• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.63-68
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• 2005

Hydrogen peroxide ($H_2O_2$) causes oxidative stress and is considered as an inducer of cell death in various tissues. Two-pore domain $K^+$ ($K_{2p}$) channels may mediate $K^+$ efflux during apoptotic volume decreases (AVD) in zygotes and in mouse embryos. In the present study, we sought to elucidate linkage between $K_{2p}$ channels and cell death by $H_2O_2$. Thus $K_{2p}$ channels (TASK-1, TASK-3, TREK-1, TREK-2) were stably transfected in HEK-293 cells, and cytotoxicity assay was preformed using cell counting kit-8 (CCK-8). Cell survival rates were calculated using the cytotoxicity assay data and dose-response curve was fitted to the $H_2O_2$ concentration. Ionic currents were recorded in cell-attached mode. The bath solution was the normal Ringer solution and the pipette solution was high $K^+$ solution. In HEK-293 cells expressing TREK-1, TREK-2, TASK-3, $H_2O_2$ induced cell death did not change in comparison to non-transfected HEK-293. In HEK-293 cells expressing TASK-1, however, dose-response curve was significantly shifted to the left. It means that $H_2O_2$ induced cell death was increased. In cell attached-mode recording, application of $H_2O_2$ (300μM) increased activity of all $K_{2p}$ channels. However, a low concentration of $H_2O_2$ ($50{\mu}M$) increased only TASK-1 channel activity. These results indicate that TASK-1 might participate in $K^+$ efflux by $H_2O_2$ at low concentration, thereby inducing AVD.

• Journal of Korean Society on Water Environment
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• v.20 no.1
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• pp.48-54
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• 2004

Two methods, a Ceriodaphnia algal uptake suppression test (CAUST) and a new toxicity test based on temperature control (TTBTC) which are based on feeding behaviour and temperature control, respectively, were developed and compared for the adoption as the better methodology for short-term toxicity screening. As previously published by Lee et aI., (1997), the CAUST method is based on the feeding behaviour of C. dubia and requires as little as 1 hour of contact time between C. dubia neonates and toxicant. However, even though CAUST requires only 1 hour of contact time, this method still take many hours for the preparation and measurement. Before the test starts, neonate digestive tracts were cleared by feeding yeast to the daphnids, Neonates were then exposed to toxicant, followed by addition of Scenedesmus subspiatus into the bioassay vessels. Daphnids were examined under the bright-field microscope with the presence of algae (indicated by a green colored digestive tract) or the absence of algae. Uptake indicated no toxic effect, whereas, absence of uptake indicated toxic inhibition. Unlike CAUST, the newly developed method (TTBTC) is based on just temperature control for the toxicity test of C. dubia. Initially, neonates are exposed to toxicants while the temperature of water bath containing media increased to $35.5^{\circ}C$. After 1.25 hour of contact time, the number of the daphnids, either live (no toxic effect) or dead (toxic effect), is counted without the aid of any instrument. In both methods, median effective concentrations ($EC_{50}$ values) were computed based on the results over a range of dosed toxicant concentrations. It showed that TTBTC was as sensitive as the standard 48-hour acute bioassay and CAUST. TTBTC and CAUST were much more sensitive than the I-hour I.Q. test and 30-minute Microtox. This study indicates that TTBTC is an easier and more rapid toxicity test than the standard 48-hour acute bioassay and even CAUST.

• Journal of Hydrogen and New Energy
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• v.18 no.4
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• pp.452-457
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• 2007

Titanium foil and mesh(anodized tubular $TiO_2$ electrode, ATTE) were anodized in a bath at $5^{\circ}C$ with 20V external bias applied, then annealed at different temperatures($450^{\circ}C{\sim}850^{\circ}C$) to obtain tubular $TiO_2$ on the Ti substrate. The prepared sample was used to investigate rate of hydrogen production as well as Cr(VI) reduction. The ATTEs annealed at relatively lower temperatures showed higher activity than those at relatively higher temperatures. In particular, the Cr(VI) reduction was pH-dependent. To improve photocatalytic Cr(VI) reduction with the ATTEs, two configurations, fixing foil type and rotating mesh type, were also compared. As a result, the rotating mesh type was much more effective for Cr(VI) reaction than the former due to the more efficient use of the light. In the rotating type reactor, as the rotating speed increased, the rate of the Cr(VI) reduction was getting faster.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.752-756
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• 2013

