• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1097-1103
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• 2007

We report a novel method to synthesize nanocomposites composed of titania nanoparticles and phosphotungstate ions with various composition ratios ranging from W/Ti = 12/10 to 12/500 by inducing the electrostatic interaction between the positively charged protonated titania sol-particles and the negatively charged phosphotungstate anions to flocculate and precipitate. The precipitates showed varied features depending on the composition. The precipitate from the tungsten-richest W/Ti = 12/10 reaction is amorphous in its powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy data. This material shows the Type II adsorption characteristics in its N2-adsorption isotherm, but with quite low surface area of 34 m2/g. To the contrary, the precipitates from the titanium-richer reactions (W/Ti = 12/50- 12/500) are composed of anatase nanoparticles of 2-6 nm by XRD, TEM and Raman and show the Type I adsorption characteristics. The surface area linearly increases with the titanium content from 131 m2/g for W/ Ti = 12/50 to 228 m2/g for 12/500. The precipitate from the reaction with the intermediate composition W/Ti = 12/20 is composed of anatase nanoparticles and does not have any pore accessible to N2. With the wide variety of the physical properties of the precipitates, the present method can be a novel, viable means to tailor synthesis of nanocomposite materials. A formation mechanism of the precipitates is based on the electrostatic interactions between the titania nanoparticles and phosphotungstate ions.

• Natural Product Sciences
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• v.16 no.3
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• pp.169-174
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• 2010

The seed of Phaseolus calcaratus Roxburgh (PHCR) is traditionally used for anti-pyretic and antiinflammatory effects. Although these effects are believed to be related to its antioxidant potential, little information is available for the mechanisms by which PHCR seed might scavenge free radicals or otherwise act as an antioxidant. In the present study, we purified some fractions from the ethanol extract of PHCR seed and evaluated each fraction's ability to scavenge free radicals generated by cell-free systems. We also identified active compound that is putatively responsible for free radical scavenging by analyzing NMR spectra. PHCR samples exhibited a concentration-dependent radical scavenging activity against hydroxyl radicals, superoxide anions, and DPPH radicals. Of the samples tested, a methanol-eluted sub-fraction from the PHCR extract, named $FF_4$, scavenged these radicals more effectively than the other fractions. We identified catechin-7-O-$\beta$-Dglucopyranoside as the active compound responsible for free radical scavenging potential of $FF_4$.

• Parasites, Hosts and Diseases
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• v.57 no.3
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• pp.319-324
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• 2019

This study aimed to investigate the tick species and give background for tick-borne investigations in Korea. Ticks were collected from the area within 2 km radius of the 4 domestic animal farms, where they were located in mountainous areas and raising animals on pasture, and from animal bodies in 2014 and 2015. In total, 7,973 nymphal and adult ticks were collected from the farms - 7,758 Haemaphysalis longicornis, 198 Haemaphysalis flava, and 17 Ixodes nipponensis, and 1,763 were collected from animals - 729 H. longicornis from cattle; 569 H. longicornis from goats; and 297 H. longicornis, 118 H. flava, 1 I. nipponensis, and 49 Amblyomma testudinarium from wild boars. As more species of ticks were collected from wild boars than domesticated animals and their habitats, various animal hosts should be considered while investigating tick species.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.122-128
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• 2023

