• The Journal of Korean Academy of Prosthodontics
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• v.52 no.1
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• pp.9-17
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• 2014

Purpose: The purpose of this study was to compare zirconia implants with titanium implants from the view point of biomechanical stability and histologic response on osseointegration when those were placed with xenograft materials. Materials and methods: Specimens were divided into two groups; the control group was experimented with eighteen titanium implants which had anodized surface and the experimental group was experimented with eighteen sandblasted zirconia (Y-TZP) implants. At the tibias of six pigs, implants were installed into bone defect sites prepared surgically and treated with resorbable membranes and bovine bone. Two pigs were sacrificed after 1, 4 and 12 weeks respectively. Each implant site was sampled and processed for histologic and histomorphometric analysis. The stability of implants was evaluated with a $Periotest^{(R)}$. And the interfaces between bone and the implant were observed with a scanning electron microscope. Results: In stability analysis there was no significant difference between Periotest values of the control group and the experimental group. In histologic analysis with a light microscope after 4 weeks, there was new bone formation with the resorption of bovine bone and the active synthesis of osteoblasts in both groups. In bone-implant contact percentage there was significant difference between both groups (P<.05). In bone area percentage there was no significant difference between both groups. In analysis of both groups with a scanning electron microscope there was a gap between bone and a surface at 4 weeks and it was filled up with bone formed newly at 12 weeks. Conclusion: When accompanied by xenograft using membrane, bone to implant contact percentage of zirconia implants used in this experiment was significantly less than that of the titanium implants by surface treatment of anodic oxidation. So, it is considered that the improvement of zirconia implant is needed through ongoing research on surface treatment methods for its practical use.

• The korean journal of orthodontics
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• v.33 no.4 s.99
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• pp.307-317
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• 2003

Conventional osseointegrated titanium implants have many limitations; large size, limited location for placement of the implant, severity of the surgery, discomfort of initial healing, difficulty of oral hygiene and uncontrollable force direction. Recently titanium miniscrew and miniplate have been used for an alternative to conventional dental implant. But in relation to miniplate, miniscrew has disadvantages in that more potential inflammation, light orthodontic force application and limited orthodontic application. This study was conducted to evaluate the effectiveness of miniplate by observing the reactions of peri-implant tissues to early orthodontic and orthopedic loading of titanium miniplate. In four adult beagle dogs 10 miniplates were inserted into the alveolar bone using 20 osseointegrated titanium screws. 4 miniplates were placed in two dogs(dogA, B) and 6 miniplates in two dogs(dogC, D). In dogA, B miniplates were loaded with 200gm of force immediately after placement for 15 weeks. In dogc, D, miniplates were loaded with 400gm of force immediately after placement for 8 weeks. Miniplates of dogA were removed, dogA was healed for 4 weeks, and the area which was removed of miniscrew was examined. Following an observation period, the miniplates including miniscrews and the surrounding bone of dogB and dogC, D were removed, respectively. Undecalcified section along the long axis of miniscrews were made and the degree of osseointegration was examined under the light microscope. The results were as follows. 1. In the histologic features there was direct contact between bone and miniscrew in all groups except one, dogC control group. The loaded miniscrew demonstrated only a slight increase of the osseous proximaty when compared with unloaded miniscrew 2. There was no significant difference of the osseointegration of Peri-miniscrew surface between dogB and dogC, D. But dogB showed slightly more increased bone apposition than dogC, D 3. The gingiva overlapping the miniplate and miniscrew showed no inflammatory sign in clinical and histological aspects. 4. The impaled hard and soft tissues at the area which was removed of miniscrews showed good healing without inflammatory reaction. 5. The mobility showed slight increase in un-loaded miniplate but that was insignificant. Based on the results of this study, miniplate(C-tube) can be used as a firm osseous orthodontic and orthopedic anchorage unit immediately after insertion.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.75-85
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• 1985

