57 research outputs found
Machine learning to predict the solar flux and geomagnetic indices to model density and Drag in Satellites
In recent years (2000-2021), human-space activities have been increasing
faster than ever. More than 36000 Earth' orbiting objects, all larger than 10
cm, in orbit around the Earth, are currently tracked by the European Space
Agency (ESA). Around 70\% of all cataloged objects are in Low-Earth Orbit
(LEO). Aerodynamic drag provides one of the main sources of perturbations in
this population, gradually decreasing the semi-major axis and period of the LEO
satellites. Usually, an empirical atmosphere model as a function of solar radio
flux and geomagnetic data is used to calculate the orbital decay and lifetimes
of LEO satellites. In this respect, a good forecast for the space weather data
could be a key tool to improve the model of drag. In this work, we propose
using Time Series Forecasting Model to predict the future behavior of the solar
flux and to calculate the atmospheric density, to improve the analytical models
and reduce the drag uncertainty
Complications of mechanical thrombectomy for acute ischemic stroke: Incidence, risk factors, and clinical relevance in the Italian Registry of Endovascular Treatment in acute stroke
BACKGROUND: There are limited data concerning procedure-related complications of endovascular thrombectomy for large vessel occlusion strokes. AIMS: We evaluated the cumulative incidence, the clinical relevance in terms of increased disability and mortality, and risk factors for complications. METHODS: From January 2011 to December 2017, 4799 patients were enrolled by 36 centers in the Italian Registry of Endovascular Stroke Treatment. Data on demographic and procedural characteristics, complications, and clinical outcome at three months were prospectively collected. RESULTS: The complications cumulative incidence was 201 per 1000 patients undergoing endovascular thrombectomy. Ongoing antiplatelet therapy (pâ<â0.01; OR 1.82, 95% CI: 1.21-2.73) and large vessel occlusion site (carotid-T, pâ<â0.03; OR 3.05, 95% CI: 1.13-8.19; M2-segment-MCA, pâ<â0.01; OR 4.54, 95% CI: 1.66-12.44) were associated with a higher risk of subarachnoid hemorrhage/arterial perforation. Thrombectomy alone (pâ<â0.01; OR 0.50, 95% CI: 0.31-0.83) and younger age (pâ<â0.04; OR 0.98, 95% CI: 0.97-0.99) revealed a lower risk of developing dissection. M2-segment-MCA occlusion (pâ<â0.01; OR 0.35, 95% CI: 0.19-0.64) and hypertension (pâ<â0.04; OR 0.77, 95% CI: 0.6-0.98) were less related to clot embolization. Higher NIHSS at onset (pâ<â0.01; OR 1.04, 95% CI: 1.02-1.06), longer groin-to-reperfusion time (pâ<â0.01; OR 1.05, 95% CI: 1.02-1.07), diabetes (pâ<â0.01; OR 1.67, 95% CI: 1.25-2.23), and LVO site (carotid-T, pâ<â0.01; OR 1.96, 95% CI: 1.26-3.05; M2-segment-MCA, pâ<â0.02; OR 1.62, 95% CI: 1.08-2.42) were associated with a higher risk of developing symptomatic intracerebral hemorrhage compared to no/asymptomatic intracerebral hemorrhage. The subgroup of patients treated with thrombectomy alone presented a lower risk of symptomatic intracerebral hemorrhage (pâ<â0.01; OR 0.70; 95% CI: 0.55-0.90). Subarachnoid hemorrhage/arterial perforation and symptomatic intracerebral hemorrhage after endovascular thrombectomy worsen both functional independence and mortality at three-month follow-up (pâ<â0.01). Distal embolization is associated with neurological deterioration (pâ<â0.01), while arterial dissection did not affect clinical outcome at follow-up. CONCLUSIONS: Complications globally considered are not uncommon and may result in poor clinical outcome. Early recognition of risk factors might help to prevent complications and manage them appropriately in order to maximize endovascular thrombectomy benefits
Hand washing with soap and water together with behavioural recommendations prevents infections in common work environment: an open cluster-randomized trial
