• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.12
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• pp.1116-1123
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• 2011

In this paper, we studied the propagation of the radio wave in the human body for WBAN system and proposed the path-loss models applicable in the MICS and ISM frequency band. Human Tissues are composed of complicate organ. So it is difficult to measure to insert the probe in human body. Accordingly, the equations were modelled by electromagnetic analysis using the numerical phantom based on the real human. The numerical analysis used XFDTD 6.5 of Remcom co. in commercial software based on the Finite-Difference Time-Domain method. Human body model used a standard adult Korean model developed by ETRI. The proposed channel models will be very helpful to design the WBAN system.

• The Journal of the Korean Society for Microbiology
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• v.13 no.1
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• pp.43-48
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• 1978

The difference in antimicrobial susceptibility of multiply drug-resistant Salmonella typhi by the methods of test was tested against chloramphenicol(Cm), tetracycline(Tc), ampicillin(Ap), kanamycin(Km), and rifampicin(Rif), and the results were compared by the minimum inhibitory concentration(MIC). No appreciable difference was noted between MICs of Cm, Tc, and Rif measured by agar plate dilution(plate) method and broth dilution(broth) method. However, MICs of Km to about a half of test strains were 4 to 8-fold higher by broth method than plate method, and MICs of Ap by broth method were also a little higher than plate method in some strains. Cm and Rif were bacteriostatic rather than bactericidal to the most of test strains in high concentrations. Tc, Ap and Km were exclusively bactericidal to the test strains.

• The Journal of the Korean Society for Microbiology
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• v.22 no.4
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• pp.435-443
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• 1987

A total of 30 strains of Candida albicans were examined for susceptibility to amphotericin B and ketoconazole using Sabouraud's dextrose broth, Kimmig broth and Supplemented yeast nitrogen base broth media. Furthermore, the growth curve and colony forming units were checked for use of stationary-phase cells and 2-hour incubation cells in the absence of atifungal agents. The viable counts were determined periodically during incubation by standard plate count techniques. The minimum inhibitory concentrations of amphotericin B for use of stationary phase cells were as follows: SDB, $0.09{\sim}0.97mcg/ml$(0.39mcg/ml); Kimmig broth, $0.19{\sim}0.39mcg/ml$(0.42 mcg/ml) and SYNB, $0.19{\sim}0.39mcg/ml$mcg/ml(0.23mcg/ml). In ketoconazole, MICs were value SDB, $3.12{\sim}25.0mcg/ml$(12.5mcg/ml); Kimmig broth, $12.5{\sim}25.0mcg/ml$ (22.5mcg/ml) and SYNB, $3.12{\sim}12.5mcg/ml$(6.71mcg/ml). The MICs of amphotericin B(0.2mcg/ml cone.) for use of 2-hour incubation cells in absence of AMB were, SDB, $0.04{\sim}0.39mcg/ml$(0.11mcg/ml); Kimmig broth, $0.09{\sim}0.39mcg/ml$(0.18mcg/ml) and SYNB, $0.09{\sim}0.19mcg/ml$(0.14mcg/ml) and in KTZ, the value of MICs were SDB, $3.12{\sim}25.0mcg/ml$(12.22mcg/ml); Kimmig broth, $0.78{\sim}25.0mcg/ml$(11.01mcg/ml) and SYNB, $1.56{\sim}12.5mcg/ml$(3.90mcg/ml). The two-log reductions in CFU per milliliter observed when 2 hour preincubation cells were treated with 0.2mcg/concentrations of AMB and 25.0mcg/ml of KTZ. However, AMB treated cells were restored to growth activity, it suggested that the AMB has no active antifungal activity.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.10-16
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• 2011

We investigated the antimicrobial activity of ether and ethylacetate fractions from Artemisia capillaris and Artemisia iwayomogi used as Injin. The antimicrobial activity of the ethylacetate fractions from Artemisia capillaris and Artemisia iwayomogi for tested microbes were stronger than those of ether fractions of the two Artemisia plants. The antimicrobial activity of fractions of Artemisia iwayomogi was higher than that of fractions of Artemisia capillaris for the tested microbes. The extracts of young shoots and leaves showed stronger antimicrobial activity than those of young leaves. The range of minimum inhibitory concentrations(MICs) of ethylacetate fractions from the part of Artemisia capillaris and Artemisia iwayomogi were 0.25~2.0 mg/ml. The MICs of ether fractions were showed higher concentration than those of ethylacetate fractions. The fractions of Artemisia iwayomogi showed lower MICs than fractions of Artemisia capillaris. The highest total polyphenol content was found in young shoots and leaves of A. capillaris. The young shoots and leaves of the two kinds of Artemisia plants showed higher content of total polyphenol.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.716-728
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• 1999

