• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.250-256
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• 2006

The revision of radio waves act, which took effect on July 1,2005, widened the bandwidth of PLC from $9kHz{\sim}450kHz$ to $9kHz{\sim}30MHz$. This high upper limit of frequency may cause the interference in HF wireless communications. From this point of view, the goal of this research is to suggest the estimation method of whether-or-not the interference occurs and furthermore offer countermeasures to avoid it hereafter. Ministry of Information and Communication Radio Research Laboratory(MIC-RRL)has been researching for the interference and devoting themselves to turn out how much it affects to HF wireless communications since the revision took effect. This research suggests some estimation methods with receivers, signal generators, or SINAD(Signal to Noise and Distortion) Meter which is so suitable for the RF environment that we can overcome the existing limit to the EMC environment. In addition, this research is focused on securing the environment for wireless communications by establishing the safety zone or suggesting the ways to prohibit the use of the bandwidth, which may cause serious interference, in order to minimize the effect of PLC on HF maritime mobile telecommunications.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.12 no.1
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• pp.18-35
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• 1999

Coptidis Rhizoma, Fraxini Cortex, Jinpisan(秦皮散) have been as eye washes of inflammatory eye disease in the oriental medicine. Especially Jinpisan(秦皮散) has been used for the disease which is similar to Peudomonas aeruginisa keratitis. This research was attempted to investigate the effect of Coptidis Rhizoma, Fraxini Cortex, Jinpisan(秦皮散), on Peudoronas aeruginisa keratitis. Pseudomonas aeruginosa keratitis causes a deep rapid intense ulceration which often leads to perforation of the cornea within 48 hours. In this research, we induced keratits in the rabbits by inoculating Pesudomonas aeruginosa(9027) and observed the effect on the keratitis and the irritation against the external eye. Also we mesured the minimum inhibitory consentration(MIC) of Coptidis Rhizoma, Fraxini Cortex, Jinpisan(秦皮散) by agar diliution method and the anti-bacterial activites by disk method. The tested bacteria were as follows : a) Pseudomonas aeruginosa (9027), b) Streptococcus pneumoniae(6303), c) Staphylococcus epidermidis(12228), d) Staphylococcus aureus(6538P). The results were as follows ; 1. The groups which were applied eye washes of Fraxini Cortex, Jinpisan reavealed a significant effect, but the group applied eye wash of Coptidis Rhizoma reveaded no effect on Pseudomonas aeruginosa keratitis. 2. Applying eye washes of Coptidis Rhizoma, Fraxini Cortex, Jinisan revealed an irritation against external eyes. 3. Coptidis Rhizoma showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylucoccus aureus by agar diliution method 4. Coptidis Rhizoma showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus by disk method. 5. Fraxini Cortex showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus by agar diliution method 6. Fraxini Cortex showed an anti-bacterial activity on Pseudomonas aeruginosa, Sireptococcus pneumoniae, Staphylococcus epidermidis, Staphy1ococcus aureus by disk method. 7. Jinpisan showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus by agar diliution method. 8. Jinpisan showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus by disk method. According to the above results, Fraxini Cortex, Jinpisan(秦皮散) are recognized to have an effective treatment on the Pesudomonas aeruginosa keratitis, so this experiment is thought to be a basic ingredient in proving the effect of Fraxini Cortex, Jinpisan which is applied many in documents and clinical medicine. In the comparison of anti-bacterial activity and results of treatment on the Pesudomonas aeruginosa keratitis, Jinpisan(秦皮散) was more effective than Coptidis Rhizoma, Fraxini Cortex.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.863-870
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• 2005

One hundred and twenty three strains of Mycoplasma pneumoniae were isolated from patients with respiratory diseases from February 2002 to April 2005 in Busan, Korea. The MICs of tetracycline and erythromycin up to $90\%$ of the 123 M. pneumoniae isolates tested were $0.5\~1.0$, and $0.5\~512{\mu}/ml$, respectively. Plasmid DNA was not isolated from all of the M. pneumoniae isolates. Out of 323 strains of M. pneumoniae, 57 ($46.3\%$) stains contain tetM gene on their chromosomal DNA, and 60 ($48.8\%$) strains were mutated in domain V of 23S rRNA for erythromycin resistance. Out of 63 strains of M. pneumoniae which were not mutated in domain V of 235 rRNA for erythromycin resistance, 36 ($57.1\%$) strains contained tetM gene, and out of 60 strains of M. pneumoniae which were mutated in domain V of 23S rRNA for erythromycin resistance, 21 ($35.0\%$) strains contained tetM gene. These results suggest that the isolation rate of erythromycin and tetracycline resistant M. pneumoniae is higher than those of other countries, and erythromycin and tetracycline are not first choice drug for M. pneumoniae infection in Korea, and it need confirm by a nationwide surveilance of antimicrobial resistance.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.283-294
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• 1987

