• Journal of Chest Surgery
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• v.29 no.1
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• pp.14-23
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• 1996

Circulatory arrest under deep hypothermia is an important auxiliary means for cardiac surgery, especially useful in pediatric patients. However, its clinical safety, particularly with regard to the neurologic outcome after long duration of circulatory arrest, is still not established. This study is a review of the eight years'clinical experience of hypothermic circulatory arrest at the Seoul national University Children's Hospital. During an eight-year period from January 1986 through December 1993, a total of 589 consecutive cardiac operations were done using circulatory arrest under deep hypothermia. Among them, 434 consecutive patients, in whom the duration of arrest was 20 minutes or more, are the subject of this study. The duration of arrest ranged from 20 minutes to 82 minutes (mean = 38.7 minutes) under rectal temperature in the range from 12.5$^{\circ}C$ to 25.8$^{\circ}C$. Early neurologic abnormalities occurred in 47 patients : seizure attacks in 28 patients, motor paralyses with or w thout seizure in 12, blindness in 2, and no recovery of consciousness in 5 patients. The rate of incidence of early neurologic abnormalities was calculated at 15.7%. 25 patients showed late neuropsychologic sequelae, such as motor paralysis (9 patients), recurrent seizures (6), developmental delay (8), and definitely low intelligence (2). The rate of incidence of late neurologic sequelae was 8.5%, By statistical analysis, the following factors were identified as the risk factors for post-arrest neurologic abnormalities ; 1) long duration of circulatory arrest, 2) lower-than-ideal body weight, 3) preexisting neurological abnormalities, 4) associated non-cardiovascular congenital anouialies, and 5) low blood pressure during the early post-arrest period. It is concluded that circulatory arrest under deep hypothermia is a relatively safe means for pediatric cardiac surgery with acceptable risk. However, to warrant maximal safety, it is desirable to limit the duration of arrest to less th n 40 minutes. In addition, it is our contention that the early post-arrest period is a very critical period during which maintenance of adequate perfusion pressure in important for the neurologic outcome.

• Fire Science and Engineering
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• v.34 no.1
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• pp.127-134
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• 2020

When a pregnant woman experiences cardiac arrest, resuscitation is of the utmost importance. Cardiac arrest in pregnant women differs from cardiac arrest in the general population since both mother and fetus need to be taken into consideration. In the event of cardiac arrest, determining whether to deliver the baby is significant. Cardiopulmonary resuscitation is not always successful, and the survival rate depends on the speed and precision of the procedure. In this study, we focus on the case of a 30-year-old pregnant woman who experienced cardiac arrest and whose family was quick to perceive her condition and call the hospital. A witness performed initial cardiopulmonary resuscitation, while rescue workers performed the advanced procedure. In this case, the patient and baby received proper treatment and left the hospital after six days. It is extremely rare for a pregnant patient to achieve return of spontaneous circulation (ROSC) or receive advanced cardiac life support before reaching the hospital. However, the woman in question in this study achieved ROSC and received both cardiopulmonary resuscitation before reaching the hospital and advanced cardiac life support at the hospital. The specifics of the case are reported in the context of a literature review.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.49-54
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• 2008

Background: Aortic diseases tend to involve the entire aorta. Hence, there is the constant possibility of the need for a secondary operation at the remnant aorta. This study analyzed our cases of secondary aortic surgery in order to determine its characteristics and problems. Material and Method: Between April 2003 and June 2007, 12 patients (6 male and 6 female) underwent thoracoabdominal aortic replacement as a secondary aortic operation. Their clinical courses were analyzed. Four of the patients underwent lower thoracobadominal aortic replacement under the normothermic femorofemoral bypass, and the others underwent an entire thoracobdominal aortic replacement under deep hypothermic circulatory arrest. Result: There was no death or paraplegia. As local complications, there were 3 cases of wound infection and 2 cases of an immediate reoperation caused by bleeding and one case of delayed wound. revision for a contaminated perigraft hematoma. As a systemic complication, there was one case of renal insufficiency, which required hemodialysis and one case of respiratory insufficiency that needed prolonged ventilator care. The mean admission period was $30{\pm}21$ days. All the patients were followed up for $626{\pm}542$ days without reoperation or other problems. Conclusion: Using properly selected patients and a careful approach, thoracoabdominal aortic replacement can be performed safely as a secondary aortic surgery.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.3
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• pp.261-267
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• 2015

To develop high-strength high-volume ground granulated blast-furnace slag (GGBFS) concrete, this study investigated the characteristics of strength development and durability of concrete with the water-to-binder ratio of 23% and the GGBFS replacement ratio of up to 65%. The results show that the compressive strength of GGBFS blended concrete is lower than that of ordinary Portland cement (OPC) concrete up to 3-day age, but the becomes higher after 7-day age. Together with strength increase, the pore structure becomes tighter, and thus the resistance to chloride ion penetration increases. Therefore, the GGBFS blended concrete has high resistance to freezing and thawing without additional air-entraining, and high resistance to carbonation despite low amount of calcium hydroxide ($Ca(OH)_2$). On the other hand, if silica fume (SF) is blended with GGBFS, the strength becomes lower than that of the concrete blended with GGBFS only, and the resistance to chloride ion penetration deceases. Therefore, it needs further studies on the reaction of SF in high-strength high-volume GGBFS concrete.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1212-1217
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• 1996

