• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.295-301
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• 1995

Background: The serious problems in retreatment of pulmonary tuberculosis are a significant proportion of drug resistance. Preferably retreatment should contain the drugs which has never used before, so drug retreatment is limited in selection. A new antibacterial substance, ofloxacin(OFX) is the activity against mycobacterium tuberculosis and it has been used in the treatment of pulmonary tuberculosis. The present report concerns the result of retreatment of pulmonary tuberculosis patients containing OFX treated at National Kongju Tuberculosis Hospital. Method: A retrospective study was made through the regular follow up of 92 smear positive cases, who were treated by four drugs regimen between Mar 1991 and June 1994 at National Kongju Tuberculosis Hospital. Four drugs were, namely prothionamide, cycloserine, ofloxacin and streptomycin(kanamycin or tuberactinomycin). The duration of follow up was over one year. Results: 1) Out of 92 cases with positive sputum AFB smear, 67(73%) achieved the negative conversion. 2) Considering the negative sputum conversion in all the groups, the vast majority(85%) of sputum conversion occurred within the first 4 months. 3) The roentgenological improvement occurred in 49 percent on the whole and when the extent of disease was minimal, moderately, far advanced pulmonary tuberculosis, sputum AFB smear negative response to retreatment was 100%, 93%, 68%, respectively. 4) When the duration of patient's illness was less than 1 year, 1 to 3 years, 3 to 5 years and more than 5 years, sputum AFB smear negative response to retreatment was 87%, 76%, 65% and 55%, respectively. 5) Adverse reaction to prothionamide, with complaints of gastrointestinal troubles was common and hepatic dysfunction without jaundice was observed in 7 percent, convulsion in 1 percent, that to cycloserine occurred renal dysfunction & psycosis & convulsion, 2%, 1%, 1%, respectively. Tinnitus with KM occurred in 1% and dirrhea with OFX in 4%. Conclusion: The duration of patient's illness was shorter, sputum AFB smear negative response rate was better. Radiologic responses were not remarkable, but extent of disease by national tuberculosis association was smaller, the result of retreatment was better. Adverse reaction of the secondary antituberculosis agent was mainly observed gastrointestinal troubles, as regard to tolerance to the secondary drugs the role of the physician is of very important value and toxic effects can be overcome by the strong confidence.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.1
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• pp.1-9
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• 2000

Purpose : Spine is one of the most common sites of the metastatic bone tumors. Conservative management such as chemotherapy or radiotherapy has been preferred in most cases. However, the neurologic deficit has not been usually improved, and the quality of life was poor. The purpose of this study was to show the efficacy of the surgical treatments for metastatic spinal tumors in terms of postoperative improvements of neurologic deficit and survival time. Materials and Methods : Authors have reviewed the literatures and analyzed 14 patients of metastatic spinal tumors who were received operative treatments between August 1991 and June 1999 at the our department of orthopaedic surgery. Results : The most frequent primary tumor was breast cancer in women and lung cancer in men. The thoracic region was the most common site. There was a preponderance of females over males, and the age ranged between 4th and 8th decade. The indications of surgical treatment comprised instability, progressive neurologic findings, resistance to radiotherapy, pathological fracture, long life expectancy( >6weeks), isolated metastasis and need for pathological diagnosis. The degree of preoperative neurological deficit might influence on the improvement of clinical symptoms after surgery. Conclusion : The surgical treatment reduced the neurological deficit and pain regardless of the operative methods. In the early stage of neurological deficit, the surgical treatment was important for better prognosis. Recently early active operative treatment was performed for metastatic spinal tumor to minimize the intractable pain and to prevent the progression of the neurologic deficit. Early intervention can improve the quality of life and long term survival.

