Valence tautomeric transition of bis(o-dioxolene) cobalt complex in solid state and solution

Valence tautomer transition occurs mainly in 3d metalorganic complexes with redox-active ligands and makes them potential candidates for single-molecular switches. The transition occurs under temperature, pressure, or light-induced stimuli and is strongly affected by the intermolecular interactions. However single-crystal x-ray diffraction is not always applicable to such systems when crystal structure is destroyed upon transition or system is studied in the solution. Such an example is bis(o-semiquinonato) cobalt complex with TEMPO-functionalized iminopyridine ancillary ligand. In this work we apply two complementary techniques-ligand-sensitive Fourier transform infrared spectroscopy (FTIR) and metal sensitive Co K-edge x-ray absorption spectroscopy (XAS). In a solid state, a temperature hysteresis of magnetization larger than 40 K was observed upon cyclic cooling-heating. So, the temperature of phase transition upon cooling is about 40 K lower than that upon heating. In solution, the x-ray absorption spectra for high-temperature and low-temperature states were similar to that in the solid form, but the hysteresis was absent. Two methods are can probe valence tautomer transition, but XAS has an advantage for the liquid phase analysis and FTIR has larger sensitivity to the ligand related interactions in solid.

Photocyclization of diarylethenes: the effect of imidazole on the oxidative photodegradation process

It was found that imidazole prevents the side process of diarylethenes photocyclization and the photodegradation of photochromic compounds.

Tetrodotoxin and its analogues profile in nemertean species from the sea of Japan

For the first time search for tetrodotoxin (TTX) and its analogues in the extracts of nemerteans using HPLC-MS/MS was performed. TTX analogues were detected in two nemertean species in addition to TTX: 7 analogues were detected in the extract of Cephalothrix simula, 3 analogues - in the extract 11-norTTX of Kulikovia manchenkoi. Presence of 5-deoxyTTX, 11-deoxyTTX, 5,6,11-trideoxyTTX and -6(R)-ol in nemerteans was shown for the first time.

[Optimization of the algorithm for the detection and the differential non-pharmacological correction of the risk factors and the preclinical stages of atherosclerosis at the level of the health resort-based primary care]

This article presents the results of a comparative prospective study of 276 subjects at the age between 40 and 65 years presenting with risk factors (RF) of atherosclerosis and its preclinical stages (APC). All of them were reckoned to be at a moderate risk of developing APC based on the results of evaluation with the use of the SCORE scale which implied the necessity of their differential non-pharmacological treatment during a two-year period with the application of a variety of preventive therapeutic strategies. The patients were allocated to three different (initially comparable) groups. The main group (group 1) was comprised of 98 subjects who received the optimized combined treatment including climatotherapy, dietary therapy, psychotherapy, hydrotherapy, physiotherapy, and hypoxytherapy; in addition, they were involved in the program of therapeutic physical exercises and in the educational program. The group of comparison (group 2) consisted of 88 subjects who were advised to withstand pernicious habits, to keep to the prescribed diet, and intensify the physical activity. The subjects included in the control group 3 were given no preventive treatment whatsoever. The optimized system for the early diagnostics and identification of the risk factors and/or ACD was employed for examining the members of group 1. By the end of the study, risk factors of atherosclerosis and APC were documented in 86.2% and 76.6% of the patients of group 1, respectively. The number of disability days averaged 7.2 per person versus 16.3 and 22.6 in comparison and control groups, respectively. There were no newly diagnosed cases of cardiovascular diseases (CVD) over the study period among the patients of group 1, in contrast to 11.4% and 25.6% such cases in groups 2 and 3, respectively. The results of this study give evidence that the optimized strategy of non-pharmacological correction of the risk factors and the preclinical stages of atherosclerosis at the level of the health resort-based primary care has advantages over the standard therapy because it makes it possible to reduce the frequency of development of new cases of cardiovascular diseases and to decrease the disability rate. It is concluded that the proposed approach enhances the effectiveness of primary prophylaxis of cardiovascular diseases associated with atherosclerosis and relieves the burden of this pathology. It can therefore be recommended for the more extensive application at the level of the health resort-based primary care settings.

