THE STUDY OF THE ION TYPE IS RESPONSIBLE FOR THE TRANSFER TO Na3DyV2O8

As a result of studying the type of ion responsible for the transfer by the Tubandt method, unipolar transfer of sodium Na+ ions in Na3DyV2O8 double vanadate was established. The ionic transfer numbers were ti ~ 1

ELECTRIC TRANSFER IN DOUBLE VANADAT YTTERBIA

Double vanadate Na3Yb(VO4)2 was synthesized and the effect of temperature on electrical conductivity, thermal expansion, and phase transformations was studied.В работе синтезирован двойной ванадат Na3Yb(VO4)2, изучено влияние температуры на электропроводность, термическое расширение и фазовые превращения

ОСОБЕННОСТИ КЛИНИЧЕСКОГО ТЕЧЕНИЯ АНТИ-N-МЕТИЛ-D-АСПАРТАТ РЕЦЕПТОРНОГО ЭНЦЕФАЛИТА (СЛУЧАИ ИЗ ПРАКТИКИ)

The article describes the clinical cases of anti-N-methylD-aspartate receptor encephalitis of two patients. An analysis of the dynamics of neurologic symptoms, the results of neurovisualization and neurophysiological examinations was carried out. It was shown that in patients with AntiN-methyl-D-aspartate receptor encephalitis, neurological symptoms are similar in their manifestations with symptoms of virus encephalitis. At the same time, the mechanism of development and etiology of this form of autoimmune pathology is not understood. Also, no pathognomonic changes were detected for MRI of the brain, PET, EEG for Anti-N-methylD-aspartate receptor encephalitis. The authors conclude that the diversity of neurological symptoms in patients with antiN-methyl-D-aspartate receptor encephalitis may be due not only to dysfunction of brain structures due to disruption of NMDA receptor activity, but also to a reversible disruption of functional interrelationships between different parts of the brain. В статье приводится описание клинического течения Анти-N-метил-D-аспарт рецепторного энцефалита у двух пациенток. Проведен анализ динамики неврологической симптоматики, результатов нейровизуализационных и нейрофизиологических обследований. Показано, что у пациентов с Анти-N-метил-D-аспартат рецепторным энцефалитом неврологическая симптоматика схожа по своим проявлениям с симптоматикой при инфекционных энцефалитах. В то же время механизм развития и этиология данной формы аутоиммунной патологии до конца не ясны. Также не выявлено патогномоничных только для Анти-N-метил-D-аспартат рецепторного энцефалита изменений на МРТ головного мозга, ПЭТ, ЭЭГ. Авторы делают вывод, что разнообразие неврологической симптоматики у пациентов с Анти-N-метил-D-аспартат рецепторным энцефалитом может быть обусловлено не только дисфункцией структур мозга в результате нарушения активности NMDA рецепторов, но и обратимым нарушением функциональных взаимосвязей между различными отделами мозга.

New Li-Mg phosphates with 3D framework : experimental and ab initio calculations

Two new lithium-magnesium phosphates LiMg6(PO4)3(P2O7) and Li(Mg5.62Sc0.19Li0.19)(PO4)3(P2O7) were synthesized by the solid-phase method. Using high-resolution time-of-flight neutron powder diffraction (TOF NPD) and X-ray powder diffraction (XRPD), we established that these phosphates have Pnma orthorhombic structure with the cell parameters a=9.14664(5) Å, b=18.83773(8) Å, c=8.27450(4) Å, V=1425.71(1) Å3 and a=9.14516(5) Å, b=18.84222(9) Å, c= 8.28204(4) Å, V=1427.12(1) Å3, respectively. The crystal structures can be described by stacking of the [Mg6O18]∞ or [Mg5.62Sc0.19Li0.19O18]∞ wavy layers, which are parallel to the (100) direction and interconnected through PO4 tetrahedra and P2O7 groups to a 3D-framework. Li atoms are located in large tunnels formed in a 3D lattice, which contributes to lithium diffusion. AC impedance spectroscopy shows that LiMg6(PO4)3(P2O7) and Li(Mg5.62Sc0.19Li0.19)(PO4)3(P2O7) have Li ion conductivity of 3.6 10-4 S/cm and 1.7 10-4 S/cm at 950 °C, with activation energy of 1.28 eV and 1.55 eV, respectively. NMR MAS studies confirmed a coexistence of pyro- and orthogroups in the structure of both phases and two lithium positions in Li(Mg5.62Sc0.19Li0.19)(PO4)3(P2O7). The first- principles method was used to study the electronic structure and stability of the two phases. The calculated formation enthalpies demonstrated that Sc is a stabilizing impurity in LiMg6(PO4)3(P2O7), while there exists a strong destabilization of olivine LiMgPO4 upon doping with Sc. This explains the failure to synthesize the Sc-doped olivine. The new phosphate LiMg6(PO4)3(P2O7) is a dielectric with band gap of 5.35 eV, which decreases to 4.85 eV due to a localized Sc 3d peak upon doping with Sc. These findings are consistent with the results obtained from UV-Vis spectroscopy. The new phase may be a good optical matrix similar to LiMgPO4

