• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.353-362
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• 2000

Minimization of hemolysis is one of the key factors for successful axial flow blood pumps. It is, however, difficult to estimate the hemolytic performance of axial flow blood pumps without experiments. Instead, the Computational Fluid Dynamics(CFD) analysis enables the prediction of hemolysis. Three-dimensional fluid dynamics of axial flow pumps with different impellers were analyzed using the CFD software, FLOTRAN. The turbulence model k-$\varepsilon$ was used. The changes in turbulent kinetic energy applied to each particle (red blood cell) flowing through the pumps were computed and displayed by the particle trace method (particle spacing of 10 msec). Also, the Reynolds shear stress was calculated from the turbulent kinetic energy. The shear stress was higher behind the impellers than elsewhere. The CFD analysis could predict in vitro results of hemolysis and also the areas where hemolysis occurred. The CFD analysis was found to be a useful tool for designing less hemolytic rotary blood pumps.

• Child Health Nursing Research
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• v.26 no.1
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• pp.98-106
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• 2020

Purpose: This study utilized data from the Korean National Health and Nutrition Examination Survey (KNHANES) to explore differences in the timing of menarche in Korean girls according to blood heavy metal concentrations. Methods: This study performed a secondary analysis of cross-sectional data from the sixth KNHANES. Data from 179 female children and adolescents aged 10~18 were included in this study. The relationships of blood heavy metal concentrations (lead, mercury, and cadmium) with age of menarche were analyzed using complex sample multiple logistic regression. Results: In the participants of this study, the geometric mean values of blood lead, mercury, and cadmium concentrations were 1.15±0.04 ㎍/dL, 1.80±0.08 ㎍/L, and 0.30±0.03 ㎍/L, respectively. Mercury poisoning (>5 ㎍/L) was found in 1.5% of participants. Furthermore, significant relationships were found between blood lead and mercury concentrations and age at menarche (p for trend: p<.001 and p=.015, respectively). Conclusion: Through an analysis of national big data, this study found evidence that Korean girls showed a younger age at menarche in response to higher blood lead and mercury concentrations. To prevent and manage precocious puberty in Korean children and adolescents, a systematic policy that monitors both exposure to environmental hazards and blood heavy metal concentrations is needed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8837-8842
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• 2014

Background: Hepatitis C virus (HCV) infection is an important cause of liver cancer in Thailand. The highest prevalence of anti-HCV positive among Thai blood donors is found in the northeastern region. The present analysis of the genotype distribution among anti-HCV positive northeastern-Thai blood donors was conducted to provide a base for the epidemiological pattern of HCV infection in this region. Materials and Methods: A total of 112 HCV seropositive healthy blood donors were randomly selected and tested for the presence of HCV-RNA by RT-PCR. HCV-RNA positive samples were genotyped by direct sequencing at core region genomes and confirmed by phylogenetic analysis. Results: HCV viremia was found in 94.6% (106/112) of HCV seropositive blood donors. There were 3 major genotypes distributed among this population. HCV genotype 3a was the most prevalent (71.7%) followed by genotypes 1a (7.5%), 1b (7.5%), 6i (3.8%), 6f (2.8%) and 6n (1.9%). Conclusions: HCV genotype 3a in asymptomatic infections in northeastern Thailand is significantly higher than other previous reports. Subgenotype 6 prevalence is less than in neighboring countries and distribution patterns differ. The findings are relevant as predictors for using interferon therapy in this population.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.161-168
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• 2011

Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

• Korean Journal of Community Nutrition
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• v.7 no.6
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• pp.803-813
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• 2002

The purpose of this study was to investigate the anthropometric and blood biochemical characteristics, the dietary behaviors and health-related lifestyles of obese children in Incheon. A cross-sectional survey was conducted using anthropometric measurements, biochemical assessments and questionnaire analysis. The subjects included 7,055 obese children residing in the Incheon area (from 106 elementary schools). The degree of obesity was classified using the Obesity Index (OI) as light 20% ＜ OI ＜ 30% ; Medium 30% ＜ OI ＜ 50% ; Severe 50% ＞ OI. The statistical analysis was conducted using SPSS 10.0 program. Most subjects fell within the medium range of obesity. Most subjects had dietary problems such as overeating, unbalanced meals and skipping breakfast. The ratio of boy subjects eating green and yellow vegetables was lowe. when compared to that of the girl subjects. The boy subjects exercised more frequently and longer than the girls. As the Obesity Index increased, hypercholesterolemia significantly increased. The blood cholesterol levels of the subjects were positively correlated with body fat, waist/hip ratio and BMI; HDL cholesterol levels of the subjects were negatively correlated with the anthropometric data and the LDL cholesterol levels of the subjects were positively correlated with body fat. The blood triglycerides levels of the subjects were positively correlated with body weight, body fat, waist/hip ratio and BMI. Therefore, proper nutritional education and intervention are required for an improvement of obese children＇s dietary behavior, heath-related factors and blood lipid profiles.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.551-557
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• 2011

The purpose of this study is to investigate the relation between brachial-ankle pulse wave velocity and the features of metabolic syndrome, and differences according to sex in patients diagnosed cerebral infarction. The study group comprised 61 patients over age 30 who were diagnosed cerebral infarction, accompanied with metabolic syndrome. The brachial-ankle pulse wave velocity, blood pressure, lipid profiles, fasting blood glucose, body mass index were measured. Also we checked past history of patients. Then we analyzed the association between brachial-ankle pulse wave velocity and the features of metabolic syndrome. Pearson correlation analysis reflected the variables affecting the brachial-ankle pulse wave velocity as follows : Age, SBP(systolic blood pressure), DBP(diastolic blood pressure), FBS(fasting blood glucose) were positively correlated. As a result of regression analysis, in patients with cerebral infarction accompanied with metabolic syndrome, the brachial-ankle pulse wave velocity is affected by age to men, SBP, FBS, DBP to women. The brachial-ankle pulse wave velocity is not affected by the components of metabolic syndrome, except blood pressure, FBS, in patients with ischemic stroke.

