• Journal of Chest Surgery
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• v.43 no.6
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• pp.614-618
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• 2010

Background: The aim of our study was to assess the extent of regression of left ventricular mass after aortic valve replacement in isolated aortic regurgitation. Material and Method: Retrospective analysis of echocardiographic data was collected preoperative and postoperative 1 year. There were 20 patients (12 males, 8 females, mean age $55.8{\pm}11.8$ years, mean body surface area $1.64{\pm}0.19m^2$) with aortic regurgitation from 2002 through 2007. We studied the change of left ventricular ejection fraction, ventricular septum and left ventricular posterior wall thickness, and left vemtricular muscle index (LVMI). The control group was age matched with normal echocardiographic study results. Patients with combined surgery or infective endocarditis were excluded. Result: Seven cases of tissue valves and thirteen cases of mechanical valve were used. The valve sizes were 21 mm (3 cases), 23 mm (13 cases) and 25 mm (4 cases). The postoperative ($125.5{\pm}42g/m^2$) LVMI has decreased than preoperative LVMI ($212.3{\pm}80g/m^2$, p=0.000) but higher than that of control group ($80.5{\pm}15.9g/m^2$, p=0.000). Postoperative septal wall (systolic/diastolic: $13.5{\pm}3.4mm/17.1{\pm}4.1mm$) and left ventricular posterior wall (systolic/diastolic: $12.9{\pm}3.4mm/16.7{\pm}3.4mm$) thickness were slightly decreased after the valve replacement but was not significantly different than preoperative levels. And postoperative interventricular septal wall and left ventricular posterior wall thickness (systolic/diastolic: $8.6{\pm}1.4mm/12.1{\pm}1.7mm$, systolic/diastolic: $8.4{\pm}1.4mm/13.2{\pm}1.9mm$) were higher than that of the control group (p<0.001). Conclusion: The significant regression of LVMI after aortic valve replacement developed at postoperative one year but the level was higher than control group. The main cause of decreased LVMI is decreased in left ventricular dimension.

• 한국산학경영학회:학술대회논문집
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• 2004.11a
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• pp.101-123
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• 2004

This study examines empirically the significant changes in tax payments when the consolidated tax return is introduced in the future. We estimate the consolidated tax payments under the eight cases which are classified as such : whether only 100% ownership subsidiaries should be included or 80% and over, whether all subsidiaries should be included or only subsidiaries with loss, and whether unrealized profits from intercompany transactions should be excluded or not. After estimating the consolidated tax payments, we test the difference between the consolidated tax payments and the sum of the individual tax payments of the subsidiaries. The results of the test show that the consolidated tax payments are significantly less than the sum of the individual tax payments of the subsidiaries. We interpret that the inclusion of the losses of the subsidiaries in the consolidated tax base makes the tax payment decrease. Based on our analysis about 3.8 billion Won per each parent company would decrease due to the introduction of the consolidated tax return. And we find that under the mandatory consolidated tax return system the significant difference between the consolidated and individual tax payment exists except that the only 100% ownership subsidiaries are included and unrealized profits from intercompany transactions are not excluded. However, when the parent companies have the discretion to select the consolidated subsidiaries, the consolidated tax payments are significantly less than the sum of the individual tax payments of the subsidiaries regardless of the ownership percentage, inclusion of the loss of the subsidiaries and exclusion of the unrealized profits.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.553-563
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• 2000

