• YAKHAK HOEJI
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• v.60 no.1
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• pp.36-45
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• 2016

This study was aimed to enhance the percutaneous absorption of tizanidine hydrochloride (TZ) across Strat-M$^{TM}$ artificial membrane and excised hairless mouse skin using various vehicles and chemical permeation enhancers. Solubility studies were performed using hydrophilic and lipophilic vehicles. To initially evaluate vehicle effects on skin permeation, Strat-M$^{TM}$ membrane was adopted using Franz-type diffusion cells loaded with 0.4 mg donor dose. Effects of fatty acids on the permeation of TZ from PG and PGMC were compared, and the effects of various hydrophilic vehicles in the presence of linoleic acid were studied using excised hairless mouse skin specimens. The mean solubility (mg/ml) of TZ in hydrophilic vehicles was higher: water > PG > DMSO > ethanol > PEG 200 > NMP > PEG 300 > PEG 400 > DGME, and solubilities in lipophilic vehicles such as PGMC, PGMC, IPM, Captex 200 and Captex 300 were much less than 1.0 mg/ml. Permeation rates through StratTM membrane from pure vehicles were in the rank order: PGMC ${\geq}$ LBF > DMSO ${\geq}$ NMP ${\geq}$ PGML ${\geq}$ PG ${\geq}$ PEG 200 ${\geq}$ DGME ${\geq}$ EtOH. However, permeation rates of TZ through hairless mouse skin from pure vehicles were very low, although PG showed the highest flux ($1.66{\pm}0.28{\mu}g/cm^2{\cdot}hr$). Therefore, PG was selected in further studies. Addition of enhancers (3 v/v%) into PG markedly increased the flux (${\mu}g/cm^2{\cdot}hr$): oleyl alcohol ($14.9{\pm}3.1$) ${\geq}$ oleic acid ($14.5{\pm}1.6$) ${\geq}$ linoleic acid ($13.7{\pm}1.3$) > capric acid ($4.4{\pm}0.6$) > caprylic acid ($2.1{\pm}0.4$). Among hydrophilic vehicles with linoleic acid, PG and DMSO revealed relatively higher permeation for TZ. Increase of donor dose in PG resulted in dose-dependent permeation fluxes. These results suggest that permeation properties of TZ from nonaqueous solutions are markedly different between Strat-$M^{TM}$ membrane and excised hairless mouse skin, and transdermal delivery of TZ would be feasible with a combination of PG and enhancers.

• Korean Journal of Plant Taxonomy
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• v.33 no.4
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• pp.339-357
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• 2003

The general morphological characters and chromosome numbers about 7 taxa of Korean Allium sect. Sacculiferum were reviewed. From the results, authors elucidated the key character as well as the range of variations in each taxon, and considered the relationships among taxa in this section. Clear taxonomic treatments also carried out based on the type specimens and the original descriptions. Shape and growing pattern of leaves, size of inflorescences, shape of perianths and tepals, as well as chromosome numbers were key characters in identifying the taxa and in estimating their relationships. On the basis of these characters, A. thunbergii var. thunbergii, A. sacculiferum and A. deltoide-fistulosum were recognised as a distinct species respectively. Hal-la-bu-chu which had been misidentified as A. cyaneum (sect. Reticulato-bulbosa) in Korea was proved to be A. taquetii and belonged to the sect. Sacculi/erum. In addition, A. cyaneum var. deltoides, had been described as a variety of A. cyaneum, was recombined as a variety of A. thunbergii [A. thunbergii var. deltoides (S. Yu, W. Lee et S. Lee) H. J. Choi et B. U. Oh] with the new Korean name of 'Se-mo-san-bu-chu'. In conclusion, Korean sect. Sacculiferum was composed of five species and two varieties. A key to identify the taxa in this section was provided.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.123-130
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• 2010

In this study, mixed recycled coarse aggregate (RCA) was produced by mixing RCA from waste concrete in order to evaluate a new method of RCA production. Bond strength between reinforcing bars and RCA concrete was qualitatively evaluated as a part of continuous studies to establish design code of reinforced concrete structural members using recycled aggregate. For practical application, specimens were manufactured with the ready mix RCA concrete. Parameters investigated include: concrete compressive strength (i.e 21, 27 and 40 MPa), replacement levels (i.e 0, 30, 60 and 100%), bar position (i.e vertical and horizontal) and bar location (75 and 225 mm). For the pull-out test, each specimen was in the form of a cube, with each side of 150 mm in length and a deformed bar, 16 mm in diameter, was embedded in the center of each specimen. From the test results, the most of HT type specimen with compressive strength of 21 and 27 MPa showed lower bond strength than the ones provided in CEB-FIP and considered in reinforcement location factor ($\alpha\;=\;1.3$). It was reasoned that bonded area of top bar specimen was reduced at the soffit of reinforcement because of bleed water of fresh concrete. Therefore the reinforcement location factor in current KCI design code should be reviewed and modified.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.273-280
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• 2011

