The conductivity mismatch in the composite insulation of high voltage direct current (HVDC) cable accessories causes electric field distribution distortion and even insulation breakdown. Therefore, a liquid silicone rubber (LSR) filled with SiC nanoparticles is prepared for the insulation of cable accessories. The micro-morphology of the SiC/LSR nanocomposites is observed by scanning electron microscopy, and their trap parameters are characterized using thermal stimulated current (TSC) tests. Moreover, the dielectric properties of SiC/LSR nanocomposites with different SiC concentrations are tested. The results show that the 3 wt % SiC/LSR sample has the best nonlinear conductivity, more than one order of magnitude higher than that of pure LSR with improved temperature and nonlinear conductivity coefficients. The relative permittivity increased 0.2 and dielectric loss factor increased 0.003, while its breakdown strength decreased 5 kV/mm compared to those of pure LSR. Moreover, the TSC results indicate the introduction of SiC nanoparticles reduced the trap level and trap density. Furthermore, the SiC nanoparticles filling significantly increased the sensitivity of LSR to electric field stress and temperature changes, enhancing the conductivity and electric field distribution within the HVDC cable accessories, thus improving the reliability of the HVDC cable accessories.
Background Posttransplant lymphoproliferative disease (PTLD) is a serious complication after pediatric liver transplantation (pLT), which may lead to death. 18F‐FDG PET/CT is rarely considered in PTLD after pLT and lacks clear diagnostic guidelines, especially in the differential diagnosis of nondestructive PTLD. The aim of this study was to find a quantifiable 18F‐FDG PET/CT index to identify nondestructive PTLD after pLT. Methods This retrospective study collected the data of patients who underwent pLT, postoperative lymph node biopsy, and 18F‐FDG PET/CT at Tianjin First Central Hospital from January 2014 to December 2021. Quantitative indexes were established using lymph node morphology and the maximum standardized uptake value (SUVmax). Results A total of 83 patients met the inclusion criteria and were included in this retrospective study. To distinguish between PTLD‐negative cases and nondestructive PTLD cases, according to the receiver operating characteristic curve, (the shortest diameter of the lymph node at the biopsy site [SDL]/the longest diameter of the lymph node at the biopsy site [LDL])*(SUVmax at the biopsy site [SUVmaxBio]/SUVmax of the tonsils [SUVmaxTon]) had the maximum area under the curve (0.923; 95% confidence interval: 0.834–1.000), and the cutoff value was 0.264 according to the maximum value of Youden's index. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 93.6%, 94.7%, 97.8%, 85.7%, and 93.9%, respectively. Conclusions (SDL/LDL)*(SUVmaxBio/SUVmaxTon) has good sensitivity, specificity, positive predictive and negative predictive values, and accuracy, and can be used as a good quantitative index for the diagnosis of nondestructive PTLD.
BackgroundDonor shortage is an important limitation of liver transplantation (LT). Split liver transplantation (SLT) may increase the sources of donors and reduce the problem of organ shortage. However, there are no standard criteria of the selection of SLT donor, especially regarding the donor age.MethodsWe retrospectively analyzed the clinical data of children who received initial SLT between January 2015 and December 2021. Based on the age of donors, the patients were divided into groups A (1–10 years old; n = 26), B (10–45 years old; n = 87), and C (45–55 years old; n = 27). The short-term (<1 year after SLT) outcomes of the recipients were analyzed.ResultsA total of 140 patients received SLT from 122 donors. The 1-, 3- and 12-month patient survival rates in group A were 100.0%, and the graft survival rates were 92.3%. The 1-, 3- and 12-month survival rates of patient and graft in group B were 97.7%, 96.6%, and 95.0%, respectively, and in group C were 85.2%, 85.2%, and 81.1%, respectively. The patient survival rate was significantly lower in group C than in groups A and B (p = 0.0082). There was no significant difference in graft survival between the three groups (p = 0.0545).ConclusionsSimilar results were obtained for pediatric SLT with donors <10 years old and 10–45 years old. Pediatric SLT can be performed with older donors (45–55 years) after strict donor selection and selection of appropriate recipients.
Rationale: Post-transplant lymphoproliferative disease (PTLD) is a serious complication after pediatric liver transplantation (pLT), which may lead to death. F-FDG PET/CT is rarely considered in PTLD after pLT and lacks clear diagnostic guidelines, especially in the differential diagnosis of non-destructive PTLD. The aim of this study was to find a quantifiable F-FDG PET/CT index to identify non-destructive PTLD after pLT. Materials and Methods: This retrospective study collected the data of patients who underwent pLT, postoperative lymph node biopsy, and F-FDG PET/CT at Tianjin First Central Hospital from January 2014 to December 2021. Quantitative indexes were established using lymph node morphology and the maximum standardized uptake value (SUVmax). Results: A total of 83 patients met the inclusion criteria and were included in this retrospective study. To distinguish between PTLD-negative cases and non-destructive PTLD cases, according to the receiver operating characteristic curve, [the shortest diameter of the lymph node at the biopsy site (SDL)/the longest diameter of the lymph node at the biopsy site (LDL)]*[SUVmax at the biopsy site (SUVmaxBio)/SUVmax of the tonsils (SUVmaxTon)] had the maximum area under the curve (0.923; 95% confidence interval, 0.834–1.000), and the cut-off value was 0.264 according to the maximum value of Youden’s index. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 93.6%, 94.7%, 97.8%, 85.7%, and 93.9%, respectively. Conclusions: (SDL/LDL)*(SUVmaxBio/SUVmaxTon) has good sensitivity, specificity, positive predictive and negative predictive values, and accuracy, and can be used as a good quantitative index for the diagnosis of non-destructive PTLD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.