• 제목/요약/키워드: Blood thickness

검색결과 543건 처리시간 0.022초

헤마토크릿에 따른 혈액의 유변학적 특성 변화 (Effect of hematocrit on hemorheological characteristics of blood flow in a microtube)

  • 지호성;이정엽;이상준
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2006년도 추계학술대회 논문집
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    • pp.111-112
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    • 2006
  • In order to investigate flow characteristics of blood flow in a micro tube ($100{\mu}m$ in diameter) according to hematocrit, in-vitro experiments were carried out using a micro-PIV technique. The micro-PIV system consists of a microscope, a 2 head Nd:YAG laser, a 12 bit cooled CCD camera and a delay generator. Blood was supplied into the micro tube using a syringe pump. Hematocrit of blood was controlled to be 20%, 30% and 40%. The blood flow has a cell free layer near the tube wall and its thickness was changed with increasing the flow rate and hematocrit. The hemorheological characteristics such as shear rate and viscosity were evaluated using the velocity field data measured. As the flow rate increased, the blunt velocity profile in the tube center was sharpened. The viscosity of blood was rapidly increased with decreasing shear rate, especially in the region of low shear rate, changing RBC rheological properties. The variation of velocity profile and blood viscosity shows typical characteristics of Non-Newtonian fluids. On the basis of inflection points, the cell free layer and two-phase flow consisting of plasma and suspensions including RBCs were clearly discriminated.

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대전지역 초등학교 아동의 체위 , 혈액성상 및 영양섭취에 관한 조사 연구 (A Study on Nutrients Intake , Physical and Biochemical Status of Elementary School Children in Taejon)

  • 윤은영;신은미
    • 대한영양사협회학술지
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    • 제4권2호
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    • pp.212-224
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    • 1998
  • The purpose of this study was to investigate nutrients intake, Rohrer index, serum cholesterol level, blood pressure and others for clinical and nutritional study on school children in Taejon. This survey was carried out in October, 1995. The subjects were 362 children, 6 to 11 years old. The results were summarized as follows. By Rohrer index, 4.6% of the children was lean, 69.6% was normal, 17.4% was overweight and 8.6% was obese group. Systolic blood pressure, diastolic blood pressure and skin fold thickness of all subjects were 111.7$\pm$15.7mmHg, 69.8$\pm$14.9mmHg and 14.5$\pm$7.3mm respectively. Systolic blood pressure and skin fold thickness were increased with Rohrer index. Total cholesterol, urea nitrogen and creatinine levels in blood were 160.8$\pm$23.9mm/dl, 11.5$\pm$3.5mm/dl and 0.71$\pm$0.12mm/dl respectively but not significantly different among groups. These levels have a slight tendency to increase in obese group but not significantly different among groups. Hematocrit and hemoglobin levels were 41.3$\pm$4.7%, 13.1$\pm$1.6g/dl. These levels of 11 years old girls were lower than same aged boys. Composition ratio of total energy intakes were 65% of CHO, 13% of protein and 22% of fat. Energy and most nutrients intakes were insufficient except for P and vitamin C. Especially the amount of vitamin A, Fe, Zn and folate intakes were lower than halves of RDA'S. Most nutrients intake were not significantly different among groups. Pearson' correlation in Rohrer index with nutrients intakes were all negative correlation significantly different of K, Na and Thiamin.

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초음파검사의 경동맥내중막두께와 심장이완기능의 상관관계 분석 (Correlation Analysis of Cardiac Diastolic Function and Intima-Media Thickness in the Common Carotid Artery of Ultrasonography)

  • 오송미;이상훈;지태정
    • 대한방사선기술학회지:방사선기술과학
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    • 제45권5호
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    • pp.413-422
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    • 2022
  • In this study, 230 subjects of medical examination were investigated to figure out the relationship with common carotid artery intima-media thickness and cardiac diastolic function. In addition, the change in the carotid artery intima-media thickness according to the presence or absence of metabolic syndrome was examined. As a result of the study the carotid artery intima-media thickness was thick as the age increased and there was a large difference in those in their 60s and over. There was no gender difference. As for metabolic syndrome the carotid artery intima-media thickness was thicker in the study subjects with high blood pressure diabetes and dyslipidemia. The correlation between the carotid artery intima-media thickness and diastolic function indexes was significant. As a result of hierarchical regression analysis the thicker the intima-media thickness in the carotid artery the lower cardiac diastolic function.

