• 제목/요약/키워드: pressure effects

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Effects of Intracerebroventricular Captopril on the Central Pressor Response to Bradykinin in Normotensive and Hypertensive Rats

  • Yeum, Cheol-Ho;Yoon, Pyung-Jin
    • The Korean Journal of Physiology
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    • 제28권2호
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    • pp.191-196
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    • 1994
  • Captopril, an inhibitor of angiotensin converting enzyme, is also known to inhibit the degradation of bradykinin. We examined the effects of intracerebroventricular (ICV) captopril on the central pressor response to bradykinin in normotensive, 2-kidney, 1 clip Goldblatt (GHR) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Captopril (1 mg) and bradykinin (5 nmol) were administered into the right lateral cerebral ventricle, and blood pressure and heart rate were continuously monitored throughout the experiment. ICV captopril alone did not affect the blood pressure within 10 minutes but it significantly augmented the central pressor response to bradykinin in GHR. On the contrary, captopril was without effect on the pressor response to bradykinin in normotensive and DOCA-salt rats. These findings indicate that endogenous kinins are not critical in regulating arterial pressure in normotensive and DOCA hypertensive rats. However, in GHR, an enhanced activity of the brain kallikrein-kinin system in maintaining the high blood pressure is suggested.

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표고버섯의 급여가 SHR 흰쥐의 혈압 및 혈청 지질 수준에 미치는 영향 (Supplementary Effect of Lentinus Edodes on Serum and Hepatic Lipid Levels in Spontaneously Hypertensive Rat)

  • 이성현;박홍주;조소영;정현진
    • Journal of Nutrition and Health
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    • 제37권7호
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    • pp.509-514
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    • 2004
  • This study was conducted to investigate the supplementary effects of Lentinus edodes on blood pressure and blood lipid levels in the Hypertensive Rat. We supplied 3 kinds of experimental diets (Control; CO, cap of Lentinus edodes; LC, and stipe of Lentinus edodes; LS) to spontaneously hypertensive rats (SHR) for 8 weeks. Diet intake, body weight, organ weights, and serum lipid levels were measured. There was no significant difference in diet intake, and body, liver and epididymal fat pad weights among experimental groups. The levels of systolic and diastolic blood pressure were significantly lower in LC and LS groups than CO group. The concentrations of serum total cholesterol were lower in LC and LS groups than CO group. These results suggested that Lentinus edodes decrease blood pressure levels and serum total cholesterol concentration in the spontaneously hypertensive rats. But these effects of Lentinus edodes didn't show any significant difference between animals fed cap and stipe of this mushroom.

압력 용기 도옴의 형상 및 두께 변화에 따른 비선형 응력해석 (Nonlinear Stress Analysis of Pressure Vessel for Various Dome Shapes and Thicknesses)

  • 이영신;조원만;구송회
    • 대한기계학회논문집
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    • 제17권10호
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    • pp.2634-2645
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    • 1993
  • Dome structures of pressure vessels subjected to internal pressure are usually analyzed by linear elastic theory assuming small deformation. Geometric and material nonlinear behaviors appear in actual dome structures because of large deformation and loads exceeding yield strength. In this paper, linear and nonlinear analyses were performed for various hemispherical and torispherical domes to check the effects of geometric and material nonliearity on the stress and displacement by the finite element method. The effect of the geometric nonlinearity decreased the stress levels a lot for very thin general torispherical domes, which enables more realistic and effective design. The material nonlinear effects are negligible for hemispherical and optimum torispherical domes, and those are large for most of the general torispherical domes.

KI-60606의 일반약리작용시험 (General Pharmacology of KI-60606)

  • 김은주;김현진;김동연
    • Biomolecules & Therapeutics
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    • 제10권2호
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    • pp.89-98
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    • 2002
  • In this study general pharmacological profiles of KI-60606 on the central nervous system, the cardiovascular system and the other organs were investigated. The dosages given were 0,5, 10 and 25 mg/kg and drugs were administered intravenously. The animals used for this study were mice, rats, cats and guinea pigs. KI-60606 showed no effects on general behavior, motor coordination, spontaneous locomotor activity, hexobarbital-induced hypnosis time, body temperature, analgesic activity, anticonvulsant activity and contraction of nictitating membrane in cats. Furthermore KI-60606 showed no effects on blood pressure, heart rate, LVP (left ventricular peak systolic pressure), LVEDP (left ventricular end diastolic pressure), LVDP (left ventricular developing pressure), DP(double product), CFR(coronary flow rate), smooth muscle contraction using guinea pig ileum and gastric secretion at all dosage tested except the increase of gastrointestinal transport and urinary $K^+$ excretion.

디젤기관의 연소에 미치는 분사계의 영향 (Effects of the fuel injection system on combustion in a diesel engine)

  • 권순익;김완
    • 오토저널
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    • 제15권1호
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    • pp.37-44
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    • 1993
  • Fuel injection system is an important tool in the exhaust emission and performance of a diesel engine. Effects of the fuel injection system in diesel combustion was investigated experimentally by measuring the performance and analyzing the combustion phenomena in a D.I. diesel engine. The selected injection parameters were nozzle opening pressure, nozzle projection length, and nozzle spray angle. From the measured results, it is shown that the fuel injection pipe diameter is an effective means to improve engine performance in a middle and high speed range and the 2 stage spring nozzle holder has the advantage of increasing the engine performance due to the initial injection pressure in a low speed range. It has been also shown that increasing nozzle opening pressure resulted in decrease in smoke, but increase in NO$_{x}$ from the engine.e.