Horseshoe Expander is one of Slow Maxillary Expansion(SME) which aims to accommodate the contra- lateral expansion and midpalatal suture expansion or the palate. The appliance consists of skeleton type strew embedded in split Horseshoe appliance. It is the objectives of the presentation to manifest the changes in dental & craniofacial components subsequent to the application of Horseshoe Expander. The subjects for this study consisted of 32 patients (mean age : 12.7). frontal, lateral cephalometric headfilm were taken and study casts were fabricated before and after expansion. 24 items were measured, compared preexpansion with postexpansion. Especially, palatal volume was measured by means of 'Hydro-measurement method'. Tooth axis measurement on the dental casts were made with Universal bevel protractor, and Horseshoe Expander group were compared with RME group. This study of changes to maxillary expansion with Horseshoe Expander revealed the following significant results. 1. Triangular-shaped expansion pattern appeared in frontal cephalometric headfilm. 2. Palatal plane, occlusal plane, mandibular plane and upper incisor to FH increased in lateral cephalometrir headfilm. 3. Palatal volume increased significantly. A slight bite opening, reduction of occlusal contact points showed in dental casts. 4. A 2.2:1 ratio of the amount of intermolar width in maxilla(orthodontic movement) to maxillary width (orthopedic movement) was determined. 5. Horseshoe Expander group has less buccal tipping tendency than RME group, by taking high correlation coefficients in the upper second premolar and first molar. It was suggested that Horseshoe Expander showed less orthodontic changes, less buccal tipping tendency. In addition, it was effective in maxillary expansion.

• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.691-706
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• 2008

This study analysed problems of railroadside buffer green space and suggested planting methods according to space function and planting concept in seashore reclaimed land, Ansan city. Planting density of railroadside buffer green zone of Ansan city was $0.04{\sim}0.17tree/m^2$, GVZ was $0.15{\sim}1.65m^3/m^2$ which is represented of deficiency of buffer function. In addition, soil hardness of mounded buffer green zone was $2.72{\sim}15kg/cm^2$. It was examined to have functions in terms of habitat for wildbirds and other organisms, surrounding landuse, urban greens, seasonality, landscape for function improvement of buffer green space. Functions of buffer green space were re-established as habitat for organism, buffer and landscape improvement, landscape and urban park, buffer zone and habitat. It was suggested to select Pinus thunbergii as a dominated species of planting method for buffer function and planting density in canopy and under-canopy layer was $0.4tree/m^2$, $0.5/m^2$ in shrub layer. In terms of landscape improvement function, Zelkova serrata, Prunus sargentii and Prunus armeniaca were selected as major species and it in canopy and under-canopy layer was $0.2tree/m^2$ and $0.5tree/m^2$ in shrub layer. In terms of habitat function Quercus acutissima, Prunus sargentii and Sorbus alnifolia were as major species and it in canopy layer was $0.06tree/m^2$, $0.1tree/m^2$ in under canopy layer, $0.8tree/m^2$ in shrub layer.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.173-179
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• 2018

Investigation of the optimum levels of pre-plant nitrogen for raising of hot pepper (cv. Nokkwang) plug seedlings was the objective of this research. To achieve this, the pre-plant nitrogen levels were varied to 0, 100, 250, 500, 750, 1,000, and $1,500mg{\cdot}L^{-1}$ and the other essential nutrients were controlled to equal concentrations in all treatments. All the fertilizers were added during the formulation of the mixed medium of coir dust, peatmoss, and perlite with the ratio of 35, 35, and 30% (v/v/v). The root medium containing pre-plant fertilizer was packed into 50-cell plug trays and seeds were sown. The measurement of pH and EC in every week, soil solution analysis for nutrients in week 0, 3, and 7 and growth measurements as well as tissue analysis for nutrient contents in week 7 were conducted. The pHs measured before seed sowing did not show significant differences, but the differences among treatments became significant as seedlings grow bigger. The soil solution ECs were significantly different among treatments in week 0 and these differences were diminished by degrees after week 3, resulting in no significant differences among treatments in week 7. The trends in changes of $NH_4-N$, $NO_3-N$, and other the macro-element concentrations in soil solution of root media were similar to those of ECs. The treatments of 500 and $750mg{\cdot}L^{-1}$ N were more effective than other treatments on seedling growth. The seedling growths in the treatments containing higher N than $1,000mg{\cdot}L^{-1}$ and control were severely suppressed. The elevated pre-plant N concentrations in the root medium resulted in the increase of tissue N contents. The treatments of 500 and $750mg{\cdot}L^{-1}$ N shown the highest seedling growths had 5.13% and 5.31%, respectively, in tissue N contents based on the dry weight of above ground tissue at week 7. The results of this study indicated that the optimum level of pre-plant N is 500 to $750mg{\cdot}L^{-1}$ for the raising of hot pepper plug seedlings.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.399-405
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• 2016

