• Journal of Periodontal and Implant Science
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• 제31권2호
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• pp.277-285
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• 2001

Periodontal disease is characterized by inflammation and subsequent loss and/or damage to tooth-supporting tissues such as bone, cementum,and periodontal ligament. Periodontal ligament and cementum are the key tissues in the initial process of regeneration following periodontal disease. Therefore, studies on cementoblasts, which form cementum are emphasized. It is still unclear which cells cementoblast differentiate from. This study was conducted under the hypothesis that PDL fibroblast can differentiate into either cementoblast or osteoblast depending on the conditions of surrounding tissue. Clinically, with excessive traction force of orthodontic appliances or excessive occlusion hypercementosis is observed, and this has been confirmed histologically. Consequently, activation of cementoblast can be expected in rats when mechanical stimuli are given to PDL fibroblast. Therefore, the purpose of this article is to prove that PDL fibroblast differentiates into cementoblast in rats under mechanical stimuli using histologic and molecular methods. In this study, twenty rats were given hard diet. Ten of them were sacrificed after 1 week, and the others were sacrificed after two weeks. Slides were made from tooth specimen, and they were studied under the microscope. In addition, PDL fibroblast and cementum from the extracted teeth were analyzed with Northern blotting. In histologic examination, as time passed, PDL fibroblast migrated to the dentin side, differentiated into cementoblast, and formed new cementum. In Northern blotting, it was found that mRNA expression of cementoblast-specific proteins such as BSP, OC, OPN, and type I collagen were more prominent in rats sacrificed after 2 weeks of hard-diet than rats sacrificed after 1 week. From these findings we can conclude that PDL fibroblast can differentiate into cementoblast under mechanical stimuli. We think that 'Rat Models' used in this study will be beneficial to future studies regarding cementoblast.

• 에너지공학
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• 제16권2호
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• pp.53-57
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• 2007

High oil prices and high demand supporting IOC move to frontier and NOC evolution. Most frontier area reserves are in NOC territory. IOCs need to be able to manage relationships with NOCs in order to be successful. They need to tune into what NOC priorities are. NOCs have different priorities depending on whether they are resource rich or resource poor. IOCs need to recognize $NOCs^{\circ}{\emptyset}$ priorities and differentiate themselves by using them when talking to NOCs.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.222-222
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• 2005

• Journal of Korean Neurosurgical Society
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• 제63권3호
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• pp.338-341
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• 2020

Cases of syringomyelia associated with spinal dysraphism are distinct from those associated with hindbrain herniation or arachnoiditis in terms of the suspected pathogenetic mechanism. The symptoms of terminal syringomyelia are difficult to differentiate from the symptoms caused by spinal dysraphism. Nonetheless, syringomyelia has important clinical implications, as it is an important sign of cord tethering. The postoperative assessment of syringomyelia should be performed with caution.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 1999년도 추계학술대회 논문집
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• pp.225-228
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• 1999

The formation of dioxin (term used here to refer to both polychlorinated dibenzo-p-dioxins, PCDDS, and dibenzofurans, PCBFs) in combustion processes is of concern because of the extreme toxicities of some of these compounds and because of their resistance to degradation in the environment. The number and location of chlorine substituents differentiate dioxin homologues and isomers, respectively. There are a total of 75 PCDD congeners and 135 PCDF congeners.(omitted)

• Journal of Korean Neurosurgical Society
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• 제38권2호
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• pp.147-150
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• 2005

Cavernous angiomas of the cranial nerves are rarely reported. We report a case of a 33-year-old man affected by a cavernous angioma originated in the oculomotor nerve with it's palsy. Preoperative radiological findings are difficult to differentiate it from meningioma or neurinoma. Postopertive pathological report discloses it as cavernous angioma. We discuss radiological, pathological features and management of this vascular lesion of the cranial nerve.

• 대한교통학회지
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• 제3권1호
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• pp.76-85
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• 1985

The significant role of transportation system for economic development process has been recognized, but the argument that transportation improvements stimulate economic development has brought sometimes no resonance in lacking of a plausible theory on the conditions and process of economic development by transportation investment. This paper reviews the theory on regional differentiation of transportation system and shows why and how the installation of a new transportation system or the improvements of the old transportation quality differentiate the spatial order of economic activities. It presents the interaction between the change of transportation quality with introducing of definition "transportation value" as tool of its determination and economic activities following the regional differentiation process, which result means regional defferentiation of niveau of economic development.

• Journal of Plant Biology
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• 제34권3호
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• pp.177-183
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• 1991

Patterns of morphological variation in Polygonum setaceum Baldwin ex Elliott are examined, and the taxonomic significance of the varieties recognized by Fernald is reevaluated. The diagnostic characters used to differentiate the varieties in P. setaceum demonstrate virtually continuous variation, and broad geographic intergradation is recognized. Principal components analyses of major morphological characters also fail to separate the varieties. These results strongly suggest that recognition of var. setaceum, var. interjectum, and var. tonsum by Fernald is unwarranted.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.793-794
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• 2008

The block size of intra prediction mode can differentiate the texture area from the homogeneous area of image. This information can be used to enhance the size resolution of image. Specifically, in this paper, we apply the bicubic interpolation or the bilinear interpolation adaptively selected the intra prediction mode of the H.264 compression.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.693-696
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• 1988

This paper is investigated on the improvement for steam temperature control at Boryung coal-fired drum boiler type thermal power plant. The steam temperatur control has been mainly operated by the feedback controllers. Automatic controllers are bounded and difficult. Because boiler system is nonlinear and the system time delay is very large. Optimal regulators including predictive feedforward and differentiate control are synthesized and some improved output results are presented.