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Earlier pubertal timing is an important predictor of emotional and behavioral problems during adolescence. The current study undertook a comprehensive investigation of whether the social environment can buffer or amplify the associations between pubertal timing and emotional and behavioral problems. Research questions were examined in the Adolescent Brain Cognitive Development (ABCD) Study, a large population representative sample in the United States. We examined interactions between pubertal timing and the shared effects of a range of proximal and distal social environmental influences (i.e., parents, peers, schools, neighborhoods, socioeconomic status) in 10- to 13-year-olds. Results revealed significant interaction between timing and proximal social influences (i.e., the "microsystem") in predicting emotional and behavioral problems. In general, adolescents with earlier pubertal timing and unfavorable (high levels of negative and low levels of positive) influences in the microsystem exhibited greater problems. Both males and females exhibited such associations for rule-breaking problems, while females alone exhibited associations for depressive problems. Results also illustrate the relative strength of each social context at moderating risk for emotional and behavioral problems in earlier versus later pubertal maturers. These findings highlight the importance of proximal social influences in buffering vulnerability for emotional and behavioral problems related to earlier puberty. Findings also illustrate the broad implications of latent environmental factors, reflecting common variance of multiple social influences that typically covary with one another. [ABSTRACT FROM AUTHOR]

Background: Distress tolerance (DT) has received increased attention in recent years due to its purported role in dysregulated behaviours and their clinical manifestations, such as problematic substance use (PSU), disordered eating behaviours (e.g., binge-eating and purging; DEB), and borderline personality disorder (BPD) symptomatology. Despite the proposed transdiagnostic utility of DT across PSU, DEB, and BPD, there has yet to be a systematic and comprehensive examination characterising and comparing its association with this class of impulsive-type psychopathology.Methods: A systematic search was conducted across five electronic databases using search terms designed to capture extant literature on the association between DT and PSU, DEB, and BPD symptomatology. A series of meta-analyses were undertaken on correlation coefficients from 81 studies to examine the association between DT and each psychopathology domain, as well as impulsive-type psychopathology overall. Moderator analyses were conducted to examine whether these relationships were moderated by DT measurement type, sample type, age, and gender.Results: DT shared significant, negative, medium correlations with PSU (r = -.18,), DEB (r = -.20), and BPD symptomatology (r = -.27). The magnitude of these associations was not significantly different across the three psychopathology domains, supporting transdiagnostic conceptualisation. DT measurement type, age, and sample type moderated several of these indicated relationships.Limitations: The majority of studies were conducted in adult samples from Western countries, limiting understanding of these relationships across development and different cultures.Conclusions: The present findings support the putative transdiagnostic role of DT across PSU, DEB, and BPD, which may ultimately inform novel, cross-cutting interventions. [ABSTRACT FROM AUTHOR]

Many studies have attempted to identify the sources of interindividual variability in response to theta-burst stimulation (TBS). However, these studies have been limited by small sample sizes, leading to conflicting results. This study brought together over 60 TMS researchers to form the 'Big TMS Data Collaboration', and create the largest known sample of individual participant TBS data to date. The goal was to enable a more comprehensive evaluation of factors driving TBS response variability. 118 corresponding authors of TMS studies were emailed and asked to provide deidentified individual TMS data. Mixed-effects regression investigated a range of individual and study level variables for their contribution to iTBS and cTBS response variability. 430 healthy participants' TBS data was pooled across 22 studies (mean age = 41.9; range = 17–82; females = 217). Baseline MEP amplitude, age, target muscle, and time of day significantly predicted iTBS-induced plasticity. Baseline MEP amplitude and timepoint after TBS significantly predicted cTBS-induced plasticity. This is the largest known study of interindividual variability in TBS. Our findings indicate that a significant portion of variability can be attributed to the methods used to measure the modulatory effects of TBS. We provide specific methodological recommendations in order to control and mitigate these sources of variability. • 430 healthy participants' theta-burst stimulation data was pooled across 22 studies. • Individual participant data was analysed using mixed-effects regression. • Baseline MEP amplitude, age, muscle, and time of day, predicted iTBS response. • Baseline MEP amplitude and timepoint predicted cTBS response. • Specific recommendations are proposed to reduce TBS variability. [ABSTRACT FROM AUTHOR]

Conductive metallic particulate inclusions in electroactive polymer matrix composites have been widely studied for enhanced sensitivity applicable to sensors, energy harvesters, electromechanical actuators, and high charge storage capacitors. If the metallic particulates exhibit magnetostrictive properties, the domain of applications expands due to the direct and converse coupling between electric displacement and magnetization. In this paper, the synthesis of a composite material consisting of giant magnetostrictive alloy particulates, Terfenol-D, embedded into an electroactive polymer matrix, PVDF-TrFE is discussed. The experimental protocol to elucidate the ferroelectric, dielectric, and piezoelectric properties of the novel composite is also reported. It was observed that the ferroelectric polarization was improved with a small weight fraction of Terfenol-D particles, but it was hindered when more weight fraction of the particles was added. Nonetheless, the permittivity of the composite rapidly increased with the addition of more Terfenol-D particles, which was attributed to the reduction in the polarization of the PVDF-TrFE matrix. Finally, a notable phase delay was observed in the piezoelectric strain in response to a high-frequency electric field, such a delay was directly proportionally to the addition of Terfenol-D particles. [ABSTRACT FROM AUTHOR]

