• Journal of Biomedical Engineering Research
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• v.33 no.2
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• pp.72-77
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• 2012

Phase Contrast MR Angiography(PC MRA) is excellent MRA technique for measuring the velocity of vessels in the human body. PC MRA need to at least four images for angiogram reconstruction and it caused longer scan time. Therefore, we used keyhole imaging combined PC MRA to reduce the scan time. However, keyhole imaging can lead the erroneous effects as loss of phase information or frequency discontinuous. In this study, we applied the keyhole imaging combined 2D PC MRA for improving the temporal resolution and also measured the velocity to evaluate the accuracy of phase information. We used 0.32T MRI scanner(Magfinder II, Scimedix, Korea). Using the 2D PC MRA pulse sequence, the vascular images for a human brain targeted on the Superior Sagittal Sinus(SSS) were obtained. We applied tukey window function for keyhole images to minimize the ringing artifact and erroneous factors that are induced frequency discontinuous and phase information loss. We also applied zero-padded algorithm to peripheral missing k-space lines to compare keyhole imaging results and the artifact power(AP) value was measured on the complex difference images to validate the image quality. Consider as based on our results, heavy image distortions and artifacts were shown until using at least 50% keyhole factor. Using above the 50% keyhole factors are shown well reconstructed and matched for magnitude images and velocity information measurements. In conclusion, we confirmed the image quality and velocity information of keyhole technique combined 2D PC MRA. Especially, measured velocity information through the keyhole imaging combination was similar to the velocity information of full sampled k-space image despite of frequency discontinuous and phase information loss in the keyhole imaging reconstruction process. Consequently, the keyhole imaging combined 2D PC MRA will give some clinical usefulness and advantages as improving the temporal resolution and measuring the velocity information via selecting the appropriate keyhole factor at low tesla MRI system.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.2
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• pp.266-274
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• 2013

The effect of different phytogenic feed additives on reducing odorous compounds in swine was investigated using in vitro fermentation and analyzed their microbial communities. Soybean meal (1%) added with 0.1% different phytogenic feed additives (FA) were in vitro fermented using swine fecal slurries and anaerobically incubated for 12 and 24 h. The phytogenic FAs used were red ginseng barn powder (Panax ginseng C. A. Meyer, FA1), persimmon leaf powder (Diospyros virginiana L., FA2), ginkgo leaf powder (Ginkgo biloba L., FA3), and oregano lippia seed oil extract (Lippia graveolens Kunth, OL, FA4). Total gas production, pH, ammonianitrogen ($NH_3$-N), hydrogen sulfide ($H_2S$), nitrite-nitrogen ($NO_2{^-}$-N), nitrate-nitrogen ($NO_3{^-}$-N), sulfate (${SO_4}^{--}$), volatile fatty acids (VFA) and other metabolites concentration were determined. Microbial communities were also analyzed using 16S rRNA DGGE. Results showed that the pH values on all treatments increased as incubation time became longer except for FA4 where it decreased. Moreover, FA4 incubated for 12 and 24 h was not detected in $NH_3$-N and $H_2S$. Addition of FAs decreased (p<0.05) propionate production but increased (p<0.05) the total VFA production. Ten 16S rRNA DGGE bands were identified which ranged from 96 to 100% identity which were mostly isolated from the intestine. Similarity index showed three clearly different clusters: I (FA2 and FA3), II (Con and FA1), and III (FA4). Dominant bands which were identified closest to Eubacterium limosum (ATCC 8486T), Uncultured bacterium clone PF6641 and Streptococcus lutetiensis (CIP 106849T) were present only in the FA4 treatment group and were not found in other groups. FA4 had a different bacterial diversity compared to control and other treatments and thus explains having lowest odorous compounds. Addition of FA4 to an enriched protein feed source for growing swine may effectively reduce odorous compounds which are typically associated with swine production.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.375-384
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• 2011

