Search

Objective: to evaluate circadian rhythms of the act of defecation in obese patients, depending on the presence or absence of concomitant constipation syndrome.Materials and methods: in the period from October 2020 to April 2022, 251 patients were examined. The average age of the patients was 49.8 ± 11.4 years. The ratio of men and women was 1:1.14 (117:134 people). The study included patients aged 18 to 75 years inclusive, obese: body mass index (BMI) 30 and above and waist circumference >94 cm in men and >80 cm in women who do not have organic diseases of the colon. All patients were assessed for gastroenterological complaints, stool frequency (number a week), stool type according to the Bristol scale (1–7), the time of defecation during the day to identify possible disorders of circadian rhythms, measurement of anthropometric parameters (height, body weight), calculation of BMI. Statistical data processing was performed using Statistica 10 and SAS JMP 11 programs.Results: in the study population, constipation was detected in 45.8% of obese patients. Patients with constipation were signifi cantly more concerned about pain along the colon, bloating, as well as the need for severe straining and pain in the perianal region and along the rectum after defecation (pConclusions: in patients with obesity and the presence of constipation, pronounced disorders of circadian rhythms of defecation are determined. This can contribute to the progression of chronic constipation, the formation of disorders of the gut microbiota, which leads to the development of the leaky gut syndrome, the maintenance of chronic infl ammation and, as a result, to the progression of obesity and metabolic changes. Restoration of physiological rhythms of the act of defecation is an important component of non-drug treatment in the complex therapy of obesity, metabolic syndrome, chronic constipation.

We review recent studies of the spin-dependent tunneling transport via an Aharonov–Bohm interferometer (ABI) formed by helical edge states. We focus on the experimentally relevant case of relatively high temperature, T, as compared to level spacing, Δ. The tunneling conductance of helical ABI is structureless in ballistic case but shows sharp periodic antiresonances as a function of magnetic flux with the period $$hc{\text{/}}2e$$ in presence of magnetic impurities. The incoming unpolarized electron beam acquires finite polarization after transmission through the helical ABI provided that the edges contain at least one magnetic impurity. The finite polarization appears even in the fully classical regime and is therefore robust to dephasing. There is also a quantum contribution to the polarization, which shows sharp identical resonances as a function of magnetic flux with the same period as conductance. This polarization survives at relatively high temperature. The interferometer can be described in terms of ensemble of $$\mathcal{N} \simeq T{\text{/}}\Delta $$ flux-tunable qubits giving equal contributions to conductance and spin polarization. Hence, with increasing the temperature number of active qubits participating in the charge and spin transport increases. These features of tunneling helical ABI open a wide avenue for applications in the area of quantum computing.

The environment for the development of products containing live cells as an active substance is being set up in Russia for several years. However, the acceptable regulatory framework, which would have allowed to develop and place cell therapy products on the market, complying with international requirements for safety, efficacy, and quality, has not been yet established. Moreover, in addition to the national legal framework, the Eurasian Economic Union regulatory model has emerged that introduces in parallel a more straightforward pathway for the development and clinical use of this important medical product category. In this paper we address the domestic and Eurasian regulatory systems for products containing live cells as an active ingredient and suggest certain possible approaches to support this area of biotechnology.

The renormalization of conductances in a Y junction of spinless Luttinger-liquid wires additionally coupled to acoustic longitudinal phonons is investigated in fermionic representation. This system corresponds to geometry of a tunneling experiment and exhibits the interplay between the Coulomb repulsion and the attractive retarded interaction mediated by phonons. The retardation effects related to the propagation of phonons through the junction with arbitrary transmission and reflection amplitudes are taken into account. The appearing logarithmic corrections to conductances of the junction are treated in a renormalization group approach, and scaling exponents are calculated up to infinite order in the interaction after RPA-type summation. The fixed points and corresponding scaling exponents are considered in various non-equilibrium regimes. We show that the boundary exponent and the bulk anomalous dimension of fermion operator are characterized by two different Luttinger parameters, referring to the main wire, thanks to non-local character of phonon-mediated interaction. In the limiting case of the junction of only two wires, the scaling exponents found by our method are in exact correspondence with previous bosonization analysis., 20 pages, 10 figures

We discuss spin-dependent transport via tunneling Aharonov-Bohm interferometer formed by helical edge states tunnel-coupled to helical leads. We focus on the experimentally relevant high-temperature case as compared to the level spacing and obtain the full 4×4 matrix of transmission coefficients in the presence of magnetic impurities. We show that spin conserving and spin-flip transmission coefficients of the setup can be effectively tuned by the magnetic flux. These features are attractive due to possible applications for spintronics, magnetic field detection, and quantum computing.

