• Journal of Chest Surgery
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• v.30 no.12
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• pp.1225-1231
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• 1997

Spontaneous pneumothorax is the sudden collapse of a lung usually caused by air leakage from a subvisceral pleural blob. Responses to closed thoracostomy,thoracentesls and simple observation are usually prompt and effective. But in some cases, these are unsucceful and open thoracotomy is indicated. A clinical evaluation was performed on 242 cases(236 patients) of open thoracotomy in spontaneous pneumoth rax who were admitted and treated at department of Thoracic and Cardiovascular Surgery. Masan Samsung General Hospital during the past 9 years from January 1988 to December 1996. The results were as follows 1. The sex ratio was male predominance(M:F=11.7:1) 2. The most common age group were 2nd, 3rd decades(2nd=29.3%, 3rd=30.2%). 3. The most common chief complaints were chest pain and dyspnea(chest pain=41.7%. dryspnea= 36.8). 4. The etiologic factors of spontaneous pneumothorax were primary spontaneous pneumothorax(86.4%), tuberculosis(9.1%), COPD(3.7%) and pleuritis(0.8%). 5. The site of spontaneous pneumothorax was 52.1% in right, 45.4% in left and 2.5% in both. 6. The common indications of open thoracotomy were recurrence(44.2%), persistent air leakage(31.8%) and inadequate expansion(15.7%). 7. The operative procedures were bullectomy or mechanical pleurodesis through posterolateral thoracotomy or median sternotomy. 8. The most frequent location of bulla or blob were apical segme t oi RUL(35.1%) and apicoposterior segment of LUL(41.3 %). 9. The number of bulla or blob were mainly 1 to 5(88%), and there were no significant differences among operation indications. 10. The size of bulla or bleb were mainly below 5cm(81%)and small bulla($\leq$1cm) were predominant in recurrence group but large bulla(>5cm)were predominant in persistent air leakage and inadequate expansion group. 11. The pleural adhesion was seen in 54.5%.(Recurrence group 64.1%,Persistent air leakage group 51.9%,Inadequate expansion group 47.4%).

• Journal of Chest Surgery
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• v.36 no.4
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• pp.261-266
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• 2003

Background: Surgery of abdominal aortic aneurysm revealed high operative mortality. We reviewed our 11-years' experiences of abdominal aortic aneurysm operation and wish to obtain information on the treatment. Material and Method: From Jan. 1990 to Dec. 2000, 48 patients were operated due to abdominal aortic aneurysm in Yonsei Cardiovascular Center Mean age was $62.8{\pm}12.7$ and there were 40 males and 8 females. Among 48 patients, nine patients had ruptured abdominal aortic aneurysm, and mean aneurysm diameter of non-ruptured cases was $8.8{\pm}2.4$cm. Result: There were 6 early deaths, and early mortality was 12.5%. Among 9 patients of preoperative aneurysm rupture, three patients died (33.3%), and among 39 patients of non-ruptured cases, 3 patients died (7.7%). Among preoperative variables, age (p<0.05), preoperative BUN level (p<0.05), and DM (p<0.05) were risk factors of early mortality. Among discharged 42 patients, 40 patients were followed up (f/u rate=95.2%) and mean follow up was $3.6{\pm}0.2$ years. During follow up periods, five patients died (late mortality=11.9%), and Kaplan-Meier survival analysis revealed $81.7{\pm}7.6$% survival rate at five and ten year. Linealized incidence of graft related event was 3.53% per patient-year. Conclusion: Surgical mortality of ruptured abdominal aortic aneurysm was higher than non-ruptured cases; therefore, early resection of the aneurysm can decrease the surgical mortality.

