Background: Nurses at the frontline of caring for COVID-19 patients might experience mental health challenges and supportive coping strategies are needed to reduce their stress and burnout. The aim of this study was to identify stressors and burnout among frontline nurses caring for COVID-19 patients in Wuhan and Shanghai and to explore perceived effective morale support strategies. Method: A cross-sectional survey was conducted in March 2020 among 110 nurses from Zhongshan Hospital, Shanghai, who were deployed at COVID-19 units in Wuhan and Shanghai. A COVID-19 questionnaire was adapted from the previous developed "psychological impacts of SARS" questionnaire and included stressors (31 items), coping strategies (17 items), and effective support measures (16 items). Burnout was measured with the Maslach Burnout Inventory. Results: Totally, 107 (97%) nurses responded. Participants mean age was 30.28 years and 90.7% were females. Homesickness was most frequently reported as a stressor (96.3%). Seven of the 17 items related to coping strategies were undertaken by all participants. Burnout was observed in the emotional exhaustion and depersonalization subscales, with 78.5 and 92.5% of participants presenting mild levels of burnout, respectively. However, 52 (48.6%) participants experienced a severe lack of personal accomplishment. Participants with longer working hours in COVID-19 quarantine units presented higher emotional exhaustion (OR = 2.72, 95% CI 0.02-5.42; p = 0.049) and depersonalization (OR = 1.14, 95% CI 0.10-2.19; p = 0.033). Participants with younger age experienced higher emotional exhaustion (OR = 2.96, 95% CI 0.11-5.82; p = 0.042) and less personal accomplishment (OR = 3.80, 95% CI 0.47-7.13; p = 0.033). Conclusions: Nurses in this study experienced considerable stress and the most frequently reported stressors were related to families. Nurses who were younger and those working longer shift-time tended to present higher burnout levels. Psychological support strategies need to be organized and implemented to improve mental health among nurses during the COVID-19 pandemic.

Several properties associated with the field-induced phase change between the antiferroelectric and ferroelectric states in tetragonal (Pb0.97 La0.02 )(Sn,Ti,Zr)O3 antiferroelectric ceramic family were investigated for high-strain displacement transducer applications. The longitudinal field-induced strain accompanying the phase change is in the range of 0.2%–0.9%. The single-shot switching time between the two states is on the order of 1–2 μs. Under continuous ac field driving, the hysteretic heating effect introduces a temperature rise, changing the original room-temperature switching behavior. The ceramics degrade under ac field excitation, the average life cycles is in the range of 106 –107 cycles which can be greatly improved by carefully polishing the sample surfaces.

systematic study in the 1960s was done at Clevite laboratories to explore the use of phase change compositions in capacitive energy storage.334 Uchino et al. studied this effect for the shape memory appli~ation.~ For the same composition, an antiferroelectric form has a smaller lattice volume than the paraelectric form, while a ferroelectric form has a larger lattice volume than the paraelectric form.6 Therefore, if the change directly from an antiferroelectric to the ferroelectric can be accomplished by an electric field, large shape change should take place. However, the field-forced phase change was not considered for actuator applications.In an earlier paper,7 we demonstrated the large field-induced strain in BaTi03 single crystal by the mechanisms of field-forced paraelectric-to-ferroelectric phase change and 90" domain reonentation, and in another paper' we demonstrated the large fieldinduced strain in PLZT ceramic compositions near the tetragonalrhombohedral phase boundary by a mechanism of non-180" domain reorientation. In this paper, we present the field-induced strain Electric-field-forced antiferroelectric-to-ferroelectric phase transitions in several compositions of modified lead zirconate titanate stannate antiferroelectric ceramics are studied for ultra-high-field-induced strain actuator applications. A maximum field-induced longitudinal strain of 0.85% and volume expansion of 0.95% are observed in the ceramic coriposition Pb~.~7Lao.02(Zro.66Tio.wSn0.25)03 at room temperature. Switching from the antiferroelectric form to the ferroelectric form is controlled by the nucleation of the ferroelectric phase from the antiferroelectric phase. A switching time of <1 ps is observed under the applied field above 30 kV/cm. The polarization and strains associated with the field-forced phase transition decrease with increasing switching cycle, a so-called fatigue effect. Two types of fatigue effects are observed in these ceramic compositions. In one, the fatigue effects only proceed to a limited extent and the properties may be restored by annealing above the Curie temperature, while in the other, the fatigue effects proceed to a large extent and the properties cannot be restored completely by heat treatment. Hydrostatic pressure increases the transition field and the switching time. But when the applied electric field is larger than the transition field, the induced polarization and strain are not sensitive to increasing hydrostatic pressure until the transition field approaches the applied field. [