Bond formation at polycarbonate | X interfaces (X = Al2_2O3_3, TiO2_2, TiAlO2_2) studied by theory and experiments

Interfacial bond formation during sputter deposition of metal oxide thin films onto polycarbonate (PC) is investigated by ab initio molecular dynamics simulations and X-ray photoelectron spectroscopy (XPS) analysis of PC | X interfaces (X = Al$_2$O$_3$, TiO$_2$, TiAlO$_2$). Generally, the predicted bond formation is consistent with the experimental data. For all three interfaces, the majority of bonds identified by XPS are (C-O)-metal bonds, whereas C-metal bonds are the minority. Compared to the PC | Al$_2$O$_3$ interface, the PC | TiO$_2$ and PC | TiAlO$_2$ interfaces exhibit a reduction in the measured interfacial bond density by ~ 75 and ~ 65%, respectively. Multiplying the predicted bond strength with the corresponding experimentally determined interfacial bond density shows that Al$_2$O$_3$ exhibits the strongest interface with PC, while TiO$_2$ and TiAlO$_2$ exhibit ~ 70 and ~ 60% weaker interfaces, respectively. This can be understood by considering the complex interplay between the metal oxide composition, the bond strength as well as the population of bonds that are formed across the interface

Study of the transition from self-organised to homogeneous plasma distribution in chromium HiPIMS discharge

Publisher's version (útgefin grein)The self-organised plasma patterns, known as spokes or ionisation zones in magnetron sputtering discharges, were observed in a wide range of power densities, from low power direct current magnetron sputtering (dcMS) discharge to high power impulse magnetron sputtering (HiPIMS) discharge. For some target materials and non-reactive gases, it was observed that at very high power densities (>3 kW cm-2) the plasma exhibits a transition from a regime where spokes are observed to a homogeneous plasma regime. In this contribution, we present a comparison of plasma properties: plasma emission (optical emission spectroscopy) and flux of argon and chromium ions (mass spectrometry), measured both in the spoke regime and in the homogeneous plasma regime, aimed to expand the understanding of the plasma transition between the two modes. A simple biased flat probe was used to distinguish between the spoke regime and the homogeneous plasma regime. It was found that the flux of multiply charged ions (Ar2+, Cr2+, Cr3+, Cr4+) increases abruptly at the transition between the spoke regime and the homogeneous plasma regime. Similarly, the emission from Cr+ ions exhibits a strong increase of about 50% when the plasma torus becomes homogeneous. These observations are interpreted as an increase in electron temperature and a change in the electron heating mode, from a combination of secondary electron heating and Ohmic heating towards pure Ohmic heating. The transition to the homogeneous plasma regime and pure Ohmic heating is only observed in non-reactive HiPIMS discharges for target atoms with the second ionisation potential higher than the first ionisation potential of Ar (15.76 eV), and a self-sputter yield larger than 1.This research has been supported by project LM2018097 funded by the Ministry of Education, Youth and Sports of the Czech Republic and project GA19-00579S funded by the Czech Science Foundation. This work has been supported by the German Science Foundation (DFG) within the frame of the collaborative research centre SFB-TR 87Peer Reviewe

Aggressive systemische Mastozytose mit erhöhter diffuser 18F-FDG-Aufnahme im Knochenmark [Aggressive systemic mastocytosis with diffuse bone marrow 18F-FDG uptake]

Mastocytosis is a clonal hematopoietic disorder characterized by proliferation of abnormal mast cells in various organs including the skin, digestive system, lymph nodes, and bone marrow. We report on a 75-year-old woman presenting with abdominal pain, vomiting, diarrhoea, myalgia, and weight loss. Abdominal CT showed hepatosplenomegaly with heterogeneous splenic parenchyma, lymphadenopathy, and osteopenia with areas of osteosclerosis but no primary tumour. An <sup>18</sup> F-FDG PET/CT revealed an overall low metabolic activity of the lesions with a diffuse bone marrow involvement raising suspicion of a haematological neoplasm. Subsequently, bone marrow and peripheral blood examinations confirmed the diagnosis of aggressive systemic mastocytosis

18F-FDG PET/CT pattern of Erdheim-Chester disease – a group of Czech patients

Introduction: Erdheim-Chester disease (ECD) is a rare unit of histiocytic diseases. The goal of our work was to assess 18F-FDG PET/CT presentation of this disease in patients from the Czech Republic. Methods: We analyzed overall 44 18F-FDG PET/CT examinations in 6 patients with this disease. We assessed 18F-FDG accumulation in staging examinations of these 6 patients at usual localizations, i.e. bones, brain, orbit, paranasal sinuses, periaortal space, heart, lungs, perirenal space and skin. Results: Bone 18F-FDG accumulation was detected in all patients; in 5 mostly in lower extremities. Maxillar sinuses were involved in 5/6 patients. Vascular and perirenal involvement was detected in 4/6 patients. Two patients had involved skin and hypophysis, one patient also orbits and heart. Lung involvement was not detected in any patient. Conclusions: 18F-FDG avid involvement of skeleton was the main and regular characteristic of PET/CT presentation of Erdheim-Chester disease. Also other localizations of 18F-FDG avid involvement (cardiovascular, CNS, paranasal sinuses, orbitis, skin, perirenal space) confirm known observations in ECD.

Reduction of transient regime in fast preionized high-power pulsed-magnetron discharge

A high-power pulsed-magnetron discharge (several \un{kW/cm^2}) is described. It operates at pulse duration of the order of few μs, significantly shorter than in usual similar devices. The breakdown delay was reduced by using a low-current DC preionization. The study was performed for Cu target in Ar and He buffer gases by optical emission spectroscopy and electrical measurements. Saturation magnetron current is reached in a few μs which permits to shorten the pulse duration avoiding arc formation. Unusual high current density up to 10\un{A/{cm^2}} induces very fast transition toward the stable self-sputtering regime. High plasma density favours high ion flux to the substrate. Preliminary result on Cu deposit in trenches is reported