• Journal of Mechanical Science and Technology
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• 제19권9호
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• pp.1761-1772
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• 2005

In blood flow passing through the mechanical heart valve (MHV) and elastic blood vessel, hemolysis and platelet activation causing thrombus formation can be seen owing to the shear stress in the blood. Also, fracture and deformation of leaflets can be observed depending on the shape and material properties of the leaflets which is opened and closed in a cycle. Hence, comprehensive study is needed on the hemodynamics which is associated with the motion of leaflet and elastic blood vessel in terms of fluid-structure interaction. In this paper, a numerical analysis has been performed for a three-dimensional pulsatile blood flow associated with the elastic blood vessel and curved bileaflet for multiple cycles in light of fluid-structure interaction. From this analysis fluttering phenomenon and rebound of the leaflet have been observed and recirculation and regurgitation have been found in the flow fields of the blood. Also, the pressure distribution and the radial displacement of the elastic blood vessel have been obtained. The motion of the leaflet and flow fields of the blood have shown similar tendency compared with the previous experiments carried out in other studies. The present study can contribute to the design methodology for the curved bileaflet mechanical heart valve. Furthermore, the proposed fluid-structure interaction method will be effectively used in various fields where the interaction between fluid flow and structure are involved.

• Proceedings of the Korean Magnestics Society Conference
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.216.2-216.2
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• 2008

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1681-1685
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• 2012

A sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed to determine valproic acid in human red blood cell (RBC). It is important to measure the drug concentration of the RBC as well as that of the plasma because of drug partitioning for pharmacokinetic and pharmacodynamic study. The method was linear over the dynamic range of 1-100 ${\mu}g$/mL with a correlation coefficient $r$ = 0.9997. The linearity of this method was established from 1 to 100 ${\mu}g$/mL for valproic acid in red blood cell with accuracy and precision within 15% at all concentrations. The intra-run and inter-run assay accuracy and coefficient of variations are all within 15% for all QC samples prepared in plasma and red blood human samples. Then, valproic acid amount by protein precipitation in plasma was quantified by LC-MS/MS mass spectrometry. The distribution ratio of VPA in RBC and plasma was analyzed by clinical samples. Based on measurement of the valproic acid in human red blood cell, this method has been applied to clinical research for study of distribution ratio of valproic acid in blood.

• Journal of the East Asian Society of Dietary Life
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• 제4권2호
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• pp.17-26
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• 1994

This study was an attempt to investigate various factions, such as the calorie, nutrient intake, physical activity, blood lipids, obesity prevalence and body fat distribution on NIDDM male diabetics. General characteristics, physical activity and exercise levels of subjects were invesigated by interviewing, daily calorie and nutrient intake were measured by convenient method. The following anthropometric measurements were made on all participats : weight, height. Also waist and hip circumference were measured on 174 male diabetics to get waist-to-hip circumference ratio as index of the body fat distribution. For measurement of plasma lipids, 12-hour fasting blood samples were drawn The results of this study were summarized as follows : 1. At the onset of diabetes, the major self-diagnosed symptoms were polydipsia, fatigue, and body weight redution 2. The average of daily energy intake of male diabetics was 2106 Kcal which is 96% of the RDA Percentage of energy is that carbohydrate:protein : pat=70:14:16. 3. Among the NIDDM male subjects, 59% was exercise regularly. 4. Obese subjects above in the ideal body weight of 120% are presently 17%, but 39% of subjects were reported to be obese in the past. The mean BMI of the male NIDDM diabetics is 23.3${\pm}$2.6 and the past mean BMI was 25.2${\pm}$2.7 The mean WHR was 0.93${\pm}$0.10. 5. When diabetics were divided into obese and nonobese group according to RBW, energy intake, blood pressure, blood glucose and total cholesterol were not significantly different between the two groups, but LDL and VLDL-cholesterol were significantly higher in the obese group. 6. RBW did not correlate with cholesterol and triglyceride, but WHR correlated significantly with cholesterol and triglyceride. In conclusion, these results from a present study support previous findings indicating that not only the degree of obesity but also the localization of fat is a risk factor for diabetes.

