• The Journal of Advanced Prosthodontics
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• v.5 no.2
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• pp.198-203
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• 2013

PURPOSE. The purpose of this study was to investigate the effect of resin cements and primer on the retentive force of zirconia copings bonded to zirconia abutments with insufficient retention. MATERIALS AND METHODS. Zirconia blocks (Lava, 3M ESPE, St. Paul, MN, USA) were obtained and forty sets of zirconia abutments and copings were fabricated using CAD/CAM technology. They were grouped into 4 categories as follows, depending on the types of resin cements used, and whether the primer is applied or not:Panavia F2.0 (P), Panavia F2.0 using Primer (PRIME Plus, Bisco Inc, Schaumburg, IL, USA) (PZ), Superbond C&B (S), and Superbond C&B using Primer (SZ). For each of the groups, the cementation was conducted. The specimens were kept in sterilized water ($37^{\circ}C$) for 24 hours. Retentive forces were tested and measured, and a statistical analysis was carried out. The nature of failure was recorded. RESULTS. The means and standard deviations of retentive force in Newton for each group were $265.15{\pm}35.04$ N (P), $318.21{\pm}22.24$ N (PZ), $445.13{\pm}78.54$ N (S) and $508.21{\pm}79.48$ N (SZ). Superbond C&B groups (S & SZ) showed significantly higher retentive force than Panavia F2.0 groups (P & PZ). In Panavia F2.0 groups, the use of primer was found to contribute to the increase of retentive force. On the other hand, in Superbond C&B groups, the use of primer did not influence the retention forces. Adhesive failure was observed in all groups. CONCLUSION. This study suggests that cementation of the zirconia abutments and zirconia copings with Superbond C&B have a higher retentive force than Panavia F2.0. When using Panavia F2.0, the use of primer increases the retentive force.

• Journal of Pharmacopuncture
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• v.18 no.2
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• pp.67-75
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• 2015

Objectives: This study was carried out to analyze the single-dose toxicity of ShinYangHur (SYH) herbal acupuncture injected into the muscles of Sprague-Dawley (SD) rats. Methods: The SYH herbal acupuncture was made in a clean room at the Korean Pharmacopuncture Institute (KPI, Korea-Good Manufacturing Practice, K-GMP). After the mixing process with sterile distilled water, the pH was controlled to between 7.0 and 7.5. Then, NaCl was added to make a 0.9% isotonic solution by using sterilized equipment. All experiments were conducted at Biotoxtech, an institution authorized to perform non clinical studies under the regulations of Good Laboratory Practice (GLP). SD rats were chosen for the pilot study. Doses of SYH herbal acupuncture, 0.25, 0.5, and 1.0 mL, were administered to the experimental groups, and a dose of normal saline solution, 1.0 mL, was administered to the control group. This study was conducted under the approval of the Institutional Animal Ethics Committee. Results: No deaths or abnormalities occurred in any of the four groups. No significant changes in weight, hematological parameters or clinical chemistry between the control group and the experimental groups were observed. To check for abnormalities in organs and tissues, we used microscopy was used to examine representative histological sections of each specified organ; the results showed no significant differences in any of the organs or tissues. Conclusion: The above outcomes suggest that treatment with SYH herbal acupuncture is relatively safe. Further studies on this subject are needed to yield more concrete evidence.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.270.1-270.1
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• 2013

Zinc oxide (ZnO) is one of the most powerful materials for purifying organic pollutants using photocatalytic activity. In this study, we have introduced a novel method to design highly photoreactive flexible 3 dimensional (3D) ZnO nanocomposite [F-ZnO-m (m: reaction time, min)] by electrospinning and simple-step ZnO growth processing (one-step ZnO seed coating/growth processing). Significantly, the F-ZnO-m could be a new platform (or candidate) as a photocatalytic technology for both morphology control and largearea production. The highest photocatalytic degradation rate ([k]) was observed for F-ZnO-m at 2.552 h-1, which was 8.1 times higher than that of ZnO nanoparticles (NPs; [k] = 0.316 h-1). The enhanced photocatalytic activity of F-ZnO-m may be attributed to factors such as large surface area. The F-ZnO-m is highly recyclable and retained 98.6% of the initial decolorization rate after fifteen cycles. Interestingly, the F-ZnO-m samples show very strong antibacterial properties against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) after exposure to UV-light for 30 min. The antibacterial properties of F-ZnO-m samples are more effective than those of ZnO NPs. More than 96.6% of the E. coli is sterilized after ten cycles. These results indicate that F-ZnO-m samples might have utility in several promising applications such as highly efficient water/air treatment and inactivation of pathogenic microorganisms.

• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.677-687
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• 1996

This study was conducted to evaluate the tissue responses histologically to three root canal cements : Sealapex, AH-26, and zinc oxide-eugenol cement. Twelve white female Sprague-Dawley rats, weighing between 350 and 400 gm, were anesthetized with an intraperitoneal injection of Ketamine hydrochloride(0.4 ml). After shaving the sites selected(left and right scapular areas, left and right pelvic areas), the animal's backs were scrubed with soap and water, and sterilized with absolute alcohol. Each material was mixed to a thin consistency to flow out easily through a 24-guage needle, and loaded into a sterile, disposable plastic 1-ml syringe. All of the rats were injected subcutaneously with 0.1 ml of the three test sealers. Normal saline was used as a control. Animals were sacrificed after 48hr, 1, 4, and 12 weeks by overanesthetization using jars containing anesthetic ether. The tested sites were surgically removed with the surrounding tissue and fixed with 10% formalin. After 48 hours specimens were embedded in paraffin, sectioned to an average thickness of $6{\mu}m$ thick, stained with hematoxylin-eosin. The slides were examined under the light microscope. The results were obtained as follows 1. All material except the control showed various degree of inflammation on 48 hr. 2. Sealapex : In early stage, severe inflammatory cell infiltration was observed. At the 4th weeks observation, graunlomatous tissue with macrophage and foreing body giant cells containing many dark particles in their cytoplasm was observed. 3. AH-26 : Mild inflammatoy reaction was observed with AH-26 throughout the experimental period. 4. Zinc oxide-eugenol cement : Severe inflammatory cell infiltration, necrosis along the material, edema could be seen in early stage. Zinc oxide-eugenol cement maintained a moderate/severe reaction throughout the experimental period.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.273-277
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• 2011

This study evaluated the cytotoxicity and anti-inflammatory activities of natural herbal extracts including Houttuynia cordata and Eucommia ulmoides against human mast cell (HMC-1). Houttuynia cordata (HC) and Eucommia ulmoides(EU) were extracted with distilled water (at $75^{\circ}C$) and then freeze-dried for 5 days. Finally, the mixture of HC and EU were sterilized by ${\gamma}$-rays irradiation. Cytotoxicity of the mixture against HMC-1 cell was measured using cell counting kit-8 (CCK-8) assay. In addition, inflammatory mediator cytokines such as TNF-${\alpha}$, IL-6 and IL-8 were evaluated by ELISA kit on the HMC-1 cells with calcimycin A23187 and phorbol 12-myristate 13-acetate (PMA). The results showed that mixture of HC and EU had no cytoxicity and reduced TNF-${\alpha}$, IL-6, IL-8 response on HMC-1 cells.

• Journal of Radiation Industry
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• v.6 no.1
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• pp.11-15
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• 2012

This study confirmed the cytotoxicity and anti-inflammatory activities of natural herbal extracts (HE) including Eucommia ulimoides and Ulmus davidiana against human mast cell (HMC-1). HE was extracted with distilled water (at $75^{\circ}C$) and then freeze-dried for 5 days. Finally, the HE was sterilized by gamma radiation with $^{60}Co$ ${\gamma}$ source at room temperature. Cytotoxicity of the HE against HMC-1 cell was measured using cell counting kit-8 (CCK-8) assay. In addition, inflammatory cytokines such as $TNF-{\alpha}$, IL-6 and IL-8 were evaluated by ELISA kit on the HMC-1 cells with calcimycin A23187 and phorbol 12-myristate 13-acetate (PMA). The results showed that HE had no toxicity and reduced $TNF-{\alpha}$, IL-6, IL-8 response on HMC-1 cells.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.88-107
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• 2023

In the present investigation, bacterial isolates from infected apple trees causing apple canker during winter were studied in the northern Gyeongbuk Province, Korea. The pathogen was identified as Pseudomonas syringae pv. syringae (Pss) through various physiological and biochemical characterization assays such as BIOLOG, gas chromatography of fatty acid methyl esters, and 16S rRNA. Bioassays for the production of phytotoxins were positive for syringopeptin and syringomycin against Bacillus megaterium and Geotrichum candidum, respectively. The polymerase chain reaction (PCR) method enabled the detection of toxin-producing genes, syrB1, and sypB in Pss. The differentiation of strains was performed using LOPAT and GATTa tests. Pss further exhibited ice nucleation activity (INA) at a temperature of -0.7℃, indicating an INA⁺ bacterium. The ice-nucleating temperature was -4.7℃ for a non-treated control (sterilized distilled water), whereas it was -9.6℃ for an INA^- bacterium Escherichia coli TOP10. These methods detected pathogenic strains from apple orchards. Pss might exist in an apple tree during ice injury, and it secretes a toxin that makes leaves yellow and cause canker symptoms. Until now, Korea has not developed antibiotics targeting Pss. Therefore, it is necessary to develop effective disease control to combat Pss in apple orchards. Pathogenicity test on apple leaves and stems showed canker symptoms. The pathogenic bacterium was re-isolated from symptomatic plant tissue and confirmed as original isolates by 16S rRNA. Repetitive element sequence-based PCR and enterobacterial repetitive intergenic consensus PCR primers revealed different genetic profiles within P. syringae pathovars. High antibiotic susceptibility results showed the misreading of mRNA caused by streptomycin and oxytetracycline.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.36-36
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• 2021

