Previous structure zone models used for the interpretation of the experimental results were constructed by compiling the various structures found in thick polycrystalline films deposited at different ...temperatures and parameters. The present paper shows that while the temperature dependence of surface and bulk diffusion can not adequately describe the evolution mechanisms of various polycrystalline thin film structure, the fundamental structure forming phenomena, including the contribution of impurities introduced by the authors make possible the comprehensive description of the structure forming mechanisms. Real structure zone models including also the related textures, are constructed by considering the concentration of impurities (co-deposited additives) in the vapour beam as a new deposition parameter, and the fundamental structure forming phenomena. These are phenomena composed of atomic processes, and can give account for the global effect of the atomic processes and are directly responsible for the structure evolution. Impurities (additives) can promote or inhibit the operation of the structure forming phenomena (promoter or inhibitor resp.). The new structure zone models can be used to tailor polycrystalline film structures of large variety (from large grained through columnar to the micro- or nanocrystalline structures) and to diagnose technologies.
Full text
Available for:
IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Rituximab, a monoclonal antibody directed against the B-lymphocyte antigen CD20, has shown promise in several autoimmune disorders. Pulmonary alveolar proteinosis (PAP) is an autoimmune disorder ...characterised by autoantibodies to granulocyte-macrophage colony-stimulating factor (GM-CSF). An open-label, proof-of-concept phase II clinical trial was conducted in 10 PAP patients. The intervention consisted of two intravenous infusions of rituximab (1,000 mg) 15 days apart. Bronchoalveolar lavage (BAL) fluid and peripheral blood samples were collected. The primary outcome was improvement in arterial blood oxygenation. Both arterial oxygen tension and alveolar-arterial oxygen tension difference in room air improved in seven out of the nine patients completing the study. Lung function and high-resolution computed tomography scans, which were secondary outcomes, also improved. Peripheral blood CD19+ B-lymphocytes decreased from mean ± sem 15 ± 2% to <0.05% (n = 10) 15 days post-therapy. This decrease persisted for 3 months in all patients; at 6 months, CD19+ B-cells were detected in four out of seven patients (5 ± 2%). Total anti-GM-CSF immunoglobulin (Ig)G levels from baseline to 6 months were decreased in BAL fluids (n = 8) but unchanged in sera (n = 9). In this PAP cohort: 1) rituximab was well-tolerated and effectively ameliorated lung disease; and 2) reduction in anti-GM-CSF IgG levels in the lung correlated with disease changes, suggesting that disease pathogenesis is related to autoantibody levels in the target organ.
Eutectic composition Cu–Ag alloy thin films were prepared by co-deposition at room temperature onto oxidized Si substrates by thermal evaporation. Morphological development, structure and phase state ...of the films were investigated by transmission electron microscopy. The films possess fibre morphology 10–30
nm in diameter and strong texture is present. The fibres are nanocrystalline composed of 2–3
nm size zones of Cu and Ag rich solid solution phases and a model for morphological development and phase separation is described. In the early stages of growth phase separation occurs by nucleation in melted islands and a eutectic of randomly oriented crystallites forms. In later stages of growth the phase separation takes place by spinodal decomposition. It results in a strain stabilized unique morphology corresponding to an intermediate stage of phase separation.
Full text
Available for:
IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this series of articles, a method is presented that performs (semi)quantitative phase analysis for nanocrystalline transmission electron microscope samples from selected area electron diffraction ...(SAED) patterns. Volume fractions and degree of fiber texture are determined for the nanocrystalline components. The effect of the amorphous component is minimized by empirical background interpolation. First, the two-dimensional SAED pattern is converted into a one-dimensional distribution similar to X-ray diffraction. Volume fractions of the nanocrystalline components are determined by fitting the spectral components, calculated for the previously identified phases with a priori known structures. These Markers are calculated not only for kinematic conditions, but the Blackwell correction is also applied to take into account dynamic effects for medium thicknesses. Peak shapes and experimental parameters (camera length, etc.) are refined during the fitting iterations. Parameter space is explored with the help of the Downhill-SIMPLEX. The method is implemented in a computer program that runs under the Windows operating system. Part I presented the principles, while part II elaborated current implementation. The present part III demonstrates the usage and efficiency of the computer program by numerous examples. The suggested experimental protocol should be of benefit in experiments aimed at phase analysis using electron diffraction methods.
An ambitious objective in the development of self-lubricating wear-resistant coatings is to make use of lubricious phases such as graphite, amorphous carbon or MoS2 incorporated into coatings. A ...series of (Ti,Al)(N,C) coatings with different carbon contents (0-28 at.%) have been deposited by reactive magnetron sputtering of TiAl in a mixture of Ar, N2 and CH4 gases. The microstructure and constitution of these coatings have been investigated using electron microprobe analysis, atomic force microscopy, X-Ray photoelectron spectroscopy, cross sectional transmission electron microscopy, Raman spectroscopy, X-ray diffraction and pole figure analyses. Starting from a pure TiAlN coating significant changes in the microstructure of the coatings were observed dependent on the carbon concentration. Under optimum conditions nanocomposite coatings with a structure of a coexisting metastable hard, nanocrystalline fcc TiAlNC phase and an amorphous carbon phase (a-C) have been deposited. The localization of an amorphous carbon phase has been shown by high-resolution transmission electron microscopy.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Single-phase cubic Ti
1
−
x
Al
x
N thin films with high Al content are preferred in industrial applications as they combine superior mechanical properties with good oxidation protection.