Whole oil and ketonic fraction (KF) of Leptospermum scoparium have been tested for their antimicrobial activity and combination effect with several antibiotics against various bacterial strains and fungi by using microbiological assay methods. Antibacterial activities of KF against a number of test strains were 2-3 fold stronger than those of whole oil. MICs of the KF were $65~125{\;}{\mu\textrm{g}}/ml$ against seven gram positive bacterial strains, $65~250{\;}{\mu\textrm{g}}/ml$ against 19 methicillin resistance Staphylococcus aureus strains, and $65~50{\;}{\mu\textrm{g}}/ml$ against 14 quinolone resistance strains. However, KF showed little or no activity against gram negative bacteria. MICs of the KF were $16~250{\;}{\mu\textrm{g}}/ml$ against more than 50% of the anaerobic bacterial strains tested. KF showed the higher antibacterial activity than bacitracin against 10 strains of Bacteroids thetaiotaomicron, or three strains of Bacteroides ovatus, and the more active than ciprofloxacin against one strain of Bacteroides thetaiotaomicron and three strains of Bacteroids ovatus. The MICs of KF was 63 and $250{\;}{\mu\textrm{g}}/ml$ against Aspergillus niger and Candida albicans, respectively. Antibacterial activities of KF in combination with 19 antibiotics against 14 strains and with four antifungal agents against one fungal strain were determined by paper strip diffusion method. While most of combination showed additivity, KF showed synergism with bacitracin, exfadroxil, cephradin, and meropenem for 29~57% of the strains tested. However, ofloxacin, enoxacin, sparfloxacin showed antagonism with KF for 43~71% of the strains. KF alone and in combination with bacitracin, gentamycin, neomycin, itraconazole, fluconazole, terfinafine and ketoconazole against five bacterial strains or one fungus strain synergistic effect was demonstrated against 33% of strains examined with FIC index value below 0.5 by checkerboard study. Synergistic effect of KF with gentamicin against Staphylococcus epidermidis 329 (QRS) was found by time-kill study.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.115-119
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• 2005

This study was performed to investigate inhibitory effect on growth of Staphylococcus aureus and Bacillus cereus in lactic acid, hydrogen peroxide and combination of lactic acid and hydrogen peroxide. The minimun inhibitory concentration (MIC) of lactic acid in Staphylococcus aureus were 2500 ppm at pH 7.0, 1250 ppm at pH 5.5, 6.0 and 6.5, while in Bacillus cereus 625 ppm at pH 5.5 and 6.0, 1250 ppm at pH 6.5 and 7.0, respectively. MICs of hydrogen peroxide in Staphylococcus aureus were 50 ppm at pH 6.0, 75 ppm at pH 6.5 and 7.0, while in Bacillus cereus was 75 ppm at pH 5.0, 5.5 and 6.0, respectively. MICs of combined treatment of lactic acid and hydrogen peroxide in Staphylococcus aureus were 1250 ppm of lactic acid with 25 ppm of hydrogen peroxide and 625 ppm of lactic acid with 50 ppm of hydrogen peroxide. When Bacillus cereus were with 1250 ppm of lactic acid with 50 ppm of hydrogen per-oxide and 625 ppm of lactic acid with 75 ppm of hydrogen peroxide at 6.5. The correlations between MICs of lactic acid and hydrogen peroxide in S. aureus and B. cereus obtained through the coefficient of determination ($R^2$). $R^2$ value were 0.9934 and 0.9986, respectively. The inhibitory effect of lactic acid and hydrogen peroxide in S. aureus and B. cereus could be confirmed from the result of this experiment.

