• Journal of Chest Surgery
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• v.29 no.3
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• pp.331-336
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• 1996

Four operative cases of aortic valvuloplasty with leaflet extension technique using glutaraldehyde preserved tautologous pericardium are described. All patients had severe aortic regurgitation on preoperative echocardiogram, and Grade W AR on oath-angiogram. The causes of aortic regurgitation were rheumatic fever in 2 cases, degenerative change in 1 case, and 1 case of unknown cause. The autologous pericardium was fixed In a 0.625% glutaraldehyde solution for 15 minutes and rinsed in saline for an additional 15 minutes. Leaflet extension technique varied in 4 patients depending on the site and the extent of the leaflet size and lesion. There was no hospital mortality and no thromboembolic episode without anticoagulation. Post-operative cardiac size was reduced on simple chest film in all cases, and LVESD and LVEDD were reduced on folio w- up echo cardi o gram . This experience permits us to conclude that leaflet extension technique is simple and safe in valve r construction, allowing repair of aortic valves that need to be replaced.

• Journal of Environmental Science International
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• v.11 no.5
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• pp.419-436
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• 2002

The current paper reports on the enhancement of O$_3$, CO, NO$_2$, and aerosols during the Asian dust event that occurred over Korea on 1 May 1999. To confirm the origin and net flux of the O$_3$, CO, NO$_2$, and aerosols, the meteorological parameters of the weather conditions were investigated using Mesoscale Meteorological Model 5(MM5) and the TOMS total ozone and aerosol index, the back trajectory was identified using the Hybrid Single-Particle Lagrangian Integrated Trajectory Model(HYSPLIT), and the ozone and ozone precursor concentrations were determined using the Urban Ashed Model(UAM). In the presence of sufficiently large concentrations of NO$\sub$x/, the oxidation of CO led to O$_3$ formation with OH, HO$_2$, NO, and NO$_2$ acting as catalysts. The sudden enhancement of O$_3$, CO, NO$_2$ and aerosols was also found to be associated with a deepening cut-off low connected with a surface cyclone and surface anticyclone located to the south of Korea during the Asian dust event. The wave pattern of the upper trough/cut-off low and total ozone level remained stationary when they came into contact with a surface cyclone during the Asian dust event. A typical example of a stratosphere-troposphere exchange(STE) of ozone was demonstrated by tropopause folding due to the jet stream. As such, the secondary maxima of ozone above 80 ppbv that occurred at night in Busan, Korea on 1 May 2001 were considered to result from vertical mixing and advection from a free troposphere-boundary layer exchange in connection with an STE in the upper troposphere. Whereas the sudden enhancement of ozone above 100 ppbv during the day was explained by the catalytic reaction of ozone precursors and transport of ozone from a slow-moving anticyclone area that included a high level of ozone and its precursors coming from China to the south of Korea. The aerosols identified in the free troposphere over Busan, Korea on 1 May 1999 originated from the Taklamakan and Gobi deserts across the Yellow River. In particular, the 1000m profile indicated that the source of the air parcels was from an anticyclone located to the south of Korea. The net flux due to the first invasion of ozone between 0000 LST and 0600 LST on 1 May 1999 agreed with the observed ground-based background concentration of ozone. From 0600 LST to 1200 LST, the net flux of the second invasion of ozone was twice as much as the day before. In this case, a change in the horizontal wind direction may have been responsible for the ozone increase.

• Journal of Oral Medicine and Pain
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• v.38 no.3
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• pp.267-274
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• 2013

This study was performed to investigate the skeletal factors related to open lock of the temporomandibular joint(TMJ). We compared the skeletal measurements on the cephalogram and transcranial radiograph among 3 groups, open lock group consisting of consecutively filed 50 patients with at least one open lock episode within recent 1 year, temporomandibular disorder(TMD) group of 50 TMD patients without open lock diagnosed by Research Diagnostic Criteria for TMD (RDC/TMD) Axis I, and normal group of 50 patients without TMD or open lock. The patients of TMD and normal group were randomly selected in an age-and-gender-matched way with ones of open lock group. Open lock group showed smaller saddle angle than normal group on cephalograms and steeper inclination of the articular eminence than TMD and normal groups on transcranial radiographs. These results imply that the patients with the joint located more anterior and the articular eminence with steeper inclination might be riskier to TMJ open lock.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.1
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• pp.48-53
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• 2004

