752 research outputs found

    Headache disorders as risk factors for sleep disturbances in school aged children.

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    Several epidemiological studies have shown the presence of comorbidity between various types of sleep disorders and different headache subtypes. Migraine without aura is a sensitive risk factor for disorders of initiating and maintaining sleep (odds ratio (OR) 8.2500), and chronic tension-type headache for sleep breathing disorders (OR 15.231), but headache disorder is a cumulative risk factor for disorders of excessive somnolence (OR 15.061). This result has not been reported in the clinical literature. © Springer-Verlag Italia 2005

    Growth and remodeling in highly stressed solid tumors

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    Growing biological media develop residual stresses to make compatible elastic and inelastic growth-induced deformations, which in turn remodel the tissue properties modifying the actual elastic moduli and transforming an initially isotropic and homogeneous material into a spatially inhomogeneous and anisotropic one. This process is crucial in solid tumor growth mechanobiology, the residual stresses directly influencing tumor aggressiveness, nutrients walkway, necrosis and angiogenesis. With this in mind, we here analyze the problem of a hyperelastic sphere undergoing finite heterogeneous growth, in cases of different boundary conditions and spherical symmetry. By following an analytical approach, we obtain the explicit expression of the tangent elasticity tensor at any point of the material body as a function of the prescribed growth, by involving a small-on-large procedure and exploiting exact solutions for layered media. The results allowed to gain several new insights into how growth-guided mechanical stresses and remodeling processes can influence the solid tumor development. In particular, we highlight that— under hypotheses consistent with mechanical and physiological conditions—auxetic (negative Poisson ratio) transformations of the elastic response of selected growing mass districts could occur and contribute to explain some not yet completely understood phenomena associated to solid tumors. The general approach proposed in the present work could be also helpfully employed to conceive composite materials where ad hoc pre-stress distributions can be designed to obtain auxetic or other selected mechanical properties

    Moving mass over a viscoelastic system: asymptotic behaviours and insights into nonlinear dynamics

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    Moving masses are of interest in many applications of structural dynamics, soliciting in the last decades a vast debate in the scientific literature. However, despite the attention devoted to the subject, to the best of the authors’ knowledge, there is a lack of analysis about the fate of a movable mass when it rolls or slips with friction on a structure. With the aim of elucidating the dynamics of the simplest paradigm of this system and to investigate its asymptotic response, we make reference to a two-degree-of-freedom model made of an elastically vibrating carriage surmounted by a spherical mass, facing the problem both theoretically and experimentally. In case of linear systems, the analytical solutions and the laboratory tests performed on ad hoc constructed prototypes highlighted a counterintuitive asymptotic dynamics, here called binary: in the absence of friction at the interface of the bodies’ system, the mass holds its initial position or, if nonzero damping acts, at the end of the motion it is in a position that exactly recovers the initial relative distance carriage–sphere. While the first result might be somewhat obvious, the second appears rather surprising. Such a binary behaviour is also confirmed for a Duffing-like system, equipped with cubic springs, while it can be lost when non-smooth friction phenomena occur, as well as in the case of elastic springs restraining the motion of the sphere. The obtained analytical results and the numerical findings, also confirmed by experimental evidences, contribute to the basic understanding of the role played by the damping parameters governing the systems’ dynamics with respect to its asymptotic behaviour and could pave the way for designing active or passive vibration controllers of interest in engineering

    Lamotrigine versus valproic acid as first-line monotherapy in newly diagnosed typical absence seizures: an open-label,randomized, parallel-group study

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    Purpose: To compare the efficacy of lamotrigine (LTG) and valproic acid (VPA) in newly diagnosed children and adolescents with typical absence seizures. Methods: A randomized, open-label parallel-group design was used. After undergoing an awake video-EEG recording, which included one to two trials of 3 min of hyperventilation and intermittent photic stimulation, eligible patients were randomized to receive LTG or VPA. LTG was initiated at a daily dose of 0.5 mg/kg for 2 weeks in two divided doses, followed by 1.0 mg/kg/day for an additional 2 weeks. Thereafter, doses were increased in 1-mg/kg/day increments every 5 days until seizures were controlled, intolerable adverse effects occurred, or a maximum dose of 12 mg/kg/day had been reached. VPA was equally uptitrated according to clinical response, starting at 10 mg/kg and increasing by 5 mg/kg/24 h every 3 days, if required, to a maximum of 30 mg/kg/day in three divided doses. Patients were seen in the clinic every month for ≤12 months.The primary efficacy end point at each visit was seizure freedom, defined as lack of clinically observed seizures since the previous visit and lack of electroclinical seizures during ambulatory 24-h EEG testing and a video-EEG session with hyperventilation. Results: Thirty-eight children (17 boys, 21 girls), aged from 3 to 13 years (mean, 7.5 years), all newly diagnosed with childhood or juvenile typical absence seizures, were enrolled. After 1 month of treatment, 10 (52.6%) of 19 children taking VPA and one (5.3%) of 19 taking LTG were seizure free (p = 0.004). By the 3-month follow-up, 12 (63.1%) children taking VPA and seven (36.8%) taking LTG were controlled (p = 0.19). After 12 months, 13 children taking VPA (dose range, 20–30 mg/kg/day; mean serum level, 76.8 mg/L; range, 51.4–91 mg/L) and 10 taking LTG (dose range, 2–11 mg/kg/day; mean serum level, 8.1 mg/L; range, 1.1–18 mg/L) were seizure free (p=0.51). Side effects were mostly mild and transient and were recorded in two (10.6%) children treated with VPA and in six (31.8%) treated with LTG. Conclusions: Both VPA and LTG can be efficacious against absence seizures, although VPA shows a much faster onset of action, at least in part because of its shorter titration schedule. KeyWords: Lamotrigine—Valproic acid—Typical absences— Monotherapy. Valproic acid (VPA) and ethosuximide (ESM) have been shown to be equally effective as monotherapy for typical absence seizures (1,2), and, at present, they are generally considered first-choice drugs for this seizure type. VPA controls absences in∼75% of patients, in addition to being effective against generalized tonic–clonic seizures (70%) and myoclonic seizures (75%). However, its use may involve safety risks for postmenarchal women (3). ESM produces complete control of absences in 70% of treated patients (4,5), but it is unsuitable as monotherapy Accepted Ma

