• 제목/요약/키워드: Time-kill

검색결과 167건 처리시간 0.023초

Antimicrobial Activities of the Anti-acne Compounds from Natural Sources (천연물유래 여드름 치료제제의 항균활성 측정)

  • Kim, Na-Rae;Lim, Young-Hee;Park, Sul-Woong;Nam, Eun-Sil
    • Microbiology and Biotechnology Letters
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    • 제37권1호
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    • pp.80-84
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    • 2009
  • The in vitro antibacterial activities of anti-acne agents prepared from the extracts of natural sources were investigated against several bacteria including antibiotic-susceptible and -resistant Propionibacterium acnes. SD-1 and SD-2 were prepared with different formulations and they showed strong antibacterial activities. The anti-acne agents completely inhibited the growth of the tested strains at the concentration of 0.5%. There was no difference in antibacterial activity between antibiotic-susceptible and -resistant P. acnes. The inhibitory activities of two agents showed time-dependent manner. In S. aureus, time-kill curve demonstrated 2.8- and 3.4-$log_{10}$-unit killing after 8 h with SD-1 and SD-2, respectively. In P. acnes, time-killing curve demonstrated 5.1- and 6.1-$log_{10}$-unit killing after 24 h with SD-1 and SD-2, respectively. SD-2 showed stronger antimicrobial activity than SD-1. From these results, we expect that SD-1 and SD-2 have strong antibacterial activities and have advantages for treating acne.

The Effect Analysis of Missile Warning Radar Using Probability Model (확률 모델을 이용한 미사일 경고 레이다의 효과도 분석)

  • Park, Gyu-Churl;Hong, Sung-Yong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • 제20권6호
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    • pp.544-550
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    • 2009
  • To analyze the threat decision performance of MWR(Missile Warning Radar) give analysis on condition that we decide the effective threat using the POC(Probability of Over Countermeasure)/PUC(Probability of Under Countermeasure). Thus, we execute the simulation using the Monte-Carlo method to analyze effect, but the execution time of simulation took longer than we expected. In this paper, the effect analysis is proposed using the probability model to reduce the execution time of simulation. We present the setting method of parameter for probability model and the effect analysis result of MWR using the simulation. Also, we present the comparison result of simulation execution time for Monte-Carlo and probability model.

Antibacterial Effects and Cellular Responses of Imipenem-resistant Pseudomonas aeruginosa Exposed to Green Tea Polyphenols (녹차 폴리페놀에 노출된 Imipenem 내성 Pseudomonas aeruginosa의 항균효과 및 세포반응)

  • Song, You-Jin;Cho, Yun-Seok;Oh, Kye-Heon
    • Microbiology and Biotechnology Letters
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    • 제38권2호
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    • pp.198-206
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    • 2010
  • The aim of this work was to investigate the synergically bactericidal effects and cellular responses of tea polyphenols (TPP) and imipenem on imipenem-resistant Pseudomonas aeruginosa. Imipenem-resistant Ps. aeruginosa was isolated from patient in hospital. The bactericidal effects of TPP and imipenem were evaluated on the basis of its minimum inhibitory concentrations (MIC). The combined use of TPP and imipenem resulted in 16-fold and 8-fold reductions in the MICs of imipenem for the imipenem-susceptible and imipenem-resistant Ps. aeruginosa, respectively. The bactericidal effects of the imipenem and TPP against the Ps. aeruginosa was evaluated using the time-kill assay. The synergetic effects of the combinations of TPP and imipenem against Ps. aeruginosa were confirmed. Western blot using anti-DnaK and anti-GroEL monoclonal antibodies was performed to investigate the expression of stress shock proteins (SSPs) in imipenem-susceptible and imipenem-resistant strains exposed to TPP. The amount of SSPs were induced as the exposure time increased and decreased. The molecular weights of DnaK and GroEL were 70 kDa and 60 kDa, respectively. SDS-PAGE with silver staining revealed that the amount of lipopolysaccharides (LPS) increased or decreased in the strain treated to different concentrations and exposing periods of TPP. Scanning electron microscopic analysis demonstrated the presence of umblicated and wrinkled surfaces for cells treated with TPP or imipenem.

