The purposes of this study was to assess the youth mental health after the coronavirus disease 19 (COVID-19) occurred in China two weeks later, and to investigate factors of mental health among youth ...groups. A cross-sectional study was conducted two weeks after the occurrence of COVID-19 in China. A total of 584 youth enrolled in this study and completed the question about cognitive status of COVID-19, the General Health Questionnaire(GHQ-12), the PTSD Checklist-Civilian Version (PCL-C) and the Negative coping styles scale. Univariate analysis and univariate logistic regression were used to evaluate the effect of COVID-19 on youth mental health. The results of this cross-sectional study suggest that nearly 40.4% the sampled youth were found to be prone to psychological problems and 14.4% the sampled youth with Post-traumatic stress disorder (PTSD) symptoms. Univariate logistic regression revealed that youth mental health was significantly related to being less educated (OR = 8.71, 95%CI:1.97–38.43), being the enterprise employee (OR = 2.36, 95%CI:1.09–5.09), suffering from the PTSD symptom (OR = 1.05, 95%CI:1.03–1.07) and using negative coping styles (OR = 1.03, 95%CI:1.00–1.07). Results of this study suggest that nearly 40.4% of the youth group had a tendency to have psychological problems. Thus, this was a remarkable evidence that infectious diseases, such as COVID-19, may have an immense influence on youth mental health. Therefor, local governments should develop effective psychological interventions for youth groups, moreover, it is important to consider the educational level and occupation of the youth during the interventions.
This study aims to explore the relationship between psychological distress and post-traumatic stress disorder among Chinese participants as the result of COVID-19 outbreak. This study was conducted ...within 1 month after COVID-19 appeared in China, it included 570 participants age from 14 to 35. The results indicated that 12.8% of all participants with the symptoms of post-traumatic stress disorder and the effects of psychological distress on post-traumatic stress disorder was mediated by negative coping style. Gender moderated the direct effect between psychological distress and post-traumatic stress disorder, which is a significant discovery for relevant departments to take further measures.
The increase of wind generation (WG) has challenged the conventional way of probabilistic load flow (PLF) calculation. A reliable and efficient PLF method is required to face the stochastic nature of ...various power systems with WG. Firstly, the paper analyzes several typical cumulant methods (CMs) for PLF, such as Gram-Charlier expansion of type A (GCA), Gram-Charlier expansion of type C (GCC), and maximum entropy (ME). Then, an improved integrated CM by probability distribution pre-identification is proposed for power systems with WG based on doubly fed induction generations (DFIGs). The skewness and kurtosis are used as probability distribution pre-identification indices in the CM framework. Meanwhile, the influence of the DFIG control strategy on reactive power is considered in the load flow model and the moment calculation. Finally, the accuracy and efficiency of the proposed method are validated with the IEEE test system. In various scenarios, suitable CM is selected and applied to the PLF based on pre-identifying distribution characteristics. Results reveal that probabilistic density functions (PDFs) of bus voltages and line flows obtained by the proposed method have both accuracy and efficiency.
Background:
It is well known that some lifestyle-related behaviors are related to depressive symptoms, but the unique and cumulative effects of lifestyle-related behaviors on depressive symptoms ...among Chinese adolescents are still controversial.
Aims:
The aims of this study were to examine the unique and cumulative effects of lifestyle-related behaviors on depressive symptoms among Chinese adolescents, and explored the potential influences of gender difference on these associations.
Methods:
We conducted a cross-sectional study among 3967 Chinese adolescents aged 11 to 19 from Jilin, China during September and October of 2018. Students reported their lifestyle factors including sleep duration, time spent on computer, time spent on television, time spent on homework, eating breakfast, smoking, drinking, physical activity, and outdoor activity. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale (CES-D).
Results:
The prevalence of depressive symptoms was 28.2% among Chinese adolescents. Multivariate logistic regression analysis revealed that sleep duration <8 hour/day, time spent on homework ⩾3 hour/day, skipping breakfast, alcohol use, physical activity <3 days/week, and outdoor activity <2 hour/day were positively associated with depressive symptoms in both girls and boys. Time spent on computer ⩾2 hour/day was an independent risk predictor for depressive symptoms in males, while smoking only showed higher risk of depressive symptoms in females. There was an additive relationship between the lifestyle risk index scores and the risk of depressive symptoms for both genders, the relationship being strongest among females.
Conclusion:
The important role of lifestyle factors should be taking into consideration when create intervention programs to prevent and reduce depressive symptoms among adolescents. In addition, preventive interventions may need to focus on gender-informed approaches when targeting multiple lifestyle factors.
