Surface-enhanced Raman spectroscopy in 3D electrospun nanofiber mats coated with gold nanorods

Nanofibers functionalized by metal nanostructures and particles are exploited as effective flexible substrates for SERS analysis. Their complex three-dimensional structure may provide Raman signals enhanced by orders of magnitude compared to untextured surfaces. Understanding the origin of such improved performances is therefore very important for pushing nanofiber-based analytical technologies to their upper limit. Here we report on polymer nanofiber mats which can be exploited as substrates for enhancing the Raman spectra of adsorbed probe molecules. The increased surface area and the scattering of light in the nanofibrous system are individually analyzed as mechanisms to enhance Raman scattering. The deposition of gold nanorods on the fibers further amplifies Raman signals due to SERS. This study suggests that Raman signals can be finely tuned in intensity and effectively enhanced in nanofiber mats and arrays by properly tailoring the architecture, composition, and light-scattering properties of the complex networks of filaments.Comment: 29 pages, 9 figures, 1 Tabl

The motivational antecedents of the development of mental toughness: a self-determination theory perspective

Mental toughness is a topic that has received growing attention in psychological literature over the past decade. Although some researchers have attempted to understand how mental toughness is developed, little effort has been made to integrate an understanding of mental toughness development with established psychological theory and research. The aim of our review is to demonstrate the utility of theory and research on motivation for understanding mental toughness and its development. In particular, we propose that self-determination theory provides a sound basis for understanding the motivational antecedents of mental toughness. To achieve our aim, we consider concepts that bridge mental toughness and self-determination theory literature, namely striving, surviving, and thriving. We conclude our review with suggestions for future lines of empirical enquiry that could be pursued to further test our propositions

Implicit Theories of Mental Toughness: Relations With Cognitive, Motivational, and Behavioral Correlates

People differ in their implicit theories about mental toughness, that is, whether they believe this quality is immutable (entity theorists) or changeable (incremental theorists). The aim of this study was to explore whether peoples’ implicit theories of mental toughness are related to cognitive, motivational, and behavioral variables considered as hallmarks of this personal quality. We conducted 3 studies with participants from different achievement contexts: 444 undergraduate students aged 17 to 26 years (M 19.25); 395 employees aged 25 to 79 years (M 48.78); and 230 adolescent athletes aged 11 to 17 years (M 14.98). Students completed a measure of implicit theories of mental toughness, fear of failure, and perceived stress. Employees completed a measure of implicit theories and were rated on performance and creativity by their supervisor. Athletes completed a measure of implicit theories of mental toughness, resilience, and thriving. Across all 3 samples, cluster analyses supported the existence of an incremental theory (high incremental theory, low entity theory) alongside an ambivalent group (moderate scores on both theories). These clusters differed on fear of failure, stress, performance, creativity, resilience, and thriving consistent with theoretical expectations. The current findings suggest that people’s implicit theories of mental toughness may have important implications for understanding cognitive, motivational, and behavioral correlates considered hallmarks of this psychological concept

Evaluating the effectiveness of home exercise programmes using an online exercise prescription tool in children with cerebral palsy: protocol for a randomised controlled trial.

Introduction: Children with cerebral palsy (CP) and other neurodevelopmental disabilities often receive a home programme of exercises to assist in reaching their therapy goals. Adherence to exercise programmes is necessary to attain the level of practice required to achieve goals; however, adherence can be difficult to accomplish. In this paper, we describe the protocol for a randomised controlled trial to evaluate the effectiveness of delivering a home exercise programme to school-age children with disabilities using Physitrack, an online exercise prescription tool with a website or app interface. Methods and analysis: Participants aged 6–17 years, with CP or other neurodevelopmental disabilities, receiving community physiotherapy services in Western Australia, will be recruited. Participants will be stratified by age and functional mobility and randomised to either the intervention group, who will complete an 8-week home exercise programme using Physitrack, or the control group, who will complete an 8-week exercise programme without Physitrack. Researcher blinding to group allocation, and participant blinding to outcome, will be maintained. The primary outcome measures are adherence to the home exercise programme with weekly collection of home exercise logs; achievement of individualised goals by phone interview before and after intervention; and correctness of exercise performance by collection and analysis of videos of participants performing home exercises. Secondary outcome measures include enjoyment of physical activity, confidence to complete exercise programme, preferred method of delivery of programme and usability of Physitrack. A sample size of 58 participants will be necessary to see an effect on home programme adherence. Data will be analysed using the intention-to-treat principle. Ethics and dissemination: Ethical approval was obtained from Curtin University Human Research Ethics Committee in July 2016 (10391). Outcomes will be disseminated through publication in peer-reviewed journals and presentations at scientific conferences. Trial registration number: ACTRN12616000743460; Pre-results

The cortisol awakening response and resilience in elite swimmers.

