Ultra-robust graphene based bio-nanocomposites and their electronic applications

This study is focused on the fundamental principles of fabricating polymer nanocomposite materials and optimizing their structural and functional properties. The status of the research on polymer nanocomposites has been critically reviewed and the motivation and challenges to develop ultra-robust, functional nanocomposite films are presented. Biopolymers, such as silk fibroin (SF) and cellulose nanocrystals (CNC), and graphene oxide (GO) are chosen as the model system to investigate the optimized interfacial interactions between biomacromolecules and the heterogeneous, most widely available graphene derivative. Two different aspects of the polymer nanocomposites were the focus of this study with multiple examples presented: 1) the mechanical enhancement by the synergistic reinforcement between the nanofiller and polymer matrix, and 2) the effective improvement of electrical properties of the graphene oxide component in the nanocomposite for electrical and functional applications. We suggest that the understanding of the integration of biopolymers and graphenes using versatile assembly techniques and the successive chemical modification of the electrical properties of the nanocomposite discussed in this study can be important for tackling the challenges faced by the employment of flexible and robust structural and bio-microelectronic materials.Ph.D

Cognitive Defusion and Psychological Flexibility Predict Negative Body Image in the Chinese College Students: Evidence from Acceptance and Commitment Therapy

Body dissatisfaction is a global phenomenon. Despite the significant cultural difference, most research on negative body image was conducted in Western countries. How do cognitive fusion and psychological flexibility relate to negative body image in the Chinese population? In the present study, this question was investigated through the intervention technique, Acceptance and Commitment Therapy (ACT). Here, 86 young Chinese university students with high negative physical self were invited, in which 42 students received 10 sessions of group-based ACT intervention in a clinical setting while the remained acted as the control group with no intervention. Pretests showed no statistical differences in negative body image between these two groups, while both cognitive fusion and psychological flexibility predicted negative body image. Post-pre tests showed no change in the control group, while enhanced cognitive defusion and psychological flexibility in the ACT group. Individual differences in psychological flexibility and cognitive defusion enhancement predicted improved body image. A strong association of implicit body image with Fatness and Shortness changes suggested that although with individual differences, those components could be internalized during the intervention in the College students

Sulfur content of gasoline and diesel fuels in northern China

In order to investigate vehicle fuel quality in northern China, the sulfur content of fuels purchased from the market has been studied. 235 samples from urban areas and highway service stations were collected and tested with energy dispersive X-ray fluorescence spectrometry. 88% of the gasoline samples contained sulfur below 500 ppm, the limit then in effect, and 92.5% of the diesel fuel samples were below 2000 ppm, the required limit. China's Ministry of Environmental Protection recommend lower sulfur to assure that the vehicles using the fuels comply with the China III emission standards--those limits are 150 ppm sulfur for gasoline and 350 ppm for diesel fuel. The recommended limits were not often met: in Jinan, Shanghai, Changchun and Xi'an, 0%, 11%, 46% and 60% of the gasoline sampled were below 150 ppm sulfur. For samples from highway stations, only 14-58% of gasoline was under the 150 ppm sulfur and only 0-67% of diesel samples below 350 ppm in different regions. This mismatch, between fuel sulfur levels that would enable vehicle emission controls to operate effectively, and the actual fuel sulfur levels at service stations, results in unnecessarily high pollution from potentially cleaner vehicles.Sulfur content Northern China Emission standard

The roles of risk perception, negative emotions and perceived efficacy in the association between COVID-19 infection cues and preventive behaviors: a moderated mediation model

Abstract Preventive behaviors during the COVID-19 pandemic are especially critical to the protection of individuals whose family members or acquaintances have been infected. However, limited research has explored the influence of infection cues on preventive behaviors. This study proposed an interaction model of environment-cognitive/affective-behavior to elucidate the mechanism by which infection cues influence preventive behaviors and the roles of risk perception, negative emotions, and perceived efficacy in that influence. To explore the relationships among these factors, we conducted a cross-sectional online survey in 34 provinces in China during the first wave of the COVID-19 pandemic. A total of 26,511 participants responded to the survey, and 20,205 valid responses (76.2%) were obtained for further analysis. The moderated mediation results show that infection cues positively predicted preventive behaviors in a manner mediated by risk perception and negative emotions. Moreover, perceived efficacy moderated the influence of infection cues not only on preventive behaviors but also on risk perception and negative emotions. The higher the perceived efficacy, the stronger these influences were. These findings validated our model, which elucidates the mechanisms underlying the promoting effect of infection cues on preventive behaviors during the initial stage of the COVID-19 pandemic. The implications of these results for the COVID-19 pandemic and beyond are discussed

