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A novel high-entropy (TiVCrMo) 3 AlC 2 MAX with a solid solution of Ti, V, Cr, and Mo atoms in its lattice is synthesized. The tribological properties as well as the wear mechanism of the high-entropy MAX against a Si 3 N 4 counterpart in a wide temperature range from room temperature to 800 ºC in the air are systematically studied. Combined with the experimental observations and the theoretical simulations, the effects of high-entropy structure on the tribological behaviors of the (TiVCrMo) 3 AlC 2 MAX are illuminated. Benefited from the high-entropy structure, the (TiVCrMo) 3 AlC 2 MAX presents an improved hardness and oxidation resistance, which contributes to a dry-sliding tribological behavior in the temperature window of R.T.–600 °C. While further increasing the operating temperature to 800 °C, hydrodynamic lubrication emerges, which boosts the lubricity in the high-entropy (TiVCrMo) 3 AlC 2 MAX. [ABSTRACT FROM AUTHOR]

In this work, the Cr-Ti-Mo ternary o -MAX ceramics based on the Cr 2 TiAlC 2 phase are synthesized, and their tribological performance at elevated temperatures up to 800 ºC in the air is evaluated. With Si 3 N 4 as a tribocouple, an unexpected ultra-low wear rate reaching 6.1 × 10−8 mm3 N−1 m−1 is observed in Cr 1.9 Ti 0.9 Mo 0.2 AlC 2 at 800 ºC, accompanied by a stable coefficient of friction (COF) around 0.33 in a wide temperature range. X-ray photoelectron spectroscopy (XPS) depth profiling confirms a tribofilm with gradient composition, which simultaneously offers fluid lubricating at elevated temperatures and self-healing after cooling. Particularly, confirmed by the theoretical simulations, the doping of Mo improves the interlayer binding as well as alters the oxidation behaviors of Cr 2 TiAlC 2. With an optimal interlayer binding strength and oxidation rate, the Cr 1.9 Ti 0.9 Mo 0.2 AlC 2 can generate a tribofilm possessing ideal composition, which simultaneously promotes lubrication and anti-wear performance at elevated temperatures. [ABSTRACT FROM AUTHOR]

Summary: Adolescents' sleep problems and their association with mental health is an important public health concern. This study aimed to investigate sleep and mental health status and the association of sleep with mental health in Chinese high school students. Data came from a cross‐sectional study in Guangdong province which included 42,077 high school students. Sleep quality and sleep duration were obtained through self‐report. The Depression Anxiety and Stress Scale (DASS‐21) was used to measure mental health. The association between sleep quality, sleep duration, and mental health was analysed using logistic regression. The prevalence of depression, anxiety, and stress symptoms were 35.27%, 42.32%, and 21.87% in high school students, respectively. And only 17.71% and 34.41% of the high school students had very good sleep quality and ≥8 h sleep duration, respectively. Poorer sleep quality and shorter sleep duration were risk factors for mental health problems in high school students. Compared to high school students with very good sleep quality and ≥8 h sleep duration, the high school students with poor or very poor sleep quality and <6 h sleep duration had the highest risk of depression symptoms (odds ratio [OR] 5.02, 95% confidence interval [CI] 4.40–5.72), anxiety symptoms (OR 6.02, 95% CI5.25–6.89), and stress symptoms (OR 6.12, 95% CI5.30–7.06). Considering the combined association of sleep quality and sleep duration on mental health, it is important not only to ensure that high school students have sufficient sleep duration, but also to improve their sleep quality. [ABSTRACT FROM AUTHOR]

