Study of single antigen-antibody interactions on the silicon surface in biosensors based on field-effect transistors with a nanowire channel
Study of single antigen-antibody interactions on the silicon surface in biosensors based on field-effect transistors with a nanowire channel
D. E. Presnov$^1$, G. V. Presnova$^2$, I. I. Tsiniaikin$^1$, G. V. Nibudin$^1$, O. V. Snigirev$^1$, A. S. Trifonov$^1$, M. M. Ulyashova$^2$, V. A. Krupenin$^1$, M. Yu. Rubtsova$^2$
Here we report a study of single interactions of antibodies with prostate-specific antigen (PSA) on the surface of pure silicon modified with 5 nm gold nanoparticles to create highly sensitive biosensors based on field-effect transistors with a silicon nanowire channel (FET). The method of digital registration of immune complexes by the scanning electron microscopy technique with gold nanoparticles 25 nm in diameter as a visualizing label of antibodies was used. A special algorithm was developed to calculate the density of nanoparticles on the silicon surface. To study the covalent immobilization of antibodies, different methods of chemical modification of silicon using (3-glycidoxypropyltrimethoxysilane (GOPS), 3-mercaptopropyltrimethoxysilane (GOPS-SH), and 3-aminopropyltriethoxysilane (APTES), bifunctional reagents and polyethyleneglycol were used. It was shown that chemical modification methods using GOPS are characterized by a lower detection limit of PSA, a biomarker of prostate tumors. The structures of biosensors based on field-effect transistors with nanowires channels, with surfaces, modified by two different methods using GOPS, were fabricated, and their sensitivity to pH was studied. It was shown that the modification method using GOPS-SH is characterized by a maximum pH sensitivity of 70 mV/pH and is the most promising for the creation of highly sensitive biosensors for determination of biomarkers.
Show AbstractSearching for bosonic dark matter with the iDREAM neutrino detector at Kalinin Nuclear Power Plant
Searching for bosonic dark matter with the iDREAM neutrino detector at Kalinin Nuclear Power Plant
A. V. Abramov$^1$, R. R. Alyev$^2$, M. B. Gromov$^{3,4}$, I. N. Zhutikov$^{1,5}$, K. K. Kiselev$^5$, S. M. Kiselev$^2$, A. V. Konstantinov$^1$, D. S. Kuznetsov$^1$, E. A. Litvinovich$^{1,5}$, I. N. Machulin$^{1,5}$, A. E. Murchenko$^1$, A. M. Nemeryuk$^1$, R. R. Nugmanov$^1$, A. Yu. Oralbaev$^{1,5}$, D. V. Popov$^{1,5}$, A. A. Rastimeshin$^{1,5}$, M. A. Strizh$^1$, V. A. Khvatov$^2$, A. S. Chepurnov$^3$, D. A. Chmykhalo$^{1,5}$, A. V. Etenko$^{1,5}$
Bosonic dark matter search results obtained with the iDREAM neutrino detector at Kalinin Nuclear Power Plant are presented. Using data on composition of the active core of VVER-1000 nuclear reactor and fission fractions of primary fissile isotopes, the γ-radiation energy spectrum in the active core is calculated. Assuming that the dark bosons can be produced in the active core via γ-scattering on electrons and can be detected via an inverse process inside the iDREAM detector, experimental bounds on the coupling constant gX between the dark boson and Standard Model charged leptons are derived.
Show AbstractMeasurement of the VVER-1000 reactor power output by its antineutrino fluх from the core
Measurement of the VVER-1000 reactor power output by its antineutrino fluх from the core
A. V. Abramov$^3$, R. R. Alyev$^2$, M. B. Gromov$^{1,4}$, I. N. Zhutikov$^{3,5}$, S. M. Kiselev$^2$, A. V. Konstantinov$^3$, D. S. Kuznetsov$^3$, E. A. Litvinovich$^{3,5}$, I. N. Machulin$^{3,5}$, A. M. Nemeryuk$^3$, R. R. Nugmanov$^3$, A. Yu. Oralbaev$^{3,5}$, D. V. Popov$^{3,5}$, A. A. Rastimeshin$^{3,5}$, M. D. Skorokhvatov$^3$, M. A. Strizh$^{1,3}$, S. V. Sukhotin$^3$, A. A. Hvatov, A. S. Chepurnov$^1$, D. A. Chmykhalo$^{3,5}$, A. V. Etenko$^{3,5}$
In this paper we present the results of the measurements of the industrial nuclear reactor power output by its antineutrino flux from the core. The measurements were carried out with the iDREAM detector at a distance of 19.5 m from the center of the core of the VVER-1000 reactor at the Kalinin NPP (Russia). Estimates of the sensitivity of the iDREAM detector to changes in reactor power were obtained for 2-, 4-, and 6-hour intervals of collecting data on antineutrino interactions.
