ABSTRACT
【Objective】 To analyze the discriminatory positive rate(DPR)of individual donor-nucleic acid test (ID-NAT)mode of blood screening laboratories in the Beijing-Tianjin-Hebei Region, explore the possible reasons for DPR differences among blood station laboratories and the measures to lesson the differences, in order to lay a foundation for realizing the homogenization of detection quality of blood screening laboratories in Beijing-Tianjin-Hebei Region. 【Methods】 The number of triplex-positive samples and discriminatory -positive samples of A, B, C, and D blood station laboratories, which submitted to ID-NAT system, in Beijing-Tianjin-Hebei Region from January to December 2018 were collected by a questionnaire of Quality Supervise Index of Blood Station Laboratories in Beijing-Tianjin-Hebei Region. The triplex-positive samples were divided into solo-positive samples(NAT+ ELISA-) and dual-positive samples(NAT+ ELISA+ ). The changes of total DPR of A, B and C blood screening laboratories in different months was analyzed and compared respectively. The differences of total DPR of ID-NAT, DPR of NAT+ ELISA+ samples, and DPR between NAT+ ELISA-samples and NAT+ ELISA+ samples of A, B, and C blood screening laboratories during January 2018 to December 2018 was analyzed and compared. The difference of DPR of NAT+ ELISA-samples among A, B, C, and D blood station laboratories was also compared. 【Results】 Significant difference in total DPR was noticed in different months of A, B, and C blood station laboratories from January to December 2018(P<0.05), with the highest DPRs of A, B and C laboratory at 91.67%, 72.73%. and 80.39%, the lowest DPRs at 65.88%, 21.05%, and 7.69%, respectively. Significant statistical differences in the total DPR and the DPR of NAT+ ELISA+ samples were found among A, B, and C blood station laboratories(P<0.05). Significant statistical differences in the DPR of NAT+ ELISA- samples were found among A, B, C, and D laboratories(P<0.05). The DPR of NAT+ ELISA+ samples of A and B blood station laboratories (95.97% and 85.25%) were significantly higher than those of NAT+ ELISA-samples (36.36% and 30.71%)(P<0.05). However, the DPR of NAT+ ELISA+ samples of C blood station laboratory (32.63%) was significantly lower than that of NAT+ ELISA-samples (44.39%)(P <0.05). 【Conclusion】 There were significant differences in the total DPR, the DPR of NAT+ ELISA-samples and NAT+ ELISA+ samples that were detected by ID-NAT system in 2018 among blood station laboratories in the Beijing-Tianjin-Hebei Region, and the total discriminatory positive rate in different months was also different for the same blood station. It is necessary to explore the reasons leading to the differences and seek solutions in order to achieve the homogenization of detection quality of blood screening laboratories in Beijing-Tianjin-Hebei Region.
ABSTRACT
BACKGROUND:To overcome the disadvantages of traditional mechanical analysis of specimens, and establish the finite element model of realistic foot, are the important basements for the finite element mechanical analysis on foot. OBJECTIVE:To establish three-dimensional finite element model of foot and lay the foundation for the finite element analysis of normal foot and foot injury. METHODS:A healthy female volunteer was involved in this study and was detected with spiral CT scanning on the feet. The resulting image was used to reconstruct the three-dimensional model by using Mimics software. Then entity model was generated in Geomagic software. Final y three-dimensional finite element model was established based on the digital main structure in Ansys. RESULTS AND CONCLUSION:The established finite element digital model of human foot included al bone, cartilage and ligament, skin and soft tissue. The three-dimensional finite element model of human foot was established based on CT data and using Mimics, Geomagic, Ansys softwares. The established model had similar size and shape with skeletal mode, and can rotate freely in any angle for a variety of measurement, the foot bones can be arbitrarily split or merge, which is suitable for biomechanical analysis.