• Bulletin of the Korean Chemical Society
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• v.21 no.9
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• pp.923-928
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• 2000

[FeIII(BBA)DBC]ClO4 as a new functional model for catechol dioxygenases has been synthesized, where BBA is a bis(benzimidazolyl-2-methyl)amine and DBC is a 3,5-di-tert-butylcatecholate dianion.The BBA complex has a structuralfeature that iron cent er has a five-coordinate geometry similar to that of catechol dioxygenase-substrate complex.The BBA complex exhibits strong absorptionbands at 560 and 820 nm in CH3CN which are assigned to catecholate to Fe(III) charge transfer transitions. It also exhibits EPR signals at g = 9.3 and 4.3 which are typical values for the high-spin FeIII (S = 5/2) complex with rhombicsymmetry. Interestingly, the BBA complex reacts with O2 within an hour to afford intradiol cleavage (35%) and extradiol cleavage (60%) products. Surprisingly, a green color intermediate is observed during the oxygenation process of the BBA com-plex in CH3CN. This green intermediate shows a broad isotropic EPR signal at g = 2.0. Based on the variable temperature EPR study, this isotropic signalmight be originated from the [Fe(III)-peroxo-catecholate] species havinglow-spin FeIII center, not from the simple organic radical. Consequently,it allows O2 to bind to iron cen-ter forming the Fe(III)-superoxide species that converts to the Fe(III)-peroxide intermediate. These present data can lead us tosuggest that the oxygen activation mechanism take place for the oxidative cleavingcatechols of the five-coordinate model systems for catechol dioxygenases.

• Journal of the Optical Society of Korea
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• v.19 no.3
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• pp.284-296
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• 2015

It has been thought that males tend to use their brain hemispheres more laterally than females. However, recent fMRI studies have shown that there may be no difference in brain lateralization between genders. Functional near-infrared spectroscopy (fNIRS) presents a unique opportunity to acquire real time measurements of blood oxygenation changes to observe neural activity specific to the brain's left and right hemispheres. Using an in-house built multichannel fNIRS system, brain lateralization was observed from seven males and four females according to specially designed tasks for left and right hemisphere activation. The Pearson correlation coefficient and a modified Lateralization Index metric for continuous wave fNIRS systems were calculated to quantify brain lateralization. The preliminary results point to no significant difference in lateral hemodynamic changes between the genders. However, the correlation of symmetrical channel pairs decreased as the experiments progressed. To further develop this study, the subject's performance and the removal of global interference must be implemented for an improved study of brain lateralization.

• Journal of Chest Surgery
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• v.54 no.5
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• pp.396-399
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• 2021

A 58-year-old man, incapable of maintaining oxygen saturation with mechanical ventilation, was admitted to our hospital for veno-venous extracorporeal membrane oxygenation (ECMO) treatment. He was diagnosed with acute respiratory distress syndrome (ARDS) due to influenza A pneumonia. His condition stabilized with antibiotics and steroid administration, but weaning from ECMO failed due to post-infectious pulmonary sequelae. On day 84 after admission, he underwent bilateral lung transplantation. In the postoperative phase, he did not regain consciousness even after discontinuation of sedatives for 3 days. However, spontaneous pupillary reflex and eye movements were preserved, while communication and upper and lower limb movements were affected. The nerve conduction study was diagnostic of Guillain-Barré syndrome. He was managed with intravenous immunoglobulins and plasmapheresis. Mild recovery of the facial muscles was seen, but he died 24 days post-surgery due to progressive ARDS and sepsis.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.103-112
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• 2018

This study aimed to identify specific psychological and brain activation responses relating to the processing of negative emotions in patients with alcohol dependency. The authors hypothesized that patients with alcohol dependency would demonstrate the abnormal functioning of brain regions involved in negative emotions. Eleven male patients diagnosed with alcohol dependence in an inpatient alcohol treatment facility and 13 social drinkers with similar demographics were scanned using functional magnetic resonance imaging (fMRI) as they viewed film clips that evoked negative emotions. During exposure to negative emotional stimuli, the control group evinced significantly greater activity in the right anterior cingulate cortex (ACC) in comparison to patients with alcohol dependency. Correlation analyses demonstrated a negative association in the relationship between beta values from the right ACC and amygdala in participants classified in the control group. No statistically significant relationship was observed for blood oxygenation level-dependent (BOLD) changes between the two regions in the patient group during the elicitation of negative emotions. On the other hand, patients exhibited a greater activation of the amygdala as negative emotions were induced. These results suggest that alcoholism presents pathophysiology of brain activation that is distinct from the responses of healthy individuals functioning as controls.

