533 research outputs found

    The antimicrobial activity of oil-in-water microemulsions is predicted by their position within the microemulsion stability zone

    Get PDF
    It has been shown previously that thermodynamically stable oil-in-water microemulsions have significant antimicrobial activity against planktonic cells and biofilm cells over short periods of exposure. It was the aim of this study to identify whether the position of the microemulsion within the microemulsion stability zone of the pseudo-ternary phase structure predicts the efficiency of the antimicrobial action of the microemulsion. Microemulsions were formulated at different points within the microemulsion stability zone. Experiments were performed to observe the kinetics of killing of these microemulsions against selected test microorganisms (Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231, Staphylococcus aureus ATCC 6538 and Aspergillus niger ATCC 16404). The results indicated that the antimicrobial activity of the microemulsion is dependant upon its position within the zone of stability and is greater nearer the centre of that zone. The results indicate that significant antimicrobial activity can be observed at all points within the zone of microemulsion stability, but that maximal activity is to be found at the centre of that area

    Determinants Influencing Foreign Students' Decision to Study in UUM: A Study of UUM International Students

    Get PDF
    It is important that Higher Education Institutions recognized themselves as contributing in the service industry to meet with the increasing demand of their stakeholders. In competing globally, Malaysian institutions are becoming popular destination for overseas studies. This study investigates the relationship between Perception of the International students And Quality of Reputation, Promotion, Institutional Culture and People culture, Price and Quality and expertise of staff. The study involved foreign students who were studying at Universiti Utara Malaysia (Northern Malaysian University). A total number of 123 valid responses were collected through questionnaire-based survey method representing a total of 82% per cent response rate. The result of this study had indicated that there was a significant relationship between the determinants that influencing foreign student's decision to study in UUM

    SYNTHESIS, STRUCTURAL ELUCIDATION AND ANTIMICROBIAL EVALUATION OF 2-{4-(T-AMINO)-2-(BUT-2-YN-1-YL)}-1, 3 BENZOTHIAZOLE DERIVATIVES

    Get PDF
    Objective: A new series of 2-{4-(t-amino)-2-(but-2-yn-1-yl)}-1,3-benzothiazole derivatives, 2-[4-(pyrrolidin-1-yl)but-2-yn-1-yl]-1,3-benzothiazole (BZ2), 2-[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]-1,3-benzothiazole (BZ3), 2-[4-(piperidin-1-yl) but-2-yn-1-yl]-1,3-benzothiazole (BZ4), 2-[4-(azepan-1-yl)but-2-yn-1-yl]-1,3-benzothiazole (BZ5), 2-[4-(4-methylpiperazin-1-yl) but-2-yn-1-yl]-1,3-benzothiazole (BZ6), 2-[4-(2, 6-dimethylpiperidin-1-yl) but-2-yn-1-yl]-1, 3-benzothiazole (BZ7) were synthesized and screened in vitro as potential antimicrobial agents.Methods: In-vitro antimicrobial activity evaluation was done, by agar diffusion method and broth dilution test against Staphylococcus aureus ATCC 6538p, Candida albicans ATCC 10231, Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 8739, and Bacillus subtilis ATCC 6633. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) were determined. The results of antimicrobial testing were compared to two positive control drugs ciprofloxacin (5 µg/ml) and fluconazole (500µg/ml).Results: Compound 2-[4-(azepan-1-yl) but-2-yn-1-yl]-1,3-benzothiazole (BZ5) showed the highest antibacterial activity against S. aureus with MIC value of 15.62 µg/ml while; Compound 2-[4-(2,6-dimethylpiperidin-1-yl)but-2-yn-1-yl]-1,3-benzothiazole (BZ7) exhibited the highest antibacterial activity against P. aeruginosa with MIC value of 31.25 µg/ml. Compounds 2-[4-(pyrrolidin-1-yl)but-2-yn-1-yl]-1,3-benzothiazole (BZ2) and 2-[4-(azepan-1-yl)but-2-yn-1-yl]-1,3-benzothiazole (BZ5) showed the highest antifungal activity against C. albicans with MIC value of 15.62 µg/ml (for both).Conclusion: The results obtained showed variation in the antibacterial and antifungal activity based on the structure of the cyclic amines in these amino acetylenic benzothiazole derivatives. Keywords: Benzothiazole, Aminoacetylenic, Antibacterial, Antifungal, Mannich reactio

    Design methodology for general enhancement of a single-stage self-compensated folded-cascode operational transconductance amplifiers in 65 nm CMOS process

    Get PDF
    The problems resulting from the use of nano-MOSFETs in the design of operational trans-conductance amplifiers (OTAs) lead to an urgent need for new design techniques to produce high-performance metrics OTAs suitable for very high-frequency applications. In this paper, the enhancement techniques and design equations for the proposed single-stage folded-cascode operational trans-conductance amplifiers (FCOTA) are presented for the enhancement of its various performance metrics. The proposed single-stage FCOTA adopts the folded-cascode (FC) current sources with cascode current mirrors (CCMs) load. Using 65 nm complementary metal-oxide semiconductor (CMOS) process from predictive technology model (PTM), the HSPICE2019-based simulation results show that the designed single-stage FCOTA can achieve a high open-loop differential-mode DC voltage gain of 65.64 dB, very high unity-gain bandwidth of 263 MHz, very high stability with phase-margin of 73°, low power dissipation of 0.97 mW, very low DC input-offset voltage of 0.14 uV, high swing-output voltages from −0.97 to 0.91 V, very low equivalent input-referred noise of 15.8 nV/Hz, very high common-mode rejection ratio of 190.64 dB, very high positive/negative slew-rates of 157.5/58.3 V⁄us, very fast settling-time of 5.1 ns, high extension input common-mode range voltages from −0.44to 1 V, and high positive/negative power-supply rejection ratios of 75.5/68.8 dB. The values of the small/large-signal figures-of-merits (s) are the highest when compared to other reported FCOTAs in the literature

