• Journal of Pharmacopuncture
• /
• v.19 no.1
• /
• pp.37-44
• /
• 2016

Objectives: This study examined the relative efficacies of a derivative of betulinic acid (dBA) and its poly (lactide-co-glycolide) (PLGA) nano-encapsulated form in A549 lung cancer cells in vivo and in co-mutagen [sodium arsenite (SA) + benzo[a]pyrene (BaP)]-induced lung cancer in mice in vivo. Methods: dBA was loaded with PLGA nanoparticles by using the standard solvent displacement method. The sizes and morphologies of nano-dBA (NdBA) were determined by using transmission electron microscopy (TEM), and their intracellular localization was verified by using confocal microscopy. The binding and interaction of NdBA with calf thymus deoxyribonucleic acid (CT-DNA) as a target were analyzed by using conventional circular dichroism (CD) and melting temperature (Tm) profile data. Apoptotic signalling cascades in vitro and in vivo were studied by using an enzyme-linked immunosorbent assay (ELISA); the ability of NdBA to cross the blood-brain barrier (BBB) was also examined. The stage of cell cycle arrest was confirmed by using a fluorescence-activated cell-sorting (FACS) data analysis. Results: The average size of the nanoparticles was ~ 110 nm. Confocal microscopy images confirmed the presence of NdBA in the cellular cytoplasm. The bio-physical properties of dBA and NdBA ascertained from the CD and the Tm profiles revealed that NdBA had greater interaction with the target DNA than dBA did. Both dBA and NdBA arrested cell proliferation at G0/G1, NdBA showing the greater effect. NdBA also induced a greater degree of cytotoxicity in A549 cells, but it had an insignificant cytotoxic effect in normal L6 cells. The results of flow cytometric, cytogenetial and histopathological studies in mice revealed that NdBA caused less nuclear condensation and DNA damage than dBA did. TEM images showed the presence of NdBA in brain samples of NdBA fed mice, indicating its ability to cross the BBB. Conclusion: Thus, compared to dBA, NdBA appears to have greater chemoprotective potential against lung cancer.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.3
• /
• pp.330-336
• /
• 2005

The ozone injection method was proposed to improve the catalytic process for the removal of nitrogen oxides ($NO_x$). Nitric oxide (NO) in the exhaust gas was first oxidized to nitrogen dioxide ($NO_2$) by ozone produced by dielectric barrier discharge, and then the exhaust gas containing the mixture of NO and $NO_2$ was directed to the catalytic reactor where both NO and $NO_2$ were reduced to $N_2$ in the presence of ammonia as the reducing agent. A commercially available $V_2O_5-WO_3/TiO_2$ catalyst was used as the catalytic reactor. The $NO_2$ content in the mixture of NO and $NO_2$ was changed by the amount of ozone added the exhaust gas. The effect of reaction temperature, initial $NO_x$ concentration, feed gas flow rate, and ammonia concentration on the removal of $NO_x$ at various $NO_2$ contents was examined and discussed. The increase in the content of $NO_2$ by the ozone injection remarkably improved the performance of the catalytic reactor, especially at low temperatures. The present ozone injection method appears to be promising for the improvement of the catalytic reduction of $NO_x$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.264-264
• /
• 2010

