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71.
72.
Aram Alizadeh Mojtaba Salouti Hamed Alizadeh Ali Reza Kazemizadeh Ali Asghar Safari Sanaz Mahmazi 《IET nanobiotechnology / IET》2017,11(8):942
In recent years, the problems associated with bacterial resistance to antibiotics caused nanodrugs to be considered as a new way for infectious diseases treatment. The main purpose of this study was to develop a new agent against Pseudomonas aeruginosa, a very difficult bacterium to treat, based on azlocillin antibiotic and silver nanoparticles (AgNPs). Azlocillin was conjugated with AgNPs by chemical methods and its antimicrobial activity was studied against P. aeruginosa using well diffusion agar method. Then, minimum inhibitory concentration and minimum bactericidal concentration of the new conjugate was specified with macro‐dilution method. The animal study showed the considerable enhanced antibacterial effect of azlocillin in conjugation with AgNPs against P. aeruginosa in comparison with azlocillin alone, AgNPs alone and azlocillin in combination with AgNPs.Inspec keywords: antibacterial activity, silver, nanoparticles, organic compounds, microorganisms, drugs, nanomedicine, biomedical materials, diseases, diffusion, nanofabricationOther keywords: Ag, macrodilution method, minimum bactericidal concentration, minimum inhibitory concentration, well diffusion agar method, P. aeruginosa, antimicrobial activity, chemical methods, azlocillin antibiotic nanoparticles, infectious diseases treatment, nanodrugs, bacterial resistance, Pseudomonas aeruginosa, silver nanoparticles, antibacterial effect 相似文献
73.
Influence of electrolytes of Li salts,EMIMBF4, and mixed phases on electrochemical and physical properties of Nafion membrane
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Electrolyte‐soaked Nafion is commonly used as an ionic polymer in soft actuators. Here, a multitechnique investigation was applied to correlate the electrochemical behavior of Nafion membranes with their microstructures and nanostructures as a function of electrolyte type. The influence of electrolytes of Li salts with different counteranions on the Nafion membranes was investigated in terms of hydration level, structure (using X‐ray diffraction and small angle X‐ray scattering), stress–strain characteristics, and electrochemical behavior (by cyclic voltammetery and electrochemical impedance spectroscopy). The effects of using ionic liquid (IL), as the electrolyte, addition of different supporting solvent and the addition of Li+ ions to water‐free IL‐soaked membranes on the structural and electrochemical properties of Nafion were examined. The nano‐ and microstructure of the Nafion changed considerably as a function of the identity of the electrolyte solution. The electrochemical behavior of the IL‐soaked samples was compared with that of the water‐soaked Li+‐exchanged Nafion. It was seen that the ionic conductivity of the Nafion membranes was reduced significantly when water was replaced by pure IL. Using the supporting solvents increased the conductivity of IL‐soaked Nafion membranes dramatically. The presence of a small amount of Li+ ions together with the IL ions caused a significant decrease in charge transfer resistance and increases in double layer capacitance and in ionic conductivity over that of the water‐free sample and also over water‐soaked Li+‐exchanged Nafion. These findings can be useful to improve the knowledge on Nafion's microstructure and also to improve the electromechanical behavior of Nafion‐based ionic polymer–metal composites actuators. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45239. 相似文献
74.
Lipase-catalyzed interesterification of butterfat was carried out in a cosurfactant-free microemulsion system containing mixtures
of Span 60 and Tween 60 (ICI Specialty Chemicals Altemix Inc., Brantford, Ontario, Canada) as surfactants. Four commercial
lipases were used—Lipozyme 10,000L (Novo Nordisk, Copenhagen, Denmark) and N, D and MPA (Amano Pharmaceutical Co. Ltd., Nagoya,
Japan). Stereospecific analyses of fractionated selected high-molecular weight triacylglycerols were performed by enzymatic
deacylation with commercial pancreatic lipase, random generation ofrac-1,2-diacylglycerols by Grignard degradation, synthesis ofrac-phosphatidylcholines and a stereospecific release ofsn-1,2 diacylglycerols by phospholipase A2. The results showed that the hydrolytic affinity of commercial lipases demonstrated an acyl-group specificity toward lower-molecular
weight fatty acids C4–C14∶0. Stereospecific analyses of fatty acids of interesterified selected triacylglycerols of butterfat
catalyzed by lipase N demonstrated a 46% increase in the proportion of C18∶1cis Δ9 at thesn-2 position, whereas those catalyzed by lipases MAP, D and Lipozyme 10,000L were enriched with C16∶0 at the same position
by 21, 35 and 41%, respectively. 相似文献
75.
