Understanding Complex Interplay among Different Instabilities in Multiferroic BiMnO Using Fe Probe Mössbauer Spectroscopy.

Here, we report the results of a Mössbauer study on hyperfine electrical and magnetic interactions in quadruple perovskite BiMnO doped with Fe probes. Measurements were performed in the temperature range of 10 K < < 670 K, wherein BiMnFeO undergoes a cascade of structural ( ≈ 590 K, ≈ 442 K, and ≈ 240 K) and magnetic ( ≈ 57 K, ≈ 50 K, and ≈ 24 K) phase transitions. The analysis of the electric field gradient (EFG) parameters, including the dipole contribution from Bi ions, confirmed the presence of the local dipole moments , which are randomly oriented in the paraelectric cubic phase ( > ).

The globalizability of temporal discounting.

Economic inequality is associated with preferences for smaller, immediate gains over larger, delayed ones. Such temporal discounting may feed into rising global inequality, yet it is unclear whether it is a function of choice preferences or norms, or rather the absence of sufficient resources for immediate needs. It is also not clear whether these reflect true differences in choice patterns between income groups.

Single-cell all-optical coherence elastography with optical tweezers.

The elastic properties of cells are important for many of their functions, however the development of label free noninvasive cellular elastography method is a challenging topic. We present a novel single-cell all-optical coherence elastography method that combines optical tweezers producing mechanical excitation on the cell membrane or organelle and phase-sensitive optical coherence microscopy measuring sample response and determining its mechanical properties. The method allows living cells imaging with a lateral resolution of 0.

Direct measurements of forces induced by Bloch surface waves in a one-dimensional photonic crystal.

An experimental study of the interaction between a single dielectric microparticle and the evanescent field of the Bloch surface wave in a one-dimensional (1D) photonic crystal is reported. The Bloch surface wave-induced forces on a 1 μm polystyrene sphere were measured by photonic force microscopy. The results demonstrate the potential of 1D photonic crystals for the optical manipulation of microparticles and suggest a novel approach for utilizing light in lab-on-a-chip devices.

Competition and interplay of various intermolecular interactions in ultrafast excited-state proton and electron transfer reactions.

The main features of the photoinduced kinetics of both ultrafast excited-state proton and electron transfer reactions that occur in the picosecond (ps) and femtosecond (fs) time domains are compared. Proton transfer (PT) reaction kinetics can be described in terms of several discrete values of rate coefficients in the form of polyexponential functions where each value of the rate coefficient can be attributed to a definite physical behavior of the reaction mechanism. In contrast, electron transfer (ET) reaction kinetics requires a consideration of a continuous distribution of rate coefficients.

Analysis of transformations of the ultrafast electron transfer photoreaction mechanism in liquid solutions by the rate distribution approach.

Representation of the experimental reaction kinetics in the form of rate distribution is shown to be an effective method for the analysis of the mechanisms of these reactions and for comparisons of the kinetics with QC calculations, as well as with the experimental data on the medium mobility. The rate constant distribution function P(k) can be obtained directly from the experimental kinetics N(t) by an inverse Laplace transform. The application of this approach to kinetic data for several excited-state electron transfer reactions reveals the transformations of their rate control factors in the time domain of 1-1000 ps.

Microphase mechanism of "superquenching" of luminescent probes in aqueous solutions of DNA and some other polyelectrolytes.

A new approach in terms of microphase model of aqueous solutions of polyelectrolytes is proposed for explanation of a very strong quenching of luminescent probes ("superquenching") in these solutions. This phenomenon is used in literature for creation of extremely sensitive chemical and biosensors and was attributed predominantly to efficient energy or electron transfer. Microphase approach considers this phenomenon in terms of local concentrations of both the luminescent compound and of the quencher in microphase, formed by DNA and other polyelectrolytes, which can be several (4-10) orders of magnitude greater than their apparent concentrations in solution.

[Variability of DNA simple sequence repeats in peripheral blood of humans subjected to prolonged exposures of ionizing radiation].

Long-term post-radiation changes in the level of microsatellite DNA polymorphism in peripheral blood of the male "Mayak" employees (Ozyorsk, Russia), who had been exposed to prolonged gamma-irradiation during professional activities, were studied. DNA samples were obtained from the Radiobiology Repository of Human Tissue (Southern-Urals Biophysics Institute FMBA) and used as templates for arbitrarily primed PCR. Comparative analysis of the obtained samples of DNA fragments showed a significant increase in the number of high-molecular fragments and reduction in the number of amplified low molecular weight DNA fragments in comparison with the control.

[Dynamics of microsymbiocenoses of upper respiratory tract in normal state and in pathology].

Aim: Study of features of interaction of bacteria in microsymbiocenoses of upper respiratory tract in dynamics in individuals with various state of health: healthy individuals, individuals after tonsillitis and bacteria carriers.

Materials And Methods: Modification of pathogenicity factors (hemolytic, lecitovitellase, lysozyme and anti-lysozyme activity) in intermicrobial interactions of 226 strains of microorganisms isolated during quintuple analysis of upper respiratory tract biocenoses of examined individuals was studied. A hierarchical structure of each microbiocenosis was built based on the data obtained, and its temporal dynamics evaluated.

Giant Goos-Hänchen effect and Fano resonance at photonic crystal surfaces.

