• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6A
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• pp.977-988
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• 2006

The goal of this study is to develop a realistic methodology for determination of the Life-Cycle Cost (LCC)-effective optimal seismic retrofit and maintenance strategy of deteriorating bridges. The proposed methodology is based on the concept of minimum LCC which is expressed as the sum of present value of seismic retrofit costs, expected maintenance costs, and expected economic losses with the constraints such as design requirements and acceptable risk of death. The proposed methodology is applied to the LCC-effective optimal seismic retrofit and maintenance strategy of a steel bridge considered as a example bridge in the accompanying study, and various conditions such as corrosion environments and Average Daily Traffic Volumes (ADTVs) are considered to investigate the effects on total expected LCC. In addition, to verify the validity of the developed methodology, the results are compared with the existing methodology. From the numerical investigation, it may be positively expected that the proposed methodology can be effectively utilized as a practical tool for the decision-making of LCC-effective optimal seismic retrofit and maintenance strategy of deteriorating bridges.

• Korean Journal of Radiology
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• v.22 no.12
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• pp.2082-2093
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• 2021

Objective: We conducted a systematic review and meta-analysis of the tissue adequacy and complication rates of percutaneous transthoracic needle biopsy (PTNB) for molecular analysis in patients with non-small cell lung cancer (NSCLC). Materials and Methods: We performed a literature search of the OVID-MEDLINE and Embase databases to identify original studies on the tissue adequacy and complication rates of PTNB for molecular analysis in patients with NSCLC published between January 2005 and January 2020. Inverse variance and random-effects models were used to evaluate and acquire meta-analytic estimates of the outcomes. To explore heterogeneity across the studies, univariable and multivariable metaregression analyses were performed. Results: A total of 21 studies with 2232 biopsies (initial biopsy, 8 studies; rebiopsy after therapy, 13 studies) were included. The pooled rates of tissue adequacy and complications were 89.3% (95% confidence interval [CI]: 85.6%-92.6%; I² = 0.81) and 17.3% (95% CI: 12.1%-23.1%; I² = 0.89), respectively. These rates were 93.5% and 22.2% for the initial biopsies and 86.2% and 16.8% for the rebiopsies, respectively. Severe complications, including pneumothorax requiring chest tube placement and massive hemoptysis, occurred in 0.7% of the cases (95% CI: 0%-2.2%; I² = 0.67). Multivariable meta-regression analysis showed that the tissue adequacy rate was not significantly lower in studies on rebiopsies (p = 0.058). The complication rate was significantly higher in studies that preferentially included older adults (p = 0.001). Conclusion: PTNB demonstrated an average tissue adequacy rate of 89.3% for molecular analysis in patients with NSCLC, with a complication rate of 17.3%. PTNB is a generally safe and effective diagnostic procedure for obtaining tissue samples for molecular analysis in NSCLC. Rebiopsy may be performed actively with an acceptable risk of complications if clinically required.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2182-2189
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• 2024

The high-purity germanium gamma-ray spectrometer was used to measure the radioisotope in surface water of lakes in a Chinee petroleum industrial area. 92 samples were collected from surface water of three lakes. Activity concentrations of ²³²Th, ²²⁶Ra and ⁴⁰K in three lakes were measured, distributed in the range of 101.8-209.4, 192.1-224.9 and 335.0-548.9 mBq/L, respectively. Results were all within the limits of WHO and China. Potential environmental and health risks were assessed by calculating some radiation hazard indicators, radium equivalent index, annual effective dose, excess lifetime cancer risk, absorbed dose rate, external hazard index, internal hazard index, annual gonadal dose equivalent, activity utilization index and representative gamma index, which ranged 0.38-0.54 Bq/L, 0.06-0.08 mSv/y, 0.23 × 10^-3-0.31 × 10^-3, 0.17-0.24 nGy/h, 1.01 × 10^-3-1.46 × 10^-3, 1.55 × 10^-3-2.02 × 10^-3, 1.16-1.66 μSv/y, 3.13 × 10^-3-4.45 × 10^-3 and 2.60 × 10^-3-3.77 × 10^-3. The results were all at acceptable levels, meaning no impact on human health. The relationship between the electrical conductivity of surface water and the activity concentration of ²³²Th, ²²⁶Ra and ⁴⁰K was evaluated. The electrical conductivity value was 0.241-0.369 mS/cm, showing a significant correlation coefficient between ²²⁶Ra and ⁴⁰K and electrical conductivity. Multivariate statistical methods were used to determine the relationship between the activity concentrations of ²³²Th, ²²⁶Ra, and ⁴⁰K, radiation hazard indicators and electrical conductivity.