Purpose: The advent of microsurgical technique and instruments, particularly in the field of perforator flap and supermicrosurgery, which have expanded the scope of microsurgery. However, supermicroanastomosis without any compression, tension, or distortions must be achieved to reach successful outcomes. Small-caliber vessels, such as those with an internal diameter less than 0.2 mm, are susceptible to inadvertent twisting of the anastomosis. In this study, using the superficial inferior epigastric artery (SIEA)-based flap model in Sprague-Dawley (SD) rats, we evaluated the acceptable limits of twisting effects on supermicroanastomotic sites. Methods: A total of 20 supermicroanastomoses were performed using the SIEA-based flap model in 10 male SD rats, 10-weeks-of-age, weighing 300~350 g. Rats were divided into five groups of two with four flaps as follows: 1) sham, 2) control group with end to end SIEA arterial supermicroanastomosis, 3) experimental I (EA1) with $90^{\circ}$ twisting, 4) experimental II (EA2) with $180^{\circ}$ twisting, and 5) experimental III (EA3) with $270^{\circ}$ twisting of the supermicroanastomosis. Each SIEA was anastomosed using six 11-0 $Ethilon^{(R)}$ (Ethicon Inc. Co., NJ, USA) stitches except in the sham group where the SIEA was only clamped with Supermicro vascular $clamps^{(R)}$ (S&T, Neuhausen, Switzerland) for 20 minutes. Results: The anastomosed arterial patency showed no remarkable changes according to doppler waveforms measured with a Smardop 45 Doppler System (Hadeco Inc., Kawasaki, Japan). The pulsatility index (PI) was increased at postoperative day 10 in the EA2 and EA3 groups, and the resistance index (RI) showed no statistically significant difference between preoperative and postoperative values at 10 days. Histologic specimens from the EA3 group showed increased tunica media necrosis, convolution of the internal elastic lamina, densely packed platelets, fibrin, and erythrocytes. Flap viability and anastomosed vessel patency were not significantly affected by the degree of arterial twisting in this study, other than in the EA3 group where minor effects on arterial patency of the microanastomoses were encountered. Conclusion: It appears that minor twisting on small caliber arteries, used in supermicroanastomoses, can be tolerated. However, twisting should be avoided as much as possible, and more than $180^{\circ}$ twisting must be prevented in clinical practice.

• Journal of Life Science
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• v.23 no.6
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• pp.804-811
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• 2013

Melanopsin is an opsin-like photopigment found in the small proportion of photosensitive ganglion cells of the retina. It is involved in the regulation of the synchronization of the circadian cycle as well as in the control of pupillary light reflex. The purpose of the present study is to investigate whether melanopsin is also expressed in the other areas of the central visual system outside the retina. We have studied the distribution and morphology of neurons containing melanopsin in the mouse visual cortex with antibody immunocytochemistry. Melanopsin immunoreactivity was mostly present in neuronal soma, but not in nuclei. We found that melanopsin was present in a large subset of neurons within the adult mouse visual cortex with the highest density in layer II/III. In layer I of the visual cortex, melanopsin-immunoreactive (IR) neurons were rarely encountered. In the mouse visual cortex, the majority of the melanopsin-IR neurons consisted of round/oval cells, but was varied in morphology. Vertical fusiform and pyramidal cells were also rarely labeled with the anti-melanopsin antibody. The labeled cells did not show any distinctive distributional pattern. Some melanopsin-IR neurons in mouse visual cortex co-localized with nitricoxide synthase, calbindin and parvalbumin. Our data indicate that melanopsin is located in specific neurons and surprisingly widespread in visual cortex. This finding raises the need of the functional study of melanopsin in central visual areas outside the retina.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.417-417
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• 2016

Global environmental deterioration has become more serious year by year and thus scientific interests in the renewable energy as environmental technology and replacement of fossil fuels have grown exponentially. Photoelectrochemical (PEC) cell consisting of semiconductor photoelectrodes that can harvest light and use this energy directly to split water, also known as photoelectrolysis or solar water splitting, is a promising renewable energy technology to produce hydrogen for uses in the future hydrogen economy. A major advantage of PEC systems is that they involve relatively simple processes steps as compared to many other H2 production systems. Until now, a number of materials including TiO2, WO3, Fe2O3, and BiVO4 were exploited as the photoelectrode. However, the PEC performance of these single absorber materials is limited due to their large charge recombinations in bulk, interface and surface, leading low charge separation/transport efficiencies. Recently, coupling of two materials, e.g., BiVO4/WO3, Fe2O3/WO3 and CuWO4/WO3, to form a type II heterojunction has been demonstrated to be a viable means to improve the PEC performance by enhancing the charge separation and transport efficiencies. In this study, we have prepared a triple-layer heterojunction BiVO4/WO3/SnO2 photoelectrode that shows a comparable PEC performance with previously reported best-performing nanostructured BiVO4/WO3 heterojunction photoelectrode via a facile solution method. Interestingly, we found that the incorporation of SnO2 nanoparticles layer in between WO3 and FTO largely promotes electron transport and thus minimizes interfacial recombination. The impact of the SnO2 interfacial layer was investigated in detail by TEM, hall measurement and electrochemical impedance spectroscopy (EIS) techniques. In addition, our planar-structured triple-layer photoelectrode shows a relatively high transmittance due to its low thickness (~300 nm), which benefits to couple with a solar cell to form a tandem PEC device. The overall PEC performance, especially the photocurrent onset potential (Vonset), were further improved by a reactive-ion etching (RIE) surface etching and electrocatalyst (CoOx) deposition.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.1751-1758
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• 2015