맥상 분류 기준에 대한 방법론적 고찰 - "빈호맥학(瀕湖脈學)"을 중심으로 - (The Methodic Study on a Standard of Classification of Pulse Condition -a Focus of ${\ulcorner}$The Pulse Studies of Bin-Ho(瀕湖脈學)${\lrcorner}$-)

  • 이주호;최환수;김철중
    • 한국한의학연구원논문집
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    • 제10권1호
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    • pp.49-61
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    • 2004
  • The Standardization of terms in The Pulse studies(脈學) is a need for development of learning. This study, for the correction of existing misused terms in The Pulse studies, we study on modernly and objectively the terms in The Pulse studies. By a focus of ${\ulcorner}$The Pulse Studies of Bin-Ho(瀕湖脈學)${\lrcorner}$, we studies on the new classification of pulse condition. The error of a existing technical books on Pulse studies begin that the classification of pulse condition is not establish a Standardization. For the correction of existing misused terms in The Pulse studies, we study on the pulse condition is expressed objectively a blood vessel that it is a subject of pulse condition. The expression of blood vessel contain a depth of blood vessel, a speed of pulsation, a curve of blood vessel, thickness of blood vessel, a diameter of blood vessel in expand and contract of blood vessel, a interval in expand and contract of blood vessel, a distinctness on a boundary of blood vessel, a speed of blood flow in blood vessel, a volume of blood flow in blood vessel, a condition of blood in blood vessel, a propelling power of blood vessel. These is standard of the new classification of pulse condition.

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아동혈압의 시계열 변화 양상 및 평균혈압에 관련된 요인 분석 (The Change of Children's Blood Pressure and Factors Affecting the Level of Blood Pressure In Children)

  • 서일;김일순;남정모;이순영;오희철;김춘배;박은철
    • Journal of Preventive Medicine and Public Health
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    • 제22권3호
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    • pp.303-312
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    • 1989
  • To show the distribution and change of blood pressure according to age and to find factors affecting the level of blood pressure in primary school children, a follow-up study was conducted from 1986 to 1989 on 401 first grade children attending primary school in Kangwha County in 1986 and their parents. The blood pressure of the children was significantly increased according to age. The average annual increase was 1.8mmHg in systolic blood pressure and 2.5mmHg in diastolic blood pressure. The level of blood pressure did not show any significant difference in both sexes. Among children who were at or above the 80th percentile of blood pressure in the first grade, 35 and 30% of them have remained at the same level of systolic and diastolic blood pressure respectively in the fourth grade. But we could not find any significance in the tracking of blood pressure of children who were at or above the 90th percentile of blood pressure in the first grade. Weight and pulse rate were shown to be significant factors affecting systolic blood pressure in children of both sexes and mother's blood pressure and skinfold thickness were also affected systolic blood pressure in girls. The variables significantly affecting diastolic blood pressure were arm circumference and pulse rate for boys and height and pulse rate for girls.

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초음파로 측정된 내장지방두께의 복부 비만지표로서의 유용성 (The Usefulness of Visceral Fat Thickness Measured by Ultrasonography as an Abdominal Obesity Index)

