Detection of the eroding surface in the EDM process based on the current signal in the gap

To achieve a high removal rate and low electrode wear in a sinking electrical discharge machining process (EDM), rough machining parameters have to be selected according to the size of the eroding surface. In general, the size of the eroding surface varies according to the depth of the machining. Thus, it has to be determined on-line. This paper shows that the electric current signal in the gap depends on the size of the eroding surface. The significance of the process attributes of the electric current signal is established by inductive machine learning and the general decision rules are derived. The size of the eroding surface can be detected on-line by monitoring and evaluating the electric current signal in the gap.     

Levels of Circulating PD-L1 Are Decreased in Patients with Resectable Cholangiocarcinoma

Tumor resection represents the only curative treatment option for patients with biliary tract cancers (BTCs), including intrahepatic cholangiocarcinoma (CCA), perihilar and extrahepatic CCA and gallbladder cancer. However, many patients develop early tumor recurrence and are unlikely to benefit from surgery. Therefore, markers to identify ideal surgical candidates are urgently needed. Circulating programmed cell death 1 ligand 1 (PD-L1) has recently been associated with different malignancies, including pancreatic cancer which closely resembles BTC in terms of patients’ prognosis and tumor biology. Here, we aim at evaluating a potential role of circulating PD-L1 as a novel biomarker for resectable BTC. Methods: Serum levels of PD-L1 were analyzed by ELISA in 73 BTC patients and 42 healthy controls. Results: Circulating levels of preoperative PD-L1 were significantly lower in patients with BTC compared to controls. Patients with low PD-L1 levels displayed a strong trend towards an impaired prognosis, and circulating PD-L1 was negatively correlated with experimental markers of promalignant tumor characteristics such as CCL1, CCL21, CCL25 and CCL26. For 37 out of 73 patients, postoperative PD-L1 levels were available. Interestingly, after tumor resection, circulating PD-L1 raised to almost normal levels. Notably, patients with further decreasing PD-L1 concentrations after surgery showed a trend towards an impaired postoperative outcome. Conclusion: Circulating PD-L1 levels were decreased in patients with resectable BTC. Lack of normalization of PD-L1 levels after surgery might identify patients at high risk for tumor recurrence or adverse outcome.     

Achieving profitably,operationally, and environmentally compromise flow‐sheet designs by a single‐criterion optimization

Compromise designs that can be achieved to a certain extent in process flow‐sheet optimization not only by multicriteria but also by single‐criterion optimization are described. A well‐balanced compromise between the profitability, operational, and environmental efficiencies can be achieved using a suitable economic criterion. From the financial point of view, the net present value (NPV) is the correct criterion for selection from among mutually exclusive solutions and, hence, for evaluating different designs in process optimization. Other criteria are also often used in engineering practice. It is shown that optimal designs obtained using different economic objectives vary not only in their investment and other financial indicators, but also in operational efficiencies and environmental indicators. Operationally more efficient and environmentally less harmful solutions can be obtained at lower profitability, by increasing the invested funds. The net present value generates the best compromise between these objectives, as illustrated by three flow‐sheet synthesis problems. © 2011 American Institute of Chemical Engineers AIChE J, 2012