• 대한수혈학회지
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• 제29권3호
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• pp.229-239
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• 2018

순환계는 혈액의 흐름이 원활하게 되도록 그 해부학적 구조와 혈류의 물리학적 특성이 연결되어있다. 혈액의 흐름에 영향을 주는 혈액의 물리학적 특성을 혈유변학적 인자(Hemorheologic factors)라 하며, 혈액의 점도(blood viscosity) 및 적혈구 응집도(erythrocyte aggregation)와 같은 혈유변학적 특성은 헤마토크리트(hematocrit; Hct)와 밀접한 관계를 가진다. 헤마토크리트가 높을수록 혈액 점도가 증가하고 적혈구 응집도는 증가하며 순환을 저해하고 조직에 산소 전달 능력을 방해한다. 혈청 페리틴은 과도하게 있을 경우 산화유리기(oxygen free radial)를 통하여 혈관 내피세포(vascular endothelial cell)와 혈구 세포(blood cell)에 산화 손상을 유발하여 심혈관계 손상을 유발한다. 이러한 기전을 근거로 사혈 혹은 헌혈을 심혈관계 질환의 예방 및 치료에 응용하려는 시도가 오랫동안 있었다. 사혈은 의학에 있어 오랜 역사를 가지면서 특히 한방의 치료적 개념으로 최근까지도 사용되고 있으나 그 과학적 근거가 불충분하고 아직까지 논란의 여지도 있어 근거 중심의 의학을 근간으로 하는 의학에서는 도외시되어왔다. 하지만 혈액량이 증가하면 혈유변학적 인자들(hemorheological factors) 역시 악화되면서 대 순환에서 동맥경화의 발생 및 진행에 영향을 주고, 모세순환(microcirculation)을 악화시키는 것으로 알려져 있으며 심뇌혈관 사건에 영향을 주는 것으로 보고되고 있다. 정기적인 헌혈자(regular blood donors)에게 혈유변학적 인자들을 저명하게 호전시키고 과도한 철분의 함량을 줄여서 산화유리기에 의한 혈구 및 내피세포의 산화 손상을 줄임으로써, 순환계내에서 혈액순환을 촉진시킬 수 있다는 증거들이 보고되고 있다. 헌혈의 효과가 심혈관계 질환에 이익이 된다는 확고한 장기적 코호트 연구결과가 도출된다면 절대적으로 헌혈 혈액량이 부족한 현실과 심혈관계 질환의 예후를 호전시킬 수 있다는 측면에서 중요한 역할을 할 수 있다고 생각된다.

• Korea-Australia Rheology Journal
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• 제12권3_4호
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• pp.143-149
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• 2000

In this article, we considered shear-induced microstructure and rheological behavior of micellar solutions of cationic surfactant, cetylpyridinium chloride (CPC) in the presence of a structure-forming additive, sodium salicylate (NaSal). Shear viscosity, shear moduli and flow birefringence were measured as functions of the surfactant and additive concentrations. In the presence of NaSal, the micellar solution exhibited the non-linear rheological behavior due to the formation of supramolecular structures when the molar ratio of NaSal to CPC exceeded a certain threshold value. Flow birefringence probed the change in micelle alignment under shear flow. At low shear rates, the flow birefringence increased as the shear rate increased. On the other hand, fluctuation of flow birefringence appeared from the shear rate near the onset of shear thickening, which was caused by shear-induced coagulation or aggregation. These results were confirmed by the SEM images of in situ gelified micelle structure through sol-gel route.

• 대한한방내과학회지
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• 제17권1호
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• pp.34-50
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• 1996

The present experiment was desinged to investigate the effects of Tongdosan water extracts on the Cardiovascular System in the Experimental Animals. Thus, the changes of blood pressure and heart rate were measured after oral admini- stration. Measurment of Mortality rate was observed for measuring the effect of Tongdosan water extract. Tongdosan water extract against pulmonary thrombo- embolism induced by collagen the mixture(0.1ml/10g, 2mg/kg B.W) plus serotonin(5mg/kg B.W) in mouse. The effect of Tongdosan water extract was examined by observing the change of collagen-induced platelet aggregation, coagulation activity, ex vivo and in vitro fibrinolytic activity of euglobulin fraction in rats. The results were summarized as followings. 1. Tongdosan dropped the blood pressure in spontaneous hypertensive rat. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 4. The drug inhibited the death rate of mouse which was led to thromboembo- lism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The drug reduced the fibrinogen lyses time of rat ex vivo assay and lyses area was increased. 8. Tongdosan reduced fibrinogen lyses time of rat in vitro assay. According to the above mentioned results, Tongdosan increased the blood flow and dropped the blood pressure by the dilation of blood vessel. And the drug presented the antithrombin acivity, inhibited the platelet aggregation.