There has been a strong, positive correlation between opisthorchiasis-associated cholangiocarcinoma and infection with Helicobacter. Here a rodent model of human infection with Opisthorchis viverrini was utilized to further investigate relationships of apparent co-infections with O. viverrini and H. pylori. A total of 150 hamsters were assigned to five groups: i) Control hamsters not infected with O. viverrini; ii) O. viverrini-infected hamsters; iii) non-O. viverrini infected hamsters treated with antibiotics (ABx); iv) O. viverrini-infected hamsters treated with ABx; and v) O. viverrini-infected hamsters treated both with ABx and praziquantel (PZQ). Stomach, gallbladder, liver, colonic tissue, colorectal feces and O. viverrini worms were collected and the presence of species of Helicobacter determined by PCR-based approaches. In addition, O. viverrini worms were cultured in vitro with and without ABx for four weeks, after which the presence of Helicobacter spp. was determined. In situ localization of H. pylori and Helicobacter-like species was performed using a combination of histochemistry and immunohistochemistry. The prevalence of H. pylori infection in O. viverrini-infected hamsters was significantly higher than that of O. viverrini-uninfected hamsters ($p{\leq}0.001$). Interestingly, O. viverrini-infected hamsters treated with ABx and PZQ (to remove the flukes) had a significantly lower frequency of H. pylori than either O. viverr-iniinfected hamsters treated only with ABx or O. viverrini-infected hamsters, respectively ($p{\leq}0.001$). Quantitative RT-PCR strongly confirmed the correlation between intensity H. pylori infection and the presence of liver fluke infection. In vitro, H. pylori could be detected in the O. viverrini worms cultured with ABx over four weeks. In situ localization revealed H. pylori and other Helicobacter-like bacteria in worm gut. The findings indicate that the liver fluke O. viverrini in the biliary tree of the hamsters harbors H. pylori and Helicobacter-like bacteria. Accordingly, the association between O. viverrini and H. pylori may be an obligatory mutualism.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.421-431
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• 2002

C-shaped canal configuration is very difficult to treat because that clues about preoperative canal anatomy cannot be ascertained from clinical crown morphology and limited information can be derived from radiographic examination. This study was done to get more informations about the root and canal configuration of C-shape root by 3-dimensionally reconstructing for the purpose of enhancing success rate of endodontic treatment. 30 mandibular molars with C-shaped root were selected. Six photo images from occlusal, apical, mesial, distal, buccal, lingual directions and radiographic view were taken as preoperative ones to compare them with 3-D image. After crown reduction to the level of 1-2mm over pulpal floor was performed, teeth were stored in 5.25% sodium hypochlorite solution for the removal of pulp tissue and debris. They were cleaned under running water, allowed to bench dry and embedded in a self-curing resin. This resin block was serially ground with a microtome (Accutom-50, Struers, Denmark) and the image of each level was recorded by digital camera (FinePix S1-pro, Fuji Co., Japan). The thickness of each section was 0.25mm. Photographs of serial sections through all root canal were digitized using Adobe Photoshop 5.0 and then minimum thickness of open and closed sites were measured (open site is the surface containing occluso-apical groove closed site is oppsite). After dizitization using 3-D Doctor (Able software Corp, USA). 3D reconstruction of the outer surface of tooth and the inner surface of pulp space was made. Canal classsification of C-shaped roots was performed from this 3-D reconstructed image. The results were as follows : 1. Most C-shape rooted teeth showed lingual groove (28/30). 2 According to Vertuccis' calssification, type I, II, III, IV, VII were observed. but also new canal types suck as 2-3-2, 1-2-3-2. 2-3-2-1, 2-3-2-3 were shown. 3 There was little difference in minimum thickness on coronal and apical portions, but open site were thinner than closed site on mid portion. Conclusively, 3D reconstruction method could make the exact configurations of C-shape root possible to be visualized and analyzed from multi-directions. Data from minimum thickness recommend cleaning and shaping be more carefully done on dangerous mid portion.

• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.275-280
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• 2008

One of the limitation for Agrobacterium-mediated transformation via organogenesis from cotyledon explants routinely in cucumber is the production of chimeric plants. To overcome the limitation, Agrobacterium-mediated transformation system via somatic embryogenesis from hypocotyl explants of cucumber (c.v., Eunsung) on the selection medium with paromomycin as antibiotics was developed. The hypocotyl explants were inoculated with Agrobacterium tumefaciens strain EHA101 carrying binary vector pPTN290; then were subsequently cultured on the following media: co-cultivation medium for 2 days, selection medium for $5{\times}14$ days, and regeneration medium. The T-DNA of the vector (pPTN290) carried two cassettes, Ubi promoter-gus gene as reporter and 35S promoter-nptll gene conferring resistance to paromomycin as selectable agent. The confirmation of stable transformation and the efficiency of transformation was based on the resistance to paromomycin indicated by the growth of putative transgenic calli on selection medium amended with 100mg/L paromomycin, and GUS gene expression. Forty eight clones (5.2%) with GUS gene expressed of 56 callus clones with resistance to paromomycin were independently obtained from 928 explants inoculated. Of 48 clones, transgenic plants were only regenerated from 5 clones (0.5%) at low frequency. The histochemical GUS assay in the transgenic seeds ($T_1$) also revealed that the gus gene was successfully integrated and segregated into each genome of transgenic cucumber.

• Journal of Life Science
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• v.18 no.7
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• pp.940-946
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• 2008

Neurotransmitter transporters, which remove neurotransmittesr from the synaptic cleft, are regulated by second messenger such as protein kinases and binding proteins. Neuronal ${\gamma}-aminobutyric$ acid transporters (GATs) are responsible for removing the inhibitory neurotransmitter ${\gamma}-aminobutyric$ acid (GABA) from the synaptic cleft. ${\gamma}-aminobutyric$ acid transporters 2 (GAT2/BGT1) is involved in regulating neurotransmitter recycling, but the mechanism how they are stabilized and regulated by the specific binding protein has not yet been elucidated. Here, we used the yeast two-hybrid system to identify the specific binding protein(s) that interacts with the C-terminal region of GAT2 and found a specific interaction with the mammalian LIN-7b (MALS-2). MALS-2 protein bound to the tail region of GAT2 but not to other GAT members in the yeast two-hybrid assay. The "T-X-L" motif at the C-terminal end of GAT2 is essential for interaction with MALS-2. In addition, this protein showed specific interactions in the glutathione S-transferase (GST) pull-down assay. An antibody to GAT2 specifically co-immunoprecipitated MALS associated with GAT2 from mouse brain extracts. These results suggest that MALS may stabilize GAT2 in brain.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.554-563
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• 1999

For the purpose of elucidating the polymerization modes of dual-cure restorative materials and comparing them with single-cure restorative materials, a study was performed on the light-cured composite resin, dual-cure composite resin, dual-cure glass ionomer cement and chemical-cure glass ionomer cement. By measuring the microhardness of each material at 0mm, 1mm and 3mm depth during initial 24 hours with predetermined interval, the state of polymerization and degree of conversion was indirectly evaluated for each material, and obtained results are as follows : 1. All of four materials tested showed significant increase in microhardness after 24hrs compared with just after curing starts. 2. In all materials except Ketac-fil, there showed a significant difference in microhardness between each depth at each time interval. 3. In the test of lap time till final curing for each material, the polymerization process was revealed to last longer in the dual-cure type materials than in single-cure type materials at 3mm depth. Based on the results above, it was demonstrated with materials of dual-cure mode that the degree of conversion increases by successive curing reactions even in the deeper layers where sufficient curing light is impermeable.