Purpose: Besides interferencence of esophageal motor function by the nasogastric tube, a decline of the positive gastro-esophageal pressure gradient caused by intermittent positive pressure ventilation seems to have a major role in the pathogenesis of gastroesophageal reflux (GER) in mechanically ventilated preterm infants. The aim of this study was to determine the incidence of GER and associated risk factors in mechanically ventilated preterm infants. Methods: Twenty four hour esophageal pH monitorings were performed using a antimony electrode on 11 mechanically ventilated preterm infants in Neonatal Intensive Care Unit in Pusan National University Hospital. We evaluated the following reflux parameters; reflux index, reflux episodes/hour, reflux episodes ${\geq}5min/hour$, duration of longest episode, and percent episodes ${\geq}5min$. Patients were considered to have significant GER if more than 2 among 5 parameters were satisfied. Results: The mean gestational age of the patients was 30.9 weeks, mean birth weight was 1,568 g, and mean age at the time of pH monitoring was 2.8 days. Significant GER was detected in 4 patients (36.4%). There was no relationship between the incidence of GER and gestational age, birth weight, postnatal age, or the ventilator settings. Conclusion: The incidence of GER in mechanically ventilated preterm infants was similar, compared with other previous studies. Associated risk factors of GER in these patients were not detected. Therefore, mechanical ventilation in preterm infants does not seem to be the high risk factor of GER.

• Neonatal Medicine
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• v.17 no.2
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• pp.254-261
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• 2010

Little is known about neonatal mitochondrial disease, though mitochondrial metabolic disorders may often present in the neonatal period because of the high energy requirement of neonate. In newborn period, common presentations are not specific and the disease course may be rapid and fatal. In this study, we report three cases of neonatal mitochondrial disease. The first case was strongly suspected because of sudden seizure and mental change with severe lactic acidosis, and multiorgan failure. Plasma lactate/pyruvate (L/P) ratio was increased to 55.6 with marked lactic aciduria and increased plasma alanin up to 2,237 nmol/mL. In the second patient, a peritoneal dialysis was performed for acute adrenal and renal failure, but metabolic acidosis persisted. Plasma L/P ratio was increased to 23.9, and MRC I (mitochondrial respiratory chain defect) was diagnosed through the enzymatic analysis of the muscles. The third case showed repetitive episode of lactic acidosis during the first two months of life, hypotonia, failure to thrive and feeding difficulties. We found markedly increased cerebrospinal fluid L/P ratio up to 57 though plasma L/P ratio(19.4) was borderline with increased plasma lactate. The lactate peak was prominent in brain magnetic resonance spectroscopy (MRS). MRC II was confirmed through muscle biopsy. Plasma lactate level and lactate peak of brain MRS were normalized after conservative treatment.

• The Journal of the Petrological Society of Korea
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• v.27 no.2
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• pp.73-84
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• 2018

In the northern Cheongsong, there are occurred igneous intrusions: Cheongsong dike swarm, Jungtaesan laccolith, Galpyeongji stock. The swarm is composed of rhyolitic dikes that have developed many various spherulites. The dikes represent an geometrically radical pattern centering the Galpyeongji stock, but also geochemistry of the intrusions indicate the swarm source. Here we report the compositional data for 28 samples from the three intrusions. All of the intrusions belong to rhyolitic composition, but according to compositional correlation, there are considerable overlaps between intrusion compositions. In particular, the Cheongsong dike swarm is divided into several dike groups by rock color and shows compositional diversity, but the composition of the dikes generally overlap with compositions of other intrusions. The Jungtaesan laccolith is enriched in alkali, $K_2O$ and $Al_2O_3$ and depleted in $Fe_2O_3{^t}$, $TiO_2$ and REE compared to the Cheongsong dike swarm. In contrast, the Galpyeongji stock is narrow in composition range, and commonly has sharp compositional overlaps with the Cheongsong dike swarm. According to the compositional correlations, the stock is considered to be a source of the swarm and it is connected to an episode of volcanism.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.475-478
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• 2006

Background: The simultaneous bilateral spontaneous pneumothorax is a rare clinical event. Contrary to the unilateral pneumothorax, the patients with simultaneous bilateral spontaneous pneumothorax sometimes complains of severe respiratory distress, cyanosis and chest pain without tention pneumothorax. It is often dangerous; therefore, the chest drain should be inserted immediately. Material and Method: Between March 1994 and February 2004, 802 patients were treated in our department for spontaneous pneumothorax. Among these, the simultaneous bilateral spontaneous pneumothorax developed in 14 patients (1.7%). Result: Out of fourteen patients, two females and twelve males presented with simultaneous bilateral spontaneous pneumothorax. The patient age ranged between 0 and 79 years with mean age of 31.2 years. In eleven patients, this was the first episode of pneumothorax. One patient had combined hemopneumothorax and two patients had combined pyopneurnothorax. Six patients had smoking history (42.8%, average 17.3 p-y). Five patients had pulmonary tuberculosis history and among these, two patients had active pulmonary tuberculosis. Three patients were died due to meconium-aspiration pneumonia (1 patient) and ARDS (Acute Respiratory Distress Syndrome) with pneumonia (2 patients). We treated these patients with nasal oxygen inhalation, chest drain insertion, thoracotomy, VATS (Video-Assisted Thoracoscopic Surgery) and chemical pleurodesis. Conclusion: The simultaneous bilateral spontaneous pneumothorax developed in 14 patients (1.7%) among 802 patients. Prompt insertion of chest drain is needed for a relief of severe symptoms, and to reduce the risk of recurrence, early thoracotomy or VATS should be performed rather than chest drain insertion only.

