Influence of biochar-based urea substituting urea on rice yield, bacterial community and nitrogen cycling in paddy fields.

BACKGROUND: There is an increasing understanding of the importance of biochar-based fertilizers in agroecosystems. However, no research has evaluated the effects of partial substitution of urea with biochar-based urea on rice yields and soil microbial communities. We therefore investigated the rice yields, bacterial communities, and gene abundance involved in nitrogen in silty clay and sandy loam soil paddy fields treated with urea (U), total substitution of urea with biochar-based urea (BSU), partial substitution of urea with biochar-based urea in basal and tillering fertilizers (BSU1), and partial substitution of urea with biochar-based urea in panicle fertilizers (BSU2). RESULTS: Compared with U, applying biochar-based urea increased rice yields, with BSU2 having the most notable effect. Principal coordinate analysis revealed that bacterial communities treated with BSU2 in both soils were significantly different from those treated with U and BSU, most probably due to the decrease in pH caused by the decrease in the concentration of ammonium. The relative abundance of Subdivision3_genera_incertae_sedis, Azotobacter, Geobacter, Buchnera, and Terrimonas in silty clay soils and Saccharibacteria_genera_incertae_sedis and Geobacter in sandy loam soils significantly increased when treated with BSU2 and was positively correlated with rice yields, indicating that the improvements in rice yield were associated with changes in bacterial communities. Based upon amoA/narG related to nitrate accumulation and norB/nosZ related to nitrous oxide emissions, BSU2 enabled a lower risk of nitrate leaching and nitrous oxide emissions in both soils, in comparison with the U and BSU treatments. CONCLUSION: The BSU2 treatment had a stronger yield-increasing effect than biochar-based urea alone and lowered the risk of nitrogen pollution, which is beneficial to the sustainable development of paddy fields. © 2022 Society of Chemical Industry.

Perioperative application of midline catheter and PICC in Patients with gastrointestinal tumors.

PURPOSE: This study aimed to compare the application value of midline catheter and peripherally inserted central catheter (PICC) in patients with gastrointestinal tumors during the perioperative period. METHODS: 487 patients with gastrointestinal tumors admitted to Qingdao Municipal Hospital from August 2016 to September 2018 were selected and retrospectively analyzed. 279 patients treated with midline catheters during the treatment were regarded as the study group, and another 208 patients treated with PICC were regarded as the control group. The incidence of perioperative adverse reactions, the cost of daily catheter maintenance and the the total cost of catheter indwelling were compared between the two groups. Meanwhile, each patient was investigated for treatment satisfaction at the time of discharge. RESULTS: The total incidence of adverse reactions in the study group was significantly lower than that in the control group (p=0.0001). The catheter indwelling duration in the study group was significantly shorter than that in the control group (p<0.001). The 24-h drainage volume in the study group was significantly higher than that in the control group (p<0.001). The average cost of daily maintenance and total cost of catheter indwelling in the study group were significantly lower than those in the control group (p<0.001). The satisfaction rate in the study group (69.53%) was significantly higher than that in the control group (51.92%) (p<0.001). The dissatisfaction rate in the study group (3.23%) was significantly lower than that in the control group (15.38%) (p<0.001). CONCLUSION: Compared with PICC, the perioperative application of midline catheter in patients with gastrointestinal tumors can effectively reduce catheter-related adverse reactions, with higher medical economic benefits and satisfaction rate, and is worthy of clinical promotion and application.