Ammonia oxidation to nitrogen mediated by electrogenerated active chlorine on Ti/PtOx-IrO2

The electrochemical oxidation of ammonia (NH3 and/or NH4+) in the presence of chloride was investigated on a Ti/PtOx-IrO2 electrode. It was shown that ammonia is effectively removed from solution via electrogenerated active chlorine. Based on mass balances, nitrogen is postulated to be the main product of ammonia electrolysis. In the bulk, the concentration of chloramines was low. This could be explained by the fact that the oxidation of ammonia takes place close to the electrode surface where an excess of chlorine relative to ammonia is ensured during the process. This results in the oxidation of ammonia to N-2 and in a local pH decrease. As a result, chloramines were decomposed in the proximity of the electrode prior to diffusing into the bulk. (C) 2010 Elsevier B.V. All rights reserved

Diffusion of barium ions in the Ba3-3xLa2x?x(VO4)2 solid solution

Diffusion coefficients for 133Ba, 90Sr, and 45Ca radionuclides in the solid solution Ba3-3xLa2x?x(VO4)2 (x = 0, 0.05, 0.1, 0.15) are measured in the temperature range 800 to 1000°C using the layer-by-layer radiometric analysis. It is established that Dca* ? DSr? > DBa*. Increasing the concentration of vacancies ? in the barium sublattice leads to an increase in the diffusion coefficients of the alkaline-earth metal cations. The activation energies for the radionuclide diffusion are determined; their values (?1.1 eV) are close to the activation energy for ionic conduction. Cations M2+ are shown to migrate via the positions of Ba(2). © 1999 MAHK "Hayka/Interperiodica Publishing"

Structure and transport properties of La0.5Sr0.5 (-) xCaxFeO3 (-) (delta)

Effects of calcium doping on the structure, dimensional stability, and mixed oxygen-ion and electron conductivity of perovskite-like La0.5Sr0.5 - xCaxFeO3 - delta(x = 0-0.3) were studied in light of potential membrane applications. The incorporation of relatively small Ca2+ cations into the lanthanum-strontium ferrite lattice decreases unit cell volume, oxygen nonstoichiometry variations and chemical contribution to the thermal expansion in air. These changes correlate with rising tendency to local oxygen-vacancy ordering and the formation of nano-sized domains with the brownmillerite and LaCa2Fe3O8-type lattices, as revealed by electron diffraction. The resultant vacancy trapping, changing domain structure and enlargement of the interfacial boundary area lead to non-linear relationships between the partial ion conductivity and cation composition, while the apparent activation energy for ion transport at temperatures below 900 degrees C remains almost constant, 0.6-0.7 eV. The n-type electron contribution to the total conductivity, measured in the oxygen pressure range 10(-20)-0.5 atm at 700-950 degrees C, is also essentially independent of the calcium concentration. (C) 2013 Elsevier B.V. All rights reserved

ANTI-N-METHYL-D-ASPARTATE RECEPTOR ENCEPHALITIS (CASE REPORTS)

The article describes the clinical cases of anti-N-methylD-aspartate receptor encephalitis of two patients. An analysis of the dynamics of neurologic symptoms, the results of neurovisualization and neurophysiological examinations was carried out. It was shown that in patients with AntiN-methyl-D-aspartate receptor encephalitis, neurological symptoms are similar in their manifestations with symptoms of virus encephalitis. At the same time, the mechanism of development and etiology of this form of autoimmune pathology is not understood. Also, no pathognomonic changes were detected for MRI of the brain, PET, EEG for Anti-N-methylD-aspartate receptor encephalitis. The authors conclude that the diversity of neurological symptoms in patients with antiN-methyl-D-aspartate receptor encephalitis may be due not only to dysfunction of brain structures due to disruption of NMDA receptor activity, but also to a reversible disruption of functional interrelationships between different parts of the brain