skin texture and also eliminate metabolic waste and toxins in the body. Thalassotherapy is recommended for post-natal and postsurgery recovery period, chronic fatigue, circulatory problems, cellulite control and dermatological problems. It's also possible to enjoy the thalassotherapy SPA as a day guest. Be sure to try the jansu massage, given in the heated sea water pool. As a trained therapist gently whisks clients through the womb-warm water, clients can practically feel the toxins leave their body. Many women from all over the world have been kept up beautiful skin with applying thalassotherapy to their faces and bodies since long times and these days in France, they are getting great curative clinical effects from renovative and scientific technological combination. Thus thalassotherapy will be absolutely ultimate form of natural healing which can keep and recover human's health and beauty.

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Efficient Design of Plate Spring for Improving Performance of Sound Wave Vibration Massage Chair (음파진동 안마의자제품의 성능향상을 위한 판스프링의 효율적 설계)

  • Kim, Chang-Gyum;Park, Soo-Yong;Jo, Eun-Hyeon;Lee, Dong-Hyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.42 no.4
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    • pp.1-7
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    • 2019
  • The customer of massage chair is expanding day by day from middle age to all ages. In 2018, the market size was 700 billion KRW, an increase of 30 times over 10 years. However, most related SMEs suffer from excessive competition by the market monopoly of some major companies. In this situation, in order for a related company to survive, it is necessary to steadily research and develop new products. Founded in 2009, company L produces massage chairs for health and relaxation of customers. L's products use a sound wave vibration module that is favorable for human body, unlike other products that use vibration motor type. However, frequent breakdowns of massage chair due to the vulnerability of plate (leaf) springs, which play an important role in sound wave vibration modules, made sap its competitiveness. In this paper, we propose a method to design desirable plate spring structure by sequentially experimenting with five different plate springs. The results of this study are expected to contribute to improve the quality of plate spring and the reliability of sound wave vibration module. In the future, it is necessary to find a way to use it in the development of foot massage or scalp management device as well as continuous research to find optimal plate spring structure through various analysis.

Analysis of Creep Effective Stress in Austenitic Heat Resistant Steel (오스테나이트계 내열강의 크리프 유효응력 해석)

  • Nam, Ki-Woo;Park, In-Duck
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.7
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    • pp.1317-1323
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    • 2002
  • This paper describes the comparison of calculated effective stress with experimental one in austenitic heat resistant steels, STS310J1TB and STS310S with and without a small amount of Nb and N. Based on a solute atoms diffusion model, contribution from soluble nitrogen to the high-temperature strength was numerically examined for austenitic heat-resisting Fe-Cr-Ni-N(STS310J1TB) and Fe-Cr-Ni (STS310S) alloys. The solute atmosphere dragging stress of dislocation was calculated in optional dislocation velocity of STS310J1TB and STS310S at $650^{\circ}C$, $675^{\circ}C$ and $700^{\circ}C$. As a result of the numerical calculation, the solute atmosphere dragging stress of STS310J1TB was about 50 times larger than that of STS310S. When the temperature became high, the maximum value of solute atmosphere dragging stress was small and the velocity of moving dislocation was fast. From the relationship between the dislocation rate and the solute atmosphere dragging stress, the relation of both was proportional and the inclination is about 1 in the level with low velocity of moving dislocation. From above results, the mechanism of dislocation movement in STS310J1TB was the solute atmosphere dragging stress. The solute atmosphere dragging stress, which was calculated from the numerical calculation was close to the effect stress in stress relaxation tests.

Development and Field Application of Psychological services to Decrease Stage-Anxiety of Actor (배우의 무대불안극복을 위한 심리적 중재 프로그램 개발 및 고찰)

  • Oh, Jin-Ho
    • The Journal of the Korea Contents Association
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    • v.12 no.1
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    • pp.234-243
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    • 2012
  • The purpose of this study was to develop psychological skill training program for actor with considering the ecological validity of social, cultural environment in Korean but also examine the effect of psychological skill training through psychological counseling and field study to decrease stage-anxiety. The experimental group were 2 actors, who were selected by purposive sampling. The psychological skill training program to decrease stage-anxiety for actor was composed of five stages, 12times and categorized as orientation, breathing regulation, progressive relaxation training, group counseling, heart rate bio-feedback training, self concentration, routine training, behavior therapy & self reinforcement, image training. The effects was examined on stage performance anxiety scale, psychological counseling and observation of experts. As the result of applying the psychological skill training to decrease stage-anxiety, cognitive state anxiety, somatic state anxiety were decreased. According to the result of counseling and observation, they were changed affirmative on self confrontation, harmony and rapport between actor and object. This result demonstrated the psychological skill training & counseling to decrease stage-anxiety for actor were effective.

