Enhancing the dimensional accuracy of a low-cost 3D printer

3D printing is widely used in the entertainment industry by filmmakers, effect studios and game designers to easily and fast fabricate characters or objects that are first virtually modelled through Computer Graphics. There are several commercial proposals in the field of low-cost 3D printers, with prices starting from a few hundred euros for kits that the users should assemble by themselves. However, their performances in terms of part accuracy are quite limited and are basically the consequence of a lack of optimization both in mechanical terms as in software. Starting from these considerations, an optimization project was assigned to the students of the Specializing Master in Industrial Automation of the Politecnico di Torino. The Master is developed in collaboration with COMAU S.p.a., a company worldwide leader in automation expecially for the automotive sector. The task of enhancing the performances of the 3D printer Prusa i3, that is supplied in the assembly box, was assigned to sixteen engineers attending the Master who were divided into 4 groups. The activities have led to the birth of four new 3D printers: Fluo, Ghost, Metallica and Print-Doh. In order to assess and validate the improvements, a benchmarking activity was carried out to evaluate the dimensional accuracy of the four printers. The benchmarking was based on the manufacturing of an innovative reference artifact whose geometrical features are designed to fit within different ISO basic sizes. Each group printed a replica of the reference part with their own new printer and then the replicas were measured by means of a coordinate measuring machine (CMM). Measures were used to compare the performances of the four printers and the results of the benchmarking considers the dimensional accuracy of the replicas in terms of ISO IT grades, but also the form errors of the geometrical features through GD&T tolerances

A Discrete Event Simulation Based Approach for Digital Twin Implementation

Nowadays, manufacturing companies need to improve their production monitoring and prediction to be more flexible and re-configurable. To do so, the digitization of the manufacturing environment is a very critical issue. This paper proposes an approach to develop digital twins in this environment. Digital twins are virtual systems, real time connected with their physical counterpart, which replicate exactly their behaviour. Discrete event simulation models, connected in real-time with their real system counterparts, are developed in this work. Two industrial use cases are analysed, to show the benefits that this promising technology can bring to the manufacturing industry

Menadione-induced oxidative stress re-shapes the oxylipin profile of Aspergillus flavus and its lifestyle

Aspergillus flavus is an efficient producer of mycotoxins, particularly aflatoxin B1, probably the most hepatocarcinogenic naturally-occurring compound. Although the inducing agents of toxin synthesis are not unanimously identified, there is evidence that oxidative stress is one of the main actors in play. In our study, we use menadione, a quinone extensively implemented in studies on ROS response in animal cells, for causing stress to A. flavus. For uncovering the molecular determinants that drive A. flavus in challenging oxidative stress conditions, we have evaluated a wide spectrum of several different parameters, ranging from metabolic (ROS and oxylipin profile) to transcriptional analysis (RNA-seq). There emerges a scenario in which A. flavus activates several metabolic processes under oxidative stress conditions for limiting the ROS-associated detrimental effects, as well as for triggering adaptive and escape strategies

Early Monitoring Response to Therapy in Patients with Brain Lesions Using the Cumulative SUV Histogram

Featured Application The study proposes a methodology to evaluate the response of patients with brain lesions to Gamma Knife treatments through the use of Positron Emission Tomography imaging. Gamma Knife treatment is an alternative to traditional brain surgery and whole-brain radiation therapy for treating cancers that are inaccessible via conventional treatments. To assess the effectiveness of Gamma Knife treatments, functional imaging can play a crucial role. The aim of this study is to evaluate new prognostic indices to perform an early assessment of treatment response to therapy using positron emission tomography imaging. The parameters currently used in nuclear medicine assessments can be affected by statistical fluctuation errors and/or cannot provide information on tumor extension and heterogeneity. To overcome these limitations, the Cumulative standardized uptake value (SUV) Histogram (CSH) and Area Under the Curve (AUC) indices were evaluated to obtain additional information on treatment response. For this purpose, the absolute level of [11C]-Methionine (MET) uptake was measured and its heterogeneity distribution within lesions was evaluated by calculating the CSH and AUC indices. CSH and AUC parameters show good agreement with patient outcomes after Gamma Knife treatments. Furthermore, no relevant correlations were found between CSH and AUC indices and those usually used in the nuclear medicine environment. CSH and AUC indices could be a useful tool for assessing patient responses to therapy

optimizing patient referral and center capacity in the management of chronic hepatitis c lessons from the italian experience

