• Journal of fish pathology
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• v.24 no.2
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• pp.85-93
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• 2011

Edwardsiella tarda is a broadly infectious agent against freshwater and seawater fishes. In the present study, E. tarda specific phage was isolated from fish farms on the west coast of Korea, and the effect of environmental factors such as pH and water temperature on the phage activity was investigated. As a fish model, Nile tilapia (Oreochromis niloticus) was used and the interaction between E. tarda and phage was investigated. The phage activity, in pH test, appeared even higher in seawater than freshwater and was evenly constant up to $50^{\circ}C$. The phage and E. tarda were inoculated in tilapia and the phage activity and E. tarda viability were checked on the time intervals. As a result, the number of E. tarda in the group of E. tarda plus phage was constantly reduced to 24 hr post-inoculation compared to the control group without phage, whereas the phage activity was slightly increased in the experiment group. The results suggest that it might be possible to use phage to control the fish disease caused by E. tarda.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.1
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• pp.21-28
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• 2017

Background: The skin consists of tightly connected keratinocytes, and prevents extensive water loss while simultaneously protecting against the entry of microbial pathogens. Excessive cellular levels of reactive oxygen species can induce cell apoptosis and also damage skin integrity. Propofol (2,6-diisopropylphenol) has antioxidant properties. In this study, we investigated how propofol influences intracellular autophagy and apoptotic cell death induced by oxidative stress in human keratinocytes. Method: The following groups were used for experimentation: control, cells were incubated under normoxia (5% $CO_2$, 21% $O_2$, and 74% $N_2$) without propofol; hydrogen peroxide ($H_2O_2$), cells were exposed to $H_2O_2$ ($300{\mu}M$) for 2 h; propofol preconditioning (PPC)/$H_2O_2$, cells pretreated with propofol ($100{\mu}M$) for 2 h were exposed to $H_2O_2$; and 3-methyladenine $(3-MA)/PPC/H_2O_2$, cells pretreated with 3-MA (1 mM) for 1 h and propofol were exposed to $H_2O_2$. Cell viability, apoptosis, and migration capability were evaluated. Relation to autophagy was detected by western blot analysis. Results: Cell viability decreased significantly in the $H_2O_2$ group compared to that in the control group and was improved by propofol preconditioning. Propofol preconditioning effectively decreased $H_2O_2$-induced cell apoptosis and increased cell migration. However, pretreatment with 3-MA inhibited the protective effect of propofol on cell apoptosis. Autophagy was activated in the $PPC/H_2O_2$ group compared to that in the $H_2O_2$ group as demonstrated by western blot analysis and autophagosome staining. Conclusion: The results suggest that propofol preconditioning induces an endogenous cellular protective effect in human keratinocytes against oxidative stress through the activation of signaling pathways related to autophagy.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.2
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• pp.200-213
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• 2000

Lasers have given dentistry a new rapid, economic, and accurate technique for metal joining. Although laser welding has been recommended as an accurate technique, there are some limitations with this technique. For example, the two joining surfaces must have a tight-fitting contact, which may be difficult to achieve in some situations. The tensile samples used for this study were made from a custom-made pure titanium and type III gold alloy plates. 27 of 33 specimens were sectioned perpendicular to their long axis with a carborundum disk and water coolant. Six specimens remained and served as the control group. A group of 6 specimens was posed as butt joints in custom parallel positioning device with a feeler gauge at each of three gaps : 0.00, 0.25. and 0.50mm. All specimens were then machined to produce a uniform cross-sectional dimension, none of the specimens was subjected to any subsequent form of heat treatment. Scanning electron microscopy was performed on representative tested specimens at fractured surfaces in both the parent metal and the weld. Vickers hardness was measured at the center of the welds with a micropenetrometer using a force of 300gm for 15 seconds. Measurement was made at approximately $200{\mu}m\;and\;500{\mu}m$ deep from each surface. One-way analysis of variance (ANOVA) and Scheffe's test was calculated to detect differences between groups. The purpose of this study is to compare the strength and properties of the joint achieved at various butt Joint gaps by the laser welding of type III gold alloy and pure titanium tensile specimens in an argon atmosphere. The results of this study were as follows : 1. When indexing and welding pure titanium, there was no decrease in ultimate tensile strength as compared with the unsectioned alloys for indexing gaps of 0.00 to 0.50mm, although with increasing gap size may come increased distortion (p>0.05). 2. When indexing and welding type III gold alloy, there were significant differences in ultimate tensile strength among groups with weld gaps of 0.00mm, 0.25 and 0.50mm, and the control group. Group with butt contact without weld gap demonstrated a significant higher ultimate tensile strength than groups with weld gaps of 0.25 and 0.50mm (p<0.05). 3. When indexing and welding the different metal combination of type III gold alloy and pure titanium, there were significant differences in ultimate tensile strength between groups with weld gaps of 0.00, 0.25, and 0.50mm. However, the mechanical properties of the welded joint would become too brittle to be acceptable clinically (p<0.05). 4. The presence of large pores in the laser welded joint appears to be the most important factor in controlling the tensile strength of the weld in both pure titanium and type III gold alloy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1281-1287
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• 2012

