RESUMEN
Natural rubber (NR) composites containing bio-based chitin nanofibers (ChNFs) exhibit a wide range of mechanical properties - from rubber to plastic behavior - with increasing chitin contents. A constrained 3-dimensional network can be formed by mixing natural rubber latex and a modified zwitterionic rigid chitin counterpart. By inclusion of highly anisotropic chitin nanofibers (30 wt%), strain-induced NR crystallization occurs at a much lower strain of 50%. More intriguingly, 2D-WAXD results reveal that the strain-induced crystallization of NR/ChNFs composites show 3-dimensionally oriented crystallite formation behaving similar to "3D-single crystals orientation" when the content of ChNFs is over 5 wt%. It is suggested that not only c-axis (NR chains) orients along the stretching direction, but also the a- and b-axes deliberately arrange along the normal direction and transverse direction, respectively. Structure and morphology in 3-dimensional spaces after strain-induced crystallization of the NR/ChNFs30 composite are investigated in detail. Therefore, this study might pave a new way to enhance mechanical properties by incorporation of ChNFs, obtaining 3-dimensionally oriented crystallites of novel multifunctional NR/ChNFs composite with shape memory ability.
RESUMEN
The hydrophilic polysaccharides (PS) were isolated and purified from the tuberous roots of Pseudostellaria heterophylla. The extraction process of PS from Pesudostellariae radix was optimized by single-factor experiments and orthogonal design. The extract was purified by DEAE cellulose column to obtain the pure polysaccharide PHP. Then PHP was treated with different intensities of sonication to study the effect of sonication on PHP's characteristics and its biological activity in vitro and in vivo. The results of this study revealed that ultrasound treatment did not significantly change the properties of PHP. Further, with the increase of ultrasound intensity, PHP enhanced the proliferation and phagocytosis of macrophage RAW264.7. Meanwhile, it could also significantly improve the body's antioxidant activity and immune function. The results of this study demonstrated that PHP has the potential as a food additive with enhanced antioxidant and immune functions, and its biological activities could be enhanced by sonication.
Asunto(s)
Antioxidantes , Caryophyllaceae , Antioxidantes/farmacología , Aditivos Alimentarios , Ultrasonografía , Polisacáridos/farmacologíaRESUMEN
Music performance anxiety (MPA) is recognized as a distinct emotional behavior rather than merely a motor control disorder and is influenced by specific conditioning experiences. This study investigates the interrelationships between MPA, self-efficacy, and future career expectations among music students within the Chinese context. The participants of this study were 340 high school students majoring in music education and performance, drawn from three music schools in China. Data were collected using several questionnaires: the MPA Inventory for Adolescents (MPAI-A), the Self-Efficacy Formative Questionnaire, and the Career Futures Inventory (CFI). The findings indicate that MPA is negatively associated with self-efficacy and future career expectations. Additionally, self-efficacy acts as a partial moderator between MPA and career expectations, suggesting that enhancing the self-efficacy of music students can boost their future career aspirations and mitigate the adverse effects of MPA. This research explores the complex relationships among MPA, self-efficacy, and future career expectations, emphasizing the importance of curriculum and pedagogical strategies in music schools. Music students with high levels of self-efficacy may exhibit more confidence and stable performances before audiences. According to the panel regression analysis, self-efficacy significantly positively influences career expectations. An appropriate educational environment and supportive pedagogical approaches to MPA can foster the early career development of musicians.