[Early diagnostics, prophylaxis, and non-pharmacological treatment of the preclinical stages of atherosclerosis and arterial hypertension]

Cardiovascular diseases remain the leading cause of death in most countries, including Russia. Non-pharmacological-modalities intended for the primary prevention of cardiovascular disease including hypertension and atherosclerosis currently acquire special significance. The objective of the present*study was to develop a system of methods for early diagnostics, prevention and treatment of the preclinical stages of atherosclerosis and hypertension Another objective was to estimate the effectiveness of these methods. A total of 310 patients at risk-of arterial hypertension and atherosclerosis or with pre-clinical stages of these conditions were examined during a two year observation period. The system of early diagnosis and non-pharmacological primary prevention of cardiovascular disease was developed and evaluated using climatotherapeutic and physiotherapeutic methods in combination with and personalized dietary therapy, hypoxic-hypercapnic factors and educational programs. The study has demonstrated that the proposed system allowed to significantly (p < 0.05) reduce cardiovascular morbidity. The patients of the main group experienced the reduction of abdominal obesity and blood pressure along with the improvement of the blood lipid profile and other indicators. These parameters remained unaltered in the patients comprising the control group. In the main group, the incidence of coronary heart disease and hypertension was 62.5% and 81.25% lower respectively than in the control group.

Dynamic quantification of antigen molecules with flow cytometry

Traditional methods for estimating the number of expressed molecules, based on the detection of target antigens bound with fluorescently labeled antibodies, assume that the antigen-antibody reaction reaches equilibrium. A calibration procedure is used to convert the intensity of the fluorescence signal to the number of target molecules. Along with the different limitations of every calibration system, this substantially limits the applicability of the traditional approaches especially in the case of low affinity antibodies. We address this problem here with studies in which we demonstrate a new approach to the antigen molecule quantification problem. Instead of using a static calibration system, we analyzed mean fluorescence values over time by flow cytometry during antibody-antigen binding. Experimental data obtained with an LSRII cytometer were fitted by a diffusion-reaction mathematical model using the Levenberg-Marquardt nonlinear least squares curve-fitting algorithm in order to obtain the number of target antigen molecules per cell. Results were compared with the Quanti-BRITE calibration system. We conclude that, instead of using experiment-specific calibration, the value of the binding rate constant for each particular antibody-antigen reaction can be used to quantify antigen molecules with flow cytometry. The radius of CD8 antibody molecule binding site was found, that allows recalculating the binding rate constant for other conditions (different sizes of reagent molecules, fluorescent label, medium viscosity and temperature). This approach is independent of specially prepared calibration beads, antibody reagents and the specific dye and can be applied to both low and high affinity antibodies, under both saturating and non-saturating binding conditions. The method was demonstrated on a human blood sample dataset investigating CD8α antigen on T cells in stable binding conditions.

[Optimization of the-spa-and-resort treatment of the patients with metabolic syndrome]

The present study included 271 patients presenting with metabolic syndrome. It was designed to compare the efficacy of traditional and optimized therapeutic modalities for the management of this condition. The modified treatment program included climatotherapy, dietary therapy, physical exercises, hydro-balneotherapy, hypoxic hyperkapnotherapy, and education. The study demonstrated that the proposed therapeutic program increased the efficiency of the spa-and-resort treatment.

[Nucleus DNA content measurement methods features]

We suggest a new theoretical method of the flow cytometry DNA histograms and apply it for Drosophila melanogaster imaginal discs cells. The model gives a possibility to determine the proportions of cells in G1, G2 (M) and S cell cycle phases. We show that the precision of G1 and G2 (M) DNA content measurements is limited by the precision of device zero signal arrangement. The usage of calculated device zero and dividing cells as the DNA content standards may improve the precision of DNA content measurements. We also compared the precisions of different DNA content methods and draw the conclusion that the current precisions of different methods are similar and lie within 2-6% interval.