One hundred and fifty-seven strains of staphylococci isolated from various clinical specimens and 80 of Gram-negative bacilli from urine of patients with urological diseases were tested for resistance to antimicrobial drugs by microdilution broth method. Among staphylococci, 50 to 89% of the strains were resistant to gentamicin(Gm), kanamycin(Km), erythromycin(Em), nalidixic acid(Na), and tetracycline. Ninety per cent MIC was lowest in ciprofloxacin(Cp), followed by vancomycin(Vc), trimethoprim(Tp), enoxacin(Ex), and norfloxacin(Nf) with the values of two ${\mu}g/ml$ or lower. Twenty-seven strains were resistant to methicillin(MR), with 24 strains of Staphylococcus aureus and 3 of S. epidermidis. All strains of MR S. aureus were resistant to oxacillin, rifampin(Rf), Gm, Km, Em, Na, and Tc, and no strain was resistant to Vc and Tp. Almost all staphylococci isolated from urine were S. epidermidis and sensitive to most drugs tested without MR strain. Among Gram-negative bacilli from urine, Escherichia coli(43 strains) was most frequently isolated, and followed by Klebsiella spp.(11), Proteus spp.(10), Serratia spp.(10), and Pseudomonas aeruginosa(6) in the decreasing order. The majority of E. coli and Serratia spp. were resistant to chloramphenicol(Cm), Tc, streptomycin, sulfisomidine(Su), ampicillin(Ap), Km, and carbenicillin(Cb), and 50 and 90% MICs of these drugs were also high. In Klebsiella spp., 54% or more were resistant to Cm, Su, Ap, cephalothin, and Cb. Proteus spp. were susceptible to most drugs tested, but Pseudomonas were resistant to nearly all drugs tested except Rf, amikacin, and moxalactam(Mx). All Gram-negative bacilli tested were found to be susceptible to Mx. New quinolone carboxylic acid compounds, such as Nf, Ex, and Cp showed very high antimicrobial activities against the majority of organisms tested except Pseudomonas, and 50 and 90% MICs of Nf and Ex were always equal or 2 to 4 times higher than Cp. Organisms multiply resistant to drugs were noted in almost all isolates tested. Twenty-seven strains of staphylococci were multiply resistant to 11 or more drugs, and 6 of Klebsiella spp. to 8 to 11 drugs. The most frequent multiplicity of durg resistance were 7 and 8, 12, and 13 in E. coli, Serratia spp., and Pseudomonas, respectively. No strain was resistant to more than 5 drugs in Proteus spp..

• The Korea Journal of Herbology
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• v.28 no.1
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• pp.59-64
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• 2013

Objectives : Methicillin-Resistant Staphylococcus aureus (MRSA) is a cephalosporin and beta-lactam antibiotic-resistant strains. In most cases, that is spread from infected patients and infection rates are growing increasingly. Thus, accordingly, increased resistance to antibiotics is causing serious problems in the world. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infections diseases. Methods : The antibacterial activities of Sinhyowoldosan were evaluated against 3 strains of Methicillin-resistant staphylococcus aureus(MRSA) and 1 standard Methicillin-susceptible S. aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MICs) assay, colorimetric assay using MTT test, checkerboard dilution test and time-kill assay was performed under dark. Results : The MIC (minimum inhibitory concentration) of Sinhyowoldosan water extract against S. aureus strains ranged from 500 to 2,000 ${\mu}g/mL$, so we have confirmed it on a strong antibacterial effect. Also, the combinations of Sinhyowoldosan water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Sinhyowoldosan water extract against MRSA have antibacterial activity, it has potential as alternatives to antibiotic agent. the combination test was used, Triton X-100 (TX) and DCCD for measurement of membrane permeability and inhibitor of ATPase. As a result, antimicrobial activity of SH is affected by the cell membrane were assessed. Conclusion : We suggest that the Sinhyowoldosan water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.

