• Restorative Dentistry and Endodontics
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• v.38 no.4
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• pp.234-240
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• 2013

Objectives: This study evaluated the effects of intraradicular moisture on the pushout bond strength of a fibre post luted with several self-adhesive resin cements. Materials and Methods: Endodontically treated root canals were treated with one of three luting cements: (1) RelyX U100, (2) Clearfil SA, and (3) G-Cem. Roots were then divided into four subgroups according to the moisture condition tested: (I) dry: excess water removed with paper points followed by dehydration with 95% ethanol, (II) normal moisture: canals blot-dried with paper points until appearing dry, (III) moist: canals dried by low vacuum using a Luer adapter, and (IV) wet: canals remained totally flooded. Two 1-mm-thick slices were obtained from each root sample and bond strength was measured using a push-out test setup. The data were analysed using a two-way analysis of variance and the Bonferroni post hoc test with p = 0.05. Results: Statistical analysis demonstrated that moisture levels had a significant effect on the bond strength of luting cements (p < 0.05), with the exception of G-Cem. RelyX U100 displayed the highest bond strength under moist conditions (III). Clearfil SA had the highest bond strength under normal moisture conditions (II). Statistical ranking of bond strength values was as follows: RelyX U100 > Clearfil SA > G-Cem. Conclusions: The degree of residual moisture significantly affected the adhesion of luting cements to radicular dentine.

• Journal of KIISE:Software and Applications
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• v.28 no.12
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• pp.910-920
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• 2001

We developed a SIFC(Slice-based Information Flow Graph) For modeling the information flow on program on the basis of the information flow of a data tokens on program slices. Then we defined a SCM(Slice-based Complexity Measure) for measuring the program complexity by measuring the complexity of information flow on SIFG, We showed that, according to Zuse's approach, it assumed ordinal scale based on atomic modifications on SIFG and that it was additive to binary operation MBSEQ and that it was not additive to binary operation MBALT but satisfied Weyuker's 9th axiom. Also based on comparison with the existing measures, we showed that SCM could measure not only the control and data flow in program but also the physical size of program.

• Journal of Ginseng Research
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• v.40 no.1
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• pp.55-61
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• 2016

Background: A number of neurological and neurodegenerative diseases share impaired cognition as a common symptom. Therefore, the development of clinically applicable therapies to enhance cognition has yielded significant interest. Previously, we have shown that activation of lysophosphatidic acid receptors (LPARs) via gintonin application potentiates synaptic transmission by the blockade of $K^+$ channels in the mature hippocampus. However, whether gintonin may exert any beneficial impact directly on cognition at the neural circuitry level and the behavioral level has not been investigated. Methods: In the current study, we took advantage of gintonin, a novel LPAR agonist, to investigate the effect of gintonin-mediated LPAR activation on cognitive performances. Hippocampus-dependent fear memory test, synaptic plasticity in the hippocampal brain slices, and quantitative analysis on synaptic plasticity-related proteins were used. Results: Daily oral administration of gintonin for 1 wk significantly improved fear memory retention in the contextual fear-conditioning test in mice.We also found that oral administration of gintonin for 1 wk increased the expression of learning and memory-related proteins such as phosphorylated cyclic adenosine monophosphate-response element binding (CREB) protein and brain-derived neurotrophic factor (BDNF). In addition, prolonged gintonin administration enhanced long-term potentiation in the hippocampus. Conclusion: Our observations suggest that the systemic gintonin administration could successfully improve contextual memory formation at the molecular and synaptic levels as well as the behavioral level. Therefore, oral administration of gintonin may serve as an effective noninvasive, nonsurgical method of enhancing cognitive functions.

