On multi-phase machines and current harmonic injection for torque capability improvement

The increased energy demand and the need for electrical machines capable to deliver high torque and power in small volumes is pushing the research community to identify suitable solutions for this target. Nowadays, electrical machines are deeply used also in applications where the weight containment is important such as automotive and aerospace. Multi-phase electrical machines are a suitable candidate to help to get this goal. They present different advantages with respect to classical three-phase machines for example an increased machine torque capability and more tolerance to sustain fault conditions. The average torque is increased thanks to an improved winding factor whereas the fault tolerance improvement is due to the higher number of machine phases. In addition, the torque ripple is lower thanks to an improved magneto-motive force distribution. Moreover, the voltage on the single converter is lower, supplying the machine with the same current of a three-phase system. Another important advantage for the multi-phase arrangement is the possibility to control more harmonics of magnetic field independently thanks to the more degrees of freedom. It means new possibilities to implement various control techniques for improving the machine performance by the injection of additional harmonics higher than the fundamental. This thesis describes the work which has been carried out in the past three years, during the Ph.D program with the results achieved by analytical model implementations, finite element analysis simulations and experimental tests. The main target is to improve the machine torque capability and/or reduce its permanent magnet content. To reach this goal, the multi-phase re-arrangement of three-phase machines and current harmonic injection techniques are proposed for different machine topologies. An analytical model is implemented to reduce the magnet content in surface permanent magnet machines without affecting Joule losses and the average torque. The analytical model is validated via FEA. A model-free technique to improve the torque capability by current harmonic injection is proposed and its concept is validated experimentally on a V-Shape interior permanent magnet machine. Sensitivity analyses are carried out to optimise the V-Shape rotor configuration to improve the torque under fifth current harmonic injection. Studying the flux density in the stator core on a classical three-phase surface permanent magnet machine with a distributed winding layout, it is possible to highlight another advantage of multi-phase machines which consists in a better flux density distribution. The proposed work gives a contribution to the research community in terms of new solutions for increasing the torque capability and/or reducing the permanent magnet content in the machine without affecting its efficiency for different rotor topologies. Moreover, the proposed stator flux density analysis can give important information about the electromagnetic behaviour in three-phase distributed winding surface permanent magnet machines

Cannabis; epidemiological, neurobiological and psychopathological issues: an update

This document is the Accepted Manuscript version of the following article: Maria Antonietta De Luca, Gaetano Di Chiara, Cristina Cadoni, Daniele Lecca, Laura Orsolini, Duccio Papanti, John Corkery, Fabrizio Schifano, 'Cannabis; Epidemiological, Neurobiological and Psychopathological Issues: An Update', CNS & Neurological Disorders - Drug Targets, Vol. 16, 2017. The published manuscript is available at EurekaSelect via https://doi.org/10.2174/1871527316666170413113246. Published by Bentham Science.Cannabis is the illicit drug with both the largest current levels of consumption and the highest reported lifetime prevalence levels in the world. Across different countries, the prevalence of cannabis use varies according to the individual income, with the highest use being reported in North America, Australia and Europe. Despite its ‘soft drug’ reputation, cannabis misuse may be associated with several acute and chronic adverse effects. The present article aims at reviewing several papers on epidemiological, neurobiological and psychopathological aspects of the use of cannabis. The PubMed database was here examined in order to collect and discuss a range of identified papers. Cannabis intake usually starts during late adolescence/early adulthood (15-24 years) and drastically decreases in adulthood with the acquisition of working, familiar and social responsibilities. Clinical evidence supports the current socio-epidemiological alarm concerning the increased consumption among youngsters and the risks related to the onset of psychotic disorders. The mechanism of action of cannabis presents some analogies with other abused drugs, e.g. opiates. Furthermore, it has been well demonstrated that cannabis intake in adolescence may facilitate the transition to the use and/or abuse of other psychotropic drugs, hence properly being considered a ‘gateway drug’. Some considerations on synthetic cannabimimetics are provided here as well. In conclusion, the highest prevalence of cannabis use and the social perception of a relatively low associated risk are in contrast with current knowledge based on biological and clinical evidence. Indeed, there are concerns relating to cannabis intake association with detrimental effects on both cognitive impairment and mental health.Peer reviewe

