7,275 research outputs found
Dynamics of a particle confined in a two-dimensional dilating and deforming domain
Some recent results concerning a particle confined in a one-dimensional box
with moving walls are briefly reviewed. By exploiting the same techniques used
for the 1D problem, we investigate the behavior of a quantum particle confined
in a two-dimensional box (a 2D billiard) whose walls are moving, by recasting
the relevant mathematical problem with moving boundaries in the form of a
problem with fixed boundaries and time-dependent Hamiltonian. Changes of the
shape of the box are shown to be important, as it clearly emerges from the
comparison between the "pantographic", case (same shape of the box through all
the process) and the case with deformation.Comment: 13 pages, 2 figure
Paediatric ambulatory care sensitive hospitalisation and Italian deprivation index. Retrospective multilevel analysis of administrative data from 2008 to 2018 in the Abruzzo Region (Southern Italy)
OBJECTIVES: to estimate and analyse the trend of paediatric hospitalisations for Ambulatory Care Sensitive Conditions (ACSCs) from 2008 to 2018 in a region of southern Italy and to assess the association with the socio-economic deprivation index (DI). DESIGN: retrospective observational study. SETTING AND PARTICIPANTS: ACSC hospitalisations in children (<=18 years) were identified. Discharges for ACSC of the Abruzzo Region from 2008 to 2018 were selected and the deprivation index of the municipality of residence was assigned to the hospital discharge record where the patient's residence was reported. MAIN OUTCOME MEASURES: the rate of paediatric preventable admissions (PPHs) related to ACSC, standardized by age and gender with the direct method, was calculated for the years of observation. The average annual percentage change (AAPC) was calculated with a trend analysis. In addition, the odds ratios (ORs) of hospitalisation for ACSC were calculated using a hierarchical logistic regression model. RESULTS: 252,513 hospitalisations were examined, of which 16,264 (6.4%) attributable to ACSC. During the study period, the hospitalisation rate decreased from 8.59 per 1,000 to 6.12 per 1,000 residents, with an AAPC of -3.7, which was statistically significant (p<0.05). Furthermore, an association was highlighted between hospitalisations related to ACSC and the deprivation of the municipality of residence. Using as a comparison people residing in the municipalities belonging to the first quintile, the least deprived, the strength of the association between PPHs and DI increased from the third quintile (OR 1.13; CI95% 1.02-1.24) up to the fifth quintile, most deprived (OR 1.14; CI95% 1.01-1.30). CONCLUSIONS: paediatric patients residing in Abruzzo have a risk of undergoing a preventable hospitalisation associated with an ACSC which depends on the deprivation index of the municipality of residence. Although it is difficult to evaluate the mechanisms involved in the relationship between economic deprivation and hospitalisation, DI can be useful to identify the areas which are most at risk on which to prioritize public health interventions
Spectral Graph Convolutions for Population-based Disease Prediction
Exploiting the wealth of imaging and non-imaging information for disease
prediction tasks requires models capable of representing, at the same time,
individual features as well as data associations between subjects from
potentially large populations. Graphs provide a natural framework for such
tasks, yet previous graph-based approaches focus on pairwise similarities
without modelling the subjects' individual characteristics and features. On the
other hand, relying solely on subject-specific imaging feature vectors fails to
model the interaction and similarity between subjects, which can reduce
performance. In this paper, we introduce the novel concept of Graph
Convolutional Networks (GCN) for brain analysis in populations, combining
imaging and non-imaging data. We represent populations as a sparse graph where
its vertices are associated with image-based feature vectors and the edges
encode phenotypic information. This structure was used to train a GCN model on
partially labelled graphs, aiming to infer the classes of unlabelled nodes from
the node features and pairwise associations between subjects. We demonstrate
the potential of the method on the challenging ADNI and ABIDE databases, as a
proof of concept of the benefit from integrating contextual information in