Abstract It is well established that older adults are less able to perform attentionally demanding motor tasks, placing them at greater risk of accident-related injury. The primary purpose of this study was to investigate whether the interplay between prefrontal and motor cortex activity could predict such age-related performance deficits. Using a dual-task (DT) paradigm, 15 younger and 15 older adults participated in experiment 1, where brain activity was simultaneously measured using functional near infrared spectroscopy (fNIRS) and transcranial magnetic stimulation (TMS). Experiment 1 demonstrated poorer performance for the older group across a range of DTs combining visuomotor arm tracking with a secondary cognitive or motor task. Interestingly however, older adults' DT performance error was isolated to the motor component of DTs. TMS data revealed reduced motor cortex (M1) inhibition during DTs for older adults, and a trend for this correlating with poorer performance. In contrast, poorer performing younger adults showed significantly higher M1 inhibition. Experiment 2 was conducted given a high amount of movement artifact in experiment 1 fNIRS data. Using fNIRS to measure prefrontal, premotor, and motor cortex activity in an additional 15 older adults, we found no evidence of an interplay between these regions predicting DT performance. Nevertheless, performance data replicated experiment 1 in showing that DT error was isolated to motor tasks in older adults, with no significant cognitive task error. Overall, this study shows that older adults seemed to adopt a 'cognitive-first' prioritisation strategy during the DTs involved in our study, and that deficits in DT performance may be related to the modulation of M1 inhibitory mechanisms. We propose that clinicians advise older adults to allocate greater attention to motor tasks during activities where they may be at risk of accident-related injury. Highlights • Older adults' performance error isolated to motor component of dual-tasks • Lower M1 inhibition for older adults during dual-tasking • Higher M1 inhibition for poorer performing younger adults • Trend for lower M1 inhibition for poorer performing older adults • We suggest a 'cognitive-first' prioritisation strategy for older adults [ABSTRACT FROM AUTHOR]

Hydrophilic polymers, or hydrogels, are used for a wide variety of biomedical applications, due to their inherent ability to withhold a high-water content. In recent years, a large effort has been focused on tailoring the mechanical properties of these hydrogels to become more appropriate materials for use as anatomical and physiological structural supports. A few of these such methods include using diverse types of polymers, both natural and synthetic, varying the type of molecular cross-linking, as well as combining these efforts to form interpenetrating polymer network hydrogels. While multiple research groups have characterized these various hydrogels under quasi-static conditions, their dynamic properties, representative of native physiological loading scenarios, have been scarcely reported. In this study, an E-glass fiber reinforced family of alginate/PAAm hydrogels cross-linked by both divalent and trivalent cations are fabricated and investigated. The effect of the reinforcement phase on the dynamic and hydration behaviors is then explicated. Additionally, a micromechanics framework for short cylindrical chopped fibers is utilized to discern the contribution of the matrix and fiber constituents on the hydrogel composite. The addition of E-glass fibers resulted in the storage modulus exhibiting a ~50%, 5%, and ~120%, increase with a mere addition of 2 wt% of the reinforcing fibers to Na-, Sr-, and Al-alginate/PAAm, respectively. In studying the cross-linking effect of various divalent (Ba, Ca, Sr) and trivalent (Al, Fe) cations, it was noteworthy that the hydrogels were found to be effective in dissipating energy while resisting mechanical deformation when they are cross-linked with higher molecular weight elements, regardless of valency. This report on the dynamic properties of these hydrogels will help to improve their optimization for future use in biomedical load-bearing applications. [ABSTRACT FROM AUTHOR]

Individuals accessing treatment within the youth alcohol and other drug (AoD) sector represent a highly vulnerable population who present with complex patterns of substance use and mental health comorbidity. Current treatments often fail to address this complexity. Emotion regulation (ER) has been identified as a promising transdiagnostic treatment target for this population of young people. The current study aimed to investigate the acceptability and feasibility of an adjunct ER intervention, ERIC (Emotion Regulation and Impulse Control) in young people receiving AoD treatment at a residential rehabilitation service. A mixed methods case series design was utilized. Ten participants aged between 16–20 years old completed 4–6 sessions of ERIC as an adjunct to their existing residential treatment. Participants undertook a post intervention feedback session and completed a number of self-report measures of ER, depression and anxiety at baseline and 2 weeks after receiving ERIC. Qualitative feedback from young people following the delivery of ERIC was positive, and suggested that ERIC was a viable and useful intervention. Participants reported that the components of ERIC, which involved metaphors and experiential exercises, were particularly beneficial and memorable. Pre-post measures indicated that 60% of the young people had both reliable and clinically significant reductions in overall emotion dysregulation, while reliable and clinically significant reductions in depression and anxiety were observed in 50% and 60% of participants respectively. Results support the acceptability of ERIC for this cohort of young people with complex substance use and mental health needs. Furthermore, these findings support the viability of delivering flexible and adjunctive ER treatments to young people seeking AoD treatment. [ABSTRACT FROM AUTHOR]

