分类: 医学、药学 >> 预防医学与公共卫生学 提交时间: 2023-03-29
摘要:Emerging in December 2019, coronavirus disease 2019 (COVID-19) eventually became a pandemic and posed a tremendous threat to global public health. However, the origins of SARS-CoV-2, the causative agent of COVID-19, remain to be determined. It has been reported that a certain number of the early case clusters had a contact history with the Huanan Seafood Market. Therefore, surveillance of SARS-CoV-2 within the market is of vital importance. Herein, we presented the SARS-CoV-2 detection results of 1380 samples collected from the environment since 1st Jan and animals since 18th Jan within the market in early 2020. By SARS-CoV-2-specific RT-qPCR, 73 environmental samples tested positive for SARS-CoV-2 and three live viruses were successfully isolated. The viruses from the market shared nucleotide identity of 99.99% to 100% with the human isolate HCoV-19/Wuhan/IVDC-HB-01/2019. The A lineage (8782T and 28144C), as the likely ancestral SARS-CoV-2 lineage, was found in an environmental sample. No virus was detected in the animal swabs covering 18 species of animals in the market. The RNA-seq analysis of SARS-CoV-2 positive/negative environmental samples showed the abundance of different vertebrata genera. In summary, this study provided convincing evidence of the prevalence of SARS-CoV-2 in the Huanan Seafood Market during the early stage of COVID-19 outbreak.
分类: 物理学 >> 核物理学 提交时间: 2016-09-01
摘要:We investigate the charmed baryon production reaction pp¯→ΛcΛ¯c in an effective Lagrangian approach. Besides the t-channel D0 and D∗0 mesons exchanges, the s-channel Y(4630) meson exchange is taken into account. For the total cross sections, the D0 and D∗0 mesons provide minor background contributions, while the Y(4630) state gives a clear peak structure with the magnitude of 10 μb at center of mass energy 4.63 GeV. Basing on the results, we suggest that the reaction of pp¯→ΛcΛ¯c can be used to search for the 1−− charmonium-like Y(4630) state, and our predictions can be tested in future by theP¯ANDA facility.