• The Bulletin of The Korean Astronomical Society
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• 제45권1호
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• pp.70.3-70.3
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• 2020

Previous numerical simulations on planet-disk interactions revealed a lot of interesting phenomena including the planetary migration and the formation of many sub-structures inside the disks. However, these simulations were limited to an isothermal or adiabatic equation of state which does not account for various heating and cooling processes in the disks. Recent studies showed that the behavior of the planet-disk interaction can be significantly influenced by the disk thermodynamics. We develop a radiative diffusion module based on the two-temperature flux-limited diffusion approximation accounting for viscous heating and the accretion feedback. In this presentation, we describe our radiative diffusion solver, present some test results, and discuss potential applications of the module to planet-disk interactions,

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.873-893
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• 1999

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue and repair of function. For more than a decade there have been many efforts to develop materials and bioactive molecule(such as growth factor and differentiation factors) to promote periodontal wound healing. Among the bioactive molecules, bone morphogenetic protein(BMP) was studied for periodontal wound healing. Since Urist demonstrated that demineralized bone matrix could induce the formation of cartilage and bone in ectopic site, many studies on BMP have been reported. Among those BMPs, it was reported that rhBMP-2 enhanced the healing of bone defects in animal studies and clinical studies. However, its efficacy in periodontal regeneration, especially 1-wall intrabony defects is still unknown. The purpose of this study was to examine the effect of rhBMP-2/ACS on the epithelial migration, gingival connective tissue adhesion, cementum formation, alveolar bone regeneration in intrabony defects of dogs. Four millimeter deep and four millimeter wide 1-wall defects were surgically created in the mesial aspects of the 3rd incisors. The test group received rhBMP-2/ACS with a flap procedure and the control underwent buffer/ACS with a flap procedure. Histologic analysis after 8 weeks of healing revealed the following results: 1. The length of epithelial growth(the distance from alveolar crest to the apical end of JE) was $0.9{\pm}1.5mm$ in the control group and $1.2{\pm}1.4mm$ in the test group. There was no statistically significant difference between the two groups. 2. The length of connective tissue adhesion was $2.4{\pm}1.3mm$ in the control group and $1.2{\pm}1.1mm$ in the test group. The control group showed significantly enhanced adhesion(P<0.05). 3. The length of new cementum was $0.9{\pm}1.0mm$ in the control group and $1.7{\pm}0.8mm$ in the test group. The test group showed significantly enhanced cementum regeneration(P<0.05). 4. The length of new bone height was $1.9{\pm}0.6mm$ in the control group and $2.4{\pm}0.9mm$ in the test group. There was no statistically significant difference between the two groups. 5. The new bone area was $4.7{\pm}1.7mm^2$ in the control group and $8.0{\pm}2.0mm^2$ in the test group. The test group showed significantly enhanced bone formed area(P<0.05). 6. The new bone density was $73.0{\pm}8.6%$ in the control group and $66.6{\pm}15.3%$ in the test group. There was no statistically significant difference between the two groups. These results suggest that the use of rhBMP-2 in 1-wall intrabony defects has significant effect on new cementum and new bone formation area, but doesn't have any significant effect on the prevention of junctional epithelium migration and new bone formation height.

• Physical Therapy Rehabilitation Science
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• 제5권4호
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• pp.193-197
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• 2016

Objective: In the present study, the effects of visual restriction and unstable base dual-task training (VUDT), stable base dual-task training (SDT), and on stroke patients' balance and concentration abilities were examined. Design: Two-group pretest-posttest design. Methods: Dual-task training was conducted for thirty persons with chronic stroke who were hospitalized or receiving physical therapy and were randomly assigned to either the VUDT group (n=15) or the SDT group (n=15). The subjects were divided into two groups of 15 participants each, the VUDT group and the SDT group. Dual-task training was administered for 30 minutes per session, three times a week for 8 weeks. The participants' balance was measured via the center of pressure migration distances, functional reach test (FRT), Berg Balance Scale (BBS), and attention was measured using the trail-making test and the Stroop test. Results: In comparisons within each group, the two groups showed significant differences before and after the training (p<0.05). In the comparisons between the groups, the VUDT group showed significant improvements in center of pressure (COP), FRT, and BBS, and TMT compared to the SDT group (p<0.05). Conclusions: It would be more effective to conduct dual-task training as a rehabilitation training program under vision restriction and unstable supporting surface conditions than to conduct the test under unstable supporting plane conditions to improve balance and attention in chronic stroke patients.

