Background The prevalence of COVID-19 highlights the shortage of human medical resources, and improving medical students' professional identity is crucial to improving this situation. The sources of confidence in overcoming COVID-19 and medical students' attention to COVID-19 were significant factors affecting their professional identity. However, no study has investigated the mediating role of medical students' attention to COVID-19 in their relationship. This study investigates the relationship between these three factors in three medical university students in Hunan Province. Methods A cross-sectional survey study that used convenience sampling method was conducted on 2775 medical students from three universities in the Hunan Province of China from March 15 to April 19, 2020. An intermediary model was established to evaluate the role of medical students' attention to COVID-19 in the sources of confidence in overcoming COVID-19 and the improvement of medical students' professional identity. Results The sources of confidence in overcoming COVID-19, medical students' attention to national crisis events, and the improvement of medical students' professional identity was positively associated with each other (β = 0.328 ~ 0.464, P < 0.001). The mediating effect accounted for 23.3% of the total effect and 30.4% of the direct effect. Medical students' attention to COVID-19 partially mediates the relationship between the sources of confidence to overcome COVID-19 and the improvement of medical students' professional identity. Conclusions This study found that the sources of confidence in overcoming COVID-19 and medical students' attention to national crisis events have a significant predictive effect on the improvement of medical students' professional identity. Medical students' attention to COVID-19 mediated the relationship between the sources of confidence to overcome COVID-19 and the improvement of medical students' professional identity. The findings have emphasized the theoretical and practical significance of professional identity education for medical students.

Background The prevalence of COVID-19 highlights the shortage of medical human resources, and improving medical students' professional identity is a key condition to improve this situation. The sources of confidence in overcoming major public health events and medical students' attention to major public health events were key factors affecting their professional identity, but no study has yet investigated the mediating role of medical students' attention to major public health events in the relationship between them. This study aims to investigate the relationship among these three in medical university students in Hunan Province. Methods This was a cross-sectional survey of 2,960 medical students’ questionnaires collected from three universities in Hunan Province. An intermediary model was established to evaluate the role of medical students' attention to major public health events in the sources of confidence in overcoming major public health events and the improvement of medical students' professional identity. Results The sources of confidence in overcoming major public health events, medical students' attention to national crisis events, the improvement of medical students' professional identity were positively associated with each other (β = 0.328 ~ 0.464, P < 0.001). The mediating effect accounted for 23.3% of the total effect and 30.4% of the direct effect. Medical students' attention to major public health events plays a partial mediating role in the relationship between the sources of confidence to overcome major public health events and the improvement of medical students' professional identity. Conclusions This study found that the sources of confidence in overcoming major public health events, medical students' attention to national crisis events have a signifcant predictive effect on the improvement of medical students' professional identity. Medical students' attention to major public health events mediated the relationship between the sources of confidence to overcome major public health events and the improvement of medical students' professional identity. The findings have emphasize the theoretical and practical significance of professional identity education for medical students.

Evidence has shown that exposure to environmental pollutants such as microcystins (MCs), arsenic (As), and cadmium (Cd) can lead to the occurrence and development of chronic kidney disease (CKD). There is a synergistic effect between MCs and Cd. However, the combined effect of MCs and As exposures on CKD remains unclear. In Hunan province, China, 135 controls and 135 CKD cases were enrolled in a case-control study. Serum MCs, plasma As and Cd concentrations were measured for all participants. We investigated the association between MCs/As and CKD risk using conditional logistic regression. The additive model explored the interaction effect, and the Bayesian kernel machine regression (BKMR) models investigated the combined effects of MCs, As, and Cd on CKD. The results showed that MCs and As were significantly associated with CKD risk. Participants in the highest MCs concentration had a 4,81-fold increased risk of CKD compared to those in the lowest quartile (95% confidence interval [CI]: 1,96 to 11,81). The highest quartile of As concentrations corresponded to an adjusted odds ratio of 3.40 (95% CI: 1.51, 7.65) relative to the lowest quartile. MCs/As and CKD risk exhibited significant dose–response correlations (all p for trend < 0.01). In addition, a positive interaction effect of MCs and As on CKD was also reported. The CKD risk due to interaction was 2.34 times (95% CI: 0.14, 4.54) relative to the CKD risk without interaction, and the attributable proportion of CKD due to interaction among individuals with both exposures was 56% (95% CI: 0.22, 0.91). In the BKMR, the combined effect of MCs, As, and Cd was positively associated with CKD. In conclusion, both MCs and As are independent risk factors for CKD, exerting a synergistic effect between them. Combined exposure to MCs, As, and Cd can increase the risk of CKD.