  • 김용균;한만석
    • 대한방사선기술학회지:방사선기술과학
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    • 제31권3호
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    • pp.249-258
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    • 2008
  • 목적 : 복부비만 특히 내장지방의 과잉축적은 대사증후군 발생에 밀접한 관련이 있는 것으로 알려져 있다. 따라서 내장지방의 정확한 평가는 중요하며, 초음파 측정법은 간편하고, 안전하게 내장지방을 평가할 수 있는 방법으로 보고되고 있다. 본 연구는 초음파에 의해 측정된 복부 내장지방두께와 신체계측지표 및 대사증후군 관련인자와의 연관성을 확인하고, 대사증후군 예측을 위한 내장지방두께 기준을 알아보고자 하였다. 대상 및 방법 : 2008년 1월부터 4월까지 대전 D 건강검진센터에 내원한 건강검진자 중 400명(남자 200명, 여자 200명)을 대상으로 하였다. 초음파 검사로 제대 바로 위에서 내장지방 및 피하지방두께를 측정하였고, 신체계 측지표로 체질량지수, 허리둘레, 허리둘레/키 비를 측정하였으며, 대사증후군 관련인자로 혈압, 고밀도콜레스테롤(HDL-C), 중성지방(TG), 공복혈당(FBS)을 측정하였다. 초음파 측정지표와 신체계측지표 및 대사증후군 관련인자와의 상관관계를 분석하였으며, ROC곡선을 이용하여 대사증후군 예측을 위한 내장지방두께를 산출하였다. 결과 : 내장지방두께는 허리둘레(r=0.683/남, r=0.604/여), 허리둘레/키 비(r=0.633/남, r=0.595/여) 및 체질량지수(r=0.621/남, r=0.534/여)와 남녀 모두에서 유의한 상관관계가 있었으며, 수축기혈압(r=0.229/남, r=0.232/여), 이완기혈압(r=0.285/남, r=0.254/여), 고밀도콜레스테롤(r=-0.254/남, r=-0.326/여), 중성지방(r=0.475/남, r=0.411/여), 공복혈당(r=0.158/남, r=0.234/여)과 남녀 모두에서 유의한 상관관계가 있었다. 대사증후군 예측을 위한 내장지방두께의 cut-off value는 남자 4.58cm (민감도 89.2%, 특이도 71.2%), 여자 3.50cm (민감도 61.2%, 특이도 80.8%)이었으며, 내장지방두께가 남자에서 6cm, 여자에서 5cm 이상부터 대사중후군 위험성이 급격히 증가하였다. 결론 : 초음파로 측정된 내장지방두께는 신체계측지표 및 대사증후군 관련인자와 남녀 모두에서 유의한 상관 관계가 있었으며, 대사증후군 예측을 위한 내장지방두께 기준은 남자 4.58cm, 여자 3.50cm 이었다. 초음파로 측정된 내장지방두께는 복부비만의 유의한 지표가 될 수 있을 것으로 생각된다. 다만 임상에서 복부 비만 지표로 활용되기 위해서는 측정방법의 표준화가 이루어져야 할 것으로 사료된다.

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일부 농촌 지역 성인에서 C-reactive protein농도와 경동맥 내중막 두께 (C-reactive Protein and Carotid Intima-media Thickness in a Population of Middle-aged Koreans)

  • 서민아;이주영;안성복;김현창;서일
    • Journal of Preventive Medicine and Public Health
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    • 제42권1호
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    • pp.29-34
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    • 2009
  • Objectives : This study was performed to evaluate the relationship between C-reactive protein(CRP) and carotid intima-media thickness(carotid IMT) in a population of middle-aged Koreans. Methods : A total of 1,054 men and 1,595 women(aged 40-70 years) from Kanghwa County, Korea, were chosen for the present study between 2006 and 2007. We measured high-sensitivity CRP and other major cardiovascular risk factors including anthropometrics, blood pressure, blood chemistry, and carotid ultrasonography. Health related questionnaires were also completed by each study participant. Carotid IMT value was determined by the maximal IMT at each common carotid artery. The relationship between CRP level and carotid IMT was assessed using multiple linear and logistic regression models after adjustment for age, body mass index, menopause(women), systolic blood pressure, total/HDL cholesterol ratio, triglyceride level, fasting glucose, smoking, and alcohol consumption. Results : Mean carotid IMT values from the lowest to highest quartile of CRP were 0.828, 0.873, 0.898, and 0.926 mm for women(p for trend<0.001), and 0.929, 0.938, 0.949, and 0.979 mm for men(p for trend=0.032), respectively. After adjustment for major cardiovascular risk factors, the relationship between CRP and carotid IMT was significant in women(p for trend=0.017), but not in men(p for trend=0.798). Similarly, adjusted odds ratio of increased IMT, defined as the sex-specific top quartile, for the highest versus lowest CRP quartiles was 1.55(95% CI=1.06-2.26) in women, but only 1.05(95% CI=0.69-1.62) in men. Conclusions : CRP and carotid IMT levels appear to be directly related in women, but not in men.