Abstract Aims In 2017 the Italian Drug Agency (Agenzia Italiana del Farmaco, AIFA) revised the criteria for access to therapy for patients with chronic hepatitis C as part of a three-year plan to eradicate HCV. We conducted a Delphi study to determine strategies to identify and treat patients with HCV and to develop through a shared pathway, a model to manage patient referral and optimize prescription center capacity with the overall aim of increasing access to therapy. Methods The process took place in two phases – Phase I (January 2017), before the criteria for treatment of HCV were revised and Phase II (May 2017) when AIFA developed a framework for the eradication of HCV infection in Italy. Two questionnaires were devised with Q1 administered in Phase I and Q2 in Phase II. Results Q1 was sent to 823 hepatitis specialists working in 235 Italian HCV centers authorized to prescribe direct-acting antiviral drugs (DAAs). Overall, 167 centers (71%) participated with a good geographical representativeness (North 69%, Centre 74%; South and islands 70%). 548 prescribers (68.8%) provided responses to Q1 and 443 (80%) specialists who responded to Q1 completed Q2. Over 70% considered that to meet the new therapy targets local/regional networks need to be consolidated and reinforced with GPs providing the 'missing link' in current regional networks. Adherence to therapy was considered important by 75% of clinicians with reduction in follow-up intervals/length considered important by 65% – to free up staff/resources to manage increasing numbers of new patients. About 80% of respondents stated that medical personnel were principally involved in follow-up with follow-up having a significant impact on center capacity. Conclusion Enhancing patient referral, the need for an increased role of GPs, increasing center capacity in particular medical personnel in outpatient centers and greater liaison between Hub centers and healthcare professionals currently managing high-risk groups as yet untreated, were factors that need to be streamlined in order to meet treatment targets for eradication of HCV

Immunohistochemical Analysis of Myenteric Ganglia and Interstitial Cells of Cajal in Ulcerative Colitis

Ulcerative colitis (UC) is an inflammatory bowel disease with alterations of colonic motility, which influence clinical symptoms. Although morpho-functional abnormalities in the enteric nervous system have been suggested, in UC patients scarce attention has been paid to possible changes in the cells that control colonic motility, including myenteric neurons, glial cells, and interstitial cells of Cajal (ICC). This study evaluated the neural-glial components of myenteric ganglia and ICC in the colonic neuromuscular compartment of UC patients by quantitative immunohistochemical analysis. Full-thickness archival samples of the left colon were collected from 10 patients with UC (5 M, 5 F; age range, 45-62 years) who underwent elective bowel resection. The colonic neuromuscular compartment was evaluated immunohistochemically in paraffin cross-sections. The distribution and number of neurons, glial cells and ICC were assessed by anti-HuC/D, -S100β and -c-Kit antibodies, respectively. Data were compared with findings on archival samples of normal left colon from 10 sex- and age-matched control patients, who underwent surgery for uncomplicated colon cancer. Compared to controls, patients with UC showed: (a) reduced density of myenteric HuC/D-positive neurons and S100β-positive glial cells, with a loss over 61% and 38%, respectively, and increased glial cell/neuron ratio; (b) ICC decrease in the whole neuromuscular compartment. The quantitative variations of myenteric neuro-glial cells and ICC indicate considerable alterations of the colonic neuromuscular compartment in the setting of mucosal inflammation associated with UC, and provide a morphological basis for better understanding the motor abnormalities often observed in UC patients

Application of Phage Therapy in a Case of a Chronic Hip-Prosthetic Joint Infection due to Pseudomonas aeruginosa: An Italian Real-Life Experience and In Vitro Analysis

Background: Prosthetic joint infection (PJI) caused by Pseudomonas aeruginosa represents a severe complication in orthopedic surgery. We report the case of a patient with chronic PJI from P. aeruginosa successfully treated with personalized phage therapy (PT) in combination with meropenem. Methods: A 62-year-old woman was affected by a chronic right hip prosthesis infection caused by P. aeruginosa since 2016 . The patient was treated with phage Pa53 (I day 10 mL q8h, then 5 mL q8h via joint drainage for 2 weeks) in association with meropenem (2gr q12h iv) after a surgical procedure. A 2-year clinical follow up was performed. An in vitro bactericidal assay of the phage alone and in combination with meropenem against a 24-hour-old biofilm of bacterial isolate was also carried out. Results: No severe adverse events were observed during PT. Two years after suspension, there were no clinical signs of infection relapse, and a marked leukocyte scan showed no pathological uptake areas. In vitro studies showed that the minimum biofilm eradicating concentration of meropenem was 8 µg/mL. No biofilm eradication was observed at 24 hours incubation with phages alone (108 plaque-forming units [PFU]/mL). However, the addition of meropenem at suberadicating concentration (1 µg/mL) to phages at lower titer (103 PFU/mL) resulted in a synergistic eradication after 24 hours of incubation. Conclusions: Personalized PT, in combination with meropenem, was found to be safe and effective in eradicating P. aeruginosa infection. These data encourage the development of personalized clinical studies aimed at evaluating the efficacy of PT as an adjunct to antibiotic therapy for chronic persistent infections

Local Control and Toxicity of Adaptive Radiotherapy Using Weekly CT Imaging: Results from the LARTIA Trial in Stage III NSCLC

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