A spherical model with directional interactions: I. Static properties

We introduce a simple spherical model whose structural properties are similar to the ones generated by models with directional interactions, by employing a binary mixture of large and small hard spheres, with a square-well attraction acting only between particles of different size. The small particles provide the bonds between the large ones. With a proper choice of the interaction parameters, as well as of the relative concentration of the two species, it is possible to control the effective valence. Here we focus on a specific choice of the parameters which favors tetrahedral ordering and study the equilibrium static properties of the system in a large window of densities and temperatures. Upon lowering the temperature we observe a progressive increase in local order, accompanied by the formation of a four-coordinated network of bonds. Three different density regions are observed: at low density the system phase separates into a gas and a liquid phase; at intermediate densities a network of fully bonded particles develops; at high densities -- due to the competition between excluded volume and attractive interactions -- the system forms a defective network. The very same behavior has been previously observed in numerical studies of non-spherical models for molecular liquids, such as water, and in models of patchy colloidal particles. Differently from these models, theoretical treatments devised for spherical potentials, e.g. integral equations and ideal mode coupling theory for the glass transition can be applied in the present case, opening the way for a deeper understanding of the thermodynamic and dynamic behavior of low valence molecules and particles.Comment: 11 pages, 11 figure

Ocular tolerance and efficacy of short-term tamponade with double filling of polydimethyloxane and perfluoro-n-octane

Stefano Zenoni1, Mario R Romano2, Sonia Palmieri1, Natalia Comi1, Edoardo Fiorentini1, Piero Fontana11Ospedali Riuniti di Bergamo, Bergamo, Italy; 2Istituto Clinico Humanitas IRCSS, Rozzano, Milan, ItalyObjective: The aim of the study was to evaluate the ocular tolerance and efficacy of double filling with perfluoro-n-octane (n-C8F18) (PFO) and polydimethyloxane (PDMS) as a temporary vitreous substitute in patients with retinal detachment complicated by proliferative vitreoretinopathy (PVR).Material and methods: Tamponade was performed in 30 eyes of 30 patients by double filling with 30% PFO and 70% PDMS for an average of 23 (standard deviation 2.2) days. The follow-up visits were scheduled 1 week, 1 month, and 3 months after surgery. The main outcome measures were visual acuity, intraocular pressure (IOP), PVR reproliferation, and electrophysiological parameters.Results: The primary success rate was 80% (24/30). Fourteen patients (46.7%) had a postoperative improvement in visual acuity, 12 patients (40.0%) maintained their preoperative visual acuity, and four patients (13.3%) experienced a reduction in visual acuity. The mean postoperative IOP was 19.7 mm Hg (11–32 mm Hg); nine cases (30.0%) developed an IOP increase that was treated with topical drops and/or systemic carbonic anhydrase inhibitors. The electroretinogram (ERG) and the bright flash electroretinogram (bf ERG) parameters showed a statistically significant difference of means between 4- and 8-week follow-up visits.Conclusion: Our experience with double filling in selected cases of retinal detachment has been positive. No electroretinographic signs of retinal toxicity and a low incidence of PVR reproliferation were observed.Keywords: double filling, proliferative vitreo-retinopathy, perfluoro-n-octane, polydimethyloxane, retinal detachment, retinal detachment electrophysiolog

Intronic Variant in CNTNAP2 Gene in a Boy With Remarkable Conduct Disorder, Minor Facial Features, Mild Intellectual Disability, and Seizures

Introduction: Mutations in the contactin-associated protein-like 2 (CNTNAP2) gene (MIM#604569) encoding for CASPR2, a cell adhesion protein of the neurexin family, are known to be associated with autism, intellectual disability, and other neuropsychiatric disorders. A set of intronic deletions of CNTNAP2 gene has also been suggested to have a causative role in individuals with a wide phenotypic spectrum, including Pitt-Hopkins syndrome, cortical dysplasia-focal epilepsy syndrome, Tourette syndrome, language dysfunction, and abnormal behavioral manifestations. Case presentation: A 10-years-old boy was referred to the hospital with mild intellectual disability and language impairment. Moreover, the child exhibited minor facial features, epileptic seizures, and notable behavioral abnormalities including impulsivity, aggressivity, and hyperactivity suggestive of the diagnosis of disruptive, impulse-control and conduct disorder (CD). Array comparative genomic hybridization (CGH) revealed a copy number variant (CNV) deletion in the first intron of CNTNAP2 gene inherited from a healthy father. Conclusions: A comprehensive description of the phenotypic features of the child is provided, revealing a distinct and remarkable alteration of social behavior not previously reported in individuals affected by disorders related to CNTNAP2 gene disruptions. A possible causative link between the deletion of a non-coding regulatory region and the symptoms presented by the boy has been advanced

Forze impulsive e sormonti su muri ricurvi soggetti ad onde non frangenti

Opere a parete verticale di tipo ricurvo per la riduzione delle portate di tracimazione. Azioni impulsive generate da onde non frangenti su pareti ricurve. Nuovo fenomeno fisico identificato e denominato "crest-confined impact"

