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Compared with non-degradable materials, biodegradable biomaterials play an increasingly important role in the repairing of severe bone defects, and have attracted extensive attention from researchers. In the treatment of bone defects, scaffolds made of biodegradable materials can provide a crawling bridge for new bone tissue in the gap and a platform for cells and growth factors to play a physiological role, which will eventually be degraded and absorbed in the body and be replaced by the new bone tissue. Traditional biodegradable materials include polymers, ceramics and metals, which have been used in bone defect repairing for many years. Although these materials have more or fewer shortcomings, they are still the cornerstone of our development of a new generation of degradable materials. With the rapid development of modern science and technology, in the twenty-first century, more and more kinds of new biodegradable materials emerge in endlessly, such as new intelligent micro-nano materials and cell-based products. At the same time, there are many new fabrication technologies of improving biodegradable materials, such as modular fabrication, 3D and 4D printing, interface reinforcement and nanotechnology. This review will introduce various kinds of biodegradable materials commonly used in bone defect repairing, especially the newly emerging materials and their fabrication technology in recent years, and look forward to the future research direction, hoping to provide researchers in the field with some inspiration and reference.

Background Frailty, depression, and loneliness are significant risk factors that hinder successful aging. Physical exercise has been widely recognized as an effective intervention to improve both the physical and mental health of older adults. Guided by the integral conceptual model of frailty, this study aimed to explore the relationships among physical exercise, frailty, depression, and loneliness, providing theoretical support for designing targeted exercise interventions to alleviate loneliness in older adults. Methods This study employed a structural equation model (SEM) and bootstrap method to examine a serial mediation model, investigating the roles of frailty and depression in the relationship between physical exercise and loneliness. A descriptive and cross-sectional design was adopted, and data were collected from 505 older adults aged 60 and above in China between February and July 2023. The data were collected using the Physical Activity Rating Scale (PARS-3), the UCLA Loneliness Scale (ULS-8), the Tilburg Frailty Indicator (TFI) and the Patient Health Questionnaire-9 (PHQ-9). Results The findings revealed a significant direct negative relationship between physical exercise and loneliness (Effect = -0.063, 95% CI: -0.085 to -0.040). Furthermore, frailty and depression were found to mediate this relationship both independently and serially. The independent mediation effect of frailty was − 0.072 (95% CI: -0.090 to -0.055), while the independent mediation effect of depression was − 0.010 (95% CI: -0.019 to -0.003). The serial mediation effect of frailty and depression was − 0.007 (95% CI: -0.011 to -0.002). Collectively, the total indirect effect of the three mediation pathways accounted for 58.55% of the observed relationship. Conclusions This study demonstrated a negative correlation between physical exercise and loneliness among older adults, with frailty and depression serving as significant mediators in this relationship. The findings suggest that physical exercise may alleviate loneliness in older adults by enhancing physiological function and fostering psychosocial empowermen.

Athlete engagement is influenced by several factors, including cohesion, passion and mental toughness. Machine learning methods are frequently employed to construct predictive models as a result of their high efficiency. In order to comprehend the effects of cohesion, passion and mental toughness on athlete engagement, this study utilizes the relevant methods of machine learning to construct a prediction model, so as to find the intrinsic connection between them. The construction and comparison methods of predictive models by machine learning algorithms are investigated to evaluate the level of predictive models in order to determine the optimal predictive model. The results show that the PSO-SVR model performs best in predicting athlete engagement, with a prediction accuracy of 0.9262, along with low RMSE (0.1227), MSE (0.0146) and MAE (0.0656). The prediction accuracy of the PSO-SVR model exhibits an obvious advantage. This advantage is mainly attributed to its strong generalization ability, nonlinear processing ability, and the ability to optimize and adapt to the feature space. Particularly noteworthy is that the PSO-SVR model reduces the RMSE (7.54%), MSE (17.05%), and MAE (3.53%) significantly, while improves the R 2 (1.69%), when compared to advanced algorithms such as SWO. These results indicate that the PSO-SVR model not only improves the accuracy of prediction, but also enhances the reliability of the model, making it a powerful tool for predicting athlete engagement. In summary, this study not only provides a new perspective for understanding athlete engagement, but also provides important practical guidance for improving athlete engagement and overall performance. By adopting the PSO-SVR model, we can more accurately identify and optimise the key factors affecting athlete engagement, thus bringing far-reaching implications for research and practice in sport science and related fields.

The major task of a wireless sensor network (WSN) is data collection. Key predistribution (KP) is to establish pairwise keys for secure communication in a WSN, such that all collected data could be securely sent to a backend database. Most research on KP-like schemes is dedicated to enhancing resiliency against node capture attack (NA) and retaining the link connectivity in the meantime. For large-scale wireless sensor networks, a more common approach is to use a multiple-sink WSN (MWSN) to support a large number of sensor nodes. In MWSNs, there are different clusters (referred to as groups). We took the lead in studying KP in the MWSN environment. Based on the new MWSN environment, we present intragroup and intergroup KP (I2KP) to fulfill both requirements of security and energy efficiency when gathering data via various sink nodes in a large-scale WSN. Three types of I2KP with respective pros and cons are proposed. Theoretical analysis and numerical simulation demonstrate their effectiveness.

