• Journal of Preventive Medicine and Public Health
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• v.34 no.1
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• pp.9-20
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• 2001

Objectives : To explore the relationship between Percutaneous Transluminal Coronary Angioplasty(PTCA) volume and the associated immediate outcome. Methods : A total of 1,379 PTCAs were peformed in 25 hospitals in Korea between October 8 and December 31 in 1997. Data from 1,317 PTCAs (95.5%) were collected through medical record abstraction. Inter-observer reliability of the data was examined using the Kappa statistic on a subsample of 110 PTCA procedures from five hospitals. Intra-observer reliability of the data was also examined. PTCA success and immediate adverse outcomes were selected as the outcome variables. A successful PTCA was defined as a case that shows less than 50% diameter stenosis and more than 20% reduction of diameter stenosis. Immediate adverse outcomes included deaths during the same hospitalization, emergency coronary artery bypass graft (CABG) within 24 hours after PTCA, and acute myocardial infarction within 24 hours after PTCA. The numbers of PTCAs performed in 1997 per hospital were used as the volume variables. Results : Without adjusting for patient risk factors that may affect outcomes, procedures at high volume hospitals ($\geq200$ cases per year) had a greater success rate (P=0.001) than low volume hospitals. There was a marginally significant difference (P=0.070) in major adverse outcome rates between high and low volume hospitals. After adjusting for risk factors, there were significant differences in procedural failure and major adverse outcome rates between high and low volume hospitals. Conclusions : After adjusting for patient clinical risk factors, the hospital volume of PTCA was associated with immediate outcomes. It is recommended that a PTCA volume per year be established in order to improve the immediate outcome of this procedure in Korea.

• Korean Journal of Materials Research
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• v.10 no.4
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• pp.312-316
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• 2000

A study has been made to investigate the effects of hot isostatic pressing(HIP ping) on bond strength and elevated temperature characteristics of thermal barrier coating(TBC). The specimens were prepared by HIPping of TBC which is composed of the ceramic top coat(8wt%$Y_2$$O_3$-$ZrO_2$) and the metallic bond coat on the matrix of IN738LC superalloy. The results showed that the porosity and microcracks in the ceramic top coat of TBC were significantly decreased by HIP. As a result, the bond strength of the HIPped coating was increased above 48% compared to that of as-coated specimen and microstructure was homogenized. It was found that the thermal cycle resistance of HIPped coating was inferior to that of as-coated specimen. It was considered that this result was mainly caused by the reduction of internal defects in the top coat layer which could play a role in relaxing the thermal stress due to a large difference in thermal expansion between TBC and matrix.

• Journal of Korean Foot and Ankle Society
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• v.2 no.1
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• pp.19-29
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• 1998

The characteristics of the patients after the calcaneal fracture that were associated with an unsatisfactory outcome were subtalar incongruity, decreased Bohler angle ratio of the fractured to the normal side, an age of more than fifty years, work involving strenuous labor, and increased time missed from work due to the injury. The purpose of this study was to examine the reliability of measurements of the range of motion of the subtalar joint. To determine reliability, evaluates of the correlatioinship between the degree of the displacement of the subtalar joint and Circle draw test after the calcaneal fracture. Fifty patients who had had fifty five calcaneal fractures were managed with open reduction and internal fixation. The results were reviewed retrospectively, between 4months and three years after the operation, with use of an evaluation system for the subtalar joint and with plain radiographs. At follow up evaluation, the result was assessed on the basis of restoration of anatomy and function of the subtalar joint. We evaluated the subtalar joint with plain films that consist of anteroposterior projection, lateral projection, calcaneal axial view, and Broden's view, and the measurements of the displacement of the subtalar joint surface after the calcaneal fracture. And we evaluated the range of motion of the subtalar joint with Circle draw test for physical evaluation. Circle draw test was evaluated and demonstrated the motion of flexion-supination-adduction and extension-pronation-abduction of the subtalar joint. And there are correlationship between the degree of the displacement and range of motion of the subtalar joint after the calcaneal fracture. The report critically reviews methords used to measure Circle draw test for physical examination of the follow up after the calcaneal fracture.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.510-516
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• 1995