Background Impulsivity is implicated as a contributing factor to ongoing heroin use. This study aimed to determine the inter-relatedness of a battery of self-reported and performance-based behavioural measures of impulsivity in opioid-dependent individuals. Methods Seventy-two participants on opioid substitution pharmacotherapy completed a battery of impulsivity measures. We analysed the correlations and factor structure of the impulsivity tasks. Results We observed correlations between self-report measures, but self-report measures were unrelated to the performance-based tasks. For the performance-based tasks, correlations were only observed between outcome measures of the same task, and between outcome measures of the impulsive decision-making tasks. Principal components analysis revealed five components that we labelled self-reported impulsivity, impulsive decision-making with learning, impulsive decision-making without learning, sensitivity index, and responding without consideration of consequences. Discussion This study reinforces the distinction between multiple facets of impulsivity. This may assist with comparisons between studies that use different measures of impulsivity, and to design improved treatment interventions that target specific aspects of impulsivity. [ABSTRACT FROM AUTHOR]

The occurrence of repetitive behaviours that are often harmful has been attributed to traits traditionally described as "impulsive" or "compulsive" e.g. substance dependence, excessive gambling, and hoarding. These behaviours are common and often co-occur in both the general population and psychiatric populations. The lack of measures to concurrently index a range of such behaviours led to the development of the Impulsive-Compulsive Behaviours (ICB) Checklist. This study aims to validate the ICB Checklist in a general community sample. Factor analyses revealed a two-factor structure, demonstrating good model fit in two independent samples. These were labelled Impulsive-Compulsions and Compulsive-Impulsions, comprising of classically compulsive and impulsive behaviours respectively. Reliability and construct validity were further confirmed using correlations with existing measures of impulsivity and compulsivity. Results suggest that the ICB Checklist is a valid and practical assessment that can be used to monitor behavioural clusters characterised by deficits in inhibition. [ABSTRACT FROM AUTHOR]

Introduction: Several factors are associated with an increased risk of adolescent problem gambling, including positive gambling attitudes, higher levels of gambling involvement, ineffective coping strategies and unhelpful parenting practices. It is less clear, however, how these factors interact or influence each other in the development of problem gambling behavior during adolescence. The aim of the current study was to simultaneously explore these predictors, with a particular focus on the extent to which coping skills and parenting styles may moderate the expected association between gambling involvement and gambling problems.Methods: Participants were 612 high school students. The data were analyzed using a zero-inflated Poisson (ZIP) regression model, controlling for gender.Results: Although several variables predicted the number of symptoms associated with problem gambling, none of them predicted the probability of displaying any problem gambling. Gambling involvement fully mediated the relationship between positive gambling attitudes and gambling problem severity. There was a significant relationship between gambling involvement and problems at any level of problem focused coping, reference to others and inconsistent discipline. However, adaptive coping styles employed by adolescents and consistent disciplinary practices by parents were buffers of gambling problems at low levels of adolescent gambling involvement, but failed to protect adolescents when their gambling involvement was high.Conclusions: These findings indicate that research exploring the development of gambling problems is required and imply that coping and parenting interventions may have particular utility for adolescents who are at risk of development gambling problems but who are not gambling frequently. [ABSTRACT FROM AUTHOR]