Show AbstractReproduction of hydrothermodynamic characteristics of the Russian Western Arctic Seas with assimilation of sea surface temperature and sea ice concentration data
Reproduction of hydrothermodynamic characteristics of the Russian Western Arctic Seas with assimilation of sea surface temperature and sea ice concentration data
I. I. Panasenkova$^{1,2}$, V. V. Fomin$^{1,2,3}$, N. A. Diansky$^{1,3,4}$
Accurate forecasting of meteorological, hydrothermodynamic and ice characteristics in the Russian Western Arctic Seas using atmospheric circulation, marine circulation and sea ice models is currently impossible without assimilation of observational data. It improves the quality of the initial model state including hydrophysical and ice characteristics for carrying out forecasts. In this paper we present a technique for assimilation of sea surface temperature (SST) and sea ice concentration (SIC) satellite data in the INMOM marine circulation model using the DART (Data Assimilation Research Testbed) software with an assessment of the correctness of the assimilation algorithm used. A comparative analysis of the forecasts’ accuracy of the hydrothermodynamics reproduction with the assimilation of SST and SIC satellite data and without assimilation is carried out. It is shown that satellite data assimilation reduces the RMSE of the forecasts and observational data by ~80% for SST and by 60–80% for SIC compared to the simulation without assimilation. Temporal variability of the RMSE in the SST and SIC forecasts shows that their largest errors are observed during the periods of intense heating of the upper sea layer and ice melting. The importance of joint SST and SIC data assimilation is noted: a more accurate reproduction of SST improves the accuracy of calculations of heat and salt fluxes at the ocean-ice boundary, which regulate the processes of thermal accretion/melting of ice, and, as a result, the reproduction of the ice area and its edge is improved. In turn, a more correct SIC calculation directly improves the accuracy of heat flux calculations at the water-air boundary and, thereby, SST improves.
Show AbstractSimple finite-dimensional model of the metastable state
Simple finite-dimensional model of the metastable state
A. I. Dubikovsky, P. K. Silaev
We have constructed an approximate analytical solution of the spectral problem for a finite-dimensional matrix of a special kind, which turns out to be a very simple and quite satisfactory model of the metastable state. Most of the characteristic properties of the metastable state are reproduced: line shape, decay dynamics, and density of states. The correctness of the approximate analytical solution was verified by direct numerical calculations. The proposed model is a finite-dimensional analog of the Fano formalism.
Show AbstractElectromagnetic form factors of the deuteron in the dibaryon model of NN interaction
Electromagnetic form factors of the deuteron in the dibaryon model of NN interaction
M. N. Platonova, I. T. Obukhovsky
The electromagnetic form factors of the deuteron have been calculated within the dibaryon model for nuclear forces, which is based on the resonance mechanism of formation of a six-quark bag (dibaryon) in a NN collision. The calculations take into account both the single-nucleon currents (impulse approximation) and additional contributions induced by the formation of an intermediate dibaryon. For the calculations of form factors, two versions of the dibaryon model, of 2002 and 2022, have been used. It is shown that both versions of the model reproduce experimental data well for all three deuteron form factors in the region of transferred momenta Q < 0.8 GeV/c. At higher values of Q, the predictions of different versions of the model deviate from each other, with one of them (2002) better describing the magnetic form factor, and the other (2022) - the charge one. Possible reasons for the discrepancy found between the theoretical calculations and experimental data for large momentum transfers are discussed.
Show AbstractNumerical models of nonlinear acoustic waves propagation in problems of medical ultrasound and in some applications of aero- and underwater acoustics
Numerical models of nonlinear acoustic waves propagation in problems of medical ultrasound and in some applications of aero- and underwater acoustics
P. V. Yuldashev$^1$, O. A. Sapozhnikov$^3$, M. M. Karzova$^1$, S. A. Tsysar$^2$, A. V. Kvashennikova$^3$, E. O. Konnova$^1$, V. A. Khokhlova$^3$
The paper considers numerical algorithms used to solve one-way wave propagation equations of nonlinear acoustics, such as the Burgers equation, the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, and the Westervelt equation. The main results obtained using the developed numerical models in problems of medical ultrasound, in nonlinear aeroacoustics, and in the analysis of nonlinear interactions of intense pump waves in a parametric antenna created in the field of an underwater transducer are presented. The generalization of one-way models to the case of the presence of inhomogeneities of the propagation medium using wide-angle parabolic approximation methods in three-dimensional problems is discussed.