A multidisciplinary weight control program was conducted for obese women. The major components of the program included low calorie diet therapy, exercise, behavior modification and nutritional education and counseling. Sixteen healthy volunteers in excess of body fat, above 30%, were enrolled in the group support program. But 5 person were dropped out in the 2nd week of treatment. During the 1st week of group orientation, individual cause of obesity was assessed through a computer program including survey of dietary intake, activity, eating habits and life styles. During the 5 weeks of treatment, 4.8kg of average weight loss was accomplished using a following program ; low calorie diet(1200kcal/day with all essential nutrients), low impact aerobic exercise(50~60% of $VO_{2max}$, 1 hour/day in a group, 3~5 days/week), behavior modification of individual life styles and eating habits causing obesity and nutritional education concerning nutrition, role of exercise such as brisk walking, importance of slow eating in regular meal pattern and internal motivation for weight reduction, health risk of obesity and rapid weight loss, weight recycling and yo-yo syndrome, etc. Nutritional conseling was conducted 3 times per week with checking self-records of foods, activity, emotional state and tiredness. Before and immediately after 5 weeks of treatment, blood pressure, fasting blood glucose, cholesterol and triglyceride were measured and comparied with paired t-test. After 5 weeks of treatment, body weight, body mass index, body fat and circumferences of waist, upper arm and hip were significantly decreased. Also LDL-cholesterol was significantly decreased after obesity treatment.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.385-391
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• 1998

A new balancing method of atrial pressures balancing for the moving actuator total artificial heart(TAH) without an extra compliance chamber was developed. The asymmetric operation of the pendulous moving actuator have made it possible to compensate the left and right pump output difference by utilizing the interventricular air space as an internal compliance chamber in a pump housing. Furthermore, the balancing performance between left and right pump outputs is increased through the improvement of the flexibility of part of the polyurethane housing. However, the increase of the flexibility of the pump housing causes a little loss of the cardiac output due to the reduction of active filling property. In this paper., a good condition between the balance and pump output performance is evaluated by adjusting the air volume in the interventricular space through a series of in vitro experiments. This new pump was implanted in a sheep weighting 63kg, and it survived for 3 days and the average cardiac output during postoperative days was about 4.2 L/mim with the atrial pressures under 15 mmHg.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.389-394
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• 2019

In this study, a functional inorganic insulation as TiO₂ and inorganic wet fly ash were used to evaluate the physical performance and thermal environment of an exterior finish that can improve the thermal environment of a building. The performance evaluation of the finish was based on the KS F 4715 thin coating material and the thermal environment. When TiO₂ was added, the physical performance was lowered at 10% or more, and the inorganic wet-treated fly ash increased the physical performance by 10%. In the thermal environmental evaluation, the surface temperature reduction effect of the inorganic wet-treated fly ash was low, but when used in combination with TiO₂, it was effective to reduce the surface temperature and the internal temperature. As a result, the optimum combination of TiO₂ and inorganic wet-treated fly ash for thermal environment control was found to be optimal when 5% of each mixture was used.

• Journal of Energy Engineering
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• v.24 no.1
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• pp.32-41
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• 2015

The Metropolitan Area Green Heat Project (MAGHP), which collects unused heat gathered from power plants, steel works, landfills in western Metropolitan area and distribute it to integrated energy business (IEB) companies, is proposed for the purpose of enhancing energy efficiency and providing low-price heat for IEB companies. Therefore, in order to decide on whether to initiate the MAGHP, the economic feasibility analysis of the project is widely demanded. This paper attempts to consider and measure four economic benefits: heat supply benefit, production cost reduction benefit, greenhouse gas mitigation benefit, and air quality improvement benefit. In addition, the paper tries to conduct the economic feasibility analysis. The project requires three-year investment and thirty-year operation. Three important findings emerge from the analysis. First, its net present value is computed to be 1,269 billion won and more than zero. Second, its benefit/cost ratio is calculated to be 1.72 and bigger than 1.0. Third, its internal rate of return is estimated to be 24.26% and larger than the social rate of return, 5.5%. In conclusion, the MAGHP is socially profitable and should be conducted immediately.

