• The korean journal of orthodontics
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• v.34 no.6 s.107
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• pp.526-536
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• 2004

This study was undertaken to determine the effect of a 2.2mg/Kg/day intraoral administration of NaF on the amount of root resorption and osteoclastic activity during or after a rapid maxillary expansion procedure. Ten puerile female dogs were divided into two groups: a control group and a NaF-treated group. A fixed type maxillary expansion device was delivered to all dogs. The appliance was activated twice daily throughout a 20-day period, causing a 5-mm expansion of maxillary bone. After the expansion procedure, the animals were sacrificed at days 0, 15, 30, 45, and 60 of the retention period. The buccal surface of the root of each maxillary canine was examined by means of a surface electron microscope (SEM). Using SEM, web-like resorption lacunae were observed on the bone or the tooth surface at the site of osteoclastic activity; these observations were verified by histological methods. No peculiar resorption lacunae were found in the apical tip of the roots of either the control group or the NaF-treated group animals. The NaF-treated retention group was found to have less resorption lacunae formation on day 45 and day 60. The preventative effect of NaF on resorption lacunae formation on the surface of the bone covering the anchor tooth was confirmed. Larger areas of resorption lacunae were found on the surface of the bone covering the canines in the control group animals, as compared to those of the NaF-treated group, especially on day 30 and day 60. Using SEM, the present study revealed a difference between the control group and the NaF-treated group in the prevalence and the size of the resorption lacunae formation on the cemental root surface. The preventative effect of NaF on bone resorption was confirmed. Further studies concerned with the optimum concentration of NaF that has an effect in vivo are necessary.

• Korean Journal of Materials Research
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• v.23 no.4
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• pp.227-232
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• 2013

Al-based alloys have recently attracted considerable interest as structural materials and light weight materials due to their excellent physical and mechanical properties. For the investigation of the potential of Al-based alloys, a surface porous $Al_{88}Cu_6Si_6$ eutectic alloy has been fabricated through a chemical leaching process. The formation and microstructure of the surface porous $Al_{88}Cu_6Si_6$ eutectic alloy have been investigated using X-ray diffraction and scanning electron microscopy. The $Al_{88}Cu_6Si_6$ eutectic alloy is composed of an ${\alpha}$-Al dendrite phase and a single eutectic phase of $Al_2Cu$ and ${\alpha}$-Al. We intended to remove only the ${\alpha}$-Al phase and then the $Al_2Cu$ phase would form a porous structure on the surface with open pores. Both acidic and alkaline aqueous chemical solutions were used with various concentrations to modify the influence on the microstructure and the overall chemical reaction was carried out for 24 hr. A homogeneous open porous structure on the surface was revealed via selective chemical leaching with a $H_2SO_4$ solution. Only the ${\alpha}$-Al phase was successfully leached while the morphology of the $Al_2Cu$ phase was maintained. The pore size was in a range of $1{\sim}5{\mu}m$ and the dealloying depth was nearly $3{\mu}m$. However, under an alkaline NaOH, aqueous solution, an inhomogeneous porous structure on the surface was formed with a 5 wt% NaOH solution and the morphology of the $Al_2Cu$ phase was not preserved. In addition, the sample that was leached by using a 7 wt% NaOH solution crumbled. Al extracted from the Al2Cu phase as ${\alpha}$-Al phase was dealloyed, and increasing concentration of NaOH strongly influenced the morphology of the $Al_2Cu$ phase and sample statement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.187-191
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• 2006

This study was carried out to analyze antioxidative effects of extracts of Korean herbal materials, Diospyros kaki, Teucerium veronicoides and Zanthoxylum schinifolium. Total phenol compound content of Diospyros kaki extacts was higher than those of other extracts. The electron donating ability was $70\%$ in 250 ppm of D. kaki extracts, but was $70\%$ in 1,000 ppm of T. veronicoides and Z. schinifolium extracts. The superoxide dismutase (SOD)-like activity of T. veronicoides and Z. schinzfolium extract was 25, $30\%$ in 1,000 ppm of concentration, respectively, but those of D. kaki extracts was $99\%$. The nitrate scavenging ability of D. kaki extracts was $99\%$ in pH 1.2 and 1,000 ppm of extract solution, but those of T. veronicoides and Z. schinifolium extracts was 53, $72\%$, respectively. The nitrate scavenging ability of D. kaki, Z. schinifolium and T. veronicoides extract was 93, 55, and $40\%$ in pH 3.0 and 1,000 ppm of extract solution, respectively. The nitrate scavenging ability of extracts were $10\~20\%$ in pH 6.0. The nitrate scavenging ability of extracts was decreased according to increase of pH. The nitrate scavenging ability of D. kaki extracts was higher than those of T. veronicoides and Z. schinifolium extracts.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.83-91
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• 1986

