Predicting the roughness of overhanging surfaces in laser powder bed fusion via in-situ thermal imaging

The production of overhanging surfaces in Laser Powder-Bed Fusion (LPBF) has long been a challenging task due to poor heat dissipation and lack of support of loose powder, resulting in surface defects and increased roughness due to dross formation and sintering. Surface quality is a critical aspect of AM mechanical components that undergo fatigue loading, as a rough surface can act as a preferential crack initiation site and lead to premature failure. Predicting the quality of the as-built surfaces could be used to identify critical areas that require rework or post-processing, or to find regions that require optimization of the process parameters to improve the final quality. The orientation of the surface itself (i.e., the degree of inclination of the surface) could be used to predict the final surface quality and will be employed as benchmarking reference throughout the work (referred to as “geometry-based” model). This study demonstrates the effectiveness of using data mining on high-speed thermal video images to create a real-time predictive model based on “in-situ” data for estimating surface roughness (Sa) of overhanging surfaces printed at different inclinations. The results showed that the model based on “in-situ” data has a prediction accuracy that is more than 2 times higher than the one obtained with a model that is purely based on geometric data, i.e., a model that relies only on the inclination angle of the surface during the print. The proposed method is tested on different materials (AISI 316L stainless steel and AlSi10Mg) and process conditions (continuous and pulsed laser, low and high power) to show the flexibility and extended applicability of the proposed solution. The newly developed method opens new possibilities for in-situ quality control and process optimization of surface quality in Laser Powder Bed Fusion (LPBF)

Analysis of Video Content for a Multi-Layer Navigation of Multimedia Documents

This paper describes a set of automatic extraction tools so as to generate a three-layer organization of video documents. The underlying coarse to fine description allows for a fast navigation throughout the document, depending on the degree of details which is desired. Once the time-codes of the individual segments for each layer of the hierarchy have been identified, it is possible to map them into a Description Scheme (DS), which maintains the hierarchy and linear structure of the video document. This structural DS serves the role of a table of content for the multimedia document, the same way it is done in books. The particular interest of the proposed approach lies in the automatic solutions that can be used to generate the different segments at each level of the DS, and in the browsing tool that can be easily derived to navigate throughout the document

Chemoselective surface immbolization of proteins through a cleavable peptide

Surface immobilization of biomolecules is a fundamental step in several experimental techniques such as surface plasmon resonance analysis and microarrays. Oxime ligation allows reaching chemoselective protein immobilization with the retention of native-like conformation by proteins. Beside the need for chemoselective ligation of molecules to surface/particle, equally important is the controlled release of the immobilized molecules, even after a specific binding event. For this purpose, we have designed and assessed in an SPR experiment a peptide linker able to (i) anchor a given protein (enzymes, receptors, or antibodies) to a surface in a precise orientation and (ii) release the immobilized protein after selective enzymatic cleavage. These results open up the possibility to anchor to a surface a protein probe leaving bioactive sites free for interaction with substrates, ligands, antigens, or drugs and successively remove the probe-ligand complex by enzymatic cleavage. This peptide linker can be considered both an improvement of SPR analysis for macromolecular interaction and a novel strategy for drug delivery and biomaterial developments

Consumers demand for social farming products: An analysis with discrete choice experiments

This paper analyses the demand for social farming (SF) products. In particular, we investigate the preferences of consumers who buy their products from large retailers, rather than from solidarity purchasing groups or other niche markets using a sample of 225 consumers. In this regard, a discrete choice experiment (DCE) was carried out to estimate the willingness to pay (WTP) a premium price for the purchase of a common product (i.e., eggs) from farms that employ disabled people. The attributes considered in our DCE design are the employment of disabled people and two additional attributes which may have ethical implications for the choices. The results indicate that consumers are interested in buying SF products, with about 74% of the sample willing to buy the eggs produced by social farms and the average WTP being equal to \u20ac1.36 for a pack of six eggs. Moreover, the average WTP for the use of labour of disabled people attribute amounted to \u20ac0.69 for a pack of six eggs

Nebivolol: haemodynamic effects and clinical significance of combined beta-blockade and nitric oxide release.

