Doping of KDP single crystals with cerium: Growth and optical properties

The features of doping of KDP crystals with cerium ions and organocerium complexes with alizarin complexon and arsenazo III have been investigated. It is established that “direct” doping by introducing cerium salts into the initial solution cannot be implemented. The effect of organometallic complexes of cerium on the crystal growth has been studied. Organocerium complexes predominantly enter the prismatic or pyramidal growth sectors. It is shown that the complex arsenazo III + Ce blocks the growth of the prismatic sector. Cerium-doped KDP crystals exhibit a photoluminescence band peaking at the wavelength λ_max= 350 nm.     

Magnetic poly(glycidyl methacrylate) microspheres prepared by dispersion polymerization in the presence of electrostatically stabilized ferrofluids

Fine magnetite nanoparticles, both electrostatically stabilized and nonstabilized, were synthesized in situ by precipitation of Fe(II) and Fe(III) salts in alkaline medium. Magnetic poly(glycidyl methacrylate) (PGMA) microspheres with core‐shell structure, where Fe₃O₄ is the magnetic core and PGMA is the shell, were obtained by dispersion polymerization initiated with 2,2′‐azobisisobutyronitrile (AIBN), 4,4′‐azobis(4‐cyanovaleric acid) (ACVA), or ammonium persulfate (APS) in ethanol containing poly(vinylpyrrolidone) or ethylcellulose stabilizer in the presence of iron oxide ferrofluid. The average microsphere size ranged from 100 nm to 2 μm. The effects of the nature of ferrofluid, polymerization temperature, monomer, initiator, and stabilizer concentration on the PGMA particle size and polydispersity were studied. The particles contained 2–24 wt % of iron. AIBN produced larger microspheres than APS or ACVA. Polymers encapsulating electrostatically stabilized iron oxide particles contained lower amounts of oxirane groups compared with those obtained with untreated ferrofluid. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5827–5837, 2004     

A Distributional Approach to Multiple Stochastic Integrals and Transformations of the Poisson Measure

We study a class of ‘nonpoissonian’ transformations of the configuration space and the corresponding transformations of the Poisson measure. For some class of Poisson measures we find conditions which are sufficient for the transformed measure (which in general is nonpoissonian) to be absolutely continuous with respect to the initial Poisson measure and get the expression for the corresponding Radon–Nikodym derivative. To solve this problem we use a distributional approach to Poisson multiple stochastic integrals.     

The transition of spontaneous polymerization of acrylamide to “explosive” regime

Experimental results related to the transition of spontaneous polymerization of acrylamide complexes with metal nitrates to the “explosive” regime at room temperature are presented. It is suggested that the “explosion” has a thermal nature. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 859–861, April, 1997.     

On the optimization of approximate integration by Monte Carlo methods

We solve the problem of optimization of monte Carlo methods for approximate integration over an arbitrary absolutely continuous measure. We propose a convenient model of Monte Carlo methods which uses the notion of transition probability.     

Widths and optimal quadrature formulas for convolution classes

We compute Kolmogorov widths in the space L₁ for classes of periodic functions representable in the form of a kernel convolution that does not increase the number of sign changes with values in a given transposition invariant set of functions, and solve the optimization problem for quadrature formulas in these classes.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 43, No. 9, pp. 1135–1148, September, 1991.     

Interactions of D-Maltose and Sucrose with Some Amino Acids in Aqueous Solutions

Calorimetric titrations have been performed at 298.15 K in aqueous solutions to derive the stability constants and thermodynamic parameters of the interactions of D-maltose and sucrose with some amino acids (glycine, DL-alanine, DL-leucine, and L-serine). The apparent molal volumes of the disaccharides in dilute aqueous solutions of the amino acids have been determined from density measurements at 298.15 K. In contrast to D-maltose, sucrose was found to associate with the amino acids and these associated species are preferentially entropy stabilized. These results are interpreted in terms of the influence of the nature of the solutes, their specific conformations, and hydration, on the ability of the disaccharides to form associated complexes with the amino acids.     

Methanol electrooxidation on platinum mesh electrodes bonded to solid polymer electrolytes

Methanol electrooxidation on smooth platinum electrodes bonded to solid polymer electrolytes was studied in water and acid solution by voltammetric measurements with different scanning rates. An enhancement of the oxidation rates was observed in these systems as compared to identical platinum electrodes in contact with liquid electrolytes. This electrocatalytic effect strongly depends on the measuring conditions and on the electrode potential. The reasons for the catalytic effects at different potentials are discussed. Received: 8 January 1997 / Accepted: 1 December 1997     

Functional characterization of two-dimensional gel-separated proteins using sequential staining

Proteins separated by two-dimensional (2-D) gel electrophoresis can be visualized using various protein staining methods. This is followed by downstream procedures, such as image analysis, gel spot cutting, protein digestion, and mass spectrometry (MS), to characterize protein expression profiles within cells, tissues, organisms, or body fluids. Characterizing specific post-translational modifications on proteins using MS of peptide fragments is difficult and labor-intensive. Recently, specific staining methods have been developed and merged into the 2-D gel platform so that not only general protein patterns but also patterns of phosphorylated and glycosylated proteins can be obtained. We used the new Pro-Q Diamond phosphoprotein dye technology for the fluorescent detection of phosphoproteins directly in 2-D gels of mouse leukocyte proteins, and Pro-Q Emerald 488 glycoprotein dye to detect glycoproteins. These two fluorescent stains are compatible with general protein stains, such as SYPRO Ruby stain. We devised a sequential procedure using Pro-Q Diamond (phosphoprotein), followed by Pro-Q Emerald 488 (glycoprotein), followed by SYPRO Ruby stain (general protein stain), and finally silver stain for total protein profile. This multiple staining of the proteins in a single gel provided parallel determination of protein expression and preliminary characterization of post-translational modifications of proteins in individual spots on 2-D gels. Although this method does not provide the same degree of certainty as traditional MS methods of characterizing post-translational modifications, it is much simpler, faster, and does not require sophisticated equipment and expertise in MS.