Single-walled carbon nanotubes (SWCNTs) were grown on a Si wafer by using thermal chemical vapor deposition (t-CVD). We investigated the effect of the catalyst deposition rate on the types of CNTs grown on the substrate. In general, smaller islands of catalyst occur by agglomeration of a catalyst layer upon annealing as the catalyst layer becomes thinner, which results in the growth of CNTs with smaller diameters. For the same thickness of catalyst, a slower deposition rate will cause a more uniformly thin catalyst layer, which will be agglomerated during annealing, producing smaller catalyst islands. Thus, we can expect that the smaller-diameter CNTs will grow on the catalyst deposited with a lower rate even for the same thickness of catalyst. The 0.5-nm-thick Fe served as a catalyst, underneath which Al was coated as a catalyst support as well as a diffusion barrier on the Si substrate. The catalyst layers were. coated by using thermal evaporation. The deposition rates of the Al and Fe layers varied to be 90, 180 sec/nm and 70, 140 sec/nm, respectively. We prepared the four different combinations of the deposition rates of the AI and Fe layers. CNTs were synthesized for 10 min by flowing 60 sccm of Ar and 60 sccm of $H_2$ as a carrier gas and 20 sccm of $C_2H_2$ as a feedstock at 95 torr and $810^{\circ}C$. The substrates were subject to annealing for 20 sec for every case to form small catalyst islands prior to CNT growth. As-grown CNTs were characterized by using field emission scanning electron microscopy, high resolution transmission electron microscopy, Raman spectroscopy, UV-Vis NIR spectroscopy, and atomic force microscopy. The fast deposition of both the Al and Fe layers gave rise to the growth of thin multiwalled CNTs with the height of ${\sim}680\;{\mu}m$ for 10 min while the slow deposition caused the growth of ${\sim}800\;{\mu}m$ high SWCNTs. Several radial breathing mode (RBM) peaks in the Raman spectra were observed at the Raman shifts of $113.3{\sim}281.3\;cm^{-1}$, implying the presence of SWCNTs (or double-walled CNTs) with the tube diameters 2.07~0.83 nm. The Raman spectra of the as-grown SWCNTs showed very low G/D peak intensity ratios, indicating their low defect concentrations.

• Journal of Periodontal and Implant Science
• /
• v.25 no.2
• /
• pp.267-278
• /
• 1995

Human polymorphonuclear leukocytes(PMN) are the most numerous host cell in periodontal pockets and their presumed role is to form a protective barrier between the bacteria and periodontal tissues. Microbial component LPS activates macrophages to produce $IL-1{\beta}$, $MIP-1{\alpha}$, $-1{\beta}$, $TNF-{\alpha}$ and IL-6, etc. These cytokines have autocrine function to the macrophages, and paracrine function to other cell such as PMN and affect them to produce some biological functions. In the present study, human PMN were tested for the expression of $IL-1{\beta}$ and $MIP-1{\alpha}$ mRNA. Also we performed the receptor binding assay and in vitro assay for the antimicrobial action of HL-60 cell to determine whether HL-60 can replace the peripheral PMN in analyzing the biological functions. PMN were stimulated with $IL-1{\beta}$, TPA, $MIP-1{\alpha}$, LPS, IL-2 and total cytoplasmic RNA were extracted for the northern blot analysis. In order to determine the induction kinetics of $IL-1{\beta}$ or $MIP-1{\alpha}$ mRNA expression, cells were stimulated for 0,1,2,3 hours. We found peak expression of $IL-1{\beta}$ mRNA after 1hr of induction with $IL-1{\beta}$, LPS and after 2hr of induction with TPA. $MIP-l{\alpha}$ also induced but a scarce $IL-l{\beta}$ message from PMN. In contrast to the $IL-l{\beta}$ mRNA expression, $MIP-1{\alpha}$ were not induced from PMN in any culture conditions. Receptors for $MIP-1{\alpha}$ were identified on dibutyryl cyclic AMP(dbcAMP)-treated HL-60 as well as peripheral PMN. dbcAMP treatment significantly enhanced antimicrobial action of undifferentiated HL-60 cell. MIP-1 further increased enhancing effect of dbcAMP. $IL-1{\beta}$, to a lesser extent, also increased dbcAMP-induced enhancing effect of antimicrobial action of HL-60 cell.