• Journal of Chest Surgery
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• v.39 no.11 s.268
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• pp.838-843
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• 2006

Background: The lung is the most common site of metastatic colorectal cancer comprising 10% of all curative resection of colorectal cancer. The reported 5 year survival rate varies among institutions. The purpose of the present study was to present the retrospective analysis of colorectal metastatic lung cancer surgery at our institution. Material and Method: A total of 61 patients undergoing surgery for metastatic colorectal lung cancer between July 1996 and December 2003 were included in the present study. The stage of the primary colorectal cancer, site of pulmonary metastasis, method of lung resection, the number and size of the metastatic nodules, the recurrence rate, and survival were assessed. Result: The 3 and 5 year survival rates were 66% and 41%, respectively. No significant risk factors were identified among the studied variables by either univariate or multivariate analysis. The mean disease free survival rate was 17 months. The most common recurrent site was lung, and among these patients, 3 underwent a second operation and two are still alive. Conclusion: The results of the above data suggest that pulmonary resection of metastatic lung cancer in select patients after curative resection of colon cancer may be a good therapeutic option with the potential for excellent results.

• Journal of Chest Surgery
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• v.30 no.8
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• pp.786-792
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• 1997

A clinical study of 71 cases of pulmonary tuberculosis that had had surgical resection during the period of 7 years and 6months from January 1989 to June 1996 in National Masan Tuberculosis Hospital. The results were as follows. 1. The ratio of male to female was 3.7:1 and in the age incidence the fourth decade was 22%, the third decade 15%. Although medical treatment was performed for more than 3 to 6 months, preoHeratively the conversion failure rate of positive sputum to negative state was 66.2%(47 cases). Of the failure cases, multiple-drug-resistant(MDR) patients were 41 cases(87.2%), 3. In MDR group, preoperatively conversion failure rate was 71.9%. 4. From the view of indica ion for lung resection on the radiographic finding, cavitary lesions were 43 cases(60.6%), destroyed lung lesions were 24 cases(33.8%). 5. The incidence of postoperative complication was 28.2%(20 cases). All cases were MDR 6. group and the most common of complication was tuberculosis spreading. In bilateral lesion, incidence of postoperative tuberculosis spreading was 25%(7 cases). Of the 7 cases, there was the cavitary lesion in 6 cases(86.7%). Total conversion rate of AFB positive sputum to negative state related to resectional sugery was 76.6% and in MDR group conversion rate of AFB positive sputum to negative state was 73.2% Conversion rate of MDR group with bilateral lesion was the lowest(60%). Conversion rate of drug-sensitivity group was 100% regardeless of lesions Slt to. In conclusion, despite of long-standing medical treatment, it is difficult to converse sputum-positive to negative state in multiple-drug resistance patients and that increases postoperative complications su h as tuberculosis relapse as a lack of appropriate drugs postoperatively. Postoperative conversion rate of sputum-positive to negative state was decreased in multiple-drug resistance patients. Because multiple-drug resistance patients have inireased due to several factors in Korea, it is important to prevent spreading of multiple-drug resistnce patients through the aggressive operative treatment. When the first medical therapy is fail or drug-resistance is found, operative treatment should be considered with the secondary medical therapy. The operation should be aggressively attempted even though at first medical treatment if indicated.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.1
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• pp.3263-3291
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• 1974

