Effect of Micro-Area pH Value on Formation of Different Rust Phases of Weathering Steel in Initial Corrosion Period

The formation of protective rust layer of atmospheric corrosion resistance was discussed for weathering steel. The rust layers of experimental steels were made by using an accelerating industrial atmospheric corrosion test of dry-wet cyclic immersion. Furthermore XRD were used to measure and analyze the rust layers. The initial corrosion processes below thin water film were observed and the changes of micro-area pH value were measured. The results are as follows： The corrosion processes of P-RE weathering steel are obviously different from those of carbon steel. The surface of P-RE weathering steel rapidly forms a-FeOOH and the micro-area pH value is above 5.4 during the initial corrosion period. While the component of the rust layer for the carbon steel is mainly Fe3O4 and the microarea pH value is below 3.8.

Analysis of sensitivity and specificity:precise recognition of neutrophils during regeneration of contused skeletal muscle in rats

In this report,we applied the TissueFAXS 200 digital pathological analysis system to rapidly and accurately identify neutrophils during regeneration of contused skeletal muscle,and to provide information for follow-up studies on neutrophils to estimate wound age.Rat injury model was established,and skeletal muscle samples were obtained from the control group and contusion groups at 1,1.5,2,3,4,and 6 h,as well as at 1,3,5,and 15 d post-injury(n紏5 per group).The expression of nuclei and neutrophils was detected by hematoxylin and eosin(HE)staining and immunohistochemical(IHC)staining.A total of 20 injury site areas of 0.25mm^(2)(0.5mm0.5mm)were then randomly selected at all time points.A TissueFAXS 200 digital pathological analysis system was used to identify the positive and negative numbers.Knowledge of five professional medical workers were considered the gold standard to measure the false positive rate(FPR),false negative rate(FNR),sensitivity,specificity,and area under the curve(AUC)of receiver operating characteristic(ROC)curves.As a result,with a staining area of neutrophils from 8 μm^(2) to 15 μm^(2),the FPR was 4.28%–12.14%,the FNR was 12.42%–64.08%,the sensitivity was 35.92%–87.58%,the specificity was 87.86%–95.72%,the Youden index was 0.316–0.754,the accuracy was 82.80%–88.30%,and the AUC was 0.771–0.826.The AUC was largest when the cut-off value of the staining area was 12 mm^(2).Our results show that this software-based method is more accurate than the human eye in evaluating neutrophil infiltration.Based on the sensitivity and specificity,neutrophils can be accurately identified during regeneration of contused skeletal muscle.The TissueFAXS 200 digital pathological analysis system can also be used to optimize conditions for different cell types under various injury conditions to determine the optimal cut-off value of the staining area and provide optimal conditions for further study.Furthermore,it will provide evidence for forensic pathology cases.