• Journal of Soil and Groundwater Environment
• /
• v.12 no.6
• /
• pp.38-45
• /
• 2007

Trichloroethylene (TCE) is a representative dense non-aqueous phase liquid (DNAPL) and has contaminated substance environments including soil and groundwater due to leakage and careless. DNPAL, has been treated by surfactant-enhanced aquifer remediation (SEAR). After application of SEAR, groundwater contains still surfactant as well as little amount of residual TCE. Permeable reactive barrier using zero-valent iron (ZW) is a very effective technology to treat the residual TCE in groundwater. In this study, the effect of the residual surfactant on the reductive dechlorination of residual TCE was investigated using ZVI. Mixed surfactant composed of nonioinic surfactant and cationic surfactant was used as a residual surfactant because of toxicity and enhancement of dechlorination rate. Structure of surfactant affected significantly the decrhlorination rate of TCE. Mixed surfactant system with relatively short polyethylene oxide (PEO) chain in nonionic surfactant, cationic surfactant did not affect TCE dechlorination rate. However, mixed surfactant system with relatively long PEO chain in nonionic surfactant shows that TCE dechlorination rate was significantly dependent on fraction of cationic surfactant and HLB of nonionic surfactant. Cationic surfactant with trimethyl ammonium group enhanced reductive dechlorination rate compared to that surfactant with pyridinium group.

• Journal of Periodontal and Implant Science
• /
• v.23 no.3
• /
• pp.359-373
• /
• 1993

The ultimate objective of periodontal therapy is not only stopping the progression of periodontal disease, but also promoting the regeneration of lost periodontal tissue. Guided Tissue Regeneration, which is based on the principle that the goal of periodontal regeneration can be achieved by preventing apical migration of gingival epithelium and blocking cells originating from connective tissue, has been developed and used as a clinical procedure, and although it has shown excellent results in connective tissue healing, there have not been many studies showing its effect on the regeneration of alveolar bone loss due to periodontal disease. The objectives of this study are to investigate the result of 12 months-long treatment following guided tissue regeneration using expanded polytetrafluoroehylene membrane, and to observe the presence of regenerated alveolar bone. Forty-one teeth from 28 patients with clinical diagnosis of periodontitis has been selected. In fifteen of those interproximal intrabony defects, only flap operation had been carried out, and designated as the control group. Twenty-six intrabony defects received e-PTFE membrane following flap operation, and designated as the experimental group. Eleven teeth whose membrane had been exposed were excluded from the experiment. Various measurements including probing depth, loss of attachment, probing bone level and gingival recession have been recorded at 6th month and 12th month, and the significance of the changes has been analyzed. The results are as follows: 1. Probing depth at 6th and 12th month has shown a significant decrease in both groups (p<0.01), but significantly higher decrease was found in the experimental group compared to the control at the month(p<0.05). 2. Loss of attachment at 6th and 12th month has shown a significant decrease in both groups, but significantly higher decrease was found in the experimental group compared to the control (p<0.05). 3. Probing bone level at 6th and 12th month has shown a insignificant decrease in the control group and significant decrease in the experimental group (p<0.01). Significantly higher decrease in probing bone level was found in the experimental group (p<0.05). 4. Gingival recession at 6th and 12th month has shown a statistically significant increase (p<0.05), and the control group showed higher increase compared to the experimental group although no statistical significance was found. As these results have shown, the use of e-PTFE membrane in intrabony pockets results in marked decrease in the loss of attachment and probing bone level. This seems to indicate that e-PTFE membrane may play a role in alveolar bone regeneration in intrabony defects.

• Biomedical Science Letters
• /
• v.17 no.1
• /
• pp.55-60
• /
• 2011

Skin is a physical barrier against diverse injury and damages. Exposure to ultraviolet (UV) radiation causes detrimental skin injuries such as inflammation and cell death. The value of natural pigments could be applied to many usages including cosmetics. This study was conducted to examine the protective effect of natural pigments extracted from mulberry, balsam pear, purple-colored sweet potato, pehmannia root, gardenia fruit, and black rice against UV-induced cell death in HaCaT cells, human keratinocyte cell lines. In the present study, the exposure of 50 mJ/$cm^2$ UV-B for 24 hr induced cell death in HaCaT cells, which was prevented by the pretreatment of extracts of mulberry, balsam pear, purple-colored sweet potato, rehmannia root, gardenia fruit, and black rice. In addition, the exposure of 50 mJ/$cm^2$ UV-B for 24 hr also increased lipid peroxide (LPO) formation, compared to control in HaCaT cells, which was prevented by the pretreatment of extracts of mulberry, balsam pear, purple-colored sweet potato, rehmannia root, gardenia fruit, and black rice. In conclusion, the extracts of mulberry, balsam pear, purple-colored sweet potato, rehmannia root, gardenia fruit, and black rice prevented the UV-B-induced cell apoptosis via the inhibition of oxidative stress in HaCaT cells.

