• Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.135-139
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• 2006

We optimized the biological and physical parameters for DNA delivery into thalli of the red alga Porphyra yezoensis using a particle bombardment device. The efficiency of transformation was determined using the ${\beta}-glucuronidase$ (GUS) assay. The optimal helium pressure, distance of tungsten particle flight, and ratio of DNA to tungsten particles were $23kgf/cm^2$, 8 cm, and $5{\mu}g/mg$ tungsten, respectively. During bombardment, osmotic treatment with a mixture of 0.6 M mannitol and sorbitol increased the efficiency of GUS transformation. After 2 days, the blue color indicating GUS activity was observed using a histochemical assay.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.348-352
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• 1999

We have intended to accelerate the secretion of human lysozyme(HLY) with permeabilizing agents from the cultivated cells of the recombinant Saccharomyces cerevisiae. The five agents CaCl2, Tween 80, ethanol, Triton X 100, and cetyltrimethylammonium bromide(CTAB) were used as permeabilizing agents. Treatments of the yeast cell with CaCl2, Tween 80, and ethanol were effective to increase the secretion from the yeast cells. Especially, treatment of 10% ethanol increased the extracellular HLY activity by 38.6% at 30oC for 48 h in culture broth. But Triton X 100 and CTAB unexpectedly didn't play a role in increase of HLY secretion. Recovery of a foreign protein by permeabilizing agents is easier than by osmotic shock, and is less expensive than enzymatic digestion.

• Journal of Plant Biology
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• v.37 no.1
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• pp.27-36
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• 1994

For establishing a transformation system of rice, an efficient introduction of foreign genes into embryogenic cell suspension by particle bombardment was conducted. The particle inflow gun based on the acceleration of DNA-coated tungsten particles using pressurized helium was constructed for delivery of DNA into rice cells. Several bombardment parameters were optimized using the transient expression of GUS gene. The conditions that gave the highest GUS gene expression of about 1000 blue spots per g fresh weight of bombarded cells include treatment of the cells with 0.5 M osmotic pressure, and use of the 410 kPa helium, 110 mm target distance, 13 mm syringe filter holder and 5 $\mu$L DNA/tungsten mixtures. It was also confirmed that rice actin promoter-intron construct gave the highest expression of all promoter-sequences studied. Eight weeks after the bombardment, stably transformed calluses were obtained on the selection medium containing 100 mg/L G418 and showed the strong activity in in situ GUS assay.

• Membrane and Water Treatment
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• v.3 no.2
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• pp.77-98
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• 2012

A two-dimensional (2D) steady state numerical model of concentration polarisation (CP) phenomena in a membrane channel has been developed using the commercially available computational fluid dynamics (CFD) package CFX (Ansys, Inc., USA). The model incorporates the transmembrane pressure (TMP), axially variable permeate flux, variable diffusivity and viscosity, and osmotic pressure effects. The model has been verified against several benchmark analytical and empirical solutions from the membrane literature. Additionally, the model is able to predict the rejection of an arbitrary solute by the membrane using a pore model, given some basic knowledge of the geometry of the solute molecule or particle, and the membrane pore geometry. This allows for predictive design of membrane systems without experimental determination of the membrane rejection for the specified operating conditions. A demonstration of the model is presented against experimental results for two uncharged test compounds (sucrose and PEG1000) from the literature. The model will be extended to incorporate charge effects, transient simulations, three-dimensional (3D) geometry and turbulent effects in future work.

• KSBB Journal
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• v.13 no.4
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• pp.399-403
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• 1998

This study was carried out to optimize the concentration of Ca2+ and pH of fusion medium which affected electrofusion frequency of protoplasts isolated from Nicotiana tabacum L. (cv. BY4) mesophyll cells and callus. The protoplasts were electrofused in the fusion media containing two different Ca2+ concentrations and three different pH regions. Fusion frequency was lower in the fusion medium containing only 13% mannitol as osmotic stabilizer. However, higher degree of fusion frequency (47.3%) was observed in the fusion medium containing 50mM CaCl2 at pH 10.5 than any other conditions. Cell viability was decreased by Ca2+ and high pH treatment in the fusion media, while fusion frequency was increased. It is concluded that Ca2+ is involved in electrofusion of protoplasts.

