Strong 3D correlations in vortex system of Bi2212:Pb

The experimental study of magnetic flux penetration under crossed magnetic fields in Bi2212:Pb single crystal performed by magnetooptic technique (MO) reveals remarkable field penetration pattern alteration (flux configuration change) and superconducting current anisotropy enhancement by the in-plane field. The anisotropy increases with the temperature rise up to $T_m = 54 \pm 2 K$. At $T = T_m$ an abrupt change in the flux behavior is found; the correlation between the in-plane magnetic field and the out-of-plane magnetic flux penetration disappears. No correlation is observed for $T > T_m$. The transition temperature $T_m$ does not depend on the magnetic field strength. The observed flux penetration anisotropy is considered as an evidence of a strong 3D - correlation between pancake vortices in different CuO planes at $T < T_m$. This enables understanding of a remarkable pinning observed in Bi2212:Pb at low temperatures.Comment: 8 pages, 9 figure

Inter- and intragrain currents in bulk melt-grown YBaCuO rings

A simple contactless method suitable to discern between the intergrain (circular) current, which flows in the thin superconducting ring, and the intragrain current, which does not cross the weakest link, has been proposed. At first, we show that the intergrain current may directly be estimated from the magnetic flux density $B(\pm z_0)$ measured by the Hall sensor positioned in the special points $\pm z_0$ above/below the ring center. The experimental and the numerical techniques to determine the value $z_0$ are discussed. Being very promising for characterization of a current flowing across the joints in welded YBaCuO rings (its dependencies on the temperature and the external magnetic field as well as the time dissipation), the approach has been applied to study corresponding properties of the intra- and intergrain currents flowing across the $a$-twisted grain boundaries which are frequent in bulk melt-textured YBaCuO samples. We present experimental data related to the flux penetration inside a bore of MT YBaCuO rings both in the non-magnetized, virgin state and during the field reversal. The shielding properties and their dependence on external magnetic fields are also studied. Besides, we consider the flux creep effects and their influence on the current re-distribution during a dwell.Comment: 13 pages, 16 figures (EPS), RevTeX4. In the revised version, corrections to perturbing effects near the weak links are introduced, one more figure is added. lin

Педиатрическое аутоиммунное нейропсихиатрическое расстройство, ассоциированное со стрептококковой инфекцией (PANDAS-синдром): мировая практика и клиническое наблюдение

Group A beta-hemolytic streptococcus is one of the most important infectious agents leading to both direct damage to organs, and to various cross-reactions with body antigens. One of these forms, manifested by the defeat of subcortical ganglia, is PANDAS syndrome. This paper describes the international criteria and clarifies the differences between this disorder and other forms of brain damage. Paper also describes the clinical case of PANDAS syndrome in a 7-year-old child.Бета-гемолитический стрептококк группы А является одним из важных инфекционных агентов, приводящих как к непосредственному повреждению органов и тканей, так и к различным перекрестным реакциям с антигенами организма. Одной из таких нозологических форм, проявляющихся поражением подкорковых ганглиев, является синдром PANDAS. В данной статье приведены критерии, уточнены отличия данного расстройства от других форм поражения головного мозга, представлен клинический случай PANDAS синдрома у ребенка 7 лет

Перинатальные факторы программирования девиаций физического развития преждевременно родившихся младенцев

The analysis of obstetric anamnesis and indicators of heart rate variability in the neonatal period in prematurely born children who had deviations of somatometric parameters from reference values at the age of 12 months was carried out. Excessive due to various reasons, the level of adrenomimetics supplied with maternal blood caused an increase in the intensity of metabolism in the fetal body and inhibition of the activity of sympathoadrenal systems. The insufficient provision of the fetal and newborn organism with energy and plastic materials that arose under these conditions initiated perinatal metabolic programming of deviations in the physical development of prematurely born infants.Материалы и методы. Проводился анализ акушерского анамнеза и показателей вариабельности сердечного ритма в неонатальном периоде у преждевременно родившихся детей, имевших отклонения соматометрических показателей от референсных значений в возрасте 12 месяцев.Результаты. Избыточный вследствие различных причин уровень адреномиметиков, поступавших с материнской кровью, вызывал в организме плода повышение интенсивности метаболизма и ингибирование активности симпатоадреналовых систем. Возникавшее в этих условиях недостаточное обеспечение организма плода и новорожденного энергетическими и пластическими материалами инициировало перинатальное метаболическое программирование девиаций физического развития преждевременно родившихся младенцев

Temperature Dependence of Magnetization Reversal of Thin Manganite Film

The magnetic domain structure, its transformation with temperature, and the magnetization reversal in 20 nm $La_{0.7}Sr_{0.3}MnO_{3}$ film grown on $LaAlO_{3}$ substrate by off-axis magnetron sputtering at 700°C and post-annealed at 600°C were studied in a wide temperature range. The magnetic domains with either in-plane- or out-of-plane-orientation of the vector of spontaneous magnetization were observed in the same film depending on the prehistory. The domains with the in-plane magnetization were found to be more stable. Magnetization reversal of the film was shown to occur via the nucleation and motion of 180-degree head-to-head domain walls, the number and the type of which were found to be dependent on temperature. Moreover, the transition between two magnetization reversal regimes was found at 30 K

Temperature Dependence of Magnetization Reversal of Thin Manganite Film

The magnetic domain structure, its transformation with temperature, and the magnetization reversal in 20 nm $La_{0.7}Sr_{0.3}MnO_{3}$ film grown on $LaAlO_{3}$ substrate by off-axis magnetron sputtering at 700°C and post-annealed at 600°C were studied in a wide temperature range. The magnetic domains with either in-plane- or out-of-plane-orientation of the vector of spontaneous magnetization were observed in the same film depending on the prehistory. The domains with the in-plane magnetization were found to be more stable. Magnetization reversal of the film was shown to occur via the nucleation and motion of 180-degree head-to-head domain walls, the number and the type of which were found to be dependent on temperature. Moreover, the transition between two magnetization reversal regimes was found at 30 K

Pediatric autoimmune neuropsychiatric disorder associated with Streptococcal infection (PANDAS syndrome): real-world practice and clinical case

Group A beta-hemolytic streptococcus is one of the most important infectious agents leading to both direct damage to organs, and to various cross-reactions with body antigens. One of these forms, manifested by the defeat of subcortical ganglia, is PANDAS syndrome. This paper describes the international criteria and clarifies the differences between this disorder and other forms of brain damage. Paper also describes the clinical case of PANDAS syndrome in a 7-year-old child