• Journal of dental hygiene science
• /
• v.9 no.4
• /
• pp.405-412
• /
• 2009

The purpose of this study investigated the effect of Au coating on adhesion between porcelain matrix and metal substructure interface. Titanium, Ni-Cr alloy and Co-Cr alloy are well known as proper metal for the dental restorations. The success of a porcelain fused to metal (PFM) restoration depends upon the quality of the porcelain-metal bond. However, adhesion between dental alloys and porcelain is related to diffusion of oxygen during ceramic firing. The excessive oxidized layers make hard adhesion between dental alloy and ceramic. Ni-Cr and Co-Cr specimens were divided into test and a control group and Titanium specimens were divided into three test groups and a control group. Each group had 20 specimens. The adhesion characteristics of porcelain and metal with Au coating layer and without Au coating layer were observed with scanning electron microscopy(SEM). The adhesion was evaluated by a biaxial flexure test and volume fraction of adherent porcelain was determined by SEM/EDS analysis. Result of this study suggest that Au coating layer is effective barrier to diffuse oxide layer completely protect non-precious alloys from oxidation during the porcelain firing. The SEM photomicrographs of cross-section specimens showed a smooth interface between Au coating layer and metals and porcelain which suggested proper chemical bonding, and no gap, porosity were observed. The mode of failure was mainly adhesive for Ti tested specimens, but mixed failures with adhesive and cohesive were observed in Ni-Cr and Co-Cr specimens. The adhesion between non-precious metals and porcelain would not be improved by Au coating agent. However, It is suggested that the continuous study is required further investigation and development.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.36 no.2
• /
• pp.115-120
• /
• 2010

The formidable barrier property of the stratum cornemum and the high hydrophilicity of active ingredient make it difficult to permeate through the skin and reach to its site of action. The aim of this study was to investigate the effect of chemical penetration enhancers on the skin permeation of a hydrophilic cosmetic active ingredient, such as arbutin. The enhancing effects of N-methyl-2-pyrrolidone (NMP) on the permeation of a hydrophilic cosmetic active ingredient were evaluated by using Franz diffusion cell. The study indicated that NMP has considerable influence on the skin permeability. NMP was not only the most effective enhancer but also increased the skin permeability of arbutin approximately 1.3~1.5 fold compared with control without penetration enhancer. The lag time did not change with NMP, which suggested no effect of NMP on skin lipid fluidity. This suggest that arbutin co-permeated with NMP. The results indicate NMP is effective enhancer of a hydrophilic cosmetic active ingredient in penetration, with potential applications for drug delivery system.

• Journal of Soil and Groundwater Environment
• /
• v.7 no.1
• /
• pp.33-40
• /
• 2002

The study was performed to evaluate the effect of landfill leachate on the hydraulic conductivity of Geosynthetic Clay Liner (GCL) with two types of leachate. GCL used in waste landfills have a significant ability as a barrier material, however, they also have a potential danger when exposed to some organic and inorganic leachate as well as humic materials. In this study, swelling tests and hydraulic conductivity tests were performed to evaluate the effect of humic materials and landfill leachate on the hydraulic characteristics of the GCL. The result of swelling tests showed that the amount of humic materials and high electronic conductivity caused a decrease of the swelling of bentonite. This is expected to increase the hydraulic conductivity of GCL. The increasing of hydraulic conductivity observed for GCL permeated with 0-leachate was significantly higher than that of Y-leachate. This result shows that humic materials are obviously affecting with the increasing of hydraulic conductivity of GCL.