Polyurea is used in military and civilian applications where exposure to the sun is commonly of long duration, which can deteriorate its mechanical performance to suboptimal levels. This study reports on the ultrasonic properties of polyurea as a function of ultraviolet radiation exposure duration and temperature. Six sets of samples were continuously exposed to ultraviolet radiation for different durations up to 15 weeks. Control samples were also tested that did not receive UV exposure. The ultrasonic properties were measured using high-frequency contact ultrasound transducers in pitch-catch configuration. All exposed samples exhibited significant color changes from transparent yellow to opaque light brown. Changes of color were observed as early as 3 weeks of UV exposure. Nonetheless, crazing was only observed in samples of 6, 9, 12, and 15 weeks of continuous exposure. The size of the surface cracks increased as the duration of exposure continued. The effect of extended UV radiation on the acoustic properties was noted to be minimal, where elastic and shear moduli decreased monotonically after an initial increase during the first 3 weeks of exposure. The attenuation properties were measured at 23 °C and 40 °C. The p-wave attenuation did not show any notable change, while the s-wave attenuation monotonically decreased as the temperature and UV exposure duration increased. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: Vascular calcification independently predicts cardiovascular disease (CVD), and computed tomography (CT) is a useful tool to evaluate and quantify not only coronary but also thoracic aortic calcification (TAC). Previous TAC progression reports were limited to dialysis and renal transplant patients. This is the first study to evaluate TAC progression in a large multiethnic cohort without clinically evident CVD at entry.Methods: Non-contrast-enhanced cardiac CTs were obtained in 5886 of 6814 Multi-Ethnic Study of Atherosclerosis (MESA) participants (mean age, 62 years; 48% males; 40% white, 27% black, 21% Hispanic, and 12% Chinese). Baseline and follow-up TAC scores were derived.Results: Overall, 4308 (73%) participants had no detectable baseline TAC. Mean follow-up duration was 2.4 ± 0.8 years, during which 12% developed TAC. The overall incidence rate was 4.8%/year and was greater with age across gender and ethnic groups; TAC incidence was significantly lower in blacks than whites. After adjustment for follow-up duration, regression analyses showed age, systolic blood pressure, antihypertensives, and smoking were associated with incident TAC. A total of 1578 (27%) participants had TAC at baseline with a positive association between average annual TAC change and baseline age. Although the overall median change was 32.9 (-1.4 to 112.2) Agatston units, 27% showed an annual score change of ≥100 and blacks showed the lowest median across ethnic groups; 22.7 (-3 to 86.8). Age, systolic blood pressure, lipid-lowering medication, diabetes, and smoking were associated with TAC progression.Conclusions: In MESA, traditional CV risk factors were related to both TAC incidence and progression. Blacks had the lowest incidence and median change across ethnic groups, consistent with previous findings for coronary calcification. [ABSTRACT FROM AUTHOR]

A 72-year-old Tongan female was admitted to our facility with dyspnea and refractory hypoxia. She became febrile and blood cultures were positive for Enterococcus faecalis . Transesophageal echocardiography was performed showing two large vegetations on the tricuspid valve causing severe regurgitation. The tricuspid regurgitant jet with the assistance of a large Chiari network was being directed across an ostium secundum atrial septal defect. This clinical scenario represented an unusual cause of acute right to left shunt explaining the patient’s refractory hypoxia. < Learning objective: Acute right to left intra-cardiac shunts occur rarely however should be considered in any patient with acute onset refractory hypoxia.> [ABSTRACT FROM AUTHOR]

This work investigates the load-bearing and energy absorption capacities of hexagonal honeycombs with syntactic cell walls and spatial gradation of cell densities. Structures are processed and property-tuned by varying the volume fraction of hollow microspheres (microballoons), cell wall thickness, and spatial gradation of cell densities. The mechanical behavior of the structures is characterized by subjecting them to in-plane compression. Full-field deformation and failure responses of these structures at meso- and macro-scales are characterized by digital image correlation (DIC) and postmortem fracture analyses, respectively. Mesoscale analyses reveal heterogeneous strain accumulation at the cell hinges, which leads to a fracture in the vicinity of the hinge. Failure is characterized by a brittle mode in all samples. It is shown that the energy absorption capacity of the structures can be improved with the spatially-controlled incorporation of microballoons into the cell struts, at the penalty of reduced overall strength. In addition, cell-density gradation offers a notable improvement to the energy absorption performance over uniform density structures and a mechanism to lower structural density while achieving high mechanical performance. [ABSTRACT FROM AUTHOR]

Objective: The affectional bond experienced by a mother toward her developing fetus/infant has been theorized to be a critical factor in determining infant developmental outcomes; yet there remains a paucity of research in this area, and a lack of high-quality longitudinal studies. This study aimed to examine the extent to which mother-to-infant bonding predicted infant development in a multi-wave longitudinal pregnancy cohort study (N = 1,347).Method: Self-reported bonding was assessed using the Maternal Antenatal Attachment Scale at each trimester, and the Maternal Postnatal Attachment Scale at 8 weeks and 12 months postpartum. Infant development was assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) at 12 months.Results: Bonding predicted indicators of infant social-affective development, including social-emotional, behavioral, and temperamental outcomes. Effect sizes ranged from small to moderate, increasing over the perinatal period (β = 0.11-0.27). Very small effects were also identified in the relationship between bonding and cognitive, language, and motor development (β = 0.06-0.08).Conclusion: Findings suggest that a mother's perceived emotional connection with her child plays a role in predicting social-affective outcomes; prediction may not extend to other domains of infant development. Maternal bonding may therefore be a potentially modifiable predictor of infant social-affective outcomes, offering important considerations for preventive intervention. [ABSTRACT FROM AUTHOR]

