The Stabilization of Superconductivity by Magnetic Field in Out-of-Equilibrium Nanowires

A systematic study has been carried out on the previously reported "magnetic-field-induced superconductivity" of Zn nanowires. By varying parameters such as magnetic field orientation and wire length, the results provide evidence that the phenomenon is a nonequilibrium effect associated with the boundary electrodes. They also suggest there are two length scales involved, the superconducting coherence length and quasiparticle relaxation length. As wire lengths approach either of these length scales, the effect weakens. We demonstrate that it is appropriate to consider the effect to be a stabilization of superconductivity, that has been suppressed by an applied current.Comment: (Updated Version) 9 pages, 8 figure

The Effect of Air Density on Atmospheric Electric Fields Required for Lightning Initiation from a Long Airborne Object

The purpose of the work was to determine minimum atmospheric electric fields required for lightning initiation from an airborne vehicle at various altitudes up to 10 km. The problem was reduced to the determination of a condition for initiation of a viable positive leader from a conductive object in an ambient electric field. It was shown that, depending on air density and shape and dimensions of the object, critical atmospheric fields are governed by the condition for leader viability or that for corona onset. To establish quantitative criteria for reduced air densities, available observations of spark discharges in long laboratory gaps were analyzed, the effect of air density on leader velocity was discussed and evolution in time of the properties of plasma in the leader channel was numerically simulated. The results obtained were used to evaluate the effect of pressure on the quantitative relationships between the potential difference near the leader tip, leader current and its velocity; based on these relationships, criteria for steady development of a leader were determined for various air pressures. Atmospheric electric fields required for lightning initiation from rods and ellipsoidal objects of various dimensions were calculated at different air densities. It was shown that there is no simple way to extend critical ambient fields obtained for some given objects and pressures to other objects and pressures

Integrated approach to radiodiagnosis of follicular thyroid neoplasia: a retrospective cohort trial

Background. An evidence-based diagnostic tactics for follicular thyroid gland neoplasia is lacking to date. First-line priority are radiography diagnostic techniques, which vary in capacities and therefore must be regulated in use.Objectives. An efficacy evaluation of multiparametric ultrasound (US), sonoelastography (SEG) and radionuclide scintigraphy (RS) in diagnosis of follicular thyroid neoplasms (FTN).Methods. Preoperative examination was interpreted in 222 FTN patients (86 with follicular thyroid adenoma, FTA, and 136 with follicular thyroid cancer, FTC) with subsequent surgery. A retrospective statistical data analysis was performed for B-mode US, colour Doppler imaging (CDI), power Doppler imaging (PDI), sonoelastography and Tc-99m pertechnetate scintigraphy.Results. Novel FTN descriptive evidence has been obtained. Particularly, an FTA vs. FTC trait comparison showed no reliable US marker of a node assignment to FTA or FTC. Trials of the national-manufactured TI-RADS system showed its good diagnostic potential: FTN sensitivity 89.55, specificity 77.58 and accuracy 83.52%. A SEG picture of FTN was typically motley-colour and mosaic. Young’s modulus in FTA was 27.5 ± 7.1 kPa, a higher stiffness (62.1 ± 12.1 kPa) in FTC indicated a higher likelihood of malignancy. Scintigraphy exhibited a modest capacity for FTN diagnosis (sensitivity 86.67, specificity 48.08 and accuracy 56.72%). AUC values (0.617) indicate its limited use for differential FTN diagnosis, mainly in hyperfunctioning nodules. Our experience elaborated an original algorithm for radiographic techniques application in FTN diagnosis.Conclusion. Several radiographic methods are warranted in suspected FTN. First-line is multiparametric US B-mode imaging to detect FTN priority markers and US symptom complexes. Sonoelastography is second-line in ambiguous cases to further clarify structure (stiffness) of the thyroid nodule examined. Unlike SEG, scintigraphy assesses the functional traits of thyroid nodule and so has limited indications, an important factor to consider in FTN

Biological diversity of the coastal zone of the Crimean peninsula: problems, preservation and restoration pathways

The results of complex hydrochemical, hydrobiological and ichthyological investigations by IBSS, NAS of Ukraine, realized in 6 regions of the coastal zone of the Crimean peninsula in the Black Sea and the Sea of Azov are given. The main negative factors causing changes in structural and functional characteristics of hydrobiocenoses in the regions studied are analyzed and “hot ecological spots” are isolated. Variants of different methods of management of the coastal ecosystems, including construction of artificial reefs and usage of biological filters for water cleaning, protection and recreation of biological diversity are taken into consideration