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뇌수술환자에서 두부상승체위가 중심정맥압과 두개강내압에 미치는 영향 (Effects of Backrest Position on Central Venous Pressure and Intracranial Pressure in Brain Surgery Patients)

  • 김현주;송경애
    • 대한간호학회지
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    • 제36권2호
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    • pp.353-360
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    • 2006
  • Purpose: This study was done to investigate the effects of backrest elevation of 0 degree and 30 degrees that minimize the risk of increasing ICP when CVP is measured. Methods: Subjects were sixty-four patients who stayed in the neurosurgical intensive care unit after brain surgery at two university-based hospitals. CVP, blood pressure, heart rate and ICP were measured along with position changes in order of backrest position with primary 30 degrees backrest position, 0 degree backrest position and secondary 30 degrees backrest position. For data analysis, one-group, repeated-measures analysis of variance design was used in SAS program. Results: Backrest elevations from 0 degree to 30 degrees did not alter the CVP without increasing the ICP. Therefore, 30 degrees backrest position is a preventive position without increasing ICP. Conclusion: 30 degrees backrest position might be appropriate for brain injury patients when CVP is measured.

이방압밀이 흙의 강도에 미치는 영향 (Effects of Anisotropic Consolidation on Strength of Soils)

  • 강병희
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 가을 학술발표회 논문집
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    • pp.3-14
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    • 2000
  • Anisotropic consolidation, shear, a transportational component during or after deposition each may produce anisotropic fabrics, which result in the anisotropic properties of soils. Nevertheless, the isotropically consolidated compression triaxial tests are commonly used in practice to determine the strength of the anisotropically consolidated soils because of their practicality and simplicity. In this paper the effects of anisotropic consolidation on the strength properties of soils are discussed. For the sandy soils consolidated under a constant vertical consolidation pressure, the deformation modulus decreases with decreasing consolidation pressure ratio($\sigma$$\sub$3c/'/$\sigma$ sub 1c/'), but the liquefaction resistance increases. For the saturated cohesive soils, both the undrained shear strength and undrained creep strength decrese with decreasing the consolidation pressure ratio. When the in-situ strength properties of the anisotropically and normally consolidated soils are determined by the isotropically consolidated tests, the undrained shear strength and creep strength of saturated cohesive soils as well as the deformation modulus of sandy soils are measured to be higher than the rear in-situ values. This, therefore, could lead to a dangerous judgement in stability analysis

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초음속 회전익의 앞전 형상이 공력 성능에 미치는 효과에 대한 수치적 연구 (Numerical Study on The Effects of Blade Leading Edge Shape to the Performance of Supersonic Rotors)

  • 박기철
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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    • pp.149-155
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    • 2001
  • Recently, it is required to design higher stage pressure ratio compressor while maintaining equal adiabatic efficiency. To increase the stage pressure ratio, blade rotational speed or diffusion factor should be increased. In the case of increasing rotational speed, relative speed of flow at blade leading edge is well supersonic. In supersonic blade, total pressure loss is mainly due to shock wave and blade leading edge thickness should be very thin to minimize the shock wave loss. As a result, the blade is like to be week in terms of mechanical strength and the manufacturing cost is very high because NC machining is necessary. It is also one of big hurdle to overcome to make small compressor. In this paper, the effects of blade leading edge to the performance of supersonic blade In terms of total pressure loss. The efficiency of already known method to make thin blade leading edge from the casted blade with rather thick leading edge thickness is also assessed.

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급수관로계에 설치된 수격흡수기의 수격흡수효과에 관한 실험적 연구 (Experimental Study on the Water Hammer Absorption Effects of Water Hammer Arrester in the Water Supply Piping System)

  • 최중근;이석종;이명호;성재용
    • Journal of Advanced Marine Engineering and Technology
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    • 제30권3호
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    • pp.396-402
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    • 2006
  • In this study, dynamic characteristics of water hammer pressure in water supply piping system with water hammer arrester has been investigated experimentally to characterize the transient pressure of water hammer in high rise building. Experiments were conducted to verify the absorption effects by water hammer arresters with 3 different gas volumes of water hammer pressure generated by sudden valve closure. As the results, it has been found that zoning and sizing of pipe diameter for suitable flow velocity and water hammer arresters with effective pressure absorption capacity have to be installed to protect water hammer problems in building water supply piping system.

General Pharmacology of PEG-Hemoglobin SB1

  • Kim, Eun-Joo;Lee, Rae-Kyong;Bak, Ji-Yeong;Choi, Gyu-Kap
    • Biomolecules & Therapeutics
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    • 제7권2호
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    • pp.170-177
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    • 1999
  • PEG-hemoglobin SB1 (SB1), which is a hemoglobin-based oxygen carrier, is intended to use as a safe blood substitute against brain ischemia and stroke. The general pharmacological profiles of SB1 were studied. The doses given were 0, 5, 10, 20 ml/kg and drugs were administered intravenously. The animals used for this study were mouse, rat and guinea pig. SB1 showed no effects on general behavior, motor coordination, spontaneous locomotor activity, hexobarbital sleeping time, anticonvulsant activity, analgesic activity, blood pressure and heart rate, left ventricular peak systolic pressure, left ventricular end diastolic pressure, left ventricular developing pressure, double product, heart rate, coronary flow rate, smooth muscle contraction using guinea pig ileum, gastrointestinal transport, gastric secretion, urinary volume and electrolyte excretion at all doses tested except the decrease of body temperature. These findings demonstrated that SB1 possesses no general pharmacological effects at all doses tested.

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