574 research outputs found
Virtualit\ue0 al quadrato: proposta di sperimentazione di un ambiente didattico universitario in Second Life
Il presente lavoro intende esplorare le possibilit\ue0 offerte da
Second Life in ambito online-learning, sperimentando un
percorso di allestimento di ambienti di apprendimento in
ambito universitario attraverso metodologie didattiche e
strumenti che si avvalgono della sinergia fra due tecnologie:
da una parte, la ricostruzione tridimensionale di un contesto
formativo accademico utilizzando la piattaforma Second Life
valorizzata dall'introduzione di nuovi tool, dall'altra
l'interfacciamento con Moodle, nella delineazione di un
possibile utilizzo a livello didattico
Hemorrhagic risk after intravenous thrombolysis for ischemic stroke in patients with cerebral microbleeds and white matter disease
Objectives: Aim of this study was to evaluate the association between cerebral microbleeds (CMBs) and white matter disease (WMD) with intracerebral hemorrhage (ICH) after intravenous thrombolysis (IVT) with rt-PA. We also evaluated whether CMBs characteristics and WMD burden correlate with symptomatic ICH and outcome. Methods: We included acute ischemic stroke (AIS) patients treated with IVT. The number and location of CMBs as well as severity of WMD were rated analyzing pre- or post-treatment MRI. Multivariable regression analysis was used to determine the impact of CMB and WMD on ICH subgroups and outcome measures. Results: 434 patients were included. CMBs were detected in 23.3% of them. ICH occurred in 34.7% of patients with CMBs. Independent predictors of parenchymal hemorrhage were the presence of CMBs (OR 2.724, 95% CI 1.360â5.464, p = 0.005) as well as cortical-subcortical stroke (OR 3.629, 95% CI 1.841â7.151, p < 0.001) and atherothrombotic stroke subtype (OR 3.381, 95% CI 1.335â8.566, p = 0.010). Either the presence, or number, and location of CMBs, as well as WMD, was not independently associated with the development of SICH. No independent association between the presence, number, or location of CMBs or WMD and outcome measures was observed. Conclusions: The results of our study suggest that the exclusion of eligible candidates to administration of IV rt-PA only on the basis of CMBs presence is not justified. The clinical decision should be weighed with a case-by-case approach. Additional data are needed to evaluate the benefit-risk profile of rt-PA in patients carrying numerous microbleeds
Picosecond Internal Dynamics of Lysozyme as Affected by Thermal Unfolding in Nonaqueous Environment
AbstractA neutron-scattering investigation of the internal picosecond dynamics of lysozyme solvated in glycerol as a function of temperature in the range 200â410K has been undertaken. The inelastic contribution to the measured intensity is characterized by the presence of a bump generally known as âboson peakâ, clearly distinguishable at low temperature. When the temperature is increased the quasielastic component of the spectrum becomes more and more intrusive and progressively overwhelms the vibrational bump. This happens especially for T>345K when the protein goes through an unfolding process, which leads to the complete denaturation. The quasielastic term is the superposition of two components whose intensities and linewidths have been studied as a function of temperature. The slower component describes motions with characteristic times of âŒ4ps corresponding to reorientations of polypeptide side chains. Both the intensity and linewidth of this kind of relaxations show two distinct regimes with a crossover in the temperature range where the melting process occurs, thus suggesting the presence of a dynamical transition correlated to the protein unfolding. Conversely the faster component might be ascribed to the local dynamics of hydrogen atoms caged by the nearest neighbors with characteristic time of âŒ0.3ps
Stroke care in Italy: An overview of strategies to manage acute stroke in COVID-19 time
Purpose: To analyse structural and non-structural modifications of acute stroke care pathways undertaken at healthcare institutions across the regions of Italy due to the coronavirus disease 2019 (COVID-19) pandemic. Methods: Research on National decrees specific for the pandemic was carried out. The stroke pathways of four Italian regions from North to South, such as Lombardy, Veneto, Lazio and Campania, were analysed before and after the pandemic outbreak. Findings: On 29 February 2020, the Italian Minister of Health issued national guidelines on how to address the COVID-19 emergency. Stroke management was affected and required changes, basically resulting in the need to prioritise the ongoing COVID-19 emergency. In the most affected regions, the closure of departments and hospitals led to a complete reorganisation of previously functioning stroke networks. With the closure of several Stroke Units and Stroke Centres, the transportation time to hospital lengthened significantly, especially for the outlying populations. Discussion: The COVID-19 pandemic outbreak has been spreading rapidly in Italy and placing an overwhelming burden on healthcare systems. In response to this, political and healthcare decision-makers worked together to develop and implement efforts to sustain the national healthcare system while fighting the pandemic. Stroke care pathways changed during the pandemic and different organisational models were applied in the most affected regions. Conclusions: Stroke treatment pathways will need to be redesigned so to guarantee that severe and acute disease patients do not lose their rights to the access and delivery of care during the COVID-19 pandemics
Double dynamical regime of confined water
The Van Hove self correlation function of water confined in a silica pore is
calculated from Molecular Dynamics trajectories upon supercooling. At long time
in the relaxation region we found that the behaviour of the real space
time dependent correlators can be decomposed in a very slow, almost frozen,
dynamics due to the bound water close to the substrate and a faster dynamics of
the free water which resides far from the confining surface. For free water we
confirm the evidences of an approach to a crossover mode coupling transition,
previously found in Q space. In the short time region we found that the two
dynamical regimes are overimposed and cannot be distinguished. This shows that
the interplay between the slower and the faster dynamics emerges in going from
early times to the relaxation region, where a layer analysis of the
dynamical properties can be performed.Comment: 6 pages with 9 figures. RevTeX. Accepted for pulbication in J. Phys.
