• Title/Summary/Keyword: 모세관 모델

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Antiangiogenic Activity of Coptis chinensis Franch. Water Extract in in vitro and ex vivo Angiogenesis Models (In vitro와 ex vivo 혈관신생 모델에서 황련 냉수추출물의 신생혈관 억제효과)

  • Kim, Eok-Cheon;Kim, Seo Ho;Lee, Jin-Ho;Kim, Tack-Joong
    • Journal of Life Science
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    • v.27 no.1
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    • pp.78-88
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    • 2017
  • Angiogenesis, the formation of new blood vessels, plays an important role in tumor growth and metastasis; therefore, it has become an important target in cancer therapy. Novel anticancer pharmaceutical products that have relatively few side effects or are non-cytotoxic must be developed, and such products may be obtained from traditional herbal medicines. Coptis chinensis Franch. is an herb used in traditional medicine for the treatment of inflammatory diseases and diabetes. However, potential antiangiogenic effects of C. chinensis water extract (CCFWE) have not yet been studied. The purpose of this study was to determine the antiangiogenic effect of CCFWE in order to evaluate its potential for an anticancer drug. We found that the treatment with CCFWE inhibited the major steps of the angiogenesis process, such as the endothelial cell proliferation, migration, invasion, and capillary-like tube formation in response to vascular endothelial growth factor (VEGF), and also resulted in the growth inhibition of new blood vessels in an ex vivo rat aortic ring assay. We also observed that CCFWE treatment arrested the cell cycle at the G0/G1 phase, preventing the G0/G1 to S phase cell cycle progression in response to VEGF. In addition, the treatment reduced the VEGF-induced activation of matrix metalloproteinases 2 and 9. Taken together, these findings indicate that CCFWE should be considered a potential anticancer therapy against pathological conditions where angiogenesis is stimulated during tumor development.

Model on the Contact Lens Movement from Eye-lid Blinking (순목 작용에 의한 콘택트 렌즈의 운동 모델)

  • Kim, Daesoo
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.1
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    • pp.145-159
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    • 2004
  • A mathematical model and its computer solution program were proposed to analyze the motion of contact lenses which are being subject to lid-blinking. The equation was derived by incorporating an acceleration induced lid's force exerting on the contact lens, the viscous damping resistance in the tear layer beneath the lens and the sliding frictional force between the lid and the contact lens surface into the formulation of differential equation describing the vibration. The model predicts the time-dependent displacement from the equilibrium postion during/after the blinking. During the blinking, as the time for the completion of one cycle of blinking decreases the off-the-equilibrium displacement of contact lens increases while the decrease of diameter in the contact cause the opposite effect. It is found that lid pressure exerting on the lens cause an insignificant lens displacement from the equilibrium position. After blinking the frequency of damped oscillation of contact lens decreases as the diameter of lens increases, due to the incresed surface while the reduced blinking time does not cause a significant frequency change. This is because that driving force for the contact lens movement posterior to blinking is the capillary-induced force not the lid force.

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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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Analysis on Forces Acting on the Contact Lens Fitted on the Cornea (콘택트 렌즈에 작용하는 힘의 해석)

  • Kim, Dae-Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.2
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    • pp.1-11
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    • 2002
  • A mathematical model is proposed to analyze the force; acting on the hard contact lens fitted on the cornea. The model incorporates the nonlinear equations and their numerical solution program, based on the formulations of surface tension force arising from the capillary action in the tear-film layer between the lens and cornea. The model simulates how the adhesion between lens and cornea varies according to the base curves and diameters of the lenses. When the spherical lens is fitted on the spherical cornea it is to rotate downward due to the weight of lens itself until it reaches an equilibrium position along the cornea where the counter(upward) moment caused by net force between the upper and lower portion of the periphery of lens. It is found that both the adhesion and displacement of lens along the cornea, where the gravity of lens balances the capillary-induced upward force, increases rapidly as the base curve of lens increases, i.e., as the lens gets flatter, while the increase in the diameter of lenses has resulted in the less increase in the rotation and adhesion. With the base curve and diameters of lenses being remained constant the increase in surface tension of tear film yields the increase in the adhesion between the cornea and lens while the initial rotation of lens is inversely proportional to the surface tension of the tear film.

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Enhanced Removal of Benzene-NAPL in Soil using Concurrent Injection of Cosolvent and Air (Cosolvent와 공기 동시 주입 공정에 의한 토양 내 벤젠-NAPL 세정 증대 연구)

  • Song, Chung-Hyun;Jeong, Seung-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.11
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    • pp.1095-1101
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    • 2008
  • Nonaqueous phase liquids (NAPL) are the continuous source for soil and groundwater contamination. The first objective of the study was to verify the effect of co-injection of cosolvent and air on NAPL removal from soil-column system. The second objective of the study was to investigate the effect of alcohol-partitioning property on the NAPL removal by the co-injection process of cosolvent and air. Enhanced removal of benzene-NAPL by the co-injection process of ethanol and air was also verified within the soilcolumn system. However, the co-injection process of Tert-butanol (TBA) and air showed no enhancement of benzene-NAPL removal. This study found that the viscous pressure of TBA was so higher than the capillary pressure and TBA easily displaced the benzene-NAPL and air present in soil pores. Air of the coinjection process did not work for NAPL removal but hindered NAPL mobilization. NAPL partitioning property and viscous pressure of cosovlent should be considered for application of the co-injection process of cosolvent and air.

