• Title/Summary/Keyword: Capillary Pressure

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A case of Pleural effusion (심부전(心不全)에의한 흉막삼출증(胸膜渗出症)으로 의심되는 환자(患者) 1례(例)에 대(對)한 임상적(臨床的) 고찰(考察))

  • Kim, Hee-Chul;Lee, Kang-Nyung;Lee, Dong-Joon;Lee, Young-Soo;Lim, Jin-Hoon;Lee, Young-Yoon;Kim, Il-Ryul;Choi, Chang-Won
    • The Journal of Internal Korean Medicine
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    • v.21 no.4
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    • pp.671-676
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    • 2000
  • Pleural effusion is a state, retention of a mount of liquid in pleural cavity. Main causes of pleural effusion is Congestive Heart Failure that is caused by left ventricular heart failure. And that of Congestive heart failure is caused by increase of pleural capillary pressure or remain of effusion in pleural cavity. Bilateral venous pressure of pleura make worse pleural effusion and one way of venous pressure of that bring out pleural effusion. The purpose of this study is to examine the efficacy of oriental treatment for pleural effusion is caused by heart failure. One woman of 86 years old complained the symptom of general weakness, dyspnea, flank pain, anorexia, insomnia, coughing, secretion mixed blood. The symptom is caused by effusion that is brought out acute pneumonia, heart failure. At the time of Admission, in the diagnosis of Admission, in the diagnosis of Hyuneum(懸飮) she had taken Kungha-tang hap pleurisy-bang,(芎夏湯合助膜炎方), so improved dyspnea, flank pain, insomnia, coughing. In views of examination, decrease of heart failure' s symptom and pleural effusion. After 13days of admission, she had taken palmul-tang.(八物湯). As a conseguence of that, the symptom of general weakness. anorexia is improved and she was discharged.

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Acute Hemodynamic Effects of CJ-10513, an Angiotensin IIReceptor Antahonest, in Dog Treated with High Friquency Ventricular Pacing (안지오텐신 ll 수용체 길항약 CJ-10513이 고민도 심실 pacing 천에서의 혈행동태에 미치는 영향)

  • Kim, Young-Hoon;Jeong, Seong-Mok;Shin, Jae-Kyu;Choi, Jae-Mook;Jeong, Seong-Hak;Bae, Hoon;Lee, Gun-Ho;Kim, Je-Hak;An, Yang-Soo
    • Biomolecules & Therapeutics
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    • v.6 no.2
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    • pp.199-203
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    • 1998
  • Acute hemodynamic effects of CJ-18513, a non-peptide angiotensin IIreceptor antagonist, were examined in mongrel dogs treated with high frequency ventricular pacing for one week. Rapid ventricular pacing reduced mean blood pressure (mBP), Lvdp/dt and cardiac output (CO), and increased the left ventricular end-diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP). Continuous infusion of CJ-10513 at doses of 10 and 20$\mu$g/kg/min, respectively, for 30 minutes reduced mBP, LVEDP and myocardial oxygen consumption rate (MVO,) and shifted the cardiac function curve (CO-LVEDP ourve) to the left in this dog model. In conclusion, CJ-10513 decreased the preload and afterload and increased the cardiac function in dogs with pacing-induced heart failure.

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AN EXPERIMENTAL STUDY ON THE VASCULAR CHANGES OF RAT MOLAR PERIODONTAL LIGAMENT FOLLOWING ORTHODONTIC TOOTH MOVEMENT USING VASCULAR CORROSION CASTING METHOD (백서구치의 실험적 치아이동시 치근막 혈관변화에 관한 혈관주형법을 이용한 연구)

