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 sol–gel transition during heating, and reversibly gel–sol transition during cooling. According to the pertinent literature on HPMC aqueous systems, at room temperature, the loss modulus (G”) is higher than the storage modulus (G’). During the heating ramp, the viscoelastic response follows a peculiar path: initially, G” and G’ smoothly decrease, then drop to a minimum and finally increase. Eventually, G’ overcomes G”, indicating the gel formation. A recent explanation of this behaviour considers a two‐step mechanism: first, phase separation occurs, then fibrils form from a polymer-rich phase and entangle, leading to a three‐dimensional network. Based on this, our research focuses on the rheological analysis of the different steps of the sol–gel 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

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 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

Thermal and mechanical properties of polycaprolactone-based composites with diatomaceous earth and halloysite nanotubes

1. Introduction The biodegradable polymers have been attracted interest for the design of green composites in recent decades to face the urgent environmental issues. Polycaprolactone (PCL) is one of the most promising environmentally friendly polymers. Recent studies have reported that blending PCL with different types of fillers may affect its physic-chemical properties and crystallization rate. Halloysite nanotubes (HNT) and diatomaceous earth (DE) have been recently investigated for the preparation of PCL-based composites with appealing performances1,2. Both are naturally occurring materials with nanoscale dimensions and a structure that lend them also absorbent properties. Potentialities of such materials in polymer composites need to be further developed for environmental remediation applications3. For the study, binary blends of PCL with HNT and DE were prepared by melt mixing, starting from 5 w/t% of filler to the maximum miscible concentration to the polymer. The thermal and mechanical properties of the obtained composites were investigated. Thermogravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis were employed for the research purposes. 2. Results and Discussion Thermogravimetric analysis (TGA): The measurements were carried out by using the Q5000 IR instrument (TA Instruments) under nitrogen flow of 25 cm3/min by heating the samples from 20° to 800 °C. with a rate of 1°C/min. The degradation temperature of the pristine materials and their composites were taken at the maximum of the first order derivative curves of mass percentage vs. temperature. It was observed that concentration of HNTs up to 15 w/t% did not affect the thermal stability of PCL. The recorded Tmax values show no significant variations compared to pristine PCL. Higher content of HNT, beyond these levels, leads to a significative decrease in the thermal stability of the PCL matrix, resulted in a lower onset decomposition temperature. The addition of DE did not significatively affect the thermal stability of the composites, with a similar onset temperature for all of composites as the DE content increased. Graphs of the residue vs filler concentration showed a good dispersion degree of the filler particles throughout the polymeric matrix. Differential scanning calorimetry (DSC): The melting and crystallization behaviour testing of the composites and of pristine materials were carried out by using the differential scanning calorimeter TA Instrument DSC (2920 CE). Samples of approximately 5 mg were heated from 25°C to 80°C at a rate of 1 °C/min, under nitrogen atmosphere. The melting temperatures at the onset (Tmi), at the peak (Tmp) and the enthalpy of melting (ΔHm) per gram of PCL in the composites were calculated. The heating thermograms showed melting temperatures values constant for both PCL-based composites as compared to the neat PCL. The crystallinity degree (ꭓc) of PCL did not change for blends with DE while significant variations were observed in PCL/HNT nanocomposites. The results showed that, up to the filler concentration of 15 wt%, ꭓc increase, indicating that the well-dispersed HNT acted as nucleating agents in the PCL matrix. At higher concentrations, the crystallinity degree decreased, affected by the achievement of the percolation threshold of HNT and by the consequent decrease in molecular mobility of the PCL chains in the nanocomposites. Dynamic mechanical analysis (DMA): Dynamic mechanical measurements were performed by using the DMA Q800 (TA Instruments). The temperature range was 30° to 80°C with a scan rate of 2°C/min, at an applied oscillation frequency of 1 Hz and strain of 0.5%. The shear gear method with samples of a surface of 100 mm2 were employed to measure the elastic (storage modulus) and the viscous (loss modulus) components and tan delta parameters. For the study, the peak maximum of the loss modulus curves was considered. It was observed that these values reduced in the filled system as compared to the pristine counter parts, which is due to the reduction of viscous component of the polymer matrix by the presence of HNT and DE. 3. Conclusions Well-dispersed binary blends of PCL with HNT and DE were prepared by melt mixing. Composites with the maximum miscible concentration to the polymer were obtained since there is a lack of information in the literature on the evolution of crystallization rate in PCL composites containing high percentages of fillers. TGA and DSC analysis evidenced that the thermal properties of the polymer are mostly affected by the HNT addition and that the HNT concentration of 15 w/t% represents a sort of critical threshold after which a change in the behaviour of the composites occurs. Viscoelastic measurements showed that both fillers increase the capacity of PCL to store energy during mechanical stress as their content percentage increases. The reported data are the result of a preliminary characterization of sustainable composites whose potential for environmental remediation applications is currently being studied. References 1. Kassa, A.,et al. Effects of montmorillonite, sepiolite, and halloysite clays on the morphology and properties of polycaprolactone bionanocomposites. Polym.Compos. 28(2020) 2. Oun, A. A.,et al. Comparative study of oregano essential oil encapsulated in halloysite nanotubes and diatomaceous earth as antimicrobial and antioxidant composites. Appl. Clay Sci. 224(2022) 3. Cavallaro, G.,et al. Organic-nanoclay composite materials as removal agents for environmental decontamination. RSC Adv. 9(2019

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 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