• Journal of Genetic Medicine
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• v.13 no.2
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• pp.89-94
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• 2016

Purpose: Molecular genetic analysis is the main approach used for prenatal diagnosis of hemophilia A and B. However, in certain cases, such analysis is uninformative. In such situations, direct measurement of fetal coagulation factor levels is still the best option, and it may be the only option in some cases. This study was conducted to determine the normal ranges of mid-trimester cord blood factor VIII (FVIII) and IX (FIX) in a Korean population. Materials and Methods: Twenty-six FVIII samples and 29 FIX samples were assayed in fetal cord blood acquired by ultrasound-guided cordocentesis. Sampling was conducted during gestational ages of 19-24 weeks. Results: The mean and standard deviations for FVIII and FIX activity were $45.5{\pm}30.5%$ and $19.9{\pm}12.2%$, respectively. Ranges for FVIII and FIX were 1.5-125.0% and 6.0-52.0%, respectively. Conclusion: Our study revealed the normal ranges and lowest level of factor VIII and factor IX in non-affected normal fetus by fetal cord blood sampling during the mid-trimester in a Korea population. The factor assay of the fetal cord blood is invasive but feasible and provides important basic data related to hemophilia.

• 한국가시화정보학회:학술대회논문집
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• 2006.12a
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• pp.121-124
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• 2006

The arteries are very important in cardiovascular system and easily adapt to varying flow and pressure conditions by enlarging or shrinking to meet the given hemodynamic demands. The blood flow in arteries is dominated by unsteady flow phenomena due to heart beating. In certain circumstances, however, unusual hemodynamic conditions cause an abnormal biological response and often induce circulatory diseases such as atherosclerosis, thrombosis and inflammation. Therefore quantitative analysis of the unsteady pulsatile flow characteristics in the arterial blood vessels plays important roles in diagnosing these circulatory diseases. In order to verify the hemodynamic characteristics, in-vivo measurements of blood flow inside the extraembryonic arterial bifurcation cascade of chicken embryo were carried out using a micro-PIV technique. To analyze the unsteady pulsatile flow temporally, the (low images of RBCs were obtained using a high-speed CMOS camera at 250fps with a spatial resolution of $30{\mu}m\times30{\mu}m$ in the whole blood vessels. In this study, the unusual flow conditions such as flow separation or secondary flow were not observed in the arterial bifurcations. However, the vorticity has large values in the inner side of curvature of vessels. In addition, the mean velocity in the arterial blood vessel was decreased and pulsating frequency obtained by FFT analysis of velocity data extracted in front of the each bifurcation was also decreased as the bifurcation cascaded.

• Journal of Preventive Medicine and Public Health
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• v.44 no.2
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• pp.93-100
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• 2011

Objectives: This study was performed to identify the socioeconomic factors, health behavior factors and dietary patterns that have an influence on the fasting blood glucose in adults. Methods: This study used data collected from the 2007, 2008, 2009 Korea National Health and Nutrition Examination Survey. The final sample included 4163 subjects who were 30-59 years old and who had completed the necessary health examinations, the health behaviors survey and nutrition survey. Results: Eleven dietary patterns emerged from the factor analysis with different factor loading. After controlling for potential confounders, multiple regression analysis of the dietary patterns showed that 'fruits', 'alcohols', and 'starchy foods' affected the fasting blood. Lower consumption of 'fruits' and higher consumption of 'alcohols' and 'starch foods' were significantly associated only with an increased risk of high blood glucose. Conclusions: In the light of the results of this study, it appears pretty likely that the risk of developing high blood glucose can be reduced by changing a person's dietary patterns.

• Journal of Information Processing Systems
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• v.18 no.3
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• pp.302-310
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• 2022

Efficient use of limited blood products is becoming very important in terms of socioeconomic status and patient recovery. To predict the appropriateness of patient-specific transfusions for the intensive care unit (ICU) patients who require real-time monitoring, we evaluated a model to predict the possibility of transfusion dynamically by using the Medical Information Mart for Intensive Care III (MIMIC-III), an ICU admission record at Harvard Medical School. In this study, we developed an explainable machine learning to predict the possibility of red blood cell transfusion for major medical diseases in the ICU. Target disease groups that received packed red blood cell transfusions at high frequency were selected and 16,222 patients were finally extracted. The prediction model achieved an area under the ROC curve of 0.9070 and an F1-score of 0.8166 (LightGBM). To explain the performance of the machine learning model, feature importance analysis and a partial dependence plot were used. The results of our study can be used as basic data for recommendations related to the adequacy of blood transfusions and are expected to ultimately contribute to the recovery of patients and prevention of excessive consumption of blood products.