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Gwangyang, South Korea

Baik K.S.,Sunchon National University | Choe H.N.,Sunchon National University | Park S.C.,Sunchon National University | Hwang Y.M.,Sunchon National University | And 3 more authors.
International Journal of Systematic and Evolutionary Microbiology | Year: 2013

Two yellow-pigmented, Gram-reaction-negative strains, designated 01SU5-PT and 03SU3-PT, were isolated from the freshwater of Woopo wetland, Republic of Korea. Both strains were aerobic, non-motile and catalase-negative. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates belong to the genus Sphingopyxis, showing the highest level of sequence similarity with respect to Sphingopyxis witflariensis W-50T (95.4-95.7%). The two novel isolates shared 99.4% sequence similarity. DNA-DNA hybridization between the isolates and the type strain of S. witflariensis clearly suggested that strains 01SU5-PT and 03SU3-PT represent two separate novel species in the genus Sphingopyxis. The two strains displayed different fingerprints after PCR analysis using the repetitive primers BOX, ERIC and REP. Several phenotypic characteristics served to differentiate these two isolates from recognized members of the genus Sphingopyxis. The data from the polyphasic study presented here indicated that strains 01SU5-PT and 03SU3-PT should be classified as representing novel species in the genus Sphingopyxis, for which the names Sphingopyxis rigui sp. nov. and Sphingopyxis wooponensis sp. nov., respectively, are proposed. The type strain of Sphingopyxis rigui sp. nov. is 01SU5-PT (=KCTC 23326T=JCM 17509T) Printed in Great Britain. Source


Kim J.,Chonnam National University | Lee C.M.,Chonnam National University | Kim D.-W.,Gwangyang Health College | Lee K.-Y.,Chonnam National University
Polymer (Korea) | Year: 2013

The purpose of this study was to develop an aloin-loaded wound dressing with an enhanced healing effect. The cross-linked hydrogel films were prepared with polyvinyl alcohol) (PVA) and carboxyl methyl cellulose (CMC) using a freeze-thawing (F-T) method. Their gel properties, release of drug, in vivo wound healing effect and histopathology were then evaluated. In the wound healing test, this aloin loaded PVA/CMC hydrogel showed faster healing of the wound made in rat dorsum than the aloin carbomer 934 gel or the control (carbomer 934 gel) due to phytochemical activity of aloin and moisture of CMC. In conclusion, the aloin-loaded wound dressing composed of 5% PVA, 5% CMC and 0.125% aloin is a potential wound dressing with enhanced wound healing effect. Source


Kim J.,Chonnam National University | Bea S.K.,Chonnam National University | Bea S.K.,SION BSK Co. | Kim Y.H.,Chonnam National University | And 4 more authors.
Biotechnology and Bioprocess Engineering | Year: 2015

We prepared and characterized calcium carbonate nanoparticles (CC NPs) that were surface-modified with oleic acid (OA) and phosphatidylcholine (PC) in order to improve their suspension stability in an aqueous solution. The improvement in the suspension stability of CC NPs in an aqueous solution may be helpful to extend their applicability to a wider range of biological applications. The CC NPs were coated with OA by making use of their electrostatic potential and were then decorated with PC. The CC NPs surface-modified with OA and PC were successfully constructed, and the existence of the decorated OA and PC in the surface of the PC-OA-CC NPs was observed via transmission electron microscopy (TEM) and was confirmed by thermo gravimetric analysis (TGA), Xray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) analyses. The PC-OA-CC NPs floating in an aqueous solution exhibited better stability when compared to non-surface-modified CC NPs. The DLS and TEM results revealed that the degree of size agglomeration for the CC NPs was significantly reduced by the surface modification with OA and PC. The PC-OA-CC NPs showed a very low cytotoxicity at a high concentration in terms of the cell viability of the RAW264.7 cells. Consequentially, the stability in suspension of the CC NPs in an aqueous solution could be effectively improved through surface-modification with OA and PC. PC-OACC NPs could be useful in increasing the range biological applications for CC NPs. © 2015, The Korean Society for Biotechnology and Bioengineering and Springer-Verlag Berlin Heidelberg. Source


Joo K.-J.,Gwangju University | Shin J.-W.,Gwangju University | Shin J.-W.,Chonbuk National University | Dong K.-R.,Gwangju University | And 5 more authors.
Journal of the Korean Physical Society | Year: 2013

Reducing the exposure dose from a periapical X-ray machine is an important aim in dental radiography. Although the radiation exposure dose is generally low, any radiation exposure is harmful to the human body. Therefore, this study developed a method that reduces the exposure dose significantly compared to that encountered in a normal procedure, but still produces an image with a similar resolution. The correlation between the image resolution and the exposure dose of the proposed method was examined with increasing distance between the dosimeter and the X-ray tube. The results were compared with those obtained from the existing radiography method. When periapical radiography was performed once according to the recommendations of the International Commission on Radiological Protection (ICRP), the measured skin surface dose was low at 7 mGy or below. In contrast, the skin surface dose measured using the proposed method was only 1.57 mGy, showing a five-fold reduction. These results suggest that further decreases in dose might be achieved using the proposed method. © 2013 The Korean Physical Society. Source


Kim C.-B.,Gwangju University | Dong K.-R.,Gwangju University | Dong K.-R.,Dongshin University | Gho H.-J.,Chosun University | And 4 more authors.
Journal of the Korean Physical Society | Year: 2013

This study examined the changes in the center frequency according to the fat content the using a self-manufactured phantom. In addition, the change in the fat saturation image according to when the center frequency was applied automatically or adjusted manually was analyzed to determine the importance of a manual adjustment of the center frequency. Distilled water and animal fat were solidified in a 10-ml syringe to manufacture nine phantoms for each condition (18 in total). A MR scanner at 1.5 Tesla was used to obtain a T1-weighted three dimensional fast low-angle shot (T1 3D FLASH) dynamic fat saturation image according to the spectral attenuated inversion recovery(SPAIR) method. The images obtained were classified into the following before analyzing the center frequencies for each image: Test A (image where fat was not saturated), Test B (image where fat was saturated in an automatic adjustment of the center frequency), and Test C (image where fat was saturated in a manual adjustment of the center frequency). The signal intensity (SI) values of water, fat and background were measured to calculate the signal to noise ratio (SNR) before examining the difference in the SNRs of water and fat (SNR difference = water SNR - fat SNR). The mean center frequency in Tests A, B and C was 63.631179 MHz when the fat content was 70% or lower. The mean center frequency for Tests A and B was 63.631002 MHz when the fat content was 80% or higher, which was 226 Hz lower than that for Test C (63.631228 MHz). The water SIs of Tests A, B and C with increasing fat content showed a pattern of change similar to that of the fat SIs of Tests A and C. On the other hand, the fat SI of Test B was similar to that of Test A when the fat content was 80%, which showed a large difference in change. The water SNRs of Tests A, B and C, and the fat SNR and SNR differences of Tests A and C showed similar changes according to the fat content. The difference between the fat SNR and the SNR of Test B was similar to that of Test A when the fat content was 80%. © 2013 The Korean Physical Society. Source

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