Search results for "cART"
showing 10 items of 2010 documents
Il tempo ritrovato di Masha e Orso
2015
L'articolo si colloca all'interno del lavoro di analisi dei cartoni animati rivolti alla prima infanzia nella loro dimensione intermediale.
Construction and evaluation of sponge scaffolds from hyaluronic acid derivatives for potential cartilage regeneration
2020
A two or one pot synthesis has been used for the reaction of hyaluronic acid (HA) with octadecylamine (C-18) and hydrazine (Hy). In both cases, the chemical derivatization involved primary hydroxyl groups of hyaluronic acid and not its carboxyl groups, whose presence is important for receptor interaction. In this way, Hy-HA-C-18 derivatives have been obtained with appropriate hydrophobic and hydrophilic character. Their ability to form homogeneous physical hydrogels has been evaluated as well as the possibility to obtain porous sponges through salt leaching technology. Sponges showing the highest porosity, potentially compatible with cell entrapment, have been characterized with regard to t…
High resolution X-ray tomography – three-dimensional characterisation of cell–scaffold constructs for cartilage tissue engineering
2014
AbstractSynchrotron radiation based microcomputed tomography (SR-μCT) has become a valuable tool for the structural analysis of different types of biomaterials. This methodology allows the non-destructive investigation of specimens in their three-dimensional context. In the present paper, articular cartilage is taken as an exemplary tissue to demonstrate the suitability of the SR-μCT method for the investigation of biomaterials for different tissue engineering approaches. Thus, a biodegradable scaffold for cartilage tissue engineering in different modifications was analysed. Using enhanced phase contrast imaging, it was possible to demonstrate single cells without further metal staining. Th…
Der HEPFIEx-Simulator, eine Apparatur zur Bestimmung der Reibzahlen zwischen Hüftkopf-Prothesen und Knorpel / The HEPFlEx Simulator, a Device for Mea…
2002
We describe a device designed to investigate friction between various femoral head prostheses and human acetabula. It enables not only the determination of friction and the relevance of the play between the femoral head and acetabulum, but also the evaluation of the kinematic behaviour of bipolar prostheses. In the simulator, the various femoral head prostheses are placed on a special cone and tested against a human cadaveric acetabulum. The swiveling range of the device is uniaxial, and the swiveling angle is +/- 35 degrees. The maximum force produced pneumatically is 5kN. Testing of the simulator with a TEP was successful and friction-coefficients of < 0.1 were measured, as are reported i…
Experimental Characterization of the Human Meniscal Tissue
2018
The meniscus plays a critical role in load transmission, stability and energy dissipation in the knee joint. Loss of the meniscus leads to joint degeneration and osteoarthritis. In a number of cases replacement of the resected meniscal tissue by a synthetic implant might avoid the articular cartilage degeneration. None of the available implants presents optimal biomechanics characteristic due to the fact the biomechanics functionality of the meniscus is not yet fully understood. Mimicking the native biomechanical characteristics of the menisci seems to be the key factor in meniscus replacement functioning. This is extremely challenging due to its complex inhomogeneous microstructure, the la…
Historical Events in the Background of Hilbert’s Seventh Paris Problem
2015
David Hilbert’s lecture, “Mathematical Problems,” [Hilbert 1900] delivered in Paris in 1900 at the Second International Congress of Mathematicians, has long been recognized as marking a milestone in the history of mathematics. Certainly for Hilbert himself, this marked the single greatest event and a true turning point in his storied career. When historians and mathematicians have written about the so-called Hilbert problems, they have usually looked forward into the twentieth century, sometimes by viewing their resolution as markers for mathematical progress.
Sub-Finsler Geodesics on the Cartan Group
2018
This paper is a continuation of the work by the same authors on the Cartan group equipped with the sub-Finsler $\ell_\infty$ norm. We start by giving a detailed presentation of the structure of bang-bang extremal trajectories. Then we prove upper bounds on the number of switchings on bang-bang minimizers. We prove that any normal extremal is either bang-bang, or singular, or mixed. Consequently, we study mixed extremals. In particular, we prove that every two points can be connected by a piecewise smooth minimizer, and we give a uniform bound on the number of such pieces.
Homogeneous Weyl connections of non-positive curvature
2015
We study homogenous Weyl connections with non-positive sectional curvatures. The Cartesian product $\mathbb S^1 \times M$ carries canonical families of Weyl connections with such a property, for any Riemmanian manifold $M$. We prove that if a homogenous Weyl connection on a manifold, modeled on a unimodular Lie group, is non-positive in a stronger sense (streched non-positive), then it must be locally of the product type.
Tensor tomography on Cartan–Hadamard manifolds
2017
We study the geodesic X-ray transform on Cartan-Hadamard manifolds, and prove solenoidal injectivity of this transform acting on functions and tensor fields of any order. The functions are assumed to be exponentially decaying if the sectional curvature is bounded, and polynomially decaying if the sectional curvature decays at infinity. This work extends the results of Lehtonen (2016) to dimensions $n \geq 3$ and to the case of tensor fields of any order.
Translating Solitons Over Cartan-Hadamard Manifolds
2020
We prove existence results for entire graphical translators of the mean curvature flow (the so-called bowl solitons) on Cartan-Hadamard manifolds. We show that the asymptotic behaviour of entire solitons depends heavily on the curvature of the manifold, and that there exist also bounded solutions if the curvature goes to minus infinity fast enough. Moreover, it is even possible to solve the asymptotic Dirichlet problem under certain conditions.