• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.210-221
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• 1995

The purpose of this study was performed to investigate the mineralization and differentiation of osteobalsts for bone regeneration in vitro and the effect of rate of the composition in periodontal cells on mineralization. For this study, healthy gingival tissues were surgically obtained from the patients during 1st premolar extraction for the purposes of orthodontic treament. Gingival tissue was washed several time with Phosphate buffered saline contained high concentration of antibiotics and antifungal agent, and cultured in Dulbecco's Modified Eagle's Medium(DMEM, Gibco, U.S.A.). Every cell were cultured in state at $37^{\circ}C$, 100% of humidity, 5% of $CO_2$ incubator. Bone marrow stromal cells were isolated from 5-clay-old rat femur with using medium irrigation mathod by syringe. Cell suspension medium were centrifuged at 1500 rpm for 5 min and then cultured in the petri dish. Two kinds of cell were freezed and stocked in the liquid nitrogen tank until experiment. Cell were incubated into the 24 multi-well plate with $5{\times}10^4$cell/well of medium at $37^{\circ}C$, 100% of humidity 5% $CO_2$ incubator for 24 hours. After discarded of the supernatent of medium, O.5ml of medium were reapplied and incubated. And counted the number of cell using the hemocytometer and inverted light microscope. We have measured the number of mineralized nodule with using Alizarin red S. staining in microscope. Furthermore every cell were observed the morphological change between every rate of co-culture of the two kinds of cell. The results were as follows; The rate of proliferation of co-culture cell revealed high rate tendency compared the bone marrow stromal cell only and low growth rate to compared with gingival fibroblast only. The tendency of formation of the mineralized nodule were observed dose-depend pattern of bone marrow stromal cell. It is concluded that the gingival fibroblast may inhibit the formation of mineralized nodule in the culture of the bone marrow stromal cell.

• Biomolecules & Therapeutics
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• v.23 no.4
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• pp.350-356
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• 2015

Functional dyspepsia (FD) is a prevalent idiopathic upper gastrointestinal (GI) disorder characterized by diverse symptomatology including epigastric pain or discomfort, postprandial fullness, and early satiety. Although its pathophysiological mechanisms have not yet been fully established, the available studies suggest that the etiology of FD is invariably multifactorial. Benachio-F$^{(R)}$ (BF) is a proprietary liquid formulation of 7 herbal extracts that has been proposed to address this multifactorial etiology using multi-drug phytotherapy. The pharmacological effects of BF, in comparison with those of two other herbal products (Whalmyungsu$^{(R)}$; WM and Iberogast$^{(R)}$; IB) were evaluated in rats. In a laparotomy-induced rat model of delayed GI transit, BF significantly accelerated the delayed gastric emptying caused by morphine, apomorphine, and cisplatin, and also significantly increased mean gastric transit, as compared to the control animals. BF markedly increased gastric accommodation in rats and produced higher gastric volume values than did the control treatment. The effects of BF were generally comparable or superior to those of WM and IB in these models. Furthermore, BF significantly stimulated biliary flow, as compared to the control treatment. These results indicated that BF might have great potential as an effective phytotherapeutic agent capable of reducing GI symptoms and increasing quality of life in FD patients.

• Progress in Medical Physics
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• v.16 no.4
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• pp.214-219
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• 2005

As part of Korean retinal prosthesis project, we have provided preliminary experimental results regarding voltage parameters for the stimulation of chemically degenerated rabbit retina. Since our APB-treated chemically degenerated retina is only ON-pathway blocked, now we switch our experiments to more appropriate retinal degeneration model, genetically degenerated retina model (RD mouse: rd/rd (C3H/HeJ)). Before studying with RD mouse, we started control experiments with normal SD rat to understand characteristics of retinal ganglion ceil activity with postnatal maturation in rodents. Ganglion cell activities were recorded with 8${\times}$8 multi-electrode array. Moving spontaneous bursts appeared until postnatal day of 15. During pre-eye opening period, no light evoked response appeared. After postnatal day of 2 weeks (post-eye opening period), ON-, OFF- and ON/OFF response appeared. The fractional distributions of ON, OFF, and ON/OFF ganglion cell is about $40\%,\;50\%$, and $5\%$. The percentage ($\%$) of light evoked response in each dorso-temporal, ventral, and dorso-nasal area of eye is about $50\%,\;37.5\%$ and $12.5\%$, respectively. We concluded that the optimal period for experiment in rodent is about postnatal day of 2${\~}$3 weeks.