[Sanatorium and spa treatment of patients with isolated and combined pathology of the cardiovascular system and metabolism]

The present study involved 720 patients with metabolic syndrome, diabetes mellitus, coronary heart disease, hypertensive disease, and various combinations of these conditions examined in the course of sanatorium and spa treatment. The patients received either traditional or modified therapy. The latter modality included climato-balneotherapy, hypoxytherapy, bioresonance therapy, and hypercapnotherapy supplemented by the intake of Arfazetin herbal tea, Magnerot tablets, and Chvizhepse mineral water. Results of the study indicate that the proposed combined treatment had more pronounced curative effect compared with traditional therapy in patients of all groups included in this study.

Experimental study of the heat transport processes in dusty plasma fluid

The results are given of an experimental investigation of heat transport processes in fluid dusty structures in rf-discharge plasmas under different conditions: for discharge in argon, and for discharge in air under an action of electron beam. The analysis of steady-state and unsteady-state heat transfer is used to obtain the coefficients of thermal conductivity and thermal diffusivity under the assumption that the observed heat transport is associated with a thermal conduction in the dusty component of plasmas. The temperature dependence of these coefficients is obtained, which agrees qualitatively with the results of numerical simulation for simple monatomic liquids.

Three-particle correlations in nonideal dusty plasma

Results are given of experimental investigation of three-particle correlations for liquid plasma-dust structures formed in the electrode layer of a high-frequency capacitive discharge. The obtained three-particle correlation functions for experimental and numerical data are analyzed and compared with the superposition approximation. The forming of clusters of macroparticles in plasma-dust systems being analyzed is revealed.

Large-amplitude dust waves excited by the gas-dynamic impact in a dc glow discharge plasma

A large-amplitude wave with two humps of dust density, separated by a dip was generated. To excite the wave in the dc glow discharge dusty plasma a gas-dynamic impact was used. The structure obtained had several interesting properties such as strong compression of dust in the humps, supersonic dust particles in the rarefaction zone, reconstruction of the initial dust configuration after the passing of the wave. The peculiarities of the phenomenon observed are discussed. The mechanism of generation and propagation for such kind of perturbation is proposed.

[Comparative analysis of topological organization in Metazoa]

Topological patterns in Metazoa, using previously elaborated methodology with employment of the genus of the surface (p) as topological invariant are considered. The term "density of the genus of the surface" is introduced. In sponges and in a lesser degree among Cnidaria and, Ctenophoria an increase of genus p up to indefinite high values and the shaping of topologically complicated quasifractal systems (irrigation system in sponges and gastro-vascular system in Radiata) are evident. In most Bilateria a stable topological pattern with open digestive tube is formed and subsequent topological complications of other systems may occur. Complicated topological patterns increasing the genus of the surface are evolved on the base of quasifractal systems: gut pockets in turbellaria, tracheal system in arthropods, bronchial system in birds, gills in bivalve mollusks, etc. Peculiarities of ordered and disordered topological patterns as well as topological origin of the increase of the genus of the surface are considered.

Mathematical modeling the kinetics of cell distribution in the process of ligand-receptor binding

A statistical approach is presented to model the kinetics of cell distribution in the process of ligand-receptor binding on cell surfaces. The approach takes into account the variation of the amount of receptors on cells assuming the homogeneity of monovalent binding sites and ligand molecules. The analytical expressions for the kinetics of cell distribution have been derived in the reaction-limited approximation. In order to demonstrate the applicability of the mathematical model, the kinetics of binding the rabbit, anti-mouse IgG with Ig-receptors of the murine hybridoma cells has been measured. Anti-mouse IgG was labeled with fluorescein isothiocyanate (FITC). The kinetics of cell distribution on ligand-receptor complexes was observed during the reaction process by real-time measuring of the fluorescence and light-scattering traces of individual cells with the scanning flow cytometer. The experimental data were fitted by the mathematical model in order to obtain the binding rate constant and the initial cell distribution on the amount of receptors.