Microscopic theory of thermal phase slips in clean narrow superconducting wires

We consider structure of a thermal phase-slip center for a simple microscopic model of a clean one-dimensional superconductors in which superconductivity occurs only within one conducting channel or several identical channels. Surprisingly, the Eilenberger equations describing the saddle-point configuration allow for exact analytical solution in the whole temperature and current range. This solution allows us to derive a closed expression for the free-energy barrier, which we use to compute its temperature and current dependences

The synthesis of p-tert-butyl thiacalix[4]arenes functionalized with secondary amide groups at the lower rim and their extraction properties and self-assembly into nanoscale aggregates

In this work, the synthesis of novel p-tert-butyl thiacalix[4]arenes functionalized with the secondary amide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations is described. The ability of novel thiacalixarene derivatives to form dimeric associates held together by hydrogen bonds of p-tert-butyl thiacalixarenes and to recognize metal ions of s (Li+, Na+, K+, Cs+, Mg2+, Ca2+, Ba2+), p (Al3+, Pb2+), and d (Fe3+, Co3+, Ni2+, Cu2+, Ag+, Cd2+, Hg2+) elements was investigated by the picrate extraction method and dynamic light scattering (DLS). As was established, the thiacalix[4]arenes investigated are poor extractants for all the metal ions. Meanwhile they self-associate to form dimers of similar size (1.1-2.7 nm) and nanoscale particles consisting of p-tert-butyl thiacalix[4]arenes and silver cations with hydrodynamic diameters of 70-170 nm. © 2008 Elsevier Ltd. All rights reserved

Solvent extraction and self-assembly of nanosized aggregates of p-tert-butyl thiacalix[4]arenes tetrasubstituted at the lower rim by tertiary amide groups and monocharged metal cations in the organic phase

New p-tert-butyl thiacalix[4]arenes functionalized with morpholide and pyrrolidide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations were synthesized, and their receptor properties for monocharged cations (alkali metal and silver ions) were studied using the picrate extraction method and dynamic light scattering (DLS). To evaluate the ability of the p-tert-butyl thiacalix[4]arene derivatives to recognize metal ions, liquid-liquid extraction of their picrate salts has been carried out in a mutually saturated water-dichloromethane system. The degrees of extraction and the extraction constants for monocharged metal cations (Li+, Na+, K+, Cs+) have been determined. The ability of the systems, consisting of host and guest molecules, to self-assembly was proved by DLS using a Zetasizer Nano ZS particle size analyzer. It was shown that all the investigated thiacalix[4]arenes are able to form nanoscale particles with silver cations under the experimental conditions. The pyrrolidide derivative in the cone conformation showed both self-association and aggregation processes with lithium cations. The degree of extraction for all the investigated systems that formed nanoscale aggregates in the organic phase was more than 67% and the extraction constants, log Kex determined by the picrate extraction method, more than 6. © 2008 Elsevier Ltd. All rights reserved

Silica nanoparticles surface-modified with thiacalixarenes selectively adsorb oligonucleotides and proteins

We prepared silica nanospheres 360 nm in diameter surface-modified with p-tert-butylthiacalix[4]arenes containing amine, carboxyl, and guanidinium groups. We found that these silica nanoparticles selectively adsorb model oligonucleotides and proteins. The particles modified with the macrocycle containing guanidinium fragments selectively adsorbed long-chain oligonucleotides and those modified with the macrocycle containing amine groups adsorbed BSA and hemoglobin with pH-dependent selectivity. We compared this behavior with that of silica nanoparticles carrying amine and carboxyl groups, and concluded that both electrostatic interactions and specific binding are responsible for the observed selectivity. © 2013 Springer Science+Business Media Dordrecht

Self-assembly of stereoisomers of p-tert-butyl thiacalix[4]arenes tetrasubstituted at the lower rim by a tertiary amide group with cations of p- and d-elements in the organic phase

The ability of p-tert-butyl thiacalix[4]arenes tetrasubstituted at the lower rim by morpholide and pyrrolidide groups in cone, partial cone, and 1,3-alternate conformations to recognize cations of p- (Al3+, Pb 2+) and d- (Fe3+, Co3+, Ni2+, Cu2+, Cd2+, Hg2+) elements has been studied by the picrate extraction method, dynamic light scattering (DLS), and atomic force microscopy (AFM). The hydrodynamic diameters of supramolecular associates, polydispersity index of host-guest systems, and molecular weight of nanoscale aggregates consisting of p-tert-butyl thiacalix[4]arenes and metal nitrates have been determined by the correlation spectroscopy method. It was shown that the investigated macrocycles are effective extractants for metal cations. All the investigated thiacalix[4]arenes are able to form dimers of about 1 nm with metal cations and nanoscale particles of 238 and 212 nm with Ni2+ and Pb2+ cations, respectively. © 2009 American Chemical Society

Immune pathogenesis and immune therapy of a sclerosing variant of vulvar lichen sclerosus: a prospective cohort study

