Ultrasound-enhanced localized chemotherapy of drug-sensitive and multidrug resistant tumors

Journal ArticleA new modality of targeted tumor chemotherapy is based on the drug encapsulation in polymeric nanoparticles followed by a localized release at the tumor site triggered by focused ultrasound. Effect of 1 MHz and 3 MHz unfocused ultrasound applied locally to the tumor on the Doxorubicin (DOX) biodistribution and tumor growth rates was measured for ovarian carcinoma tumors in nu/nu mice. The bioeffects of ultrasound were investigated on the systemic and cellular levels. Growth rates of A2780 ovarian carcinoma tumors were substantially reduced by combining micellar drug delivery with tumor irradiation. Ultrasound effect was not thermal as manifested by intratumoral temperature measurements during sonication. Biodistribution studies showed that ultrasound did not enhance micelle extravasation. Main mechanisms of the ultrasound-enhanced chemotherapy included (i) passive targeting of drug-loaded micelles to the tumor interstitium; (ii) ultrasound-triggered localized drug release from micelles in the tumor volume; (iii) enhanced micelle and drug diffusion through the tumor interstitium; and (iv) ultrasound-triggered cell membrane damage resulting in the enhanced micelle and drug uptake by tumor cells

Controlling cluster synchronization by adapting the topology

We suggest an adaptive control scheme for the control of zero-lag and cluster synchronization in delay-coupled networks. Based on the speed-gradient method, our scheme adapts the topology of a network such that the target state is realized. It is robust towards different initial condition as well as changes in the coupling parameters. The emerging topology is characterized by a delicate interplay of excitatory and inhibitory links leading to the stabilization of the desired cluster state. As a crucial parameter determining this interplay we identify the delay time. Furthermore, we show how to construct networks such that they exhibit not only a given cluster state but also with a given oscillation frequency. We apply our method to coupled Stuart-Landau oscillators, a paradigmatic normal form that naturally arises in an expansion of systems close to a Hopf bifurcation. The successful and robust control of this generic model opens up possible applications in a wide range of systems in physics, chemistry, technology, and life science

Growing Scale-Free Networks with Tunable Clustering

We extend the standard scale-free network model to include a ``triad formation step''. We analyze the geometric properties of networks generated by this algorithm both analytically and by numerical calculations, and find that our model possesses the same characteristics as the standard scale-free networks like the power-law degree distribution and the small average geodesic length, but with the high-clustering at the same time. In our model, the clustering coefficient is also shown to be tunable simply by changing a control parameter - the average number of triad formation trials per time step.Comment: Accepted for publication in Phys. Rev.

Interlayer Registry Determines the Sliding Potential of Layered Metal Dichalcogenides: The case of 2H-MoS2

We provide a simple and intuitive explanation for the interlayer sliding energy landscape of metal dichalcogenides. Based on the recently introduced registry index (RI) concept, we define a purely geometrical parameter which quantifies the degree of interlayer commensurability in the layered phase of molybdenum disulphide (2HMoS2). A direct relation between the sliding energy landscape and the corresponding interlayer registry surface of 2H-MoS2 is discovered thus marking the registry index as a computationally efficient means for studying the tribology of complex nanoscale material interfaces in the wearless friction regime.Comment: 13 pages, 7 figure

Model of the propagation of very low-frequency beams in the Earth–ionosphere waveguide: principles of the tensor impedance method in multi-layered gyrotropic waveguides

The modeling of very low-frequency (VLF) electromagnetic (EM) beam propagation in the Earth–ionosphere waveguide (WGEI) is considered. A new tensor impedance method for modeling the propagation of electromagnetic beams in a multi-layered and inhomogeneous waveguide is presented. The waveguide is assumed to possess the gyrotropy and inhomogeneity with a thick cover layer placed above the waveguide. The influence of geomagnetic field inclination and carrier beam frequency on the characteristics of the polarization transformation in the Earth–ionosphere waveguide is determined. The new method for modeling the propagation of electromagnetic beams allows us to study the (i) propagation of the very low-frequency modes in the Earth–ionosphere waveguide and, in perspective, their excitation by the typical Earth–ionosphere waveguide sources, such as radio wave transmitters and lightning discharges, and (ii) leakage of Earth–ionosphere waveguide waves into the upper ionosphere and magnetosphere. The proposed approach can be applied to the variety of problems related to the analysis of the propagation of electromagnetic waves in layered gyrotropic and anisotropic active media in a wide frequency range, e.g., from the Earth–ionosphere waveguide to the optical waveband, for artificial signal propagation such as metamaterial microwave or optical waveguides

Strategic Priorities in Innovative-Technological Development in Physical Education and Sports

Непрекращающиеся изменения, связанные с геополитической ситуацией, эпидемиологической обстановкой и многими другими факторами, которые на протяжении последних лет заставляют общество моментально реагировать и трансформироваться, не обходят стороной ни одну сферу деятельности. Так, сфера физической культуры и спорта, следуя современным тенденциям, ставит перед собой задачи по цифровизации отрасли, развитию спортивной индустрии в части создания технологического суверенитета по производству спортивного оборудования и инвентаря, совершенствованию медико-биологического обеспечения и мн. др. В статье определены основные направления инновационно-технологического развития сферы физической культуры и спорта.Unending changes connected to the geopolitical situation, epidemiological situation and different other factors that over the years force the population to react and transform touch upon every field of activity. And so, the field of physical education and sports following modern tendencies sets for itself goals in the digitalization of the field and the development of the sports industry in the creation of technological sovereignity in the production of sports equipment and inventory, perfection of medical support and much more. In this paper are shown the main directions of innovative technological development in the field of physical education and sports

Creation of the Ural Industrial-Sports Cluster in the Sverdlovsk Region

Одной из приоритетных задач развития физической культуры и спорта Российской Федерации является выполнение Указа Президента в части увеличения к 2030 году доли населения до 70 %, систематически занимающегося физической культурой и спортом. Создание и развитие необходимой спортивной инфраструктуры оказывает огромное влияние на этот показатель. Также развитие спортивной инфраструктуры является важнейшим общефедеральным вопросом, залогом будущего развития не только отрасли физической культуры и спорта, но и общества, и государства в целом. Создание индустриально-спортивных кластеров — новая веха в развитии сферы физической культуры и спорта. В статье представлен опыт Свердловской области в части создания Уральского индустриально-спортивного кластера.One of the prioritized missions in the development of physical education and sports in the Russian Federation is completing President Vladimir Putin’s task of increasing the percent of the population that participates in physical education and sports to 70 % until 2030. The creation and development of necessary systems greatly influences the number of people that participate. Also, the development of a sports infrastructure is one of the most vital federal tasks that is the foundation for future development of not just physical education and sports but of the population and of the government in general. The creation industrialsports clusters — is a new branch of development in the field of physical education and sports. In this paper are presented ways that the Sverdlovsk region helped develop a Ural Industrialsports cluster

Approximating multi-dimensional Hamiltonian flows by billiards

Consider a family of smooth potentials $V_{\epsilon}$, which, in the limit $\epsilon\to0$, become a singular hard-wall potential of a multi-dimensional billiard. We define auxiliary billiard domains that asymptote, as $\epsilon\to0$ to the original billiard, and provide asymptotic expansion of the smooth Hamiltonian solution in terms of these billiard approximations. The asymptotic expansion includes error estimates in the $C^{r}$ norm and an iteration scheme for improving this approximation. Applying this theory to smooth potentials which limit to the multi-dimensional close to ellipsoidal billiards, we predict when the separatrix splitting persists for various types of potentials