• Journal of Mechanical Science and Technology
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• v.15 no.5
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• pp.613-622
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• 2001

Interaction of blood flow and leaflet behavior in a bileaflet mechanical heart valve was investigated using computational analysis. Blood flows of a Newtonian fluid and a non-Newtonian fluid with Carreau model were modeled as pulsatile, laminar, and incompressible. A finite volume computational fluid dynamics code and a finite element structure dynamics code were used concurrently to solve the flow and structure equations, respectively, where the two equations were strongly coupled. Physiologic ventricular and aortic pressure waveforms were used as flow boundary conditions. Flow fields, leaflet behaviors, and shear stresses with time were obtained for Newtonian and non-Newtonian fluid cases. At the fully opened phase three jets through the leaflets were found and large vortices were present in the sinus area. At the very final stage of the closing phase, the angular velocity of the leaflet was enormously large. Large shear stress was found on leaflet tips and in the orifice region between two leaflets at the final stage of closing phase. This method using fluid-structure interaction turned out to be a useful tool to analyze the different designs of existing and future bileaflet valves.

• Journal of Korean Biological Nursing Science
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• v.13 no.2
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• pp.134-141
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• 2011

Purpose: Although the risk factors of metabolic syndrome have been extensively studied, the association between osteoporosis and metabolic syndrome has remained unclear in Korean elderly women. Yet to be determined are the effect of risk factors of metabolic syndrome on osteoporosis in these subjects. The purpose of this study was to investigate how the risk factors of metabolic syndrome affect the bone mineral density in Korean elderly women. Methods: One hundred twenty one elderly women from a community center in Seoul elderly welfare center participated in this study. A structured questionnare was used to assess their demographics and lifestyles. Participants' anthropometric information was also obtained by measuring heights, weights, and waist circumferences. The blood samples were also obtained to measure blood glucoses and blood lipids. Bone mineral density was measured with the use of ultra sono. Results: The prevalence of metabolic syndrome in our subjects was 58%. In multivariate regression analysis, fasting plasma glucose level (p=.036) and triglycerides (p=.006) were significant factors predicting bone mineral density after adjusting age and other factors of metabolic syndrome. In age-adjusted analysis, women with metabolic syndrome had significantly higher bone mineral density as compared to those without metabolic syndrome (p=.026). Conclusion: Bone mineral density among elderly Korean women is associated with the level of blood glucose and triglycerides.

• Environmental Analysis Health and Toxicology
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• v.20 no.4 s.51
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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.

• Progress in Medical Physics
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• v.9 no.1
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• pp.23-28
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• 1998

We measured the flow at peripheral blood vessel of finger dorsum surface using noninvasive LDF(Laser Doppler Flowmeter). We investigated the flow properties between the normal and the diabetic with the Amplitude Spectral Densities of FFT analysis. We classified the diabetic as four groups of negative neuropathy, positive neuropathy, hyperthyroid and hypothyroid. And tested the neuropathic and thyroid effects of peripheral blood flow. As the results, the diabetic, the positive neuropathic and the hypothyroid respectively showed the abnormal blood flow properties on the contrary of the normal flow of negative neuropathic and hyperthyroid.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5691-5695
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• 2015

Background: Continuous surveillance of pattern of blood stream infection is necessary in febrile neutropenia (FN)especially with the recent escalating trend in the management of pediatric cancer patients towards intensified regimens and with the increase in infections caused by resistant organisms limiting the choice of antibiotics. Aim: To monitor change in pattern of blood stream infections (BSI) in FN pediatric cancer patients. Materials and Methods: Surveillance of FN episodes with positive BSI was prospectively monitored and compared to a previous surveillance in the same pediatric oncology unit. Results: A total of 232 BSI positive episodes were documented in 192 patients during a 6 months period. The results of recent surveillance analysis showed an increase in intensified regimens of chemotherapy, antimicrobial resistance, fungal infections, and prolonged duration of episodes when compared to previous surveillance, with p value sof <0.001, 0.005, 0.021, and <0.001, respectively. There was an apparent decrease in the crude mortality but this was not statistically significant, to 6% in 2011 from 10 % in 2006. Conclusions: The pattern of BSI at our institution is still inclining towards gram positive organisms but is showing a shift towards more antibiotic resistance and fungal infections.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.753-758
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• 2003

