Crossover of texture and morphology in (Ti1 − xAlx)1 − yYyN alloy films and the pathway of structure evolution

In our earlier published work, we have shown that there is a composition range of the (Ti 1 − x Al x ) 1 − y Y y N alloy films (0.72 b Ti/Al b 0.88) deposited at oblique vapour beam incidence and 500 °C (corresponding to zone T) in which mixed cubic TiN (c-TiN) and wurtzite AlN (w-AlN) structures were formed together with an unusual complex texture. The texture of c-TiN phase changed from 〈001〉 to b111N at a certain thickness forming a definite crossover. Moreover the c-TiNb111N and the w-AlN〈0001〉 crystals were epitaxially related with axes tilted to the direction of the vapour beam. Based on a comprehensive transmission electron microscopy (TEM) and diffraction (XRD and selected area electron diffraction (SAED)) structure and morphology analysis, we discovered the details of this exotic structure making it possible to construct the complex pathway of structure evolution including the formation of the w-AlN phase and the change of the dominating texture of c-TiN phase with thickness in dependence of the Ti/Al ratio and the deposition parameters. This pathway could be deduced from the fundamental phenomena of structure formation and may be generalised for multi-component thin film systems. A composition structure zone model has been also proposed for the (Ti 1 − x Al x ) 1 − y Y y N thin film system in the 0 b x b 1 composition range

Crossover of texture and morphology in (Ti 1 − x Al x ) 1 − y Y y N alloy films and the pathway of structure evolution

In our earlier published work, we have shown that there is a composition range of the (Ti 1 − x Al x ) 1 − y Y y N alloy films (0.72 b Ti/Al b 0.88) deposited at oblique vapour beam incidence and 500 °C (corresponding to zone T) in which mixed cubic TiN (c-TiN) and wurtzite AlN (w-AlN) structures were formed together with an unusual complex texture. The texture of c-TiN phase changed from 〈001〉 to b111N at a certain thickness forming a definite crossover. Moreover the c-TiNb111N and the w-AlN〈0001〉 crystals were epitaxially related with axes tilted to the direction of the vapour beam. Based on a comprehensive transmission electron microscopy (TEM) and diffraction (XRD and selected area electron diffraction (SAED)) structure and morphology analysis, we discovered the details of this exotic structure making it possible to construct the complex pathway of structure evolution including the formation of the w-AlN phase and the change of the dominating texture of c-TiN phase with thickness in dependence of the Ti/Al ratio and the deposition parameters. This pathway could be deduced from the fundamental phenomena of structure formation and may be generalised for multi-component thin film systems. A composition structure zone model has been also proposed for the (Ti 1 − x Al x ) 1 − y Y y N thin film system in the 0 b x b 1 composition range

Mesenchymal stem cell-conditioned medium reduces disease severity and immune responses in inflammatory arthritis

We evaluated the therapeutic potential of mesenchymal stem cell-conditioned medium (CM-MSC) as an alternative to cell therapy in an antigen-induced model of arthritis (AIA). Disease severity and cartilage loss were evaluated by histopathological analysis of arthritic knee joints and immunostaining of aggrecan neoepitopes. Cell proliferation was assessed for activated and naïve CD4+ T cells from healthy mice following culture with CM-MSC or co-culture with MSCs. T cell polarization was analysed in CD4+ T cells isolated from spleens and lymph nodes of arthritic mice treated with CM-MSC or MSCs. CM-MSC treatment significantly reduced knee-joint swelling, histopathological signs of AIA, cartilage loss and suppressed TNFα induction. Proliferation of CD4+ cells from spleens of healthy mice was not affected by CM-MSC but reduced when cells were co-cultured with MSCs. In the presence of CM-MSC or MSCs, increases in IL-10 concentration were observed in culture medium. Finally, CD4+ T cells from arthritic mice treated with CM-MSC showed increases in FOXP3 and IL-4 expression and positively affected the Treg:Th17 balance in the tissue. CM-MSC treatment reduces cartilage damage and suppresses immune responses by reducing aggrecan cleavage, enhancing Treg function and adjusting the Treg:Th17 ratio. CM-MSC may provide an effective cell-free therapy for inflammatory arthritis

Membrane vesicles, current state-of-the-art: emerging role of extracellular vesicles

Release of membrane vesicles, a process conserved in both prokaryotes and eukaryotes, represents an evolutionary link, and suggests essential functions of a dynamic extracellular vesicular compartment (including exosomes, microparticles or microvesicles and apoptotic bodies). Compelling evidence supports the significance of this compartment in a broad range of physiological and pathological processes. However, classification of membrane vesicles, protocols of their isolation and detection, molecular details of vesicular release, clearance and biological functions are still under intense investigation. Here, we give a comprehensive overview of extracellular vesicles. After discussing the technical pitfalls and potential artifacts of the rapidly emerging field, we compare results from meta-analyses of published proteomic studies on membrane vesicles. We also summarize clinical implications of membrane vesicles. Lessons from this compartment challenge current paradigms concerning the mechanisms of intercellular communication and immune regulation. Furthermore, its clinical implementation may open new perspectives in translational medicine both in diagnostics and therapy

Effect of Mn Alloying on the Internal and Surface Structure of Cu Thin Films Designed for Interconnect Applications

Internal and surface structure of Cu - Mn alloys as prospective contact and interconnect material for memory and IC applications were studied. A combinatorial preparation was used as a quick method to overview the characteristics as a function of composition of the DC sputtered Cu - Mn thin films. At low Mn content the alloys exhibit fcc - Cu(Mn) solid solution phas e, around 50 at% Mn content an amorphous phase , while at high Mn content an Mn(Cu) solid solution phase . The three single - phase regions are separated by two two - phase regions composed of crystalline and amorphous phase s . The dependences of the grain size and surface roughness on film composition show s imilar, parabol ic behaviour . The grain size distributions obtained from AFM and TEM images show good correlation, although differe nt from th ose obtained by the Scherrer formula around 25 at % Mn content . From the difference spontaneous phase separation process could be concluded at this composition

The nanostructure and mechanical properties of nanocomposite Nb-x-CoCrCuFeNi thin films

The relation between the nanostructure and the mechanical properties of Nb-x-CoCrCuFeNi high entropy alloy thin films was explored. With increasing Nb concentration (0 to 24 at.% Nb), a transition from a single phase face-centered cubic solid solution to an amorphous phase is observed. At intermediary Nb fractions (5 to 15 at.% Nb) a nanocomposite structure is formed that consists of nanosized crystallites embedded in an amorphous matrix. The nanocomposite structure leads to an increase in hardness beyond the Hall-Petch breakdown. The shear and Young's moduli decrease with increasing Nb concentration, which is beneficial for the alloy ductility. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

HETEROEPITAXIAL SPUTTERED GE ON SI (100): NANOSTRUCTURE AND INTERFACE MORPHOLOGY

Epitaxial growth of Ge thin films onto (100) silicon by DC-Pulsed Magnetron Sputtering was realized and proved by X-ray and electron diffraction. Transmission and high-resolution electron microscopy across the interface region directly confirmed a high degree of epitaxy and show that planar defects and threading dislocations are the relevant lattice imperfections. Electron microscopy shows that a post-deposition rapid thermal annealing process, up to 673 K, is effective to defect annihilation. The films grow single crystalline, slightly misoriented, below 0.1 degrees. A weak roughness around 0.6 nm, was measured both at the Ge-Si interface and at the film surface. The Ge films grown onto n-type Si show the rectifying electrical behaviour typical of p-type semiconductors