The activity of the liver cells of greenling, Agrammus agrammus were histologically investigated under photo-and electron microscopy, and studied by comparing seasonal changes of hepatosomatic index (HSI). The materials were monthly collected at the costal area of Tongbaeksom, Pusan, Korea, from September 1983 to August 1984. The annual variations of HSI of male were not distinct, but those of HSI in female began to increase in autumn, and reached the maximum in winter when the ovary was getting mature. During the period of yolk accumulation in the oocytes, the female liver and its hepatic cells were seen to large and nuclei and nucleoli were hypertrophic also. At this time the amounts of glycogen and lipid in the cells gradually decreased, while basophilic substance (RNA) increased. And well-developed granular endoplasmic reticula binding ribosomes were supposed to play the leading role in protein synthesis and deposition for vitellogenin in the cystoplasm. Just prior to spawning, glycogen and lipid droplets were decreased, but basophilic substances(RNA) were found in a high concentration especially at the peripheral region of the liver cells of females. In the liver cells of males, were hardly altered by gonadal maturation, basophilic substances gradually increased, glycogen particles and lipid droplets were still observed in large quantities. After spawning, basophilic subtances decreased in the liver cells of female and male.

• Applied Microscopy
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• v.31 no.2
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• pp.185-197
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• 2001

Human gastric adenocarcinomas are fixated with low energy of microwave (LEM) to study fixation effects in level of ultrastructure and antigenicity of the cancer. For the Ag-Ab reactions , the LEM fixated sdenocarcinomas are incorporated with monoclonal mouse anti-human p53 (IgG2b, kappa) and rabbit anti human cerbB-2. The retrieval of antigenicity are easily recognizable in the LEM fixated sections compared with that of frozen sections which show often diffused colour reactions. And the LEM fixation methods have preserved ultrastructures of the adenocarcinoma, but it was often difficult to maintain constancy in fixation effects. For the constancy, LEM was coupled with low concentration of chemical fixatives, such as glutaraldehyde (<1%) and $OsO_4$ (<0.5%). The results were acceptable, but there are tendencies that the adenocarcinoma requisitioned rather weak microwave energy to come into the optimal fixation effects. Therefore , cultured HeLa cells were fixated with lower energy of microwave than that used to the adenocarcinoma. The ultrastructures of the single HeLa cell have been preserved. The results may imply that a different energy levels of microwave are requisitioned in accordance with kinds of cells and tissues for the optimal fixation effects. It is reported and discussed that the fixation methods of LEM used in this work could be applied routinely to conceal a insufficient diffusion rate of chemical fixatives into some kinds of cancer without compromising the ultrastructures as well as to improve antigenic quality of frozen sections.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.1
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• pp.41-58
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• 2009

Objectives: The purpose of this study was to investigate the effects of Hyolbuchukeo-tang extracts on the hyperlipidemia rats induced by high fat diet. Methods and Materials: In vitro; The extracts prepared for Hyolbuchukeo-tang by hot water extraction (HH), fermentation(HF) and UMPM extraction(HU) method. The extracts were examined for levels of polyphenol compounds, antioxidant activities, and inhibitory potencies for HMG-CoA reductase. In vivo; Sprague-Dawley male rats of weighing $150{\pm}5g$ were randomly divided into six groups ; normal control diet(NC), and high fat diet(HC), high fat diet with treated lovastatin of 10mg/kg(PC), high fat diet with Hyolbuchukeo-tang extracts; HH, HF and HU treated extracts of 300mg/kg, respectively. Also, we compared the effects of the extracts of HH, HF and HU on rats fed high fat diet for four weeks. Results: 1. The content of polyphenol compounds and electron donating abilities(EDAs) was the HF higher than HH and HU. The superoxide dismutase(SOD)-like activities were proportionate in consistency and they appeared highly from all extracts. The HMG-CoA reductase inhibition activities was highest activities in the HU. 2. The activities of serum GOT and GPT were significantly lower in the HH and HF groups. The level of serum triglyceride was significantly decreased in the HF group. HH and HU groups were significantly decreased in the atherogenic index(AI). The total cholesterol concentration in liver was significantly decreased in the HF group, and HU showed more significantly decreased in the triglyceride than of the lovastatin. Also, photomicrographs of liver tissue showed higher fat accumulation in the HC group than in the HH, HF and HU groups. Conclusions: These result suggest that the hyper-lipidemia caused by a high fat diet was effectively inhibited the administration of HF and HU.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.151-159
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• 2005

