Moscow Institute of Physics and Technology

Many studies have reported gut microbiome alterations in psoriasis patients, suggesting dysbiosis. While evidence for dysbiosis and its link to pathogenesis remains inconclusive, murine models of psoriasis suggest that gut microbiome alterations develop in response to psoriasis-like inflammation. Hence, the dominant narrative about gut microbiome alterations’ impact on disease should be evaluated critically with more data and a well-powered approach. In this case-control study, we used deep sequencing of fecal samples from 53 psoriasis patients and 47 healthy donors to reconstruct the strain/species-level content of the gut microbiome. Unlike previous studies, we first identified matched pairs for each patient with healthy donors to adjust for microbiome variability and increase power. We found no evidence for depleted gut community diversity and apparent divergence in structure between patients and healthy individuals. However, our matched-pair approach identified a subtle but systematic increase in select bacteria among patients, e.g., Megasphaera elsdenii and Eubacterium CAG 180 . We next showed that these enriched species were correlated with elevated biomarkers of intestinal and systemic inflammation and liver function. Functionally, one of the top species, Megasphaera elsdenii , is a potent lactate utilizer in the context of intestinal lactic acidosis and inflammation. While our findings hardly support overt dysbiosis in the large intestine, the observed microbial changes correlate with moderately elevated calprotectin, albeit at levels not enough to diagnose ongoing inflammation. Hence, the sources of elevated inflammatory markers in patients’ intestines remain unclear and warrant further investigation to clarify their cause-and-effect relationship with the disease. IMPORTANCE With sufficient taxonomic resolution and sample size, this study critically evaluates new and published data on the gut microbiome in psoriasis patients. It shows that observed taxonomic changes in patients are modest and do not meet strict criteria for gut dysbiosis, at least in the large intestine. Instead, observed taxonomic changes in psoriasis patients can be explained by the microbial response to possible low-grade inflammation with unknown localization in the intestine and unclear impact on the host. The authors point out that published endoscopic data point to the small intestine as the site of gut inflammation. Therefore, further research focused on the small intestine would be informative to clarify the hypothetical gut-psoriasis link.

The solid thin films of Py/Pt and Py/W heterostructures have been studied using the ferromagnetic resonance method. The temperature dependences of the Gilbert damping parameter and voltage of the the inverse spin Hall effect (ISHE) have been obtained in the 5–290 K temperature range. An anomalous increase in the Gilbert damping parameter in the vicinity of 50 K and a change in the voltage of ISHE has been found. It has been concluded that an increase in the Gilbert damping parameter is of spin-orbital nature.

In this paper, we propose generalizations of the Sokolov–Ternov and Unruh effects, and discuss the possibility to measure them on different experiments.

In this paper, we consider the counting function ${{\,\mathrm{{{\,\mathrm{\mathcal {E}}\,}}_{{{\,\mathrm{\mathcal {P}}\,}}}}\,}}(y) = |{{\,\mathrm{\mathcal {P}}\,}}_{y} \cap {{\,\mathrm{\mathbb {Z}}\,}}^{n_x}|$ for a parametric polyhedron ${{\,\mathrm{\mathcal {P}}\,}}_{y} = \{ x \in {{\,\mathrm{\mathbb {R}}\,}}^{n_x} :A x \le b + B y\}$, where $y \in {{\,\mathrm{\mathbb {R}}\,}}^{n_y}$. We give a new representation of ${{\,\mathrm{{{\,\mathrm{\mathcal {E}}\,}}_{{{\,\mathrm{\mathcal {P}}\,}}}}\,}}(y)$, called a piece-wise step-polynomial with periodic coefficients, which is a generalization of piece-wise step-polynomials and integer/rational Ehrhart’s quasi-polynomials. It gives the fastest way to calculate ${{\,\mathrm{{{\,\mathrm{\mathcal {E}}\,}}_{{{\,\mathrm{\mathcal {P}}\,}}}}\,}}(y)$ in certain scenarios. The most important cases are the following:We show that, for the parametric polyhedron ${{\,\mathrm{\mathcal {P}}\,}}_y$ defined by a standard-form system $A x = y,\, x \ge 0$ with a fixed number of equalities, the function ${{\,\mathrm{{{\,\mathrm{\mathcal {E}}\,}}_{{{\,\mathrm{\mathcal {P}}\,}}}}\,}}(y)$ can be represented by a polynomial-time computable function. In turn, such a representation of ${{\,\mathrm{{{\,\mathrm{\mathcal {E}}\,}}_{{{\,\mathrm{\mathcal {P}}\,}}}}\,}}(y)$ can be constructed by an ${{\,\textrm{poly}\,}}\bigl (n, \Vert A\Vert _{\infty }\bigr )$-time algorithm; Assuming again that the number of equalities is fixed, we show that integer/rational Ehrhart’s quasi-polynomials of a polytope can be computed by FPT-algorithms, parameterized by sub-determinants of A or its elements; Our representation of ${{\,\mathrm{{{\,\mathrm{\mathcal {E}}\,}}_{{{\,\mathrm{\mathcal {P}}\,}}}}\,}}$ is more efficient than other known approaches, if A has bounded elements, especially if it is sparse in addition; Additionally, we provide a discussion about possible applications in the area of compiler optimization. In some “natural” assumptions on a program code, our approach has the fastest complexity bounds.