• Journal of Acupuncture Research
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• v.18 no.2
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• pp.111-122
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• 2001

Objectives ; This study was undertaken to determine if Salviae Radix herb-acupuncture (SRA) exerts protective effect against alterations in membrane transport function in rabbits with mercury chloride (Hg)-induced acute renal failure. Methods and Results ; The administration of Hg at a subcutaneous single dose of 10mg/kg caused a reduction in GFR to 9.4% of the basal value and an increase in fractional Na+ excretion to 10-fold, indicating generation of acute renal failure. When animals were acupunctured with $0.5m{\ell}$ of SRA extract (0.1%) in both sides of Shinsu(BL23) for 7 days prod to Hg administration, such changes were significantly attenuated. The fractional excretion of glucose and phosphate was increased to approximately 132-fold and 7-fold, respectively, in rabbits treated with Hg alone, but the fractional excretion of glucose was increased to 26-fold and that of phosphate was not different from the basal value in SRA-pretreated rabbits. Uptakes of glucose and phosphate in purified isolated brush-border membrane and $Na^+-K^+$-ATPase activity in microsomal fraction were inhibited in rabbits treated with Hg alone, suggesting that impairment in proximal reabsorption of glucose and phosphate is resulted from a direct damage of membrane transport carriers and disruption of the normal $Na^+$ gradient. Conclusions ; Such changes were prevented by SRA. Uptakes of organic ions, PAH and TEA, in renal cortical slices were inhibited by the administration of Hg, which was prevented by SRA. Pretreatment of an antioxidant DPPD attenuated the increase in the fractional excretion of glucose and phosphate induced by the administration of Hg.

• International Journal of Oral Biology
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• v.38 no.3
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• pp.127-134
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• 2013

Xylitol is a sugar alcohol with a variety of functions including bactericidal and anticariogenic effects. However, the cellular mechanisms underlying the role of xylitol in bone metabolism are not yet clarified. In our present study, we exploited the physiological role of xylitol on osteoclast differentiation in a co-culture system of osteoblastic and RAW 264.7 cells. Xylitol treatment of these co-cultures reduced the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells induced by 10 nM $1{\alpha},25(OH)_2D_3$ in a dose-dependent manner. A cell viability test revealed no marked cellular damage by up to 100 mM of xylitol. Exposure of osteoblastic cells to xylitol decreased RANKL, but not OPG, mRNA expression in the presence of $10^{-8}M$ $1{\alpha},25(OH)_2D_3$ in a dose-dependent manner. Furthermore, bone resorption activity, assessed on bone slices in the coculture system, was found to be dramatically decreased with increasing xylitol concentrations. RANKL and OPG proteins were assayed by ELISA and the soluble RANKL (sRANKL) concentration was decreased with an increased xylitol concentration. In contrast, OPG was unaltered by any xylitol concentration in this assay. These results indicate that xylitol inhibits $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis by reducing the sRANKL/OPG expression ratio in osteoblastic cells.

• Imaging Science in Dentistry
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• v.40 no.4
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• pp.179-185
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• 2010

Purpose : Cortical bone thickness is one of the important factor in mini-implant stability. This study was performed to investigate the buccal cortical bone thickness at every interdental area as an aid in planning mini-implant placement. Materials and Methods : Two-dimensional slices at every interdental area were selected from the cone-beam computed tomography scans of 20 patients in third decade. Buccal cortical bone thickness was measured at 2, 4, and 6 mm levels from the alveolar crest in the interdental bones of posterior regions of both jaws using the plot profile function of $Ez3D2009^{TM}$ (Vatech, Yongin, Korea). The results were analyzed using by Mann-Whitney test. Results : Buccal cortical bone was thicker in the mandible than in the maxilla. The thickness increased with further distance from the alveolar crest in the maxilla and with coming from the posterior to anterior region in the mandible (p<0.01). The maximum CT value showed an increasing tendency with further distance from the alveolar crest and with coming from posterior to anterior region in both jaws. Conclusion : Interdental buccal cortical bone thickness varied in both jaws, however our study showed a distinct tendency. We expect that these results could be helpful for the selection and preparation of mini-implant sites.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1137.1-1141
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• 2001

