• Archives of Plastic Surgery
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• v.40 no.5
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• pp.496-504
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• 2013

Background Amniotic-fluid-derived stem cells and amniocytes have recently been determined to have wound healing effects, but their mechanism is not yet clearly understood. In this study, the effects of amniotic fluid stem cells and amniocytes on wound healing were investigated through animal experiments. Methods On the back of Sprague-Dawley rats, four circular full-thickness skin wounds 2 cm in diameter were created. The wounds were classified into the following four types: a control group using Tegaderm disc wound dressings and experimental groups using collagen discs, amniotic fluid stem cell discs, and amniocyte discs. The wounds were assessed through macroscopic histological examination and immunohistochemistry over a period of time. Results The amniotic fluid stem cell and amniocyte groups showed higher wound healing rates compared with the control group; histologically, the inflammatory cell invasion disappeared more quickly in these groups, and there was more significant angiogenesis. In particular, these groups had significant promotion of epithelial cell reproduction, collagen fiber formation, and angiogenesis during the initial 10 days of the wound healing process. The potency of transforming growth factor-${\beta}$ and fibronectin in the experimental group was much greater than that in the control group in the early stage of the wound healing process. In later stages, however, no significant difference was observed. Conclusions The amniotic fluid stem cells and amniocytes were confirmed to have accelerated the inflammatory stage to contribute to an enhanced cure rate and shortened wound healing period. Therefore, they hold promise as wound treatment agents.

• Membrane Journal
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• v.19 no.3
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• pp.189-193
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• 2009

The present work was attempted to improve the performance for the removal of water from ethanol/water mixtures through the ion-exchanged zeolite membrane in which $Na^{+}$ ion was substituted to either $K^{+}$ or $Ca^{2+}$ ion. The membranes were ion-exchanged with 0.5 mole/L aqueous solution of either KCl or $CaCl_2$ at $80^{\circ}C$ for 4 hrs. In case of the ion-exchanged membrane in which $Na^{+}$ ion was substituted to $K^{+}$ ion, the total flux was decreased from $900\;g/m^2{\cdot}hr{\sim}2,500\;g/m^2{\cdot}hr$ to $600\;g/m^2{\cdot}hr{\sim}2,000\;g/m^2{\cdot}hr$ and the separation factor was increased from $600{\sim}2,200$ to $850{\sim}2,500$ compared to the NaA type zeolite membrane. And in case of the ion-exchanged membrane in which $Na^{+}$ ion is substituted to $Ca^{2+}$ ion, both the total flux and selectivity of water showed the similar tendency compared to the NaA type zeolite membrane. It is thought that the improved separation would be possible if the pore size of the zeolite membrane is controlled by the ion exchange.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.15-26
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• 2018

The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of $NO_3-N$ is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen's slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.204-211
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• 2011

A dynamic analysis procedure is developed to provide a better estimation of the dynamic responses of bridge during the passage of high speed railway vehicles. Particularly, a three dimensional numerical model including the structural interaction between high speed vehicles, bridges and railway endures to analyse accurately and evaluate with in-depth parametric studies for dynamic responses of various bridge span lengths running KTX railway locomotive up to increasing maximum speed(450km/h). Three dimensional frame element is used to model the simply supported pre-stressed concrete (PSC) box bridges for four span lengths(40~25m). Track irregularity employed as a stationary random process from the given spectral density functions and irregularities of both sides of the track are assumed to have high correlation. The high-speed railway vehicle (KTX) is used as 38-degree of freedom system. Three displacements (Vertical, lateral, and longitudinal) as well as three rotational components (Pitching, rolling, and yawing) are considered in the 38-degree of freedom model. The dynamic amplification factors are evaluated by the developed procedure under various traveling conditions, such as track irregularity camber, train speed and ballast. The dynamic analysis such as Newmark-${\beta}$ and Runge-Kutta methods which are able to analyse considering the dynamic impact factors are compared and contrasted.

