ABSTRACT
The nitrapyrin was easily adsorbed by soil, but most current studies have focused on comparing the effects of nitrapyrin application at different soil organic matter levels and in different soil types. The adsorption kinetics and isotherm adsorption of the nitrification inhibitor nitrapyrin in black soil, chernozem and planosol were studied in this paper. The adsorption kinetics were fitted by quasi-second-order kinetic equation (R2 ≥ 0.8907, p < 0.05) with a lower acting energy of adsorption (Ea < 8.0 kJ mol-1). The isotherm was fitted by the Langmuir equation (R2 ≥ 0.9400*, p < 0.05). The adsorption mechanism was determined to involve a spontaneous endothermic reaction accompanied mainly by physical adsorption to the surface that belonged to the 'L' isotherm curve (n > 1). Temperature promoted the adsorption of nitrapyrin in these three soils, and the maximum adsorption occurring at different temperatures following the order of black soil > planosol > chernozem. The adsorption capacity and rate decreased with decreasing soil organic matter. For the black soil, the nitrapyrin EC adsorption rate was more than seven times higher than that of nitrapyrin CS. The result would determine the dose of nitrapyrin required for availability in different types of soils and to provide a theoretical basis for elucidating the adsorption of nitrapyrin in the soil environment.
ABSTRACT
BACKGROUND Breast cancer (BC) is the most common malignant tumor in females. This study investigated the role and utility of CTC monitoring in evaluating the prognosis of triple-negative breast cancer patients. MATERIAL AND METHODS We enrolled 286 female triple-negative breast cancer patients who were diagnosed at and received radical resection surgery in our hospital. Peripheral venous blood samples were collected preoperatively and at 3 and 7 days postoperative, and the Cell Search system was used to detect CTC in peripheral blood. We analyzed the relationship between preoperative CTC level and clinical pathological characteristics of patients. Kaplan-Meier method was used to establish progression-free survival curves and overall survival curves, we used the log-rank test to compare the survival rate, and we explored the effects of preoperative and postoperative CTC levels on patient survival. RESULTS Compared with preoperative levels, the average CTC content in peripheral blood of breast cancer patients was significantly increased at 3 days after surgery, and then decreased to the preoperative baseline level by 7 days after surgery. The 3-year overall survival rate and progression-free survival rate in patients with CTC >5/7.5 mL peripheral blood were significantly lower than in patients with CTC <5/7.5 mL peripheral blood detected preoperatively and at 3 and 7 days postoperatively. CONCLUSIONS Dynamic monitoring of preoperative and postoperative CTC levels can accurately predict recurrence and progression of disease, and is important in postoperative monitoring and prognosis evaluation.
