• The Korean Journal of Pain
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• v.23 no.2
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• pp.142-146
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• 2010

Background: Stellate ganglion block (SGB) is known to increase blood flow to the innervations area of the stellate ganglion. Near infrared spectroscopy reflects an increased blood volume and allows continuous, non-invasive, and bedside monitoring of regional cerebral oxygen saturation ($rSO_2$). We investigated the influence of SGB on bilateral cerebral oxygenation using a near infrared spectroscopy. Methods: SGB was performed on 30 patients with 1% lidocaine 10 ml using a paratracheal technique at the C6 level and confirmed by the presence of Horner's syndrome. The blood pressure (BP), heart rate (HR) and rSO2 were measured before SGB and 5, 10, 15 and 20 minutes after SGB. Tympanic temperature of each ear was measured prior to SGB and 20 minutes after SGB. Results: The increments of the $rSO_2$ on the block side from the baseline were statistically significant at 5, 10, 15 and 20 minutes. The $rSO_2$ on the non-block side compared with the baseline, however, decreased at 15 and 20 minutes. The difference between the block and the non-block sides was significant at 15 and 20 minutes. The BP at 10, 15 and 20 minutes was increased and the HR was increased at 10 and 15 minutes. Conclusions: We observed an increment of the $rSO_2$ on the block side from the baseline; however, the $rSO_2$ on the non-block side decreased.

• Journal of Soil and Groundwater Environment
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• v.11 no.4
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• pp.10-17
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• 2006

Laboratory-scale two-dimensional aquifer physical model studies were conducted to assess the effect of air injection rate and air injection pattern on the removal of disel contaminated soil and groundwater by air/bio-sparging. The experimental results were represented that the optimal conditions in this experiment were as air injection rate of 1,000 ml/min and pulsed air injection pattern(15 min on/off). The results of the TPH reduction, DO consumption and $CO_2$ production indicate the effective biodegradation evidence of diesel. Based on our results, The minimal $O_2$ supply and pulsed air injection pattern could effectively enhance the diesel removal and the pulsing air injection had effect on oxygenation in this system. Thus, the cost of operating air/bio-sparging system will be reduced if optimal air injection rate and pulsed air injection pattern are applied to remediate contaminants.

• Journal of Chest Surgery
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• v.51 no.1
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• pp.22-28
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• 2018

Background: Lung transplantation is a life-saving procedure in patients with end-stage lung disease, and is increasingly performed in Korea. Methods: We retrospectively evaluated the outcomes of patients who received a lung transplant at Asan Medical Center between January 2008 and December 2016. Thirteen of 54 patients experienced multiorgan transplantation; the remaining 41 who received only lung grafts were included. Results: The mean age of the lung transplant recipients was 44.6 years; 27 were men and 14 were women. The most frequent reasons were idiopathic interstitial pneumonia (21 of 41 patients, 51.2%), interstitial lung disease (9 of 41, 22.0%), and bronchiolitis obliterans after bone marrow transplantation (7 of 41, 17.1%). The median waiting time was 47 days, and many patients received preoperative intensive care (27 of 41, 65.9%), ventilator support (26 of 41, 63.4%), or extracorporeal life support (19 of 41, 46.3%). All 41 patients received bilateral lung grafts. Ten deaths occurred (24.3%), including 5 cases of early mortality (12.2%) and 5 cases of late mortality (12.2%). The 1-, 3-, and 5-year survival rates were 78.9%, 74.2%, and 69.3%, respectively. Conclusion: Despite a high percentage of patients who required preoperative intensive care, the transplantation outcomes were acceptable.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.622-624
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• 2015

Tumor hypoxia caused by the unique characteristics of solid tumor sites such as lowered vascular density, irregular vasculature, longitudinal oxygen gradient, and unbalanced oxygen consumption has decreased therapeutic efficacy in several clinical trials such as radiation, chemotherapy, and surgery. Hence, tumor oxygenation studies at microvascular levels are important to provide better understanding of the complexity of microvasculature oxygen transport and exchange with tissue. However, polarographic microelectodes, was employed to measure $pO_2$ at the microvasculature level, but it is difficult to perform and does not provide significant spatial and temporal information of oxygen delivery. In this research, we introduce the hyperspectral imaging system able to provide a wide range of vascular characteristics by spatial maps on hemoglobin saturation information for better understanding of the relationship between blood oxygen delivery, hypervascularity, aberrant angiogenesis at microvasculature levels during tumor growth.

