Lonene-coated sulfonated silica as a packing material in the packed-capillary mode of electrochromatography

An aliphatic ionene (2-10-ionene) has been selected as a modifier to prepare a novel polymer-coated packing material for capillary electrochromatography. The packing material was produced by dynamical modification of a commercially available sulfonated silica Exsil-100 SCX. Strong ion-exchange interactions in the capillary packed with ionene-modified sulfonated silica have been demonstrated by the example of the retention of p-aminobenzoic acid. The total calculated anion-exchange capacity of the sorbent in the capillary was about 4 x 10(-9) mol. A fast separation (about 15 min) of several aromatic acids was achieved with the packing material. The highest number of theoretical plates obtained was about 120,000. Limits of detection of the aromatic acids were 2-5 microg/ml. The advantages and lacks of the approach are discussed briefly.     

Suppression of the anomaly of low-frequency permittivity in ferroelectric triglycine sulfate by microwaves

Microwave dielectric spectra of ferroelectric triglycine sulfate are measured in the littlestudied frequency range from 90 to 150GHz, and the suppression of low-frequency dielectric anomaly by microwaves at these frequencies is investigated. It is shown that suppression occurs only in the range of non-Debye dielectric dispersion. An additional dispersion mechanism based on the activation-diffusion model of orientational polarization and transit-time effects for quasi-free carriers is proposed to explain the microwave impact.     

Method for direct determination of mitomycin C in urinary bladder for surface cancer treatment

A technique was developed for the quantitative determination of mitomycin C in urinary-bladder tissues. We used the method of gradient high-performance liquid chromatography with mass-spectrometry detection in the electrospray ionization mode. The range of linearity of the calibration plot was 20?C440 ??g/L. The detection limit was 15 ng/L. We proposed a sampling procedure that consisted of water extraction. Importantly, this procedure allows one to determine the quantity of mitomycin C in tissues. In our study, this method was utilized to estimate the quantity of mitomycin C in the urinary bladder.     

Dust Temperature Profiles in Dense Cores Related to the High-Mass Star-Forming Regions

Radiophysics and Quantum Electronics - We obtained continuum maps at a wavelength of 350 μm for eight gas–dust clouds from the southern hemisphere using the APEX-12m telescope. The...     

An algorithm for selecting marker substances in gas chromatographic analysis of medicinal-plant raw materials

Two complementary chromatographic methods, viz., ion-exclusion chromatography and gas-liquid chromatography, are suggested for studying the chemical composition and the standardization of medicinal-plant raw materials and plant mixtures. An algorithm for selecting one of two methods, which takes into account the component composition in plant mixtures, as well as the classification of marker sub-stances according to the degree of their occurrence in specific types of medicinal-plant raw materials, are proposed.     

General covariance violation and the gravitational dark matter: Vector graviton

The (four-component) vector graviton contained in the metric, the scalar component incorporated, is attributed to the violation of the general covariance to the residual isoharmonic one. In addition to the previously studied (singlet) scalar graviton, the vector graviton may constitute one more fraction of the gravitational dark matter. The gravity interactions of the vector graviton, as well as its impact on the continuous medium, are studied. The text was submitted by the author in English.     

Comparison of the Possibilities of Thermal-Lens Detection in Capillaries and Microchips

The conditions of thermal-lens detection are compared for samples with small path lengths: capillaries and microchannels of chemical microchips. The optimum parameters of the optical configuration of a thermal lens spectrometer (beam diameters and their in-sample ratios, and the detector position) were calculated from the theory and confirmed experimentally. The limits of detection of a model chemical substance (ferroin) are estimated at 1 × 10^–8 M for microchips and 5 × 10^–8 M for capillaries. The absolute limits of detection are the same and equal to 3 × 10^–17 M. The advantages and disadvantages of thermal lens detection in capillaries and microchips are discussed.     

Computation of the lifetime of metal cathode coatings

We propose a method of computing the service time of protective coatings as functions of the geometric and physical characteristics of the aggressive medium-coating-base system. The method is based on representing the destruction process as a series of successive time stages. We analyze the possibility of loss of protective properties of a metallic cathode covering both as a consequence of mechanical failure and as a result of flaking.Translated fromMatematicheskie Metody i Fiziko-Mekhanicheskie Polya, Issue 35, 1992, pp. 24–34.