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

Revisiting "Southern" Sprawl : Urban Growth, Socio-Spatial Structure and the Influence of Local Economic Contexts

Given its unpredictable nature, urban sprawl in the Mediterranean region is considered an intriguing (and intricate) socioeconomic issue.Since the 1970s, urban dispersion advanced rapidly in southern Europe-irrespective of a city's size and morphology-withurbanization rates growing faster than population. A comparison between the metropolitan areas of Barcelona, Rome and Athens reveals how sprawl has occurred in different ways in the three cities, highlighting peculiar relationships between urbanization, land-use and economic structures. Sharing common drivers of change related to population dynamics, socio-spatial structure and deregulated urban expansion, sprawl has adapted to the local economic, cultural and environmental context. Barcelona shows a dispersion pattern towards a more spatially-balanced morphology, with expanding sub-centres distributed around the central city, Rome appears to be mostly scattered around the historical city with fragmentedGiven its unpredictable nature, urban sprawl in the Mediterranean region is considered an intriguing (and intricate) socioeconomic issue. Since the 1970s, urban dispersion advanced rapidly in southern Europe-irrespective of a city's size and morphology-with urbanization rates growing faster than population. A comparison between the metropolitan areas of Barcelona, Rome and Athens reveals how sprawl has occurred in different ways in the three cities, highlighting peculiar relationships between urbanization, land-use and economic structures. Sharing common drivers of change related to population dynamics, socio-spatial structure and deregulated urban expansion, sprawl has adapted to the local economic, cultural and environmental context. Barcelona shows a dispersion pattern towards a more spatially-balanced morphology, with expanding sub-centres distributed around the central city, Rome appears to be mostly scattered around the historical city with fragmente

Histochemical Detection of Collagen Fibers by Sirius Red/Fast Green Is More Sensitive than van Gieson or Sirius Red Alone in Normal and Inflamed Rat Colon

Collagen detection in histological sections and its quantitative estimation by computer-aided image analysis represent important procedures to assess tissue localization and distribution of connective fibers. Different histochemical approaches have been proposed to detect and quantify collagen deposition in paraffin slices with different degrees of satisfaction. The present study was performed to compare the qualitative and quantitative efficiency of three histochemical methods available for collagen staining in paraffin sections of colon. van Gieson, Sirius Red and Sirius Red/Fast Green stainings were carried out for collagen detection and quantitative estimation by morphometric image analysis in colonic specimens from normal rats or animals with 2,4-dinitrobenzenesulfonic acid (DNBS) induced colitis. Haematoxylin/eosin staining was carried out to assess tissue morphology and histopathological lesions. Among the three investigated methods, Sirius Red/Fast Green staining allowed to best highlight well-defined red-stained collagen fibers and to obtain the highest quantitative results by morphometric image analysis in both normal and inflamed colon. Collagen fibers, which stood out against the green-stained non-collagen components, could be clearly appreciated, even in their thinner networks, within all layers of normal or inflamed colonic wall. The present study provides evidence that, as compared with Sirius Red alone or van Gieson staining, the Sirius Red/Fast Green method is the most sensitive, in terms of both qualitative and quantitative evaluation of collagen fibers, in paraffin sections of both normal and inflamed colon

Alteration of colonic excitatory tachykininergic motility and enteric inflammation following dopaminergic nigrostriatal neurodegeneration

Background: Parkinson's disease (PD) is frequently associated with gastrointestinal (GI) symptoms, including constipation and defecatory dysfunctions. The mechanisms underlying such disorders are still largely unknown, although the occurrence of a bowel inflammatory condition has been hypothesized. This study examined the impact of central dopaminergic degeneration, induced by intranigral injection of 6-hydroxydopamine (6-OHDA), on distal colonic excitatory tachykininergic motility in rats. Methods: Animals were euthanized 4 and 8 weeks after 6-OHDA injection. Tachykininergic contractions, elicited by electrical stimulation or exogenous substance P (SP), were recorded in vitro from longitudinal muscle colonic preparations. SP, tachykininergic NK1 receptor, and glial fibrillary acidic protein (GFAP) expression, as well as the density of eosinophils and mast cells in the colonic wall, were examined by immunohistochemical analysis. Malondialdehyde (MDA, colorimetric assay), TNF, and IL-1 beta (ELISA assay) levels were also examined. The polarization of peritoneal macrophages was evaluated by real-time PCR. Results: In colonic preparations, electrically and SP-evoked tachykininergic contractions were increased in 6-OHDA rats. Immunohistochemistry displayed an increase in SP and GFAP levels in the myenteric plexus, as well as NK1 receptor expression in the colonic muscle layer of 6-OHDA rats. MDA, TNF, and IL-1 beta levels were increased also in colonic tissues from 6-OHDA rats. In 6-OHDA rats, the number of eosinophils and mast cells was increased as compared with control animals, and peritoneal macrophages polarized towards a pro-inflammatory phenotype. Conclusions: The results indicate that the induction of central nigrostriatal dopaminergic degeneration is followed by bowel inflammation associated with increased oxidative stress, increase in pro-inflammatory cytokine levels, activation of enteric glia and inflammatory cells, and enhancement of colonic excitatory tachykininergic motility