• Korean Journal of Exercise Nutrition
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• v.13 no.1
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• pp.15-21
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• 2009

Ergogenic aids are substances, devices, and practices that enhance an individual's energy use and production, and recovery from fatigue. L-carnitine increases enhance performance and aerobic capacity by stimulating lipid oxidation in muscle cells during long term exercise. L-carnitine is a well known and widely used ergogenic aid. In the present study, the effect of L-carnitine at concentrations of 100 nM, 1 μM, 10 μM, and 100 μM on the amplitude of field potential in rat cardiac muscle slices was measured using multi-channel extracellular recording (MED 64) system. In the present result, L-carnitine was shown to enhance field potential as a does-dependent manner. The increasing effect of the L-carnitine on field potential was not affected by application of the glibenclamide, an ATP-dependant K⁺ channel antagonist. The increasing effect of L-carnitine on field potential was suppressed by application of the diazoxide, an ATP-dependent K⁺ channel agonist. Present data show that L-carnitine potentiates field potentials by inhibition on ATP-dependant K⁺ channel in cardiac muscles. The enhancing effect of the L-carnitine on the field potential in cardiac muscles can be suggested as one of the underlying mechanism of ergogenic aid of the L-carnitine.

• Nutritional Sciences
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• v.6 no.4
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• pp.209-215
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• 2003

This research was performed to investigate the effects of the supplementation of multi-extracts of mori folium (MF) and of exercise on blood lipid profiles and tissue differentiation in streptozotocin (STZ)-induced diabetic rats. The animal groups consisted of a normal-control group, a STZ-control group, three STZ-induced diabetic groups supplemented ad libitum with various amounts of MF extracts (MF-720, MF-360, and MF-180 groups), and a STZ-induced diabetic group supplemented with MF-360 combined with exercise; eight male Sprague-Dawley rats, 4 weeks old, were assigned to each experimental group and were raised in the laboratory for a 10 week experimental period. The MF supplementation group showed a significant reduction in levels of serum total cholesterol and triglyceride compared to the STZ-control group. HDL-cholesterol levels were significantly increased in the MF supplementation group compared to STZ-control group. The ratio of HDL-cholesterol to total cholesterol was significantly higher in MF supplementation group compared to the STZ-control group. The Atherogenic Index (AI) values in the MF supplementation groups were found to be significantly lower than in the STZ-control group. Serum AST and ALT levels were significantly reduced in the MF-supplementation groups compared to the STZ-control group. Total cholesterol level in the liver tissue was significantly decreased in the MF-360 group and in the MF-360 + exercise group compared to the STZ-control group. In immunohistochemical staining of the pancreatic islets of the MF-supplemented groups, a significantly higher number of insulin-immunoreactive cells were observed compared to the STZ-control group. In the MF supplementation groups, Bowman's capsules were clearly observed as hypertrophy of the glomeruli was not obvious. In the MF supplementation groups, a relative reduction in the hypertrophy of the basement membrane of the glomeruli and a significant reduction in the mesangium were observed compared to the STZ-control group. The results of this study suggest that supplementation of MF has beneficial effect in improving plasma lipid and tissue metabolism in streptozotocin-induced rats.

• Nutritional Sciences
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• v.6 no.4
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• pp.201-208
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• 2003

This research was conducted to study the effects of the supplementation of multi-extracts of mori folium (MF) and of exercise on plasma insulin and glucose levels in streptozotocin (STZ)-induced diabetic rats. Eight male Sprague-Dawley rats, 4 weeks old, were assigned to each experimental group and were raised in the laboratory for 10 weeks. The animal groups consisted of a normal-control group, a STZ-control group, 3 STZ-induced diabetic groups supplemented ad libitum with various amounts of MF extracts (MF-720, MF-360, and MF-180 groups), and a STZ-induced diabetic group supplemented with MF-360 along with exercise. In the normal-control group, glucose tolerance tests resulted in the peak blood glucose level being achieved in 15 minutes and a fasting blood glucose level being achieved in 60 minutes. In the STZ-control group, the peak blood glucose level was reached after 60 minutes and, even after 90 minutes, blood glucose shown at a significantly higher level compared to the fasting levels. In the groups supplemented with MF extracts, the blood glucose level peaked after 30 minutes of glucose challenge, and returned to the fasting level after 90 minutes; the MF-360 and MF-360+exercise groups showed the best levels of glucose tolerance. Blood glucose levels in the STZ-induced diabetic groups were significantly higher compared to the normal-control group. However, after 7 weeks of supplementation with MF extracts, a significant lowering of blood glucose levels was observed in all groups supplemented with the MF extract. The best effect was observed in the group given MF extract combined with exercise. Compared to the normal-control group, blood insulin levels were significantly lower in all STZ-induced diabetic groups; however, a significantly higher level of insulin was observed in the groups given MF extracts compared to the STZ-control group. This study shows that the supplementation of MF extracts in STZ-induced diabetic rats resulted in increased blood insulin levels and lower blood glucose levels.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.2
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• pp.104-109
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• 2016

