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1.
Vibrio cholerae causes epidemic diarrhea throughout the world. Fluid replacement is the primary therapy for cholera; however, high mortality rates often necessitate the use of antibiotics. V. cholerae, like most bacteria, has developed resistance to some antibiotics. In the early 1990s a new serotype strain, Bengal 0139, began a new wave of cholera epidemics. Bengal isolates showed unique trends in antimicrobial resistance. Many clinical laboratories use automated antibiotic susceptibility testing for V. cholerae. It is important to know if automated susceptibility test results for V. cholerae coincide with reported trends in antibiotic susceptibility. In the present study, we used the Vitek automated susceptibility system to determine the susceptibilities of 79 V. cholerae O1 isolates, 100 O139 isolates, and 112 non-O1 isolates. Vitek susceptibilities for V. cholerae showed a good correlation with preestablished epidemiological data. Although the new O139 serogroup showed a trend of increased resistance to trimethoprim-sulfamethoxazole and nitrofurantoin, it was more susceptible to ampicillin than previous serogroup O1 and non-O1 strains. Regardless of serogroup, > or = 98% of the V. cholerae isolates tested were susceptible to most antibiotics tested by us. It is important to continue susceptibility testing of all new isolates of V. cholerae because of emerging resistant strains. However, V. cholerae remains susceptible to most of the available antibiotics. 相似文献
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Mahmoud A. Hamad 《Journal of Superconductivity and Novel Magnetism》2014,27(7):1777-1780
Magnetocaloric effect in half-metallic double perovskite Sr0.4Ba1.6?x La x FeMoO6 (x = 0, 0.1, 0.2, 0.3) were investigated. It is shown that Sr0.4Ba1.6?x La x FeMoO6 exhibits the largest magnetic entropy change (ΔS M ) of 0.086 J/kg K upon 0.2 T magnetic field variation. Furthermore, ΔS M distribution of the Sr0.4Ba1.6?x La x FeMoO6 is much more uniform than that of gadolinium. Through these results, polycrystalline samples of Sr0.4Ba1.6?x La x FeMoO6 have some potential applications for magnetic refrigerants in a wide temperature range, including room temperature. 相似文献
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Mahmoud A. Hamad 《Journal of Superconductivity and Novel Magnetism》2014,27(11):2569-2572
In this work, low-enhanced magnetic field magnetocaloric effect for Ga1?X Al X CMn3 (X = 0, 0.05, 0.07, 0.12, and 0.15) system near a second-order phase transition from a ferromagnetic to a paramagnetic state is investigated theoretically. It is found that magnetic entropy change distribution is much more uniform than that of gadolinium, which is desirable for an Ericson-cycle magnetic refrigerator. Moreover, the results show that the magnetocaloric effect in this system is tunable by Al doping, which is beneficial for manipulating magnetocaloric refrigeration that occurs in various temperature ranges including room temperature. This makes the Ga1?X Al X CMn3 samples potential candidates for practical applications. 相似文献
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V. S. Vendamani Syed Hamad V. Saikiran A. P. Pathak S. Venugopal Rao V. V. Ravi Kanth Kumar S. V. S. Nageswara Rao 《Journal of Materials Science》2015,50(4):1666-1672
We report a detailed study on the synthesis of ultra-small (1–10 nm) colloidal silicon nanoparticles (Si NPs) by ablating porous silicon (pSi) in acetone using femtosecond laser pulses. Porous silicon is considered as a target material for ablation because it contains a large number of light emitting silicon nanoparticles. The pSi samples were prepared by anodic etching of silicon in aqueous HF solution for different etching current densities. Transmission electron microscope measurements confirmed the successful formation of well-isolated spherical silicon nanoparticles. The average size of spherical NPs were estimated to be ~7.6, ~7, and ~6 nm when anodic etching current densities of 5, 10, and 20 mA/cm2 were used respectively for preparing pSi targets. The crystallinity of these Si NPs was confirmed by selective area electron diffraction and Raman spectroscopy measurements. The observed blue shift in the absorption and emission spectra are attributed to reduction in the average particle size with increase in etching current density. These Si NPs may be useful for fabricating low-dimensional microelectronic compatible photonic devices. 相似文献
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Mehdi Salih Shihab Abbas Hadi Alshukrawi Wedad Hamad Aldahhan 《Protection of Metals and Physical Chemistry of Surfaces》2016,52(6):1086-1092
In the present work, sodium 4-[(4-formylbenzylidene) amino] benzoiate (4) was synthesized and its structure was confirmed using spectroscopic techniques. Prepared compound was successfully applied as a corrosion inhibitor for C1010 carbon steel in 3.5% NaCl solution at 25°C. Different electrochemical measurements such as linear polarization resistance (LPR), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) were used to evaluate the suggested inhibitor (4). The results of different electrochemical measurements show that inhibition efficiencies obtained from EIS curves are in consistence with the results of potentiodynamic polarization and LPR measurements due to increase corrosion inhibition efficiency by increasing the concentration of organic inhibitor (4). Semi-empirical calculations with PM3 method were used to find relationship between molecular structure and inhibiting effect of suggested inhibitor (4). 相似文献
10.
Ayman M. Atta Hamad A. Al-Lohedan Abdelrahman O. Ezzat Zuheir A. Issa Ahmad B. Oumi 《Journal of Polymer Research》2016,23(4):69
In this work, we aimed to develop a feasible method for in situ preparation of a magnetite ionic polymer nanocomposite at room temperature. For this purpose, acrylonitrile (AN) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) monomers were copolymerized and crosslinked using different monomer mol ratios in the presence of N,N-methylenebisacrylamide (MBA) as crosslinker to produce ionic crosslinked polymers P(AN-co-AMPS. The nitrile groups were converted to amine amidoxime by reacting with hydroxylamine to increase the adsorption characteristics of the ionic polymers. The produced polymers were swelled in iron cations produced from the reaction of ferric chloride and potassium iodide, followed by reaction with an ammonium hydroxide solution to produce magnetite nano-polymer composites. We performed FT-IR and XRD analysis to determine the chemical and crystalline structures, and assessed the morphologies and magnetite content using SEM, TEM and TGA analyses. We investigated the adsorption capacity and mechanism of the prepared magnetite nano-composites as adsorbents for methylene blue, Co2+ and Ni2+ cations from water. 相似文献