• Journal of Pharmacopuncture
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• v.26 no.1
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• pp.27-37
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• 2023

Objectives: Moroccan Arbutus unedo is an essential medicinal plant; however, little is known about the biological properties of its leaves mentioned in Moroccan traditional medicine. Methods: Various standard experiments were performed to evaluate the phytochemical, antidiabetic, antioxidant, antibacterial, and acute and sub-chronic toxicity characteristics of A. unedo leaves. Results: Phytochemical screening led to the identification of several phytochemical classes, including tannins, flavonoids, terpenoids, and anthraquinones, with high concentrations of polyphenols (31.83 ± 0.29 mg GAEs/g extract) and flavonoids (16.66 ± 1.47 mg REs/g extract). Further, the mineral analysis revealed high levels of calcium and potassium. A. unedo extract demonstrated significant antioxidant and anti-diabetic activities by inhibiting α-amylase (1.350 ± 0.32 g/mL) and α-glucosidase (0.099 ± 1.21 g/mL) compared to the reference drug Acarbose. Also, the methanolic extract of the plant exhibited significantly higher antibacterial activity than the aqueous extract. Precisely, three of the four examined bacterial strains exhibited substantial susceptibility to the methanolic extract . Minimum bactericidal concentration (MBC)/minimum inhibitory concentration (MIC) values indicated that A. unedo harbor abundant bactericidal compounds. For toxicological studies, mice were administered with A. unedo aqueous extract at single doses of 2,000 and 5,000 mg/kg. They did not exhibit significant abnormal behavior, toxic symptoms, or death during the 14-day acute toxicity test and the 90-day sub-chronic toxicity test periods. The general behavior, body weight, and hematological and biochemical status of the rats were assessed, revealing no toxicological symptoms or clinically significant changes in biological markers observed in the mice models, except hypoglycemia, after 90 days of daily dose administration. Conclusion: The study highlighted several biological advantages of A. unedo leaves without toxic effects in short-term application. Our findings suggest that conducting more comprehensive and extensive in vivo investigations is of utmost importance to identify molecules that can be formulated into pharmaceuticals in the future.

• Radiation Oncology Journal
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• v.18 no.2
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• pp.120-126
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• 2000

Purpose : Tumor hypoxia can be overcome with hypoxic cytotoxin. In mouse tumor, tirapazamine's efficacy of the potentiating radiation effect was tested by the tumor oxygenation status combined with hype facti on ated rad iotherapy .:The control and hypoxic mouse tumors we established by inoculation of RIF-1 tumor cells into the normal or previously irradiated back and thigh of C3H mice. When the tumors reached a proper size, both the control and hypoxic tumors were given hypefractionated treatments (8fractions/4 days) with saline (0.02 ml/g), tirapazamin (0.08 mM/0.02 ml/kg), irradiation (2.5 Gy), irradiation combined with tirapazamine given 30 minutes prior to each irradiation. The response was evaluated by the growth delay assay by measuring tumor size from day 0 (12 hrs prior to the first fractionation) to the day when the volume had 4-fold increase or cross sectional area had 2-fold increase. Results : Overall growth pattern showed that tirapazamine Potentiated radiation effect in back and thigh tumors grew in the normal and preirradiated tumor bed. With growth delay assay using reference point of initial tumor volume or cross sectional area, tirapazamine potentiated radiation effect 1.9 times for the control and 2.4 times for the hypoxic tumors in back, and 1.85 times for the control and 1.6 times for the hypoxic tumors. With reference of 4-fold increase of the initial volume or 2-fold increase of the cross sectional area, tirapazamine potentiated radiation effect 1.48 times for the control and 2.02 times for the hypxic tumors in back, and 1.85 times for the control and 1.6 times for the hypoxic tumors. Conclusions : Present result indicated that radiation response of hypoxic tumors was potentiated by tirapazamine in the back or thigh tumors grew in the control or preirradiated tumor bed, and potentiation of the hypoxic tumors was eDual to or greater than that of the control tumors in the back or thigh.

