【Objective】 To explore the recruitment and retention strategy of blood donors by investigating the age composition of blood donors in some areas of China, so as to promote blood donation and enhance clinical blood supply. 【Methods】 Through the working platform of Practice Comparison Working Group of China’s Mainland Blood Collection and Supply Institutions, the average age and age composition of blood donors from 22 blood centers were collected, and statistical analysis was conducted after eliminating invalid data. 【Results】 The median average age of blood donors during the survey year was 30.02.The median age in 2.89% of the blood centers was lower than 25. The average age of different genders was statistically significant only in 2018(P<0.05). Fot first-time blood donors, the median constituent ratio of donors <25 and ≥25 years old was 54.53% and 44.28%, with median retention rate at 10.30% and 9.61%, respectively. The median overall participation rate of blood donors was 2.7%, with median participation rate of blood donors <25 years old at 5.1%. 【Conclusion】 The recruitment and retention of blood donor is crucial to enhance clinical blood supply. Blood donors <25 years old, with a longer period for future donation, should be the main target of blood donation recruitment. Meanwhile, the revision of upper age limit for blood donation is another important initiative to grow the blood donor pool.

The fcl gene encodes GDP-fucose synthase, which catalyzes two-step differential isomerase and reductase reactions in the synthesis of GDP-L-fucose from GDP-D-mannose. It also participates in the biosynthesis of amino sugar and ribose sugar, and is one of the key enzymes to regulate the metabolism of sugar and nucleotides in organisms. The presence of fcl gene in Saccharopolyspora pogona was found through sequencing result of genome. The mutant S. pogona-fcl and S. pogona-Δfcl were constructed by gene engineering technology. The results showed that the gene had an effects on growth and development, protein expression and transcriptional level, insecticidal activity, and biosynthesis of butenyl-spinosyn of Saccharopolyspora pogona. The results of HPLC analysis showed that the yield of butenyl-spinosyn in S. pogona-Δfcl was 130% compared with that in S. pogona, which reduced by 25% in S. pogona-fcl. The results of determination of insecticidal activity showed that S. pogona-Δfcl had a stronger insecticidal activity against Helicoverpa armigera than that of S. pogona, while the S. pogona-fcl had a lower insecticidal activity against Helicoverpa armigera compared with S. pogona. Scanning electron microscopy (SEM) was used to observe the morphology of the mycelia. It was found that the surface of the S. pogona-Δfcl was wrinkled, and the mycelium showed a short rod shape. There was no significant difference in mycelial morphology between S. pogona-fcl and S. pogona. Aboved all showed that deletion of fcl gene in S. pogona hindered the growth and development of mycelia, but was beneficial to increase the biosynthesis of butenyl-spinosyn and improve insecticidal activity. Whereas the fcl gene over-expression was not conducive to the biosynthesis of butenyl-spinosyn and reduced their insecticidal activity. SDS-PAGE results showed that the difference of protein expression among the three strains was most obvious at 96 hours, which was identified by real-time fluorescence quantitative polymerase chain reaction, the results showed that there were significant differences of related genes in transcriptional levels among the three strains. Based on the results of the study, a network metabolic control map was constructed to analyze the effect of fcl gene on growth and the regulation pathway of butenyl-spinosyn biosynthesis, which provided an experimental basis for revealing the regulation mechanism of butenyl-spinosyn biosynthesis and related follow-up studies.
Bacterial Proteins ; Genetic Engineering ; Insecticides ; Macrolides ; Saccharopolyspora