Show AbstractReservoir network based on single impurity atoms in silicon
Reservoir network based on single impurity atoms in silicon
A. S. Andreeva, A. S. Trifonov, V. V. Shorokhov, D. E. Presnov, O. V. Snigirev, V. A. Krupenin
This work is aimed at solving the problem of experimental implementation and study of single-electron reservoir networks with As impurity atoms in a quasi-two-dimensional near-surface layer of a solid-state matrix based on silicon-on-insulator (SOI) material. The study of electron transport in the fabricated experimental structures showed the presence of horizontal sections of the Coulomb blockade on the current-voltage characteristics (CVC), typical of single-electron transport. The shape of the recorded CVC between a pair of selected control electrodes of the reservoir network significantly depended on the potentials of the remaining surrounding electrodes, which changed the structure of the conducting channels passing through the impurity centers. Restructuring the control voltages, using the internal nonlinearity of the system of disordered single As impurity atoms, which has a colossal state space, made it possible to demonstrate the possibility of implementing a tunable nanoscale current switch and the logical functions "NOT", "AND", "OR" in a single-electron reservoir network. To find the configuration of the reservoir network necessary for the implementation of functional elements, a vector tuning method was used.
Show AbstractAnalysis of cell death and proliferative activity of cell cultures under proton irradiation in flash mode
Analysis of cell death and proliferative activity of cell cultures under proton irradiation in flash mode
V. V. Martynova, S. V. Akulinichev, I. A. Yakovlev
The study of biological effects of accelerated protons with ultra-high dose rate in and outside the Bragg peak on tumor and normal cell lines is necessary for understanding the consequences of this effect and choosing optimal doses and modes for further use in tumor radiotherapy. In this work, human colon adenocarcinoma cells (HT-29) and normal mesenchymal stem cells (ADSC) of human adipose tissue - fibroblasts were irradiated. Irradiation was carried out using a high-current linear proton accelerator of the INR RAS, which allows varying the energy in the range of 70-230 MeV. The dose was delivered in three different modes: conventional mode (dose rate Ḋ < 3 Gy/s), flash mode (Ḋ ~ 100 Gy/s) and single-pulse flash mode (Ḋ > 104 Gy/s) in the modified Bragg peak region. To analyze cell death, staining with propidium iodide and annexin was performed. For proliferative potential, the EdU test was reproduced. After 24 h, an increase in the number of apoptotic HT-29 cells was detected in all modes, for fibroblasts, an increase in the number of necrotic cells was observed with the conventional irradiation mode and a higher dose compared to other modes. After 48 h, with all irradiation modes, a tendency towards a decrease in the number of necrotic HT-29 cells depending on the dose was observed with the flash/splash modes and a low level of such for fibroblasts. The number of DNA-synthesizing cells by 120 h significantly decreased with all doses and irradiation modes. The curves for the flash and splash irradiation modes were almost parallel. Further studies are needed using wider ranges of cell lines and doses.
Show AbstractTwo Supernovae in NGC 4666: ASASSN-14lp and 2019yvr
Two Supernovae in NGC 4666: ASASSN-14lp and 2019yvr
D. Yu. Tsvetkov$^1$, N. N. Pavlyuk$^1$, N. P. Ikonnikova$^1$, M. A. Burlak$^1$, A. A. Belinski$^1$, A. V. Dodin$^1$, S. A. Potanin$^1$, N. I. Shatsky$^1$, I. M. Volkov$^1$, P. V. Baklanov$^{1,2,3}$, M. G. Ushakova$^{1,2}$, V. A. Echeistov$^1$, V. M. Lipunov$^1$
We present the results of photometric observations for two Supernovae in NGC\,4666: SN Ia ASASSN-14lp and SN Ib 2019yvr, and also spectroscopic observations for SN\,2019yvr. The light curves are constructed and their main parameters are derived. Supernova ASASSN-14lp is a typical object of class Ia with low rate of brightness decline and large interstellar extinction. An estimate of disance to the galaxy NGC\,4666 is obtained using the dependence of maximum luminosity of SNe Ia on the parameters of the light curves. The spectra of SN\,2019yvr near maximum light, the maximum luminosity and the shape of the light curves during first 90 days after maximum revealed characteristics of typical SN Ib, with interstellar extinction larger than for ASASSN-14lp. The decrease of the rate of brightness decline at phase about 90 days is found. We performed modeling of the light curves with STELLA code, the physical parameters of the optimal model are presented. The agreement of the model with observations breaks after $\sim$40 days past maximum, the model with extra source of energy from magnetar rotation slowdown is proposed to account for this divergence.
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