• Journal of Chest Surgery
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• v.32 no.1
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• pp.43-48
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• 1999

Background: Although treatment of spontaneous pneumothorax by video-assisted thoracic surgery(VATS) has generally shown better clinical results than conventional thoracotomy, treatment of spontaneous pneumothorax by midaxillary thoracotomy(MAXT) has also shown good clinical results. The author studied to compare the clinical results of MAXT group I and VATS group II. Material and Method : Group I included 30 midaxillary thoracotomy among 83 operative cases of spontaneous pneumothorax from Jan. 1992 to Dec. 1993. Group II included 30 VATS among 101 operative cases of pneumothorax from Jan. 1994 to Aug. 1995. The author selected the 30 patients, age 18 to 25 years, with recurrent spontaneous pneumothorax in each group. The author analyzed the operative indication, gender, operating time, amounts of the used staplers, tube drainage, total amounts of analgesics used during postoperative 24hr, tube stay time, postoperative complications and mortality. Result: The follow-up periods of both procedures were from 6 to 43 months. The operating time from start of skin incision to end of skin closure was 84.79${\pm}$21.70(from 40 to 150) minutes in MAXT group I and 108.8${\pm}$42.02(from 58 to 120) minutes in VATS group II(P<0.001). The numbers of the used staples useo was 1.31${\pm}$0.6(from 0 to 3) in group I and 3.41${\pm}$2.37(from 0 to 11) in group II. The amounts of postoperative 24hour tube drainage were 220.76${\pm}$106.73(from 65 to 400) ml in group I and 260.63${\pm}$233.18(from 70 to 320) in group II(P>0.05). The amounts of postoperative 24 hourly used analgesics(Tarasyn ) was 1.38${\pm}$1.32(from 0 to 5) amples in group I and 0.72${\pm}$1.02(from 0 to 4) amples in group II (P<0.05). The postoperative tube stay is 5.45${\pm}$30.9 (from 3 to 7) days in group I and 4.75${\pm}$3.1(9 from 2 to 14) days in group II(P>0.05). The number of complications after operations was 2 cases of prolonged air leakage in group I, and in group II. (P is not significant). The number of recurrence after the operation was one in group I and also one in group II(P is not significant). In conclusion, there were no statistical differences in the postoperative 24 hour chest tube drainage, days of postoperative tube stay, postoperative complications and recurrence in the analysis between group I and group II. Conclusion: The author found that group II of VATS between 18 years and 25 years of age in recurrent spontaneous pneumothorax, statistically, requires longer operative time, more number of autosuture staples and less postoperative analgesic dosage than the midaxillary thoracotomy group I.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.287-293
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• 1999

Background: Medical treatment of multiple drug resistant(MDR) pulmonary tuberculosis has been quite unsuccessful. We analyzed our experience to identify the benefits and complications of the pulmonary resection in MDR pulmonary tuberculosis. Material and Method: A retrospective review was performed in 27 patients who unerwent pulmonary resection for MDR pulmonary tuberculosis between January 1994 and March 1998. Mean age was 40 years and the average history of diagnosis prior to surgery was 3.1 years. All had resistance to an average of 4.4 drugs, and received second line drugs selected according to the drug sensitivity test. Most patients (93%) had cavitary lesions as the main focus. Bilateral lesions were identified in 19 patients (70%), however, the main focus was recognized in one side of the lung. Eleven patients (41%) were converted to negative sputum smear and/or culture before surgery. Result: Pneumonectomy was performed in 9 patients, lobectomy in 16 and segmentectomy in 2. There was no operative mortality. Morbidity had occurred in 7 patients (26%), prolonged air leak in 3 patients, reoperation due to bleeding in 2, bronchopleural fistula in 1, and reversible neurologic defect in 1. Median follow up period was 15 months (3-45 months). Sputum negative conversion was initially achieved in 22 patients (82%), and with continuous postopertive chemotherapy negative conversion was achieved in other 4 patients (14%). Only one pneumonectized patient (4%) failed due to considerable contralateral cavity. Conclusion: For patients with localized MDR pulmonary tuberculosis and with adequate pulmonary reserve function, surgical pulmonary resection combined with appropriate pre and postoperative anti-tuberculosis chemotherapy can achieve high success rate with acceptable morbidity.

