• The Journal of the Korean dental association
• /
• v.10 no.12
• /
• pp.809-812
• /
• 1972

This present paper is concerned with four unit fixed bridge construction by one piece casting technique in the case of missing of upper left second premolar and first molar. The authors had good clinical results with following advantages. 1. The complete bridge can be delivered to the patient for two appointments. 2. The laboratory procedures for solder joint are not necessary. 3. A one piece casting can be properly shaped without weak joints. 4. The casting can be heat-treated to insure an ideal molecular structure. 5. Porcelain veneers can be applied without weakening or melting solder joints.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.119.1-119.1
• /
• 2011

Since Gratzel et al. reported the first efficient dye-sensitized solar cells(DSSCs) in 1991, they have attracted much attention due to their relatively high power conversion efficiency and potentially low cost production. To date, high performance and good stability of DSSC based on Ru-dyes as a photosensitizer had been widely addressed in the literatures. However, the Ru-dyes are facing the problem of manufacturing costs and environmental issues. In order to obtain even cheaper photosensitizers for DSSC, the metal-free organic photosensitizers are strongly desired. The metal-free organic dyes offer superior molar extinction coefficients, low cost, and diverse molecular structures as compared to the conventional Ru-dyes, In this work, we have studied on the synthesis and characterization of the organo dendritic dyes containing different number of electron acceptor moieties in a molecule.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.6
• /
• pp.1031-1035
• /
• 2007

Prostate specific $antigen-{\alpha}_1-antichymotrypsin$ was detected by a double-enhancement strategy involving the exploitation of both colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation. The AuNPs were synthesized and conjugated with horse-radish peroxidase-PSA polyclonal antibody by physisorption. Using the protein-colloid for SPR-based detection of the PSPJACT complex showed their enhancement as being consistent with other previous studies with regard to AuNPs enhancement, while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the signal. The limit of detection was found at as low as 0.027 ng/ml of the PSA/ACT complex (or 300 fM), which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.203-203
• /
• 2006

In this study, a novel strategy to prepare a crystallized sample of terpolymer containing high content of ${\gamma}-form$ was experimentally sought. By the foaming process, it was possible for the first time to produce a commercial high molar-mass terpolymer being in a high content of ${\Box}-form$. The large amount of nuclei produced during the foaming process by FIC is ascribed to be the reason. It accounts for the structural disorder in the crystallite formation because of excess amount of chains length for the formation of a stable crystallite.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.322-322
• /
• 2006

Well-defined poly(N-vinylcarbazole), poly(NVC), was synthesized by macromolecular design via interchange of the xanthate (MADIX)/reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of a suitable xanthate-type chain transfer agent (CTA). Good control of the polymerization was confirmed by the linear first-order kinetic plot, the molecular weight controlled by the monomer/CTA molar ratio, linear increase in the molecular weight with the conversion, and the ability to extend the chains by the second addition of the monomer. Star polymers having various architectures were also synthesized using this technique.

• The korean journal of orthodontics
• /
• v.4 no.1
• /
• pp.41-48
• /
• 1974

The author has selected 70 non-extraction and extraction cases. The linear measurements were made in the maxillary dental cast at pre-and post-treatment. The purpose of this study was to detect out the changes occured during orthodontic treatment. On the basis of findings of this study, the following results are made: 1. In extraction cases: 1) The maxillary intercanine width increased. 2) The maxillary dental arch width decreased. 3) The maxillary inter first molar width decreased. 4) The maxillary dental arch length decreased. 5) The maxillary dental arch length (I-3) increased. 2. In non-extraction cases, the maxillary intercanine width decreased in Angle's class III.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.6
• /
• pp.602-605
• /
• 2000

Human alveolar bone cells were isolated from alveolar bone fragments obtained from normal individual undergoing third molar extractions. Alveolar bone fragments were cultured as explant. Cells began to migrate in the first $5{\sim}7$ day and were confluent in $5{\sim}7$ week. Matrix mineralization was observed by 4 week. Our studies utilize established protocols for the characterization of these cells as osteoblasts by means of alkaline phosphatase activity determination, identification of osteocalcin antigens, establishing the presence of cells expressing type I collagen and determining the ability of cells to produce calcification. Transmission electron microscopic observations confirmed the presence of a collagen matrix undergoing a mineralization process. This new model, using human alveolar bone cells, may provide a tool to investigate alveolar bone development and physiology and to set up new therapeutic approaches.

• The Journal of the Korean dental association
• /
• v.12 no.9
• /
• pp.691-694
• /
• 1974

The trends of restoration on abrased teethis mostly based on gnathology or on practical experience. This study was performed on plaster models from 60 young men whose teeth and occlusion are clinically normal. A pair, upper and lower models, were mounted on HANAU articulator. Iron ball bearing 0.2mm 0.5mm 0.7mm and 1.0mm in diameter was attached on mesiobuccal cusp of upper first molar. [table I] Long ribbon shape of cold cure resin was inserted and jaw was closed gently so as not to move disturb original position of iron ball. The resin bite registration was measured minimun thickness from each lingual cusps of upper jaw and buccal cusps of lower jaw by means of Bowley gauge. The results were as follows (graph). 1) The distance from upper lingual cusps and lower buccal cusps: backward cusps showed smaller than standard cusp (upper mesio-buccal cusp) and forward cusps showed longer than standard. 2) The measurements from upper lingual cusps are not coincide with lower buccal cusps.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.28 no.2
• /
• pp.521-537
• /
• 1998

The calcifying epithelial odontogenic tumor is a rare benign odontogenic neoplasm which was first described by Pindborg in 1955 and accounts for less than 1％ of all odontogenic tumors. The tumor occurs primarily in the molar-premolar region of the mandible, and 52％ of cases are associated with an unerupted tooth. The clinical feature is most commonly a slow-growing painless swelling. The tumor may show considerable radiographic variation and usually characteristic histopathologic features. In this study, we report a case of the calcifying epithelial odontogenic tumor on the left mandibular body and ramus area in a 28-year-old male with a brief review of the concerned literatures.

• Journal of the Korean Society of Safety
• /
• v.12 no.4
• /
• pp.93-101
• /
• 1997

A modified procedure for electroplating wastewater treatment using formaldehyde and hydrogen peroxide can destroy free cyanide. The representative diagram which is quite sensitive on reaction temperature is showed for this kinds of treatment. Principally free cyanide and some kinds of cyanide complex should be treated first, and then toxic heavy metals can be removed because cyanide component will be inhibited to remove other pollutants, if it is not destroyed perfectly. Formaldehyde and hydrogen peroxide are added in controlled amounts to cyanide treatment tank. Reasonable amounts of these chemicals are (HCHO/CN)=0.9 and ($H_2O_2/CN$)=1.1 in molar ratios, it is also variable on reaction temperature. Of course, actual treatment processes depending on plating material and chemical are good applicable, also to systematize operation manual for treating electroplating wastewater process, further works are desirable.