This study was carried out to investigate the effect of cooking condition on the water-soluble flavor precursors relevant to postmortem glycogen metabolisms in various beef muscles from Hanwoo (Korean cattle). The loins, striploins, top rounds, and eye of rounds from 40-mon-old heifers were cooked in either with $100^{\circ}C$ water bath (wet-cooking) or $180^{\circ}C$ household electric oven (dry-cooking) until attained to about $80^{\circ}C$ of internal temperature before the measurements of amounts of macroglycogen, proglycogen, free glucose, and lactate. The macroglycogen and proglycogen contents were not significant differences in all beef muscles between the wet-cooking and dry-cooking treatments. Regardless of cooking condition, the both loin and top round had higher (p<0.05) two types of glycogen than the eye of round. The free glucose and lactate contents presented higher trends in the dry-cooking treatment compared with the wet-cooking treatment. The wet-cooked top round had higher (p<0.05) free glucose than the wet-cooked eye of round. Moreover, the top round contained the highest lactate content regardless of cooking condition. Consequently, it is considered that the dry-cooking treatment would be more beneficial to the flavor of cooked beef muscles than the wet-cooking treatment.

• Journal of Technologic Dentistry
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• v.34 no.4
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• pp.337-344
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• 2012

Purpose: This study examined the corrosion level by alloy type and pH, and used the corrosion levels as the dental health data. The study utilized one Ni-Cr alloy for the full and removable partial denture metal frameworks and two Ni-Cr alloys for porcelain-fused-to-metal crown, among the non-beryllium dental casting non-precious Ni-Cr alloys. Methods: The alloy specimens were manufactured in $10cm^2$ and stored in the corrosive solution(pH 2.2-4.4) in the electrical water bath($37^{\circ}C$) for seven days. Afterwards, the metal ions were quantitatively analyzed using the ICP. Results: Of the three metal alloys, Bellabond-Plus$^{(R)}$alloy and SOLIBOND N$^{(R)}$alloy, with 22% or higher chrome chemical contents, had higher corrosion resistance than Jdium-100$^{(R)}$alloy with 20% chrome chemical content. In all three alloys, the corrosion of Ni was highest, and metal ion corrosion was higher in the pH 2.2 corrosive solution. Conclusion: Although Ni-Cr alloy was not very corrosive, a Ni-allergic patient should not have Ni-Cr alloy prosthesis. The Ni-Cr alloy for porcelain-fused-to-metal crown should be designed for the dental porcelain to cover the whole crown.

• Fashion & Textile Research Journal
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• v.15 no.2
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• pp.286-293
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• 2013

This study investigates the attachment of glycyrrhizin to fabric using an X-ray photoelectron spectrophotometer( XPS). XPS spectra analysis showed that carbon content on treated fabrics with 0.2% glycyrrhizin increased to 2.699% for silk, 2.829% for nylon, 1.505% for cotton, respectively. The results show that glycyrrhizin is absorbed on treated fabrics. The glycyrrhizin extraction method makes radix glycyrrhizae powder 10g treat the first and the second treatment with ethanol, remove impurities on $75^{\circ}C$; subsequently, it is treated for 10 hours with ethanol 75% on $85^{\circ}C$ and lyophilizated. As the result, glycyrrhizin is extracted 1.7g in GL-I, 1.1 g in GL-II. As the result of abstracting glycyrrhizin with two methods, pure glycyrrhizin was abstracted 45.9% in GL-I, 74.9% in GL-II. GL-I, GL-II; in addition, glycyrrhizin( Japan) on TLC plate was separated in Rf 0.6. By GL-II extract method, this experiment obtained glycyrrhizin 15 g treated in a bath ratio set to 1: 100. Silk fabric was treated at $80^{\circ}C$, 60 min. in, nylon fabric $10^{\circ}C$, 70 min., and cotton fabric $30^{\circ}C$, 80 min.; subsequently, silk, nylon, cotton fabrics showed a 99.9% antibacterial activity for Staphylococcus aureus and Klebsiella pneumoniae.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.633-636
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• 2002

Six adult Garole rams maintained under a semi-intensive system were used as semen donors for this study. Semen was collectied daily during the monsoon season with the help of an artificial vagina and examined for its quality characteristics. Ejaculates of thick consistency, rapid wave motion, ${\geq}80%$ motility and intense movement of motile spermatozoa were diluted at the rate of 1:1 with egg yolk McIllvaine glucose diluent at $30^{\circ}C$ in water bath. Estrus in ewes was detected by parading aproned rams of proven vigour at 12 h intervals. The ewes (54 Malpura and 23 Avikalin) in estrus were artificially inseminated with fresh diluted ram semen. The overall conception rate was 94.8%, (range 91.7 to 100%). The overall lambing percent was 80.5 with a range of 75.0 to 84.6%. There was no significant (p>0.05) difference in lambing and conception rate because of individual rams. Fertility was significantly lower (p<0.05) in ewes of less than two years and more than six years of age. Breed (Malpura and Avikalin) effect was not observed in conception and lambing rate (p>0.05). No significant difference (p>0.05) in birth weight and 12 month weight was observed between Garole${\times}$Avikalin and Garole${\times}$Malpura crossbred lambs but there was significant (p<0.05) difference at three month and six months body weight of both the crossbred lambs.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.5
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• pp.305-310
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• 2010