A Study on the Antibacterial Activity of Combined Administration of Jakyakgamcho-tang and Antibiotics Against MRSA (MRSA에 대한 작약감초탕과 항생제 병용투여의 항균활성에 관한 연구)

  • Dam Hee Kang;Ok Hwa Kang;Hee-Sung Chae;Dong Yeul Kwon
    • Korean Journal of Pharmacognosy
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    • 제54권2호
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    • pp.72-79
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    • 2023
  • MRSA is Staphylococcus aureus resistant to β-lactam antibiotics, and is a worldwide infectious disease. Even with the discovery of new antibiotics, resistance develops rapidly, so new alternatives are needed. Jakyakgamcho-tang (JGT) is a combination of Jakyak and Gamcho, and has been mainly used as an antispasmodic and analgesic in oriental medicine. This study was conducted to find out whether there is an effect on MRSA in relation to the anti-inflammatory effect of JGT and the antibacterial effect of Jakyak and Gamcho found in previous studies. In this study, in order to investigate the antibacterial activity of JGT and the combined effect of existing antibiotics, after extracting JGT with 70% EtoH, the disc diffusion method, minimum inhibitory concentration (MIC), drug combination effect (FICI), and time-kill analysis (Time-kill assay), metabolic inhibition, Western blot and qRT-PCR analysis were used to confirm the antibacterial activity mechanism of MRSA of JGT. As a result of the experiment, all of MRSA showed antibacterial activity in JGT's disc diffusion method, and the MIC was 250-1000 ㎍/mL. When existing antibiotics and JGT were combined with drugs, most had synergy or partial synergy. In addition, it was confirmed that the degree of bacterial growth was suppressed over time when simultaneous administration for 24 hours. JGT showed a synergistic effect when administered together with the ATPase-inhibitor DCCD, suggesting that it affected the inhibition of ATPase. As a result of observing the expression of PBP2a, and hla protein in the JGT-treated group and the untreated control group through wstern blot, it was confirmed that the protein expression of the JGT-treated group was significantly suppressed, and the expression levels of mecA, mecR1 and hla genes were also suppressed during JGT treatment. was observed by qRT-PCR. Combining the results of the experiment, it can be seen that JGT has antibacterial activity in MRSA, and when combined with existing antibiotics, the effect was increased compared to treatment with the drug alone. This suggests that JGT can be an alternative to treatment for antibiotic resistance of MRSA.

Framework of Weapon Effects Calculator for Hardened Targets (견고표적 무기효과 산출 알고리즘에 관한 연구)

  • Park, Jong Yil
    • Journal of the Korea Institute of Military Science and Technology
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    • 제16권3호
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    • pp.340-347
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    • 2013
  • Weapon effect is a key issue throughout the life cycle of weapon systems. Only when weapon effect is considered properly, Effects Based Operation(EBO), Effects Based Acquisition(EBA), and Effects Based Development(EBD) could be possible. Because the transfer of weapon effect technologies is restricted in most foreign counties, independent development is necessary. In this paper, framework of weapon effects calculator for hardened targets is proposed to meet the own development needs. It is designed focusing on running time, validation and expandibility by adoption of modular architecture. Required technologies for each module are identified, and unclassified ones are summarized.

Development of a Dynamic Geometry Environment to Collect Learning History Data

  • Mun, Kill-Sung;Han, Beom-Soo;Han, Kyung-Soo;Ahn, Jeong-Yong
    • Journal of the Korean Data and Information Science Society
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    • 제18권2호
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    • pp.375-384
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    • 2007
  • As teachings that use the ICT are more popular, many studies on the dynamic geometry environment(DGE) are under way. An important factor emphasized in the studies is to practical use learning activities of learners. In this study, we first define the learning history data in DGE. Second we develop a prototype of the DGE that is able to collect and analyze the learning history data automatically. The environment enables not only to grasp leaning history but also to create and manage new learning objects.

