Investigation on ultrasonic cavitation erosion of TiMo and TiNb alloys in sulfuric acid solution.

Two kinds of Ti-alloys, i.e., TiMo and TiNb alloys are manufactured in this paper, and their ultrasonic cavitation erosion behaviors in 0.1 M H2SO4 solution are evaluated by the mean depth erosion (MDE), SEM and white light photograph. The results show that MDE of TiMo and TiNb alloys obviously increase with increasing the cavitation erosion time, however, they evidently decrease with the increment of Mo or Nb content at each fixed cavitation erosion time, and even some large blank areas (uneroded areas) still exist on the sample surface after ultrasonic cavitation erosion for 2 h in the case of Ti10Mo and Ti20Nb samples, implying the enhanced anti-cavitation erosion property of Ti-alloy by adding Mo or Nb element. The MDE of Ti10Mo or Ti20Nb sample is lower than that of TC4 sample in the case of each cavitation erosion time, indicating the better cavitation erosion resistance of of Ti10Mo or Ti20Nb sample. The influences of Mo and Nb on the passivity of TiMo and TiNb alloys during the ultrasonic cavitation erosion are detected by potentiodynamic curves. The results display that Ti, TC4, TixMo (x = 1, 5, 10) and TixNb (x = 5, 10, 20) samples are all almost in the passive state within the potential region from 0VSCE to 1.5VSCE during ultrasonic cavitation erosion, and the passive current density evidently decreases with increasing Mo or Nb content, indicating the enhanced passive characteristic by adding Mo or Nb alloys during the ultrasonic cavitation erosion.

Association of de novo human leukocyte antigen and major histocompatibility complex class I chain-related gene-A antibodies and proteinuria with graft survival 5 years after renal transplantation.

BACKGROUND: Association of de novo human leukocyte antigen (HLA) and major histocompatibility complex class I chain-related gene-A (MICA) antibodies and proteinuria with graft survival 5 years after renal transplantation. De novo presence of HLA and MICA antibodies after renal transplantation is associated with poor graft survival. Proteinuria after transplantation is also considered a risk factor for premature graft loss. In this study, we investigated the association of de novo HLA and MICA antibodies on proteinuria after renal transplantation and the association of proteinuria and de novo antibodies with graft survival. METHODS: We enrolled 275 patients without preexisting HLA and MICA antibodies followed for >5 years after renal transplantation. All donor organs were from living-related donors or from an organ donation program. HLA and MICA antibodies were detected by the Luminex method. Patients with proteinuria (>150 mg/d) underwent intermittent 24-hour proteinuria examination. RESULTS: The frequencies of de novo HLA and MICA antibody 5 years after transplantation were 25.8% and 12%, respectively. In total, 26.5% of patients had proteinuria at the 5-year follow-up. De novo HLA antibody was associated with increased proteinuria after transplantation (relative risk, 3.12). HLA antibody and proteinuria were both associated with poor 5-year graft survival (P = .027 and P = .006, respectively). CONCLUSION: De novo HLA and MICA antibodies and proteinuria after renal transplantation are all associated with poor graft survival. De novo HLA antibody is independent risk factor for posttransplant proteinuria, and proteinuria affects the association of de novo antibodies with decreased graft survival after transplantation.