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Treating Coulomb scattering of two free electrons in a stationary approach, we explore the momentum and spin entanglement created by the interaction. We show that a particular discretisation provides an estimate of the von Neumann entropy of the one-electron reduced density matrix from the experimentally accessible Shannon entropy. For spinless distinguishable electrons the entropy is sizeable at low energies, indicating strong momentum entanglement, and drops to almost zero at energies of the order of 10 keV when the azimuthal degree of freedom is integrated out, i.e. practically no entanglement and almost pure one-electron states. If spin is taken into account, the entropy for electrons with antiparallel spins should be larger than in the parallel-spin case, since it embodies both momentum and spin entanglement. Surprisingly, this difference, as well as the deviation from the spin-less case, is extremely small for the complete scattering state. Strong spin entanglement can however be obtained by post-selecting states at scattering angle π /2. [ABSTRACT FROM AUTHOR]

The transition from (inter)metallic to substoichiometric regime and therewith associated microstructural modifications within arc evaporated Al-Cr-based oxide coatings was investigated. The dense columnar intermetallic structure is subject to grain refinement when increasing the O 2 flow rate during the deposition. Cr-rich, O-depleted crystalline domains (initially short columnar, then equiaxed globular) and an amorphous Al- and O-enriched boundary phase develops—with increasing volume fraction for higher O 2 flow rates. Such nanocomposites, originating from preferred oxide phase formation of Aluminium, can effectively be adjusted by the amount of oxygen and the nominal cathode composition used during synthesis. [ABSTRACT FROM AUTHOR]

Abstract: Controlled cryopreservation is an important method for storage of tissue grafts in skin banking, reproductive medicine and other domains. Although the availability of cryopreserved flexor tendons would be highly beneficial in reconstructive surgery, especially in complex reconstructions for which grafting material is limited, only a few studies have dealt with transplanted tendons. We achieved successful cryopreservation of porcine flexor tendons in 2 cryoprotective media: dimethyl sulfoxide and glycerol. Their viability was shown using a quantitative colorimetric MTT (3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide) assay. For comparison of native and cryopreserved tendons (n = 7 samples each), the adopted viability index was the ratio of MTT-dependent optical density and tendon weight. The viability index of native samples did not change significantly after cryopreservation and thawing. The proliferative capacity of tendon fibroblasts after thawing was shown in primary cell cultures. The described cryopreservation protocol and MTT assay may provide a basis for future autografting of human tendons. [Copyright &y& Elsevier]