Raman spectroscopy characterization of diamond films on steel substrates with titanium carbide arc-plated interlayer

Diamond chemical vapour deposition (CVD) on steel represents a difficult task. The major problem is represented by large diffusion of carbon into steel at CVD temperatures. This leads to very low diamond nucleation and degradation of steel microstructure and properties. Recent work [R. Polini, F. Pighetti Mantini, M. Braic, M. Amar, W. Ahmed, H. Taylor, Thin Solid Films 494 (2006) 116] demonstrated that well-adherent diamond films can be grown on high-speed steels by using a TiC interlayer deposited by the PVD-arc technique. The resulting multilayer (TiC/diamond) coating had a rough surface morphology due to the presence of droplets formed at the substrate surface during the reactive evaporation of TiC. In this work, we first present an extensive Raman investigation of 2 μm, 4 μm and 6 μm thick diamond films deposited by hot filament CVD on TiC interlayers obtained by the PVD-arc technique. The stress state of the diamond was dependent on both the films thickness and the spatial position of the coating on the substrate. In fact, on the top of TiC droplets, the stress state of the diamond was much lower than that of diamond in flatter substrate areas. These results showed that diamond films deposited on rough TiC interlayers exhibited a wide distribution of stress values and that very large compressive stress exists in the diamond film grown on flat regions of steel substrates with a TiC interlayer. Diamond films could accommodate stresses as large as 10 GPa without delamination.     

PDMS content affects in vitro hemocompatibility of synthetic vascular grafts

An unsolved problem when employing small-diameter vascular grafts for aorto-coronary by-pass and peripheral reconstruction is the early thrombotic occlusion. The PEtU-PDMS is a new elastomeric material, composed of poly(ether)urethane and polydimethylsiloxane, synthesized to realize grafts with improved hemocompatibility characteristics. In order to investigate the effect of PDMS content on hemocompatibility, three different percentages of PDMS containing grafts (10, 25 and 40) were evaluated. Grafts realized with Estane 5714-F1 and silicone medical grade tubes were used as references. The hemocompatibility was investigated by an in vitro circuit in which human anticoagulated blood was circulated into grafts by a peristaltic pump modified to obtain a passive flow. For each experiment, 40 cm length graft was closed into a circular loop and put in rotation for 2 h at 37 degrees C. At the end of the experiments different parameters regarding platelet adhesion and activation were evaluated: circulating platelets count, beta-thromboglobulin release, platelet CD62P expression and amount of monocyte-platelet conjugates. PEtU-PDMS grafts with 25 and 40% of PDMS induced the lowest platelet adhesion, plasma level of beta-TG and amount of monocyte-platelet conjugates. No significative variations were observed in CD62P expression. In conclusion, PDMS content significatively affects blood-graft surface interaction, in fact higher PDMS percentage containing grafts showed the best in vitro hemocompatibility.     

Assessment of the GSM-R susceptibility to repetitive transient disturbance

The transients produced by the pantograph electric arc and captured by a GSM-R antenna mounted on the roof top are characterized in the time domain and in the joint time–frequency domain, in order to quantify the noise produced on the GSM-R channels. The recorded signals are also characterized in order to evaluate the behavior of the GSM-R protocol in relation to burst noise with transients undergoing different repetition intervals. To this aim the GSM-R protocol is considered in particular with respect to data bit protection and for the relationship between signal-to-noise ratio, bit error rate and frame error rate, evaluated by repeated laboratory tests based on recorded transients. The measurements were performed on a 25 kV 50 Hz French railway line.     

Towards the development of mixed MT(1)-agonist/MT(2)-antagonist melatonin receptor ligands

Herein we report attempts to optimize the pharmacological properties of 5-(2-hydroxyethoxy)-N-acetyltryptamine (5-HEAT), a melatonin receptor ligand previously described by us. Several 5-substituted and 2,5-disubstituted N-acyltryptamines were synthesized and evaluated in vitro for the human cloned MT(1) and MT(2) receptors. From this series of N-acyltryptamines the 2-bromo derivative (5 c) retains the interesting efficacy profile of 5-HEAT and shows increased melatonin receptor affinities; it represents one of the first examples of a high-affinity MT(1) agonist/MT(2) antagonist. Some other full agonists for both melatonin receptors which exhibit similar or increased affinity relative to that of melatonin were obtained.     

The relationship between attachment scales and group therapy alliance growth differs by treatment type for women with binge-eating disorder.