The purpose of the present study was to establish the mechanism of the generation of atherosclerosis by analyzing the hemodynamic variables in the coronary artery where atherosclerosis occurs frequently. From the previous results, the stenosis phenomena due to atherosclerosis were related to not only biochemical reaction between blood and blood vessel but also the hemodynamic factors like flow separation and oscillatory wall shear stress. The present study aimed to investigate the causes of the generation and progression of atherosclerosis in the coronary artery. This study also aimed to develop the softwares which generate automatically three dimensional vascular models obtained by the angiogram images and the computer vision techniques. In the present study, the flow patterns for full three-dimensional hemodynamic characteristics were analyzed. To understand the three-dimensional hemodynamic characteristics, the wall shear stress distributions and secondary flows were investigated quantitatively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.729-735
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• 2005

This study was to analyze the difference between blood type and blood constitution according to Sasang constitution. The subjects were 302 men who visited blood donation house. Data collection was performed by using questionnaire that included three types of Sasang constitution. The data were analyzed as frequency, percentage, ${\chi}$2-test and ANOVA using SPSS 10.0 WIN Program. There was significant difference statistically in frequency of blood type as per Sasang constitution(${\chi}$2 =53.254, p=.000). Soyangin got most number in B type(34.7%), O type(26.7%), A type(21.8%), AB type(16.8%) in order. Taewumin got most number in O type (45.8%), A type(31.3%), B type(22.1%) and AB type(0.8%) in order, and in case of Sowumin, most in A type(54.3%), B type(24.3%), O type (11.4%) and AB type(10.0%) in order. In weight, height, fatness, hemoglobin, Hematocrit, platelet, ALT, AST and cholesterol, it appears that there is significant difference according to Sasang constitution. If proper regimen according to Sasang constitution by grasping the special features as per Sasang constitution through analyzing the difference as per Sasang constitution based on the results of above study is applied.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.149-155
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• 2013

For in-depth research of blood flow, it is important to create pulsating flow like the blood flow from heart beat. In this study, we developed a heart mimicking pulsatile pump and evaluated its performances. Main body of pump was produced using a piston pump, and its rpm and duty ratio was modulated by DC motor and encoder. To determine the part dimensions, principle stress theory and simple fluidic pressure analysis were used. The performance of pulsating pump was evaluated by comparing the pressure values and their deviations according to experimental variables. For the results, the output value of pressure followed the distribution of pulsating flow and its deviation was negligible. Through this study, we expect the established pulsating pump can be widely used in study of blood flow produce easy ways to related researchers.

• Journal of the Korean Chemical Society
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• v.57 no.5
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• pp.568-573
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• 2013

A selective and sensitive method for simultaneous determination of copper in blood by adsorptive differential pulse cathodic stripping voltammetry is presented. The procedure involves an adsorptive accumulation of Cu(II)-ETSC (4- ethyl-3-thiosemicarbazide) on a hanging mercury drop electrode, followed by a stripping voltammetry measurement of reduction current of adsorbed complex at about -715 mV. The optimum conditions for the analysis of copper (II) ion are : pH 10.3, concentration of 4-ethyl-3-thiosemicarbazide $3.25{\times}10^{-6}$ M and an accumulation potential of -100 mV. The peak current is proportional to the concentration of copper over the range 0.003-125 ng/mL with a detection limit of 0.001 ng/mL and an accumulation time of 60 s. Moreover, with the use of the proposed method, there is a considerable improvement in the detection limit, the linear dynamic range and the deposition time, compared with the methods of adsorptive stripping voltammetry for the determination of copper. The developed method was validated by analysis of whole blood certified reference materials.

• The Korean Journal of Emergency Medical Services
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• v.9 no.1
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• pp.111-119
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• 2005

Glucose is the most importantenergy source in the central nervous system. Because the central nervous system cannot synthesize or store glucose. low blood glucose even for a short period results in no functionally normal activity of the brain. In addition, continuous low blood glucosecan cause irreversible brain damage and brain death. Therefore, the current status of emergency care by first aid staffs during transfer of patients with hypoglycemia has been investigated in this study, 114 patients who have visited the hospital using 119 Emergency Medical Service from January 1, 2004 till December, 2004 and shown blood glucose of 2.8 mmol/L and less on arrival have been involved. In case of nurses, assistant nurses, first aid staffs receiving first aid training and second-class emergency medical technicians(EMTs), they provided basic life support (BLS). In case of first-class EMTs, they measured blood sugar and then they orally administered glucose to conscious patients or provided simple first aids and prompt transfer for unconscious patients. As a result of analysis, it is suggested that first aid retraining is required.