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The acid pre-washing of zero valent iron for improving removal efficiency would deduce the secondary pollution in groundwater, and more fine particles of zero valent iron would reduce the permeability of aquifers. In order to better understand the approaches of nitrate removal, a series of laboratory experiments was conducted in this study. Batch tests showed that washed zero valent iron powder and activated carbon are more efficient for removing nitrate than cemarite and zeolite, similar with the acid pre-washing zero valent iron. X-ray diffraction phase analysis showed that a kind of oxide Fe3O4 generated on the surface of the washed iron powder particles, which is mixed with Fe2O3 and FeO, is relatively loose and can improve the efficiency of nitrate removal. A continuous flow column system test showed that the coarse sand-zero valent iron mix (R1), the coarse sand-zero valent iron-activated carbon mix (R4), and the coarse sand-zero valent iron-sawdust mix (R5) are more effective for reducing nitrate than the coarse sand-activated carbon mix (R2) and the coarse sand-sawdust mix (R3). Components such as NO2-N and NH4 +-N would have environmental concerns as well. Further chemical analysis on the fluids from nitrate removal treatment indicates that R1 and R4 are the most effective and also environmentally friendly media for nitrate removal. This study showed that R1 and R4 media could be developed into a viable technology for the removal of nitrate in high concentration of polluted groundwater. [ABSTRACT FROM AUTHOR]

The aim of the present study was to perform the accurate prognosis of different molecular types breast cancer (BC) by using the partitioning calculation method of the Ki-67 index. Partitioning calculation was used to judge the Ki-67 index and the molecular type was classified according to the 2019 Chinese Society of Clinical Oncology guidelines in 199 cases of BC. The association between the Ki-67 index and overall survival (OS), disease-free survival (DFS) and molecular types was analyzed using the Chi-squared test. Survival analysis was performed using the Kaplan-Meier method with statistical SPSS 18.0 software. The results revealed that the 5-year survival rate of patients with BC was 18.60% (8/43), the 6-year survival rate was 38.24% (26/68), while the 10-year survival rate of patients with BC was 73.08% (133/182); the results indicated that almost 80% patients succumbed during the 5 years following diagnosis. Marked differences were found between the OS of patients with BC and the Ki-67 index (between 50 to 54%) (χ2=4.83, P=0.028; χ2=4.60, P=0.032 respectively). All 14 cases of luminal A subtype BC with a Ki-67 index ≤4% survived at the end of follow-up time (69-156 months). At the same time, there was a marked difference between two groups of patients with overexpression HER-2 while using 50% as a cut-off point of Ki-67 (χ2=5.54, P=0.019). On the whole, the present study demonstrates that the partitioning calculation of the Ki-67 index can be used to judge the prognosis of patients with BC accurately. The prognosis of patients with different molecular subtypes of BC may be associated with the different Ki-67 index. [ABSTRACT FROM AUTHOR]