The present study was conducted to analyze agronomic characteristics of 8 ecotypes of Arundinella hirta (A. hirta) and the correlation among them. Changes in phenotypic characteristics of 8 ecotypes were measured at equal intervals of time from May to September. Among ecotypes, Jangsoo-1 has the highest plant height (172.33 cm), number of leaves (9.00) and leaf length (55 cm) while the ecotype Youngduk has the highest leaf width (1.57 cm), fresh mass (26.63 g), dry mass (7.06 g), number of spikelets per spike (53.33), amount of seeds per spike (0.74 g) and amount of seeds per 10 spikes (7.23 g). The ecotype Jinju-1 has the shortest plant height (119 cm) and leaf number (6.33), while Okgye-2 has shortest leaf length (30.67 cm), leaf width (0.93 cm), fresh mass (12.60 g), dry mass (3.30 g), spike length (30.33 cm), spikelet per spike (39.67), amount of seeds per spike (0.61 g) and amount of seeds per 10 spikes (6.00 g). Correlation coefficients were estimated among the studied agronomic characteristics which showed positive and significant association with each other. In the present study, the agronomic data collected would be useful to understand the potential of A. hirta as a forage resource and helpful in selecting the high-yielding genetic resource for future forage improvement.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.56-61
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• 2003

The purpose of the present study was to screen the effective of lactic acid bacteria (LAB), as probiotics which are able to protect bacterial fish diseases and investigate their characteristics. Twenty strains of lactic acid bacteria were isolated from fish intestine. fermented fish foods and kimchis. These bacteria were screened for antagonistic activity against fish pathogenic bacteria. Seven tested LAB strains were able to inhibit the fish pathogenic bacteria, including Vibrio anguillarum, Edwardsiella tarda and Streptococcus sp. Of the probiotic candidates, BK19 strain which from fermented pollack viscera indicated the largest inhibition activity. This particular probiotic bacteria was identified and named as Lactobacillus sakei BK19. In the scanning electron microscope observation, L. sakei BK19 supernatant treated V.anguillarum cell wall had been destroyed incubate after 3 hr.

• Journal of Veterinary Clinics
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• v.25 no.4
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• pp.292-294
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• 2008

The purpose of this study was to evaluate the cause of lens luxation and to determine the frequency of vision loss, glaucoma, cataract, and corneal edema before and after intracapsular lens extraction (ICLE). The medical records of 8 dogs underwent ICLE for the correction of anterior lens luxation at the Veterinary Medical Teaching Hospital of Seoul National University from August 2005 to September 2007 were reviewed. The most frequently affected breed was Miniature Poodle (n = 3). The mean age was $10.8{\pm}2.1$ years. Preoperatively, 5 eyes (67.5%) with anterior luxation had secondary glaucoma, 7 eyes (87.5%) had vision loss, and all eyes (100.0%) had corneal edema. Four weeks after ICLE, 6 eyes (75.0%) had normal intraocular pressure (IOP), and 4 eyes (50.0%) regained vision. Corneal edema was reduced after ICLE in all eyes, but still remained in 4 eyes. It was considered that ICLE was beneficial in the management of anterior lens luxation, but the eyes without glaucoma before ICLE had more favorable prognosis than eyes with.

• Korean Journal of Veterinary Research
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• v.51 no.1
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• pp.7-14
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• 2011

This study was focused on the genotyping and quantification of Porcine circovirus type 2 (PCV2) in thirty PCV2-positive pigs with different clinical symptoms (PCV2-infected without wasting, PCV2-infected with wasting, PCV2-infected with wasting and lymphoid depletion). The quantity of PCV2 DNA in diverse tissues was significantly differed among these groups. (One-way ANOVA test, p<0.001) Interestingly, PCV2-DNA load in tissues of PCV2-infected pigs without wasting and PCV2-infected pigs with wasting and lymphoid depletion were not significantly differed (p = 0.38), while they were all significantly higher when compared with PCV2-infected pigs with wasting-only. PCV2 DNA quantity in tissues was significantly higher in PCV2a and 2b co-infected pigs compared to the PCV2b only-infected pigs (Wilcoxon test, p = 0.039). The PCV2a and 2b co-infected pigs had increased wasting and lymphoid depletion rate but it was not statistically significant. Therefore, this cross-sectional study suggested that PCV2 DNA load in tissues was diverse by clinical and histological findings. Furthermore, co-infection of PCV2a and 2b affected to the PCV2 DNA load in tissues with increased rate of wasting and lymphoid depletion.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.1
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• pp.25-28
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• 2003