Objectives: To examine the incidence of subglottic stenosis in children with congenital heart disease undergoing surgical repair and the contributing factors to such a complication. Design: A retrospective chart review. Setting: Tertiary care children''s hospital heart center. Patients: Children with congenital heart disease undergoing cardiac surgical repair and presenting with subglottic stenosis in the postoperative period. Measurements and Main Results: The authors reviewed their practice for a 4-year period (2002-2005) and identified 17 of 809 children <2 years old with congenital heart disease diagnosed with significant subglottic stenosis in the postoperative period. The incidence was 2.3% in children <1 year old and 2.1% in children <2 years old; the overall incidence was 1.08% in all children <18 years old (17/1,572) undergoing cardiac surgical repair in the same time period. Intubation duration of <24 hours had an incidence of 0.58% compared with 16% in those intubated for >96 hours. The common use of cuffed endotracheal tubes (783/809 children <2years) did not result in an increased risk of subglottic stenosis in the authors'' practice. Conclusion: Subglottic stenosis is an uncommon complication in children undergoing surgical repair of congenital heart defects. The most important risk factors are younger age and prolonged postoperative ventilation. Early diagnosis, referral, and intervention resulted in a favorable outcome in most of the authors'' patients. [Copyright &y& Elsevier]

Transfer functions could model biomechanical parameters to conveniently analyze the system dynamics of the lower limb during daily activities, e.g., walking. The current study evaluates the feasibility of transfer functions as a means of predicting surface electromyography (sEMG) of lower limb muscles based on axial tibial (ATA) and femoral (FA) accelerations. Since the transfer functions are comparable in accuracy to commonly used long short-term memory models (LSTM), the transfer function-based methodology can assist in the design of novel prostheses while being competitive with mainstream models. Data were collected from eight participants with no medical history that would alter their gait cycles. The data included the sEMG of four primary muscle groups, ATA and FA, and heel-strike triggering signal, while the subjects walked at 5.28 km/h on a treadmill. A fast Fourier transform (FFT) was performed on the filtered ensemble averages of the ATA, FA and normalized average rectified sEMG signals, which were used to approximate the time domain Fourier series. Transfer functions relating ATA-to-sEMG and FA-to-sEMG were derived from the Fourier series equations to generate time-domain intra-subject predictions of sEMG signals. With respect to predictive accuracy, these transfer functions were compared with sEMG-to-sEMG LSTM models trained on sEMG data from some of the participants. It was hypothesized that the transfer functions would be at least comparable to the LSTM models. The results indicate that the predicted sEMG signals were able to capture the temporal characteristics of the measured sEMG signal based on either ATA or FA. The muscle activities and acceleration were in good agreement with the walking gait cycle events. Only 13 Fourier terms were needed to effectively predict the sEMG from the acceleration signals, indicating the computational efficiency of the investigated analysis framework. For the ATA-to-sEMG transfer functions, the mean square difference (MSD) between the predicted and measured sEMG signals was low and comparable to the LSTM models. Overall, the feasibility and competitiveness of the transfer functions with LSTM models was confirmed with respect to predictive accuracy. Potential applications of the transfer functions include the control of powered prosthetics and the detection of gait pathologies. [ABSTRACT FROM AUTHOR]

The current study examined associations between preconception diagnoses of major depressive disorder (MDD) and anxiety disorders in adolescence and young adulthood and perinatal depression and anxiety symptoms in early fatherhood. In an Australian community cohort study of health and development, earlier history of MDD and anxiety disorders (extending back to adolescence) were assessed retrospectively in the third trimester of pregnancy via the Composite International Diagnostic Interview. Paternal perinatal depression and anxiety were then assessed prospectively over three timepoints (third trimester of pregnancy, 8 weeks and 12 months postpartum), using established cut-points on the Edinburgh Postnatal Depression Scale and the Depression Anxiety Stress Scales (anxiety subscale). Mixed-effects regression models examined risk associations between preconception diagnoses of MDD and anxiety disorders, and perinatal depression and anxiety symptoms at each timepoint, adjusting for socio-demographic factors and concurrent maternal mental health difficulties. The odds of clinically concerning levels of paternal perinatal depression and anxiety were 6-fold and 4-fold higher, respectively, in men with a preconception history of MDD. The odds of perinatal depression were 3-fold higher in men with a preconception history of an anxiety disorder. Less evidence was found for an association between preconception diagnoses of an anxiety disorder and perinatal anxiety in fathers. Interventions aimed at improving mental health in men during adolescence and young adulthood may promote continued psychological health in men during early fatherhood. [ABSTRACT FROM AUTHOR]