Chapter Il rilievo di strada tra conoscenza e valorizzazione urbana: via dei Papareschi a Roma

The 43rd UID conference, held in Genova, takes up the theme of ‘Dialogues’ as practice and debate on many fundamental topics in our social life, especially in these complex and not yet resolved times. The city of Genova offers the opportunity to ponder on the value of comparison and on the possibilities for the community, naturally focused on the aspects that concern us, as professors, researchers, disseminators of knowledge, or on all the possibile meanings of the discipline of representation and its dialogue with ‘others’, which we have broadly catalogued in three macro areas: History, Semiotics, Science / Technology. Therefore, “dialogue” as a profitable exchange based on a common language, without which it is impossible to comprehend and understand one another; and the graphic sign that connotes the conference is the precise transcription of this concept: the title ‘translated’ into signs, derived from the visual alphabet designed for the visual identity of the UID since 2017. There are many topics which refer to three macro sessions: - Witnessing (signs and history) - Communicating (signs and semiotics) - Experimenting (signs and sciences) Thanks to the different points of view, an exceptional resource of our disciplinary area, we want to try to outline the prevailing theoretical-operational synergies, the collaborative lines of an instrumental nature, the recent updates of the repertoires of images that attest and nourish the relations among representation, history, semiotics, sciences

Enteric dysfunctions in experimental Parkinson's disease: alterations of excitatory cholinergic neurotransmission regulating colonic motility in rats

Parkinson's disease (PD) is frequently associated with gastrointestinal symptoms, mostly represented by constipation and defecatory dysfunctions. This study examined the impact of central dopaminergic denervation, induced by injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle, on distal colonic excitatory cholinergic neuromotor activity in rats. Animals were euthanized 4 and 8 weeks after 6-OHDA injection. In vivo colonic transit was evaluated by radiological assay. Electrically and carbachol-induced cholinergic contractions were recorded in vitro from longitudinal and circular muscle colonic preparations, while acetylcholine levels were assayed in their incubation media. Choline acetyltransferase (ChAT), HuC/D (pan-neuronal marker), muscarinic M2 and M3 receptors. As compared with control rats, at week 4 6-OHDA-treated animals displayed the following changes: decreased in vivo colonic transit rate; impaired electrically evoked neurogenic cholinergic contractions; enhanced carbachol-induced contractions; decreased basal and electrically stimulated acetylcholine release from colonic tissues; decreased ChAT immunopositivity in the neuromuscular layer; unchanged density of HuC/D immunoreactive myenteric neurons; increased expression of colonic muscarinic M2 and M3 receptors. The majority of such alterations were detected also at week 8 post-6-OHDA injection. These findings indicate that central nigrostriatal dopaminergic denervation is associated with an impaired excitatory neurotransmission characterized by a loss of myenteric neuronal ChAT positivity and decrease in acetylcholine release, resulting in a dysregulated smooth muscle motor activity, which likely contributes to the concomitant decrease in colonic transit rate

Redesigning Service Delivery for Hypertensive Patients: A Methodological Guideline to Improve the Management of Chronic Diseases

Best care is not necessarily the most expensive, but the most appropriate, and prevention is the most powerful tool to promote health. A novel approach might envision the reduction of hospital admittance (thus meeting a requirement from long term condition patients: they would rather not being hospitalized!) and the enforcement of peripheral (both on the territory and at home) assistance. In this direction, experiences of reshaping new service deliveries towards an integrated disease management, namely clinical pathways, can be observed in Europe and in different parts of the world. Aim of this paper is to provide a methodological guideline to support the management in planning clinical pathways, also outlining the main barriers limiting the process. In particular, we present the results of planning a clinical pathway at the Centre for Hypertension of the Federico II University Hospital (Naples, Italy). The case study showed that the introduction of a similar service impacts on the organisation of the structure. An analysis of organizational processes “as are” and the re-design of processes “to be” are necessary to integrate the clinical pathway into the actual activities