Kochujang-gulbi, a traditional food in Chonnam province of Korea, was prepared with kochujang and dried gulbi slices. The crude lipid contents of kochujang and gulbi in the product were 3.08% and 15.6% at 0 day, respectively. After 7 days, the lipid contents were changed to 8.15% and 9.72%. The moisture content and VBN of kochujang and gulbi in the product were reached to the equilibrium after 7 days. In the kochujang-gulbi product, the TBARS value in gulbi was reduced because the lipid from gulbi permeated into kochujang, while the value in kochujang was increased. To prevent the growth of microorganisms and lipid oxidation from the kochujang-gulbi, 0.5% (w/v) garlic extract, citron essential oil, or ethanol was added to the product. The garlic extract and ethanol were very effective to inhibit the growth of mold and yeast at 2$0^{\circ}C$. The products treated with the garlic extract and citron oil were shown significantly lower microbial number than control for 30 days storage. The addition of citron oil to kochujang-gulbi showed lower TBARS value than other treatment.

• Journal of IKEEE
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• v.24 no.1
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• pp.52-58
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• 2020

This paper describes a hardware implementation of a true random number generator (TRNG) for information security applications. A new approach for TRNG design was proposed by adopting random transition rules in cellular automata and applying different transition rules at every time step. The TRNG circuit was implemented on Spartan-6 FPGA device, and its hardware operation generating random data with 100 MHz clock frequency was verified. For the random data of 2×10⁷ bits extracted from the TRNG circuit implemented in FPGA device, the randomness characteristics of the generated random data was evaluated by the NIST SP 800-22 test suite, and all of the fifteen test items were found to meet the criteria. The TRNG in this paper was implemented with 139 slices of Spartan-6 FPGA device, and it offers 600 Mbps of the true random number generation with 100 MHz clock frequency.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.111-111
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• 2002

Purpose： This study is to compare the distinct brain activation between implicit and explicit memory retrieval tasks using a non-invasive blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging(fMRI). Materials ＆ Methods： We studied seven right-handed, healthy volunteers aged 21-25 years(mean；22 years) were scanned under a 1.5T Signa Horizon Echospeed MR imager(GE Medical Systems, Milwaukee, U.S.A.). During the implicit and explicit memory retrieval tasks of previously teamed words under the conceptual processing, we acquired fMRI data using gradient-echo EPI with 50ms TE, 3000ms TR, 26cm${\times}$26cm field-of-view, 128${\times}$128 matrix, and ten slices(6mm slice thickness, 1 mm gap) parallel to the AC-PC(anterior commissure and posterior commissure) line. By using the program of statistical parametric mapping(SPM99), functional activation maps were reconstructed and quantified.

• Investigative Magnetic Resonance Imaging
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• v.20 no.4
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• pp.215-223
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• 2016

Purpose: The management of metal-induced field inhomogeneities is one of the major concerns of distortion-free magnetic resonance images near metallic implants. The recently proposed method called "Slice Encoding for Metal Artifact Correction (SEMAC)" is an effective spin echo pulse sequence of magnetic resonance imaging (MRI) near metallic implants. However, as SEMAC uses the noisy resolved data elements, SEMAC images can have a major problem for improving the signal-to-noise ratio (SNR) without compromising the correction of metal artifacts. To address that issue, this paper presents a novel reconstruction technique for providing an improvement of the SNR in SEMAC images without sacrificing the correction of metal artifacts. Materials and Methods: Low-rank approximation in each coil image is first performed to suppress the noise in the slice direction, because the signal is highly correlated between SEMAC-encoded slices. Secondly, SEMAC images are reconstructed by the best linear unbiased estimator (BLUE), also known as Gauss-Markov or weighted least squares. Noise levels and correlation in the receiver channels are considered for the sake of SNR optimization. To this end, since distorted excitation profiles are sparse, $l_1$ minimization performs well in recovering the sparse distorted excitation profiles and the sparse modeling of our approach offers excellent correction of metal-induced distortions. Results: Three images reconstructed using SEMAC, SEMAC with the conventional two-step noise reduction, and the proposed image denoising for metal MRI exploiting sparsity and low rank approximation algorithm were compared. The proposed algorithm outperformed two methods and produced 119% SNR better than SEMAC and 89% SNR better than SEMAC with the conventional two-step noise reduction. Conclusion: We successfully demonstrated that the proposed, novel algorithm for SEMAC, if compared with conventional de-noising methods, substantially improves SNR and reduces artifacts.