Laser powder bed additive manufacturing: A review on the four drivers for an online control

Online control of Additive Manufacturing (AM) processes appears to be the next challenge in the transition toward Industry 4.0 (I4.0). Although many efforts have been dedicated by industry and research in the last decades, there remains substantial room for improvement. Additionally, the existing scientific literature lacks a wide-ranging identification and classification of the primary drivers that enable online control of AM processes. This article focuses on online control of one of the most industrially widespread AM processes: metal Laser Powder Bed Fusion (L-PBF), with particular emphasis on two subcategories, namely Selective Laser Sintering (SLS) and Selective Laser Melting (SLM). Through a systematic literature review, this article initially identified over 200 manuscripts. The search was conducted utilizing a defined research query within the Scopus database, double checked on Scholar. The results were refined through multiple phases of inclusion/exclusion criteria, culminating in the selection of 95 pertinent papers. This article aims to provide a systematic and comprehensive review of four identified drivers i) Online controllable input parameters, ii) Online observable output signatures, iii) Online sensing techniques, iv) Online feedback strategies, adopted from the general Deming control loop Plan-Do-Check-Act (PDCA). Ultimately, this article delves into the challenges and prospects inherent in the online control of metal L-PBF

Innovative transcatheter procedures for the treatment of heart failure

The prevalence of heart failure (HF) continues to rise over time, with aging of the population and increased survival of incident cases. Major improvements occurred in drug therapy but morbidity and mortality of HF patients remain high. Some non-pharmacologic approaches to HF are already part of standard treatment for HF, including implantable cardioverter-defibrillators, cardiac resynchronization therapy (CRT) and left ventricular assist devices (LVADs). A number of transcatheter treatments and devices have been developed to improve management of valvular heart diseases (VHD), and some of them are being used or tested in specific HF conditions. For example, transcatheter aortic valve implantation (TAVI) to unload the left ventricle in patients with moderate aortic stenosis (AS) and HF or TAVI for severe aortic regurgitation (AR) in patients with LVADs. Similarly, percutaneous mitral valve repair can be used to improve prognosis and quality of life in patients with functional mitral valve regurgitation, and has been proposed as a bridge-to-LVAD or to heart transplant in selected patients. Other devices have been specifically developed for the treatment of chronic HF. In this review we describe the main devices used in the treatment of HF associated with aortic and mitral valve disease, as well as novel transcatheter interventions for chronic HF with different pathophysiologic targets

Beyond ungulate density: Prey switching and selection by the wolf in a recolonised area

The analysis of mechanisms underlying prey use and selection is crucial for understanding the potential for apex predators to shape ecological processes across trophic levels. Significant implications for the conservation and management of ecosystems can ensue, especially in human-modified landscapes characterised by the recent recovery of apex predators, such as those of Europe. Generalist predators may show frequency-dependent prey selection, leading to prey switching; however, there is no ubiquitous support for positive relationships between prey abundance and prey selection. In a protected area recently recolonised by the wolf Canis lupus and hosting abundant wild prey (>20 individuals/km2), we assessed prey use and selection (>3000 wolf scats analysed) throughout 7 years since wolf settlement (April 2016-to-March 2023), during which prey density was relatively stable. Wolf diet was dominated by wild boar Sus scrofa and fallow deer Dama dama (>70 % of occurrences and volume); the roe deer Capreolus capreolus and coypu Myocastor coypus represented main secondary prey. The wolf showed a clear prey switching throughout the study. In the first two years, the fallow deer was the main prey and was positively selected. Then, wild boar replaced fallow deer as main prey, and was positively selected, with a progressive decrease in the use of fallow deer throughout the years. Selection indices of wild boar were negatively associated with those of fallow deer. The relationship between selection indices and population density was inconsistent across species, being negative for the wild boar and weakly positive for the fallow deer, although the latter showed no sharp decline in the area. Concurrent studies showed increased diurnal activity of fallow deer and a consequent reduced temporal overlap with the wolf throughout years since the settlement of this predator, suggesting temporal avoidance. By supporting a minor role of prey density in mediating prey switching, our results suggest a major role of other factors (e.g., antipredator behavioural responses). Alternative substantial prey are important to buffer apex predators not only towards changes in the abundance of main prey, but also towards the effects of other factors potentially reducing prey detectability, e.g., antipredator behaviour

A nonlinear complementary filter for underwater navigation using inertial measurements

This paper describes a nonlinear complementary filter capable of estimating the course motion variables namely the position, velocity, heading and accelerometers bias of an agile, over-actuated AUV during underwater operations, using the inertial sensors (IMU), the DVL, the depth sensor and the compass. The proposed work is within the framework of the V-Fides project, co-funded by Tuscany Region (Italy) and developed by a team lead by WASS S.p.A. (Whitehead Sistemi Subacquei, Livorno). The aim of the project was to develop and evaluate an high-depth, over-actuated, long endurance Autonomous Underwater Vehicle (AUV). The paper proposes the mathematical development of the observer, together with some experimental results, able to demonstrate the capabilities of the estimation scheme, compared with the estimations obtained via a standard Kalman Filter

Localization of lipopolysaccharide from Escherichia Coli into human atherosclerotic plaque