Objectives: Lifestyles, accounting for 53% in determining death, play a vital role in improving the health of older adults. Thus, this study aimed to explore the influencing factors of the health-promoting-lifestyles and interaction mechanisms among older adults.Methods: A total of 8526 elders were selected by a three-stage stratified random cluster sampling method. Socioeconomic status, family relationships, social support, health-related quality of life (QOL), and health-promoting-lifestyles (HPLP) of older adults were assessed with the Social Support Rating Scale, the short form 36 health survey (SF-36) and Health-Promoting Lifestyle Profile. A structural equation model (SEM) was conducted to test the direct and indirect association between influencing factors with HPLP.Results: In this study, there were 4901 older adults who were empty nesters, and 3625 were non-empty nesters. Of all respondents, the average QOL score of older adults was 62.28 ± 16.51, average social support score was 78.06 ± 7.50. The HPLP score of older adults was 105.9 ± 19.6, and the average score of subscales was 2.5 ± 0.5, which was at the medium level. Social support had a positive and direct effect on HPLP of older adults (total effect, 0.34). Meanwhile, social support mediated the relationship between socioeconomic (total effect, 0.17), QOL (total effect, 0.33) and HPLP. Family relationships had a small indirect effect on HPLP via social support (0.01).Conclusions: Social support is the strongest influencing factor in the health-promoting-lifestyles among older adults, followed by socioeconomic, health-related quality of life and family support. Thus, maintaining higher social support was important to improve the HPLP of older adults. [ABSTRACT FROM AUTHOR]

Background: Depression is the most frequent psychiatric disorder among the older adults, the purpose of this study is to explore the mediation effect of health promoting lifestyle on the relationship between Socioeconomic Status (SES) and depression, so as to provide practical reference for effectively preventing and alleviating depression of the older adults.Methods: A multi-stage random sampling method was conducted in Shanxi Province. A total 8526 older adults were included in the analysis. Regression analysis was used to explore the relationship between the socioeconomic status, health promoting lifestyle and depression, and the mediation effect test process was used to verify the mediating mechanism of health promoting lifestyle on this relationship.Results: 62.1% of the older adults had depression symptoms in this study, and there were significant differences in depression scores among the older adults with gender, age, residence, marital status, endowment pattern, self-care ability, exercise frequency, physical examination frequency, daily diet rules(P<0.05). The results of mediating effect analysis showed that health promoting lifestyle as mediation effect between social economic status and depression was established, and the mediating effect was accounted for (a*b/c) 63.1%.Limitations: Given the cross-sectional study, it is not possible to make causal inferences.Conclusions: There were different degrees of depression in the older adults. The lower the SES is, the higher the risk of depression is. This result once again confirms the social causation theory. Combined with the theory of health risk behavior, the study further confirmed the applicability of lifestyle mechanism in the intermediate mechanism of the relationship between SES and depression in the elderly. Thus, in addition to providing material support and financial assistance, helping the elderly develop a healthy lifestyle is also effective measure to improve their depression. [ABSTRACT FROM AUTHOR]

Background: In China, aging has become a serious social problem, and the number of empty-nest elderly is on the rise. The aim of this study is to clarify the prevalence of depressive symptoms among empty-nest elderly in Shanxi province and evaluate the effects of sociodemographic factors and health-promoting lifestyles so as to provide a scientific reference for preventing and intervening their depression.Methods: A cross-sectional study, which used a multi-stage random cluster sampling way, was conducted among 4901 empty-nest elderly in Shanxi. An independent t-test and a chi square test were used to compare the sociodemographic factors, depression scores, and health-promoting lifestyle scores of the empty-nest elderly. Multinomial logistic regression was used to analyze the potential influencing factors for depression.Results: The prevalence of depressive symptoms in the population was 64.2%. Among all participants 1,776 (36.2%) had mild depression, 1,236 (25.2%) had moderate depression, and 135 (2.8%) had severe depression. The health-promoting lifestyle of the empty nesters in this study was at the medium level (2.51 ± 0.47). Gender, education level, old-age provision model, exercise frequency, chronic disease, relationships with children, self-care ability, and health-promoting lifestyles were found to be influencing factors of depression and all variables had different effects on different degrees of depression.Limitations: This was a cross-sectional study, so the results cannot establish causal relationships among the study variables.Conclusions: Depression was prevalent among the empty-nest elderly in Shanxi. Maintaining good interpersonal relationships, developing extensive interests, and maintaining healthy lifestyles including good nutrition habits and regular exercises can reduce the incidence of depression among empty nesters. [ABSTRACT FROM AUTHOR]