• Journal of Microbiology
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• v.38 no.4
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• pp.265-269
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• 2000

Iron increased the susceptibilities of clinical isolates Pseudomonas aeruginosa to quinolones. In the presence of iron, increased susceptibilities to ofloxacin were observed in twenty-six out of thirty isolates and with no change in four isolates. In the case of norfloxacin, iran increased susceptibilities of twelve isolates but did not render any change in eighteen isolates. In the case of ciprofloxacin, iron decreased the MICs (Minimal Inhibitory Concentration) of twenty isolates, increased the MIC of one isolate, and did net change the MICs of nine isolates. To find out how iron increased susceptibility to ofloxacin, bacterial cells were grown in Muller Hinton (MH) media and succinate minimal media (SMM) to induce iran acquisition systems and the intracellular ofloxacin concentrations were assayed in the presence of iron. The addition of iron to the media decreased the MICs of cells whether they were grown in MH or SMM. Siderophores, carbonyl cyanide m-chlorophenylhydrazone (an inhibiter of proton motive force), and ouabain (an inhibitor of ATPase) did not decrease the effect of iron. Results suggested that the increase in the intracellular ofloxacin concentration by iron is accomplished not by decreasing the efflux but by increasing the of ofloxacin permeability.

• ETRI Journal
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• v.37 no.2
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• pp.204-211
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• 2015

For this study, we designed an implantable rectangular spiral antenna for medical biotelemetry in the Medical Implant Communications Service band (402 MHz to 405 MHz). The designed antenna has a U-shaped loop for impedance matching. The antenna impedance is easily adjusted by controlling the shape and length of the U-shaped loop. Significant design parameters were studied to understand their effects on the antenna performance. To verify the potential of the antenna for the desired applications, we fabricated a prototype and measured its performance in terms of the resonant characteristics and gain radiation patterns of the antenna. In the testing phase, the prototype antenna was embedded in human skin tissue-emulating gel, which was developed to simulate a real operation environment. The measured resonant characteristics show good agreement with the simulations, and the -10 dB frequency band is within the range of 398 MHz to 420 MHz. The antenna exhibits a maximum gain of -22.26 dBi and an antenna efficiency of 0.215%.

• International Journal of Oral Biology
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• v.30 no.2
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• pp.59-63
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• 2005

Postantibiotic effects (PAE) refer to suppression of the bacterial growth following limited periods of exposure to an antibiotic and subsequent to the removal of the antibiotic agent. Fusobacterium nucleatum and Porphyromonas gingivalis are Gram-negative anaerobic bacteria associated with several periodontal diseases. In this study, postantibiotic effects (PAE), postantibiotic sub-MIC effect (PA SME) and sub-MIC effect (SME) of antibiotics on F. nucleatum ATCC 25586 and P. gingivalis W50 were investigated. The PAE was induced by 10X the MIC of antibiotic and antibiotic was eliminated by washing. The PA SMEs were studied by addition of 0.1, 0.2 and 0.3X MICs during the postantibiotic phase of the bacteria, and the SMEs were studied by exposition of the bacteria to antibiotic at the sub-MICs only. Amoxicillin, doxycycline and tetracycline induced PAE for F. nucleatum ATCC 25586 and P. gingivalis W50. But metronidazole and penicillin induced PAE for only F. nucleatum ATCC 25586. Metronidazole and doxycycline induced PA SME and SME for both species of anaerobic bacteria used in this study. The PA SME values for both strains were substantially longer than the SME values. The present study showed the existence of PAE, PA SME and SME for various antibiotics against F. nucleatum ATCC 25586 and P. gingivalis W50.

• The Journal of the Korean Society for Microbiology
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• v.21 no.3
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• pp.381-385
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• 1986

Twenty strains of penicillin(PC)-resistant Staphylococcus aureus ($MIC{\geqq}32U/ml$) were chosen randomly from recent isolates and submitted to the present experiment to see what effect the combined antibiotic action of moxalactam(MX) and fosfomycin(FM) would bring about on the cells, using MS-2 system. 1. The conventional agar dilution method and the rapid automatic MS-2 system were used in measuring the MICs of MX and FM against each strain and the comparison of the data obtained revealed no significant difference between the two methods in the titer and distribution of the MICs. 2. The automatic MS-2 system was, therefore, used alone in determining the combined growth inhibitory effect of MX and FM because of its more rapidness, and the obtained results were that most of the PC-resistant strains(16 out of 20, 80%) were synergistically inhibited by the two antibiotic combination while additive effect was observed in the remaining 4 strains(20%). 3. Thus, it is suggested that the growth of PC-resistant staphylococcal cells may be synergistically inhibited by MX and FM combination and the efficiency of two antibiotic action as well as MIC of single antibiotic may be more rapidly determined by the MS-2 system than by the conventional method.