Hopkins’ syndrome

Hopkins’ syndrome is a rare disease that affects the anterior horn of the spinal cord after an acute episode of asthma in children with atopic disease. A viral infection or immunological suppression in atopic subjects might be the cause of occurrence of this syndrome, although the mechanism due to the etiopathogenesis of the disease still remains unknown.In general, this disease is manifested by a few days to a few weeks after an acute asthma attack, with flaccid paralysis of one or more limbs and in some cases residual muscle atrophy. The response to corticosteroid therapy is good and rare the possibility of recurrence

Chromosome 15q BP3 to BP5 deletion is a likely locus for speech delay and language impairment: Report on a four-member family and an unrelated boy

Background: Deletions in chromosome 15q13 have been reported both in healthy people and individuals with a wide range of behavioral and neuropsychiatric disturbances. Six main breakpoint (BP) subregions (BP1-BP6) are mapped to the 15q13 region and three further embedded BP regions (BP3-BP5). The deletion at BP4-BP5 is the rearrangement most frequently observed compared to other known deletions in BP3-BP5 and BP3-BP4 regions. Deletions of each of these three regions have previously been implicated in a variable range of clinical phenotypes, including minor dysmorphism, developmental delay/intellectual disability, epilepsy, autism spectrum disorders, behavioral disturbances, and speech disorders. Of note, no overt clinical difference among each group of BP region deletions has been recorded so far. Methods: We report on a four-member family plus an additional unrelated boy affected by a BP3-BP5 deletion that presented with typical clinical signs including speech delay and language impairment. A review of the clinical features associated with the three main groups of BP regions (BP4-BP5, BP3-BP5, and BP3-BP4) deletions is reported. Results: Array-CGH analysis revealed in the mother (case 1) and in her three children (cases 2, 3, and 4), as well as in the unrelated boy (case 5), the following rearrangement: arr (hg19) 15q13.1-q13.3 (29.213.402-32.510.863) x1. Conclusion: This report, along with other recent observations, suggests the hypothesis that the BP region comprised between BP3 and BP5 in chromosome 15q13 is involved in several brain human dysfunctions, including impairment of the language development and, its deletion, may be directly or indirectly responsible for the speech delay and language deficit in the affected individuals

Cognitive profile in idiopathic autonomic failure: relation with white matter hyperintensities and neurofilament levels

To disclose the nature of cognitive deficits in a cohort of patients with idiopathic autonomic failure (IAF) by exploring the relation among cognitive functions, cardiovascular autonomic failure (AF) and clinical progression to another α-synucleinopathy (phenoconversion)

Characterization of an In-Beam PET Prototype for Proton Therapy With Different Target Compositions

At the University of Pisa, the DoPET (Dosimetry with a Positron Emission Tomograph) project has focused on the development and characterization of an ad hoc, scalable, dual-head PET prototype for in-beam treatment planning verification of the proton therapy. In this paper we report the first results obtained with our current prototype, consisting of two opposing lutetium yttrium orthosilicate (LYSO) detectors, each one covering an area of 4.5 × 4.5 cm2. We measured the β+-activation induced by 62 MeV proton beams at Catana facility (LNS, Catania, Italy) in several plastic phantoms. Experiments were performed to evaluate the possibility to extract accurate phantom geometrical information from the reconstructed PET images. The PET prototype proved its capability of locating small air cavities in homogeneous PMMA phantoms with a submillimetric accuracy and of distinguishing materials with different 16O and 12C content by back mapping phantom geometry through the separation of the isotope contributions. This could be very useful in the clinical practice as a tool to highlight anatomical or physiological organ variations among different treatment sessions and to discriminate different tissue types, thus providing feedbacks for the accuracy of dose deposition

Can we use the pharmacy data to estimate the prevalence of chronic conditions? a comparison of multiple data sources

<p>Abstract</p> <p>Background</p> <p>The estimate of the prevalence of the most common chronic conditions (CCs) is calculated using direct methods such as prevalence surveys but also indirect methods using health administrative databases.</p> <p>The aim of this study is to provide estimates prevalence of CCs in Lazio region of Italy (including Rome), using the drug prescription's database and to compare these estimates with those obtained using other health administrative databases.</p> <p>Methods</p> <p>Prevalence of CCs was estimated using pharmacy data (PD) using the Anathomical Therapeutic Chemical Classification System (ATC).</p> <p>Prevalences estimate were compared with those estimated by hospital information system (HIS) using list of ICD9-CM diagnosis coding, registry of exempt patients from health care cost for pathology (REP) and national health survey performed by the Italian bureau of census (ISTAT).</p> <p>Results</p> <p>From the PD we identified 20 CCs. About one fourth of the population received a drug for treating a cardiovascular disease, 9% for treating a rheumatologic conditions.</p> <p>The estimated prevalences using the PD were usually higher that those obtained with one of the other sources. Regarding the comparison with the ISTAT survey there was a good agreement for cardiovascular disease, diabetes and thyroid disorder whereas for rheumatologic conditions, chronic respiratory illnesses, migraine and Alzheimer's disease, the prevalence estimates were lower than those estimated by ISTAT survey. Estimates of prevalences derived by the HIS and by the REP were usually lower than those of the PD (but malignancies, chronic renal diseases).</p> <p>Conclusion</p> <p>Our study showed that PD can be used to provide reliable prevalence estimates of several CCs in the general population.</p