• Journal of the Korean Society of Groundwater Environment
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• v.7 no.1
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• pp.55-58
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• 2000

Methyl tertiary butyl ether (MTBE) is a gasoline additive that boosts the oxygen content in fuel (an oxygenate), resulting in less air-polluting carbon monoxide being released from vehicle exhaust systems. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc.. Studies on the chemical and these problems are going on abroad vigorously. These studies should be performed in our country as well more actively. This paper reviews on articles on these studies and focuses on the identification of the chemical as a groundwater contamination source.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1138-1142
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• 1996

Video-assisted thoracic surgery is a new modality that allows visualization of and access to the intrathoracic organs without making a thoracotomy Incision. 52 patients underwent thoracic procedures using this technique. There were pneumothorax in 40 patients, diffuse interstital lung disease in 6 patients, hyperhidrosis in 3 patients, pulmonary tuberculoma in 1 patient, aspergilloma in 1 patient and localized fibrous tumor of pleura in 1 patient. We had performed a variety of procedures(36 wedge resections with mechanical pleurodesis, 8 wedge resections only, 4 mechanical pleurodeses, 3 bilateral sympathectomys and 1 segmentectomy). The period of chest tube indwelling and postoperative hospitalization were 2.00 $\pm$ 1.32 days(range : 0~6 days) and 3.55 $\pm$ 1.45 days(range : 1~8 days). Four postoperative complications occurred(2 pleural effusion, 1 recurrent pneumothorax and 1 high fever). Conversion to open thoracotomy was done in 1 p tient due to massive air leakage. Patients undergoing video-assisted thoracic surgery seem to have reduced postoperative pain, shorter hospitalization, and quicker recovery times.

• Journal of Chest Surgery
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• v.35 no.11
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• pp.807-811
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• 2002

Due to its less invasive nature and superior visual field, video-assisted thoracescopic excision of mediastinal mass is thought to be comparable to open thoracotomy. Material and Method : From January 1995 to August 2001, the medical records of 38 patients who underwent video-assisted thoracoscopic excision of mediastinal mass was retrospectively analyzed. The outcome of these patients were compared with 5 patients who converted to thoracotomy Result: Male to female ratio was 13(34.2%) : 25(65.8%), and mean age was 39.2$\pm$35.4 years. Regarding the pathology, there were 8 neurilemmomas(21.1%), 6 thymic cysts (15.8%), 5 teratomas(13.2%), 5 ganglioneuromas(13.2%), 4 bronchogenic cysts(10.5%), 3 pericardial cysts(7.9%), 3 thymomas(7.9%), and 2 lymphangiomas(5.3%). The mean operation time was 110.6$\pm$7.0 minutes, mean postoperative tube stay was 4.2$\pm$0.4 days, mean postoperative hospital stay was 5.2$\pm$0.4 days, and mean number of injection of analgesics was 1.9$\pm$0.4 times. Although the mean values for the above indices were less than those of the thoracotomy conversion cases, they were statistically insignificant. Postoperative complications of videoassisted thoracoscopic excision included chylothorax, prolonged air leakage, and unilateral phrenic nerve palsy, all of which recovered before patient discharge. There was, however, permanent unilateral ptosis in one patient. Conclusion : As video-assisted thoracoscopic excision of mediastinal mass is safe, less painful, conducive to earlier recovery and cosmetically more appealing, a more active application of this technique is recommeded.

• Journal of Chest Surgery
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• v.50 no.2
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• pp.86-93
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• 2017

