[Reverse remodelling of the heart after atrial fibrillation ablation in patients with heart failure with reduced ejection fraction].

AIM: To evaluate the effect of atrial fibrillation (AF) catheter ablation (CA) on long-term freedom from AF and left heart reverse remodeling in patients with heart failure with reduced ejection fraction (HFrEF). METHODS: There were 47 patients (mean age 53.3 ± 10 years, 39 males) enrolled into single-center observational study, with left ventricular ejection fraction (LVEF) <40 %. Patients underwent CA for AF refractory to antiarrhythmic drugs. Baseline clinical data and diagnostic tests results were obtained during personal visits and / or via secure telemedical services. Personal contact with evaluation of recurrence of AF and echocardiographic values was performed with 30 (64 %) patients. RESULTS: Paroxysmal AF was present in 12 (40 %) patients, persistent - in 18 (60 %). During mean follow-up of 3 years (0.5-6 years) redo ablation was performed in 9 patients (30 %) with average number of 1.3 procedures per patient. At 6 months 24 (80 %) patients were free from AF, at last follow-up - 16 (53 %). The mean time to first recurrence following CA was 15.6±13.3 months. Follow-up echocardiography revealed significant LVEF improvement (р<0,0001), reduction of left atrium size (р<0,0001), left ventricle end-diastolic volume (р<0,002) and left ventricle endsystolic volume (p<0,0001) and mitral regurgitation (р=0,001). CONCLUSION: AF CA in patients with HFrEF is associated with improvement in systolic function and left heart reverse remodeling. Durable long-term antiarrhythmic effect often requires repeated procedures.

Doublon relaxation in the Bose-Hubbard model.

The decay of a high-energy double occupancy state, doublon, in a narrow-band lattice requires the creation of a coherent many-particle excitation. This leads to an exponentially long relaxation time of such a state. We show that, if the average occupation number is sufficiently small, the corresponding exponent may be evaluated exactly. To this end we develop the quasiclassical approach to calculation of the high-order tree-level decay amplitudes.

Critical velocity of a mobile impurity in one-dimensional quantum liquids.

We study the notion of superfluid critical velocity in one spatial dimension. It is shown that, for heavy impurities with mass M exceeding a critical mass Mc, the dispersion develops periodic metastable branches resulting in dramatic changes of dynamics in the presence of an external driving force. In contrast to smooth Bloch oscillations for M

Quantum decay of dark solitons.

Unless protected by the exact integrability, solitons are subject to dissipative forces, originating from a thermally fluctuating background. At low enough temperatures T background fluctuations should be considered as being quantized which enables us to calculate finite lifetime of the solitons τ∼T(-4). We also find that the coherent nature of the quantum fluctuations leads to long-range interactions between the solitons mediated by the superradiation. Our results are of relevance to current experiments with ultracold atoms, while the approach may be extended to solitons in other media.

Ion exchange phase transitions in water-filled channels with charged walls.

Ion transport through narrow water-filled channels is impeded by a high electrostatic barrier. The latter originates from the large ratio of the dielectric constants of the water and the surrounding media. We show that "doping," i.e., immobile charges attached to the walls of the channel, substantially reduces the barrier. This explains why most of the biological ion channels are "doped." We show that at rather generic conditions the channels may undergo ion exchange phase transitions (typically of the first order). Upon such a transition a finite latent concentration of ions may either enter or leave the channel, or be exchanged between the ions of different valences. We discuss possible implications of these transitions for the Ca-vs-Na selectivity of biological Ca channels. We also show that transport of divalent Ca ions is assisted by their fractionalization into two separate excitations.

Counting statistics of an adiabatic pump

We use the Schwinger-Keldysh formalism to derive the charge counting statistics of an adiabatic pump based on an open quantum dot. The distribution function of the transmitted charge in terms of the time-dependent S matrix is obtained. It is applied to a few simple examples of the pumping cycles. By a chiral gauge transformation the problem is mapped onto a problem of pumping by voltage pulses. The role of the chiral anomaly arising in this mapping is emphasized. Conditions for the ideal noiseless quantized pump are discussed.

Electroinjection analysis. The introduction of a new variant of flow-injection analysis and comparison with electrophoretically-mediated microanalysis.

A new method of mixing sample and reagent due to the difference in their electrophoretic mobilities is introduced. Unlike electrophoretically-mediated microanalysis, sample and reagent are injected from the opposite ends of a capillary tube. This method is compared with electrophoretically-mediated microanalysis. Experiments are performed showing the possibilities of this new method.

Optical investigations on the biaxial smectic- A phase of a bent-core compound.

Several unique optical properties have been obtained from freestanding films of a bent-core compound. Our experimental results indicate the existence of the antiferroelectric biaxial smectic-A (Sm A) phase. The critical exponent associated with the biaxiality through the uniaxial-antiferroelectric biaxial Sm A transition has been measured to be 0.82+/-0.04 , which is in good agreement with our theoretical calculation. Our theoretical advances further demonstrate that the critical behavior of the optical biaxiality with the order parameter being a vector is described by the secondary-order parameter of the three-dimensional XY model. We also observe a remarkable even-odd layering effect exhibited by the surface layers of freestanding films under an applied electric field (approximately 20 V/cm) in the film plane.

[The participation of intracellular regulatory systems in the reactions of the cat cerebral cortical neurons to fosfakol]. / Uchastie vnutrikletochnykh reguliatornykh sistem v reaktsiiakh neironov kory golovnogo mozga koshki na fosfakol.

The effects of paraoxon (1.5-4.5 LD50) on the levels of intracellular regulatory components, such as membrane-bound calcium (Ca(b)) and polyphosphoinositides (PPI) were studied along with microcirculation and neuronal bioelectric activity control in the feline cerebral cortex. There was a relation between these parameters, which supports the important role of Ca(b) and PPI in the mechanism of paraoxon's neurotoxic action. Taking into account the findings, it is advisable to use a complex of drugs in organophosphate intoxication, which will correct the mechanisms of intracellular signal transduction.

[Fluorine level in the bone and cartilage in children treated with ciprofloxacin (data obtained from the femur distal part]. / Soderzhanie ftora v kosti i khriashche u detei, poluchavshikh tsiprofloksatsin (na modeli distal'nogo otdela bedrennoi kosti)

Comparative data on the content of fluorine in various sections of the left femur distal part, i.e. spongy bone, process zone and articular cartilage are presented. The examination was performed on postmortem sections from 10 pediatric cases (the average age of 9.5 years) with mucoviscidosis or aplastic anemia treated before the death for up to 12 months with ciprofloxacin in a dose of 20 to 40 mg/kg body weight. The control postmortem sections were from 10 practically healthy children (the average age of 10.4 years) killed in a car accident. The sections were subjected to 2-stage dry ashing with ionometric determination of the fluorine ions. The results were treated according to the V.Yu. Urbach procedure. It was shown that the content of fluorine in the sponge bone and process zone in both the groups did not significantly differ. A comparatively high content of fluorine was detected only in the postmortem sections of the articular cartilage from the children of the main group who however had no chondrotoxic symptoms while alive. That means that the difference is statistically and clinically insignificant.