Evaluation of the Transverse Crack Depth of Rail Bottoms Based on the Ultrasonic Guided Waves of Piezoelectric Sensor Arrays.

A method based on the high-frequency ultrasonic guided waves (UGWs) of a piezoelectric sensor array is proposed to monitor the depth of transverse cracks in rail bottoms. Selecting high-frequency UGWs with a center frequency of 350 kHz can enable the monitoring of cracks with a depth of 3.3 mm. The method of arranging piezoelectric sensor arrays on the upper surface and side of the rail bottom is simulated and analyzed, which allows the comprehensive monitoring of transverse cracks at different depths in the rail bottom. The multi-value domain features of the UGW signals are further extracted, and a back propagation neural network (BPNN) is used to establish the evaluation model of the transverse crack depth for the rail bottom. The optimal evaluation model of multi-path combination is reconstructed with the minimum value of the root mean square error (RMSE) as the evaluation standard. After testing and comparison, it was found that each metric of the reconstructed model is significantly better than each individual path; the RMSE is reduced to 0.3762; the coefficient of determination R2 reached 0.9932; the number of individual evaluation values with a relative error of less than 10% and 5% accounted for 100% and 87.50% of the total number of evaluations, respectively.

Efficacy and prognostic factors of imatinib plus CALLG2008 protocol in adult patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia.

A CALLG2008 protocol was developed by the Chinese Acute Lymphoblastic Leukemia Cooperative Group for adult acute lymphoblastic leukemia (ALL). We retrospectively analyzed 153 newly diagnosed adult patients with Philadelphia chromosome (Ph)-positive ALL enrolled into imatinib (400 mg/d) plus CALLG2008 regimen between 2009 and 2015. The median age was 40 years (range, 18-68 years), with 81 (52.3%) males. The overall hematologic complete remission (CR) rate was 96.7% after induction. With a median follow-up of 24.2 months, the estimated 3-year overall survival (OS) and event-free survival (EFS) rates were 49.5%(95%confidence interval (CI): 38.5%-59.5%) and 49.2% (95% CI: 38.3%-59.2%), respectively. Fifty-eight (36 with haploidentical donor) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first CR. Among the patients in CR1 after induction, both the 3-year OS and EFS were significantly better in the allo-HSCT group than in the without allo-HSCT group (73.2%, 95% CI: 58.3%-83.5% vs. 22.2%, 95% CI: 8.7%-39.6% and 66.5%, 95% CI: 50.7%-78.2% vs. 16.1%, 95% CI: 5.1%-32.7%, respectively). Multivariate analysis showed that allo-HSCT and achievement of major molecular response were associated with favorable OS or EFS independently. Interestingly, in the allo-HSCT cohort, the donor type (haploidentical versus matched donors) had no significant impact on EFS or OS. All these results suggested that imatinib plus CALLG2008 was an effective protocol for Ph-positive ALL. Haploidentical donors can also be a reasonable alternative expedient donor pool.