In this work, tribological properties of Ti 3 AlC 2 , Cr 2 TiAlC 2 , and Mo 2 TiAlC 2 MAX are evaluated in a wide temperature range of 25–800 ℃. By replacing the 4 f Wyckoff site Ti atoms of Ti 3 AlC 2 with Cr or Mo, the MAXs deliver lower coefficient of friction (COF) than Ti 3 AlC 2. Interestingly, as confirmed by the morphological, structural, and chemical analyses, the two MAXs are applicable in different temperatures. For Cr 2 TiAlC 2 , the lowest wear rate is 2.30 × 10−7 mm3 N−1 m−1 at 800 ℃, while the lowest wear rate of Mo 2 TiAlC 2 is achieved at room temperature of 3.83 × 10−7 mm3 N−1 m−1. These distinct tribological behaviors are ascribed to the altered M-A and M-C bindings, as well as the properties of the produced oxides. [ABSTRACT FROM AUTHOR]

Backgrounds: Adverse childhood experiences are co-occurring factors of multimorbidity and depression in mid-late life, but the combined effect of ACEs and multimorbidity on depression over life has not been fully studied.Methods: We used data from the China Health and Retirement Longitudinal Study which includes 4,440 middle-aged and older adults. Different types of ACEs experienced up to the age of 17 were assessed based on self-reports. We used parallel process Latent Growth Curve modelling to evaluate the longitudinal mediation role of ACEs, multimorbidity and depression.Results: People who had more ACEs were found to have a higher level of multimorbidity (intercept: 0.057, 95% CI: 0.031 to 0.079) and depression (intercept: 0.047, 95% CI: 0.013 to 0.076) at the baseline and a faster increase in multimorbidity (slope: 0.107, 95%CI: 0.078 to 0.136) and depression (slope: 0.074, 95%CI: 0.035 to 0.153). The mediation analysis indicated that there was a positive indirect association of ACEs via the multimorbidity intercept with the intercept of depression (0.028, 95%CI: 0.012 to 0.043), and a small negative association with the slope of depression (-0.002, 95%CI: -0.003 to -0.001). We also found a positive indirect association of ACEs via the multimorbidity slope with the intercept (0.035, 95%CI: 0.021 to 0.049) and slope (0.008, 95%CI: 0.004 to 0.011) of depression.Conclusions: ACEs were related to higher depression partly via elevated multimorbidity. Public health services and behavioural interventions to prevent and reduce the occurrence of ACEs might help to lower the risk of multimorbidity and depression in later life. [ABSTRACT FROM AUTHOR]

Background: Few studies have shed light on the mechanisms underlying the link between activities of daily living (ADL) and psychological distress. This study aimed to explore the multiple mediating roles of loneliness and sleep quality in this relationship among Chinese older adults.Methods: A total of 3250 older adults completed the Barthel Index, UCLA 20-item Loneliness Scale, Pittsburgh Sleep Quality Index, and Depression, Anxiety, and Stress Scale Questionnaire. Serial multiple mediation analysis was conducted using Hayes' PROCESS macro.Results: ADL was found to directly impact psychological distress through three significant mediation pathways: (1) loneliness (B=-0.124, 95% CI=-0.140, -0.109), which accounted for 23.98% of the total effect, (2) sleep quality (B=-0.050, 95% CI=-0.063, -0.039), which accounted for 9.67% of the total effect, and (3) loneliness and sleep quality (B=-0.015, 95% CI=-0.020, -0.012), accounting for 2.91% of the total effect. The total mediating effect was 36.56%.Limitations: The cross-sectional design we used limited causal interpretations. Future studies could examine longitudinal changes in outcome measures.Conclusions: These findings highlight the role of loneliness and sleep quality as serial mediators of the relationship between ADL and psychological distress. Thus, for the early detection and prevention of psychological distress, it is necessary to conduct loneliness and sleep quality interventions for older adults with ADL limitations. [ABSTRACT FROM AUTHOR]

