COVID-19 Stressors and Aggression among Chinese College Students: The Mediation Role of Coping Strategies.

Although college students experienced excessive stressors (COVID-19 disease and negative COVID-19 news) during the COVID-19 pandemic, few studies have been aimed at coping strategies used by college students to deal with stress caused by the pandemic. Coping strategies are efforts to deal with anxiety in the face of a perceived threat or stress. Aggression is harmful social interaction with the intention of inflicting damage or harm upon another individual. In the present study, we aimed to examine the direct effect of stressors resulting from the pandemic on college students' aggression, as well as the indirect effect via their coping strategies. Through a cross-sectional survey of 601 Chinese college students (M-age = 20.28), we tested the proposed framework. We first found that information stressors of COVID-19 ranked highest among the four stressors of the pandemic. Results also indicated that college students' stressors of COVID-19 were directly and positively associated with their aggressive behavior. For the indirect effect, college students would adopt both adaptive coping strategies (self-help strategy) and maladaptive coping strategies (avoidance strategy and self-punishment strategy) with the stressors of COVID-19. Furthermore, adaptive coping strategy (approach strategy) was negatively related to their aggression, whereas maladaptive coping strategy (avoidance strategy and self-punishment strategy) was positively related to their aggressive behavior. The present research extends the general strain theory in the COVID-19 context. Practical implications are also discussed.

Electrochemical Synthesis of Nb-Doped BaTiO3 Nanoparticles with Titanium-Niobium Alloy as Electrode.

In this paper, Nb-doped BaTiO3 nanoparticles (BaNb0.47Ti0.53O3) were prepared using an electrochemical method in an alkaline solution, with titanium-niobium alloy as the electrode. The results indicated that under relatively mild conditions (normal temperature and pressure, V < 60 V, I < 5 A), cubic perovskite phase Nb-doped BaTiO3 nanoparticles with high crystallinity and uniform distribution can be synthesized. With this increase in alkalinity, the crystallinity of the sample increases, the crystal grain size decreases, and the particles become more equally dispersed. Furthermore, in our study, the average grain size of the nanoparticles was 5−20 nm, and the particles with good crystallinity were obtained at a concentration of 3 mol/L of NaOH. This provides a new idea and method for introducing foreign ions under high alkalinity conditions.

[A theoretical analysis of respiratory mechanics in mechanical ventilation].

As a non-physiological way of ventilation, mechanical ventilation has a great effect on the respiratory mechanics. The biggest problem of artificial airway is that it brings extra airway resistance to the respiratory tract. For different parts of the lung, positive pressure ventilation could cause different mechanic states. We can find the formation and influencing factors of transpulmonary pressure, transchest wall pressure, trans-lung-chest pressure, trans-diaphragmatic pressure, trans-pulmonary-diaphragmatic pressure, intrapleural pressure, plateau pressure and driving pressure, by analyzing the mechanic state in a unit area of the chest or diaphragm position in the way of basic mechanics. It is obviously different in the pulmonary pressure gradient caused by inspiratory driving between in spontaneous breathing and in mechanical ventilation. The pressure is transmitted from the periphery to the center in spontaneous breathing in physiological state, playing a traction role for lung tissue. The pressure is transmitted from the center to the periphery in positive pressure ventilation without spontaneous breathing, playing a pushing role for lung tissue. It can be divided into two stages in positive pressure ventilation with spontaneous breathing. The first stage is from inspiratory trigger effort to trigger sensitivity. It is similar to spontaneous inspiration in physiological state. The pressure gradient in this stage is from the peripheral to center. But the period is very short. The second stage is the positive pressure ventilation progress after the trigger sensitivity. The pressure gradient is caused by the pulling of the patient's spontaneous inhalation and the pushing of the positive pressure ventilation of the ventilator. There is a certain complementarity in the distribution and transmission of pressure, especially for non-physiological positive pressure ventilation. Therefore, through these basic mechanical analysis, clinical medical staff can better understand the impact of mechanical ventilation on respiratory mechanics.