In this study, soy milk jellys with medicinal herbs (MH) composites showing cognitive effects were prepared and their characteristics were examined. Eight kinds of medicinal herbs were extracted with hot water and added to soy milk based on their contents. Medicinal herbs showed cognitive effects, namely promoting acetylcholinesterase (AChE) inhibition. In the preparation of soy milk jellys containing MH extracts of various contents (0%, 5%, 10%, 15% and 20%), pH of all groups significantly (p<0.05) decreased with increasing MH extracts compared to the control group. The brix of the soy milk jellys was the highest in the 5% content of MH extracts among all groups. The "a" and "b" values of soy milk jellys increased with the content of MH extracts, while the "L" value decreased adding to the content of MH extracts compared to the control. The hardness, gumminess, and chewiness of soy milk jellys were improved the most by the addition of 15~20% MH extracts, while the fracturability, adhesiveness, springiness, cohesiveness, and resilience of soy milk jelly was not significantly different (p<0.05) among all groups. Through a sensory evaluation, it was revealed that the taste, texture, overall preference, flavor, and sweetness of soy milk jellys was not significantly different (p<0.05) among all groups. Therefore, since the addition of 20% MH extracts did not significantly alter the sensory evaluation, it can usually be adjusted to make soy milk jellys with cognitive effects.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.399-399
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• 2008

Synthesis and characterization of ZnO structure such as nanowires, nanorods, nanotube, nanowall, etc. have been studied to multifunctional application such as optical, nanoscale electronic and chemical devices because it has a room-temperature wide band gap of 3.37eV, large exiton binding energy(60meV) and various properties. Various synthesis methods including chemical vapor deposition (CVD), physical vapor deposition, electrochemical deposition, micro-emulsion, and hydrothermal approach have been reported to fabricate various kinds of ZnO nanostructures. But some of these synthesis methods are expensive and difficult of mass production. Wet chemical method has several advantage such as simple process, mass production, low temperature process, and low cost. In the present work, ZnO nanorods are deposited on ITO/glass substrate by simple wet chemical method. The process is perfomed by two steps. One-step is deposition of ZnO seeds and two-step is growth of ZnO nanorods on substrates. In order to form ZnO seeds on substrates, mixture solution of Zn acetate and Methanol was prepared.(one-step) Seed layers were deposited for control of morpholgy of ZnO seed layers by spin coating process because ZnO seeds is deposited uniformly by centrifugal force of spin coating. The seed-deposited samples were pre-annealed for 30min at $180^{\circ}C$ to enhance adhesion and crystallinnity of ZnO seed layer on substrate. Vertically well-aligned ZnO nanorods were grown by the "dipping-and-holding" process of the substrates into the mixture solution consisting of the mixture solution of DI water, Zinc nitrate and hexamethylenetetramine for 4 hours at $90^{\circ}C$.(two-step) It was found that density and morphology of ZnO nanorods were controlled by manipulation of ZnO seeds through rpm of spin coating. The morphology, crystallinity, optical properties of the grown ZnO nanostructures were carried out by field-emission scanning electron microscopy, high-resolution electron microscopy, photoluminescence, respectively. We are convinced that this method is complementing problems of main techniques of existing reports.

