• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2017.05a
• /
• pp.77-77
• /
• 2017

Titanium and its alloys offer attractive properties in a variety of applications. These are widely used for the field of biomedical implants because of its good biocompatibility and high corrosion resistance. Titanium anodizing is often used in the metal finishing of products, especially those can be used in the medical devices with dense oxide surface. Based on SAE/AMS (Society of Automotive Engineers/Aerospace Material Specification) 2488D, it has the specification for industrial titanium anodizing that have three different types of titanium anodization as following: Type I is used as a coating for elevated temperature forming; Type II is used as an anti-galling coating without additional lubrication or as a pre-treatment for improving adherence of film lubricants; Type III is used as a treatment to produce a spectrum of surface colours on titanium. In this study, we have focused on Type II anodization for the medical (dental and orthopedic) application, the anodized surface was modified with gray color under alkaline electrolyte. The surface characteristics were analyzed with Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM), surface roughness, Vickers hardness, three point bending test, biocompatibility, and corrosion (potentiodynamic) test. The Ti-6Al-4V alloy was used for specimen, the anodizing procedure was conducted in alkaline solution (NaOH based, pH>13). Applied voltage was range between 20 V to 40 V until the ampere to be zero. As results, the surface characteristics of anodic oxide layer were analyzed with SEM, the dissecting layer was fabricated with FIB method prior to analyze surface. The surface roughness was measured by arithmetic mean deviation of the roughness profile (Ra). The Vickers hardness was obtained with Vickers hardness tester, indentation was repeated for 5 times on each sample, and the three point bending property was verified by yield load values. In order to determine the corrosion resistance for the corrosion rate, the potentiodynamic test was performed for each specimen. The biological safety assessment was analyzed by cytotoxic and pyrogen test. Through FIB feature of anodic surfaces, the thickness of oxide layer was 1.1 um. The surface roughness, Vickers hardness, bending yield, and corrosion resistance of the anodized specimen were shown higher value than those of non-treated specimen. Also we could verify that there was no significant issues from cytotoxicity and pyrogen test.

• Journal of Trauma and Injury
• /
• v.26 no.3
• /
• pp.111-124
• /
• 2013

Purpose: We should prepare proper medical service for disaster control as South Korea is not free from terrorism and war, as we experienced through the two naval battles of the Yeonpyeong, one in 1999 and the other in 2002, the sinking of Cheonan in 2010, and the attack against the border island of Yeonpyeong in 2010. Moreover, North Korea's increasingly bellicose rhetoric and mounting military threats against the world demand instant action to address the issue. The aim of this article is to describe our experience with three patients with combat-related gunshot and explosive injuries to their extremities and to establish useful methods for the management of patients with combat-related injuries. Methods: Three personnel who had been injured by gunshot or explosion during either the second naval battle of the Yeonpyeong in 2002 or the attack against the border island of Yeonpyeong in 2010 were included in our retrospective analysis. There were one case of gunshot injury and two cases of explosive injuries to the extremities, and the injured regions were the left hand, the right foot, and the right humerus. In one case, the patient had accompanying abdominal injuries, and his vital signs were unstable. He recovered after early initial management and appropriate emergency surgery. Results: All patients underwent emergent surgical debridement and temporary fixation surgery in the same military hospital immediately after their evacuations from the combat area. After that, continuous administration of antibiotics and wound care were performed, and definite reconstructions were carried out in a delayed manner. In the two cases in which flap operations for soft tissue coverage were required, one operation was performed 5 weeks after the injury, and the other operation was performed 7 weeks after the injury. Definite procedures for osteosynthesis were performed at 3 months in all cases. Complete union and adequate functional recovery were achieved in all cases. Conclusion: The patient should be stabilized and any life-threatening injuries must first be evaluated and treated with damage control surgery. Staged treatment and strict adherence to traditional principles for open fractures are recommended for combat-related gunshot and explosive injuries to the extremities.

• Korean Journal of Ecology and Environment
• /
• v.46 no.1
• /
• pp.86-93
• /
• 2013

We monitored 32 wetlands in order to investigate the influence of aquatic plants on zooplankton density and diversity in the littoral zone in Gyeongsangnam-do from May to June in 2011. A total of 65 zooplankton species were identified in the study sites. Among them, the diversity of epiphytic zooplankton were higher (40 species) than planktonic zooplankton. Littoral zones of all wetlands were covered by various aquatic plants, and influenced the epiphytic zooplankton assemblages. Based on the data from $1{\times}1$ (m) quadrat sampling, epiphytic and planktonic rotifer density showed no significant relationships with macrophyte cover. However, the epiphytic cladocerans density significantly increased under high aquatic plant cover ($r^2=0.39$, p<0.05, n=32). Types of aquatic plants strongly influenced epiphytic zooplankton density. Upo and Jangcheok are locations which have well developed Phragmites communis and Ceratophyllum demersum communities in the littoral zone, and a higher density of epiphytic zooplankton was recorded on the surface of C. demersum. Especially, rotifers such as Lepadella, Monostyla and Testudinella showed obvious differences (One-way ANOVA, p<0.05 for all three species). This result suggests that epiphytic zooplankton have a substrate preference for larger surface areas, likely for adherence, on C. dimersum. In conclusion, the complex structure of the littoral plant community is expected to provide diverse refuge and microhabitats to epiphytic zooplankton.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.3
• /
• pp.616-625
• /
• 2005

