• 한국측량학회지
• /
• 제9권2호
• /
• pp.81-91
• /
• 1991

본 연구에서는 원격탐사 수치화상 데이타의 분류단계에 가중치를 고려한 Bayesian MLC를 적용하여 그 분석 정확도를 향상시키고자 하였다. 우선, Bayesian 결정법칙을 원격탐사분야 측면에서 분석해 보고 정규확률 밀도함수를 이용하여 n차원으로 확장시켰다. 이 유도과정에서 정의되는 사천확률 항에, 평행육면체 분류결과를 가중치로 적용하여 분류를 실행하였다 그리고 최종적 분류정확도는 확률함수데이타에$x^2$분포를 가정한 임계치 처리를 하므로써 오분류확률이 높은 화소를 추출하여 그 양을 기준으로 평가하였다. 연구의 전체 처리과정에 사용한 인공위성 데이타는 LANDSAT TM(1985년 10월 21일 ; 116-34)이며 연구 대상지역은 서울시 행정구역 내이다. 가중치를 적용해 본 결과 5.21%의 분석정확도 향상을 이루었으며, 따라서 본 기법은 도시 지역과 같이 복잡한 분포특성을 가지는 지형에 효과적으로 활용될 수 있다고 생각된다.

• Restorative Dentistry and Endodontics
• /
• 제23권2호
• /
• pp.550-560
• /
• 1998

Prevotella intermedia has been known as one of the important bacterial species involved in the endodontic infections and various periodontal diseases. Polyphosphate has been widely used to prevent decomposition of food and known to have an inhibitory effect on the growth of gram positive bacteria. The purpose of this study was to evaluate the effect of poly phosphate on the growth of Prevotella intermedia, a gram negative bacterium. Prevotella intermedia G8GK3(ATCC 49046) was grown in the presence of polyphosphates with different chain lengths. Inhibitory effect of each polyphosphate, which was added at the beginning or at the early exponential growth phase of Prevotella intermedia, was determined by measuring optical density of the bacterial cells at 540nm, viable cells and lysis of Prevotella intermedia. The results from this study were as follows : 1. Poly phosphate inhibited the growth of Prevotella intermedia. 2. The minimum inhibitory concentration(MIC) of poly phosphate appeared to be 0.05%. 3. Polyphosphates with chain lengths of 5 and 65 demonstrated the greatest inhibitory effect on the growth of Prevotella intermedia. 4. Polyphosphate was bactericidal to Prevotella intermedia, demonstrating the growth inhibition of the bacterium. 5. Polyphosphate induced lysis of Prevotella intermedia. The overall results suggest that polyphosphate has a bactericidal effect on Prevotella intermedia, causing the lysis of the bacterium.

• 한국자원식물학회지
• /
• 제24권1호
• /
• pp.10-16
• /
• 2011

본 실험은 인진으로 쓰이는 사철쑥과 더위지기의 항미생물활성을 검정한 것으로 추출용매에 따른 항미생물활성은 gram양성균 3종과 gram음성균 2종 모두에서 ethylacetate 추출물들이 ether추출물들보다 전반적으로 높았다. 실험미생물 중 B. subtilis와 B. cereus에 대한 추출물들의 활성이 다른 실험미생물에 비하여 강하게 나타났으며 더위지기 추출물들이 사철쑥 추출물들에 비하여 높은 활성을 보였다. 추출용매에 따른 최소저해농도는 ethylacetate추출물이 ether추출물보다 낮은 농도에서 대부분의 미생물들의 생육을 억제하였고, 더위지기와 사철쑥 부위별로는 잎과 줄기에서 잎에 비하여 낮은 농도에서 미생물들의 생육을 억제하였으며 더위지기 추출물들의 최소저해농도가 사철쑥 추출물들보다 낮았다.총 폴리페놀함량은 사철쑥 잎과 줄기 추출물에서 27.57 mg/g으로 가장 높게 나타났으며 대체로 잎과 줄기 추출물에서 잎 추출물에서보다 높은 함량을 나타내었다.

