1,727 research outputs found
Pediatric chronic migraine severity and maternal stress
Primary headache is an increasing phenomenon in pediatric age, and very often, it causes disabling limitations in children's daily activities, negatively affecting family well-being. There are conflicting data in the literature on the impact of children's migraines on parental experienced stress. This study aimed to evaluate maternal stress in a sample of school-aged children with a migraine without aura (MwoA) and its correlation with migraine intensity and frequency. A total of 474 mothers aged between 31 and 55 participated in the study: 237 were mothers of children with MwoA, and 237 were mothers of typical developing children. All participants were administered the Parent Stress Index-Short Form (PSI-SF) for the assessment of parental stress; the Pediatric Migraine Disability Assessment (PedMIDAS) was administered to children with MwoA to assess the presence of a related disability migraine. The results showed a significantly higher rate of stress in mothers of MwoA children (p < 0.001) in all the domains explored by the PSI-SF and a statistically significant correlation between the maternal stress total score and the intensity and frequency of migraine attacks (p < 0.0001). This study highlights the need for the holistic contribution of the family to be considered in the clinical management of pediatric migraines
Headache disorders as risk factors for sleep disturbances in school aged children.
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
ENG 5000-001: Intro to Methods in English Studies
The rheological behavior of a non-Brownian Newtonian concentrated suspension is investigated under
oscillatory shear at different strain amplitudes and at two frequencies. The data are in agreement with the literature
showing that the complex viscosity varies both with the number of oscillations imposed to the material and with the strain
amplitude. We here also show that the response to the oscillatory shear depends on the applied frequency. This result is
unexpected for a Newtonian suspension and implies the existence of some mechanism able to introduce a characteristic
time into the system. Can it be cage elasticity
HPMC Hydrogel Formation Mechanisms Unveiled by the Evaluation of the Activation Energy
Aqueous solutions of hydroxypropyl methylcellulose (HPMC) show inverse thermoreversible gelation, i.e., they respond to small temperature variations exhibiting solâgel transition during heating, and reversibly gelâsol transition during cooling. According to the pertinent literature on HPMC aqueous systems, at room temperature, the loss modulus (Gâ) is higher than the storage modulus (Gâ). During the heating ramp, the viscoelastic response follows a peculiar path: initially, Gâ and Gâ smoothly decrease, then drop to a minimum and finally increase. Eventually, Gâ overcomes Gâ, indicating the gel formation. A recent explanation of this behaviour considers a twoâstep mechanism: first, phase separation occurs, then fibrils form from a polymer-rich phase and entangle, leading to a threeâdimensional network. Based on this, our research focuses on the rheological analysis of the different steps of the solâgel transition of an HPMC aqueous solution. We perform different viscoelastic tests: thermal ramps, time sweeps, and frequency sweeps at selected characteristic temperatures. We couple classical analysis of the SAOS experiments with an innovative approach based on the evaluation of the activation energy (Ea), made possible by the instrument intrinsic temperature oscillations around the target value. Results show that Ea can be a valid tool that contributes to further clarifying the peculiar microstructural evolution occurring in this kind of thermoreversible gel
Acupressure therapy for insomnia in adolescents: a polysomnographic study
Background: The purpose of this study was to assess the efficacy of acupressure therapy in a sample of adolescents with insomnia using a standard polysomnographic evaluation.
Methods: For this study, 25 adolescents affected by psychophysiological insomnia (mean age 15.04 \ub1 1.18 years, 12 boys) were enrolled. A device known as the Sea-Band\uae was used by the patients in order to improve their symptoms related to difficulty in falling asleep. All subjects enrolled underwent two sets of consecutive overnight polysomnographic studies in the Sleep Laboratory of the Clinic of Child and Adolescent Neuropsychiatry, comprising two studies at baseline (before treatment) and another two studies at the end of 6 months of treatment.
Results: At the end of 6 months of treatment, there was a significant increase in all macrostructural parameters of sleep duration, and a reduction in sleep onset latency, wake after sleep onset, and stage 2 sleep. Moreover, the study group showed a significant increase in percent sleep efficiency (P , 0.001) and in slow wave sleep representation.
Conclusion: Acupressure is a noninvasive, safe, and effective method for the management of insomnia in adolescents, with good compliance and no adverse effects
Hypersonnia in children affected by migraine whitout aura: a questionnaire-based case-control study
Growth and remodeling in highly stressed solid tumors
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 thatâ under hypotheses consistent with mechanical and physiological conditionsâauxetic (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
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 authorsâ 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 bodiesâ 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 carriageâsphere. 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 systemsâ dynamics with respect to its asymptotic behaviour and could pave the way for designing active or passive vibration controllers of interest in engineering
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