    Comparing home and parcel lockers’ delivery systems: a math-heuristic approach

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    E-commerce is a continuously growing sector worldwide, with important repercussions on the delivery system in urban area and especially in the Business to Consumer (B2C) sector. The delivery of a package to a consumer's address involves not only high costs for couriers (greater number of kilometres travelled), but also increased congestion and greater environmental pollution (greater volume of pollutants released into the air). To rationalize deliveries in urban areas the use of collection points, equipped with lockers, to store the goods that users have ordered has been considered in literature. This work compares two alternative delivery options: deliveries to the consumer's home versus to Lockers. To make this comparison we used a cluster first route second math-heuristic approach. In the clustering phase, we experimented a new clustering function, while the routing phase consists in solving an instance of the Traveling Salesman Problem for each generated cluster. Finally, we applied the math-heuristic to a real case (the Italian municipality of Dolo near Venice) and compared the two delivery alternatives. We evaluate the performance considering two different fleets of vehicles, with small and medium capacity. In addition, since additional trips might be performed by consumers to pick up parcels at Lockers, a sensitivity analysis was carried out to analyse the sustainability of the proposed city logistics scheme

    Biofilms: Novel strategies based on antimicrobial peptides

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    The problem of drug resistance is very worrying and ever increasing. Resistance is due not only to the reckless use of antibiotics but also to the fact that pathogens are able to adapt to different conditions and develop self-defense mechanisms such as living in biofilms; altogether these issues make the search for alternative drugs a real challenge. Antimicrobial peptides appear as promising alternatives but they have disadvantages that do not make them easily applicable in the medical field; thus many researches look for solutions to overcome the disadvantages and ensure that the advantages can be exploited. This review describes the biofilm characteristics and identifies the key features that antimicrobial peptides should have. Recalcitrant bacterial infections caused by the most obstinate bacterial species should be treated with a strategy to combine conventional peptides functionalized with nano-tools. This approach could effectively disrupt high density infections caused by biofilms. Moreover, the importance of using in vivo non mammalian models for biofilm studies is described. In particular, here we analyze the use of amphibians as a model to substitute the rodent model

    Healthcare costs for treating relapsing multiple sclerosis and the risk of progression: a retrospective Italian cohort study from 2001 to 2015

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    Background Disease modifying treatments (DMTs) are the main responsible for direct medical costs in multiple sclerosis (MS). The current investigation aims at evaluating possible associations between healthcare costs for treating relapsing remitting MS (RRMS) and disease evolution. Methods The present cohort study retrospectively included 544 newly diagnosed RRMS patients, prospectively followed up for 10.1±3.3 years. Costs for DMT administration and management were calculated for each year of observation. Following clinical endpoints were recorded: time to first relapse, 1-point EDSS progression, reaching of EDSS 4.0, reaching of EDSS 6.0, and conversion to secondary progressive MS (SP). Covariates for statistical analyses were age, gender, disease duration and EDSS at diagnosis. Results At time varying Cox regression models, 10% increase in annual healthcare costs was associated with 1.1% reduction in 1-point EDSS progression (HR = 0.897; p = 0.018), with 0.7% reduction in reaching EDSS 6.0 (HR = 0.925; p = 0.030), and with 1.0% reduction in SP conversion (HR = 0.902; p = 0.006). Conclusion Higher healthcare costs for treating MS have been associated with a milder disease evolution after 10 years, with possible reduction of long-term non-medical direct and indirect costs

    A Revised Sex Assessment of the Epigravettian Human Remain ST1 from San Teodoro Cave (Messina, Sicily)

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    Bias in skeletal sexing is well known and depends upon the completeness of the skeletal remains. The problem is very hard concerning prehistorical remains. We applied \u2018Visual methods\u2019 and \u2018Probabilistic Sex Diagnosis\u2019 (DSP) on the coxal bones on the Epigravettian skeleton (ST1) from San Teodoro (Messina, Sicily). On the basis of cranial characters and the overall robustness of the postcranial skeleton, it was suggested, since the time of the discovery, a male sex for ST1. This determination was later modified on the basis of the pelvic girdle morphology, and the skeleton was attributed the female sex for many years by large consensus. Our results indicate without ambiguity that ST1 is a male and show the importance of applying update methods of sex determination to ancient remains
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