Evidence for spin-triplet superconducting correlations in metal-oxide heterostructures with non-collinear magnetization

Heterostructures composed of ferromagnetic La0.7Sr0.3MnO3, ferromagnetic SrRuO3, and superconducting YBa2Cu3Ox were studied experimentally. Structures of composition Au/La0.7Sr0.3MnO3/SrRuO3/YBa2Cu3Ox were prepared by pulsed laser deposition, and their high quality was confirmed by X-ray diffraction and reflectometry. A non-collinear magnetic state of the heterostructures was revealed by means of SQUID magnetometry and polarized neutron reflectometry. We have further observed superconducting currents in mesa-structures fabricated by deposition of a second superconducting Nb layer on top of the heterostructure, followed by patterning with photolithography and ion-beam etching. Josephson effects observed in these mesa-structures can be explained by the penetration of a triplet component of the superconducting order parameter into the magnetic layers.Comment: 10 pages, 6 figure

Magnetic proximity effect at interface between a cuprate superconductor and an oxide spin valve

Heterostructures consisting of a cuprate superconductor YBa2Cu3O7x and a ruthenate/manganite (SrRuO3/La0.7Sr0.3MnO3) spin valve have been studied by SQUID magnetometry, ferromagnetic resonances and neutron reflectometry. It was shown that due to the influence of magnetic proximity effect a magnetic moment is induced in the superconducting part of heterostructure and at the same time the magnetic moment is suppressed in the ferromagnetic spin valve. The experimental value of magnetization induced in the superconductor has the same order of magnitude with the calculations based on the induced magnetic moment of Cu atoms due to orbital reconstruction at the superconductor-ferromagnetic interface. It corresponds also to the model that takes into account the change in the density of states at a distance of order of the coherence length in the superconductor. The experimentally obtained characteristic length of penetration of the magnetic moment into superconductor exceeds the coherence length for cuprate superconductor. This fact points on the dominance of the mechanism of the induced magnetic moment of Cu atoms due to orbital reconstruction.Comment: 20 pages, 9 figure

ПОСТИНФЕКЦИОННЫЙ ОБЛИТЕРИРУЮЩИЙ БРОНХИОЛИТ У ДЕТЕЙ

Literature review describes the problem of bronchiolitis obliterans in children. The review analyzes modern date on etiology, morphological sings, clinical course, treatment and prognosis of diseas. The modern capabilities of diagnosis based on chest X-ray, computed tomography and pulmonary function testing are discussed. Обзор литературы посвящен проблеме постинфекционного облитерирующего бронхиолита у детей. В обзоре анализируются современные сведения об этиологии, морфологических особенностях, клиническом течении, терапии и прогнозе заболевания. Рассмотрены современные возможности диагностики на основе использования рентгенографии легких и компьютерной томографии и методик исследования функции внешнего дыхания.

Dirac states with knobs on: interplay of external parameters and the surface electronic properties of 3D topological insulators

Topological insulators are a novel materials platform with high applications potential in fields ranging from spintronics to quantum computation. In the ongoing scientific effort to demonstrate controlled manipulation of their electronic structure by external means, stoichiometric variation and surface decoration are two effective approaches that have been followed. In ARPES experiments, both approaches are seen to lead to electronic band structure changes. Such approaches result in variations of the energy position of bulk and surface-related features and the creation of two-dimensional electron gases.The data presented here demonstrate that a third manipulation handle is accessible by utilizing the amount of illumination a topological insulator surface has been exposed to under typical experimental ARPES conditions. Our results show that this new, third, knob acts on an equal footing with stoichiometry and surface decoration as a modifier of the electronic band structure, and that it is in continuous competition with the latter. The data clearly point towards surface photovoltage and photo-induced desorption as the physical phenomena behind modifications of the electronic band structure under exposure to high-flux photons. We show that the interplay of these phenomena can minimize and even eliminate the adsorbate-related surface band bending on typical binary, ternary and quaternary Bi-based topological insulators. Including the influence of the sample temperature, these data set up a framework for the external control of the electronic band structure in topological insulator compounds in an ARPES setting. Four external knobs are available: bulk stoichiometry, surface decoration, temperature and photon exposure. These knobs can be used in conjunction to tune the band energies near the surface and consequently influence the topological properties of the relevant electronic states.Comment: 16 pages, 8 figure