• Proceedings of the KSME Conference
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1923-1929
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• 2003

The present study investigated the microcirculation of blood in the left common artery (LCCA). In order to develop a mathematical model for microcirculation in LCCA, the present study adopted preexisted set of measured morphological data on anatomy, mechanical properties of the coronary vessels, viscosity of blood, the basic laws of physics, and the appropriate boundary conditions. In this study, the statistical distribution of blood pressure, blood flow, and blood volume in the LCCA were determined based on the anatomical branching pattern of the coronary arterial tree and the statistical data of blood vessel dimensions. Our calculations were in good agreement with the previous studies. The present results showed that the mean longitudinal pressure drop profile was function of the vessel order numbers. It was found that the normalized pressure drop was a logarithmic function of the compliance.

• Archives of Pharmacal Research
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• 제2권1호
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• pp.65-70
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• 1979

Distribution and binding properties of sodium salicylate the human red blood cells were studied under various experimental conditions. The effect of tonicity and hemolysis on the steady state level of the drug within the human red blood cells were accounted for in this study. When the washed cells were suspended in normal saline solution, the drug was so rapidly permeated into red cells. Since the pH of the system forces nearly complete ionization of the drug, ionic diffusion through aqueous pores is thought to be the mode of salicylate transport. Human red cell binding capacity and association constant for salicylate were estimated. This work supports the view that the red cells act asan important reservior of salicylate.

• Environmental Analysis Health and Toxicology
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• 제20권4호통권51호
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• pp.303-309
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• 2005

Essential hypertension has been considered as multifactorial disease resulted from the interaction of both environmental and genetic factors. The renin-angiotensin system (RAS) plays an important role in the regulation of blood pressure homeostasis. Recently, a homologue of angiotensin I converting enzyme, ACE2 has been focused on as a candidate gene of essential hypertension in the experiments using animal model and human being. In this study, we carried out an association study in order to clarify the relationship between the A 1075G polymorphism in the ACE2 gene and essential hypertension in Korean subjects. Because this polymorphism is located on human chromosome X, the statistical analysis for each gender was performed separately. There were no significant differences in allele distribution of the A 1075G polymorphism in the ACE2 gene between normotensives and hypertensives in the both gender groups, respectively. However, this polymorphism was significantly associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) values in only female groups (P< 0.05). Thus, these results may suggest the probable role of ACE2 gene in the inter-individual susceptibility of female group to blood pressure variability.

• YAKHAK HOEJI
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• 제50권1호
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• pp.8-14
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• 2006

A 1 : 1 mixture of acriflavine (ACF; CAS 8063-24-9) and guanosine is currently being evaluated as a possible antitumor agent in preclinical studies. Guanosine is known to potentiate the anticancer activity of some compounds. However, the distributions of trypaflavine (TRF) or proflavine (PRF) have not been investigated in mammals. We, therefore, investigated the distribution of TRF and PRF after i.m. administration of the combination mixture (ACF and guanosine) at a dose of 30 mg/kg ACF in rats. to analyze TRF and PRF levels in biological samples, we used an HPLC-based method. The calibration curves for TRF and PRF in the samples were linear over the concenration range of $0.05{\sim}200\;{\mu}g/ml$. The intra- and inter-day assay accuracies of this method were within ${\pm}15\%$ of norminal values and the precision did not exceed $15\%$ of relative standard diviation. The lower limits of quantitation were 50 ng/ml for both TRF and PRF. The distribution of TRF or PRF was determined by 48 h after i.m. administration of the combination mixture at a dose of 30 mg/kg ACF. TRF and PRF were distributed as the following order; kidney>lung>liver>small intestine>muscle. Of the various tissues, TRF and PRF were mainly distributed to the kidney and lung. The concentrations of TRF or PRF in the tissues 24 h after i.m. administration decreased to undetectable levels. The concentrations of TRF or PRF in the blood cells were comparable to those for the plasma. However, the concentrations of TRF or PRF in the both plasma and blood cells 12 h after i.m. administration were not detected. The number of the platelets in the 1 ml of the blood was calculated to be $0.183{\times}10^8/ml$ of blood. The PRF concentration in platelets was higher than that of TRF at initial times after i.m. administration of the combination mixture. However, both the TRF and PRF concentrations in the plateles 24 h after i.m. administration of the combination mixture were below the quantifiable limit. In conclusion, the concentrations of TRF or PRF in the various tissues, plasma, blood cells, and plateles decreased to undetectable levels 24 h after i.m. administration of the combination mixture at a dose of 30 mg/kg ACF.