Ion channel inhibitors are widely used for pharmacological discrimination between the different channel types as well as for determination of their functional role. In the present study, we tested the hypothesis that 4-aminopyridine (4-AP) could affect the large conductance $Ca^{2+}$-activated $K^+$ channel ($BK_{Ca}$) currents using perforated-patch or cell-attached configuration of patch-clamp technique in the rabbit pulmonary arterial smooth muscle. Application of 4-AP reversibly inhibited the spontaneous transient outward currents (STOCs). The reversal potential and the sensitivity to charybdotoxin indicated that the STOCs were due to the activation of $BK_{Ca}$. The $BK_{Ca}$ currents were recorded in single channel resolution under the cell-attached mode of patch-clamp technique for minimal perturbation of intracellular environment. Application of 4-AP also inhibited the single $BK_{Ca}$ currents reversibly and dose-dependently. The membrane potential of rabbit pulmonary arterial smooth muscle cells showed spontaneous transient hyperpolarizations (STHPs), presumably due to the STOC activities, which was also inhibited by 4-AP. These results suggest that 4-AP can inhibit $BK_{Ca}$ currentsin the intact rabbit vascular smooth muscle. The use of 4-AP as a selective voltage-dependent $K^+$ (KV) channel blocker in vascular smooth muscle, therefore, must be reevaluated.

• The Journal of the Korean dental association
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• v.55 no.7
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• pp.457-466
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• 2017

In the case of failed fixed implant prosthesis accompanied by abutment screw fracture, fractured screw fragment must be removed to use the existing implant fixtures. A 61-year-old male patient, who had a failed maxillary fixed implant prosthesis accompanied by three abutment screw fracture, hoped to reconstruct the maxillary implant prosthesis, while maintaining the existing implant fixtures. To use the existing implant fixtures, fractured screw fragments were removed. A maxillary implant overdenture using available existing implants was planned. Bar-attachment with Locator was used for implant splinting, denture stability, and retention. Final impression was taken after treatment of peri-implantitis. Jaw relation registration was taken to evaluate available interarch space for bar-attachment. After fabricating bar-attachment, centric relation was taken. Implant overdenture using bar-attachment with Locator was delivered after wax-denture evaluation. This case report showed that a satisfactory clinical result was achieved by implant overdenture using existing implant fixtures in a maxillary edentulous patient.

• Journal of Microbiology and Biotechnology
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• v.31 no.6
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• pp.833-839
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• 2021

Bacillus subtilis CH3-5 isolated from cheonggukjang secretes a 28 kDa protease with a strong fibrinolytic activity. Its gene, aprE3-5, was cloned and expressed in a heterologous host (Jeong et al., 2007). In this study, the promoter of aprE3-5 was replaced with other stronger promoters (P_cry3A, P₁₀, P_SG1, P_srfA) of Bacillus spp. using PCR. The constructed chimeric genes were cloned into pHY300PLK vector, and then introduced into B. subtilis WB600. The P10 promoter conferred the highest fibrinolytic activity, i.e., 1.7-fold higher than that conferred by the original promoter. Overproduction of the 28 kDa protease was confirmed using SDS-PAGE and fibrin zymography. RT-qPCR analysis showed that aprE3-5 expression was 2.0-fold higher with the P10 promoter than with the original promoter. Change of the initiation codon from GTG to ATG further increased the fibrinolytic activity. The highest aprE3-5 expression was observed when two copies of the P₁₀ promoter were placed in tandem upstream of the ATG initiation codon. The construct with P10 promoter and ATG and the construct with two copies of P10 promoter in tandem and ATG exhibited 117% and 148% higher fibrinolytic activity, respectively, than that exhibited by the construct containing P10 promoter and GTG. These results confirmed that significant overproduction of a fibrinolytic enzyme can be achieved by suitable promoter modification, and this approach may have applications in the industrial production of AprE3-5 and related fibrinolytic enzymes.