Experimental studies showed that gut-derived lipopolysaccharide (LPS) is pro-atherogenic, however, its relationship with human atherosclerosis is still to be defined. We investigate if gut-derived LPS from Escherichia Coli localizes in human carotid plaque and its potential role as pro-inflammatory molecule in the atherosclerotic lesion. LPS from Escherichia Coli and Toll-like receptor 4 (TLR4) were studied in specimens from carotid and thyroid arteries of 10 patients undergoing endarterectomy and 15 controls matched for demographic and clinical characteristics. Blood LPS were significantly higher in patients compared to controls. Immunochemistry analysis revealed positivity for antibodies against LPS and TLR4 coincidentally with positivity for CD68 only in the atherosclerotic plaque of carotid arteries but not in thyroid arteries; the positivity for LPS and TLR4 was greater in the area with activated macrophages. LPS concentration similar to that detected in atherosclerotic plaque resulted in a dose-dependent TLR4-mediated Nox2 up-regulation by human monocytes. These data provide the first evidence that LPS from Escherichia Coli localizes in human plaque and may contribute to atherosclerotic damage via TLR4-mediated oxidative stress

Assessment of management of a golf course by means of sustainability indicators

Golf courses are supposed to produce remarkable negative effects on the environment, due to some techniques involved in their management. To provide data useful for the proper assessment of the agro-environmental sustainability of a golf course, the framework agro-environmental sustainability information system (AESIS) was used, utilizing a set of indicators suitable to evaluate different dimensions of sustainability (physical, ecological, productive and social). The management of areal golf course located in Tuscany (central Italy) was compared to an alternative land use of the same area represented by an ordinary farm based on a sunflower-wheat rotation. Assessment indicators were selected by applying a conceptual model based on ecology theory and were calculated considering site-specific production and pedo-climatic features of the area. Different weighting scenarios were hypothesized in order to have different management options assessed and to carry out a targeted sensitivity analysis. Main results confirmed the significant impact of golf management on some ecological characteristics but the holistic assessment of AESIS approach permitted an overall evaluation that comprised a wide range of different issues. AESIS demonstrated to be a practical and adaptive tool able to perform an efficient comparison of possible land destinations

Comparison between crown thinning and girdling to enhance sporadic tree species in a coppice stand in Central Italy

Sporadic valuable tree species and especially Sorbus species have gained importance in forest management as they increase tree biodiversity, ensure a higher resilience of the stand to climate change, and enhance valuable timber production. This paper reports the first results of a trial carried out in Central Italy in a Turkey oak coppice stand (aged 17 years) where three different silvicultural treatments (crown thinning, girdling and unthinned control) were applied to favour sporadic tree species. The monitoring was carried out for 5 years and showed the limits of girdling application as Mediterranean species like Turkey oak form easily scar cords and epicormic sprouting. Furthermore, the progressive reduction of canopy cover of the competitors resulted from girdling and the effect of the thinning and girdling on the growth of selected service trees (Sorbus domestica L.) were evaluated. The first results of this research have pointed out some difficulties in the girdling application and a higher effect of crown thinning in stimulating the growth of selected service trees

A 30-years Review on Pharmacokinetics of Antibiotics: Is the Right Time for Pharmacogenetics?

Drug bioavailability may vary greatly amongst individuals, affecting both efficacy and toxicity: in humans, genetic variations account for a relevant proportion of such variability. In the last decade the use of pharmacogenetics in clinical practice, as a tool to individualize treatment, has shown a different degree of diffusion in various clinical fields. In the field of infectious diseases, several studies identified a great number of associations between host genetic polymor-phisms and responses to antiretroviral therapy. For example, in patients treated with abacavir the screening for HLA-B*5701 before starting treatment is routine clinical practice and standard of care for all patients; efavirenz plasma levels are influenced by single nucleotide polymorphism (SNP) CYP2B6-516G> T (rs3745274). Regarding antibiotics, many studies investigated drug transporters involved in antibiotic bioavailability, especially for fluoroquinolones, cephalosporins, and antituberculars. To date, few data are available about pharmacogenetics of recently developed antibiotics such as tigecycline, daptomycin or linezolid. Considering the effect of SNPs in gene coding for proteins involved in antibiotics bioavailability, few data have been published. Increasing knowledge in the field of antibiotic pharmacogenetics could be useful to explain the high drug inter-patients variability and to individualize therapy. In this paper we reported an overview of pharmacokinetics, pharmacodynamics, and pharmacogenetics of antibiotics to underline the importance of an integrated approach in choosing the right dosage in clinical practice

Cooperative scientific literature search and socialization through virtual teams

The scientific literature search is a key enabler for the research process. However, since it presents a lack of systematic procedure, is one of the most problematic and inefficient activities that researchers need to face during the development of their state of the arts. Moreover, most University students never experience sci- scientific literature search despite research is the main mission of the universities and one of the major activities of their professors as well as a primary param- enter for their careers. The aim of this paper is to i) present a new approach for sci- scientific literature search based on virtual team collaboration ii) explore the team dynamics of the knowledge building process in a virtual environment and, iii) propose a blog tool for open knowledge sharing both for experienced researchers and beginning students