Injury caused by reactive oxygen species (ROS), known as oxidative stress, is one of the major damaging factors in plants exposed to environmental stress. Chloroplasts are specially sensitive to damage by ROS because electrons that escape from the photosynthetic electron transfer system are able to react with relatively high concentration of $O_2$ in chloroplasts. To cope with oxidative stress, plants have evolved an efficient ROS-scavenging enzymes such as superoxide dismutase (SOD) and ascorbate peroxidase (APX), and low molecular weight antioxidants including ascorbate, glutathione and phenolic compounds. To maintain the productivity of plants under the stress condition, it is possible to fortify the antioxidative mechanisms in the chloroplasts by manipulating the antioxidation genes. A powerful gene expression system with an appropriate promoter is key requisite for excellent stress-tolerant plants. We developed a strong oxidative stress-inducible peroxidase (SWPA2) promoter from cultured cells of sweetpotato (Ipomoea batatas) as an industrial platform technology to develop transgenic plants with enhanced tolerance to environmental stress. Recently, in order to develop transgenic sweetpotato (tv. Yulmi) and potato (Solanum tuberosum L. cv. Atlantic and Superior) plants with enhanced tolerance to multiple stress, the genes of both CuZnSOD and APX were expressed in chloroplasts under the control of an SWPA2 promoter (referred to SSA plants). As expected, SSA sweetpotato and potato plants showed enhanced tolerance to methyl viologen-mediated oxidative stress. In addition, SSA plants showed enhanced tolerance to multiple stresses such as temperature stress, drought and sulphur dioxide. Our results strongly suggested that the rational manipulation of antioxidative mechanism in chloroplasts will be applicable to the development of all plant species with enhanced tolerance to multiple environmental stresses to contribute in solving the global food and environmental problems in the 21st century.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1182-1187
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• 2003

This study was performed to evaluate the potentiality of Reynoutria elliptica Migo., being used as a folk remedy and a herb medicine for urethritis, cystitis, etc., on growth inhibition of Helicobacter pylori which is known as the ulcerogenic pathogen. The minimum inhibitory concentration (MIC) value of methanol extract from Reynoutria elliptica Migo, was determined to be 120 ppm for H. pylori and urease activity derived from H. pylori was inhibited over 80% by the extract at 2 mg/mL in urea broth. Among various solvent fraction of the methanol extract, the hexane fraction showed a significant inhibitory effect on the growth of H. pylori reducing both its growth and urease activity. Scanning and transmission electron micrographs of H. pylori treated with the methanol extract at 2 mg/mL for 3 hr showed that the cell walls and membranes were disrupted so that the cytoplasmic components were leaked from the body. These results suggest that Reynoutria elliptica Migo. possesses a therapeutic potential on the gastric disease caused by H. pylori.

• Applied Biological Chemistry
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• v.46 no.3
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• pp.251-256
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• 2003

The polyphenol fractions of Korean ginseng were purified using Sephadex LH-20, MCI gel, Bondapak $C_{18}$ TLC, and HPLC from the 60% acetone soluble fraction. Fraction I showed 48.16%, 79.71% and 43.55% inhibition at 150 ppm against lipid oxidation in the presence of copper ion, superoxide and hydrogen peroxidation. Electron donating abilities of fraction II showed 35.17% inhibition at 200 ppm. Fraction III showed 48.49% and 25% inhibition at 150 ppm against lipid oxidation in the presence of ferrous ion and hydroxy radical ion. The phospholipase $A_2$ inhibitory effect of fraction III was 48.9% at the concentration of $60\;{\mu}g/ml$. The cytotoxic effects of fraction II was the highest (73.29% at 0.25 mg/ml) among the tested polyphenol fractions.

• Research in Plant Disease
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• v.15 no.2
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• pp.68-71
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• 2009

Cucumber green mottle mosaic virus (CGMMV) was not infected in figleaf gourd by sap inoculation. However CGMMV was detected by RT-PCR from the figleaf gourd collected from a field growing cucumber grafted onto figleaf gourd in Cheonan, Chungcheongnam Province in 2008. Which field showed 100% infection rate of the virus disease. In the experiment grafted with cucumber onto figleaf gourd, transportation of CGMMV through cucumber to figleaf gourd was confirmed by RT-PCR when the virus was mechanically inoculated on the leaves of the cucumber. The amplified DNA concentration of the virus on electrophoresis gel was much higher in the cucumber than in the figleaf gourd. However, the virus particles from the figleaf gourds were not observed under electron microscopy, also sap of the figleaf gourds was not transmittable to Nicotiana benthamiana. To identify the existence of CGMMV particle, the virus was purified from figleaf gourd and cucumber growing together in the graft system. CGMMV solution extracted from the cucumber represented a typical absorption spectrum of the virus but that from the figleaf gourd did not. Only a few CGMMV particles were observed in the purified preparation from the figleaf gourd. These results confirmed that CGMMV only passed through figleaf gourd in the grafting system. This study indicated that figleaf gourd is not a host of CGMMY.