This study aimed to determine the total amount of carbon stored in the aboveground, belowground tree biomass, dead trees, and organic matter in the forest floor and soil of the 36-year-old Pinus rigida stands in Muju. A total of three plots were selected to measure the carbon stored in live trees, dead trees, forest floor, and soil. Results showed that the carbon stocks of P. rigida stands amounted to 51.0 ton C/ha in aboveground biomass and 29.6 ton C/ha in belowground biomass. The distribution ratios of carbon stocks were as follows: 41.0% in stem wood, 36.8% in roots, 12.8% in branches, 6.0% in stem bark and 3.4% in foliage. The carbon stocks in dead tree amounted to 0.65 ton C/ha while it was 6.40 ton C/ha in organic matter in forest floor. The total amount of carbon stocks found in soil was 51.62 ton C/ha: 20.27 ton C/ha at 0~10 cm depth, 12.83 ton C/ha at 10~20 cm depth, 12.27 ton C/ha at 20~30 cm depth, and 6.24 ton C/ha at 30~50 cm depth. It was also observed that, as the soil depth increased, the soil carbon stocks tended to decrease. Results showed that the total amount of carbon stocks of P. rigida stands in Muju was 139.27 ton C/ha; the highest portion of the cumulative carbon stocks was found to be in soil at 37.1%, followed by the aboveground biomass with 36.6%, belowground biomass with 21.3%, forest floor with 4.6 % and dead trees with 0.5 %. This study is expected to provide forest managers accurate estimates of carbon stored in the habitat of P. rigida stands in Muju.

• Journal of Animal Environmental Science
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• v.11 no.3
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• pp.197-206
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• 2005

This study was carried out to investigate the concentration and characteristics of dust originating from windowless broiler building in each season. 12.0m width and 46m tenth with side wall height of 3.0m was investigated and capacity was 12,800 birds at a stock density of 23.2 birds per square meter. Dust concentrations in terms of total suspended particles (TSP), and particulate matter of sizes $10{\mu}m(PM10),\;2.5{\mu}m (PM2.5),\;and\;1{\mu}m(PM1)$ were measured at 30-minute intervals. On the basis of broiler age, the average dust concentration in summer in TSP as follows: 1,229 904.5 558.8 and $1,053{\mu}g/m^3$ on the broilers' first to fourth week of age, respectively. But during winter, the average dust concentration showed an increasing pattern, as follows: 465.4, 1,401, 4,497, 5,097 and $6,873{\mu}g/m^3$ on the broilers' first to fifth week of age, respectively. The maximum dust concentration of $11,132{\mu}g/m^3$ was observed on the fifth week. On a daily basis, the maximum dust concentration during summer was detected in early morning, and the minimum in the afternoon. The aerial dust particle size of $0.05\~0.35{\mu}m$ was the highest in number. But on volume basis, particle size of 16~99 un had the largest percentage in the broiler house. Crude protein of the dust $(42.8\~65.2\%)$, on dry matter basis, was higher than that $(20.5\~24.5\%)$ fed to the broilers. Heavy metal concentration of the dust also had high levels compared with that of the feed.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.89-99
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• 2004