Background: The influence of lifestyle diseases on postoperative complications and long-term survival in patients with non-small cell lung cancer (NSCLC) is unclear. The aim of this study was to determine whether lifestyle diseases were significant risk factors of perioperative and long-term surgical outcomes in elderly patients with stage I NSCLC. Methods: Between December 1995 and November 2013, 110 patients aged 65 years or older who underwent surgical resection of stage I NSCLC at Dong-A University Hospital were retrospectively studied. We assessed the presence of the following lifestyle diseases as risk factors for postoperative complications and long-term mortality: diabetes, hypertension, chronic obstructive pulmonary disease, stroke, and ischemic heart disease. Results: The mean age of the patients was 71 years (range, 65 to 82 years). Forty-six patients (41.8%) had hypertension, making it the most common lifestyle disease, followed by diabetes (n=23, 20.9%). The in-hospital mortality rate was 0.9% (n=1). The 3-year and 5-year survival rates were 78% and 64%, respectively. Postoperative complications developed in 32 patients (29.1%), including 7 (6.4%) with prolonged air leakage, 6 (5.5%) with atrial fibrillation, 5 (4.5%) with delirium and atelectasis, and 3 (2.7%) with acute kidney injury and pneumonia. Univariate and multivariate analyses showed that the presence of a lifestyle disease was the only independent risk factor for postoperative complications. In survival analysis, univariate analysis showed that age, smoking, body mass index, extent of resection, and pathologic stage were associated with impaired survival. Multivariate analysis revealed that resection type (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.08 to 4.49; p=0.030) and pathologic stage (HR, 1.89; 95% CI, 1.02 to 3.49; p=0.043) had independent adverse impacts on survival. Conclusion: This study demonstrated that the presence of a lifestyle disease was a significant prognostic factor for postoperative complications, but not of survival, in elderly patients with stage I NSCLC. Therefore, postoperative complications may be influenced by the presence of a lifestyle disease.

• Neonatal Medicine
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• v.18 no.1
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• pp.153-157
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• 2011

Pneumopericardium is a rare form of neonatal air leakage. Tension pneumopericardium is much more infrequent, but can cause a cardiovascular deterioration with high mortality up to 80% and neurodevelopmental morbidity in half of the cases. We report two cases of preterm infants who successfully recovered from tension pneumopericardium that developed during mechanical ventilator assistance. The patients displayed a sudden increase in oxygen demand and subsequent cardiovascular deterioration. Immediate needle aspiration of the pneumopericardium performed after checking X-ray images rescued each of patient. Since the clinical symptoms are non-specific, clinicians' suspicion is most important when patients show sudden refractory cardiovascular collapse, especially in ventilator-assisted neonates. This life threatening complication demands instant diagnosis and intervention.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.183-183
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• 2014

Recently, multiferroic materials gain much attention due to their fascinating fundamental physical properties. These materials offer wide range of potential applications such as data storage, spintronic devices and sensors, where both electronic and magnetic polarizations can be coupled. Among single-phase multiferroic materials, $BiFeO_3$ is typical because of the room-temperature magnetoelectric coupling in view of long-range magnetic- and ferroelectric-ordering temperatures. However, $BiFeO_3$ is well known to have large leakage current and small spontaneous polarization due to the existence of oxygen vacancies and other defects. Furthermore the magnetic moment of pure $BiFeO_3$ is very weak owing to its antiferromagnetic nature. Recently, various attempts have been performed to improve the multiferroic properties of $BiFeO_3$ through the co-doping at the A and the B sites, by making use of the fact that the intrinsic polarization and magnetization are associated with the lone pair of $Bi^{3+}$ ions at the A sites and the partially-filled 3d orbitals of $Fe^{3+}$ ions at the B sites, respectively. In this study, $BiFeO_3$, $Bi_{0.9}Ho_{0.1}FeO_3$, $BiFe_{0.97}Ni_{0.03}O_3$ and $Bi_{0.9}Ho_{0.1}Fe_{0.97}Ni_{0.03}O_3$ bulk compounds were prepared by solid-state reaction and rapid sintering. High-purity $Bi_2O_3$, $Ho_2O_3$, $Fe_2O_3$ and $NiO_2$ powders with the stoichiometric proportions were mixed, and calcined at $500^{\circ}C$ for 24 h to produce the samples. The samples were immediately put into an oven, which was heated up to $800^{\circ}C$ and sintered in air for 1 h. The crystalline structure of samples was investigated at room temperature by using a Rigaku Miniflex powder diffractometer. The field-dependent and temperature-dependent magnetization measurements were performed with a vibrating-sample magnetometer and superconducting quantum-interference device.

