• 제목/요약/키워드: activity spectrum

검색결과 905건 처리시간 0.024초

Broad Spectrum Antibacterial Activity of Allium cepa, Allium roseum, Trigonella foenum graecum and Curcuma domestica

  • Omoloso, A.D.;Vagi, J.K.
    • Natural Product Sciences
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    • 제7권1호
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    • pp.13-16
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    • 2001
  • In many parts of the world Allium cepa, Allium roseum, Trigonella foenum graecum and Curcuma domestica are extensively used as food and are popular in herbal medicine. The four were screened against 26 pathogens and all exhibited broad-spectrum anti-bacterial activity. The aqueous as well as fractionated methanol extract of Allium cepa and A. roseum demonstrated broader level of activity against most of the organisms. On the other hand the unfractionated methanol extracts as well as the fractions of both Trigonella foenum graecum and Curcuma domestica showed broad spectrum of activity. Fractionation was found to improve their level of activity. In both cases the ethyl acetate fractions exhibited higher level of activity. All the materials tested were inactive against any of the four moulds. Allium cepa, Allium roseum, Trigonella foenum graecum and Curcuma domestica are proposed as non toxic, safe, broad spectrum antibacterial agents.

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Momordica charantia and Allium sativum : Broad Spectrum Antibacterial Activity

  • Khan, M.R.;Omoloso, A.D.
    • 생약학회지
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    • 제29권3호
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    • pp.155-158
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    • 1998
  • In the Asian sub-continent Momordica charantia and Allium sativum are extensively used as food and are popular in herbal medicine. The two were screened against 15 pathogens and both exhibited broard spectrum antimicrobial activity. As compared to the standard antibiotics, M. charantia demonstrated broader and higher level of activity against most of the organisms. On the other hand A. sativum showed comparable activity to the standard antibiotics. Both M. Charantia and A. sativum are proposed as non toxic, safe, broad spectrum antibacterial agents.

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카오스 특성에 의한 뇌의 활동도 분석 (Brain activity analysis by using chaotic characteristics)

  • 김택수;김현술;박상희
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.1844-1847
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    • 1997
  • Assuming that EEG(electroencephalogram), which is generated by a nonlinear electrical of billions of neurons in the brain, has chaotic characteristics, it is confirmend by frequency spectrum analysis, log frequency spectrum analysis, correlation dimension analysis and Lyapunov exponents analysis. Some chaotic characteristics are related to the degree of brain activity. The slope of log frequency spectrum increases and the correlation dimension decreasess with respect to the activities, while the largest Lyapunov exponent has only a rough correlation.

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보리잎에서 분리된 용매 추출물의 항산화 작용 (Antioxidant Activity of Solvent Extract Isolated from Barley Leaves)

  • 이영철;손종연
    • 한국식품영양학회지
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    • 제7권4호
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    • pp.332-337
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    • 1994
  • The antioxidant activity of solvent extracts isolated from barley leaves was investigated by measuring peroxide value. The fractions of methanol extract obtained from preparative TLC was also studies, with UV-Visible spectrum, total phenol contents and hydrogen donating ability(HDA) The antioxidant activity of various solvent extracts was, in decreasing order, methanol> ethyl ether> methylene chloride $\geq$ ethyl acetate $\geq$acetone> hexane. The antioxidant activity of the fractions of methanol extract was, in decreasing order, fraction 2> fraction 3> fraction 1 and their activity was all superior to that of tocopherol at 500 ppm level. All fraction(1, 2 and 3) exhibited a strong UV absorption at 280 m which would be specifically produced by phenolic compound. UV absorption at 280 m of fraction 2 was greater than those of fraction 1 and 3. In the visible spectrum of these fractions, the maximum .absorption wavelengths of fraction 1, 2 and 3 were 660, 460 and 460 m, respectively. Antioxidant activity of barley leaves seemed to be due to the flavonoids containing phenolic group by UV spectrum and total phenol content.

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A Novel Prediction-based Spectrum Allocation Mechanism for Mobile Cognitive Radio Networks

  • Wang, Yao;Zhang, Zhongzhao;Yu, Qiyue;Chen, Jiamei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권9호
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    • pp.2101-2119
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    • 2013
  • The spectrum allocation is an attractive issue for mobile cognitive radio (CR) network. However, the time-varying characteristic of the spectrum allocation is not fully investigated. Thus, this paper originally deduces the probabilities of spectrum availability and interference constrain in theory under the mobile environment. Then, we propose a prediction mechanism of the time-varying available spectrum lists and the dynamic interference topologies. By considering the node mobility and primary users' (PUs') activity, the mechanism is capable of overcoming the static shortcomings of traditional model. Based on the mechanism, two prediction-based spectrum allocation algorithms, prediction greedy algorithm (PGA) and prediction fairness algorithm (PFA), are presented to enhance the spectrum utilization and improve the fairness. Moreover, new utility functions are redefined to measure the effectiveness of different schemes in the mobile CR network. Simulation results show that PGA gets more average effective spectrums than the traditional schemes, when the mean idle time of PUs is high. And PFA could achieve good system fairness performance, especially when the speeds of cognitive nodes are high.