It is likely that maltose could provide a good substrate for the bacteria in the intestine, when the pathogenic bacteria invade and colonize in human gut. For better understanding of this organism's maltose metabolism, a mutant that was not able to grow with maltose as a sole carbon source was screened from a library of mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, malPQ genes encoding a maltodextrin phosphorylase and a 4-${\alpha}$-glucanotransferase, were identified and cloned from Vibrio vulnificus. The deduced amino acid sequences of malPQ from V. vulnificus were 48 to $91\%$ similar to those of MalP and MalQ reported from other Enterobacteriaceae. Functions of malPQ genes were assessed by the construction of mutants whose malPQ genes were inactivated by allelic exchanges. When maltose was used as the sole carbon source, neither malP nor malQ mutant was able to grow to a substantial level, revealing that the MalP and MalQ are the only enzymes for metabolic utilization of maltose. The malQ mutant exhibited decreased adherence toward intestinal epithelial cells in vitro, but there was no difference in the $LD_{50}s$ of the wild-type and the malQ mutant in mice. Therefore, it appears that MalQ is less important in the pathogenesis of V. vulnificus than would have been predicted by considering maltose as a most common sugar in the intestine, but not completely dispensable for virulence in mice.

• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.5
• /
• pp.601-610
• /
• 2007

Statement of problem: The adhesion between titanium and ceramic is less optimal than conventional metal-ceramic bonding, due to reaction layer form on cast titanium surface during porcelain firing. Purpose: This study characterized the effect of titanium-ceramic adhesion after gold and TiN coating on cast and wrought titanium substrates. Material and method: Six groups of ASTM grade II commercially pure titanium and cast titanium specimens$(13mm{\times}13mm{\times}1mm)$ were prepared(n=8). The conventional Au-Pd-In alloy served as the control. All specimens were sandblasted with $110{\mu}m\;Al_2O_3$ particles and ultrasonically cleaned for 5min in deionized water and dried in air before porcelain firing. An ultra-low-fusing dental porcelain (Vita Titankeramik) was fused on titanium surfaces. Porcelain was debonded by a biaxial flexure test at a cross head speed of 0.25mm/min. The excellent titanium-ceramic adherence was exhibited by the presence of a dentin porcelain layer on the specimen surface after the biaxial flexure test. Area fraction of adherent porcelain (AFAP) was determined by SEM/EDS. Numerical results were statistically analyzed by one-way ANOVA and Student-Newman-Keuls test at ${\alpha}=0.05$. Results: The AFAP value of cast titanium was greatest in the group 2 with TiN coating, followed by group 1 with Au coating and the group 3 with $Al_2O_3$ sandblasting. Significant statistical difference was found between the group 1, 2 and the group 3 (p<.05). The AFAP value of wrought titanium was greatest in the group 5 with TiN coating, followed by the group 4 with Au coating and the group 6 with $Al_2O_3$ sandblasting. Conclusion: No significant difference was observed among the three groups (p>.05). The AFAP values of the cast titanium and the wrought titanium were similar. However the group treated with $Al_2O_3$ sandblasting showed significantly lower value (p<.05).

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.2
• /
• pp.357-369
• /
• 2005

Streptococci are Gram-positive, facultative anaerobes and have no catalase activities. Among mutans streptococci containing ${\alpha}-type$ hemolytic activity, S. mutans is a causative agent for dental caries. As well as acid production yielding the demineralization of tooth enamel, adherence and colonization of S. mutans to the teeth are also important for its virulence. These early colonization are accomplished by the bacterial fibrillar protein, Antigen I/II (Ag I/II) and glucosyltransferase (GTF). Therefore, Ag I/II and GTF are reasonable targets for the development of vaccine against S. mutans GS-5. The ag I/II and gtfD genes from S. mutans GS-5 were cloned and sequenced. Sequence analyses showed the nucleotides sequence of cloned genes had high homology to the sequences previously reported. The sequence alignment of 280 nucleotides between the cloned Ag I/II and the available sequence of the corresponding S. mutans GS-5 showed the perfect match. Comparing with the sequence of gtfD from S. mutans UA159, the corresponding nucleotide sequence of S. mutans GS-5 showed some mismatches and the mismatches introduced changes in four residues out of 105 amino acids, yielding four missense mutations.