    Physico-Chemical and Microbiological Studies on Jordanian Honey and Propolis as Potential Self-Preserving Pharmaceutical Systems

    Get PDF
    The aim of this project was to study the physico-chemical and antimicrobial properties of Jordanian honey and propolis in order to determine their potential as pharmaceutical preservation systems. This study undertook a physico-chemical analysis of several Jordanian honeys and one propolis type, in order to evaluate several physico-chemical properties including, pH and free acidity, moisture content, ash content and HydroxyMethylFurfural content in three honey samples, and total flavonoid content in the propolis sample. The antimicrobial activity of honey and propolis samples was then evaluated by determining the minimum inhibitory concentration (MIC) against Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Candida albicans ATCC 10231. Subsequently, Honey 1 (H1) was selected for further study and combined with propolis to test their potential synergistic activity. Finally, a preservative effectiveness test was conducted in order to assess the possibility of using honey and propolis as natural preservatives in aqueous dosage forms, such as syrups. The results of this study showed that all the tested honey samples and propolis possessed significant antimicrobial activity against the standard test microorganisms, and that honey with propolis exhibited synergistic activity that enhanced their antimicrobial activity and resulted in up to 90% reduction in their MIC values. This study also confirmed that honey and propolis could be used as a natural preservative system for pharmaceutical formulae. Our results reveal the possibility of using honey-propolis mixtures as natural preservatives in oral aqueous pharmaceutical dosage forms and other local application products

    CHEMICAL CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF JORDANIAN PROPOLIS AND NIGELLA SATIVA SEED OIL AGAINST CLINICALLY ISOLATED MICROORGANISMS

    Get PDF
    Objective: Increasing use of medicinal plants in the treatment of infectious diseases are due to the development of multi-antibiotics resistant microorganisms, and had alerted our interest in the examination of some natural products. This study was carried out to investigate the antimicrobial activity of Jordanian propolis, black seed oil (Nigella sativa) extract, alone or in combination against clinically isolated microorganisms (bacteria and fungi).Methods: Jordanian propolis samples were collected. Aqueous and alcoholic extractions were done; black seed oil was extracted from Nigella sativa seeds. Seven clinical isolated microorganisms namely: Micrococcus luteus, Bacillus pumilus, Bordetella bronchisptica, Enterococcus fecalis, Bacillus subtilis, and Staphylococcus aureus, and one yeast strain namely Candida albicans were used. The antimicrobial activity was investigated by agar diffusion technique and microplate dilution to determine the MIC.Results: The results indicated that the alcoholic propolis extract showed higher antimicrobial activity than the aqueous propolis extract. The antimicrobial activity of black seed oil was significantly higher than that of the propolis. Mixing propolis with black seed oil showed synergism effects against some microorganisms as Enterococcus fecalis (24±1.1), Bordetella bronchisptica (20±0.9) and Candida albicans (40±2.3), and additive with others as Bacillus subtilis (28±1.8).Conclusion: Black seed oil and propolis might be used as a potential source of safe and effective natural antimicrobial in pharmaceutical and food industries

    Oral Test-Based Assessment in The Book Arabiyah Linnasyiin: An Alternative Assessment of Arabic Reading Skills

    Get PDF
    This study aims to Strategy the instrument for assessing the maharah qira'ah test in the book al-Arabiyah linasyi'in volume 5, and to analyze the instrument to be studied, qualitative research methods are used to examine comprehensively and in depth related to the quality of assessment, research This study uses descriptive qualitative, data used in this study in the form of fact findings or content of the material and patterns of the aspects of the questions in the assessment from the book al'arabiyah linasyi’in volume 5. It was found that there were four aspects of the assessment instrument that contained in   the book include: understanding, pronunciation (ta'bir), mufradahat and use of language, and aspects of qawāid nahwu. This study focuses on aspects of maharah qirā'ah assessment. Based on the research results, there are updates in the assessment aspect using the method of reading aloud and silently with a rubric assessment system on a scale of 1-5 by determining quality, so that this scientific contribution can be used directly in the field of oral examinations

    Designing carbon nanotube-based oil absorbing membranes from gamma irradiated and electrospun polystyrene nanocomposites

    Get PDF
    Carbon-based materials are outstanding candidates for oil spill clean-ups due to their superhydrophobicity, high surface area, chemical inertness, low density, recyclability, and selectivity. The current work deals with the fabrication of membrane oil absorbents based on carbon nanotube (CNT) reinforced polystyrene (PS) nanocomposites by electrospinning technique. The spun membranes are also irradiated with the gamma radiation to induce enough crosslinks and thus good polymer-filler interactions. The structural, morphological, and surface properties in addition to the oil/water separation efficiency were investigated by varying the concentration of CNT and the dose of γ-irradiation. Fabricated nanofiber membranes show superior hydrophobicity and selective oil absorption at 0.5 wt.% of CNT concentration. The best mechanical properties are also obtained at this particular concentration and at 15 KGy optimum γ-irradiation dosage. The gamma irradiated PS/0.5 wt.% CNT membrane also exhibits good antibacterial effects against the bacteria, Escherichia coli, in the form of bacterial inhibition rings around the membranes. The present study thus shows the environmental applicability of the fabricated PS/CNT membranes in treating oil-contaminated water
    corecore