Matching fields of a long superconducting film

We obtain the vortex configurations, the matching fields and the magnetization of a superconducting film with a finite cross section. The applied magnetic field is normal to this cross section, and we use London theory to calculate many of its properties, such as the local magnetic field, the free energy and the induction for the mixed state. Thus previous similar theoretical works, done for an infinitely long superconducting film, are recovered here, in the special limit of a very long cross section.Comment: Contains a REVTeX file and 4 figure

Medico-Sanitary and Parasitological Aspects of Rock Pigeon Ecology (<i>Columba livia</i>)

Collected are the data on sanitary-hygienic and parasitological aspects of rock pigeon vital activity in Saratov. Distinguished are the types of pigeon exterior pathologies, their character and frequency of occurrence. Synanthropic population and nests of the birds are searched for the presence of helminthes and ectoparasites. Identified is the role of nesting sites, located in attics of residential buildings, in sanitary and epidemiological situation of the city settlement zone

Superconducting-coil--resistor circuit with electric field quadratic in the current

It is shown for the first time that the observed [Phys. Lett. A 162 (1992) 105] potential difference Phi_t between the resistor and the screen surrounding the circuit is caused by polarization of the resistor because of the kinetic energy of the electrons of the superconducting coil. The proportionality of Phi_t to the square of the current and to the length of the superconducting wire is explained. It is pointed out that measuring Phi_t makes it possible to determine the Fermi quasimomentum of the electrons of a metal resistor.Comment: 2 pages, 1 figur

Magnetic Pinning of Vortices in a Superconducting Film: The (anti)vortex-magnetic dipole interaction energy in the London approximation

The interaction between a superconducting vortex or antivortex in a superconducting film and a magnetic dipole with in- or out-of-plane magnetization is investigated within the London approximation. The dependence of the interaction energy on the dipole-vortex distance and the film thickness is studied and analytical results are obtained in limiting cases. We show how the short range interaction with the magnetic dipole makes the co-existence of vortices and antivortices possible. Different configurations with vortices and antivortices are investigated.Comment: 12 pages, 12 figures. Submitted to Phys. Rev.

Symmetry of the remanent state flux distribution in superconducting thin strips: Probing the critical state

The critical-state in a thin strip of YBaCuO is studied by magneto-optical imaging. The distribution of magnetic flux density is shown to have a specific symmetry in the remanent state after a large applied field. The symmetry was predicted [PRL 82, 2947 (1999)] for any Jc(B), and is therefore suggested as a simple tool to verify the applicability of the critical-state model. At large temperatures we find deviations from this symmetry, which demonstrates departure from the critical-state behavior. The observed deviations can be attributed to an explicit coordinate dependence of $j_c$ since both a surface barrier, and flux creep would break the symmetry in a different way.Comment: 5 pages including 5 eps figures, submitted to PR

Superconductivity in multi-phase Mg-B-O compounds

Structures of MgB2-based materials manufactured under pressure (up to 2 GPa) by different methods having high superconducting performance and connectivity are multiphase and contain different Mg-B-O compounds. Some oxygen can be incorporated into MgB2 and boron into MgO structures, MgBx (X=4-20) inclusions contain practically no oxygen. Regulating manufacturing temperature, pressure, introducing additions one can influence oxygen and boron distribution in the materials and thus, affect the formation, amount and sizes of Mg-B-O and MgBx inclusions and changing type of pinning, pinning force and so affect critical current density jc. The boron concentration increase in initial Mg and B mixture allows obtaining sample containing 88.5 wt% of MgB12 with Tc of 37.4 K (estimated magnetically)

Incidence and prognostic value of acute kidney injury in pulmonary embolism: data from the SIRENA registry

Aim. To evaluate the incidence and severity of acute kidney injury (AKI), as well as its ability to reclassify the risk of premature mortality and association with inhospital mortality in patients with pulmonary embolism (PE) in the Russian population.Material and methods. From April 2018 to April 2019, the SIRENA Russian Multicenter Registry included patients with PE, as well as the deceased, in whom the PE was detected by autopsy. AKI was diagnosed according to current KDIGO guidelines (2012). Creatinine calculated according to the MDRD equation and corresponding to a glomerular filtration rate of 75 ml/min/1,73 m2 (baseline) was taken as the initial one, with subsequent assessment relative to the parameter value upon admission. The risk stratification of early death was carried out in accordance with the current ESC clinical guidelines (2019).Results. A total of 604 patients with PE were examined (men — 293 (49%), women — 311 (51%), mean age — 64±15 years). AKI was diagnosed in 223 (37%) of them. Stage 1 AKI was detected in 146 (65%), 2 — in 55 (25%), 3 — in 22 (10%) patients. Prior chronic kidney disease was recorded in 61 (10%) patients. Seventy-one (12%) patients had a high risk of death, 364 (61%) — intermediate risk, and 164 (27%) — low risk. The AKI incidence increased as the severity of PE increased: at low risk of death — 26%, intermediate — 38%, high — 59% (p&lt;0,0001). In total, 107 (18%) patients died in the hospital. AKI led to an increase in mortality within following risk groups: at low risk, this effect was a trend (6 (5%) vs 6 (14%); p=0,052); at intermediate and high risk, significant differences was obtained (30 (13%) vs 41 (30%), p&lt;0,001; 4 (14%) vs 19 (45%), p=0,006, respectively). Multivariate Cox regression demonstrated that AKI is a predictor of inhospital death (odds ratio (OR), 3,66 (95% confidence interval (CI): 2,37-5,66; p&lt;0,0001), regardless of increased troponin levels (OR, 1,31 (95% CI: 0,80-2,14; p=0,28) and right ventricular dysfunction (OR, 1,23 (95% CI: 0,74-2,04; p=0,42).Conclusion. Thirty-seven percent of Russian patients with PE have AKI diagnosed by baseline creatinine. In 2/3 of the examined patients, stage 1 AKI is observed. The AKI incidence increases as the severity of PE increases. The presence of AKI reclassifies patients into a higher risk category for death and is associated with a significant increase in inhospital mortality