• Archives of design research
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• v.16 no.4
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• pp.185-196
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• 2003

The demand for an environment-friendly transportation system, equipped with low energy consumption, and low-or zero-pollution has been on the increase since the beginning of the World Trade Organization era. Simultaneously, the consistent growth of high-speed tram technology, combined with market share, has sparked a fierce competition among technologically-advanced countries like France, Germany, and Japan in an effort to keep the lead in high-speed train technology via extensive Research and development(R＆D) expenses. These countries are leaders in the race to implement the next-generation transportation system, build intercontinental rail way networks and export the high-speed train as a major industry commodity. The need to develop our own(Korean) 'high-speed train' technology and its core system technology layouts including original technology serves a few objectives: They boost the national competitive edge; they develop an environmental friendly rail road system that can cope with globalization and minimize the social and economic losses created by the growing traffic-congested delivery costs, environment pollution, and public discomforts. In turn, the 'G7 Project-Development of High Speed Railway Technology' held between 1996 and 2002 for a six-year period was focused on designing a domestic train capable of traveling at a speed of 350km/h combined and led to the actual implementation of engineering and producing the '2000 high-speed train:' This paper summarizes and introduces one of the G7 Projects-specifically, the design segment achievement within the development of train system engineering technology. It is true that the design aspect of the Korean domestic railway system program as a whole was lacking when compared with the advanced railroad countries whose early phase of train design emphasized the design aspect. However, having allowed the active participation of expert designers in the early phase of train design in the current project has led to a new era of domestic train development and the implementation of a way to meet demand flexibly with newly designed trains. The idea of a high-speed train in Korea and its design concept is well-conceived: a faster, more pleasant, and silent based Korean high-speed train that facilitates a new travel culture. A Korean-type of high-speed train is acknowledged by passengers who travel in such trains. The Korean high-speed prototype train has been born, combining aerodynamic air-cushioned design, which is the embodiment of Korean original design of forehead of power car minimized aerodynamic resistance using a curved car body profile, and the improvement of the interior design with ergonomics and the accommodation of the vestibule area through the study of passenger behavior and social culture that is based on the general passenger car.

• Clinical and Experimental Pediatrics
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• v.46 no.8
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• pp.777-783
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• 2003

Purpose : The aim of this study was to evaluate the effect of inhaled nitric oxide(iNO) on gas exchange, hemodynamics and pulmonary inflammation in newborn piglets with E. coli induced septic lung. Methods : Twenty three instrumented and ventilated piglets were randomized into three groups : CON(n=6), PCON(n=9), and PNO(n=8). In the piglets of the PCON and PNO groups, E. coli septic lung was induced by endotracheal instillation of E. coli. Ten ppm iNO was given continuously in the PNO group after endotracheal instillation of E. coli. All animals were mechanically ventilated for six hour with a peak inspiratory pressure of 30 $cmH_2O$, frequency of 25 breaths/min, $FiO_2$ 1.0 and a positive end-expiratory pressure of 4 $cmH_2O$. All measurements were made at one hour intervals during the experiment. At the end of the experiment, lung tissue was harvested for the analysis of myeloperoxidase activity, indicative of lung inflammation. Results : All piglets with pulmonary instillation of E. coli developed E. coli sepsis. Piglets in the PCON group developed progresseve pulmonry hypertension, hypoxemia and hypercarbia compared to the CON group due to increased pulmonary vascular resistance, intrapulmonary shunt fraction and physiologic dead space fraction. iNO did not reverse pulmonary hypertension in the PNO group. However iNO significantly improved oxygenation, which was attributed to marked improvement of venous admixture and partial attenuation of increase in dead space fraction. Increased myeloperoxidase activity in PCON compared to CON was significantly attenuated in PNO. Conclusion : iNO improves oxygenation and lung inflammation in newborn piglets with E. coli induced septic lung.

