Taming the zoo of supersymmetric quantum mechanical models

We show that in many cases nontrivial and complicated supersymmetric quantum mechanical (SQM) models can be obtained from the simple model describing free dynamics in flat complex space by two operations: (i) Hamiltonian reduction and (ii) similarity transformation of the complex supercharges. We conjecture that it is true for any SQM model.Comment: final version published in JHE

Generalized N = 2 Super Landau Models

We generalize previous results for the superplane Landau model to exhibit an explicit worldline N = 2 supersymmetry for an arbitrary magnetic field on any two-dimensional manifold. Starting from an off-shell N = 2 superfield formalism, we discuss the quantization procedure in the general case characterized by two independent potentials on the manifold and show that the relevant Hamiltonians are factorizable. In the restricted case when both the Gauss curvature and the magnetic field are constant over the manifold and, as a consequence, the underlying potentials are related, the Hamiltonians admit infinite series of factorization chains implying the integrability of the associated systems. We explicitly determine the spectrum and eigenvectors for the particular model with CP^1 as the bosonic manifold.Comment: 26 page

Shear-induced chemical segregation in a Fe-based bulk metallic glass at room temperature.

Shear-induced segregation, by particle size, is known in the flow of colloids and granular media, but is unexpected at the atomic level in the deformation of solid materials, especially at room temperature. In nanoscale wear tests of an Fe-based bulk metallic glass at room temperature, without significant surface heating, we find that intense shear localization under a scanned indenter tip can induce strong segregation of a dilute large-atom solute (Y) to planar regions that then crystallize as a Y-rich solid solution. There is stiffening of the material, and the underlying chemical and structural effects are characterized by transmission electron microscopy. The key influence of the soft Fe-Y interatomic interaction is investigated by ab-initio calculation. The driving force for the induced segregation, and its mechanisms, are considered by comparison with effects in other sheared media

Large microwave generation from d.c. driven magnetic vortex oscillators in magnetic tunnel junctions

Spin polarized current can excite the magnetization of a ferromagnet through the transfer of spin angular momentum to the local spin system. This pure spin-related transport phenomena leads to alluring possibilities for the achievement of a nanometer scale, CMOS compatible and tunable microwave generator operating at low bias for future wireless communications. Microwave emission generated by the persitent motion of magnetic vortices induced by spin transfer effect seems to be a unique manner to reach appropriate spectral linewidth. However, in metallic systems, where such vortex oscillations have been observed, the resulting microwave power is much too small. Here we present experimental evidences of spin-transfer induced core vortex precessions in MgO-based magnetic tunnel junctions with similar good spectral quality but an emitted power at least one order of magnitude stronger. More importantly, unlike to others spin transfer excitations, the thorough comparison between experimental results and models provide a clear textbook illustration of the mechanisms of vortex precessions induced by spin transfer

On form factors in N=4 sym

In this paper we study the form factors for the half-BPS operators $\mathcal{O}^{(n)}_I$ and the $\mathcal{N}=4$ stress tensor supermultiplet current $W^{AB}$ up to the second order of perturbation theory and for the Konishi operator $\mathcal{K}$ at first order of perturbation theory in $\mathcal{N}=4$ SYM theory at weak coupling. For all the objects we observe the exponentiation of the IR divergences with two anomalous dimensions: the cusp anomalous dimension and the collinear anomalous dimension. For the IR finite parts we obtain a similar situation as for the gluon scattering amplitudes, namely, apart from the case of $W^{AB}$ and $\mathcal{K}$ the finite part has some remainder function which we calculate up to the second order. It involves the generalized Goncharov polylogarithms of several variables. All the answers are expressed through the integrals related to the dual conformal invariant ones which might be a signal of integrable structure standing behind the form factors.Comment: 35 pages, 7 figures, LATEX2

Manufacturing of CD19 Specific CAR T-Cells and Evaluation of their Functional Activity in Vitro