Sisal fiber exhibits a fibrous and porous structure with significant surface roughness, making it highly suitable for storing phase change materials (PCMs). Its intricate morphology further aids in ...mitigating the risk of PCM leakage. This research successfully employs vacuum adsorption to encapsulate paraffin within sisal fiber, yielding a potentially cost-effective, durable, and environmentally friendly phase change energy storage medium. A systematic investigation was carried out to evaluate the effects of sisal-to-paraffin mass ratio, fiber length, vacuum level, and negative pressure duration on the loading rate of paraffin. The experimental results demonstrate that a paraffin loading rate of 8 wt% can be achieved by subjecting a 3 mm sisal fiber to vacuum adsorption with 16 wt% paraffin for 1 h at -0.1 MPa. Through the utilization of nano-CT imaging enhancement technology, along with petrographic microscopy, this study elucidates the mechanism underlying paraffin storage within sisal fiber during vacuum adsorption. The observations reveal that a substantial portion of paraffin is primarily stored within the pores of the fiber, while a smaller quantity is firmly adsorbed onto its surface, thus yielding a durable phase change energy storage medium. The research findings contribute to both the theoretical foundations and the available practical guidance for the fabrication and implementation of paraffin/sisal fiber composite phase change energy storage mediums.
The present study aimed to determine the mediating effects of depression and anxiety on the association between life satisfaction and quality of life. We used the Patient Health Questionnaire ...(PHQ-9), Generalized Anxiety Disorder Scale (GAD-7), and EuroQol Five Dimensions Questionnaire (EQ-5D) to measure depression, anxiety, and quality of life, respectively. A single question was used to measure the life satisfaction of participants. Life satisfaction was significantly related with depression (r = −0.17), anxiety (r = −0.18), and quality of life (r = 0.19). Depression and anxiety were also related to quality of life. Depression and anxiety had full mediating effects (β = −0.274; β = −0.208) on the association between life satisfaction and quality of life. For those with poor life satisfaction, people were more likely to have high level of depression and anxiety, which in turn experienced poor quality of life.
The study aimed to investigate the level of life satisfaction (LS) among Chinese female workers after resuming work during the COVID-19 epidemic, and to further explore the potential mediating and ...moderating roles in the association between family stress and LS. Self-reported questionnaires were completed by 10,175 participants. Results showed that the level of LS decreased. The family stress had a negative effect on LS, and the effect was mediated by anxiety symptoms. Additionally, age moderated the direct and indirect effects within this relationship. Interventions aiming to improve LS should consider these aspects and younger workers should be given special attention.
How to eliminate the thermal history present in differential scanning calorimetry, this question has been widely concerned. Benzil has a serious thermal history that is not well eliminated by ...conventional thermal history methods. Herein, using benzil as a target, we developed a freeze-gradient temperature rate heating up method to eliminate the thermal history of DSC. Compared with the conventional method, this method avoids the introduction of new thermal histories by new crystalline forms that may appear during the cooling crystallization process. The results show that the peak shape of the melting peak is sharper and the peak emergence position is closer to the theoretical melting point after the elimination of the thermal history by the freeze-gradient heating up method. Based on this method, we optimized other factors to establish a complete method for the determination of melting point by DSC, analyzed the uncertainty of the method, and obtained an extended uncertainty of 0.19°C for DSC in this method. The validation results show that the p-nitrotoluene of the melting point reference substance was 52.64°C, which is within its reference value of (52.53 ± 0.20) °C, showing that this method is reliable. This study provides a reference for other thermal analysis methods to eliminate thermal history.
Embedded ultrasonic technology has the potential for a wide range of applications in structural health monitoring. In this study, embedded ultrasonic transducers were prepared with cement ...powder/epoxy resin composites as the matrix of each structural layer. It was found that the incorporation of cement powder has a toughening effect on epoxy resin, which results in the composite material having stronger deformability and higher strength. The packaging layer material was also used for the matching layer, which effectively simplified the transducer fabrication process; the acoustic impedance of the matching layer was close to the acoustic impedance of hardened cement. When the thickness of the backing layer was 5 mm, the transducer had the best sensitivity or resolution. After shielding, the transducer embedded in concrete was effectively protected against external noise and interference. The application of the transducer for monitoring the early hydration and hardening process of concrete showed that the acquired ultrasonic signal had high stability, repeatability, and recognizability. Embedding the transducer in concrete did not decrease the bearing capacity of concrete. The developed transducer can be used as a “smart aggregate” for large-scale, networked, and low-cost active ultrasonic monitoring of concrete buildings.
This study examined the correlation between depressive symptoms, interpersonal sensitivity, and social support before and during the COVID-19 pandemic and verified causal relationships among them. ...The study used Social Support Scale and Symptom Self-Rating Scale to investigate relevant variables. A total of 1,414 employees from company were recruited for this longitudinal study, which a follow up study was conducted on the same group of participants 1 year later. Paired sample
-test results showed that significant differences were only found in social support, not in depressive symptoms or interpersonal sensitivity. The results of correlation analysis showed that social support, depressive symptoms, and interpersonal sensitivity were significantly correlated between wave 1 and wave 2. The cross-lag autoregressive pathway showed that employees' social support level, depressive symptoms, and interpersonal sensitivity all showed moderate stability. Crossing paths showed that wave 1 social support could significantly predict wave 2 depressive symptoms (
= -0.21,
< 0.001) and wave 2 interpersonal sensitivity (
= -0.21,
< 0.001). Wave 1 depressive symptoms (
= -0.10,
< 0.01) could significantly predict wave 2 social support, while wave 1 interpersonal sensitivity (
= 0.07,
= 0.10) could not predict wave 2 social support. Social support can be considered as a protective factor against mental health problems.
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