Observation of subkelvin superconductivity in Cd₃As₂ thin films

We report an experimental observation of superconductivity in Cd3As2 thin films without application of external pressure. The films under study were synthesized by magnetron sputtering. Surface studies suggest that the observed transport characteristics are related to the polycrystalline continuous part of the investigated films with a homogeneous distribution of elements and the Cd-to-As ratio close to stoichiometric Cd3As

Joule Heating and Current-Induced Instabilities in Magnetic Nanocontacts

We consider the electrical current through a magnetic point contact in the limit of a strong inelastic scattering of electrons. In this limit local Joule heating of the contact region plays a decisive role in determining the transport properties of the point contact. We show that if an applied constant bias voltage exceeds a critical value, the stationary state of the system is unstable, and that periodic, non-harmonic oscillations in time of both the electrical current through the contact and the local temperature in the contact region develop spontaneously. Our estimations show that the necessary experimental conditions for observing such oscillations with characteristic frequencies in the range $10^8 \div 10^9$ Hz can easily be met. We also show a possibility to manipulate upon the magnetization direction of a magnetic grain coupled through a point contact to a bulk ferromagnetic by exciting the above-mentioned thermal-electric oscillations.Comment: 9 pages, 6 figures, submitted to Physical Review

Targeting dsRNA-specific single-chain Fv antibody fragments to different cellular locations in Nicotiana tabacum L.

Expression of antibodies or antibody fragments in plants is a useful tool for producing active antibody derivatives for diagnostic or pharmaceutical purposes as well as for immunomodulation. We investigated the effect of cellular expression site on the stability and yield of double-stranded RNA (dsRNA)-specific single-chain Fv-fragments (scFv) in transgenic tobacco. Two antibodies (J2 and P6) belonging to the V23(J558) heavy chain variable gene family but differing in the light chain variable domain were used. scFvs were targeted to the cytoplasm – with or without anchoring them in the plasma membrane –, into the endoplasmic reticulum (ER) and to the apoplast. Although high mRNA concentrations were detected in all cases, scFv proteins accumulated only when scFvs were made ER-resident by appropriate signal sequences. When the ER retention signal was removed to allow scFv-secretion to the apoplast, no scFv-proteins were detected. Despite the strong homology of the VH-sequences of J2 and P6 antibodies, only P6 provided a stable scFv scaffold for intracytoplasmic expression. J2-scFv could not be stabilised neither by adding a C-terminal stabilisation signal nor by anchoring the protein at the cytoplasmic side of the plasma membrane (PM). It was found that dsRNA-specific J2-scFvs are active in vivo and enhance Potato Virus Y induced symptoms in infected tobacco. This is the first report describing the expression and biological effect of RNA-specific antibodies in plants

The Strategic Perspectives of Using GIS-Technologies for Creating of Integrative Antarctic Geo-base of Scientific Data

Strategic prospects use GIS technologies are presented in report for making integrated geodatabase of scientific data, designed on base of the lifelengths operating in the field of automations of the information handling in National antarctic scientific centre MES of Ukraine (NASC). It is shown, that given decision effectively, in good time, corresponds to the world standard of the collection, processing and presentation of scientific data.У доповіді подано стратегічні перспективи використання ГІС технології для створення інтегрованої геобази наукових даних, яка проектується на основі багаторічних напрацювань в галузі автоматизації обробки інформації в Національному антарктичному науковому центрі МОН України (НАНЦ). Показано, що дане рішення є ефективним та своєчасним, відповідає світовим стандартам збирання, обробки та презентації наукових даних.Ключові слова: ГІС-технологія, Геобаза, ArcGIS, Серверні технології.В докладе представлены стратегические перспективы использования ГИС технологии для создания интегрированной геобазы научных данных, проектируемой на основе многолетних наработок в области автоматизации обработки информации в Национальном антарктическом научном центре МОН Украины (НАНЦ). Показано, что данное решение эффективно, своевременно, соответствует мировым стандартам сбора, обработки и презентации научных данных

Обоснование защиты нейроваскулярной единицы на клинической модели искусственного кровообращения

This analytical review presents data on brain injury in surgical management of congenital heart disease. A brief description of mechanisms of brain injury and methods of its prevention are given, moreover, a clinical case applying such techniques is given. The neurovascular unit in vitro model and its advantages are presented. The protocol for modelling, the further application of the model, and the prospects of using it for studying intraoperative hypoxia and systemic inflammatory response on the patient`s brain are described.В данной работе проанализирована актуальность изучения повреждения головного мозга при коррекции врожденных пороков сердца у детей. Дана краткая характеристика механизмов церебрального повреждения и способов его профилактики с описанием клинического случая применения таких методик. Кроме того, представлена концепция экспериментов in vitro на модели нейроваскулярной единицы и оценено преимущество таких исследований. Описаны протокол формирования используемой модели и дальнейшей работы с ней, а также перспективы ее применения для изучения интраоперационного влияния гипоксии и системного воспалительного ответа на головной мозг пациента

Current-induced magnetic superstructures in exchange-spring devices

We investigate the potential to use a magneto-thermo-electric instability that may be induced in a mesoscopic magnetic multi-layer (F/f/F) to create and control magnetic superstructures. In the studied multilayer two strongly ferromagnetic layers (F) are coupled through a weakly ferromagnetic spacer (f) by an "exchange spring" with a temperature dependent "spring constant" that can be varied by Joule heating caused by an electrical dc current. We show that in the current-in-plane (CIP) configuration a distribution of the magnetization, which is homogeneous in the direction of the current flow, is unstable in the presence of an external magnetic field if the length L of the sample in this direction exceeds some critical value Lc ~ 10 \mu m. This spatial instability results in the spontaneous formation of a moving domain of magnetization directions, the length of which can be controlled by the bias voltage in the limit L >> Lc. Furthermore, we show that in such a situation the current-voltage characteristics has a plateau with hysteresis loops at its ends and demonstrate that if biased in the plateau region the studied device functions as an exponentially precise current stabilizer.Comment: 8 pages, 6 figure