RESUMO
An optical frequency domain reflectometry (OFDR) shape sensor was demonstrated based on a femtosecond-laser-inscribed weak fiber Bragg grating (WFBG) array in a multicore fiber (MCF). A WFBG array consisting of 60 identical WFBGs was successfully inscribed in each core along a 60â cm long MCF using the femtosecond-laser point-by-point technology, where the length and space of each WFBG were 2 and 8â mm, respectively. The strain distribution of each core in two-dimensional (2D) and three-dimensional (3D) shape sensing was successfully demodulated using the traditional cross correlation algorithm, attributed to the accurate localization of each WFBG. The minimum reconstruction error per unit length of the 2D and 3D shape sensors has been improved to 1.08% and 1.07%, respectively, using the apparent curvature vector method based on the Bishop frame.
RESUMO
A wide-range OFDR strain sensor was demonstrated based on femtosecond-laser-inscribed weak fiber Bragg grating (WFBG) array in standard SMF. A WFBG array consisting of 110 identical WFBGs was successfully fabricated along a 56â cm-long SMF. Compared with SMF, the cross-correlation coefficient of WFBG array was improved to 0.9 under the strain of 10,000⠵ε. The position deviation under the strain of 10,000⠵ε, i.e., 2.5 mm, could be accurately obtained and compensated simply by using peak finding algorithm. The maximum measurable strain of single- and multi-point strain sensing was up to 10,000⠵ε without using any additional algorithms, where the sensing spatial resolution was 5 mm.
RESUMO
Tumor markers (TMs) play an important role in clinical rapid screening and diagnosis for prostate cancer (PCa). In this study, we describe a competitive method to establish the multiplex suspension array by tumor biomarkers coated on distinguishable microbeads which competing with free biomarkers for their complementary antibodies (Ab) in one single reaction system for simultaneous and combined detection of prostate TMs in human serum. The volumes of the targets coupled onto the beads and their complementary Abs were optimized. The suspension array standard curves correlated well with PCa biomarkers (R(2)>0.9968). PCa biomarker levels were quantified using median fluorescent intensities. The working ranges of prostate-specific antigen (PSA), prostate stem cell antigen (PSCA), prostate-specific membrane antigen (PSMA) and prostatic acid phosphatase (PAP) were 0.47-502.94, 1.00-923.35, 1.00-524.79, and 1.73-176.07ngmL(-1) in serum samples, respectively. This method was compared to indirect competitive enzyme linked immunosorbent assay. It was found that high concordance between the two technologies resulted from serum samples of the eight PCa patients. The multiplex suspension array technology is specific to PCa biomarkers, displayed no significant cross-reactivity, and remains stable for 6 months. We also characterized the bead surface microstructures under different conditions employing a field emission scanning electron microscope. The suspension array is a straightforward and reliable method for analysis of multiple TMs with simple operation, high sensitivity at a low cost.
