• Title/Summary/Keyword: Pressure relaxation

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Effect of Korean Red Ginseng on Rabbit and Rat Corpus Cavernosal Smooth (고려인삼 복용이 토끼 및 횐쥐의 음경해면체 평활근에 미치는 효과)

  • 최영득;마상열
    • Journal of Ginseng Research
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    • v.21 no.2
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    • pp.98-103
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    • 1997
  • On the precontracted rabbit cavernosal muscle strips with phenylephrine ($5\ast10^{-6}$M), Increasing concentrations of acetylcholine (10-7, 10-6, 10-5, 10-4M) showed relaxation effect dose-dependently in control group ($10^{-7}$M : 15.32%, $10^{-6}$M : 35.44%, 10-5M : 59.45%, 10-4M : 76.54%). After 3 months administering Korean red ginseng, the relaxation action of acetylcholine was significantly increased ($10^{-7}$M : 34.18%, $10^{-6}$M : 56.35%, $10^{-5}$M : 75.33%, $10^{-4}$M : 89.86%). Relaxation effect of Korean red ginseng was significantly increased after 3 months administering Korean red ginseng. Intracavernous pressure response to electrostimulation wan 107.52 cm$H_2O$ in control group and significantly increased to 138.34 cm $H_2O$ after 3 month administering Korean red ginseng. With these results, we can confirm that long-term administration of Korean red ginseng enhances the erectly capacity and that its action is mediated by endothelium derived relaxing factor and peripheral neurophysiologic enhancement.

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Effects of 3D Compression Suits on EEG Analysis during and after Walking (운동 중과 휴식 시 3D 컴프레션 수트 착용에 따른 정량적 뇌파 분석)

  • Choi, Jiyoung;Kim, Namyim;Wu, Yanjun;Hong, Kyunghi
    • Journal of the Korean Society of Clothing and Textiles
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    • v.38 no.4
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    • pp.440-454
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    • 2014
  • This study examined the wearing effect of 3D compression suits on quantitative electroencephalogram (EEG) during walking and rest. Ten males in their 20s wore three types of experimental clothing, a loose-fit wear (BS), a 3D compression suit (3D CS), and a power film welded on CS (3D WCS); in addition, EEG signals were measured during resting, walking, after walking, and after sit-ups. The results showed that a higher pressure (due to 3D CS and 3D WCS) increased the 'Concentration' level and the 'Cognitive load' of brain waves during treadmill walking due to a higher cortex activity level when walking. Differentiation was shown between two compression suits and BS was enhanced during walking on a treadmill; however, the brain waves of 'Relaxation' between two compression suits were significantly different after walking, i.e., 'Relaxation' level of 3D WCS was the highest. Rigorous exercise such as sit-ups was inefficient to distinguish the effect of compression suits on EEG. Participants perceived a higher pressure due to compression suits; however, the wear comfort of two compression suits was maintained. Two compression suits were rated as supportive and helpful during walking. Various EEG parameters such as the indices of 'Relaxation', 'Concentration' and 'Cognitive load' were effective to observe the effect of 3D compression suits on wearers' brain waves during and after walking.

Mechanism of the relaxant action of imipramine in isolated rat aorta (흰쥐 대동맥에서 imipramine의 혈관이완 작용기전)

  • Kang, Hyung-sub;Lee, Sang-woo;Baek, Sung-su;Joe, Sung-gun;Kim, Jin-shang
    • Korean Journal of Veterinary Research
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    • v.43 no.4
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    • pp.597-606
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    • 2003
  • Although the antidepressant effects of imipramine (IMI) have been well known in several studies, the effects on cardiovascular system, particularly the vasorelaxant effects, have not known clearly. We hypothesis that IMI-induced vasorelaxation involves NO (nitrie oxide), activation of guanylate cyclase (GC) and $Ca^{2+}$ channel. The possible roles of the endothelium and $Ca^{2+}$ in IMI-induced responses were investigated using isolated rings of rat thoracic aorta and anesthesized rats. In KCl-precontracted rings. IMI produces endothelium-dependent and endothelium-independent relaxations in intact (+E) as well as endothelium-denuded (-E) rat aorta in a concentration-dependent manner. In phenylephrine (PE)-precontracted rings, the IMI-induced relaxation was significantly greater in +E rings. The IMI-induced relaxations were suppressed by nitric oxide synthase (NOS) inhibitors, N(G)-nitro-L-arginine (L-NNA), N(omega)-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine, a non-selective GC inhibitor, methylene blue, $Na^+$ channel blockers, lidocaine and procaine, or $Ca^{2+}$ channel blockers, nifedipine and verapamil, in PE-precontracted +E rings, but not in PE-precontracted -E rings. These relaxations were also suppressed by lidocaine or procaine in -E aortic rings. However, IMI-induced relaxations were not inhibited by a PLC inhibitor 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC), an inositol monophosphatase inhibitor, lithium, indomethacin and dexamethasone in +E and -E rings. In vivo, infusion of IMI elicited significant decrease in arterial blood pressure. After intravenous injection of saponin, NOS inhibitors. MB and nifedipine, infusion of IMI inhibited the IMI-lowered blood pressure markedly. These findings suggest that the endothelium-dependent relaxation induced by IMI is mediated by activation of NO/cGMP signaling cascade or inhibition of $Ca^{2+}$ entry through voltage-gated channel, and this mechanism may contribute to the hypotensive effects of IMI in rats.