The Goos-Hänchen effect and Fano resonance are studied in photonic crystals that are considered Fourier counterparts in wave-vector-coordinate space. The Goos-Hänchen effect, which is enhanced by the excitation of Bloch surface electromagnetic waves, is visualized using far-field microscopy and measured at the surface of photonic crystals by angular spectroscopy. The maximal Goos-Hänchen shift is observed to be 66  μm.

High resolution capabilities of all-silica cantilevered probes for near-field optical microscopy.

We report on the possibility of performing Near-field Scanning Optical Microscopy in illumination mode by means of microfabricated, metal-coated silica probes based on transparent cantilevers. A low spring constant silica cantilever hosts a silica tip at its end showing an hyperbolic profile and a circular symmetry. After evaporation of 100 nm of aluminium on the tip and the cantilever we processed the tip apex by means of a FIB, thus obtaining either a probe apex with an optical aperture or an apertureless probe having a thin metal layer on the top.

[Study of nasal and tonsillar mucosal microbiocenoses as one of the health indices].

The qualitative and quantitative compositions of nasal and tonsillar mucosal biocenoses were studied in healthy individuals and patients with chronic tonsillitis as an ecological criterion for assessing the stability of biocenosis and human health. The qualitative composition of tonsillar mucosal biocenosis turned out to be steady-state both in health and disease. The human nasal mucosa showed itself as an indicator system.

[Evaluation of malignancy of squamous cell lung cancer by clinico-morphological, immunohistochemical and prognostic study of tumor markers].

An immunological study was carried out in 127 cases of surgical treatment of squamous cell lung cancer. Cryostat sections were used to identify markers of proliferation (Ki-67 and topoisomerase IIalpha), apoptosis (p53 and CAS) and intercellular adhesion (E-cadcherin). It was shown that Ki-67 and topoisomerase IIalpha proliferation rates and CAS expression may be interpreted as additional factors of squamous cell cancer aggressiveness while E-cadcherin expression--as a favorable prognosticator.

Evolution of the reaction mechanism during ultrafast photoinduced electron transfer.

Specific features of ultrafast photoinduced electron transfer (ET) in concentrated liquid solutions and in neat electron donating solvents are discussed in terms of continuous distribution of ET rate constants, related to electron tunneling with statistical distribution of electronic coupling matrix element and distances between reactant molecules. Available data on photoinduced electron transfer in solutions for several systems are analyzed. Electron tunneling approach is shown to provide global description of nonexponential kinetics of excited states decay at various concentrations of reactant and in neat solvents.

The behavior of exciplex decay processes and interplay of radiationless transition and preliminary reorganization mechanisms of electron transfer in loose and tight pairs of reactants.

Exciplex emission spectra and rate constants of their decay via internal conversion and intersystem crossing are studied and discussed in terms of conventional radiationless transition approach. Exciplexes of 9-cyanophenanthrene with 1,2,3-trimethoxybenzene and 1,3,5-trimethoxybenzene were studied in heptane, toluene, butyl acetate, dichloromethane, butyronitrile, and acetonitrile. A better description of spectra and rate constants is obtained using 0-0 transition energy and Gauss broadening of vibrational bands rather than the free energy of electron transfer and reorganization energy.

[Correlation of proliferation, apoptosis, angiogenesis and metastasizing in various histogenetic types of pulmonary cancer (an immunohistochemical investigation)].

Surgical material from 157 patients with lung carcinoma was studied. Immunohistochemical detection of the following oncomarkers was performed: Ki67, p53, CD34, CAS, Topoisomerase II alfa, nm23 protein, E-cadherin. The existence of association between proliferation, tumour cell apoptosis and formation of vessels in the tumour stroma is established.

Evidence for diffusion-controlled electron transfer in exciplex formation reactions. Medium reorganisation stimulated by strong electronic coupling.

Diffusion-controlled rates of formation were found from the temperature dependence of apparent quenching rate constants for exciplexes, when the driving force of excited-state electron transfer -0.1 < deltaG(ET)* < +0.1 eV.

[Interaction of human thrombin I fragment, prethrombin I, and alpha-thrombin with tissue thromboplastin].

The binding of 125I-labeled prothrombin fragment I. prethrombin I and alpha-thrombin to native and papain-treated tissue thromboplastin in the presence of CaCl2 of EDTA was studied. The experimental curves plotted in the Scatchard coordinates testify to the presence in thromboplastin of two types of fragment I binding sites: those with a high (Kd = 7.

[The use of nucleolytic enzymes (ribonucleases, polynucleotide phosphorylases and endonuclease from Serratia marcescens) for producing initial blocks of synthetic endoribonucleases].

The simplest variant of synthetic substrate-ribozyme complex has been proposed. The schemes of potential ribozyme "subunits" synthesis have been worked out: R1--GCUUGAAACAAA; R2--AAAAACUGAUGAAAGC. The macroscale synthesis of dinucleoside monophosphate ApU, GpC, CpU catalyzed by immobilized ribonucleases of different specificity and preparation of oligoadenylates by hydrolysis of poly-A in the presence of endonuclease Serratia marcescens, as well the synthesis of conservative sequences of potential ribozyme such as ApUpG, CpUpG, GpApU, ApApApG and others have been described.

[Interaction of human prothrombin with tissue thromboplastin].

The binding of 125I-labeled human prothrombin to native and papain-treated tissue thromboplastin in the presence of CaCl2 or EDTA was studied. The Scatchard plots for the protein binding suggest the presence at thromboplastin surface of two types of binding sites, high affinity [Kd(app) = 7.4.