• Journal of Preventive Medicine and Public Health
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• 제19권2호
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• pp.167-176
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• 1986

For the purpose of determinating the normal values of some parameters relevant to lead exposure, a study was carried out from April 1 to June 30, 1986 on 258 healthy Korean adults who have had no apparant lead exposure. The lead indices subjected to this study were as follows; blood lead (PbB), hemoglobin (Hb), zinc protoporphyrin in blood (ZPP), delta-aminolevulinic acid dehydratase (ALAD) activity in blood, coproporphyrin in urine (CPU), delta-aminolevulinic acid in urine (ALAU). 1) The mean value of PbB was $17.17{\pm}7.87{\mu}g/100ml$, and there was no statistically significant difference by age & sex. The distribution of PbB fitted to the log-normal distribution ($x^2=7.38$, p>0.1). 2) The mean value of Hb in male ($15.17{\pm}1.56g/100ml$) was higher than in female ($13.22{\pm}1.51g/100ml$)(p<0.01). The distribution of Hb fitted to the normal distribution ($x^2=9.40$, p>0.1). 3) The mean value of ZPP was $32.61{\pm}8.78{\mu}g/100ml$, and there was no statistically significant difference by age & sex. The distribution of ZPP fitted to the normal distribution ($x^2=13.93$, p>0.05). The correlation of ZPP & ALAD (r=-0.229), CPU (r=0.183) was statistically significant respectively. 4) The mean value of ALAD was $30.20{\pm}10.96{\mu}mol$ ALA/min/L of R.B.C., and there was no statistically significant difference by age & sex. The distribution of ALAD activity did not fit to the normal distribution. The correlation between ALAD & PbB (r=-0.219) was statistically significant 5) The mean value of CPU was $36.10{\pm}24.54{\mu}g/L$, and there was no statistically significant difference by age & sex. The distribution of CPU did not fit to the normal distribution. The correlation between CPU & PbB (r=0.185), ZPP (r=0.183) was statistically signinificant respectively. 6) The mean value of ALAU was $1.94{\pm}0.96mg/L$, and there was no statistically significant difference by age & sex. The distribution of ALAU fitted to the normal distribution ($x^2=9.76$, p>0.1).

• Journal of Preventive Medicine and Public Health
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• 제17권1호
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• pp.95-106
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• 1984

To acquire the essential basic data to the establishment of control measure for the hazardous health effect that could be caused by harmful metals, the author measured the concentrations of trace metals in whole blood of women of $20{\sim}39$ years old living in urban and rural area using atomic absorption spectrophotometer. The summarized results were as follows; 1. The mean concentration of zinc in whole blood was $10.69{\pm}8.07{\mu}g/ml$ in rural area. The frequency distribution by zinc concentration level was nearly L-type and the cumulative frequency distribution was showed bimodal type in both area. 2. The mean iron concentration in whole blood was $323.09{\pm}87.15{\mu}g/ml$ and $322.07{\pm}104.74{\mu}g/ml$ in urban and rural area, respectively. The frequency distribution was similar to normal distribution type in both area, but the cumulative distribution was unimodal type in urban area and bimodal type in rural area. 3. The mean magnesium concentration was $41.08{\pm}19.58{\mu}g/ml$ and $40.28{\pm}16.82{\mu}g/ml$ in the area, respectively. The frequency distribution type had skewness to the right and the cumulative frequency distribution was unimodal type in both area. 4. The mean copper concentration was $1.417{\pm}0.761{\mu}g/ml$ and $1.375{\pm}0.743{\mu}g/ml$ in the area, respectively. The frequency distribution type had skewness to the right and the cumulative frequency distribution was bimodal type in both area. 5. The mean manganese concentration was $0.079{\pm}0.039{\mu}g/ml$ and $0.07{\pm}0.058{\mu}g/ml$ in the area, respectively. The frequency distribution type had skewness to the right in both area but slight irregular in rural area and the cumulative distribution was unimodal and bimodal type in urban and rural area, respectively. 6. The mean cadmium concentration in whole blood was $0.031{\pm}0.026{\mu}g/ml$ in urban and $0.028{\pm}0.023{\mu}g/ml$ in rural area. The frequency distribution type had skewness to the right and cumulative frequency distribution was bimodal type in both area.