Peking University

Guangdong Province in China is endemic for hepatitis B virus (HBV) infection with a high prevalence of chronic HBV infection in pregnant women. Measures have been taken to reduce mother-to-child transmission (MTCT) of HBV. This study aims to analyze the trends in these preventive measures in hepatitis B surface antigen (HBsAg)-positive pregnant women from 2021 to 2023. Data were obtained from the case report forms of HBsAg-positive pregnant women and their newborns that were completed and reported in Guangdong Province through the Information System of the National Integrated Prevention of Mother-to-Child Transmission of HIV, syphilis and hepatitis B Programme from January 1, 2021, to December 31, 2023. The Cochran-Armitage test was employed to analyze trends in maternal hepatitis B e antigen (HBeAg) positivity rates across different age groups of pregnant women, antiviral treatment rates in the total and HBeAg-positive populations, and the coverage of timely birth dose of the hepatitis B vaccine (HepB-BD) and hepatitis B immunoglobulin (HBIG) among infants born to the total and HBeAg-positive pregnant women from 2021 to 2023. A total of 283,959 HBsAg-positive pregnant women and their newborns were included in the study. The HBeAg positivity rate among the HBsAg-positive pregnant women was 26.1%. The prevalence of HBeAg positivity among HBsAg-positive pregnant women in Guangdong Province experienced a declining trend from 2021 to 2023. Over the same period, the uptake of antiviral treatment increased in both the overall population and the HBeAg-positive subgroup, with the proportion of HBeAg-positive pregnant women receiving antiviral therapy rising from 23.8% in 2021 to 51.8% in 2023. The proportion of HBV-exposed newborns receiving both HepB-BD and HBIG within 12 hours of birth also increased steadily, with coverage exceeding 97% in 2023. This study highlights significant progress in reducing MTCT of hepatitis B in Guangdong Province from 2021 to 2023. HBeAg positivity among HBsAg-positive pregnant women declined, while both the uptake of antiviral therapy and the timely administration of HepB-BD and HBIG to HBV-exposed infants improved markedly. These findings underscore the important role of public health interventions while emphasizing the need for sustained efforts, particularly for young HBeAg-positive pregnant women.

The opportunistic pathogen Aspergillus fumigatus represents a major threat to immunocompromised individuals and is increasingly resistant to antifungal therapies. Resistance selection primarily takes place through environmental selection to azole fungicides, but in-host resistance may develop in patients with chronic aspergillosis receiving azole therapy. In this study, we examine clinical A. fumigatus isolates that exhibit irregular growth and accumulated mutations rapidly during antifungal treatment. Whole-genome sequencing of serial isolates revealed an accelerated mutation rate as the likely driver of the observed phenotype. The mutation frequency of this isolate was approximately 15-times higher than other A. fumigatus strains. We identified non-synonymous single nucleotide polymorphisms (SNPs) as potential loci involved in the increased mutation rate. Using CRISPR/Cas9 gene editing and comprehensive genomic analysis, we show that a mutation in mre11, a gene critical for genomic stability during DNA replication, is responsible for this elevated mutation rate. Mutations within mre11 result in a 27% reduction in radial growth, highlighting the fitness cost associated with the higher mutation rate. All mre11-mutant isolates in this study belong to clade B, a lineage that rarely carries environmental azole-resistance mutations, potentially supporting in-host adaptation. The Phe332Leu allele was observed both in clinical and environmental isolates, suggesting that the mutator phenotype may represent a general adaptive strategy, allowing A. fumigatus to persist under prolonged azole pressure. We hypothesize that this heightened mutation background could facilitate the rapid spread of antifungal resistance alleles within A. fumigatus populations.

Piezoelec. semiconductor (PSC) devices, which have both piezoelec. and semiconducting properties, have recently received particular attention in engineering practice.However, the insufficiencies of researches in wave motion and the influence of biasing elec. field limit the designs of smart PSC devices.In this paper, three-dimensional dynamic governing equations of PSC with initial biasing elec. fields are first derived under linear assumptions, and then, based on the Hamilton variational principle, the wave motion equations of PSC beam under biasing elec. field are deduced to anal. obtain the complex dispersion equations of flexural waves.From the complex dispersion relations of flexural waves, the influences of initial electron concentration and biasing elec. field on flexural waves in PSC beam are discussed.Comparing with the numerical results of flexural wave propagation in time-domain, the validation of derived theor. model is proved to show a good consistence.Results indicate that for the case of no external biasing elec. field, the propagating flexural wave will attenuate due to the damping effect of electron.However, when the biasing elec. field is applied, the flexural wave will exhibit gain effect during propagation.Therefore, the derived model can be a good theor. guidance for designing PSC devices including sensors, transistor, resonators as well as other wave motion devices.