• Journal of the Korea Concrete Institute
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• v.25 no.1
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• pp.11-18
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• 2013

Cement concrete pavement offers long-term service life and excellent applicability for heavy traffic. It is easier to purchase and more durable and economical than the asphalt pavement. However, it is difficult to repair and rehabilitate compared to the asphalt pavement when it comes to the maintenance problem. Since the crack is the main reason of the damage of concrete pavement, it is necessary to control the early and long-term crack in the concrete pavement. In this experimental study, the basic performance tests have been carried out to investigate the effect of hybrid fibers which were composed of micro fibers with small diameter and high aspect ratio and macro fibers with large diameter and low aspect ratio on the concrete pavement, in which lower water ratio and larger aggregates were used compared to the general concrete mixture. The test results showed that the flexural strength and toughness of concrete pavement mixture have been increased with the use of hybrid fibers in the concrete pavement mixture, even though they were less effective compared to the normal concrete mixture. It was found that the hybrid fibers were effective to control the early shrinkage of the concrete pavement which is one of the main reasons of the damage in the concrete pavement.

• Korean journal of applied entomology
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• v.59 no.1
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• pp.41-54
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• 2020

Two mosquito species were collected in still-water near farming area in Andong, Korea. Based on morphological characters, these two mosquitoes were identified as Aedes koreicus and Culex vagans, respectively. DNA barcode analyses supported the identification. An entomopathogenic bacterium, Bacillus thuringiensis subsp. israelensis (BtI), exhibited insecticidal activities against the two mosquito species and its virulence was more potent than that of B. thuringiensis subsp. kurstaki. It has been known that the bacterial metabolites of Xenorhabdus spp. suppress insect immunity and enhance pathogenicity of B. thuringiensis. This study tested the effect of the bacterial culture broth of Xenorhabdus spp. on enhancing BtI pathogenicity. Among three Xenorhabdus spp., culture broth of X. ehlersii (Xe) was relatively effective to enhance BtI pathogenicity against both mosquito species. Indeed, organic extracts of Xe culture broth suppressed the hemocyte-spreading behavior, suggesting the presence of immunosuppressant in the culture broth. These results suggest a formulation of BtPlus by mixing BtI spore and Xe culture broth to be applied to control the two mosquito species.

• Journal of Korean Medicine Rehabilitation
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• v.26 no.2
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• pp.29-50
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• 2016

Objectives There is few Korean medicinal studies about post-operation wound healing despite much effort for minimizing wound or post-op scar. The aim of this study is to evaluate the wound healing effect of Gyejibokryeong-hwan (Guizhifuling-wan, GBH) after skin suture. Methods < In vitro > We observed anti-oxidative and anti-inflammatory effect by using lipopolysaccharide (LPS)-treated RAW 264.7 cells. For anti-oxidation, we mesured the total amount of polyphenol, flavonoid, DPPH scavenging ability, ABTS scavenging ability and the value of ROS production, and for anti-inflammation, we mesured the amount of NO and pro-inflammatory cytokines ($TNF-{\alpha}$, $IL-1{\beta}$, IL-6). < In vivo > Thirty SD rats were divided into five equal groups (n=6, one normal, two controls and two experimentals). All groups except normal group were made a scar (around $1{\times}4cm^2$) in the back by the depth of the fascia and then sutured by a thread and needle. Normal group rats received no treatment at all. Control group rats were fed distilled water, and positive control group rats were percutaneously applied terramycin once in 2 days. GBH 200 group rats were orally medicated GBH 200 mg/kg, and GBH 400 group rats were orally medicated GBH 400 mg/kg per day for two weeks. We analyzed the blood samples (WBC, neutrophil, lymphocyte, monocyte, eosinophil), and the serums (TIMP-1, MMP-2, MMP-2. $PGE_2$, $TGF-{\beta}$, VEGF), and examined the wounded skin tissue histopathologically. Results < in vitro > 1. DPPH and ABTS scavenging activity was increased concentration-dependantly, and ROS production was significantly increased in GBH treated cells ($100{\mu}g/ml$). Therefore in this study, Gyejibokryeong-hwan appears to have the anti-oxidative. 2. NO production was significantly reduced in GBH treated cells ($100{\mu}g/ml$), and $IL-1{\beta}$ production was significantly reduced in GBH treated cells ($1{\mu}g/ml$). But, $TNF-{\alpha}$ and IL-6 did not show uneffective action. Therefore in this study, Gyejibokryeong-hwan did not show any significant effect on anti-inflammatory process. < in vivo > 1. Monocyte and neutrophil was significantly increased in GBH (200, 400) groups. WBC, lymphocyte and eosinophil did not show significant change. 2. TIMP-1, MMP-2, VEGF were significantly increased in GBH 400 group, $PGE_2$ was significantly reduced in GBH 400 group. $TGF-{\beta}$ was significantly increased in GBH (200, 400) groups, and MMP-9 was increased concentration-dependantly in GBH groups, but there was no significance. 3. In histopathological examinations, collagen was significantly increased and keratin was significantly decreased in GBH (200, 400) groups. Conclusions According to in vitro experiment, GBH appears to have the anti-oxidative effect and in vivo experiment, GBH stimulate the wound healing process hematologically and histopathologically. In conclusion, the results suggest that GBH promotes wound healing after skin suture.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.4
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• pp.386-396
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• 2004