Ten high-strength concrete beam specimens, which have various combinations of different types of flexural reinforcement and short fibers were constructed and tested. Six beams were reinforced with two layers of steel, CFRP, and GFRP bar combinations. The other four beams were reinforced with two layers of single type CFRP and GFRP bars, with steel and synthetic short fibers. An investigation was performed on the influence of the parameters on the load-carrying capacity, post cracking stiffness, cracking pattern, deflection behavior, and ductility. The low post cracking stiffness, large deflection, deep crack propagation, large crack width, and low ductility of FRP bar-reinforced beams were controlled and improved by positioning steel bars in the inner layer of the FRP bar layer. In addition, the addition of fibers increased the first-cracking load, ultimate flexural strength, and ductility as well as the deep propagating cracks were controlled in the FRP bar-reinforced concrete beams. The increased ultimate concrete strain of fiber-reinforced concrete should be determined and considered when FRP bar-reinforced concrete members with fibers are designed.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.129-142
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• 2002

Epithelial-mesenchymal interaction plays a important role in cell growth and differentiation. This interaction is already well known to have an importance during the organ development as well as cell growth and differentiation. However, in vitro experimental model is not well developed to reproduce in vivo cellular microenvironment which provide a epithelial-mesenchymal interaction. Because conventional monolayer culture lacks epithelial-mensenchymal interaction, cultivated cells have an morphologic, biochemical, and functional characteristics differ from in vivo tissue. Moreover, it's condition is not able to induce cellular differention due to submerged culture condition. Therefore, the aims of this study were to develop and evaualte the in vitro experimental model that maintains epithelial-mesenchymal interaction by organotypic raft culture, and to characterize biologic properties of three-dimensionally reconstituted oral keratinocytes by histological and immunohistochemical analysis. The results were as follow; 1. Gingival keratinocytes reconstituted by three-dimensional organotypic culture revealed similar morphologic characteristics to biopsied patient specimen showing stratification, hyperkeratinosis, matutation of epithelial architecture. 2. Connective tissue structure was matured, and there is no difference during stratification period of epithelial 3-dimensional culture. 3. The longer of air-exposure culture on three-dimensionally reconstituted cells, the more epithelial maturation, increased epithelial thickness and surface keratinization 4. In reconstitued mucosa, the whole epidermis was positively stained by anti-involucrin antibody, and there is no difference according to air-exposured culture period. 5. The Hsp was expressed in the epithelial layer of three-dimensionally cultured cells, especially basal layer of epidermis. The change of Hsp expression was not significant by culture stratification. 6. Connexin 43, marker of cell-cell communication was revealed mild immunodeposition in reconstitued epithelium, and there is no significant expression change during stratification. These results suggest that three-dimensional oragnotypic co-culture of normal gingival keratinocytes with dermal equivalent consisting type I collagen and gingival fibroblasts results in similar morphologic and immunohistochemical characteristics to in vivo patient specimens. And this culture system seems to provide adequate micro-environment for in vitro tissue reconstitution. Therefore, further study will be focused to study of in vitro gingivitis model, development of novel perioodntal disease therapeutics and epithelial-mensenchymal interaction.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.6
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• pp.545-559
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• 2002

