• Molecules and Cells
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• v.41 no.5
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• pp.413-422
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• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• Molecules and Cells
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• v.41 no.6
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• pp.515-522
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• 2018

Patients with head and neck cancer are treated with therapeutic irradiation, which can result in irreversible salivary gland dysfunction. Because there is no complete cure for such patients, stem cell therapy is an emerging alternative for functional restoration of salivary glands. In this study, we investigated in vitro characteristics of primarily isolated epithelial cells from human salivary gland (Epi-SGs) and in vivo formation of acini-like structures by Epi-SGs. Primarily isolated Epi-SGs showed typical epithelial cell-like morphology and expressed E-cadherin but not N-cadherin. Epi-SGs expressed epithelial stem cell (EpiSC) and embryonic stem cell (ESC) markers. During long-term culture, the expression of EpiSC and ESC markers was highly detected and maintained within the core population with small size and low cytoplasmic complexity. The core population expressed cytokeratin 7 and cytokeratin 14, known as duct markers indicating that Epi-SGs might be originated from the duct. When Epi-SGs were transplanted in vivo with Matrigel, acini-like structures were readily formed at 4 days after transplantation and they were maintained at 7 days after transplantation. Taken together, our data suggested that Epi-SGs might contain stem cells which were positive for EpiSC and ESC markers, and Epi-SGs might contribute to the regeneration of acini-like structures in vivo. We expect that Epi-SGs will be useful source for the functional restoration of damaged salivary gland.

• Korean Journal of Medicinal Crop Science
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• v.5 no.2
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• pp.108-112
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• 1997

This experiment was carried out to clarify the effect of cultural years on the growth and yield of Fritillaria thunbergii. It was planted on Middle September, with high ridge between $100cm\;(2 lines){\times}interrow 9cm$ and N-P-K=8.1-11.2-8kg/10a of fertilizers treated basal application. Cultural years were 1, 2 and 3 years, the block of 2 or 3 years was additional same amount of fertilizers at early spring. The results were summarized are as follows. Rapid bulb filling stage was begun 32 days after sprouting, and completed bulb growth needed 72 days. Dry weight/fresh ratio of bulb was ranged from $27.2{\sim}30.3$%. Rate of over 5g bulb weight was 89% at 1 year, 87% at 2 years and 77% at 3 years and bulb yield were 638kg/10a at 1 year. Compared with yield at 1 year, the yield increased 88% at 2 years and 189% at 3 years.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.78-83
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• 1987

This study was attempted to evaluate the combining effect of HBR (homobrassinolide) with the known growth regulators such as GA (gibberellic acid), BA(6-benzyl aminopurine), IAA (indole-3-acetic acid), B-9 (N-dimethylamino succinamic acid) and CCC (2-chloroethyl-trimethylammonium chloride) on the growth of radish hypocotyl. A single application of HBR increased hypocotyl growth as its rates increased from 0.1 to 1.0 ppm, showing a maximum increase at 1.0 ppm. GA and BA had no direct effects on hyopcotyl growth, but IAA showed some effect as its concentration increased. However, the mixed application of HBR with GA, BA and IAA increased the length of radish hypocotyl as the concentration of HBR became higher. The mixture of HBR with GA and BA showed antagonistic reaction on radish hypocotyl growth, but synergistic effect was shown in the higher rate mixture of HBR with IAA in the range of HBR at 0.03 to 0.30 ppm with IAA at 3.0 to 10.0 ppm, but antagonistic or additive response at the mixture of low rates. An increased growth of hypocotyl by HBR was ified by CCC, showing the strong antagonistic reaction, but B-9 was not able to ify HBR's effect on hypocotyl growth.