• 한국미생물·생명공학회지
• /
• 제42권3호
• /
• pp.238-248
• /
• 2014

The metalloid arsenic (Z = 33) is considered to be a significant potential threat to human health due to its ubiquity and toxicity, even in rural regions. In this study a rural region contaminated with arsenic, located at longitude $85^{\circ}$ 32'E and latitude $25^{\circ}$ 11'N, was initially examined. Arsenic tolerant bacteria from the rhizosphere of Amaranthas viridis were found and identified as Bacillus licheniformis through 16S rRNA gene sequencing. The potential for the uptake and removal of arsenic at 3, 6 and 9 mM [As(V)], and 2, 4 and 6 mM [As(III)], and for the reduction of the above concentrations of As(V) to As(III) by the Bacillus licheniformis were then assessed. The minimal inhibitory concentrations (MIC) for As(V) and As(III) was determined to be 10 and 7 mM, respectively. At 3 mM 100% As(V) was uptaken by the bacteria with the liberation of 42% As(III) into the medium, whereas at 6 mM As(V), 76% AS(V) was removed from the media and 56% was reduced to As(III). At 2 mM As(III), the bacteria consumed 100%, whereas at 6 mM, the As(III) consumption was only 40%. The role of pH was significant for the speciation, availability and toxicity of the arsenic, which was measured as the variation in growth, uptake and content of cell protein. Both As(V) and As(III) were most toxic at around a neutral pH, whereas both acidic and basic pH favored growth, but at variable levels. Contrary to many reports, the total cell protein content in the bacteria was enhanced by both As(V) and As(III) stress.

• 한국수산과학회지
• /
• 제49권6호
• /
• pp.800-806
• /
• 2016

In total, 151 Escherichia coli isolates from Ruditapes philippinarum in Gomso Bay were analyzed for their susceptibility to 18 different antimicrobial agents and for genes associated with virulence. For virulence genes, each strain of the isolates was positive for the enterotoxigenic E. coli (ETEC)-specific heat-stable toxin (estA), enteroinvasive E. coli (EIEC)-specific invasion-associated locus (iaa) gene and enteropathogenic E. coli (EPEC)-specific attaching and effacing (eae) gene. According to a disk diffusion susceptibility test, resistance to ampicillin was most prevalent (23.2%), followed by resistance to amoxicillin (22.5%), ticarcillin (20.5%), tetracycline (18.5%), nalidixic acid (12.6%), ciprofloxacin (10.6%), streptomycin (9.9%), and chloramphenicol (6.6%). More than 35.8% of the isolates were resistant to at least one antimicrobial agent, and 19.9% were resistant to four or more classes of antimicrobials; these were consequently defined as multidrug resistant. Minimum inhibitory concentration (MIC) ranges for the antimicrobial resistance of the 15 different antimicrobial agents of 54 E. coli strains were confirmed by varying the concentrations from $32-2,048{\mu}g/mL$. Overall, these results not only provide novel insights into the necessity for seawater and R. philippinarum sanitation in Gomso Bay but they also help to reduce the risk of contamination by antimicrobial-resistant bacteria.

• 약학회지
• /
• 제40권3호
• /
• pp.357-368
• /
• 1996

The in vitro antibacterial activity of a novel fluoroquinolone, DWP20373(1-Cyclopropyl-6-fluoro-8-methoxy-7-(2,7-diazabicyclo[3,3,0]oct-4-ene-7-yl)-1,4-dihydro-4 oxoquino line-3carboxylic acid) was compared with those of ciprofloxacin (CPFX), sparfloxacin (SPFX) and ofloxacin (OFLX). DWP20373 was more active than SPFX and OFLX but was less potent than CPFX against gram-negative bacteria. DWP20373 showed an excellent activity against L-MRSA and H-MRSA ($MlC_{90}=0.781{\sim}1.563{\mu}g/ml$).The activity of DWP20373 decreased moderately in the presence of 5mM $Mg^{2+}$. However, pH and serum had no effect on the activity of DWP20373. DWP20373 possessed a rapid bactericidal activity against gram-positive and gram-negative strains.

• Bulletin of the Korean Chemical Society
• /
• 제33권12호
• /
• pp.4180-4184
• /
• 2012

The target compounds 6-11a-e were synthesized by condensing 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones 5a-f with various aromatic carboxylic acids in the presence of phosphorous oxychloride. The structures of newly synthesized compounds were characterized by IR, $^1H$ NMR, $^{13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were screened for their antibacterial activity. Almost all the tested compounds were potent against four different strains of bacteria when compared with that of reference drug ciprofloxacin. Compounds 6c, 6e, 8d, 9b, 9e, 11a and 11b showed nearly equal or lower MIC values than standard drug, against all four tested bacterial strains but rest of the compounds showed excellent antibacterial activities.

