Psychological responses to the COVID-19 pandemic and situational impact: A network analysis in Hong Kong residents.

BACKGROUND: The COVID-19 pandemic has had situational impacts and induced various psychological responses among residents. The present study aims to analyze the network structure of psychological responses to the pandemic and their relationships with situational impact, resilience, and well-being through a network approach. METHODS: An online survey recruited 1122 residents (mean age = 32.5 years, 65.4 % female) in Hong Kong from October 2020 to October 2021. The participants completed the Mental Impact and Distress Scale: Psychological Response (MIDc-PR) and other validated measures. Gaussian graphical modeling was conducted in R to identify the central MIDc-PR symptoms and their bridge linkages with situational impact, resilience, and well-being. RESULTS: In the MIDc-PR network, the central symptoms were 'Routine' and 'Images' for Anticipation and 'Tense' and 'Lonely' for Modulation, with 12 bridge edges between the two clusters. In the combined network, the MIDc-PR nodes showed 12 bridge edges with situational impact, particularly in the health domain. 'Concerned', 'Sleep', and 'Lonely' showed negative linkages with resilience; 'Unmotivated' and 'Trapped' showed negative linkages with well-being. The network models showed good levels of stability and did not differ significantly in network structure and global strength across gender and age groups. LIMITATIONS: The cross-sectional study design only allowed undirected associations in the network and could not model the within-subject effects. CONCLUSIONS: The study findings contributed to the literature by elucidating the network structure of psychological responses to the pandemic. The central and bridge symptoms have clinical implications as potential targets for future interventions.

Side-Chain-Type High Dielectric-Constant Dipolar Polyimides with Temperature Resistance.

Innovative dielectric materials with high-temperature resistance and outstanding dielectric properties have attracted tremendous attention in advanced electronical fields. Polyimide(PI) is considered a promising candidate for the modern electronic industry due to its excellent dielectric properties and comprehensive properties. However, the limited-adjustable range of dielectric constant and the difficulty to obtain a high dielectric constant restrict the application of PI as high dielectric materials. Herein, a novel diamine monomer (2,2'-bis((methylsulfonyl)methyl)-[1,1'-biphenyl]-4,4'-diamine (BSBPA)) containing a rigid biphenyl structure and high dipolar sulfonyl pendant groups is designed for high dielectric polyimides. The rigid biphenyl and polar sulfonyl pendant groups can reasonably optimize the molecular structure and orientational polarization of polyimides to improve their dielectric properties and thermal properties. Moreover, the effect of different bridge linkages on the dielectric properties is studied by using the different dianhydrides. Thus, the PI-BSBPA films especially the DSDA-BSBPA film (DSDA: 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride) achieve great thermal properties (T5%d of 377 °C and Tg of 358 °C) and excellent dielectric properties (6.95 at 1 kHz) along with high discharged energy density of 5.25 J cm-3 and charge-discharge efficiency of 90%. The collaborative control of main-chain and side-chain engineering is effective to endow the polyimides with high-temperature tolerance and high dielectric performance.