A typical polyanionic based material Na3V2(PO4)2O2F (Na3VPO2F) attracts much interest as a cathode for large‐scale sodium‐ion batteries in consideration of its stable structure and remarkable energy density. Nevertheless, the large coulombic attraction and repulsion suffered by the mobile Na+ from structural anions and surrounding Na+, respectively, result in a torpid reaction kinetics and inferior rate capability. Herein, Br−‐doped and Na+ vacancy preinstalled Na3−yVPO2−xBrxF is prepared to dilute the charges on and inside the Na+ transportation tunnel. In virtue of density functional theory analysis, Na3−yVPO2−xBrxF reveals a reduction in the bandgap and an increase in electronic conductivity. Meanwhile, the almost electrostatically shielded tunnel in Na3−yVPO2−xBrxF alleviates the coulombic hindrance imposed on Na+ during its (de)intercalation, which demonstrates a Na+ diffusivity about five times higher than that of Na3VPO2F. Consequently, the Na3−yVPO2−xBrxF cathode shows a superior rate capacity of 77.7 mAh g−1 under 50 C and great cycling property corresponding to a high capacity retention of 94.4% over 800 cycles at 10 C. The assembled Na3−yVPO2−xBrxF//hard‐carbon sodium‐ion full‐cell presents excellent specific energy/power (226 Wh kg−1@15424.2 W kg−1) as well as outstanding long‐term cyclic stability over 1000 cycles at 5 C. [ABSTRACT FROM AUTHOR]

With the acceleration of the ageing process, the number of empty-nest older adults (aged ≥60 years) has increased dramatically in China. As a vulnerable group, empty-nest older adults face more urgent health problems than their non-empty-nest counterparts. We aimed to examine the effect of the self-mutual-group (SMG) health management model on quality of life in these older adults to provide a scientific reference for improving their health. We did an open-label, randomised controlled trial at six communities in Taiyuan, China. We enrolled empty-nest older adults (≥60 years) who had no cognitive disorder or other mental illnesses, were willing and able to complete the investigation, and were dwelling in the community at least 1 year before the study. We randomly assigned participants by random number tables to the intervention group, which received a 7-month SMG-based intervention, or the control group, with a 7-month follow-up without any intervention. Informed consent was obtained from all participants. The primary outcome was the Short Form 36-Item Health Survey, which we used to measure the quality of life of participants. Analysis was by ANCOVA on measurement values after the intervention, controlling for scores before the intervention. This trial was approved by the institutional review boards of Shanxi Medical University. This trial is registered with the Chinese Clinical Trial Register, ChiCTR1800015884. Between Aug 1, 2016, and Aug 30, 2017, 396 adults were enrolled, with 204 in the intervention group and 192 in the control group. After 7 months of SMG-based intervention, 350 empty-nest older adults completed the study continuously, of which 167 completed the 7-month SMG-based intervention and 183 completed the 7-month routine follow-up. We found a significant increase between the intervention group and the control group in the mean scores of mental component scores (F =105·146, p<0·0001, Cohen's d =0·62), physical component scores (F =73·922, p<0·0001, Cohen's d =0·32), role emotional (F =71·127, p<0·0001, Cohen's d =0·62), vitality (F =35·404, p<0·0001, Cohen's d =0·35), social function (F =112·945, p<0·0001, Cohen's d =0·53), mental health (F =76·223, p<0·0001, Cohen's d =0·48), and general health (F =20·150, p=0·0001, Cohen's d=0·31). SMG-based health management has a positive effect on improving the quality of life among empty-nest older adults. It provides a new perspective to improve their quality of life. Furthermore, future research can use different measurements to assess better the long-term effects of interventions on quality of life. National Natural Science Foundation of China, China Postdoctoral Science Foundation Project, Planning Project of Philosophy and Social Science in Shanxi, Program for the Philosophy and Social Sciences Key Research Base of Higher Education Institutions of Shanxi, and Fund Program for the Selected Post Doctorate in Zhejiang Province. [ABSTRACT FROM AUTHOR]

