Event Log Privacy Based on Differential Petri Nets

Process mining uses event logs to improve business processes, but such logs may contain privacy information. One popular research problem is the privacy protection of event logs. Publishing logs with differential privacy is one of major research directions. Existing research achieves privacy protection primarily by injecting random noise into event logs, or merging similar information. The former ignores the fact that injecting random noise will produce apparently unreasonable activity traces, and the latter will cause a loss of process information in the process mining perspective. To solve the above problems, this article proposes a differential algorithm based on randomized response to model Petri nets for the original event logs, select the important labels in the logs by the weak sequential relationship of control flow between activities, inject noise into the Petri net model based on the important labels using the randomized response approach, and establish a differential Petri net model. Experiments on public datasets show that the event logs produced by the approach proposed do not contain unreasonable traces. Compared with the baseline approach, the proposed approach performs better on Fitness metrics with consistent privacy requirements and retains more process variants, reducing the loss of original event log process information

Ruthenium Poly(ethylenimine)/Gold Nanoparticles Immobilized on Dendritic Mesoporous Silica Nanoparticles for a CA15‑3 Electrochemiluminescence Immunosensor via Cu₂O@PDA Dual Quenching

The development of a specifically sensitive approach for CA15-3 detection is of great significance for the early diagnosis and treatment monitoring of breast cancer. In the present work, an electrochemiluminescence (ECL) immunosensor was constructed for the sensitive and selective detection of CA15-3 based on a dual-quenching strategy. Ru­(dcbpy)32+, poly­(ethylenimine) (PEI), and gold nanoparticles (AuNPs) were immobilized on dendritic mesoporous silica nanoparticles (DMSNs) (Ru-PEI/AuNPs@DMSNs) with high ECL efficiency due to the high loading amounts of Ru­(dcbpy)32+, the shortened electron-transfer path between the luminophore and coreactant, and the excellent conductivity and localized surface plasmon resonance effect of AuNPs. In the presence of CA15-3, a Cu2O nanoparticles coated with poly­(dopamine) (Cu2O@PDA) nanocomposite was introduced to the synthesized Ru-PEI/AuNPs@DMSNs through antigen–antibody interaction, resulting in a remarkable ECL quenching due to the dual quenchers of Cu2O and PDA. Under the optimal conditions, the fabricated sensor was used to detect CA15-3 in a wide linear range of 5.0 × 10–5–6.0 × 102 U mL–1 with a low limit of detection of 2.4 × 10–6 U mL–1. The dual-quenching ECL immunosensor was successfully applied for the determination of CA15-3 in patient serum, indicating the potential applicability of the present immuosensor for the clinical determination of CA15-3 and other cancer biomarkers