Factors associated with poor mental health outcomes in nurses in COVID-19-designated hospitals in the postepidemic period in Guangdong Province: a cross-sectional study.

OBJECTIVE: The early days of the COVID-19 pandemic placed enormous pressure and subsequent negative psychological problems on nurses, but at this stage of the year-long COVID-19 outbreak, the level of stress and negative emotions that nurses experience is unclear. Our study attempted to assess the factors influencing mental health status in nurses during the postepidemic period of COVID-19. DESIGN: Cross-sectional study. SETTING: COVID-19 designated hospitals. PARTICIPANTS: 1284 Chinese nurses. MAIN OUTCOME MEASURES: Electronic questionnaires, including the Chinese version of the Perceived Stress Scale (CPSS) and Symptom Checklist-90 (SCL-90), were distributed for self-evaluation. Regression analysis was used to analyse the associated factors of psychological stress among variables such as age, years of nursing experience, weekly working hours, anxiety symptoms, somatisation symptoms and compulsive symptoms. RESULTS: A total of 1284 respondents from COVID-19-designated hospitals in Guangdong Province were studied. The average CPSS score for all respondents was 22.91±7.12. A total of 38.5% of respondents scored ≥26 on the CPSS, indicating a significant degree of psychological stress. Nurses with high psychological stress had higher levels of anxiety symptoms (41.7% vs 8.0%), somatisation symptoms (31.4% vs 7.7%) and compulsion symptoms (62.3% vs 27.0%) than nurses with low psychological stress. Stepwise multiple linear regression revealed that weekly working hours, years of nursing experience, anxiety symptoms, somatisation symptoms and compulsion symptoms had a linear relationship with the participants' psychological stress scores. CONCLUSION: Nurses experienced significant physical and psychological risk while working in the postepidemic period. Our findings suggest that nurses still need support to protect their physical and mental health.

[Effects of slope direction on soil nutrient and its ecological stoichiometry in bamboo forest]. / å¡å‘å¯¹æ¯›ç«¹æž—åœŸå£¤å »åˆ†åŠå ¶ç”Ÿæ€åŒ–å­¦è®¡é‡ç‰¹å¾çš„å½±å“.

We analyzed the effects of slope direction on soil nutrients and ecological stoichiometry by collecting soil samples from different slope directions (shady slope and sunny slope) of the bamboo forest in Longyou County, Zhejiang Province. The results showed that soil nutrients were affected by slope direction and soil depth. The nutrients level of soils in the sampling area showed the trends of shady slope > sunny slope, and surface soil > bottom soil. Compared to sunny slope, the cation exchange capacity (CEC), the contents of total organic carbon, total nitrogen, alkaline hydrolyzed nitrogen, available phosphorus, total potassium and available potassium of shady soils significantly increased by 43.7%, 103.8%, 92.0%, 75.5%, 22.4%, 89.4% and 240.7%, respectively. There was no significant difference in total phosphorus contents between shady slope and sunny slope. At all soil layers, there was no significant difference of C/N ratio between shady and sunny slopes. The average C/P ratio of shady slope was 180.8%, 42.0% and 54.3% higher than that of sunny slope at 0-20 cm, 20-40 cm and 40-60 cm, respectively. At each soil layer, the average C/K and N/K ratios between shady and sunny slopes had no significant difference. The average C/K and N/K ratios of shady slope and sunny slope were all significantly different among the three soil layers. In the shady slope, the contents of soil organic carbon showed significantly positive correlation with total nitrogen, total phosphorus, total potassium, and soil available nutrients. Overall, soil nutrients and ecological stoichiometry characteristics of shady slope of bamboo forest were superior to those of sunny slope.

Effect of bone marrow mesenchymal stem cells on the polarization of macrophages.

Inflammation is a defensive response in the living tissue of the vascular system that acts against damage factors and involves various types of immune cells, including macrophages, neutrophils, endothelial cells and other associated immune molecules. If the release of inflammatory mediators is excessive, systemic inflammatory response syndrome may develop. Sepsis is the most common complication of severe burns and is a systemic inflammatory response syndrome that is caused by infectious factors and is capable of leading to multiple organ dysfunction and potentially death. Research concerning the mechanism and treatment of sepsis is crucial. Macrophages are an important type of immune cell that remove invasive pathogens and are involved in innate and adaptive immune responses. It has been previously reported that bone marrow mesenchymal stem cells (BMSCs) affect macrophages by regulating immunity. The present study aimed to investigate the effect of BMSCs on macrophage polarization in vivo and in vitro, in addition to the potential therapeutic effect of these cells on experimental sepsis. BMSCs and peritoneal macrophages were isolated from Sprague­Dawley rats and co­cultured overnight as a mixed culture or Transwell system, and subsequently stimulated with 100 ng/ml lipopolysaccharide (LPS). After 12 h, the medium was replaced with normal complete medium for various durations and supernatants were collected to extract proteins and cells for ELISA, western blot and flow cytometry analysis to investigate different aspects of macrophages. Sepsis was induced in Sprague­Dawley rats by injection of LPS (5 mg/kg), followed by tail vein injection of BMSCs or PBS 1 h later. After 6, 12, 24 and 48 h, lung tissues were harvested for pathological observation and peritoneal macrophages were collected for flow cytometry analysis to assess the expression of markers, including cluster of differentiation (CD)68 (used for gating), CD11c and CD206. The results demonstrated that, in the culture medium, LPS stimulation increased the expression of CD11c in macrophages, and the levels of tumor necrosis factor­α and inducible nitric oxide synthase were also increased. By contrast, in macrophages treated with BMSCs directly, the expression of CD11c was reduced compared with the LPS­stimulated macrophage alone group. However, the secretion of interleukin­10, transforming growth factor­ß and arginase­1 was increased in the direct co­culture group, compared with the LPS­stimulated macrophage alone group. BMSCs reduced the inflammation in lung tissues and inhibited macrophage expression of CD11c in the rat model of sepsis. The results of the present study demonstrated that BMSCs co­cultured with macrophages directly inhibited macrophage differentiation into the M1 phenotype and reduced inflammation in macrophages stimulated by LPS. In vivo, BMSCs decreased the expression of CD11c in peritoneal macrophages and reduced the pathological inflammatory response in the lungs. The findings of the present study demonstrated that BMSCs may reduce the extent of the systemic inflammatory response, which may contribute to the development for a novel type of treatment for sepsis in the future.