• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.80-86
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• 2008

Uncontrolled regeneration characteristics of two different type SiC DPFs(diesel particulate filters) were investigated by DPF test rig devised to facilitate DPF evaluation, especially for regeneration and MSL(maximum soot loading) test similar to engine dynamometer test. In order to estimate the limits of maximum filter temperature and temperature gradient causing filter fracture, such as crack or whitening, the temperature distributions inside the filter were measured by thermocouples. The maximum filter temperature was observed near the rear plane of central filter region due to heat accumulation by exothermic reaction of PM but the maximum temperature gradient occurred at the boundary of high filter temperature. These two parameters induced the different SiC DPFs to fracture with different modes, whitening and crack.

• Journal of Institute of Convergence Technology
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• v.1 no.1
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• pp.41-47
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• 2011

With the world-wide demand on the emission minimization, the needs on the diesel aftertreatment devices with high efficiency are also increasing. In order to effectively develop or design a high-performance diesel particulate filter, a clear understanding on the deposition and regeneration mechanism is required. In the present study, a theory on the lumped parameter model for wall-flow type diesel particulate filters is described focusing on the deposition efficiency, pressure drop inside the filter. The fourth order explicit Runge-Kutta method is utilized for the mass flow rate computation. Engine operation modes with controlled and uncontrolled regeneration options are selected. The computational lumped parameter model is validated by comparing the computed results with the measured data.

• Journal of Korean Foot and Ankle Society
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• v.26 no.4
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• pp.187-191
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• 2022

The author experienced a case of autologous platelet-rich plasma (PRP) affecting the recovery of a chronic neuropathic diabetic foot ulcer combined with infection. A 65-year-aged male with uncontrolled diabetes presented with a Wagner grade 2 diabetic foot ulcer on his left forefoot of more than 2 weeks duration. Osteomyelitis, gangrene, and ischemia requiring acute intervention were absent. Although infection was controlled to a moderate degree, wound healing was unsatisfactory following surgical debridement and simple dressing. Therefore, intralesional autologous PRP injection was performed 5 times as an adjuvant regeneration therapy, and the recalcitrant ulcer healed in 3 months. Intralesional PRP injections are worthwhile as they promote wound regeneration, are evidence-based, safe, and can be easily performed in ambulatory care facilities.

• Korean Institute of Interior Design Journal
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• v.27 no.1
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• pp.21-28
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• 2018

Environmental issues had arisen following industrialization with rapid physical growth of city and its consequences: widened metropolitan areas, uncontrolled reconstructions of new metropolitan areas, many social issues, such as declines of existing metropolitan areas. Due to these issues, new development policies have been made in order to find identities and reconstruct new images of cities. This research aims to remind the meaning of conservation of modern construction and building re-use, and to identify values of modern architectures in the context of a city. Regeneration of cities is not only finding national identities, but also expecting to increase inflow of foreign travellers. However, this regeneration hasn't stayed sustainable, focusing only on short-term curing of the problem in limited areas. This work analyzes cases of modern architecture, historic buildings from various cultures: Western, Japanese, Chinese. The result of the analysis shows that the value of existing buildings and citizen participation is necessary to revitalize cities. Four characteristics have been also identified: historic relationship, spatial identity, spatial presence, and approachable efficiency. For a potential solution, cities need to be viewed from multiple perspectives to find a method to generate new vitality for a city whose values should be recognized as an asset through sustainable re-use, by transforming modern construction as a heritage.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.46-52
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• 2009

The maxillary posterior edentulous region presents unique and challenging conditions in implant dentistry. The height of the posterior maxilla is reduced greatly as a result of dual resorption from the crest of the ridge and pneumatization of the maxillary sinus after the loss of teeth. Materials previously used for sinus floor grafting include autogenous bone, allogeneic bone, xenogenic bone and alloplastic materials. Autogenous bone is the material of choice, but its use is limited by donor-site morbidity, complications, sparse availability, uncontrolled resorption and marked volume loss. One way to overcome this problem would be to use bone substitutes alone as a osteoconductive scaffold for bone regeneration from the residual bone or in combination with allogeneic bone, which also has osteoinductive properties. The purpose of this article is to describe a double layers technique of demineralized and mineralized bone graft materials instead of autogenous bone in sinus floor augmentation of deficient posterior maxillary alveolar process and to report our experience with this technique. Our results show that maxillary sinus augmentation using mineralized and demineralized bone materials, when installed simultaneously with the implant or not, is good results for bone healing.

• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.455-464
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• 2021

Uncontrolled inflammation is considered the pathophysiological basis of many prevalent metabolic disorders, such as nonalcoholic fatty liver disease, diabetes, obesity, and neurodegenerative diseases. The inflammatory response is a self-limiting process that produces a superfamily of chemical mediators, called specialized proresolving mediators (SPMs). SPMs include the ω-3-derived family of molecules, such as resolvins, protectins, and maresins, as well as arachidonic acid-derived (ω-6) lipoxins that stimulate and promote resolution of inflammation, clearance of microbes, and alleviation of pain and promote tissue regeneration via novel mechanisms. SPMs function by binding and activating G protein-coupled receptors, such as FPR2/ALX, GPR32, and ERV1, and nuclear orphan receptors, such as RORα. Recently, several studies reported that SPMs have the potential to attenuate lipid metabolism disorders. However, the understanding of pharmacological aspects of SPMs, including tissue-specific biosynthesis, and specific SPM receptors and signaling pathways, is currently limited. Here, we summarize recent advances in the role of SPMs in resolution of inflammatory diseases with metabolic disorders, such as nonalcoholic fatty liver disease and obesity, obtained from preclinical animal studies. In addition, the known SPM receptors and their intracellular signaling are reviewed as targets of resolution of inflammation, and the currently available information on the therapeutic effects of major SPMs for metabolic disorders is summarized.