The sports environment is stress-eliciting in that it encapsulates perceived uncontrollability, unpredictability and requires ego-involvement. The HPA axis has been shown (indicated by cortisol release) to respond to anticipated sports competition up to a week prior to the event. Research also alludes to the importance of individual differences, such as optimism and trait perfectionism, in moderating the impact of cortisol upon performance. In total, 41 (male n=27) national (n=38) and international (n=3) swimmers were recruited from northeast England and Australia. Swimmers completed a measure of resilience and also provided buccal saliva swabs, from which total cortisol release prior to and during the event was calculated. Findings revealed that resilience significantly predicted performance and the influence of AUC (cortisol release) upon performance was moderated by resilience. These findings suggest that resilience can influence athletic performance either directly or indirectly, through appraisal (i. e., interpretation of the stressor to be facilitative and non-threatening)

The cortisol awakening response and resilience in elite swimmers.

The sports environment is stress-eliciting in that it encapsulates perceived uncontrollability, unpredictability and requires ego-involvement. The HPA axis has been shown (indicated by cortisol release) to respond to anticipated sports competition up to a week prior to the event. Research also alludes to the importance of individual differences, such as optimism and trait perfectionism, in moderating the impact of cortisol upon performance. In total, 41 (male n=27) national (n=38) and international (n=3) swimmers were recruited from northeast England and Australia. Swimmers completed a measure of resilience and also provided buccal saliva swabs, from which total cortisol release prior to and during the event was calculated. Findings revealed that resilience significantly predicted performance and the influence of AUC (cortisol release) upon performance was moderated by resilience. These findings suggest that resilience can influence athletic performance either directly or indirectly, through appraisal (i. e., interpretation of the stressor to be facilitative and non-threatening)

Stress, Physical Activity, and Resilience Resources: Tests of Direct and Moderation Effects in Young Adults

Stress is an important consideration for understanding why individuals take part in limited or no physical activity (PA). The effects of stress on PA do not hold for everyone, so examinations of possible moderators that protect individuals from the harmful effects of stress are required. Aligned with a resilience framework, individual resources (e.g., hope and self-efficacy) may buffer the maladaptive effects of stress, such that people who have access to these resources in greater quantity may be more "resilient" to the deleterious effects of stress on PA. This study was designed to test this expectation. In total, 140 Australian undergraduate students (70.7% female, Mage = 21.68 ± 4.88) completed a multisection survey and provided a sample for hair cortisol concentration analysis using immunoassays. Main effects demonstrated primarily small and nonsignificant associations between perceived stress and hair cortisol concentration with different intensities of PA. Similar findings were observed between individual-level resilience resources and PA intensities, with the exception of hope (i.e., positive association with vigorous PA and negative association with sitting), self-efficacy (i.e., positive association with vigorous PA), and resilience (i.e., positive association with walking). Although certain individual-level resilience resources were perceived as beneficial for PA and sedentary time, the moderating role of resilience resources was not supported by the findings. The direct and moderating effects between stress, PA, and resilience resources require further testing using longitudinal designs in which stressful periods occur naturally (e.g., exams for students) or are experimentally manipulated

Light depolarization effects in tip enhanced Raman spectroscopy of silicon (001) and gallium arsenide (001)

We report on the effects of light depolarization induced by sharp metallic tips in Tip-Enhanced Raman Spectroscopy (TERS). Experiments on Si(001) and GaAs(001) crystals show that the excitation field depolarization induces a selective enhancement of specific Raman modes, depending on their Raman tensor symmetry. A complete polarization analysis of the light backscattered from the tip confirms the TERS findings. The spatial confinement of the depolarization field is studied and its dependence on the excitation wavelength and power are explored