From Dec. 1993 to May 1995, 9 male and 5 female patients ranging in age from 25 to 65 years, were operated on for ascending aorta and/or aortic arch diseases. Six patients had acute aortic dissection, type A(ruptured in 4 cases); four had ruptured ascending aortic aneurysm; three had annuloaortic ectasia(ruptured in 1 cases); one had aortic arch aneurysm. The diagnostic procedures were echo cardiography and dynamic CT scan in all patients having acute dissection or rupture. The aortic angiography was performed in two cases. Indications for operations were rupture in five cases, acute aortic dissection in five cases, severe congestive heart failure in two cases, progressive aortic insufficiency in one case and impending rupture in one case. The emergent repair was performed in ten cases(71%). The surgical treatment consisted of 6 Cabrol operations, a Cabrol operation combined with arch replacement, a modified Bentall operation, 4 replacement of ascending aorta, a replacement of aortic arch, and a replacement of ascending aorta and aortic arch. Complications were a hypoxic encephalopathy, two atrial fibrillations, a sternal deheiscence, and a mediastinitis. Two early mortality(14%) were due to intractable bleeding and multiple organ failure, and one late mortality(7%) was due to ventricular arrhythmia. In eleven survivors, follow-up period was from 2 months to 12 months and the course was uneventful.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1405-1423
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• 2021

Precipitation is one of the main factors that affect water and energy cycles, and its estimation plays a very important role in securing water resources and timely responding to water disasters. Satellite-based quantitative precipitation estimation (QPE) has the advantage of covering large areas at high spatiotemporal resolution. In this study, machine learning-based rainfall intensity models were developed using Himawari-8 Advanced Himawari Imager (AHI) water vapor channel (6.7 ㎛), infrared channel (10.8 ㎛), and weather radar Column Max (CMAX) composite data based on random forest (RF). The target variables were weather radar reflectivity (dBZ) and rainfall intensity (mm/hr) converted by the Z-R relationship. The results showed that the model which learned CMAX reflectivity produced the Critical Success Index (CSI) of 0.34 and the Mean-Absolute-Error (MAE) of 4.82 mm/hr. When compared to the GeoKompsat-2 and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks (PERSIANN)-Cloud Classification System (CCS) rainfall intensity products, the accuracies improved by 21.73% and 10.81% for CSI, and 31.33% and 23.49% for MAE, respectively. The spatial distribution of the estimated rainfall intensity was much more similar to the radar data than the existing products.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.138-144
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• 2023

In this study, the effect of electrochemical treatment in mitigating alkali leaching into an aquatic environment was investigated. To modify the surface of cement paste, 1000 mA/m² of the direct current was passed through anodic graphite to the external mesh for 4 weeks. Then, the cement paste specimen was exposed to still water in air-tight condition to prevent natural healing of alkali leaching in the water. For 100 days of monitoring in water, the pH value was marginally increased at the electrochemical treatment, while control specimen ranked to the even higher pH accounting for 13.2 in the pH. Moreover, after the pH monitoring, the pH profile for the paste specimen indicated that the electrochemical treatment was effective in securing the higher alkalinity of cement matrix. The water obtained from alkali leaching process, was used to ecological test for Daphnia magna. It was evident that the electrochemical treatment had minimal adverse effect on ecological impact, while control specimen mostly immobilized the standard Daphnia magna.

• Journal of Chest Surgery
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• v.38 no.12 s.257
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• pp.852-855
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• 2005

A 85-day-old infant was successfully operated on for truncus arteriosus (type I) with interrupted aortic arch (type A) using one-stage anterior approach without circulatory arrest. Aortic arch was reconstructed by direct anastomosis of ascending aorta and descending aorta with regional perfusion and continuity of right ventricle to pulmonary artery was established with $Shelhigh^{circledR}$ pulmonic conduit. The patient experienced left bronchus compression by descending aorta immediately postoperatively, which was improved with positional change and physiotherapy. The patient had reoperation due to stenosis of valved conduit at 13 months later. The patient is currently well under follow-up of 14 months from initial repair.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.107-112
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• 2016

Safety Critical Instrumentation and Control Systems perform those functions to maintain nuclear power plants' parameters within acceptable limits established for a design basis events and anticipated operating occurrence to ensure safety function. Those digitalized systems shall protect inadvertent and non-malicious behavior to ensure the reliable operation of systems, known as a Secure Development and Operational Environment(SDOE). SDOE would be established through managerial and technical controls. The objective of this paper is to evaluate the effectiveness of Cyclic Redundancy Checksum diagnostic, which is one of technical controls for SDOE, that can confirm the integrity of software of I&C systems to establish the secure environment. The results of this assessment would be the practical implementation of design and safety review of nuclear I&C systems.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.375-379
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• 2009

Difficulty in exposing anastomotic sites is a frequently encountered problem during surgical repair of a distal aortic arch aneurysm via median sternotomy or lateral thoracotomy. Endovascular repair has th limitation that it usually requires surgical rerouting of some of the brachiocephalic branches in order to get sufficient length for proximal fixation of the stent-graft. To take advantage of each approach, we fixed the distal end of the prosthetic graft by means of a pre-mounted metallic stent instead of performing conventional surgical anastomosis during the repair of distal arch aneurysms with using median sternotomy and hypothermic circulatory arrest. We report here on our experience with such 3 patients.