A multi-port power conversion system for the more electric aircraft

In more electric aircraft (MEA) weight reduction and energy efficiency constitute the key figures. Additionally, the safety and continuity of operation of its electrical power distribution system (EPDS) is of critical importance. These sets of desired features are in disagreement with each other, because higher redundancy, needed to guarantee the safety of operation, implies additional weight. In fact, EPDS is usually divided into isolated sections, which need to be sized for the worst-case scenario. Several concepts of EPDS have been investigated, aiming at enabling the power exchange among separate sections, which allows better optimization for power and weight of the whole system. In this paper, an approach based on the widespread use of multi-port power converters for both DC/DC and DC/AC stages is proposed. System integration of these two is proposed as a multiport power conversion system (MPCS), which allows a ring power distribution while galvanic isolation is still maintained, even in fault conditions. Thus, redundancy of MEA is established by no significant weight increase. A machine design analysis shows how the segmented machine could offer superior performance to the traditional one with same weight. Simulation and experimental verifications show the system feasibility in both normal and fault operations

Gefitinib in Non Small Cell Lung Cancer

Gefitinib is an oral, reversible, tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) that plays a key role in the biology of non small cell lung cancer (NSCLC). Phase I studies indicated that the recommended dose of gefitinib was 250 mg/day. Rash, diarrhea, and nausea were the most common adverse events. The positive results obtained in early phase 2 clinical trials with gefitinib were not confirmed in large phase 3 trials in unselected patients with advanced NSCLC. The subsequent discovery that the presence of somatic mutations in the kinase domain of EGFR strongly correlates with increased responsiveness to EGFR tyrosine kinase inhibitors prompted phase 2 and 3 trials with gefitinib in the first line-treatment of EGFR-mutated NSCLC. The results of these trials have demonstrated the efficacy of gefitinib that can be now considered as the standard first-line treatment of patients with advanced NSCLC harbouring activating EGFR mutations

Treatment persistence with aripiprazole once monthly: a 4-year follow-up

Objectives: Treatment persistence refers to the act of continuing a treatment as prescribed and reflects the patient's or doctor's judgment about efficacy, tolerability, and acceptability. In patients with schizophrenia, antipsychotic persistence is often poor, because of issues such as lack or loss of efficacy, side effects, and poor adherence, which is often related to the degree to which patients find the medication and overall intervention to be helpful, tolerable, fair, reasonable, appropriate, and consistent with expectations of treatment. Despite the poor antipsychotic persistence that has been reported to date in patients with schizophrenia, we previously observed a relatively high (86%) 6 months persistence with aripiprazole once-monthly (AOM) in a group of patients with schizophrenia, treated in the real world Italian clinical practice. The present study explores the longer term persistence with AOM, over a mean follow-up period of 48 months. Methods: This was a multicenter, retrospective, non-interventional follow-up study, aimed at evaluating the longer term persistence with AOM in a group of patients with schizophrenia who had already shown persistence over a period of at least 6 months. The study included 161 individuals who had participated in our previous study, where 86% of participating individuals had shown persistence with AOM for at least 6 months. Non-persistence was defined as discontinuing the medication for any reason. Baseline demographic and clinical characteristics of patients who continued AOM were then compared to those of patients who discontinued the medication. Results: Study subjects were predominantly male (64.4%) and their mean age was 39.7 (SD: 12.24). Treatment persistence with AOM was 69.6% and 112 out of 161 patients were still receiving AOM treatment at the last follow-up visit. The mean duration of AOM treatment until the last recorded observation was 55.87 months (median 56.17, SD6.23) for the 112 persistent patients and 32.23 (median 28.68.SD 15.09) months for the 49 non-persistent individuals. The mean observation period for all patients (persistent and non-persistent) was 48.78 months (median 52.54, SD 14.64). For non-persistent subjects, the observation period ended with the discontinuation of AOM. Subjects treated with AOM at 400 mg presented a 69.6% lower risk of all-cause treatment discontinuation when compared with patients treated with 300 mg (HR: 0.314; 95% confidence interval [CI] 0.162-0.608; P = 0.001). The main reasons for discontinuation were lack of efficacy (30.6%), patient/caregiver choice (18.4%), physician's choice (16.3%), non-adherence (12.2%) and inconvenience (6.1%). Only 3 patients (6.1%) discontinued AOM for tolerability issues. Conclusions: In subjects with schizophrenia, who had already shown a 6 months persistence with AOM, a high number of patients (69.6%) continued to be persistent over a 4-year follow-up period. This may reflect a favourable profile of efficacy, tolerability, and acceptability. Larger and prospective studies are warranted to confirm our observations