In practical engineering, whilst estimating the jacking force of rectangular pipe jacking using an empirical formula, the results obtained from said formula deviate from reality and manifest inadequate engineering guidance. The equations governing the applied force during the installation of rectangular pipe jacking have been derived for various contact states involving the interaction between the pipe, slurry, and soil. The distinct stress conditions in the pipe jacking process as well as the shear-friction mechanism between the pipe and the surrounding soil have been taken into account. The displacement control method is introduced to simulate the pipe–slurry–soil contact friction during the pipe jacking process in FLAC 3D . Additionally, the pipe jacking behavior, pipe–slurry–soil contact frictional force, and variation law of the jacking force are also simulated. Mutual verification was carried out using the results obtained from field monitoring, numerical and theoretical. The findings are as follows: the established equations for calculating pipe jacking force are highly applicable across various conditions of pipe–slurry–soil contact, and the outcomes derived from theoretical formulas align remarkably well with those obtained through field monitoring and numerical simulation. During the jacking process, the sidewalls exhibit initial partial sliding followed by a complete movement as the jacking force intensifies and subsequently diminishes, eventually attaining stability during the behavior adjustment phase. Moreover, the bottom pipe–soil contact is the most common situation in actual construction.

Coach-athlete relationship (CAR), thriving and athlete engagement are important psychological variables that affect sports performance. On the basis of self-determination theory, this study constructs a mediation model to examine the influence of CAR on athlete engagement and the mediating effect of thriving between them. This cross-sectional study involves a questionnaire survey with 287 Chinese active athletes (M = 19.63, SD = 2.53) aged 14-26 years (64.5% male, 35.5% female) from eight sports. CAR, thriving and athlete engagement were assessed using the CAR Questionnaire, the Thriving Scale, and the Athlete Engagement Questionnaire, respectively. CAR and its dimensions can significantly and positively predict athlete engagement, complementarity, commitment, and closeness, accounting for 35.1%, 34.6%, and 30.4% of the cumulative variance in dominance analysis, respectively. The direct and indirect paths show that CAR affects athlete engagement through the mediating effect of thriving. The mediating effect model has a good fit and indirect effects account for 56.9% of the total effects. The effect of CAR on athlete engagement reflects a practical application of interpersonal dynamics in competitive sports to a certain extent. The following suggestions can be used to improve athlete engagement. First, setting common goals, emphasizing mutual cooperation, and building trust and support, promote coaches and athletes to have a higher sense of commitment and complementarity to each other, thereby helping improve athlete engagement. Second, meeting the vitality and progress needs of athletes effectively mobilizes CAR resources to promote athlete engagement, which can be manipulated by cultivating closeness, commitment, and complementarity. Third, to ensure the athletes' sports state and mental health, the sports team should focus on the cultivation of athletes' capacities to thrive and internally form a dynamic and positive sports atmosphere in their team. In the future, we can track and compare the influence of the improvement of CAR on thriving and athlete engagement can be tracked and compared from the dual perspectives of coaches and athletes.

Release of ATP from astrocytes is required for Ca 2+ wave propagation among astrocytes 1 , 2 , 3 and for feedback modulation of synaptic functions 2 , 4 , 5 . However, the mechanism of ATP release and the source of ATP in astrocytes are still not known. Here we show that incubation of astrocytes with FM dyes leads to selective labelling of lysosomes. Time-lapse confocal imaging of FM dye-labelled fluorescent puncta, together with extracellular quenching and total-internal-reflection fluorescence microscopy (TIRFM), demonstrated directly that extracellular ATP or glutamate induced partial exocytosis of lysosomes, whereas an ischaemic insult with potassium cyanide induced both partial and full exocytosis of these organelles. We found that lysosomes contain abundant ATP, which could be released in a stimulus-dependent manner. Selective lysis of lysosomes abolished both ATP release and Ca 2+ wave propagation among astrocytes, implicating physiological and pathological functions of regulated lysosome exocytosis in these cells.

Background Loneliness is a risk factor for numerous negative life outcomes and diseases among older adults. Physical exercise can reduce social isolation among older adults and improve their health status. This study focused on the relationships among physical exercise, perceived social support, resilience and loneliness to provide theoretical support for physical exercise interventions to address loneliness in older adults. Methods This study used a structural equation model and bootstrap method to test a serial mediation model of physical exercise and loneliness and the role of perceived social support and resilience. In this descriptive and cross-sectional study, a questionnaire survey was conducted on 516 older adults from 5 January 2024 to 20 January 2024. The data were collected using the physical activity rating scale (PARS-3), UCLA loneliness Scale-8 (ULS-8), perceived social support scale (PSSS) and Connor-Davidson Resilience Scale (CD-RISC). Results The results showed that physical exercise among older adults had a direct negative relationship with loneliness (Effect = -0.049, 95% CI: -0.072 to -0.027). In addition, perceived social support and resilience mediated the relationship between physical exercise and loneliness both independent and serially, with the independent mediation effect of perceived social support being − 0.041 (95% CI: -0.056 to -0.028), the independent mediation effect of resilience being − 0.018 (95% CI: -0.026 to -0.011), and the serial mediation effect of perceived social support and resilience being − 0.009 (95% CI: -0.015 to -0.005). The total indirect effect of the three mediation paths was 58.47%. Conclusions (1) In this study, physical exercise and loneliness in older adults were negatively correlated. Perceived social support and resilience play mediating roles in the relationship between physical exercise and loneliness. (2) This study suggests that participation in group events or team sports is valuable for alleviating loneliness caused by a lack of social interaction.