• 대한한방내과학회지
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• 제18권1호
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• pp.97-113
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• 1997

The present experiment was designed to investigate the effects of Sambutang water extracts on the serum cholesterol levels and the cardiovascular system in the experimental animals. Thus, the changes of blood pressure and heart rate were measured after oral administration. Measurment of Mortality rate was observed for measuring the effect of Sambutang water extract. Sambutang water extract against pulmonary thromboembolism induced by collagen the mixture(0.1 ml/10 g, 2 mg/kg) plus serotonin(5 mg/kg) in mouse. The effect of Sambutang water extract was examined by observing the change of collagen-induced platelet aggregation, coagulation activity, ex vivo and in vitro fibrinolytic activity of euglobulin fraction in rats. The results were summarized as follows. 1. Sambutang decreased the serum cholesterol levels in rats. 2. Sambutang dropped the blood pressure in spontaneous hypertensive rat. 3. The drug increased the auricular blood flow in rabbit. 4. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 5. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 6. The drug inhibited the platelet aggregation in rat. 7. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 8. The drug increased the antithrombin activity in rat and the fibrinogen lysis time was reduced and lysis area was increased. 9. Sambutang reduced fibrinogen lysis time of rat in vitro assay. According to the above mentioned results. Sambutang increased the blood flow and dropped the blood pressure by the dilation of blood vessel. And the drug presented the antithrombin activity, inhibited the platelet aggregation.

• 대한한방내과학회지
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• 제16권1호
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• pp.197-213
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• 1995

The present experiment was desinged to investigate the effects of Sopungtang water extracts on the Cardiovascular System in the Experimental Animals. Thus, the changes of blood pressure and heart rate were measured after oral administration. Measurments of Mortality rate were observed for measuring the effect of Sopungtang water extract. Sopungtang water extract against pulmonary thromboembolism induced by collagen the mixture(0.1ml/10g, 2mg/kg B.W) plus serotonin(5mg/kg B.W) in mouse. The effects of Sopungtang water extract were examined by observing the change of collagen-induced platelet aggregation, coagulation activity, ex vivo and in vitro fibrinolytic activity of euglobulin fraction in rats. The results were summarized as followings. 1. Sopungtang dropped the blood pressure in spontaneous hypertensive rat. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 4. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The drug increased the antithrombin activity in rat and the fibrinogen lyses time was reduced and lyses area was increased. 8. Sopungtang reduced fibrinogen lyses time of rat in vitro assay. According to the above mentioned results, Sopungtang increased the blood flow and dropped the blood pressure by the dilation of blood vessel. And the drug presented the antithrombin acivity, inhibited the platelet aggregation.

• 대한한의학회지
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• 제18권1호
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• pp.299-315
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• 1997

The present experiments were designed to investigate the effects of Samsaengyeum. water extracts on the Cardiovascular System in the Experimental Animals. Thus, the changes of blood pressure and heart rate were measured after oral administration. Measurement of Mortality rate was observed for measuring the effect of Samsaengyeum water extract Samsaengyeum water extract against pulmonary thromboembolism induced by collagen the mixture(0.1me/10g, 2mg/kg B.W) plus serotonin(5mg/kg B.W) in mouse. The effect of Samsaengyeiim water extract was examined by observing the change of collagen-induced platelet aggregation, coagulation activity, ex vivo and in vitro fibrinolytic activity of euglobulin fraction in rats. The results were summarized as followings. 1. Samsaengyeum dropped the blood pressure in spontaneous hypertensive rat. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 4. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The drug reduced the fibrinogen lyses time and increased the lyses area of rat. 8. Samsaengyeum reduced fibrinogen lyses time of rat in vitro assay. According to the above mentioned results, Samsaengyeum increased the blood flow and dropped the blood pressure by the dilation of blood vessel. And the drug inhibited the platelet aggregation.

