• The Korea Journal of Herbology
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• v.30 no.5
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• pp.15-21
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• 2015

Objectives : Methicillin-resistantStaphylococcus aureus(MRSA) is a human pathogen. New antibacterial agents are needed to treat MRSA-related infections. This study investigated the antibacterial activity of EtOH 70% extracts ofTonghyeonipal-dan(THD) which prescription is composed of oriental medicine against MRSA.Methods : The antibacterial activity of THD was evaluated against MRSA strains by using the Disc diffusion method, broth microdilution method, Checkerboard dilution test, and Time-kill test; its mechanism of action was investigated by bacteriolysis, detergent or ATPase inhibitors were used.Results : The minimum inhibitory concentration (MIC) of THD is 1,000~2,000 μg/mL against MRSA. In the checkerboard dilution test, fractional inhibitory concentration index (FICI) of THD in combination with antibiotics indicated synergy or partial synergism againstS. aureus. Furthermore, a time-kill assay showed that the growth of the tasted bacteria was considerably inhibited after 24 h of treatment with the combination of THD with selected antibiotics. For measurement of cell membrane permeability, THD 500 μg/mL along with concentration of Triton X-100 (TX) and Tris-(hydroxymethyl) aminomethane (TRIS) were used. In the other hand, N,N-dicyclohexylcarbodimide (DCCD) and Sodium azide (NaN3) were used as an inhibitor of ATPase. TX, TRIS, DCCD and NaN3 cooperation againstS. aureusshowed synergistic action.Conclusions : Accordingly, antimicrobial activity of THD was affected by cell membrane and inhibitor of ATPase were assessed. These results suggest that THD has antibacterial activity, and that THD extract offers great potential as a natural antibiotic against MRSA.

• Journal of dental hygiene science
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• v.11 no.1
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• pp.37-40
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• 2011

Oleanolic acid (OA) and ursolic acid (UA) are triterpenoid compound present in many plants. This study examined the antimicrobial activity of OA and UA against Streptococcus downei. The antimicrobial activity was evaluated by the minimal inhibitory concentration (MIC) and time kill curves. The MIC values of OA and UA for S. downei isolated from the Korean population were $8{\mu}g/ml$. OA and UA had a bactericidal effect on S. downei ATCC $33748^T$ above $2{\times}MIC$, $16{\mu}g/ml$ and $8{\mu}g/ml$, respectively. The results suggest that OA and UA can be used in the development of oral hygiene products for the prevention of dental caries.

• Journal of dental hygiene science
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• v.10 no.3
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• pp.161-165
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• 2010

The aim of this study was to investigate the antimicrobial effect of (-)-epigalocatechin on Fusobacterium nucleatum, Prevotella intermedia, and Porphyromonas gingivalis. To test the antimicrobial effect of (-)-epigalocatechin, the minimum inhibitory concentration (MIC) of against 4 strains of F. nucleatum, 2 strains of P. intermedia, and 2 strains of P. gingivalis was measured by broth dilution method. Time-kill curves were assessed for susceptible bacteria, testing $0{\times}MIC$ (control group), $0.5{\times}MIC$, $1{\times}MIC$, and $2{\times}MIC$ for (-)-epigalocatechin, by counting viable bacteria after 3, 90, 180, 360, 720, 1440 minutes. The MIC of (-)-epigalocatechin was 0.312-0.625, 0.625, and 0.625 mg/ml on the strains of F. nucleatum, P. intermedia, and P. gingivalis, respectively. Time-kill curves demonstrated (-)-epigalocatechin had bactericidal activity on P. intermedia ATCC $25611^T$, P. gingival is ATCC 53978, and F. nucleatum subsp. fusiforme ATCC $51190^T$. The results suggest that (-)-epigalocatechin can be useful in developing the oral hygiene product such as tooth past and gargling solution for the prevention of periodontal diseases.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.289-294
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• 2010

Salvia miltiorrhiza Bunge (S. miltiorrhiza) is a traditional Korean medicine that is commonly used for the treatment of inflammatory diseases such as edema, arthritis, and hepatitis. The present study investigated the antimicrobial activity of methanol (MeOH) extract of S. miltiorrhiza roots against oral bacteria using broth the microdilution method and the checkerboard and time-kill methods evaluated the synergistic effects of treatment with antibiotics. The MeOH extract was demonstrated as a higher antibacterial activity (MICs, 8 to $64\;{\mu}g/mL$; MBCs, 16 to $64\;{\mu}g/mL$) against all tested oral bacteria. Additionally, the extract was observed to have a synergistic effect with ampicillin or gentamicin. A time-kill study evaluating the effects of the extract indicated that the extract treatment in combination with ampicillin or gentamicin showed rapid bactericidal activity. The results suggest that MeOH extract of S. miltiorrhiza could be employed as a natural antibacterial agent against dental caries.