Previous study has identified a connection between intimate partner violence (IPV) and depressive symptoms. However, the underlying mechanisms of this connection have not yet been well understood. The aim of this study was to investigate the roles of big five personality traits and perceived social support on the association between IPV and depressive symptoms among Chinese college students. A cross-sectional questionnaire survey was conducted among college students in 23 provinces, 5 autonomous regions, and 4 municipalities in China from June to August 2022. Intimate Partner Violence Questionnaire was used to measure the frequency of exposure to IPV. The big five personality traits were measured by 10-item Big Five Inventory, Perceptive Social Support Scale-3 items was used to estimate the degree of perceived social support and the data on depressive symptoms were collected by Patient Health Questionnaire-9 items. We used data from the "Psychology and Behavior Investigation of Chinese Residents in 2022", which includes 6686 valid questionnaires of college students. The PROCESS macro developed by Hayes was utilized to perform moderated mediation analysis. Among college students, IPV had a significant direct impact on depressive symptoms. Extroversion, agreeableness, conscientiousness and neuroticism mediated the association between IPV and depressive symptoms (β = −0.08, P < 0.001; β = −0.08, P < 0.001; β = −0.14, P < 0.001; β = 0.20, P < 0.001). Perceived social support significantly moderated the mediating role of the big five personality traits between IPV and depressive symptoms. Furthermore, perceived social support moderated the direct relationship between IPV and depressive symptoms (β = 0.34, P < 0.001), as well as the indirect path of extroversion, agreeableness, neuroticism and the first half of the mediating role of conscientiousness. Moreover, perceived social support was one of the preventive factors that could effectively mitigate the harmful effects of IPV, neuroticism and depressive symptoms. As this was a cross-sectional study, we were unable to investigate causal relationships between variables. The prevalence of IPV and depressive symptoms were self-reported by the college students, and there may be reporting bias. Additionally, this study only explored the influence and mechanism from the integrated dimension of IPV and PSSS, due to spatial constraints. The findings contribute to the existing understanding by clarifying the fundamental mechanisms linking IPV and depressive symptoms. These results may serve as a valuable reference for the Chinese government to improve mental health among college students. • The study is to explore the roles of big five personality traits and PSSS may play between IPV and depressive symptoms. • The big five personality traits partially mediated the relationship between IPV and depressive symptoms, except for openness. • PSSS moderated the link between IPV and depressive symptoms directly and indirectly. • The cultivation of sound personality traits and high PSSS could be benefit to the health promotion among college students. [ABSTRACT FROM AUTHOR]

Background: As China's aging trend intensifies and the proportion of empty nests increases, the health-related quality of life of the elderly is the focus of social attention. Previous studies focused on the quality of life of the elderly, rather than empty nesters, and lacked the discussion of the mechanism of influencing factors. Thus, this study aimed to explore the influencing factors of the quality of life (QOL) and interaction mechanisms among empty nesters in Shanxi Province, China, so as to provide practical reference for improving the QOL of empty nesters.Methods: A total of 4901 empty nesters in Shanxi Province, China, were selected using multi-stage random cluster sampling method in this cross-sectional study. The quality of life was assessed with the Short Form 36 Health Survey (SF-36). Multiple linear regression analysis (stepwise) was performed to examine the factor associated with QOL. Structural equation model (SEM) approach was conducted to test the direct and indirect association between QOL influencing factors with QOL.Results: The average QOL score of empty nesters was 63.34 (SD = 17.23). The multiple linear regression revealed that gender, age, education, monthly income, drinking status, exercise frequency, physical examination frequency, attention to daily nutritional health, relationship with a spouse and relationship with children were significant predictors of the empty nester's QOL (P < 0.05) (R2 = 0.128). SEM showed that behavioral lifestyle had a direct effect on QOL (β = 0.446, P < 0.001). Socio-economic status had an indirect effect (β = 0.288, P < 0.001) on QOL through behavioral lifestyle. The family relationship had an indirect effect (β = 0.115, P < 0.001) on QOL.Conclusion: Behavioral lifestyle was the strongest influencing factor in the quality of life among empty nesters, followed by socio-economic status and family relationships. Thus, maintaining a healthy behavioral lifestyle was important to improve the QOL of the empty nesters. Our findings provide a concrete and strong reference for the formulation of targeted intervention strategies. [ABSTRACT FROM AUTHOR]