• Journal of the Korean Wood Science and Technology
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• v.49 no.1
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• pp.23-43
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• 2021

In this study, we selected two essential oils, Citrus unshiu and Cinnamomum cassia with superior antioxidant effects from the essential oils of 7 wild plants in South Korea and examined their antimicrobial activity against Candida albicans, which causes dermatitis to identify the antimicrobial components in the essential oils. As a result of measuring DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, SC50 value of the Citrus unshiu essential oil was 0.010 mg/mL, while for the Cinnamomum cassia essential oil, SC50 value was 0.09 mg/mL. In addition, when ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was measured, SC50 value of the Citrus unshiu essential oil was 0.09 mg/mL, while for the Cinnamomum cassia essential oil, it was 0.06 mg/mL, exhibiting high antioxidant activity. For the minimum inhibitory concentration (MIC), the essential oil of Cinnamomum cassia was 1.25 mg/mL and that of Citrus unshiu was 5 mg/mL, demonstrating a high antimicrobial activity of the Cinnamomum cassia essential oil. Through the thin layer chromatography (TLC) bioassay, we assessed the antimicrobial activity against C. albicans according to the fraction components of the two essential oils. Also, by using preparative TLC (prep. TLC), we obtained the active fractions, and by performing GC/MS analysis of the components with the same Rf value, we identified the antimicrobial-active components. As a result, the main components having antioxidant and antimicrobial activities were cinnamyl acetate, eucalyptol, linalool, and citral of the Cinnamomum cassia essential oil and linalool from the Citrus unshiu essential oil. Also, based on the analysis of the fractional components that showed antioxidant and antimicrobial activities in both of the two essential oils, it was found that linalool has antioxidant activity, while cinnamyl acetate, eucalyptol, citral, and geranyl acetate have antioxidant and antimicrobial activities.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.13-20
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• 2010

Biological activities such as anti-oxidative and anti-microbial of the Seungmakalgeuntang, a traditional prescription, were evaluated. The electron donating ability of water, ethanol, supercritical fluid and 1,3-butylene glycol extract of Seungmakalgeuntang showed more than 50% at a 100 ppm concentration. At a 1000 ppm concentration, the superoxide dismutase-like activities of ethanol and supercritical fluid extract of Seungmakalgeuntang showed less than 50%. xanthine oxidase inhibition effect of the supercritical fluid extract showed more than 70% at a 1,000 ppm concentration, which was higher than vitamin C. From the measurement on lipid oxidation, the $Fe^{2+}$ chelating abilities of the supercritical fluid extract of Seungmakalgeuntang was more than 60% at a 100 ppm concentration. Also the $Cu^{2+}$ chelating abilities of supercritical fluid extract Seungmkalgeuntang was showed more than 60% at a 500 ppm concentration. Clear zones formed by sample against the human skin-resident microflora such as Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acne of ethanol and supercritical fluid extract of Seungmakalgeuntang showed the highest among all the extracts tested using a 4mg/disc. The minimum inhibitory concentration (MIC) against both S. epidermidis and S. aureus showed 2,500 ppm in the extract of the supercritical fluid.

• Biomedical Science Letters
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• v.1 no.1
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• pp.55-72
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• 1995

Forty gentamicin-resistant isolates of Enterococcus faecalis were selected from various clinical materials, determined their antimicrobial susceptibility, and studied there R-plasmid characteristics and polypeptide patterns. All of the isolates were susceptible to vancomycin. The MICs($\mu$/ml) of antimicrobial agents to the isolates were as follows; the MIC of gentamicin was 128 and $\geq$2040, ampicillin 1 and 1, chlorarmphenicol 2 and 8, erythromycin 32 and 256, and vancomycin 1 and 2. E. faecalis HL-1 strain had 8 plasmid DNA elements, HL-2 and HL-3 strains had 6, HL-4 had 7, HL-5 had 4, and HL-6 had 5. The 51.7 Kb of gentamicin resistance plasmid DNA was conjugally transferred from two strains of E. faecalis HL-1 and HL-6 to S. aureus SK 982. The plasmid transfer frequency between S. aureus SK 982 and E. faecalis HL-1 or E. faecalis HL-6 was 6.3$\times10^{-4} and 3.7$\times10^{-5}$, respectively. Plasmid curing ratio after the treatment of ethidium bromide(10$\mu$/ml) to E. faecalis tarnsconjugants R-1 and R-6 were about 51% and 67%, respectively. The tetracycline gene was located in 2.15 Kb plasmid of E. faecalis HL-1, but it was not found in the E. faecalis HL-6 by Southern blot analyses. The antigenic components of E. faecalis HL-1, HL-6, R-1 and R-6 strains were analyzed by SDS-PAGE and immunoblotting. The E. faecalis strains had 7 to 16 polypeptide bands, however their major proteins were 97.8 and 26.8 Kd. At the Immunoblotting, 97.8, 95.8, 74.8, 63.5, 33.7 and 26.8 Kd polypeptides of the strains showed major antigenic activities with patient's sera infected intra-abdominally with an E. faecalis strain.