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Dynamics of Heterogeneous Warfare

  • Park, Kyung-Soo
    • Journal of the Korean Statistical Society
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    • 제6권1호
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    • pp.65-76
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    • 1977
  • The relative importance of single-shot kill probabilities, rates of fire, weapon allocation strategies, and the size of initial force in warfare between two force with heterogeneous multiple weapon systems are considered by examining their effect on a natural measure of effectiveness, the expected number of survivors. Attrition equations are derived via stochastic formulation to represent the mean course of battle having an underlying probability distribution. It is assumed that each side uses indirect area fires. Level of intelligence activities are reflected in the availability of spontaneous information on the current enemy status. Depending on the availability of the information on the current enemy status, each participatory unit may follow 1) a prescribed attack pattern (fraction of the available units assigned to various enemy targets) or 2) an adaptive attack pattern depending on the enemy status at that time. Conditions for possible stalemate are discussed.

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How the New York Times Portrayed the 2010 Brazil-Turkey-Iran Nuclear Deal: A Critical Discourse Analysis

  • Esfandiary, Esmaeil
    • Journal of Contemporary Eastern Asia
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    • 제14권2호
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    • pp.57-68
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    • 2015
  • This paper examines the New York Times' reaction to the 2010 Brazil-Turkey-Iran (BTI) nuclear deal, the very last diplomatic effort before the imposition of international sanctions track over the following years. The New York Times' (NYT) coverage of the deal is examined using the Critical Discourse Analytic (CDA) approach formulated by Teun van Dijk. The results show a strong bias against the BTI deal throughout the NYT's news coverage. The overarching theme in cover-age of the deal is the imputation of malignant intentions on the part of both Iran ("to kill time to further its nuclear weapons program") and Brazil and Turkey ("to advance their own business dealings with Iran and gaining international recognition"). Also, non-relevant information is used to imply a threat of Iranian development of nuclear weapons. Moreover, the NYT leaves almost totally "unsaid" that president Obama had asked Brazilian and Turkish leaders to go to Tehran and get this deal. Therefore, the NYT basically echoed, and legitimized, discursive practices of the U.S. government on the deal.

A Study of Psychopaths' Make-up Coordination Expressed on the Slasher Films (슬래셔 영화에 나타난 사이코패스의 분장 코디네이션 연구)

  • Chang, Mee-Sook
    • Fashion & Textile Research Journal
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    • 제10권3호
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    • pp.399-406
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    • 2008
  • The purpose of this paper is to show how psychopaths' psychological factors are expressed on the characters' visual styles in the make-up coordination of slasher films. Psychopath is an ordinary person who has suffered some terrible trauma (humiliation, the death of a loved one, rape, psychological abuse), and features a disorder that consists of multiple components ranging on the emotional, interpersonal, and behavioral spectrum. Slasher films are sub genre of horror films that psychopathy characters, namely, Leather Face, Michael Myers, Jason Voorhees, Kenny Hampson, Harry Warden, Freddy Kruger and Billy kill the unfamiliar victims by cruel weapons with mercilessly. Their aesthetic characteristics of make-up coordination were shown in concealment, cruelty and suggestion. The concealment was presented by killers' masks, the cruelty was represented by their weapons, and the suggestion, especially space-time and status was depicted by their garments.

3-D Nonlinear Magnetostatic Analysis by using FEM (FEM을 이용한 3-D 비선형 정자계 모델의 해석)

  • Kang, Byung-Kill;Ryu, Jae-Seop;Koh, Chang-Seop
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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    • pp.324-326
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    • 2000
  • A 3D magnetostatic field is analyzed considering the non-linear characteristics of the material using finite element method. In the finite element formulation, the edge element is adopted since it reduces the required computer memory and the computing time. The modified Newton-Raphson method is also used for non-linear analysis. A numerical example with the TEAM workshop problem 13 is analyzed, and the results are proved to concide well with measured ones.

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