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The title compound was synthesized by Ullmann cross‐coupling in low yield as the first representative of [n]phenylene containing hydrocarbon and fluorocarbon rings. Stille/Suzuki‐Miyaura cross‐coupling reactions, as well as substitution of fluorine in suitable starting compounds, failed to give the same product. The geometric and electronic structures of the title compound were studied by X‐ray diffraction, cyclic voltammetry and density functional theory calculations, together with Hirshfeld surface and reduced density gradient analyses. The crystal structure features head‐to‐tail π‐stacking and other fluorine‐related secondary bonding interactions. From the nucleus‐independent chemical shifts descriptor, the four‐membered ring of the title compound is antiaromatic, and the six‐membered rings are aromatic. The Janus molecule is highly polarized; and the six‐membered fluoro‐ and hydrocarbon rings are Lewis π‐acidic and π‐basic, respectively. The electrochemically‐generated radical cation of the title compound is long‐lived as characterized by electron paramagnetic resonance, whereas the radical anion is unstable in solution. The title compound reveals electrical properties of an insulator. On expanding its molecular scaffold towards partially fluorinated [n]phenylenes (n≥2), the properties presumably can be transformed into those of semiconductors. In this context, the title compound is suggested as a prototype scaffold for ambipolar materials for organic electronics and spintronics. Synthesized, structurally and functionally defined 1,2,3,4‐tetrafluorobiphenylene is suggested as a prototype Janus‐headed scaffold for ambipolar materials.

Quantitative estimates related to the classical Borsuk problem of splitting set in Euclidean space into subsets of smaller diameter are considered. For a given \\(k\\) there is a minimal diameter of subsets at which there exists a covering with \\(k\\) subsets of any planar set of unit diameter. In order to find an upper estimate of the minimal diameter we propose an algorithm for finding sub-optimal partitions. In the cases \\(10 k 17\\) some upper and lower estimates of the minimal diameter are improved. Another result is that any set \\(M R^3\\) of a unit diameter can be partitioned into four subsets of a diameter not greater than \\(0.966\\).

We consider the problem of partitioning a two-dimensional flat torus \\(T^2\\) into \\(m\\) sets in order to minimize the maximal diameter of a part. For \\(m 25\\) we give numerical estimates for the maximal diameter \\(d_m(T^2)\\) at which the partition exists. Several approaches are proposed to obtain such estimates. In particular, we use the search for mesh partitions via the SAT solver, the global optimization approach for polygonal partitions, and the optimization of periodic hexagonal tilings. For \\(m=3\\), the exact estimate is proved using elementary topological reasoning.

Methods of computational quantum chemistry provide accurate approximations of molecular properties crucial for computer-aided drug discovery and other areas of chemical science. However, high computational complexity limits the scalability of their applications. Neural network potentials (NNPs) are a promising alternative to quantum chemistry methods, but they require large and diverse datasets for training. This work presents a new dataset and benchmark called \\(^2\\)DFT that is based on the nablaDFT. It contains twice as much molecular structures, three times more conformations, new data types and tasks, and state-of-the-art models. The dataset includes energies, forces, 17 molecular properties, Hamiltonian and overlap matrices, and a wavefunction object. All calculations were performed at the DFT level (\\(\\)B97X-D/def2-SVP) for each conformation. Moreover, \\(^2\\)DFT is the first dataset that contains relaxation trajectories for a substantial number of drug-like molecules. We also introduce a novel benchmark for evaluating NNPs in molecular property prediction, Hamiltonian prediction, and conformational optimization tasks. Finally, we propose an extendable framework for training NNPs and implement 10 models within it.

This study considers the full waveform inversion (FWI) method based on the asymptotic solution of the Helmholtz equation. We provide frequency-dependent ray tracing to obtain the wave field used to compute the FWI gradient and calculate the modeled data. With a comparable quality of the inverse problem solution as applied to the standard finite difference approach, the speed of the calculations in the asymptotic method is an order of magnitude higher. A series of numerical experiments demonstrate the approach’s effectiveness in reconstructing the macro velocity structure of complex media for low frequencies.

