Effect of the Structural Scale of Plasma-Sprayed Alumina Coatings on Their Friction Coefficients

The objective of this study is to compare the tribological properties of alumina coatings with two different structural scales, a micrometer-sized one manufactured by atmospheric plasma spraying and a sub-micrometer-sized one manufactured by suspension plasma spraying. Coating architectures were analyzed and their friction coefficients in dry sliding mode measured. Sub-micrometer-sized structured coatings present a lower friction coefficient than micrometer ones, thanks to their higher cohesion and smaller characteristic structural feature sizes.     

Reliability and credibility of young children's reports: From research to policy and practice.

In this article, some issues, concerns, and research regarding the interviewing of young child witnesses are reviewed. The article focuses on research on suggestibility and the influence of various interviewing techniques on the reliability and credibility of young children's reports. Implications of this research for future research and for policy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nanoindentation study of the mechanical and damage behaviour of suspension plasma sprayed TiO2 coatings

TiO₂ coatings can be used as self-cleaning surfaces owing to their photocatalytic and hydrophilic properties. Suspension plasma spray (SPS) has proven to be a feasible and cheap technique for producing self-cleaning surfaces with acceptable photo-activity. This paper presents a nanoindentation study of the mechanical properties (hardness, Young's modulus and scratch resistance) of photoactive layers of suspension plasma sprayed TiO₂ coatings applied on to glass substrates. Microstructure observation showed that the rutile grains were surrounded by fine anatase crystals. Under the same spraying conditions, the resulting anatase/rutile concentrations varied depending on the cooling rate (the substrate being either cooled with water or in air). The results showed that higher concentrations of anatase, which is softer than rutile, reduced the scratch damage and increased the friction coefficient.     

Within-Host Adaptation of Staphylococcus aureus in a Bovine Mastitis Infection Is Associated with Increased Cytotoxicity

Within-host adaptation is a typical feature of chronic, persistent Staphylococcus aureus infections. Research projects addressing adaptive changes due to bacterial in-host evolution increase our understanding of the pathogen’s strategies to survive and persist for a long time in various hosts such as human and bovine. In this study, we investigated the adaptive processes of S. aureus during chronic, persistent bovine mastitis using a previously isolated isogenic strain pair from a dairy cow with chronic, subclinical mastitis, in which the last variant (host-adapted, Sigma factor SigB-deficient) quickly replaced the initial, dominant variant. The strain pair was cultivated under specific in vitro infection-relevant growth-limiting conditions (iron-depleted RPMI under oxygen limitation). We used a combinatory approach of surfaceomics, molecular spectroscopic fingerprinting and in vitro phenotypic assays. Cellular cytotoxicity assays using red blood cells and bovine mammary epithelial cells (MAC-T) revealed changes towards a more cytotoxic phenotype in the host-adapted isolate with an increased alpha-hemolysin (α-toxin) secretion, suggesting an improved capacity to penetrate and disseminate the udder tissue. Our results foster the hypothesis that within-host evolved SigB-deficiency favours extracellular persistence in S. aureus infections. Here, we provide new insights into one possible adaptive strategy employed by S. aureus during chronic, bovine mastitis, and we emphasise the need to analyse genotype–phenotype associations under different infection-relevant growth conditions.     

Genetic Dominant Variants in STUB1, Segregating in Families with SCA48, Display In Vitro Functional Impairments Indistinctive from Recessive Variants Associated with SCAR16

Variants in STUB1 cause both autosomal recessive (SCAR16) and dominant (SCA48) spinocerebellar ataxia. Reports from 18 STUB1 variants causing SCA48 show that the clinical picture includes later-onset ataxia with a cerebellar cognitive affective syndrome and varying clinical overlap with SCAR16. However, little is known about the molecular properties of dominant STUB1 variants. Here, we describe three SCA48 families with novel, dominantly inherited STUB1 variants (p.Arg51_Ile53delinsProAla, p.Lys143_Trp147del, and p.Gly249Val). All the patients developed symptoms from 30 years of age or later, all had cerebellar atrophy, and 4 had cognitive/psychiatric phenotypes. Investigation of the structural and functional consequences of the recombinant C-terminus of HSC70-interacting protein (CHIP) variants was performed in vitro using ubiquitin ligase activity assay, circular dichroism assay and native polyacrylamide gel electrophoresis. These studies revealed that dominantly and recessively inherited STUB1 variants showed similar biochemical defects, including impaired ubiquitin ligase activity and altered oligomerization properties of the CHIP. Our findings expand the molecular understanding of SCA48 but also mean that assumptions concerning unaffected carriers of recessive STUB1 variants in SCAR16 families must be re-evaluated. More investigations are needed to verify the disease status of SCAR16 heterozygotes and elucidate the molecular relationship between SCA48 and SCAR16 diseases.     

Preparation and characterization of plasticized starch/halloysite porous nanocomposites possibly suitable for biomedical applications

Novel porous bionanocomposites based on halloysite nanotubes as nanofillers and plasticized starch as polymeric matrix were successfully prepared by melt‐extrusion. Foaming was obtained by adding water as natural blowing agent, and by increasing the die temperature. Both the expansion ratio and the porosity increase with increasing die temperature. Addition of high water content allows reducing the foaming temperature. Moreover, the introduction of halloysite has double benefits: these fillers act both as a nucleating agent increasing the porosity and as a barrier agent increasing the proportion of small cells. Foams based on plasticized starch with a blend of glycerol and sorbitol loaded with 6 wt % of halloysite, extruded at 117°C, present the cellular structure and the mechanical properties required for scaffold applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41341.     

Solubility of non-psychoactive cannabinoids in supercritical carbon dioxide and comparison with psychoactive cannabinoids

The solubilities of two different non-psychoactive cannabinoids i.e., cannabigerol (CBG) and cannabidiol (CBD), in supercritical carbon dioxide (CO₂) have been determined at 315, 326 and 334 K and in the pressure range from 11.3 to 20.6 MPa. These solubility data have been compared to the previously determined solubilities of two psychoactive cannabinoids i.e., (−)-Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and cannabinol (CBN), in supercritical CO₂. An analytical method with a quasi-flow apparatus was used for the experimental determination. Within the investigated temperature and pressure range, the molar solubility of CBG ranged from 1.17 to 1.91 × 10⁻⁴ and the molar solubility of CBD ranged from 0.88 to 2.69 × 10⁻⁴. The solubility of the different cannabinoids in supercritical CO₂ increases at 326 K in the following order: Δ⁹-THC < CBG < CBD < CBN. The solubility data were correlated using the Peng-Robinson equation of state in combination with Van der Waals mixing rules. Deviations between calculated results and the experimental data ranged from 0.81 to 6.35% absolute average relative deviation (AARD), except for CBD at 334 K, where the AARD was 18.4%.