<p>Abstract</p> <p>Background</p> <p>Hand hygiene is considered as an important means of infection control. We explored whether guided hand hygiene together with transmission-limiting behaviour reduces infection episodes and lost days of work in a common work environment in an open cluster-randomized 3-arm intervention trial.</p> <p>Methods</p> <p>A total of 21 clusters (683 persons) were randomized to implement hand hygiene with soap and water (257 persons), with alcohol-based hand rub (202 persons), or to serve as a control (224 persons). Participants in both intervention arms also received standardized instructions on how to limit the transmission of infections. The intervention period (16 months) included the emergence of the 2009 influenza pandemic and the subsequent national hand hygiene campaign influencing also the control arm.</p> <p>Results</p> <p>In the total follow-up period there was a 6.7% reduction of infection episodes in the soap-and water arm (p = 0.04). Before the onset of the anti-pandemic campaign, a statistically significant (p = 0.002) difference in the mean occurrence of infection episodes was observed between the control (6.0 per year) and the soap-and-water arm (5.0 per year) but not between the control and the alcohol-rub arm (5.6 per year). Neither intervention had a decreasing effect on absence from work.</p> <p>Conclusions</p> <p>We conclude that intensified hand hygiene using water and soap together with behavioural recommendations can reduce the occurrence of self-reported acute illnesses in common work environment. Surprisingly, the occurrence of reported sick leaves also increased in the soap-and water-arm.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00981877">NCT00981877</a></p> <p>Source of funding</p> <p>The Finnish Work Environment Fund and the National Institute for Health and Welfare.</p
A study of dialogic expansion and contraction in spoken discourse using corpus and experimental techniques
A pathway care model allowing low-risk patients to gain direct admission to a hospital medical ward â a pilot study on ambulance nurses and Emergency Department physicians
Towards Richer Assisted Living Environments
This paper describes an ongoing research project which explores the design and use of inexpensive robotics, artificial intelligence techniques, and humanâcomputer interaction methods, to enrich assisted living environments. Such environments provide help to the inhabitants of a home or office, assisting them to perform daily activities, helping them to socialize and interact with others, and to provide enhanced levels of security and safeness. We present the development of an inexpensive robotic solution to help people with disabilities and/or older adults to perform their daily activities. It can be used as a remote controlled surveillance system, and also as a personal assistant. It is able to recognize each inhabitant, his/her emotions, and detect abnormal situations such as falls and health problems. The whole system is designed to operate solely within a local network and special attention is given to the privacy and data protection of the users.authorsversionpublishe
QT-interval evaluation in primary percutaneous coronary intervention of ST-segment elevation myocardial infarction for prediction of myocardial salvage index
Assessing the efficacy of revascularization therapy in patients with ST-segment elevation myocardial infarction (STEMI) is extremely important in order to guide subsequent management and assess prognosis. We aimed to determine the relationship between corrected QT-interval (QTc) changes on standard sequential ECG and myocardial salvage index in anterior STEMI patients after successful primary percutaneous coronary intervention. Fifty anterior STEMI patients treated by primary percutaneous coronary intervention underwent quantitative ECG analysis and cardiac magnetic resonance. For each patient the difference (ÎQTc) between the QTc of ischemic myocardium (maximum QTc in anterior leads) versus remote myocardium (minimum QTc in inferior leads) during the first six days after STEMI was measured. The QTc in anterior leads was significantly longer than QTc in inferior leads (p<0.0001). At multivariate analysis, ÎQTC and peak troponin I were the only independent predictors for late gadolium enhancement while ÎQTc and left ventricular ejection fraction were independent predictors of myocardial salvage index <60%. The receiver operative curve of ÎQTc showed an area under the curve of 0.77 to predict a myocardial salvage index <0.6. In conclusion, in a subset of patients with a first occurrence of early revascularized anterior STEMI, ÎQTc is inversely correlated with CMR-derived myocardial salvage index and may represent a useful parameter for assessing efficacy of reperfusion therapy
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