• Transactions on Electrical and Electronic Materials
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• 제2권3호
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• pp.12-17
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• 2001

It is shown in the present study that during the HTS (hot temperature storage) test, the metal contamination by impure elements can be highly susceptible to the void formation, leading to the open failure of the power line in the memory device. Such a functional failure associated with the metal contamination was investigated to be dominant in the early stages of the HTS test while the formation of a stress-driven void is mainly observed in the later stages. In particular, it was found that the void formed in the contaminated metal takes on a slit-like shape which has been known to be characteristic of the stress-related voiding. The impure elements leading to the metal degradation were identified to be carbon and oxygen introduced during the metal sputtering process. The experimental works show that the device reliability was significantly improved by reducing the level of such impure elements within metal. It is shown in the present study that during the HTS (hot temperature storage) test, the metal contamination by impure elements can be highly susceptible to the void formation, leading to the open failure of the power line in the memory device. Such a functional failure associated with the metal contamination was investigated to be dominant in the early stages of the HTS test while the formation of a stress-driven void is mainly observed in the later stages. In particular, it was found that the void formed in the contaminated metal takes on a slit-like shape which has been known to be characteristic of the stress-related voiding. The impure elements leading to the metal degradation were identified to be carbon and oxygen introduced during the metal sputtering process. The experimental works show that the device reliability was significantly improved by reducing the level of such impure elements within metal.

• The Korean Journal of Nuclear Medicine
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• 제38권6호
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• pp.532-539
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• 2004

Purpose: There has been a renewal of interest in Macrophage migration inhibitory factor (MIF), especially correlation in pathogenesis of sepsis by many infectious diseases and in regulation of host inflammatory and immune response. We developed immunoradiometric assay (IRMA) to determine serum human MIF concentration. Materials and Methods: The IRMA system utilizes solid phase bound monoclonal anti-recombinant human MIF (rhMIF) antibody as a capture antibody, biotinylated polyclonal anti-rhMIF antibody as a detector antibody. We applied with rhMIF that concentration of standard solutions increased from 0 ng/ml to 100 ng/ml. We used $^{125}I$-streptavidin (SA) as radiotracer to determination of rhMIF concentration. Streptavidin was labeled with $^{125}I$ by Chloramine-T method and $^{125}I$-SA was purified by ultracentrifugation. $^{125}I$-SA stability was evaluated by ITLC analysis at $4^{\circ}C$ and room temperatures until 60days. To validate IRMA system for MIF, we experimented intra-assay and inter-assay coefficients of variation, recovery test and dilution test. Results: Radiolabeling yield of $^{125}I$-SA was 87% and purified $^{125}I$-SA retained above 99% radiochemical purity. $^{125}I$-SA showed above 93% stability in $4^{\circ}C$ until 60days that it is good for immunoradiometric assay as radiotracer. Plotted standard dose response curve showed that increased concentration of rhMIF linearly correlated (R2=0.99) with bound radioactivity of $^{125}I$-SA. The highest intra- and inter-assay coefficients of variation were 5.5% and 7.6%, respectively. The average of recovery of MIF in samples was 102%. In dilution test, linear response curves were obtained (R2=0.97). Conclusion: Radioimmunoassay using $^{125}I$-SA as radiotracer thought to be useful for the determination of serum MIF concentration, and further, its data will be used to evaluate the correlation between clinical significance and serum MIF concentration in patients with various inflammatory diseases.

• Journal of the Korea Concrete Institute
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• 제16권3호
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• pp.319-326
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• 2004

This paper investigates the effect of the concrete containing mineral admixtures(pozzolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete replaced mineral admixtures for 3${\~}$4 replacement ratios under water-binder ratios ranged from 0.40 to 0.55. For the electro-migration test, Tang and Nilsson's method was used to estimate the diffusion coefficient of chloride ion. As a results, the water-binder ratios, kinds of mineral admixtures and replacement ratios, water curing periods had a great effect on the diffusion coefficient of chloride ion, and the optimal replacement ratios had a limitation for each mineral admixtures. Also, the use of mineral admixtures by mass(replacement of OPC) enhance the resistance ability against chloride penetration compared with the plain concrete. The compressive strength was shown related to the diffusion coefficient of chloride ion, the compressive strength increases with the diffusion coefficient of chloride ion decreasing. Below the 50 MPa, the variation of diffusion coefficient of concrete replaced mineral admixtures was bigger than that of plain concrete.