Experimental work of grain bin was carried out to develop the methods of natural air in-bin drying and storage. The method is considered to be more economical, labour saving, and an effective countermeasure to grain loss. To examine the possibility of farm use of the grain bin and to analyze the related factors concerned with in-bin grain drying and storage, ambient air conditions (especially the change of air temperature and relative humidity) and grain quality during drying and storage periods were investigated. A laboratory model bin was constructed to investigate the effect of different forced air conditions on the drying characteristics of rice. In addition, a grain bin with 2.2m diameter and 1.8m height, considered to be the optimum size for the average Korean farm, was constructed and tested to examine the drying and storing characteristics of rice. The weather data analyzed in this study was the nine-year (from 1964 to 1972) record of air temperature and relative humidity in the Suweon area, and the thirty-year (from 1931 to 1960) record of pentad normal relative humidity and air temperature in the Seoul area. From the results of the weather data analyses, the adequate air delivery hours (which was arbitrary defined as the condition to give less than 75% relative humidity) to dry the rice during October were about nine hours (from approximately 10 A.M. to 7 P.M, ) a day, in which the average air temperature was about 15.9$^{\circ}C$ and average relative humidity was 66%. The occurence of days having three hours of such conditions was 1, 2, and 1-day within the 1st, 2nd add last 10-day periods for the month of October, respectively. Therefore, it may be considered that the weather condition in October was satisfactory for the forced natural air drying. The results of the laboratory model bin test were analyzed to obtain the drying curve and drying rate for different drying stages and grain layers in the bin corresponding to various conditions of forced natural air. A drying experiment with a prototype grain bin showed that an approximate 5 percent grain moisture gradient through a 1.6 meter grain deposit was observed after 80 hours of intermittent drying, giving an over dried zone in the lower grain layers and an extremely high grain moisture zone in the upper layers. This indicates that an effective measure should be taken to reduce this high moisture gradient. In order to investigate the drying characteristics of bulk grain in a layerturning operation a grain bin test was performed. This showed a significant improvement of uniform drying. In this test, approximate 107 hours were required to dry a depth of 1.6 meter of grain from an initial moisture content of 22.2 percent to a moisture content of 16.7 percent using an air delivery rate of 2.8 cubic meter per a minute per every cubic meter of grain. This resulted in a 2 percent moisture gradient from the top to the bottom of the bin. During storage period, till the end of June the average temperature of grain was 2~3$^{\circ}C$ higher than ambient air temperature. But during July when the grain moisture content went up slightly (less than 1 percent), the average temperature of the grain also increased to 3~5$^{\circ}C$ higher than ambient air temperature. It is therefore recommended that for safe grain storage, grain should not be stored in sheet metal bins after mid May. From the above results, in-bin rice drying and storage can be used effectively on Korean farms. It is strongly recommended that the use of grain-bin system should be implemented for farm use to improve farm drying and storage of rice.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.203-213
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• 2011

Agriculture modern environments can vary due to factors such as land consolidation and ditch enhancement projects. But, these improvements projects can include cover-ing-up of irrigation ditches with concrete, increasing the drop between paddy field and drainage ditches, which might decrease the abundance and diversity of fish fauna around paddy fields. In this study, for the management of agrobiodiversity on fish in paddy fields, we installed a small-scale fishways between paddy fields and drainage ditches, and evaluated the effects on the eco-connection of the paddy fields, ditches and stream. Five fish species were recovered at the drainage ditches. The species exhibited characteristics spawning and growth based on the paddy field. The results indicate that the five fish species could ascend the paddy fields through the small-scale fishways. There are no difference of species numbers at ditches of environment-friendly agriculture paddy fields (A) and good agricultural practices (B) region, but individual numbers were higher at the B region. This result could be interpreted as indicating that ditch diversity was affected by positional properties rather than farming practices because the water flow and connection to adjacent stream of B region were better than A region. After ascertaining the fish species capable of ascending in a pre-survey of the drainage ditches, we set up small-scale fishways at the drop between paddy fields and drainage ditches. Three species of fish (Aphyocypris chinensis, Misgurnus anguillicaudatus, M. mizolepis) arrived at the paddy fields via small-scale fishways. The main movement time was from 18:00~24:00 and 00:00~06:00, indicating a preference for the night time period rather than the day period for migration. Concentrating the operation time from night to dawn seems prudent for effective management of small-scale fishways.

• Journal of Life Science
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• v.26 no.1
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• pp.83-90
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• 2016

This study was investigated the improvement effects of Ledebouriella seseloides (LS) ethanol extracts on lipid parameters in an ovariectomized animal model. Sixty, nine-week old female Sprague Dawley rats were randomly assigned to four groups as follows: sham-operated rats (SHAM), ovariectomized rats (OVX-CON) and ovariectomized rats that were treated with LS ethanol extracts (50 mg/kg/day and 200 mg/kg/day, respectively). The diets were fed to the rats for six weeks after their operation. The total-cholesterol and triglyceride contents on serum increased in the OVX-CON group compared to the SHAM group, but supplementation with the LS extract caused these factors to decrease. Notably, the serum LDL-cholesterol concentration in the supplemented 200 mg/kg/day LS ethanol extract group was significantly more reduced than the OVX-CON group. In addition, the platelet aggregation ability was lower in groups treated with LS than in the OVX-CON group. The alkaline phosphatase (ALP) activity was lower in the LS extract group compared to the OVX-CON group. Collagen content, in bone and cartilage, were reduced by ovariectomy, but the supplemented LS extract groups exhibited higher concentrations in their bones. According to these results, the improvement effects of LS extract on serum lipid parameters and osteogenesis in ovariectomized rats were illuminated.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.252-259
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• 2011

