Superconducting single-mode contact as a microwave-activated quantum interferometer

The dynamics of a superconducting quantum point contact biased at subgap voltages is shown to be strongly affected by a microwave electromagnetic field. Interference among a sequence of temporally localized, microwave-induced Landau-Zener transitions between current carrying Andreev levels results in energy absorption and in an increase of the subgap current by several orders of magnitude. The contact is an interferometer in the sense that the current is an oscillatory function of the inverse bias voltage. Possible applications to Andreev-level spectroscopy and microwave detection are discussed

The development of Russian health-care system: problems and prospects

Thus, the implementation of the above mentioned points will assist the efficiency of a modem health-care system in general. It also helps to provide affordable and quality medical service on the basis of common requirements and approaches according to the latest achieve ments of scientific and technical progress, which will be guarantee of sustainable socio­ economic development of Russia in the long ter

Phase Dependent Thermopower in Andreev Interferometers

We report measurements of the thermopower S of mesoscopic Andreev interferometers, which are hybrid loops with one arm fabricated from a superconductor (Al), and one arm from a normal metal (Au). S depends on the phase of electrons in the interferometer, oscillating as a function of magnetic flux with a period of one flux quantum (= h/2e). The magnitude of S increases as the temperature T is lowered, reaching a maximum around T = 0.14 K, and decreases at lower temperatures. The symmetry of S oscillations with respect to magnetic flux depends on the topology of the sample.Comment: 4 pages, 4 figure

Rehabilitation of patients with geriatric foot syndrome in out-patient settings

Geriatric (senile) foot, according to various authors, is one of the most common syndromes in the elderly and senile. This article describes the developed and scientifically substantiated tactics of rehabilitation treatment of patients with age-related foot syndrome in a clinic, which consists in identifying geriatric syndromes associated with age-related foot syndrome and the use of a set of measures to prevent their progression and treatmen

Transforming Growth Factor-β Suppresses the Activation of CD8+ T-Cells When Naïve but Promotes Their Survival and Function Once Antigen Experienced : A Two-Faced Impact on Autoimmunity

OBJECTIVE—Transforming growth factor-β (TGF-β) can exhibit strong immune suppression but has also been shown to promote T-cell growth. We investigated the differential effect of this cytokine on CD8+ T-cells in autoimmunity and antiviral immunity

Subharmonic Shapiro steps and assisted tunneling in superconducting point contacts

We analyze the current in a superconducting point contact of arbitrary transmission in the presence of a microwave radiation. The interplay between the ac Josephson current and the microwave signal gives rise to Shapiro steps at voltages V = (m/n) \hbar \omega_r/2e, where n,m are integer numbers and \omega_r is the radiation frequency. The subharmonic steps (n different from 1) are a consequence of the ocurrence of multiple Andreev reflections (MAR) and provide an unambiguous signature of the peculiar ac Josephson effect at high transmission. Moreover, the dc current exhibits a rich subgap structure due to photon-assisted MARs.Comment: Revtex, 4 pages, 4 figure

Cytokines and neuron-specific proteins in pediatric viral encephalitis and convulsive syndrome. I. Viral encephalitis

Convulsive syndrome in children is manifested in the three forms: febrile convulsions in acute infections, symptomatic convulsions during acute neuroinfection, as well as onset of epilepsy requiring careful differentiation to prescribe adequate therapy. A threat of convulsive syndrome spreads beyond complications related to ongoing infection, because its development is associated with the risk of emerging symptomatic epilepsy in the future. Postencephalitic epilepsy developing in children within the first years after viral encephalitis has been specifically highlighted. A necessity to identify groups at risk of developing epilepsy gave a momentum to seek out for biomarkers of epileptogenesis reflecting the features of systemic and local inflammatory process in the central nervous system during the immune response to infection. Cytokines mainly mediating inflammation are currently examined being studied as candidate biomarkers of the risk of epilepsy. On the other hand, neuron-specific proteins known as inflammation biomarkers identified in various diseases of the central nervous system are being investigated to reveal brain cell injury in neuroinfections and epilepsy. Here we review publications assessing a potential to use inflammation biomarkers (cytokines and neuron-specific proteins) to diagnose and monitor pediatric neurological diseases associated with convulsive syndrome. The first part of the review describes the results of determining the inflammation biomarkers in the blood and cerebrospinal fluid during acute viral encephalitis/encephalopathy associated with various neurotropic viruses (herpes viruses, flaviviruses, enteroviruses). A significance of diverse biomarkers in predicting an outcome and long-term disease consequences are discussed

Electron pumping in graphene mechanical resonators

The combination of high frequency vibrations and metallic transport in graphene makes it a unique material for nano-electromechanical devices. In this letter, we show that graphene-based nano-electromechanical devices are extremely well suited for charge pumping, due to the sensitivity of its transport coefficients to perturbations in electrostatic potential and mechanical deformations, with the potential for novel small scale devices with useful applications

Nanoscale Study of Calcium Handling Remodeling in Right Ventricular Cardiomyocytes Following Pulmonary Hypertension

Pulmonary hypertension is a complex disorder characterized by pulmonary vascular remodeling and right ventricular hypertrophy, leading to right heart failure. The mechanisms underlying this process are not well understood. We hypothesize that the structural remodeling occurring in the cardiomyocytes of the right ventricle affects the cytosolic Ca2+ handling leading to arrhythmias. After 12 days of monocrotaline-induced pulmonary hypertension in rats, epicardial mapping showed electrical remodeling in both ventricles. In myocytes isolated from the hypertensive rats, a combination of high-speed camera and confocal line-scan documented a prolongation of Ca2+ transients along with a higher local Ca2+-release activity. These Ca2+ transients were less synchronous than in controls, likely due to disorganized transverse-axial tubular system. In fact, following pulmonary hypertension, hypertrophied right ventricular myocytes showed significantly reduced number of transverse tubules and increased number of axial tubules; however, Stimulation Emission Depletion microscopy demonstrated that the colocalization of L-type Ca2+ channels and RyR2 (ryanodine receptor 2) remained unchanged. Finally, Stimulation Emission Depletion microscopy and super-resolution scanning patch-clamp analysis uncovered a decrease in the density of active L-type Ca2+ channels in right ventricular myocytes with an elevated open probability of the T-tubule anchored channels. This may represent a general mechanism of how nanoscale structural changes at the early stage of pulmonary hypertension impact on the development of the end stage failing phenotype in the right ventricle