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Wire arc additive manufacturing (WAAM) enables the production of structural components with topologically optimised geometries thus leading to significant self-weight reductions for a given load-carrying capacity. A common question arises regarding the environmental performance of WAAM structural components in comparison with conventional steel structural components. Thus, a comparative cradle-to-gate life cycle assessment has been conducted where the environmental impact of producing a topologically optimised WAAM steel beam is compared with that of producing a conventional hot-rolled steel I-beam. The beams are 2 m long, simply-supported and loaded vertically at midspan. The impact of using either carbon steel or stainless steel is investigated. The results demonstrate that the carbon steel and stainless steel WAAM beams have 7% and 24%, respectively, lower climate change impact than the corresponding I-beams. It is concluded that WAAM can lead to lower CO2-eq. emissions than conventional hot-rolling, provided that mass reductions of the order of 50% (which are readily attainable) can be achieved by employing WAAM in conjunction with, for instance, topology optimisation. Furthermore, it is shown that the shielding gas contributes greatly to the environmental impact of WAAM, and that, by using higher deposition rates or by utilising renewable energy sources, the impact of WAAM can be reduced by more than 30%.

The morphology of the Milky Way is still a matter of debate. In order to shed light on uncertainties surrounding the structure of the Galaxy, in this paper, we study the imprint of spiral arms on the distribution and properties of its molecular gas. To do so, we take full advantage of the SEDIGISM survey that observed a large area of the inner Galaxy in the $^{13}$CO(2-1) line at an angular resolution of 28. We analyse the influences of the spiral arms by considering the features of the molecular gas emission as a whole across the longitude-velocity map built from the full survey. Additionally, we examine the properties of the molecular clouds in the spiral arms compared to the properties of their counterparts in the inter-arm regions. Through flux and luminosity probability distribution functions, we find that the molecular gas emission associated with the spiral arms does not differ significantly from the emission between the arms. On average, spiral arms show masses per unit length of $\sim10^5-10^6$ M$_{\odot} $kpc$^{-1}$. This is similar to values inferred from data sets in which emission distributions were segmented into molecular clouds. By examining the cloud distribution across the Galactic plane, we infer that the molecular mass in the spiral arms is a factor of 1.5 higher than that of the inter-arm medium, similar to what is found for other spiral galaxies in the local Universe. We observe that only the distributions of cloud mass surface densities and aspect ratio in the spiral arms show significant differences compared to those of the inter-arm medium; other observed differences appear instead to be driven by a distance bias. By comparing our results with simulations and observations of nearby galaxies, we conclude that the measured quantities would classify the Milky Way as a flocculent spiral galaxy, rather than as a grand-design one.

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Aims: The DESSOLVE III OCT substudy aimed to compare serially neointimal hyperplasia volume obstruction (%VO) between the thin-strut MiStent with early polymer elimination and nine-month sustained drug release from microcrystalline sirolimus and the durable polymer-coated everolimus-eluting XIENCE stent at six and 24 months after implantation. Methods and results: The efficacy endpoint was %VO, calculated as abluminal neointimal volume/stent volume. Thirty-six patients (MiStent 16 patients, 16 lesions; XIENCE 20 patients, 22 lesions) underwent serial OCT evaluation at both six and 24 months. At six months, mean abluminal %VO was significantly lower in the MiStent group than in the XIENCE group (14.54±3.70% vs 19.11±6.70%; p=0.011), whereas the difference in %VO between the two groups decreased at 24 months (20.88±5.72% vs 23.50±7.33%; p=0.24). There was no significant difference in percentage malapposed struts and percentage uncovered struts between the two groups at both time points. Conclusions: In the serial comparative OCT analysis of the MiStent versus the XIENCE, the MiStent showed a more favourable efficacy for preventing neointimal formation with comparable strut tissue coverage, as compared with the XIENCE at six months, but this difference in %VO decreased at 24 months so that the difference in neointima at 24 months was no longer significant.

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No abstract is provided for this article.

No abstract is provided for this article.

Physiological assessment of coronary artery disease (CAD) has become one of the cornerstones of decision making for myocardial revascularization, with a large body of evidence supporting the benefits of using fractional flow reserve and other pressure-based indexes for functional assessment of coronary stenoses. Furthermore, physiology allows the identification of specific vascular dysfunction mechanisms in patients without obstructive CAD. Currently, more than 10 modalities of functional coronary assessment are available, although the overall adoption of these physiological tools, of either intracoronary or image-based nature, is still low. In this paper the authors review these modalities of functional coronary assessment according to their timing of use: outside the catheterization laboratory, in the catheterization laboratory prior to the percutaneous coronary intervention (PCI), and in the catheterization laboratory during or after PCI. The authors discuss how the information obtained can be used in setting the indication for PCI, in planning and guiding the procedure, and in documenting the final functional result of the intervention. The advantages and limitations of each modality in each setting are discussed. Furthermore, the key value of intracoronary physiology in diagnosing mechanisms of microcirculatory dysfunction, which account for the presence of ischemia in many patients without obstructive CAD, is revisited. On the basis of the opportunities generated by the multiplicity of diagnostic tools described, the authors propose an algorithmic approach to physiological coronary investigations in clinical practice, with the key aims of: 1) avoiding unneeded revascularization procedures; 2) improving procedural PCI and long-term outcomes in patients with obstructive CAD; and 3) diagnosing vascular dysfunction mechanisms that can be effectively treated in patients with NOCAD. The authors believe that such structured approach may also contribute to the wider adoption of available technologies for functional assessment of patients with CAD.

Everolimus has been successfully tested in humans using both an erodable and a durable polymer in small previous studies.This single blind multi-centre non-inferiority randomised (3:1) controlled trial evaluated the safety and performance of the XIENCE V Everolimus Eluting Coronary Stent System (XIENCE V EECSS) versus the TAXUS Paclitaxel Eluting Coronary Stent System (TAXUS(R) PECSS) in the treatment of patients with a maximum of two de novo native coronary artery lesions located in two different epicardial vessels. Three hundred patients with evidence of myocardial ischaemia were allocated to stent implantation with an everolimus-eluting stent (n=223) or a paclitaxel-eluting stent (n=77). Suitable lesions had a diameter stenosis of <50-99%, a length of <28 mm, and a reference vessel diameter between 2.5 mm and 4.25 mm. The primary endpoint was in-stent late loss (LL) at 180 days. Percentage in-stent volume obstruction (%VO) was measured by intravascular ultrasound (IVUS) in a subset of 152 patients. Clinical secondary endpoints included ischaemia driven major adverse cardiac events (ID-MACE) at 180 days.At 6 months, the in-stent LL was 0.11+/-0.27 mm in the everolimus-eluting stent arm, as compared to 0.36+/-0.39 mm in the paclitaxel-eluting stent arm (p<0.0001). Percentage VO in the everolimus-eluting stent arm was 2.5+/-4.7% versus 7.4+/-7.0% in the paclitaxel-eluting stent arm (p<0.0001). Hierarchical MACE was 2.7% (6/222) in the everolimus-eluting stent arm vs. 6.5% (5/77) in the paclitaxel-eluting stent arm.This non-inferiority randomised trial not only met its primary endpoint, but also demonstrated the superiority of the everolimus-eluting stent over the paclitaxel-eluting stent in terms of in-stent late loss.