Ce³⁺, Pr³⁺ Co-Doped Lu₃Al₅O₁₂ Single Crystals and Ceramics: A Comparative Study

Ce3+, Pr3+ co-doped Lu3Al5O12 (Ce, Pr:LuAG) single crystals and ceramics were prepared using the optical floating zone (OFZ) and reactive vacuum sintering methods, respectively. The microstructure, photo- (λex = 450 nm), and radio-luminescence (under X-ray excitation) performance, as well as scintillation light yield (LY, under γ-ray, 137Cs source) of both materials, were investigated and compared. Ce, Pr:LuAG ceramics had an in-line transmittance of approximately 20% in the visible light range, while the analogous crystals were more transparent (~65%). The X-ray excited luminescent (XEL) spectra showed the characteristic Ce 3+ and Pr3+ emissions located at 310 nm, 380 nm, and 510 nm. The highest LY of the Ce, Pr:LuAG ceramics reached 34,112 pho/MeV at 2 μs time gate, which is higher than that of a single crystal. The ratio of LY values (LY2/LY0.75) between shaping times of 0.75 μs and 2 μs indicated a faster scintillation decay of ceramics regarding single crystals. It was ascribed to the lower effective concentration of luminescent activators in single crystals because of the coefficient segregation effect

高血清流行人群新生儿先天性巨细胞病毒感染筛查策略对比：一项母婴队列研究

巨细胞病毒（Cytomegalovirus，CMV）感染极为常见，感染人体后将造成终身潜伏带毒、机会性活跃，大多不引起明显的临床症状，但孕妇的CMV病毒活跃可能形成垂直传播而导致新生儿宫内先天感染，损伤胎盘并在胎儿神经细胞中复制。CMV是全球儿童感音神经性耳聋的最主要病因。及时筛查确诊新生儿CMV先天感染是改善患儿临床结局的关键。该研究团体通过多中心母婴队列观察，系统对比了基于新生儿唾液和尿液标本进行先天性巨细胞病毒感染筛查的多种策略，提出了初次筛查和再次确认检测的最优样本采集时间窗口和样本类型，对包括中国以及大多数发展中国家在内的广大巨细胞病毒感染高流行区的先天性巨细胞病毒感染防控工作具有重要指导意义。 我校博士生黄悦、硕士生王晗、高级工程师李廷栋和新密市妇幼保健院李彩红主任医师为该论文的共同第一作者。我校张军教授、葛胜祥教授和美国德克萨斯大学休斯顿健康科学中心傅通明博士为该论文的共同通讯作者。Background: Universal screening of congenital cytomegalovirus (cCMV) infection is important for monitoring and intervention during critical stages of speech and language development. This study aimed to explore the optimal detection strategy for cCMV infection screening. Methods: Serum samples from pregnant women and saliva and urine samples from their newborns were collected for the anti-CMV IgG and CMV DNA PCR tests, respectively. The sensitivity, specificity, and predictive values as well as the likelihood ratios of 12 potential screening strategies for cCMV infection, based on tests for saliva, urine, and their combination, were evaluated. Findings: A total of 6729 pregnant women were enrolled, and the seroprevalence was 98.1%. Among 6350 newborns that were followed up, 49 were defined as having cCMV infection. In the screening test, the CMV DNA positivity rate remained similar from day 0 to day 5, increased slowly from day 6 to day 13, and became high in newborns beyond 13 days of birth. In the confirmatory testing, the positive rates increased significantly beyond day 21. For the 49 newborns with cCMV infection, the proportion of agreement between saliva and urine testing was poor. Upon evaluating alternative screening strategies, using saliva and urine screening with saliva and urine confirmation as the reference strategy, saliva screening with saliva and urine confirmation showed good diagnostic accuracy and feasibility, with sensitivity, specificity, positive predictive and negative predictive values of 85.7%, 100.0%, 100.0% and 99.9%, respectively. Interpretation: In populations with high seroprevalence, saliva screening with saliva and urine confirmation might be an alternative strategy for screening cCMV infections. The suggested timeframes for screening and confirmation are within 13 (ideally 5) and 21 (ideally 13) days of birth, respectively.This work was supported by the National Natural Science Foundation of China (grants 81973058 and 81672111), the National Science and Technology Major Project of China (2017ZX10302201-002-003) and Merck & Co., Inc., Kenilworth, New Jersey, U.S.A. 该研究获得国家自然科学基金、传染病重大专项、厦门大学校长基金及美国默沙东公司支持