Epidemiological characteristics of human metapneumovirus among children in Nanjing, China.

PURPOSE: The objective of this study was to examine the molecular epidemiology and clinical characteristics of HMPV infection among children with ARIs in Nanjing. METHODS: The respiratory samples were collected from 2078 children (≤ 14 years) with acute respiratory infections and were tested for HMPV using real-time RT-PCR. Amplification and sequencing of the HMPV G gene were followed by phylogenetic analysis using MEGA 7.0. RESULT: The detection rate of HMPV among children was 4.7% (97/2078), with a concentration in those under 5 years of age. Notably, the peak season for HMPV prevalence was observed in winter. Among the 97 HMPV-positive samples, 51.5% (50/97) were available for characterization of the HMPV G protein gene. Phylogenetic analysis indicated that the sequenced HMPV strains were classified into three sublineages: A2c111nt - dup (84.0%), B1 (2.0%), and B2 (14.0%). CONCLUSION: There was an incidence of HMPV among hospitalized children during 2021-2022 in Nanjing with A2c111nt - dup being the dominant strain. This study demonstrated the molecular epidemiological characteristics of HMPV among children with respiratory infections in Nanjing, China.

Tuning 3D refractive indices via constrained uniaxial stretch in cellulose triacetate films plasticized with triethyl citrate.

Tuning 3D refractive indices of polymers is urgently needed for optical films, but it is quite challenging. Here, we proposed a simple constrained uniaxial stretch method that successfully tuned the 3D refractive indices in cellulose triacetate (TAC) films plasticized with triethyl citrate (TEC). Our results suggest that, under constrained uniaxial stretch, the main chains and side groups prefer to orientate in the stretch direction and the constrained direction, respectively. Such a unique chain arrangement differentiates the refractive indices in three directions of the film. The branched small molecule TEC is also crucial for tuning refractive indices, which promotes chain activity and enhances the chain orientation under stretching, leading to a considerable change in refractive indices before samples fracture. The polymer film we fabricated possesses a direction-dependent optical performance, where the refractive index in the film thickness direction is between that of the stretch direction and constrained direction. This work provides a fundamental understanding on the chain structure and optical performance of polymer films. The constrained uniaxial stretch method, in general, should also be applicable to tuning other 3D physical properties through tuning the direction-dependent orientation of polymers.

Regulation of orientation birefringence for cellulose acetate film: The role of crystallization and orientation.

Cellulose acetate (CA) based films are widely used in liquid crystal displays due to their outstanding transparency, and a certain orientation birefringence of CA films is required when they are used as retardation films. The regulation of orientation birefringence is usually from the perspective of stretch-induced orientation, while the effects of crystallization behaviors of CA films remain obscure. In this study, the roles of crystallization and orientation on the orientation birefringence of CA films were elucidated. For cellulose diacetate films, the orientation birefringence is dominated by the orientation degree. In comparison, apart from the orientation degree, crystallinity is another key variable to regulate the orientation birefringence of cellulose triacetate and plasticized cellulose triacetate films, originating from the birefringence heterogeneity of the crystalline and amorphous phases. These results provide valuable guidelines for the production of CA-based optical films with excellent optical performance.

Identification of Bioactive Components of Stephania epigaea Lo and Their Potential Therapeutic Targets by UPLC-MS/MS and Network Pharmacology.

Stephania epigaea, an important traditional folk medicinal plant, elucidating its bioactive compound profiles and their molecular mechanisms of action on human health, would better understand its traditional therapies and guide their use in preclinical and clinical. This study aims to detect the critical therapeutic compounds, predict their targets, and explore potential therapeutic molecular mechanisms. This work first determined metabolites from roots, stems, and flowering twigs of S. epigaea by a widely targeted metabolomic analysis assay. Then, the drug likeness of the compounds and their pharmacokinetic profiles were screened by the ADMETlab server. The target proteins of active compounds were further analyzed by PPI combing with GO and KEGG cluster enrichment analysis. Finally, the interaction networks between essential compounds, targets, and disease-associated pathways were constructed, and the essential compounds binding to their possible target proteins were verified by molecular docking. Five key target proteins (EGFR, HSP90AA1, SRC, TNF, and CASP3) and twelve correlated metabolites, including aknadinine, cephakicine, homostephanoline, and N-methylliriodendronine associated with medical applications of S. epigaea, were identified, and the compounds and protein interactions were verified. The key active ingredients are mainly accumulated in the root, which indicates that the root is the main medicinal tissue. This study demonstrated that S. epigaea might exert the desired disease efficacy mainly through twelve components interacting via five essential target proteins. EGFR is the most critical one, which deserves further verification by biological studies.

Mutations and Phylogenetic Analyses of SARS-CoV-2 Among Imported COVID-19 From Abroad in Nanjing, China.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a pandemic and is threatening human health globally. The rapid genome sequencing and bioinformatic analysis of SARS-CoV-2 have become a helpful tool in the battle against the COVID-19. Here, we report the genetic characteristics, variations and phylogenetic analysis of SARS-CoV-2 sequenced from 42 clinical specimens. The complete genomes sequencing of SARS-CoV-2 were performed using Oxford Nanopore sequencing. All genomes accumulated mutations compared to the Wuhan-Hu-1 (GenBank Accession No: MN908947.3). Our data of the 42 whole genomes revealed 16 different lineages. The B.1.1 lineage was the most frequent, and 5, 2, 2, 3, and 1 sequences were classified as lineages of B.1.1.7, B.1.351, P.1, B.1.617.2, and C.37, respectively. A total of 328 nucleotide mutation sites were found in 42 genomes, among which A23403G mutation (D614G amino acid change in the spike protein) was the most common substitution. The phylogenetic trees of 42 SARS-CoV-2 sequences and GISAID-available SARS-CoV-2 sequences were constructed and its taxonomic status was supported. These results will provide scientific basis for tracing the source and prevention and control of SARS-CoV-2 imported from abroad in Nanjing, China.