• Physical Therapy Korea
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• v.9 no.3
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• pp.93-99
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• 2002

Traditionally, ultraviolet (UV) has been used for treating the pressure sore and skin wound. The effects of UVA and UVB radiation on disinfection have been reported. The purpose of this study was to examine the effectiveness of UVC radiation on disinfection of Escherichia coli, Staphylococcus aureus, Salmonella typhimurium in vitro. Three bacterium were radiated by UVC (250 nm, 20 seconds) and incubated at $37^{\circ}C$ for 24 hours at the agar culture medium. Kill rates of all three bacterium were 99.9%. UVC radiated on three kinds of bacterium for 30 or 60 seconds. Kill rates were 99.9% both 30 and 60 seconds. This data suggests that UV light at 250 nm could be a useful method to minimize infection and shorten healing time in pressure sore and skin wound condition.

• Journal of Microbiology
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• v.43 no.1
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• pp.17-20
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• 2005

Poria cocos, a famous traditional Chinese medicine, was found to have nematicidal activity in experiments searching for nematicidal fungi. The experiment showed it could kill 94.9% of the saprophytic nematode, Panagrellus redivivue, 92.6% of the root-knot nematode, Meloidogyne arenaria, and 93.5% of the pine nematode, Bursaphelenchus xylophilus, on PDA plate within 12 hours. According to the nematicidal activity, three new compounds, 2, 4, 6-triacetylenic octane diacid, 2, 4, 5, 6-tetrahydroxyhexanoic acid and 3, 4-dihydroxy-2-keto-n-butyl 2,4,5,6-tetrahydroxyhexanate, were isolated from submerged cultures of Poria cocos. Of these, 2, 4, 6-triacetylenic octane diacid could kill 83.9% Meloidogyne arenaria and 73.4% Panagrellus redivivus at 500 ppm within 12 hours. Here, it is reported for the first time that Poria cocos has nematicidal activity.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.974-974
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• 1995

• Parasites, Hosts and Diseases
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• v.48 no.2
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• pp.179-182
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• 2010

Artemesinin-combination therapies (ACT) for falciparum malaria reduce gametocyte carriage, and therefore reduce transmission. Artemisinin derivatives will act against only young gametocytes whereas primaquine acts on mature gametocytes which are present usually in the circulation at the time when the patient presents for treatment. Both artemisinin derivatives and primaquine have short half-lives, less than 1 hr and 7 hr, respectively. Therefore, asexual parasites or young gametocytes remain after completed ACT. A single dose of primaquine (0.50-0.75 mg base/kg) at the end of ACT can kill only mature gametocytes but cannot kill young gametocytes (if present). Remaining asexual forms after completion of ACT course, e.g., artesunate-mefloquine for 3 days, may develop to mature gametocytes 7-15 days later. Thus, an additional dose of primaquine (0.50-0.75 mg base/kg) given 2 weeks after ACT completion may be beneficial for killing remaining mature gametocytes and contribute to more interruption of Plasmodium falciparum transmission than giving only 1 single dose of primaquine just after completing ACT.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1841-1851
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• 2019

Garcinol, a well-known medicinal phytochemical, was extracted and isolated from the dried fruit rinds of Garcinia quaesita Pierre. In this study, garcinol has successfully used to reduce silver ions to silver in order to synthesize garcinol-capped silver nanoparticles (G-AgNPs). The formation and the structure of G-AgNPs were confirmed by UV-visible spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The antimicrobial activity of garcinol and G-AgNPs were investigated by well diffusion assays, broth micro-dilution assays and time-kill kinetics studies against five microbial species, including Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), Candida albicans (ATCC 10231) and clinically isolated methicillin-resistant Staphylococcus aureus (MRSA). The formation of G-AgNPs is a promising novel approach to enhancing the biological activeness of silver nanoparticles, and to increase the water solubility of garcinol which creates a broad range of therapeutic applications.

• Strategy21
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• s.41
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• pp.208-231
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• 2017

The balance of power in conventional forces between the two Koreas works in favor of the South Korea in the Korea peninsula. But, the balancing mechanism between the two Koreas in asymmetric forces like nuclear and missile forces works absolutely in favor of the North Korea. That's why it should be timely for the ROK military to review existing strategy and revise a new counter strategy against the threat posed by the North Korea's nuclear and missile forces. The ROK military is now developing 4D, KAMD, KILL Chain strategies as means to cope with the North Korea's nuclear and missile threats. Considering efforts and resources invested now, the strategies are expected to be in place in next five or more years. However, approaches to those strategies seem to be rather fragmentary and conceptual than comprehensive and pragmatic. The types of strategies against the North Korea's military threats need to be a deterrence in peace time and a fighting and winning in war time in the Korean theater. But, the most important element in the deterrence strategy is the credibility. This study concludes with an new strategic concept titled "ADAD(Assured Defense, Assured Destruction)" as an alternative to existing strategies to deal with the North Korea's nuclear and missile threats.