• 물과 미래
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• 제27권3호
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• pp.115-121
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• 1994

하구수리계에 있어서 점착성류사의 운동은 응결과 응집(aggregation) 현상에 의해 크게 좌우되며, 이들 현상에 의하여 의결된 입자들의 크기, 모양, 강도는 그 퇴적율과 그리고 부유류사와 오염물질의 변동과정에 영향을 미친다. 본 연구에서는 Brownian 운동에 의해 지배되는 이동성 부유영역과 중력에 의해 지배되는 정체성 부유영역으로 분리하여 점착성입자들의 응집과 응결과정을 모의하였다. 이동성 부유영역에 있어서는 Smoluchowski 모형중 입자들의 무작위 회전을 이용한 최대연쇄 모형으로 응집물질의 사영들을 도출하였으며, 그 회전반경에 의해 사영들의 쪽거리 차원을 구하였다. 저에성 부유영역에서의 응집물질(Brownian 영역을 벗어나 침강하는 응집물질)는 비구형 입자들의 침강으로 간주되어진다. 최종 침강속도 차이로 이들 응집물들은 재차 충돌, 결합하여 보다 큰 응집 입자들을 형성하며, 이들 최종 응집입자들의 사영이 모의되어진다. 최대 Feret's 직경과 Minkowski's sausage logic 개념들을 이용하여 모의되어진 사영들의 둘레 길이에 대하여 쪽거리 차원들을 구하였다.

• 한국항해학회지
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• 제25권3호
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• pp.257-268
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• 2001

이 연구는 자연조건, 지형조건, 시설조건 및 다른 선박과의 상대적 위치 관계 등의 특정한 운항환경에서 조선자가 갖는 심리적 부담을 계량화하고, 이를 통해 해상교통의 안전성을 평가하는 환경스트레스 모델을 적용하여 부산항 접근수역의 현행 통항분리방식과 선행 연구에서 제안한 원형분리대방식에 의한 해상교통의 안전성을 상호 비교하여 그 타당성을 검증하고자 한다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2018년도 학술발표회
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• pp.325-325
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• 2018

The main purpose of this study is to suggest the more reliable flow direction methods within the framework of DEM by investigating the existing methodologies. To this end SFD(single flow direction method), MFD(multiple flow direction method) and IFD(Infinite flow direction method) are applied to determination of flow direction for water particles in Jeonjeokbigyo basin, and then assessed with respect to the variation of flow accumulation. As the main results the different patterns of flow accumulation are found out from each application of flow direction methods. As the flow dispersion increases on DEM contributing areas to outlet grow in sequence of SFD, IFD, MFD but contribution of individual pixels into outlet decreases. Especially MFD and IFD tend to make additional hydrologic abstraction from rainfall excess due to the flow dispersion within flow paths on DEM. Based on parameter estimation for power law distribution by maximum likelihood flow accumulation can be thought of as scale invariance factor. Combination of several flow direction methods could give rise to the more realistic water flow on DEM through separate treatment of flow direction methods for dispersion and aggregation effects of water flow within different topographies.

• Korea-Australia Rheology Journal
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• 제17권1호
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• pp.9-13
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• 2005

The aggregation of red blood cells (RBCs) is a major determinant of blood flow resistance passing through various veins. Available techniques for measuring RBC aggregation often require pretreating and washing after each measurement, which is not optimal for day-to-day clinical use. A laser reflection technique has been combined with a vibration-aided disaggregation mechanism, which shows significant advances in aggregometer design, operation and data analysis. The essential features of this design are in its simplicity and a disposable element that is in contact with the blood sample. Using extremely small quantities of blood, the RBCs subjected to vibrations can be quickly and completely disaggregated. This is followed by measuring the backscattered light intensity. The measurements with the present sensor were compared with those of a commercial aggregometer and a strong correlation was found between them. The newly-developed optical aggregometer can measure the RBC aggregability difference between young and old cell suspension with ease and accuracy.