Results 1 - 10 of 3699
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[en] We report a simple colorimetric approach for the detection of arsenic (III) through gold nanoparticles functionalized by polyethylene glycol. Following Turkevich procedure nanoparticles were prepared. Owing to addition of arsenic (III), lead (II), copper (II), nickel (II), iron (III), zinc (II), cobalt (II), magnesium (II) and cadmium(II) to the as synthesized gold nanoparticles we observe rapid color change from red to blue with respect to arsenic (III) containing vials. This implicates the selectivity of polyethylene glycol functionalized gold nanoparticles towards arsenic (III). Sensitivity was analyzed from absorbance spectra obtained from UV–vis spectrometer and limit of detection was found to 5 ppb from the linear response curve which is below the WHO guided value 10 ppb. (paper)
[en] Extraction of microamounts of strontium and barium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of polyethylene glycol PEG 1000 (L) has been investigated. The equilibrium data have been explained assuming that the complexes H2L2+, ML2+ and MHL3+ (M2+ = Sr2+, Ba2+) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It was found that in water-saturated nitrobenzene the stability constant of the BaL2+ cationic complex species is somewhat higher than that of the complex SrL2+. (author)
[en] Extraction of microamounts of calcium and strontium by a phenyltrifluoromethyl sulfone (FS 13) solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of polyethylene glycol PEG 400 (L) has been investigated. The equilibrium data have been explained assuming that the species HL+, CaL2+ and SrL2+ (L = PEG 400) are extracted into the organic phase. The values of extraction and stability constants of the cationic complex species in FS 13 saturated with water have been determined. It was found that in water-saturated FS 13, the stability constant of the complex SrL2+, where L is PEG 400, is somewhat higher than that of the species CaL2+ with the same ligand L. (author)
[en] We report the successful functionalization of optically accessible nanostructures, suitable for single-molecule experiments at physiological substrate concentrations, with polyethylene glycol. Characterization of the coating in terms of roughness, protein repellence, and specific immobilization of DNA is described. We present an application of this technique in the detection of polymerase activity within nanostructures, which demonstrates the opportunities made possible through the integration of nanofabricated structures with surface functionalization.
[en] The authors' previous double antibody radioimmunoassay for human AFP was run at 40C and required 48 h for completion. A method is described which permits the assay to be performed within 5 h due to an increased incubation temperature and the use of polyethylene glycol to precipitate the antigen-antibody complex. The modified radioimmunoassay was standarized against an international reference preparation of human AFP. Characteristics of this assay are discussed. (Auth.)
[en] Twenty-nine strains of Coprinus species comprising 16 strains from 12 identified species and 13 unidentified strains as well as one Arthromyces ramosus strain were screened for the production of extracellular peroxidase. Among the fungi examined, three strains of C. cinereus, UAMH 4103, UAMH 7907 and IFO 30116, as well as one Coprinus sp., UAMH 10067, which was isolated from urea treated soil, were shown to produce large amounts of extracellular peroxidase. The performance of crude peroxidase, obtained from liquid culture of C. cinereus, (CIP) on phenol removal from synthetic wastewater was evaluated and compared with that of purified horseradish peroxidase and A. ramosus peroxidase. Although crude CIP performed better than both purified enzymes, its superiority vanished in the presence of poly(ethylene glycol), a known protective agent of peroxidase. This suggests that the residual soluble substances present in crude CIP have protective effects similar to those of poly(ethylene glycol). (author)
[en] Extraction of microamounts of cesium by a phenyltrifluoromethyl sulfone FS 13) solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of olyethylene glycol PEG 400 (L) has been investigated. The equilibrium data ave been explained assuming that the species HL+ and CsL+ (L = PEG 400) re extracted into the organic phase. The values of extraction and stability onstants of the cationic complex species in FS 13 saturated with water have been determined. (author)
[en] Kinetic analysis of the non-isothermal degradation of poly(ethylene oxide) has been performed using isoconversional model-free methods, model-fitting methods, invariant kinetic parameters method and Netzsch Thermokinetics software in order to establish whether different kinetic approaches yield consistent kinetic parameters. It has been shown that these approaches yield consistent kinetic parameters and can be combined in such a way as to enhance the reliability and quality of each other and consequently the overall kinetic analysis. The most probable kinetic parameters for the non-isothermal degradation of poly(ethylene oxide) have been determined. These kinetic parameters have been used for prediction of isothermal kinetics of poly(ethylene oxide), and their potential for reliable prediction has been noticed.
[en] The correlation between crystallite structural changes and polarization properties of a linear crystallized [–CH2CH2O–]n polyethylene oxide polymer is studied. The average spherulite radius and polarization of polyethylene oxide are inspected as functions of molecular weight of polymer and crystallization temperature from melt in a nonuniform temperature field.