• International Journal of Industrial Entomology and Biomaterials
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• 제27권1호
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• pp.209-217
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• 2013

The objective of this study was to evaluate the bone regeneration capability of silk membrane plus 3% 4-hexylresorcinol (3% 4-HR plus SM) in a rabbit calvarial defect model. Twenty New Zealand white rabbits were used in this study. Bilateral round shaped defects were created in the parietal bone (diameter: 8.0 mm). And the defects were covered with (1) 3% 4-HR plus SM, (2) collagen membrane (CM), (3) no graft material. After surgery, the animals were sacrificed at 4 weeks and 8 weeks. Bone regeneration was analyzed in each section by micro-computerized tomography (${\mu}$-CT). And Hematoxylin and eosin stains were used for histological analysis. As measured by ${\mu}$-CT analysis 4 weeks after surgery, the average of new bone formation in animals treated with 3% 4-HR plus SM was greater than that of animals treated with CM. and the difference was statistically significant. And well organized lamella bones were observed in the histological view of the 3% 4-HR plus SM group. Therefore, more bone regeneration was seen in animals treated with 3% 4-HR plus SM than in those treated with CM or uncovered control.

• Journal of Periodontal and Implant Science
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• 제46권5호
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• pp.350-359
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• 2016

Purpose: The purpose of the present study was to evaluate the effectiveness of a minimal concentration of bone morphogenetic protein-2 (BMP-2) in terms of quantitative and qualitative analyses of newly formed bone in a rabbit maxillary sinus model. Methods: In 7 rabbits, sinus windows were prepared bilaterally. Biphasic calcium phosphate (BCP) loaded with 0.05 mg/mL BMP-2 was grafted into one sinus (the BMP group) and saline-soaked BCP was placed into the other (the control group) in each animal. The animals were allowed an 8-week healing period before being sacrificed. Specimens including the augmented area and surrounding tissues were then removed and evaluated both radiographically and histologically. Results: There was a difference in the mineralization of new bone between the groups. In the BMP group, the greater part of the new bone consisted of mature lamellar bone with an evident trabecular pattern, whereas the control group showed mostly woven bone, consisting only partially of lamellar bone. Histometrically, the area of new bone was significantly greater ($4.55{\pm}1.35mm^2$ vs. $2.99{\pm}0.86mm^2$) in the BMP group than in the control group (P<0.05); however, the total augmentation volumes were not significantly different between the groups. Conclusions: Within the limitations of this study, it can be suggested that a minimal concentration of BMP-2 (0.05 mg/mL) had an osteoinductive effect with accelerated mineralization in a rabbit sinus model using a BCP carrier.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권4호
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• pp.308-316
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• 2006

Objectives Despite considerable advances in technique, experience and skill, the precise place of surgery in the treatment of facial nerve injury remains uncertain. We designed a facial nerve crush injury model in rats and evaluated the recovery of crushed nerve which is the most common injury type of facial nerve using adenovirus vector mediated in vivo gene transfer of Brain derived neurotrophic factor(BDNF). Materials and methods In 48 Sprague Dawley rats, we made a facial nerve crush injury model to main trunk before the furcation, and injected a $10^{11}$pfu adenoviral BDNF in experimental group(BDNF adenoviral injection group; ad-BDNF) and $3{\mu}l$ saline in control group(Saline injection group; saline). After a period of regeneration from 10 to 40 days, nerve regeneration was evaluated with functioinal test (vibrissae and ocular movement), electrophysiologic study(threshold, peak voltage, conduction velocity) and histomorphometric study of axon density. Results Vibrissae and ocular movement, threshold and conduction velocity improved as time elapse in both group, however axon density was increased significantly only in experimental group. Functional test in 10 days and 20 days showed no difference between experimental group and control group. Vibrissae movement, threshold, conduction velocity and axon density in 30 days revealed that the regeneration in quality of experimental group was significantly superior to that of control group. Conclusion In general, there is tendency for nerve regeneration in experimental group (BDNF-adenovirus injection group) during 40 days, functional recovery was detected successfully after facial nerve crush in 30 days postoperatively.

