Nonlinear pulse shaping in optical fibres with a neural network

We use a machine-learning based paradigm to solve the direct and inverse problems relating to the shaping of optical pulses that occurs upon nonlinear propagation in optical fibres with a neural network

Quantum kinetic approach to the calculation of the Nernst effect

We show that the strong Nernst effect observed recently in amorphous superconducting films far above the critical temperature is caused by the fluctuations of the superconducting order parameter. We employ the quantum kinetic approach for the derivation of the Nernst coefficient. We present here the main steps of the calculation and discuss some subtle issues that we encountered while calculating the Nernst coefficient. In particular, we demonstrate that in the limit T=0 the contribution of the magnetization ensures the vanishing of the Nernst signal in accordance with the third law of thermodynamics. We obtained a striking agreement between our theoretical calculations and the experimental data in a broad region of temperatures and magnetic fields.Comment: 24 pages, 13 figure

Überinfusion von Verbrennungsopfern: häufig und schädlich

Zusammenfassung: Hintergrund: Schwerbrandverletzte (mehr als 20% verbrannter Körperoberfläche bei Erwachsenen) weisen in der ersten Phase (8-48h) einen durch das massive Kapillarleck bedingten Verbrennungsschock auf, der einer Infusionstherapie bedarf, um die Hämodynamik wieder herzustellen. Bis in die 80erJahre stellte eine unzureichende Flüssigkeitstherapie (Unterinfusion) die Haupttodesursache von Verbrennungspatienten dar. Seither ist die übermäßige Flüssigkeitstherapie (Überinfusion) zu einer beachtenswerten Quelle von Komplikationen geworden: abdominales Kompartmentsyndrom, Entlastungsschnitte (Escharotomie), Verschlechterung des Gasaustauschs, Verlängerung der künstlichen Beatmung und des Spitalaufenthalts. Die Überinfusion hat Ende der 90erJahre begonnen, wo innerhalb der ersten 24h Flüssigkeitsmengen zugeführt wurden, die weit über den 4ml/kg/%BSA ("burn surface area") der Parkland-Formel lagen. Ziel: Dieser Beitrag analysiert die Faktoren, welche zu einer Überinfusion führen können und zeigt Möglichkeiten, dem durch eine strikte Kontrolle der präklinischen Infusionstherapie sowie durch eine permissive Hypovolämie vorzubeuge

Nernst-Ettingshausen effect in two-component electronic liquids

A simple model describing the Nernst-Ettingshausen effect (NEE) in two-component electronic liquids is formulated. The examples considered include graphite, where the normal and Dirac fermions coexist, superconductor in fluctuating regime, with coexisting Cooper pairs and normal electrons, and the inter-stellar plasma of electrons and protons. We give a general expression for the Nernst constant and show that the origin of a giant NEE is in the strong dependence of the chemical potential on temperature in all cases

Nernst effect as a probe of superconducting fluctuations in disordered thin films

In amorphous superconducting thin films of $Nb_{0.15}Si_{0.85}$ and $InO_x$, a finite Nernst coefficient can be detected in a wide range of temperature and magnetic field. Due to the negligible contribution of normal quasi-particles, superconducting fluctuations easily dominate the Nernst response in the entire range of study. In the vicinity of the critical temperature and in the zero-field limit, the magnitude of the signal is in quantitative agreement with what is theoretically expected for the Gaussian fluctuations of the superconducting order parameter. Even at higher temperatures and finite magnetic field, the Nernst coefficient is set by the size of superconducting fluctuations. The Nernst coefficient emerges as a direct probe of the ghost critical field, the normal-state mirror of the upper critical field. Moreover, upon leaving the normal state with fluctuating Cooper pairs, we show that the temperature evolution of the Nernst coefficient is different whether the system enters a vortex solid, a vortex liquid or a phase-fluctuating superconducting regime.Comment: Submitted to New. J. Phys. for a focus issue on "Superconductors with Exotic Symmetries

Fluctuations of the superconducting order parameter as an origin of the Nernst effect