• Journal of Neurocritical Care
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• v.11 no.2
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• pp.71-80
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• 2018

Nutritional assessment and support are often overlooked in the critically ill due to other urgent priorities. Unlike oxygenation, organ dysfunction, infection, or consciousness, there is no consensus of indicators. Making it difficult to evaluate the effectiveness of an intervention. Nevertheless, appropriate nutritional support in the critically ill has been associated with less morbidity and lower mortality. But, nutritional support has been considered an adjunct, for body weight maintenance and to help patients during the inflammatory phase of illness. Thus, it has been assigned a lower priority, compared to mechanical ventilation or hemodynamic stability. Recent findings have shown that nutritional support may prevent cellular injury due to oxidative stress and help strengthen the immune response. Large-scale randomized trials and clinical guidelines have shown a shift from nutritional support to nutritional therapy, with an emphasis on the importance of protein, minerals, vitamins, and trace elements. Nutrition is also important in neurocritically ill patients. Since there are few studies or recommendations with regard to the neurocritical population, the general recommendations for nutritional support should be applied.

• Clinical and Experimental Emergency Medicine
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• v.5 no.4
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• pp.278-281
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• 2018

Central retinal artery occlusion (CRAO) is considered an ophthalmologic emergency. The prognosis of this disease is very poor. Currently, there is no generally effective therapy available to treat CRAO. Hyperbaric oxygen therapy (HBOT) can increase the volume of oxygen delivered to the ischemic retinal tissue until spontaneous or assisted reperfusion occurs. We report the case of a patient who experienced sudden visual loss due to CRAO that was treated with HBOT. The patient was an 81-year-old woman who presented with CRAO in her right eye (OD). She exhibited "hand motion" visual acuity before treatment. She underwent three sessions of HBOT at a pressure of 2.8 atmospheres absolute, performed over 3 days. After 4 days in hospital, her visual acuity improved to 0.4 (OD) for far vision and 0.5 (OD) for near vision. Her vision was stable without the supply of oxygen; therefore, she was discharged.

• Journal of Korea Multimedia Society
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• v.24 no.2
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• pp.295-304
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• 2021

Learning assistance system that continuously measures user's concentration will be helpful to grasp the concentration pattern and adjust the learning method accordingly to improve the learning efficiency. Although a lot of various learning aids have been proposed, there have been few studies on the concentration monitoring system in real time. Therefore, in this study, we developed an Android-based mobile application that can measure concentration during study by using functional near-infrared spectroscopy, which is used to measure brain activity. First, the task accuracy was predicted at a maximum level of 93.75% from the prefrontal oxygenation characteristics measured while performing the visual Q&A task on 11 college students, and a concentration calculation formula based on a linear regression model was derived. Then, a survey on the usability of the mobile application was conducted, overall high satisfaction and positive opinions were obtained. From these findings, this application can be used as a customized learning aid application for users, and further, it can help educators improve the quality of classes based on the level of concentration of learners.

• Journal of Chest Surgery
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• v.54 no.6
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• pp.543-546
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• 2021

A 55-year-old woman who had received an implantable left ventricular assist device 3 months earlier presented with dyspnea and a low-flow alarm of the device. Computed tomography and log-file analysis of the device system suggested inflow cannula obstruction. Since the patient had cardiogenic shock due to pump failure, venoarterial extracorporeal membrane oxygenation (ECMO) was initiated. With ECMO, surgical exchange of the pump was considered. However, the obstruction spontaneously resolved without surgical intervention. It turned out that an obstructive thrombus was washed out by rebooting the pump. Moreover, the thrombus was embolized in the patient's left subclavian artery. The patient underwent heart transplantation 4 months after the pump obstruction accident and continued to do well.

• Journal of Chest Surgery
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• v.55 no.4
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• pp.265-273
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• 2022

Lung transplantation is considered a viable treatment option for patients with end-stage lung disease. Recent decades have seen a gradual increase in the number of lung transplantation patients worldwide, and in South Korea, the case number has increased at least 3-fold during the last decade. Furthermore, the waiting list time is becoming longer, and more elderly patients (>65 years) are undergoing lung transplantation; that is, the patients placed on the waiting list are older and sicker than in the past. Hence, proper management during the pre-transplantation period, as well as careful selection of candidates, is a key factor for transplant success and patient survival. Although referring and transplant centers should address many issues, the main areas of focus should be the timing of referral, nutrition, pulmonary rehabilitation, critical care (including mechanical ventilation and extracorporeal membrane oxygenation), psychological support, and the management of preexisting comorbid conditions (coronary artery disease, diabetes mellitus, gastroesophageal reflux disease, osteoporosis, malignancy, viral infections, and chronic infections). In this context, the present article reviews and summarizes the pre-transplantation management strategies for adult patients listed for lung transplantation.

• Journal of Chest Surgery
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• v.56 no.3
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• pp.224-227
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• 2023

Median sternotomy is a standard surgical technique used for left ventricular assist device (LVAD) implantation. However, if sternotomy has a prohibitive surgical risk, LVAD implantation can be performed through only left thoracotomy. We managed a patient with end-stage heart failure who had recently undergone coronary artery bypass grafting (CABG) elsewhere. The patient also had a deep sternal wound infection and bacteremia. Because of refractory cardiogenic shock, we performed extracorporeal membrane oxygenation (ECMO). After multiple mediastinal washouts and omental flap placement, ECMO was converted to extracorporeal LVAD (from the left ventricular apex to the descending aorta) through a left thoracotomy. The extracorporeal LVAD was maintained for 18 days and replaced by the HeartMate 3 LVAD. The patient was discharged in good condition 115 days after CABG.