협착된 경동맥 내의 벽전단응력 및 혈관의 탄성적 거동 (Elastic Motion of the Blood Vessel and Wall Shear Stress in Carotid Artery with Stenosis)

  • 김창녕;오택열;최명진;정삼두
    • 한국정밀공학회지
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    • 제22권9호
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    • pp.179-187
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    • 2005
  • The characteristics of blood flow and the interaction between the blood vessel and blood flow play important roles in plaque cap rupture and the growth of atherosclerosis which may lead directly to a heart attack or a stroke. In this study, carotid arteries with different stenoses have been numerically simulated to investigate the wall shear stress(WSS) and the elastic motion of the vessel. Blood flow has been treated as physiological, laminar and incompressible flow. To model the shear thining behavior of the blood, the Carreau-Yasuda model has been employed but the viscoelasticity of blood has not been considered. The results show that the WSS of $severe(75\%)$ stenosis is much higher than those of $25\%\;and\;50\%$ stenosis in the region of stenosis. With the increase in the stenosis thickness, the expansion ratio of the center of the stenosis decreases while the expansion ratio of the upstream region of the stenosis increases.

Recombinant human erythropoietin을 이용한 무수혈 구강암절제 및 재건 (Oral cancer resection and reconstruction without blood transfusion by using recombinant human erythropoietin)

  • 김철환;이충현
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제37권1호
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    • pp.9-14
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    • 2011
  • Recently, the population of patients who refuse transfusion has increased for both religious and non-religious reasons, even in life threatening emergency situations. Their refusal has highlighted the need to develop nonblood transfusion surgery techniques to decrease the risk from blood transfusions. A 57-year woman with an ulcerative lesion on the gingiva of the right upper molar area visited the department of oral and maxillofacial surgery in Dankook University Dental Hospital. After a preliminary evaluation, the patient was diagnosed with squamous cell carcinoma. As she refused blood transfusion during surgery for religious reasons, surgery was planned using recombinant human erythropoietin (rHuEPO) without a blood transfusion. The patient underwent a partial maxillectomy, supraomohyoid neck dissection, free radial forearm flap and split thickness skin graft under general anesthesia. rHuEPO and iron were used before and after surgery. The hemoglobin/hematocrit (Hb/Hct) level, iron (Fe) and total iron-binding capacity (TIBC) were assessed. The patient recovered completely without any blood transfusions. rHuEPO is a viable alternative for patients with religious objections to receiving blood transfusions.

X-ray PIV 기법의 개발과 혈액 유동에의 적용연구 (Development of X-ray PIV Technique and its Application to Blood Flow)

  • 김국배;이상준
    • 대한기계학회논문집B
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    • 제29권11호
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    • pp.1182-1188
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    • 2005
  • An x-ray PIV (Particle Image Velocimetry) technique was developed to measure quantitative information on flows inside opaque conduits and on opaque-fluid flows. At first, the developed x-ray PIV technique was applied to flow in an opaque Teflon tube. To acquire x-ray images suitable for PIV velocity field measurements, refraction-based edge enhancement mechanism was employed using detectable tracer particles. The optimal distance between with the sample and detector was experimentally determined. The resulting amassed velocity field data were in reasonable agreement with the theoretical prediction. The x-ray PIV technique was also applied to blood flow in a microchannel. The flow pattern of blood was visualifed by enhancing the diffraction/interference -bas ed characteristic s of blood cells on synchrotron x-rays without any contrast agent or tracer particles. That is, the flow-pattern image of blood was achieved by optimizing the sample (blood) to detector distance and the sample thickness. Quantitative velocity field information was obtained by applying PIV algorithm to the enhanced x-ray flow images. The measured velocity field data show a typical flow structure of flow in a macro-scale channel.