• Journal of Chest Surgery
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• v.26 no.6
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• pp.475-482
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• 1993

90 patients[75 men and 15 women] with the thoracic disease underwent video-assisted thoracic surgery[VATS] during the period March 1992 to February 1993. The thoracic diseases were classified into two groups of spontaneous pneumothorax and general thoracic patients and they were 66 and 24, respectively.The mean size of the tumor resected was 4.3 $\pm$ 2.0 cm x 3.3 $\pm$ 1.1 cm x 2.7 $\pm$ 1.0 cm. The mean time of anesthesia and operation were 90.0 $\pm$ 19.9 min and 43.7 $\pm$ 13.1 min in spontaneous pneumothorax group and 123.3 $\pm$ 40.3 min and 62.8 $\pm$ 32.2 min in general thoracic group. The mean period of postoperative chest tube drainage and hospital stay were 5.0$\pm$ 5.5 days and 6.6 $\pm$ 7.4 days in spontaneous pneumothorax group and 3.5$\pm$ 1.6 days and 9.5 $\pm$ 6.1 days in general thoracic group. The indications of VATS were 71 pleural disease[78.9%: 66 spontaneous pneumothorax; 3 pleural effusions ; 1 pleural paragonimus westermanii cyst; 1 malignant pleural tumor with metastasis to the lung], 9 mediastinal disease[10.0%: 5 benign neurogenic tumor; 2 pericardial cyst; 1 benign cystic teratoma; 1 undifferentiated carcinoma], 8 pulmonary parenchymal disease[8.9%: 3 infectious disease ; 3 interstitial disease ; 2 malignant tumor ], and 2 traumatic cases of exploration and removal of hematoma[2.2%]. The applicated objectives of VATS were diagnostic[ 7 ], therapeutic[ 67 ] and both[ 16 ] and the performed procedures were pleurodesis[ 66 ], wedge resection of lung[ 59 ], parietal pleurectomy[ 11 ], removal of benign tumor[ 9 ], excision and/or biopsy of tumor[ 4 ], pleural biopsy and aspiration of pleural fluid[ 3 ] and exploration of hemothorax and removal of hematoma in traumatic 2 patients. The complication rate was 24.2%[ 16/66 ] in the spontaneous pneumothorax group and 8.3%[ 2/24 ] in the general thoracic group and so overally 20.0%[ 18/90 ]. The mortality within postoperative 30 days was 2.2%[ 2/90 ], including 1 acute renal failure and 1 respiratory failure due to rapid progression of pneumonia. The conversion rate to open thoracotomy during VATS was 5.6%[ 5/90 ], including 2 immediate postoperative massive air leakage, 1 giant bullae, 1 malignant pleural tumor with metastasis to lung and 1 pulmonary malignancy. The successful cure rate of VATS was 75.8%[ 50/66 ] in the spontaneous pneumothorax group and 76.5%[ 13/17 ] in the general thoracic group and the successful diagnostic rate was 100%[ 7/7 ]. In conclusion, although prospective trials should be progressed to define the precise role of VATS, the VATS carries a low morbidity and mortality and high diagnostic and therapeutic success rate and now can be effectively applicated to the surgical treatment of the extensive thoracic disease.

• Fire Science and Engineering
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• v.30 no.1
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• pp.111-120
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• 2016

