[Clinical and genetic analyses of hereditary factor Ⅴ deficiency cases]

Objective: To analyze the clinical phenotype and molecular pathogenesis of nine patients with hereditary factor Ⅴ (FⅤ) deficiency. Methods: Nine patients with hereditary FⅤ deficiency who were admitted to the Institute of Hematology and Blood Diseases Hospital from April 1999 to September 2019 were analyzed. The activated partial thromboplastin time, prothrombin time, and FⅤ procoagulant activity (FⅤ∶C) were measured for phenotypic diagnosis. High-throughput sequencing was employed for the F5 gene mutation screening, Sanger sequencing was adopted to confirm candidate variants and parental carrying status, Swiss-model was used for three-dimensional structure analysis, and ClustalX v.2.1 was used for homologous analysis. Results: The FⅤ∶C of the nine patients ranged from 0.1 to 10.6. Among them, eight had a hemorrhage history, with kin/mucosal bleeding as the most common symptom (three cases, 37.5%) , whereas one case had no bleeding symptom. There were five homozygotes and four compound heterozygotes. A total of 12 pathogenic or likely pathogenic mutations were detected, of which c.6100C>A/p.Pro2034Thr, c.6575T>C/p.Phe2192Ser, c.1600_1601delinsTG/p. Gln534*, c.4713C>A/p.Tyr1571*, and c.952+5G>C were reported for the first time. Conclusion: The newly discovered gene mutations enriched the F5 gene mutation spectrum associated with hereditary FⅤ deficiency. High-throughput sequencing could be an effective method to detect F5 gene mutations.

Sizing charged particles by phase Doppler anemometry

Phase Doppler anemometry (PDA) is one of the most popular optical techniques used to measure particle sizes. The configuration of PDA layout is important for accurate measurement. In this paper, considering the fact that particles are very likely charged due to many reasons, the selection of PDA layout parameters for measuring charged particles is studied. Effective regions in the receiver's configuration parameter plane are found for charged particles. When parameters are selected from the effective regions, the phase-diameter curves of the PDA are linear, which satisfies the requirement of the working principle of PDA for measuring particle diameter. It is found that the scattered power of charged particles is attenuated, and the attenuation only has small oscillation with the variation of particle diameter and is mainly dominated by the surface conductivity, a phenomenological parameter for describing net surface charges carried by particles. A method is proposed to identify charged particles as well as their surface conductivities.