Analysis of the Circulating Tumor Cell Capture Ability of a Slit Filter-Based Method in Comparison to a Selection-Free Method in Multiple Cancer Types

Circulating tumor cells (CTCs) are a promising biomarker for cancer liquid biopsy. To evaluate the CTC capture bias and detection capability of the slit filter-based CTC isolation platform (CTC-FIND), we prospectively compared it head to head to a selection-free platform (AccuCyte®-CyteFinder® system). We used the two methods to determine the CTC counts, CTC positive rates, CTC size distributions, and CTC phenotypes in 36 patients with metastatic cancer. Between the two methods, the median CTC counts were not significantly different and the total counts were correlated (r = 0.63, p < 0.0001). The CTC positive rate by CTC-FIND was significantly higher than that by AccuCyte®-CyteFinder® system (91.7% vs. 66.7%, p < 0.05). The median diameter of CTCs collected by CTC-FIND was significantly larger (13.0 μm, range 5.2–52.0 vs. 10.4 μm, range 5.2–44.2, p < 0.0001). The distributions of CTC phenotypes (CK+EpCAM+, CK+EpCAM− or CK−EpCAM+) detected by both methods were similar. These results suggested that CTC-FIND can detect more CTC-positive cases but with a bias toward large size of CTCs.

Analysis of reliability of design of stop valve of steam turbin

The stop valve is one of the «critical» elements of the steam turbine installation, the heating conditions of which determine the reliability of the power unit as a whole. The stop valve for cogeneration steam turbines of subcritical parameters of "UTZ" is unified for familiesT-110/120-130, T-185/210-130/15, ПT-140/165-30/15, P-100-130/15. The sequence of analysis of the valve design is presented for conditions, where only the static temperature and steam pressure at the inlet to the valve, the steam flow rate at the outlet of it, the restrictions for movement during heating are known. The results of the analysis of calculations of unsteady gas-thermodynamic and stress-strain state of the valve during the heating of the main steam line of the turbine T-110/120-130 from the cold state according to the standard instructions are shown. The calculations were carried out by the finite element method using a three-dimensional geometric model of the valve body with a slit filter. The height of the holes in the slit filter is 3.5 mm. The equations of the Nusselt criterion for the flange, the steam box, the lower half of the steam box and the fairing when using computers with limited computing resources are presented. It is shown that the peak of the maximum stresses occurs at the initial stage of the stop valve warming up on the inner (heated) surface of the stop valve body in the area of the flange and the cover. The maximum equivalent stresses are 300 MPa. The comparison of calculated temperatures and temperatures measured during the start-up at the CHP is presented; the temperature difference does not exceed 5–6%. It is proposed to analyze the stop valve reliability with a sequence given in this article in the design of new stop valves with significant differences from the existing prototypes.