Cryopreservation has been broadly used as an efficient method for a long-term conservation for many types of plants especially vegetatively propagated plants. Among several cryopreservation methods, a droplet-vitrification was the most widely applicable and efficient method. Studies have developed protocols for strawberry using droplet-vitrification method and suggested the practical use of the protocol for large number of germplasm with a little modification. In this study, the droplet vitrification method of shoot tip has been tested on 31 accessions provided around the world. Shoot tips were precultured on Murashige and Skoog (MS) liquid medium supplemented with 0.3~0.5M sucrose. Precultured explants were osmoprotected with loading solution, 35% of PVS3 (C4, 17.5% glycerol and 17.5% sucrose) for 40 min and exposed to dehydration solution, PVS3 (B1, 50% glycerol and 50% sucrose) for 60 min. Then, the explants were transferred onto droplets containing 2.5 uL PVS3 on sterilized aluminum foils prior to direct immersion in liquid nitrogen (LN) for 1hr. The cryopreserved shoot tips were rapidly warmed in a water bath at 40C and then unloaded in MS with 0.8M sucrose for 40 min. The shoot tips were cultured in NH₄NO₃-free MS post culture medium for 2 weeks. Subsequently, the explants were moved to the MS medium for 6 weeks and evaluated the regrowth rate. By this droplet-vitrification protocol, twenty-four accessions showed at least 40% regrowth rate. Out of 24 accessions, 'Nonsan1ho' had the highest regeneration rate of 85.8% and 'Jumbo pureberry' had the lowest with 42.1%.

• Journal of Korean Society of Forest Science
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• v.82 no.3
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• pp.221-226
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• 1993

Methods for shoot proliferation via pulse treatment onto the microshoots of Quercus acutissima, and ex vitro root induction using peat plug systems of the microshoots of 4 oak trees were described. Pulsing solution was prepared by the addition of BA and/or BA plus zeatin onto the aqueous WPM and sterilized distilled water. Using the solution, pulsing time was adjusted at different levels(0. 1, 2, 5. 9, and 24 hours). Although the effect of pulsing solution prepared by the addition of cytokinins onto the sterilized distilled water was slightly lower in shoot proliferation rate, a little higher in shoot elongation was observed compared with that of aqueous WPM. One hour of pulse treatment revealed best in shoot proliferation and its elongation, whereas the increment of pulsing time slightly suppressed the response. In addition, prolonged pulse time resulted high frequency of hyperhydric shoot appearance. Single treatment of BA was better in shoot proliferation than that of BA combination with zeatin, whereas the latter treatment usually showed rapid and healthy shoot growth. For ex vitro root induction using peat plug systems, black oaks(Q. acutissima and Q. variabilis) revealed excellent rootability compared with white oaks(Q. serrata and Q. mongolica). Shoot-tip necrosis of white oaks eras one of the big problems for survival. In this study, we discribed the effect of pulse treatment, successful ex vitro rooting system by the incorporation of peat plug, and the possibilities for the overcoming the obstacles on micropropagation of oaks.

• Food Science and Preservation
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• v.12 no.6
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• pp.558-564
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• 2005

This study was carried out to investigate the cleaning effect of sesame leaf, the sterilization effect and physicochemical properties, treated with various electrolyzed water. Initial physicochemical properties could be kept more than 1 month in electrolyzed oxidizing water(EW-1) of diaphragm type and 15 days in electrolyzed water(EW-2 and EW-3) of non-diaphragm system, there was no significant difference by storage temperature. 4 kinds of microorganism (initial total counts, $10^7\~10^9$ CFU/mL) were sterilized within $0.5\~1$ minutes by electrolyzed water. In fresh sesame leaves, total viable cell count and coliform group in the treatment of electolyzed water were decreased to about $2\~3$ log scale comparing non-treated ones. Especially Bacillus cereus was not detected until 13th day when treated with EW-l. Decaying ratio of sesame leaf appears on day 6 of storage in the untreated but the treatments of electrolyzed water has no sign until day 10 of storage. Change in color difference(${\Delta}E$) during storage was observed the treatments of electrolyzed low-alkaline water(EW-2) and electrolyzed neutral water(EW-3) were very desirable at the level $1\~2$ after day 13 of storage comparative to the untreated Change of Chlorophyll content was biggest decreased to 6.8 $mg\%$ on the untreated and decreased least to 8.35 $mg\%$ on EW-3 treated group on 13th day from initial value of $9.0\~10.3\;mg\%$ The overall sensory evaluation appeared most acceptable in the treatments of EW-2 and EW-3.