How fathers cope with stress may be critical to their mental health during the perinatal period. Using a sequential explanatory design for systematic review and meta-analysis, we aimed to identify associations and causal relations between higher- and lower-order avoidant and approach coping strategies and paternal psychopathology. We searched five electronic databases and grey literature, and used random-effects models to calculate pooled effects from 11 quantitative studies. Meta-analytic results were integrated with findings from 18 qualitative studies. Fathers' avoidant coping was positively associated with global psychopathology and depression. Approach-oriented coping, particularly problem-solving, was associated with positive affect but not psychopathology. Qualitative findings indicate distressed fathers employ avoidant coping strategies such as suppression, distraction, and social withdrawal. Approach-oriented coping strategies such as problem-solving and cognitive reappraisals appeared to be constructive components of men's coping repertoires supporting adaptation to fatherhood. Different coping strategies and approaches may reflect enactment of constrictive, moderate, or reinterpreted masculine norms. Study designs did not allow conclusions about causal relations between coping and psychopathology. Screening for, and targeting of, high avoidant coping among expectant and new fathers may help detect men at risk of or experiencing mental health difficulties and inform clinical response to psychopathology. Research examining whether different patterns of avoidant and approach coping are associated with psychopathology over time could inform interventions to support men's mental health and adaptation to fatherhood. • Avoidant coping was associated with global psychopathology and depressive symptoms. • Approach coping, specifically problem-solving, was associated with positive affect but not psychopathology. • Approach coping strategies may be important components of broader coping repertoire. • Masculine norms appear to influence paternal coping during the perinatal period. [ABSTRACT FROM AUTHOR]

To investigate whether Immersive Virtual Reality (VR) has a greater positive influence on oncology patients' physical and emotional mood states when compared to an iPad attentional control condition. Our secondary objective was to understand what factors influenced VR effectiveness. Participants were 90 oncology inpatients, aged 7–19 years, and their primary parent caregiver. Using a randomized controlled study design patients were allocated to VR (three content groups) or an iPad control condition. Pre-post-intervention self-report state measures were collected using visual analogue scales and an objective measure of physiological arousal (pulse rate). Post-intervention, patients reported on level of immersion, enjoyment and simulator sickness. Patients benefited from both Immersive VR and novel iPad intervention with no statistically significant differences found between conditions on child outcomes. However, patients accessing Immersive VR consistently reported greater positive shifts in mood state and reductions in negative symptoms when compared with iPad. No change was observed in physiological arousal levels (pulse rate) in either condition before, during or immediately after intervention. Moderation analysis showed that the degree of child illness (PedsQL), sex, age, and level of immersion were important in influencing the magnitude of differences between the VR and iPad conditions on mood, anxiety and pain. These preliminary findings support the use of Immersive VR in clinical oncology settings to improve patient well-being. Further studies examining the application of Immersive VR in supporting children adjusting to hospitalization and cancer treatment are therefore warranted. Factors found to moderate VR effectiveness provide important clinical implications. [ABSTRACT FROM AUTHOR]

• Novel polyurea foams prove to outperform off-the-shelf foam in impact mitigation. • Superior performance of polyurea foams without added weight penalty is attributed to the distinctive microcellular structure. • Finite element analysis using a linear viscoelastic model with scaled down properties of bulk polyurea results were in good agreement with experimental data. Polymeric foams are ubiquitous in body armors for civilian and military applications due to their functional and economic advantage. This class of materials offers good impact mitigation properties without the weight penalty associated with other classes of materials. Generally, foams inherit the mechanical properties of their base material while the performance can be defined by the cellular structure. In this study, new polyurea foams were manufactured and subjected to low energy dynamic impacts to experimentally validate the time-dependent response of polyurea foams based on linear viscoelastic modeling. The time-dependent properties of bulk polyurea were scaled down by accounting for the change in density and microstructure of the polyurea foam. Drop-weight testing of approximately 7 J in a fully-instrumented drop weight testing machine was conducted on newly-fabricated polyurea foams of two nominal densities, namely, 227 kg/m3 and 355 kg/m3. Simultaneous to the impact event, high-speed photography was used to capture the deformation and recovery response of the samples. The performance was then compared with a promising off-the-shelf, closed-cell foam material used to protect against biomechanical impacts. The polyurea foams proved to mitigate the impact more effectively than the benchmark foam without the addition of a severe weight penalty. The finite element simulation performed well in predicting the amplitude and the rise time of the dynamic impact testing of the two foams; the numerical results were found to be in close agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Several sports-related injuries and orthopedic treatments need the necessity of corrective shoes that can assuage the excessive pressure on sensitive locations of the foot. In the present work, we study the mechanical and energy absorption characteristics of density-graded foams designed for shoe midsoles. The stress-strain responses of polyurea foams with relative densities (nominal density of foam divided by the density of water) of 0.095, 0.23, and 0.35 are obtained experimentally and used as input to a semi-analytical model. Using this model, three-layered foam laminates with various gradients are designed and characterized in terms of their weight, strength, and energy absorption properties. We show that, in comparison with monolithic foams, significant improvement in strength and energy absorption performance can be achieved through density gradation. Our findings also suggest that there is not a single gradient that offers a superior combination of strength, energy absorption, and weight. Rather, an optimal gradient depends on the plantar location and pressure. Depending on the magnitude of the local plantar pressure, density gradients that lead to the highest specific energy absorption are identified for normal walking and running conditions. [ABSTRACT FROM AUTHOR]