We study coherent spin transport through helical edge states of topological insulator tunnel-coupled to metallic leads. We demonstrate that unpolarized incoming electron beam acquires finite polarization after transmission through such a setup provided that edges contain at least one magnetic impurity. The finite polarization appears even in the fully classical regime and is therefore robust to dephasing. There is also a quantum magnetic field-tunable contribution to the polarization, which shows sharp identical Aharonov-Bohm resonances as a function of magnetic flux - with the period $hc/2e$ - and survives at relatively high temperature. We demonstrate that this tunneling interferometer can be described in terms of ensemble of flux-tunable qubits giving equal contributions to conductance and spin polarization. The number of active qubits participating in the charge and spin transport is given by the ratio of the temperature and the level spacing. The interferometer can effectively operate at high temperature and can be used for quantum calculations. In particular, the ensemble of qubits can be described by a single Hadamard operator. The obtained results open wide avenue for applications in the area of quantum computing., 15 pages, 9 figures

We study the conductance renormalization for the four-lead junction of semi-infinite wires in the scattering state formalism. We use the model of spinless fermions with a short-range Luttinger-type interaction and find the renormalization group (RG) equations for the conductances of the system in the first order of the fermionic interaction. In contrast to the well-known cases of two-lead and three-lead junctions, the four-lead case does not admit a formulation of the RG equations solely in terms of conductances. The arising ambiguity with arbitrariness in the choice of the sign of S-matrix elements related to identical conductance matrices might be connected with a symmetry of the particle–hole type in the Hamiltonian. We show that there are two distinct RG flows from any initial point in the space of conductances. The discovered ambiguity does not affect the scaling exponents at the fixed points.

The High Threshold Cherenkov Counter (HTCC) is one of the detector systems of the CLAS12 spectrometer, and is used to generate a fast trigger signal in electron scattering experiments in the polar angle range from 5°to 35°. The HTCC is installed in front of the drift chambers and introduces a minimal amount of additional material within the acceptance. The HTCC is one unit whose core component is a multifocal mirror that consists of 60 lightweight ellipsoidal mirrors. It is important that the HTCC provides efficient coverage of the CLAS12 forward acceptance with no gaps. In order to achieve this, each sector of the CLAS12 Forward Detector is covered by 2 identical half-sector mirrors that focus Cherenkov light on 8 phototubes. The HTCC has a total of 48 channels with Electron Tubes 9823QKB photomultipliers that have a 5-in quartz face plate to detect Cherenkov light. The system provides rejection of charged π -mesons with momenta below 4.8 GeV for the reliable identification of scattered electrons. In this paper the details of the design, construction, calibration, and performance results of the HTCC are presented.

We discuss transport through interferometer formed by helical edge states tunnel-coupled to metallic leads. We focus on the experimentally relevant case of relatively high temperature as compared to the level spacing and discuss a response of the setup to the external magnetic flux $\phi$ (measured in units of flux quantum) piercing the area encompassed by edge states. We demonstrate that tunneling conductance of the interferometer is structureless in ballistic case but shows a sharp antiresonances, as a function of magnetic flux $\phi$ - with the period 1/2 - in the presence of magnetic impurity. We interpret the resonance behavior as a coherent enhancement of backward scattering off magnetic impurity at integer and half-integer values of flux, which is accompanied by suppression of the effective scattering at other values of flux. Both enhancement and suppression are due to the interference of processes with multiple returns to magnetic impurity after a number of clockwise and counterclockwise revolutions around setup. This phenomenon is similar to the well-known weak-localization-induced enhancement of backscattering in disordered systems. The quantum correction to the tunneling conductance is shown to be proportional to flux-dependent "ballistic Cooperon". The obtained results can be used for flux-tunable control of the magnetic disorder in Aharonov-Bohm interferometers built on helical edge states., Comment: 13 pages, 7 figures