Characterization of the wheat VQ protein family and expression of candidate genes associated with seed dormancy and germination.

BACKGROUND: Seed dormancy and germination determine wheat resistance to pre-harvest sprouting and thereby affect grain yield and quality. Arabidopsis VQ genes have been shown to influence seed germination; however, the functions of wheat VQ genes have not been characterized. RESULTS: We identified 65 TaVQ genes in common wheat and named them TaVQ1-65. We identified 48 paralogous pairs, 37 of which had Ka/Ks values greater than 1, suggesting that most TaVQ genes have experienced positive selection. Chromosome locations, gene structures, promoter element analysis, and gene ontology annotations of the TaVQs showed that their structures determined their functions and that structural changes reflected functional diversity. Transcriptome-based expression analysis of 62 TaVQ genes and microarray analysis of 11 TaVQ genes indicated that they played important roles in diverse biological processes. We compared TaVQ gene expression and seed germination index values among wheat varieties with contrasting seed dormancy and germination phenotypes and identified 21 TaVQ genes that may be involved in seed dormancy and germination. CONCLUSIONS: Sixty-five TaVQ proteins were identified for the first time in common wheat, and bioinformatics analyses were used to investigate their phylogenetic relationships and evolutionary divergence. qRT-PCR data showed that 21 TaVQ candidate genes were potentially involved in seed dormancy and germination. These findings provide useful information for further cloning and functional analysis of TaVQ genes and introduce useful candidate genes for the improvement of PHS resistance in wheat.

The nucleic acid positive rate and genotype distribution of human cytomegalovirus in human milk banks in China.

To determine the status of human cytomegalovirus (HCMV) infection in human milk in China, a total of 510 human milk samples obtained from three provinces, including 211 donor human milk samples from human milk banks and 299 milk samples obtained from the mothers of premature infants, were tested to detect HCMV DNA. Overall, 46.4% of the donated milk samples and 59.2% of the samples obtained from mothers of premature infants were positive for HCMV DNA. The concentration of HCMV DNA was approximately 103 -104 copies/ml in the HCMV-DNA-positive human milk samples. Based on the nucleotide sequence of a 299- to 305-bp fragment of the glycoprotein B (gB) gene, three HCMV genotypes (gB1, gB2 and gB3) were identified in human milk samples. Mixed infection with genotypes gB1 and gB3 was also found in four milk samples from mothers. Genotype gB1 was the predominant genotype in the HCMV-DNA-positive human milk samples, and it could be subdivided into three lineages. There were also some characteristic nucleotides and amino acids in the three HCMV genotypes, which were helpful for distinguishing the genotypes. This is the first study to clarify the HCMV infection status and genetic characteristics of human milk obtained from banks in China, which will be helpful in preventing postnatal HCMV infections and ensuring the safety of human milk banks.

Identification and Analysis of the GASR Gene Family in Common Wheat (Triticum aestivum L.) and Characterization of TaGASR34, a Gene Associated With Seed Dormancy and Germination.

Seed dormancy and germination are important agronomic traits in wheat (Triticum aestivum L.) because they determine pre-harvest sprouting (PHS) resistance and thus affect grain production. These processes are regulated by Gibberellic Acid-Stimulated Regulator (GASR) genes. In this study, we identified 37 GASR genes in common wheat, which were designated TaGASR1-37. Moreover, we identified 40 pairs of paralogous genes, of which only one had a Ka/Ks value greater than 1, indicating that most TaGASR genes have undergone negative selection. Chromosomal location and duplication analysis revealed 25 pairs of segmentally duplicated genes and seven pairs of tandemly duplicated genes, suggesting that large-scale duplication events may have contributed to the expansion of TaGASR gene family. Microarray analysis of the expression of 18 TaGASR genes indicated that these genes play diverse roles in different biological processes. Using wheat varieties with contrasting seed dormancy phenotypes, we investigated the expression patterns of TaGASR genes and the corresponding seed germination index phenotypes in response to water imbibition, exogenous ABA and GA treatment, and low- and high-temperature treatment. Based on these data, we identified the TaGASR34 gene as potentially associated with seed dormancy and germination. Further, we used a SNP mutation of the TaGASR34 promoter (-16) to develop the CAPS marker GS34-7B, which was then used to validate the association of TaGASR34 with seed dormancy and germination by evaluating two natural populations across environments. Notably, the frequency of the high-dormancy GS34-7Bb allele was significantly lower than that of the low-dormancy GS34-7Ba allele, implying that the favorable GS34-7Bb allele has not previously been used in wheat breeding. These results provide valuable information for further functional analysis of TaGASR genes and present a useful gene and marker combination for future improvement of PHS resistance in wheat.