Shai S. Livneh Victor F. Janas Ahmad Safari 《Journal of the American Ceramic Society》1995,78(7):1900-1906
The relic processing technique was used to fabricate fine-scale piezoelectric lead zirconate titanate (PZT) ceramic fiber/polymer shell composites. In this technique sacrificial activated carbon fabrics were soaked in a PZT precursor solution, dried, and heat treated to form piezoceramic relics. Relics were embedded with polymer, which was allowed to cure, and the resulting composites were polished, electroded, and poled. Different facets of the composite- forming process were examined: structural modifications, soaking, firing, and polymer impregnation. The physical and electromechanical properties of the unique resulting composite were evaluated. Optimized PZT shell composites with 39 vol% ceramic exhibited the following property values: K ε200, tan δε5.5%, d 33 ε290 pC/N, d h ε100 pC/N, d h g h ε6000 ± 10-15 m2 N, k p ε0.19, and k t ε0.28. 相似文献
76.
System identification based on least mean square (LMS) adaptive filters is effective due to their simplicity and robustness. Inherent physical characteristic of intended system usually make nonnegativity constraint desirable. In other words, imposing nonnegativity constraint on optimization problem leads to more feasible unknown parameter estimation. Hence, nonnegative least mean square (NNLMS) and its variants were proposed to adaptively solve the Wiener filtering problem considering constraint that makes filter weights nonnegative. In this paper, we propose a new variant of nonnegative least mean square for which its performance is analyzed both theoretically and experimentally. The proposed algorithm behavior is investigated in sparse system identification by Monte Carlo simulations in order to show validation of analysis and theory models. We compare our method with IP-NNLMS and NNLMS in order to prove the advantage of our proposed algorithm. Our proposed algorithm is also used in classification problem, and it is compared with entropy function-based online adaptive decision fusion (EADF) algorithm. 相似文献
77.
78.
Shokrolahi Seyed Moslem Karimiziarani Mohammadsepehr 《Analog Integrated Circuits and Signal Processing》2021,107(3):597-604
Analog Integrated Circuits and Signal Processing - Automatic fault diagnosis in analog electronic circuits is one of the interesting and important cases for researchers of this field that has... 相似文献
79.
Hossein Safari Farhad Gharagheizi Alireza Samadi Lemraski Mohammad Jamialahmadi Amir H. Mohammadi Milad Ebrahimi 《Neural computing & applications》2014,25(3-4):955-965
Precipitation and scaling of calcium sulfate have been known as major problems facing process industries and oilfield operations. Most scale prediction models are based on aqueous thermodynamics and solubility behavior of salts in aqueous electrolyte solutions. There is yet a huge interest in developing reliable, simple, and accurate solubility prediction models. In this study, a comprehensive model based on least-squares support vector machine (LS-SVM) is presented, which is mainly devoted to calcium sulfate dihydrate (or gypsum) solubility in aqueous solutions of mixed electrolytes covering wide temperature ranges. In this respect, an aggregate of 880 experimental data were gathered from the open literature in order to construct and evaluate the reliability of presented model. Solubility values predicted by LS-SVM model are in well accordance with the observed values yielding a squared correlation coefficient (R 2) of 0.994. Sensitivity of the model for some important parameters is also checked to ascertain whether the learning process has succeeded. At the end, outlier diagnosis was performed using the method of leverage value statistics to find and eliminate the falsely recorded measurements from assembled dataset. Results obtained from this study indicate that LS-SVM model can successfully be applied in predicting accurate solubility of calcium sulfate dihydrate in Na–Ca–Mg–Fe–Al–H–Cl–H2O system over temperatures ranging from 283.15 to 371.15 K. 相似文献
80.
Keivan H. Safari Jamal Zamani Fernando J. Ferreira Rui M. Guedes 《Polymer Engineering and Science》2013,53(4):752-761
A constitutive model is presented for large strain deformation of polycarbonate (PC) at high strain rates (above 102 s?1). The proposed model considers the primary process (α) and the two secondary rate‐activated processes (β and γ). It is shown that the secondary transitions in the material affect the yield and post yield behavior of the material at high strain rates. The constitutive model has been implemented numerically into a commercial finite element code through a user material subroutine. The experimental results, obtained using a split Hopkinson pressure bar, are supported by dynamic mechanical thermal analysis (DMTA) and DSR (Decompose/Shift/Reconstruct) method. These are employed to gain understanding of the material transitions, and to further the linkages between material viscoelastic, yield, and stress–strain behavior. Comparison of model predictions with experimental data demonstrates the ability of model to capture the characteristic features of stress–strain curve of the material such as initial linear elasticity, global yield, strain softening, and strain hardening at very high strain rates (up to 10,000 s?1). POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers 相似文献