Ternary (TiVCr) 3 AlC 2 with a semi-out-of-plane chemical ordering is synthesized, and its temperature-dependent wear behavior is assessed at the temperature from 25 to 800 ºC. In the ternary MAX, V forms a solid solution with both Ti and Cr, which keeps the out-of-plane chemical ordering of Cr while breaking the ordering of Ti. By coupling with Si 3 N 4 , a reduction of mean wear rate is detected along with increasing temperatures starting at 200 ºC, which is relied on the states of the oxide glaze. Particularly, a synergism of in-situ liquid lubrication from molten oxides and a "bearing effect" provided by refractory oxide particles are observed at 800 ºC, which contributes to a low coefficient of friction (COF) of 0.25 and a low mean wear rate of 6.60 × 10−6 mm3 N−1 m−1. [ABSTRACT FROM AUTHOR]

Background: Health promoting lifestyle (HPL) may be a facilitator for empty nesters' active aging against depression. Social support (SS) may improve their HPL. This study aimed to examine moderating effect of SS and its three sources of SS on relationship between depression and HPL among empty nesters. The compensating role of socioeconomic status (SES) for lack of SS was examined, too.Methods: A cross-sectional survey of empty nesters (n = 1593) was conducted in six districts of Taiyuan, China, using a stratified random cluster sampling method. Hierarchical multiple linear regression analyses were performed to assess moderation models by SS and its three sources.Results: The findings indicated that low depression (p < 0.001) and sufficient perceived SS (p < 0.001) could directly predict better HPL among empty nesters. The effect of SS on HPL declined with the raise of educational level (p < 0.001). Family support (β = 0.083, p < 0.001), friends support (β = 0.085, p < 0.001) and others support (β = 0.098, p < 0.001) expressed significant negative buffer effects on depression and HPL individually.Limitations: There was a cross-sectional study that limited the moderating effect of SS on depression and HPL just for empty nesters in Taiyuan, China. The results cannot explain the causal relationships among the study variables.Conclusions: SS might be a protective factor of empty nesters' health in China. Three sources of SS all showed moderating effect on the relationship between depression and HPL among empty nesters, and should be integrated to achieve maximum utility. Friends support/ others support could play complement role for lack of family support. SES expressed partial compensatory for lack of SS. [ABSTRACT FROM AUTHOR]

Deterioration of cognitive function has a significant impact on the unavoidable burden on individuals, families, and society. This study aimed to examine the serial multiple mediating effects of anxiety and depressive symptoms on the relationship between subjective sleep quality and cognitive function among older adults in China. We selected 6442 Chinese older adults aged 65 years and older from the 2018 Chinese Longitudinal Healthy Longevity Survey. The SPSS PROCESS macro was employed to perform simple and serial multiple mediation analyses. Subjective sleep quality, depressive symptoms, anxiety symptoms, and cognitive function were significantly related (P < 0.01). Poor sleep quality can have a direct negative influence on cognitive function among older adults (effect = −0.110; 95 % CI = [−0.166, −0.053]), but it can also have an indirect negative impact via three pathways: the independent mediation of anxiety symptoms (effect = −0.028; 95 % CI = [−0.048, −0.011]), the independent mediation of depressive symptoms (effect = −0.014; 95 % CI = [−0.026, −0.002]), and the serial mediation of anxiety and depressive symptoms (effect = −0.009; 95 % CI = [−0.017, −0.001]). This study used a cross-sectional design, which restricts the ability to infer causal relationships. The effect of subjective sleep quality on cognitive function was serially mediated by anxiety and depressive symptoms among older adults. Diverse therapies targeted at improving sleep quality in older adults may improve mood and cognitive functioning. • Poor sleep quality could significantly and negatively affect cognitive function. • Anxiety and depressive symptoms mediate the link between poor sleep quality and cognitive function, respectively. • The relationship between poor sleep quality and cognitive function was partially mediated through serial mediation by anxiety and depressive symptoms. [ABSTRACT FROM AUTHOR]