Numerical simulation for variations of water saturation in bentonite buffer under the effect of a rock joint using the TOUGH2 code (TOUGH2 code를 이용한 처분장 절리암반 내 벤토나이트 완충재의 포화도 변화)

  • Kim, Jin-Seop;Cho, Won-Jin;Lee, Kyung-Soo;Choi, Heui-Joo;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.6
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    • pp.575-593
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    • 2012
  • This paper briefly introduces the scope and objectives of SKB Task 8, which is an international cooperative research project. In addition, the hydraulic behaviors of bentonite buffer focusing on the interactions between bentonite and a rock mass with a joint were investigated using TOUGH2 code as part of a sub-mission of Task 8a. The effects of a rock joint and high capillary pressure of bentonite on the re-saturation properties and pressure distribution in a buffer were identified and successfully incorporated in the TOUGH2 code. Based on the numerical results, it was found that the speed of re-saturation in bentonite surrounded by a rock mass with a joint is 2.5 to 12 times faster than that in a condition without a rock joint, while the degree of saturation in the lower part of the buffer material is generally higher than in the upper part in both the cases of with and without a joint. It can be anticipated that the results obtained from this study can be applied to an estimation of the full saturation time and a determination of optimum thickness with regard to the design of the bentonite buffer in a high level waste disposal system.

Development of One-Step Immuno-Chromatography Assay System for Salmonella typhimurium (Immuno-Chromatography 방법을 이용한 식중독균(Salmonella typhimurium) 1단계 분석시스템의 개발)

  • 백세환;이창우이창섭육순학
    • KSBB Journal
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    • v.11 no.4
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    • pp.420-430
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    • 1996
  • One-step immuno-chromatography assay system for heat-killed Salmonella typhimurium antigens was developed. Three major components used were a glass fiber membrane (placed at the bottom of the system) with an antibody (specific to the analyse, detection antibody)-gold conjugate deposited in a dry state on the surface, a nitrocellulose membrane (middle) with an antibody (also, specific to the analyse but recognized different epitome: capture antibody) and anti-detection antibody immobilized in spatially separated areas, and a cellulose membrane (top) as absorption pad. These membranes were partially superimposed such that a wicking of aqueous solution containing sample can continuously take place through membranes. Variables that affected the system performance were the concentration of capture antibody, the location on the membrane, inert protein used for blocking of the membrane and for carrying the sample, and the concentration of the gold conjugate. Under optimal conditions, within 15 minutes after absorption of a sample solution from the bottom of the system antigen-antibody complexes of sandwich type were formed on the membrane surface area with immobilized capture antibody and a color signal was generated in proportion to the analyse concentration. The minimum do tection limit of the analyse was $1{\times}106$ Salmonella cells/mL.

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Effects of Bambusae Caulis in liquamen on inhibition of angiotensin-converting enzyme in vitro and blood flow in mouse model (죽력의 in vitro에서의 angiotensin-converting enzyme 저해효과와 마우스모델에서 혈행개선효과)

  • Kim, Chun dug;Ryu, Min Jung;Chun, Hyoung Sik;Choi, Geun Pyo;Hwang, Kwonteak
    • Food Science and Preservation
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    • v.24 no.7
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    • pp.992-999
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    • 2017
  • The purpose of this study was to investigate the effects of the Bambusae Caulis in liquamen (BCL) on blood circulation in animal models. Previous studies on BCL have shown effects on thrombolytic activity and angiotensin-converting enzyme (ACE) inhibitory activity. In the mouse model, the triglyceride content were 301.5 mg/dL in the high fat diet+BCL II 0.01% group, 289.2 mg/dL in the high fat diet+BCL II 0.05% group, which was significantly lower than the high fat diet group. The total cholesterol content was 311.9 mg/dL in high fat diet+BCL II 0.01% and 293.7 mg/dL in high fat diet+BCL II 0.01% 0.05%, respectively, which was significantly lower than the high fat diet group. The HDL-cholesterol level was 206.0 mg/dL for the high fat diet, 196.6 mg/dL for the high fat diet+BCL II, and 189.2 mg/dL for the high fat diet+BCL II. There was no significant difference between the 0.01% and 0.05% groups. The high-fat diet+0.05% group was significantly improved in the blood flow compare to the high fat diet and the high fat diet+0.01% group. Platelet aggregation inhibition ability was inhibited in the high fat diet+0.01% and 0.05% groups compared to the high fat diet group.

Fundamentals of Tight fitted Contact Lens Movement (Tight Fit 콘택트렌즈 운동의 기초)

  • Kim, Dae Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.3
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    • pp.17-27
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    • 2009
  • Purpose: This review article was written to determine the effects of parameters characterizing a hard contact lens (RGP included), such as BCs, diameters, edge angles, on the time interval for tight fitted lens to return to the equilibrium when it was decentered from blinking. Methods: A mathematical formulation was established to relate or calculate the restoring forces and thickness of lacrimal layer beneath the cornea with the various lens parameters when the tight fitted lens was decentered from blinking. Based on this formulation the differential equations and their numerical solution program were set up to describe the time dependence of the lens on the position and to estimate the time for the lens's return to the equilibrium after blink. Results: It is found that the time interval for the tight fitted lens to return to the equilibrium decreases as either the BC decreases or the diameter increases because both the reduction in BC and increase in diameter result in the increase in the lacrimal layer thickness between the lens and cornea increase which yielded the lowering of the viscous friction in the lens motion. As the edge angle of tight fitted lens increases the time for recentering decreases due to the increase in restoring force without change in lacrimal thickness beneath the lens. In the case of flat fitted hard lens (RGP included), the lacrimal layer thickness under the lens increases as either BC or diameter increases which results in reduction in viscous friction so that the time for the lens's return to the equilibrium were to decrease. The edge angle of flat fitted lens does not affect the lens motion. Conclusions: The effect of BCs on the lens motion (time to approach the equilibrium) was concluded to be significant with both tight and flat fitted lens where its results are contrary with each other. The edge angle of lens only affects the motion in tight fitted lenses.

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