Fragmentation channels of relativistic 7^7Be nuclei in peripheral interactions

Nuclei of $^7$Li were accelerated at the JINR Nuclotron. After the charge-exchange reaction involving these nuclei at an external target a second $^7$Be beam of energy 1.23A GeV was formed. This beam was used to expose photo-emulsion chambers. The mean free path for inelastic $^7$Be interactions in emulsion $\lambda$=14.0$\pm$0.8 cm coincides within the errors with those for $^6$Li and $^7$Li nuclei. More than 10% of the $^7$Be events are associated with the peripheral interactions in which the total charge of the relativistic fragments is equal to the charge of the $^7$Be and in which charged mesons are not produced. An unusual ratio of the isotopes is revealed in the composition of the doubly charged $^7$Be fragments: the number of $^3$He fragments is twice as large as that of $^4$He fragments. In 50% of peripheral interactions, a $^7$Be nucleus decays to two doubly charged fragments. The present paper gives the channels of the $^7$Be fragmentation to charged fragments. In 50% of events, the $^7$Be fragmentation proceeds only to charged fragments involving no emission of neutrons. Of them, the $^3$He+$^4$He channel dominates, the $^4$He+d+p and $^6$Li+pchannels constitute 10% each. Two events involving no emission of neutrons are registered in the 3-body $^3$He+t+p and $^3$He+d+d channels. The mean free path for the coherent dissociation of relativistic $^7$Be nuclei to $^3$He+$^4$He is 7$\pm$1 m. The particular features of the relativistic $^7$Be fragmentation in such peripheral interactions are explained by the $^3$He+$^4$He 2-cluster structure of the $^7$Be nucleus.Comment: 10 pages, 3 figures, 3 tables, conference: Conference on Physics of Fundamental Interactions, Moscow, Russia, 5-9 Dec 200

Prospects for SIMPLE 2000: A large-mass, low-background Superheated Droplet Detector for WIMP searches

SIMPLE 2000 (Superheated Instrument for Massive ParticLE searches) will consist of an array of eight to sixteen large active mass ($\sim15$ g) Superheated Droplet Detectors(SDDs) to be installed in the new underground laboratory of Rustrel-Pays d'Apt. Several factors make of SDDs an attractive approach for the detection of Weakly Interacting Massive Particles (WIMPs), namely their intrinsic insensitivity to minimum ionizing particles, high fluorine content, low cost and operation near ambient pressure and temperature. We comment here on the fabrication, calibration and already-competitive first limits from SIMPLE prototype SDDs, as well as on the expected immediate increase in sensitivity of the program, which aims at an exposure of $>$25 kg-day during the year 2000. The ability of modest-mass fluorine-rich detectors to explore regions of neutralino parameter space beyond the reach of the most ambitious cryogenic projects is pointed out.Comment: 19 pages, 10 figures included. New Journal of Physics, in pres

Использование локального введения кортикостероидов при лечении синдрома запястного канала

Carpal tunnel syndrome is the most frequent entrapment neuropathy. We performed a literature review of application of local corticosteroid injections. The main aim of the review is to outline the issues concerning indications for the treatment, efficiency and safety of the procedure, and the effect’s duration. Different techniques and different types of corticosteroids, outcomes of the local injections in comparsion with surgical treatment are discussed.Синдром запястного канала – наиболее часто встречающаяся туннельная нейропатия. В настоящей статье представлен обзор литературы, посвященный использованию локального введения кортикостероидов при лечении данной патологии. Рассмотрены вопросы эффективности и безопасности процедуры, существующие модификации ее выполнения. Определены показания к применению, обсуждено использование различных кортикостероидов, проведено сравнение локальных инъекций и хирургического лечения.

Role of the Nuclear and Electromagnetic Interactions in the Coherent Dissociation of the Relativistic 7^7Li Nucleus into the 3^3H + 4^4He Channel

The differential cross section in the transverse momentum $Q$ and a total cross section of $(31\pm4)$ mb for the coherent dissociation of a 3-A-GeV/$c$ $^7$Li nucleus through the $^3$H$+^4$He channel have been measured on emulsion nuclei. The observed $Q$ dependence of the cross section is explained by the predominant supposition of the nuclear diffraction patterns on light (C, N, O) and heavy (Br, Ag) emulsion nuclei. The contributions to the cross section from nuclear diffraction ($Q\le400$ MeV/$c$) and Coulomb $(Q\le50$ MeV/$c$) dissociations are calculated to be 40.7 and 4 mb, respectively.Comment: ISSN 0021-3640, Pleiades Publishing, Ltd., 200