To identify the effects of the application of the adaptive statistical iterative reconstruction (ASIR) technique in combination with the other two factors of body mass Index (BMI) and tube potential on radiation dose in cardiac CT. The patient receiving operation the cardiac CT examination was divided four groups into according to kVp.[A group(n=20), Non-ASIR, BMI < 25, 100 kVp; B group(n=20), Non-ASIR, BMI > 25, 120 kVp; C group(n=20), 40% ASIR BMI < 25, 100 kVp; D group(n=20), 40% ASIR, BMI > 25, 120 kVp] After setting up the region of interest in the main artery central part and right coronary artery and left anterior descending artery, the CT number was measured and an average and standard deviation were analyzed. There were A group and the difference which the image noise notes statistically between C. And A group was high so that the noise could note than C group (group A, 494 ${\pm}$ 32 HU; group C, 482 ${\pm}$ 48 HU: P<0.05) In addition, there were B group and the difference noted statistically between D. And B group was high so that the noise could note than D group (group B, 510 ${\pm}$ 45 HU; group D, 480 ${\pm}$ 82 HU: P<0.05). In the qualitative analysis of an image, there was no difference (p>0.05) which a group, B group, C group, and D as to average, A group 4.13${\pm}$0.2, B group 4.18${\pm}$0.1, and C group 4.1${\pm}$0.2 and D group note statistically altogether with 4.15${\pm}$0.1 as a result of making the clinical evaluation according to the coronary artery segments. And the inappropriate image was shown to the diagnosis in all groups. As to the radiation dose, a group 8.6${\pm}$0.9 and B group 14.9${\pm}$0.4 and C group 5.8${\pm}$0.5 and D group are 10.1${\pm}$0.6 mSv.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.337-371
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• 2015

In recent years, aviation safety has been facing new hazards due to the rapidly changing environment in which aircraft operation increasingly finds. Continuously increasing air traffic volume, integration of various cultures from many States, and many other changes are the causal factors of the new risks. To identify such new hazards and risks, the government of the Republic of Korea (ROK) established aviation safety reporting systems in accordance with the international standards of the Convention on International Civil Aviation. However, there are some misunderstandings by the government in operating and by the personnel who take part in these reporting systems. Everybody should understand that aviation safety reporting system is not a punitive measure but a tool for collecting data in order to improve safety. In addition, such a system can be utilized further to promote an improved awareness on the need for a proper safety culture on the part of both the government, the industry and the personnel. This paper includes studies on international standards, relevant regulations in the United States and the United Kingdom. Moreover, this paper proposes to the government of ROK several points to improve their own system, including integration of the existing reporting systems, improvement of reporting items, implementation of safety data taxonomy and the establishment of safety data protection.

• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.25-30
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• 2007

Proton exchange membrane fuel cell(PEMFC) performance could be affected by various factors such as cell temperature, total pressure, partial pressure of reactants and relative humidity. Hydrogen ion is combined with water to form hydronium ion [$H_3O^+$] and pass through membrane resulting electricity generation. Cooling system is needed to remove heat and other uses on large scale fuel cell. In case that collant conductivity is increased, fuel cell performance could be decreased because produced electricity could be leaked through coolant. In this study, triple distilled water(TDW) and antifreeze solution containing ethylene glycol was used to observe resistance change. Resistance of TDW was taken 28 days to reach preset value, and effect on fuel cell operation was not observed. Resistance of antifreeze solution was not reached to preset value up to 48 days, but performance failure occurred presumably caused by bipolar plate junction resulting stoppage resistance experiment. Generally PEMFC humidification is performed near-saturated operating conditions at various temperatures and pressures, but non-humidifying condition could be applied in small scale fuel cell to improve efficiency and reduce system cost. However, it was difficult to operate large scale fuel cell without humidifying, especially higher than $50{\sim}60^{\circ}C$. In case of small flux such as 0.78 L/min, temperature difference between inlet and outlet was occurred larger than other cases resulting performance decrease. Non-humidifying performance experiments were done at various cell temperature. When both of anode and cathode humidification were removed, cell performance was strongly depended on cell operating temperature.