The impact of the treatment context in influencing the relationship between attachment anxiety/avoidance and group therapy alliance growth was examined. Sixty-five women treatment completers with binge-eating disorder received 16 sessions of group cognitive behavioral therapy (GCBT) or group psychodynamic interpersonal psychotherapy (GPIP). Attachment scales were completed before treatment, and a group therapy alliance measure was completed after each therapy session. Growth curve modeling indicated an increasing linear growth in group therapy alliance for both treatments. For GPIP, higher attachment anxiety and lower attachment avoidance were each associated with alliance growth. These relationships were not evident for GCBT. The context of therapy likely activated (in the case of GPIP) or did not activate (in the case of GCBT) defensive attachment strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Urban runoff modelling uncertainty: Comparison among Bayesian and pseudo-Bayesian methods

Urban stormwater quality modelling plays a central role in evaluation of the quality of the receiving water body. However, the complexity of the physical processes that must be simulated and the limited amount of data available for calibration may lead to high uncertainty in the model results. This study was conducted to assess modelling uncertainty associated with catchment surface pollution evaluation. Eight models were compared based on the results of a case study in which there was limited data available for calibration. Uncertainty analysis was then conducted using three different methods: the Bayesian Monte Carlo method, the GLUE pseudo-Bayesian method and the GLUE method revised by means of a formal distribution of residuals between the model and measured data (GLUE_f). The uncertainty assessment of the models enabled evaluation of the advantages and limitations of the three methodologies adopted. The models were then tested using the quantity–quality data gathered for the Fossolo catchment in Bologna, Italy. The results revealed that all of the models evaluated here provided good calibration results, even if the model reliability (in terms of related uncertainty) varied, which suggests the adoption of a specific modelling approach with respect to the others. Additionally, a comparison of uncertainty analysis approaches showed that, regarding the models evaluated here, the classical Bayesian method is more effective at discriminating models according to their uncertainty, but the GLUE approach performs similarly when it is based on the same founding assumptions as the Bayesian method.     

Cerebrospinal fluid biomarkers in clinically isolated syndromes and multiple sclerosis

A panel of three cerebrospinal fluid (CSF) markers for clinically isolated syndromes (CIS) and multiple sclerosis (MS), based on SDS-PAGE, 2-D maps, and immunoblot results, is here proposed. No individual marker has any specificity, though, since they appear in a number of other neurological diseases. However the set of three, with the respective modulation sign (up-regulated or maintained at constant level), appears to be unique for MS. These proteins are: tau protein (levels remaining constant and undistinguishable from controls, contrary to up- and downregulation in other neurological disorders); 14-3-3 protein (strong upregulation of distinct isoforms) and cystatin C (changing in accordance to disease stage and progression). As an additional evidence, one can rely in the pattern of isoforms of 14-3-3, as obtained by 2-D maps and Western blot analysis: this pattern further distinguishes the variation of this protein from other neurological syndromes, notably sporadic Creutzfeldt-Jakob disease (sCJD), motor neuron diseases and other dementias. In contrast, a similar qualitative and quantitative upregulation of 14-3-3 is observed in Guillain-Barré syndrome (GBS), a demyelinating condition affecting the peripheral nervous system. To the best of our knowledge, this is the first time in which such a panel of biomarkers is reported in MS.     

Barriers common to mobile and disabled web users

World Wide Web accessibility and best practice audits and evaluations are becoming increasingly complicated, time consuming, and costly because of the increasing number of conformance criteria which need to be tested. In the case of web access by disabled users and mobile users, a number of commonalities have been identified in usage, which have been termed situationally-induced impairments; in effect the barriers experienced by mobile web users have been likened to those of visually disabled and motor impaired users. In this case, we became interested in understanding if it was possible to evaluate the problems of mobile web users in terms of the aggregation of barriers-to-access experienced by disabled users; and in this way attempt to reduce the need for the evaluation of the additional conformance criteria associated with mobile web best practice guidelines. We used the Barrier Walkthrough (BW) method as our analytical framework. Capable of being used to evaluate accessibility in both the disabled and mobile contexts, the BW method would also enable testing and aggregation of barriers across our target user groups.We tested 61 barriers across four user groups each over four pages with 19 experts and 57 non-experts focusing on the validity and reliability of our results. We found that 58% of the barrier types that were correctly found were identified as common between mobile and disabled users. Further, if our aggregated barriers alone were used to test for mobile conformance only four barrier types would be missed. Our results also showed that mobile users and low vision users have the most common barrier types, while low vision and motor impaired users experiencing similar rates of severity in the barriers they experienced. We conclude that the aggregated evaluation results for blind, low vision and motor impaired users can be used to approximate the evaluation results for mobile web users.