Lipid emulsions in parenteral nutrition: does one size fits all?

Dietary lipids significantly contribute to preserve the efficiency of human metabolism and restore it during disease. Therefore, in the absence of absolute contraindications, it would not appear reasonable to exclude lipid emulsions when prescribing parenteral nutrition (PN). The metabolic role of lipids has been elucidated, and is far more complex than a mere energy-dense source. Indeed, it is now clear that fatty acids impact differently on the inflammatory and immune responses, either promoting or blunting them. Omega-6 fatty acids are the substrate for the production of potent mediators of inflammation, whereas omega-3 fatty acids promote the synthesis of less active factors. Omega-9 fatty acids exert a more neutral impact on immune and inflammatory responses. These specific metabolic activities should therefore be considered when prescribing lipid emulsions in PN. Ideally, the metabolic profile of patients should guide the prescription of lipid emulsions in order to promote the inflammatory response or blunt it according to the clinical needs. This new approach would wholly exploit the metabolic activities of lipid emulsions by providing patients not only with an energy-dense source, but also by priming and/or modulating the immune and inflammatory responses in order to favour healing.Keywords: lipid emulsions; metabolism; parenteral nutrition; immune response; inflammatio

A new apparatus for deep patterning of beam sensitive targets by means of high-energy ion beam

The paper reports on a high precision equipment designed to modify over 3-dimensions (3D) by means of high-energy gold ions the local properties of thin and thick films. A target-moving system aimed at creating patterns across the volume is driven by an x-y writing protocol that allows one to modify beam sensitive samples over micrometer-size regions of whatever shape. The apparatus has a mechanical resolution of 15 nm. The issue of the local fluence measurement has been particularly addressed. The setup has been checked by means of different geometries patterned on beam sensitive sheets as well as on superconducting materials. In the last case the 3D modification consists of amorphous nanostructures. The nanostructures create zones with different dissipative properties with respect to the virgin regions. The main analysis method consists of magneto-optical imaging that provides local information on the electrodynamics of the modified zones. Features typical of non-linear current flow hint at which pattern geometry is more functional to applications in the framework of nanostructures across superconducting films.Comment: 7 page

Evidence of a new low field cross-over in the vortex critical velocity of type-II superconducting thin films

We measure current-voltage characteristics as function of magnetic field and temperature in Nb strips of different thickness and width. The instability voltage of the flux flow state related to the vortex critical velocity v* is studied and compared with the Larkin-Ovchinnikov theory. Beside the usual power-law dependence v* ~ B^-1/2, in the low field range a new cross-over field, Bcr1, is observed below which v* decreases by further lowering the external magnetic field B. We ascribe this unexpected cross-over to vortex channeling due to a fan-like penetration of the applied magnetic field as confirmed by magneto-optic imaging. The observation of Bcr1 becomes a direct evidence of a general feature in type-II superconducting films at low fields, that is a channel-like vortex motion induced by the inhomogeneous magnetic state caused by the relatively strong pinning

Control of bulk superconductivity in a BCS superconductor by surface charge doping via electrochemical gating

The electrochemical gating technique is a powerful tool to tune the surface conduction properties of various materials by means of pure charge doping, but its efficiency is thought to be hampered in materials with a good electronic screening. We show that, if applied to a metallic superconductor (NbN thin films), this approach allows observing reversible enhancements or suppressions of the bulk superconducting transition temperature, which vary with the thickness of the films. These results are interpreted in terms of proximity effect, and indicate that the effective screening length depends on the induced charge density, becoming much larger than that predicted by standard screening theory at very high electric fields

Synthesis and characterization of magnetic and antibacterial nanoparticles as filler in acrylic cements for bone cancer and comorbidities therapy

