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Aims To construct an efficient bacterial complex to degrade nicosulfuron and clarify its degradative characteristics, promote the growth of maize (Zea mays), and provide a theoretical foundation for the efficient remediation of soil contaminated with nicosulfuron. Methods and results Biocompatibility was determined by the filter paper sheet method by mixing Serratia marcescens A1 and Bacillus cereus A2 in a 1:1 ratio, yielding A12. The optimum culture conditions for the bacterial composite were obtained based on a three-factor, three-level analysis using response surface methodology, with 29.25 g l−1 for maltodextrin, 10.04 g l−1 for yeast extract, and 19.93 g l−1 for NaCl, which resulted in 92.42% degradation at 4 d. The degradation characteristics of A12 were clarified as follows: temperature 30°C, pH 7, initial concentration of nicosulfuron 20 mg l−1, and 4% inoculum. The ability to promote growth was determined by measuring the ratio of the lysosphere diameter (D) to the colony diameter (d), and the ability of the complex A12 to promote growth was higher than that of the two single strains. Conclusions Nicosulfuron degradation in sterilized and unsterilized soils reached 85.4% and 91.2% within 28 d, respectively. The ability of the strains to colonize the soil was determined by extraction of total soil DNA, primer design, and gel electrophoresis. The bioremediation effect of A12 was confirmed by the maximum recovery of fresh weight (124.35%) of nicosulfuron-sensitive crop plants and the significant recovery of soil enzyme activities, as measured by the physiological indices in the sensitive plants. [ABSTRACT FROM AUTHOR]

Arising of disasters by climate change had affected crop growth and yield, and then threaten local to global food security, particularly heat stress. Therefore, hazard assessment is essential to develop effective disaster risk management and adaptation interventions to ensure food security. In this study, the accumulated heat stress days (DAY), heat stress intensity (HSI) and heat degree-days (HDD) during the post-silking period of summer maize in The Huang-Huai-Hai Plain were investigated. Based on the optimal probability distribution function of HDD and information diffusion theory, we compute heat stress classification index and the possibility of heat stress, respectively. During 1981–2019, DAY, HSI and HDD were 11.8 d, 31.9°C and 23.6°Cd and increased by 0.67 d/decade, 0.10°C/decade and 3.14°Cd/decade, respectively. The threshold and hazard probability of mild, moderate and severe heat stress were 9.4, 19.4 and 34.2°Cd and 16.6, 9.3 and 4.5%, respectively. The heat stress hazard index (M) was 0.48, ranged from 0 to 0.77 during 1981 to 2019. M will increase in the future at all regions, particularly after 2060. Under SSP5-8.5 climate scenario, M ranged from 0.95 to 1.20 in 2080s, about two times than historical period. This could be used in optimizing agricultural management in summer maize production in order to combat heat stress under projected climate change. [ABSTRACT FROM AUTHOR]

Objective: To observe the impact of a clinical nursing teaching model based on institutional collaboration on the teaching quality of nursing programs in colleges and universities and the effectiveness of undergraduate practical nurses in practice., Methods: One hundred and twenty-three undergraduate student nurses graduating from June 2020 to July 2021 were selected for the study, 59 of whom received the traditional teaching model (control group) and 64 of whom received the institutional cooperative teaching model (research group). Upon completion of their internship, a clinical nursing skills assessment was conducted for the two groups, and the clinical internship performance was evaluated using the self-assessment scale of clinical practice behavior performance of nursing undergraduates. A teaching evaluation questionnaire was used to survey the intern nurses' evaluation of the teaching model and their satisfaction with the teaching model was surveyed in the middle and after the completion of the internship, respectively. Upon completion of the internship, the intern nurses filled out a self-satisfaction evaluation form., Results: The research group had a lower failure rate than the control group and a higher excellent rate than the control group (P < .05). There were no differences in the scores of the professional and self-development domains between the two groups (P > .05), while for all other clinical placement performances, the scores were higher in the research group than in the control group (P < .05). In addition, the research group had higher subject presentation, post-lesson acquisition, total score, and teaching satisfaction than the control group (P < .05). In terms of self-satisfaction, the number of satisfied intern nurses was also higher than the control group (P < .05)., Conclusion: The reform of clinical nursing teaching mode based on institutional cooperation can effectively improve the quality of nursing teaching in universities and the effectiveness of undergraduate practical nursing.