Diamond Wire Cutting of Marble: State of the art, Modeling and Experiments with a New Testing Machine

The use of diamond wire has been the standard industrial practice in excavation for over three decades, however only few researchers have devoted a systematic approach to understand, model and optimize this peculiar cutting process, and only in the case of granite. In addition to slabbing of stones, this technology is of interest for the construction and demolition industry. The typical configuration of diamond wire cutting in a quarry, with a cinematic scheme and the typical parameters are included in the paper. Experimental and theoretical models are examined and some initial results are also provided. Tests have been carried out on a special laboratory machine, developed within a national project, whose architecture is described

Triptans and CGRP blockade - impact on the cranial vasculature

The trigeminovascular system plays a key role in the pathophysiology of migraine. The activation of the trigeminovascular system causes release of various neurotransmitters and neuropeptides, including serotonin and calcitonin gene-related peptide (CGRP), which modulate pain transmission and vascular tone. Thirty years after discovery of agonists for serotonin 5-HT1B and 5-HT1D receptors (triptans) and less than fifteen after the proof of concept of the gepant class of CGRP receptor antagonists, we are still a long way from understanding their precise site and mode of action in migraine. The effect on cranial vasculature is relevant, because all specific anti-migraine drugs and migraine pharmacological triggers may act in perivascular space. This review reports the effects of triptans and CGRP blocking molecules on cranial vasculature in humans, focusing on their specific relevance to migraine treatment

Acute ischemic stroke with cervical internal carotid artery steno-occlusive lesion: multicenter analysis of endovascular approaches

open14noBackground Occlusions of internal carotid artery (ICA), whether isolated or in tandem lesions (TL) have a poor response to treatment with intravenous thrombolysis. Previous studies ​​have demonstrated the superiority of mechanical thrombectomy in the treatment of acute ischemic stroke (AIS) following large vessel occlusion, compared to standard intravenous fibrinolysis. The aim of our study was to describe endovascular treatment (EVT) in AIS due to ICA occlusion, whether isolated or in TL. Methods we assessed the association between 90-day outcome and clinical, demographic, imaging and procedure data in 51 consecutive patients with acute isolated ICA or TL occlusion who underwent endovascular treatment (EVT). We evaluated baseline NIHSS and mRS, ASPECTS, type of occlusion, stent placement, use of stent retrievers and/or thromboaspiration, duration of the procedure, mTICI, procedural therapy and complications. Results A favorable 90-day outcome (mRS 0–2) was achieved in 34 patients (67%) and was significantly associated with the use of dual antiplatelet therapy after the procedure (p = 0.008), shorter procedure duration (p = 0.031), TICI 2b-3 (p < 0.001) and lack of post-procedural hemorrhagic transformation (p = 0.001). Four patients did not survive, resulting in a mortality rate of 8% Conclusions EVT in the treatment of AIS due to ICA occlusion is safe and effective; mortality rates are in agreement with the current literature. The use of the stent is safe and promotes good angiographic results, as well as therapy with a GpIIb / IIIa inhibitor immediately after stent release which is also associated with better 3-month outcome and good revascularization.openLuigi Cirillo, Daniele Giuseppe Romano, Gianfranco Vornetti, Giulia Frauenfelder, Chiara Tamburrano, Francesco Taglialatela, Salvatore Isceri, Renato Saponiero, Rosa Napoletano, Mauro Gentile, Michele Romoli, Ciro Princiotta, Luigi Simonetti, Andrea ZiniLuigi Cirillo, Daniele Giuseppe Romano, Gianfranco Vornetti, Giulia Frauenfelder, Chiara Tamburrano, Francesco Taglialatela, Salvatore Isceri, Renato Saponiero, Rosa Napoletano, Mauro Gentile, Michele Romoli, Ciro Princiotta, Luigi Simonetti, Andrea Zin

Endovascular therapy versus no endovascular therapy in patients receiving best medical management for acute isolated occlusion of the posterior cerebral artery : A systematic review and meta-analysis

Background and purpose Endovascular therapy (EVT) is increasingly reported for treatment of isolated posterior cerebral artery (PCA) occlusions although its clinical benefit remains uncertain. This study-level meta-analysis investigated the functional outcomes and safety of EVT and best medical management (BMM) compared to BMM alone for treatment of PCA occlusion stroke. Methods We conducted a literature search in PubMed, Web of Science and Embase for studies in patients with isolated PCA occlusion stroke treated with EVT + BMM or BMM including intravenous thrombolysis. There were no randomized trials and all studies were retrospective. The primary outcome was modified Rankin Scale score of 0-2 at 3 months, while safety outcomes included mortality rate and incidence of symptomatic intracranial hemorrhage (sICH). Results Twelve studies with a total of 679 patients were included in the meta-analysis: 338 patients with EVT + BMM and 341 patients receiving BMM alone. Good functional outcome at 3 months was achieved in 58.0% (95% confidence interval [CI] 43.83-70.95) of patients receiving EVT + BMM and 48.1% (95% CI 40.35-55.92) of patients who received BMM alone, with respective mortality rates of 12.6% (95% CI 7.30-20.93) and 12.3% (95% CI 8.64-17.33). sICH occurred in 4.2% (95% CI 2.47-7.03) of patients treated with EVT + BMM and 3.2% (95% CI 1.75-5.92) of patients treated with BMM alone. Comparative analyses were performed on studies that included both treatments and these demonstrated no significant differences. Conclusions Our results demonstrate that EVT represents a safe treatment for patients with isolated PCA occlusion stroke. There were no differences in clinical or safety outcomes between treatments, supporting randomization of future patients into distal vessel occlusion trials.Peer reviewe

Particle monitoring capability of the Solar Orbiter Metis coronagraph through the increasing phase of solar cycle 25

Context. Galactic cosmic rays (GCRs) and solar particles with energies greater than tens of MeV penetrate spacecraft and instruments hosted aboard space missions. The Solar Orbiter Metis coronagraph is aimed at observing the solar corona in both visible (VL) and ultraviolet (UV) light. Particle tracks are observed in the Metis images of the corona. An algorithm has been implemented in the Metis processing electronics to detect the VL image pixels crossed by cosmic rays. This algorithm was initially enabled for the VL instrument only, since the process of separating the particle tracks in the UV images has proven to be very challenging. Aims. We study the impact of the overall bulk of particles of galactic and solar origin on the Metis coronagraph images. We discuss the effects of the increasing solar activity after the Solar Orbiter mission launch on the secondary particle production in the spacecraft. Methods. We compared Monte Carlo simulations of GCRs crossing or interacting in the Metis VL CMOS sensor to observations gathered in 2020 and 2022. We also evaluated the impact of solar energetic particle events of different intensities on the Metis images. Results. The study of the role of abundant and rare cosmic rays in firing pixels in the Metis VL images of the corona allows us to estimate the efficiency of the algorithm applied for cosmic-ray track removal from the images and to demonstrate that the instrument performance had remained unchanged during the first two years of the Solar Orbiter operations. The outcome of this work can be used to estimate the Solar Orbiter instrument's deep charging and the order of magnitude for energetic particles crossing the images of Metis and other instruments such as STIX and EUI.Comment: 8 pages, 6 figure