Light scattering in a magnetic medium with uncorrelated inclusions is theoretically studied in the approximation of ladder diagram. Correlation between polarizations of electromagnetic waves that are produced by infinitely-distant dipole source is considered. Here white noise disorder model with Gaussian distribution is taken into account. In such a medium the magneto-optical interaction leads to correlation between perpendicular light polarizations. Spatial field correlation matrix with nonzero nondiagonal elements is obtained in the first order on gyration., 6 pages, 3 figures

We compared anti-IIa activity of a heparin analogue and a reference product was carried out to confirm their biosimilarity. The experiment was based on the method of estimation of anti-IIa activity of a commercial sodium heparin preparation according to United States Pharmacopoeia. High similarity of the two medicinal heparin preparations by this parameter is shown. The method is recommended for the use in comparability studies.

We study four-terminal junction of spinless Luttinger liquid wires, which describes either a corner junction of two helical edges states of topological insulators or the tunneling from the spinful wire into the helical edge state. We use the fermionic representation and the scattering state formalism, in order to compute the renormalization group (RG) equations for the linear response conductances. We establish our approach by considering a junction between two possibly non-equivalent helical edge states and find an agreement with the earlier analysis of this situation. Tunneling from the tip of the spinful wire to the edge state is further analyzed which requires some modification of our formalism. In the latter case we demonstrate i) the existence of both fixed lines and conventional fixed points of RG equations, and ii) certain proportionality relations holding for conductances during renormalization. The scaling exponents and phase portraits are obtained in all cases., 10 pages, 6 figures

General principles of appropriate strategies for preclinical and clinical development of unfractionated and low-molecular-weight heparins and demonstration of their biosimilarity to corresponding reference medicinal products are provided. Demonstration of the biosimilarity of heparin-containing medicinal products constitutes the basis for their efficacy and safety during anticoagulation therapy. The main quality, safety, and efficacy characteristics of heparin products are described and the extent of non-clinical and clinical investigations necessary prior to drug marketing authorization are considered.

We consider tunneling from the spin-polarized tip into the Luttinger liquid edge state of quantum spin Hall system. This problem arose in context of the spin and charge fractionalization of an injected electron. Renormalization of the dc conductances of the system is calculated in the fermionic approach and scattering states formalism. In lowest order of tunneling amplitude we confirm previous results for the scaling dependence of conductances. Going beyond the lowest order we show that interaction affects not only the total tunneling rate, but also the asymmetry of the injected current. The helical edge state forbids the backscattering, which leads to the possibility of two stable fixed points in renormalization group sense, in contrast to the Y-junction between the usual quantum wires., Comment: 9 pages, 5 figures

We describe general principles of demonstrating biosimilarity, as well as selecting the biosimilarity margins. Any change in the structure of a biological molecule can modify its functional activity. Therefore, therapeutic equivalence between a biosimilar product and the corresponding reference product cannot be demonstrated using a single criterion. To demonstrate biosimilarity between two medicinal products, their various characteristics have to be evaluated which may, directly or indirectly, justify that clinically significant differences are absent. Insufficient understanding of 6ritical quality attributes brings a risk for the biosimilar product developer. This will either increase the number of non-clinical and clinical tests and trials needed or will result in awareness that the manufacturing process needs to be improved at the late stages of development, after investing significant resources in the development process. At the same time, the specification of the biological medicinal product cannot solely ensure safety and efficacy thereof. Properly characterized and controlled manufacturing process, which ensures consistency in its attributes not adequately controlled in specifications but influencing safety and efficacy profiles and showing their relevance in non-clinical tests and clinical trials, is an additional quality assurance factor. Justification of all development strategy details, including biosimilarity margins, has to be provided each time when the development process is initiated or when proceeding to the next steps. All problems encountered by the developer have to be resolved in close communication with the regulatory authority. In order to increase the quality of investigation and developer's adherence to good practices, clinical trial results should be published in detail.

The article gives a definition of highly variable drugs, describes currently existing regulatory guidance and approaches to the study of bioequivalence of highly variable drugs, and formulates recommendations on the design and evaluation of the results of studies of such drugs. These aspects are considered by the example of calculations based on actual data from the registration dossiers materials for rosuvastatin.