classification tasks. This has a clear impact on the quality of the
predictions, leading to 69.5% accuracy for ABIDE (outperforming the current
state of the art of 66.8%) and 77% for ADNI for prediction of MCI conversion,
significantly outperforming standard linear classifiers where only individual
features are considered.Comment: International Conference on Medical Image Computing and
Computer-Assisted Interventions (MICCAI) 201
Trend in primary caesarean delivery. A five-year experience in Abruzzo, Italy
Background: Primary caesarean section (PCS) rate is one of the main indicators of quality of care suggested by the Italian Government. Hospital rankings are usually based on it, therefore lower rates reflect more appropriate clinical practice. The aim of this study is to describe a five-year trend of PCS rate in Abruzzo region from 2009 to 2013 and to examine the medical indications for this mode of delivery. Methods: Forty-five thousand one hundred forty-nine deliveries occurring from 2009 to 2013 were collected from all hospital discharge records (HDR) and analyzed. Among them we found 12,542 PCS. Odds ratios (ORs) with 95% confidence interval (95% CI) were estimated using logistic regression methods to evaluate the relationship between maternal risk factors and PCS in hospital over 1000 delivery/yrs. Results: The five-year PCS rate was 28.9%, with a decreasing trend from 31.4% in 2009 to 26.1% in 2013. Vasto Civil Hospital shows the lowest PCS rate (17.9% in 2013) among hospitals with a maximum of 1000 deliveries per year, while Pescara Civil Hospital shows the lowest PCS rate (25.4% in 2013) among hospitals with over 1000 deliveries per year. Women with major risk factors for cesarean section delivered more frequently in maternity units over 1000 delivery/yrs. Logistic regression analyses showed as diabetes, hypertension, twin pregnancy, fetal distress and preterm delivery were significant risk factors to deliver in unit over 1000 delivery/yrs. The most frequent (overall 66.6%) discharge diagnosis recorded in Hospital discharge records (HDR) is "Caesarean Delivery Without Indication". 7.3% of PCS made in Abruzzo concerns women living in other Italian regions. 11.4% of PCS contains one of the indications to caesarean section (CS) that the Italian Guidelines consider appropriate. Conclusions: During the analyzed period, Abruzzo showed a decreasing, but still too high, PCS rate, compared to the limits fixed by the Italian Ministry of Health. Considering the limitation of this study, based on administrative data that are poor in clinical information, it is not possible to define the appropriateness of all caesarean sections
Photopolymerized thermosensitive poly(HPMAlactate)-PEG-based hydrogels : effect of network design on mechanical properties, degradation, and release behavior
Photopolymerized thermosensitive A-B-A triblock copolymer hydrogels composed of poly(N-(2-hydroxypropyl)-methacrylamide lactate) A-blocks, partly derivatizal with methacrylate groups to different extents (10, 20, and 30%) and hydrophilic poly(ethylene glycol) B-blocks of different molecular weights (4, 10, and 20 kDa) were synthesized. The aim of the present study was to correlate the polymer architecture with the hydrogel properties, particularly rheological, swelling, degradation properties and release behavior. It was found that an increasing methacrylation extent and a decreasing PEG molecular weight resulted in increasing gel strength and cross-link density, which tailored the degradation profiles from 25 to more than 300 days. Polymers having small PEG blocks showed a remarkable phase separation into polymer- and water-rich domains, as demonstrated by confocal microscopy. Depending on the hydrophobic domain density, the loaded protein resides in the hydrophilic pores or is partitioned into hydrophilic and hydrophobic domains, and its release from these compartments is tailored by the extent of methacrylation and by PEG length, respectively. As the mechanical properties, degradation, and release profiles can be fully controlled by polymer design and concentration, these hydrogels are suitable for controlled protein release
Observation of quantum interference in the plasmonic Hong-Ou-Mandel effect
We report direct evidence of the bosonic nature of surface plasmon polaritons
(SPPs) in a scattering-based beamsplitter. A parametric down-conversion source