• Restorative Dentistry and Endodontics
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• 제44권2호
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• pp.20.1-20.8
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• 2019

Objectives: To achieve pulp-dentin complex regeneration with tissue engineering, treatment efficacies and safeties should be evaluated using in vivo orthotopic transplantation in a sufficient number of animals. Mice have been a species of choice in which to study stem cell biology in mammals. However, most pulp-dentin complex regeneration studies have used large animals because the mouse tooth is too small. The purpose of this study was to demonstrate the utility of the mouse tooth as a transplantation model for pulp-dentin complex regeneration research. Materials and Methods: Experiments were performed using 7-week-old male Institute of Cancer Research (ICR) mice; a total of 35 mice had their pulp exposed, and 5 mice each were sacrificed at 1, 2, 4, 7, 9, 12 and 14 days after pulp exposure. After decalcification in 5% ethylenediaminetetraacetic acid, the samples were embedded and cut with a microtome and then stained with hematoxylin and eosin. Slides were observed under a high-magnification light microscope. Results: Until 1 week postoperatively, the tissue below the pulp chamber orifice appeared normal. The remaining coronal portion of the pulp tissue was inflammatory and necrotic. After 1 week postoperatively, inflammation and necrosis were apparent in the root canals inferior to the orifices. The specimens obtained after experimental day 14 showed necrosis of all tissue in the root canals. Conclusions: This study could provide opportunities for researchers performing in vivo orthotopic transplantation experiments with mice.

• Journal of Periodontal and Implant Science
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• 제48권6호
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• pp.383-394
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• 2018

Purpose: The purpose of this study was to evaluate the optimal diabetes duration for bone regeneration experiments in an alloxan monohydrate (ALX)-induced diabetic rabbit calvarial defect model by evaluating the association between diabetes duration and bone healing capacity. Methods: Twenty-four New Zealand white rabbits were used. Twenty-two rabbits were injected with 100 mg/kg of ALX to induce experimental diabetes. These rabbits were divided into 4 groups, including a control group and groups with diabetes durations of 1 week (group 1), 2 weeks (group 2), and 4 weeks (group 3). Calvarial defects were created at 1, 2, and 4 weeks after ALX injection and in the control rabbits. Cone-beam computed tomography (CBCT) scanning was performed on the day of surgery and at 2 and 4 weeks after surgery. The rabbits were sacrificed 4 weeks after surgery, followed by histological and immunofluorescence analysis. Results: The diabetic state of all diabetic rabbits was well-maintained throughout the experiment. Reconstructed 3-dimensional CBCT imaging showed more rapid and prominent bone regeneration in the control group than in the experimental groups. Histological staining showed notable bone regeneration in the control group, in contrast to scarce bone formation in the experimental groups. The appearance and immunoreactivity of receptor activator of nuclear factor-kappa B and osteoprotegerin did not show notable differences among the groups. Conclusion: ALX administration at 100 mg/kg successfully induced experimental diabetes in rabbits. The effect of diabetes on bone healing was evident when the interval between diabetes induction and the intervention was ${\geq}1$ week.

• 생명과학회지
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• 제31권2호
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• pp.137-143
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• 2021

근육 위축증은 근섬유의 손상으로 인한 근육세포의 감소에 의해 일어나며 심장질환, 당뇨, 각종 노인성 만성질환을 일으킨다고 알려져 있다. 본 연구는 미역 추출물 및 이의 성분인 알긴산의 근육세포보호, 근육감소억제 및 근육재생효과를 확인하고자 하였다. 미역 추출물 및 알긴산을 분화된 C2C12 myoblast 세포에 처리한 결과 TNF-α에 의한 근육섬유의 감소가 억제하였고murf1과 MaFbx의 발현량도 감소하였다. 또한, 마우스에 미역 추출물 및 알긴산을 10주간 급여한 결과 cardiotoxin에 의한 다리부종이 감소하였으며 근육단백질인 MyHC와 PGC-1α의 발현량이 증가 하였다. 따라서 미역 추출물 및 알긴산은 근감소 억제 및 근육재생 효과를 나타내어 기능성소재의 활용 가능성을 확인하였다.