Background. Today, no unified clinical classification of vulvar lichen sclerosus is registered (is yet to be registered?). Isolation of pathogenetically and clinically different variants of its course enable new approaches to the treatment to be developed. Objective. To develop a pathogenetic therapy for the sclerosing variant of vulvar lichen sclerosus, taking into account its clinical and immunological characteristics. Methods. A prospective cohort study was conducted from 2018 to 2022 on the basis of Regional Clinical Hospital No. 2, Krasonodar, Russia. 292 patients aged 20 to 70 years were histologically diagnosed with vulvar lichen sclerosus. After a clinical examination using the scale for assessing subjective and objective clinical signs of vulvar lichen sclerosus, 154 patients with a sclerosing variant of the disease course were selected for the study. The control cohort consisted of 30 women of the same age category without vulvar lichen sclerosus, taking into account the exclusion criteria. The study involved a clinical assessment (in points) of objective and subjective criteria characteristic of this variant of vulvar lichen sclerosus, as well as an assessment of the level of cytokines (interleukin-20; interleukin-23; interleukin-10; tumor necrosis factor α, interferon γ) in peripheral blood of the patients from the main and control groups. One month after the immunotherapy with sodium deoxyribonucleate, the authors evaluated its clinical efficacy (using Numerical rating scale for pain (vulvodynia) and Vulvar pruritus severity scale) and immunological efficacy (repeated assessment of the level of the studied cytokines). Analysis and statistical processing of the obtained data were performed using Graph Pad Prism version 6.0 (GraphPad Software, Inc., San Diego, CA). Results. Depigmentation of the vulvar skin against the background of vulvar sclerosis and thickening features a sclerosing variant of vulvar lichen sclerosus compared to vulvar atrophy. Stenosis of the vaginal vestibule is either absent (51.3%) or predominantly corresponds to grade I, and is less specific than depigmentation and even skin atrophy. The subjective signs include a severe vulvar pruritus without or with moderately expressed (in 68.1%) vulvodynia. An immunological study showed a statistically significant increase in the level of interleukin-20 (p < 0.0001), interleukin-23 (p < 0.0001), interferon-γ (p < 0.03), tumor necrosis factor α (p < 0.009) in patients with maximal tissue sclerosis with respect to the control group, along with a statistically significant decrease in the level of anti-inflammatory interleukin-10 (p < 0.01). The immunological efficacy of sodium deoxyribonucleate was confirmed by a statistically significant (compared to baseline) decrease in interleukin-20 (p < 0.0001), interferon-γ and tumor necrosis factor α (p < 0.002), interleukin-23 (p < 0.012) without statistical differences with the control group (except for interleukin-23, the level of which decreased after therapy but remained statistically higher (p < 0.01) than in the control group). Clinical efficacy of immunotherapy was confirmed by a statistically significant (p < 0.001) reduction in vulvodynia and vulvar pruritus after the treatment. Conclusion. The obtained data demonstrate characteristic clinical features and immunological differences in relation to the norm in women with the sclerosing variant of vulvar lichen sclerosus, thereby justifying the use of sodium deoxyribonucleate in this variant with confirmed clinical and immunological efficacy

Self-assembly of p-tert-butyl thiacalix[4]arenes and metal cations into nanoscale three-dimensional particles

The shape of supramolecular aggregates based on stereoisomers of p-tert-butyl thiacalix[4]arenes functionalized with secondary, tertiary amide and hydrazide groups at the lower rim in cone, partial cone and 1,3-alternate conformations with several metal cations were investigated by atomic force microscopy. The examined p-tert-butyl thiacalix[4]arenes form host-guest complexes; dimers, spherics ellipsoids and elongated nanoscale particles depending on the conformation of macrocycles, the nature of the binding centers and the nature of the metal cation. Only associates formed by p-tert-butyl thiacalix[4]arenes with morpholide groups at the lower rim in cone conformation with silver cations exhibited a higher antimicrobial activity. Copyright © 2012 John Wiley & Sons, Ltd

Сytokine markers for different variants of sclerotic lichen in women

Our work was aimed for studying the role of systemic of IL-23 and IL-20 levels in different clinical variants of sclerotic lichen in women. The study was based on results of clinical data (anamnesis, examination, palpation, vulvoscopy) and immunological studies (determination of IL-20 and IL-23 cytokines in peripheral blood) in the patients with sclerotic lichen (114 patients aged 42.5±15.1 years). Group I included patients with atrophic variant of sclerotic lichen (n = 58); group II, with sclerotic variant of sclerotic lichen (n = 34). Group III included women with a sclero-atrophic variant of this disorder (n = 22). The control group consisted of conditionally healthy women without present, or previously documented vulvar pathology (30 persons). Criteria for inclusion were as follows: women 20 to 60 years old, the presence of a benign vulvar disease, absence of treatment with immunotropic drugs over past year. Exclusion criteria: presence of viral infection (HPV, HSV), detection of STI, presence of acute inflammatory process (including vulvitis and vaginitis), cancer diagnosis, symptoms of autoimmune disorders, pregnancy, and the patient’s reluctance to participate in the study.Predominant increase of IL-23 was revealed in all clinical groups of the examined patients, the most pronounced increase (2.7 times) was in severe sclerotic lichen (p < 0.0001). IL-23 concentration in the 2nd clinical group corresponded to the reference age-matched values. There was a significant increase in the blood content of IL-20 in subgroup 2.2 of the patients with sclerotic lichen (p < 0.0001), as well as in patients from group 3 with a mixed clinical course of its disorder (p < 0.0001). Meanwhile, the absence of pronounced vulvar tissue sclerosis in sclerotic variant of sclerotic lichen (subgroup 2.1) was accompanied only by a tendency for increased IL-20 concentration (p = 0.502), and only a trend for decrease in atrophic variant of sclerotic lichen (p = 0.288). In general, analysis of these data presumes a significant role of IL-20 and IL-23 in pathogenesis of sclerotic lichen in women. The cytokine assays in various clinical variants of this vulvar disorder may provide additional differential diagnostics (IL-20), and to assess severity of atrophic and sclerotic changes in vulvar tissues (IL-23) in women with sclerotic lichen