The samples of EP741NP alloy destroyed during fatigue testing were investigated by means of transmission electron microscopy, energy-dispersive X-ray microanalysis and electron diffraction. The composition and crystal structure of defects detected at the boundaries of fatigue cracks were studied in details. It was shown that such defects mainly have the morphology of elongated flat "carpets" containing NiO, CTixNb1–x, amorphous AlOx, HfO2, Al2O3, β-Al2O3, Al2MgO4, Co7Mo6, Co3O4, S4Ti3, NbO2, TiO2, as well as amorphous regions containing C, O, Ca, S, Na and Cl. Assumptions were made about the source and of time formation of the studied defects.

Using a numerical solution of the Boltzmann equation, the electron drift velocity, the coefficients of their longitudinal and transverse diffusion, as well as the ionization and dissociative attachment coefficients in weakly ionized plasma of mixtures of air with water vapor are calculated in a wide range of reduced electric fields (1–650 Td, 1 Td = 10–17 V cm2) and mole fractions of water vapor (0–1). The calculation results are compared with new experimental data, and good agreement between them is obtained. It is shown that for all coefficients and the average electron energy, their dependence on the gas composition changes with increasing electric field. At low reduced fields, an increase in the content of H2O water molecules in mixtures leads to a decrease in the transport coefficients and average electron energy, while the opposite trend is observed at high fields. It is shown that for the drift velocity and electron attachment coefficient there are electric fields, in which these coefficients in gas mixtures can be greater than the coefficients in dry air and water vapor. A qualitative explanation is given for the obtained dependences of the electron coefficients on the electric field and H2O content in the mixtures.

Changes in astrocytic ultramorphology may underlie the development of neurodegenerative processes in their early stages. However, the mechanisms of its change are still poorly understood, since the size of the peripheral astrocytic processes forming the basis of the astrocytic synaptic coating are beyond the resolution of most optical microscopy (OM) methods. In turn, the disadvantage of promising methods of electron and scanning probe microscopy (EM and SPM) for such studies is the inability to determine the target area of the study due to the simultaneous use of fluorescence microscopy of immunocolored cells and the possibility of full-fledged 3D analysis of samples. In this paper, we consider the concept of solving the above problem by using an instrumental approach that combines the methods of SPM and OM together with ultramicrotomy as a method of restoring the 3D structure of the sample within a single hardware complex. To implement the proposed combined technique (optical-probe nanotomography, OPNT), the first stage of creating specialized fluorescent-contrasting labels based on conjugates of fluorescent semiconductor nanocrystals and single-domain antibodies has been developed in this work. This type of label will provide both immuno-staining of the “area of interest" for the restoration of 3D astrocytic ultramorphology, and contrast of astrocytes by the SPM method.

Plasma was heated at the second harmonic of electron cyclotron resonance (ECR) in the L-2M stellarator and the T-10 tokamak. The concept of equivalent tokamak and stellarator discharges was extended to the case of both full and partial absorption of EC power. Comparison of experimental electron temperature profiles with profiles calculated using the canonical profiles transport model allows us to estimate the efficiency of ECR heating in the L-2M discharges without suprathermal electrons, which distort the distribution function, preventing reliable measurements of temperature. The dependence of the ECR heating efficiency on the plasma density was obtained, describing experiments on the L-2M and TJ-II stellarators, and on the T-10 tokamak. The energy characteristics (the stored energy and the confinement time) for L-2M discharges were calculated. Predictions for ECR heating in the T-15MD tokamak are considered. The features of solving the ill-posed transport problem for the L-2M are discussed.

The distinctive features of the T-15MD tokamak microwave interferometer for measuring linearly integrated electron density, as well as the system for processing and recording its signals, are presented. The phase stability of microwave interferometer signals is analyzed. The results of measurements with a microwave interferometer during the first experimental campaign of the T-15MD tokamak are presented. The phase values were extracted by using an analog phase meter and post-processing of digitized microwave interferometer signals: an intermediate frequency signal and a local oscillator signal. It is shown that the results of the plasma density calculation by these two methods coincide.