is used to produce two indistinguishable photons, each of which is converted
into a SPP on a metal-stripe waveguide and then made to interact through a
semi-transparent Bragg mirror. In this plasmonic analog of the Hong-Ou-Mandel
experiment, we measure a coincidence dip with a visibility of 72%, a key
signature that SPPs are bosons and that quantum interference is clearly
involved.Comment: 5 pages, 3 figure
Balance and proprioception impairment, assessment tools, and rehabilitation training in patients with total hip arthroplasty: a systematic review
Background: Osteoarthritis and subsequent total hip arthroplasty (THA) lead to damages to hip joint mechanoceptors, which in turns lead to impairments in proprioception. One of the abilities mainly affected by an altered joint proprioception is balance. The aim of this work was to investigate the balance and proprioception impairments, current assessment tools, and rehabilitation training after THA. Methods: A systematic literature revision was conducted on PubMed, Web of Science and Cochrane databases. Articles reporting balance and proprioception impairments, current assessment tools, or rehabilitation interventions were included. Methodological quality was assessed using the Downs and Black checklist. A total of 41 articles were included, 33 discussing balance and proprioception assessment, and 8 dealing with training. Data related to type of surgical approach, type and timing of assessment protocols, assessment instrumentation, and type, volume and duration of the rehabilitation training were extracted from each study. Results: Thirty-one studies were of high quality, 2 of moderate quality and 8 of low-quality. Literature review showed an improvement in balance following THA in comparison with the pre-operative performance, although balance abnormalities persist up to 5 years after surgery, with THA patients showing an increased risk for falls. Balance training is effective in all the rehabilitation phases if specifically structured for balance enhancement and consistent in training volume. It remains unclear which assessments are more appropriate for the different rehabilitation phases, and if differences exist between the different surgical procedures used for THA. Only two studies assessed proprioception. Conclusion: Balance and proprioception show impairments up to 5 years after THA, increasing the risk of falls. However, patients with THA may benefit of an adequate balance training. Further research is needed to investigate the gaps in balance and proprioception assessment and training following THA surgery
An XMM-Newton and INTEGRAL view on the hard state of EXO 1745-248 during its 2015 outburst
CONTEXT - Transient low-mass X-ray binaries (LMXBs) often show outbursts
lasting typically a few-weeks and characterized by a high X-ray luminosity
( erg/sec), while for most of the time they are
found in X-ray quiescence ( erg/sec). EXO 1745-248
is one of them. AIMS - The broad-band coverage, and the sensitivity of
instrument on board of {\xmm} and {\igr}, offers the opportunity to
characterize the hard X-ray spectrum during {\exo} outburst. METHODS - In this
paper we report on quasi-simultaneous {\xmm} and {\igr} observations of the
X-ray transient {\exo} located in the globular cluster Terzan 5, performed ten
days after the beginning of the outburst (on 2015 March 16th) shown by the
source between March and June 2015. The source was caught in a hard state,
emitting a 0.8-100 keV luminosity of ~{\lumcgs}. RESULTS - The
spectral continuum was dominated by thermal Comptonization of seed photons with
temperature keV, by a cloud with moderate optical depth
and electron temperature keV. A weaker soft
thermal component at temperature --0.7 keV and compatible
with a fraction of the neutron star radius was also detected. A rich emission
line spectrum was observed by the EPIC-pn on-board {\xmm}; features at energies
compatible with K- transitions of ionized sulfur, argon, calcium and
iron were detected, with a broadness compatible with either thermal Compton
broadening or Doppler broadening in the inner parts of an accretion disk
truncated at gravitational radii from the neutron star. Strikingly, at
least one narrow emission line ascribed to neutral or mildly ionized iron is
needed to model the prominent emission complex detected between 5.5 and 7.5
keV. (Abridged)Comment: 14 pages, 6 figure, 2 tables. Accepted for publication on A&A
(21/03/2017
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