• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3549-3552
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• 2010

The complex formation between diazocalix[4]dipropyl (1) and diazocalix[4]crown-6 ether (2) with alkali, alkaline earth and transition metal ions was investigated by voltammetry. Electrochemical properties of compounds 1 and 2 and their selectivity toward metal ions were evaluated in $CH_3CN$ solution by comparison of voltammetric behaviors of two phenols in each compound. Compounds 1 and 2 showed almost same voltammetric behavior which is two irreversible oxidation peaks caused by intramolecular hydrogen bonding between two phenols in 1 and 2. While, however, upon interacting with various metal ions, 1 with two propyl ether groups showed no significant changes in voltammetry, 2 with crown ether group caused significant voltammetric changes upon the addition of $Ba^{2+}$ to 2. Their behavior is closely related to the complex formation by entrapment of metal ion into crown ether cavity, and ion-dipole interaction between metal ion and two phenolic groups in calix[4]crown-6.

• Imaging Science in Dentistry
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• v.48 no.4
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• pp.289-293
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• 2018

Odontomas are considered a type of odontogenic hamartoma, and are generally reported not to exceed 3 cm in diameter. Some authors have referred to odontomas with a diameter exceeding 3 cm as giant odontomas. As hamartomas, giant odontomas generally show no signs or symptoms, but if they perforate the mucosa to become exposed in the oral cavity, oral and maxillofacial infections can result. Surgical removal and a histopathological examination may also be required to differentiate them from osteomas, cemento-osseous dysplasia, or mixed odontogenic tumors. This report presents the case of a 28-year-old woman with a giant odontoma in the right mandibular third molar area. Based on a review of the literature published since 2010, only 11 cases of "giant" or "large" odontomas have been reported, most of which were of the complex odontoma type. It was confirmed that they tend to occur in the right posterior mandible.

• Journal of the Korean Chemical Society
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• v.40 no.7
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• pp.509-514
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• 1996

The three-dimensional metal complex inclusion compound $Cd(pn)Ni(CN)_4{\cdot}0.5NO_2C_6H_5$(pn: 1,2-diaminopropane=propylenediamine) crystallizes in the orthorhombic space group, $Pn2_1$a, (a=13.868(5), b=26.591(4), c=7.840(1)${\AA}$, V=2891(1)${\AA}^3$, Z=4), R=0.054 for 2800 independent reflections. The host structure of the inclusion compound appears the same one(T-type) of inclusion compound with branched aliphatic-guest molecule. The nitrobenzeneguest molecule attains the stable position in the nodal channel of T-type by placing the polar nitro group between the pn-amino groups at the node and the bulky aromatic ring in the antinodal zone of the channel. The substituted aromatic guest molecule is accommodated in the host structure of metal complex $Cd(pn)Ni(CN)_4$ with channel cavity.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.31-37
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• 1995

A ray-based approach is developed to calculate the scattering from inhomogeneous dielectric objects. This approach is a natural extension of the "shooting and bouncing ray(SBR)" technique developed earlier for calculating the radar cross section of cavity structures and complex targets. In this formulation, a dense grid of rays representing the incident field is shot toward the scatterer. The curved trajectory, amplitude, phase and polarization of the ray fields inside the inhomogeneous object are computed numerically based on the laws of geometrical optics. The contributions of the exting rays to the exterior scattered field are then calculated by using the equivalence principle in conjunction with " a ray-tube integration" scheme. The ray-based approach is applied for the effect of an arcjet plasma plume on satellite reflector performance and backscattering from inhomogeneous objects.

• Journal of Powder Materials
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• v.22 no.1
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• pp.1-5
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• 2015

Powder injection molding is an important manufacturing technology to mass produce superalloy components with complex shape. Injection molding step is particularly important for realizing a desired shape, which requires much time and efforts finding the optimum process condition. Therefore computer aided engineering can be very useful to find proper injection molding conditions. In this study, we have conducted a finite element method based simulation for the spiral mold test of superalloy feedstock and compared the results with experimental ones. Sensitivity analysis with both of simulation and experiment reveals that the melt temperature of superalloy feedstock is the most important factor for the full filling of mold cavity. The FEM based simulation matches well the experimental results. This study contributes to the optimization of superalloy powder injection molding process.

• The Journal of the Korean dental association
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• v.53 no.5
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• pp.307-317
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• 2015

Although the long-term success of osseointegrated endosseous implants for the support of fixed dental prostheses has been reported, the increasingly widespread use of implant-supported prostheses has led to problems associated with their structural integrity. The most common biomechanical complications observed in dental implant treatment are fracture and screw loosening. The nature of loosening or fracture of dental implant components is complex, since it involves fatigue, fitness, and varied chewing patterns and loads. To assess the service life of the components of the prosthetic system, a knowledge of the loads transmitted through the system is necessary. Design of the final restoration and occlusion in relation to the geometry of a prosthetic restoration has a great influence on the mechanical loading of the implant. It is proposed that control of force in oral cavity may play a larger role in failures than previously believed. Based on theoretic consideration and clinical experiences with dental implant, this article gives simple guidelines for controlling these loads.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.697-700
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• 2001

Iron is an essential nutrient for most organisms, which supplied to them in a protein-iron complex known as ferritin. Ferritins are multimeric proteins found in prokaryotes, plants and animals. They are consisted of spherical shell of 24 subunits defining a cavity of about 8nm in diameter, where an iron core is laid down. Expression of ferritin in recombinant E. coli at $37^{\circ}C$ led to the accumulation of recombinant ferritin. Insoluble form of ferritin was separated from disrupted cells, followed by various primary separation steps with two kinds of buffers. Collected samples from the primary steps were purified by DEAE-cellulose gels packed in a column. The fractions from the DEAE column were assayed to gain the amount and the purity of ferritin by using HPLC and SDS-PAGE.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.172-172
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• 2006

Molecular imprinting constitutes a valuable method of preparing polymeric materials with specific binding properties. The most conspicuous merit of molecular imprinting is that structurally three-dimensional recognition sites can be introduced into a polymer matrix with ease and low cost when compared with the complicated process of biological system for antigen and antibody. We used a thermally reversible bond for the preparation of the monomer-template complex, which allowed us to remove the template easily by means of a simple thermal reaction and to simultaneously introduce various functional groups into the cavity. This method is especially propitious for developing artificial receptors for molecules lacking strongly interactive groups.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.351-351
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• 2006

The possible interactions between cyclodextrins and biodegradable polyesters were investigated. The hydrophobicity of cyclodextrin could be varied with the methyl substitution of host CD, and the possibility of IC formation and the types of interaction between respective CDs and polyesters were subsequently changed. Further, the effect of cyclodextrins on the morphological change of biodegradable polymer was shown to depend on the degree of IC formation between cyclodextrin and biodegradable polymer as well as on the type of interaction between respective CDs and polyesters. That is, the enhancement and/or the restriction of the crystallization of P(3HB) were observed by the incorporation of various kind of cyclodextrins with different cavity size and hydrophobicity.

• International Journal of Oral Biology
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• v.45 no.3
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• pp.77-83
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• 2020

In the oral cavity, complex microbial community is shaped by various host and environmental factors. Extensive literature describing the oral microbiome in the context of oral health and disease is available. Advances in DNA sequencing technologies and data analysis have drastically improved the analysis of the oral microbiome. For microbiome study, bacterial 16S ribosomal RNA gene amplification and sequencing is often employed owing to the cost-effective and fast nature of the method. In this review, practical considerations for performing a microbiome study, including experimental design, molecular analysis technology, and general data analysis, will be discussed.