• Economic and Environmental Geology
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• v.25 no.3
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• pp.233-243
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• 1992

Ore mineralization of the Hwanghak copper deposit in the Ogsan area occurred in three stages of quartz (stage I and II) and calcite (stage III) veining along fissures in Early Cretaceous sedimentary rocks. Ore minerals are pyrite, pyrrhotite, chalcopyrite (dominant), sphalerite, hematite, galena, and Ag-, Pb-, and Bi-sulfosalts. These were deposited during the first stage at temperatures between $370^{\circ}C$ and < $200^{\circ}C$ from fluids with salinities between 0.5 and 7.6 equiv. wt. % NaCl. There is evidence of boiling and this suggests pressures of less than 180 bars during the first stage. Equilibrium thermodynamic interpretation accompanying with mineral paragenesis and fluid inclusion data indicates that copper precipitation in the hydrothermal system occurred due to cooling and changing in chemical conditions ($fs_2$, $fo_2$, pH). Gradual temperature decrease from $350^{\circ}$ to $250^{\circ}C$ of ore fluids by boiling and mixing with less-evolved meteoric waters mainly led to copper deposition through destabilization of copper chloride complexes. Sulfur isotope values of sulfide minerals decrease systematically with paragenetic time from calculated ${\delta}^{34}S_{H_2S}$ values of 8.2 to 4.7‰. These values, together with the observed change from sulfide-only to sulfide-hematite assemblages and fluid inclusion data, suggest progressively more oxidizing conditions, with a corresponding increase of the $sulfate/H_2S$ ratio of hydrothermal fluids. Measured and calculated hydrogen and oxygen isotope valutls of ore-forming fluids suggest meteoric water dominance, approaching unexchanged meteoric water values.

• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.92-99
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• 2003

A 96-well plate was applied to determine the DPPH free radical scavenging activity using 107 plant-specific enzyme inhibitors and 100 unknown plant-originated extracts. The final optimum volume was $250{\mu}L$ containing $100{\mu}M$ DPPH ethanolic solution at pH 7.8. In this condition, the radical scavenging activities were significantly increased by two known antioxidants consisting of ascorbate and a-tocopherol in a concentration-dependent manner. Among the 107 inhibitors, ampicillin and gallic acid showed 90.2% and 92.6% antioxidant activity at $100{\mu}M$, respectively, and these results were consisted with previous findings. In the tested 100 natural materials at $50{\mu}g/mL$, antioxidant activity of AT-407 resulted in the highest of 90.1%, and 10 extracts including AT-388 and AT-443 showed over 70%. Our results suggest that the use of 96-well plate for determining DPPH free radical scavenging activity would be a suitable method to select antioxidant-like substances of both synthetic compounds and natural products.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.379-388
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• 2011

Survey of mastitis management and incidence of mastitis in the Gyeongnam was started in May to September 2009 to solve mastitis problem statistically valid data for use in estimating mastitis management, isolation and antimicrobial drug susceptibility in 30 dairy farms having over 350,000/ml somatic cell count. In investigation on recognition of farmer about bovine mastitis, the ratio of understanding of differences between infectious and environmental origin, understanding of correlation between superbacteria and using indiscriminate, necessity of pathogen identification, and necessity of antimicrobial sensitivity tests were 80.0%, 73.3%, 33.3%, and 53.3%, respectively. In survey of mastitis management type, regular california mastitis test (CMT), conducting CMT test and empirical self-treatment, when detecting suspected cows, were 30.0%, 40.0%, and 46.7%, respectively. Checking and cleaning pulsators biweekly, cleaning vacuum system and replacing liners every 3~6 month, and getting milking system checked by engineers showed 80.0%, 76.7%, and 76.7% in the questionnaires, respectively. In recognition of farmer about milking hygiene for prevention of bovine mastitis, using individual towels, separated milking (milking order of cows), and teat-dipping disinfection after milking exhibited 13.3%, 86.7%, and 93.3%, respectively. In conclusion, through the questionnaires and laboratory test, we suggest that recognition of farmer about management and incidence of mastitis was very low, thus systemic educational program and public relations about mastitis management were need for dairy farmers.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.359-366
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• 1996