• The Korean Journal of Ecology
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• v.23 no.1
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• pp.1-8
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• 2000

The pattern of gap regeneration and vegetational changes were carried out in gaps with different ages and in an intact forest in a Quercus mongolica (mongolian oak) stand located at Munsubong of Mt. Worak. In the early stage of gap formation, Lespedeza maximowiczii, Fraxinus rhynchophylla, Tripterygium regelii, Quercus mongolica, and Stephanadra incisa were dominants in shrub layers. The numbers of shrubs with smaller diameters at ground surface were abundant in the early stage of gap formation. On the other hand, as gap age increased, the number of individuals of Quercus mongolica and Fraxinus rhynchophylla forming tall tree layer decreased. However the diameter at ground surface of Quercus mongolica and Fraxinus rhynchophylla increased. There were few young Quercus mongolica, but those over 130 years old appeared in mature Quercus mongolica stands. The last regeneration episode ended about 130 years ago and the new one started 40 years ago in this study site. Considering the presence of Quercus mongolica below 40 years old in gap and the absence of Quercus mongolica from 40 to 130 years old in closed stand, it is concluded that Quercus mongilica forest is maintained by discontinued regeneration.

• Journal of The Korean Association For Science Education
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• v.33 no.4
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• pp.840-862
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• 2013

This study undertook a methodological investigation on previous research that had proposed alternative methods for analyzing argumentative discourse in science classes in terms of collaborative construction and epistemic enactments of argumentation. The study also proposed a new way of analyzing argumentation discourse based on the achievements and limitations of previous research. The new method was applied to actual argumentation discourse episodes to examine its feasibility. For these purposes, we chose the studies employing Toulmin's argument layout, seeking for a method to analyze comprehensively the structure, content, and justification of arguments, or emphasizing evidence-based reasoning processes of argumentation discourse. In addition, we contrived an alternative method of analyzing argumentative discourse, Discourse Register on the Evidence-Explanation Continuum (DREEC), and applied DREEC to an argumentative discourse episode that occurred in an actual science classroom. The advanced methods of analyzing argumentative discourse used in previous research usually examined argument structure by the presence and absence of the elements of Toulmin's argument layout or its extension. Those methods, however, had some problems in describing and comparing the quality of argumentation based on the justification and epistemic enactments of the arguments, while they could analyze and compare argumentative discourse quantitatively. Also, those methods had limitations on showing participants' collaborative construction during the argumentative discourse. In contrast, DREEC could describe collaborative construction through the relationships between THEMEs and RHEMEs and the links of data, evidence, pattern, and explanation in the discourse, as well as the justification of arguments based on the flow of epistemic enactments of the argumentative discourse.

• Clinical and Experimental Pediatrics
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• v.58 no.5
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• pp.194-198
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• 2015

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronically progressive or relapsing symmetric sensorimotor disorder presumed to occur because of immunologic antibody-mediated reactions. To understand the clinical courses of CIDP, we report variable CIDP courses in children with respect to initial presentation, responsiveness to medical treatment, and recurrence interval. Four patients who were diagnosed with acute-onset and relapsing CIDP courses at Severance Children's Hospital, Seoul, Korea, were enrolled in this retrospective study. We diagnosed each patient on the basis of the CIDP diagnostic criteria developed in 2010 by the European Federation of Neurological Societies/Peripheral Nerve Society Guidelines. We present the cases of four pediatric patients diagnosed with CIDP to understand the variable clinical course of the disease in children. Our four patients were all between 8 and 12 years of age. Patients 1 and 2 were diagnosed with acute cerebellar ataxia or Guillain-$Barr{\acute{e}}$ syndrome as initial symptoms. While patients 1 and 4 were given only intravenous dexamethasone (0.3 mg/kg/day) for 5 days at the first episode, Patients 2 and 3 were given a combination of intravenous immunoglobulin (2 g/kg) and dexamethasone (0.3 mg/kg/day). All patients were maintained with oral prednisolone at 30 mg/day, but their clinical courses were variable in both relapse intervals and severity. We experienced variable clinical courses of CIDP in children with respect to initial presentation, responsiveness to medical treatment, and recurrence interval.