• Korean Journal of Medicinal Crop Science
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• v.24 no.2
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• pp.136-142
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• 2016

Background: Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replant failure in ginseng fields. Methods and Results: Solarization of infested greenhouse soil was carried out during the summer season after applying green manure (Sudan grass) and Calcium Cyanamide (CC) on the soil. Mycelium and conidia of C. destructans died at $40^{\circ}C$ after 15 h, but they did not die at $35^{\circ}C$ after 15 h. They also died after keeping the soil at $40^{\circ}C$ for 2 h daily for 9 days, and at $45^{\circ}C$ for 8 days, but they did not die at $38^{\circ}C$ for 9 days. Maximum soil temperature was $55.4^{\circ}C$ at 5 cm depth, $48.7^{\circ}C$ at 10 cm, $44.7^{\circ}C$ at 15 cm, $42.5^{\circ}C$ at 20 cm, and $31.9^{\circ}C$ at 30 cm by incorporating green manure into the soil and using solarization. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. However, the addition of CC decreased the root weight due to the increase in EC and $NO_3-N$. Conclusions: Soil disinfection using green manure and solarization in a greenhouse environment was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.

• Membrane Journal
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• v.15 no.4
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• pp.272-280
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• 2005

In this study, asymmetric polysulfone membranes were prepared by the phase inversion method and the casting solutions were containing N-methyl-2-pyrrolidone (NMP) as a solvent. Deionized water and various alcohols(methanol, ethanol, and propanol) were used as a coagulation medium in preparing asymmetric polysulfone membranes. This study investigates the effect of alcohol coagulants having different solubility parameters as a pore-former on the construction of porous structures and their pure water permeation properties. Asymmetric polysulfone membranes immersed in the pure alcohol coagulation bath solution showed the typical sponge-like structures and the reduced water permeability as compared with those of polysulfone membranes precipitated in the pure water coagulation bath solution. In the water/alcohol mixtures, asymmetric polysulfone membranes showed the finger-like structures with the sponge-like structures. Therefore, the sponge-like structure of polysulfone membrane was formed under the delayed demixing systems while the porosity of membrane was decreased significantly. The water permeability of polysulfone membrane precipitated in the pure water coagulant showed 164 [$L/m^2hr$] at 14.7 psi. In case of polysulfone membranes prepared in the pure methanol and ethanol coagulant, they showed the water permeability of 56 and 30 [$L/m^2hr$], respectively.

• Membrane Journal
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• v.19 no.4
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• pp.291-301
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• 2009

Double-layered polymer electrolyte membranes were prepared from two different sulfonated poly(aryl ether sulfone) copolymers by the two-step solution casting method for direct methanol fuel cells (DMFC). Sulfonation degrees were adjusted 10% (SPAES-10) and 50% (SPAES-50) by controlling monomer ratios, and the weight ratios of SPAES-10 copolymer were varied in the range of 5~20% to investigate the effect of thickness of coating layers on the membranes. Proton conducting layers were fabricated from SPAES-50 solutions of N-methyl-2-pyrrolidone (NMP) by a solution casting technique, and coating layers formed on the semiliquid surface of the conducting layer by pouring of SPAES-10-NMP solutions onto. It was found that double-layered polymer electrolyte membrane could significantly reduce the methanol crossover through the membrane and maintain high proton conductivities being comparable to single-layered SPAES-50 membrane. The maximum power density of membrane-electrolyte assembly (MEA) at the condition of $60^{\circ}C$ and 2 M methanol-air was $134.01\;mW/cm^2$ for the membrane prepared in the 5 wt-% of SPAES-10 copolymer, and it was corresponding to the 105.5% of the performance of the commercial Nafion 115 membrane.

• Korea Journal of Hospital Management
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• v.22 no.4
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• pp.33-49
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• 2017