• Strain mediated composite ring structures enhance magnetoelectric coefficient. • Established multiphysics framework for piezoelectric/magnetostrictive composites. • Complex magnetoelastic response captured including shielding and anisotropy. • Good agreement between multiphysics simulation and past experiments. Due to the importance of composite multiferroic structures in numerous applications including sensing, actuation, and communication, concerted analytical and experimental efforts have been afforded to these types of structures in pursuit of fundamental understanding of their behavior in the presence of different stimuli. In this study, a finite element-based Multiphysics computational framework was established to investigate a multiferroic composite ring structure consisting of an inner Terfenol-D magnetostrictive ring and an outer lead zirconate titanate (PZT) piezoelectric ring. In a precursor to the full composite investigation, the computational framework was applied to a standalone Terfenol-D magnetostrictive ring structure and was found to capture the intricacies of the interaction of the magnetic field and the geometry including magnetic shielding and shape anisotropy. When extended to the composite structure, the computational model continued to perform reasonably well in comparison to previous experimentally reported data. The forecasted converse magnetoelectric coefficient of a PZT/Terfenol-D concentric composite ring structure was found to be 357 mG/V, which is in excellent agreement with 334 mG/V experimentally reported coupling coefficient for the same geometry. Moreover, the measured and calculated mechanical strains were in reasonable agreement; given the underlying assumptions of the computational model. Future work should focus on further developing the computational model to include the nonlinear magnetostrictive and piezoelectric constitutive relationship as well as the time-dependence of the response to accelerating the development cycle of devices based on magnetoelectric composites. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The construction industry has seen a proliferation of continuous and discontinuous fiber-reinforced polymer composites due to their high strength-to-weight and stiffness-to-weight ratios while being resilience to harsh environmental and operating conditions. This paper reports a comparative experimental investigation of field-deployed E-glass/Epoxy composite panels with those freshly manufactured to elucidate the effect of deployment conditions on the performance of these panels. Samples extracted from underground vault after power-line explosion due to arcing fault were examined using optical and atomic force microscopes to assess the extent of the damage. The samples were also characterized using a dynamic mechanical analyzer to explain the change in the properties post-explosion quantitatively. Microscopy investigations show no significant change in morphology or topography of the panels as well as the absence of failure modes such as delamination, fiber-failure or core-failure. Nonetheless, surface contaminations due to service conditions were found to exaggerate the surface burn marks despite the fire retardation properties of the composite panels. The dynamic mechanical properties of the panels were found to change as a function of temperature and loading frequency slightly. A shift in transition temperatures (T β and T g) was found to be within a few degrees Celsius. The storage modulus was reduced by 21%, while the overall complex modulus remained relatively constant when comparing fresh and field-deployed samples. A frequency and temperature dependent model was used to fit the dynamic data and found to provide insights into the microstructure evolution of the polymer matrix. [ABSTRACT FROM AUTHOR]

Honeycomb structures possess unique mechanical and structural behaviors, including high specific strength, superior energy absorption, and potential for multifunctionality. The advantages of such structures are bolstered by their realization through additive manufacturing, enabling cellular geometries beyond traditionally fabricated hexagons and facilitating a pathway for hybridization using composite materials to tune the response. This research synthesized photocurable, particulate-reinforced resins using mechanically compliant matrix and glass microballoons reinforcement. The modified resins were used to additively manufacture lattice structures with circular and hexagonal unit cell geometries at different glass microballoons reinforcement weight ratios, ranging from neat to 20 wt. %. The 3D printed structures were tested under quasi-static and impact loading scenarios to elucidate the interrelationships between the cell geometry, induced deformations, and strain rates. The mechanical testing was coupled with digital image correlation (DIC) to reveal the deformation-geometry interrelationship on the global (macroscale) and local (mesoscale) levels. The multiscale analyses allowed for extensive characterization of the effect of cell geometry and increased weight reinforcement on the mechanical response at a global, sub-cellular, and cellular level, i.e. , elucidating the hierarchical dependency. The novelty leading to the current study stems from probing and revealing the deformation state of cellular structures subjected to two loading scenarios using DIC. This study intended to provide mechanistic insights for engineering lattice structures for impact mitigation applications by offering a viable approach to additive manufacturing composite materials. [ABSTRACT FROM AUTHOR]