This study is intended to find out the influence of Lignosulfonic Acid Type Admixture on compressive, tensile, flexural strength and dispersing action of mortar, and fixation of by-product of pulp industry. 1. The more Pozzolith-84 is added, the larger flow value is. The admixture of lignosulfonic acid type adhere to cement particles and the surface potential of particles is generated. On account of the repulsion among the cement particles, they are dispersed and the mortar get workable, so the production cost of precast product is curtailed and the amount of cement is reduced in a certain workability of mortar. 2. The strength of mortar is greater than plain mortar when P/C added is 0.2 and 0.4%. As time passed the potential energy is reduced and the distance of particles which lignosulfonic acid adhered to get near according as the amount of adhesion is increased. The setting and hardening reaction of morter is occurred in close state, so the strength of mortar is increased a little. The strength of mortar is less than plain mortar when amount P/C added is 0.8%. Pozzolith-84 is mainly composed of lignosulfonic acid and lignin does not influence the hardening of mortar, therefore the remained $SO_3$, $SO_3H$ are the reason of decrease of strength. 3. There is high significance between specific gravity and compressive strength. The larger specific gravity is, the more compressive strength is increased. There is high significance between 7 day's strength and 28 day's strength. The larger compressive strength is, the more tensile and flexural strength are increased. 4. Since Pozzolith-84 is a by-product of pulp industry, by using the Pozzolith-84 admixture the concreate quality is improved. The water pollusion is reduced according to fix by-products in concrete structure.

• Journal of Life Science
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• v.19 no.8
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• pp.1039-1046
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• 2009

The cytochrome P450s (P450s) metabolizing natural products are among the most versatile biological catalysts known in plants, but knowledge of the structural basis for their broad substrate specificity has been limited. The activity of p-coumarate 3-hydroxylase (C3H) is thought to be essential for the biosynthesis of lignin and many other phenylpropanoid pathway products in plants however, all attempts to express and purify the protein corresponding C3H gene have failed. As a result, no conditions suitable for the unambiguous assay of the enzyme are known. The detailed understanding of the mechanism and substrate-specificity of C3Hdemands a method for the production of active protein on the milligram scale. We have developed a bacterial expression and purification system for the plant C3H, which allows for the quick expression and purification of active wild-type C3H via introduction of combinational mutagenesis. The modified cytochrome P450 C3H ($C3H_{mod}$) could be purified in the absence of detergent using immobilized metal affinity chromatography and size exclusion chromatography following extraction from isolated membranes in a high salt buffer and catalytically activated. This method makes the use of isotopic labeling of C3H for NMRstudies and X-ray crystallography practical, and is also applicable to other plant cytochrome P450 proteins.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.181-187
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• 2004

Preparations of mesoporous materials using various templates and their applicability have been intensively investigated for many years. We studied on synthesizing mesoporous Ti02 with pores in which sensitive compounds having weak physico-chemical properties such as thermal or UV irradiation and low solubility in solvent are trapped. Prior to trapping OMC in the pores of mesoporous titania, OMC was nano-emulsified in O/W system using Lecithin. Thereafter the OMC was trapped in the pores of mesoporous titania using sol-gel method. Main focus of this work is to prepare OMC-trapped mesoporous titania and to trace the stability and solubility of nano-emulsified OMC in the pores of mesoporous titania, and compared with that of mesoporous silica. OMC-trapped mesoporous Inorganic-Organic hybrid titania showed higher factors in sun protecting and a skin penetration phenomenon was reduced.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.173-178
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• 2022

A lateral flow immunoassay (LFIA) method using carbon nanodot@silica as a signaling material was developed for analyzing the concentration of retinol-binding protein 4 (RBP4), one of the lung cancer biomarkers. Instead of antibodies mainly used as bioreceptors in nitrocellulose membranes in LFIA for protein detection, aptamers that are more economical, easy to store for a long time, and have strong affinities toward specific target proteins were used. A 5' terminal of biotin-modified aptamer specific to RBP4 was first reacted with neutravidin followed by spraying the mixture on the membrane in order to immobilize the aptamer in a porous membrane by the strong binding affinity between biotin and neutravidin. Carbon nanodot@silica nanoparticles with blue fluorescent signal covalently conjugated to the RBP4 antibody, and RBP4 were injected in a lateral flow manner on to the surface bound aptamer to form a sandwich complex. Surfactant concentrations, ionic strength, and additional blocking reagents were added to the running buffer solution to optimize the fluorescent signal off from the sandwich complex which was correlated to the concentration of RBP4. A 10 mM Tris (pH 7.4) running buffer containing 150 mM NaCl and 0.05% Tween-20 with 0.6 M ethanolamine as a blocking agent showed the optimum assay condition for carbon nanodot@silica-based LFIA. The results indicate that an aptamer, more economical and easier to store for a long time can be used as an alternative immobilizing probe for antibody in a LFIA device which can be used as a point-of-care diagnosis kit for lung cancer diseases.