Study on the Time Dependent Stress-Strain Behavior of Clay (점성토의 시간의존적 응력 - 변형 특성에 관한 연구)

  • 지인택;강우묵
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.4
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    • pp.134-153
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    • 1988
  • This paper was carried out to investigate the existence of a unique stress- strain behavior by obtaining some factors influencing the time dependent stress- strain behavior of clay. The results obtained from this study were summarized as follows ; 1. The relationship between stress ratro and strain in normally consolidated clay was in- dependent on pre-shear consolidation pressure. Therefore, shear strain could be expressed as a function with stress ratio. 2. The constitutive equation of shear strain on Modified Carn Clay Model coincided better with the observed value than Cam Clay Model. 3. The relationships between deviator stress and shear strain, between pore water pressure and shear strain were unified by the mean equivalent pressure. 4. The shear strain contour in norrnally consolidated clay was increased linearly through origin, but that in overconsolidated clay was not in accordance with the result of the former. 5. Because the effective stress path of normally consolidated clay was unified by the mean equivalent pressure, state boundary surface in (e,p,q) space was transformed into two dimensional surface. But it was considered to be suitable that the unified stress- strain in overconsolidated clay be expressed by a function with overconsolidation ratio. 6. The deviator for constant strain was increased linearly with increment of strain rate ($\varepsilon$) on semi-log scale, but pore water pressure was decreased. 7. The behavior of stress relaxation was transformed from linear to curvilinear with inc - rement of strain rate before stress relaxation test, and pore water pressure was increased in total range. 8. The strain of creep was increased linearly with increment of time on semi-log scale. The greater the strain rate before creep test became, the greater the increment of strain of creep became. And the pore water pressure during creep test was increased generally with increment of time on semi-log scale.

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Effects of Samyoo-tang Extract on Pulmonary Artery and Cerebral Blood Flow in Rabbits and Rats (삼요탕이 폐혈관 및 뇌혈류량에 미치는 영향)

  • 이원중;고영철;박병민;신조영;이시형
    • The Journal of Korean Medicine
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    • v.23 no.3
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    • pp.63-73
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    • 2002
  • Objective : This study aimed to investigate the effects Samyoo-tang Extract (SE) on the vascular systems, including changes in blood pressure and regional cerebral blood flow (rCBF), of male Sprague-Dawley rats. Methods : The changes in rCBF were determined by Laser-Doppler flowmetry through the opened cranial method and norepinephrine (NE)-induced blood vessel contractions were determined by physiograph in the pulmonary artery of isolated rabbits. Results and Conclusion : 1. Contractions evoked by NE ($ED_{50}$) were inhibited significantly by SE in the pulmonary artery. 2. SE inhibited the relaxation of NE induced contractions pretreated with propranolol. 3. SE did not inhibit the relaxation of NE induced contractions pretreated with ODQ and L-NNA. 4. Blood pressure was not affected by SE in rats. 5. rCBF was increased by SE in a dose-dependent manner. 6. Pretreatment with propranolol was increased by SE in a dose-dependent manner in blond pressure. 7. Pretreatment with methylene blue, ODQ and L-NNA did not inhibit SE induced increased in rCBF. These results indicate that SE can relax NE-induced contraction of rabbit blood vessels and increased the changes of rCBF in rats, that relate to the sympathetic nerve system.

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Crystal properties of wurtzite GaN grown under various nitrogen plasma conditions (여러 질소 플라즈마 상태에서 성장한 wurtzite GaN의 결정특성)

  • 조성환;김순구;유연봉
    • Journal of the Korean Vacuum Society
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    • v.6 no.4
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    • pp.354-358
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    • 1997
  • Crystal properties of wurtzite GaN films grown on $Al_2O_3$(0001) substrates under various nitrogen pressure and plasma power by electron cyclotron resonance molecular beam epitaxy were investigated by full width at half maximum of X-ray diffraction peak and scanning electron microscope. It was found that the nitrogen pressure has a large effect on the FWHM value of XRD, and the GaN film grown under the optimum nitrogen pressure contains high density of dislocations. These results suggest that the crystal quality is sensitive to the plasma source conditions and that the relaxation of stress depends of V/III ratio. However, substrate-surface nitridation has little effect on the relaxation of misfit stress.