• Magazine of the Korean Society of Agricultural Engineers
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• v.20 no.2
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• pp.4645-4687
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• 1978

This study was attempted to investigate the mechanical properties of concrete and crack control effects of reinforced concrete with steel and glass fiber. The experimental program includes tests on the properties of fresh concrete containing fibers, compressive strength, tensile strength, flexural strength, Young's modulus, Shrinkage and deformation of steel or glass fiber reinforced concrete. Also this study was carried out to investigate the effect of steel or glass fiber to retard the development in reinforced concrete subject to uniaxial tension and thus facilitate the use of steels of higher strength. The major conclusions that can be drawn from the studies are as follows: 1. The effect of the fibers in various mixes on fresh concrete confirmed that fibers do have a significant effect on the properties of fresh concrete, bringing much more stable and exhibiting a signiflcant reduction in surface bleeding, and that the cohesion is greatly improved and the internal resistance increases with fiber concentration. But the addition of an excess contents and length of fibers brings about the reduction of workability. 2. With the addition of steel fibers(1.5% Vol.) to concrete, the compressive strength as compared with plain concrete showed a very slight increase, but excess addition, over 1.5% Vol. of steel and glass fiber reduced its strength. 3. Splitting tensile strength of fiber reinforced concrete showed a significant increase tendency, as compared with plain concrete. In case of containing steel fiber (2.5%, 30mm), it showed that the maximum increase rate of 1.48 times as much rate, and in case of containing glass fiber (2.5%, 30mm), the increase rate of strength was 1.25 times as much rate. 4. Flexural strength of fiber reinforced concrete showed a significant tendency, as compared with plain concrete. Containing steel fiber (2.5%, 30mm) showed the maximum increase rate of 1.64 times as much rate and containing glass fiber (2.5%, 30mm) showed the increase rate of strength of 1.32 times as much rate, and in general, the 30mm length brougth the best results. 5. The strength ratio ($\sigma$b/$\sigma$c and $\sigma$t/$\sigma$c) increased, when steel fiber's average spacing was up to 3.05mm, but decreased when beyond 3.05mm, and it was confirmed that tensile or flexural strengths of steel fiber reinforced concrete are apparently governed by fiber's average spacing. 6. The compressive strain of fiber reinforced concrete showed a significant increasing tendency as the fiber was added, but Young's modulus. with the addition of steel and glass fibers, showed a slight decrease tendency. And according to the increase of flexural strength, a considerable increase was seen in toughness. 7. With the addition of fiber's the shrinkage of concrete was significantly decreased, in both case of adding steel fibers 12.5%, 30mm, and showed a significant decrease ratio, in average 30.4% and 36.7%, as compared with plain concrete. 8. With the increase of fiber volume fraction and length, the gained stress in reinforcing bar in concrete specimens increased in all crack widths, but at different rates, with the decrease of fiber diameter, the stress showed a considerable increasing tendency. And the duoform steel fibers showed the greatest improvement, as compared with the other types tested. 9. The influence of fiber dimensions in order of significanse on the machanical properties of concrete and the crack control of reinforced concrete was explained as follows: content, length, aspect ratio and dimeter.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.3
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• pp.145-160
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• 1979

The effects of organic material application on soil physical properties were reviewed in relation to soil productivity. The organic matter contents and soil physical properties of the cultivated land in Korea were summarized and the effects of organic matter were compared in terms of land uses and soil types. Soil physical properties related to crop yield potential, such as soil aggregation, permeability, water holding capacity, erodibility, and compactibility, were used in evaluating the effects of organic materials as a soil physical amendment. The benefical effects of organic matter addition on soil physical conditions include (1) better aeration and increased infiltration in silty and clayey soils, (2) increased water holding capacity and moisture availability in sandy soils, (3) decreased soil erodibility, and (4) increased resistance to compaction. It is, therefore, concluded that continuous application of organic materials could greatly improve the various soil physical properties and favor the growth and yield of crops. A high rate of organic matter addition could contribute to reducing not only the soil erosion on sloping land, but also the possible detrimental effect of farm mechanization. In general, the effects of organic matter on soil physical improvement were estimated to be much higher in upland than in paddy. Organic matter would have a more pronounced effect on low productive lands such as heavy clayey or sandy soils and newly reclaimed soil. The optimum level of soil organic matter content was estimated to be about 3.0 to 3.5% for the best soil physical condition. Since the organic matter contents of the cultivated lands in Korea are much lower than optimum level, it would be desiable to use more organic materials to soil for the increase of soil productivity, continuation of stabilized high productivity and soil erosion control.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.376-382
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• 2005