• Tuberculosis and Respiratory Diseases
• /
• v.73 no.2
• /
• pp.93-99
• /
• 2012

Background: Local adverse events associated with inhaled corticosteroid use, including dysphonia, pharyngitis and oral candidiasis, can affect adherence for treatment. 'Mouth rinsing method' has been used for reducing local adverse events, but it cannot ensure complete prevention. The goal of this pilot study was to identify whether the 'immediate diet method' can reduce local adverse events in a limited number of patients. Methods: The study was conducted in a total of 98 patients, who had been prescribed a medium-dose fluticasone propionate for the first time, from January to October in 2010. One training nurse had performed the education on how to use the inhaler, including the mouth rinsing method. And with follow-ups at one month intervals, any patient who experienced such adverse events were educated on the immediate diet method, having a meal within 5 minutes after using an inhaler and they were checked on any incurrence of adverse events with one month intervals for 2 months. Results: The mean age of patients was 65.9 years old. The local adverse events had incurred from 18.4% of the study subjects. When performed the follow-up observation in 18 patients with local adverse events after education on the immediate diet method, 14 patients (77.8%) had shown symptomatic improvements. Three of 4 patients did not show any improvement, in spite of implementing the immediate diet method. The other 1 patient did not practice the immediate diet method properly. Conclusion: The immediate diet method may be useful in reducing the local adverse events, caused by the use of inhaled corticosteroid.

• The Korea Journal of Herbology
• /
• v.31 no.5
• /
• pp.7-13
• /
• 2016

Objectives : Camellia sinensis (Theaceae) possesses a various beneficial effects such as free radical-scavenging, inactivation of urokinase in cancer cell proliferation, antibacterial, and hypotensive. Dental caries is one of the most common oral infectious disease in a human. Oral microorganisms play a significant role in the etiology of dental caries. An aberration to this ecology due to dietary habits, improper oral hygiene or systemic factors lead to an increase in cariogenic microorganisms. Cariogenic microorganisms like Streptococcus mutans and Streptococcus sobrinus encourage the accumulation and adherence of plaque biofilm by metabolizing sucrose into glucans. The purpose of this study was to investigate the antimicrobial activity of phenolic compounds of Camellia sinensis and R-carvone, monoterpenes, is can be found naturally in numerous essential oils, on Streptococcus mutans and Streptococcus sobrinus .Methods : The antimicrobial activity of these compounds was determined by the broth microdilution method and checkerboard dilution assay to investigate the potential synergistic effects of each five compounds of Camellia sinensis (C. sinensis) and R-carvone.Results : C. sinensis-isolated compounds and R-carvone were determined with MIC of more than 1,000 ㎍/mL. However, the combination test showed significant synergism against S. mutans and S. sobrinus, implicated in the lowered MICs.Conclusions : These results suggest that combinatory application of phenolic five compounds (theophyllin, l-theanine, epicatechin, epicatechin gallate, and caffeine) from C. sinensis and R-carvone has a potential synergistic effect and thus may be useful as a mouthrinse in helping control cariogenic microorganism.

• Journal of Marine Bioscience and Biotechnology
• /
• v.2 no.4
• /
• pp.250-256
• /
• 2007

The present study purified two noncyclic triterpenoids, compound 1 and compound 2, that intervene interaction of ICAM-1 and LFA-1 from ethanol extracts of Alpinia katsumadai. The compound 1 and 2 inhibited adherence of sICAM-1 to THP-1 cells with an $IC_{50}$ of $7.59{\mu}g/m{\ell}$ 및 $6.98{\mu}g/m{\ell}$, respectively, without affecting viability of the cells. The compound 1 and 2 also inhibited interaction of CHO-ICAM-1 cells with THP-1 cells with an $IC_{50}$ $6.7{\mu}g/m{\ell}$ 및 $5.5{\mu}g/m{\ell}$, respectively. These findings suggest that the noncyclic triterpenoids from Alpinia katsumadai have inhibitory activities against cell adherent molecules. The present study proposes that noncyclic triterpenoids from Alpinia katsumadai can applied to therapeutic approaches to the diseases that are associated with adhesion of inflammatory cells.

• Microbiology and Biotechnology Letters
• /
• v.35 no.2
• /
• pp.118-127
• /
• 2007

Germanium-fortified yeast (GY) is a organic germanium-fortified yeast with potent immune modulating activities including anti-inflammatory effect. Through cell line studies, we observed that GY can modulate the diverse immune activity but little evidence was provided on the mechanism of GY in modulating immune activities in other higher animals. In this study, we investigated the effect of GY on modulation of immune function in mice. GY was administered in normal mice or tumor-bearing mice and then effect of GY on modulation of host immune system was analyzed by using ex vivo isolated macrophages, B cells, NK cells. Admistration of GY in mice induced macrophage activation thereby increased effector function of macrophage such as increased phagocytosis, chemotaxis, adherence, $O_2-release$, NO, $TNF-{\alpha}$ production. In addition, GY administration Increased B lymphocyte activation and plaque forming cells. Furthermore, GY administration increased NK-cell mediated cytotoxicity. Furthermore, GY administration suppressed progression of tumor in mice by increasing $TNF-{\alpha}$ production and effector function of NK cells. Our results showed that GY has a potent immunostimulatory function in vivo mice model. Proper modulation and administration of GY in human could be helpful to maintaining immunological homeostasis by modulating host immune system.