239 research outputs found

    Optimal on-off cooperative manoeuvers for long-term satellite cluster flight

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    When a group of satellites is equipped with a particulary simple propul- sion system, e.g. cold-gas thrusters, constraints on the thrust level and total propellant mass renders cluster-keeping extremely challenging. This is even more pronounced in disaggregated space architectures, in which a satellite is formed by clustering a number of heterogenous, free-flying modules. The research described in this paper develops guidance laws aimed at keeping the relative distances between the cluster modules bounded for long mission lifetimes, typically more than a year, while utilizing constant-magnitude low-thrust, with a characteristic on-off profile. A cooperative guidance law capable of cluster establishment and maintenance under realistic environ- mental perturbations is developed. The guidance law is optimized for fuel consumption, subject to relative distance constraints. Some of the solutions found to the optimal guidance problem require only a single maneuver arc to keep the cluster within relatively close distances for an entire year

    Changing the perspective on early development of Rett syndrome

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    We delineated the achievement of early speech-language milestones in 15 young children with Rett syndrome (MECP2 positive) in the first two years of life using retrospective video analysis. By contrast to the commonly accepted concept that these children are normal in the pre-regression period, we found markedly atypical development of speech-language capacities, suggesting a paradigm shift in the pathogenesis of Rett syndrome and a possible approach to its early detection

    Italian guidelines for primary headache: 2012 revised version

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    The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105-190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedic

    Efficacy of radioembolization according to tumor morphology and portal vein thrombosis in intermediate–advanced hepatocellular carcinoma

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    Purpose: We analyzed overall survival (OS) following radioembolization according to macroscopic growth pattern (nodular vs infiltrative) and vascular invasion in intermediate-advanced hepatocellular carcinoma (HCC). Methods: Between September 2005 and November 2013, 104 patients (50.0% portal vein thrombosis [PVT], 29.8% infiltrative morphology) were treated. Results: Median OS differed significantly between patients with segmental and lobar or main PVT (p = 0.031), but was 17 months in both those with patent vessels and segmental PVT. Median OS did not differ for infiltrative and nodular HCC. Median OS was prolonged in patients with a treatment response at 3 months (p = 0.023). Prior TACE was also a significant predictor of improved OS. Conclusion: A further indication for radioembolization might be infiltrative HCC, since OS was similar to nodular types

    Home-based pulmonary rehabilitation in patients undergoing (chemo)radiation therapy for unresectable lung cancer: a prospective explorative study

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    Aims The prevention of pulmonary toxicity is an important goal for patient candidate to radiation therapy for lung cancer. There is a lack of evidence on the role of exercise training for patients with unresectable stage III lung cancer candidated to radical treatment. The aim of this study was to evaluate the feasibility of a home-based pulmonary rehabilitation (PR) program and to identify reliable tools in terms of respiratory function, exercise capacity and quality of life. Methods Patients' recruitment lasted from April 2020 till February 2022. The PR program was proposed concomitantly to radiation therapy to the first 20 patients (interventional group, IG), and the other 20 patients were identified as an observational group (OG). All patients were assessed at baseline (T0) and after 8 weeks (T2) with 6 minute walking test (6MWT), modified Borg Scale (mBORG), SF-36 questionnaire (SF-36) and pulmonary function test (PFT); after 4 weeks (T1), only SF-36 was administered. Results A decrease of 13.8 m in the walked-distance was registered in the OG between T0 and T2 (p = 0.083). Instead, an increase of 56.6 m in the distance walked was recorded in the IG between T0 and T2 (p <= 0.001). In the OG, the mBORG scores showed a negative trend. On the contrary, in the IG, these scores showed a slight improvement. In the OG, all the items of SF-36 scores decreased between T0 and T1. In the IG, an increased trend from T0 to T2 was observed for all the items of SF-36. No clinically significant variations were detected from baseline to T2 in both groups regarding PFT. Conclusion The 6MWT, mBORG and SF-36 resulted as useful tools to assess the role of a PR program. A significant gain in functional exercise capacity and a prevention of the physiological impairment of QoL during radio(chemo)therapy was registered

    Candidurie nosocomiali: analisi dei fattori di rischio, terapia ed evoluzione micologica. Risultati di una indagine nazionale

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    The multiple problems associated with the recovery of yeasts from urine specimens induced the Medical Mycology Committee (CoSM) of AMCLI to run a nationwide epidemiologic survey on candiduria in order to evaluate risk factors, involved species, treatment and outcome. Ten hospitals (Bergamo, Como, Crema, Novara,Varese,Ancona, Florence, Pescara, Palermo and Taranto) participated to this study, which was run on a 15-month period (October 1, 2001-December 31, 2002). Overall, 83 Data Forms were collected, regarding patients admitted to Intensive Care Units (45), Surgical (9) and Medical (29) wards. The most common risk factors were: bladder catheter, antibiotic therapy, parenteral nutrition, kidney failure, surgery. Candiduria, mostly asymptomatic, were often associated with fever and bacterial infections. Concurrent candidaemia was detected in 13 patients. Candida albicans was the most frequently recovered species, from both urine and blood, followed by C. glabrata. Other Candida species were occasionally isolated from urine specimens. Specific antifungal treatment was administered to 58% of the patients, mostly using fluconazole. The remaining subjects did not receive antimycotic therapy. Eradication of Candida from urine specimens was observed even without a specific therapy

    A double-blind, randomized, multicenter, Italian study of frovatriptan versus almotriptan for the acute treatment of migraine

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    The objective of this study was to evaluate patients’ satisfaction with acute treatment of migraine with frovatriptan or almotriptan by preference questionnaire. One hundred and thirty three subjects with a history of migraine with or without aura (IHS 2004 criteria), with at least one migraine attack in the preceding 6 months, were enrolled and randomized to frovatriptan 2.5 mg or almotriptan 12.5 mg, treating 1–3 attacks. The study had a multicenter, randomized, double blind, cross-over design, with treatment periods lasting <3 months. At study end patients assigned preference to one of the treatments using a questionnaire with a score from 0 to 5 (primary endpoint). Secondary endpoints were pain free and pain relief episodes at 2 and 4 h, and recurrent and sustained pain free episodes within 48 h. Of the 133 patients (86%, intention-to-treat population) 114 of them expressed a preference for a triptan. The average preference score was not significantly different between frovatriptan (3.1 ± 1.3) and almotriptan (3.4 ± 1.3). The rates of pain free (30% frovatriptan vs. 32% almotriptan) and pain relief (54% vs. 56%) episodes at 2 h did not significantly differ between treatments. This was the case also at 4 h (pain free: 56% vs. 59%; pain relief: 75% vs. 72%). Recurrent episodes were significantly (P < 0.05) less frequent under frovatriptan (30% vs. 44%), also for the attacks treated within 30 min. No significant differences were observed in sustained pain free episodes (21% vs. 18%). The tolerability profile was similar between the two drugs. In conclusion, our study suggests that frovatriptan has a similar efficacy of almotriptan in the short-term, while some advantages are observed during long-term treatment
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