• Journal of Chest Surgery
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• v.35 no.8
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• pp.573-579
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• 2002

Background: In this study, the role and the surgical outcome of the modified Blalock-Taussig shunt in the treatment of the infants with cyanotic complex congenital heart diseases were investigated. Material and Method: Over the last 12 years, 105 modified BT shunts were performed in 100 infants. Postoperative course, shunt patency rate, complications, mortality and its risk factors were reviewed restrospectively. Result: The mean age at operation was 43.0$\pm$36.6 days. Sex ratio was 60:40(M:F). The postoperative oxygen saturations were lowest after mean duration of 11 hours after the shunt procedure. The operative mortality was 8%(8) with 3 late deaths. Causes of operative death included failure of maintenance of minimum oxygenation during the procedure(2), immediate postoperative shunt occlusion(2), respiratory failure(2), low cardiac output due to heart failure and pericardial effusion(2) and sepsis(2). Late deaths resulted from acute cardiac arrest during the follow up cardiac catheterization, hypoxic myocardial failure, and arrhythmia. Year of surgery, shunt size, age at operation, and complexity of the anomalies were not the risk factors for mortality. Six month shunt patency rate was 97% and overall patency rate was 96%. Postoperative complications comprised of shunt occlusion(6), phrenic nerve palsy(3), and wound infection(2). Conclusion: We demonstrated that modified Blalock-Taussig shunt was a useful tool to palliate the infants with complex cyanotic heart disease in whom early complete repair was not feasible with acceptable mortality and patency rate. An adequate postoperative management and a meticulous surgical technique may be key factors for the better results.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.15-21
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• 2006

In order to monitor the pesticide residues in/on peppers and pepper powder and to assess their risk, pesticides in/on green pepper from 10 farmgates and fresh red pepper from 9 farmgates in Chungbuk area and pepper powder from 6 wholesale markets in Cheongju city were analyzed with a GLC and an HPLC. Also, pepper powder made by pulverization of the dried red pepper was analyzed to elucidate the change of pesticide residues in fresh red pepper by oven-drying. The number of pesticides detected from peen pepper, fresh red pepper, dried red pepper and pepper powder were 9, 12, 12, and 17, respectively, including 10 pesticides (one fungicide and nine insecticides) which were exceeded the maximum residue limits (MRLs). The exceeding rate of the MRL were higher in dried red pepper and pepper powder than in green pepper and fresh red pepper. Although some pesticides in peppers and pepper powder exceeded the MRLs, their estimated daily intake(EDI) were less than 1.6% of their acceptable daily intakes(ADIs), suggesting that it would be estimated to safe. By oven-drying of fresh red pepper at $65^{\circ}C$ for 72 hours, the weight of dried red pepper was from 1/5.9 from 1/7.8 of fresh red pepper, while the concentration of pesticide residue in dried red pepper increased from 1.7 to 8.2 times, suggesting that further reconsideration was required for the MRL of pepper powder.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.464-472
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• 2009

Background: We analyzed the clinical results and the factors for survival of patients who underwent extracorporeal life support system after adult cardiovascular surgery. Material and Method: We retrospectively reviewed the medical record of 44 patients (1.6% of the total adult cardiovascular surgical cases) who underwent the use of a ventricular assisted device or extracorporeal membrane oxygenation from January 2002 to August 2008. There were 32 (72.7%) males and their mean age was 61.7$\pm$14.9(range: 20$\sim$73) years old. The mean duration of extracorporeal life support system was 5.3$\pm$3.0 (range: 1$\sim$12) days. Result: Of these 44 patients, 24 (54.5%) patients were successfully weaned from the extracorporeal device. Eighteen (40.9%) survivors were able to be discharged from the hospital. Complications were noted in 38 patients (86.4%). An emergency operation, no usage of a concomitant intraaortic balloon pump and major complications during use of the extra corporeal life support system such as bleeding, flow instability and renal failure were identified as significant risk factors for poor survival on univariated analysis. Owing to educational support and a continuous renal replacement therapy system, the clinical outcomes of these patients have improved since 2006. On multivariated analysis, renal failure and bleeding during extracorporeal life support were significant risk factors for poor survival. Conclusion: Although using. extracorporeal life support systems after adult cardiovascular surgery revealed acceptable clinical results, determining the optimal treatment strategy and further well designed larger studies are needed to improve the survival rate of patients who undergo extracorporeal life support after adult cardiovascular surgery.

