• 디지털산업정보학회논문지
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• 제19권2호
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• pp.11-25
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• 2023

With the increasing advancement of VLSI technology, health care system is also developing to serve the humanity with better care. Therefore, biomedical implantable devices are one of the amazing important invention of scientist to collect data from the body cell for the diagnosis of diseases without any pain. This Biomedical implantable transceiver circuit has several important issues. Oscillator is one of them. For the design flexibility and complete transistor-based architecture ring oscillator is favorite to the oscillator circuit designer. This paper represents the design and analysis of the a 9-stage CMOS ring oscillator using cadence virtuoso tool in 180nm technology. It is also designed to generate the carrier signal of 403.5MHz frequency. Ring oscillator comprises of odd number of stages with a feedback circuit forming a closed loop. This circuit was designed with 9-stages of delay inverter and simulated for various parameters such as delay, phase noise or jitter and power consumption. The average power consumption for this oscillator is 9.32㎼ and average phase noise is only -86 dBc/Hz with the source voltage of 0.8827V.

• Journal of Microbiology and Biotechnology
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• 제34권3호
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• pp.538-546
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• 2024

Cinnamaldehyde is a natural compound extracted from cinnamon bark essential oil, acclaimed for its versatile properties in both pharmaceutical and agricultural fields, including antimicrobial, antioxidant, and anticancer activities. Although potential of cinnamaldehyde against plant pathogenic bacteria like Agrobacterium tumefaciens and Pseudomonas syringae pv. actinidiae causative agents of crown gall and bacterial canker diseases, respectively has been documented, in-depth studies into cinnamaldehyde's broader influence on plant pathogenic bacteria are relatively unexplored. Particularly, Pectobacterium spp., gram-negative soil-borne pathogens, notoriously cause soft rot damage across a spectrum of plant families, emphasizing the urgency for effective treatments. Our investigation established that the Minimum Inhibitory Concentrations (MICs) of cinnamaldehyde against strains P. odoriferum JK2, P. carotovorum BP201601, and P. versatile MYP201603 were 250 ㎍/ml, 125 ㎍/ml, and 125 ㎍/ml, respectively. Concurrently, their Minimum Bactericidal Concentrations (MBCs) were found to be 500 ㎍/ml, 250 ㎍/ml, and 500 ㎍/ml, respectively. Using RNA-sequencing analysis, we identified 1,907 differentially expressed genes in P. carotovorum BP201601 treated with 500 ㎍/ml cinnamaldehyde. Notably, our results indicate that cinnamaldehyde upregulated nitrate reductase pathways while downregulating the citrate cycle, suggesting a potential disruption in the aerobic respiration system of P. carotovorum during cinnamaldehyde exposure. This study serves as a pioneering exploration of the transcriptional response of P. carotovorum to cinnamaldehyde, providing insights into the bactericidal mechanisms employed by cinnamaldehyde against this bacterium.

• 한국식품조리과학회지
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• 제17권6호
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• pp.565-570
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• 2001

본 연구에서는 쇠비름을 메탄올로 추출하여 식품의 부패나 식중독성을 유발하는 세균과 곰팡이에 대한 추출물의 항균활성을 검토하고 그들의 최소생육저해농도를 결정하였으며 쇠비름 추출물의 구성성분과 함량을 분석하였다. 쇠비름은 특히 P. citreonigrum 균주에 대해 매우 높은 항균효과를 보였고 S aureus, K. pneumoniae에 대해서는 benzoic acid에 상응할 만한 항균효과를 나타내었다. 쇠비름 메탄올 추출물은 200mg/$m\ell$ 농도에서 S. aureus와 P. citreonigrum의 생육을 억제하였고, 250 mg/$m\ell$ 농도에서 K. pneumoniae의 생육을 억제하였으며, 300 mg/$m\ell$ 농도에서 P. aeruginosa와 E. coli의 생육을 억제하였다. 따라서 이들 균주에 의한 식품의 부패 및 식중독이 우려되는 식품의 항균제로서 쇠비름의 사용 가능성을 볼 수 있었다. 쇠비름 메탄올 추출물의 분석결과 전체 147가지 성분이 분석되었으며 acid 및 ester류가 41.06%로 추출물의 가장 많은 부분을 차지하고 있었다. 또한 세균, 곰팡이, 효모와 같은 미생물에 항균활성을 나타내는 것으로 보고되어 있는 2,3-dihydro-benzofuran, 4-hydroxy-3-methoxy- benzoic acid와 4-hydroxy benzeneethanol 등의 성분들이 검출되었다.