Broad Spectrum Anti-bacterial Activity of the Leaves, Stem and Root Barks of Myristica subabulata

  • Khan, M.R.;Kihara, M.;Omoloso, A.D.
    • Natural Product Sciences
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    • 제7권1호
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    • pp.9-12
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    • 2001
  • A number of Myristica species are used in herbal medicine for a variety of ailments. The methanol extracts of the leaves and the stem and root barks of Myristica subabulata were fractionated into petrol, dichloromethane and finally ethyl acetate. These were then screened against a total of 31 micro-organisms comprising of 13 G +ve, 12 G ve, one protozoa and 5 moulds. A broad-spectrum anti-bacterial activity was observed. As compared to fractionated the un-fractionated extracts exhibited much better level of activity.

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In Vitro Probiotic Properties of Indigenous Dadih Lactic Acid Bacteria

  • Surono, Ingrid S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권5호
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    • pp.726-731
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    • 2003
  • The aim of this research was to identify candidate probiotic lactic bacteria among indigenous dadih lactic isolates. Dadih is an Indonesian traditional fermented milk of West Sumatra which is fermented naturally. Viability of the strain is critical in determining the capacity of lactic bacteria to induce immune stimulation as well as to colonize in the intestinal tract. Therefore, LAB are proposed to exert health promoting or probiotic effects in human, such as inhibition of pathogenic microflora, antimutagenic, and the reduction of cholesterol levels. This manuscript reports in vitro probiotic properties of indigenous dadih lactic bacteria, especially some important colonization factors in GI tract, such as lysozyme, acid and bile tolerance. Bile Salt Hydrolase (BSH) activity, spectrum of bacteriocin, and antimutagenic activity of bacterial cells were also assessed. Twenty dadih lactic isolates were screened further for their tolerance to low pH, at pH 2 and 3 as well as their bile tolerance. There were ten isolates classified as acid and bile acid tolerant, and further screened for lysozyme tolerance, BSH activity. The spectrum of bacteriocin activity of isolates was assayed using cell-free neutralized supernatants by agar spot test against variety of pathogens. Lc. lactis subsp. lactis IS-10285, IS-7386, IS-16183, IS-11857 and IS-29862, L. brevis IS-27560, IS-26958 and IS-23427, Leu.mesen.mesenteroides IS-27526, and L. casei IS-7257 each has good survival rate at low pH values and in the presence of lysozyme, and short lag time in the presence of 0.3 % oxgall. Lc. lactis subsp. lactis IS-11857 and IS-29862 each has high BHS activity, Lc. lactis subsp. lactis IS-10285 and IS-16183 each had a positive spectrum of bacteriocin activity against E. coli 3301 and Lysteria monocytogenes ATCC 19112, while L. brevis IS-26958 has high BHS activity as well as positive spectrum of bacteriocin against E. coli 3301, Lysteria monocytogenes ATCC 19112, and S. aureus IFO 3060. All of the ten dadih lactic strains performed in vitro acid and bile tolerance, indicating a possibility to reach the intestine alive, and display probiotic activities.

자율신경계 활성도 측정 시스템 개발 (A development of measuring system for Autonomic Nervous Activity)

  • 이준하
    • 한국의학물리학회지:의학물리
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    • 제11권2호
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    • pp.141-146
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    • 2000
  • 전력 스펙트럼 분석은 자율신경계 활성도를 정량화하기 위한 강력한 비침습적인 도구이다. 본 논문에서는 자율신경계의 활성도를 측정하기 위한 시스템을 개발하였다. 시스템에서는 환자의 안전을 고려 하여 분리 전원을 채택했다. 출력으로는 ECG 시간 변이와 호흡 시간 변이를 획득하였다. 시간 변이는 자율신경계와 관련한 질병을 발견하는 데 유용하다. 시험에 적용된 범위는 심전도는 30~240 bpm 그리고 호흡에서는 15~80bpm 을 적용하였다.

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카오스 특성에 의한 뇌의 활동도 분석 (Brain Activity Analysis by using Chaotic Characteristics)

  • 김택수;김현술;최윤호;박상희
    • 대한전기학회논문지:전력기술부문A
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    • 제48권4호
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    • pp.478-485
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    • 1999
  • The purpose of this paper was the determination of the relationship between the chaotic charateristics and various levels of brain activities. Assuming that EEG(eletroencephalogram), which is generated by a nonlinear electiecal behavior of billions of neurons in the brain, has chaotic characteristics, it was confirmed by frequency spectrum analysis, log frequency spectrum analysis, correlation dimension analysis and Lyapunov exponents analysis. Chaotic characteristics are related to the degree of brain activity. The slope of log frequency spectrum increased and the correlation dimension decreased with respect to the brain activities, while the lagrest Lyapunov exponent has some rough correlation.

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Bacillus sp. B-6가 생산하는 acyl CoA 합성 효소 억제 물질의 분리 및 구조 결정 (Isolation and Structure Elucidation of Acyl CoA Synthetase Inhibitor from Bacilus sp. B-6)

  • 김경자;김태경
    • 약학회지
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    • 제42권6호
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    • pp.552-557
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    • 1998
  • Acyl CoA synthetase inhibitor, was purified from the culture broth of a Bacillus sp. B-6, which had been isolated from soil, by chloroform extract, silica gel column chro matography and preparative TLC. The purified acyl CoA synthetase inhibitor showed higher Antifungal activity against C. al-bicans (MIC: 8${\mu}$g/ml). Though the analysis of UV spectrum, melting point, IR spectrum, Mass-spectrum, $^1H$-NMR and $^{13}C$-NMR spectrum, the inhibitor could be identified as phenazine-l-carboxylic acid.

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