Objective:To investigate the status of hepatitis E virus infection in unpaid blood donors in Wenzhou.Methods:A total of 5 241 blood samples were selected from donors who successfully donated blood between October 2022 and March 2023. These samples were tested for hepatitis E virus (HEV) through HEV-IgG antibodies, HEV-IgM antibodies, and nucleic acid tests (HEV RNA). Samples that tested positive for HEV RNA underwent quantitative detection and sequencing. Data regarding the blood donors were collected, the positive rates of each test result were recorded, and the HEV infection status among different populations was analyzed.Results:The positive rate of the HEV-IgG antibody test was 23.60% (1 237/5 241), while the positive rate of the HEV-IgM antibody test was 0.29% (15/5 241). The positive rate of the HEV RNA test was 0.08% (4/5 241). The positive rate of the HEV-IgG test increased with age ( χ2 = 379.493, P < 0.05), and males had a higher positive rate than females ( χ2 = 5.12, P < 0.05). Both the positive rates of HEV-IgG and HEV-IgM tests increased as the number of blood donations increased ( χ2 = 40.87, 8.30, both P < 0.05). Furthermore, the positive rates were significantly higher in 2023 than in 2022 ( χ2 = 51.03, 13.35, both P < 0.05), and they were also significantly higher in spring than in winter ( χ2 = 51.03, 13.35, both P < 0.05). Only one HEV RNA-positive blood donor tested positive for both HEV-IgG and HEV-IgM antibodies, while the remaining three donors tested negative. Only one case was genotyped, and it belonged to genotype Ⅳ. Conclusion:The incidence of HEV infection among unpaid blood donors in Wenzhou of Zhejiang Province is relatively high, with the prevalent HEV genotype being type Ⅳ. Characteristics such as sex, age, and the number of blood donations can be utilized as auxiliary screening reference indicators.

Non-contrast enhanced MR angiography(NCE-MRA)has been widely used in clinic since advantages of non-radiation and non-contrast media.The image quality of NCE-MRA could be effectively improved using ultra-high field MR scanner,yet 7.0T devices were limited by coils and usually used for cerebrovascular scanning.The invention of 5.0T ultra-high field MR system brings new opportunities for whole body NCE-MRA.The preliminary application of 5.0T whole body NCE-MRA in human body were explored in this article.

ω-transaminase (ω-TA) is a natural biocatalyst that has good application potential in the synthesis of chiral amines. However, the poor stability and low activity of ω-TA in the process of catalyzing unnatural substrates greatly hampers its application. To overcome these shortcomings, the thermostability of (R)-ω-TA (AtTA) from Aspergillus terreus was engineered by combining molecular dynamics simulation assisted computer-aided design with random and combinatorial mutation. An optimal mutant AtTA-E104D/A246V/R266Q (M3) with synchronously enhanced thermostability and activity was obtained. Compared with the wild- type (WT) enzyme, the half-life t_1/2 (35 ℃) of M3 was prolonged by 4.8-time (from 17.8 min to 102.7 min), and the half deactivation temperature (T¹⁰₅₀) was increased from 38.1 ℃ to 40.3 ℃. The catalytic efficiencies toward pyruvate and 1-(R)-phenylethylamine of M3 were 1.59- and 1.56-fold that of WT. Molecular dynamics simulation and molecular docking showed that the reinforced stability of α-helix caused by the increase of hydrogen bond and hydrophobic interaction in molecules was the main reason for the improvement of enzyme thermostability. The enhanced hydrogen bond of substrate with surrounding amino acid residues and the enlarged substrate binding pocket contributed to the increased catalytic efficiency of M3. Substrate spectrum analysis revealed that the catalytic performance of M3 on 11 aromatic ketones were higher than that of WT, which further showed the application potential of M3 in the synthesis of chiral amines.
Transaminases/chemistry* ; Molecular Docking Simulation ; Amines/chemistry* ; Pyruvic Acid/metabolism* ; Enzyme Stability