The empathy-autistic trait relationship is complex and controversial. Empathy research is often undermined by unidimensional approaches to defining and measuring a multidimensional construct. This study regresses autistic trait level variation onto cognitive and emotional empathy variables across modalities (self-report, behavioural, and physiological) using a non-clinical adult sample (N = 123). We also account for several important covariates (age, sex, IQ, years of education and visual attentional behaviour). Self-report (trait-based) cognitive and emotional subscales predicted AQ more strongly and frequently than lab-based measures (behavioural/physiological; state-based), in directions consistent with prior findings. Emotional empathy questionnaire subscales differed in predictive directionality; a finding discussed with reference to state-trait measurement divergences and problematic subscales such as the personal distress scale of the Interpersonal Reactivity Index, which may contribute inconsistency in emotional empathy findings. Visual (in)attention was a consistent covariate predictor of AQ, highlighting the importance of accounting for gaze in autism trait studies to avoid erroneous conclusions. Findings are discussed with reference to the challenge of bridging the gaps between lab, theory, and application. Results further support the broader autism phenotype notion and contribute to debate concerning the relationship between empathy and autistic traits. • Empathy-AQ relationship explored across multiple modes and domains • Self-report (trait) empathy stronger predictors of AQ than any state measure. • Trait-emotional empathy subscales differ in valence of AQ association. • Visual attention covariate significantly influences AQ-empathy relationship. [ABSTRACT FROM AUTHOR]

Background Soluble ST2 (sST2) is an emerging biomarker of cardiac remodelling and fibrosis. Studies indicate that it is predictive of mortality in acutely decompensated heart failure. The role of sST2 in chronic heart failure (CHF) is less well defined. No studies have examined serial measurements in optimised patients as a potential monitoring tool. This study aimed to prospectively determine the prognostic utility of serial sST2 in patients with pharmacologically optimised stable CHF. Methods 41 patients with pharmacologically optimised CHF and left ventricular ejection fraction ≤ 40% were recruited. Clinical review and blood sampling took place at baseline, and one, three and six months. N-terminal pro-brain natriuretic peptide (NTproBNP), sST2 and renal profile were measured on all samples. 12 lead electrocardiogram (ECG) was performed at baseline. Decompensation was defined as a composite endpoint of cardiovascular admission or worsening renal function (≥ 25% increase in serum creatinine from baseline). Results Receiver operator curve analysis of percentage change in sST2 from baseline to six months was strongly reflective of decompensation with area under the curve (AUC) of 0.778. This was significantly better than NTproBNP (AUC 0.425; p = 0.013). Correlation of baseline concentrations to surface ECG showed that both sST2 and NTproBNP were positively correlated with duration of the QRS wave, with higher level of significance demonstrated by sST2 (0.415 (p = 0.007) and 0.362 (p = 0.020) respectively). Conclusions Percentage changes in sST2 are better able to predict cardiovascular admission or worsening renal function in patients with pharmacologically optimised CHF than NTproBNP. Compared with NTproBNP, sST2 appears to be a promising candidate for monitoring these patients. [ABSTRACT FROM AUTHOR]

Abstract: We report dynamic fracture energy measurements for E-glass/polyurea/steel joints at a peak strain rate of 1.2×107 s−1. Experiments were done by initiating a crack at the steel/polyurea interface by a laser-generated stress wave, whose profile was recorded using optical interferometry. The critical energy release rate or the energy delivered by the propagating stress wave to the crack-tip region at crack initiation was computed by using a wave dynamics simulation. An average value of 359 (±19)J/m2 was obtained. The effect of moisture on the fracture energy values was also examined. Results showed that the values reduced by only 3% to 349±19J/m2 in samples that were exposed to 75% RH at 65°C for 30days. In addition to using the data as a local failure criterion in large-scale simulation of structural joints, it can be used to estimate the residual fracture energy of the E-glass/polyurea/steel joints in service. [Copyright &y& Elsevier]

Bridging between micromechanics response and macroscopic behavior is at the core of multiscale investigations in heterogeneous materials. As such, quantitative characterization of the transitional length scales that correlate micro and macroscale behaviors is of great importance. Experimental characterization of the so-called transitional length scales in foams and other cellular structures is extremely scarce. The present work reports on an experimental-statistical approach proposed to quantify the micro-to-macro transition length scale in polymeric foams. The approach proposed in this work uses full-field strain distributions measured by digital image correlation (DIC) at two scales as input. The physical dimensions of the transition length scale are identified by implementing a statistical algorithm based on spatial averaging of the local strain data obtained from DIC. Interestingly, the transition between micro and macroscale deformation is found to be a function of material density but independent of global strain and stresses applied. The present results provide direct validations to representative volume element (RVE) size in cellular solids determined by computational methods. • A multiscale experimental approach is used to identify RVE size in foams. • Strain fields are measured using multiscale optical digital image correlation. • A strain averaging technique is utilized to characterize micro-to-macro transition scale. • RVE size is shown to be a function of foam density. [ABSTRACT FROM AUTHOR]