  • Lim, Yong-Kyu;Yang, Won-Sik
    • The korean journal of orthodontics
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    • v.24 no.1 s.44
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    • pp.37-62
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    • 1994
  • This study was undertaken to investigate the three dimensional vascular changes of periodontal ligament following orthodontic tooth movement. Experimental tooth movement was carried out in 96 Sprague-Dawley rats with the weight of 250g. They were divided into four experimental groups (each 24 rats). The left maxillary first molar was moved mesially with 25g force in group I, and with 75g force in group II. Each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days. In group III, 25g mesial force was applied for 3 days, and in group IV, 75g mesial force was applied for 3 days. Then the appliances were removed, and each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days from removal of appliance. The contralateral molars were used for control group. Casting media was injected via left ventricle and polymerized in warm water. After corrosion of surrounding soft tissue, three dimensional vascular changes were examined using scanning electron microscopy. The findings of this study were as follows: 1. Pressure side of group I and II showed degenerative vascular changes such as vascular compression, reduction of vasculature, leakage of casting media. But, regenerative changes were dominant after 7 days of tooth movement. Although the degenerative vascular changes were more severe in group II, which was exposed to heavy force, the timing of these changes was not different between two groups. 2. Periodontal vasculature was reestablished by the growth of new capillaries and their differentiation and union from the remaining periodontal vessels and vessels of alveolar bone marrow. Although vascular regeneration was more rapid in group I, which was exposed to light force, the vasculature was not fully normalized in both groups even after 21 days. 3. There was no remarkable changes in tension side of group I and II, but looping of capillary, new capillary growth, dilation of vessels, redirection of vessels in the direction of tensile force were occurred. 4. In pressure side of group III and IV, in which appliance was removed after 3 days of orthodontic force, bone resorption was continued even after removal of appliance. Regeneration of vasculature was initiated after 1-6 hours, and it was more rapid in group III than group IV. In both groups, the vasculature was not fully normalized even after 21 days. 5. After removal of appliance, tension side of group III and IV showed vascular compression and loss of vasculature.

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Fundamentals of Contact Lens Movement (콘택트렌즈 운동의 기초)

  • Kim, Dae Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.1
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    • pp.5-13
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    • 2008
  • Purpose: This review article was written to investigate what kind of forces are acting on the contact lens fitted on the cornea and its subsequent motion. Methods: A capillary action-induced force develops in the tear layer between the lens and cornea, which leads to the restoring force due to difference in layer thickness according to lens rotation. The characteristics of the lens movement can be determined by the various factors such as friction between eyelid and lens, acceleration force based on blinking and the restoring force incorporated with the viscous damping force. A mathematical model which consists of the differential equations and their numerical solution was proposed to analyze the damped motion of lenses. The model predicts the time dependence of lenses during and after the blink varying the BC, blink period and eyelid pressure. Results: It was found that both the blink period and lid pressure increases the movement increases because of the enhanced lid friction. As the BC increases the viscous damping reduces due to the lacrimal layer's increase which resulted in the enhanced lens motion. After blink the lens illustrates the damped oscillation because of the restoring force by the increased lacrimal layer thickness and reduced viscous resistance. The time for the lens to return to the equilibrium shortens as the BC increase because of the resistance reduction. Conclusions: The movement of the contact lens is governed by the characteristics of the lacrimal layer between the lens and cornea as well as the lid blink.

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Soil-Water Characteristic Curve of Sandy Soils Containing Biopolymer Solution (바이오폴리머를 포함한 모래지반의 흙-습윤 특성곡선 연구)

  • Jung, Jongwon
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.10
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    • pp.21-26
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    • 2018
  • Soil-water characteristic curve, which is called soil retention curve, is required to explore water flows in unsaturated soils, relative permeability of water in multi-phase fluids flow, and change to stiffness and volume of soils. Thus, the understanding of soil-water characteristic curves of soils help us explore the behavior of soils inclduing fluids. Biopolymers are environmental-friendly materials, which can be completely degraded by microbes and have been believed not to affect the nature. Thus, various biopolymers such as deacetylated power, polyethylene oxide, xanthan gum, alginic acid sodium salt, and polyacrylic acid have been studies for the application to soil remediation, soil improvement, and enhanced oil recovery. PAA (polyacrylic acid) is one of biopolymers, which have shown a great effect in enhanced oil recovery as well as soil remediation because of the improvement of water-flood performance by mobility control. The study on soil-water characteristic curves of sandy soils containing PAA (polyacrylic acid) has been conducted through experimentations and theoretical models. The results show that both capillary entry pressure and residual water saturation dramatically increase according to the increased concentration of PAA (polyacrylic acid). Also, soil-water characteristic curves by theoretical models are quite well consistent with the results by experimental studies. Thus, soil-water characteristic curves of sandy soils containing biopolymers such as PAA (polyacrylic acid) can be estimated using fitting parameters for the theoretical model.