• The Plant Pathology Journal
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• 제21권2호
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• pp.127-131
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• 2005

In this comparative study, the effects of temperature, pH, and bactericides on the growth of Erwinia pyrifoliae and Erwinia amylovora were investigated. The maximum temperature for the growth of both Erwinia species was estimated to be $36{\circ}C$. The maximum specific growth rates of E. pyrifoliae and E. amylovora were observed at $27{\circ}C$ and $28{\circ}C$, respectively, and no significant growth differences were shown at their optimum temperatures. However, at lower temperatures ranging from 12-$21{\circ}C$, E. pyrifoliae showed higher growth rates with doubling times shorter than those of E. amylovora. Distinct growth rates at these temperatures revealed that E. pyrifoliae is more cold-tolerant than E. amylovora. The optimum pH for the growth of both pathogens was 7.5 and growth was not seen at pH ${\le}$ 5.0 and ${\ge}$ 10.0. These results showed that the effect of pH on the growth of E. pyrifoliae and E. amylovora was similar. Minimum inhibitory concentrations (MICs) of copper sulfate, oxolinic acid, streptomycin, and tetracycline, which inhibited growth of E. pyrifoliae and E. amylovora, were determined. The strains of both pathogens were able to grow at 0.08-0.32 mM copper sulfate, but not at higher concentrations. However, none of the tested strains grew in the presence of oxolinic acid (0.001 mM), streptomycin (0.1 mM), and tetracycline (0.01 mM) concentrations. These results suggested that all strains of both Erwinia species were sensitive to tested bactericides and indicated no occurrence of resistant strains of E. pyrifoliae in Korea.

• 한국식품영양학회지
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• 제21권1호
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• pp.15-21
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• 2008

In this study, the minimum inhibition concentration(MIC), growth inhibition activity, and colony forming inhibitory activity of water soluble propolis against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Streptococcus mutans, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae and Salmonella enteritidis were tested. The MICs of the water soluble propolis against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Streptococcus mutans, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, and Salmonella enteritidis were 312.5 ppm, below 156.3 ppm, 625 ppm, 10,000 ppm, above 10,000 ppm, 10,000 ppm, above 10,000 ppm, above 10,000 ppm, 10,000 ppm, and above 10,000 ppm, respectively. The growth inhibition concentrations against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Streptococcus mutans, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, and Klebsiella pneumoniae were 156.3 ppm, below 156.3 ppm, 625 ppm, 5,000 ppm, 10,000 ppm, 10,000 ppm, 10,000 ppm, 10,000 ppm, and 5,000 ppm, respectively. However, 10,000 ppm did not inhibit the growth of Salmonella enteritidis. Finally, the colony forming inhibitory activities against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Streptococcus mutans, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, and Salmonella enteritidis were 98.0%, 99.8%, 69.8%, 98.1%, 62.0%, 63.1%, 79.5%, 61.9%, 79.6%, and 0.0%, respectively.

• 대한약침학회지
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• 제19권4호
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• pp.312-318
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• 2016

Objectives: Bacterial resistant infections have become a global health challenge and threaten the society's health. Thus, an urgent need exists to find ways to combat resistant pathogens. One promising approach to overcoming bacterial resistance is the use of herbal products. Green tea catechins, the major green tea polyphenols, show antimicrobial activity against resistant pathogens. The present study aimed to investigate the effect of catechins, green tea extract, and methylxanthines in combination with gentamicin against standard and clinical isolates of Staphylococcus aureus (S. aureus) and the standard strain of Pseudomonas aeruginosa (P. aeruginosa). Methods: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interactions of green tea extract, epigallate catechin, epigallocatechin gallate, two types of methylxanthine, caffeine, and theophylline with gentamicin were studied in vitro by using a checkerboard method and calculating the fraction inhibitory concentration index (FICI). Results: The MICs of gentamicin against bacterial strains were in the range of $0.312-320{\mu}g/mL$. The MIC values of both types of catechins were $62.5-250{\mu}g/mL$. Green tea extract showed insufficient antibacterial activity when used alone. Methylxanthines had no intrinsic inhibitory activity against any of the bacterial strains tested. When green tea extract and catechins were combined with gentamicin, the MIC values of gentamicin against the standard strains and a clinical isolate were reduced, and synergistic activities were observed (FICI < 1). A combination of caffeine with gentamicin did not alter the MIC values of gentamicin. Conclusion: The results of the present study revealed that green tea extract and catechins potentiated the antimicrobial action of gentamicin against some clinical isolates of S. aureus and standard P. aeruginosa strains. Therefore, combinations of gentamicin with these natural compounds might be a promising approach to combat microbial resistance.