Респираторные последствия бронхолегочной дисплазии у детей, подростков и взрослых

Prematurity and bronchopulmonary dysplasia (BPD), which is a complication of the neonatal respiratory distress-syndrome and respiratory therapy in neonates, are currently considered as possible risk factors of chronic obstructive pulmonary disease (COPD) in adults. Persisting reduction in the lung size in prematurely born children and pathological lesion typical for BPD can lead to ventilation disorders and clinical signs of chronic respiratory failure and / or bronchial obstruction in the children, adolescents and adults. Clinical, functional and morphological consequences of prematurity and BPD in preschool and school-aged children, adolescents and adults are discussed in this review considering the authors’ experience and the published data. The lung function abnormalities persist for lifetime. The lung tissue structural lesions, such as emphysema, fibrosis, the bronchial wall thickening, could be found on computed tomography. Therefore, patients with the history of BPD should be treated as risk group for early development of COPD.Недоношенность, а также осложнение респираторного дистресс-синдрома новорожденных и респираторной терапии в неонатальном периоде – бронхолегочная дисплазия (БЛД) – в настоящее время рассматриваются как высоковероятные факторы риска развития хронической обструктивной болезни легких (ХОБЛ) у взрослых. Персистирующие уменьшение размеров легких у недоношенных и патогистологические изменения, свойственные БЛД, обусловливают нарушения вентиляционной способности легких и клинические симптомы хронической дыхательной недостаточности и / или бронхиальной обструкции как в детском возрасте, так и нередко – у подростков и взрослых. В обзоре на основании собственных и литературных данных приведены сведения о клинических, функциональных и структурных последствиях недоношенности и БЛД у детей дошкольного и школьного возраста, подростков и взрослых. Представленные клинические данные являются результатами исследования функции внешнего дыхания методами спирографии, спирометрии, эргоспирометрии, плетизмографии, вымывания азота, тестов с физической нагрузкой и метахолином, исследования диффузионной способности легких и свидетельствуют о длительном сохранении нарушений функции дыхания в старшем возрасте, а также структурных изменениях легочной ткани при проведении компьютерной томографии в виде эмфиземы, фиброза, утолщения стенок бронхов. Приводится обоснование отнесения пациентов с БЛД в анамнезе к группе риска раннего развития ХОБЛ

Retention of knowledge on blood pressure measurement among medical students within preparation for primary accreditation

Aim. To assess the retained knowledge of sixth year medical students on noninvasive blood pressure (BP) measurement.Material and methods. The study included 148 6th year medical students. According to the curriculum, in the fall semester, students studied the procedure of BP measurement according to checklists developed based on ROSOMED. In the spring semester, as part of the preparation course for accreditation, the retained knowledge of students was assessed. A completed skill was assessed at 1 point, not completed — 0 points. Thus, each student can score a maximum of 50 points. The teacher assessed the manipulations during their performing by filling in the checklist items for each student.Results. None of the students completed the full range of manipulations. The number of completed skills ranged from 15 (30%) to 49 (98%) and averaged 33 points on the checklist (66%). In addition, 74% of students (n=109) completed more than half of the required skills. Almost the only item completed by all students (99%, n=146) was a greeting, which was comparable with self-presentation (92%, n=136) and identification of a patient’s personal data (surname and first names) (80%, n=118). The rest of checklist items was performed in the range from 39% (n=57) for “remeasurement of BP on the other hand” to 87% (n=129) for “finding a radial pulse”. Thus, the average fulfillment rate was 67% (n=99). There were following most common mistakes in BP measurement: 39% of students did not measure a patient’s upper arm diameter and did not select the cuff size; every second student (51%) placed the phonendoscope diaphragm under the cuff; 40% of students reduced the cuff pressure with inadequate rate.Conclusion. The retention of knowledge on measuring BP within six months after a detailed analysis and passing a test remains insufficient, but comparable with foreign studies. The data obtained indicate the need for additional trainings both using simulators and in conditions closer to real ones, including with simulated patients