The Picosecond Kinetic of Luminescence in Hydrophilic Colloidal CdS Quantum Dots

The picosecond kinetic of luminescence in conglomerations of hydrophilic colloidal CdS quantum dots with an average diameter of 2.5 nm in gelatin was investigated. It was observed in the recombination luminescence band with a maximum at 580 nm. A complicated character of depending in the time interval from 300 ps to 1800 ns was found. Obtained dependences were interpreted in terms of radiative recombination at the donor-acceptor pairs (different sizes), complicated non-radiative transitions involving localized charge carriers on deeper levels. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3527

Microsurgery of Cell Membrane with Femtosecond Laser Pulses for Cell Fusion and Optical Injection

We report on results of using femtosecond laserscalpel for microsurgery of plasma membrane ofliving cells. Femtosecond laser pulses were appliedto initiate cell fusion as well as to performreversible permeabilization of cell membranerequired for efficient injection of extrinsicsubstances into the target cells. Laser-based cellfusion of mammalian embryo blastomeres as wellas fusion of cell bodies of neurons of molluskLymnaea stagnalis were successfully carried out byapplying single femtosecond laser pulses (secondharmonic of a Cr:Forsterite laser system) 620 nm,100 fs with the fluences of 0.42-0.71 J/cm2. It wasshown that the fusion of cells was completed within5-60 minutes depending on the cell type. Successfulpermeabilization of a cell membrane andoptoinjection of a membrane impermeable dye wasperformed with the help of a compact laser systemfor cell microsurgery DissCell-F (ytterbium laser,1050 nm, 75 MHz, ~115 fs). In both cases the laserirradiation parameters were thoroughly optimized toachieve high viability of treated cells and highefficiency of the procedures of cell fusion andoptical injection

The Semileptonic Decays D→π(ρ)eνD\to \pi(\rho) e \nu and B→π(ρ)eνB\to \pi (\rho) e \nu from QCD Sum Rules

We investigate the semileptonic decays of B and D mesons into $\pi$ and $\rho$ mesons, respectively, by means of QCD sum rules. We find that for the vector formfactors involved the pole dominance hypothesis is valid to good accuracy with pole masses in the expected range. Pole dominance, however, does not apply to the axial formfactors which results in specific predictions for the predominant polarization of the $\rho$ meson and the shape of the lepton spectrum. For the total decay rates we find $\Gamma (\bar B^0 \to \pi^+ e^- \bar\nu) = (5.1\pm 1.1)\,|V_{ub}|^2\, 10^{12}\,{\rm s^{-1}}$, $\Gamma ( D^0 \to \pi^- e^+ \nu) = (8.0\pm 1.7)\,|V_{cd}|^2\, 10^{10}\,{\rm s^{-1}}$, $\Gamma (\bar B^0 \to \rho^+ e^- \bar\nu) = (1.2\pm 0.4\,)\,|V_{ub}|^2\, 10^{13}\,{\rm s^{-1}}$ and $\Gamma (D^0 \to \rho^- e^+\nu) = (2.4\pm 0.7)\,|V_{cd}|^2\, 10^{9}\,{\rm s^{-1}}$.Comment: 23 pages, 12 figures included as uu-encoded file, needs REVTEX, TUM--T31--39/9

The Picosecond Kinetic of Luminescence in Hydrophilic Colloidal CdS Quantum Dots

The picosecond kinetic of luminescence in conglomerations of hydrophilic colloidal CdS quantum dots with an average diameter of 2.5 nm in gelatin was investigated. It was observed in the recombination luminescence band with a maximum at 580 nm. A complicated character of depending in the time interval from 300 ps to 1800 ns was found. Obtained dependences were interpreted in terms of radiative recombination at the donor-acceptor pairs (different sizes), complicated non-radiative transitions involving localized charge carriers on deeper levels. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3527

Microwave conductivity of a d-wave superconductor disordered by extended impurities: a real-space renormalization group approach

Using a real-space renormalization group (RSRG) technique, we compute the microwave conductivity of a d-wave superconductor disordered by extended impurities. To do this, we invoke a semiclassical approximation which naturally accesses the Andreev bound states localized near each impurity. Tunneling corrections (which are captured using the RSRG) lead to a delocalization of these quasiparticles and an associated contribution to the microwave conductivity.Comment: 8 pages, 4 figures. 2 figures added to previous versio

Gap Fluctuations in Inhomogeneous Superconductors

Spatial fluctuations of the effective pairing interaction between electrons in a superconductor induce variations of the order parameter which in turn lead to significant changes in the density of states. In addition to an overall reduction of the quasi-particle energy gap, theory suggests that mesoscopic fluctuations of the impurity potential induce localised tail states below the mean-field gap edge. Using a field theoretic approach, we elucidate the nature of the states in the `sub-gap' region. Specifically, we show that these states are associated with replica symmetry broken instanton solutions of the mean-field equations.Comment: 11 pages, 3 figures included. To be published in PRB (Sept. 2001

Cefpodoxime proxetil – new opportunities in antibacterial therapy of respiratory infections

The purpose of the expert council was to determine the place of cefpodoxime in the ABT algorithms for upper and lower respiratory tract infections and to form a consensus position on its use in clinical practice. Based on the available data, the possibility of including cefpodoxime in national guidelines for the treatment of rhinosinusitis, acute tonsillopharyngitis, community-acquired pneumonia (CAP), as well as infectious exacerbations of chronic bronchitis (CB) and chronic obstructive pulmonary disease (COPD) is being considered