• Journal of the Korean Ceramic Society
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• v.40 no.9
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• pp.891-896
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• 2003

Novel fabrication technique was developed for high strength Reaction-Bonded SiC (RBSC) hot gas filter for use in IGCC (Integrated Gasification Combined Cycle) system. The room and high temperature fracture strengths for Si-melt infiltrated reaction-bonded SiC were 50-123, and 60-66 MPa, respectively. The average pore size was 60-70 $\mu\textrm{m}$ and the porosity was about 34 vol％. RBSC infiltrated with molten silicon showed improved fracture strength at high temperature, as compared to that of clay-bonded SiC, due to SiC/Si phase present within SiC phase. The thickness for SiC/Si phase was increased with increasing powder particle size of SiC from 10 to 34 $\mu\textrm{m}$. Pressure drop with dust particles showed similar response as compared to that for Schumacher type 20 filter. The filter fabricated in the present study showed good performance in that the filtered powder size was reduced drastically to below 1 $\mu\textrm{m}$ within 4 min.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.347-352
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• 1999

Background: The atrial fibrillation in patients with mitral valvular heart disease is frequently converted to sinus rhythm after the mitral valve surgery. This sinus restoration implies an important meaning in that it not only helps postoperative convalescence in patients with unstable hemodynamics but also reduces the rate of postoperative thromboembolism. Material and Method: We retrospectively analyzed 184 patients who received mitral valve surgery from June 1986 to December 1996 to investigate the trend of rhythm change following mitral valve surgery and thus to clarify the predisposing factors of postoperative sinus rhythm conversion and its maintenance. Result: The sinus rhythm was restored after the operation in 54 out of 139 patients with atrial fibrillation preoperatively(38.8%). However, the atrial fibrillation recurred in 41 patients at the time of discharge showing a recurrence rate of 75.9 percent. The mean duration of sinus rhythm in patients with eventual atrial fibrillation recurrence was 8.2${\pm}$5.9 days. Only 15 patients were in sinus rhythm at the time of late follow-up with the mean follow-up period of 84.4${\pm}$34.7 months. While the age, duration of symptoms, duration of atrial fibrillation, left atral size, and pulmonary artery pressure were thought to be the predisposing factors for sinus conversion after the operation, only the duration of atrial fibrillation and ejection fraction were considered risk factors for the recurrence of the atrial fibrillation following sinus conversion. Conclusion: This study suggests that the early operation is mandatory for the satisfactory result regarding postoperative rhythm. Moreover, additional operative measure in adjunct to the intervention of mitral valve should be considered for the maintenance of restored sinus rhythm as reflected by high postoperative recurrence rate of atrial fibrillation.

• Clinical and Experimental Pediatrics
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• v.46 no.11
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• pp.1073-1079
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• 2003

Purpose : Recently there has been a decrease in ventilator care rate and duration of very low birth weight infants(VLBWI) in Fatima Hospital. The aims of this study were to survey the frequency and duration of ventilation in VLBWI and to develop a non-invasive neonatal intensive care unit (NICU) policy. Methods : We performed a retrospective study of 284 newborn of infants less than 1,500 gm admitted to NICU and discharged from January 1998 to December 2001. Patients were intubated or applied continuous positive airway pressure(CPAP) via nasal prong immediately after presenting signs of respiratory distress. We analyzed epidemiologic data to study the changes in ventilator care rate, duration and outcome of ventilator care groups. Results : Of 284 newborn infants, 146 required invasive management, such as endotracheal intubation and assisted ventilation. The characteristics, the severity of clinical symptoms and laboratory findings in ventilator care groups at birth showed no significant differences. The annual proportion of infants requiring assisted ventilation decreased according to increasing gestational age. The median duration of ventilation decreased markedly from 6.0 days in 1998 to 2.7 days in 2001. Final complications and outcomes in ventilator care groups showed no significant differences. Conclusion : Our study shows a significant reduction in the invasiveness of the treatment of VLBW infants, which was not associated with an increased mortality or morbidity. A non-invasive strategy for the VLBW infant with minimal to moderate respiratory distress after birth in NICU is better than immediate invasive management. Non-invasive nasal CPAP is a simpler and safer method than invasive assisted ventilation.