We show that the strong Nernst signal observed recently in amorphous superconducting films far above the critical temperature is caused by the fluctuations of the superconducting order parameter. We demonstrate a striking agreement between our theoretical calculations and the experimental data at various temperatures and magnetic fields. Besides, the Nernst effect is interesting not only in the context of superconductivity. We discuss some subtle issues in the theoretical study of thermal phenomena that we have encountered while calculating the Nernst coefficient. In particular, we explain how the Nernst theorem (the third law of thermodynamics) imposes a strict constraint on the magnitude of the Nernst effect.Comment: 6 pages, 5 figures, extended versio

End-to-end Interpretable Learning of Non-blind Image Deblurring

Non-blind image deblurring is typically formulated as a linear least-squares problem regularized by natural priors on the corresponding sharp picture's gradients, which can be solved, for example, using a half-quadratic splitting method with Richardson fixed-point iterations for its least-squares updates and a proximal operator for the auxiliary variable updates. We propose to precondition the Richardson solver using approximate inverse filters of the (known) blur and natural image prior kernels. Using convolutions instead of a generic linear preconditioner allows extremely efficient parameter sharing across the image, and leads to significant gains in accuracy and/or speed compared to classical FFT and conjugate-gradient methods. More importantly, the proposed architecture is easily adapted to learning both the preconditioner and the proximal operator using CNN embeddings. This yields a simple and efficient algorithm for non-blind image deblurring which is fully interpretable, can be learned end to end, and whose accuracy matches or exceeds the state of the art, quite significantly, in the non-uniform case.Comment: Accepted at ECCV2020 (poster

NAF-1 and mitoNEET are central to human breast cancer proliferation by maintaining mitochondrial homeostasis and promoting tumor growth

Mitochondria are emerging as important players in the transformation process of cells, maintaining the biosynthetic and energetic capacities of cancer cells and serving as one of the primary sites of apoptosis and autophagy regulation. Although several avenues of cancer therapy have focused on mitochondria, progress in developing mitochondria-targeting anticancer drugs nonetheless has been slow, owing to the limited number of known mitochondrial target proteins that link metabolism with autophagy or cell death. Recent studies have demonstrated that two members of the newly discovered family of NEET proteins, NAF-1 (CISD2) and mitoNEET (mNT; CISD1), could play such a role in cancer cells. NAF-1 was shown to be a key player in regulating autophagy, and mNT was proposed to mediate iron and reactive oxygen homeostasis in mitochondria. Here we show that the protein levels of NAF-1 and mNT are elevated in human epithelial breast cancer cells, and that suppressing the level of these proteins using shRNA results in significantly reduced cell proliferation and tumor growth, decreased mitochondrial performance, uncontrolled accumulation of iron and reactive oxygen in mitochondria, and activation of autophagy. Our findings highlight NEET proteins as promising mitochondrial targets for cancer therapy

Исследование остаточных углеводородов в ходе деструкции гептана углеводородокисляющими микроорганизмами рода Pseudomonas и Rodococcus

Molding of micro structures by injection molding leads to special requirements for the molds e.g. regarding wear resistance and low release forces of the molded components. At the same time it is not allowed to affect the replication precision. Physical vapor deposition (PVD) is one of the promising technologies for applying coatings with adapted properties like high hardness, low roughness, low Young's modulus and less adhesion to the melt of polymers. Physical vapor deposition technology allows the deposition of thin films on micro structures. Therefore, the influence of these PVD layers on the contour accuracy of the replicated micro structures has to be investigated. For this purpose injection mold inserts were laser structured with micro structures of different sizes and afterwards coated with two different coatings, which were deposited by a magnetron sputter ion plating PVD technology. After deposition, the coatings were analyzed by techniques regarding hardness, Young's modulus and morphology. The geometries of the micro structures were analyzed by scanning electron microscopy before and after coating. Afterwards, the coated mold inserts were used for injection molding experiments. During the injection molding process, a conventional and a variothermal temperature control of the molds were used. The molded parts were analyzed regarding roughness, structure height and structure width by means of laser microscopy