The Frost Heaving Characteristics of Subgrade Soils Using Laboratory Freezing System (실내동결시스템을 이용한 노상토의 동상 특성)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Park, Jeong-Jun
    • International Journal of Highway Engineering
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    • v.12 no.2
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    • pp.71-79
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    • 2010
  • The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing system test simulating closely the thermal conditions in the field. During the winter season, the climate is heavily influenced by the cold and dry continental high pressure. Because of siberian air mass, the temperature of January is $-6{\sim}-7^{\circ}C$ on average. This chilly weather generate the frost heaving by freezing the moisture of soil and damage potential of the road structure. In the freezing soil, the ice lenses increase the freeze portion of soil by absorbing the ground water with capillary action. However, the capillary characteristics differ from the sort of soil on the state of freezing condition. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure. In this Paper, the evaluation of frost susceptibility was conducted by means of the mechanical property test and laboratory freezing system apparatus. The temperature, heaving amount, heaving pressure and unfrozen water contents of soil samples, the subgrade soils of highway construction site, were measured to determine the frost susceptibility.

Analysis of Sildenafil and its Analogues by LC/MS/MS (LC/MS/MS를 이용한 sildenafil 및 그 유사체 분석)

  • Myung, Seung-Woon;Park, So-Hee;Cho, Hyun-Woo
    • Analytical Science and Technology
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    • v.16 no.6
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    • pp.488-498
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    • 2003
  • By LC/MS/MS, the analytical method of sildenafil and its analogues (homosildenafil, vardenafil and tadalafil) used as used medical treatment of impotence was established. electrosprary ionization (ESI) and atmospheric pressure chemical ionization (APCI) as a ionization method were applied. Several parameter were varied and the sensitivity and reproducibility were compared. In LC/ESI-MS method, capillary voltage, cone voltage, extractor, entrance and RF lens to create appropriate productr ions for multiple reaction monitoring (MRM) were variable parameter, but the formation of the other product ions except the precursor ion could not detect. And the value of entrance, collision energy, exit, corona voltage, cone voltage, extractor, RF lens, cone gas, and desolvation gas in APCI mode were varied, only the creation pattern of fragment ions by the change of RF lens value were detected, and the limit of detection was decreased due to the increase of S/N. Ten millimole ammonium formate (pH 4.8):acetonitrile=70:30 by isocratic elution in HPLC system was shown the maximum sensitivity in MS, the detection limit of sildenafil, homosildenafil, vardenafil and tadalafil obtained by ESI-MRM were 0.10, 0.025, 0.025, and $0.25{\mu}g/mL$ at S/N>5, respectively.

Autogenous Shrinkage of High-Performance Concrete Containing Mineral Admixture (광물질 혼화재를 함유한 고성능 콘크리트의 자기수축)

  • Lee, Chang-Soo;Park, Jong-Hyok;Kim, Yong-Hyok;Kim, Young-Ook
    • Journal of the Korean Society of Hazard Mitigation
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    • v.7 no.3
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    • pp.19-31
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    • 2007
  • Humidity and strain were estimated for understanding the relation between humidity change by self-desiccation and shrinkage in high-performance concrete with low water binder ratio and containing fly ash and blast furnace slag. Internal humidity change and shrinkage strain were about 10%, 10%, 7%, 11%, 11% and $320{\times}10^{-6}$, $270{\times}10^{-6}$, $231{\times}10^{-6}$, $371{\times}10^{-6}$, $350{\times}10^{-6}$ respectively on OPC30, O30F10, O30F20, O30G40, O30G50 and from the results, fly ash made humidity change and strain decrease but slag increase comparing with ordinary portland cement. Considering only relation internal humidity and shrinkage by self-desiccation, humidity change and shrinkage represented the strong linear relation regardless of mineral admixture. For specifying the relation on internal humidity change and autogenous shrinkage strain, shrinkage model was established which is driven by capillary pressure in pore water and surface energy in hydrates on the assumption of a single network and extended meniscus in pore system of concrete. This model and experimental results had a similar tendency so it would be concluded that the internal humidity change by self-desiccation in HPC originated in small pores less than 20nm, therefore controlling plan on autogenous shrinkage might be focused on surface tension of water and degree of saturation in small pore.