The human $ether$-$a$-$go$-$go$-related gene ($hERG$) channel is important for repolarization in human myocardium and is a common target for drugs that prolong the QT interval. We studied the effects of two antipsychotics, tiapride and sulpiride, on hERG channels expressed in $Xenopus$ oocytes and also on delayed rectifier $K^+$ currents in guinea pig cardiomyocytes. Neither the amplitude of the hERG outward currents measured at the end of the voltage pulse, nor the amplitude of hERG tail currents, showed any concentration-dependent changes with either tiapride or sulpiride ($3{\sim}300{\mu}M$). However, our findings did show that tiapride increased the potential for half-maximal activation ($V_{1/2}$) of HERG at $10{\sim}300{\mu}M$, whereas sulpiride increased the maximum conductance ($G_{max}$) at 3, 10 and $100{\mu}M$. In guinea pig ventricular myocytes, bath applications of 100 and $500{\mu}M$ tiapride at $36^{\circ}C$ blocked rapidly activating delayed rectifier $K^+$ current ($I_{Kr}$) by 40.3% and 70.0%, respectively. Also, sulpiride at 100 and $500{\mu}M$ blocked $I_{Kr}$ by 38.9% and 76.5%, respectively. However, neither tiapride nor sulpiride significantly affected the slowly activating delayed rectifier $K^+$ current ($I_{Ks}$) at the same concentrations. Our findings suggest that the concentrations of the antipsychotics required to evoke a 50% inhibition of IKr are well above the reported therapeutic plasma concentrations of free and total compound.

• Journal of Life Science
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• v.24 no.4
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• pp.428-436
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• 2014

Loop-mediated isothermal amplification (LAMP) technique relies on autocycling strand displacement DNA sysnthesis without template denaturation steps under isothermal conditions. LAMP has more advantages than modern PCR, as it requires only basic laboratory equipment like an isothermal water bath, oven, and heating cabinet. Hence, in this study, five random primers were designed with Streptococcus parauberis, shikimate kinase Arok gene sequences (Genbank accession number: CP0024711). Two primers were selected based on the ladder pattern. Other optimum reaction conditions like temperature, time, and sensitivity were established and confirmed with conventional SYBR-green PCR. Results confirmed that the designed random primers were species specific, without any non-target DNA amplification under isothermal conditions. Hence, this study suggests that LAMP techniques could be used in the diagnosis of fish pathogen, specifically S. parauberis.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.3
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• pp.211-220
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• 2006

Need of porcelain-repair system is largely demanding as dental porcelain restorations are increased in clinical dentistry. This study investigated shear bond strength of commercial porcelain-repair systems on dental porcelain and their reliability. Experimental groups were as follows; Group A Super Bond C&B, Group B Porcelain repair kit, Group C Ceramic repair, and Group D Spectrum system as a control. Porcelain disks were fired and embedded in epoxy resin. Porcelain surface were ground using 220 grit SiC disk, then cleaned in ultrasonic bath. Then porcelain specimens were treated with each repair system. A clear polystyrene cylinder 3.5 mm in internal diameter was filled with composite resin. Then the resin cylinder was polymerized with a visible light curing unit. Thirty one specimens at each group were prepared and stored at $37^{\circ}C$ distilled water for 48 h. Specimens were tested in an Instron testing machine according to ISO TR 11405. Mean shear bond strength and standard deviation of each group was $15.7{\pm}4.1MPa$ (Group A), $12.8{\pm}4.9MPa$ (Group B), $7.2{\pm}3.0MPa$ (Group C) and $9.6{\pm}2.2MPa$ (Group D). ANOVA and Tukey HSD post-hoc test showed that there were significant differences between groups (p<0.05). Data of bond strength were analyzed with two-parameter Weibull distribution. Confidence interval of Weibull modulus (m-parameter) at 95% of Group A (3.5-6.3) and Group D (3.6-6.0) were significantly higher than Group B (2.2-3.7) and Group C (2.0-3.4). There was little correlation between mean shear bond strength and Weibull modulus. Results indicated that acid-etching of porcelain surface increased porcelain-resin shear bonding strength.