In this paper, a localization method for multiple robots based on Bayesian inference is proposed when multiple robots adopting multi-RAT (Radio Access Technology) communications exist in cognitive radio networks. Multiple robots are separately defined by primary and secondary users as in conventional mobile communications system. In addition, the heterogeneous spectrum environment is considered in this paper. To improve the performance of localization for multiple robots, a realistic multiple primary user distribution is explained by using the probabilistic graphical model, and then we introduce the Gibbs sampler strategy based on Bayesian inference. In addition, the secondary user selection minimizing the value of GDOP (Geometric Dilution of Precision) is also proposed in order to overcome the limitations of localization accuracy with Gibbs sampling. Via the simulation results, we can show that the proposed localization method based on GDOP enhances the accuracy of localization for multiple robots. Furthermore, it can also be verified from the simulation results that localization performance is significantly improved with increasing number of observation samples when the GDOP is considered.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.152-162
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• 1988

Benzene and toluene, which are widely used aromatic hydrocarbons in workplace, are recently proved to cause health hazards due to their toxic effects. This study investigated the influence of toluene on the urinary excretion of benzene metabolite by administering short term exposure limit(STEL) of these compounds(i.e., 13.8mg/kg of benzene and 108.8 mg/kg of toluene) intraperitoneally into Sprague-Dawley rats. After administration, urinary phenol concentration of rat was measured by gas chromatography for every three hours. Data were analyzed by non-parametric statistical methods using Kruskal-Wallis multi-sample test and Mann-Whitney U test. The following results were obtained : 1. Administration of STEL-benzene increased urinary phenol concentration in lats. 2. Urinary phenol concentration was increased logarithmically according to the dosage of benzene. 3. Excretion of phenol in urine was decreased when benzene and toluene were administered simultaneously compared with administering benzene alone. In summary, these results reveal that administration of STEL of toluene has antagonistic effect of urinary excretion of benzene metabolite in rats.

• Journal of Chest Surgery
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• v.21 no.6
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• pp.979-983
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• 1988

Calcium channel blockers may prevent myocardial injury during cardioplegia and reperfusion. This study was done to evaluate the effects of diltiazem cardioplegia on myocardial protection during ischemic arrest and recovery of myocardial function after reperfusion. Four formulations of crystalloid cardioplegic solutions, GIK solution[group I, n=12], diltiazem[lug/ml GIK] in GIK solution[group II, n=7], ],diltiazem[2ug/ml GIK] in GIK solution[group III, n=6] and diltiazem[4ug/ml GIK] in GIK solution[group IV, n=6] were compared in isolated working rat heart subjected to a long period [2 hours] of hypothermic arrest with multi-dose infusion. Diltiazem cardioplegia[group II, III and IV]was found to be superior in nearly all aspects. Diltiazem cardioplegia showed faster recovery of regular rhythm and lower incidence of ventricular fibrillation than group I did. In comparing mechanical function in all experimental hearts, the mean postischemic recoveries of aortic flow, cardiac output, peak aortic pressure, stroke volume and stroke work[expressed as a percentage of its preischemic control] were significantly greater in group II, III and IV[diltiazem cardioplegia] than in group I. The infused amount of cardioplegic solution was more increased by the addition of diltiazem to GI K solution. [p < 0.01] Creatine kinase leakage tended to be lower in hearts receiving diltiazem cardioplegia, especially in group III and IV[p<0.05] than in those receiving GIK solution only[group I]. Diltiazem cardioplegia results in the increased flow of cardioplegic solution and the decreased ischemic injury of myocardium during ischemic arrest and the improved recovery of myocardial function after reperfusion, and a dose-response relation must be established before clinical use.

• Journal of Communications and Networks
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• v.11 no.4
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• pp.368-374
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• 2009

This paper focuses on a distributed multiple spectrum pricing scheme to maximize system capacity in next generation multiaccess systems, where multimode user equipments (MUEs) can connect simultaneously to multiple base stations (BSs) with multiple radio access technologies (RATs). The multi-price based scheme provides a distributed decision making for an optimal solution where radio resource allocations are determined by each MUE, unlike most centralized mechanisms where BS controls the whole radio resource. By the proposed optimal solution, MUEs can decide their share of spectrum bands and power allocation according to the spectrum price of each RAT, and at the same time the multiaccess system can achieve maximized total throughput. Numerical analysis shows that the proposed scheme achieves the maximal capacity by distributed resource allocation for the multiaccess system.