Statement of problem: It is not clear how to make a stable bonding between zirconia ceramic and resin cement. And the study about surface treatment of zirconia ceramic or bonding resin cement are not enough. Purpose: To measure and compare the shear bond strength of some resin cements on zirconia ceramic after different surface treatments. Material and method: 48 ceramic discs were made of 3 ceramic materials, zirconia ceramics (Zi-Ceram), heat-pressed ceramics (IPS Empress 2) and slip cast alumina ceramics (In-Ceram). According to the surface treatments of ceramic specimens and resin cements, specimens were classified into 6 groups and each group was composed of 8 specimens. For the surface treatment of Zi-Ceram group (test group), sandblasting and diamond bur preparation were applied and Superbond C&B and Panavia F were bonded respectively. For IPS Empress 2 group (control group), Variolink II was bonded after sandblasting, acid etching, silanization and for In-Ceram ALUMINA group (control group), Panavia F was bonded after sandblasting. After storing specimens in distilled water for 24 hours, the shear bond strength was measured by the universal testing machine. Results and conclusion: 1. Zi-Ceram group with Superbond C&B cement showed higher bond strength than with Panavia F cement regardless to the surface treatments (p<0.05). 2. In Zi-Ceram group with Superbond C&B cement, sandblasting treatment group (12.1MPa) showed higher bond strength than diamond bur treatment group (7.7MPa) (p<0.05). In Zi-Ceram group with Panavia F cement, there were no significant differences in the bond strength according to the surface treatments (p>0.05). 3. Zi-Ceram group with sandblasting and Superbond C&B cement (12.1MPa) showed the highest bond strength. The bond strength of this group was not significantly different from In-Ceram ALUMINA group (10.4MPa) (p>0.05) and lower than IPS Empress 2 group (15.9MPa) (p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.341-349
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• 2017

Blood decontamination is an important factor in success of the orthodontic bracket. The purpose of this study is to evaluate the shear bond strength affected by blood decontamination. The shear bond strength was measured on blood decontamination before and after primer photopolymerization. And the adhesive remnants type and surface patterns was evaluated under scanning electron microscopy. A total of 50 human premolars were prepared. Group I was attached using conventional resin-acid etching method as control group. Group II and III were blood contaminated before curing primer and groups IV and V were blood contaminated after curing primer. Group II and IV were treated only with cotton pellet and Groups III and V were treated with cotton pellet after water washing. The mean shear bond strengths were in the order of groups I, V, III, II, and IV. In scanning electron micrographs group III and V showed more uniform surface than group II and IV. The ARI was significantly different between the control group and the experimental groups (p <0.05).