Monitoring the December 2015 summit eruptions of Mt. Etna (Italy): Implications on eruptive dynamics

A lengthy period of eruptive activity fromthe summit craters ofMt. Etna started in January 2011. It culminated in early December 2015 with a spectacular sequence of intense eruptive events involving all four summit craters (Voragine, Bocca Nuova,NewSoutheast Crater, and Northeast Crater). The activity consisted of high eruption columns, Strombolian explosions, lava flows andwidespread ash falls that repeatedly interferedwith air traffic. The most powerful episode occurred on 3 December 2015 from the Voragine. After three further potent episodes fromthe Voragine, activity shifted to the NewSoutheast Crater on 6 December 2015, where Strombolian activity and lava flow emission lasted for two days and were fed by the most primitive magma of the study period. Activity once more shifted to the Northeast Crater, where ash emission and weak Strombolian activity took place for several days. Sporadic ash emissions from all craters continued until 18 December, when all activity ceased. Although resembling the summit eruptions of 1998–1999, which also involved all four summit craters, thismultifaceted eruptive sequence occurred in an exceptionally short time window of less than three days, unprecedented in the recent activity of Mt. Etna. It also produced important morphostructural changes of the summit area with the coalescence of Voragine and Bocca Nuova in a single large crater, the “Central Crater”, reproducing themorphological setting of the summit cone before the formation of Bocca Nuova in 1968. The December 2015 volcanic crisis was followed closely by the staff of the Etna Observatory to monitor the on-going activity and forecast its evolution, in accordance with protocols agreed with the Italian Civil Protection Department.Published53-695V. Dinamica dei processi eruttivi e post-eruttiviJCR Journa

Clinical governance of patients with acute coronary syndromes

Aims Using the principles of clinical governance, a patient-centred approach intended to promote holistic quality improvement, we designed a prospective, multicentre study in patients with acute coronary syndrome (ACS). We aimed to verify and quantify consecutive inclusion and describe relative and absolute effects of indicators of quality for diagnosis and therapy. Methods and results Administrative codes for invasive coronary angiography and acute myocardial infarction were used to estimate the ACS universe. The ratio between the number of patients included and the estimated ACS universe was the consecutive index. Co-primary quality indicators were timely reperfusion in patients admitted with ST-elevation ACS and optimal medical therapy at discharge. Cox-proportional hazard models for 1-year death with admission and discharge-specific covariates quantified relative risk reductions and adjusted number needed to treat (NNT) absolute risk reductions. Hospital codes tested had a 99.5% sensitivity to identify ACS universe. We estimated that 7344 (95% CI: 6852-7867) ACS patients were admitted and 5107 were enrolled-i.e. a consecutive index of 69.6% (95% CI 64.9-74.5%), which varied from 30.7 to 79.2% across sites. Timely reperfusion was achieved in 22.4% (95% CI: 20.7-24.1%) of patients, was associated with an adjusted hazard ratio (HR) for 1-year death of 0.60 (95% CI: 0.40-0.89) and an adjusted NNT of 65 (95% CI: 44-250). Corresponding values for optimal medical therapy were 70.1% (95% CI: 68.7-71.4%), HR of 0.50 (95% CI: 0.38-0.66), and NNT of 98 (95% CI: 79-145). Conclusion A comprehensive approach to quality for patients with ACS may promote equitable access of care and inform implementation of health care delivery. Registration ClinicalTrials.Gov ID NCT0425553

Identification and characterization of the nano-sized vesicles released by muscle cells

Several cell types secrete small membranous vesicles that contain cell-specific collections of proteins, lipids, and genetic material. The function of these vesicles is to allow cell-to-cell signaling and the horizontal transfer of their cargo molecules. Here, we demonstrate that muscle cells secrete nano-sized vesicles and that their release increases during muscle differentiation. Analysis of these nanovesicles allowed us to characterize them as exosome-like particles and to define the potential role of the multifunctional protein Alix in their biogenesis