• Clinics in Shoulder and Elbow
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• v.12 no.1
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• pp.44-52
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• 2009

Purpose: We assessed the radiographic and clinical results of one surgeon's experience treating proximal humerus fractures with a locked proximal humeral plate. Materials and Methods: Twenty patients with unstable proximal humerus fractures were treated with a locking compression plate between February 2005 and September 2007. The average age of the patients was 60.6 years, and the average postoperative follow-up period was 22.3 months. The clinical results were evaluated using the Constant and DASH scores. The radiologic results were evaluated by the Paavolainen method, which measures the neck shaft angle and humeral head height. Results: At the last follow-up examination, the mean Constant score was 75.3 and 15 cases (75%) had excellent or good results; the mean DASH score was 16.4. The mean neck shaft angle was $137.1^{\circ}$, and 19 cases (95%) had good results by the Paavolainen method. There was one delayed union, malunion, and screw loosening. Conclusion: The patients treated with a locking compression plate had relatively good clinical and radiologic results, and a low complication rate. Moreover, the patients could exercise earlier due to good reduction and initial stability. Treatment of unstable proximal humerus fractures with a locking compression plate is a reliable method.

• Clinics in Shoulder and Elbow
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• v.10 no.2
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• pp.220-226
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• 2007

Purpose: The distal clavicle has a biomechanical structure different from that of the proximal or middle 1/3 clavicle, and delayed union or nonunion occurs frequently in a distal clavicle fracture. The authors obtained favorable results from an open reduction and bone grafting of the distal clavicle nonunion. We report the results together with review of the relevant literature. Materials and Methods: The subjects were 8 patients(average age, 38.9) who had undergone surgery for distal clavicle nonunion from August 2003 to May 2006. Nonunion occurred after surgical treatment in 4 cases, and after conservative treatment in the other 4. In all cases, the patients complained of pain. Results: The mean follow-up duration was 14 months, and radiological union was observed in 8 weeks on average. In all cases, the range of shoulder joint motion was normal at the end of the follow-up observation. In the functional evaluation, 7 cases showed excellent results and 1 case showed good results. Conclusion: Surgical treatment is a safe and reliable treatment for distal clavicle fracture nonunion because it can achieve early rehabilitation and union.

• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.251-259
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• 1995

Pharmacokinetics and pharmacodynamics of metoprolol, a selective beta-l blocker, were examined for 360 minutes after intravenous bolus administration of metoprolol to 6 dogs. Plasma concentration and excreted amount in the urine metoprolol were measured by liquid chromatography with fluorescence detection. PR interval and heart rate were measured by ECG monitoring. Blood pressure was monitored through intraarterial catheter in femoral artery and cardiac output by thermodilution method using Swan-Ganz catheter. To analyze the effect site concentration-response relationship, plasma concentration and pharmacological effects were simultaneously fitted to a two pharmacokinetic compartment linked to pharmacodynamic model with NONLIN program. Results are as follows. 1) The plasma concentration of metoprolol after intrvenous injection decreased biexponentially. The terminal half-life estimated was $1.33{\pm}0.40$ hours and the volume of distribution at steady state (Vdss) and the total body clearance were $1.04{\pm}0.4\;L/kg,\;6.55{\pm}2.21\;L/hr$, respectively. The central compartment volume of distribution and peripheral compartment volume of distribution were $0.35{\pm}0.14L/kg\;and\;0.69{\pm}0.34L/kg$. The renal clearance and intercompartment clearance were $0.53{\pm}0.25\;L/min\;and\;0.35{\pm}0.19\;L/min$. 2) Simulated biophase concentration-response curve shows hyperbolic relationship and the estimated concentration-effect relationship was best explained by Emax model when the prolongation of PR interval and the reduction of the heart rate were used as pharmacodynamic parameters. Emax and EC50 were estimated to be $26.3{\pm}4.7\;msec\;and\;88.8{\pm}82.3\;g/ml$ for PR interval, and $48.7{\pm}18.8\;beats/min\;and\;113.5{\pm}78.7\;ng/ml$ for heart rate, respectively. 3) The changes of cardiac output-effect site concentration relationship was best fitted by a linear model and the slope of the relationship was $0.005{\pm}0.003$. Diastolic blood pressure-effect site concentration relationship was also explained by the linear model and the slope of the relationship was $0.038{\pm}0.034$.