• Journal of Periodontal and Implant Science
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• v.28 no.1
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• pp.133-143
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• 1998

Diabetes mellitus is a systemic disease with profound effects on oral health and periodontal wound healing. Uncontrolled diabetes adversely affects surgical wound healing and is often associated with abnormal proliferation of fibroblasts. Human gingival fibroblasts and PDL cells were chosen because they are intimately involved in periodontal therapy and are important for the success of surgical procedure such as guided tissue regeneration. The aim of the present study was to elucidate whether cellular activity and collagen synthesis by glucose pre-treated human gingival fibroblasts and PDL cells are influenced by insulin, and whether healthy cells differ from glucose treated cells. Cells were cultured with DMEM at $37^{\circ}C$, 5% $CO_2$, 100% humidified incubator. To evaluate the effect of glucose on gingival fibroblasts and periodontal ligament cells, the cells were seeded at a cell density of $1{\times}10^4\;cells/well$ culture plates and treated with 20 and 50mM of glucose for 5 days. Then MTT assay was carried out. To evaluate the effect of insulin on glucose-pretreated cells, the cells were seeded at a cell density of $1{\times}10^4\;cells/well$ culture plates and treated with 20 and 50mM of glucose for 5 days. After incubation, $10^3$, $10^4$ and $10^5mU/l$ of insulin were also added to the each well and incubated for 2 days, respectively. Then, MTT assay and collagen synthesis assay were carried out. The results indicate that cellular activity of gingival fibroblasts significantly increased by glucose while periodontal ligament cells were unaffected and cellular activity of gingival fibroblasts and periodontal ligament cells were unaffected by insulin. Collagen synthesis of gingival fibroblast with 20mM glucose and insulin unaffected, but 50mM glucose and insulin increased than control. Collagen synthesis of periodontal ligament cell with 20mM glucose and $10^5mU/l$ insulin significantly increased than other groups and 50mM glucose pretreated PDL cells significantly increased at $10^3mU/l$ insulin but decreased at $10^4mU/l$ insulin. Our findings indicated that these cell types differed in their growth response to glucose, and the increase in collagen synthesis was significantly raised at insulin level of $10^3mU/l$ in gingival fibroblasts and periodontal ligament cells except 20mM glucose pretreated periodontal ligament cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.4
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• pp.301-311
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• 2011

Introduction: This study examined the effect of the application of low intensity pulsed ultrasound on bone healing after an injection of adipose tissue-derived stem cells (ADSCs) during the implantation of a titanium implant in the tibia of diabetes-induced rats. Materials and Methods: Twelve Sprague-Dawely rats were used. After inducing diabetes, the ADSCs were injected into the hole for the implant. Customized screw type implants, 2.0 mm in diameter and 3.5 mm in length, were implanted in both the tibia of the diabetes-induced rats. After implantation, LIPUS was applied with parameters of 3 MHz, 40 mW/$cm^2$, and 10 minutes for 7 days to the left tibiae (experimental group) of the diabetesinduced rats. The right tibiae in each rat were used in the control group. At 1, 2 and 4 week rats were sacrificed, and the bone tissues of both tibia were harvested. The bone tissues of the three rats in each week were used for bone-to-implant contact (BIC) and bone area (BA) analyses and the bone tissues of one rat were used to make sagittal serial sections. Results: In histomorphometric analyses, the BIC in the experimental and control group were respectively, $39.00{\pm}18.17%$ and $42.87{\pm}9.27%$ at 1 week, $43.74{\pm}6.83%$ and $32.27{\pm}6.00%$ at 2 weeks, and $32.62{\pm}11.02%$ and $47.10{\pm}9.77%$ at 4 weeks. The BA in experimental and control group were respectively, $37.28{\pm}3.68%$ and $31.90{\pm}2.84%$ at 1 week, $20.62{\pm}2.47%$ and $15.64{\pm}2.69%$ at 2 weeks, and $11.37{\pm}4.54%$ and $17.69{\pm}8.77%$ at 4 weeks. In immunohistochemistry analyses, Osteoprotegerin expression was strong at 1 and 2 weeks in the experimental group than the control group. Receptor activator of nuclear factor kB ligand expression showed similar staining at each week in the experimental and control group. Conclusion: These results suggest that the application of low intensity pulsed ultrasound after an injection of adipose tissue-derived stem cells during the implantation of titanium implants in the tibia of diabetes-induced rats provided some positive effect on bone regeneration at the early stage after implantation. On the other hand, this method is unable to increase the level of osseointegration and bone regeneration of the implant in an uncontrolled diabetic patient.