Factorization of quantum charge transport for non-interacting fermions

We show that the statistics of the charge transfer of non-interacting fermions through a two-lead contact is generalized binomial, at any temperature and for any form of the scattering matrix: an arbitrary charge-transfer process can be decomposed into independent single-particle events. This result generalizes previous studies of adiabatic pumping at zero temperature and of transport induced by bias voltage.Comment: 13 pages, 3 figures, typos corrected, references adde

Computational Prediction and Rational Design of Novel Clusters, Nanoparticles, and Solid State Materials

The creation of new materials is absolutely essential for developing new technologies. However, experimental efforts toward the material discovery are usually based on trial-and-error approach and thus require a huge amount of time and money. Alternatively, computational predictions can now provide a more systematic, rapid, inexpensive, and reliable method for the design of novel materials with properties suitable for new technologies. This dissertation describes the technique of theoretical predictions and presents the results on the successfully predicted and already produced (in some cases) unusual molecules, clusters, nanoparticles, and solids. The major part of scientific efforts in this dissertation was devoted to rationalizing of size- and composition-dependent properties of the materials based on understanding of their electronic structure and chemical bonding. It was shown that understanding relations between bonding and geometric structure, bonding and stability, and bonding and reactivity is an important step toward rational design of new, yet unknown materials with unusual properties. Our findings led to the discovery of the first simplest inorganic double helix structures, which can be used in the design of novel molecular devices. A significant part of this work also deals with the pseudo John-Teller effect, which potentially can be a powerful tool for rationalizing and predicting molecular and solid state structures, their deformations, transformations, and properties. Therefore, the works on the pseudo Jahn-Teller effect presented in this dissertation can be considered the steps toward further generalization and elevation of the pseudo Jahn-Teller effect to a higher level of understanding of the origin of molecular and solid state properties

Effects of cholesterol- or 7-ketocholesterol-containing liposomes on colony-forming ability of cultured cells

AbstractExperiments with cultured Chinese hamster cells showed that incubation of the cells with (phosphatidylcholine + cholesterol + 7-ketocholesterol)-containing liposomes (4:3:1 by weight) during two hours led to a decrease in the colony-forming ability of cells down to zero, while (phosphatidylcholine + cholesterol)-containing liposomes (1:1 by weight) reduce this parameter by 90%. Furthermore, the cholesterol-containing liposomes (without 7-ketocholesterol) induce a decrease in the number of the maximal-site colonies accompanied by the corresponding increase in the number of the middle-size colonies

NMR solution conformation of gramicidin A double helix

AbstractThe conformation of species 3 of Val-gramicidin A in dioxane has been determined by two-dimensional NMR spectroscopy. It is presented by the left handed ⇅ππ5.6LD double helix, a suitable model of an ion permeable pore across the membrane matrix

The path similarity method for phase measurements disambiguation

We introduce the technique for phase measurements disambiguation based on the paths similarity identification. To obtain these paths, we use phase and amplitude measurements. By simulation, the performance of the presented approach is established. Its application for the phase measurements disambiguation is demonstrated by the example of the phase correlative direction finder for which the amplitude correlative direction finding mode is activated without any hardware changes

Rare decay pi0 -> e+e-: theory confronts KTeV data

Within the dispersive approach to the amplitude of the rare decay pi0 -> e+e- the nontrivial dynamics is contained only in the subtraction constant. We express this constant, in the leading order in (m_e/\Lambda)^2 perturbative series, in terms of the inverse moment of the pion transition form factor given in symmetric kinematics. By using the CELLO and CLEO data on the pion transition form factor given in asymmetric kinematics the lower bound on the decay branching ratio is found. The restrictions following from QCD allow us to make a quantitative prediction for the branching B(pi0 -> e+e-) =(6.2\pm 0.1)*10^{-8} which is 3\sigma below the recent KTeV measurement. We confirm our prediction by using the quark models and phenomenological approaches based on the vector meson dominance. The decays \eta -> l^+l^- are also discussed.Comment: 7 pages, 1 figur

Two-dimensional 1H-NMR study of bacterioopsin-(34–65)-polypeptide conformation

AbstractConformation of the synthetic 32-residue polypeptide, an analog of membrane spanning segment B (residues 34–65) of the Halobacterium halobium bacteriorhodopsin in the membrane mimetic system, methanol/chloroform (1:1), was investigated by 1H-NMR spectroscopy. Previously it was shown by 19F-NMR spectroscopy that this medium retains the native conformation of membrane bound BR and its fragments. The spectrum resonance was assigned by means of the sequential signal assignment porcedure using phase-sensitive DQF-COSY, MLEV17 HOHAHA and NOESY techniques. Interproton nuclear Overhauser effects, spin-spin coupling constant of vicinal H-NCα-H protons and deuterium exchange rates of individual NH groups were derived from two-dimensional NMR spectra. The data unequivocally define the peptide conformation as the right-handed α-helix, extremely rigid in the central region from Phe 42 to Nle 60 and flexible in the N- and C-terminal parts

Towards a Unified Theory of Massless Superfields of All Superspins

We describe the ``universal'' action for massless superfields of all superspins in N = 1, D = 4 anti-de Sitter superspace as a gauge theory of unconstrained superfields taking their values in the commutative algebra of analytic functions over a one-sheeted hyperboloid in $R^{3,1}$. The action is invariant under N = 2 supersymmetry transformations which form a closed algebra off the mass-shell.Comment: 12 pages, LaTe