• 동의생리병리학회지
• /
• 제21권6호
• /
• pp.1564-1568
• /
• 2007

In this study fourteen ethanol extracts from Nepalese medicinal plants were screened for their in vitro antimicrobial and antiradical activity and their total phenolic content was evaluated. The antiradicalactivity was evaluated by free radical scavenging assay, using 2,2-diphenyl-1-picryl hydrazyl radical (DPPH). Plant extracts showed a wide range of radical scavenging activity, with $IC_50$ value ranging in between $5.38\; {\mu}g/\;mL$ - $429.61\;{\mu}g/mL$. Strong radical scavenging activity was shown by flower extract of Woodfordia fruticosa ($5.38\;{\mu}g/\;mL$) and stem bark extract of Azadirachta indica ($5.58 {\mu}g/\;mL$)that also contained high phenolic content. Most of the sample showed activity below the concentration of $100\; {\mu}g/mL$. For antimicrobial activity three test microorganisms namely Staphylococcus aureus, Streptococcus epidermidis, and Candida albicans were used. The minimum inhibitory concentration (MIC) of the plant extracts was determined. Most of the plant extracts were effective against bacterial strains only at higher concentration ($800\;-\;1,600\;{\mu}g/mL$) but none of these were effective against Candida albicans below $1,600\;{\mu}g/mL$.

• 대한약침학회지
• /
• 제15권1호
• /
• pp.23-28
• /
• 2012

Objective: This experimental study was designed to investigate the safety and the effectiveness of Samjeong pharmacopuncture solution (SPS) manufactured by using a the lowtemperature extract on process. Methods: To identify the safety and the effectiveness of using SPS as eye drops, we performed applied eye irritation tests on rabbits and antibacterial tests for Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Aspergillus niger, Fusarium oxysporum, and Candida albicans. The eye irritation test was performed according to the toxicity testing regulation of the Korea Food & Drug Administration (2009. 8. 24, KFDA 2009-116). After SPS had been applied on the left eye of the rabbits, eye irritation in the cornea, iris and conjunctiva was observed on the 1st, 2nd, 3rd, 4th & 7th day. After SPS had been dropped on bacterial species that cause keratitis, the minimum inhibition concentration and the size of the inhibition zone were measured. The anti-bacterial potency was also measured by taking the size of inhibition zone. Results: After SPS had been administered on the left eye of the rabbits, none of nine rabbits were found to show abnormal signs or weight changes. After SPS had been administered on the left eye of the rabbits, no eye irritation in the cornea, iris and conjunctiva was observed on the 1st, 2nd, 3rd, 4th & 7th day. No specific response was detected in MIC for bacterial species Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Aspergillus niger, Fusarium oxysporum, and Candida albicans after SPS had been applied. Conclusions: This study suggests that SPS is a non-toxic and non-irritant medicine that does not cause any of eye irritation in rabbits, but it has no antibacterial effects on bacterial species that are well known to cause keratitis. These results suggest that more research is required on extracts from herbal medicines for treating keratitis.

• 한국작물학회지
• /
• 제26권2호
• /
• pp.185-191
• /
• 1981

옥수수 생장발육의 한 Scheme을 작성하기 위하여 조생종 MIC-1과 만생종 수원 19호를 공시하여 1980년 4월 25일부터 6월 24일까지 12일 간격으로 6파종기를 두고, 휴폭 60cm에 주간 15cm로 파종하여 본시험을 실시하였다. 여기에서는 작물체의 주요기관 즉 엽, 기, 자종의 형태적 변화를 주로 조사하였으며 그 결과를 요약하면 다음과 같다. 1. 엽신의 발육을 그 전개정도에 따라 10등액으로 구분하여 Leaf Development Index(LDI)를 정의하였다. 2. 엽출현율(LAR)은 평균 3일로써 품종간, 재배시기간 큰 차가 없었다. 3. 출현 후 약 1개월 후에 절간이 신장하기 시작하여 절위별로 신장하며 지상부 제 1절이 벽출되는 시기는 제 8-9엽기에 해당되었다. 4. Silks의 형태적 변화는 종실의 발달과 밀접한 관계가 있었다(표 4참조). 5. 영양생장기간은 품종간 및 재배시기간에 차이가 현저하였지만 생식생장기간은 별차이가 없었다. 6. 완전전개된 엽수, 비대된 절수 그리고 Silks의 형태적 변화 및 종실발달 등으로 옥수수의 Scheme을 제시하였다.