• The Korean Society of Law and Medicine
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• v.19 no.1
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• pp.113-142
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• 2018

In recent years, there have been opinions in which physicians are liable to the revocation of their medical license if they are sentenced to above a certain level for criminal charges regardless of the types of offenses. Accordingly, a revised bill of law was submitted in the National Assembly, and related discussions are thus expected to commence. Considering the morality and ethics or the level of the rule of law that the general public expects of physicians, as well as the license revocation system in other professional sectors, it is assessed that medical license revocation due to criminal convictions of physicians is appropriate to some degree. However, if a poorly devised system is established based on unrefined inferences or emotional judgements, unexpected side-effects are likely to arise. With regard to serious criminal acts that society generally perceives as unacceptable, it can be assessed that the revocation of physicians' licenses would appropriately protect the general public from threats. However, given the life-saving characteristics of high-risk medical practices, higher malpractice exposures, and social values, it is difficult to assess charges of professional negligence resulting in death(or in injury) and minor offences in the same manner as anti-social criminal offences are handled. Physicians need to be treated the same as any other professions. At the same time, they are engaged in administering medical treatment to patients in the face of great risks as professionals. Under the circumstances, a discussion on the introduction of a more specific and empirical system is needed by considering the intrinsic characteristics of medical treatment and the need for an equitable health and medical policy. Accordingly, based on the above judgment and perception, this study explores the code of ethics for physicians and medical license revocation related to criminal offences at home and abroad, and examines various legislative alternatives appropriate for the Republic of Korea. In doing so, the purpose of the study is to contribute to the development of a reasonable system for handling criminal offences by physicians.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.660-667
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• 1998

Background: This study is to evaluate the effectiveness and application of Lecompte procedure as a treatment for various complex cardiac anomalies with pulmonary outflow tract obstruction. Methods: Between July 1988 and December 1997, 44 patients underwent Lecompte procedure in Seoul National University Children's Hospital. The male to female ratio was 24 to 20 and the mean age was 29.2 months(range, 3 to 83). Of these patients, 28(63.6%) had transposition of great arteries with ventricular septal defect and pulmonary stenosis(or pulmonary atresia), 14(31.8%) had double outlet right ventricle with pulmonary stenosis(or pulmonary atresia), and so on. The principles of the technique are 1) extension of the ventricular septal defect or conal resection, 2) construction of a intracardiac tunnel connecting the left ventricle to the aorta, and 3) direct connection, without a prosthetic conduit, of the pulmonary trunk to the right ventricle. Results: There were 3 in-hospital deaths and their causes were sustained hypoxia, myocardial failure, and sepsis, respectively. There was 1 late death due to sepsis. Reoperations were performed in 6 patients who had pulmonary outflow tract obstructions(4 cases), residual muscular ventricular septal defect(1 case), and recurrent septic vegetation(1 case). The cumulative survival rates by the Kaplan-Meier method were 92.7%, 92.7%, and 92.7% at 1, 2, and over 4 years. The reoperation free survival rates were 92.7%, 92.7%, and 70.2% at 1, 3, and over 5 years. Among the risk factors for the operative death, aortic cross clamping time had statistical significance(p<0.05) and all the risk factors for the recurrent pulmonary stenosis such as age, pulmonary artery index, and materials used for the pulmonary outflow tract reconstruction had no statistical significance(p>0.05). Conclusions: Our review suggests that Lecompte procedure is an effective treatment modality for various complex cardiac anomalies with pulmonary outflow tract obstruction. Repair in early age is possible and the rates of mortality and morbidity are also acceptable.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.154-159
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• 2004