Recently we ...showed that yttrium, which can further increase the oxidation resistance by the reactive element effect, shifts the cubic stability range of Ti
1
−
x
Al
x
N to lower AlN mole fractions. Already the addition of 1 at.% Y to single-phase cubic Ti
0.45Al
0.55N promotes the hexagonal phase formation.
Based on X-ray diffraction and transmission electron microscopy studies we reveal that DC magnetron sputtering (DC-MS) from Ti
0.49Al
0.49Y
0.02 compound targets in Ar–N
2 atmosphere results in the formation of mixed cubic-hexagonal structured (Ti
1
−
x
Al
x
)
1
−
y
Y
y
N films, whereas the cubic structure can be stabilized by employing bipolar pulsed magnetron sputtering. This can be correlated to an increase in the Ti/Al ratio of the film and increased ion bombardment with increasing pulse duration, triggered by increases in the plasma electron temperature and ion fluxes. For pulsed DC-MS with 80 kHz and increasing pulse duration from 0 (DC-MS) to 4976 ns the composition of the coatings changes from Ti
0.41Al
0.57Y
0.02N to Ti
0.46Al
0.52Y
0.02N and the structure from a mixed cubic-hexagonal to a single-phase cubic, resulting in hardness increases from 23.5 to 34.6 GPa, respectively.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Malignant glioblastomas grow very rapidly and are generally resistant to either DNA-damaging drugs or gamma-irradiation. If tumor cells could be made more susceptible to cell death with treatments, ...this would clearly represent a significant improvement in the success of treatment. Recently, telomerase has become a focus of interest among oncologists as a target for treating cancer cells. Telomerase elongates telomeric DNA repeats (TTAGGG)n and is important in protecting and replicating DNA. The vast majority of tumor cells, indeed, express telomerase activity whereas normal somatic cells, except for a few cells, do not. Since telomerase is essential for protecting DNA, we may be able to make tumors more sensitive to treatments with DNA-damaging drugs by inhibiting telomerase activity. In this study, we used cis-diamminedichloroplatinum (cisplatin)-sensitive U87-MG cells and cisplatin-resistant U251-MG of human malignant glioblastoma cell lines. U87-MG cells did not express telomerase activity, whereas telomerase was highly detected in U251-MG cells. Interestingly, inhibition of telomerase with an antisense telomerase expression vector not only decreased telomerase activity but also increased susceptibility to cisplatin-induced apoptotic cell death in U251-MG cells. These findings suggest that treatment with antisense telomerase may represent a new chemosensitisation for tumors resistant to anticancer drugs.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In our earlier published work, we have shown that there is a composition range of the (Ti1−xAlx)1−yYyN alloy films (0.72<Ti/Al<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 at a certain thickness forming a definite crossover. Moreover the c-TiN 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 (Ti1−xAlx)1−yYyN thin film system in the 0<x<1 composition range.
•The texture of cubic phase changes from 〈001〉 to with increasing thickness.•Simultaneous crossover of texture and film morphology occurs at oblique deposition.•TiN type and AlN type 〈0001〉 oriented crystals are epitaxially related.•These crystals are of a few nm in size and form an epitaxial nanocomposite.•Pathway of structure evolution is proposed for (Ti1−xAlx)1−yYyN thin film system.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Malignant gliomas are the most common intracranial tumors and are considered incurable. Therefore, exploration of novel therapeutic modalities is essential. Telomerase is a ribonucleoprotein enzyme ...that is detected in the vast majority of malignant gliomas but not in normal brain tissues. We, therefore, hypothesized that telomerase inhibition could be a very promising approach for the targeted therapy of malignant gliomas. Thus, 2-5A (5'-phosphorylated 2'-5'-linked oligoadenylate)-linked antisense against human telomerase RNA component (2-5A-anti-hTER) was investigated for its antitumor effect on an intracranial malignant glioma model. 2-5A is a mediator of one pathway of IFN actions by activating RNase L, resulting in RNA degradation. By linking 2-5A to antisense, RNase L degrades the targeted RNA specifically and effectively. Prior to the experiments using intracranial tumor models in nude mice, we modified the in vitro and in vivo treatment modality of 2-5A-anti-hTER using a cationic liposome to enhance the effect of 2-5A-anti-hTER. Here we demonstrate that 2-5A-anti-hTER complexed with a cationic liposome reduced the viability of five malignant glioma cell lines to 20-43% within 4 days but did not influence the viability of cultured astrocytes lacking telomerase. Furthermore, treatment of intracranial malignant gliomas in nude mice with 2-5A-anti-hTER was therapeutically effective compared with the control (P < 0.01). These findings clearly suggest the therapeutic potentiality of 2-5A-anti-hTER as a novel approach for the treatment of intracranial malignant gliomas.
PDF