Background Solute carrier family 7 member 11 (SLC7A11) is overexpressed in multiple human tumours and functions as a transporter importing cystine for glutathione biosynthesis. It promotes tumour development in part by suppressing ferroptosis, a newly identified form of cell death that plays a pivotal role in the suppression of tumorigenesis. However, the role and underlying mechanisms of SLC7A11‐mediated ferroptosis in hepatoblastoma (HB) remain largely unknown. Methods Reverse transcription quantitative real‐time PCR (RT‐qPCR) and western blotting were used to measure SLC7A11 levels. Cell proliferation, colony formation, lipid reactive oxygen species (ROS), MDA concentration, 4‐HNE, GSH/GSSG ratio and cell death assays as well as subcutaneous xenograft experiments were used to elucidate the effects of SLC7A11 in HB cell proliferation and ferroptosis. Furthermore, MeRIP‐qPCR, dual luciferase reporter, RNA pulldown, RNA immunoprecipitation (RIP) and RACE‐PAT assays were performed to elucidate the underlying mechanism through which SLC7A11 was regulated by the m6A modification in HB. Results SLC7A11 expression was highly upregulated in HB. SLC7A11 upregulation promoted HB cell proliferation in vitro and in vivo, inhibiting HB cell ferroptosis. Mechanistically, SLC7A11 mRNA exhibited abnormal METTL3‐mediated m6A modification, which enhanced its stability and expression. IGF2 mRNA‐binding protein 1 (IGF2BP1) was identified as the m6A reader of SLC7A11, enhancing SLC7A11 mRNA stability and expression by inhibiting SLC7A11 mRNA deadenylation in an m6A‐dependent manner. Moreover, IGF2BP1 was found to block BTG2/CCR4‐NOT complex recruitment via competitively binding to PABPC1, thereby suppressing SLC7A11 mRNA deadenylation. Conclusions Our findings demonstrated that the METTL3‐mediated SLC7A11 m6A modification enhances HB ferroptosis resistance. The METTL3/IGF2BP1/m6A modification promotes SLC7A11 mRNA stability and upregulates its expression by inhibiting the deadenylation process. Our study highlights a critical role of the m6A modification in SLC7A11‐mediated ferroptosis, providing a potential strategy for HB therapy through blockade of the m6A‐SLC7A11 axis. Upregulation of SLC7A11 promotes hepatoblastoma tumorigenesis by enhancing ferroptosis resistance. METTL3/IGF2BP1/m6A modification enhances the SLC7A11 mRNA stability and expression via inhibiting the deadenylation in an m6A‐dependent manner. The competitive binding of IGF2BP1 blocks PABPC1 from recruiting the BTG2/CCR4‐NOT complex, thereby suppressing the deadenylation of SLC7A11 mRNA.

Background: Passion is an important motivational variable that profoundly affects athletes’ cognition, emotion, and behavior. This study constructed a mediating model to explore the mechanism of cohesion toward passion and mental toughness of Chinese team sports athletes and to investigate the mediating effect of harmonious passion and obsessive passion on cohesion and mental toughness. Methods: A questionnaire survey was conducted on 326 Chinese active athletes (M = 19.63, SD = 6.51) aged 14–26 years (54% male, 46% female) from eight sports. Results: Cohesion and its dimensions can positively predict athletes’ mental toughness, and ATG-T is more important in advantage analysis. The direct and indirect paths show that cohesion affects mental toughness through the mediating effect of harmonious passion and obsessive passion. Mediating effect model has a good fit and explained 22.1% of the variance in mental toughness. Conclusion: The relationship between cohesion, passion, and mental toughness reflects the psychological dynamic process from environment to motivation to sports performance. The development of team sports athletes’ mental toughness can be carried out from the following points. First, the team should define a sports goal and take the needs of members into account in goal-setting. Second, the sports team should build a team culture that is enterprising, inclusive, and cooperative and emphasizes members’ recognition of them. Third, the team should attach importance to the passion of the members and make good use of the team atmosphere. To protect the psychological health and long-term development of athletes, team culture should pay more attention to the cultivation of athletes’ harmonious passion. Improving cohesion is beneficial to athletes’ mental toughness in team sports. To protect the psychological health and long-term development of athletes, team culture should pay more attention to the cultivation of athletes’ harmonious passion.