• Journal of Chest Surgery
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• v.38 no.2 s.247
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• pp.157-163
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• 2005

Background: Clinical outcomes of esophageal cancer have not been satisfactory in spite of the development of surgical skills and protocols of adjuvant therapy. We analyzed the results of corrective surgical patients for esophageal cancer from January 1992 to July 2002. Material and Method: Among 129 patients with esophageal cancer, this study was performed in 68 patients who received corrective surgery. The ratio of sex was 59 : 9 (male : female) and mean age was $61.07\pm7.36$ years old. Chief complaints of this patients were dysphagia, epigastric pain and weight loss, etc. The locations of esophageal cancer were 4 in upper esophagus, 36 in middle, 20 in lower, 8 in esophagogastric junction. 60 patients had squamous cell cancer and 7 had adenocarcinoma, and 1 had malignant melanoma. Five patients had neoadjuvant chemotherapy. Result: The postoperative stage I, IIA, IIB, III, IV patients were 7, 25, 12, 17 and 7, respectively. The conduit for replacement of esophagus were stomach (62 patients) and colon (6 patients). The neck anastomosis was performed in 28 patients and intrathoracic anastomosis in 40 patients. The technique of anastomosis were hand sewing method (44 patients) and stapling method (24 patients). One of the early complications was anastomosis leakage (3 patients) which had only radiologic leakage that recovered spontaneously. The anastomosis technique had no correlation with postoperative leakage, which stapling method (2 patients) and hand sewing method (1 patient). There were 3 respiratory failures, 6 pneumonia, 1 fulminant hepatitis, 1 bleeding and 1 sepsis. The 2 early postoperative deaths were fulminant hepatitis and sepsis. Among 68 patients, 23 patients had postoperative adjuvant therapy and 55 paitents were followed up. The follow up period was $23.73\pm22.18$ months ($1\~76$ month). There were 5 patients in stage I, 21 in stage 2A, 9 in stage IIB, 15 in stage III and 5 in stage IV. The 1, 3, 5 year survival rates of the patients who could be followed up completely was $58.43\pm6.5\%,\;35.48\pm7.5\%\;and\;18.81\pm7.7\%$, respectively. Statistical analysis showed that long-term survival difference was associated with a stage, T stage, and N stage (p<0.05) but not associated with histology, sex, anastomosis location, tumor location, and pre and postoperative adjuvant therapy. Conclusion: The early diagnosis, aggressive operative resection, and adequate postoperative treatment may have contributed to the observed increase in survival for esophageal cancer patients.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.556-560
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• 1999

Background: The cause of spontaneous pneumothorax is not yet but it is certain that intrathoracic air comes from ruptured bulla. Video-assisted thoracoscopic surgery(VATS) or open thoracotomy is recommended for thoracic incision in recurrent pneumothorax. However, recurrent rate after bullectomy with the VATS is very high compared to mini-thoracotomy, 3% to 20% and below 2%, respectively. Material and Method: This retrospective analysis was performed on 16 re-operated cases among 446 surgically treated pneumothorax of the 737 cases of spontaneous pneumothorax diagnosed at Yongdong Severance Hospital from Nov. 1992 to June 1997. Result: Among the 446 surgically-treated patients in 737 case of spontaneous pneumothorax, 16 patients underwent re-operation, showing a 3.5% re-operation rate. Male-to-female ratio was 15 to 1 and mean age at initial attack was 20.2 years(ranging from 15 to 50). Mean hospital stay was 6.34 days(ranging from 2 to 20 days) and mean chest tube indwelling period was 4.2 days(ranging from 1-10 days). Median follow-up was 46 months(range 10-66 months). Three different surgical methods were applied : video-assisted thoracoscopic surgery(VAST) in 281 cases, of whom 2 underwent local anesthesia; subaxillary mini-thoracotomy in 159 cases and limited lateral thoracotomy in the remaining 6 cases. Three different re-operative surgical methods were applied ; video-assisted thoracoscopic surgery (VAST) in 6 cases, subaxillary mini-thoracotomy in 9 cases, and limited lateral thoracotomy in the remaining 1 case. The underlying etiological factors of the recurrent pneumothorax after bullectomy were o erlooking type(9) and new growing type(7). Mean recurrent period from previous operation was 1 month for overlooking type and 18 months for new growing type. Conclusion: The underlying etiological factors of recurrent pneumothorax lead to re-operation were new-growing and over-looking type. We need additional treatments besides resecting blebs of prevent the recurrence rate and more gentle handling with forceps due to less damage to the pleura.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.333-339
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• 2009