Background : Eosinophilic leukocytes are prominent cellular participants in the pathogenesis of allergic disease and asthma. Chemotaxis is still a very useful method in evaluating the response of human eosinophil to novel modulators. Degranulated mast cells and activated T lymphocytes are responsible for the pathophysiology of asthma and tryptase is one of most important proteases released after activation of mast cells. The purpose of this study was to investigate the actions of trypsin and chymotrypsin on eosinophils in terms of chemotaxis and activation. Method : Eosinophils were isolated by negative immunoselection from the peripheral blood of atopic donors. Chemotaxis was studied by using micro-Boyden chambers and ECP release was assayed by fluoroimmunoassay. Results : Eosinophil showed a chemotactic response to trypsin. Maximal chemotactic response was with $1000{\mu}g/ml$ trypsin ($56.52{\pm}14.50$/HPF) which was comparable to PAP. But chymotrypsin showed no significant chemotactic response to eosinophils. Trypsin at the concentration of 10, 100, $1000{\mu}g/ml$ induced secretion of ECP, which at the concentration of $10{\mu}g/ml$ represented about 2.7 times of the spontaneous rate of release. Soybean protease inhibitor reduced trypsin induced ECP release. Conclusion : Trypsin can induce chemotactic response to eosinophils and activation of eosinophils that can induce secretion of ECP. On the contrary, chymotrypsin showed no direct effect on eosinophils. We propose a role of trypsin on the chemotaxis and activation of eosinophils.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.345-356
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• 2017

We investigated 52 livestock farming complexes in Gyeong-Gi and Incheon provinces based on low, medium, and high livestock density and groundwater quality. The objective of this study was to evaluate a relationship between nitrate N concentration in groundwater and animal factors, such as livestock density and animal species. 2,200 groundwater samples for 3 years from 2012 to 2014 at Gyeong-Gi and Incheon provinces were collected and analyzed for pH, EC, DO, ORP, temperature, major anions and cations, such as $NO_3-N$, ${HCO_3}^-$, ${PO_4}^-$, ${SO_4}^{2-}$, $Cl^-$, $NH_4-N$, $K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$, T-N, and TOC. Average concentration of total N for generated load density was $23,973g\;day^{-1}\;km^{-2}$ for cattle, $51,551g\;day^{-1}\;km^{-2}$ for pig, and $52,100g\;day^{-1}\;km^{-2}$ for poultry. For animal feeding species, average ratio for generated load over discharge load was 16.1% for cattle, 7.8% for pig, and 7.1% for poultry. Therefore, cattle feeding region is highly vulnerable for water pollution compared to pig and poultry feeding areas. The concentrations of chloride, nitrate, and total N in the groundwater samples were higher at high animal farming regions than other regions. The average concentration of nitrate, and chloride in groundwater samples was $5.0mg\;L^{-1}$, $16.6mg\;L^{-1}$ for low livestock density, $6.9mg\;L^{-1}$, $17.7mg\;L^{-1}$ for medium livestock density and $7.6mg\;L^{-1}$, $22.7mg\;L^{-1}$ for high livestock density and total nitrogen (T-N) was $7.7mg\;L^{-1}$ for low livestock density, $9.4mg\;L^{-1}$ for medium livestock density, $10.7mg\;L^{-1}$ for high livestock density. In conclusion, based on this research, for managing groundwater quality near livestock farming regions, $Ca-(Cl+NO_3)$ group from the Piper diagram is more efficient than using 19 factors for water quality standard.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.600-604
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• 1995

Lymphangioleiomyomatosis, a rare disease in women of childbearing age, is the result of benign nodular hypertrophy of the smooth muscle of the lypmhatics and other tissues of the abdomen and thorax. We report a 36-years-old woman with pulmonary and retroperitoneal lymphangioleiomyomat.osis who responded with hormone treatment. She developed vaginal pruritis and a pelvic ultraound was done given her significant past medical history. Ultrasound examination demonstrated a large mass in the right side of her pelvis. Therefore she was admitted to St. Michael's Hospital in Toronto for laparoscopy. Result of cytology was to be consistent with the diagnosis of retroperitoneal lymphangioleiomyomatosis. High resolution CT sacn of the thorax demonstrated multiple small cystic lesions, without associated nodularity compatible with a diagnosis of pulmonary lymphangioleiomyomatosis. She has been taking Provera tablets 100mg po tid since Dec. 15, 1993. We have given her a prescription for Depo provera 500mg IM monthly since she came back to Korea. and made arrangements for regular follow up monthly. We performed chest X-ray, CT of chest(high resolution), abdomen and pelvis, pulmonary function tests and arterial blood gas analysis. Chest X-ray and CT findings showed no significant change since July. 20, 1993.