• Molecules and Cells
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• 제40권2호
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• pp.117-122
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• 2017

Despite the fact that porcine embryonic stem cells (ESCs) are a practical study tool, in vitro long-term maintenance of these cells is difficult in a two-dimensional (2D) microenvironment using cellular niche or extracellular matrix proteins. However, a three-dimensional (3D) microenvironment, similar to that enclosing the inner cell mass of the blastocyst, may improve in vitro maintenance of self-renewal. Accordingly, as a first step toward constructing a 3D microenvironment optimized to maintain porcine ESC self-renewal, we investigated different culture dimensions for porcine ICM-derived cells to enhance the maintenance of self-renewal. Porcine ICM-derived cells were cultured in agarose-based 3D hydrogel with self-renewal-friendly mechanics and in 2D culture plates with or without feeder cells. Subsequently, the effects of the 3D microenvironment on maintenance of self-renewal were identified by analyzing colony formation and morphology, alkaline phosphatase (AP) activity, and transcriptional and translational regulation of self-renewal-related genes. The 3D microenvironment using a 1.5% (w/v) agarose-based 3D hydrogel resulted in significantly more colonies with stereoscopic morphology, significantly improved AP activity, and increased protein expression of self-renewal-related genes compared to those in the 2D microenvironment. These results demonstrate that self-renewal of porcine ICM-derived cells can be maintained more effectively in a 3D microenvironment than in a 2D microenvironment. These results will help develop novel culture systems for ICM-derived cells derived from diverse species, which will contribute to stimulating basic and applicable studies related to ESCs.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2002년도 제23회 학술발표회 초록집
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• pp.177-177
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• 2002

• Journal of Photoscience
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• 제10권2호
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• pp.199-202
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• 2003

The relationship between the morphology of nanostructured TiO$_2$ films and the photo-injected electron transport has been investigated using intensity-modulated photocurrent spectroscopy (IMPS). For this purpose, three different TiO$_2$ films with 5 ${\mu}{\textrm}{m}$ thickness are prepared: The rutile TiO$_2$ film with 500 nm-sized cluster-like spherical bundles composed of the individual needles (Tl), the rutile TiO$_2$ film made up of non-oriented, homogeneously distributed rod-shaped particles having a dimension of approximately 20${\times}$80 nm (T2), and the anatase TiO$_2$ film with 20 nm-sized spherically shaped particles (T3). Cross sectional scanning electron micrographs show that all of the TiO$_2$films have a quite different particle packing density: poorly packed Tl film, loosely packed T2 film and densely packed T3 film. The electron transport is found to be significantly influenced by film morphology. The effective electron diffusion coefficient D$_{eff}$ derived from the IMPS time constant is an order of magnitude lower for T2 than for T3, but the D$_{eff}$ for the Tl sample is much lower than T2. These differences in the rate of electron transport are ascribed to differences in the extent of interparticle connectivity associated with the particle packing density.ity.

• Journal of Life Science
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• 제12권1호
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• pp.19-21
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• 2002

The pathway of embryos formed anther culture in herbaceous peony was influenced by addition of 2,4-D. MS medium with 2,4-Dichlorophenoxy acetic acid (2,4-D) alone did not arise direct embryogenesis, but was proliferate callus. Embryos through calli were produced on medium containing 0.2 mg/1 zeatin or without growth regulators. Direct embryogenesis was obtained from MS basal medium. However, after the anthers were cultured on medium with 0.1 mg/1 2,4-D, 3 g/1 AC, 30 g/1 sucrose, 2 g/1 gelrite for 40 days. Its efficiency (32.3 %) was markedly improved when anthers cultured on medium without 2,4-D. Embryo morphology was also affected by the 2,4-D used in medium. The induction of normal embryos with two cotyledons was higher in the embryos formed through direct embryogenesis than those formed callus. The embryos formed from calli were mainly showed abnormal embryo with one, three, four cotyledons or hors and bowling pin type.

• Journal of the Korean earth science society
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• 제31권2호
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• pp.129-138
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• 2010

A number of dinosaur tracksites located at southern coast of the Korean Peninsula have continuously been damaged by sea-waves and weathering. To protect the dinosaur tracksites from the damage permanently and safely, we need to develop conservation programs as well as to collect data documenting the sites. We specifically applied digital photogrammetry to extensively record and document dinosaur tracks in the Namhae Gain-ri tracksite (Natural Monument No. 499) and were able to obtain 3D images data with it. The data of 3D images enable us to produce permanent documentation and preservation of the morphology of dinosaur tracks and tracksites. Moreover the weathering rate on time can be numerically analyzed by periodic measurements of the dinosaur tracksite and comparison of those measurements. The 3D modeling techniques also can be used in various ways including analyzing morphology of tracks, duplicating replicas for museum exhibitions, and posting the results on the Internet homepage.