Avermectin (AVM) $B_{1a}$ produced by Streptomyces avermitilis via polyketide pathway is a secondary metabolite with powerful anthelmintic and insecticidal activities, thus being used as an efficient agent in the field of agriculture and animal health. It has been reported that a precursor for AVM $B_{1a}$ biosynthesis was isoleucine and the biosynthetic pathway of AVM $B_{1a}$ was closely similar to that of fatty acid. Based on understanding of the biosynthetic pathway of AVM $B_{1a}$, we intended to screen various mutants resistant against O-methyl threonine (OMT), an isoleucine-anti metabolite, and/or mutants resistant against p-fluoro phenoxy acetic acid (pFAC), an inhibitor of fatty acid biosynthesis. It was inferred that these mutants could produce AVM $B_{1a}$ more efficiently, due to the acquired capability of not only overproducing isoleucine intracellularly but also channelling metabolized carbon-sources into the polyketide pathway, thus leading to enhanced biosynthesis of AVM $B_{1a}$. The resulting mutant (PFA-1 strain) resistant against 100 ppm of pFAC was able to produce approximately 42 fold higher amount of AVM $B_{1a}$ compared to the parallel mother strain (4,200 vs. 100 units/l). In addition, through the process of continuous strain improvement program carried out by gradually increasing the OMT concentration, it was possible to obtain a more attractive mutant with greater AVM $B_{1a}$ production capacity (9,000 units/l). Notable was that significantly higher producer (12,000 units/l) could be selected through further screening of the resistant mutants, this time, to even higher concentration of PFAC. Meanwhile, through the analysis of AVM Bla production histograms (i.e., number of strains according to their AVM $B_{1a}$ biosynthetic ability) for the earlier strains in comparison with the high producers having the characteristics of resistance to OMT and pFAC, it was found that production stability of the high-yielding producers were remarkably improved, as demonstrated by the fact that larger proportion of the mutated strains had greater capability of AVM $B_{1a}$ biosynthesis ($71\%$ in the range between 5,000 and 7,000 units/L; $47\%$ in the range between 6,000 and 7,000 units/l). Based on these consequences, it was concluded that the rational screening strategy based on the understanding of the biosynthetic pathway of AVM $B_{1a}$ was very effective in obtaining high-yielding mutants with the features of enhanced production stability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.417-423
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• 2002

The edible films were prepared from the protein of alaska pollack, Theragra chalcogrmma. Effects of plasticizer, cross linker and laminated film on physical properties such as tensile strength (TS), elongation (E) and water vapor permeability (WVP) of films were investigated. In adding various kinds of plasticizers, TS of the films prepared with propylene glycol (PG) was the highest, and followed sorbitol, polyethylene glycol 200 (PEG 200) and glycerol. Elongation of the films prepared with glycerol was the highest, then sorbitol, PEG 200 and PG. WVP of films showed lower in order of PG, sorbitol, glycerol and PEG 200.75 decreased with the increment of plasticizer concentration, but elongation increased, The addition of both PG and PEG 200 effected weakly on elongation, so they were inadequate as plasticizer for the film. Mixtures of glycerol and sorbitol, which showed opposing both TS and elongation in the films, could control the physical properties of the films. With increasing relative humidity, TS decreased, while elongation and equilibrium moisture content increased. By adding the cross linkers such as ascorbic acid, citric acid and succinic acid, TS and m of films increased, while elongation decreased. Ascorbic acid, citric acid, succinic acid were most effective for TS at 0.2, 0.1 and $0.1\%, respectively. Laminated film with alaska pollack protein and corn zein improved TS above two times, reduced WVP about $20\~30\%$, as compared with the Elm from alaska pollack protein. Two films did not show the difference to oxygen permeability, but they showed about tenfold greater oxygen resistance than polyethylene film. Laminated film showed higher b and $\Delta$E value of color difference, lower a and L value than the film from alaska pollack protein.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.169-175
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• 1998