The arteriovenous fistula (AVF), which maintains satisfactory blood flow, is necessary to the patients of end-stage renal disease for the long term hemodialysis. We performed the snuffbox fistula as the first operation for hemodialysis vascular access. This study was performed to investigate the patency rates, complications, risk factors for occlusion of the AVF, and the types of reoperations. Material and Method: We performed 146 snuffbox fistulas from Jun. 1994 to Dec. 2001 The records of the patients except six patients who were lost from follow up were analyzed retrospectively, Mean age and male:female ratio were 52$\pm$15 years (range, 17∼79 years) and 80 : 60 respectively. Diabetes mellitus and hypertension were combined in 47 patients and 101 respectively. Preoperative levels of creatinine and potassium were 9.09$\pm$3.68 mg/dL (range, 2.55∼20.09 mg/dL) and 4.7$\pm$0.9 mmol/L (range, 2.3∼8.1 mmol/L). One hundred thirteen cases of the snuffbox fistulas were done at left side hand and the others at right hand. Result: Mean follow up period of the patients was 41.8$\pm$31.0 months (range, 0.2∼108,8 months). During the follow up period, 35 occlusions of AVF occurred and these AVFs were patent for 9.8$\pm$10.1 months (range, 0.1∼40.4 months). The patency rates of f month, and 1, 2, 3, 5 years were known as 92.8, 80.2, 73.8, 71.3, 69.6% respectively. Right sided snuffbox fistulas (p-value=0.045) and old age (p-value=0.048) were revealed as significant risk factors for occlusion of AVF. The postoperative complications consisted of occlusions of AVF caused by intimal hyperplasia of vein in 24, thrombosis in nine, stenosis of anastomosis site in three, and venous hypertensions in two. After the first operation 37 patients underwent 86 reoperations. Conclusion: The snuffbox fistulas showed acceptable patency rates and low complication rates. The snuffbox fistulas as the first operation for AVF formation can be a good option for the patients with end-stage renal disease.

• Journal of Chest Surgery
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• v.43 no.2
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• pp.127-132
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• 2010

Background: Femoropopliteal artery bypss grafting is an effective form of treatment for infrainguinal artery occlusive disease in those patients who have either intermittent claudication or resting critical ischemia. The objective of this analysis was to evaluate the long-term patency of a femoropopliteal bypass graft that is classified as an above-the-knee saphenous vein graft or an above-the-knee PTFE (polytetrafluoroethylene) graft. Material and Method:From January 1998 to February 2005, 103 above-the-knee femoro-popliteal bypasses were performed on 87 patients. There were 74 male and 13 female patients with a mean age of $65.7{\pm}9.69$ (range: 31~82). The surgical indications were intermittent claudication in 65 cases (74.7%), foot ulceration in 2 cases (2.3%), foot necrosis in 10 ases (11.5%) and toe necrosis in 10 cases (11.5%). For the bypass graft, a reversed saphenous vein was used in 31 limbs and a polytetrafluoroethylene (PTFE) prosthesis was used in 72 limbs (6 mm: 27 limbs, 8 mm: 45 limbs). The perioperative risk factors were diabetes mellitus in 33 cases (37.9%), hypertension in 47 cases (54.0%), a history of ischemic heart disease in 13 cases (14.9%) and smoking in 72 cases (82.8%). Result:There were three perioperative deaths (3.4%) and seven late deaths (8.3%). Major leg amputation was necessary in 12 patients (13.8%) during the entire course of the study. The primary patency rate at 5 years for the vein grafts, the 8 mm-PTFE grafts and the 6 mm-PTFE grafts were 84.7%, 77.4% and 74.2%, respectively and the overall primary patency rate was 78.7%, and there were no significant statistical differences among the graft groups. By using multivariate analysis, the number of patent tibial arteries was determined to be a significant factor that influenced the primary graft patency rate (p<0.005), but risk factors such as diabetes mellitus, ischemic heart disease, smoking and age had no statistically significant affect on the primary graft patency rates. Conclusion: The great saphenous vein is considered the most durable conduit for infrainguinal revascularization, but the overall results of this study show that saphenous vein and PTFE grafts have comparable patency rates when used above the knee in patients with claudication or critical ischemia. The use of PTFE above the knee is a reasonable alternative for a femoro-poplitael bypass and it is associated with acceptable long term patency rates.