• Journal of computational fluids engineering
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• v.21 no.1
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• pp.103-109
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• 2016

With the rapid increase in the number of patients with cardiopulmonary diseases, more cardiopulmonary circulatory assist devices are also needed. These devices can be employed when heart and/or lung function poorly. Due to the critical role they take, these devices have to be designed optimally from both mechanical and biomechanical aspects. This paper presents the CFD results of a baseline model of a centrifugal blood pump for the ECMO condition. The details of flow characteristics of the baseline model together with the performance curves and the modified index of hemolysis(MIH) are investigated. Then, the geometry of baseline impeller and the volute are modified in order to improve the biomechanical performance and reduce the MIH value. The numerical simulations of two cases represent that when impeller radius and prime volume decrease the MIH value also decreases. In addition, the modified geometry shows more uniform pressure distribution inside the volute. The findings provide valuable information for further modification and improvement of centrifugal blood pumps from both mechanical and biomechanical aspects.

• Journal of Korean Critical Care Nursing
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• v.9 no.1
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• pp.66-76
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• 2016

Purpose: This study was conducted to examine the relationship between lateral position change and sternal complications after cardiac surgery through median sternotomy. Methods: This study was a retrospective descriptive case-control study, involving 241 patients who underwent cardiac surgery through median sternotomy. Data from October 2011 to September 2014 were collected. Results: Sternal complications (i.e. dehiscence, sternal instability, mediastinitis) developed in 33 patients (13.7%). Primary symptoms of complications were discharge and erythema, and the mean time difference from surgery to appearance of symptoms was 15 days (range, 1-138 days). The factors associated with sternal complications were cancer comorbidity (${\chi}^2=5.22$, p=.039), internal mammary artery procedure (${\chi}^2=4.16$, p=.041), and duration of extra-corporeal membrane oxygenation (p=.033). Position change was not related to incidence of sternal complications (${\chi}^2=0.14$, p=.704). Pressure ulcers appeared in 63 patients (26.1%). Mean time difference from surgery until occurrence of ulcers was 6.7 hours (range, 0-323.0 hours), but position change was started from 132.4 hours (range, 27.1-503.2 hours) after intensive care unit admission. Conclusions: These results provide baseline data to create a standard position change and activity protocol for patients after median sternotomy. Furthermore, the study could help clinical practitioners establish evidence-based nursing practices.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.94-94
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• 2001

Prostaglandin endoperoxide H synthase (PGHS) catalyzes the committed step in prostaglandins and thromboxane A$_2$-- oxygenation of arachidonic acid to the hydroperoxy endoperoxide PGG$_2$, followed by reduction PGG$_2$to the alcohol PGH$_2$. The two reactions by PGHS -- cyclooxygenase and peroxidase -- occur at distinct but structurally and functionally interconnected sites. The peroxidase reaction occurs at a heme-containing active site located near the protein surface. The cyclooxygenase reaction occurs in a hydrophobic channel in the core of the enzyme. Initially a peroxide reacts with the heme group, yielding Compound I and an alcohol derived from the oxidizing peroxide. Compound I next undergoes an intramolecular reduction by a single electron traveling from Tyr385 along the peptide chain to the proximal heme ligand, His388, and finally to the heme group. Following the binding of arachidonic acid, Tyr385 tyrosyl radical initiates the cyclooxygenase reaction by abstracting the 13-pro(5) hydrogen atom to give an arachidonyl radical, which sequentially reacts with two molecules of oxygen to yield PGG$_2$. In order to characterize PGHS peroxidase active site, we examined various lipid peroxides with purified recombinant ovine PGHS proteins and determined the rate constants. The results have shown that twenty-carbon unsaturated fatty acid hydroperoxides have similar efficiency in peroxidation by PGHS, irrespective of either the location of hydroperoxy group or the number of double bonds. It was also confirmed by the subsequent study with PGHS peroxidase active site mutants.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.352-355
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• 2002