Muscle Properties Analysis of SCM Muscle using Smartphone postures (자세유형별 스마트폰 사용에 따른 목빗근의 근육 속성 분석)

  • Kim, In-Suk;Kim, Kyun-Young;Park, Sang-Gwan;Choi, Young-Woo;Noh, Han-Na;Kim, Jin-A
    • Journal of Korean Clinical Health Science
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    • v.5 no.4
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    • pp.991-997
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    • 2017
  • Purpose. The purpose of this study was to muscle properties analysis of SCM(sternocleidomastoid) Muscle according to posture type when using smartphone. Methods. This study was conducted on 73 college students who are using smartphone. Subjects were analyzed myotonPRO to confirm, prone posture group, stand posture group, drop head above $45^{\circ}$in sit posture on a chair group and drop head below $45^{\circ}$in sit posture on a chair group were measured SCM muscle. The myotonPRO were measured one measurer, total 3 times. Comparative analysis of the each groups were investigated of SCM muscle properties. Results. We found that Frequency, Stiffness, Creep and Relaxation were appeared difference in each posture. F index was increased at drop head below $45^{\circ}$group than stand posture group. S index was increased at drop head above $45^{\circ}$group than prone posture group. C index was decreased at drop head below $45^{\circ}$group and drop head above $45^{\circ}$group than prone posture group. R index was decreased at drop head above $45^{\circ}$group than prone posture group. Conclusions. The muscle properties were appeared difference in each posture of SCM muscle using smartphone.

A Study on the Aesthetic Thought and Expression Tendency of Contemporary Architecture from the Concept of the Uncanny (언캐니 개념으로 바라 본 현대건축의 미적사유와 표현경향 연구)

  • Park, Kyoung-Ah
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.164-173
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    • 2013
  • This study aims to analyze the aesthetic thought and expression tendency appeared in contemporary architecture by looking at today's architectural art based on the concept of the uncanny that Sigmund Freud contended as an aesthetic principle, of the aesthetic concepts tossed around to define the contemporary times in the aesthetics field and discuss the architectural analysis possibility of the concept of the uncanny. The generation structure of the uncanny that generates experiences of fear and surprise is classified into dual structure, trauma, threatening structure, and repetition compulsion. This is the principle that evokes a sense of experiencing subject, incorporates sensibility, and vitalizes internal process. This is also the methodology to organize and structure the concept of the uncanny. When seen from the four factors drawn from the concept of the uncanny and aesthetic expressions, the uncanny expression characteristics of contemporary architecture includes isolation, subversion, trace, absence, oblique line, flotation, concealment, and disturbance. Isolation and subversion refers to producing the space of the pressure of tension and relaxation caused by repression and relief from repression and eliciting the maximum expansion of the sense of space through spatial change. Trace and absence indicates being able to elicit more intense emotions from the experiencing subject by applying the images of alienation and absence in the way to reproduce historical trauma. This happens by implementing the potential value of physical activity. Oblique line and flotation means visual impulse. This happens in the way to visualize uneasy points. This causes uncanny by threatening the survival. Finally, concealment and disturbance refers to creating unpredictable space. The concept of masquerade and maze space composition are applied in the way to activate spatial perception, including space exploration and unintended subject's forced selection. As stated above, the uncanny expression characteristics shown in contemporary architecture can be presented as indicators that are available to analyze the undecided and diversified contemporary architecture aesthetically. In this respect, this study has great significance.

Effect of aggregation on shear and elongational flow properties of acrylic thickeners

  • Willenbacher, N.;Matter, Y.;Gubaydullin, I.;Schaedler, V.
    • Korea-Australia Rheology Journal
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    • v.20 no.3
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    • pp.109-116
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    • 2008
  • The effect of intermolecular aggregation induced by hydrophobic and electrostatic interactions on shear and elongational flow properties of aqueous acrylic thickener solutions is discussed. Complex shear modulus is determined at frequencies up to $10^4$ rad/s employing oscillatory squeeze flow. Extensional flow behavior is characterized using Capillary Break-up Extensional Rheometry. Aqueous solutions of poly(acrylic acid)(PAA)/poly(vinylpyrrolidone-co-vinylimidazole) (PVP-VI) mixtures exhibit unusual rheological properties described here for the first time. Zero-shear viscosity of the mixtures increases with decreasing pH and can exceed that of the pure polymers in solution by more than two orders of magnitude. This is attributed to the formation of complexes induced by electrostatic interactions in the pH range, where both polymers are oppositely charged. PAA/PVP-VI mixtures are compared to the commercial thickener Sterocoll FD (BASF SE), which is a statistical co-polymer including (meth) acrylic acid and ethylacrylate (EA) forming aggregates in solution due to "sticky" contacts among hydrophobic EA-sequences. PAA/PVP-VI complexes are less compact and more deformable than the hydrophobic Sterocoll FD aggregates. Solutions of PAA/PVP-VI exhibit a higher zero-shear viscosity even at lower molecular weight of the aggregates, but are strongly shear-thinning in contrast to the weakly shear-thinning solutions of Sterocoll FD. The higher ratio of characteristic relaxation times in shear and elongation determined for PAA/PVP-VI compared to Sterocoll FD solutions reflects, that the charge-induced complexes provide a much stronger resistance to extensional flow than the aggregates formed by hydrophobic interactions. This is most likely due to a break-up of the latter in extensional flow, while there is no evidence for a break-up of complexes for PAA/PVP-VI mixtures. These flexible aggregates are more suitable for the stabilization of thin filaments in extensional flows.