Cond. Mat
A large-area double rotating-crystal monochromator for time-focusing neutron instruments
We present the principle and the first prototypes of a double rotating-crystal monochromator, based on an assembly of smaller rotating elements. Such a device was developed as the key element to implement a parallel-beam modification of the time-focusing technique for neutron spectrometers. This concept is particularly promising for long-pulse sources and can bring specific advantages on continuous sources as well. Neutron tests performed on the first prototypes validate the mechanical reliability of the proposed design and the feasibility of a large-area double rotating-crystal monochromator based on this technology
European Stroke Organisation (ESO) guideline on screening for subclinical atrial fibrillation after stroke or transient ischaemic attack of undetermined origin
We aimed to provide practical recommendations for the screening of subclinical atrial fibrillation (AF) in patients with ischaemic stroke or transient ischaemic attack (TIA) of undetermined origin. These guidelines are based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. Five relevant Population, Intervention, Comparator, Outcome questions were defined by a multidisciplinary module working group (MWG). Longer duration of cardiac rhythm monitoring increases the detection of subclinical AF, but the optimal monitoring length is yet to be defined. We advise longer monitoring to increase the rate of anticoagulation, but whether longer monitoring improves clinical outcomes needs to be addressed. AF detection does not differ from in- or out-patient ECG-monitoring with similar monitoring duration, so we consider it reasonable to initiate in-hospital monitoring as soon as possible and continue with outpatient monitoring for more than 48 h. Although insertable loop recorders (ILR) increase AF detection based on their longer monitoring duration, comparison with non-implantable ECG devices for similar monitoring time is lacking. We suggest the use of implantable devices, if feasible, for AF detection instead of non-implantable devices to increase the detection of subclinical AF. There is weak evidence of a useful role for blood, ECG and brain imaging biomarkers for the identification of patients at high risk of AF. In patients with patent foramen ovale, we found insufficient evidence from RCT, but prolonged cardiac monitoring in patients >55 years is advisable for subclinical AF detection. To conclude, in adult patients with ischaemic stroke or TIA of undetermined origin, we recommend longer duration of cardiac rhythm monitoring of more than 48 h and if feasible with IRL to increase the detection of subclinical AF
Prevention of venous thromboembolism in acute spontaneous intracerebral haemorrhage: A survey of opinion
INTRODUCTION: People immobilized following acute spontaneous intracerebral haemorrhage (ICH) are at risk of venous thromboembolism (VTE) but the role of short-term prophylactic anticoagulation remains uncertain. We surveyed UK clinical practice and opinion regarding preventing VTE after ICH. PATIENTS AND METHODS: An online survey was sent to stroke healthcare professionals within the United Kingdom and Ireland via a professional society (British and Irish Association of Stroke Physicians (BIASP)). RESULTS: One hundred and twenty-three staff members responded to the survey, of whom 80% were consultant stroke physicians. All responders except one considered the issue to be important or extremely important, but only 5 (4%) were âextremely certainâ and 51 (41%) âfairly certainâ regarding the optimal treatment approach. Intermittent pneumatic compression (IPC) devices alone were the most used method (in 60%) followed by IPC devices and switching to low molecular weight heparin (LMWH) (in 30%). We identified high levels of uncertainty regarding the role of anticoagulation, and its optimal timing; uncertainty was greater in lobar compared to deep ICH. Most respondents (93%) consider a randomised controlled trial investigating the role of pharmacological VTE prophylaxis after acute ICH as important and would consider participation. DISCUSSION AND CONCLUSION: The optimal method for the prevention of VTE in non-traumatic ICH patients remains an area of clinical uncertainty. Clinical trials assessing short-term anticoagulation in patients after acute ICH would be beneficial in providing evidence to resolve this clinical dilemma
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