• Molecular & Cellular Toxicology
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• 제5권2호
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• pp.126-132
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• 2009

The usage and types of chemicals are advancing, specializing, large-scaled increasing, and new chemical exposed workers are concerning to occupational disease. The generation of reactive oxygen in the body from carcinogen, mutation and DNA damage in cancer is protected by natural antioxidants (phytochemicals) with antimutagenic effect. There were many reports of ginsenoside Rb$_1$, Rg$_1$ grievances of the genetic mutation to suppress the effect confirm the genetic toxicity test with chromosomal aberration test and the Comet (SCGE) assay confirmed the suppression effect occurring chromosomal DNA damage. We had wanted to evaluate the compatibility and sensitivity between the chromosomal aberration (CA) test and the Comet assay. We used the CA test and Comet assay to evaluate the anti-genotoxicity of ginsenoside Rb$_1$ and Rg$_1$, in CHO-K1 (Chinese hamster ovary fibroblast) cell in vitro, composed negative control (solvent), positive control (benzo[a]pyrene), test group (carcinogen+variety concentration of ginsenoside) group. The positive control was benzo[a]pyrene (50 $\mu$M), well-known carcinogen, and the negative control was the 1 % DMSO solvent. The test group was a variety concentration of ginsenoside Rb$_1$, Rg$_1$ with 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1%, 10%. In chromo-somal aberration test, we measured the number of cells with abnormally structured chromosome. In Comet assay, the Olive tail moment (OTM) and Tail length (TL) values were measured. The ratio of cell proliferation was increased 8.3% in 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1%, 10% Rb$_1$ treated groups, and increased 10.4% in 10$^{-10}$%, 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1% Rg$_1$ treated groups. In the CA test, the number of chromosomal aberration was decreased all the Rb$_1$ and Rg$_1$ treated groups. In the Comet assay, the OTM values were decreased in all the Rb$_1$ and Rg$_1$ treated groups. To evaluate the compatibility between CA and Comet assay, we compared the reducing ratio of chromosomal abnormalities with its OTM values, it was identified the antimutagenicity of ginsenoside, but it was more sensitive the CA test than the Comet assay. Ginsenoside Rb$_1$ and Rg$_1$ significantly decrease the number of cells with chromosomal aberration, and decrease the extent of DNA migration. Therefore, ginsenoside Rb$_1$, Rg$_1$ are thought as an antioxidant phytochemicals to protect mutagenicity. The in vitro Comet assay seems to be less sensitive than the in vitro chromosomal aberration test.

• Journal of Forest and Environmental Science
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• 제34권1호
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• pp.82-86
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• 2018

Loblolly pine (Pinus taeda L.) is widely distributed in the southern part of the United States and it has been used as a major economic species in the region due to its excellent growth and stem straightness. The tree also grows only in the southern part of Korea because it is susceptible to cold. Recently climate changes have had widespread impacts on forest trees. Thus, the use of good quality seeds is prerequisite for assessing assisted migration adaptation trial. In this study, we conducted to investigate its cone and seed characteristics of each family, which is expected to improve seeds productivity for planting valuable timber trees. A total of 14 families were selected from the experimental forest in Boseong, Jeonnam province in 1981. The seed production capacity was estimated to range from 87.2 to 129.4 among families and the average was 111.3. The number of aborted ovules was investigated in the range of 11.4 to 29.5 for the first test and 7.4 to 22.2 for the second test. The average number of empty and filled seeds was 1.4 and 79.2 per cone, respectively. Based on the results, we can conclude that there is a strong correlation between the number of fertile scale and the seed production ability.

• Journal of the Korea institute for structural maintenance and inspection
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• 제17권6호
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• pp.104-111
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• 2013

Deterioration is accelerated due to additional intrusion of chloride ion in crack width in cracked concrete. In this paper, modeling on equivalent diffusion coefficient in cracked concrete is performed for 1-D (Anisotropic) and 2-D (Isotropic) diffusion based on steady state condition. In the previous research, rectangular shape of crack was considered but the shape was modified to wedge shape with torturity. For verification of the proposed model, crack is induced in concrete sample and migration test in steady state is performed for 1-D diffusion. For 2-D diffusion, previous test results are adopted for verification. Through considering wedge shape of crack with torturity, diffusion coefficients in 1-D and 2-D diffusion are reduced, and the more reasonable prediction is obtained. The results from the proposed model with torturity of 0.10~0.15 are shown to be in the best agreement with the test results.

• Journal of Korean Orthopaedic Sports Medicine
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• 제1권1호
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• pp.26-30
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• 2002

Purpose: To estimate the initial and early phase fixation power of the human bone interference screw in reconstruction of the anterior cruciate ligament with bone-patellar tendon-bone allograft. Materials and Methods: The results of twenty eight knees of reconstruction with bone-patellar tendon-bone allograft were analysed in 6 weeks, 12 weeks, 6 months and one year following operation. Physical examination including Lachman test, flexion rotation drawer test and jerk test were performed. The KT-1000 measurement was performed at the same time. In Lachman test 0 $\~$2mm anterior displacement of the tibia was considered normal. The KT-1000 measurement of normal side was compared with operation side and the difference of the two was recorded. The MRI was checked at final follow-up. Results: All but one knee showed normal in physical examination. The failed case showed proximal migration of the graft due to insufficient number of interference screw fixation in widened tibial tunnel. Conclusions: The human cortical bone interference screw showed sufficient initial and early phase fixation power in reconstruction of the anterior cruciate ligament.