MAX phase ceramics attract increased attention for lead-cooled fast reactors due to their promising compatibility with lead-bismuth eutectic (LBE). This work systematically investigates the corrosion behaviors of five Ti 3 Al 1−x Si x C 2 MAXs with Al/Si complex A component in static LBE at 550 ºC up to 3000 h. Based on the lattice structure, mechanical properties, surface morphologies, and elemental composition during corrosion, a synergism of Al and Si during oxidation and diffusion is found, which contributes to a continuous and well-attached Al 2 O 3 layer with improved LBE corrosion resistance. Therefore, the multi-element design will bring a broad space for the applications of MAX ceramics. • Ti3Al1−xSixC2 presents an enhanced corrosion resistance in Pb-Bi eutectic. • The continuous Al2O3 layer is proven as the crucial anti-corrosion species. • Moderate amount of Si is beneficial for a thin and continuous Al2O3 layer. [ABSTRACT FROM AUTHOR]

Background: Depression is the most prevalent mental disorder among older adults. This study aimed to explore the mediating effect of sleep quality on the relationship between chronic diseases and depressive symptoms, and the moderating role of empty nest status in the mediating model.Methods: A cross-sectional survey was conducted among 3637 older adults from Taiyuan, China, using a multi-stage random cluster sampling method. The data was collected with the general questionnaire for the elderly, with the Short Form Geriatric Depression Scale (GDS-15), and the Pittsburgh Sleep Quality Index (PSQI). The Bootstrap program and simple slope method were used to test the mediating effect of sleep quality and the moderating effect of empty nest status.Results: The overall prevalence of depressive symptoms in the population was 33.4%. The mediating effect analysis showed that chronic diseases had a significant direct impact on depressive symptoms in the elderly (β = 0.431, P < 0.001). Sleep quality as a mediation effect of 43.4% between chronic diseases and depressive symptoms was proven. The further moderating effect found that chronic diseases had a more significant impact on the sleep quality of the elderly who are in the empty nest status than those who are not (β = -0.431, P < 0.05 ).Limitations: Given the cross-sectional study, the results cannot explain the causal relationships among the study variables.Conclusions: Chronic diseases had a major impact on the depressive symptoms of the elderly. Sleep quality mediated the relationship between chronic diseases and depressive symptoms, and the empty nest status moderated the first half of the path in the mediation model. Therefore, to reduce the incidence of the depressive symptoms of the elderly, sleep quality and empty nest status should be the primary concern. [ABSTRACT FROM AUTHOR]

As a promising working medium for thermal transportation, nitrate-based molten salts are widely adopted for current concentrating solar power (CSP) plants. However, their corrosive nature also brings severe safety hazards to the system, e.g., the impellers and cover in molten salt pumps. To study the potential application of MAX ceramics as a proactive coating for these parts, tribo-corrosion behaviors of Ti 3 AlC 2 and its Si-substituted analogs against GCr15 steels are evaluated in the molten Solar Salt at 300 °C to simulate the operating condition of the cold-salt pump. The Si-substituted MAXs present higher anti-wear performance than pristine Ti 3 AlC 2. With an optimal composition of Ti 3 Al 0.6 Si 0.4 C 2 , about a 25% reduction in mean wear rate to that of Ti 3 AlC 2 is achieved. Through a comprehensive analysis of the morphological and chemical states of both tribo-corroded and static corroded surface, the effects of Si on the tribo-corrosion behaviors of Ti 3 AlC 2 is illuminated. The enhanced performance after Si addition is ascribed to the facilitated formation of aluminosilicates as corrosion products on the surface, which act as a lubricant as well as impeding the dissolution of Al into the molten Solar Salt. • Tribo-corrosion behaviors of Ti 3 AlC 2 with Si-substitution was studied in molten Solar salt. • Si reduces grain size while increases the hardness, which affects the tribo-corrosion behaviors. • Surface formed aluminosilicate impedes the dissolution of Al from MAX to the molten salt. [ABSTRACT FROM AUTHOR]