The mechanism of governments' and individuals' influence on protective behaviours during the second wave of COVID-19: a multiple mediation model

Background: The SARS-CoV-2 virus continues to spread and resurge globally with signs of a second wave, despite actions by governments to curb the COVID-19 pandemic. However, evidence-based strategies to combat COVID-19 recurrence are poorly documented. Objective: To reveal how governments and individuals should act to effectively cope with future waves, this study proposed a preventive model of COVID-19 resurgence. Method: A questionnaire survey was conducted among 1,137 residents of Beijing, where the epidemic reoccurred. Structural equation model was used to explore the mechanism among government intervention, perceived efficacy, positive emotions, posttraumatic growth (PTG) and protective behaviours. Results: Data analysis revealed that during COVID-19 resurgence, government intervention could directly and indirectly influence protective behaviours through individual factors (i.e. perceived efficacy, positive emotions), and PTG could mediate the indirect pathway to protective behaviours. Conclusions: These findings implied that government intervention needs to be integrated with individual factors to effectively control repeated COVID-19 outbreaks

Fairness decision-making of opportunity equity in gain and loss contexts

Social equity consists of opportunity equity and outcome equity. Although numerous studies have used ultimatum games to examine individuals' decision-making behavior in outcome distributions, few studies have explored this behavior in opportunity distributions. Our study used a modified version of the ultimatum game to explore fairness decision-making behavior and the underlying psychological mechanisms of opportunity equity in gain and loss contexts. We found that opportunity equity had a similar influence as outcome equity on people's fairness perception and decision-making behavior, even though the number of opportunities had nothing to do with the outcome. However, we also found that there were some differences between opportunity equity and outcome equity in the behavior pattern of evaluation and reaction processes. Our results provide evidence of inequity aversion for inequality of opportunity and expand inequity aversion theory. These findings may contribute to the reduction of social inequity and promote the development of a more harmonious society

Social comparisons differentially affect fair and unfair processing in ultimatum bargaining

Several theoretical frameworks have attempted to illustrate the influence of social contexts on decision-making and well-being. Traditional economic models assume that absolute income is the crucial determinant of one???s well-being, while the comparative models state that social comparisons influence and even determine well-being and decisions. Here we investigated the impact of social comparisons on decision-making using a modified three -player Ultimatum Game and ERP technique. We found two independent effects: First, social comparisons did not affect decision-making when a fair norm was enforced. Second, social comparisons affected fairness consideration for unfair offers only???responders were less likely to accept unfair offers in upward comparisons but more likely to accept unfair offers in downward comparisons. These results revealed that people were envy -free of fair offers while affected mainly by social comparisons when the equality norm was broken. Event-related brain potentials showed that in the early time window (260???320 ms), compared to fair offers, unfair offers elicited a larger negative-going medial frontal negativity (MFN) in upward than parallel and downward com-parisons, and in the late stage (320???650 ms), compared to fair offers, unfair offers led to equally less positive -going P300 in upward and downward comparisons relative to parallel comparison. Although partly consistent with the relative standing assumption, both traditional economic models and comparative models require revision to account for the results

Neural substrates of deficient cognitive control in individuals with severe internet gaming disorder

Background and aims: Internet gaming disorder (IGD) is rapidly becoming a worldwide health concern. The prefrontal-subcortical model of self-regulation emphasizes that an impaired prefrontal cognitive control system and an overwhelming subcortical reward-seeking system are both crucial factors in health problems, including addiction. This study focused on the cognitive control system of IGD, aiming to investigate whether cognitive control is altered and the underlying neural correlates in college students with IGD. Methods: Thirty college students with IGD and twenty-five matched healthy controls were asked to complete a stop-signal task that measures cognitive control while being monitored by functional magnetic resonance imaging (fMRI). Results: Compared to the controls, only the college students with severe IGD, rather than those with mild IGD, had deficient brain activity involved in inhibitory control and response execution (specifically, the inferior frontal gyrus, anterior cingulate cortex and primary motor cortex); this result implies that cognitive control deficits are closely linked to addiction severity in individuals with IGD. Regarding performance monitoring function, college students with IGD exhibited unabated behavioral and brain activity, as did the control group. Conclusions: Combined with our previous finding that the subcortical reward system was enhanced in individuals with IGD, the present findings extend the prefrontal-subcortical model of self-regulation from the perspective of IGD in a college student population and thus provide useful insight for the effective prevention and treatment of IGD.</p