Numerical study on the effect of viscoelasticity on pressure drop and film thickness for a droplet flow in a confined microchannel

  • Chung, Chang-Kwon;Kim, Ju-Min;Ahn, Kyung-Hyun;Lee, Seung-Jong
    • Korea-Australia Rheology Journal
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    • v.21 no.1
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    • pp.59-69
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    • 2009
  • The prediction of pressure drop for a droplet flow in a confined micro channel is presented using FE-FTM (Finite Element - Front Tracking Method). A single droplet is passing through 5:1:5 contraction - straight narrow channel - expansion flow domain. The pressure drop is investigated especially when the droplet flows in the straight narrow channel. We explore the effects of droplet size, capillary number (Ca), viscosity ratio ($\chi$) between droplet and medium, and fluid elasticity represented by the Oldroyd-B constitutive model on the excess pressure drop (${\Delta}p^+$) against single phase flow. The tightly fitted droplets in the narrow channel are mainly considered in the range of $0.001{\leq}Ca{\leq}1$ and $0.01{\leq}{\chi}{\leq}100$. In Newtonian droplet/Newtonian medium, two characteristic features are observed. First, an approximate relation ${\Delta}p^+{\sim}{\chi}$ observed for ${\chi}{\geq}1$. The excess pressure drop necessary for droplet flow is roughly proportional to $\chi$. Second, ${\Delta}p^+$ seems inversely proportional to Ca, which is represented as ${\Delta}p^+{\sim}Ca^m$ with negative m irrespective of $\chi$. In addition, we observe that the film thickness (${\delta}_f$) between droplet interface and channel wall decreases with decreasing Ca, showing ${\delta}_f{\sim}Ca^n$ Can with positive n independent of $\chi$. Consequently, the excess pressure drop (${\Delta}p^+$) is strongly dependent on the film thickness (${\delta}_f$). The droplets larger than the channel width show enhancement of ${\Delta}p^+$, whereas the smaller droplets show no significant change in ${\Delta}p^+$. Also, the droplet deformation in the narrow channel is affected by the flow history of the contraction flow at the entrance region, but rather surprisingly ${\Delta}p^+$ is not affected by this flow history. Instead, ${\Delta}p^+$ is more dependent on ${\delta}_f$ irrespective of the droplet shape. As for the effect of fluid elasticity, an increase in ${\delta}_f$ induced by the normal stress difference in viscoelastic medium results in a drastic reduction of ${\Delta}p^+$.

Establishment of the Heart Failure Model by Coronary Artery Ligation in Sheep (양에서 관상동맥 결찰에 의한 심부전 모델의 확립)

  • 나찬영;홍장수;박정준;김원곤;강문철;서정욱
    • Journal of Chest Surgery
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    • v.35 no.1
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    • pp.1-10
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    • 2002
  • Background: Despite the relatively high mortality rates in the chronic heart failure model induced by coronary artery ligation are relatively high, this model has been a subject of continuos research because of its clinical correlation. Chronic heart failure model of large-sized animals is very useful to analyse mechanical or biological effects on circulatory system which is difficult in small-sized animals. The purpose of this study is to establish the heart failure model by coronary artery ligation in sheep. Material and Method: Among 9 Corridale sheep, the homonymous artery and the diagonal branch were ligated simultaneously in 2 sheep and remaining 7 sheep were assigned to successive ligation of both arteries at an interval of 1 hour. Both coronary arteries were ligated from the point 40% proximal to the apex of the heart. Hemodynamic and echocardiographic parameters were analyzed before the ligation of the coronary artery, after the ligation of the homonymous artery, and after additional ligation of the diagonal branch. The experimental animals were sacrificed after 2 or 3 months of growth and histopathologic studies were performed Result: Immediate postoperative death occurred in the 2 sheep that had received simultaneous ligation of the homonymous artery and diagonal branch. On the other hand, all the 7 sheep that were lifated in succession were survived up to 3 months. Arterial pressure was sifnificantly decreased immediately after ligation of the homonymous artery(p<0.05), and the cardiac output was decreased and pulmonary capillary wedge pressure was increased after further ligation of the diagonal branch(p<0.05). Central venous pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, left ventricular end-diastolic dimension and end-systolic dimension were markedly increased 3 months after ligation of coronary arteries. Anteroseptal akinesia or dyskinesia was developed after the ligation of coronary arteries. Histopathologic study revealed we]1-demarcated ischemic area of fibrosis. Conclusion: Using methods of successive ligation of the homonymous artery and diagonal branch, chronic heart failure model could be reliably established in sheep.