In this work, a series of epoxy-based composites with high Ti 3 C 2 T x MXene-content are successfully fabricated as the solid lubricant. With an optimized MXene-content of 70 wt%, the composite presents a dramatically reduced coefficient of friction (COF) to about 34% lower than that of the pure epoxy, which is as low as 0.39 at a normal loading of 5 N. Based on the evolution of surface morphology and chemical composition, the critical role of epoxy as a functional binder on forming the stably transferred tribofilm with good adhesion and lubricating performance is proposed. Additionally, the friction behaviors and lubrication mechanism of the Ti 3 C 2 T x /epoxy composite are also presented, which is attributed to the gap-filling and sliding medium roles of the Ti 3 C 2 T x nanoflakes. • Composites with MXene-content up to 90 wt% are first fabricated and evaluated. • Low COF and mean wear rate are achieved with optimal MXene-content of 70 wt%. • The formation of transferred tribofilm and the roles of each component are drawn. [ABSTRACT FROM AUTHOR]

Background: In China, the problems of population aging and empty nesting have become important issues which will affect the social stability and economic development. The aim of this study was to explore the health promoting lifestyles and influencing factors among empty nesters and compare with non-empty nesters to find out their differences, so as to provide a scientific evidence for people to formulate health management strategies for elderly.Methods: A cross-sectional survey which used a stratified random cluster sampling method, was conducted among 500 elders in six districts of Taiyuan, China, there were 288 empty nesters and 212 non-empty nesters. The general information and health- promoting lifestyles were investigated by using the self-made General Information Questionnaire and Health Promoting Lifestyle Scale(HPLP). Two-sample t-test and Chi-square test were used to compare the sociodemographic factors, HPLP scores of empty nesters to non-empty nesters; Multiple stepwise linear regression was performed to estimate influencing factors related to the HPLP of empty nesters and non-empty nesters.Results: The current findings showed that there were differences between the empty nesters and non-empty nesters in gender, resident, marital status, education and income, self-care ability, source of income, relationship with spouse and social activities (P < 0.05). Empty nesters were mostly male, married, had a higher education level, self-care ability and income and lived in urban compared with non-empty nesters. The health promoting lifestyles of the elderly in this survey were in the medium level, the highest score for all dimensions in both groups was in nutrition, whereas health responsibility was executed worst. The HPLP and six subscales scores of the empty nesters were higher than non-empty nesters, there were significant differences in total score of HPLP, self-realization and health responsibility (P < 0.01). Multiple regression analysis showed that the main predictive factors for the empty nesters were education, self-care ability and resident, whereas the main predictive factors for the non-empty nesters were parents-child relationship, source of income and age; social activity was the common factor for two group.Conclusion: The health promoting lifestyles of the empty nesters was better than that of the non-empty nesters. Health responsibility, interpersonal relations and stress management were key dimensions to be improved. Except social activity, education, self-care ability and resident were the unique influencing factors of health-promoting lifestyles for empty nesters, while the parents-child relationship, income and age were unique factors for non-empty nesters. The main target of Intervention strategy for elderly health promoting lifestyles should be the enhance of health responsibility, interpersonal relations and stress management by improving social activities, parent-child relationship, education and income of elderly. [ABSTRACT FROM AUTHOR]