The effect of the spatial distribution of electric potential on the separating properties of the plasma mass separator that operates in a configuration with crossed radial electric and longitudinal magnetic fields is studied. The single-particle approximation is used to obtain analytical expressions that connect the electric potential distribution and the angular mass spectrum. A mathematical algorithm is described that allows one to recover the distribution of electric potential from the given shape of the mass spectrum. It is shown that the local inhomogeneity of the electric potential profile allows one to achieve the deposition of mass groups in the diametrically opposite regions of the separator. Data is presented that confirms the possibility of creating experimentally both the positive and the negative local inhomogeneity of the potential. The results of this work can be used to increase the efficiency of the process of plasma mass separation of ions of different elements.

This publisher’s note reports corrections to Appl. Opt. 63, 8503 (2024).APOPAI0003-693510.1364/AO.539960

The issue of the occurrence of seismicity induced by injection of fluid into the subsurface is considered. A model of nested fractures is presented, which allows simulating the process of fluid filtration in a rock containing fractures or faults, taking into account the change in the filtration properties of the latter during the change in pore pressure. The process of fault deformation is described using the displacement discontinuity method. The model is used to analyze the effect of fluid injection in the immediate vicinity of a fault on its subsequent deformation. The transition of fault slip from aseismic to seismic is investigated when the parameters of the friction law or fluid injection parameters change. Conditions have been found under which seismic slip may occur within the framework of the proposed model.

Oncolytic viruses (OVs) have emerged as a class of novel cancer immunotherapeutic. Members of both DNA and RNA viruses developed as OVs for treating diverse types of human cancers. Preclinical research assessing immunotherapeutic efficacy is an essential step toward further development of these OVs. Mice tumor model systems are widely used in preclinical oncolytic viral therapies for evaluating the treatment regimens’ efficacy. However, choosing the most appropriate model for a study can be challenging. Here, we describe a simple method of establishing subcutaneous tumors in immunocompetent mice, intratumoral injection of the virus, measuring tumor burden, and studying the survival of mice for preclinical development of oncolytic myxoma virus (MYXV).

В работе рассматривается семейство линейных операторов на $L_2(\mathbb{R}_+)$, диагонализуемых преобразованием Ганкеля. Для определителей Фредгольма данных операторов, ограниченных на $L_2[0, R]$, выводится точное выражение, позволяющее установить их скорость сходимости при $R\to\infty$. Мы используем связь этих определителей с распределением аддитивных функционалов в детерминантном точечном процессе с ядром Бесселя и получаем оценку на расстояние Колмогорова-Смирнова между распределением последних и гауссовым. Библиография: 27 названий.

Grammatical Error Correction is one of the core Natural Language Processing tasks. At the moment, the open source state-of-the-art Sequence Tagger for English is GECToR model. For the Russian language, this problem does not have solutions with the same good results due to the lack of labeled datasets, therefore we decided to contribute to the aforementioned task. In this research, we described the process of creating a synthetic dataset and training a model on it. We adapt GECToR architecture for Russian language and call it RuGECToR. We use this architecture because, unlike Sequence-to-Sequence approach, it is easy to interpret and does not require a lot of training data. Our goal was to train the model in such a way that it does not adapt to a specific sample, but generalizes the morphological properties of the language. The presented model achieves an F0.5 of 82.5 on synthetic data and an F0.5 of 22.2 on RULEC dataset which was not in the training set.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a standard treatment for advanced Parkinson's disease (PD). The precise positioning of the electrode can significantly influence the results of DBS and the overall improvement in the quality of life for PD patients receiving this therapy. We hypothesize that single unit activity (SUA) features can serve as a valid marker of the optimal DBS‐electrode insertion trajectory, leading to the most favorable outcome of STN‐DBS surgery. We analyzed spontaneous SUA data recorded during microelectrode recording (MER) for 21 patients with PD who underwent DBS surgery. We compared 29 linear and six nonlinear characteristics of the STN neural activity recorded along different microelectrode insertion paths to determine features corresponding to favorable stimulation outcomes. Our research indicated that the SUA features of pause neurons in a dorsal STN region significantly affected stimulation outcomes. For the trajectories chosen for lead insertion, firing rate, burst rate and oscillatory activity at 8–12 and 12–20 bands were significantly decreased. Moreover, nonlinear feature analysis showed a significant increase in mutual information for the chosen trajectories. Our findings highlight the significance of specific indicators, such as the activity of pause neurons in the dorsal region and numerous linear SUA characteristics, in determining the optimal lead installation trajectory. Furthermore, our findings emphasize the importance of investigating paths rejected during test stimulation to understand motor impairment in Parkinson's disease and its treatment mechanisms.