This study was done to determine if there is any difference in microleakage between experimental composite resins, in which various proportions of three component photoinitiators (Camphoroquinone, OPPI, Amine) were included. Four kinds of experimental composite resin were made by mixing 3.2% silanated barium glass (78 wt.%, average size; 1 ${\mu}m$) with each monomer system including variously proportioned photoinitiator systems used for photoinitiating BisGMA/BisEMA/TEGDMA monomer blend (37.5:37.5:25 wt.%). The weight percentage of each component were as follows (in sequence Camphoroquinone, OPPI, Amine): Group A - 0.5%, 0%, 1% / Group B - 2%, 0.2%, 2% / Group C - 0.2%, 1%, 0.2% / Group D - 1%, 1%, 2%. Each composite resin was used as a filling material for round class V cavities (diameter: 2/3 of mesiodistal width; depth: 1.5 mm) made on extracted human premolars and they were polymerized using curing light unit (XL 2500, 3M ESPE) for 40 s with an intensity of 600 mW/$cm^2$. Teeth were thermocycled fivehundred times between $50^{\circ}C$and $550^{\circ}C$for 30s at each temperature. Electrical conductivity (${\mu}A$) was recorded two times (just after thermocycling and after three-month storage in saline solution) by electrochemical method. Microleakage scores of each group according to evaluation time were as follows [Group: at first record / at second record; unit (${\mu}A$)]: A: 3.80 (0.69) / 13.22 (4.48), B: 3.42 (1.33) / 18.84 (5.53), C: 4.18 (2.55) / 28.08 (7.75), D: 4.12 (1.86) / 7.41 (3.41). Just after thermocycling, there was no difference in microleakage between groups, however, group C showed the largest score after three-month storage. Although there seems to be no difference in microleakage between groups just after thermocycling, composite resin with highly concentrated initiation system or classical design (Camphoroquinone and Amine system) would be more desirable for minimizing microleakage after three-month storage.

• Advances in pediatric surgery
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• v.1 no.2
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• pp.140-148
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• 1995

To study the clinical profiles and outcome of surgery in infants with esophageal atresia, we reviewed 96 esophageal atresia cases who were treated from April, 1978 to June, 1995. There were 51 male and 45 female infants, a ratio of 1.1:1. The low birth weight(<2500g) patients were 32%. Clinical findings at the time of diagnosis included drooling in 57%, choking in 50%, cyanosis in 38%, respiratory distress in 27% and swallowing difficulty in 20%. Gross classification included 6 cases of type A esophageal atresia(6%), 79 cases of type C(82%), 3 cases of type E (3%) and 8 cases of type F(8%). Associated anomalies occurred in 34 infants(35%). Among them, cardiac anomalies were most common(60%). A primary repair of the defect was carried out in 76 patients with type A or C. A staged operation comprising a repair or gastric tube interposition after gastrostomy was performed in 8 patients. In all 3 infants with H-type, a division of fistula was performed. Esophageal resection and anastomosis was done in 8 infants with esophageal stenosis. In one infant, a gastrostomy was performed and he expired before staged operation. Anastomotic complications included leakage in 16 cases(17%), stricture in 37 cases(39%) and recurrent tracheoesopohageal fistula in 3 cases(3%). The mortality rate was 14% and the leading cause of death was pneumonia. The overall survival rate was 86%, and according to Waterston criteria, the survival rates were 93%, 85% and 58% in class A, Band C, respectively. 75 patients were followed up with median follow up 6.4 years. Among them, 93% were uneventful and 7% had frequent pneumonia.

• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.469-480
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• 2015

The study was conducted on the effects of time of defoliation on fruit quality of pear (Pyrus pyrifolia Nakai) trees, managing with low-pesticides, and regrowth of stem cuttings in vitro. Treatments included for 40% of uniform defoliation at early-August, end-August, and early-September, as well as control (no defoliation). Defoliation at early-September and control increased growth of water sprouts as well as concentrations of carbohydrates, total nitrogen, and free sugar in one-year old shoots. Defoliation at early-September and control increased fruit yield and mean fruit weight, with high soluble solids content and fruit surface color of $a^*$ observed for both defoliation at end-August and early-September. Defoliation at early-August increased rates of electrolyte leakage in stem cuttings at $-18^{\circ}C$ in vitro. There were no significantly different for germination rates of the cuttings between the treatments at -18 and $-21^{\circ}C$ in vitro, with the highest germination of the cuttings observed for defoliation at early-September and control at $-27^{\circ}C$. Therefore, orchard management should be performed to be minimized for defoliation of the spur leaves until end-August, causing from precipitation and pests.