Electrocaloric Response of the Dense Ferroelectric Nanocomposites

Using the Landau-Ginzburg-Devonshire approach and effective media models, we calculated the spontaneous polarization, dielectric, pyroelectric, and electrocaloric properties of BaTiO$_3$ core-shell nanoparticles. We predict that the synergy of size effects and Vegard stresses can significantly improve the electrocaloric cooling (2- 7 times) of the BaTiO$_3$ nanoparticles with diameters (10-100) nm stretched by (1-3)% in comparison with a bulk BaTiO$_3$. To compare with the proposed and other known models, we measured the capacitance-voltage and current-voltage characteristics of the dense nanocomposites consisting of (28 -35) vol.% of the BaTiO$_3$ nanoparticles incorporated in the poly-vinyl-butyral and ethyl-cellulose polymers covered by Ag electrodes. We determined experimentally the effective dielectric permittivity and losses of the dense composites at room temperature. According to our analysis, to reach the maximal electrocaloric response of the core-shell ferroelectric nanoparticles incorporated in different polymers, the dense composites should be prepared with the nanoparticles volume ratio of more than 25 % and fillers with low heat mass and conductance, such as Ag nanoparticles, which facilitate the heat transfer from the ferroelectric nanoparticles to the polymer matrix. In general, the core-shell ferroelectric nanoparticles spontaneously stressed by elastic defects, such as oxygen vacancies or any other elastic dipoles, which create a strong chemical pressure, are relevant fillers for electrocaloric nanocomposites suitable for advanced applications as nano-coolers.Comment: 38 pages, including 10 figures and 2 appendixe

Experimental study of the potential use of diffusing wave spectroscopy to investigate the structural characteristics of blood under multiple scattering

The extension of the photon correlation spectroscopy (PCS) in multiple scattering regime, so-called diffusing wave spectroscopy (DWS) was employed to the study of blood samples. Multiple scattered light from a helium–neon (He–Ne) laser beam incident on the blood samples was detected by a photomultiplier, and both the temporal autocorrelation intensity functions g2(τ) and power spectra S (w) were measured by a spectrum analyzer. The potentials of using DWS for the qualitative and quantitative determination of the structural characteristics of the blood elements were studied experimentally. The experimental studies made, permits the use of DWS for blood cells monitoring in a multiple scattering regime. This paper describes our initial attempts at applying DWS to the study of the discrete blood samples of both healthy donors and patients with the cardiac ischemia. The subsequent experiments provide a verification of DWS of blood cells shape monitoring under multiple scatt

OPPORTUNITIES TO OPTIMIZE ANTIEPILEPTIC THERAPY WITH USE OF PHARMACOGENETIC BIOMARKERS

Pharmacogenetics allows to determine the cause of the ineffectiveness of drug therapy for certain groups of people who do not respond to treatment or exhibiting an inadequate response to a standard dose of the drug. Pharmacogenetic test can predict the speed and features of a metabolism of antiepileptic drugs in patients with epilepsy, depending on the activity involved in their metabolism enzyme systems and conveyors, that allows to individualize drug therapy in epileptological practice, to avoid side effects

OUR EXPERIENCE IN APPLICATION OF AUTOLOGOUS BONE-MARROW-DERIVED MESENCHYMAL STEM CELLS FOR THERAPY OF PATIENTS WITH SYMPTOMATIC EPILEPSY

Abstract: an article presented the data on application of autologous multipotent mesenchymal stem cells (MMSCs) from bone marrow for therapy of 10 patients suffering from drug-resistant symptomatic epilepsy. Intravenous injection of 40.0-101.0Ч106 (mean 68.2± 8,48Ч106) MMSCs endolumbal injection of 2.7-8.0Ч106 (mean 6.34±0.72Ч106) neuroinduced MMSCs did non induced in patients unfovarable reactions an complications. Moreover, during 3-11 months of monitoring 5 of 10 patients demonstrated decrease the frequency or disappearance of seizures, severity the incidence of seizures. 2 patients demonstrated increase of cognitive functions, 2 patients – decrease the level of anxiety. We concluded that application of MMSC-base cellular therapy id safe and enable to facilitate seizure status in patients with drug-resistant symptomatic epilepsy