• Bulletin of the Korean Chemical Society
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• v.6 no.6
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• pp.337-343
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• 1985

A statistical mechanical approach to elucidate the solvent effects on the high polymer solutions has been carried out on the basis of the simple model of liquids improved by Pak. In our works, the partition function of the polymer solutions is formulated by the lattice model and our simple treatment of liquid structures. For the ideal polymer solutions proposed by Flory, thermodynamic functions of the polymer solutions are obtained and equations of mixing properties and partial molar quantities are derived from the presented partition function of the polymer solutions. Partial molar quantities are calculated for the rubber solutions in carbon disulfide, benzene and carbon tetrachloride. Comparisons have been made between our equations and those of Flory's original paper for partial molar properties of the rubber-benzene system. Comparing the experimental data of the osmotic pressure of polystyrene-cyclohexane system with our calculated values and those of Flory's, our values fit to the agreeable degrees better than those of Flory's.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.265-273
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• 1995

Seeds of chicory were collected and selected with good germination, emergence and productivity. To develop chicory as a new forage crop seeds were primed with polyethylene glycol (PEG 6000) and coated with some chemicals, and tested in laboratory and field. The results obtained are summarized as follows: 1. Among the seed lines collected, PUlgAH, PU21TH, PU37CH and PU30TK were germinated more quickly and took less time for germination than the others. 2. PUI8AH was the best in emergence and growth although PU21TH showed superior germinative ability among the lines collected. 3. Chicory seeds primed with 20~25% PEG solution for three days at $10^{\circ}C$, or the seeds treated with 25% PEG solution at $15^{\circ}C$ regardless the treatment period showed good germination performances. 4. Osmotic priming with PEG accelerated the germination of chicory, but not in the field. 5. Coated seeds geminated more slowly in Petridishes but showed superior emergence and growth to those of primed or untreated seeds. Treatment 3 showed the best performances in pot experiment. 6. Coated seeds showed remarkable increase in establishment and dry matter yield especially in sod sowing compared to the other sowing method. 7. Most nutrient contents except iron and manganese of chicory were much higher than those of mixed pasture .

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.6
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• pp.377-384
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• 2010

The present study examined whether metformin treatment prevents isoporterenol-induced cardiac hypertrophy in mice. Chronic subcutaneous infusion of isoproterenol (15 mg/kg/24 h) for 1 week using an osmotic minipump induced cardiac hypertrophy measured by the heart-to-body weight ratio and left ventricular posterior wall thickness. Cardiac hypertrophy was accompanied with increased interleukin-6 (IL-6), transforming growth factor (TGF)-${\beta}$, atrial natriuretic peptide (ANP), collagen I and III, and matrix metallopeptidase 2 (MMP-2). Coinfusion of metformin (150 mg/kg/24 h) with isoproterenol partially inhibited cardiac hypertrophy that was followed by reduced IL-6, TGF-${\beta}$, ANP, collagen I and III, and MMP-2. Chronic subcutaneous infusion of metformin did not increase AMP-activated protein kinase (AMPK) activity in heart, although acute intraperitoneal injection of metformin (10 mg/kg) increased AMPK activity. Isoproterenol increased nitrotyrosine levels and mRNA expression of antioxidant enzyme glutathione peroxidase and metformin treatment normalized these changes. These results suggest that metformin inhibits cardiac hypertrophy through attenuating oxidative stress.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.173-179
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• 2009

Dentigerous cyst is an odontogenic cyst which occurs in unerupted tooth crown. After the crown formation, enamel epithelium remnants surrounded continuously proliferates and it forms effusionfluid cyst and expands due to increased internal osmotic pressure. Treatments of cysts are mainly enucleation, marsupialization and de-compression. When deciding the way of treatment, the age of a patient, the anatomical circumstances, the region of lesion and the size of cyst should be considered. Marsupialization is that some parts of internal cystic wall would be converted into oral mucosa if the cyst is large size and is concerned about neighboring anatomic structure. It can be accompanied by enucleation later and eruption of related tooth can be possible. If there is a limitation of spontaneous tooth eruption, eruption of tooth can be induced by orthodontic apparatus. There were 3 patients had dentigerous cyst and underwent marsupialization, their impacted teeth had preserved and had induced eruption, all showing satisfactory results.

• Journal of Environmental Science International
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• v.7 no.2
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• pp.209-216
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• 1998

Nanofiltration[NF45] and reverse osmosis membrane(HR98PP) separation treatment of dyestuff wastewater was carried out In order to separate relatively pure water from synthetic dyestuff wastewater, which consists of reactive dye, acid dye, basic dye, direct dye, and disperse dye. The experiments were performed by using the plate and frame membrane module. In the nanofiltration and reverse osmosis membrane separation, When the NaCl concentration was 0.1, 5.0, and 20.091, retention was 63.0, 46.0, 0.9%, respectively. When permeate flux was 125.0, 67.5, and 45.0 L/$m^2$ h, the osmotic pressure increased with Increasing the NaCl concentration. Permeate flux of two membranes Increased as temperature Increased due to segmental movement of polymer of the membrane and the rejection rate of dyestuff was decreased gradually. It was found that the rejection rate was about 95% in the nanofiltratlon, while the reverse osmosis membrane showed a high rejection rate of 99% under all temperature and pressures conditions.