Quantitative Determination of Hydroxycoric Acids and the Analysis of the Dynamics of Their Accumulation in Malus sylvestris Leaves

Abstract—The presence of hydroxycinnamic acids in the leaves of Malus sylvestris Mill. and Malus domestica Borkh. is established by using HPLC analysis. The quantitative determination of hydroxycinnamic acids is carried out by spectrophotometric analysis. It is found that the maximum amount of hydroxycinnamic acids accumulates in the plant during the fruiting phase.     

Universal optical conductance of graphite

We find experimentally that the optical sheet conductance of graphite per graphene layer is very close to (pi/2)e2/h, which is the theoretically expected value of dynamical conductance of isolated monolayer graphene. Our calculations within the Slonczewski-Weiss-McClure model explain well why the interplane hopping leaves the conductance of graphene sheets in graphite almost unchanged for photon energies between 0.1 and 0.6 eV, even though it significantly affects the band structure on the same energy scale. The f-sum rule analysis shows that the large increase of the Drude spectral weight as a function of temperature is at the expense of the removed low-energy optical spectral weight of transitions between hole and electron bands.     

Preliminary results of the cross-section measurement of e<Superscript>+</Superscript>e<Superscript>−</Superscript> → φ(1020)η process with the CMD-3 detector at VEPP-2000 collider

We report preliminary results on the cross section of the process e⁺e^? → φ(1020)η measured at 30 center-of-mass energy points in the range from 1.59 up to 2.0 GeV. Data analysis is based on the integrated luminosity of 22 pb^?1 collected with the CMD-3 detector in 2011–2012. The obtained cross section agrees with the BaBar measurement and has better statistical accuracy.     

Complexes of the ATP-dependent Lon protease and DNA aptamers with G-quadruplexes as a model for developing a nanosensor biomagnetic immunoassay system

The binding to Lon protease through biotinylated aptamers whose structures contain G-quadruplex fragments with magnetic nanoparticles (MNPs) functionalized by streptavidin was investigated. The conditions of binding of target aptamers to MNPs are met. The resulting complexes are proposed for detection of Lon protease in different biological sources and for constructing a novel biomagnetic nanosensor immunoassay system.     

Acentric 2-D ensembles of D-br-A electron-transfer chromophores via vectorial orientation within amphiphilic n-helix bundle peptides for photovoltaic device applications

We show that simply designed amphiphilic 4-helix bundle peptides can be utilized to vectorially orient a linearly extended donor-bridge-acceptor (D-br-A) electron transfer (ET) chromophore within its core. The bundle's interior is shown to provide a unique solvation environment for the D-br-A assembly not accessible in conventional solvents and thereby control the magnitudes of both light-induced ET and thermal charge recombination rate constants. The amphiphilicity of the bundle's exterior was employed to vectorially orient the peptide-chromophore complex at a liquid-gas interface, and its ends were tailored for subsequent covalent attachment to an inorganic surface, via a "directed assembly" approach. Structural data, combined with evaluation of the excited state dynamics exhibited by these peptide-chromophore complexes, demonstrate that densely packed, acentrically ordered 2-D monolayer ensembles of such complexes at high in-plane chromophore densities approaching 1/200 ?(2) offer unique potential as active layers in binary heterojunction photovoltaic devices.     

Competition between pairing and deformation in finite Fermi systems

The problem of the possible deformation of finite Fermi systems with particle numbers of ≤10⁴ is studied within the Bardeen-Cooper-Schrieffer model. It is shown that for slight deformations of a spherical system consisting of one valence l shell (l ≫ 1), the results of the quasi-particle theory and the exact Richard- son theory virtually coincide. Analysis of the equilibrium deformation of a cluster shows that the system does not keep its spherical form even at a low number of valence particles.     

The Stability of Mononuclear and Binuclear Complexes of Silver(I) with Thiosemicarbazide in an Aqueous Solution

Moscow University Chemistry Bulletin - The complexation process of silver(I) ions with thiosemicarbazide (Tsc) in a wide range of concentrations of silver(I) and thiosemicarbazide at T =...     

Synthesis and Heterogeneous Structure of Anionic Networks of Oligoester Acrylates

Anionic polymerization has been used for the synthesis of polymeric networks based on α,ω-dimethacrylbis(triethylene glycol) phthalate, α,ω-dimethacrylbis(diethylene glycol) phthalate, and α,ω-dimethacrylbis(ethylene glycol) phthalate. The dependence of network polymer yields on catalyst concentration has a maximum. The correlation between the value and position of maxima and the length of the initial oligomeric chain has been established. The network polymers were studied by use of small-angle x-ray scattering. The parameters of heterogeneous structure and their relation to the peculiarities of the polymerization process have been established. It was established that the microheterogeneous structure of the networks is determined by the geometric characteristics of the initial oligomeric chains and the conditions of synthesis.