There has been increasing use of IPS Empress $2^{(R)}$ owing to easy fabrication method, high esthetics similar to natural teeth, good marginal accuracy, and sufficient fracture strength. However, in clinical application, although a luting agent and the tooth cementation bonding procedure influence the marginal accuracy and fracture strength restoration, there has been a controversy in the selection of proper luting agent. This study was to measure the marginal fidelites and fracture strength of IPS Empress crowns according to three cement types, Protec $cem^{(R)}$, Variolink $II^{(R)}$ and Panavia $21^{(R)}$. After construction of 12 experimental dies for each group, IPS Empress $2^{(R)}$ crowns were fabricated and luted the metal master die prepartion of the maxillary right premolar. Marginal gaps before cementation and after cementation were measured. Buccal incline on the functional cusp of specimens were loaded until the catastrophic failure and fracture strength was measured. The results of this study were as follows: 1. The range of gap was $34.04{\pm}4.84{\mu}m$ before cementation and $37.88{\pm}5.00{\mu}m$ after cementation, which showed significant difference by paired t-test (p<0.05). The difference in the results from marginal accuracy according to measuring point proved to be not statistically significant by two-way ANOVA test (p>0.05). 2. The difference in the results from marginal accuracy according to three cement types Proved that The Variolink $II^{(R)}$ cement group had the least gap, $35.43{\pm}5.03{\mu}m$, and showed superior marginal accuracy while there existed statistic significance in Protec $cem^{(R)}$ cement group, $39.06{\pm}4.41{\mu}m$ or Panavia $21^{(R)}$ cement group, $39.16{\pm}4.39{\mu}m$ by two-way ANOVA test & multiple range test (p<0.05). 3. The difference in the results from fractures strength testing according to three cement type groups proved to be statistically significant (p<0.05). The Variolink $II^{(R)}$ cement group shows highest fracture strength of $1257.33{\pm}226.77N$, Panavia $21^{(R)}$ cement group has $1098.08{\pm}138.45N$, and Protec $cem^{(R)}$ cement group represents the lowest fracture strength of $926.75{\pm}115.75N$. 4. Three different cement groups of different components showed acceptable marginal fidelity and fracture strength. It is concluded that IPS Empress $2^{(R)}$ crowns luted using Variolink $II^{(R)}$ cement group had stronger fracture strength and smaller marginal gap than the other cement groups. Although Variolink $II^{(R)}$ resin cement seemed acceptable to clinical applications in IPS Empress $2^{(R)}$ system, the IPS Empress $2^{(R)}$ system still requires long-term research due to the lack of data in clinical applications.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.180-185
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• 2005

Purpose: Among tumor-associated antigens, MAGE (melanoma antigen) was named as cancer/testis specific antigens because they are detected exclusively in the testis or cancer cells, including gastric carcinomas. Due to the elicitation of autoimmunitiy to tumors by these antigens either in vitro or in vivo and their tumor specificity, these antigens, thus, appear to be potential targets for tumor-specific immunotherapy. Materials and Methods: The fresh tumor tissue and normal gastric tissue samples were obtained from resected surgical specimens in 53 patients with gastric carcinomas. From the obtained cells, total cellular mRNA was extracted, and RT-PCR and nested PCR were run in 30 and 35 cycles respectively, with two different kinds of primers specially designed to detect six subtypes of MAGE DNA simultaneously. Results: In the 53 normal tissue, there was no expression of MAGE, but in the 53 cancer tissues, MAGE was expressed in 13 tissues (24.5%). Our data did not exhibit any correlation with the expression of the MAGE gene and clinicopathological factors. Conclusion: In our data, since 24.5% of gastric cancer tissues expressed MAGE, it should become possible to immunize a significant proportion of patients with advanced gastric carcinomas against the antigens encoded by these genes, provided that more antigenic peptides encoded by the genes of the MAGE family can be identified in the near future. (J Korean Gastric Cancer Assoc 2005;5:180-185)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.413-420
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• 2011

An experiment was conducted to suggest the road pavement material combining wooden chip crushed from little useful roots and branches from logging sites or wood waste from construction sites with urethane resin. For the specimen, the mass ratio of urethane resin to construction wood waste chip/lumber waster chip was set to three different levels of 0.5, 0.75, and 1.0, which was measured, mixed with mixer, and molded; 7 days after, tensile strength test, elasticity test using golf balls and steel balls, permeability coefficient measurement, and flammability test were executed. As the result, the tensile strength of the specimen at the dry state in the air exhibited the range of 0.2-1.1MPa, and there was no change after 7 days of aging. When submerged in water, however, the strength was partially diminished; the diminishing rate was greater for less urethane resin usage, and therefore it appears desirable to set the mass ratio of resin to the wood waste chip over 0.75 to consider the moisture intrusion by precipitation and such. As the result of elasticity test, the GB and SB coefficients of the specimen using wood waste chips and urethane resin were measured to be low at below 20%, exhibiting excellent elasticity as road pavement material. Also, the permeability coefficient was over 0.5mm/sec for specimens of all combinations, exceeding the standard value required after construction for permeable pavement material, and the flammability of wood-type pavement material was evaluated to have no practical issues.

• Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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• 2003.05a
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• pp.20-20
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• 2003