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Dielectric Relaxation Properties of DMPC Organic Thin Films for Nanotechnology (나노기술을 위한 DMPC 유기박막의 유전완화특성)

  • Chol, Young-Il;Cho, Su-Young
    • 전자공학회논문지 IE
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    • v.49 no.1
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    • pp.7-11
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    • 2012
  • In this paper, evaluation of physical properties about dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of phospolipid monomolecular DMPC using pressure stimulus. As a result, It is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area. When electric bias is applied across the manufactured MIM device by the deposition condition of phospolipid monomolecular, it is found that be characteristic of insulation generated it wasn't breakdown when the higher electric field to impress by increase of deposition layers.

Effect of Progressive Muscle Relaxation using Biofeedback on Perceived Stress, Stress Response, Immune Response and Climacteric Symptoms of Middle-Aged Women (바이오피드백을 이용한 점진적 근육이완이 중년여성의 지각된 스트레스, 스트레스반응, 면역반응 및 갱년기 증상에 미치는 효과)

  • 정인숙
    • Journal of Korean Academy of Nursing
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    • v.34 no.2
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    • pp.213-224
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    • 2004
  • Purpose: This study was aimed to evaluate the effect of progressive muscle relaxation training using biofeedback on perceived stress, stress response, immune response and climacteric symptoms, Method: This was a crossover, pre-post test design, The study subjects are 36 middle-aged women who were selected at 2 public health centers, The independent variable was Biofeedback training for 4 weeks, twice a week and home training for 4 weeks, Dependent variables were perceived stress, stress response, immune response, and climacteric symptoms measured with Hildtch's scale (1996), Result: Progressive muscle relaxation training using biofeedback was not effective in reducing perceived stress, but it was shown to be effective in reducing physiological stress responses such as pulse rate and EMG, Though blood pressure and skin conductance were repeatedly down, and skin temperature slowly increased, there were no statistically significant differences. Progressive muscle relaxation training using biofeedback was not effective in reducing serum cortisol, enhancing immune responses, or decreasing climacteric symptoms. Conclusion: The findings point to a pressing need for further, well-controlled and designed research with consideration in selection of subjects and instruments, frequency of measurements, the sampling method, and intervention modalities.

Ginsenosides Evoke Vasorelaxation in Rat Aortic Rings: Involvement of $Ca^{2+}$-dependent $K^+$ Channels

  • Nak Doo Kim;Soo
    • Proceedings of the Ginseng society Conference
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    • 1998.06a
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    • pp.182-189
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    • 1998
  • Administration of ginsenosides, a mixture of saponin extracted from Panax ginseng, decreased blood pressure in rat. Previous studies have shown that ginsenosides caused endothelium-dependent relaxation, which was associated with the formation of cyclic GMP, suggested that ginsenosides caused release of nitric oxide (NO) from the vascular endothelium. The aim of the present study was to characterize the endothelium-independent relaxation to ginsenosides in the isolated rat aorta. Ginsenosides caused a concentration-dependent relaxation of rat aortic rings without endothelium constricted with 25 mM KCI but affected only minimally those constricted with 60 mM KCI. Ginsenoside Rg3 (Rg3) was a more potent vasorelaxing agonist than total ginsenoside mixture and also the ginsenoside PPT and PPD groups. Relaxation to ginsenosides were markedly reduced by TEA, but not by glibenclamide. Rg3 significantly inhibited Cal'-induced concentration-contraction curves and the "50a2'influx in aortic rings incubated in 25 mM KCI whereas those responses were not affected in 60 mM KCI. Rg3 caused efflux of $"Rb in aortic rings that was inhibited by tetraethy- lammonium (TEA), an inhibitor of Ca"-dependent K'channels, but not by glibenclamide, an inhibitor of AfP-dependent K'channels. These findings indicate that ginsenosides may induce vasorelaxation via activation of Ca2'-dependent K'channels resulting in hyperpolarization of the vas- cular smooth muscle with subsequent inhibition of the opening of voltage-dependent Caf'channels. These effects could contribute to explain the red ginseng-associated vasodilation and the beneficial effect on the cardiovascular system.

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A Study on Earth Pressure Calculating Method about Shield TBM Tunnel Segments in the Rock (암반층에서 쉴드 TBM 터널 세그먼트의 작용하중 산정방법에 관한 연구)

  • Chun, Byungsik;Ki, Jungsu;Kang, Taehee;Kwag, Yunehyeong;Byun, Yoseph
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.5
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    • pp.13-21
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    • 2014
  • This study analyzed the differences in the analysis techniques through a comparative analysis of the various segment's modeling techniques of Shield TBM method and proposed reasonable modeling techniques. Also, this study suggested reasonable estimating methods of load to be applicable in the field through the load analysis and three-dimensional finite element analysis by estimating model of rock mass relaxation load. Estimating method of relaxation area by rock mass rating makes no odds of output in subgrade with high rock mass rating, but so the difference of output is large, that is judged to set conservative design off. In estimating result of rock mass relaxation area by three-dimensional analysis relaxation area of subgrade with low-grade soil was predicted to be positioned at medium-range of many methods, in case of designing segment in subgrade with low-grade soil it needs to actively review estimation of relaxation area through three-dimensional analysis reflecting mechanical tunnel excavation.