Background: Health care utilizations and costs of the patients with degenerative lumbar spine disease in Korea increased dramatically. We analyzed whether hospital market competition is associated with charges and length of stay for patients with degenerative lumbar spine disease. Methods: We used Medical claims data of 2002 and 2010 from the nationwide representative sample of National Health Insurance Service of Korea. The study subjects were inpatients with degenerative lumbar spine disease (N=24,768) in 2002 and 2010. We employed a multilevel linear mixed model that included patient- and hospital-level variables in hierarchical data. Results: Higher hospital competition was associated with lower charges (${\beta}=57.5$, p<.0001 in 2002; ${\beta}=353.7$, p<.0001 in 2010) and shorter length of stay (${\beta}=0.3$, p<.0001 in 2002; ${\beta}=0.9$, p<.0001 in 2010) in both 2002 and 2010. Compared to 2002, the magnitude of such association became greater in 2010. However, subgroup analyses show that the influence of competition on charges and length of stay differed by hospital size. Conclusions: This study showed that hospital market structure (e.g., hospital competition) affects hospital efficiency (i.e., hospital charges and length of stay). It is necessary to continue to monitor how changing market structure influences hospital outcomes, including more detailed outcomes such as patient satisfaction.

• Research in Community and Public Health Nursing
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• v.16 no.1
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• pp.86-94
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• 2005

Purpose: This study investigated the Korean nurses' international migration to provide the basic data for establishing plans of supply and demand for nurses and the status of Korean nurses' application for foreign nurse licenses and overseas employment. Method: The subjects were 5.447 nurses who requested English written nurse license to the Ministry of Health and Welfare for the application of foreign nurse license examinations and overseas employment. Human Resources Development of Korea provided documents of nurses migrated to Saudi Arabia. Data were collected from December, 2002 to July, 2003 and analyzed by using descriptive statistics. Result: The total applicants for foreign nurse license were 3,149 for 2 years. In the year 2001, 1.129 nurses applied, 2,020 nurses in the year 2002. Out of 3,149 total subjects, 2,705(85.9%)nurses applied for U. S. A. nurse license. Eighty percent of the applicants of the U. S. A. nurse license examination applied for the New York states. The number of applicants for Canada was 215(6.8%), followed by Australia 88(2.8%), U. K. 86(2.7%), and New Zealand 45(1.4%). Average age of the applicants was 31, 49.0% of them were in their twenties. Three year college graduates accounted for 64.1% B.S.N. 33.9%. Applicants graduated from universities or colleges of Seoul area were 37.3%, followed by Daegu. The total number of nurses employed overseas were 1,291 during 2001 and 2002. Seven hundred thirty eight nurses(57.2%) were employed in the U. S. A.. Average age was 34, 60.9% were 3year college graduates, nurses graduated from Seoul area were 44.9%. No one applied for Saudi Arabian nurse license, 172 nurses were employed during 1999 and 2002, 39.5% of them were in their thirties. Conclusion: The results of this study shows relatively young and experienced nurses have intention to migrate internationally and they actually migrate to other countries. Comparing the number of nurses migrating to other country with the number of newly issued nurse licenses in Korea every year. the percentage of overseas employment was relatively high. To cope with Korean nurses international migration. new policy to monitor the status of nurse's international migration and an institution to deal with the affairs should be established. And the further study is needed to measure nurse's competence and influencing factors of Korean nurses employed in the U. S. A.

• Journal of Environmental Health Sciences
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• v.44 no.1
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• pp.98-105
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• 2018

Objectives: In Mongolian housing, they use coal as a fuel for indoor heating and cooking. The combustion of coal releases particulate matter, which can affect indoor air quality. The purpose of this study was to analyze the concentrations of indoor $PM_{2.5}$ in winter time dwellings in ger town. Methods: In this study, indoor $PM_{2.5}$ concentrations, temperature and humidity in houses were measured by a real-time PM monitor, while the time activity patterns of the residents were also observed. Results: The correlation between factors that may affect the indoor air quality was analyzed.The indoor $PM_{2.5}$ concentrations were $178.4{\pm}152.7{\mu}g/m^3$ (n=37). Five types of indoor $PM_{2.5}$ concentrations have been classified, which were associated with indoor activity. The stove type, fuel types and indoor activities such as cleaning, cooking and opening the stoves were not significantly associated with indoor $PM_{2.5}$ levels. Conclusions: Further study is needed to determine the effect of stove type through 24hours of indoor air quality monitoring.