Background. The most promising variant of adoptive immunotherapy of the B-line oncohematological diseases includes the use of cells with the chimeric antigen receptor (CAR T-cells), that showed extraordinary results in clinical studies. Aim. To manufacture CAR T-cells for the clinical use and to study their cytotoxicity in vitro. Methods. Human T-lymphocytes were transduced by the lentiviral vector containing anti-CD19-CAR, RIAD, and GFP genes. The T-cell transduction efficacy was assessed on the basis of GFP protein signal by flow cytometry. Propidium iodide was used to analyse the cell viability. Cytotoxic activity of the manufactured CAR T-cells was studied in the presence of the target cells being directly co-cultivated. Analysis of the number and viability of CAR T-cells and cytokine expression was performed by flow cytometry. Results. The viability of the transduced T-cells and GFP expression reached 91.87 % and 50.87 % respectively. When cultured in the presence of IL-2 and recombinant CD19 (the target antigen), the amount of CAR-T after 120 h of the process was 1.4 times larger compared with the period of 48 h. In the cytotoxic test of co-cultivation CAR-T with the K562-CD19+ cells the percentage of CAR-T increased to 57 % and 84.5 % after 48 h and 120 h of exposure respectively. When cultured with the K562 cells (test line not expressing CD19) the number of CAR T-cells decreased to 36.2 % within 48 h while the number of K562 cells increased to 58.3 %. The viability of target cells in the experimental and control groups was 3.5 % and 36.74 % respectively. Comparison of IL-6 level in the control and experimental groups revealed that the differences are insignificant, as opposed to the level of other cytokines (IFN-γ, IL-2, TNF) which proved to be different in both groups. Conclusion. The present work resulted in the production of anti-CD19 CAR T-cells with adequate viability. The in vitro model demonstrated their cytotoxicity. Manufacturing of CAR T-cells for clinical use is the first step of the development of adoptive immunotherapy in the Russian Federation

Spin torque resonant vortex core expulsion for an efficient radio-frequency detection scheme

Spin-polarised radio-frequency currents, whose frequency is equal to that of the gyrotropic mode, will cause an excitation of the core of a magnetic vortex confined in a magnetic tunnel junction. When the excitation radius of the vortex core is greater than that of the junction radius, vortex core expulsion is observed, leading to a large change in resistance, as the layer enters a predominantly uniform magnetisation state. Unlike the conventional spin-torque diode effect, this highly tunable resonant effect will generate a voltage which does not decrease as a function of rf power, and has the potential to form the basis of a new generation of tunable nanoscale radio-frequency detectors

Transmutation operators as a solvability concept of abstract singular equations

One of the methods of studying differential equations is the transmutation operators method. Detailed study of the theory of transmutation operators with applications may be found in the literature. Application of transmutation operators establishes many important results for different classes of differential equations including singular equations with Bessel operato

Algorithm for the classification of multi-modulating signals on the electrocardiogram

This article discusses the algorithm to measure electrocardiogram (ECG) and respiration simultaneously and to have the diagnostic potentiality for sleep apnoea from ECG recordings. The algorithm is composed by the combination with the three particular scale transform of a(j)(t), u(j)(t), o(j)(a(j)) and the statistical Fourier transform (SFT). Time and magnitude scale transforms of a(j)(t), u(j)(t) change the source into the periodic signal and τ(j) = o(j)(a(j)) confines its harmonics into a few instantaneous components at τ(j) being a common instant on two scales between t and τ(j). As a result, the multi-modulating source is decomposed by the SFT and is reconstructed into ECG, respiration and the other signals by inverse transform. The algorithm is expected to get the partial ventilation and the heart rate variability from scale transforms among a(j)(t), a(j+1)(t) and u(j+1)(t) joining with each modulation. The algorithm has a high potentiality of the clinical checkup for the diagnosis of sleep apnoea from ECG recordings