• The Journal of the Korea Contents Association
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• 제16권2호
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• pp.546-557
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• 2016

Tooth carving practice is required for novice learners in dentistry to understand dental morphology and acquire clinically underlying skills. Tooth carving practice is more effective when sequential models can be observed. The purpose of this study is to suggest a tooth carving practice model and to develop a mobile practice supporting tool based on tutorial providing 3D modeling information about steps of tooth carving. As a result, tooth carving practice model consists of the class activity including tooth information lecture and practice and mobile seamless learning connecting learners' practice and regular learning with the mobile tutorial tool. The mobile tutorial tool is implemented with tooth morphology dictionary, tooth carving practice/training tutorial, and 3D tooth modeling. The experts' evaluation on the developed contents shows that the content and function are valid(content validity: 5.0, interface validity: 4.53). Therefore, the mobile tutorial tool is suitable for supporting mobile seamless learning for tooth carving practice. Further researches are expected to be conducted to develop instructional models utilizing ICT and mobile contents in dentistry.

• Imaging Science in Dentistry
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• 제43권4호
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• pp.273-281
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• 2013

Purpose: This study was performed to evaluate the general anatomy and morphology of the nasopalatine canal using cone-beam computed tomography (CBCT) and to determine the human anatomic variability of the nasopalatine canal in relation to age and gender. Materials and Methods: The study included 100 subjects aged between 20 and 86 years who were divided into the following 3 groups: 1) 20-34 years old; 2) 35-49 years old; 3) ${\geq}50$ years old. The subjects were equally distributed between the genders. CBCT was performed using a standard exposure and patient positioning protocol. The data of the CBCT images were sliced in three dimensions. Image planes on the three axes (X, Y, and Z) were sequentially analyzed for the location, morphology and dimensions of the nasopalatine canal by two independent observers. The correlation of age and gender with all the variables was evaluated. Results: The present study did not reveal statistically significant differences in the number of openings at the nasal fossa; diameter of the nasal fossa openings; diameter of the incisive fossa; shape, curvature, and angulation of the canal as viewed in the sagittal sections; antero-posterior dimensions and length of the canal in the sagittal sections; or the level of division of the canal in the coronal plane by age. However, males and females showed significant differences in the length of the canal in the sagittal sections and level of the division of the canal in the coronal plane. Conclusion: The present study highlighted important variability observed in the anatomy and morphology of the nasopalatine canal.

• KIPS Transactions on Software and Data Engineering
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• 제6권1호
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• pp.23-28
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• 2017

Shape from focus (SFF) is a technique used to reconstruct 3D shape of objects from a sequence of images obtained at different focus settings of the lens. In this paper, a new shape from focus method for 3D reconstruction of microscopic objects is described, which is based on gradient operator in Mathematical Morphology. Conventionally, in SFF methods, a single focus measure is used for measuring the focus quality. Due to the complex shape and texture of microscopic objects, single measure based operators are not sufficient, so we propose morphological operators with multi-structuring elements for computing the focus values. Finally, an optimal focus measure is obtained by combining the response of all focus measures. The experimental results showed that the proposed algorithm has provided more accurate depth maps than the existing methods in terms of three-dimensional shape recovery.

• Journal of the Korean Institute of Telematics and Electronics S
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• 제34S권7호
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• pp.78-88
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• 1997

A three dimensional-two spatical dimensions plus time-image segmentation is widely used in a very low bit rate image sequence coding because it can solve the region correspondence problem. Mathematical morphology is a very efficient tool for the segmentation because it deals well with geometric features such as size, shape, contrast and connectivity. But if the motion in the image sequence is large in time axis, the conventional 3D morphological segmentation algorithm have difficulty in solving region correspondence problem. To alleviate this problem, we propose the hierarchical image sequence segmentation algorithm that uses the region motion information. Since the motion of a region in previous level affects that in current level uses the previous motion information to increase region correspondence. Simulation result shows improved performance for sequence frames with large motion.

• Journal of Biomedical Engineering Research
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• 제39권1호
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• pp.22-29
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• 2018

Intervertebral disc(IVD) mainly consists of Annulus fibrosus(AF) and Nucleus pulposus(NP), playing a role of distributing a mechanical load on vertebral body. IVD tissue engineering has been developed the methods to achieve anatomic morphology and restoration of biological function. The goal of present study is to identify the possibilities for creating a substitute of IVD the morphology and biological functions are the same as undamaged complete IVD. To fabricate the AF and NP combine biphasic IVD tissue, AF tissue scaffolds have been printed by 3D bio-printing system with natural biomaterials and NP tissues have been prepared by scaffold-free culture system. We evaluated whether the combined structure of 3D printed AF scaffold and scaffold-free NP tissue construct could support the architecture and cell functions as IVD tissue. 3D printed AF scaffolds were printed with 60 degree angle stripe patterned lamella structure(the inner-diameter is 5mm, outer-diameter is 10 mm and height is 3 mm). In the cytotoxicity test, the 3D printed AF scaffold showed good cell compatibility. The results of histological and immunohistochemical staining also showed the newly synthesized collagens and glycosaminoglycans, which are specific makers of AF tissue. And scaffold-free NP tissue actively synthesized glycosaminoglycans and type 2 collagen, which are the major components of NP tissue. When we combined two engineered tissues to realize the IVD, combined biphasic tissues showed a good integration between the two tissues. In conclusion, this study describes the fabrication of Engineered biphasic IVD tissue by using enable techniques of tissue engineering. This fabricated biphasic tissue would be used as a model system for the study of the native IVD tissue. In the future, it may have the potential to replace the damaged IVD in the future.