Flux-Induced Vortex in Mesoscopic Superconducting Loops

We predict the existence of a quantum vortex for an unusual situation. We study the order parameter in doubly connected superconducting samples embedded in a uniform magnetic field. For samples with perfect cylindrical symmetry, the order parameter has been known for long and no vortices are present in the linear regime. However, if the sample is not symmetric, there exist ranges of the field for which the order parameter vanishes along a line, parallel to the field. In many respects, the behavior of this line is qualitatively different from that of the vortices encountered in type II superconductivity. For samples with mirror symmetry, this flux-induced vortex appears at the thin side for small fluxes and at the opposite side for large fluxes. We propose direct and indirect experimental methods which could test our predictions.Comment: 6 pages, Latex, 4 figs., uses RevTex, extended to situations far from cylindrical symmetr

Investigation of nonlinearity in inverse problems of satellite dynamics

В данной работе представлены результаты исследования полной и внутренней нелинейностей применительно к далеким спутникам Юпитера, наблюдавшихся на короткой дуге. Выявлена взаимосвязь между нелинейностью и условиями спутниковых наблюдений. В частности, показано, что полная нелинейность очень сильная, когда период наблюдений меньше 0.1 от орбитального периода, в то время как внутренняя нелинейность достаточно слабая для всех спутников, что указывает на возможность применения нелинейных методов для адекватного моделирования их орбитальной неопределенности.The report presents the results of a study of the total and intrinsic nonlinearities as applied to the outer satellites of Jupiter observed on a short arc. The relationship between the nonlinearities and the conditions of satellite observations is revealed. In particular, it is shown that the total nonlinearity is very strong when the observation period is less than 0.1 of the orbital period, while the intrinsic nonlinearity is weak enough for all satellites, which indicates the possibility of using nonlinear methods for adequate modeling of their orbital uncertainty.Работа выполнена в рамках государственного задания Министерства науки и высшего образования Российской Федерации (тема № 0721-2020-0049)

Shorter Disease Duration Is Associated With Higher Rates of Response to Vedolizumab in Patients With Crohn's Disease But Not Ulcerative Colitis.

Background &amp; aimsPatients with Crohn's disease (CD), but not ulcerative colitis (UC), of shorter duration have higher rates of response to tumor necrosis factor (TNF) antagonists than patients with longer disease duration. Little is known about the association between disease duration and response to other biologic agents. We aimed to evaluate response of patients with CD or UC to vedolizumab, stratified by disease duration.MethodsWe analyzed data from a retrospective, multicenter, consortium of patients with CD (n = 650) or UC (n = 437) treated with vedolizumab from May 2014 through December 2016. Using time to event analyses, we compared rates of clinical remission, corticosteroid-free remission (CSFR), and endoscopic remission between patients with early-stage (≤2 years duration) and later-stage (&gt;2 years) CD or UC. We used Cox proportional hazards models to identify factors associated with outcomes.ResultsWithin 6 months initiation of treatment with vedolizumab, significantly higher proportions of patients with early-stage CD, vs later-stage CD, achieved clinical remission (38% vs 23%), CSFR (43% vs 14%), and endoscopic remission (29% vs 13%) (P &lt; .05 for all comparisons). After adjusting for disease-related factors including previous exposure to TNF antagonists, patients with early-stage CD were significantly more likely than patients with later-stage CD to achieve clinical remission (adjusted hazard ratio [aHR], 1.59; 95% CI, 1.02-2.49), CSFR (aHR, 3.39; 95% CI, 1.66-6.92), and endoscopic remission (aHR, 1.90; 95% CI, 1.06-3.39). In contrast, disease duration was not a significant predictor of response among patients with UC.ConclusionsPatients with CD for 2 years or less are significantly more likely to achieve a complete response, CSFR, or endoscopic response to vedolizumab than patients with longer disease duration. Disease duration does not associate with response vedolizumab in patients with UC