The purpose of this study was to investigate whether or not acupuncture of GB34 produces a significant response of the modulation of somatomotor areas by functional magnetic resonance imaging (fMRI) study. The acupoint, GB34, located in the back of the knee, is known to be effective in recovering motor function after stroke. Using 3T MRI scanner, functional MR imaging of the whole brain was performed in 12 normal healthy subjects during two stimulation paradigms; acupuncture manipulation on GB 34 and sham points. This study investigates the activation of the mortor cortex elicited by a soft and an intensified stimulation of GB 34. Three different paradigms were carried out to detect any possible modulation of the Blood Oxygenation Level Dependent (BOLD) response in the somatomortor area to motor stimulation through acupuncture. Group analysis from seven individuals showed that bilateral sensorimotor areas (BA 3,4,6 and 7) showed stimulation related BOLD signal contrast of approximately 6% whereas very few areas were activated when sham stimulation is given. The present study shows that acupuncture fMRI study can be safely conducted in 3T MRI environment, and acupuncture stimulation in GB34 modulates the cortical activities of the somatomotor area in human. The present findings may shed light on the CNS mechanism of motor function by acupuncture and form a basis for future investigations of motor modulation circuits in the stroke patients.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.347-356
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• 2005

The wound healing process in fetus is quite different form that of adult. Regeneration plays an important role and scarless wound healing is possible in early gestational fetal period. Recently, the various effects of the hypoxia and reoxygenation in the wound healing process have been investigated by many researchers. The hypoxic state is known to alter protein synthesis and gene expression of TGF-${\beta}$, VEGF. The authors hypothesize there may be differences between fetal and adult fibroblast and this difference may play a possible role in the mechanism of scarless fetal wound healing. In this study, we investigated the growth of fibroblast, the amount of collagen deposition, the amount of protein synthesis and gene expression in TGF-${\beta}$(transforming growth factor-${\beta}$), VEGF(vascular endothelial growth factor) under the various hypoxic and reoxygenation conditions. Through these processes, we tried to determine the relationships between scarless fetal wound healing and hypoxic condition. In control group, fetal and adult fibroblasts were cultured under normoxic condition. The experimental groups were allocated into four different groups. The differences in TGF-beta, VEGF under 24, 48, 72 hours were statistically investigated. Compared to adult fibroblast group, there was a statistically significant increase (p<0.01) in the rates of protein synthesis in TGF-beta and VEGF of fetal fibroblast. In this study, these results may reflect the possibility that fetal fibroblast are more susceptible to change in oxygen and has a superior rate of angiogenesis through increased VEGF expression. The possible superiority of angiogenesis in fetal fibroblast may play an important role in scarless wound healing.

• Journal of The Korean Society of Clinical Toxicology
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• v.3 no.1
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• pp.27-32
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• 2005

Purpose: The frequency of carbon monoxide poisoning has been decreased in the interior of the Korea. But occasionally it is occurred and the risk of exposure is high in working place so far. Because of the characteristics of gas, the detection of exposure and poisoning could be delayed and fatality is high. We should apprehend of carbon monoxide poisoning. So we would report analysis of patients with carbon monoxide poisoning. Methods: A retrospective review of CO poisoned patients visited emergency department from January 2000 to December 2004 was conducted. Results: 24 patients were enrolled. Their average of age was $37.6\pm20.9$ years old and COHb was $19.4\pm13.32\%$. The blood level of initial COHb and mental status on arrival were not correlated each other. The blood level of initial COHb and loss of consciousness were not correlated, too. Initial electrocardiography (EKG) was not correlated with cardiac enzymes such as CK-MB and troponin I. But base excess was correlated with mental status on arrival and complication such as rhabdomyolysis. Hyperbaric oxygen therapy was correlated with base excess and mental status on arrival. Conclusion: The clinical features of carbon monoxide poisoning are nonspecific. For proper diagnosis, it is important that we should consider patient's environment and take patient's history carefully. The blood level of initial COHb does not reflect severity of poisoning accurately. So We should determine the treatment of choice depending on patient's status.