In the summers of 1997 and 1998 and in February of 2000 we made 570 measurements of the ambient geomagnetic field 120 cm above the pavement surface of State Route 130, south of Pahoa, the island of Hawaii using a three-component fluxgate magnetometer. We measured at every 15.2 m (50 feet) interval covering a distance of 6, 310 m (20, 704 ft) where both historic and pre-historic highly magnetic basalt flows underlie. We also collected 197 core samples from eight road cuts, 489 specimens of which were subject to AF demagnetizations at 5 - 10 mT level up to a maximum field of 60 mT. We observed significant inclination anomalies ranging from a minimum of $31^{\circ}$ to a maximum $40^{\circ}$ where a uniform inclination value of $36.7^{\circ}$ (International Geomagnetic Reference Field, IGRF) was expected. Since the mean of the observed inclinations is approximately $35^{\circ}$ we assume that the study area is slightly affected by the magnetic terrain effect to a systematically shallower inclinations for being located in the regionally sloping surface of the southern side of the island (Baag, et al., 1995). We observed inclination anomalies showing wider (spacial) wavelength (160 - 600 m) and higher amplitudes in the historic lava flows area than in the northern pre-historic flows. Our observations imply that preexisting inclination anomalies such as those that we observed would have been interpreted as paleosecular variation (PSV). These inclination anomalies can best be attributed to concealed underground highly magnetic dikes, channel type lava flows, on-and-off hydrothermal activities through fissure-like openings, etc. Both the within- and between-site dispersions of natural remanent magnetization (NRM) are largest (up to ${\pm}7^{\circ}$) above the flows of 1955, while the area of pre-historic flows in the northern part of the study area exhibit the smallest dispersion. Nevertheless, mean inclinations of each historic flow of 1955 and 1790 are almost identical to that of the corresponding present field, whereas mean of NRM (after AF demagnetization) inclinations for each of the four pre-historic lava flow units is twelve to thirteen degrees lower than the present field inclination. We observed three cases of very large inclination variations from within a single flow, the best fitting curves of which are linear, second and third order polynomials each from within a single flow, whereas no present field variations are observed. This phenomena can be attributed to the notion that local magnetic anomalies on the surface of an active volcano are not permanent, but are transient. Therefore we believe that local magnetic anomalies of an active volcano may be constantly modified due to on going subsurface injections and circulations of hot material and also due to wide spacial and temporal distribution of highly magnetic basaltic flows that will constantly modify the topography which will in turn modify the local ambient geomagnetic field (Baag, et al., 1995). Our observations bring into question the general reliability of PSV data inferred from volcanic rocks, because on-going various geologic and geophysical activities associated with active volcano would continuously deflect and modify the ambient geomagnetic field.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.6
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• pp.732-746
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• 2003

Statement of problem. Soft lining materials, also referred to as tissue conditioning materials, tissue heating materials, relining materials, soft liners or tissue conditioners, were first introduced to dentistry by a plastic manufacturer in 1959. Since the introduction of the materials to the dental field, their material properties have been continually improved through the effort of many researchers. Soft lining materials have become widely accepted, particularly by prosthodontists, because of their numerous clinical advantages and ease of manipulation. Unfortunately, few reports have been issued upon the topic of increasing the bond strength between the base metal alloy used in cast denture bases and PMMA soft liner modified with 4-META, nor upon the pattern of debonding and material change in wet environment like a intra oral situation. Purpose. The purposes of this study were comparing the bond strength between base metal alloy used for the cast denture bases and PMMA soft liner modified with 4-META, and describing the pattern of debonding and material property change in wet environment like the intraoral situation. Material and Methods. This study consisted of four experiments: 1. The in vitro measurement of shear bond strength of the adhesive soft liner. 2. The in vitro measurement of shear bond strength of the adhesive soft liner after 2 weeks of aging. 3. A comparison of debonding patterns. 4. An evaluation the Relation time of modified soft liner. The soft liner used in this study was commercially available as Coe-soft (GC America.IL.,USA), which is provided in forms of powder and liquid. This is a PMMA soft liner commonly used in dental clinics. The metal primer used in this study was 4-META containing primer packed in Meta fast denture base resin (Sun Medical Co., Osaka, Japan). The specimens were formed in a single lap joint desist which is useful for evaluating the apparent shear bond strength of adhesively bonded metal plate by tensile loading. Using the $20{\times}20mm$ transparent grid, percent area of adhesive soft liner remaining on the shear area was calculated to classify the debonding patterns. To evaluate the change of the initial flow of the modified adhesive soft liner, the gelation time was measured with an oscillating rheometer (Haake RS150W/ TC50, Haake Co., Germany). It was a stress control and parallel plate type with the diameter of 35mm. Conclusion. Within the conditions and limitations of this study, the following conclusions were drawn as follows. 1. There was significant increase of bond strength in the 5% 4-META, 10% 4-META containing groups and in the primer coated groups versus the control group(P<0.05). 2. After 2 weeks of aging, no significant increase in bond strength was found except for the group containing 10% 4-META (P<0.05). 3. The gelation times of the modified soft liner were 9.3 minutes for the 5% 4-META containing liner and 11.5 minutes for the 10% 4-META liner. 4. The debonding patterns of the 4-META containing group after 2 weeks of aging were similar to those of immediaely after preparation, but the debonding pattern of the primer group showed more adhesive failure after 2 weeks of aging.