Dynamic features of autodyne signals

On the example of classical single-circuit oscillator influenced by reflected signal, a solution of system of differential autodyne equations is obtained by the high-order quasi-static approximation method for the general case of arbitrary delay time of the reflected signal, fast motion of a point-sized reflecting object, and inertia of the oscillator itself. The special features of forming the autodyne response are considered with allowance for the oscillator inertia and its internal parameters, including anisochronous and non-isodromic properties, and dependences of the signal waveform, constant component, and nonlinear distortion coefficient on the distance and the direction of object motion are established. © 2013 Springer Science+Business Media New York

Model of ionic currents through microtubule nanopores and the lumen

It has been suggested that microtubules and other cytoskeletal filaments may act as electrical transmission lines. An electrical circuit model of the microtubule is constructed incorporating features of its cylindrical structure with nanopores in its walls. This model is used to study how ionic conductance along the lumen is affected by flux through the nanopores when an external potential is applied across its two ends. Based on the results of Brownian dynamics simulations, the nanopores were found to have asymmetric inner and outer conductances, manifested as nonlinear IV curves. Our simulations indicate that a combination of this asymmetry and an internal voltage source arising from the motion of the C-terminal tails causes a net current to be pumped across the microtubule wall and propagate down the microtubule through the lumen. This effect is demonstrated to enhance and add directly to the longitudinal current through the lumen resulting from an external voltage source, and could be significant in amplifying low-intensity endogenous currents within the cellular environment or as a nano-bioelectronic device.Comment: 43 pages, 6 figures, revised versio

Coherent x-ray radiation generated near the axis of the beam of relativistic electrons in an artificial periodic structure

A theory of the coherent X-ray radiation produced by a beam of relativistic electrons in an artificial periodic structure and propagating along the electron-beam axis is developed. Expressions describing the spectral-angular densities of parametric X-ray radiation in the direction close to the electron velocity vector (FPXR) and of transition radiation (TR) and their interference are obtained in the Bragg scattering geometry. An analysis based on the obtained expressions for the spectral-angular density shows possibilities of their use to determine the optimal parameters of the experiment recording the FPX

NEW APPROACHES TO THERAPY OF CLASSICAL PH-NEGATIVE MYELOPROLIFERATIVE DISEASES: THE EXPERIENCE OF EARLY THERAPY WITH CEPEGINTERFERON ALPHA-2B

Background. Even 100 years after the first attempts to introduce the chemotherapeutic approaches (in 1918) and despite the completely formed notions of myeloproliferative diseases as a group of malignant neoplasms, in the majority of patients with Ph-negative myeloproliferative neoplasms (MPN), a symptomatic, in fact, therapy approach – the impact on peripheral blood indices and nonspecific thromboprophylaxis – is allowed. The limitations of classical cytoreduction and current targeted therapy, as well as the conviction of most specialists in the impossibility of adequately containment of disease progression, continue to be the main factors that keep physicians from the early start of pathogenetic therapy.Objective: to study the efficacy and safety of cepeginterferon alpha-2b (cePEG-IFN alpha-2b) in early (non-risk-adjusted) therapy of classical Ph-negative myeloproliferative neoplasms in initial use and after therapy with other pegylated interferons (PEG-IFN).Materials and methods. Twenty seven patients with polycythemia vera or essential thrombocythemia, without considering risk, received cePEG-IFN alpha-2b: initially, or after 6 or 12 months of other pegylated interferon therapy, in a dosage of 200 μg per week, with a decrease to 100 μg per week if 2 degree hematological toxicity developed. Hematological and molecular responses were assessed. Follow-up – from 20 to 46 months.Results. In all groups, a hematologic response comparable in depth and dynamics, as well as a molecular response as a steady decrease in the JAK2V617F allelic load, was achieved. There was no effect on the results of change to therapy with cePEG-IFN alpha-2b. CePEGIFN alpha-2b showed less dose-limiting toxicity for neutropenia and better pharmacoeconomic feasibility.Discussion. New data about mechanisms of antiproliferative effects of interferon alfa preparations are given. The pharmacological advantages of cePEG-IFN alpha-2b are discussed: superiority in pharmacokinetic parameters, the presence of one position isomer purity of the drug substance, the convenience of self-application. Conclusion. Early administration of an effective pathogenic therapy is an independent preventive measure to prevent the MPN progression and complications development. The use of cePEG-IFN alpha-2b may help to improve the care of MPN patients

Development of an Information Modeling System of Coal-Dust Fuel Injection into Tuyeres of a Blast Furnace

Abstract: The article considers a mathematical model of the combustion zone of a blast furnace working with the use of the injection of coal-dust fuel. In this model, two subsystems were identified: (1) subsystem of heating the particles of coal dust and volatiles released in the combustion zone; (2) subsystem of heat exchange and combustion processes in the tuyere. A two-dimensional velocity field of gas in the combustion zone was investigated. The combustion processes are considered as a set of simultaneously developing phenomena of coke burning in a layer, single pieces of coke and particles of coal dust. The model includes the following equations: total gas mass balance, gas component mass balance, gas heat balance, movement of coal dust particles, and heat balance of coal dust particles. The model calculates maximum burning temperature in the combustion zone, the distance from the cut of the tuyere to the focus of combustion, the length of the oxygen combustion zone, gas temperature, the content of gas phase components, and the degree of carbon burnout of pulverized coal at the outlet of the tuyere combustion zone. An information-modeling system has been developed. It allows for the investigation of the influence of combined blast characteristics, the properties of coke and coal-dust fuel, the geometric dimensions of tuyeres, and other factors on the temperature fields and concentrations of components of the gas phase in the combustion zone. The model also helps to select a rational mode of pulverized coal that will ensure completeness of its combustion in the tuyere combustion zone. The main functions of the program are as follows: representation of results of calculation in form of tables and diagrams, storage of options of basic data in a database, and export of results of calculation to Microsoft Excel. Conclusions were made on the reduction of the combustion temperature in the combustion zone and the approach of the focus of combustion to the tuyere when pulverized coal was injected. The authors also have established the need to use coals with certain quality characteristics and place where coal dust was introduced into the blast stream. © 2019, Allerton Press, Inc