Stretch-activated channels (SACs) responds to membrane stress with changes in open probability (Po). They play essential roles in regulation of cell volume and differentiation, vascular tone, and in hormonal secretion. SACs highly present in Xenopus oocytes and Ascidian oocytes are suggested to be involved in the regulation of pH and fluid transport to balance the osmotic pressure, but remain unclear in mammanlian oocytes. This study was investigated to find the presence of SACs in hamster oocytes and to examine their electrophysiological properties. To infer a role of SAC in relation to the development of early stage, we followed up to the stage of two-cell zygote with patch clamp techniques. Single channels were elicited by negative pressure (lower than ­15 cm$H_2O$). Interestingly, SACs were dependent on permeable cations such as $Na^+$ or $K^+$. As permeable cation removed from both sides across the membrane, SAC activity completely disappeared. When permeable cations present only in intracellular compartment, outward currents appeared at positive potentials. In contrast to this, inward currents occurred only at the negative voltage when permeable cation absent in cell interior. These result suggests that SAC carry cations through the nonselective cation channel (NSC channel). Taken together, we found that stretch activated channels present in hamster oocyte and the channel may carry cations through NSC channels. This stretch activated-NSC channels may play physiological role(s) in oocyte growth, maturation, fertilization and embryogenesis in fertilized oocytes to two-cell zygotes of hamster.

• Progress in Medical Physics
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• v.17 no.3
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• pp.131-135
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• 2006

A commercial ion chamber matrix was examined the characteristics and its performance for radiotherapy qualify assurance. The device was the I'mRT 2D-MatriXX (Scanditronix-Wellhofer, Schwarzenbruck, Germany). The 2D-MatriXX device consists of a 1020 vented ion chamber array, arranged in $24{\times}24cm^2$ matrix. Each ion chamber has a volume of $0.08cm^3$, spacing of 0.762 cm and minimum sampling time of 20 ms. For the investigation of the characteristics, dose linearity, output factor, short-term reproducibility and dose rate dependency were tested. In the testing of dose linearity. It has shown a good signal linearity within 1% in the range of $1{\sim}800$cGy. Dose rate dependency was found to be lower than 0.4% (Range: 100-600 Mu/min) relative to a dose rate of 300 Mu/min as a reference. Output factors matched very well within 0.5% compared with commissioned beam data using a ionization chamber (CC01, Scanditronix-Wellhofer, Schwarzenbruck, Germany) in the range of field sizes $3{\times}3{\sim}24{\times}24cm^2$. Short-term reproducibility (6 times with a interval of 15 minute) was also shown a good agreement within 0.5%, when the temperature and the pressure were corrected by each time of measurement. in addition, we compared enhanced dynamic wedge (EDW, Varian, Palo Alto, USA) profiles from calculated values in the radiation planning system with those from measurements of the MatriXX. Furthermore, anon-uniform IMRT dose fluence was tested. All the comparison studies have shown good agreements. In this study, the MatriXX was evaluated as a reliable dosimeter, and it could be used as a simplistic and convenient tool for radiotherapy qualify assurance.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.30-37
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• 2009

Early enamel caries is commonly remineralized by the patient‘s improved oral hygiene or fluoridation, however the result is clinically unreliable. As an alternative, we tried to seal the lesions with low-viscosity light-curing resin. The aim of the present study was to search the proper methods of the adequate pretreatment prior to applying adhesive resin on natural proximal caries lesions. Thirty nine extracted deciduous molar teeth showing proximal early caries lesion were used for this study. They were divided into 5 groups : Group 1; only carefully cleaned with water, group 2; etched with 15% HCl for 15s, group 3; etched with 35% phosphoric acid for 15s, group 4; etched with 35% phosphoric acid for 30s, and group 5; cleaned with 0.5% NaOCl. Following results were obtained by evaluating with SEM and CLSM after applied with adhesive resin. 1. As a result of SEM evaluation, group 2 showed clearly removed surface layer, group 3,4 showed partially removed surface layer irregularly, group 5 showed slightly removed surface layer. 2. Group 2 showed the deepest infiltration depth, followed by group 4, group 3, group 5, group 1 and besides group 5, other groups showed significantly deep infiltration depth. (p < 0.01) In conclusion, the best methods of the adequate pretreatment on natural proximal caries lesion for deep infiltration of adhesive resin was to etch with 15% HCl for 15s.