• 한국임상약학회지
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• 제7권1호
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• pp.40-44
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• 1997

Helicobacter pylori(HP) has been implicated as the cause of acute and chronic gastritis, peptic ulcer, and gastric carcinoma. To date the most successful treatment in eradicating HP is known to be the combination of two or more antibiotics with an anti-ulcer drug. In this study, in vitro antimicrobial activity against two was assessed, when proton pump inhibitors (PPIs), omeprazole and lansoprazole, were added to antibiotics at different concentrations. The assays in the absence of PPIs gave minimum inhibitory concentration(MIC) value of 0.63 mg/l for amoxicillin, 4 mg/l for tetracycline, 0.08 mg/l for clarithromycin and 0.16 mg/l for azithromycin. At the concentrations of 125 mg/l, 25 mg/1 and 0.5 mg/l of omeprazole, and the concentrations of 31.25 mg/l, 6.25 mg/l and 1 mg/l of lansoprazole, the MICs of clarithromycin and azithromycin were reduced by $50\%$. Also, lansoprazole at the highest concentration 31.25 mg/l reduced the MIC of amoxicillin by $50\%$, and omeprazole at the highest concentration of 125 mg/l reduced the MIC of tetracycline by $50\%$. In conclusion, the in vitro combination of PPIs and antibiotics led to improvement in the MIC of antibiotics against HP associated gastric disease.

• Natural Product Sciences
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• 제17권1호
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• pp.33-37
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• 2011

The plant species reported here are used by traditional healers in Gabon for different ailments such as wounds, malaria, fever, gonorrhea or diarrhea. The aim of this study was to evaluate the antimicrobial activities of 7 plants (Strombosiopsis tetrandra, Tetraberlinia bifoliolata, Dichapetalum barbatum, Guibourtia demeusii, Dacryodes normandii, Manniophytum fulvum, Paropsia grewoides) against different strains of both Methicillin-Resistant Staphylococcus aureus (MRSA) and Salmonella. Disc diffusion was first used to determine the antimicrobial effectiveness of the plants' ethanolic extracts. Then the minimum inhibitory concentrations of the crude extracts of either leaves or stem barks of the 7 plants were determined using broth micro-dilution. The ethanolic plant extracts showed very good activity against both MRSA and Salmonella strains where the MICs ranged from $250\;{\mu}g/ml$ to $1000\;{\mu}g/ml$. The study shows that many of the tested plants used by Gabonese traditional healers have antimicrobial activities and give support to their traditional use.

• 대한의생명과학회지
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• 제22권4호
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• pp.167-173
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• 2016

The broth microdilution technique used to measure the minimal inhibitory concentration (MIC) of natural compounds against bacteria is problematic: it is difficult to visualize bacterial growth due to the color of the natural compound. Therefore, the use of a colorimetric method with a redox indicator by broth microdilution can simplify it and increase its objectivity. This study evaluated the usefulness of the colorimetric method in measuring the MIC of Phellinus baumii against methicillin-resistant Staphylococcus aureus (MRSA). The inhibition in disc diffusion method was observed from $8,192{\mu}g/mL$ P. baumii in all 10 MRSA isolates examined; however, the MIC ranges of the 10 MRSA isolates was $512{\sim}2,048{\mu}g/mL$ by broth microdilution using a colorimetric method; with the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) indicator. In addition, the MIC of P. baumii by broth microdilution using MTT as indicator yielded excellent results. However, the 2, 3, 5-triphenyltetrazolium chloride (TTC) results could not be determined due to the color of the TTC indicator. The MICs of four antibiotics against MRSA using MTT or TTC were equal to those determined by visual interpretation. In conclusion, to evaluate the antibacterial effects of a natural compound, the broth microdilution technique is considered to be better than the disc diffusion method. Moreover, to resolve the problems caused by the colors of natural compounds, a colorimetric method such as that using MTT may be very valuable.

• Natural Product Sciences
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• 제20권1호
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• pp.39-43
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• 2014

Papenfussiella kuromo (PK) is a marine plant and an abundant ecological resource for the future; it is found in almost 80% of the terrestrial biosphere. The aim of this study was to investigate the antibacterial activity of PK against methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant pathogen. The minimum inhibitory concentrations (MICs) of PK hexane fraction (PKH) against 7 strains of MRSA ranged from 1.0 to 2.0 mg/mL. In the checkerboard dilution method, a synergistic effect of the PKH and the antibiotics (oxacillin and norfloxacin) was seen. PKH markedly reduced the MIC of each of the 4 antibiotics against MRSA. The time-kill assay showed that the synergistic activity of PKH and an antibiotic reduced the bacterial counts below the lowest detectable limit after 24 h. These findings suggest that PKH has antibacterial activity, and may be important baseline data in future extensive studies of living marine resources as a source of compounds active against MRSA.