This study is intended to provide legislative direction for fire products life expectancy. Domestic and international laws relating to fire products life expectancy have been reviewed, and the results of a Fire Safety Manager Consciousness (FSMC) survey were analyzed. The FSMC survey has been designed in order to assist with the establishment of appropriate fire safety policy. A questionnaire survey was conducted with 660 fire safety administrators from 17 municipal and provincial districts, with the intention of gaining expertise on the extension of life-span for 32 fire products. The survey also asked for candidates opinions on future policy direction. Based on the survey results and the review of policies within other nations, we have devised a set of policy issues with the intention of extending the life-span of fire-safety items. The survey result revealed that 79.3% of Fire Safety Managers (FSMs) concurred with the establishment of legislation regarding the maintenance and correct care of fire-safety products. Overall, over 30% of FSMs were in favor of regulations regarding Ddry chemical fire extinguishers (77.3%), fire detectors (44.6%), fire hoses (44.4%), gaseous agent fire extinguisher (40.6%), automatic descending life lines (36.2%), exit lights (35.9%), air respirators (35.9%), extinguishing systems for residential cooking facilities (33.9%), automatic spray-type extinguishing units (33.9%), emergency lights (31.2%), and gas leakage detectors (30.7%). Especially, among these, dry chemical fire extinguishers (60.0%), detectors (20.0%), and fire hose (18.8%) were identified as the fire products primarily in need of maintenance legislation. The general consensus is that fire products older than 10 years need to be replaced. Based on the survey results, there was general agreement that fire product life expectancy is in need of legislation. This study recommends the introduction of fire product life expectancy legislation in phases.

• Analytical Science and Technology
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• v.14 no.3
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• pp.274-285
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• 2001

In this study, the thermal desorption-cryofocusing-gas chromatographic(TD-C-GC) method was developed for determination of volatile organic compounds(VOCs) in ambient air and was applied at the municipal solid waste landfill sites. On-column cryofocusing was possible only with a 100 ml dewars bottle in TD-C-GC method with a stainless steel column. However, high operating pressure was needed for purging VOCs from the absorbent trap, which was able to solve by pressure programming with a electric pressure controller. By using both pressure and temperature programming brought increasing of resolution power in on-column cryofocusing method, but the high pressure caused a leakage of sample tube with repeated use. A loop cryofocusing devise was also developed and compared with the direct on-column method. In loop cryofocusing method, VOCs were concentrated on a 0.8mm i.d. loop which is located between the injector and separation column by using liquid nitrogen. In order to purge VOCs from the absorbent trap, only 0.4 psi of pressure was need in the loop cryofocusing method. Dual detection system was applied for the analysis of VOCs; a FID was used for hydrocarbons and a FPD was used for sulfur-containing compounds. Qualitative analysis was done by on-column cryofocusing GC-MS system. Among the large number of VOCs, toluene was the most abundant. Hydrogen sulfide, dimethyl sulfide, carbon disulfide, dimethyl disulfide and methyl propyl disulfide were detected at landfill site by FPD.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.368-371
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• 2012

The present study evaluated the outcome of use of thoracostomy tube tunneling technique under the latissimus dorsi muscle for the evacuation of postoperative pneumothorax induced by thoracotomy in 11 dogs. A stab incision was made through the skin and the latissimus dorsi muscle over the rib in the fifth intercostal space caudal to a surgical window. The thoracostomy tube with a Kelly hemostat was advanced into the thoracic cavity in a cranioventral direction through the sublatissimal tunnel. After tube placement, a # 1 nylon horizontal mattress suture was placed around the skin incision. The thoracostomy tube was removed after creating a negative pressure in the thoracic cavity. Dogs were monitored after surgery for pneumothorax, subcutaneous emphysema, clinical signs including dyspnea, and tube kinking in a muscle tunnel using physical examination and postoperative radiography. There was no tube kinking in the sublatissimal tunnel in 11 dogs on introducing the tubes into the thoracic cavity. The mean (${\pm}SD$) follow-up period was $19{\pm}10$ months. On postoperative radiography, there was no evidence of pneumothorax in 11 dogs. Subcutaneous emphysema was identified around the stab incision in a dog postoperatively. The subcutaneous emphysema disappeared spontaneously within 3 days. On postoperative physical examination, there was no evidence of dyspnea in 11 dogs. Our results suggest that the sublatissimal tunneling technique for thoracostomy tube placement is effective to prevent air leakage around the thoracostomy tube while the tube remains in the thoracic cavity and along the thoracostomy tunnel after tube removal. Tunneling under the latissimus dorsi muscle should be considered the thoracostomy tube placement technique to prevent iatrogenic pneumothorax with first priority.