PO-0940: Feasibility of planning CT to MVCT deformable registration for ìdose of the dayî calculation in helical Tomotherapy

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How to pinpoint the greater palatine foramen : metrical analysis applied to a contemporary skeletal collection

Anatomy of greater palatine foramen has acquired a growing relevance in the fields of dentistry, maxillofacial surgery and otorhinolaryngology [1,2]. Several publications are available concerning the collocation of greater palatine foramen; however available literature has so far focused on few metrical measurements and has not yet performed a complete analysis for the localization of the greater palatine foramen. This study provides a novel approach to the metrical assessment of the position of the greater palatine foramen on 100 skulls belonging to the Milanese contemporary collection, based on six linear measurements and two angles. Possible differences according to sex and side were assessed through two-way ANOVA test (

Helium identification with LHCb

The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

Momentum scale calibration of the LHCb spectrometer

For accurate determination of particle masses accurate knowledge of the momentum scale of the detectors is crucial. The procedure used to calibrate the momentum scale of the LHCb spectrometer is described and illustrated using the performance obtained with an integrated luminosity of 1.6 fb-1 collected during 2016 in pp running. The procedure uses large samples of J/ψ → μ + μ - and B+ → J/ψ K + decays and leads to a relative accuracy of 3 × 10-4 on the momentum scale

Curvature-bias corrections using a pseudomass method

Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→μ + μ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→μ + μ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass

Recenti progressi nello studio dell’attivazione e dell’aggregazione delle piastrine

L\u2019interazione tra l\u2019adenosin-difosfato (ADP) e il suo recettore piastrinico P2Y12 svolge un ruolo cruciale nell\u2019attivazione piastrinica e nella trombogenesi. Farmaci che inibiscono il P2Y12 sono potenti agenti antitrombotici in pazienti con patologia coronarica. Il clopidogrel appartiene alla famiglia delle tienopiridine ed \ue8 il farmaco inibitore del P2Y12 pi\uf9 comunemente utilizzato in pazienti coronaropatici, che, tuttavia, presenta alcuni importanti svantaggi: 1) \ue8 un pro-farmaco che necessita di essere trasformato in un metabolita attivo; 2) dopo la sua sospensione, la normalizzazione della funzione piastrinica si verifica solo dopo alcuni giorni, poich\ue9 esso inibisce irreversibilmente le piastrine; 3) vi \ue8 un\u2019elevata variabilit\ue0 inter-individuale di risposta farmacologica. Il prasugrel \ue8 un\u2019altra tienopiridina, con un inizio di azione pi\uf9 rapido e pi\uf9 uniforme inibizione piastrinica rispetto al clopidogrel. Queste caratteristiche ne spiegano la maggior efficacia antitrombotica in pazienti con sindrome coronarica acuta sottoposti ad angioplastica coronarica, ma anche la minor sicurezza, in quanto al suo utilizzo si associa una maggior incidenza di complicanze emorragiche. I due antagonisti diretti del P2Y12, cangrelor e ticagrelor, sono caratterizzati da un rapido inizio di azione e dalla reversibilit\ue0 dell\u2019inibizione piastrinica. Il cangrelor non \ue8 risultato superiore al clopidogrel nella prevenzione di eventi trombotici nei pazienti sottoposti a PTCA. Il ticagrelor, primo inibitore diretto del P2Y12 somministrabile per via orale, si \ue8 dimostrato superiore al clopidogrel nella prevenzione di eventi avversi cardiaci maggiori nei pazienti con sindrome coronarica acuta. Inoltre, il ticagrelor ha ridotto l\u2019incidenza di mortalit\ue0 sia vascolare che totale. Tuttavia, anche il ticagrelor era associato a una maggior incidenza di eventi emorragici maggiori spontanei. A differenza del prasugrel, esso non si \ue8 associato a un aumento delle complicanze emorragiche di interventi di bypass aorto-coronarico.The interaction of ADP with its platelet receptor P2Y12 plays a crucial role in platelet activation and thrombogenesis. This article reviews the pharmacology and clinical trials of specific antagonists of P2Y12. Clopidogrel is a thienopyridine with proven antithrombotic efficacy, but it has some important drawbacks: i) it is a pro-drug that needs to be metabolized to its active metabolite; ii) it has a delayed onset and offset of action; iii) there is high inter-individual variability in pharmacological response. Prasugrel is also a thienopyridine, with faster onset of action andmore uniforminhibition of platelet function compared to clopidogrel, accounting for lower incidence of ischemic events in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) and higher incidence of both non-CABG (Coronary Artery Bypass Grafting) related bleeding complications. Two direct and reversible P2Y12 antagonists, cangrelor and ticagrelor, are characterized by rapid onset and reversal of platelet inhibition. Cangrelor did not prove superior to clopidogrel in preventing thrombotic events in patients undergoing PCI. Ticagrelor proved to be superior to clopidogrel in preventing-major adverse cardiac events in ACS patients, but was, like prasugrel, was associated with higher frequency of non-CABG-related bleeding complications. A shorter period of drug discontinuation before surgery was necessary in ticagrelor-treated patients compared to clopidogrel-treated patients to limit the severity of post-surgical bleeding

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Thrombopoietin receptor agonists for the treatment of primary immune thrombocytopenia : a meta-analysis and systematic review

Previous meta-analyses reported discordant results on the efficacy and safety of thrombopoietin receptor agonists (TPO-RA) as second-line treatment in patients with immune thrombocytopenia (ITP). We conducted a meta-analysis of primary ITP treatment with the TPO-RA Romiplostim, Eltrombopag and Avatrombopag, including additional studies and relevant endpoints. We searched MEDLINE, EMBASE and CENTRAL for randomized clinical trials (RCTs) and cohort studies on TPO-RA in ITP published until December 31, 2018. The primary endpoints were: risk ratio (RR) of treatment failure and bleeding of WHO grade 652; rate of remission after discontinuation of treatment. The principal safety outcome was RR and incidence of thrombotic events and liver damage. From 1044 identified records we selected 16 RCTs and 19 cohort studies. RCTs included 909 patients assigned to TPO-RA and 427 to the control arm. Treatment failure was observed in 21% TPO-RA-treated patients and 47% control arm patients (RR = 0.42, 95% CI 0.33\u20130.53) in RCTs during a median follow-up of 13 weeks, and in 29% TPO-RA-treated patients in cohort studies, during a median follow-up of 69 weeks. The incidence of remission after TPO discontinuation was 18% (5\u201336%). RR of WHO grade 652 bleeding was 0.58 (0.38\u20130.86) in TPO-RA-treated patients, compared to control arm patients. Adverse events were rare and not significantly different in the two groups of patients. All-cause mortality was significantly lower with TPO-RA (RR 0.21, 95% CI, 0.06\u20130.68). In conclusion, TPO-RA are effective and safe in patients with ITP, even in the long term