Background: Heliox is known to decrease $PaCO_2$ in patients with increased airway resistance by increasing minute ventilation and reducing work of breathing(WOB). Besides these effect, heliox is expected to decrease functional anatomic dead space owing to improvement of peak expiratory flow rate(PEFR) and enhancement of gas distribution. We investigated whether heliox can decrease $PaCO_2$ even at the same minute ventilation (VE) and WOB with $N_2-O_2$ to speculate the effect of the heliox on the anatomic dead space. Material and Method: The subjects were 8 mechanically ventilated patients with asthma or upper airway obstruction(M : F=5 : 3, $68{\pm}10$years) who were under neuromuscular paralysis. The study was consisted of three 15-minutes phases: basal $N_2-O_2$ heliox and washout Heliox was administered via the low pressure inlet of servo 900C, and respiratory parameters were measured by pulmonary monitor(CP-100 pulmonary monitor, Bicore, Irvine, CA, USA). To obtain the same tidal volume(Vt) in heliox phase, the Vt on monitor was adjusted by the factor of relative flow rate of heliox to $N_2-O_2$. Dead space was calculated by Bohr equation. Results: 1) Vt, VE, peak inspiratory pressure(PIP) and peak inspiratory flow rate(PIFR) were not different between $N_2-O_2$ and heliox. 2) PEFR was higher on heliox($0.52{\pm}0.19$L/sec) than $N_2-O_2$($0.44{\pm}0.13$L/sec)(p=0.024). 3) $PaCO_2$(mmHg) were decreased with heliox($56.1{\pm}14.1$) compared to $N_2-O_2$($60.5{\pm}15.9$)(p=0.027). 4) Dead space ventilation(%) were decreased with heliox($73{\pm}9$ with $N_2-O_2$ and $71{\pm}10$ with heliox)(p=0.026). Conclusion: Heliox decreased $PaCO_2$ even at the same VE and WOB with $N_2-O_2$, and the effect was considered to be related with the reduction of anatomic dead space.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.222-231
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• 2009

Statements of the problem: Over the past decades, conventional complete dentures were used for various patients although they have incomplete function. Overdentures using dental implants could help the improvement of denture function. Purpose: The purpose of this study was to compare the strains of abutment and bone on implant overdenture between splinted and unsplinted type of prosthesis. Additionally, the strain values of parallel placed implant model and unparallel placed implant model were compared. Material and methods: Two acrylic resin model were prepared and two implants were placed at the canine positions in each model. In the first model, two implant were placed parallel. In the second model, two implants were placed with 10 degree labiolingual divergence. Two types of abutment were connected to the fixtures alternatively. One was splint type of Hader bar, the other was unsplint type of ball abutment. Overdentures were fabricated with corresponding attachment systems and seated on abutments. Strains of abutments and labial bone simulants were measured with electric resistance strain gauges when static load from 100 N to 200 N were applied to overdentures. Results: 1. Splinted type of overdentures using bar and clip showed higher absolute strain values. But the strain was compressive and the load was shared by two implants(P<.05). 2. Unsplinted type overdentures using ball and O-ring showed low absolute strain values(P<.05). 3. Labially inclined implant showed higher tensile strain values in unsplinted type of prosthesis than in splinted type of prosthesis. Lingually inclined implant showed rather low strain values under load(P<.05). 4. Non parallel implant model showed higher absolute strain values than parallel placed implant model comprehensively(P<.05).