• Smart Structures and Systems
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• 제13권3호
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• pp.419-434
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• 2014

In this paper, the electromagnetic damper (EMD), which is composed of a permanent-magnet rotary DC motor, a ball screw and a nut, is considered to be analyzed as a semi-active damper. The main objective pursued in the paper is to study the two degrees of freedom (DOF) model of the semi-active electromagnetic suspension system (SAEMSS) performance and energy regeneration controlled by on-off and continuous damping control strategies. The nonlinear equations of the SAEMSS must therefore be extracted. The effects of the EMD characteristics on ride comfort, handling performance and road holding for the passive electromagnetic suspension system (PEMSS) are first analyzed and damping control strategies effects on the SAEMSS performance and energy regeneration are investigated next. The results obtained from the simulation show that the SAEMSS provides better performance and more energy regeneration than the PEMSS. Moreover, the results reveal that the on-off hybrid control strategy leads to better performance in comparison with the continuous skyhook control strategy, however, the energy regeneration of the continuous skyhook control strategy is more than that of the on-off hybrid control strategy (except for on-off skyhook control strategy).

• 동의생리병리학회지
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• 제22권2호
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• pp.431-437
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• 2008

Sengmaek-san(Shengmai-san; SMS) is used in oriental medicine as one of the key herbal medicine for treating diverse symptoms including cardiovascular and neurological disorders. In the present study, the effects of SMS on axonal regeneration were investigated in the rat model given sciatic nerve injury. SMS treatment enhanced axonal regrowth into and the number of non-neuronal cells in the distal area after crush injury. GAP-43 protein levels were increased in the injured sciatic nerve compared to intact nerve and further upreguated by SMS treatment. GAP-43 protein was increased similarly in the dorsal root ganglion (DRG) at lumbar 4 - 6 by nerve injury and SMS treatment, suggesting GAP-43 induction at gene expression level. SMS-mediated increase in phospho-Erk1/2 protein was observed in the DRG as well as in the injured nerve implying its retrograde transport into the cell body as the process of lesion signal transmission. The present findings suggest that SMS may be involved in enhanced axonal regeneration via dynamic regulation of regeneration-associated proteins.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권6호
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• pp.492-495
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• 2005

The role of cultured bone marrow stromal cells (BMSCs) in peripheral nerve regeneration was examined using an established rabbit peroneal nerve regeneration model. A 15-mm peroneal nerve defect was bridged with a vein filled with BMSCs $(1{\times}10^6)$, which had been embedded in collagen gel. On the contralateral side, the defect was bridged with a vein filled with collagen gel alone. When the regenerated tissue was examined 4, 8 and 12 weeks after grafting, the number and diameter of the myelinated fibers in the side with the BMSCs were significantly higher than in the control side without the BMSCs. This demonstrates the potential of using cultured BMSCs in peripheral nerve regeneration.

• 태양에너지
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• 제20권1호
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• pp.91-96
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• 2000

This study was performed to find out how much experimental factors influence on regeneration performance in a solar air conditioning system. The experimental apparatus was set up in a climate-controlled chamber where temperature and humidity could be kept constant. In order. to investigate factors' influence on the regeneration performance of the solar air conditioning system, the model experiment was done using the 600mm $\times$ 600mm black painted aluminum regenerator. The design and analysis of experiment were done by the design of experiments, especially the table of orthogonal arrays. In order to find out how much experimental factors influence on regeneration performance, the table of orthogonal arrays $L_8(2^7)$ was used. According to the results, it was found that the most influential factor to affect regeneration performance was the concentration of LiCl solution. The next influential factors were a solar radiation, an air velocity, and the temperature of LiCl solution in order.