Background/Objectives: Overcoming resistance to diuretics is extremely important in decompensated chronic heart failure (HF). The objective of this study was to assess the efficacy and safety of oral acetazolamide, in addition to standard therapy, in HF patients admitted to the hospital with decompensation requiring intravenous loop diuretic therapy. Methods: In this open-label, prospective, multicenter, randomized trial, we included 416 patients hospitalized with decompensated HF. The patients were randomized into two groups: (1) standard therapy, and (2) standard therapy + acetazolamide orally 250 mg 3 times a day in the first 3 days of hospitalization. At randomization, oral thiazide/thiazide-like and loop diuretics were stopped, and intravenous furosemide was initiated. Results: Successful decongestion within 72 h of randomization was observed in 82 patients (39.6%) in the acetazolamide group and in 83 patients (39.7%) in the standard therapy group (p = 0.983). There was a significant difference in the increase in diuresis in the first 72 h (p = 0.028) and in natriuresis on the 2nd day (p = 0.04). There were no differences between the groups in duration of stay in the intensive care unit, duration of index hospitalization, 6 min walk test distance, and clinical assessment scale scores. Death from any cause occurred in three (1.4%) patients in the acetazolamide group, and in the same number of patients in the standard therapy group (p = 0.996). Death from cardiovascular cause and due to decompensated HF also did not differ between the groups during follow-up. Conclusions: The addition of acetazolamide to standard therapy in decompensated chronic HF resulted in a higher cumulative urine output during the first 72 h and natriuresis on the 2nd day after randomization.

The complexity of astrophysical processes lies in the joint consideration of components of various nature. For example, in the collision problem of galaxies, the three-dimensional dynamics of an interstellar gas and a stellar component is considered. The modeling of these components can be based on completely different classes of numerical methods. One possible solution to this problem is to use the Eulerian-Lagrangian approach, in which physical quantities are concentrated at material points, which is typical for the SPH (Smoothed Particle Hydrodynamics) method, and the forces are calculated on an adaptive grid attached to a system of material points. This approach uniformly takes into account both the dynamics of a continuous medium and discrete particles, and also eliminates a number of drawbacks inherent in the original method. The calculation of gravitational interaction is carried out by solving the Poisson equation for the gravitational potential. In this case, all particles are projected onto the computational grid and the potential values in each cell are already calculated on it. The solution of the Poisson equation for the gravitational potential is performed using the fast Fourier transform. The article describes the new cuFFT code Virtual Planetarium for modeling astrophysical objects based on the SPH method, supplemented by the Godunov method for calculating pressure and momentum flows between particles, and the fast Fourier transform method for solving the Poisson equation for the gravitational potential. The paper describes the rationale for the transition to such a computational model, kinetic and hydrodynamic approaches are described in detail. Simulation of the collapse of an isothermal gas cloud is performed. Method to reproduce the evolution of instabilities in form of two density arms is realized.

A new code for modeling relativistic magnetohydrodynamic flows is described in the paper. The developed program code is based on a combination of adaptive nested grids. Magnetic hydrodynamics of the process is simulated using nested grids. Subgrid processes are simulated using regular grids. In the paper, we will outline the main components of program code building. These steps are common to other program codes for magnetized flows simulation.

In this paper, we present the new results of mathematical modeling of dwarf galaxy movement through the intracluster medium (ICM). Our numerical model includes self-gravity hydrodynamics equation for the gas component of the galaxy and collisionless Boltzmann equation for the stellar component. We also included important sub-grid physics: star-formation, supernova feedback, stellar wind, cooling, and heating function, and non-equilibrium chemistry to ion helium hydride. As a result of our simulation, we provide density, pressure, and temperature for destruction processes in the high-density intracluster medium.

In this paper, a new hydrodynamics code to simulate of interacting galaxies on Intel Xeon Phi processors with KNL architecture is presented. A new vector numerical method implemented in the form of a program code for massively parallel architectures is proposed in details. A detailed description is given and a parallel implementation of the code is made. A 92 per cent scalability is reached with 64 processors. The scenarios of interacting galaxies S+E is presented.