Determination of glucose concentration in biological liquids using photonic crystal waveguides

The possibility of using hollow-core photonic crystal waveguides as biological sensors is shown. The influence of the glucose concentration in solutions introduced into the waveguide core on the transmission spectrum of photonic crystal waveguides is shown. Two possible methods of determining the glucose concentration in liquids are considered, refractometric and photometric.     

Two new asterosaponins from the Far Eastern starfish Lethasterias fusca

Two new asterosaponins, lethasteriosides A (1) and B (2), were isolated along with previously known thornasteroside A (3), anasteroside A (4), and luidiaquinoside (5) from the ethanolic extract of the Far Eastern starfish Lethasterias fusca. The structures of the new compounds were elucidated by extensive NMR and ESIMS techniques, and chemical transformations. Compounds 1 and 3-5 did not show any apparent cytotoxicity against cancer cell lines T-47D, RPMI-7951, and HCT-116, but glycoside 1, at concentration of 20 microM, demonstrated considerable inhibition of the T-47D (97%), RPMI-795I (90%) and HCT-116 (90%) cell colony formations in a soft agar clonogenic assay.     

Analysis of the neutron single-particle energies of Zn, Ge, and Se isotopes within a mean field model with dispersive optical potential

The parameters of the neutron dispersive optical potential of even-even Zn, Ge, and Se isotopes (both stable and unstable) are determined from an analysis of experimental and estimated neutron single-particle energies. The imaginary part of the potential depends on the shell structure of the isotopes. The calculated energies are found to be in good agreement with the experimental and estimated energies.     

Dispersive optical potential from an analysis of neutron single-particle energies in the Ti, Cr, and Fe isotopes featuring 20 to 50 neutrons

Neutron single-particle energies in unstable Ti, Cr, and Fe isotopes containing 20 to 26 neutrons were evaluated on the basis of experimental proton energies in the mirror-symmetric nuclei. The neutron single-particle energies in the 20 ? N ? 50 Ti, Cr, and Fe isotopes were calculated on the basis of the mean-field model with a dispersive optical potential, and the results were compared with available experimental data and with the results of estimations and calculations based on the relativistic mean-field model and on the multiparticle shell model with the GXPF1 interaction.     

The thermodynamic characteristics of multicomponent reaction mixtures in the sub- and supercritical states

The paper presents mathematical models and calculation methods for solving particular research problems related to the thermodynamic characteristics of multicomponent and multiphase mixtures. The special features of chemical and phase equilibria in such mixtures are considered in the ideal gas approximation and taking nonideality into account. The conditions of equilibrium phase stability are studied for multiphase systems. The results of calculations of characteristic phase diagrams and binodal and spinodal are given for model systems with a fixed chemical composition, and a new interpretation of the mathematical model for localizing the critical point of a multicomponent mixture with a given composition is presented. A new interpretation of the well-known classic homotopy method is suggested for solving complex nonlinear systems of equations. Some anomalies of phase portraits and critical curves that are necessary to take into account in selecting (planning) experimental conditions and calculating chemical processes and reaction parameters are considered separately. The possibility of calculating thermodynamic and thermophysical properties (entropy, enthalpy, heat capacity, heat effects of reactions, and adiabatic heating) is demonstrated for the example of particular multicomponent nonideal mixtures. The conclusion is drawn that cubic equations of state can be used for predicting the deviations of these properties from the ideal gas state and their anomalies in the vicinity of the critical points of mixtures.     

A characterization of one class of graphs without 3-claws

In the first section of this note, we show that Theorem 1.8.1 of Bayer-Manin can be strengthened in the following way: If the even quantum cohomology of a projective algebraic manifold V is generically semisimple, then V has no odd cohomology and is of Hodge-Tate type. In particular, this answers a question discussed by G. Ciolli. In the second section, we prove that an analytic (or formal ) supermanifold M with a given supercommutative associative -bilinear multiplication on its tangent sheaf is an F-manifold in the sense of Hertling-Manin if and only if its spectral cover, as an analytic subspace of the cotangent bundle T _M ^*, is coisotropic of maximal dimension. This answers a question of V. Ginzburg. Finally, we discuss these results in the context of mirror symmetry and Landau-Ginzburg models for Fano varieties. To the memory of V.A. Iskovskikh     

Investigation of the shell structure of 40 ⩽ <Emphasis Type="Italic">A</Emphasis> ⩽ 132 magic and near-magic nuclei within the mean-field model involving a dispersive optical potential

Amethod for determining parameters of a dispersive optical potential is presented. This method is aimed at calculating single-particle energies of neutron and proton states of magic and near-magic nuclei. It is based on the use of global parameters of the imaginary part of the traditional-optical-model potential and experimental data on single-particle energies in the vicinity of the Fermi surface that were determined by simultaneously evaluating data on nucleon-stripping and nucleon-pickup reactions on the same nucleus. The potential of the method for describing and predicting single-particle energies of 40 ⩽ A ⩽ 132 magic and near-magic nuclei is demonstrated.     

Analysis of the new data on single-particle structure of nuclei from the middle of the 1<Emphasis Type="Italic">f</Emphasis>–2<Emphasis Type="Italic">p</Emphasis> shell within the dispersive optical model

On the basis of the most reliable experimental information about the single-particle energies of neutron and proton states in ₂₀ ⁴⁸ Ca₂₈, ₂₂ ⁵⁰ Ti₂₈, ₂₄ ⁵² Cr₂₈, and ₂₆ ⁵⁴ Fe₂₈ nuclei, single-particle energies in mirror ₂₈ ⁴⁸ Ni₂₀, ₂₈ ⁵⁰ Ni₂₂, ₂₈ ⁵² Ni₂₄ and ₂₈ ⁵⁴ Ni₂₆ nuclei have been evaluated. The evaluated single-particle energies are compared with the energies calculated within the dispersive optical model. Good agreement between the calculated and experimental single-particle energies is demonstrated.     

Structural and Electrosurface Properties of Porous Glasses of Various Composition in 1 : 1 Electrolyte Solutions

Complex studies of structural (the specific surface area, the volume porosity, the structural resistance coefficient, and the average pore radius), adsorption and electrokinetic (the electrical conductivity, the ion transport numbers, and the electrokinetic potential) characteristics as functions of pH and the concentration of KCl solution were carried out on porous glasses (PGs) with or without lead oxide and leached under various conditions. It was established that temperature of the leaching solution affects the colloidochemical parameters of PGs, while the addition of salt to the leaching solution exerts practically no influence on the PG behavior. It was shown that the addition of lead oxide results in the formation of membranes with thinner pores and higher surface charge.     

Electrosurface Properties of Microcrystalline Cellulose of Different Origin in 1 : 1 Electrolyte Solutions

Electrosurface characteristics (the exchange capacity and the electrokinetic potential) of the samples of cotton and wood microcrystalline celluloses (MCC) were studied as functions of the pH and the concentration of background electrolyte (10^–3–1M NaCl). It was found that the MCC samples are negatively charged over the studied pH range (3.5–10.0). The results of measuring exchange capacities were used for calculating constants of surface reactions. The values of dissociation constants of the surface groups allow us to state that the charge of the MCC surface within the studied pH range is mainly determined by the dissociation of carboxyl groups. The surface and electrokinetically mobile charges, concentrations of fixed and mobile ions, as well as Donnan's potentials were calculated for the studied samples.