In this work an innovative formulation of bone cement for the treatment of bone tumor and its associated complications has been designed by preparing a new class of Fe3O4–Ag nanostructures, using gallic acid as a reducing agent. The obtained nanoparticles have been introduced in polymethyl methacrylate (PMMA)-based composite cement evaluating the insertion of different amounts and the use of different mixing methods. The morphology, the composition and the antibacterial effect of Fe3O4–Ag nanostructures have been investigated together with the morphology, the composition, the mechanical properties of the nanoparticles-containing composite cements as well as their antibacterial effect. The obtained results revealed a good antimicrobial effect of Fe3O4–Ag nanostructures, a significant influence of their amount and of the used mixing method on the particles dispersion and agglomeration in the PMMA matrix and, as a result, on the mechanical properties. In particular, a better dispersion of nanoparticles was obtained by using the mechanical mixing, reducing the tendency to agglomerate. The increase of nanoparticles amount induced a slight decrease of the mechanical properties; however, the introduction of 10% w/w of Fe3O4–Ag allowed to improve the composites ability to reduce the bacteria adhesion

nutritional cancer care slowly evolving clinical practice reveals regional and professional hcp variability

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Universal temperature scaling of flux line pinning in high-temperature superconducting thin films

Dissipation-free current transport in high-temperature superconductors is one of the most crucial properties of this class of materials which is directly related to the effective inhibition of flux line movement by defect structures. In this respect epitaxially grown thin films of YBa2Cu3O7-d (YBCO) are proving to be the strongest candidates for many widescale applications that are close to realization. We show that the relation between different defect structures and flux line pinning in these films exhibits universal features which are clearly displayed in a detailed analysis of the temperature-dependent behaviour of local critical currents. This allows us to identify different pinning mechanisms at different temperatures to be responsible for the found critical currents. Additionally, the presence of grain boundaries with very low misorientation angles affects the temperature stability of the critical currents which has important consequences for future applications.Comment: 5 pages, 4 figures To be published in Journal of Physics: Condensed matte

Effect of 14.1 MeV fusion neutron irradiation on YBCO thin films and commercial REBCO tapes

The design of new tokamak machines relying on the use of high temperature superconductors (HTS) is promoting the study of HTS properties at the operating conditions required by fusion applications. In particular, the interest in the damage induced by neutron irradiation on RE Ba 2 Cu 3 O 7-δ ( RE BCO, RE = Y or lanthanide series), one of the most used family of HTS, has recently risen and several studies have been devoted to radiation hardness tests performed with ion irradiation or fission neutrons. In this work, the effect of neutron irradiation on YBCO films and commercial RE BCO tapes was investigated using, for the first time, neutrons produced by the D-T fusion reaction. The experiment was carried out at ENEA-Frascati Neutron Generator (FNG) where a deuteron beam is accelerated up to 300 keV and directed on a tritiated target to produce a nearly isotropic 14.1 MeV neutron field via the T(d,n)α fusion reaction. Different YBCO films deposited through metal-organic decomposition (MOD) route on single crystals (SrTiO 3 and LaAlO 3 ) and RE BCO commercial tapes, grown by pulsed laser deposition, were irradiated. Samples exposed to three fluences were compared with a maximum neutron fluence of 1.2·10 14 cm −2 . The properties of HTS materials were assessed before and after irradiation by means of different techniques. From these measurements, no significant effect on the considered properties was recognized indicating the robustness of films up to the explored irradiation fluences

Flux Dendrites of Opposite Polarity in Superconducting MgB2_2 rings observed with magneto-optical imaging

Magneto-optical imaging was used to observe flux dendrites with opposite polarities simultaneously penetrate superconducting, ring-shaped MgB$_2$ films. By applying a perpendicular magnetic field, branching dendritic structures nucleate at the outer edge and abruptly propagate deep into the rings. When these structures reach close to the inner edge, where flux with opposite polarity has penetrated the superconductor, they occasionally trigger anti-flux dendrites. These anti-dendrites do not branch, but instead trace the triggering dendrite in the backward direction. Two trigger mechanisms, a non-local magnetic and a local thermal, are considered as possible explanations for this unexpected behaviour. Increasing the applied field further, the rings are perforated by dendrites which carry flux to the center hole. Repeated perforations lead to a reversed field profile and new features of dendrite activity when the applied field is subsequently reduced.Comment: 6 pages, 6 figures, accepted to Phys. Rev.