RESUMEN
The COVID-19 pandemic has affected city dwellers' physical and mental health and has raised concerns about the health of urban public spaces. This field investigation research in Dalian, China, examined the perceived audio-visual environment characteristics of urban pedestrian streets with traffic noise and their influences on the environmental health of the pedestrian streets. Five indicators reflecting psychological responses to environmental characteristics (willingness to walk, relaxation, safety, beauty, and comprehensive comfort) were used to measure environmental health of pedestrian streets with traffic noise. The results showed that safety was rated the highest, and willingness to walk was evaluated as the lowest among health evaluation indicators. The imageability and openness of the streetscape were associated with each health evaluation indicator. In contrast, the rhythm and continuity of the street buildings had a greater effect on willingness to walk than the other health indicators. There were negative correlations between L Aeq for traffic noise and health evaluations. Positive health evaluations were observed when L Aeq was less than 55 dBA. In contrast, soundscape indicators showed positive correlations with health evaluations, and acoustic comfort and noise annoyance, rather than sound preference and subjective loudness were associated with each health evaluation indicator. In terms of the combined audio-visual factors, acoustic comfort, the quantity of greening, annoyance, sky visibility, spatial scale, and building distance were examined as the determining factors affecting health evaluations, and 55.40% of the variance in health evaluations was explained by the soundscape and streetscape indicators. The findings provide references for better understanding the relationships between healthy experience and audio-visual perceptions. Moreover, they enable environmental health quality optimisation of pedestrian spaces considering audio-visual indicators and approaches in the post-epidemic era.
RESUMEN
Introduction: Although the importance of teacher feedback has been confirmed by a great number of studies, the association of head teacher praise and criticism with adolescents' non-cognitive skills still needs more deeper and more extensive research. Therefore, how to improve the non-cognitive skills of adolescents, especially those with disadvantaged family and economic backgrounds, has become a key concern in the field of educational practice. Methods: Based on CEPS data, this paper used panel regression and PSM-DID methods to analyze the impact of head teacher feedback on an adolescent's non-cognitive skills measured by the big-five personality scale. Results: It found that praise from head teachers favorably influenced adolescents' extraversion, agreeableness, openness, and conscientiousness, yet significantly mitigates their neuroticism. Meanwhile, the effect of criticism from head teachers is bi-facial: It made a positive effect on adolescents' extraversion and openness but impaired their conscientiousness and neuroticism. As rural adolescents notably lag in their non-cognitive skills and are much less likely to be praised by head teachers compared to their urban peers, we estimate that when rural adolescents are frequently praised by their head teachers at the same level as urban students, their gap in extraversion, agreeableness, neuroticism, openness, and conscientiousness would be narrowed by 12.51%, 16.58%, 11.35%, 14.25%, and 24.29%. This finding has significant implications for head teacher teaching and adolescent well-being. Conclusions: The study examined the effects of head teacher praise and criticism on adolescent non-cognitive skills. The results showed that adolescents who were often praised by head teachers developed better non-cognitive skills. While the effect of head teacher criticism was two-sided: it enhances extraversion and openness as well as heightens neuroticism and corrupts conscientiousness. We further analyzed the urban-rural gap in non-cognitive skills and found that rural adolescents significantly lagged, and they have a lower possibility to be often praised by the head teacher, but a higher probability to be criticized. Through the PSM-DID quasi-experimental design, it was suggested that more head teacher praise can improve the non-cognitive skills among adolescents. When rural adolescents are estimated to receive the same amount of praise as urban adolescents, the disparities reduction in their non-cognitive skills can become possible. Our findings are of great significance to promote adolescent non-cognitive skills development and improve educational equity in urban and rural areas.
RESUMEN
A binary optical encoding strategy is proposed to meet the increasing requirements of multiplex bioassays. As illustrated in fluorescence immunodetection of multiplex antigen molecules, photonic crystal beads (PCBs) and quantum dots (QDs) can be used as biomolecular microcarriers and fluorescence labels, respectively. The categories of antigens were deciphered by the binary combination of optical spectra of PCBs and QDs as independent encoding elements. The number of categories that could be detected was theoretically m × n, where m and n represent the number of encoding PCBs and QDs, respectively. In addition, the concentrations of the antigens were determined by the fluorescence signals of the QDs. Results of sensitivity analysis indicate that a low-level detection of 58 pg/mL was achieved. Because of the special nanostructures of these two encoding elements, the binary encoding strategy demonstrated its superiority and practicability when compared with single PCB or QD encoding. This supports potential application in multiplex bioassays.