Nebivolol is a third-generation beta-adrenergic receptor antagonist (beta-blocker) with high selectivity for beta(1)-adrenergic receptors. In addition, it causes vasodilatation via interaction with the endothelial L-arginine/nitric oxide (NO) pathway. This dual mechanism of action underlies many of the haemodynamic properties of nebivolol, which include reductions in heart rate and blood pressure (BP), and improvements in systolic and diastolic function. With respect to BP lowering, the NO-mediated effects cause a reduction in peripheral vascular resistance and an increase in stroke volume with preservation of cardiac output. Flow-mediated dilatation and coronary flow reserve are also increased during nebivolol administration. Other haemodynamic effects include beneficial effects on pulmonary artery pressure, pulmonary wedge pressure, exercise capacity and left ventricular ejection fraction. In addition, nebivolol does not appear to have adverse effects on lipid metabolism and insulin sensitivity like traditional beta-blockers. The documented beneficial haemodynamic effects of nebivolol are translated into improved clinical outcomes in patients with hypertension or heart failure. In patients with hypertension, the incidence of bradycardia with nebivolol is often lower than that with other currently available beta-blockers. This, along with peripheral vasodilatation and NO-induced benefits such as antioxidant activity and reversal of endothelial dysfunction, should facilitate better protection from cardiovascular events. In addition, nebivolol has shown an improved tolerability profile, particularly with respect to events commonly associated with beta-blockers, such as fatigue and sexual dysfunction. Data from SENIORS (Study of the Effects of Nebivolol Intervention on Outcomes and Rehospitalization in Seniors with Heart Failure) showed that significantly fewer nebivolol versus placebo recipients experienced the primary endpoint of all-cause mortality or cardiovascular hospitalization. The benefits of nebivolol therapy were shown to be cost effective. Thus, nebivolol is an effective and well tolerated agent with benefits over and above those of traditional beta-blockade because of its effects on NO release, which give it unique haemodynamic effects, cardioprotective activity and a good tolerability profile

Can we improve the treatment of congestion in heart failure?

INTRODUCTION: Dyspnoea and peripheral oedema, caused by fluid redistribution to the lungs and/or by fluid overload, are the main causes of hospitalization in patients with heart failure and are associated with poor outcomes. Treatment of fluid overload should relieve symptoms and have a neutral or favorable effect on outcomes. AREAS COVERED: We first consider the results obtained with furosemide administration, which is still the mainstay of treatment of congestion in patients with heart failure. We then discuss important shortcomings of furosemide treatment, including the development of resistance and side effects (electrolyte abnormalities, neurohormonal activation, worsening renal function), as well as the relationship of furosemide - and its doses - with patient prognosis. Finally, the results obtained with potential alternatives to furosemide treatment, including different modalities of loop diuretic administration, combined diuretic therapy, dopamine, inotropic agents, ultrafiltration, natriuretic peptides, vasopressin and adenosine antagonists, are discussed. EXPERT OPINION: Relief of congestion is a major objective of heart failure treatment but therapy remains based on the administration of furosemide, an agent that is often not effective and is associated with poor outcomes. The results of the few controlled studies aimed at the assessment of new treatments to overcome resistance to furosemide and/or to protect the kidney from its untoward effects have been mostly neutral. Better treatment of congestion in heart failure remains a major unmet need

Treatment comparison in rheumatoid arthritis : head-to-head trials and innovative study designs

Over the last decades, the increasing knowledge in the area of rheumatoid arthritis has progressively expanded the arsenal of available drugs, especially with the introduction of novel targeted therapies such as biological disease modifying antirheumatic drugs (DMARDs). In this situation, rheumatologists are offered a wide range of treatment options, but on the other side the need for comparisons between available drugs becomes more and more crucial in order to better define the strategies for the choice and the optimal sequencing. Indirect comparisons ormeta-analyses of data coming fromdifferent randomised controlled trials (RCTs) are not immune to conceptual and technical challenges and often provide inconsistent results. In this review we examine some of the possible evolutions of traditional RCTs, such as the inclusion of active comparators, aimed at individualising treatments in real-life conditions. Although head-to-head RCTs may be considered the best tool to directly compare the efficacy and safety of two different DMARDs, surprisingly only 20 studies with such design have been published in the last 25 years. Given the recent advent of the first RCTs truly comparing biological DMARDs, we also review the state of the art of head-to-head trials in RA

Report of CE on Semantic DS

ISO/IEC JTC1/SC29/WG11, MPEG00/M6355, 53rd meeting, Jul. 2000, Beijing, PR